cssi/SciSciGPT-SciSciNet huggingface dataset:
Stability of a Peer-to-Peer Communication System

This paper focuses on the stationary portion of file download in an unstructured peer-to-peer network, which typically follows for many hours after a flash crowd initiation. The model includes the case that peers can have some pieces at the time of arrival. The contribution of this paper is to identify how much help is needed from the seeds, either fixed seeds or peer seeds (which are peers remaining in the system after obtaining a complete collection), to stabilize the system. The dominant cause for instability is the missing piece syndrome, whereby one piece becomes very rare in the network. It is shown that stability can be achieved with only a small amount of help from peer seeds-even with very little help from a fixed seed, peers need dwell as peer seeds on average only long enough to upload one additional piece. The region of stability is insensitive to the piece selection policy. Network coding can substantially increase the region of stability in case a portion of the new peers arrive with randomly coded pieces.
Path Integral Formulation of Stochastic Optimal Control with Generalized Costs

Abstract Path integral control solves a class of stochastic optimal control problems with a Monte Carlo (MC) method for an associated Hamilton-Jacobi-Bellman (HJB) equation. The MC approach avoids the need for a global grid of the domain of the HJB equation and, therefore, path integral control is in principle applicable to control problems of moderate to large dimension. The class of problems path integral control can solve, however, is defined by requirements on the cost function, the noise covariance matrix and the control input matrix. We relax the requirements on the cost function by introducing a new state that represents an augmented running cost. In our new formulation the cost function can contain stochastic integral terms and linear control costs, which are important in applications in engineering, economics and finance. We find an efficient numerical implementation of our grid-free MC approach and demonstrate its performance and usefulness in examples from hierarchical electric load management. The dimension of one of our examples is large enough to make classical grid-based HJB solvers impractical.
Solution Processing of Chalcogenide Semiconductors via Dimensional Reduction

The quest to develop thin-film solution processing approaches that offer low-cost and preferably low-temperature deposition, while simultaneously providing quality semiconductor characteristics, has become an important thrust within the materials community. While inorganic compounds offer the potential for outstanding electronic properties relative to organic systems, the very nature of these materials rendering them good electronic materials—namely strong covalent bonding—also leads to poor solubility. This review presents a “dimensional reduction” approach to improving the solubility of metal chalcogenide semiconductors, which generally involves breaking the extended framework up into discrete metal chalcogenide anions separated by small and volatile cationic species. The resulting soluble precursor may be solution-processed into thin-film form and thermally decomposed to yield the desired semiconductor. Several applications of this principle to the solution deposition of high-performance active layers for transistors (channel mobility >10 cm2 V−1 s−1), solar cells (power conversion efficiency of as high as 12%), and fundamental materials study will be presented using hydrazine as the deposition solvent.
ELIMINATION THEORY FOR TROPICAL VARIETIES

Tropical algebraic geometry offers new tools for elimination theory and implicitization. We determine the tropicalization of the image of a subvariety of an algebraic torus under any homomorphism from that torus to another torus.
Monochromatic imaging instrumentation for applications in aeronomy of the earth and planets

Monochromatic imaging instrumentation has been developed that uses narrow-band [12-A full width at half maximum (FWHP)] interference filters or plane reflection gratings for 2-D imaging and imaging spectrograph applications. By changing the optics in front of the filter or grating, the field of view of the instruments can be varied from 180 deg (all sky) to 6 deg (narrow field). In the case of the 2-D monochromatic imager, the 12-mm-diam. filtered image is formed at ~f/1 on the input photocathode of an intensified CCD camera (380 x 488 pixels). Regardless of the field of view of the instrument, none of the rays passing through the filter exceeds 4.5 deg to the filter normal. In the spectrograph mode, a slit is placed on the field lens (at the focus of the objective lens) and the 4-in. interference filter is replaced with a reflection grating. The spectrum is imaged at f/1 onto the previously described detector with the spatial dimension of 380 pixels and the wavelength dimension of 488 pixels. The sensitivities of the systems are approximately 50 to 100 rayleigh seconds (Rs) (SNR~2). Examples of data taken with both of these instruments include detection and mapping of Jupiter's sodium magnetonebula and stable auroral red (SAR) arcs in the terrestrial ionosphere.
Real-time resilient focusing through a bending multimode fiber

Multimode optical fibers are attractive for biomedical and sensing applications because they possess a small cross section and can bend over small radii of curvature. However, mode phase-velocity dispersion and random mode coupling change with bending, temperature, and other perturbations, producing scrambling interference among propagating modes; hence preventing its use for focusing or imaging. To tackle this problem we introduce a system capable of re-focusing light through a multimode fiber in 37ms, one order of magnitude faster than demonstrated in previous reports. As a result, the focus spot can be maintained during significant bending of the fiber, opening numerous opportunities for endoscopic imaging and energy delivery applications. We measure the transmission matrix of the fiber by projecting binary-amplitude computer generated holograms using a digital micro-mirror device controlled by a field programmable gate array. The system shows two orders of magnitude enhancements of the focus spot relative to the background.
Testing AdS/CFT drag and pQCD heavy quark energy loss

We present charm and bottom nuclear modification factors for RHIC and LHC using standard model perturbative QCD and recent AdS/CFT string drag energy loss models. We find that extreme extrapolations to LHC mask potential experimentally determinable differences in the individual RAAs but that their ratio, RcAA/RbAA, as a function of transverse momentum is a remarkably robust observable for finding deviations from either theoretical framework.
Tree-ring analysis and Quaternary geology : Principles and recent applications

Abstract Variations in annual growth rings can be utilized to assign precise calendar dates to the study of Quaternary geologic or geomorphic events such as earthquakes, mass movements, glaciations and flooding. Living trees may provide the necessary absolute dates of events or minimum ages for surfaces. Crossdating among living trees and with subfossil wood can identify missing rings and extend tree-ring chronologies further back in time. These methods can lead to the accurate dating of tree rings in both living and dead trees that may have been affected by a geomorphic process. The dating of partial to complete ring growth, compression and release, as well as dating externally apparent responses, such as tree scarring or root sprouting, can often lead to the identification of the season and the year an event occurred. Ring-width patterns when compared with control chronologies can reveal the growth anomalies in witness trees that may be related to geomorphic events. Examples of the application of tree rings to Quaternary geology and geomorphology are varied and numerous. Root shearing, topping of trees, and missing rings tie a rupture along the San Andreas fault to the year 1812 A.D. Narrow tree rings linked to defoliation and tephra fallout differentiated distinct eruptions of Mt. St. Helens in 1480 and in 1482 A.D. Ring analysis has helped unravel glacial chronologies, and tree-ring linkages with climate have also verified that late Holocene ice advances in Argentina correlated with intervals of cool, wet summers. In another application, an 1818 A.D. Quebec landslide has been tied to the growing season, whereas slides dated to 1834 and 1846 A.D. occurred during the spring.
Operation of an Annular Helicon Plasma Source

The plasma parameters of a nominally 1.5 kW annular helicon plasma source are measured and its feasibility as an ionization stage of a two-stage Hall thruster is investigated. All experiments are performed in a 4 by 7 m stainless steel vacuum chamber at pressures below 3.1 x 10 ―5 torr for argon and 5.6 x 10 ―5 torr for xenon. Ion number density, electron temperature, and electron energy distribution function measurements are taken at several axial and radial locations inside the device at each operating condition with a ratio-frequency-compensated Langmuir probe. The annular helicon plasma source is characterized over a range of applied radio frequencies (2―14 MHz), magnetic field strengths (0―400 G), and radio frequency forward-power settings (100―1400 W) for both argon and xenon propellants. The peak ion number density measured in the annular helicon is 2.6 x 10 17 m ―3 for argon and 2.4 x 10 17 m ―3 for xenon at 1000 W of radio frequency power. The annular helicon electron energy distribution function peak and shape vary with the radio frequency, from a minimum of 3.7 eV at 13 MHz to a maximum of 15.0 eV at 11 MHz for argon propellant over the preceding operating conditions.
Acres: Adaptive Coordinate Real-Space Electronic Structure

A real space approach to electronic structure calculations has several important advantages. A regular real-space mesh produces a sparse, local, and highly structured Hamiltonian, which enables effective use of iterative numerical methods and parallel computer architectures. However, a regular real space mesh has equal resolution everywhere, while actual physical systems are inhomogeneous. To remedy this inherent inefficiency without losing the advantages of a regular mesh, we carry out computations on a regular mesh in curvilinear space. There are several choices involved in the implementation of the method. These include the choice of the coordinate transform, the form of the discretized Laplacian, the regularization of the ionic potential for all-electron calculations, and the method of calculating the forces. Of particular interest is the use of error analysis to optimize the grid for a given physical system. The adaptive grid is versatile enough to describe accurately a very wide class of systems, including ones with highly inhomogeneous electronic distributions. We report all-electron calculations for atoms and molecules with 1s and 2p valence electrons, and pseudopotential calculations for molecules and solids.
Energy and angular momentum dependence of complete fusion cross sections

A model for the calculation of the cross section for complete fusion in heavy ion reactions is suggested. The model does not explicitly depend on the sharp cutoff approximation. On the contrary, it allows for a gradual transition between compound and direct process when the bombarding energy is sufficiently high above the Coulomb barrier. The energy below which the reaction cross section is exhausted by compound processes is also estimated. Comparison with experimental results supports the validity of the model.NUCLEAR REACTIONS Phenomenological model for complete fusion cross section in heavy ion reactions.
Building Confidential and Efficient Query Services in the Cloud with RASP Data Perturbation

With the wide deployment of public cloud computing infrastructures, using clouds to host data query services has become an appealing solution for the advantages on scalability and cost-saving. However, some data might be sensitive that the data owner does not want to move to the cloud unless the data confidentiality and query privacy are guaranteed. On the other hand, a secured query service should still provide efficient query processing and significantly reduce the in-house workload to fully realize the benefits of cloud computing. We propose the random space perturbation (RASP) data perturbation method to provide secure and efficient range query and kNN query services for protected data in the cloud. The RASP data perturbation method combines order preserving encryption, dimensionality expansion, random noise injection, and random projection, to provide strong resilience to attacks on the perturbed data and queries. It also preserves multidimensional ranges, which allows existing indexing techniques to be applied to speedup range query processing. The kNN-R algorithm is designed to work with the RASP range query algorithm to process the kNN queries. We have carefully analyzed the attacks on data and queries under a precisely defined threat model and realistic security assumptions. Extensive experiments have been conducted to show the advantages of this approach on efficiency and security.
The thermodynamic description of phase transitions

The historical fact of the ability of a system to avoid showing a phase transition when taken along a suitable thermodynamic path is examined and a way offered of looking at the 'critical point' problem in keeping with various prevailing viewpoints. The semi-phenomenological view is given, followed by exact results, perturbation expansions, a description of equilibrium phenomena and illustrations which involve the Riemann surface but omit the property of
NEOWISE Studies of Asteroids with Sloan Photometry: Preliminary Results

We have combined the NEOWISE and Sloan Digital Sky Survey data to study the albedos of 24,353 asteroids with candidate taxonomic classifications derived using Sloan photometry. We find a wide range of moderate to high albedos for candidate S-type asteroids that are analogous to the S complex defined by previous spectrophotometrically based taxonomic systems. The candidate C-type asteroids, while generally very dark, have a tail of higher albedos that overlaps the S types. The albedo distribution for asteroids with a photometrically derived Q classification is extremely similar to those of the S types. Asteroids with similar colors to (4) Vesta have higher albedos than the S types, and most have orbital elements similar to known Vesta family members. Finally, we show that the relative reflectance at 3.4 and 4.6 μm is higher for D-type asteroids and suggest that their red visible and near-infrared spectral slope extends out to these wavelengths. Understanding the relationship between size, albedo, and taxonomic classification is complicated by the fact that the objects with classifications were selected from the visible/near-infrared Sloan Moving Object Catalog, which is biased against fainter asteroids, including those with lower albedos.
Supersonic Flow Past Conical Bodies with Nearly Circular Cross Sections

Abstract : Inviscid, supersonic conical flows past bodies whose cross-section deviates slightly from that of a right circular cone are studied by means of a perturbation technique. The effects of small angles of attack and yaw are included. Using the hypersonic small disturbances theory approximations, we have developed explicity results for the flow field velocity components, pressure, entropy, and shock shape for cases n, m = 1, 2, 3, 4. Comparisons of theory with experiment for n = 1, 2 are favorable. The streamsurfaces of the velocity field are calculated and possible waverider geometries that can be developed therefrom are discussed.
Three-dimensional flux states as a model for the pseudogap phase of transition metal oxides

We propose that the pseudogap state observed in the transition metal oxides can be explained by a three-dimensional flux state, which exhibits spontaneously generated currents in its ground state due to electron-electron correlations. We compare the energy of the flux state to other classes of mean field states, and find that it is stabilized over a wide range of t and $\ensuremath{\delta}.$ The signature of the state will be peaks in the neutron diffraction spectra, the location and intensity of which are presented. The dependence of the pseudogap in the optical conductivity is calculated based on the parameters in the model.
A new record for 1324-avoiding permutations

We prove that the class of $$1324$$ -avoiding permutations has exponential growth rate at most $$13.74$$ .
Transition radiation as a practical X-ray source

Abstract Transition radiation is generated when an energetic electron crosses the boundary between two different media. Theoretical calculations predict soft X-ray spectra and angular distributions that agree with experimental results. Further, recent advances in microstructure technology create the possibility of designing transition radiation sources for several practical applications. For example, calculations indicate that a stack of 60 1-μm thick beryllium foils exposed to a beam of 100 MeV electrons will produce about 120 J of 1–2 keV X-rays per coulomb of incident charge. The highest intensity sources appear to be bright enough for application to microlithography.
Dynamics of Quasiconformal Fields

A uniqueness theorem is established for autonomous systems of ODEs, ˙ x = f (x) ,w heref is a Sobolev vector field with additional geometric structure, such as delta-monotonicity or reduced quasiconformality. Specifically, through every non-critical point of f there passes a unique integral curve.
Numerical Investigation of the Curvature Effects on Diffusion Flames

∗+ & Tubular diffusion flames are compared with opposed jet diffusion flames numerically to show the effect of curvature on diffusion flames. The numerical results show that, as in premixed flames, positive curvature strengthens the preferential diffusion and negative curvature weakens the preferential diffusion; the strengthening or weakening effect is proportional to the ratio of flame thickness to flame radius. Since the flame temperature is related to the preferential diffusion, flame curvature affects flame temperature and extinction stretch rate. Since the flame thickness is related to pressure, the curvature effects also depend on pressure. H2/N2–air and CH4/N2–air diffusion flames with different flame radii and pressures are presented to verify the analysis.
A Signaling Theory of Unemployment

Abstract This paper presents a signaling explanation for unemployment. Employment at an unskilled job may be regarded as a bad signal. Therefore good workers who are more likely to qualify for employment at a skilled job in the future may be better off being unemployed than accepting an unskilled job. We present conditions under which all equilibria satisfying the Cho-Kreps intuitive criterion involve unemployment. However, there always exist balanced-budget wage tax and subsidy schedules that eliminate unemployment and increase the expected incomes of all workers. Moreover, unemployment can be eliminated with tax schedules that do not raise any revenue, and that place very weak informational demands on policy makers; however these tax schedules do not always increase the expected income of every worker.
Shape-changing magnetic assemblies as high-sensitivity NMR-readable nanoprobes

Fluorescent and plasmonic labels and sensors have revolutionized molecular biology, helping visualize cellular and biomolecular processes. Increasingly, such probes are now being designed to respond to wavelengths in the near-infrared region, where reduced tissue autofluorescence and photon attenuation enable subsurface in vivo sensing. But even in the near-infrared region, optical resolution and sensitivity decrease rapidly with increasing depth. Here we present a sensor design that obviates the need for optical addressability by operating in the nuclear magnetic resonance (NMR) radio-frequency spectrum, where signal attenuation and distortion by tissue and biological media are negligible, where background interferences vanish, and where sensors can be spatially located using standard magnetic resonance imaging (MRI) equipment. The radio-frequency-addressable sensor assemblies presented here comprise pairs of magnetic disks spaced by swellable hydrogel material; they reversibly reconfigure in rapid response to chosen stimuli, to give geometry-dependent, dynamic NMR spectral signatures. The sensors can be made from biocompatible materials, are themselves detectable down to low concentrations, and offer potential responsive NMR spectral shifts that are close to a million times greater than those of traditional magnetic resonance spectroscopies. Inherent adaptability should allow such shape-changing systems to measure numerous different environmental and physiological indicators, thus providing broadly generalizable, MRI-compatible, radio-frequency analogues to optically based probes for use in basic chemical, biological, medical and engineering research.
REVIEW OF X-RAY SPECTROSCOPY FROM LASER-PRODUCED PLASMAS

Recent progress in x-ray spectroscopy from laser plasmas is reviewed. Advances in the use of K-shell spectra as a diagnostic tool is discussed. Much activity in understanding complex spectra especially from Ne I and Ni I isoelectronic series have been made. Much of the progress has been due to observation of amplification from ..delta..n = O transitions from these configurations. The spectroscopy will be discussed and examples of spectra of the amplified lines will be shown. Finally, recent work on using x-ray spectroscopy to diagnose high density implosions will be discussed. 33 refs.
Mode locking in quantum-Hall-effect point contacts.

We study the effect of an ac drive on the current-voltage (I-V) characteristics of a tunnel junction between two fractional quantum Hall fluids at filling ${\ensuremath{\nu}}^{\mathrm{\ensuremath{-}}1}$ an odd integer. Within the chiral Luttinger-liquid model of edge states, the point-contact dynamics is described by a driven damped quantum mechanical pendulum. In a semiclassical limit which ignores electron tunneling, this model exhibits mode locking, which corresponds to current plateaus in the I-V curve at integer multiples of I=e\ensuremath{\omega}/2\ensuremath{\pi}, with \ensuremath{\omega} the ac drive angular frequency. By analyzing the full quantum model at nonzero \ensuremath{\nu} using perturbative and exact methods, we study the effect of quantum fluctuation on the mode-locked plateaus. For \ensuremath{\nu}=1, quantum fluctuations smear completely the plateaus, leaving no trace of the ac drive. For \ensuremath{\nu}\ensuremath{\geqslant}1/2 smeared plateaus remain in the I-V curve, but are not centered at the currents I=ne\ensuremath{\omega}/2\ensuremath{\pi}. For \ensuremath{\nu}1/2 rounded plateaus centered around the quantized current values are found. The possibility of using mode locking in fractional quantum-Hall-effect point contacts as a current-to-frequency standard is discussed. \textcopyright{} 1996 The American Physical Society.
Pitymys meadensis Hibbard from the Valley of Mexico and the classification of North American species of Pitymys (Rodentia: Cricetidae)

ABSTRACT The microtine mouse Pitymys meadensis Hibbard, a species indicative of the late Irvingtonian mammal age in the United States, is present in a fauna of Rancholabrean age in the Valley of Mexico at El Tajo de Tequixquiac. It is closely related to the living Pitymys quasiater of Sierra Madre Oriental. Following the reasoning of Van der Meulen, the species group of Pitymys pinetorum is recognized as a distinct North American lineage and the North American species P. meadensis (fossil), P. quasiater, and P. nemoralis are considered more closely related to Old World species of Pitymys, some of which have been placed in the genus Neodon. Pitymys and its immediate ancestor Allophaiomys are known from Europe and Asia in early Irvingtonian time. Allophaiomys also dispersed southward from Beringia into North America in early Irvingtonian time, where the pinetorum species group developed from it in late Irvingtonian time. The pinetorum species group seems always to have been restricted to the dry steppes of ...
Analytical model of adoption of item level RFID in a two-echelon supply chain with shelf-space and price-dependent demand

We investigate whether it is possible for the manufacturer as well as the retailer to derive economic benefits from item-level RFID. We consider two supply chain contracts. In the first instance the manufacturer sets the wholesale price for his product and in response the retailer sets the retail price and allocates the shelf-space. We find that in this setting item-level RFID is adopted in a decentralized supply chain at the same levels of RFID costs as in an integrated supply chain with a single decision maker. The second case that we consider involves a powerful retailer setting product shelf-space prices. In this setting the manufacturer essentially rents shelf-space from the retailer. We find that in this setting, the retailer may force the adoption of RFID even if it does not maximize the chain's total profit.
The origins and early development of the psychological contract construct

The relationship between employees and their employers has been conceptualized as involving a “psychological contract” (PC). The PC construct is assumed by many to have a key role to play in understanding organizational behavior, and there has been a proliferation of writing regarding PCs in recent years. The history of the construct, however, has remained under‐reported, and largely undiscussed. This articles seeks to contribute to the evolution of the PC construct by providing a richer, more thorough historical perspective than can be presently found in the PC literature. The origins and early development of the PC construct are traced through a review of books, articles, and unpublished dissertations. Observations regarding historical developments are linked to the current state of the literature, and the implication of these observations for the future direction of the PC literature is briefly discussed.
Guidelines for infection control in intravenous therapy

Abstract Infusion-associated septicemia is an appreciable hazard to the more than 8 million patients who receive intravenous therapy in U.S. hospitals each year. Rigorous infection control measures...
A Survey of Perspectives on Intergovernmental Relations: A Comparative Analysis of the Czech and Slovak Republics

The transition from Marxist-Leninist socialism to market-oriented democracy has been difficult for most of the countries of East and Central Europe. Many observers view that process as consisting largely of the privatization of state-owned enterprises and the establishment of market relations in the countries involved. But the transition of the public sector in countries once managed by central planning regimes has also been a very important and difficult part of that historic development. The public sector under central planning was highly centralized so that the party could maintain a tight monopoly over all levels of the country’s decision-making powers. Thus, democratization has required a process of fiscal decentralization to restore some autonomy to local government.
Open membranes in matrix theory

Abstract We discuss how to construct open membranes in the recently proposed matrix model of M theory. In order to sustain an open membrane, two boundary terms are needed in the construction. These boundary terms are available in the system of the longitudinal five-branes and D0-branes.
Complexity of Gene Expression Evolution after Duplication: Protein Dosage Rebalancing

Ongoing debates about functional importance of gene duplications have been recently intensified by a heated discussion of the “ortholog conjecture” (OC). Under the OC, which is central to functional annotation of genomes, orthologous genes are functionally more similar than paralogous genes at the same level of sequence divergence. However, a recent study challenged the OC by reporting a greater functional similarity, in terms of gene ontology (GO) annotations and expression profiles, among within-species paralogs compared to orthologs. These findings were taken to indicate that functional similarity of homologous genes is primarily determined by the cellular context of the genes, rather than evolutionary history. Subsequent studies suggested that the OC appears to be generally valid when applied to mammalian evolution but the complete picture of evolution of gene expression also has to incorporate lineage-specific aspects of paralogy. The observed complexity of gene expression evolution after duplication can be explained through selection for gene dosage effect combined with the duplication-degeneration-complementation model. This paper discusses expression divergence of recent duplications occurring before functional divergence of proteins encoded by duplicate genes.
Modification of photochemical reactivity by zeolites: Cation enhanced α-cleavage of aryl alkyl ketones included in faujasites

Abstract The yield of Norrish type I products are significantly enhanced when aryl alkyl ketones are photolyzed in the cages of faujasite type zeolites. Exchangeable cations present within the supercages are suggested to be responsible for such an enhanced α-cleavage.
Bellows Vibration With Internal Cryogenic Fluid Flows

Flow induced vibrations of metal bellows with internal cryogenic fluid flow, noting effects of heat transfer, liquid state properties, external damping and condensation
A Plasma Prism Model for an Anomalous Dispersion Event in the Crab Pulsar

In 1997 October, daily monitoring observations of the Crab pulsar at 327 MHz and 610 MHz with an 85 ft telescope in Green Bank, WV, showed a jump in the dispersion measure by 0.1 cm-3 pc. Pulses were seen simultaneously at both old and new dispersions over the course of several days. During the dispersion jump, the pulsed flux diminished by an order of magnitude. In the months before this event, the average pulse profiles contained faint "ghost" pulse components offset in phase from the regular main pulse and interpulse components by a nearly frequency-independent time delay that quadratically diminished to zero over a month. After the dispersion event, there was an order of magnitude increase in the level of scattering, as measured by pulse broadening at 327 MHz. There was also a curious shift in the rotational phase, a slowing down, at both frequencies at the time of the dispersion jump, which we associate with intrinsic timing noise. All of the observed phenomena except this slowing down can be explained by the variable perturbing optics of a triangular plasma prism located in the filamentary interface between the synchrotron nebula and the supernova ejecta which crosses the line of sight over a period of months. The required density, scale length, and velocity are reasonable given previous observations and analysis of these filaments. Our study thus provides a probe of the plasma column on scales of 30 μas to 3 mas (1012-14 cm), which complements scales accessible to optical emission line studies with HST resolution (1016-18 cm). In combination, both observations provide a detailed look at a sample of the interface region that can be matched statistically to the results of numerical simulations.
Continuous distributions of D3-branes and gauged supergravity

States on the Coulomb branch ofN = 4 super-Yang-Mills theory are studied from the point of view of gauged supergravity in ve dimensions. These supersymmetric solutions provide examples of consistent truncation from type-IIB supergravity in ten dimensions. A mass gap for states created by local operators and perfect screening for external quarks arise in the supergravity approximation. Weoeraninterpretationofthesesurprising featuresintermsofensembles ofbrane distributions.
Magnetography of Solar Flaring Loops with Microwave Imaging Spectropolarimetry

We have developed a general framework for modeling gyrosynchrotron and free–free emission from solar flaring loops and used it to test the premise that 2D maps of source parameters, particularly the magnetic field, can be deduced from spatially resolved microwave spectropolarimetry data. We show quantitative results for a flaring loop with a realistic magnetic geometry, derived from a magnetic-field extrapolation, and containing an electron distribution with typical thermal and nonthermal parameters, after folding through the instrumental profile of a realistic interferometric array. We compare the parameters generated from forward-fitting a homogeneous source model to each line of sight through the folded image data cube both with the original parameters used in the model and with parameters generated from forward-fitting a homogeneous source model to the original (unfolded) image data cube. We find excellent agreement in general, but with systematic effects that can be understood as due to the finite resolution in the folded images and the variation of parameters along the line of sight, which are ignored in the homogeneous source model. We discuss the use of such 2D parameter maps within a larger framework of 3D modeling, and the prospects for applying these methods to data from a new generation of multifrequency radio arrays now or soon to be available.
The metallic microstructures and thermal histories of severely reheated chondrites

Abstract The metallographic structures of eight severely reheated chondrites (Farmington, Ramsdorf, Orvinio, Wickenburg, Lubbock, Rose City, Arapahoe and Tadjera) have been studied by optical, scanning electron microscope and electron microprobe techniques. Unreheated chondrites and experimentally heat treated chondritic material have also been examined. The following metallographic characteristics can be used to estimate the post-shock residual temperature of reheated chondrites: melted appearance of metal-troilite, presence of martensite, P enrichment of the metal, and the averaging of central metal grain compositions. Metallographic characteristics used to estimate the cooling rates of the severely reheated chondrites are the Ni content of troilite, the Ni gradients in metal grain rims, and the presence of secondary kamacite and phosphides. Farmington, Ramsdorf, Orvinio, Lubbock, Rose City and several of the heat treatment specimens have substantial P in solution in the metal grains ( > 0.1 wt%). P enrichment is apparently caused by reduction of phosphates upon severe reheating and partial melting of metal-troilite areas in chondritic meteorites. The eight severely reheated chondrites studied showed evidence of reheating to temperatures ranging from ∼ 950°C to ∼ 1250°C. Ramsdorf has the highest reheating temperature (1200–1250°C) and the fastest cooling rate ∼ 100°C/day. Wickenberg has the lowest reheating temperature (950–1000°C) and the slowest cooling rate, ∼ 1°C/100yrs. Cooling rate estimates correspond to post-reheating burial depths of less than 1 to ∼ 1000m.
Classification of Sleep Disorders

The classification of sleep disorders is necessary to discriminate between disorders and to facilitate an understanding of symptoms, etiology, and pathophysiology that allows for appropriate treatment. The earliest classification systems, largely organized according to major symptoms (insomnia, excessive sleepiness, and abnormal events that occur during sleep), were unable to be based on pathophysiology because the cause of most sleep disorders was unknown. These 3 symptom-based categories are easily understood by physicians and are therefore useful for developing a differential diagnosis. The International Classification of Sleep Disorders, version 2, published in 2005 and currently undergoing revision, combines a symptomatic presentation (e.g., insomnia) with 1 organized in part on pathophysiology (e.g., circadian rhythms) and in part on body systems (e.g., breathing disorders). This organization of sleep disorders is necessary because of the varied nature and because the pathophysiology for many of the disorders is still unknown. The International Classification of Sleep Disorders, version 2 provides relevant diagnostic and epidemiological information on sleep disorders to more easily differentiate between the disorders.
Penicillamine and wound healing in young guinea pigs

Abstract 1. 1. Young guinea pigs given penicillamine by mouth in a milk powder diet showed impaired wound healing as manifested by decreased breaking strength of 14- and 21-day wounds; added cysteine did not reverse these findings. 2. 2. Histopathological and biochemical studies showed no quantitative impairment of reparative collagen synthesis; thus, some type of qualitative change is postulated. 3. 3. A possible clinical implication of these findings for surgical patients on high-dosage penicillin therapy was presented.
Palladium-Catalyzed α-Arylation of 2-Chloroacetates and 2-Chloroacetamides

A method has been developed for the Pd-catalyzed synthesis of α-(hetero)aryl esters and amides through a Suzuki–Miyaura cross-coupling reaction. This method avoids the use of strong base, does not necessitate inert or low temperature formation of reagents, and does not require the use of a large excess of organometallic reagent. Utilization of organotrifluoroborate salts as nucleophilic partners allows a variety of functional groups and heterocyclic compounds to be tolerated.
ALKALI-METAL, RANKINE-CYCLE POWER SYSTEMS FOR ELECTRIC PROPULSION.

Electric propulsion for space exploration, discussing testing results on Rankine cycle power system
Structure and vibrational spectra of ammonium hydrazinium sulfate

Abstract The crystal structure of ammonium hydrazinium sulfate, (NH4)2N2H6(SO4)2, is reported for the first time. This compound crystallizes in a unimolecular unit cell in the triclinic space group P 1 with a = 5.600, b = 5.595, c = 8.608 A, α = 72.47, β = 74.13 and γ = 66.14°. Hydrogen bonding is noted between the sulfate ion and both the ammonium and hydrazinium ions. The room temperature Raman and infrared spectra have been measured. Band assignments of internal and external optic modes are proposed, aided by comparison with spectra of the parent compounds, ammonium sulfate and hydrazinium sulfate. A differential scanning calorimetry measurement indicates phase transitions at 56 and 125°C.
Use of concept mapping in an undergraduate introductory exercise physiology course

Physiology is often considered a challenging course for students. It is up to teachers to structure courses and create learning opportunities that will increase the chance of student success. In an...
A 600 V AC Voltage Amplifier for Power Measurements

A voltage amplifier composed of three cascaded −10:1 gain sections has been developed to extend the voltage range of primary electric power calibrations from 120 to 600 V over the 50–400-Hz frequency range. The gain and phase errors of each amplifier section are continuously measured and corrected in situ using a permuting impedance measurement technique. The amplifier design approach, measurement principles, and initial performance results are presented.
Jet veto clustering logarithms beyond leading order

Many experimental analyses separate events into exclusive jet bins, using a jet algorithm to cluster the final state and then veto on jets. Jet clustering induces logarithmic dependence on the jet radius R in the cross section for exclusive jet bins, a dependence that is poorly controlled due to the non-global nature of the clustering. At jet radii of experimental interest, the leading order (LO) clustering effects are numerically significant, but the higher order effects are currently unknown. We rectify this situation by calculating the most important part of the next-to-leading order (NLO) clustering logarithms of R for any 0-jet process, which enter as $ \mathcal{O}\left( {\alpha_s^3} \right) $ corrections to the cross section. The calculation blends subtraction methods for NLO calculations with factorization properties of QCD and soft-collinear effective theory (SCET). We compare the size of the known LO and new NLO clustering logarithms and find that the impact of the NLO terms on the 0-jet cross section in Higgs production is small. This brings clustering effects under better control and may be used to improve uncertainty estimates on cross sections with a jet veto.
Magnetic-Field-Induced Triple-Layer to Bilayer Transition

Magnetotransport measurements on a triple-layer electron system in a triple quantum well reveal a surprising transition to a bilayer system at high magnetic fields. This transition occurs in the extreme quantum limit, and is signaled by the appearance of strong fractional quantum Hall liquid states which are clearly characteristic of a bilayer system. We attribute the transition to a charge transfer from the center layer to the side layers, and argue that the associated Hartree (capacitive) energy cost is compensated by the correlation energy gained in forming two incompressible fractional quantum Hall liquid states in the side layers.
The Growing Responsibility of Entomology To Human Welfare

This historic meeting, the first annual meeting of the new Entomological Society of America, is a happy occasion. The wishes of the majority of our fellow workers have brought together, through consolidation, our two great organizations of the past, the American Association of Economic Entomologists (1889–1952) and the Entomological Society of America (1906–1952), into a single new Society whose interests- and work will cover all phases of entomology. I think it is fitting that such union take place as we enter the second century of professional entomology in this country. In the years that have passed, entomology, under the leadership of the men who founded and promoted our two beloved professional societies, has made its fair share of contributions to our national welfare. As we enter the second half of the twentieth century, with its present great struggle between two strong ideologies for the allegiance of the hearts and minds of men everywhere, we in entomology can share the satisfaction that our greatest contributions to man' s well-being lie in the years ahead. The full realization of this great service rests in a large measure with the members of the Entomological Society of America. I earnestly hope that our dedication to duty will make the profession and our Society truly great partners cooperating with other sciences in serving the welfare of mankind everywhere.
Finding Nature’s Missing Ternary Oxide Compounds Using Machine Learning and Density Functional Theory

Finding new compounds and their crystal structures is an essential step to new materials discoveries. We demonstrate how this search can be accelerated using a combination of machine learning techniques and high-throughput ab initio computations. Using a probabilistic model built on an experimental crystal structure database, novel compositions that are most likely to form a compound, and their most-probable crystal structures, are identified and tested for stability by ab initio computations. We performed such a large-scale search for new ternary oxides, discovering 209 new compounds with a limited computational budget. A list of these predicted compounds is provided, and we discuss the chemistries in which high discovery rates can be expected.
Diffuse X-Ray Emission in a Deep Chandra Image of the Galactic Center

We examine the spectrum of diffuse emission detected in the 17' ? 17' field around Sgr A* during 625 ks of Chandra observations. The spectrum exhibits He-like and H-like lines from Si, S, Ar, Ca, and Fe that are consistent with an origin in a two-temperature plasma, as well as a prominent low-ionization Fe K? line. The cooler, kT ? 0.8 keV plasma differs in surface brightness across the image in the range (0.2-1.8) ? 10-13 ergs cm-2 s-1 arcmin-2 (observed, 2-8 keV). This soft plasma is probably heated by supernovae, along with a small contribution from the winds of massive Wolf-Rayet (W-R) and O stars. The radiative cooling rate of the soft plasma within the inner 20 pc of the Galaxy could be balanced by 1% of the kinetic energy of one supernova every 3 ? 105 yr. The hotter, kT ? 8 keV component is more spatially uniform, with a surface brightness of (1.5-2.6) ? 10-13 ergs cm-2 s-1 arcmin-2 (observed, 2-8 keV). The intensity of the hard plasma is correlated with that of the soft, but they are probably only indirectly related, because neither supernova remnants nor W-R/O stars are observed to produce thermal plasma hotter than kT ? 3 keV. Moreover, a kT ? 8 keV plasma would be too hot to be bound to the Galactic center and therefore would form a slow wind or fountain of plasma. The energy required to sustain such a freely expanding plasma within the inner 20 pc of the Galaxy is ~1040 ergs s-1. This corresponds to the entire kinetic energy of one supernova every 3000 yr, which is unreasonably high. However, alternative explanations for the kT ? 8 keV diffuse emission are equally unsatisfying. The hard X-rays are unlikely to result from undetected point sources, because no known population of stellar objects is numerous enough to account for the observed surface brightness. Neither is there evidence that nonthermal mechanisms for producing the hard emission are operating, as the expected shifts in the line energies and ratios from their collisional-equilibrium values are not observed. We are left to conclude either that there is a significant shortcoming in our understanding of the mechanisms that heat the interstellar medium or that a population of faint (<1031 ergs s-1) hard X-ray sources that is a factor of 10 more numerous than cataclysmic variables remains to be discovered.
Changing the Size of a Futures Contract: Liquidity and Microstructure Effects

We analyze the relation between contract size and liquidity using data from the respecification of Sydney Future Exchange's (SFE) Share Price Index (SPI) and 90-day Bank Accepted Bill (BAB) futures contracts. Respecification of SPI and BAB contracts presents a unique opportunity to investigate the effects of a change in futures contract size. SFE decreased the size of SPI futures by a factor of four while increasing its minimum tick. The BAB contract was doubled in size with the minimum tick size left unchanged. We find, after controlling for market factors, that the respecification of the SPI futures resulted in higher trading volume, while that of BAB futures decreased trading volume. The results regarding spreads are ambiguous. Based on two cases investigated, we conclude that decreasing the futures contract size was effective in terms of enhancing liquidity while increasing the size resulted in a reduction in liquidity.
National Transonic Facility Model and Tunnel Vibrations

Since coming online in 1984, the National Transonic Facility (NTF) cryogenic wind tunnel at the NASA Langley Research Center has provided unique high Reynolds number testing capability. While turbulence levels in the tunnel, expressed in terms of percent dynamic pressure, are typical of other transonic wind tunnels, the significantly increased load levels utilized to achieve flight Reynolds numbers, in conjunction with the unique structural design requirements for cryogenic operation, have brought forward the issue of model and model support structure vibrations. This paper reports new experimental measurements documenting aerodynamic and structural dynamics processes involved in such vibrations experienced in the NTF. In particular, evidence of local un-steady airloads developed about the model support strut is shown and related to well documented acoustic features known as "Parker" modes. Two-dimensional unsteady viscous computations illustrate this model support structure loading mechanism.