cssi/SciSciGPT-SciSciNet huggingface dataset:
Personalty interests at the Constitutional Convention: new tests of the Beard thesis

Charles Beard ([1913] 2004) argued that the U.S. Constitution was created to advance the interests of people who owned personalty, particularly those at the Constitutional Convention. Because delegate votes on individual clauses at the Constitutional Convention were not publicly recorded, prior empirical analyses have been limited to inferred votes on a specific set of unrelated clauses. We extend this inquiry by inferring votes related to currency and debt issues which Beard put forth as the prime issues for those who owned personalty. Our analysis on these votes generates little support for a narrow version of the Beard thesis, which states that all personalty groups voted in a unified coalition at the Convention and supported the Constitution. Our analysis provides some support, however, for a broader interpretation that personalty and realty interests affected delegate voting behavior at the margin.
Infrared Plasmonic Metamaterials for Slow-Light Applications

A new approach to slowing light in plasmonic structures is proposed. We utilize the phenomenon of double-Fano resonance. Specific implementations of spectrally broad slow-light structures based on plasmonic antennas are presented.
Distributed asynchronous algorithms with stochastic delays for constrained optimization problems with conditions of time drift

A distributed asynchronous algorithm for minimizing a function with a nonstationary minimum over a constraint set is considered. The communication delays among the processors are assumed to be stochastic with Markovian character. Conditions which guarantee the mean square and almost sure convergence to the sought solution are presented. We also present an optimal routing application for a network that connects various U.S. cities. Results of the extensive simulation that we implemented assert the practical applicability of distributed asynchronous algorithms with stochastic delays. Comparison results for varying the probability distribution of these delays are provided. The impact of varying the communication delay bound and the stepsize is also assessed.
Recent progress in fiber fabrication techniques by vapor-phase axial deposition

Five years have passed since the invention of the VAD technique. Fabrication techniques for the various kinds of VAD fibers such as graded index fibers, single-mode fibers, high NA fibers, and single polarization fibers have been developed. This paper mainly outlines the recent improvements in the VAD fiber manufacturing techniques such as the preform fabrication technique, dehydration technique, refractive index profile formation technique, and the single-mode fiber manufacturing technique.
HIERARCHICAL QUANTUM SEARCH

Database search has wide applications and is used as a subroutine in many important algorithms. In this paper, we will consider a database with a single target item. Quantum algorithm (Grover) locates the target item faster than any classical algorithm. In addition to a full (Grover) search, it frequently occurs that one is looking for a group of items (a block) containing the target item, rather than the target item itself. This problem is known as partial search. As a generalization of the full search, partial search is of particular importance in practice. Partial search trades accuracy for speed, i.e., it works faster than a full search. There exists different versions of partial search. We will study the optimized version of the algorithm discovered by Grover and Radhakrishnan and call it GRK. GRK can be applied successively (in a sequence). First, the database is partitioned into blocks and GRK is applied to find the target block. This target block is then partitioned into subblocks and GRK is used again to find the target subblock. This procedure can be repeated if the database is large enough. (This sequence of GRK's is called a hierarchy.) Another possibility is to partition the database into subblocks directly and use GRK to find the target subblock once. In this paper, we will prove that the latter is faster (makes less queries to the Oracle).
Implementing multiple criteria ABC analysis

Abstract This article presents the results of applying multicriteria ABC analysis to maintenance inventories. A large service organization and a consumer goods manufacturer participated in the study. The managers in both organizations used cost and noncost criteria for developing the ABC categories for inventory management. The study shows that managers can develop noncost criteria and classify the inventory items in ways that combine the criteria types. Specific policies were defined for managing the items in the industrial firm. Once the benefits of the methodology were demonstrated, a year-long program for implementing the system was developed. The project is estimated to cost less than 10 to 15% of the available storeroom clerk manhours and provide substantially greater benefits.
White-light image addition and subtraction by colorimetric measurement

The theory and experiment of a new white-light image-processing technique for black-and-white image addition and subtraction by means of Fourier-plane spatial color filtering are described. Both the intensity transmittances of three (or two) processed images and the results of the addition and subtraction are expressed in a chromaticity coordinate system.
“Instant Methylide” Modification of the Corey–Chaykovsky Cyclopropanation Reaction

Abstract Treatment of various electron‐deficient alkenes in DMSO with stable, dry, equimolar mixtures of either Me3S(O)I/KOt‐Bu or Me3S(O)I/NaH cleanly afforded the corresponding substituted cyclopropanes in good yields and short reaction times (<20 min for reactions at 50–60°C using 0.4–4.0 mmol alkene).
Development Of An Optical Parallel Logic Device And A Half-Adder Circuit For Digital Optical Processing

An Optical Parallel Logic (OPAL) device which performs Boolean algebraic operations on two binary images has been developed. This device consists of a photoconductor and an electro-optic light modulating material appropriately arranged to bring about an in-teraction between the input signals. Two such OPAL devices have been interconnected to form a half-adder circuit (one of the essential components in the CPU of a futuristic digital optical processor). Operation of an 8 x 8 OPAL device containing CdS (photoconductor) and twisted nematic liquid crystal (electro-optic light modulating material) is reported. A contrast ratio of 20:1 was obtained. A circuit composed of two such devices is shown to perform addition of two 8 x 8 binary images generating SUM and CARRY images.
MICROANALYSIS OF PRECIPITATE FREE ZONES (PFZ) IN AL-ZN-MG AND CU-NI-NB ALLOYS

In order to better understand the formation of Precipitate Free Zones (PFZ), microanalysis was conducted on heat treated Al-2.2 at. pct Zn-4.7 at. pct Mg and Cu-30 at. pct Ni-0.9 at. pct Nb alloys. In both the alloys, no appreciable solute depletion at the grain boundaries was observed in the as-quenched condition. After aging, marked solute depletion was observed in the PFZ of both the alloys. In the Al-Zn-Mg alloy, the PFZ were supersaturated with respect toη andT phases up to 4 h of aging at 473 K. In the Cu-Ni-Nb alloy, the PFZ were supersaturated only with respect to theβ phase but not the metastable γ″ phase. Based on the results, the factors affecting the formation and growth of PFZ are discussed.
Critical exponents and universality in fully developed turbulence

Abstract A new perspective on the critical phenomena aspects of fully developed turbulence (FDT) is considered. The energy (or enstrophy) dissipation rate e (or τ) is pointed out to be the suitable quantity to be identified as the order parameter for the FDT problem. Multi-fractal model has been used to provide a detailed structure for the critical exponent σ associated with this order parameter that appears to exhibit an interesting universality covering radically different FDT systems in fluid and plasma dynamics. This result also appears to provide a consistent framework for classification of dissipation field into critical, subcritical and supercritical cases. Some FDT problems that exemplify these cases are discussed. This classification is validated further by considering the probability density functions (PDF) of relevant flow-variable gradients in the FDT problems exemplifying the various cases.
Economic prospects and policies in Mexico

This essay sets out to examine Mexico’s possibilities in the world economy in general and in the North American area in particular, and to consider the choice of policies that may be applied to exploit its possibilities to best advantage. As an introduction to the discussion, Section I will review the policies applied in Mexico during the 1973–83 decade of external shocks. In turn, Section II will examine the extent to which Mexico has exploited its comparative advantage in trade in manufactured goods. Finally, Section III will focus on policies that may permit Mexico to cope with its debt problem and to ensure rapid and sustained economic growth in the future.
Binary pulsars and relativistic gravity

Presented by the Department of Astronomy, the Exhibit Museum of Natural History, and the Student Astronomical Society, and sponsored by the Michigan Center for Theoretical Physics, the University Activities Center, and the College of Literature, Science, and the Arts.
Asset Markets, Tariffs, and Political Risk

Abstract This paper examines a simple model in which exogenous political risk creates uncertainty about tariffs. The model predicts a relation between consumption and tariffs that differs radically from that implied by models without asset markets or political risk. Given the probability distribution of tariffs, domestic consumption and utility (ex post) are lower in states of the world with a domestic tariff and no foreign tariff than with a foreign tariff and no domestic tariff. This conclusion emerges despite the fact that the opposite would be obtained in the absence of asset markets. So economists should not be surprised if observed relations between consumption and tariffs differ from the predictions of static theory in either time series or cross-sections.
Architecting principles for systems-of-systems

While the phrase “system-of-systems” is commonly seen, there is less agreement on what they are, how they may be distinguished from “conventional” systems, or how their development differs from other systems. This paper proposes a definition, a limited taxonomy, and a basic set of architecting principles to assist in their design. As it turns out, the term system-of-systems is infelicitous for the taxonomic grouping. The grouping might be better termed “collaborative systems.” The paper also discusses the value of recognizing the classification in system design, and some of the problems induced by misclassification. One consequence of the classification is the identification of principal structuring heuristics for system-of-systems. Another is an understanding that, in most cases, the architecture of a system-of-systems is communications. The architecture is nonphysical, it is the set of standards that allow meaningful communication among the components. This is illustrated through existing and proposed systems. © 1999 John Wiley & Sons, Inc. Syst Eng 1: 267–284, 1998
Discovery of the Barium Isotopes

Thirty-eight barium isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.
Reconstructed jets at RHIC

To precisely measure jets over a large background such as pile up in high luminosity p+p collisions at LHC, a new generation of jet reconstruction algorithms is developed. These algorithms are also applicable to reconstruct jets in the heavy ion environment where large event multiplicities are produced. Energy loss in the medium created in heavy ion collisions are already observed indirectly via inclusive hadron distributions and di-hadron correlations. Jets can be used to study this energy loss in detail with reduced biases. We review the latest results on jet-medium interactions as seen in A+A collisions at RHIC, focusing on the recent progress on jet reconstruction in heavy ion collisions.
MODEL REDUCTION FOR FLUIDS, USING BALANCED PROPER ORTHOGONAL DECOMPOSITION

Many of the tools of dynamical systems and control theory have gone largely unused for fluids, because the governing equations are so dynamically complex, both high-dimensional and nonlinear. Model reduction involves finding low-dimensional models that approximate the full high-dimensional dynamics. This paper compares three different methods of model reduction: proper orthogonal decomposition (POD), balanced truncation, and a method called balanced POD. Balanced truncation produces better reduced-order models than POD, but is not computationally tractable for very large systems. Balanced POD is a tractable method for computing approximate balanced truncations, that has computational cost similar to that of POD. The method presented here is a variation of existing methods using empirical Gramians, and the main contributions of the present paper are a version of the method of snapshots that allows one to compute balancing transformations directly, without separate reduction of the Gramians; and an output p...
Making C–C Bonds from Carbon Dioxide via Transition-Metal Catalysis

Developing more green and sustainable strategies for organic synthesis is an important modern challenge. Although carbon dioxide is an attractive reagent, because of its availability, the low reactivity of this small molecule renders it challenging to use widely in organic synthesis. The discovery of new catalysts thus plays a central role in advancing the science and impact of CO2 utilization. This perspective describes advances in metal-catalyzed carbon dioxide incorporation since Aresta’s report of the first metal-CO2 complex.
Characteristics of multiple shock wave/turbulent boundary-layer interactions in rectangular ducts

Multiple shock wave/turbulent boundary-layer interactions in a rectangular duct have been investigated using wall pressure measurements, surface oil flow visualization, spark schlieren photography, and laser Doppler velocimetry. Two undisturbed incoming Mach numbers were considered, Mach 2.45 and Mach 1.6. At Mach 2.45 the shock structure was a neutrally stable pattern of oblique shocks followed by repeated normal shocks with the level of flow confinement having only a small effect in the interaction. A large, three-dimensional separation region was observed. At Mach 1.6 the pattern consisted of a bifurcated normal shock followed by weaker, unbifurcated normal shocks. The boundary layer under the bifurcated shock was incipiently separated. In contrast to the Mach 2.45 case, the lower Mach number interaction was much steadier with the length of the interaction scaling directly with the level of flow confinement.
Uniform externalities: Two axioms for fair allocation

Abstract Positive (resp. negative) Preference Externalities say that an agent always prefers his actual welfare to his (virtual) welfare should other agents share his preferences (resp. prefers his virtual to his actual welfare). Negative Group Externalities say that an agent never prefers his actual welfare to his (virtual) welfare should he be the sole user of the resources. These two axioms unify several familiar fairness properties - and yield some new ideas as well - in the division of unproduced commodities and the cooperative production of a private or a public good. We also discuss their compatibility with No Envy and Resource Monotonicity.
Rapid synthesis of the indole-indolone scaffold via [3+2] annulation of arynes by methyl indole-2-carboxylates

The reaction of methyl indole-2-carboxylates and arynes affords a very efficient, high yielding synthesis of a novel indole-indolone ring system, which tolerates considerable functionality, is broad in scope, and proceeds under mild reaction conditions.
Carbon-carbon bond formation and pyrrole synthesis via the [3,3] sigmatropic rearrangement of O-vinyl oxime ethers.

A new method for the synthesis of 2,4- and 2,3,4-substituted pyrroles in two or three steps from commercially available ketones and allyl hydroxylamine is described. An iridium-catalyzed isomerization reaction has been developed to convert O-allyl oximes to O-vinyl oximes, which undergo a facile [3,3] rearrangement to form 1,4-imino aldehyde Paal−Knorr intermediates that cyclize to afford the corresponding pyrroles. Optimization and examples of the isomerization and pyrrole formation are discussed.
Upper bounds for ropelength as a function of crossing number

Abstract This paper provides bounds for the ropelength of a link in terms of the crossing numbers of its prime components. As in earlier papers, the bounds grow with the square of the crossing number; however, the constant involved is a substantial improvement on previous results. The proof depends essentially on writing links in terms of their arc-presentations, and has as a key ingredient Bae and Park's theorem that an n -crossing link has an arc-presentation with less than or equal to n +2 arcs.
Analysis of quorum-based protocols for distributed (k+1)-exclusion

A generalization of the majority quorum for the solution of the distributed (k+1)-exclusion problem is proposed. This scheme produces a family of quorums of varying sizes and availabilities indexed by integral divisors r of k. The cases r=1 and r=k correspond to known majority based quorum generation algorithms MAJ and DIV, whereas intermediate values of r interpolate between these two extremes. A cost and availability analysis of the proposed methods is also presented. An interesting implication of this analysis is that in a reasonably reliable environment with a large number of sites, even protocols with low communication costs attain high availability.
Economies of Scope of Lending and Mobilizing Deposits in Microfinance Institutions: A Semiparametric Analysis

Microfinance emerged as an innovation in lending to the rural poor in Asia and in response to frequent failure of previous interventions in rural financial markets such as directed and subsidized production credit disbursed by agricultural development banks. While it started “as a collection of banking practices built around providing small loans (typically without collateral) and accepting tiny savings deposits” Armendariz de Aghion and Morduch (2005, p. 1), today many microfinance institutions (MFIs) expand their services and strive to offer payment and savings facilities, insurance, housing, and longer-term loans to marginalized clientele in rural and urban settings. Estimates show that there are at least 10,000 microfinance programs worldwide. Two related and important trends are now emerging. The first is toward commercialization which essentially is transforming NGO-MFIs into regulated intermediaries with the intent to lower costs by accessing deposits as well as strengthen the organizations by privatization. The second trend is a renewed interest in experimentation to mobilize savings with emphasis on rural savings. Economies of scope imply that expansion into the savings market can be more cost efficient if done by the same MFIs, which makes it a significant factor in assessing the feasibility of these innovations. However, there are few studies that estimate the magnitude and sign of scope economies. In this paper, we present some preliminary evidence on scope economies using a large sample of MFIs.
The inapproximability of non-NP-hard optimization problems

The inapproximability of non-NP-hard optimization problems is investigated. Techniques are given to show that the problems LOG DOMINATING SET and LOG HYPERGRAPH VERTEX COVER cannot be approximated to a constant ratio in polynomial time unless the corresponding NP-hard versions are also approximable in deterministic subexponential time. A direct connection is established between non-NP-hard problems and a PCP characterization of NP. Reductions from the PCP characterization show that LOG CLIQUE is not approximable in polynomial time and MAX SPARSE SAT does not have a FPTAS under the assumption that NP ⊈ DTIME(2O(√ n log n). A number of nontrivial approximation-preserving reductions are also presented, making it possible to extend inapproximability results to more natural non-NP-hard problems such as TOURNAMENT DOMINATING SET and RICH HYPERGRAPH VERTEX COVER.
Three-dimensional numerical simulations of Rayleigh-Taylor unstable flames in Type Ia supernovae

Flame instabilities play a dominant role in accelerating the burning front to a large fraction of the speed of sound in a Type Ia supernova. We present a three-dimensional numerical simulation of a Rayleigh-Taylor unstable carbon flame, following its evolution through the transition to turbulence. A low-Mach number hydrodynamics method is used, freeing us from the harsh time step restrictions imposed by sound waves. We fully resolve the thermal structure of the flame and its reaction zone, eliminating the need for a flame model. A single density is considered, 1.5 × 107 g cm-3, and half-carbon, half-oxygen fuel: conditions under which the flame propagated in the flamelet regime in our related two-dimensional study. We compare to a corresponding two-dimensional simulation and show that while fire polishing keeps the small features suppressed in two dimensions, turbulence wrinkles the flame on far smaller scales in the three-dimensional case, suggesting that the transition to the distributed burning regime occurs at higher densities in three dimensions. Detailed turbulence diagnostics are provided. We show that the turbulence follows a Kolmogorov spectrum and is highly anisotropic on the large scales, with a much larger integral scale in the direction of gravity. Furthermore, we demonstrate that it becomes more isotropic as it cascades down to small scales. On the basis of the turbulent statistics and the flame properties of our simulation, we compute the Gibson scale. We show the progress of the turbulent flame through a classic combustion regime diagram, indicating that the flame just enters the distributed burning regime near the end of our simulation.
Crystal growth and properties of Ln2Ag1−xGa10−y (Ln=La, Ce), a disordered variant of the Ce2NiGa10-structure type

Abstract We report the flux growth and characterization of Ln2Ag1−xGa10−y (Ln=La, Ce), a disordered variant of the Ce2NiGa10 structure type. Single crystals of La2Ag1−xGa10−y (x∼0.3; y∼0.6) and Ce2Ag1−xGa10−y (x∼0.3; y∼0.9) were grown by the self-flux method and characterized using single-crystal X-ray diffraction. Transport measurements of Ce2Ag1−xGa10−y (x∼0.3; y∼0.9) reveal metallic behavior with a transition at 3 K. Magnetic measurements indicate antiferromagnetic ordering at 3 K of localized Ce3+ moments for Ce2Ag1−xGa10−y. Magnetoresistance is positive with a maximum value of 16% at 9 T. La2Ag1−xGa10−y exhibits metallic behavior with magnetic susceptibility showing temperature independent paramagnetism. We will compare Ce2Ag1−xGa10−y (x∼0.3; y∼0.9) to Ce2NiGa10 to examine the effects of transition metal substitution and to the related Ce(Ag,Ga)4 phase to examine the effects of crystal structure on the physical properties.
Maintaining visibility of a polygon with a moving point of view

The following problem is studied in this paper: Given a scene with an n-vertex simple polygon and a trajectory path in the plane, construct a data structure for reporting the perspective view from a moving point along the trajectory. We present conceptually simple algorithms for the cases of this problem in which the trajectory path consists of several line segments or of a conic curve that contains the polygon. Our algorithms take O(n log n) time and O(n) space. We also prove that the problem of reporting perspective views from successive points along a trajectory path takes Ω(n log n) time in the worst case in the algebraic computation tree model. Our data structure reports the view from any query point on the trajectory in O(k + log n) time for a view of size k.
Failure of laminated composites at thickness discontinuities under complex loading and elevated temperatures

Failure initiation of laminated composites with discontinuous thickness is examined in terms of typical structural load description (tension, shear force and bending moment) rather than in terms of micromechanics considerations. Because transverse shear produced relatively small effects in failure initiation, results are presented as tension-bending interactions. Two loading frames were designed to apply moments and tension simultaneously. Four types of specimens of different stacking sequence were examined to determine failure initiation, and analyzed subsequently via a finite element analysis (ABAQUS). Depending on the stacking sequence across the interface of the step, two different failure modes are identified: For uni-directional fiber orientation across the interface in the tension direction, failure occurs through cracking and delamination which is governed by a fracture mechanics criterion. While the initiation strength for this failure mode is higher than for the cross-ply configurations, the residual strength after initiation is only marginally higher, providing virtually no margin of safety (10%). For cases involving cross-plies on either side of the interface, failure initiation occurs by matrix cracking, with a critical strain across the fibers providing a universal failure criterion. In these cases the residual load bearing capability was 30 to 45% higher than the failure initiation loads. The interaction between moment and tension at failure initiation is linear, an observation that does not hold for the delamination failure driven by crack propagation. It is found that all failures can be described in terms of a common fracture principle; the stress or strain criteria are interchangeable with the fracture energy computations, provided one allows for a range of values of associated fracture energies. Assuming that time dependent aspects of the failure process are not dominant, elevated temperatures did not change the general results of how bending and tension loads interact, provided one accounts for residual thermal stresses; however, the stress magnitude at which the failure initiation occurs decreases with increasing temperature.
Impact of ethane and propane variation in natural gas on the performance of a model gas turbine combustor

In the area of stationary power generation, there exists a growing interest in understanding the role that gaseous fuel composition plays on the performance of natural gas-fired gas turbine systems. In this study, an atmospherically fired model gas turbine combustor with a fuel flexible fuel/air premixer is employed to investigate the impact of significant amounts of ethane and propane addition into a baseline natural gas fuel supply. The impacts of these various fuel compositions, in terms of the emissions of NO x and CO, and the coupled impact of the degree of fuel/air mixing, are captured explicitly for the present system by means of a statistically oriented testing methodology. These explicit expressions are also compared to emissions maps that encompass and expand beyond the statistically based test matrix to verify the validity of the employed statistical approach.
Effects of ammonia borane on the combustion of an ethanol droplet at atmospheric pressure

Adding hydrogen containing energetics to liquid fuels has the potential to change the combustion behavior of the fuels, thereby enhancing performance. One potential energetic additive is ammonia borane (AB), which contains 19.6 wt.% hydrogen and can be dissolved in anhydrous ethanol (up to 6.5 wt.%). Single droplet combustion experiments are performed that vary the AB concentration in ethanol from 0 to 6 wt.%. These experiments indicate that the addition of 6 wt.% of AB increases the burn rate of the fuel by 16% during normal regression. As the ethanol droplet containing AB burns, gas formation within the droplet causes it to expand slightly. Gas bubbles generated during burn reach the surface of the droplet and rupture, jettisoning liquid and increasing the burn rate. High speed (5 kHz) planar laser-induced uorescence (PLIF) measurements show an increase in OH production during combustion, indicating that the reaction rate of the fuel increases with the addition of AB. PLIF is also used to capture the jetting dynamics. The eects of hydrogen gas and other decomposition products of AB in the fuel vapor surrounding the droplet are evident in these dynamic measurements that aect the burn rate. AB addition to the fuel causes the droplet to shatter towards the end of the droplet lifetime causing atomization and rapid combustion of the remaining fuel. This droplet shattering is similar to some other systems, but has not previously been reported for ammonia borane systems.
Heterogeneous Paths Through College: Detailed Patterns and Relationships with Graduation and Earnings

Abstract A considerable fraction of college students and bachelor's degree recipients enroll in multiple postsecondary institutions. Despite this fact, there is scant research that examines the nature of the paths – both the number and types of institutions – that students take to obtain a bachelor's degree or through the higher education system more generally. We also know little about how enrollment in multiple institutions of varying quality relates to postgraduate life outcomes. We use a unique panel data set from Texas that allows us to examine in detail the paths that students take toward a bachelor's degree and estimate how enrollment in multiple institutions is related to both degree completion and subsequent earnings. We show that the paths to a bachelor's degree are diverse and that earnings and BA receipt vary systematically with these paths. Our results call attention to the importance of developing a more complete understanding of why students transfer and what causal role transferring has on the returns to postsecondary educational investment.
Strong WW scattering in unitary gauge

Abstract A method to embed models of strong WW scattering in unitary gauge amplitudes is presented that eliminates the need for the effective W approximation (EWA) in the computation of cross sections at high energy colliders. The cross sections obtained from the U-gauge amplitudes include the distributions of the final state fermions in ff → ffWW , which cannot be obtained from the EWA. Since the U-gauge method preserves the interference of the signal and the gauge sector background amplitudes, which is neglected in the EWA, it is more accurate, especially if the latter is comparable to or bigger than the signal, as occurs for instance at small angles because of Coulomb singularities. The method is illustrated for on-shell W + W + → W + W + scattering and for qq → qqW + W + .
Homogeneous Fermion Superfluid with Unequal Spin Populations

For decades, the conventional view is that an s-wave BCS superfluid can not support uniform spin polarization due to a gap Δ in the quasiparticle excitation spectrum. We show that this is an artifact of the dismissal of quasiparticle interactions Vqp in the conventional approach at the outset. Such interactions can cause triplet fluctuations in the ground state and hence non-zero spin polarization at “magnetic field” h<Δ. The resulting ground state is a pairing state of quasiparticles on the “BCS vacuum”. For sufficiently large Vqp, the spin polarization of at unitarity has the simple form m∝μ1/2. Our study is motivated by the recent experiments on Fermi gases with spin imbalance in the strongly interacting regime.
Consumption externalities, rental markets and purchase clubs

A premise of general equilibrium theory is that private goods are rival. Nevertheless, many private goods are shared, e.g., through borrowing, through co-ownership, or simply because one person’s consumption affects another person’s wellbeing. I analyze consumption externalities from the perspective of club theory, and argue that, provided consumption externalities are limited in scope, they can be internalized through membership fees to groups. Two important applications are to rental markets and “purchase clubs,” in which members share the goods that they have individually purchased.
Local Electronic Structure of Olivine Phases of LixFePO4

Changes in the local electronic structure at atoms around Li sites in the olivine phase of LiFePO4 were studied during delithiation. Electron energy loss spectrometry was used for measuring shifts and intensities of the near-edge structure at the K-edge of O and at the L-edges of P and Fe. Electronic structure calculations were performed on these materials with a plane-wave pseudopotential code and with an atomic multiplet code with crystal fields. It is found that both Fe and O atoms accommodate some of the charge around the Li+ ion, evidently in a hybridized Fe−O state. The O 2p levels appear to be fully occupied at the composition LiFePO_4. With delithiation, however, these states are partially emptied, suggestive of a more covalent bonding to the oxygen atom in FePO_4 as compared to LiFePO_4. The same behavior is found for the white lines at the Fe L_(2,3)-edges, which also undergo a shift in energy upon delithiation. A charge transfer of up to 0.48 electrons is found at the Fe atoms, as determined from white line intensity variations after delithiation, while the remaining charge is compensated by O atoms. No changes are evident at the P L_(2,3)-edges.
Cation ordering and physicochemical characterization of the quaternary diamond-like semiconductor Ag2CdGeS4

The quaternary diamond-like semiconductor, Ag{sub 2}CdGeS{sub 4}, was synthesized via high-temperature solid-state synthesis as well as structurally and physicochemically characterized. Single crystal X-ray diffraction provided a model for Ag{sub 2}CdGeS{sub 4} in the orthorhombic, noncentrosymmetric space group Pna2{sub 1} with a=13.7415(8) A, b=8.0367(5) A and c=6.5907(4) A, in contrast to a previously published model in Pmn2{sub 1} from the Rietveld analysis of laboratory X-ray powder diffraction data. The Pna2{sub 1} space group is supported by the Rietveld analysis of synchrotron X-ray powder diffraction data. Differential thermal analysis suggests that Ag{sub 2}CdGeS{sub 4} exists in two polymorphs. Optical diffuse reflectance UV/vis/NIR spectroscopy indicates that the orange compound is a semiconductor with a band gap of 2.32 eV. Optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and inductively coupled plasma optical emission spectroscopy were used to further characterize the material. - Graphical abstract: The structure of the diamond-like semiconductor Ag{sub 2}CdGeS{sub 4} has been solved and refined in the orthorhombic noncentrosymmetric space group Pna2{sub 1}. A view down the a-axis shows that all MS{sub 4} tetrahedra are pointing in the same direction along the c-axis. The structure can be derived from that of lonsdaleite. Highlights: Black-Right-Pointing-Pointer The structure of Ag{sub 2}CdGeS{sub 4}more » is solved from single crystal X-ray diffraction. Black-Right-Pointing-Pointer The structure is supported by the Rietveld analysis of synchrotron diffraction data. Black-Right-Pointing-Pointer Ag{sub 2}CdGeS{sub 4} is a semiconductor with an optical band gap of 2.32 eV. Black-Right-Pointing-Pointer Additional characterization is reported.« less
Microtribology of Magnetic Media

Scanning tunnelling microscopy (STM), atomic force microscopy (AFM) and the modifications of AFM [such as friction force microscopy (FFM)] are becoming increasingly important in the understanding of fundamental mechanisms of friction, wear and lubrication and in studying the interfacial phenomena in micro- and nanostructures used in magnetic storage devices and microelectromechanical systems (MEMS). This paper describes modified AFM and FFM techniques and presents data on microtribological studies of magnetic media-magnetic tapes and disks. Local variation in microscale friction is found to correspond to the local slope, suggesting that a ratchet mechanism is responsible for this variation. Wear rates for magnetic tapes are approximately constant for various loads and test duration. However, for magnetic disks, the wear of the diamond-like carbon overcoat is catastrophic. Evolution of the wear has also been studied using AFM. AFM has been modified for nanoindentation hardness measurements. It has been sho...
Lossy Trapdoor Functions and Their Applications

We propose a general cryptographic primitive called lossy trapdoor functions (lossy TDFs), and we use it to develop new approaches for constructing several important cryptographic tools, including (injective) trapdoor functions, collision-resistant hash functions, oblivious transfer, and chosen ciphertext-secure cryptosystems (in the standard model). All of these constructions are simple, efficient, and black-box. We realize lossy TDFs based on a variety of cryptographic assumptions, including the hardness of the decisional Diffie-Hellman (DDH) problem and the hardness of the “learning with errors” problem (which is implied by the worst-case hardness of various lattice problems). Taken together, our results resolve some long-standing open problems in cryptography. They give the first injective TDFs based on problems not directly related to integer factorization and provide the first chosen ciphertext-secure cryptosystem based solely on worst-case complexity assumptions.
Auditor fees and audit quality

– The paper aims to examine the relation between fees paid to auditors and audit quality during the period of 2000‐2003., – The paper constructs a measure of auditor profitability that is used as a proxy for auditor independence. The methodology is grounded in the notion that auditor independence is influenced by effort and risk‐adjusted fees, rather than the level of fees received from clients. Since, risk and effort are unobservable, the paper uses proxies based on client size, complexity and risk to estimate abnormal fees. Abnormal fees are derived using a fee estimation model drawn from prior literature. The paper employs two metrics to assess audit quality – the standard deviation of residuals from regressions relating current accruals to cash flows and the absolute value of performance‐adjusted discretionary accruals., – The paper documents a statistically significant negative association between total fees and both audit quality proxies over all years. These findings are robust to a variety of additional tests and several alternative design specifications. The results (pre‐ and post‐SOX) are consistent with economic bonding being a determinant of auditor behavior rather than auditor reputational concerns., – The possibility that the empirical tests do not completely capture the impact of unobserved risk cannot be ruled out, though the paper attempts to do so by employing alternative specifications and sensitivity tests., – Policy makers should note that current restrictions on the provision of non‐audit services may not sufficiently resolve the issue of economic bonding and its impact on auditor independence., – In contrast to previous studies whose results are ambiguous, the paper finds a statistically significant positive association between several measures of total fees (it uses size‐adjusted and abnormal fees) and two metrics of accruals quality in all years (2000‐2003), consistent with economic bonding being a determinant of auditor behavior rather then auditor reputation concerns.
Foldable Joints for Foldable Robots

Print-and-fold approaches to robot fabrication allow entire robots to be produced using a single uniform process: fabricating them in-plane and then folding them into their 3-D forms. Current efforts to design print-and-fold robots have been limited by a lack of understanding of what motions can be achieved by folding. In this paper, we introduce fold patterns for three basic joints commonly used in robots, and we show how the patterns can be changed to accommodate user-specified ranges of motion. The joints are composed with each other to produce joints with higher degrees of freedom and with rigid bodies to produce entire foldable linkage mechanisms. We have folded our basic joints and composed mechanisms, and they achieve the expected kinematics. We have also printed control circuitry on and attached actuators directly to three of our designs, demonstrating that it possible to print and fold robots with many different kinematics.
Exact field solution to guided wave propagation in lossy thin films

The problem of light trapping in thin film solar cells is one of mode coupling into a lossy waveguide structure. This paper therefore derives the full-field solution for electromagnetic wave propagation in a three-layer dielectric system with arbitrary complex indices of refraction. The functional form of the eigenvalue equation is identical to that of the strictly lossless case, but with complex-valued propagation constants rather than real. Lossy mode propagation is then explored in the context of photovoltaics by modeling a thin film solar cell made of amorphous silicon with an aluminum back contact.
Synchronization from deletions through interactive communication

In this paper we consider a synchronization problem between nodes A and B that are connected through a two-way communication channel. Node A contains a binary file X of length n and node B contains a binary file Y that is generated by randomly deleting bits from X, by a small deletion rate β. We offer a deterministic synchronization scheme between nodes A and B that needs O(nβ log 1/β)1 transmissions to reconstruct X at node B. The rate of our scheme matches the optimal rate for this channel up to a multiplicative constant and the running time of our scheme is O(n4β6).
Synthesis of (+)-decarestrictine L

Abstract A synthesis of (+)-decarestrictine L 1 , a cholesterol biosynthesis inhibitory metabolite isolated from Penicillium simplicissimum , is described. Beginning from tri- O -acetyl- d -glucal, alkylation with trimethylaluminum introduced the axial methyl group at C-2 in a stereoselective fashion. Chain extension at the C-6 carbon was accomplished by generation of the primary tosylate, followed by displacement with cyanide anion. The synthesis of (+)- 1 was completed in 13 steps and 6.3% overall yield.
Why fight secession? Evidence of economic motivations from the American Civil War

Why fight secession? This paper is a case study on this question, asking why the North chose to fight the South in the American Civil War. It tests a theoretical prediction that economic motivations were important, using county-level presidential election data. If economic interests like manufacturing wished to keep the Union together, they should have generated votes to do so. That prediction is borne out by the data, and explanations other than Northern economic concerns about Southern secession appear unable to explain the results, suggesting that economic motivations were important to support for fighting the South.
Exponential Control of Overlap in the Replica Method for p-Spin Sherrington-Kirkpatrick Model

In Talagrand (J. Stat. Phys. 126(4–5):837–894, 2007) the large deviations limit \(\lim_{N\to\infty}(Na)^{-1}\log \mathbb {E}Z_{N}^{a}\) for the moments of the partition function ZN in the Sherrington-Kirkpatrick model (Sherrington and Kirkpatrick in Phys. Rev. Lett. 35:1792–1796, 1972) was computed for all real a≥0. For a≥1 this result extends the classical physicist’s replica method that corresponds to integer values of a. We give a new proof for a≥1 in the case of the pure p-spin SK model that provides a strong exponential control of the overlap.
Cyclic sieving and cluster multicomplexes

Reiner, Stanton and White (2004) [10] proved results regarding the enumeration of polygon dissections up to rotational symmetry. Eu and Fu (2008) [2] generalized these results to Cartan-Killing types other than A by means of actions of deformed Coxeter elements on cluster complexes of Fomin and Zelevinsky (2003) [6]. The Reiner-Stanton-White and Eu-Fu results were proven using direct counting arguments. We give representation theoretic proofs of closely related results using the notion of noncrossing and seminoncrossing tableaux due to Pylyavskyy (2009) [9] as well as some geometric realizations of finite type cluster algebras due to Fomin and Zelevinsky (2003) [5].
Withanolides from Physalis coztomatl.

Abstract Six withanolides ( 1 – 6 ), as well as two known withanolides (physachenolide D 7 and withanoside VI 8 ), were isolated from the aerial parts of Physalis coztomatl (Solanaceae). Structural elucidations of 1 – 6 were achieved through 2D NMR and other spectroscopic techniques, while the structure of 1 was confirmed by X-ray crystallographic analysis. In addition, the stereochemical orientation of the 17-hydroxy group in withanolides was discussed in relation to 13 C NMR shifts of C-12, 13, 14 and 16. Such analysis established that coagulansin A contains a 17 α -hydroxy moiety rather than the reported 17 β -hydroxy functionality, and has been revised accordingly.
Numerical simulation of the emission and motion of neutral and charged dust from P/Halley

The present numerical model for neutral or charged dust-particle distribution prediction in P/Halley encompasses the spatial and temporal variations of the plasma parameters and magnetic field. A significant difference is noted between results for neutral dust trajectories and the trajectories of charged dust particles with radii smaller than 0.1 micron. While most of the model and in situ mass spectra were in good agreement, there is a shortage of the lowest-mass model particles, as well as an offset of the total counting rate for two outbound mass spectra. A combination of two Lorentzian particle mass-density functions with a 100:1 ratio for the number of particles with the lower and higher density functions yielded the best agreement.
Aid and the Dutch disease: Macroeconomic management when everybody loves you

Abstract Countries that undertake serious and sustained programs of stabilization and structural adjustment should expect to attract significant new inflows of capital from donor countries and international institutions. While apparently beneficial, those flows can work at crosspurpose with other goals of the policy reforms. In particular, abundant foreign exchange loans can force an appreciation of the real exchange rate (often through domestic inflation rather than a nominal appreciation). In addition, since the government is almost always the recipient of these loans, it can crowd out the private sector if it increases its aggregate demand for domestic goods and services. If the crowding out is accomplished by tight monetary policy, it will fall primarily on private investment rather than consumption. This paper shows that both of these problems have surfaced in Ghana, a country that has become a favorite of donors after demonstrating a serious commitment to policies promoted by the World Bank and International Monetary Fund. The paper also suggests modifications in macroeconomic policy that would help lower inflation and boost private investment.
UNIT ROOTS, TREND BREAKS, AND TRANSITORY DYNAMICS: A MACROECONOMIC PERSPECTIVE

It is common to interpret rejections of the unit-root null hypothesis in favor of a trend stationary process with possible trend breaks as evidence that the data are better characterized as stationary about a broken trend. This interpretation is valid only if the model postulated under the alternative hypothesis is the only plausible alternative to the model postulated under the null. We argue that there are economically plausible models that are not well captured under either the null hypothesis or the alternative hypothesis of these tests. We show that applied researchers who ignore this possibility are likely to reject the unit-root null with high probability in favor of a trend stationary process with possible breaks. Our evidence shows that this potential pitfall is both economically relevant and quantitatively important. We explore the extent to which applied users may mitigate inferential errors by using finite-sample and bootstrap critical values.