prompt_front: Now, answer the following question based on the text below, only give me the answer and do not output any other words.

Question: What is the effect of the proximity of superconductivity on the Kondo effect?

Read the following text and answer briefly.

Context 1: \section{Introduction}
\label{sec:Intro}

The exchange interactions control the magnetic order and properties of a vast number of materials
\cite{White2006Dec}
and lead to many fascinating phenomena, such as various types of the Kondo effect 
\cite{Kondo,NozieresBlandin,Pustilnik_Glazman} 
Double quantum dots (DQDs), and in general multi-impurity systems, constitute
a convenient and controllable playground,
where nearly as much different exchange mechanisms compete with each other to
shape the ground state of the system 
\emph{Local exchange} between the spin of a quantum dot (QD)
and the spin of conduction band electrons gives rise to the
Kondo effect \cite{Kondo,Hewson_book}  
\emph{Direct exchange} arriving with an additional side-coupled QD may destroy it or lead to the 
two-stage Kondo screening \cite{Pustilnik_Glazman,Cornaglia,Granger,ZitkoBonca,ZitkoPRB2010,Ferreira} 
In a geometry where the two QDs contact the same lead, conduction band electrons 
mediate the \emph{RKKY exchange} \cite{RK,K,Y}  The RKKY interaction competes
with the Kondo effect and leads to the quantum phase transition of a still debated nature
\cite{Doniach,Jones,Affleck,Bork,Neel,KondoRKKYexp,Hans,Hans2,Fabian} 
Moreover, in DQDs coupled in series also \emph{superexchange} can alter the Kondo physics significantly
\cite{Zitko_2QDEx,Sela} 

Recently, hybrid quantum devices, in which the interplay between various magnetic correlations
with superconductivity (SC) plays an important role, have become an important direction of research
\cite{hybridQDs,SCspintronics}  In particular, chains of magnetic atoms on SC surface have proven 
to contain self-organized Majorana quasi-particles and exotic spin textures
\cite{Braunecker,Klinovaja,Vazifeh,Yazdani},
while hybrid DQD structures have been used to split the Cooper pairs coherently into two entangled 
electrons propagating to separated normal leads \cite{CPS1,CPS2,CPS4,CPS5,CPS9} 
The latter is possible due to non-local (\emph{crossed}) Andreev reflections (CARs),
in which each electron of a Cooper pair tunnels into different QD, and
subsequently to attached lead  Such processes give rise to an exchange mechanism \cite{Yao},
that we henceforth refer to as \emph{the CAR exchange}, which can greatly modify
the low-temperature transport behavior of correlated hybrid nanostructures 

The CAR exchange may be seen as RKKY-like interaction between
two nearby impurities on SC surface \cite{Yao} 
The effect can be understood as a consequence
of spin-dependent hybridization of the Yu-Shiba-Rusinov (YSR)
states \cite{Yu,Shiba,Rusinov} in SC contact,
caused both by the overlap of their wave functions
and their coupling to Cooper-pair condensate 
This process is the most effective when the YSR states 
are close to the middle of the SC gap, {\it e g } in the YSR-screened phase \cite{YSRscreening} 
The mechanism presented here is essentially the same,
yet in the considered regime can be understood
perturbatively without referring to YSR states,
as a consequence of the non-local pairing induced by SC electrode  
In particular, the presence of YSR bound states close to the Fermi level 
is not necessary for significant consequences for the Kondo physics, 
as long as some inter-dot pairing is present  


The proximity of SC induces pairing in QDs \cite{RozhkovArovas,Buitelaar} 
and tends to suppress the Kondo effect if the superconducting energy gap $2\Delta$ 
becomes larger than the relevant Kondo temperature $T_K$ 
\cite{Buitelaar2002Dec,adatomsSC,Kondo_vs_SC1,Kondo_vs_SC2,Zitko_Kondo-Andreev,Zitko_S-QD-N,IW_Sau,YSRscreening} 
Moreover, the strength of SC pairing can greatly affect the Kondo physics in the sub-gap transport regime:
For QDs attached to SC and normal contacts, it can enhance the Kondo effect
\cite{DomanskiIW,KWIW,part1}, while
for DQD-based Cooper pair splitters, it tends to suppress both the $\mathrm{SU}(2)$ and $\mathrm{SU}(4)$ Kondo effects \cite{IW_Kacper} 
Our main result is that the non-local pairing induced by superconducting 
proximity effect, which gives rise to CAR exchange, can be the sole cause of the Kondo screening 
Moreover, relatively small values of coupling to SC, $\GS{}\ll U$, are sufficient for the effect to occur 
This is in contrast to the DQD system considered in Ref ~\cite{part1},
where only one of the quantum dots is proximized, such that 
CAR exchange cannot arise,
and the Kondo physics becomes qualitatively
affected only for $\GS{}\sim U/2$ %


\begin{figure}[bt]
\centering
\includegraphics[width=1\linewidth]{Fig1 png}
\caption{
		 (a) Schematic of the considered system  Left/right (L/R) lead
		 is coupled to the first quantum dot (QD1), while superconductor
		 is attached to both QD1 and QD2 
		 (b)-(d) illustrate an example of direct spin exchange:
		 spin-up electron from the initial state (b) hops to the other QD (c) and spin-down electron 
		 hops back (d)  Note, that the final state is in fact the same singlet state, 
		 only with opposite sign 
		 (e)-(g) show an example of process contributing to crossed Andreev reflection (CAR) exchange 
		 A Cooper pair from SC approaches DQD (e) and two singlets of the same charge 
		 are formed (f), before the Cooper pair is re-emitted (g) 
		 (h)-(j) present an example of RKKY process: an electron scattered off
		 one QD (h) mediates the spin exchange towards the other (i), before it is finally scattered
		 off there, too (j) 
		 }
\label{fig:system}
\end{figure}


In this paper we discuss the CAR-induced Kondo screening in a setup comprising T-shaped DQD
with normal and superconducting contacts, see \fig{system}(a) 
We note that despite quite generic character of CAR exchange,
and its presence in systems containing at least two localized electrons
coupled close to each other to the same SC bath,
to best of our knowledge CAR-induced screening
has hardly been identified in previous studies
\cite{CPS1,CPS2,CPS4,CPS5,CPS9,IW_Kacper,IW_Sau,Zitko_Josephson,Zitko_S2QD,Martinek2017} 
In the system proposed here [\fig{system}(a)], its presence is evident 
Moreover, CAR exchange magnitude can be directly related to the relevant energy scales, such as the Kondo 
temperature, which provides a fingerprint for quantitative experimental verification of our predictions  

The paper is organized as follows  In \Sec{model} we describe the considered system 
and present the model we use to study it  In \Sec{scales} the relevant energy scales are estimated
to make the discussion of main results concerning CAR-induced Kondo effect in \Sec{main} more clear  
Finally, the influence of effects neglected in \Sec{main} are presented in the following sections,
including CAR exchange interplay with RKKY interaction (\Sec{RKKY}), particle-hole asymmetry (\Sec{asym}),
couplings asymmetry (\Sec{x}) and reduced efficiency of CAR coupling (\Sec{coef})  In summary,
the effects discussed in \Sec{main} remain qualitatively valid in all these cases 
The paper is concluded in \Sec{conclusions} 


\section{Model}
\label{sec:model}

The schematic of the considered system is depicted in \fig{system}(a) 
It contains two QDs attached to a common SC lead 
Only one of them (QD1) is directly attached to the left (L) and right (R) normal leads,
while the other dot (QD2) remains coupled only through QD1 
The SC is modeled by the BCS Hamiltonian, 
$H_{\mathrm{S}}=\sum_{\mathbf{k}\sigma}\xi_{\mathbf{k}}a_{\mathbf{k}\sigma}^{\dag}a_{\mathbf{k}\sigma}-\Delta\sum_{\mathbf{k}}(a^\dag_{\mathbf{k}\uparrow}a_{-\mathbf{k}\downarrow}^{\dag}+a_{-\mathbf{k}\downarrow}a_{\mathbf{k}\uparrow})$,
with energy dispersion $\xi_{\mathbf{k}}$, energy gap $2\Delta>0$ and $a_{\mathbf{k}\sigma}$ annihilation operator 
of electron possessing spin $\sigma$ and momentum $\mathbf{k}$  The coupling between
SC and QDs is described by the hopping Hamiltonian 
$H_{\mathrm{TS}}=\sum_{i\mathbf{k}\sigma}v_{\mathrm{S}i}(d^\dagger_{i\sigma}a^{}_{\mathbf{k}\sigma}+h c )$,
with $d^\dagger_{i\sigma}$ creating a spin-$\sigma$ electron at QD$i$  The matrix element 
$v_{\mathrm{S}i}$ and the normalized density of states of SC in normal state, $\rho_{\rm S}$, 
contribute to the coupling of QD$i$ to SC electrode as $\GS{i} = \pi \rho_{\rm S} |v_{{\rm S}i}|^2$  
We focus on the sub-gap regime, therefore, we integrate out SC degrees of freedom lying outside the energy gap \cite{RozhkovArovas} 
This gives rise to the following effective Hamiltonian,
$H_{\mathrm{eff}}=H_{\mathrm{SDQD}}+H_{\rm L}+H_{\rm R}+H_{\rm T}$, 
where 
\begin{eqnarray}
H_{\rm SDQD} 	& = & 
				\sum_{i\sigma} \varepsilon_{i} n_{i\sigma} 
				+\sum_{i} U n_{i\uparrow} n_{i\downarrow} 
				+U' (n_1-1)(n_2-1) 
				\nonumber\\
				&+&\sum_\sigma t(d^\dagger_{1\sigma}d^{}_{2\sigma} + h c ) 
				+J \vec{S}_1\vec{S}_2
				\nonumber\\
				&+&\sum_{i} \!\!\left[ \Gamma_{{\rm S}i} (d^\dagger_{i\uparrow} d^\dagger_{i\downarrow} \!+\! h c )
				+\Gamma_{\rm SX} (d^\dagger_{i\uparrow} d^\dagger_{\bar{i}\downarrow} \!+\! h c ) \right]
	\label{H_DQD} 
\end{eqnarray}
is the Hamiltonian of the SC-proximized DQD
\cite{IW_Kacper,Walldorf2018Feb}, with QD$i$ energy level $\varepsilon_i$,
inter-site (intra-site) Coulomb interactions $U'$ ($U$),
inter-dot hopping $t$, and CAR coupling $\GS{\rm X}$ 
$n_{i\sigma}=d^\dagger_{i\sigma}d^{}_{i\sigma}$ denotes the electron number operator 
at QD$i$, $n_i=n_\uparrow+n_\downarrow$, and $\bar{i}\equiv 3-i$  
Our model is strictly valid in the regime where $\Delta$ is the largest 
energy scale  Nevertheless, all discussed phenomena are
present in a full model for energies smaller than SC gap 
Moreover, by eliminating other consequences of the presence of SC lead,
our model pinpoints the fact that the non-local pairing is 
sufficient for the occurrence of the CAR exchange 
The presence of out-gap states shall result mainly in additional broadening of DQD energy levels,
changing the relevant Kondo temperatures 
We note that the procedure of integrating out out-gap states neglects the 
RKKY interaction mediated by SC lead and other possible indirect exchange mechanisms%
 \footnote{
 Note, that by RKKY interaction we mean only such an effective exchange, 
 which arises due to multiple scattering of a single electron or hole, see \fig{system}(h)-(j) 
 Other mechanisms leading to the total indirect exchange are considered separately 
 In particular, in the large gap limit, exchange described in Ref ~\cite{Yao} is in fact reduced to
 the CAR exchange, and additional antiferromagnetic contribution would arise for finite gap 
 }  
To compensate for this,
we explicitly include the Heisenberg term $ J \vec{S}_1\vec{S}_2$ in
$H_{\rm SDQD}$, with $\vec{S}_i$ denoting the spin operator of QD$i$
and a Heisenberg coupling $J$ substituting the genuine RKKY exchange 

The normal leads are treated as reservoirs of noninteracting electrons,
$H_{r}=\sum_{\mathbf{k}\sigma}\varepsilon_{r\mathbf{k}}c^\dagger_{r\mathbf{k}\sigma}c^{}_{r\mathbf{k}\sigma}$,
where $c^{}_{r\mathbf{k}\sigma}$ annihilates an electron of spin 
$\sigma$ and momentum $\mathbf{k}$ in lead $r$ ($r={\rm L,R}$) with the corresponding energy $\varepsilon_{r\mathbf{k}\sigma}$ 
The tunneling Hamiltonian reads,
$H_{\rm T} = \sum_{r\mathbf{k}\sigma} v_{r} (d^\dagger_{1\sigma}c^{}_{r\mathbf{k}\sigma} + h c )$,
giving rise to coupling between lead $r$ and QD$i$ of strength $\Gamma_r = \pi \rho_r |v_r|^2$,
with $\rho_r$ the normalized density of states of lead $r$ and $v_r$ the 
local hopping matrix element, assumed momentum-independent 
We consider a wide-band limit, assuming constant $\Gamma_r=\Gamma/2$
within the cutoff $\pm D = \pm 2U$ around the Fermi level  

For thorough analysis of the CAR exchange mechanism and its consequences
for transport, we determine the linear conductance between the two normal leads from
\begin{equation}
G = \frac{2e^2}{h} \pi \Gamma \int \left[ -\frac{\partial f_T}{\partial\omega} \right] \mathcal{A}(\omega) {\rm d} \omega ,
\label{G}
\end{equation}
where $f_T$ is the Fermi function at temperature $T$,
while $\mathcal{A}(\omega)$ denotes the normalized local spectral density 
of QD1 \cite{fn1} 
Henceforth, unless we state otherwise, we assume a maximal CAR coupling, 
$\GS{\rm X} = \sqrt{\GS{1}\GS{2}}$ \cite{IW_Kacper,Walldorf2018Feb},
$\GS{1}=\GS{2}=\GS{}$ and consider DQD tuned to the particle-hole symmetry point, 
$\varepsilon_1=\varepsilon_2=-U/2$  However, these assumptions are not crucial for the results presented
here, as discussed in Secs ~\ref{sec:asym}-\ref{sec:coef} 

\section{Estimation of relevant energy scales}
\label{sec:scales}

Since we analyze a relatively complex system, let us build up the understanding of its behavior starting
from the case of a QD between two normal-metallic leads, which can be obtained in our 
model by setting $t=\GS{}=J=U'=0$  Then, the conductance as a function of temperature, $G(T)$, grows
below the Kondo temperature $T_K$ and reaches maximum for $T\to 0$, $G(T\!=\!0)=G_{\rm max}$ 
At particle-hole symmetry point, the unitary transmission is achieved, $G_{\rm max}= G_0 = 2e^2/h$;
see short-dashed line in \fig{G-T}(a) 
An experimentally relevant definition of $T_K$ is that at $T=T_K$ 
$G(T)=G_{\rm max}/2$  $T_K$ is exponentially small in 
the local exchange $J_0 = 8\Gamma / (\pi \rho U)$, and is approximated by
$T_K \approx D \exp[-1/(\rho J_0)]$ \cite{Hewson_book} 

The presence of a second side-coupled QD, $t,U'>0$, significantly enriches the physics of the system 
by introducing direct exchange between QDs, see \fig{system}(b-d) 
In general, effective inter-dot exchange can be defined as energy difference between 
the triplet and singlet states of isolated DQD, 
$J^{\mathrm{eff}} = E_{S=1} - E_{\rm GS}$  Unless $U$ becomes very large, superexchange can be neglected
\cite{Zitko_2QDEx} and $J^{\mathrm{eff}}$ is determined by \emph{direct exchange}, $J^{\mathrm{eff}}\approx 4t^2/(U-U')>0$ 
When the hopping $t$ is tuned small \cite{CPS1}, one can expect $J^{\mathrm{eff}}\lesssim T_K$, which 
implies the two-stage Kondo screening \cite{Pustilnik_Glazman,Cornaglia} 
Then, for $T \ll T_K$, the local spectral density of QD1 serves as a band of width $\sim T_K$ for QD2 
The spin of an electron occupying QD2 
experiences the Kondo screening below the associated Kondo temperature
\begin{equation}
T^* = a T_K \exp(- b T_K / J_{\rm eff})
\label{Tstar}
\end{equation}
with $a$ and $b$ constants of order of unity \cite{Pustilnik_Glazman,Cornaglia} 
This is reflected in conductance, which drops to $0$ with lowering $T$, maintaining characteristic 
Fermi-liquid 
$G\sim T^2$ dependence \cite{Cornaglia}; see the curves indicated with squares 
in \fig{G-T}(a)  Similarly to $T_K$, experimentally relevant definition of $T^*$ is that 
$G(T\!=\!T^*) = G_{\rm max}/2$  Even at the particle-hole 
symmetry point $G_{\rm max} < G_0$, because the single-QD strong-coupling fixed point 
is unstable in the presence of QD2 and $G(T)$ does not achieve $G_0$ exactly,
before it starts to decrease 


The proximity of SC gives rise to two further exchange mechanisms that
determine the system's behavior  First of all, the (conventional)
\emph{RKKY interaction} appears, $J \sim \GS{}^2$ \cite{RK,K,Y}  
Moreover, the \emph{CAR exchange} emerges as a consequence of finite $\GS{}$ \cite{Yao}  
It can be understood on the basis 
of perturbation theory as follows  DQD in the inter-dot singlet state may absorb
and re-emit a Cooper pair approaching from SC; see \fig{system}(e)-(g)  As a second-order
process, it reduces the energy of the singlet, which is the ground state of isolated DQD 
A similar process is not possible in the triplet state due to spin conservation 
Therefore, the singlet-triplet energy splitting $J^{\mathrm{eff}}$ is increased (or generated for $t=J=0$)  
More precisely, the leading ($2$nd-order in $t$ and $\GS{}$) terms
in the total exchange are 
\begin{equation}
J^{\mathrm{eff}} 	\approx 	J + \frac{4t^2}{U-U'+\frac{3}{4}J} + \frac{4\GS{}^2}{U+U'+\frac{3}{4}J} 
\label{Jeff}
\end{equation}
Using this estimation, one can predict $T^*$ for finite $\GS{}$, $t$ and $J$ with \eq{Tstar} 
Apparently, from three contributions corresponding to:
(i) RKKY interaction, (ii) direct exchange and (iii) CAR exchange, only the first may bear a negative (ferromagnetic) sign 
The two other contributions always have an anti-ferromagnetic nature 
More accurate expression for $J^{\mathrm{eff}}$ is derived in Appendix~\ref{sec:downfolding}
[see \eq{A_J}] by the Hamiltonian down-folding procedure  The relevant terms differ 
by factors important only for large $\GS{}/U$  
Finally, it seems worth stressing that normal leads are not necessary for CAR exchange to occur 
At least one of them is inevitable for the Kondo screening though, and two symmetrically coupled 
normal leads allow for measurement of the normal conductance 


It is also noteworthy that inter-dot Coulomb interactions
decrease the energy of intermediate states contributing to direct exchange 
[\fig{system}(c)], while increasing the energy of intermediate
states causing the CAR exchange [\fig{system}(f)] 
This results in different dependence of corresponding terms in \eq{Jeff} on $U'$ 
As can be seen in \figs{G-T}(b) and \ref{fig:G-T}(c), it has a significant effect 
on the actual values of $T^*$ 

\begin{figure}
\includegraphics[width=1\linewidth]{Fig2 pdf}
\caption{(a) Linear conductance $G$ as function of $T$ calculated for 
		 $\varepsilon_1=\varepsilon_2=-U/2$, $\Gamma=U/5$, $U'=U/10$ and different situations, 
		 as indicated  The quantity $\xi\equiv\sqrt{\GS{}^2+t^2}$ is fixed 
		 for different curves drawn with the same dashing style 
		 Note the logarithmic scale on both axes 
		 %
		 (b) Points show $T^*/T_K$ calculated by NRG from curves in subfigure (a)  
		 Lines present the fit to \eq{Tstar} with $J^{\mathrm{eff}}$ obtained from \eq{Jeff} 
		 %
		 (c) The same as (b), only for $U'=0$ 
		 %
		 (d) and (e) show the residual conductance $G_{\mathrm{min}} \equiv G(T \!=\! 0)$ as a function of
		 $\GS{}$ for $t=0$ (denoted "CAR") and $t=\GS{}$ (denoted "Both")  
		 Dotted line is a guide for eyes  $U'=U/10$ in (b) and (d) and $U'=0$ in (c) and (e) 
		}
\label{fig:G-T}
\end{figure}

\section{CAR exchange and Kondo effect}
\label{sec:main}

To verify \eqs{Tstar}-(\ref{Jeff}) we calculate $G$ using
accurate full density matrix numerical renormalization group (NRG) technique \cite{WilsonNRG,Weichselbaum,FlexibleDMNRG,fn2} 
We compare $U'=0$ case with experimentally relevant value $U'=U/10$ \cite{Keller2013Dec} 
While for two close adatoms on SC surface RKKY interactions may lead to prominent consequences
\cite{Klinovaja}, the conventional ({\it i e } non-CAR) contribution should 
vanish rapidly when the inter-impurity distance $r$ exceeds a few lattice constants \cite{RKKYrange,SC_RKKY}  
Meanwhile, the CAR exchange may remain significant for $r$ of the order
of coherence length of the SC contact \cite{Yao}  Therefore, we first neglect the conventional RKKY coupling and analyze its consequences in Sec ~\ref{sec:RKKY} 

The main results are presented in \fig{G-T}(a), showing the temperature dependence of $G$
for different circumstances  
For reference, results for $\GS{}=0$ are shown, exhibiting 
the two-stage Kondo effect caused by \emph{direct} exchange mechanism 
As can be seen in \figs{G-T}(b) and \ref{fig:G-T}(c), an excellent agreement of $T^*$ found from NRG calculations and \eq{Tstar} 
is obtained with $a=0 42$ and $b=1 51$, the same for both $U'=0$ and $U'=U/10$  Note, 
however, that $J^{\mathrm{eff}}$ is different in these cases, cf  \eq{Jeff},
and $U'$ leads to increase of $T^*$ 

Furthermore, for $t=0$ and $\GS{}>0$ the two-stage Kondo effect caused solely by the \emph{CAR
exchange} is present; see \fig{G-T}(a) 
Experimentally, this situation
corresponds to a distance between the two QDs smaller than the superconducting coherence length,
but large enough for the exponentially suppressed direct hopping to be negligible 
While intuitively one could expect pairing to compete with any kind of magnetic ordering,
the Kondo screening induced by CAR exchange is a beautiful example of a superconductivity
in fact leading to magnetic order, namely the formation of the Kondo singlet 
This CAR-exchange-mediated Kondo screening is our main finding 
For such screening, \eq{Tstar} is still fulfilled with very similar 
parameters, $a=0 37$ ($a=0 35$) and $b=1 51$ ($b=1 50$) for $U'=0$ ($U'=U/10$),
correspondingly; see \figs{G-T}(b-c) 
Moreover, as follows from \eq{Jeff}, $U'$ reduces CAR exchange, and therefore diminishes $T^*$ 
For the same values of $J^{\mathrm{eff}}$, the dependence of $G(T)$ for $t=0$ and $\GS{}>0$ is hardly different 
from the one for $\GS{}=0$ and $t>0$ for $T\geq T^*$ (results not shown) 
However, $G(T)$ saturates at residual value $G_{\mathrm{min}}$ as $T\to 0$ only for finite
$\GS{}$, which at particle-hole symmetry makes $G_{\mathrm{min}}$
the hallmark of SC proximity and the corresponding CAR exchange processes 
From numerical results, one can estimate it as
\begin{equation}
G_{\mathrm{min}} = \frac{e^2}{h} \cdot c \, \frac{\GS{}^2}{U^2} 
	\qquad {\scriptstyle (\GS{1}=\GS{2}=\GS{})} ,
\label{Gmin}
\end{equation}
with $c\approx 2 25$, barely depending on $U'$ and getting smaller for $t>0$  
This is illustrated in \figs{G-T}(d-e), where the dotted line corresponds to \eq{Gmin} with $c=2 25$  

Lastly, in \fig{G-T}(a) we also present the curves obtained for $t=\GS{}$ chosen such, 
that the quantity $\xi=\sqrt{t^2+\GS{}^2}$ remains the same 
in all the cases 
This is to illustrate what happens when \emph{both} (direct and CAR) exchange interactions are
present  \fig{G-T}(c) clearly shows that $T^*$ remains practically unaltered for $U'=0$ 
The comparison with \fig{G-T}(b) proves that in this case it practically does not depend 
on $U'$  The enhancement of direct exchange is compensated by the decrease of the CAR one  
On the contrary, $G_{\mathrm{min}}$ decreases for larger $t$ below the estimation given by Eq ~(\ref{Gmin}), 
as can be seen in \figs{G-T}(d-e)  

While analyzing the results concerning $G_{\mathrm{min}}(\GS{})$ plotted in \figs{G-T}(d-e) 
one needs to keep in mind that $G_{\mathrm{min}}$ is obtained at deeply cryogenic conditions  To illustrate
this better, $G(\GS{})$ obtained for $t=0$ and $T=10^{-6}U$ is plotted with solid line 
in \fig{3}  Clearly, for weak $\GS{}$ the system exhibits rather conventional (single-stage)
Kondo effect with $G=G_{\mathrm{max}}\approx 2e^2/h$, while QD2 is effectively decoupled ($G_{\mathrm{max}}<2e^2/h$
in the proximity of SC lead \cite{KWIW})  Only for larger values of $\GS{}$
the CAR exchange is strong enough, such that $T^*>T$ and the dependence $G(\GS{})$ continuously 
approaches the $T=0$ limit estimated by \eq{Gmin} and presented in \figs{G-T}(d-e) 

\section{CAR-RKKY competition}
\label{sec:RKKY}

\begin{figure}
\includegraphics[width=0 98\linewidth]{Fig3 pdf}
\caption{Linear conductance $G$ vs  $\GS{}$ calculated
		 for $t=0$, $\Gamma=U/5$, $U'=U/10$, finite $T=10^{-6}U$
		 and different values of RKKY coupling $J$, as indicated  
		 Inset shows QD1 spectral function $\mathcal{A}(\omega)$ as a function of energy $\omega$
		 for points on $J=-0 1U$ curve, indicated with corresponding symbols 
		}
\label{fig:3}
\end{figure}

Let us now discuss the effects introduced by the conventional RKKY interaction 
We choose $t=0$ for the sake of simplicity and
analyze a wide range of $\GS{}$, starting from the case of anti-ferromagnetic 
RKKY interaction ($J>0$)  Large $J>0$ leads to the formation of a molecular singlet in the 
nanostructure  This suppresses the conductance, unless $\GS{}$ becomes of the order of $U/2$, 
when the excited states of DQD are all close to the ground state  This is illustrated 
by double-dotted line in \fig{3} 
Smaller value of $J>0$ causes less dramatic consequences, namely it just increases $J^{\mathrm{eff}}$ according
to \eq{Jeff}, leading to enhancement of $T^*$, cf  \eq{Tstar}  This is presented with
dot-dashed line in \fig{3} 

The situation changes qualitatively for ferromagnetic RKKY coupling, $J<0$ 
Then, RKKY exchange and CAR exchange have opposite signs and compete with each other 
Depending on their magnitudes and temperature, one
of the following scenarios may happen 

For $J^{\mathrm{eff}} > 0$, {\it i e } large enough $\GS{}$, and $T<T^*$, the system is in the 
singlet state due to the two-stage Kondo screening of DQD spins  $G(T\!=\!0)$ is reduced 
to $G_{\mathrm{min}}$, which tends to increase for large negative $J$; see dashed lines in \fig{3}  
In the inset to \fig{3}, the spectral density of QD1 representative for this regime is plotted 
as curve indicated by triangle  It corresponds to a point on the $J=-0 1U$ curve in the main 
plot, also indicated by triangle  The dip in $\mathcal{A}(\omega)$ has width of order of $T^*$ 

For finite $T$, there is always a range of sufficiently small $|J^{\mathrm{eff}}|$, where QD2 becomes effectively
decoupled, and, provided $T<T_K$, $G$ reaches $G_{\mathrm{max}}$ due to conventional Kondo effect 
at QD1  This is the case for sufficiently small $\GS{}$ for $J=0$ or $J=-0 01U$, and in the narrow
range of $\GS{}$ around the point indicated by a circle in \fig{3} for $J=-0 1U$ (for $J=0 01U$, 
the considered $T$ is close to $T^*$ and $G$ does not reach $G_{\rm max}$)  The conventional Kondo effect manifests itself with 
a characteristic peak in $\mathcal{A}(\omega)$, as illustrated in the inset in \fig{3} with line denoted by circle 

Finally, large enough $J^{\mathrm{eff}} < 0$ and low $T$, give rise to an effective ferromagnetic coupling of DQDs 
spins into triplet state  Consequently, the underscreened Kondo effect occurs 
\cite{Mattis,NozieresBlandin} for weak $\GS{}$ and, {\it e g }, $J=-0 1U$; 
see the point indicated by square in \fig{3} 
This leads to $G=G_{\mathrm{max}}$ and a peak in $\mathcal{A}(\omega)$, whose shape is significantly different from the
Kondo peak, cf  the curve denoted by square in the inset in \fig{3}  



\section{Effects of detuning from the particle-hole symmetry point}
\label{sec:asym}

\begin{figure}
\includegraphics[width=0 98\linewidth]{Fig4 pdf}
\caption{
         (a) Linear conductance between the normal leads $G$ as a function of temperature $T$
         for parameters corresponding to \fig{G-T}(a) with $\xi=U/10$, and additional curves for finite 
         detuning from particle-hole symmetry point, $\delta_1=-\delta_2$, 
         and two values of $\xi=\sqrt{t^2+\GS{}^2}$, as indicated in the figure 
         (b) $G_{\mathrm{min}} \equiv G(T \!=\! 0)$ as a function of QD1 detuning $\delta_1$ for different
         exchange mechanisms, $\xi=U/10$ and $\delta_2=\pm\delta_1$ (as indicated) 
		}
\label{fig:asym}
\end{figure}

At PHS $G_{\mathrm{min}}=G(T \!=\! 0)=0$ in the absence of superconducting lead, making $G_{\mathrm{min}} > 0$ a hallmark
of SC-induced two-stage Kondo effect  However, outside of PHS point $G_{\mathrm{min}} > 0$ even in the case of 
the two-stage Kondo effect caused by the direct exchange  
Exact PHS conditions are hardly possible in real systems, and the fine-tuning of the QD energy
levels to PHS point is limited to some finite accuracy 
Therefore, there may appear a question, if the results obtained at PHS are of any importance for the
realistic setups  As we show below --- they are,
in a reasonable range of detunings $\delta_i=\varepsilon_i +U/2$ 

In \fig{asym}(a) we present the $G(T)$ dependence in and outside the PHS, corresponding to 
parameters of \fig{G-T}(a)  
Clearly, for considered small values of $\delta_1=\delta_2=\delta$, 
$G_{\mathrm{min}}<10^{-3}e^2/h$ for direct exchange only, while $G_{\mathrm{min}}$ in the presence of a superconductor is 
significantly increased and close to the PHS value  Furthermore, for $|\delta_1| \sim |\delta_2| 
\sim \delta$, the residual conductance caused by the lack of PHS, $G_{\mathrm{min}} \approx e^2/h \cdot (\delta/U)^2$,
which is a rapidly decreasing function in the vicinity of PHS point, as illustrated in \fig{asym}(b)
with lines denoted by a square  Evidently, in the regime $|\delta_i| < 0 01U$ the residual conductance
caused by SC is orders of magnitude larger, leading to the plateau in $G_{\mathrm{min}}(\delta_1)$ dependence,
visible in \fig{asym}(b) 
Taking into account that the realistic values of $U$ in the semiconductor quantum dots are rather 
large, this condition seems to be realizable by fine-tuning of QD gate voltages 

Lastly, let us point out that while in the presence of only one exchange mechanism, \emph{CAR} or
\emph{direct}, $G_{\mathrm{min}}(\delta_1)$ dependencies depicted in \fig{asym}(b) are symmetrical with respect
to sign change of $\delta_1$, for \emph{both} exchange mechanisms the dependence is non-symmetric  

\section{Effects of asymmetry of couplings to superconductor}
\label{sec:x}

\begin{figure}
\includegraphics[width=0 98\linewidth]{Fig5 pdf}
\caption{
		 (a) Linear conductance between the normal leads, $G$, as a function of temperature, $T$,
		 for parameters corresponding to \fig{G-T}(a) with $\xi=U/10$, for different values 
		 of asymmetry coefficient $x$ [see \eq{xGS}], in the presence of \emph{CAR} exchange only 
		 %
		 (b) The second-stage Kondo temperature $T^*$ normalized by $T_K$ as a function of $x$, 
		 calculated with the aid of NRG (points) and a fit to \eq{Tstar} (lines) 
		 with $J^{\mathrm{eff}}$ from \eq{Jeff} 
		 %
		 (c) The zero-temperature conductance $G_{\mathrm{min}}$ as a function of QD1 coupling to SC lead, $\GS{1}$,
		 compiled from data obtained at different circumstances (as indicated in the legend)
		 for different $x$  Dotted line corresponds to \eq{Gmin2} with $c=2 25$ 
		}
\label{fig:x}
\end{figure}

Similarly to PHS, the ideal symmetry in the coupling between respective QDs and SC lead is hardly possible
in experimental reality  As shown below, it does not introduce any qualitatively new features 
On the other hand, it decreases the second stage Kondo temperature, which is already small, therefore,
quantitative estimation of this decrease may be important for potential experimental approaches 
To analyze the effects of $\GS{1}\neq\GS{2}$, we introduce the asymmetry parameter $x$ and extend
the definition of $\GS{}$,
\beq
x = \frac{\GS{1}-\GS{2}}{\GS{1}+\GS{2}}, \quad \GS{} = \frac{\GS{1}+\GS{2}}{2} 
\label{xGS}
 \end{equation} 
Note, that even for a fixed $\GS{}$, the actual CAR coupling $\GS{\rm X}=\GS{}\sqrt{1-x^2}$ decreases
with increasing $|x|$, which is a main mechanism leading to a decrease of $T^*$ outside the $x=0$ point
visible in \figs{x}(a) and (b)  To illustrate this, the curves corresponding to \emph{both} exchange
mechanisms were calculated using $x$-dependent $t=\GS{\rm X}$ instead of $t=\xi/\sqrt{2}$  
Therefore, $\xi$ was generalized for $x\neq 0$ by setting $\xi=\sqrt{t^2(1-x^2)^{-1}+\GS{}^2}$ 
Clearly, in \fig{x}(b) the curves for different exchange mechanisms are very similar and differ mainly 
by a constant factor, resulting from different influence of $U'$; see \Sec{scales}  
The magnitude of $T^*$ changes is quite large, exceeding an order of magnitude for $x=\pm 0 5$ 
and $\xi=U/20$  Moreover, $T^* \to 0$ for $x\to\pm 1$  Consequently, for strongly asymmetric
devices one cannot hope to observe the second stage of Kondo screening 

A careful observer can note that the $T^*(x)$ dependency is not symmetrical; note for example different 
$T^*$ for $x=\pm 0 5$ in \fig{x}(a)  This is caused by the dependence of the first stage Kondo temperature
$T_K$ on $\GS{1}$ \cite{part1,DomanskiIW},
\beq
\widetilde{T}_K(\GS{1}) = T_K \cdot \exp\!\left( \frac{\pi}{2} \frac{\GS{1}^2}{\Gamma U}\right) 
 \end{equation} 
Here, $T_K$ is, as earlier, defined in the absence of SC, while $\widetilde{T}_K$ is a function 
of $\GS{1}$, such that $G(\widetilde{T}_K) = G_{\rm max}(\GS{1})/2$ in the absence of QD2  
As $\widetilde{T}_K$ grows for increasing $\GS{1}$ (or $x$), $T^*$ decreases according to \eq{Tstar}  
Its $\GS{}$ dependence can be accounted for by small changes in the coefficients $a$ and $b$ in \eq{Tstar}, 
as long as $x$ is kept constant  

To close the discussion of $T^*(x)$ dependence let us point out, that in \eq{A_J} 
there appears a correction to \eq{Jeff} for $x\neq 0$  However, it is very small due to additional
factor $\GS{}^2/U^2$ in the leading order  Its influence on curves plotted in \fig{x}(b) is hardly visible 

In turn, let us examine the $x$ dependence of the $T=0$ conductance $G_{\mathrm{min}}$  As can be seen 
in \fig{x}(a), it monotonically increases with $x$, as it crosses $x=0$ point  In fact, \eq{Gmin}
can be generalized to
\beq
G_{\mathrm{min}} = \frac{e^2}{h} \cdot c \, \frac{\GS{1}^2}{U^2} ,
\label{Gmin2}
 \end{equation} 
with $c\approx 2 25$ (indicated by a dotted line in \fig{x}(c))  Note that $G_{\mathrm{min}}$ is proportional to 
$\GS{1}^2=(x+1)^2 \GS{}^2$, instead of simply $\GS{}$, cf  \eq{Gmin}  The values of $G_{\mathrm{min}}$ obtained
from all analyzed $G(T)$ dependencies for different $x$ have been compiled in \fig{x}(c) 
It is evident, that \eq{Gmin2} is approximately fulfilled for all the considered cases 

Finally, it seems noteworthy that the normal-lead coupling asymmetry, 
$\Gamma_{\rm L}\neq \Gamma_{\rm R}$, is irrelevant for the results except for a constant factor
diminishing the conductance $G$ \cite{KWIWJB-asym} 



\section{The role of CAR efficiency}
\label{sec:coef}

\begin{figure}[tb]
\includegraphics[width=0 98\linewidth]{Fig6 pdf}
\caption{Linear conductance between the normal leads
		 $G$ as a function of coupling to SC lead, $\GS{}$, for indicated values of RKKY exchange $J$
		 and the efficiency of CAR processes reduced by factor (a) $\mathcal{C}=0 9$ and (b) $\mathcal{C}=0 5$ 
		 Other parameters as in \fig{3} 
		 Insets: QD1 local spectral density $\mathcal{A}(\omega)$ as a function of energy $\omega$
		 for points on $J=-0 1U$ curve, indicated with corresponding symbols 
		} 
\label{fig:C}
\end{figure}

Up to this point we assumed $\GS{\rm X} = \sqrt{\GS{1}\GS{2}}$, which is valid when the two 
quantum dots are much closer to each other than the coherence length in the superconductor 
This does not have to be the case in real setups, yet relaxing this assumption does not 
introduce qualitative changes  Nevertheless, the model cannot be extended to inter-dot 
distances much larger than the coherence length, where $\GS{\rm X}\to 0$ 

To quantitatively analyze the consequences of less effective Andreev coupling we define the 
CAR efficiency as $\mathcal{C} \equiv \GS{\rm X} / \sqrt{\GS{1}\GS{2}}$ and analyze $\mathcal{C} < 1$
in the wide range of $\GS{1}=\GS{2}=\GS{}$ and other parameters corresponding to \fig{3}  
The results are presented in \fig{C} 

Clearly, decreasing $\mathcal{C}$ from $\mathcal{C}=1$ causes diminishing of $\GS{\rm X}$, and consequently of CAR 
exchange  For a change as small as $\mathcal{C}=0 9$, the consequences reduce to some shift of the 
conventional Kondo regime, compare \fig{C}(a) with \fig{3}  Stronger suppression of CAR may, 
however, increase the SC coupling necessary to observe the second stage of Kondo screening caused
by CAR outside the experimentally achievable range, see \fig{C}(b)  Moreover, the reduced $T^*$
leads to narrowing of the related local spectral density dip, while the
increased critical $\GS{}$ necessary for the observation of the second stage of screening leads to the
shallowing of the dip  This is visible especially in the inset in \fig{C}(b) 


\section{Conclusions}
\label{sec:conclusions}

The CAR exchange mechanism is present in any system comprising at least
two QDs or magnetic impurities coupled to the same superconducting contact
in a way allowing for crossed Andreev reflections 
In the considered setup, comprised of two quantum dots in a T-shaped geometry 
with respect to normal leads and proximized by superconductor,
it leads to the two-stage Kondo
screening even in the absence of other exchange mechanisms 
This CAR induced exchange screening is characterized by a residual 
low-temperature conductance at particle-hole symmetric case 
We have also shown that the competition between CAR exchange and RKKY
interaction may result in completely different Kondo screening scenarios 

The presented results bring further insight into the low-temperature
behavior of hybrid coupled quantum dot systems, which hopefully could be verified
with the present-day experimental techniques 
Moreover, non-local pairing is present also in bulk systems such as non-$s$-wave superconductors 
The question if an analogue of discussed CAR exchange may play a role there
seems intriguing in the context of tendencies of many strongly correlated materials
to possess superconducting and anti-ferromagnetic phases 


\begin{acknowledgments}
This work was supported by the National Science Centre in Poland through project no 
2015/19/N/ST3/01030 
We thank J  Barna\'{s} and T  Maier for valuable discussions 
\end{acknowledgments}





Context 3: July | 2012 | Chico Taxpayers Association
Keep a Knockin’ but you can’t come in! Come back next Tuesday night and try it again! And be sure to bring plenty of your friends 
Toby Schindelbeck has finally been rewarded for his persistence – he’s been going before Chico City Council, asking that Finance MisDirector Jennifer Hennessy comply with city code and give a budget report at every meeting  City clerk Debbie Presson has informed him that this subject will be “discussed” at the August 7 council meeting 
But we know, it won’t be a very good “discussion” unless a bunch of people come in and demand some action  Toby has observed that issues like Corporate Personhood and the “single-use” plastic bag ban have drawn fairly small crowds – he estimates 25 – 30 people, and I’d say he’s being generous  The city has acted on these issues, with only that small fraction of the population in support  So, Toby believes there needs to be an even stronger presence to get a decent discussion on this matter, and I agree 
Like Toby and Stephanie Taber and others have been saying, the city code calls for a monthly budget report, with sticky details like receipts, etc, and Jennifer Hennessy admits she has not made such a report in the seven years she’s been with the city of Chico  Try not paying your taxes for seven years – you’ll get the same treatment as the man from Touch of Class Florist – 68 years old, and he’s being sent to PRISON  But Jennifer Hennessy and her boss Dave Burkland, and their overseer, Mayor Ann Schwab, get to flog the law right in front of everybody, and Ann just steps right into that little red convertible and drives off to her palatial estate in Forest Ranch 
The law is a piece of paper  It takes people to demand law enforcement  We’ve got a serious law enforcement problem in our town  The police say they aren’t paid enough to enforce the laws in the streets, and now Dave Burkland says, he just doesn’t have to 
And your mayor won’t make him either  He’s retiring, on more than $150,000 a year, for the rest of his life, but she’s up for election in November – time to take out the trash 
That meeting is scheduled for August 7, the usual time, the usual place  I’ll keep you posted 
Tags: Ann Schwab Chico CA, Ann Schwab for city council, Dave Burkand Chico Ca, Friends of Ann Schwab, Jennifer Hennessy Chico Ca
Stephanie Taber answers Quentin Colgan’s letter to the News and Review
I get complaints from friends and strangers, and it has also been my own experience, that the editor of the Chico News and Review is not always objective in deciding which letters received from the public will be printed in the paper and which ones won’t  Robert Speer has offered me excuses, but I have always found him to be disingenuous  For example – he told me he would only run letters that referenced an article or letter recently printed in the paper – untrue a million times over  He also told me he wouldn’t print letters that had already run in the Enterprise Record – also untrue a million times over  The man has his own reasons for running or not running letters 
David Little is more objective, but he’s got his faults too – once he threw out a letter from my husband and later admitted he had thought I’d written it and used my old man’s name  He just threw it out without even calling the phone number or e-mailing, just assumed I’d do something like that when I’d never done anything like that before, because he was mad at me over a snit we were having at the time 
I think Little gets his nose out at people personally, and Hell hath no fury, know what I mean? With Speer it can personal but I think it’s most often political  Suffice to say, they both carry what my dad used to call a “Shit List,” and if you’re on it, you don’t get ink in their rag 
Of course either paper is equally likely to print a total wad of lies or misinformation without so much as a google fact check  I will never forget the time Dave Little printed a letter saying the cops had been called to my house on a dog complaint  The letter writer insinuated that this was why I often wrote letters complaining about the cop contracts  I called Little and told him the letter was false, nothing like that had ever happened – but he wouldn’t retract it  I had to look the old man up in the phone book and call him myself, tell him he had been misinformed, and ask him to write a retraction  He apologized profusely and the apology was in the paper within three days  He wouldn’t tell me where he got the information, but later I found out he was a member of VIPS, and he still is  I think that’s something Dave Little could have looked into before he printed a story like that about me and my family, not to mention my dogs, but he didn’t see it that way  Poor journalism, is how I see it, and that’s what I’ve come to expect out of both the daily and the weekly 
So, pardon me if I was not surprised when my friend Stephanie mentioned to me that she didn’t think Speer would run her response to a letter from Quentin Colgan, regarding our current fiscal morass  QC made an argument he has been swinging around town lately – that Fire Station 5 had to be closed recently because the Tea Party forced the city to have a $150,000 election over Measure A 
The first problem I have with this argument is, the city is out a heck of a lot more than $150,000  The second problem I have is, I happen to know that over 8,000 Chicoans signed that petition, and there’s not more than 600 active members of the Tea Party  I also know the Tea Party didn’t sponsor the petition drive, nor were they the only people that marched out with those petitions  Colgan’s argument doesn’t make sense to me, but it’s amazing what kind of “facts” the general populace will believe if you just keep repeating them 
Some folks are trying to use the Tea Party as a target to rile up their peanut gallery, using Measure A as their rally call  They keep banging the same old drum  They refuse to have a rational discussion about the situation we’re facing, because it’s going to mean some sour beans for them and their trough-dwelling friends 
So, it’s up to a rational person like Stephanie Taber to lay it out straight for those who like facts  Stephanie attends the meetings, she reads the reports, she goes to the trouble of putting questions in writing for $taff, and then waiting persistently for an answer that practically has to be deciphered by a lawyer  She has followed this budget conversation since the day then-city-manager and first rat to jump, Greg Jones, expressed his grave concerns that we were headed straight for bankruptcy  She has followed the figures and checked the facts until she has forced these rats right to the wall – they have lately begun to dig their feet in and refuse to obey the sunshine laws, refusing to give the fiscal reports demanded by the city charter  Some people can try to run their little smokescreen of repetitive nonsense, but more rational people are finding out the truth  Thanks to Stephanie Taber for writing this letter below, which may or may not run in the Chico News and Review:
I’d like to take this opportunity to respond to Quentin Colgan’s letter of July 12th; primarily because the costs surrounding the Special Election held regarding Measure A have been distorted  Yes, it did cost $150,000, but why? That’s the elephant in the room  The progressives on the City Council chose the method by which the election would be held  Per the City Charter (which is the City’s Constitution) Section 501 clearly states “The City Council may determine that any Special Election shall be held by mailed ballot” etc  That would have cut the cost by half, at least  But the Council chose the most expensive means possible, voting at the precinct  They were afraid that just telling the students they were being disenfranchised, which was an obvious lie, would not be sufficient to defeat it 
As to “it’s all the Tea Party’s fault”; I was the only signature to the Measure  I felt no need to consult the Tea Party before I took that action; but did enlist the help of many concerned citizens to gather the more than 8,000 signature required to put it on the ballot 
Toby Schindelbeck has called upon our Finance Director to adhere to Section 908 of the City’s Charter which states “(the) Finance Director shall submit to the Council through the City Manager monthly statements of receipts, disbursements and balances in such form as to show the exact financial condition of the City”  It does not state when you may want to or if you have time to; it says “shall”  No one on the Council or otherwise can remember when that may have happened last  If it was being done as the Charter states it would have been recognize that the City was facing a financial Armageddon and steps could have been taken much earlier in the fiscal year to avoid the closing of Fire Station 5 
Tags: Ann Sc hwab Chico Ca, Ann Schwab for city council, Chico Enterprise Record, Chico News and Review, Chico Tea Party Patriots, City of Chico, David Little, Friends of Ann Schwab, Quentin Colgan, Robert Speer, Stephanie Taber
City Art Director Mary Gardner is foisting a new “Art Tax” on us to pay her own salary
To mgardner@ci chico ca us, gerimahood@yahoo com, mcbergarts@gmail com
(Mary Gardner, city of Chico public arts director, city of Chico, Geraldine Mahood and Monica Berg of the Arts Commission)
I recently read your memo here
Chico-Arts-Building-Tax pdf
I think it’s despicable Ms  Gardner that you are trying raise revenues for your own salary by foisting a new “Art Tax” on new development 
Ms  Mahood, Ms  Berg, nobody wants eggsuckers like you telling them how to spend their money or what’s “art”  You people make me sick 
The Chico Taxpayers Association will fight this grab, as will other civic groups through the area  That’s why you’ve kept your efforts “under the radar” I assume – you don’t want people to know about this, because you don’t want to hear what they think about it  Or YOU!
You people need to get real jobs and quit sucking off the public teat 
http://www norcalblogs com/adhoc/
Sincerely, Juanita Sumner, Chico CA
Tags: Ann Schwab Chico CA, Ann Schwab for city council, Chico Arts Commission, City of Chico "Art Tax", City of Chico Arts Policy Manual, Friends of Ann Schwab, Geraldine Mahood, Mary Gardner, Monica Berg
Jennifer Hennessy is incompetent – she can’t do her job and Burkland says she doesn’t have to
I’ll never forget my first real job – a clerical position at a manufacturing plant  I would compare it to the story of the miller’s daughter  On the first day, I was told that the employee I was to be replacing would stick around for a week to train me  At noon that day, having shown me where everything was and how to use the coffee maker, she got up from her chair, smiled, and told me she thought I could “handle it,” then left  At one o’clock, the plant manager came over to my desk followed by several “production” workers  They brought cart loads of microfilm, on rolls, in little white boxes  I was to label all of those boxes, three carts, piled high  This job had gotten held up, he explained, it would be “great!” if it could go out today  Did I think I could get them done by 4 o’clock? I wanted to make everybody happy, so said I yes without thinking, and set to work loading the labels into the typewriter 
It was a disaster  I had never typed anything like those labels before – typing class had been all about letters and envelopes, columns and reports  The labels skittered all over the platen, getting glue all over the inside of the typewriter  About every 50 or so labels, the platen had to be taken out and cleaned with alcohol  I typed and typed  By 3 o’clock I knew I was in trouble  The production workers had come over to my desk to help me affix the sticky labels  We were nervous, labels were getting screwed up  At 3:30 the office manager and receptionist came back to my desk to help with the labels  I typed and typed, and tried not to cry



ground_truth: It tends to suppress the Kondo effect.

prompt_front: Now, answer the following question based on the text below, only give me the answer and do not output any other words.

Question: What is the problem encountered when building the fuselage sides?

Read the following text and answer briefly.

Context 2: Probably one of the most frustrating things about building experimental aircraft, especially when starting with a minimum of pre-fabricated parts, is to start building and ending up with an unexpected result  Every builder starts a new project by wanting it to go "perfectly " So when things aren't going well, especially at the beginning, the frustration can lead to an unfinished airplane 
This is the first article in a series dedicated to helping builders of the Rand Robinson KR series planes build a straight and true fuselage -- the first part of the construction process  Borrowing from modern boatbuliding techniques, focus will be on the KR-2S, but the principles apply to the entire lineup of KR-1 & KR-2 series planes 
While building the KR-2(s) a common surprise is encountered by builders when the completed fuselage sides are laid into position to form the fuselage box section  With many hours spent building the sides flat, finding the once straight longerons that now bow up from the building surface, form a most dissatisfying "banana" shape  Especially when using the preformed fiberglass parts, this curve in the top longeron is not acceptable  The builder is left wondering what went wrong and no amount of clamping or brute force forming will solve the problem to any degree of satisfaction  The problem is not the builder's fault  The solution starts by understanding the three dimensional relationship of the assembled parts being built 
First understand that the plans show the finished form of the plane  They show the "projected" form as you would expect to see it if viewing an actual plane from the top, ends and from the side  Since the sides are sloped (flared) outward, looking from the side, the distances given by measuring the profile drawing are "foreshortened" and don't give the proper shape for building the fuselage with a flat top longeron  What needs to be done is to "develop" the "true" distances and shape of the flat panel so that when it is curved into position, the longerons lay flat 
Second, understand that the dimensions called for in the plans put a twist in the sides that tends to work the panel in two directions of curvature  This twist makes the panel "undevelopable" meaning that that shape cannot be unrolled into an equivalent flat shape  This is important when laying out the side and bottom panels onto flat plywood  To illustrate this, try forming a piece of paper around a soda can  The paper can be formed flat around the can either straight or at a diagonal to it's length  It has only one direction of curvature and is by definition "developable"  Now try to form the same piece of paper around a baseball  It won't lie flat on the surface without some deformation (folding, wrinkling or tearing) of the paper  The ball has curvature in more that one direction and is a "compounded" shape  Paper (or plywood) can only be readily formed in developable shapes as opposed to aluminum or other metal which can accept in plane deformation  A developable surface is needed to lay out a curved surface when the materials used can't be deformed with any degree of in-plane strain 
Initially, the fuselage sides are laid out flat with reference to the top longeron measured to a straight chalk line  The bowing problem starts when the side panels are bent and sloped to form the fuselage box section  If the sides were not sloped (tumbled home), the section formed would be cylindrical and the longerons would lie flat  Since the sides are tumbled home, the section formed is now conical  When a conical shape is cut with a plane (building surface) not perpendicular to it's axis, the shape formed is elliptical -- exactly what happens with the top longeron  When it's built flat, bent to form a cylindrical section, and sloped to form a conical section, it takes on an elliptical shape firewall to tailstock 
This method borrows heavily from proven techniques used in the marine trades  It should be stressed at this point that although the layout procedure is not complicated, it is important to take your time  If the layout is not going well initially, start over! Better to erase layout errors now than to have them built it and cause surprises later 
Layout to ensure a fair and true fuselage starts by drawing a reference line (baseline) on the building surface  Refer to figures 2 & 3 and use a wire guide to draw a very straight baseline  About 500 lbs  Of tension should be adequate  One could use a chalk line, but we're talking airplanes here, not house framing 
The main layout difference is that the baseline isn't used as a reference for the top longeron  The baseline references the mid point of the firewall for the developed (and true dimensioned) side panel  Although the baseline will still be the reference, the top and bottom longerons will be laid separately 
Layout differences don't end there  Each of the stations (vertical members) will be laid out with a calculated separation so that when the panels are formed into position, they land on the spacing called for in the plans  Another major difference is that the bottom & side panels are applied after forming the fuselage box section  This is mainly to obtain the ability to "fair" the side and bottom surfaces and insure a straight and true shape 
Refer to figure 1 for the layout of the new developed side panel  The firewall (station a) is layed out perpendicular to the baseline  Longitudinal (station) measurements are given along the length of the baseline from the firewall  Vertical dimensions are given to reference the angle and breadths of the station at the baseline 
Notice that the top longeron is bowed outward and that the stations are spaced slightly greater than called out in the plans  When the panels are formed into the box frame section ,they will work into the dimensions specified in the plans 
Strike a centerline, longer than is needed on the building surface using a wire guide  Draw off the firewall line perpendicular to the centerline at one end 
Using the distances listed in the balloons, mark them off on the centerline  Distances are measured to the nearest sixteenth of an inch  Take time to mark them off carefully  Don't mark off the distances in a cumulative fashion  Use the firewall as a common reference 
Using the angles listed at each station, mark off a station line longer than is needed  The angles are measured to the nearest hundredth of a degree  Take time to mark them off carefully 
At each station, start by marking off each short (bottom longeron) line distance from the centerline  Use your set of trammels or beam compass for doing this  Mark the intersection of the short line with the station line 
At each station, mark off each long (top longeron) line distance from the intersection of the short line distance and the station line  Again the trammels or beam compass is best for completing this step  Mark the intersection of the long line distance with the station line 
Using the longeron as a batten, trace out the inside and outside curves of the longeron  After the batten is secure, in between each station, fasten a keeper block inside and outside to preserve the shape of the longeron taking care to avoid potential future interference with the diagonal members to be installed later  The fairing blocks can be removed or left in place if they won't interfere with building  The vertical station members and their diagonals can now be measured and positioned  Remember to refer to the plans for the material thickness direction 
After vertical and diagonal members are cut and fitted, take time to draw their outlines on the building surface to cut down on time and confusion when laying out the opposite side 
Finishing the side panel is accomplished in a manner similar to that called for in the handbook with the exception that the side and bottom skin panels will be attached later 
The next article in the series will discuss jigging and building techniques to ensure alignment and straightness of the flat built side panels  Also covered will be building a "strongback" jig to assure alignment of the side panels when they are formed into their final shape 
Part 3 in the series will cover assembly of the side panels using the jigs  Some joint details will be discussed that will ensure a stronger and more fair fuselage assembly  Also covered will be the layout & attachment of the side and bottom ply skins 
U S  Mail: Densmore Associates, inc 
ANSI "D" size, computer generated plots of all the layout drawings in this series are available from the author for $30 plus postage & handling  Full (true size) scale plots may be made available depending on demand 
"Scarfing" is the practice of splicing plywood so that short pieces of plywood can be used to span long distances  On the KR, it is required on both the fuselage skins and spar webs  The angle of the splice should be 10 to 12 degrees to maintain strength across the joint  Also, joints should coincide with structural members, such as spar webs or fuselage truss members 
This scarfer is made by mating a regular plunge router (this one costs about $50) to a table saw  Obviously, you really only need a table saw to cut the chamfer, but it does make a nice heavy table for scarfing  You could just as easily use a large work table as the base First, set the table saw for a 5 5 degree cut (for a 1:12 joint, or 6 5 degree cut for a 10:1 joint), and run a 1 x 6 through on edge to chamfer a corner on the board  Then drill the board for three router mounting holes (two are countersunk) and connect the assembly to the table saw with two 1/4 inch bolts  Use a long (2-3 inch) straight cutting bit to do the cutting  Adjust the bit so it doesn't interfere with your table top, and go to town  Keep pressure on the plywood to ensure contact with the table while you're scarfing  Make sure you feed your material from the same end as you would if you were sawing, or the router will take your plywood away from you and put a big dent in your garage door 
In the late 60's Ken Rand and Stuart Robinson were working as flight system engineers for Douglas Avionics  Ken was working as an electrical engineer, having previously worked for Sperry as an autopilots project engineer, while Stu's degree was in aeronautical engineering from Northrop University  They were two of the guys at the end of the DC-8,9, and 10 assembly lines responsible for correcting some of the nits and picks in various systems before delivery to the customer 
They both wanted to build a fast, inexpensive airplane which was also economical to maintain  Several designs were considered, and plans were bought first for the Jeanie's Teenie and then the Taylor Monoplane  The Monoplane was more to their liking, but would require some modification to fit their needs  A cooperative redesign effort ensued, with virtually no dimensions left untouched  Only the basic fuselage structure, airfoil, and powerplant were retained  The tail shape was Stu's, and came directly from the big DC-8s parked on the ramp outside his office window  The landing gear was designed by Ken, after seeing the gear on a Dewey Bird at Santa Paula airport 
Ken was killed in his KR2 a short time later while flying over Cajon Pass in what was apparently a bad weather / low fuel accident  Ken's wife Jeanette became owner of RR overnight, and stepped up to keep the plans and parts coming  Much of the engineering needs are handled by Bill Marcy of Denver, who's been helping out since early '79 
To date, almost 6000 KR1, 9200 KR2, and 760 KR2S plan sets have been sold  1200 KR2s are estimated to be flying, with 5 KR2Ss now in the air  Much of the development work done on KR's is now done by the builders themselves  KR builders tend to be innovative, which leads to some interesting modifications  Some of the mods that work eventually creep into the plans  The KR2S is a case in point  Many builders who'd heard of the pitch sensitivity and tight cabin of the KR2 began to build an enlarged version, with the length determined by the most commonly available longeron material  The result is a KR2 that is stretched 2" between firewall and main spar, and 14" behind the main spar  Higher gross weights dictated more wing area, with the new standard becoming the Diehl wing skin  Those who plan to carry passengers commonly stretch the cabin width a few inches, although 1 5 inches is the limit if you still want to use RR's premolded parts 
Mike Stearns addresses the KR Forum crowd 
This year's KR Forum featured guest speakers Mike Stearns, Steve Trentman, and Bill Marcey  Mike Stearns spoke on several topics, including the many sources for KR and homebuilding information available on the Internet  He also mentioned KRNet, the list server devoted entirely to KR aircraft, as well as several notable World Wide Web home pages  He also brought a sample of the new Rand Robinson wing skins with him, and discussed their high temperature core prepreg construction  His KR2S will receive the first set, which is currently being installed at Hinson Composites 
Steve Trentman spoke on his turbine installation  It uses a turbine engine which saw duty as an A7 attack jet starter engine  Total weight is about 85 pounds, while putting out around 90 horsepower  There is a small stockpile of these engines available from government surplus  sources  This engine can only be throttled back to 52% power, which leads to some pretty interesting landings  One inflight failure has been logged so far, with very little damage to the aircraft  More on this exciting development in next month's issue of KROnline 
Les Palmer's KR2 N202LP won Best KR2, Best Engine Installation, and People's Choice awards at the 1995 KR Gathering at Columbia, TN  After researching the KR series, and reading Neil Bingham's "A Critical Analysis of the KR2" (Jan 88 Sport Aviation), Les decided to build his as a single seater, stretched 24" in the tail, while maintaining a stock width firewall  His fuselage is made from Douglas fir, which weighs in at 4 lbs heavier than if constructed from spruce  It is skinned with 1/8" birch plywood  Spars are covered with plywoood on both fore and aft sides, ala KR2S  Diehl wing skins provide the lift  Horizontal stabilizer and elevator were stretched 7" longer on each side, while the vertical stabilizer and rudder were stretched 8" taller    The fuselage to cowling junction was made more graceful by adding 1 5 inches to the height of the firewall end of the fuselage sides 
Les's canopy is a Dragonfly, using a four linkage system to swing forward when opening  The canopy frame fits snugly into a recess in the foward deck, providing an excellent wind and water seal  The fiberglass work is exemplary 
Seating is luxurious for one 
The cowling is also a work of art, and uses NACA ducts for efficiency  Female molds were made for all the fiberglass parts on Les's plane, so he could proabably be persuaded to make more, if demand dictates  Les also machines a multitude of KR aluminum and steel parts which he now offers for sale 
The firewall was reinforced with aluminum brackets and angles bolted between the longerons in anticipation of the 200 lb Subaru EA-81 engine installation  His 100 HP Asian version is outfitted with an American Holley 5200 caburetor and manifold  It uses a PSRU of Les's own design, featuring two spur gears with a 1 69:1 reduction ratio and a toothed belt  Other than tapping the crank for larger bolts to mount the redrive, no other engine modifications were required  Also, this is probably the only air conditioned KR2 on the planet  The prop is a 60/63 Hegy 
Originally built as a taildragger, the fixed gear is made from 4130 steel tubing  Custom cast 6 00x6 aluminum wheels and steel rotors are mated with 6" Cleveland calipers for braking  An early taxi test accident damaged the main gear, and prompted Les to change to tricycle gear  Again, he designed his own fiberglass main gear, and uses a Diehl nose wheel fork with a 4130 strut and 6" wheel up front 
Early tests revealed cooling problems, which prompted a radiator move from the firewall to a lower cowling location 
The first flight was almost a disaster, as test pilot Randy Smith lost power right after takeoff  He managed a 180 with a safe downwind landing with only minor nosewheel pant damage  The culprit proved to be a spark plug with too much reach, which was quickly remedied  Subsequent flights have shown water temp to be about 210 degrees, oil temp is 220-230, and airspeed is about 180 mph 
Shopping for the Partially Built KR 
This story starts about twenty years ago when I first started looking at the KR-2 as the plane I'd like to build  The only problem at that time was a lack of money, lack of knowledge, and a lack of job stability  I liked the design, except for the low ground clearance of the retractable gear and that a KR was going to be a tight fit for me to fly 
Over the past twenty years I've owned a number of planes, but still always wanted to build my own  I needed one that would fit me, my budget requirements, and have the speed and performance that I wanted  When "KITPLANES" published the article featuring Roy Marsh's new KR-2S, it was the first I had heard of any major modifications or improvements to the same old KR design  I believe that article and Roy Marsh's workmanship have probably been the greatest boon to Rand Robinson (RR) in the last twenty years  It certainly caught my eye! Here was the same design I had decided I wanted to build twenty years ago, with all of the improvements I wanted  It was sitting on fixed gear with some reasonable ground clearance  It had the capability to be built large enough to accommodate me  It has enough prefab parts available that it didn't have to be 100% scratch built if I decided to hurry the project along  And it had the speed I wanted  I knew that Roy's published speeds were probably not realistic expectations for the average KR, but after knocking around for the last three years in my Champ, anything over 90 mph seems pretty fast to me 
After purchasing the info kit and the sales video from Rand Robinson, the next step after deciding for sure to build this plane was to order the KR-2 plans and the KR-2S addendum  I finally got my plans and was putting together my first order to start the plane, when my partner in the Champ pointed out that there was a partially completed KR-2S for sale in Trade-a-plane  My initial answer was "No, I don't even want to look at it  I want to build my own from scratch " My partner insisted that for the advertised price and the fact that it wasn't too far away, I ought to at least give the guy a call and investigate it  "No, I don't think I want to buy someone else's problems," I persisted  That night I went home and crunched up some numbers on the calculator and finally came to the conclusion that for the sake of my budget for the next several years, I really should give this guy a call 
Three days later, I flew to his place about 400 miles away to take a look at his project  At this point I should probably mention that I consider myself to be fairly knowledgeable about airplane construction, although the vast majority of my experience is with tube and fabric  The rest of this article deals with what I looked for and more importantly what I missed and have had to repair in the last year since I purchased the project 
When we went to the seller's house, I found that the left wing was built using the Dan Diehl wing skins and the right wing skins were leaning against the wall inside the house  Also the canopy was in the house with the canopy covered with paper and tape  I wanted to inspect the fuselage first, so off we went to the shop 
There I found a fuselage sitting on it's gear painted in primer gray  The first step was to inspect the quality of workmanship of what could be seen as it sat  The interior of the fuselage looked as if it had been built with a great deal of care  The fit and finish of all of the interior wood was very nice  Even the gussets looked like they had been painstakingly perfectly fitted  The glass work on the turtle back also looked very precise and clean  It was evenly faired into the vertical and horizontal stabs  The tail also appeared to be well built with the exception of a depression directly over the front and rear spars in the horizontal stabs  He explained that when he moved recently, that he had shot the plane with gray primer to protect it from the weather since he wouldn't have ready access to a shop to put it in right away  It ended up sitting out in the hot south Texas summer sun for a few weeks before he got a shop rented to work in  That caused the glass (or possibly the foam inside the horizontal stab) to swell, except that it held onto the spar, so it was slightly ballooned in front of and behind the spars  His recommendation was to fill it back smooth with micro 
I also found a small linear crack in the lower left wing spar cap on the left wing stub  It appeared to be from over tightening the rear spar wing attach fitting bolts  His explanation was that the crack wasn't important because the rear spars only job is to keep the wings from folding back  I also noticed that the holes for attaching the outer wing to the wing stub were badly rounded out on the rear spar  He explained that the Diehl wing skins require the rear spar to be swept slightly more forward than the stock wings  This won't allow you to use the rear spar attach fittings from RR and that I would need to fabricate a new set of rear spar attach fittings 
I also found that the aileron bellcranks were not built or installed as per plans, but found that they looked professional  I couldn't check for function since the right bellcrank and sheeve wasn't installed, the left wing also wasn't installed, and the right wing didn't exist yet 
Next we pulled the inspection panels off of the fuselage and tail and looked at everything I could see with a good flashlight  I didn't find anything else that might be questionable about the fuselage except for a cracked elevator trim tab that was damaged when it fell off it's hanging place on the wall 
Next we spent some time going over his builders log and builders photo album  I still hadn't seen anything that would dissuade me from buying this project 
At this point it was starting to get late and my ride down needed to get airborne for the flight home  I needed to make a decision about whether I wanted this project or not, but I hadn't inspected the wings and canopy yet  I took a cursory look at the left wing and saw lots on micro built up on it and some bubbles in the leading edge, but nothing that looked seriously wrong to my amateur eye  The right wing was only a set of spars in the shop and the Diehl wing skins in the house, so there wasn't much to look at there  The canopy was wrapped in paper and tape, so there wasn't much to look at there either  I decided that even if there were serious problems in the wing that was built, I would be money ahead to go ahead and buy the project  For the advertised price, I could build a new set of wings and still be way ahead financially  We negotiated a final price, shook hands, took my ride to the airport, and started off in search of a U-haul to haul the project home 
Now, at this point, some of you are thinking about what I surely must have forgotten to inspect and why didn't I take a local A & P or EAA member along for the ride  First of all, I don't know any mechanics locally that have any experience with glass and our EAA chapter of which I am VP is woefully lacking in fiberglass knowledge  Secondly, as you will see, I missed plenty  Some by ignorance, some by just not looking close enough 
Now for a list of the problems that I found over the last year and a few of the fixes that I came up with 
I found that the lower set of rear spar attach fittings on the left rear spar were installed backwards with the longer spaced hole towards the fuselage  Since this is the same place that also had the cracked spar cap, it required a major change  Also in the same area he had drilled through the rear spar with a hole saw to create a place for the aileron cable to pass through and managed to cut out the second from the outside vertical brace in the spar  Then he chose to install the aileron bellcranks in front of the rear spar, and cut another hole through the rear spar for the aileron push rod  He also managed to cut out the outside vertical brace in the spar  Since the holes were already drilled through the spar, the choices were to either cut out that section of spar cap and scarf a new piece in, cut the whole rear spar carrythrough out of the fuselage including ruining the left lower wing skin, or do something else creative to reinforce the spar cap and install a custom built set of attach fittings 
I also found that after I built and installed the right side wing stub ribs and skin that the aileron bellcrank setup would not work as installed  The cable that crosses between the two bellcranks had a sharp uphill from the sheeve to the bellcrank in the last 12 inches on either side  This combined with the radius that the bellcranks turn caused the cross cable to pull up tight when the ailerons were pushed to either end of their travel, but allowed the cables to go very slack when the ailerons were centered  Also the Aileron pushrods needed to pass directly through the lower set of rear wing attach fittings to attach to the aileron  This whole rear spar and aileron bellcrank setup was going to either have to be redesigned or cut out and built to plans  The bottom line is that the problems I observed when I inspected this part were much more serious than expected when I had to fix it 
I decided that I had to remove the rear fittings from the left wing to be replaced with the new set that my neighborhood machinist was cutting out for me  When I put the wing on the work bench to start removing the rear fittings, I thought I had better take a closer look at the bubbles in the leading edge  I found that as I pushed on the leading edge, it delaminated between the glass lay-up on top and the upper and lower wing skin edges that were floxed together underneath  I concluded that that area had to come apart and took a belt sander to the leading edge  What I found was that the leading edge had been floxed together and glassed over, but the mold release had never been scrubbed off the leading edge of the wing  It peeled apart for rebuild quite easily 
When I got back to removing the rear spar attach fittings, I noticed that the woodwork inside the wing looked awfully dull  The reason was that the wing had been closed up without varnishing any of the woodwork  This was rectified with a small hole saw, a number of extensions and a modified undercoating sprayer 
I also found that the aluminum drain fitting in the bottom of the left wing tank had been glassed into place upside down  The tapered pipe threads were tapered the wrong way to install the draincock into the tank  Retapping the fitting the right direction seemed to be a good fix for that problem 
When I finally got around to attaching the wing to the fuselage, I found that the front spar attach fittings were badly misaligned  Although they could be forced into alignment, I didn't think I needed that kind of preload on the main spar fittings  This problem was fixed by calling on my local neighborhood machinist to build me an aligning fixture and reaming the attach holes to the next larger size and ordering the new sized bolts 
On the fuselage I found that although it had new Cleveland wheels and brakes on it, one of the brakes had a severe wobble to it  I must complement the manufacturers for taking care of that problem  One call to the Cleveland factory and they shipped me a new set of wheels and brakes even though the receipt for this set was over four years old and in the original builders name  Their only concern was that this set had never been placed in service yet 
I chose to sand the load of micro off the left wing to see what it was covering  When I got down to the glass, I found that there was no glass for the aft inch and a half of the underside of the wing in front of the aileron hinge  With the Diehl wing skins, you build the wings, then cut the ailerons out of trailing edge of the wing  He had mismeasured and cut too much material off the bottom side of the trailing edge in front of the aileron  It was filled by floxing a piece of spruce into the gap to fill the space between the back edge of the fiberglass and the aileron mount  I chose to wrap the trailing edge of that wing, and the other wing to match with a couple of lay-ups of glass 
When I sanded the primer off the aforementioned damaged trim tab, I found that the hinge was floxed to the leading edge of the foam insides of the tab, but not the glass  I also chose to wrap the front of the trim tab with a lay-up of glass 
I decided to pull the paper off the canopy and take a look at it before I'm ready to bolt it on and fly  The original builder had blown his own canopy and after some of the previous problems, I was beginning to have some concerns about not having looked it over closely enough  The canopy turned out to have been blow a little too large  It ended up with a little larger bubble for headroom, which I didn't object to  However, it had more headroom on the right side than the left  Yes, it was just a little bit lopsided  The main problem was that the canopy is stretched thin enough that it can be easily pushed in with one hand when the weather is warm   My fear was that this is just thin enough that it may decide to lay on my head or in my lap when flying on a warm day  It will have to be replaced 
I'm sure that many that are reading this could see several of the potential problems before I mentioned them, but some others may not have and I'm sure that there could have been many other problems that didn't but could have existed on this project  This is also not intended to be critical of the gentleman that started this project as many parts of it, especially the wood work are better than I could have done and much of his work is outstanding  I prefer to think that I'll end up with a better plane with his woodwork combined with my glasswork  This article is intended to feature some of the problems that you may run into in buying someone else's project 
The final question is, knowing what I have found over the past year, would I have still purchased this project  The answer is yes, but primarily because the price was right in that I am still money and work ahead of where I would be if I had started the project from scratch  There are a few things that I would have done differently, but nothing that I can't live with  Although I won't be able to say that I built it all from scratch, I have built and rebuild enough of the plane that I should have no problem qualifying under the 51% rule 
You can send comments directly to the author via e-mail at "jscott@LANL GOV" 
Here is an brief explanation of how I built my turtledecks  The jig was constructed from scrap plywood and a few 1x4s that I ripped into stringers  I made two temporary bulkheads from the plywood, one for each end  Remember the forward bulkhead needs to be shaped in a way that will closely match the aft end of your canopy frame  Make an aft bulkhead by placing a straight edge at the top of your forward bulkhead and the trailing edge of your horizontal stabilizer  This will give you an idea of how tall your aft bulkhead needs to be  As far as location, I placed my aft bulkhead just forward of the lower/front of my vertical fin  I constructed the jig on the fuselage, it is glued together with automotive bondo 
After the bulkheads were bondoed to the fuselage I used the stringers that I ripped from the 1x4s and bondoed them to the bulkheads  This gave me a male form to cover with thin plastic or posterboard  I stapled two layers of posterboard to the jig(thin plastic would work better)  The posterboard wraps down two inches onto the fuselage  After I was satisfied with the way it looked, I then covered the entire thing with duct tape (fiberglass will not stick to duct tape) On top of this I wetout one layer of tri-ply cloth (22oz) that I had left over from an earlier project, and one layer of 8oz  bid  Remember to mask off your fuselage so you don't get epoxy on it  If you are not familiar with composite lay-ups, you should plan on razor cutting your lay-ups 4 to 6 hours after wetout while the lay-up is still soft enough to cut with a razorblade 
After the lay-up cured (2 or 3 days) it was removed from the jig, and the jig was removed from the fuselage and discarded  (be careful, the bondo sticks very well to the spruce, you could splinter your wood during removal) I now have a fiberglass skin that tends to hold the shape of the jig but is still flexible enough to work with  I made two bulkheads out of 1/4 last-a-foam (AS&S) using the plywood formers from the jig as a guide  I covered these foam bulkheads with one 8oz layer of glass on each side, with a glass to glass edge on the bottom  After cure these bulkheads were bondoed into place (to the fuselage)and the fiberglass skin was pulled down tight and floxed to the bulkheads  When the flox cured the bondo joints were broken, again being careful not to harm the wood  The turtledeck was removed from the fuselage and 2 inch tapes added to the bulkheads inside and out 
At this point the turtledeck looked great and only weighed about 5lbs  but I noticed you could deform the skin by pushing hard on the outside  So I flipped the turtledeck over and from 1/4 inch last-a-foam, I cut two inch wide strips that would run the entire length, forward and aft inside the turtledeck  In effect these would act as composite stringers, I made enough of these two inch wide strips to make up three stringers  One down the center (sort of a backbone) and one on each side of the "backbone" half the distance to the edge of the turtledeck  I sanded the edge of the foam so that when covered with a layer of bid @ 45degrees there would be a nice transition from the turtledeck skin up onto the foam and then back onto the turtledeck I scuff sanded and glued the foam stringers in with micro  I covered the foam stringers with one layer of 8oz bid @ 45degrees 
Context 3: 
We didn’t make it  The plant manager was flustered  The salesman who’d promised the job was really pissed off, he said mean things  I apologized again and again, they told me it wasn’t all my fault, but could I please be more careful what I committed myself to in future  I could tell they also expected me to get a hell of a lot faster, but they were just trying to be nice 
So, I got faster  I came in early in the morning and worked through lunch until I got better at my job  I had signed up for a typing job, nobody had described all the weird stuff they expected me to type  It started with typing and labeling, not only sticky labels, but microfiche jackets  They have a little quarter inch tall label strip across the top that chips and peels if you aren’t careful loading them into the typewriter, and strips or frames of 35 and 16 mm film that falls out in your typewriter  Then there were the three-part work orders, with carbon paper, and the three-part shipping labels, also with carbon paper  There were the mistakes – whole orders that had been indexed incorrectly, and therefore typed incorrectly, and therefore had to be corrected and typed all over again  I won’t describe what I had to go through to correct microfiche labels, it was too stupid  I hated doing that, so I asked for my own little “eye-loup” – a little magnifier that you hold up to a light to look at the tiny little page numbers on the film – to make sure the cards had been indexed correctly before I typed them 
I’m not perfect, but I know I’m competent, cause I kept that job for five years while I watched others get fired, for everything from showing up late to breaking expensive equipment to stealing  I was given new jobs and increased responsibility as time went by  I got good job reviews from my supervisors, and good raises  Morale was high, we liked our co-workers and our managers, we felt like a team  Our customers were nice to us too  We worked for cities and counties, hospitals, banks – anybody who needed to keep records  We were trusted to handle confidential records, like people’s medical records  As we handled these confidential files we were simply told, “Don’t look at them,” so we didn’t 
I left in 1984 in finish school  Over the next decade computers killed the microfilm industry, and the company went out of business 
Excuse me if I compare my experiences in the private sector with stuff I’ve seen coming out of our city $taff  I keep waiting for some professional behavior, some professional accountability out of the people who run our town, and I start to wonder if I will ever get it  For a couple of months now, Toby Schindelbeck and Stephanie Taber, among others, have been asking council and Finance MisDirector Jennifer Hennessy to provide a simple accounting of city finances, as is required by the city charter, and she just plain refuses to give it  City Mangler Dave Burkland won’t make her 
Last month she actually admitted, she is UNABLE to do it  At the June 5 meeting she admitted that she is incompetent to follow the city charter  She said that when she came to her position seven years ago, she “struggled” with doing such a report – something every house wife does – and went whining to then-city-manager Tom Lando, who apparently patted her on the head and told her she didn’t have to do it anymore 
I don’t know about you guys, but I go over my check book every month, just to make sure everything is straight  I’ve found big, dumb mistakes, in the 100’s column even, that could have caused big, dumb problems down the road  I’m no math instructor, like Mary Goloff, but it’s not exactly rocket science – you just add your deposits and subtract your checks and withdrawals  I’ll admit, when my kids were little, I felt like I never had time to do that, and stuff would get screwed up  So now that I’ve got time, I make it a regularly scheduled event, and it’s amazing how much easier it is  And, I can keep the figures in my head, I know essentially how much I can afford to spend when I’m at the grocery store, or what kind of activities we can plan  My husband and son are enjoying a weekend trip right now that is already paid for, thankyouverymuch 
But Jennifer Hennessy is unable to do that? And she has expectable stuff – over 80 percent of her budget is payroll  She doesn’t have that many emergencies  The biggest emergency she’s had lately, is that the state has taken back the fund she’s been mis-using – the RDA  She was paying salaries and benefits out of a fund that’s supposed to be reserved for emergency public works projects  In other words, she’s been dipping into the till to pay her own salary!
The mayor is to blame here, she’s the captain of our ship  Unfortunately, like the captain of the Costa Concordia, she’s abandoned ship for a party onshore  While she and her college chums bully their bag ban down our throats, our ship is sinking  We have less than $200,000 in our reserve fund, we have un-secured pension obligations totaling in the millions and growing every day, and we have $taff who are using blackmail to get their way – they are just refusing to do their jobs  Hennessy won’t give the report she’s required to give because it’s BAD  I think the mayor is completely behind her on this – Ann Schwab doesn’t want us to hear that report either  Would you?
Please write a letter to council demanding that Hennessy do her job, or get out 
Tags: Ann Schwab Chico CA, Ann Schwab for city council, bankruptcy, City of Chico, Dave Burkland, embezzlement, Friends of Ann Schwab, Jennifer Hennessy, malfeasance
Scranton, Pennsylvania cuts workers to minimum wage – only $130,000 in their cash reserves
I finally got a chance to watch the video of last Tuesday’s council meeting  It cut on me during the meeting, just after Walker and Goloff were mopping up their attack on Sorensen, and I didn’t get it back til yesterday  I have watched the video in bits and snatches  I made it to the noise ordinance conversation last night, but had to turn it off after Jessica Allen and a couple of her friends got up to demand their rights to be bad neighbors 
One thing I learned is that the city of Chico has less than $200,000 in the reserve fund  No, I did not forget a zero on that figure, that’s it – less than $200,000  Read it and weep – and then call them to ask what they did with that property tax check you just sent in 
You can look at the budget report here: http://www chico ca us/finance/budget asp
You see the millions the city takes in, in sales tax (over $17 million) property tax (over $11 million), even taxes on your PG&E, phone and water (almost $7 million), and your visitors’ motel rooms (over $2 million)  To me that seems petty – “bed tax”? Some people think it’s a good idea to shake down the visitors of your town, as if it’s not enough that they spend money on your motels, restaurants and shopping centers  It’s a common grab all over California, every city does it  A lot of distasteful things become “common” when no decent person stands up to say “enough is enough ”
In Chico, as has been oft repeated, over 80 percent of our budget is in salaries and benefits  That’s the elephant in the room, and everybody’s getting pretty hip deep in elephant shit around here  It’s a simple concept, no matter how convoluted $taff and council try to make it: if they spend all the money on salaries, benefits, and the Great Pension Stock Market Disaster, there’s no money left to pay for supplies to say, clean up leaks in the sewer and water lines that are causing the state to fine us by the day, widen the roads that we are required to widen because of the permitting of Meriam Park, etc  And you can just get used to those pot holes in the street out front of your house  Got bad neighbors? Get a lawyer 
What’s really frustrating are the reactions of the cops and fire – they act like they don’t get paid at all  Those guys take most of the 80 percent  They get overtime written into their schedules  According to Hennessy, both fire and the cops are over budget on their workman’s comp claims for at least the third year in a row  The city just slammed another cop contract past us without public review, and signed the new chief’s contract three days before it was made available to the public, and then only by request and a direct visit to the clerk’s office Downtown 
So, we will get another year of poor response times, bitching and moaning from cops and fire  Get ready for your homeowners and your car insurance to go up – the insurance companies know when your local police and fire departments are a pile of shit 
And don’t think I’m not wondering about all those suspicious house fires 
You can just forget about any of the services a city is supposed to offer  Try to get something out of the city clerk these days – if you can catch her in the office!
Well, here’s the story of Scranton, Pennsylvania – home of Michael Scott!
http://bottomline msnbc msn com/_news/2012/07/10/12659748-scranton-pa-slashes-workers-pay-to-minimum-wage?lite
The mayor of Scranton, when faced with a situation similar to Chico’s mess, did what needed to be done  Unfortunately, he waited until it was too late to do something rational  I’m afraid it’s come to that with our city council – if you think that scene between Goloff and Sorensen was rational, well, you deserve to live here 
Tags: Ann Schwab for city council, Bob Evans for city council, Chico City council eletions 2012, cities declare bankruptcy, Friends of Ann Schwab, pensions, phone tax, salaries, sales tax increase
Marysville council rejects sales tax ploy by retiring city administrator – where’s Chico’s knight in shining armor?
I am not a member of the Chico Chamber of Commerce, but I check in to their website regularly to see what they’re up to  Sometimes I believe, they are the real Chico City Council  While our elected leaders frolic and cavort in their stupid committee meetings, the Chamber is working on a “Top 10 Economic Development Action List” 
Yeah, sounds great, until you consider, one of their “Top 10” is a proposal to raise the local sales tax 
One prominent member of the Chamber who might be able to fill us in on the discussion is Bob Evans  I’ve asked Bob where he stands on this tax increase, but he just keeps saying he hasn’t seen a proposal yet  Lately I have asked him if he would require Lando and the other sales tax increase proponents to get the legal number of signatures on a petition before he votes to put this proposal on the ballot, but he won’t answer me  His downright refusal to discuss the tax increase is frustrating to me – I want to believe Bob is a “fiscal conservative ” After all, he had some high and mighty things to say about his opposition to the phone tax  But, he knew the phone tax didn’t need his support to get on the ballot  It’s easy to posture as the good guy when you know others will achieve the end result you really want  Evans’ resistance to making a pledge against a sales tax increase is screaming in my ear like a fire alarm 
In Marysville, Mayor Bill Harris had no trouble making himself clear when his city mangler proposed a half-cent sales tax increase: “This will be viewed as the City Council coming to them wanting more money again ”
Well, the article mentioned, the city mangler is retiring, so I would also see it as his way of securing his f-ing pension, but nobody mentions that 
City councilwoman Christina Billeci echoed a sentiment I’ve been hearing increasingly in Chico – “We need to balance the budget with the revenues we have,” she said



ground_truth: The longerons bow up from the building surface, forming a "banana" shape.

prompt_front: Now, answer the following question based on the text below, only give me the answer and do not output any other words.

Question: According to the text, what is Toby Schindelbeck's observation about the police?

Read the following text and answer briefly.

Context 3: 
Other council members cited lack of support from citizens, including one councillor who claimed to have got “angry reactions” to the proposal  One council member said he might have supported the move before the June election, “But the cigarette tax was voted down, and that should have been a slam dunk,” he said  “I would see this as a waste of effort and money ”
The only council member who supported the notion, Head Start administrator Ricky Samayoa, made some pretty disparaging remarks about the town 
“There’s a lot of people that know there’s a lack of resources here for us to have a proper city and manage it,” he said  Oooo! A “proper city”! What a bitch! Does he have letters from constituents to support this statement, or is he just using “a lot of people” to describe himself and his co-workers? Not enough drive through coffee stands for you Ricky? Not enough 5 Star restaurants or pink boutiques? Sorry, we’ve never been ones for putting on the Ritz here in the North State, better get in your zip car and drive back to the Bay Area 
In the Enterprise Record story, Samoyoa further claimed that “continued cuts to maintenance and other aspects of the city’s budget hurt chances for an economic recovery ” I imagine Marysville has the same problem Chico has – too many $100,000+ salaries and not enough $20,000 – $50,000 workers  While he’s sitting down there under the air conditioner vent at Head Start in a fresh shirt and manicure, the streets are going unmaintained, the classrooms overcrowded, the police and fire departments underfunded – is that the problem Mr  Samayoa?
“The way we’re continuing to go, it’s just going to be a dying city, even if the economy picks up,” he said  Now, that statement doesn’t even make sense  This is a typical example of scare tactics  “The way we’re continuing to go…” You mean, paying $100,000+ salaries to fat bureaucrats, while cutting services to the public? Somehow I don’t think that’s what he’s talking about  ” …it’s just going to be a dying city…” Wow, what an idiot – obviously no knowledge of local history  Marysville has been through so many booms and busts, it ought to be called “Bouncyville ” If you get to know Marysville, you see it has everything needed to be a wonderful place to live, in good times and bad, regardless of carpetbaggers like Samayoa 
“Give folks the opportunity to have this debate,” Mr  Samayoa suggests  Sounds like the rhetoric coming from Andy Holcombe and the rest of the sales tax increase proponents  Hey, that’s a swell idea! People should talk about these things, hash them out  And then, if enough of them sign a petition to put such a proposal on a legal ballot, well, they can VOTE on it! But that costs alot of money – best for those who really believe in this cockamamie idea to get the petition first, show the need to spend all that money on an election  That’s what rational people would do, anyway 
But if you ask Holcombe to discuss the pending proposal, he denies there is any such thing  The only member of Chico City Council who is willing to discuss this proposal at all has been Mark Sorensen – thanks Mark  At least Mark has been good enough to answer our questions about the mechanics of such a proposal and getting it onto the ballot  Evans and Holcombe have both denied knowing anything about it, although Holcombe has made it good and clear he’d support raising the sales tax and Evans has been seen at Chamber discussions on the matter  The others have been mum to the public, but I’m guessing they will support it  Holcombe, Schwab, Goloff, Walker, Gruendl – and Evans? – are all banking on more revenues to rescue the city from the Shit Creek they’ve floated us up  Evans, while he will admit we’re in deep shit, will not offer so much as a suggestion of a paddle  He seems to be holding back until after he gets himself safely re-elected in November  Then he’s got a year to get that sales tax voted in and three years to make the public forget he had anything to do with it 
Well Bob, is that what you’re up to?
I’ll say, if he were at least honest, I might be able to hold my nose and support him, but this game he’s playing is a real turn-off 
Tags: Ann Schwab Chico CA, Ann Schwab for city council, Bob Evans Chico Ca, Bob Evans for city council, chico city council race 2012, city of Chico bankruptcy, city of Chico sales tax increase, Friends of Ann Schwab, Ricky Samayoa Marysville Ca
Council video feed still not available – $taff seems to have taken the Summer off!
I know, there’s probably a perfectly legitimate explanation for this  Debbie Presson isn’t sure why the feed is off, but she’s got somebody working on it  Not yesterday though, cause she was out of her office 
I’ll tell you what else is interesting – there haven’t been any of those morning meetings lately – in fact, it looks like all the committee meetings for July are CANCELLED  In fact, there hasn’t been an “Economic Development” committee meeting for months that I’m aware  For all intents and purposes, the city of Chico seems to be on Summer Vacation! How nice for them!
But, as you see, the town runs along without them  In fact, I’m wishing the public works department would also take a hike – they’re TOO BUSY right now, tearing up the streets Downtown  Oh well, the college students have “gone home” – what do we need Downtown for when the college students have gone home?
That seems to be the gist of if – the city of Chico is here to serve the college students  The rest of us can just get along – as long as we keep paying our taxes, nobody will bother us!
I just have to wonder, what are these $85,000, $95,000, $134,000 $taffers doing right now, and why do we need to keep paying them?
Tags: Ann Schwab Chico CA, Ann Schwab for city council, City of Chico, embezzlers, Friends of Ann Schwab, malfeasance
New police chief’s contract signed last Tuesday, made available to the public Friday – gotta love that “sunshine”!
Last Tuesday night we got a new police chief – Kirk Trostle  Only a month ago city manager Dave Burkland issued a statement – “police chief candidates not knockouts” according to the Enterprise Record  Trostle is a refugee from the Oroville police department, where, as chief, he certainly had his critics  He came to Chico only about a year and a half ago, from a department that was not without it’s problems  The council made their appointment without any elaboration – he was essentially the best thing they could come up with on short notice 
But shouldn’t we be able to negotiate a better contract with this man? Retiring Chief Porky Mike Maloney is getting over $165,000 a year, just in salary  He will be getting over $100,000 to retire, for the rest of his life, plus medical benefits  Frankly, I predict he’s carrying a colostomy bag within five years 
Have you seen Trostle’s contract? They signed it at council last Tuesday  But when we asked for it, they said we wouldn’t be able to look at it until Friday  I was invited to go down to the clerk’s office, at her convenience, 9 – 5, during MY WORK DAY, to look at a contract that had already been signed  Why in the hell would I want to do that? They don’t even offer you a decent cup of coffee 
So no, I haven’t seen it yet, but I’m guessing, it’s worse than Maloney’s contract  A fellow taxpayer went down Friday and reports he has the contracts, but has not given me any details  I don’t know if he had to pay for paper copies or what, but you can view it for free if you want to go down there  I’ll get back to you when I got something 
Tags: Ann Schwab Chico CA, Ann Schwab for city council, Chico Police Department, Chico Police Officers Association, City of Chico, Friends of Ann Schwab, Kirk Trostle chief of police chico ca, mike maloney retires at 50 what a pig
Mary Goloff and Jim Walker gang jump Mark Sorensen on the dais – just another lovely Chico city council meeting!
I’m sitting here in disbelief of the attack I just watched Mary Goloff and Jim Walker wage on Mark Sorensen at city council tonight  I couldn’t make the meeting, so I have been watching it via computer 
Sorensen had been challenged by a smarmy Jim Walker to list what changes he would make to balance the budget  Sorensen carefully began to explain that city funds had been depleted by millions over the last few years, with escalating costs leaving revenues in the dirt  He also explained that the lion’s share of our expenses are “operating costs,” meaning, salaries  He also carefully explained that there were programs we simply could not afford anymore, meaning, salaries 
Mary Goloff could be heard heckling him off microphone  If you or I did what she was doing we’d be asked to leave the room, possibly with police escort  But Mayor Schwab just sat there looking at Goloff, saying nothing  Goloff finally got on mike, interrupted Sorensen, and asked him to be specific  So, Sorensen offered housing, saying it had been a mistake to undertake so many housing projects, and he also specified the arts programs – such as the requirement that any capital project include one percent of the total cost of that project be added for art 
At this point Goloff began to interrupt Sorensen  She started heckling him about how “we all agree” that the arts are important, yadda, yadda  She just kept at Sorensen, not allowing him to answer any of her out-there questions, until Sorensen asked her to stop interrupting him 
After a quick exchange Walker butted in to attack Sorensen  Out of nowhere, Walker bashed Sorensen about wanting to spend more money on the police department, asking Sorensen where he would get the money to hire more police  This question was off base, Sorensen hadn’t even gotten that far before Goloff had completely derailed him 
Jim Walker is just sitting out his time, he seems to be enjoying himself at all of our expense  He, like so many “public servants,” seems to think he is elected to do what he wants, what seems like “the right thing” in his fairy tale mind, instead of carry out the law 
Mary Goloff seems to think she has been anointed Queen in some farcical aquatic ceremony to lead us all in the light of her cough syrup-induced wisdom  She seems to love the sound of her own voice, while here at my house, it sets off the hounds for blocks 
My computer started failing at this point, and I was unable to watch the rest of the meeting  I am going on vacation tomorrow, I’ll see you folks on the flip flop 
Tags: Ann Schwab Chico CA, Ann Schwab for city council, Friends of Ann Schwab
Turn that S*** UP!
We had a lively discussion down at the library yesterday about how we are going to fight the phone tax increase in November 
The key here is to inform the public  $taff has already done their best to make this measure confusing and deceptive, actually writing into the measure that it will lower taxes  They mean, they are lowering the rate half a cent, but of course, this half-cent will be an ice cube in hell when they apply the tax to all the new stuff this measure allows – starting with cell phones, texting, paging, and adding whatever new technology comes along  All the voter needs to know is, this measure will raise his/her taxes, noticeably 
Even people on welfare will pay this tax, even though they qualify for the rate-assistance plans offered by the phone companies – utility tax is based on the total bill, before the adjustment for the rate assistance  And, this tax includes those prepaid phone cards 
The hardest hit will be commercial customers  A friend of mine who owns a little manufacturing business in town tells me the city of Chico thinks all business owners are “rich sugar daddies” 
My friend always tells me, that while I am in these meetings Downtown, he is in Oroville or Redding or Modesto or some other town, dealing with his business  He says these towns have better, more workable $taff  He is among the business owners who have used the word “hostile” to describe Dave Burkland, and the city business climate in general 
We have to get the word out to people like my friend that NOW IS THE TIME to get involved  I like that band, Rage Against the Machine – they say, “it has to start somewhere, it has to start sometime  What better place than here, what better time than NOW!”
We’re fighting the city, which will use public money to fund this tax increase initiative  For example, they have already used $taff time to research and write the measure, and now council members and $taff will create the “for” argument to be placed on the ballot  Our city attorney makes over $190,000 a year in salary alone – Mark Sorensen figured the cost of an hour of her time, but I forget the figure  More than most people make in a day, is all I remember 
The city will turn over their arguments in favor in August – at that point we can take this dog and pony show on the road  Until then, let’s keep working  Thanks all!




ground_truth: Toby Schindelbeck's observation is that the police say they aren't paid enough to enforce the laws in the streets.