cssi/SciSciGPT-SciSciNet huggingface dataset:
Evolution of uranium and thorium minerals

The origins and near-surface distributions of the ~250 known uranium and/or thorium minerals elucidate principles of mineral evolution. This history can be divided into four phases. The first, from ~4.5 to 3.5 Ga, involved successive concentrations of uranium and thorium from their initial uniform trace distribution into magmatic-related fluids from which the first U4+ and Th4+ minerals, uraninite (ideally UO2), thorianite (ThO2), and coffinite (USiO4), precipitated in the crust. The second period, from ~3.5 to 2.2 Ga, saw the formation of large low-grade concentrations of detrital uraninite (containing several wt% Th) in the Witwatersrand-type quartz-pebble conglomerates deposited in a highly anoxic fluvial environment. Abiotic alteration of uraninite and coffinite, including radiolysis and auto-oxidation caused by radioactive decay and the formation of helium from alpha particles, may have resulted in the formation of a limited suite of uranyl oxide-hydroxides. Earth’s third phase of uranium mineral evolution, during which most known U minerals first precipitated from reactions of soluble uranyl (U6+O2)2+ complexes, followed the Great Oxidation Event (GOE) at ~2.2 Ga and thus was mediated indirectly by biologic activity. Most uraninite deposited during this phase was low in Th and precipitated from saline and oxidizing hydrothermal solutions (100 to 300 °C) transporting (UO2)2+-chloride complexes. Examples include the unconformity- and vein-type U deposits (Australia and Canada) and the unique Oklo natural nuclear reactors in Gabon. The onset of hydrothermal transport of (UO2)2+ complexes in the upper crust may reflect the availability of CaSO4- bearing evaporites after the GOE. During this phase, most uranyl minerals would have been able to form in the O2-bearing near-surface environment for the first time through weathering processes. The fourth phase of uranium mineralization began ~400 million years ago, as the rise of land plants led to non-marine organic-rich sediments that promoted new sandstone-type ore deposits. The modes of accumulation and even the compositions of uraninite, as well as the multiple oxidation states of U (4+, 5+, and 6+), are a sensitive indicator of global redox conditions. In contrast, the behavior of thorium, which has only a single oxidation state (4+) that has a very low solubility in the absence of aqueous F-complexes, cannot reflect changing redox conditions. Geochemical concentration of Th relative to U at high temperatures is therefore limited to special magmatic-related environments, where U4+ is preferentially removed by chloride or carbonate complexes, and at low temperatures by mineral surface reactions. The near-surface mineralogy of uranium and thorium provide a measure of a planet’s geotectonic and geobiological history. In the absence of extensive magmatic-related fluid reworking of the crust and upper mantle, uranium and thorium will not become sufficiently concentrated to form their own minerals or ore deposits. Furthermore, in the absence of surface oxidation, all but a handful of the known uranium minerals are unlikely to have formed.
Reconciling semiclassical and Bohmian mechanics. V. Wavepacket dynamics

In previous articles [B. Poirier J. Chem. Phys. 121, 4501 (2004); C. Trahan and B. Poirier, ibid. 124, 034115 (2006); 124, 034116 (2006); B. Poirier and G. Parlant, J. Phys. Chem. A 111, 10400 (2007)] a bipolar counterpropagating wave decomposition, ψ=ψ++ψ−, was presented for stationary states ψ of the one-dimensional Schrodinger equation, such that the components ψ± approach their semiclassical Wentzel–Kramers–Brillouin analogs in the large action limit. The corresponding bipolar quantum trajectories are classical-like and well behaved, even when ψ has many nodes, or is wildly oscillatory. In this paper, the method is generalized for time-dependent wavepacket dynamics applications and applied to several benchmark problems, including multisurface systems with nonadiabatic coupling.
ON THE GENERATION, PROPAGATION, AND REFLECTION OF ALFVEN WAVES FROM THE SOLAR PHOTOSPHERE TO THE DISTANT HELIOSPHERE

We present a comprehensive model of the global properties of Alfven waves in the solar atmosphere and the fast solar wind. Linear non-WKB wave transport equations are solved from the photosphere to a distance past the orbit of the Earth, and for wave periods ranging from 3 s to 3 days. We derive a radially varying power spectrum of kinetic and magnetic energy fluctuations for waves propagating in both directions along a superradially expanding magnetic flux tube. This work differs from previous models in three major ways. (1) In the chromosphere and low corona, the successive merging of flux tubes on granular and supergranular scales is described using a two-dimensional magnetostatic model of a network element. Below a critical flux-tube merging height the waves are modeled as thin-tube kink modes, and we assume that all of the kink-mode wave energy is transformed into volume-filling Alfven waves above the merging height. (2) The frequency power spectrum of horizontal motions is specified only at the photosphere, based on prior analyses of G-band bright point kinematics. Everywhere else in the model the amplitudes of outward and inward propagating waves are computed with no free parameters. We find that the wave amplitudes in the corona agree well with off-limb nonthermal line-width constraints. (3) Nonlinear turbulent damping is applied to the results of the linear model using a phenomenological energy loss term. A single choice for the normalization of the turbulent outer-scale length produces both the right amount of damping at large distances (to agree with in situ measurements) and the right amount of heating in the extended corona (to agree with empirically constrained solar wind acceleration models). In the corona, the modeled heating rate differs by more than an order of magnitude from a rate based on isotropic Kolmogorov turbulence.
Fast Bilateral Filter With Arbitrary Range and Domain Kernels

In this paper, we present a fast implementation of the bilateral filter with arbitrary range and domain kernels. It is based on the histogram-based fast bilateral filter approximation that uses uniform box as the domain kernel. Instead of using a single box kernel, multiple box kernels are used and optimally combined to approximate an arbitrary domain kernel. The method achieves better approximation of the bilateral filter compared to the single box kernel version with little increase in computational complexity. We also derive the optimal kernel size when a single box kernel is used.
A mild method for extracting amines under neutral conditions

Abstract Copper (II) ion-exchanged zeolites are highly active reagents for selective complexation of amines in aqueous or organic solution.
Cavity atom optics and the `free atom laser'

Abstract The trap environment in which Bose–Einstein condensates are generated and/or stored strongly influences the way they interact with light. The situation is analogous to cavity QED in quantum optics, except that in the present case, one tailors the matter-wave mode density rather than the density of modes of the optical field. Just as in QED, for short times, the atoms do not sense the trap and propagate as in free space. After times long enough that recoiling atoms can probe the trap environment, however, the way condensates and light fields are mutually influenced differs significantly from the free-space situation. We use as an example the condensate collective atomic recoil laser, which is the atomic matter-wave analog of the free-electron laser.
A New Preparation of Esters from Carbonyl Compounds Following Lithium Aluminum Hydride Reduction

Abstract A modified work-up procedure for the lithium aluminum hydride (LiAlH4) reduction of esters and other carbonyl compounds is described. The one pot procedure converts an ester to its “homo-reverse ester” and other carbonyl compounds to esters. The key step is trapping the resulting intermediate aluminum alkoxide during reflux with an ester.
Elementary Rate Laws of Diffusion-Limited Species in the A+T→T Reaction in Low Dimension

Through computer simulation we look at the elementary reaction rate laws of the trapping reaction A+T→T reaction on a one-dimensional lattice. In particular, we calculate the heterogeneity exponent h of the integrated reaction rate law. However, as the reaction probability p is varied, the heterogeneity exponent becomes a function of time. We find a bifurcation of asymptotic values of h: 1/2 for reactions where p ≤ 1.0 and 0 where p=0. In addition, the usual constraints of the trapping problem have been relaxed, and we look at systems where the A’s move and the T remains immobile and the reverse case, where the T moves and the A’s sit.
The hadronic recoil mass spectrum in semileptonic $B$ decays and extracting $|V_{ub}|$ in a model-insensitive way

We present an extended discussion of the previously noted possibility to extract $|V_{ub}|$ from an analysis of the hadronic recoil mass spectrum in $B\rightarrow X_u\,\ell \nu$ decays. Invariant mass spectra containing perturbative as well as nonperturbative corrections are given; their shape is manifestly sensitive to the three basic quantities $\mu _\pi ^2$ , $m_b$ and $\alpha_s$ , whereas the total integrated rate is much less so. Only a small fraction of $b\rightarrow u$ transitions generates a recoil mass $M_X$ of at least $M_D$ . Moreover we find that the fraction of events with $M_X \leq 1.5\,\mbox{GeV}$ (to reject leakage from $b \rightarrow c$ due to measurement errors) exhibits fairly little dependence on $\mu_\pi^2$ , $m_b$ and $\alpha_s$ ; $|V_{ub}|$ can then be extracted in a largely model-insensitive way. This conclusion is based on the applicability of the OPE to actual semileptonic $B$ decays. A direct cross-check of this assumption and a determination of the required basic parameters of the heavy quark expansion will be possible in the future with more experimental data.
Perinatal Endocrinology: Common Endocrine Disorders in the Sick and Premature Newborn

Endocrine disorders are common in infants in the neonatal ICU. They often are associated with prematurity, low birth weight or very low birth weight, and small size for gestational age. They also frequently occur in infants who are critically ill or stressed. This article describes the most common conditions and current knowledge regarding management.
Creative dynamics approach to neural intelligence

The thrust of this paper is to introduce and discuss a substantially new type of dynamical system for modelling biological behavior. The approach was motivated by an attempt to remove one of the most fundamental limitations of artificial neural networks — their rigid behavior compared with even simplest biological systems. This approach exploits a novel paradigm in nonlinear dynamics based upon the concept of terminal attractors and repellers. It was demonstrated that non-Lipschitzian dynamics based upon the failure of Lipschitz condition exhibits a new qualitative effect — a multi-choice response to periodic external excitations. Based upon this property, a substantially new class of dynamical systems — the unpredictable systems — was introduced and analyzed. These systems are represented in the form of coupled activation and learning dynamical equations whose ability to be spontaneously activated is based upon two pathological characteristics. Firstly, such systems have zero Jacobian. As a result of that, they have an infinite number of equilibrium points which occupy curves, surfaces or hypersurfaces. Secondly, at all these equilibrium points, the Lipschitz conditions fails, so the equilibrium points become terminal attractors or repellers depending upon the sign of the periodic excitation. Both of these pathological characteristics result in multi-choice response of unpredictable dynamical systems. It has been shown that the unpredictable systems can be controlled by sign strings which uniquely define the system behaviors by specifying the direction of the motions in the critical points. By changing the combinations of signs in the code strings the system can reproduce any prescribed behavior to a prescribed accuracy. That is why the unpredictable systems driven by sign strings are extremely flexible and are highly adaptable to environmental changes. It was also shown that such systems can serve as a powerful tool for temporal pattern memories and complex pattern recognition. It has been demonstrated that new architecture of neural networks based upon non-Lipschitzian dynamics can be utilized for modelling more complex patterns of behavior which can be associated with phenomenological models of creativity and neural intelligence.
Symposium on Market Microstructure: A Review of Empirical Research

This paper provides a review of empirical research in four topics within the area of market microstructure. Specifically, the paper provides an overview of issues related to (a) the estimation of the components of the bid-ask spread, (b) the effects of order flow characteristics and regulations on market liquidity, (c) the differences and similarities between the NYSE and the Nasdaq and (d) the interaction between the options and underlying stock markets.
The use of dyes as an aid to coal petrography

Abstract Polished coal pellets from three coals (Ro random, 0.30, 0.49, 0.67), were immersed in solutions of sixteen synthetic dyes selected from Gurr's classification, and examined under the coal microscope using reflected light. In addition, a coal (Ro random 0.35) and six cationic dyes were included in this study. The striking affinity of class 2:1 (cationic) dyes for huminite and low-rank vitrinite macerals is explained by binding of the dyes to peripheral functional groups, possibly hydroxyl and carboxyl groups. The action of these cationic dyes is shown to be both specific and rank dependent. Enhancement of the cellular detail of certain huminite and low-rank vitrinite macerals was observed with the class 2:1 dyes. A lack of affinity of the class 2:1 dyes for certain corpohuminite and corpocollinite macerals was noted. Rhodamine B, a cationic, slightly amphoteric dye was observed to stain the epoxy binder in addition to huminite and low-rank vitrinite macerals. Methyl red, an anionic dye was found to exhibit the same affinity for huminite and low-rank vitrinite macerals as did the cationic dyes. It is suggested that Methyl red was reduced to a cationic form and behaved like a group 2 dye. Some of the possible applications of dyes in coal petrography and petroleum exploration are: (1) to distinguish clay-like liptinite macerals and true clay minerals; (2) to enhance the cellular structure of certain huminite and vitrinite macerals; and (3) to distinguish immature and mature source rocks. It is further suggested that dyes may be useful for petrographic examination of lignites and possibly residues from hydrogenation vessels.
Observation of Bose-Einstein Condensation in a Dilute Atomic Vapor

A Bose-Einstein condensate was produced in a vapor of rubidium-87 atoms that was confined by magnetic fields and evaporatively cooled. The condensate fraction first appeared near a temperature of 170 nanokelvin and a number density of 2.5 x 10 12 per cubic centimeter and could be preserved for more than 15 seconds. Three primary signatures of Bose-Einstein condensation were seen. (i) On top of a broad thermal velocity distribution, a narrow peak appeared that was centered at zero velocity. (ii) The fraction of the atoms that were in this low-velocity peak increased abruptly as the sample temperature was lowered. (iii) The peak exhibited a nonthermal, anisotropic velocity distribution expected of the minimum-energy quantum state of the magnetic trap in contrast to the isotropic, thermal velocity distribution observed in the broad uncondensed fraction.
Existence, uniqueness, and stability of equilibrium in an overlapping-generations model with productive capital

Abstract This paper analyzes the existence, uniqueness, and stability of a steady-state equilibrium in an overlapping-generations model with productive capital. It is shown that for any feasible set of well-behaved preferences there exists a production function that satisfies the Inada conditions under which the economy experiences global contraction and the steady-state equilibrium is characterized by the absence of production and consumption. The study establishes a strengthened Inada condition which is necessary to preclude global contraction. and sufficient conditions for the existence of a unique and globally stable non-trivial steady-state equilibrium.
The Rossby wave extra invariant in the physical space

Abstract It was found out in 1991 that the Fourier space dynamics of Rossby waves possesses an extra positive-definite quadratic invariant , in addition to the energy and enstrophy. This invariant is similar to the adiabatic invariants in the theory of dynamical systems. For many years, it was unclear if this invariant—known only in the Fourier representation—is physically meaningful at all, and if it is, in what sense it is conserved. Does the extra conservation hold only for a class of solutions satisfying certain constraints (like the conservation in the Kadomtsev–Petviashvili equation)? The extra invariant is especially important because this invariant (provided it is meaningful) has been connected to the formation of zonal jets (like Jupiter’s stripes). In the present paper, we find an explicit expression of the extra invariant in the physical (or coordinate) space and show that the invariant is indeed physically meaningful for any fluid flow. In particular, no constraints are needed. The explicit form also enables us to note several properties of the extra invariant.
A measurement approach to conservatism and earnings management

This paper formalizes a two-step representation of accounting measurement and uses it to formalize a general rationale for conservatism as a measurement principle. A transaction's economic substance manifests itself in characteristics of the transaction, and an accounting rule is a mapping from transaction characteristics to an accounting report. Managers who have stakes in the accounting report are able to influence transaction characteristics. Such earnings management is ex post rational for managers but ex ante inefficient. To safeguard against such ex post opportunism, the optimal ex ante accounting rule is conservative in the sense that it requires more verification of the transaction characteristics favorable to managers. Thus, this rationale for conservatism is as general as the managers' ability and incentive to inflate transaction characteristics. By opening the black box of accounting measurement, the two-step representation also formalizes some classic accounting concepts, such as relevance, reliability, verifiability, verification, and accounting-motivated transactions.
An efficient synthesis and acylation of α-amino-β-keto-esters: Versatile intermediates in the synthesis of peptide mimetics.

Abstract A flexible and high yield synthesis of α-amino-β-keto esters has been developed via acylation of the ketimine derivatives of α-amino esters. These α-amino-β-keto-esters were acylated with chiral amino acid derivatives in 36–95% yields.
New Classes of Counterexamples to Hendrickson’s Global Rigidity Conjecture

We examine the generic local and global rigidity of various graphs in ℝd . Bruce Hendrickson showed that some necessary conditions for generic global rigidity are (d+1)-connectedness and generic redundant rigidity, and hypothesized that they were sufficient in all dimensions. We analyze two classes of graphs that satisfy Hendrickson’s conditions for generic global rigidity, yet fail to be generically globally rigid. We find a large family of bipartite graphs for d>3, and we define a construction that generates infinitely many graphs in ℝ5. Finally, we state some conjectures for further exploration.
ACCURATE IONIZATION THRESHOLDS OF ATOMS SUBJECT TO HALF-CYCLE PULSES

The evolution of Rydberg states of hydrogen and alkali-metal atoms subject to short half-cycle pulses is studied. The convergence of the numerical solutions of the time-dependent Schrodinger equation based on an expansion of the electronic wave function in a finite basis set of Sturmian functions is analyzed in detail. It is shown that the accuracy of such calculations can be established by investigating the stabilization of the transition probabilities with respect to the parameters that define the basis set. The dependence of the quantum and classical ionization thresholds on the pulse shape is investigated. The calculations are compared with experimental data for various pulse profiles, which feature slow or fast rise times. The results show that the ionization thresholds for long pulses are very sensitive to the rise time of the electric field. @S1050-2947~98!00309-6# PACS number~s!: 32.80.Rm, 02.60.2x During the last few years, the ionization and excitation of Rydberg atoms by pulsed unidirectional electric fields, termed half-cycle pulses ~HCPs!, have been investigated ex- tensively. Experiments have reached the regime in which the effective duration of the pulses T p and the peak fieldsFp are of the order of the classical electron orbital period Tni 52pn i and the Coulomb electric field Fn i 5n i4 in the
REJUVENATING POWER SPECTRA. II. THE GAUSSIANIZED GALAXY DENSITY FIELD

We find that, even in the presence of discreteness noise, a Gaussianizing transform (producing a more Gaussian one-point distribution) reduces nonlinearities in the power spectra of cosmological matter and galaxy density fields, in many cases drastically. Although Gaussianization does increase the effective shot noise, it also increases the power spectrum's fidelity to the linear power spectrum on scales where the shot noise is negligible. Gaussianizing also increases the Fisher information in the power spectrum in all cases and resolutions, although the gains are smaller in redshift space than in real space. We also find that the gain in cumulative Fisher information from Gaussianizing peaks at a particular grid resolution depends on the sampling level.
Seesaw induced Higgs mechanism

We discuss a two scalar doublets model which induces the Higgs mechanism by means of a seesaw mechanism. This model naturally predicts a light Higgs scalar whose mass is suppressed by the grand unification scale. The model requires an intermediate scale between the electroweak symmetry breaking scale and the grand unification scale at 109 GeV. Below this intermediate energy scale the usual standard model appears as an effective theory. An implementation of this mechanism in models where the Planck scale is in the TeV region is discussed.
Costs of a motivational enhancement therapy coupled with cognitive behavioral therapy versus brief advice for pregnant substance users.

Objectives To determine and compare costs of a nurse-administered behavioral intervention for pregnant substance users that integrated motivational enhancement therapy with cognitive behavioral therapy (MET-CBT) to brief advice (BA) administered by an obstetrical provider. Both interventions were provided concurrent with prenatal care. Methods We conducted a micro-costing study that prospectively collected detailed resource utilization and unit cost data for each of the two intervention arms (MET-CBT and BA) within the context of a randomized controlled trial. A three-step approach for identifying, measuring and valuing resource utilization was used. All cost estimates were inflation adjusted to 2011 U.S. dollars. Results A total of 82 participants received the MET-CBT intervention and 86 participants received BA. From the societal perspective, the total cost (including participants’ time cost) of the MET-CBT intervention was $120,483 or $1,469 per participant. In contrast, the total cost of the BA intervention was $27,199 or $316 per participant. Personnel costs (nurse therapists and obstetric providers) for delivering the intervention sessions and supervising the program composed the largest share of the MET-CBT intervention costs. Program set up costs, especially intervention material design and training costs, also contributed substantially to the overall cost. Conclusions Implementation of an MET-CBT program to promote drug abstinence in pregnant women is associated with modest costs. Future cost effectiveness and cost benefit analyses integrating costs with outcomes and benefits data will enable a more comprehensive understanding of the intervention in improving the care of substance abusing pregnant women.
Effects of oxidation/reduction treatments on the morphology of silica-supported rhodium catalysts

Abstract The effects of oxidation, reduction, and alternating oxidation/reduction treatments on the oxidation state and the morphology of silica-supported Rh catalysts have been examined by temperature-programmed reduction and transmission electron microscopy. Oxidation of the catalyst leads to two forms of Rh oxide which are distinguished by different reduction temperatures. Microbeam electron diffraction identified these two species as a crystalline Rh 2 O 3 and a disordered stoichiometric equivalent of Rh 2 O 3 . The disordered Rh 2 O 3 is characterized by crystal domains less than 6.0 nm which can exist as segregated particles or as part of larger particles. The well-ordered crystalline Rh 2 O 3 is associated with particles greater than 10.0 nm. The two forms of Rh 2 O 3 can be interconverted—crystalline Rh 2 O 3 formed by high-temperature oxidation can be converted to the disordered form by low-temperature reduction followed by a mild reoxidation. These observations support previous studies which suggest that the morphology of small Rh particles differs from that of large Rh particles. Moreover, our observations indicate that detailed characterization of the microstructure of supported Rh catalysts will be crucial to understanding their reduction, oxidation, and catalytic properties.
DYTEST: a self-learning algorithm using dynamic testability measures to accelerate test generation

A self-learning algorithm called DYTEST, which uses a dynamic testability measure (DTM) to accelerate test generation, is presented. DYTEST's DTM guides the choice of a potential main sensitizing path during test generation. A full-logic value label backward implication creates estimates of logic values for the primary inputs. Dependent and k-limited backtracks are used to further reduce the number of backtracks. >
Manganese‐Catalyzed and Promoted Reactions of H‐Phosphinate Esters

Manganese catalyzed reactions of H-phosphinates with various alkenes give the corresponding alkylated products.
Singular trajectories in airplane cruise-dash optimization

Optimal cruise-dash trajectories are obtained for the case of time-fuel optimization using a linear combination of time and fuel as the performance index. For the case of the steady-state arc being flown at full throttle, the skeletal transient trajectories are also flown at full throttle and the transients approach the cruise-dash points monotonically in an asymptotic fashion. When the steady-state arc is flown at an intermediate throttle, the transient trajectories follow a singular control law and exhibit a complex structure that differs from that of the full-throttle transients. With respect to optimality of the steady-state arc, it is found that although steady-state cruise fails a Jacobi-type condition, steady-state cruise-dash can satisfy this condition if the emphasis on time is sufficiently large.
Pitfalls in the Theory of Growth: An application to the balance of payments constrained growth model

(2003). Pitfalls in the Theory of Growth: An application to the balance of payments constrained growth model. Review of Political Economy: Vol. 15, No. 1, pp. 75-84.
X-Ray Fluorescence Correlation Spectroscopy: A Method for Studying Particle Dynamics in Condensed Matter

We have demonstrated that x-ray fluorescence correlation spectroscopy, in conjunction with microfocused synchrotron x-ray beams, can be used for elucidating particle dynamics. The dynamics of gold and ferromagnetic colloidal particles and aggregates undergoing both diffusion and sedimentation in water has been studied by measuring the time autocorrelation of the x-ray fluorescence intensity from a small illuminated volume. The dynamical parameters obtained are in excellent agreement with theoretical estimates and other measurements. Potential applications of the technique are discussed. {copyright} {ital 1998} {ital The American Physical Society}
High gain and high extraction efficiency from a free electron laser amplifier operating in the millimeter wave regime

Abstract Experiments at the Electron Laser Facility have generated peak microwave power of 180 MW at 35 GHz. The facility is operated as a single pass amplifier. Gain in excess of 30 dB/m has been observed up to saturation of the amplifier. For the 3.6 MeV, 850 A electron beam, the radiation corresponds to 6% energy extraction from the electron beam. Beyond saturation, the electron beam output power exhibits oscillations corresponding to the synchrotron motion of the trapped electrons in the ponderomotive well. In addition, the TE 21 and TM 21 modes have been studied and have power levels comparable to the fundamental. Third harmonic (105 GHz) radiation has been measured at power levels on the order of a few percent of the peak fundamental power.
High-Resolution X-Ray Photoemission Spectrum of the Valence Bands of Gold

High-resolution gold-valence-band photoemission spectra were obtained by the use of monochromatized $\mathrm{Al} K\ensuremath{\alpha}$ radiation and a single-crystal specimen. After background and scattering corrections were made, the results were compared directly with broadened theoretical density-of-states functions. The following conclusions were drawn: (i) Relativistic band-structure calculations are required to fit the spectrum. (ii) Both the Korringa-Kohn-Rostoker calculation of Connolly and Johnson and the relativistic-augmented-plane-wave calculation by Christensen and Seraphin give density-of-states results that (after broadening) follow the experimental curve closely. (iii) Of the theoretical functions available to date, those with full Slater exchange agree best with experiment (perhaps because of a cancellation of errors). Fractional ($\frac{2}{3} or \frac{5}{6}$) exchange gives $d$ bands that are too wide. (iv) Eastman's 40.8-eV ultraviolet photoemission spectrum is similar to the x-ray spectrum, suggesting little dependence on photon energy above 40 eV. (v) Both (ii) and (iv) imply an absence of strong matrix-element modulation in the photoemission spectrum of gold.
Long-run costs of piecemeal reform: Wage inequality and returns to education in Vietnam

Abstract In this paper, we examine changes in wage structure and wage premia during Vietnam’s transition from command to market economy. Relative to other work in this literature, our paper is unique in that we identify the policies that lead to such changes. By examining skill premium trends along the two dimensions of particular importance to the transition—state or non-state firms, and traded or non-traded industries—we are able to separate the contribution of external liberalization to wage growth and rising skill premia from that of domestic labor market reforms, and to examine potential interactions between the two types of reform. The results point to the high cost of incomplete reform in Vietnam. Capital market segmentation creates a two-track market for skills, in which state sector workers earn high salaries while non-state workers face lower demand and lower compensation. Growth is reduced directly by diminished allocative efficiency and reduced incentives to acquire education, and indirectly by higher wage inequality and rents for workers with access to state jobs.
Ergodic Actions of Universal Quantum Groups on Operator Algebras

We construct ergodic actions of compact quantum groups on C*-algebras and von Neumann algebras, and exhibit phenomena of such actions that are of different nature from ergodic actions of compact groups.
A Low Cost High Energy Density Carbon Black Fuel Mix For Heat Engines

Abstract An efficient economically attractive process is described for production of carbon black and the by-product hydrogen from any carbonaceous raw material and especially from coal. The HYDROCARB process consists of two steps. The first step is the hydropyrolysis of coal to produce methane and the second step is the thermal decomposition of the methane to carbon black and hydrogen, part of which is recycled. The process is essentially a cracking of the coal to its elements C and H2, removal of oxygen as water, leaving behind the ash and sulfide residue. The carbon black can then be mixed either with a liquid hydrocarbon or an alcohol in a carbon-fuel-mix (CARBOL1NE-CFM) or with water to produce a carbon-water-mix (CARBOL1NE CWM). A 65% CWM fuel has been produced which has an energy density of 108,000 Btulgal. Addition of 50% carbon black to kerosene jet fuel increases its energy density from 140,000 to 170,000 Btulgal. Some of the rheological and combustion characteristics of carbon black, CWM, and C...
High-fidelity aeroelastic computations of a flapping wing with spanwise flexibility

Abstract A high-order (up to 6th order) Navier–Stokes solver is coupled with a structural solver that decomposes the equations of three-dimensional elasticity into cross-sectional, small-deformation and spanwise, large-deformation analyses for slender wings. The resulting high-fidelity aeroelastic solver is applied to the investigation of rigid, moderately flexible and highly flexible rectangular wings undergoing a pure plunging motion. Comparisons of the computed results with available experimental measurements demonstrate good agreement. A description of the complex interaction between the unsteady aerodynamics and the flexible wing structural dynamics is given. Connections between the results of this analysis and enhanced loads for the moderately flexible wing are made. Results presented suggest that an optimum amount of flexibility exists for the case of a plunging wing and is associated with wing motions where the wing tip deflection and wing root motion are in phase over much of the plunge cycle.
Polynomial-sized semidefinite representations of derivative relaxations of spectrahedral cones

We give explicit polynomial-sized (in $$n$$n and $$k$$k) semidefinite representations of the hyperbolicity cones associated with the elementary symmetric polynomials of degree $$k$$k in $$n$$n variables. These convex cones form a family of non-polyhedral outer approximations of the non-negative orthant that preserve low-dimensional faces while successively discarding high-dimensional faces. More generally we construct explicit semidefinite representations (polynomial-sized in $$k,m$$k,m, and $$n$$n) of the hyperbolicity cones associated with $$k$$kth directional derivatives of polynomials of the form $$p(x)=\det (\sum _{i=1}^{n}A_i x_i)$$p(x)=det(?i=1nAixi) where the $$A_i$$Ai are $$m\times m$$m×m symmetric matrices. These convex cones form an analogous family of outer approximations to any spectrahedral cone. Our representations allow us to use semidefinite programming to solve the linear cone programs associated with these convex cones as well as their (less well understood) dual cones.
Synthesis and studies of new tris(trimethylsilyl)silyl derivatives of germanium and tin

Abstract The reactions of (THF)3LiSi(SiMe3)3 with Me3GeCl, Ph3GeCl and GeCl4 give R3GeSi(SiMe3)3, RMe (75%), Ph (79%) and Cl (20%), respectively. The products, colorless, crystalline solids, unreactive toward air except for Cl3GeSi(SiMe3)3 which is hygroscopic and rapidly hydrolyzed, were characterized by elemental analyses, GC-MS and their 1H, 13C and 29Si NMR spectra. An X-ray structure determination established that crystals of Ph3GeSi(SiMe3)3 are monoclinic, C2/c, with a=17.102(6), b=9.997(3), c=37.368(9) A, β=91.61(2)o, V=6386 A3 and Z=8. Examination of the structural parameters revealed the presence of twisting distortions among the phenyl and trimethylsilyl substituents evidently relieving steric strain along the GeSi vector. Bond distances and angles predicted from force field calculations closely matched those determined by diffraction for the phenyl derivative. Calculations on Me3GeSi(SiMe3)3 and Cl3GeSi(SiMe3)3 confirmed the expectation that steric strain is minimal in those molecules. The reactions of (Me3Si)3SiSnCl3·THF and ((Me3Si)3Si)2SnCl2 with LiAlH4 in ether were investigated as a possible means to prepare silyltin(IV) hydrides. Despite use of a variety of conditions following those in published preparations of alkyltin(IV) hydrides, no silyltin hydrides were isolated. MNDO calculations indicated that decomposition of ((Me3)3Si)3SiSnH3 to ((Me3)3Si)SiH, Sn and H2 is thermodynamically favored.
The Impact of Uruguay's 2007 Tax Reform on Equity and Efficiency

type="main"> In 2007, the Uruguayan government implemented a tax reform which introduced a new progressive labour income tax and a flat capital income tax, and reduced some indirect taxes, with the objective of improving fiscal balance, income distribution and economic growth. This article evaluates the impact of such tax reform on equity and efficiency on the basis of data derived from the Encuesta Continua de Hogares (ECH) for 2006 and 2009. Using a Difference-in-Differences technique, it shows that the new system reduced inequality by 2 Gini points without producing any discernible disincentive effect, suggesting that suitably designed reforms of direct taxation can simultaneously promote equity and efficiency.
Vortex washboard voltage noise in type-II superconductors

In order to characterize flux flow through disordered type-II superconductors, we investigate the effects of columnar and point defects on the vortex velocity/voltage power spectrum in the driven non-equilibrium steady state. We employ three-dimensional Metropolis Monte Carlo simulations to measure relevant physical observables including the force-velocity/current-voltage (I-V) characteristics, vortex spatial arrangement and structure factor, and mean flux line radius of gyration.Our simulation results compare well to earlier findings and physical intuition.We focus specifically on the voltage noise power spectra in conjunction with the vortex structure factor in the presence of weak columnar and point pinning centers. We investigate the vortex washboard noise peak and associated higher harmonics,and show that the intensity ratios of the washboard harmonics are determined bythe strength of the material defects rather than the type of pins present.Through varying columnar defect lengths and pinning strengths as well as magnetic flux density we further explore the effect of the material defects on vortex transport.It is demonstrated that the radius of gyration displays quantitatively uniquefeatures that depend characteristically on the type of material defects presentin the sample.
The crystal structure on the set of Mirkovic-Vilonen polytopes

Abstract In an earlier work, we proved that MV polytopes parameterize both Lusztig's canonical basis and the Mirkovic–Vilonen cycles on the affine Grassmannian. Each of these sets has a crystal structure (due to Kashiwara–Lusztig on the canonical basis side and due to Braverman–Finkelberg–Gaitsgory on the MV cycles side). We show that these two crystal structures agree. As an application, we consider a conjecture of Anderson–Mirkovic which describes the BFG crystal structure on the level of MV polytopes. We prove their conjecture for sl n and give a counterexample for sp 6 . Finally we explain how Kashiwara data can be recovered from MV polytopes.
Flow of Clay Suspensions Through Porous Media

This study was undertaken to investigate the transient behavior of particulate plugging of porous media. The objectives of the experiments were to study in detail a well-characterized system and to check the validity of theoretical predictions. Experiments included injection of clay suspensions under different conditions into sandpacks, measurement of pore-size distribution, and monitoring of permeability and effluent particle concentrations.
Intimacy with Outlaws: The Role of Relational Distance in Recruiting, Paying, and Interviewing Underworld Research Participants

The past quarter century has witnessed the emergence of a substantial literature devoted to the mechanics of recruiting, paying, and interviewing currently active offenders. Absent from that literature, however, is a theoretical framework within which to understand, test, modify, and further develop efforts to locate such offenders and gain their cooperation. This note, based on the authors' research with active drug sellers in Atlanta and St. Louis, explores the ways in which relational distance, that is, the nature and degree of intimacy between recruiter, interviewee, and researcher, affects the behavior of active offender research. The note concludes with theoretically situated, practical advice for (1) recruiting active criminals, (2) cost containment, and (3) maximizing the quantity and validity of data produced in interviews.
Experimentation and Conjectures in the Real Schubert Calculus for Flag Manifolds

The Shapiro conjecture in the real Schubert calculus, while likely true for Grassmannians, fails to hold for flag manifolds, but in a very interesting way. We give a refinement of the Shapiro conjecture for flag manifolds and present massive computational experimentation in support of this refined conjecture. We also prove the conjecture in some special cases using discriminants and establish relationships between different cases of the conjecture.
Catalyzed Olefin Isomerization Leading to Highly Stereoselective Claisen Rearrangements of Aliphatic Allyl Vinyl Ethers

Iridium(I)-catalyzed olefin isomerization in bis(allyl) ethers is integrated into a generally applicable strategy for affecting highly stereoselective Claisen rearrangements. Catalyzed alkene isomerization affords allyl vinyl ethers from easily prepared di(allyl) ethers; direct thermolysis of these reaction mixtures leads to highly diastereoselective [3,3] sigmatropic rearrangements affording syn-2,3-dialkyl-4-pentenal derivatives. An easily executed strategy for realizing asymmetric variants of the isomerization-Claisen rearrangement (ICR) reactions is also described.
Palladium-catalyzed decarboxylative benzylation of diphenylglycinate imines.

General reaction conditions for the Pd-catalyzed decarboxylative benzylation of benzyl diphenylglycinate imines are described. The overall procedure requires a simple catalyst/ligand combination to form a new Csp3−Csp3 bond. Microwave irradiation greatly accelerated the transformation. Moreover, various heteroaromatic moieties are tolerated in both the imine and ester components.
Land use effects on soil carbon fractions in the southeastern United States. I. Management-intensive versus extensive grazing

Changes in grassland management intended to increase productivity can lead to sequestration of substantial amounts of atmospheric C in soils. Management-intensive grazing (MiG) can increase forage production in mesic pastures, but potential impacts on soil C have not been evaluated. We sampled four pastures (to 50 cm depth) in Virginia, USA, under MiG and neighboring pastures that were extensively grazed or hayed to evaluate impacts of grazing management on total soil organic C and N pools, and soil C fractions. Total organic soil C averaged 8.4 Mg C ha–1 (22%) greater under MiG; differences were significant at three of the four sites examined while total soil N was greater for two sites. Surface (0–10 cm) particulate organic matter (POM) C increased at two sites; POM C for the entire depth increment (0–50 cm) did not differ significantly between grazing treatments at any of the sites. Mineral-associated C was related to silt plus clay content and tended to be greater under MiG. Neither soil C:N ratios, POM C, or POM C:total C ratios were accurate indicators of differences in total soil C between grazing treatments, though differences in total soil C between treatments attributable to changes in POM C (43%) were larger than expected based on POM C as a percentage of total C (24.5%). Soil C sequestration rates, estimated by calculating total organic soil C differences between treatments (assuming they arose from changing grazing management and can be achieved elsewhere) and dividing by duration of treatment, averaged 0.41 Mg C ha–1 year–1 across the four sites.
Quantum-critical theory of the spin-fermion model and its application to cuprates: Normal state analysis

We present the full analysis of the normal state properties of the spin-fermion model near the antiferromagnetic instability in two dimensions. The model describes low-energy fermions interacting with their own collective spin fluctuations, which soften at the antiferromagnetic transition. We argue that in 2D, the system has two typical energies—an effective spin-fermion interaction g¯ and an energy ωsf below which the system behaves as a Fermi liquid. The ratio of the two determines the dimensionless coupling constant for spin-fermion interaction λ2 ∝ g¯/ωsf. We show that λ scales with the spin correlation length and diverges at criticality. This divergence implies that the conventional perturbative expansion breaks down. We develop a novel approach to the problem—the expansion in either the inverse number of hot spots in the Brillouin zone, or the inverse number of fermionic flavours—which allows us to explicitly account for all terms which diverge as powers of λ, and treat the remaining, O(log λ) terms...
Effects of an Exercise Program on Physiological Functions in Postmenopausal Women with Metabolic Syndrome

The purpose of this study was to examine effects of mixed interval aerobic and strength training (MAST) program on physiological functions in older women with metabolic syndrome. 12 subjects were randomly assigned to the exercise group (16-week MAST program) or the control group. Outcomes included oxygen uptake (VO2max), cerebral blood flow velocity (BFV) and cognitive functions. The exercise group demonstrated increased VO2max and certain improvements in cognitive functions. No changes were observed in BFV for both groups. These results can be used as a preliminary data for planning larger studies.
New and unified model for Schottky barrier and III–V insulator interface states formation

For n- and p-doped III-V compounds, Fermi-level pinning and accompanying phenomena of the (110) cleavage surface have been studied carefully using photoemission at hv≲ 300 eV (so that core as well as valence band levels could be studied). Both the clean surfaces and the changes produced, as metals or oxygen are added to those surfaces in submonolayer quantities, have been examined. It is found that, in general, the Fermi level stabilizes after a small fraction of a monolayer of either metal or oxygen atoms have been placed on the surface. Most strikingly, Fermi-level pinning produced on a given semiconductor by metals and oxygen are similar. However, there is a strong difference in these pinning positions depending on the semiconductor: The pinning position is near (1) the conduction band maximum (CBM) for InP, (2) midgap for GaAs, and (3) the valence band maximum (VBM) for GaSb. The similarity in the pinning position on a given semiconductor produced by both metals and oxygen suggests that the states responsible for the pinning resulted from interaction between the adatoms and the semiconductor. Support for formation of defect levels in the semiconductor at or near the surface is found in the appearance of semiconductor atoms in the metal and in disorder in the valence band with a few percent of oxygen. Based on the available information on Fermi energy pinning, a model is developed for each semiconductor with two different electronic levels which are produced by removal of anions or cations from their normal positions in the surface region of the semiconductors. The pinning levels have the following locations, with respect to the VBM: GaAs, 0.75 and 0.5 eV; InP, 0.9 and 1.2 eV (all levels + 0.1 eV).