cssi/SciSciGPT-SciSciNet huggingface dataset:
Generalized Bose-Einstein Condensation in Superconductivity

Unification of the BCS and the Bose-Einstein condensation (BEC) theories is surveyed in detail via a generalized BEC (GBEC) finite-temperature statistical formalism. Its major difference with BCS theory is that it can be diagonalized exactly. Under specified conditions it yields the precise BCS gap equation for all temperatures as well as the precise BCS zero-temperature condensation energy for all couplings, thereby suggesting that a BCS condensate is a BE condensate in a ternary mixture of kinematically independent unpaired electrons coexisting with equally proportioned weakly-bound two-electron and two-hole Cooper pairs. Without abandoning the electron-phonon mechanism in moderately weak coupling it suffices, in principle, to reproduce the unusually high values of Tc (in units of the Fermi temperature TF) of 0.01-0.05 empirically reported in the so-called "exotic" superconductors of the Uemura plot, including cuprates, in contrast to the low values of Tc/TF ≤ 10-3 roughly reproduced by BCS theory for conventional (mostly elemental) superconductors. Replacing the characteristic phonon-exchange Debye temperature by a characteristic magnon-exchange one more than twice in size can lead to a simple interaction model associated with spin-fluctuation-mediated pairing.
Genericity and contragredience in the local Langlands correspondence

We prove the recent conjectures of Adams-Vogan and D. Prasad on the behavior of the local Langlands correspondence with respect to taking the contragredient of a representation. The proof holds for tempered representations of quasi-split real K-groups and quasi-split p-adic classical groups (in the sense of Arthur). We also prove a formula for the behavior of the local Langlands correspondence for these groups with respect to changes of the Whittaker data.
Nested BDDC for a saddle-point problem

We propose a Nested BDDC for a class of saddle-point problems. The method solves for both flux and pressure variables. The fluxes are resolved in three-steps: the coarse solve is followed by subdomain solves, and last we look for a divergence-free flux correction and pressure variables using conjugate gradients with a Multilevel BDDC preconditioner. Because the coarse solve in the first step has the same structure as the original problem, we can use this procedure recursively and solve (a hierarchy of) coarse problems only approximately, utilizing the coarse problems known from the BDDC. The resulting algorithm thus first performs several upscaling steps, and then solves a hierarchy of problems that have the same structure but increase in size while sweeping down the levels, using the same components in the first and in the third step on each level, and also reusing the components from the higher levels. Because the coarsening can be quite aggressive, the number of levels can be kept small and the additional computational cost is significantly reduced due to the reuse of the components. We also provide the condition number bound and numerical experiments confirming the theory.
Catalysts for the reactions of epoxides and carbon dioxide

Abstract Oxiranes and carbon dioxide are known to cycloadd and/or copolymerize in the presence of a variety of catalysts. Indeed, cyclic carbonates are prepared on a technical scale by coupling epoxides and carbon dioxide. The fact that cyclic carbonate formation represents one of the few examples of successful carbon dioxide utilization, coupled with the high reactivity of epoxides, has resulted in many papers which reveal a remarkable variety of active catalysts for the CO2/epoxide coupling processes. Catalysts include simple alkali metal salts, ammonium salts, phosphines, main-group metal complexes, and both non-oxidative and oxidative transition-metal complexes. The purpose of this review is to compile the different catalysts into their general groups of similarity, with the hopes of shedding light on some of the important differences in reaction pathways. There generally appears to be a lack of detailed mechanistic studies; therefore, it is hoped that this review will emphasize where mechanistic clarification is most importantly needed. Furthermore, we anticipate that this review will provide insight into cyclic carbonate vs. polycarbonate production from the CO2/epoxide coupling process.
Identification of appropriate source models for accurate diffusion modeling of radiative transfer in a non-absorbing foam layer

The diffusion approximation is used to model the propagation of radiation scattered from a pulsed laser beam incident on a non-absorbing foam layer. Various mathematical models for the source term are considered, and integral transforms are used to solve the differential equation. Comparison of the calculated reflectance profiles with the results of Monte Carlo simulations indicates that careful selection of the source model leads to improved results. Diffusion theory source models which provide accurate predictions for radiative transfer and the limits on their accuracy are identified.
A Marcinkiewicz maximal-multiplier theorem

For r < 2, we prove the boundedness of a maximal operator formed by applying all multipliers m with $\|m\|_{V^r} \leq 1$ to a given function.
Organomercury compounds in organic synthesis

I. Introduction.- References.- II. Preparation of Organomercury Compounds.- A. Introduction.- B. Direct Mercuration of Organic Halides.- C. Organomagnesium and -Lithium Procedures.- D. Organoboranes.- E. Other Transmetallation Reactions.- F. Mercuration of Carbon Monoxide.- G. Mercury Substitution in Activated C-H Containing Compounds.- H. Mercuration of Cyclopropanes.- I. Mercuration of Alkenes.- J. Mercuration of Alkynes.- K. Mercuration of Aromatic Compounds.- L. Mercury Substitution in Aryldiazonium Salts, Hydrazines, Hydrazones, and Diazo Compounds.- M. Decarboxylation of Mercury Carboxylates.- N. Sulfinate and Sulfonate Elimination Reactions.- References.- III. Hydrogen and Halogen Substitution.- A. Hydrogen Substitution.- B. Halogen Substitution.- References.- IV. Synthesis of Heteroatom-Containing Compounds.- A. Introduction.- B. Oxygen Compounds.- C. Sulfur, Selenium, and Tellurium Compounds.- D. Nitrogen Compounds.- E. Phosphorus Compounds.- F. Silicon Compounds.- G. Conclusion.- References.- V. Dimerization.- References.- VI. Alkylation.- References.- VII. Alkene and Alkyne Addition and Substitution Reactions.- References.- VIII. Carbonylation.- References.- IX. Acylation.- References.- X. Divalent Carbon Transfer Reactions.- A. Introduction.- B. Preparation of the Reagents.- C. Synthesis of Cyclopropanes.- D. Organomercurial Reactivity.- E. Mechanism of Cyclopropane Formation.- F. Synthesis of Cyclopropenones.- G. Ring Expansion Reactions.- H. Reactions with Oxygen, Nitrogen and Sulfur Compounds.- J. Insertion Reactions in Metal-Carbon, Metal-Halide and Metal-Metal Bonds.- References.- Subject Inde.
Generic representation theory of finite fields in nondescribing characteristic

Abstract Let Rep ( F ; K ) denote the category of functors from finite dimensional F -vector spaces to K-modules, where F is a field and K is a commutative ring. We prove that, if F is a finite field, and char F is invertible in K, then the K-linear abelian category Rep ( F ; K ) is equivalent to the product, over all n ≥ 0 , of the categories of K [ GL n ( F ) ] -modules. As a consequence, if K is also a field, then small projectives are also injective in Rep ( F ; K ) , and will have finite length. Even more is true if char K = 0 : the category Rep ( F ; K ) will be semisimple. In the last section, we briefly discuss ‘ q = 1 ’ analogues and consider representations of various categories of finite sets. The main result follows from a 1992 result by L.G. Kovacs about the semigroup ring K [ M n ( F ) ] .
A Numerical and Theoretical Study of Certain Nonlinear Wave Phenomena

An efficient numerical method is developed for solving nonlinear wave equations typified by the Korteweg-de Vries equation and its generalizations. The method uses a pseudospectral (Fourier transform) treatment of the space dependence together with a leap-frog scheme in time. It is combined with theoretical discussions in the study of a variety of problems including solitary wave interactions, wave breaking, the resolution of initial steps and wells, and the development of nonlinear wavetrain instabilities.
An analysis of reproductive behaviour in Canada: results from an intertemporal optimizing model.

Results based on a sample of Canadian households challenge the findings of most studies which show significant negative effects of schooling on the fertility of women under the age of 45. This is due to the application of methods to an optimization model which distinguish between those households which have completed their reproductive behaviour from those which have not. Completion status and the desired number of children are used to infer characteristics of the optimal programme which are then employed to derive a likelihood function. Traditional demographic methods have so far not fully utilized the distinction between incomplete and completed households in sample surveys. These methods also lead to the conclusion that completed fertility had increased from its all time low in the nineteen seventies.
Effects of Pressure and a Microporous Coating on HFC-245fa Pool Boiling Heat Transfer

A study was conducted to experimentally characterize the pool boiling performance of hydrofluorocarbon (HFC)-245fa. The motivation for this research is to characterize the performance of candidate refrigerants for potential use in automotive power electronics two-phase cooling systems. The HFC-245fa pool boiling experiments were conducted using horizontally oriented 1-cm2 heated surfaces to quantify the effects of pressure and a microporous-enhanced coating on heat transfer coefficients and critical heat flux (CHF) values. Experiments were carried out at pressures ranging from 0.15 MPa to 1.1 MPa (reduced pressure range: 0.04–0.31). To enhance boiling heat transfer, a copper microporous coating was applied to the test surfaces. The coating was found to enhance heat transfer coefficients by as much as 430% and CHF by approximately 50%. Increasing pressure decreased the magnitude of the heat transfer coefficient enhancements but had minimal effect on CHF enhancements. The experimental data were then used to generate correlations for the boiling heat transfer coefficients and CHF values. Finally, the performance of HFC-245fa was compared to the performance of hydrofluoroolefin (HFO)-1234yf and HFC-134a at conditions of equivalent saturation temperatures and reduced pressures.Copyright © 2013 by ASME
A 0.1–1.5 GHz 8-bit Inverter-Based Digital-to-Phase Converter Using Harmonic Rejection

This paper presents a digital-to-phase converter (DPC) with 8-bits of resolution and a wide frequency range for the input/output clocks. A harmonic rejection (HR) filter is introduced to improve linearity across a frequency range of 0.1-1.5 GHz. Instead of using time-domain averaging of phase interpolators (PI) in a conventional DPC, the frequency-domain filter directly cancels the 3rd- and 5th-order harmonics of the phase interpolated signal. The architecture is designed using an inverter-based PI circuit structure to improve power consumption and area. The inverter nonlinearity is improved using resistive averaging. The residual INL and DNL are further reduced by nonlinear weighting of the interpolation. Designed and fabricated in 65-nm CMOS technology, the DPC demonstrates a maximum INL and DNL of 1.33 and 0.52 LSB while consumes a power of 4.3 mW and occupies 0.06 mm2 area.
A powerful chiral counterion strategy for asymmetric transition metal catalysis.

Traditionally, transition metal–catalyzed enantioselective transformations rely on chiral ligands tightly bound to the metal to induce asymmetric product distributions. Here we report high enantioselectivities conferred by a chiral counterion in a metal-catalyzed reaction. Two different transformations catalyzed by cationic gold(I) complexes generated products in 90 to 99% enantiomeric excess with the use of chiral binaphthol–derived phosphate anions. Furthermore, we show that the chiral counterion can be combined additively with chiral ligands to enable an asymmetric transformation that cannot be achieved by either method alone. This concept of relaying chiral information via an ion pair should be applicable to a vast number of metal-mediated processes.
THEORETICAL ASPECTS OF THE NUCLEON-NUCLEON WORKSHOP

This report concentrates on the inelastic NN system from 300 to 1500 MeV. Topics covered include the visibility of quark signals, dibaryons, the model dependence of predicted NN inelasticities, and a review of how well present conventional models compare with a rapidly expanding database. The general conclusion is that there is so far no clear evidence in the NN system at intermediate energies for unconventional dibaryon resonances. Short remarks are also made concerning one theoretical contribution on elastic scattering and on new experimental results for deuteron photo-disintegration and pion-nucleon charge exchange. 11 references.
Currents between tethered electrodes in a magnetized laboratory plasma

Laboratory experiments on important plasma physics issues of electrodynamic tethers were performed. These included current propagation, formation of wave wings, limits of current collection, nonlinear effects and instabilities, charging phenomena, and characteristics of transmission lines in plasmas. The experiments were conducted in a large afterglow plasma. The current system was established with a small electron-emitting hot cathode tethered to an electron-collecting anode, both movable across the magnetic field and energized by potential difference up to V approx.=100 T(sub e). The total current density in space and time was obtained from complete measurements of the perturbed magnetic field. The fast spacecraft motion was reproduced in the laboratory by moving the tethered electrodes in small increments, applying delayed current pulses, and reconstructing the net field by a linear superposition of locally emitted wavelets. With this technique, the small-amplitude dc current pattern is shown to form whistler wings at each electrode instead of the generally accepted Alfven wings. For the beam electrode, the whistler wing separates from the field-aligned beam which carries no net current. Large amplitude return currents to a stationary anode generate current-driven microinstabilities, parallel electric fields, ion depletions, current disruptions and time-varying electrode charging. At appropriately high potentials and neutral densities, excess neutrals are ionized near the anode. The anode sheath emits high-frequency electron transit-time oscillations at the sheath-plasma resonance. The beam generates Langmuir turbulence, ion sound turbulence, electron heating, space charge fields, and Hall currents. An insulated, perfectly conducting transmission line embedded in the plasma becomes lossy due to excitation of whistler waves and magnetic field diffusion effects. The implications of the laboratory observations on electrodynamic tethers in space are discussed.
Quantum double Schubert polynomials represent Schubert classes

The quantum double Schubert polynomials studied by Kirillov and Maeno, and by Ciocan-Fontanine and Fulton, are shown to represent Schubert classes in Kim's presentation of the equivariant quantum cohomology of the flag variety. We define parabolic analogues of quantum double Schubert polynomials, and show that they represent Schubert classes in the equivariant quantum cohomology of partial flag varieties. For complete flags Anderson and Chen have announced a proof with different methods.
Diophantine properties of measures invariant with respect to the Gauss map

Motivated by the work of D. Y. Kleinbock, E. Lindenstrauss, G. A. Margulis, and B. Weiss [8, 9], we explore the Diophantine properties of probability measures invariant under the Gauss map. Specifically, we prove that every such measure which has finite Lyapunov exponent is extremal, i.e., gives zero measure to the set of very well approximable numbers. We show, on the other hand, that there exist examples where the Lyapunov exponent is infinite and the invariant measure is not extremal. Finally, we construct a family of Ahlfors regular measures and prove a Khinchine-type theorem for these measures. The series whose convergence or divergence is used to determine whether or not µ-almost every point is ψ-approximable is different from the series used for Lebesgue measure, so this theorem answers in the negative a question posed by Kleinbock, Lindenstrauss, and Weiss [8].
Marketing approaches used by high-tech firms

Abstract In this article, the authors investigate the use of marketing approaches by 164 high tech-firms. The findings should serve as a reference for practitioners to gauge their own efforts.
Review of the American Physical Society Light Water Reactor Safety Study

The issue of light-water reactor (LWR) safety has been the subject of a part-time, year-long study sponsored by the American Physical Society and supported by the National Science Foundation and the former Atomic Energy Commission. The goal of the study was the assessment of some of the technical aspects of the safety of large light water nuclear power reactors typical of present commercial practice in the United States. The Report examines issues related to the safe operation of LWRs; the research and development program responsible for establishing and enhancing safety; and the consequences of accidents for public health and welfare. A number of recommendations are contained within the Report, mainly addressed to ways in which the safety of the present LWRs can be improved and better understood. A brief summary of the Report is presented.
A Proof of Walsh's Convergence Theorem Using Couplings

Walsh has recently proved the norm convergence of all nonconventional ergodic averages involving polynomial sequences in discrete nilpotent acting groups. He deduces this convergence from an equivalent, `finitary' assertion of stability over arbitrarily long time-intervals for these averages, which is proved by essentially finitary means. The present paper shows how the induction at the heart of Walsh's proof can also be implemented using more classical notions of ergodic theory: in particular, couplings and characteristic factors.
The Observations of Redshift Evolution in Large-Scale Environments (ORELSE) Survey. I. The Survey Design and First Results on CL 0023+0423 at z = 0.84 and RX J1821.6+6827 at z = 0.82

We present the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) Survey, a systematic search for structure on scales greater than 10 h^(–1)_70 Mpc around 20 well-known clusters at redshifts of 0.6 < z < 1.3. The goal of the survey is to examine a statistical sample of dynamically active clusters and large-scale structures in order to quantify galaxy properties over the full range of local and global environments. We describe the survey design, the cluster sample, and our extensive observational data covering at least 25' around each target cluster. We use adaptively smoothed red galaxy density maps from our wide-field optical imaging to identify candidate groups/clusters and intermediate-density large-scale filaments/walls in each cluster field. Because photometric techniques (such as photometric redshifts, statistical overdensities, and richness estimates) can be highly uncertain, the crucial component of this survey is the unprecedented amount of spectroscopic coverage. We are using the wide-field, multiobject spectroscopic capabilities of the Deep Multiobject Imaging Spectrograph to obtain 100-200+ confirmed cluster members in each field. Our survey has already discovered the Cl 1604 supercluster at z ≈ 0.9, a structure which contains at least eight groups and clusters and spans 13 Mpc × 100 Mpc. Here, we present the results on the large-scale environments of two additional clusters, Cl 0023+0423 at z = 0.84 and RX J1821.6+6827 at z = 0.82, which highlight the diversity of global properties at these redshifts. The optically selected Cl 0023+0423 is a four-way group-group merger with constituent groups having measured velocity dispersions between 206 and 479 km s^–1. The galaxy population is dominated by blue, star-forming galaxies, with 80% of the confirmed members showing [O II] emission. The strength of the Hδ line in a composite spectrum of 138 members indicates a substantial contribution from recent starbursts to the overall galaxy population. In contrast, the X-ray-selected RX J1821.6+6827 is a largely isolated, massive cluster with a measured velocity dispersion of 926 ± 77 km s^(–1). The cluster exhibits a well-defined red sequence with a large quiescent galaxy population. The results from these two targets, along with preliminary findings on other ORELSE clusters, suggest that optical selection may be more effective than X-ray surveys at detecting less-evolved, dynamically active systems at these redshifts.
A model-based feed-forward controller scheme for accurate chilled water temperature control of inlet guide vane centrifugal chillers

Capacity control in most commercial centrifugal chillers is achieved by inlet guide vanes which are activated by the leaving chilled water temperature sensor. Due to mechanical reasons, vane control is done discretely, and not continuously. The control module compares the value provided by the temperature sensor to pre-set control band values, and if those bands are exceeded, it sends a signal to the vane control motor to adjust the vane position by one step which could be upwards or downwards. The advantage of this type of discrete control method is its simplicity. Normally, the accuracy in the outlet chilled water temperature is of the order of 0.5 °C, which is acceptable for normal cooling plants such as used in office buildings. However, there are applications such as in pharmaceutical processes, mechanics labs, or instances in chemical processes where more accurate control is required (sometimes as low as 0.05 °C). This paper proposes a simple method to achieve such tight control without any hardware modifications. The basis of this method is a transient physical inverse model of the refrigerant boiling process in the evaporator in conjunction with a feed-forward control scheme. The model parameters need to be identified from monitored data since they are chiller-specific. This paper describes the model, and applies it to one-minute monitored data from an actual chiller plant of 1580 kW (450 Tons). It is demonstrated that for this specific chiller such a control scheme has the potential to improve control accuracy by about 28% as compared to the traditional control method.
Eventually Number-Conserving Cellular Automata

Although it is undecidable whether a one-dimensional cellular automaton obeys a given conservation law over its limit set, it is however possible to obtain sufficient conditions to be satisfied by a one-dimensional cellular automaton to be eventually number-conserving. We present a preliminary study of two-input one-dimensional cellular automaton rules called eventually number-conserving cellular automaton rules whose limit sets, reached after a number of time steps of the order of the cellular automaton size, consist of states having a constant number of active sites. In particular, we show how to find rules having given limit sets satisfying a conservation rule. Viewed as models of systems of interacting particles, these rules obey a kind of Darwinian principle by either annihilating unnecessary particles or creating necessary ones.
THE EXPONENTIAL FORMULA FOR THE WASSERSTEIN METRIC

A recurring obstacle in the study of Wasserstein gradient flow is the lack of convexity of the square Wasserstein metric. In this paper, we develop a class of transport metrics that have better convexity properties and use these metrics to prove an Euler−Lagrange equation characterizing Wasserstein discrete gradient flow. We then apply these results to give a new proof of the exponential formula for the Wasserstein metric, mirroring Crandall and Liggett’s proof of the corresponding Banach space result [M.G. Crandall and T.M. Liggett, Amer. J. Math. 93 (1971) 265–298]. We conclude by using our approach to give simple proofs of properties of the gradient flow, including the contracting semigroup property and energy dissipation inequality.
Tax competition with interregional differences in factor endowments

Abstract This paper studies ‘tax competition’ between two regions that tax interregionally mobile capital to finance local public goods. In the Nash equilibrium, residents of a relatively small region, measured by population size, are better off than residents of the large region; and they are better off than they would be under the economy's Pareto efficient tax rates, if their region is sufficiently small. These results are compared with related findings in the international trade and local public economics literatures. The same results are proved for a model where both capital and labor are taxed to satisfy an exogenous expenditure requirement.
High oxygen pressure synthesis of new copper oxide superconductors

The unique coordination of the copper ions in +1, +2, and +3 oxidation states, which are stable in a range of oxygen partial pressure. 10−6 1 atm. These materials, La2CuO4+δ, La2−xCaxCuO4, and YSr2−xLaxCu3O7+δ, offer a unique opportunity to study the relationship between superconductivity and structural, magnetic, and chemical properties.
Suppressing flavor anarchy

We present a new mechanism, which does not require any flavor symmetry, to explain the small Yukawa couplings and CKM mixing angles. The Yukawa matrices are assumed to be random at short distances and the hierarchical structure is generated in the infrared by renormalization group flow. The generic qualitative predictions of this mechanism are in good agreement with observation. We give several simple examples in supersymmetric theories. We show that our mechanism can also ameliorate the supersymmetric flavor problem, and make predictions for the superpartner mass spectrum. The mechanism is fully consistent with grand unification, and in SU(5)-based models of neutrino mass, predicts a large mixing angle for νμ↔ντ oscillations.
CD4 regulatory T cells Control CD8 T cell responses to human Herpesvirus 8 lytic and latency proteins

Methods Longitudinal PBMC samples were obtained from subjects with various outcomes of HHV-8 infection over many years in the Multicenter AIDS Cohort Study. The PBMC were tested by HLA A*0201 multimer staining specific for memory CD8 T cell epitopes of viral lytic and latency proteins, and polyfunctional flow cytometry to detect HHV8-specific, polyfunctional CD8 T cell populations. The effect of Treg was examined by depleting CD4CD25 cells.
Synthesis and comparative evaluation of two antiviral agents: β-l-Fd4C and β-d-Fd4C

The synthesis of beta-D-Fd4C was achieved in a stereoselective fashion from D-xylose. The antiviral activity and cytotoxicity of beta-D-Fd4C was compared with that of beta-L-Fd4C and 3TC (Lamivudine). Of the three agents compared, beta-L-Fd4C was found to be the most potent antiviral agent.
Projections of multidimensional data for use in man-computer graphics

The utility of man-computer graphics as an engineering design tool is now well recognized. With the use of an interactive visual display it is possible for a designer to input information graphically or digitally, observe the results of his input and then modify his data to achieve a more satisfactory result. By using preprogrammed subroutines the designer can quickly perform quite complex manipulations on data and observe the result.
Managerial Agency and Bond Covenants

Based on an analysis of the agency risk for bondholders from managerial entrenchment and fraud, we derive and test refutable hypotheses about the influence of managerial agency risk on bond covenants, using a comprehensive database of corporate bonds from the 1993--2007 period. Managerial entrenchment and the risk of managerial fraud significantly influence the use of covenants, in the direction predicted by the agency-theoretic framework. Our analysis highlights the varied effects of entrenchment on different types of agency risks faced by bondholders: Entrenched managers aggravate investment risk, but ameliorate risk from shareholder opportunism. Covenant use also responds efficiently to the quality of information available regarding the risk of managerial fraud. The Author 2009. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.
The Effective Cross Section of Positive Alkali Ions with Respect to Gas Molecules

The absorption of positive sodium ions with velocities of 40 to 400 equivalent volts has been studied in hydrogen, nitrogen and oxygen. The nature of the collision processes has, in each case, been studied to determine the relative importance of neutralization, retardation or small angle scattering. The mean free paths and effective cross section of the sodium ions with respect to the gas molecules is found to be a function of the pressure of the gas, the velocity of the ion and the nature of the gas-ion combination. The effective cross section of each gas-ion combination approaches the kinetic theory value at low velocity of the ion while at high velocities it approaches a minimum considerably smaller than the kinetic theory value. At any given velocity over the range studied, the effective cross section of the gas-ion combination increases in the order hydrogen, nitrogen, oxygen. The values for nitrogen and oxygen are essentially, within experimental errors, equal. An improved furnace for the production of positive ions has been developed.
The Pedagogy of Slowing Down: Teaching Talmud in a Summer Kollel

This article explores a set of practices in the teaching of Talmud called “the pedagogy of slowing down.” Through the author's analysis of her own teaching in an intensive Talmud class, “the pedagogy of slowing down” emerges as a pedagogical and cultural model in which the students learn to read more closely and to investigate the multiplicity of meanings inherent in the Talmudic text, thus bridging the gap between an ancient text and its contemporary students. This article describes the specific techniques in the pedagogy of slowing down, and the ways in which this teaching practice contributes both to students' becoming more attentive readers and to the ongoing development of their religious voices.
Effects of test techniques on wheel performance

Abstract : A study was made of the effects of various testing techniques on the performance of a test wheel mounted with a pneumatic tire operating in an air-dry desert sand. Tests employing both controlled-slip and controlled-pull techniques were conducted with a single-wheel, dynamometer-equipped carriage. The results are presented in the form of graphs with emphasis placed upon the pull-slip and torque-slip relations. For the conditions tested, wheel performance was found to be independent of testing techniques with one exception: Consistent differences were noted when comparing results of programmed-increasing and programmed-decreasing slip tests. Although this disagreement occurred only for a narrow range of slip (approximately -10 to +10 percent), it can be important. A brief analysis of the horizontal forces acting on the dynamometer is given to amplify certain relations, particularly difference in pull-slip and drawbar pull-slip responses. It is shown that because of the inability to always attain a stable condition, controlled-slip tests are better than controlled-pull tests for defining pull-slip and torque-slip relations.
Ionic conductivity of stabilized zirconia networks in composite SOFC electrodes

Abstract The effective oxygen conductivities in the zirconia networks of porous LSM–YSZ and LSM–SYSZ composites [i.e. La 0.85 Sr 0.15 MnO 3 –(Y 2 O 3 ) 0.08 (ZrO 2 ) 0.92 and La 0.85 Sr 0.15 MnO 3 –Sc 2 O 3 ) 0.1 (Y 2 O 3 ) 0.01 (ZrO 2 ) 0.89 , respectively] were evaluated by an AC impedance technique using specimens in which LSM was removed by hydrochloric acid leaching. The oxygen conductivities of porous YSZ and SYSZ alone followed a Koh–Fortini relationship. LSM-containing zirconia network conductivities were additionally decreased by the presence of the LSM. Grain boundary resistances were not measurably increased. Network constriction resistances were estimated to have a minor effect for well-formed networks. The significant microstructural differences of the YSZ and SYSZ, when formed with and without LSM, then indicate that the significant decrease in network effective ion conductivity is likely to be attributable to an increase in network interruptions and anomalously high constriction resistances resulting from differential densification promoted by the LSM.
The Ellipsoid Algorithm: A New Method for Feedback Gain Optimization

Abstract In this paper we discuss the use of an ellipsoid algorithm for the determination of output feedback gains in a linear time-invariant control system. The gains are chosen to minimize a quadratic performance criterion subject to an explicit constraint on system stability. Several numerical examples are studied in which not all of the state variables are accessible. Comparisons are made between the ellipsoid algorithm approach and four other commonly employed methods of solution. The ellipsoid algorithm is shown to be practical, accurate, robust, and relatively insensitive to large errors in the initial estimates of the gains.
Rate theory description of atomic stick-slip friction

We assess the validity of assumptions that underpin common low-dimensional rate theory descriptions of nanoscale stick-slip friction by completely specifying harmonic transition state theory kinetic parameters from an atomistic model. The resultant kinetic model is able to reliably reproduce the temperature and velocity dependence of friction as obtained by direct fully atomistic accelerated molecular-dynamics simulations. Analysis of the parameters extracted from the model indicates that, while energetics of the transition pathways can be adequately captured by low-dimensional effective Hamiltonians, rate theory prefactors contain inherently high-dimensional entropic contributions that cannot be accounted for. Despite these limitations, we show that simplified models can still be sufficiently robust to capture the prominent features of stick-slip friction.
Pseudo-Diagonals and Uniqueness Theorems

We examine a certain type of abelian C*-subalgebra that allows one to give a unified treatment of two uniqueness theorems: for graph C*algebras and for certain reduced crossed products. This note is meant to complement the paper [NR], which provides one of the two main examples of our results, by offering a conceptual treatment of the Uniqueness Theorem for the C*-algebras associated with graphs satisfying condition (L) and its generalization found in [Sz]. As pointed out in many places in graph C*-algebra literature (see for instance [Re1]), for graphs satisfying condition (L), a natural abelian C*-subalgebra (which is referred to in [NR] as the “diagonal”) turns out to give substantial information about the ambient (graph) C*-algebra. A similar treatment was proposed by Kumijian in [Ku], where he introduced the notion of C*-diagonals. In this paper we explain how, by considerably weakening several hypotheses in Kumjian’s definitions (in particular by getting rid of normalizers entirely), one can still obtain several key results, the most significant one being an “abstract” uniqueness property (see Theorem 3.1 below). Another illustration of this general approach is given in the context of reduced crossed products of abelian C*-algebras by essentially free actions of discrete groups, where we recover another uniqueness result due to Archbold and Spielberg [AS]. Our treatment focuses on the unique state extension property, as discussed in [KS] and [An], by weakening the global requirement made in the so-called Extension Property discussed in [An]. 1. Notation and preliminaries Notation. For any C*-algebra A, we denote by S(A) its set of states and by P (A) the set of pure states. Given a C*-subalgebra B ⊂ A, using the Hahn-Banach Theorem, it follows that any φ ∈ S(B) has at least one extension to some ψ ∈ S(A), so the set Sφ(A) = {ψ ∈ S(A) : ψ ∣∣ B = φ} is non-empty, convex and weak*-compact. Remark that if φ ∈ P (B), then every extreme point in Sφ(A) is in fact an extreme point in S(A); thus the intersection Sφ(A) ∩ P (A) is non-empty. Received by the editors June 26, 2011 and, in revised form, March 8, 2012. 2010 Mathematics Subject Classification. Primary 46L10; Secondary 46L30.
Cosmic ray and neutrino tests of special relativity

Abstract Searches for anisotropies due to Earth's motion relative to a preferred frame — modern versions of the Michelson-Morley experiment — provide precise verifications of special relativity. We describe other tests, independent of this motion, that are or can become even more sensitive. The existence of high-energy cosmic rays places strong constraints on Lorentz non-invariance. Furthermore, if the maximum attainable speed of a particle depends on its identity, then neutrinos, even if massless, may exhibit flavor oscillations. Velocity differences far smaller than any previously probed can produce characteristic effects at accelerators and solar neutrino experiments.
Implications of Jovian X‐ray emission for magnetosphere‐ionosphere coupling

[1] The first observations of Jupiter made by the Chandra X-Ray Observatory revealed a powerful X-ray aurora located in the polar caps. The X-ray emission exhibited a 40-min periodicity. Such 40-min periodicities have previously been seen in energetic particle fluxes and in Jovian radio emission. This paper develops scenarios in which the X-ray emission is produced by energetic heavy ion precipitation, either on open field lines connecting to the solar wind or on closed field lines reaching to the outer magnetosphere. In order to produce enough X-ray power, both scenarios require the existence of field-aligned electric fields located somewhere between the ionosphere and the magnetosphere, most likely at a radial distance of a few Jovian radii. The potential needed for solar wind ions to produce the observed X-rays is about 200 kV and the potential needed for the magnetospheric ions is at least 8 MV. Protons and helium ions are also accelerated by the potential and should produce an intense ultraviolet aurora. Downward electrical current is carried by the precipitating ions and also by upwardly accelerated secondary electrons produced by the primary ion precipitation. The estimated downward Birkeland current is about 1000 MA for the solar wind case and is about 10 MA for the magnetospheric case. For the magnetosphere scenario, this observed current represents part of the “return” current portion of the magnetospheric circuit associated with the departure of the mass-loaded magnetospheric plasma from corotation. The auroral X-ray emission maps at least part of this return current in the polar cap, whereas the main oval, produced by electron precipitation, is thought to map the region of upward Birkeland currents. The accelerated secondary electrons could be responsible for the periodic radio emission (i.e., QP-40 bursts).
Synthesis of methyl 2,3,6-trideoxy-3-(dimethylamino)-β-l-xylo-hexopyranoside

Abstract The title amino sugar was synthesized in six steps from methyl 4,6-O-benzylidene-2,3,-dideoxy-3-trifluoroacetamido-α- d -arabino-hexopyranoside in a route based on Horton's synthesis of 3-amino-2,3,6-trideoxy sugars, but modified to avoid the problem of anhydro bridge formation. This modification was successful and all steps in the synthesis, except the final catalytic reduction, went cleanly in good to excellent yields.
Deconvolving the information from an imperfect spherical gravitational-wave antenna

We have studied the effects of imperfections in spherical gravitational-wave antenna on our ability to properly interpret the data it will produce. The results of a numerical simulation are reported that quantitatively describe the systematic errors resulting from imperfections in various components of the antenna. In addition, the results of measurements on a room-temperature prototype are presented that verify it is possible to accurately deconvolve the data in practice.
Applications of 1-Alkenyl-1,1-Heterobimetallics in the Stereoselective Synthesis of Cyclopropylboronate Esters, Trisubstituted Cyclopropanols and 2,3-Disubstituted Cyclobutanones

1-Alkenyl-1,1-heterobimetallics are potentially very useful in stereoselective organic synthesis but are relatively unexplored. Introduced herein is a practical application of 1-alkenyl-1,1-heterobimetallic intermediates in the synthesis of versatile cyclopropyl alcohol boronate esters, which are valuable building blocks. Thus, hydroboration of 1-alkynyl-1-boronate esters with dicyclohexylborane generates 1-alkenyl-1,1-diboro species. In situ transmetalation with dialkylzinc reagents furnishes 1-alkenyl-1,1-borozinc heterobimetallic intermediates. Addition of the more reactive Zn—C bond to aldehydes generates the key B(pin) substituted allylic alkoxide intermediates. An in situ alkoxide directed cyclopropanation proceeds with the formation of two more C—C bonds, affording cyclopropyl alcohol boronate esters with three new stereocenters in 58−89% isolated yields and excellent diastereoselectivities (>15:1 dr). Oxidation of the B—C bond provides trisubstituted α-hydroxycyclopropyl carbinols as single diaste...
Stereoselective construction of the azabicyclic core applicable to the biologically important polyguanidinium alkaloids batzelladine A and D using a free radical cyclization

Abstract The intramolecular addition of the free radical derived from the alkyl bromide 13 provides an expeditious and stereoselective approach to the azabicyclic core 14 , which is applicable to the biologically important polyguanidinium alkaloids batzelladine A ( 1 ) and D ( 2 ).
Scanning the phases of QCD with BRAHMS

BRAHMS has the ability to study relativistic heavy ion collisions from the final freeze-out of hadrons all the way back to the initial wavefunction of the gold nuclei. This is accomplished by studying hadrons with a very wide range of momenta and angles. In doing so we can scan various phases of QCD, from a hadron gas, to a quark gluon plasma and perhaps to a colour glass condensate.
Ion clusters and the Venus ultraviolet haze layer.

THE daytime ionosphere of Venus is observed between 100 and 500 km altitude and has a peak electron concentration of 5 × 105 cm−3 at 140 km (ref. 1). Below 200 km CO2+ is thought to be the principal ion2,3 unless oxygen is present. I suggest that at altitudes less than 130 km CO2+ · CO2 is an important ionic constituent of the Venus ionosphere. Below 100 km ion clustering processes combine with the low temperature at the mesopause to form coagulates giving rise to the ultraviolet haze layer which has frequently been observed.
ELECTRONIC STRUCTURE OF GRAPHENE NANORIBBONS SUBJECTED TO TWIST AND NONUNIFORM STRAIN

Graphene nanoribbons exhibit band gap modulation when subjected to strain. While band gap creation has been theoretically investigated for uniaxial strains, other deformations such as nanoribbon twist have not been considered. Our main objective in this paper is to explore band gap opening in twisted graphene nanoribbons that have metallic properties under tight-binding approximation. While simple considerations based on the Huckel model allow to conclude that zigzag graphene nanoribbons exhibit no band gap when subjected to twist, the Huckel model overall may be inaccurate for band gap prediction in metallic nanoribbons. We utilize Density Functional Theory Tight-Binding Approximation together with a requirement that energy of twisted nanoribbons is minimized to evaluate band gap of metalic armchair nanoribbons. Besides considering twisting deformations, we also explore the possibility of creating band gap when graphene nanoribbons are subject to inhomogeneous deformation such as sinusoidal deformations.
A note on strong Jordan separation

We establish a strengthening of Jordan separation, to the setting of maps f : X --> Sn+1, where X is not necessarily a manifold, and f is not necessarily injective.
Thermionic work function of chemically vapor deposited rhenium on tungsten

The vacuum work function of chemically vapor deposited (CVD) rhenium was investigated. The thermionic emission technique was used in order to obtain high temperature data. Data were collected as a function of temperature and time, and the total pressure was recorded. X-ray analysis showed that the rhenium was preferentially deposited with the 0001 planes approximately parallel to the emitting surface. The effective work function data were compared with the results of Campbell et al. [1]. It was concluded that the residual gas pressure was responsible for conflicting work function data.
Enzymatic oxidative coupling of hydroxyphenylglycine derivatives

Abstract In contrast to N-protected tyrosine derivatives, N-protected hydroxy-D-phenylglycine derivatives underwent decarboxylation to give 4-hydroxybenzaldehyde under the normal incubation conditions. When both the carboxyl and amino groups of hydroxy-D-phenylglycine are blocked, the CC and CO coupling products were obtained in 48% and 32% yields respectively. No racemization of the chiral center was observed for all the substrates examined.
Multistep synthesis of amides from alcohols and amines in continuous flow microreactor systems using oxygen and urea hydrogen peroxide as oxidants

By integrating a heterogeneous oxidation step, gas–liquid separation, and an oxidative amidation reaction to form a continuous system, a multistep synthetic protocol has been demonstrated to produce amides under mild conditions using alcohols and amines as the starting materials. The use of inexpensive oxygen and urea hydrogen peroxide as the only oxidants affords an economical and adaptable synthetic route for amides.
Fermion to boson mappings revisited

Abstract We briefly review various mappings of fermion pairs to bosons, including those based on mapping operators, such as Belyaev-Zelevinskii, and those on mapping states, such as Marumori; in particular we consider the work of Otsuka-Arima-Iachello, aimed at deriving the Interacting Boson Model. We then give a rigorous and unified description of state-mapping procedures which allows one to systematically go beyond Otsuka-Arima-Iachello and related approaches, along with several exact results.
Enantioselective Organo-Singly Occupied Molecular Orbital Catalysis: The Carbo-oxidation of Styrenes

The first enantioselective organocatalytic carbo-oxidation of styrenes has been accomplished using singly occupied molecular orbital (SOMO) catalysis. Geometrically constrained radical cations are generated from the one-electron oxidation of enamines formed from the condensation of aldehydes with a secondary amine catalyst. These SOMO-activated radical cations are susceptible to attack by commercially available styrenes, forming γ-oxyaldehyde products with uniformly high levels of asymmetric induction. Broad latitude in both the aldehyde and styrene scope is readily tolerated. This report highlights the potential of SOMO catalysis to enable the development of entirely new classes of asymmetric reactions that have no traditional catalytic equivalents.