cssi/SciSciGPT-SciSciNet huggingface dataset:
Scandium(III)-catalyzed enantioselective allylation of isatins using allylsilanes.

The scandium(III)-catalyzed enantioselective Hosomi–Sakurai allylation of isatins with various substituted allylic silanes is described. A catalyst loading as low as 0.05 mol % is utilized at room temperature to afford the 3-allyl-3-hydroxy-2-oxindoles in excellent yields and enantioselectivity up to 99% ee, including a demonstration of a gram-scale reaction. The effects of additives and varying silyl groups were explored to demonstrate the scope and application.
STOCHASTIC GROWTH IN THE UNITED STATES AND EURO AREA

This paper estimates, using data from the United States and the Euro Area, a two-country stochastic growth model in which both neutral and investment-specific technology shocks are nonstationary but cointegrated across economies. The results point to large and persistent swings in productivity, both favorable and adverse, originating in the United States but not transmitted to the Euro Area. More specifically, the results suggest that while the Euro Area missed out on the period of rapid investment-specific technological change enjoyed in the United States during the 1990s, it also escaped the stagnation in neutral technological progress that plagued the United States in the 1970s.
Structural characterization of crystalline inclusion complexes formed from 1,3,5-triaroylbenzene derivatives—a new family of inclusion hosts

A series of crystalline inclusion complexes formed from substituted 1,3,5-triaroylbenzene hosts and small molecule guests has been structurally characterized by X-ray crystallography. The new inclusion hosts examined do not possess functional groups capable of participating in strong non-covalent interactions, thus C–H⋯O hydrogen bonding appears to significantly influence the crystal packing observed in most of the solid state structures. The thermochemical properties of the inclusion complexes were examined using differential scanning calorimetry.
Synthesis of 2-Dodecanoyl-3,5-dihydroxy-2-cyclohexen-1-one

Abstract 2-Dodecanoyl-3,5-dihydroxy-2-cyclohexen-1-one, identified from the setal exudate of immature andromeda lace bug nymphs, Stephanitis takeyai , was synthesized. Key steps involved construction of the cyclohexanedione ring containing a phenyldimethylsilyl substituent as a masked hydroxyl group, protection of the 1,3-dicarbonyl system as an isoxazole, oxidative desilylation, and reductive disassembly of the isoxazole.
Preferred frequencies for coupling of seismic waves and vibrating tall buildings

Abstract We study a model for the so-called “city effect” in which an earthquake can be locally enhanced by the collective response of tall buildings in a large city. We use a set of equations coupling vibrations in buildings to motion under the ground. These equations were previously studied exclusively in the case of a finite set of identical, equally spaced, buildings. These two restrictions are lifted in this paper. We may now simulate geometries involving infinitely many buildings as long as an initial pattern of buildings is repeated. Our new method using periodic domains and periodic Green׳s functions yields much faster computations. This is the main reason why we are now able to study systems of buildings of variable height, mass, and rigidity. We show how solving for the wavenumber in a non-linear equation involving the integral of a function solution to an adequate integral equation, we are able to find resonant frequencies coupling seismic waves and vibrating tall buildings. Interestingly, in the case of non-identical buildings, our simulations indicate that the response to this coupling phenomenon may differ drastically from one building to another.
Optical and magnetic signatures of localized excitations in polyaniline

Using a tight-binding Hamiltonian we study the lattice configurations and electronic structures of three forms of polyaniline: leucoemeraldine base (LEB), emeraldine base (EB) and pernigraniline base (PNB). Both bond length and ring rotation angle are considered in the structure relaxation. The dominant elementary excitations of isolated chains are found to be solitons is PNB and bipolarons in EB and in LEB. Optical absorptions of the ground states and of the solitonic and polaronic excitations are calculated and compared with experiments. The spin density profile of a single neutral soliton in PNB is discussed in connection with magnetic measurements.
A high-capacity aeronautical mobile satellite system

A conceptual system design is described for a satellite-based aeronautical safety communications system capable of serving both general aviation (GA) aircraft and commercial aviation (CA) aircraft in the contiguous US (CONUS) in the mid-1990s. It is shown how the large system capacity that is required can be obtained using a 15-m deployable antenna onboard a high-power commercial communications satellite expected to be available in the mid-1990s. >
Simulation of a standing-wave free electron laser☆

Abstract The standing-wave free electron laser (FEL) differs from a conventional linear-wiggler microwave FEL in using irises along the wiggler to form a series of standing-wave cavities and in reaccelerating the beam between cavities to maintain the average energy. The device has been proposed for use in a two-beam accelerator (TBA) because microwave power can be extracted more effectively than from a traveling-wave FEL. The standing-wave FEL is modeled in the continuum limit by a set of equations describing the coupling of a one-dimensional beam to a TE 01 rectangular-waveguide mode. Analytic calculations and numerical simulations are used to determine the time variation of the reacceleration field and the prebunching required so that the final microwave energy is the same in all cavities. The microwave energy and phase are found to be insensitive to modest spreads in the beam energy and phase and to errors in the reacceleration field and the beam current, but the output phase appears sensitive to beam-energy errors and to timing jitter.
Elastic scattering and direct detection of Kaluza-Klein dark matter

Recently a new dark-matter candidate has been proposed as a consequence of universal compact extra dimensions. It was found that to account for cosmological observations, the masses of the first Kaluza-Klein (KK) modes (and thus the approximate size of the extra dimension) should be in the range 600-1200 GeV when the lightest Kaluza-Klein particle (LKP) corresponds to the hypercharge boson and in the range 1-1.8 TeV when it corresponds to a neutrino. In this paper, we compute the elastic scattering cross sections between KK dark matter and nuclei both when the LKP is a KK mode of a weak gauge boson, and when it is a neutrino. We include nuclear form factor effects which are important to take into account due to the large LKP masses favoured by estimates of the relic density. We present both differential and integrated rates for present and proposed germanium, NaI and xenon detectors. Observable rates at current detectors are typically less than one event per year, but the next generation of detectors can probe a significant fraction of the relevant parameter space.
Non-Isothermal Crystallization of Poly(trimethylene terephthalate) (PTT)/Clay Nanocomposites

The non-isothermal crystallization of intercalated poly(trimethylene terephthalate) (PTT)/clay nanocomposites was investigated quantitatively by different methods. Non-isothermal crystallization of pure PTT can be described by the Ozawa equation, but the Ozawa theory is not valid for PTT/clay nanocomposites. The addition of clay into PTT decreases the crystallization half-time while increasing the crystallinity and crystallization rate. The PTT/modified clay nanocomposites, in turn, have a higher crystallization rate parameter, k l/n , and a lower crystallization half-time compared to unmodified clay/PTT composites. The crystallization activation energy, calculated from Kissinger equation, of PTT, PTT/unmodified clay, and PTT/modilied clay composites are 100, 180, and 198-230 kJ.mol -1 respectively. Similarly, the nucleating activities of the unmodified clay and modified clays are 0.73 and 0.51-0.58, respectively. Although the addition of clay increases the crystallization activation energy, the clay still acts as an effective nucleating agent and increases the crystallization rate are crystallinity of PTT. Further, the modified nanoscale clays rate more effective nucleating agents than the unmodified counterpats, and the most effective nucleating concentration of nano-clay is between 1.0-3.0 wt.-%.
Living to Work and Working to Live: Income as a Driver of Organizational Behavior

AbstractIncome as a relatively stable aspect of a job (e.g. annual salary, non-incentive wages, or weekly or hourly pay) has received relatively little consideration in organizational theorizing and research, despite its critical importance to workers, organizations, and society at large. Income inequality has similarly received scant attention, although it is a topic of great intellectual and practical importance. In this paper we describe the ways in which income and income inequality affect how people behave in both their professional and personal lives, and suggest ways in which organizations may influence, and be influenced by, these effects. We integrate research from a number of disciplines, highlight leading findings across them, and suggest ways in which organizational scholarship can inform research and practice in this domain. Our goal is to facilitate the development of income-related research programs in organizational science.
Improving Silica Fume for Concrete by Surface Treatment

Abstract Surface treatment of silica fume with sulfuric acid prior to incorporation in a cement matrix resulted in composites exhibiting increases in tensile strength by 12%, tensile modulus by 72%, tensile ductility by 57%, abrasion resistance by 20%, loss tangent by 30–80%, flexural storage modulus by 80–120%, and flexural loss modulus by 160–300%, relative to the values obtained by using as-received silica fume.
Recent developments of analysis for hydrodynamic flow of nematic liquid crystals

The study of hydrodynamics of liquid crystals leads to many fascinating mathematical problems, which has prompted various interesting works recently. This article reviews the static Oseen–Frank theory and surveys some recent progress on the existence, regularity, uniqueness and large time asymptotic of the hydrodynamic flow of nematic liquid crystals. We will also propose a few interesting questions for future investigations.
The Conley Conjecture

We prove the Conley conjecture for a closed symplectically aspherical symplectic manifold: a Hamiltonian diffeomorphism of such a manifold has infinitely many periodic points. More precisely, we show that a Hamiltonian diffeomorphism with finitely many fixed points has simple periodic points of arbitrarily large period. This theorem generalizes, for instance, a recent result of Hingston establishing the Conley conjecture for tori.
An Analysis of Factors Related to Receipt of Accommodations and Services by Postsecondary Students With Disabilities

A secondary analysis of the National Longitudinal Transition Study–2 examined the relationship between demographic, disability-related, secondary school preparation, and transition planning variables and receipt of accommodations and other disability-specific services at the postsecondary level for 2,470 postsecondary students with disabilities. The results indicated that secondary students who received transition planning education were more likely to receive accommodations and other disability-specific services in 2-year colleges and that those who had a transition plan that specified postsecondary accommodations and supports as a needed post–high school service were more likely to receive those types of services in 2-year colleges and in career and technical education schools. These findings suggest that secondary schools can influence the likelihood that students will seek out and receive postsecondary accommodations and other disability-specific services.
Supersymmetric deformations of maximally supersymmetric gauge theories

We study supersymmetric and super Poincare invariant deformations of tendimensional super Yang-Mills theory and of its dimensional reductions. We describe all infinitesimal super Poincare invariant deformations of equations of motion of ten-dimensional super Yang-Mills theory and deformations of the reduction to a point. We also discuss how these infinitesimals can be extended to formal deformations. Our methods are based on homological algebra, in particular, on the theory of L-infinity and A-infinity algebras. The exposition of this theory as well as of some basic facts about Lie algebra homology and Hochschild homology is given in appendices.
Noncommutative ampleness for multiple divisors

Abstract The twisted homogeneous coordinate ring is one of the basic constructions of the noncommutative projective geometry of Artin, Van den Bergh, and others. Chan generalized this construction to the multi-homogeneous case, using a concept of right ampleness for a finite collection of invertible sheaves and automorphisms of a projective scheme. From this he derives that certain multi-homogeneous rings, such as tensor products of twisted homogeneous coordinate rings, are right noetherian. We show that right and left ampleness are equivalent and that there is a simple criterion for such ampleness. Thus we find under natural hypotheses that multi-homogeneous coordinate rings are noetherian and have integer GK-dimension.
Determining the Number of Resonance Structures in Concealed Non-Kekuléan Benzenoid Hydrocarbons

The number of resonance structures (SC) for previously published concealed non-Kekulean benzenoid hydrocarbons is determined. Using a simple computer program, analytical expressions for determining SC for various classes of non-Kekulean (free-radical) benzenoid hydrocarbons are derived, and some properties of concealed non-Kekulean benzenoid hydrocarbons are studied.
The dirichlet problem for a complex Monge-Ampère equation

where G' denotes the Jacobian determinant of G. Furthermore, if G4=(0 . . . . . 0), then (d d ~ log h G I) "= 0. Thus, for f = 0, (1) is a natural generalization of the Dirichlet problem for harmonic functions in the complex plane. Other extended Dirichlet problems were studied in connection with function theory in several variables by S. Bergman [2, 3] (on domains with distinguished boundary surfaces) and more generally by H. Bremermann [4]. In Section 8 it is shown that the solution of the problem discussed by Bremermann actually solves (1), in a generalized sense, with f = 0 . The problem (1) seems to be a reasonable candidate for a (nonlinear) potential theory associated with the theory of functions of several complex variables. The question of uniqueness for the problem (1) is related to the question of existence of "inner functions" on the domain O. If h is a bounded analytic function
Wind Tunnel Wall Effects at Extreme Force Coefficients

Wind tunnel wall constraints effects at extreme force coefficients during V/STOL testing shown different from effects in conventional aircraft testing
Novel structures and physics of nanomagnets (invited)

Nanoscale magnets with characteristic dimensions in the range of 1–100 nm are important in several areas of nanoscience and technology. First, this length scale spans the typical important dimensions of exchange lengths and domain-wall widths, which means that significant control of magnetic properties can be obtained by varying grain or particle dimensions. Second, the nonequilibrium synthetic processes used for clusters, particles, and films, often lead to new real-space crystal structures with completely novel spin structures and magnetic properties. Third, a basic-science challenge in this class of matter involves the spin-polarized quantum mechanics of many-electron systems containing 10–10 000 atoms. Finally, the materials under study may have important future applications in high-density data storage, ultra-small spintronic devices, or high-energy magnetic materials. In this article, we discuss our recent work on novel Fe-Au nanoclusters, MnAu-Mn coreshell structures, and complex high-anisotropy Co-rich intermetallic compound clusters. We also present new results on Fe-based alloys including the magnetic properties of semiconducting FeSi2 nanoclusters and spin correlations in FeGe nanocluster films. V C 2015 AIP Publishing LLC.
Octahedral Nickel(II) dithiocarboxylates

Abstract Two nickel(II) complexes, NiL 2 Cl 2 and NiL 2 – (NO 3 ) 2 ·0.3EtOH, with the ligand 1,3-dimethyl- imidazoliumdithiocarboxyalato (L) have been synthesized and characterized by infrared and electronic spectroscopy and magnetic susceptibilities. The complexes exhibit the normal paramagnetism characteristic of octahedral nickel(II). The magnetic moments decrease with falling temperature, indicative of antiferromagnetic coupling, which is greater for the chloride than for the nitrate adduct. Columnar structures with chloro and nitrato bridging are proposed.
Higgs bosons, electroweak symmetry breaking, and the physics of the Large Hadron Collider

The Large Hadron Collider, a 7 {circle_plus} 7 TeV proton-proton collider under construction at CERN (the European Laboratory for Particle Physics in Geneva), will take experiments squarely into a new energy domain where mysteries of the electroweak interaction will be unveiled. What marks the 1-TeV scale as an important target? Why is understanding how the electroweak symmetry is hidden important to our conception of the world around us? What expectations do we have for the agent that hides the electroweak symmetry? Why do particle physicists anticipate a great harvest of discoveries within reach of the LHC?
Tight integrality gaps for Lovasz-Schrijver LP relaxations of vertex cover and max cut

We study linear programming relaxations of Vertex Cover and Max Cutarising from repeated applications of the "lift-and-project" method of Lovasz and Schrijver starting from the standard linear programming relaxation.For Vertex Cover, Arora, Bollobas, Lovasz and Tourlakis prove thatthe integrality gap remains at least 2-e after Ωe(log n) rounds, where n is the number ofvertices, and Tourlakis proves that integrality gap remains at least 1.5-e after Ω((log n)2) rounds. Fernandez de laVega and Kenyon prove that the integrality gap of Max Cut is at most 12 + e after any constant number of rounds. (Theirresult also applies to the more powerful Sherali-Adams method.We prove that the integrality gap of Vertex Cover remains at least 2-e after Ωe (n) rounds, and that theintegrality gap of Max Cut remains at most 1/2 +e after Ωe(n) rounds.
Human Genetics Studies: The Case for Group Rights

In this essay, the author focuses on an underlying theoretical issue which she believes seriously affects our collective response to the idea of group rights in the genetic-control context. That issue is to what extent are our responses to claims of group rights hampered by our bringing to the table (consciously or unconsciously) a model which is structured to acknowledge only individual concerns? Put another way, to what extent are our objections to group rights in this context a product of our inability (or refusal) to imagine the idea of group rights, rather than the product of truly substantive concerns?
Understanding why universal service obligations may be unnecessary: The private development of local Internet access markets

Abstract This study analyzes the geographic spread of commercial Internet Service Providers (ISPs), the leading suppliers of Internet access. The geographic spread of ISPs is a key consideration in US policy for universal access. We examine the Fall of 1998, a time of minimal government subsidy, when inexpensive access was synonymous with a local telephone call to an ISP. Population size and location in a metropolitan statistical area were the single most important determinants of entry, but their effects on national, regional and local firms differed, especially on the margin. The thresholds for entry were remarkably low for local firms. Universal service in less densely-populated areas was largely a function of investment decisions by ISPs with local focus. There was little trace of the early imprint of government subsidies for Internet access at major US universities.
Synthesis of tetrahydropyran derivatives via a novel indium trichloride mediated cross-cyclization between epoxides and homoallyl alcohols

Abstract A cross-cyclization between epoxides and homoallyl alcohols catalyzed by indium chloride generates tetrahydropyran derivatives in high yields.
Facially selective Cu-catalyzed carbozincation of cyclopropenes using arylzinc reagents formed by sequential I/Mg/Zn exchange.

Described is a Cu-catalyzed directed carbozincation of cyclopropenes with organozinc reagents prepared by I/Mg/Zn exchange. This protocol broadens the scope with respect to functional group tolerance and enables use of aryl iodide precursors, rather than purified diorganozinc precursors. Critical to diastereoselectivity of the carbozincation step is the removal of magnesium halide salts after transmetalation with ZnCl2.
Influence of long-term thermal aging on the microstructural evolution of nuclear reactor pressure vessel materials: an atom probe study

Abstract Atom probe field ion microscopy (APFIM) investigations of the microstructure of unaged (as-fabricated) and long-term thermally-aged (~100 000 h at 280°C) surveillance materials from commercial reactor pressure vessel steels were performed. This combination of materials and conditions permitted the investigation of potential thermal aging effects. This microstructural study focused on the quantification of the compositions of the matrix and carbides. The APFIM results indicate that there was no significant microstructural evolution after a long-term thermal exposure in weld, plate and forging materials. The matrix depletion of copper that was observed in weld materials was consistent with the copper concentration in the matrix after the stress relief heat treatment. The composition of cementite carbides aged for 100 000 h were compared to the Thermocalc™ prediction. The APFIM comparisons of materials under these conditions are consistent with the measured change in mechanical properties such as the Charpy transition temperature.
Influence of Channel Curvature on Flow, Pressure Distribution, and Power Requirements of Screw Pumps and Melt Extruders

The influence of channel curvature on flow through screw pumps and melt extruders is derived for infinite channel aspect ratios. Flow rate and horsepower relations for flow of Newtonian liquids are given as functions of design parameters. The results of this cylindrical theory are compared with those of conventional theories. Curvature factors converting the equations of the flat plate theory to those of the cylindrical theory are shown. Pressure distributions in screw pump channel are analyzed.
AN UPPER BOUND TO THE SPACE DENSITY OF INTERSTELLAR COMETS

Two well-studied white dwarfs with helium-dominated atmospheres (DBs) each possess less hydrogen than carried by a single average-mass comet. Plausibly, the wind rates from these stars are low enough that most accreted hydrogen remains with the star. If so, and presuming their nominal effective temperatures, then these DBs have faced minimal impact by interstellar comets during their 50 Myr cooling age; interstellar iceballs with radii between 10 m and 2 km contain less than 1% of all interstellar oxygen. This analysis suggests that most stars do not produce comets at the rate predicted by “optimistic” scenarios for the formation of the Oort Cloud. There are two reasons to imagine that interstellar comets could be widespread. First, they could be an important as-yet undetected reservoir of interstellar oxygen. Second, models for the formation of the solar system’s Oort Cloud predict that more comets are ejected into the interstellar medium than remain gravitationally bound to the Sun. If our solar system is at all typical, then the birth of stars and planets might commonly lead to the creation of many interstellar comets. Despite decades of effort, analysis of the rate of appearance of new comets in the solar system has not provided a strong constraint on the space density of interstellar comets. Substantial progress may require another approach. In this spirit, Shull & Stern (1995) argued that one possible explanation for the “low” observed frequency of gamma ray bursts arising from the Milky Way is that there are few interstellar comets impacting upon neutron stars. However, there are enough uncertainties in this approach that their result that fewer than 4% of stars have Oort Clouds similar to the Sun’s is not completely firm. While also employing degenerate stars as a tool, here, we proceed somewhat differently. We argue that the small amounts of hydrogen accumulated by warm DB white dwarfs significantly limits the rate of iceball impact with these stars and therefore the space density of interstellar comets. Our method requires combining an understanding of the interstellar medium with the physics of external pollution of white dwarfs. We therefore subdivide this
Transient Formation of Super-Explosives under High Pressure for Fast Ignition*

Dense matter, if put under high pressure, can undergo a transformation from an atomic to a molecular configuration, where the electron orbits go into lower energy levels. If the rise in pressure is very sudden, for example by a strong shock wave, the electrons change their orbits rapidly under the emission of photons, which for more than 100 Mbar can reach keV energies. With the opacity of dense matter going in proportion to the density, the photons can be efficiently released from the surface of the compressed matter by a rarefaction wave. The so produced X-ray photons can be used for the fast ignition of a thermonuclear target. The proposed mechanism may be also responsible for the large keV X-ray bursts observed in exploding wire arrays, which can not be explained by conversion of kinetic into thermal energy.
The Use of an Artificial Diffusion Term to Improve a Distributed-Parameter Model of a Flat-Plate Solar Collector

Etude comparative de deux modeles de la distribution de temperature dans un collecteur solaire a plaque plane: le 1er tient compte de la temperature de la plaque pour determiner la temperature du fluide; le 2eme, modifie par l'addition d'un terme de diffusion artificielle, n'utilise pas la temperature de la plaque
Bioinformatics: A New Field in Engineering Education

Bioinformatics is a new engineering field poorly served by traditional curricula. Bioinformatics concerns the use of computer and statistical methods to understand biological data, such as the voluminous data produced by high-throughput biological experimentation. As the demand has outpaced the supply of bioinformaticians, the University of California, Santa Cruz, School of Engineering is establishing undergraduate and graduate degrees in bioinformatics. In this paper we explore the blend of mathematics, engineering, science, and bioinformatics topics and courses needed for an undergraduate degree in this new field.
Sequential Cycloaddition Approach to the Tricyclic Core of Vibsanin E. Total Synthesis of (±)-5-epi-10-epi-Vibsanin E

A direct access to (±)-5-epi-10-epi-vibsanin E is described, based on three key cycloaddition steps, a rhodium-catalyzed [4 + 3] cycloaddition, a heteronuclear [4 + 2] cycloaddition, and a photochemically induced [4 + 2] cycloaddition.
Foreign Policy Decision Making in Familiar and Unfamiliar Settings: An Experimental Study of High-Ranking Military Officers

The concept of policy makers’ familiarity with a decision task has received considerable attention in recent years in the literature on decision making by analogy, intuitive decision making, and dynamic versus static decision making. The effect of familiarity on the decision strategy change of high-ranking officers of the U.S. Air Force is tested to see whether and how familiar versus unfamiliar decision tasks affect decision strategy change during the decision-making process. Results support the noncompensatory principle of political decision making and poliheuristic theory: Leaders are sensitive to negative political advice, which is often noncompensatory. They first use dimensions to eliminate noncompensatory alternatives and then evaluate acceptable alternatives. This two-stage process is even more pronounced in unfamiliar decision settings with low or high levels of ambiguity—a situation that characterizes many foreign policy crises.
Majorana fermions, exact mapping between quantum impurity fixed points with four bulk fermion species, and solution of the “unitarity puzzle”

Abstract Several quantum impurity problems with four flavors of bulk fermions have zero temperature fixed points that exhibit non-Fermi liquid behavior. These include the two-channel Kondo effect, the two-impurity Kondo model, and the fixed point occurring in the four-flavor Callan-Rubakov effect. We re-interpret the exact conformal field theory (CFT) solution of these fixed points using abelian bosonization, with an extremely simple linear boundary condition on the free bosonic fields. We recover all results of the CFT solution, such as e.g. correlation functions, thermodynamics, partition functions, boundary states, etc. In particular, for the two-channel Kondo fixed point, we derive the single-particle Green function and the square-root singularity of the resistivity using the abelian bosonized formulation. We provide a unified description for all three fixed points, by exploiting the SO (8) symmetry of the four species of bulk fermions. This leads to an exact mapping between correlation functions of the different models. Furthermore, we show that the two-impurity Kondo fixed point and the Callan-Rubakov fixed point are identical theories. All these models have the puzzling property that the S -matrix for scattering of fermions off the impurity seems to be non-unitary. We resolve this paradox by showing that the conduction electrons scatter into (non-local) collective soliton-like excitations, which transform in the spinor representation of the SO (8) Lie algebra; the effect of the quantum impurity can be represented as the ‘triality’ operation of SO (8).
Giant Optical Nonlocality near the Dirac Point in Metal-Dielectric Multilayer Metamaterials

The giant optical nonlocality near the Dirac point in lossless metal-dielectric multilayer metamaterials is revealed and fully investigated through the band structure analysis of the multilayer stack, iso-frequency contour analysis, and numerical simulation.
Asymptotic behavior of Ext functors for modules of finite complete intersection dimension

Let R be a local ring, and let M and N be finitely generated R-modules such that M has finite complete intersection dimension. In this paper we define and study, under certain conditions, a pairing using the modules \({{\rm {Ext}}_R^i(M,N)}\) which generalizes Buchweitz’s notion of the Herbrand difference. We exploit this pairing to examine the number of consecutive vanishing of \({{\rm {Ext}}_R^i(M,N)}\) needed to ensure that \({{\rm {Ext}}_R^i(M,N)=0}\) for all \({i\gg 0}\) . Our results recover and improve on most of the known bounds in the literature, especially when R has dimension at most two.
Non-abelian tensor-multiplet anomalies

We use the anomaly cancellation of the M-theory fivebrane to derive the R-symmetry anomalies of the AN (0,2) tensor-multiplet theories. This result leads to a simple derivation of black hole entropy in d = 4, = 2 compactifications of M-theory. We also show how the formalism of normal bundle anomaly cancellation clarifies the Kaluza-Klein origin of Chern-Simons terms in gauged supergravity theories. The results imply the existence of interesting 1/N corrections in the AdS/CFT correspondence.
Experiments to evaluate behavior of containment piping bellows under severe accident conditions

Bellows are an integral part of the containment pressure boundary in nuclear power plants. They are used at piping penetrations to allow relative movement between piping and the containment wall. In a severe accident they may be subjected to high pressure and temperature and a combination of axial and lateral deflections. A test program to determine the leak-tight capacity of containment penetration bellows is being conducted at Sandia National Laboratories, Albuquerque, NM. Several different bellows geometries representative of actual containment bellows are being subjected to extreme deflections along with pressure and temperature loads. The bellows geometries and loading conditions are described along with the testing apparatus and procedures. A total of 13 tests have been conducted. The tests showed that bellows are capable of withstanding relatively large deformations up to or near the point of full compression before developing leakage. The test data are presented and discussed.
Proton-Proton Near-Forward Hard Elastic Scattering

Abstract We calculate the leading twist contribution to near-forward proton-proton (and proton-anti-proton) elastic scattering with large momentum transfer, in the multiple scattering (Landshoff) mechanism. The near-forward amplitude in this perturbative approach is dominated by singlet exchange for all three valence quark-quark scatterings. We assume the existence of a hard singlet quark-quark amplitude, which we estimate to be O( α s 2 / t ). For a three-quark state whose transverse size is less than 1/ Λ QCD , Sudakov resummation accounts for both approximate d σ pp /d t ∼ t −8 at moderate t , and d σ pp /d t ∼ t −10 at larger t . The transition from approximate t −8 to t −10 behavior is strongly correlated with the transverse size of the valence three-quark state in the proton.
A Pseudomonas aeruginosa Toxin that Hijacks the Host Ubiquitin Proteolytic System

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen chronically infecting the lungs of patients with chronic obstructive pulmonary disease (COPD), pneumonia, cystic fibrosis (CF), and bronchiectasis. Cif (PA2934), a bacterial toxin secreted in outer membrane vesicles (OMV) by P. aeruginosa, reduces CFTR-mediated chloride secretion by human airway epithelial cells, a key driving force for mucociliary clearance. The aim of this study was to investigate the mechanism whereby Cif reduces CFTR-mediated chloride secretion. Cif redirected endocytosed CFTR from recycling endosomes to lysosomes by stabilizing an inhibitory effect of G3BP1 on the deubiquitinating enzyme (DUB), USP10, thereby reducing USP10-mediated deubiquitination of CFTR and increasing the degradation of CFTR in lysosomes. This is the first example of a bacterial toxin that regulates the activity of a host DUB. These data suggest that the ability of P. aeruginosa to chronically infect the lungs of patients with COPD, pneumonia, CF, and bronchiectasis is due in part to the secretion of OMV containing Cif, which inhibits CFTR-mediated chloride secretion and thereby reduces the mucociliary clearance of pathogens.
The postsunset vertical plasma drift and its effects on the generation of equatorial plasma bubbles observed by the C/NOFS satellite

The prereversal enhancement (PRE) of the vertical plasma drift in the postsunset sector is an important factor that controls the generation of equatorial plasma bubbles. In this study, we use the measurements of the ion velocity meter on board the Communication/Navigation Outage Forecasting System satellite during 2008–2014 to identify the PRE and its effects on the occurrence of plasma bubbles. The seasonal and longitudinal distributions of the PRE are derived at different solar flux levels. Large PRE occurs at 240–360° longitudes in equinoctial months and December solstice, and small or downward PRE occurs around ±60° in June solstice. The seasonal and longitudinal distributions of large-amplitude equatorial spread F (ESF) (ΔN > 5 × 1010 m−3) are similar to that of the PRE, while the occurrence probability of ESF including smaller-amplitude perturbations (ΔN > 1 × 1010 m−3) can be quite high at any longitude in any season. A quantitative relationship between the PRE and the ESF occurrence probability is derived and well characterized by the cumulative distribution function of a continuous probability distribution. Such a distribution implies that the occurrence of ESF is a probability event. The ESF occurrence probability is small when the PRE is zero or downward and becomes larger than 80% when the PRE is greater than 40 m s−1. Both the ESF occurrence probability and the amplitude increase with the solar radio flux.
Theory of computation of multidimensional entropy with an application to the monomer--dimer problem

Consider all colorings of a finite box in a multidimensional grid with a given number of colors subject to given local constraints. We outline the most recent theory for the computation of the exponential growth rate of the number of such colorings as a function of the dimensions of the box. As an application we compute the monomer-dimer constant for the 2-dimensional grid to 9 decimal digits, agreeing with the heuristic computations of Baxter, and for the 3-dimensional grid with an error smaller than 1.35%.
The 2D Euler–Boussinesq Equations in Planar Polygonal Domains with Yudovich’s Type Data

We address the well-posedness of the 2D (Euler)–Boussinesq equations with zero viscosity and positive diffusivity in the polygonal-like domains with Yudovich’s type data, which gives a positive answer to part of the questions raised in Lai (Arch Ration Mech Anal 199(3):739–760, 2011). Our analysis on the the polygonal-like domains essentially relies on the recent elliptic regularity results for such domains proved in Bardos et al. (J Math Anal Appl 407(1):69–89, 2013) and Di Plinio (SIAM J Math Anal 47(1):159–178, 2015).
A Facile Synthesis of 6-Alkyl-6, 7-dihydro-5H-dibenz[c,e]azepines: Potent Hypolipidemics

Abstract 6-Alkyl-6, 7-dihydro-5H-dibenz[c,e]azepines were synthesized in two steps in 63–88% overall yield by utilizing an efficient borane-tetrahydrofuran reduction of imides.
Highly enantioselective and recyclable organocatalytic Michael addition of malonates to α,β-unsaturated aldehydes in aqueous media.

A new type of pyrrolidine-based organocatalyst, which was developed earlier in our lab, has been found to be very effective for the Michael addition reaction in aqueous solvents involving a wide range of α,β-unsaturated aldehydes and malonate derivatives. For the reactions studied, good to excellent yields (73%–96%) and high to excellent enantioselectivities (up to 97%) were obtained using this catalyst. In addition, the catalyst could be recycled up to four times with gradual reductions in yields and enantioselectivity observed after the second cycle.
The international evidence on discouraged small businesses

Abstract We use a unique firm-level survey database compiled by the World Bank to examine the drivers of discouraged small businesses in various developing economies around the world. We confirm that older and larger firms are less likely to be discouraged and that the level of competition and the relationships of the firms with banks have a significant impact on the probability of a firm in being discouraged. Further analysis suggests that the drivers of borrower discouragement might work differently for firms operating in relatively developed versus underdeveloped economies.
X-ray variability of AGN and correlations with spectral properties

Abstract Rapid flux changes in the X-ray emission from active galactic nuclei are commonly observed. The power-density spectra show a pseudo power-law form with a turnover at low frequencies and a high frequency break, similar to galactic black-hole candidates. There have been a few claims for periodicities but these are not a well-established property of the class. The amplitude of variability depends on a number of source parameters, including luminosity and spectral properties. The variability amplitude is correlated with X-ray spectral index, and anti-correlated with the width of the permitted optical lines. In one particularly well-observed case, NGC 7469, we see a relationship between the X-ray and UV variability, which indicates that the dominant emission process for the X-rays is thermal Comptonization. Variations in the X-ray emission are related to changes in the UV seed photons, but it appears there must also be a mechanism - perhaps that which heats the Comptonizing corona - that induces rapid variability intrinsic to the X-rays.
On the Formation and Evolution of Common Envelope Systems

We discuss the formation of a common envelope system following dynamically unstable mass transfer in a close binary and the subsequent dynamical evolution and final fate of the envelope. We base our discussion on new three-dimensional hydrodynamic calculations that we have performed for a close binary system containing a 4 M☉ red giant with a 0.7 M☉ main-sequence star companion. The initial parameters are chosen to model the formation of a system resembling V471 Tau, a typical progenitor of a cataclysmic variable binary. The calculations are performed using the smoothed particle hydrodynamics (SPH) method with up to 5 × 104 particles. As initial condition we use an exact hydrostatic equilibrium configuration at the onset of dynamically unstable mass transfer. The nonlinear development of the instability is followed using SPH until a quasi-static common envelope configuration is formed. In our highest resolution calculation, we find evidence for a corotating region of gas around the central binary. This is in agreement with the theoretical model proposed by Meyer & Meyer-Hofmeister for the evolution of common envelope systems, in which this central corotating region is coupled to the envelope through viscous angular momentum transport only. We also find evidence that the envelope is convectively unstable, in which case the viscous dissipation time could be as short as ~100 dynamical times, leading to rapid ejection of the envelope. For V471 Tau our results, and the observed parameters of the system, are entirely consistent with rapid envelope ejection on a timescale ~1 yr and an efficiency parameter αCE 1.
The BBN manifesto

Abstract In this manifesto I review the current status of standard big bang nucleosynthesis in light of recent observational data and discuss the importance of near-future observations as direct tests of the standard BBN.
The WALRAS Algorithm: A Convergent Distributed Implementation of General Equilibrium Outcomes

The WALRAS algorithm calculates competitive equilibria via a distributed tatonnement-like process, in which agents submit single-good demand functions to market-clearing auctions. The algorithm is asynchronous and decentralized with respect to both agents and markets, making it suitable for distributed implementation. We present a formal description of this algorithm, and prove that it converges under the standard assumption of gross substitutability. We relate our results to the literature on general equilibrium stability and some more recent work on decentralized algorithms. We present some experimental results as well, particularly for cases where the assumptions required to guarantee convergence do not hold. Finally, we consider some extensions and generalizations to the WALRAS algorithm.
Dynamic Store Release of Ice Models from a Cavity into Mach 2.9 Flow

An investigation was conducted into store separation from a cavity in a Mach 2.94 freestream using both experimental and computational methods. Both approaches used an open cavity with a length-to-depth ratio of 4.5, and for the sake of simplicity, release of a spherical model was analyzed. The experimental process used a piezoresistive pressure transducer to collect the time-varying content of the pressure signal, while schlieren visualization and high-speed photography capture the dynamic response of a store released from the cavity. Computationally, the OVERFLOW solver was applied with higher-order numerical methods, Chimera grids, and the delayed detached-eddy simulation/shear-stress transport hybrid turbulence model. Tests were performed in a blowdown tunnel exhausting to a vacuum, which enabled robust control of the total pressure, and computational conditions were selected to match the experiment. The studies demonstrated that the shock wave formed on the bottom surface of the sphere led to the los...
Preliminary Study of the Effects of a Reversible Chemical Reaction on Gas Bubble Dissolution

A preliminary investigation of the effects of a reversible chemical reaction upon the dissolution of an isolated, stationary gas bubble in a glassmelt is presented. The exact governing equations, for the model system, are formulated and discussed. The approximate quasi-steady state version of these equations are solved analytically and bubble dissolution rates are computed. These results are compared with numerical solutions obtained from the finite difference form of the exact governing equations.
Uniqueness of equilibrium in sealed high-bid auctions ✩

Abstract For the case of two buyers we show that equilibrium in the sealed high-bid auction is unique when (i) buyers' reservations prices are drawn independently from distributions with finite support and positive mass at the lower endpoint; (ii) buyers have private values; and (iii) buyers' preferences are log supermodular. For more than two buyers, we obtain the same result under the additional assumptions that (iv) buyers with the same reservation price have the same preferences; (v) buyers are risk neutral or risk averse with non-increasing absolute risk aversion; and (vi) the supports of the different buyers' distributions of reservation prices have the same upper endpoint.
Data secrecy in distributed storage systems under exact repair

The problem of securing data against eavesdropping in distributed storage systems is studied. The focus is on systems that use linear codes and implement exact repair to recover from node failures. The maximum file size that can be stored securely is determined for systems in which all the available nodes help in repair (i.e., repair degree d = n -1, where n is the total number of nodes) and for any number of compromised nodes. Similar results in the literature are restricted to the case of at most two compromised nodes. Moreover, new explicit upper bounds are given on the maximum secure file size for systems with d <; n - 1. The key ingredients for the contribution of this paper are new results on subspace intersection for the data downloaded during repair. The new bounds imply the interesting fact that the maximum amount of data that can be stored securely decreases exponentially with the number of compromised nodes. Whether this exponential decrease is fundamental or is a consequence of the exactness and linearity constraints remains an open question.
A comment on the role of prices for excludable public goods

Blomquist and Christensen [(2005). The role of prices for excludable public goods, International Tax and Public Finance, 12 ,61–79] argue that welfare is initially decreasing in the price of an excludable public good and that the case for a positive price for an excludable public good price is weak. We argue that this result follows from their particular characterization of the public good and that an alternative and equally reasonable characterization overturns their result. Hence, the policy case for a positive price on the public good is stronger than Blomquist and Christiansen suggest.
[TeSe3]2- and [TeSe2]2- as synthons.

The [Au2(TeSe2)2]2− anion has been prepared from the reaction of [TeSe3]2− with AuCN in DMF in the presence of PEt3 and from the reaction of [TeSe2]2− with AuCN in DMF. Reaction of [TeSe2]2− with AuCN in DMF in the presence of PEt3 leads ultimately to the [Au2(Te2)2]2− anion.