cssi/SciSciGPT-SciSciNet huggingface dataset:
Bounding the Mass of the Graviton Using Eccentric Binaries

We describe a method by which gravitational wave observations of eccentric binary systems could be used to test general relativity's prediction that gravitational waves are dispersionless. We present our results in terms of the graviton having a nonzero rest mass, or equivalently a noninfinite Compton wavelength. We make a rough estimate of the bounds that might be obtained following gravitational wave detections by the Laser Interferometer Space Antenna. The bounds we find are comparable to those obtainable from a method proposed by C. M. Will and several orders of magnitude stronger than other dynamic (i.e., gravitational wave-based) tests that have been proposed. The method described here has the advantage over those proposed previously of being simple to apply, as it does not require the in-spiral to be in the strong field regime nor correlation with electromagnetic signals. We compare our results with those obtained from static (i.e., non-gravitational wave-based) tests.
Requirements for a rapid access data file

General-purpose business-dataprocessing machines now on the market are limited in their performance mostly by the electronic file systems associated with them. The only file medium that has proved itself acceptable from the standpoint of both cost and speed is magnetic tape. In the quest for better, i.e., faster, cheaper, etc., general-purpose machines, a "random access" file has been held out as perhaps the key to the next step of progress. "Random access," however, is a misleading term if it is used to describe what an ideal file should be, rather than adopted. The considerations which, taken together, point to the requirements for a rapid access data file in a general-purpose data processor will be presented here.
Experimental Determination of Transition Reynolds Number for Unsteady Film Cooling

In order to investigate the unsteady effect on transition in film cooling, an 11-m long Ludwieg Tube, consisting of a test section placed between the high pressure and low pressure sections of a shock tube, has been constructed. With this device, a controlled unsteady, low subsonic flow lasting for a period of several milliseconds is obtained. The transition Reynolds Number is determined from the output of thin film heat flux transducers having a response time of a fraction of a microsecond. The results indicate that, in the case of flow without gas injection into the boundary layer, the transition Reynolds Number is one order of magnitude smaller than the critical Reynolds Number for steady wedge flow with the same pressure gradient. With injection, the transition Reynolds Number is small near the injection slot; far downstream, it increases asymptotically to the value for flow without injection.Copyright © 1981 by ASME
Gait deviations and compensations in adolescents with coxa antetorta

s / Gait & Posture 39S (2014) S1–S141 S7 legs, dependent on affected side, and three trials of participants were considered. Linear MixedModels were used to determine the main effects within retained principal components (PCs). Results: PatientsmeanAntetorsionwas38.6◦(SD6.1◦), basedon CT-scans. There were no significant group differences in sex, age, BMI and walking speed, but patients showed significant less hip external rotation in clinical examination. Group effects based on LinearMixedModels revealed that patientswalkedwith significant more internal foot progression angle (FPA) andmore external ankle rotation (ARA) than controls. There were no alterations observed in knee kinematics. Patients walked with significant more anterior pelvic tilt (SPA) and at hip joint level with more internally rotated (THA) and flexed (SHA) hips. Group effects in kinetics revealed that patients showed a significant lower knee adductionmoment (FKM) andhip adductionmoment (FHM).Differentiation into primary and secondary passive effects was derived from clinical considerations. Discussion and conclusions: Deviations in FPA and THA were stated as primary deviations. Due to the reduced hip external rotation patientswere not able to counterbalance for primary deviations. Passive secondary effects were detected in ARA, SHA, SPA, FKM and FHM. In order to achieve normal gait, patients walked with external ankle rotation, flexed hips and more anterior pelvic tilt. During gait internal hip rotation induced anterior pelvic tilt andmore hip flexion by straining iliofemoral ligaments. Moreover, anterior pelvic tilt may have wide-ranging consequences as it may induce increased lordosis of the lumbar spine and extension of the thoracic spine. Although in the current study FKM mean gait waveform indicated a tendency for an increased knee adduction moment in patients, the application of Linear Mixed Models on PC-scores of retained PCs showed a significant group effect in PC3 (explaining 16.74% of total variance), representing a lower knee adduction moment in patients. In hip the only significant group effect corresponded to a lower hip adduction moment in patients (PC2, explaining 15.32% of total variance), whereas mean gait waveform indicated a higher hip adduction moment. In summary coxa antetorta is not mainly a cosmetic problem in general. Modifications in kinematics and kinetics may cause physical complaints and osteoarthritis in future. Therefore, conducting 3DGA is recommended for individual clinical decision-making and planning surgical corrections in patients with coxa antetorta.
Bose Condensation in Spin-Polarized Atomic Hydrogen

A phenomenological description of spin-polarized hydrogen is proposed in terms of two Bose fields which correspond in the low-density limit to the two lowest atomic hyperfine states. Experiments should initially populate both states and the equilibration time of the relative population will be long. When Bose condensation occurs in both states, a spontaneous coherent magnetization perpendicular to the stabilizing field will appear that may be observable in a magnetic resonance experiment.
Interaction with constraints in 3D modeling

The purpose of our research is to simplify and improve the effectiveness of the interactive definition of geometric objects in computer aided geometric modeling. To achieve this goal, two ways of defining geometric objects are combined and interfaced 1) the definition of objects by graphical interaction and 2) the specification of objects by geometric constraints. To demonstrate the practicability of the proposed approach, a geometric modeling system was implemented. In this system, interactive modeling operations automatically generate constraints to maintain the properties intended by their invocatio~ and constraints, in turn, determine the degrees of freedom for further int eractive mouse-controlled modeling operations. A symbolic geometric constraint solver is employed for solvings ystems of constraints. Group hierarchies are utilized for representing dependencies and for locfllzing systems of constraints.
Studying reionization with Lyα emitters

We show that observations of high-redshift Lyα emitters (LAEs) have the potential to provide definitive evidence for reionization in the near future. Using 200-Mpc radiative transfer simulations, we calculate the effect that patchy reionization has on the line profile, on the luminosity function, and, most interestingly, on the clustering of emitters for several realistic models of reionization. Reionization increases the measured clustering of emitters, and we show that this enhancement would be essentially impossible to attribute to anything other than reionization. Our results motivate looking for the signature of reionization in existing LAE data. We find that for stellar reionization scenarios the angular correlation function of the 58 LAEs in the Subaru Deep Field 2 = 6.6 photometric sample is more consistent with a fully ionized universe (mean volume ionized fraction x i ≈ 1) than a universe with x i 2σ confidence level. Measurements in the next year on Subaru will increase their z = 6.6 LAE sample by a factor of 5 and tighten these limits. If the clustering signature of reionization is detected in an LAE survey, a comparison with a Lyman-break or an Ha survey in the same field would confirm the reionization hypothesis. We discuss the optimal LAE survey specifications for detecting reionization, with reference to upcoming programmes.
Instrumental and contingent saccharin-licking in rats: Response deprivation and reinforcement

Instrumental licking of .4% saccharin solution was increased by the contingent opportunity to lick a less-preferred saccharin solution when the contingency schedule deprived the subject of the contingent response, but not otherwise. Schedules that imposed comparable amounts of response deprivation produced comparable increases in instrumental responding. The results support the hypothesis that instrumental responding will increase if and only if the contingency schedule deprives the subject of the contingent response. They also support the implication that the predicted increase will occur even if the contingent response has a lower operant level than the instrumental response.
Hydration of the upper troposphere by tropical cyclones

[1] Tropical cyclones in the Atlantic and Pacific ocean basins are found to have a significant impact on the amount of water vapor in the tropical and subtropical upper troposphere. Measurements from AIRS on Aqua and MLS on Aura are used to reveal details of the water vapor and temperature structure of the upper troposphere in the vicinity of tropical cyclones that have been unavailable from previous satellite observations. These measurements show that the most intense tropical cyclones (categories 4 and 5) increase average water vapor mixing ratios between 300 and 150 hPa in a roughly 1500 km2 area around the cyclones by 10–50% over their lifetimes. Category 3 and weaker tropical cyclones hydrate the upper troposphere on average roughly half as effectively as the most intense cyclones. The most intense cyclones also increase average water vapor in the upper troposphere by 2–10% in the entire ocean basin in which they occur. This amount of hydration of the tropical upper troposphere suggests that tropical cyclones play a role in the water vapor budget, and associated climate feedbacks, in a region much larger than the cyclone vicinity.
Reduced Form Auctions Revisited

This note uses the Theorem of the Alternative to prove new results on the implementability of general, asymmetric auctions, and to provide simpler proofs of known results for symmetric auctions. The tradeoff is that type spaces are taken to be finite.
Enol silyl ethers via copper(II)-catalyzed C-O bond formation.

Copper(II) acetate catalyzes the coupling of pinacol vinylboronates with silanols producing enol silyl ethers. This represents a novel enol silyl ether synthesis via formation of the C–O bond inste...
System integration of pattern recognition, adaptive aided, upper limb prostheses

Abstract An integrated externally energized artificial arm which combines computer control techniques and sensory feedback is presented. The arm, which is intended for above elbow amputees, contains the functions of prehension, wrist rotation, elbow flexion and extension and humeral rotation. The paper outlines the nature of control problems in artificial limbs and reviews techniques for their solutions. A detailed description of the system involving myoelectric pattern control, adaptive computer aiding and electrocutaneous feedback is included with a discussion of the integration and interfaces of these factors.
A refined model for spinning dust radiation

We present a comprehensive treatment of the spectrum of electric dipole emission from spinning dust grains, updating the commonly used model of Draine & Lazarian. Grain angular velocity distributions are computed using the Fokker–Planck equation; we revisit the drift and diffusion coefficients for the major torques on the grain, including collisions, grain-plasma interactions and infrared emission. We use updated grain optical properties and size distributions. The theoretical formalism is implemented in the companion code, spdust, which is publicly available. The effect of some environmental and grain parameters on the emissivity is shown and analysed.
Sustained positive consumption in a model of stochastic growth: The role of risk aversion

Abstract In a stochastic economy, long run consumption and output may not be bounded away from zero even when productivity is arbitrarily high near zero and uncertainty is arbitrarily small. In the one-sector stochastic optimal growth model with i.i.d. production shocks, we characterize the nature of preferences that lead to this phenomenon for a stochastic Cobb–Douglas technology. For the general version of the model, we outline sufficient conditions under which the economy expands its capital stock near zero and long run consumption is bounded away from zero with certainty. Our conditions highlight the important role played by risk aversion for small consumption levels.
The synthesis of some alkylbenzocarbazoles

Syntheses de Fischer a partir de phenylhydrazines et de tetrahydro-1,2,3,4 naphtalenones (ou de cyclohexanones); obtention de carbazoles, benzo [a] carbazoles, benzo [c] carbazoles, dibenzo [a,i] carbazoles et dibenzo [c,g] carbazoles
Thermal expansion coefficients of graphite crystals

Abstract Graphite crystal expansions were derived as a function of temperature using the theoretical relationships of Riley; the resultant equations provide reasonable fits to the measured lattice expansion data over the temperature range 300–3000°K
SOME NATURAL VARIATIONS IN THE RELATIVE ABUNDANCE OF COPPER ISOTOPES

Abstract The relative isotopic abundance of copper has been measured in a number of minerals and a few plant materials. Suites of samples from Michigan and the Colorado Plateau have been examined in more detail to determine if local variations due to isotopic exchange or diffusion could be found. The relative isotopic abundance of copper in specimens from several other localities was also determined. The variations noted were small but in some cases were felt to be significant because they were larger than the experimental error (0·1 per cent in the ratio). A total spread of −1 to +8 parts per mil compared to the standard was found in the specimens tested.
Distribution of twisted Kloosterman sums modulo prime powers

In this paper, we study Kloosterman sums twisted by multiplicative characters modulo a prime power. We show, by an elementary calculation, that these sums become equidistributed on the real line with respect to a suitable measure.
Basic Residue at Position 14 is not Required for Fast Assembly and Disassembly Kinetics in Neural Cadherin

In spite of their structural similarities, epithelial (E-) and neural (N-) cadherin are expressed at different types of synapses and differ significantly in their dimerization kinetics. Recent studies proposed a transient intermediate in E-cadherin as the key requirement for rapid disassembly kinetics of the adhesive dimer. This E-cadherin intermediate comprises four intermolecular ionic and H-bonding interactions between adhesive partners. These interactions are not preserved in N-cadherin except for a basic residue at the 14th position, which could stabilize the intermediate through either H-bonding or ionic interactions with the partner protomer. To investigate the origin of the rapid dimerization kinetics of N-cadherin in the presence of calcium, studies reported here systematically test the role of ionic and H-bonding interactions in dimerization kinetics using R14S, R14A, and R14E mutants of N-cadherin. Analytical size-exclusion chromatographic and bead aggregation studies showed two primary results...
Spectral Sensitivity of the Circadian System

Light exposure regulates several circadian functions in normal humans including the sleep-wake cycle. Individuals with Alzheimer’s Disease (AD) often do not have regular patterns of activity and rest, but, rather, experience random periods of sleep and agitation during both day and night. Bright light during the day and darkness at night has been shown to consolidate activity periods during the day and rest periods at night in AD patients. The important characteristics of bright light exposure (quantity, spectrum, distribution, timing and duration) for achieving these results in AD patients is not yet understood. Recent research has shown that moderate (~18 lx at the cornea) blue (~470 nm) light is effective at suppressing melatonin in normal humans. It was hypothesized that blue light applied just before AD patients retire to their beds for the night would have a measurable impact on their behavior. A pilot study was conducted for 30 days in a senior health care facility using four individuals diagnosed with mild to moderate levels of dementia. Four AD patients were exposed to arrays of blue light from light emitting diodes (max wavelength = 470 nm) in two-hour sessions (18:00 to 20:00 hours) for 10 days. As a control, they were exposed to red light (max wavelength = 640 nm) in two-hour sessions for 10 days prior to the blue light exposure. Despite the modest sample size, exposure to blue LEDs has shown to affect sleep quality and median body temperature peak of these AD patients. Median body temperature peak was delayed by approximately 2 hours after exposure to blue LEDs compared to exposure to red LEDs and sleep quality was improved. This pilot study demonstrated that light, especially LEDs, can be an important contribution to helping AD patients regulate their circadian functions.
Videodraw: a video interface for collaborative drawing

This paper describes VideoDraw, a shared drawing tool, and the process by which it is being designed and developed. VideoDraw is a prototype, videobased, tool that provides a shared “virtual sketchbook” among two or more collaborators. It not only allows the collaborators to see each others’ drawings, but also conveys the accompanying hand gestures and the process of creating and using those drawings. Its design stems from studying how people collaborate using shared drawing spaces. Design implications raised by those studies were embodied in a prototype, which was in turn observed in use situations. Continued research studying the use of VideoDraw (in comparison with other collaborative media) will lead to a better understanding of collaborative drawing activity and inform the continued technical development of VideoDraw.
Retribution and the Secondary Aims of Punishment

Punishing criminals involves more than visiting unwelcome experiences the rack, the gallows, confinement, sitting in a corner-upon them. Privations such as these constitute the behavioral substratum, the raw material of punishment. But behaviors such as confinement become the acts that they are, including acts of punishment by confinement, according to the justifying aim(s) which suffuse(s) the behavior. For behaviors such as confinement are ambiguous; limiting another's freedom of movement may be constitutive of a number of different human acts, including quarantine, kidnapping, institutionalization, and imprisonment for crime. Same behavior, different acts. Each of the ends of punishment shapes privations imposed upon criminals into human actions commonly called "punishment."
Self-tuning controllers for nonlinear systems

Abstract Two new self-tuning control (STC) strategies for nonlinear control problems are proposed. These strategies are applicable to a broad class of nonlinear single-input, single-output systems which can include arbitrary nonlinear functions of the output and the old inputs as well as the products of these functions and any power of the most recent input. Simulation results for a stirred-tank chemical reactor demonstrate that the new nonlinear STC strategy provides significant improvement over conventional STCs based on linear models.
Verapamil suppresses atherosclerosis in cholesterol-fed rabbits

The effect of verapamil, a drug that reduces the concentration of intracellular calcium, on atherogenesis was evaluated in rabbits fed a cholesterol-rich diet for 10 weeks. Ten rabbits received oral verapamil, 8 mg/kg daily; eight received the same oral dose and 0.5 mg/kg daily subcutaneously; nine received oral lanthanum, 35 mg/kg daily, and nine were controls. Over the 10 week period, all groups had average serum cholesterol levels greater than 1,500 mg/dl (normal = 90 ± 63 mg/dl). At the end of the experiment, the aortas were removed, opened and stained for lipid with Sudan IV. The extent of atherosclerosis was determined by planimetry. The group receiving oral and parenteral verapamil had significantly less atherosclerosis (25 ± 26% of total intimai area; mean ± standard deviation), as compared with the controls (73 ± 24%). Reduction of atherosclerosis with oral verapamil (51 ± 22%) and lanthanum (59 ± 31) was not statistically significant. Indexes of contractility in isolated right ventricular papillary muscles (developed tension at maximal length [Lmax] and maximal velocity of shortening [Vmax]) were reduced in the group treated with oral and parenteral verapamil, but not in the others. It is concluded that verapamil suppresses the development of atherosclerosis in rabbits fed a cholesterol-rich diet.
The flash hydropyrolysis of lignite and sub-bituminous coals to both liquid and gaseous hydrocarbon products

Abstract Lignite and sub-bituminous coals, ground to minus 100 mesh, have been hydrogenated with preheated hydrogen in a highly instrumented 1-in. I.D. × 8-ft, entrained downflow tubular reactor system designed to be operated at up to 900°C and 4000 p.s.i. The heat-up rate of the coal particles have been calculated to be in the order of 30,000 to 50,000°C/sec. Product yields of 10% BTX were observed when using lignite and 13% when using sub-bituminous coal, based on conversion of carbon contained in the coal, and when operating at 2000 to 2500 p.s.i. and 750° to 775°C. Methane yields in excess of 80% have been observed at 2500 p.s.i. and 875° to 900°C. Coal particle residence times are in the order of 4 to 12 sec and the effect of residence time is studied by the use of product sample taps located along the length of the reactor. Hydrogen to coal feed ratios as low as approximately 0.2 (lb/lb) were studied and methane concentrations as high as 34% in the process stream were obtained. Nitrogen and sulfur balances were made on the coal, char products and both the liquid and gaseous effluents. A reaction scheme and kinetics model have been developed to which the experimental data is applied to calculate rate constants and activation energies. Relative economic evaluations are made using the most recent experimental results assuming an integrated system using flash hydropyrolysis to produce: (a) motor fuel; (b) pipeline gas; and (c) motor fuel and pipeline gas.
BURYING A BINARY: DYNAMICAL MASS LOSS AND A CONTINUOUS OPTICALLY THICK OUTFLOW EXPLAIN THE CANDIDATE STELLAR MERGER V1309 SCORPII

V1309 Sco was proposed to be a stellar merger and a common envelope transient based on the pre-outburst light curve of a contact eclipsing binary with a rapidly decaying orbital period. Using published data, I show that the period decay timescale of V1309 Sco decreased from ~1000 to ~170 yr in 6 yr, which implies a very high value of . I argue that V1309 Sco experienced an onset of dynamical mass loss through the outer Lagrange point, which eventually obscured the binary. The photosphere of the resulting continuous optically thick outflow expands as the mass-loss rate increases, explaining the ~200 day rise to optical maximum. The model yields the mass-loss rate of the binary star as a function of time and fits the observed light curve remarkably well. It is also possible to observationally constrain the properties of the surface layers undergoing the dynamical mass loss. V1309 Sco is thus a prototype of a new class of stellar transients distinguished by a slow rise to optical maximum that are driven by dynamical mass loss from a binary. I discuss the implications of these findings for stellar transients and other suggested common envelope events.
Music, mind, and meaning

Speculating about cognitive aspects of listening to music, this essay discusses: how metric regularity and thematic repetition might involve representation frames and memory structures, how the result of listening might resemble space-models, how phrasing and expression might evoke innate responses and finally, why we like music — or rather, what is the nature of liking itself.
LSI: implications for future design and architecture

We attempt to justify a number of ways in which we believe LSI is most likely to affect systems design and architecture. It is not only the physical componentry of systems that will undergo change, but also our thinking, as an industry, about the goals, methods, uses and people associated with data processing. LSI will enlarge the scope of computer usage, while simultaneously reducing and altering the human effort required to install and use systems.
Reducing Foodborne Disease—What Are the Priorities?

Recent estimates by the US Centers for Disease Control indicate there are approximately 76 million cases of foodborne illness in the United States annually, resulting in 325 000 hospitalizations and 5000 deaths.1 Only an estimated 14 million of the cases are attributed to known pathogens, whereas 62 million illnesses are of unknown etiology. Clearly, the magnitude of foodborne disease in the US is alarming, with approximately one in four of the population suffering a foodborne illness each year. Three pathogens dominate the list of 28 well-known agents of food-associated illnesses, with Norwalk-like viruses, Campylobacter jejuni, and Salmonella each year responsible for 9 200 000, 1 963 000, and 1 342 000 cases, respectively. Although not as common, Escherichia coli O157:H7 (estimated 62 500 foodborne illnesses) and Listeria monocytogenes (estimated 2500 foodborne illnesses) cause severe, often incapacitating, maladies in many who are affected. Hence, although some pathogens may not be frequent agents of disease, their manifestations of illness are so devastating that extraordinary precautions are taken to prevent their contamination of food.
LASER TECHNIQUES FOR SPECTROSCOPY OF CORE-EXCITED ATOMIC LEVELS

We discuss three techniques which allow the use of tunable lasers for high resolution and picosecond time scale spectroscopy of core-excited atomic levels. These are: anti-Stokes absorption spectroscopy, laser induced emission from metastable levels, and laser designation of selected core-excited levels.
Tracial gauge norms on finite von Neumann algebras satisfying the weak Dixmier property

Abstract In this paper we set up a representation theorem for tracial gauge norms on finite von Neumann algebras satisfying the weak Dixmier property in terms of Ky Fan norms. Examples of tracial gauge norms on finite von Neumann algebras satisfying the weak Dixmier property include unitarily invariant norms on finite factors (type II 1 factors and M n ( C ) ) and symmetric gauge norms on L ∞ [ 0 , 1 ] and C n . As the first application, we obtain that the class of unitarily invariant norms on a type II 1 factor coincides with the class of symmetric gauge norms on L ∞ [ 0 , 1 ] and von Neumann's classical result [J. von Neumann, Some matrix-inequalities and metrization of matrix-space, Tomsk. Univ. Rev. 1 (1937) 286–300] on unitarily invariant norms on M n ( C ) . As the second application, Ky Fan's dominance theorem [Ky Fan, Maximum properties and inequalities for the eigenvalues of completely continuous operators, Proc. Natl. Acad. Sci. USA 37 (1951) 760–766] is obtained for finite von Neumann algebras satisfying the weak Dixmier property. As the third application, some classical results in non-commutative L p -theory (e.g., non-commutative Holder's inequality, duality and reflexivity of non-commutative L p -spaces) are obtained for general unitarily invariant norms on finite factors. We also investigate the extreme points of N ( M ) , the convex compact set (in the pointwise weak topology) of normalized unitarily invariant norms (the norm of the identity operator is 1) on a finite factor M . We obtain all extreme points of N ( M 2 ( C ) ) and some extreme points of N ( M n ( C ) ) ( n ⩾ 3 ). For a type II 1 factor M , we prove that if t ( 0 ⩽ t ⩽ 1 ) is a rational number then the Ky Fan tth norm is an extreme point of N ( M ) .
Components of Pore Water Pressure and their Engineering Significance

Pore fluid pressures that develop within soil masses as a result of both mechanical and physico-chemical effects influence the magnitude of the intergranular or effective stresses. The intergranular stresses control, in many cases, soil behavior in shear and compression. The physical significance of pore water pressure in a cohesive soil is examined in terms of several components which combine to give the total pressure. An analysis of fluid pressures at various points within a soil mass based on a condition of no flow at equilibrium shows that changes in any one component of the total pressure from point to point are offset by changes in other components.
Reduction of the effects of the communication delays in scientific algorithms on message passing MIMD architectures

The efficient implementation of algorithms on multiprocessor machines requires that the effects of communication delays be minimized. The effects of these delays on the performance of a model problem on a hypercube multiprocessor architecture is investigated and methods are developed for increasing algorithm efficiency. The model problem under investigation is the solution by red-black Successive Over Relaxation YOUN71 of the heat equation; most of the techniques described here also apply equally well to the solution of elliptic partial differential equations by red-black or multicolor SOR methods. Methods for reducing communication traffic and overhead on a multiprocessor are identified and results of testing these methods on the Intel iPSC Hypercube reported. Methods for partitioning a problem's domain across processors, for reducing communication traffic during a global convergence check, for reducing the number of global convergence checks employed during an iteration, and for concurrently iterating on multiple time-steps in a time-dependent problem. Empirical results show that use of these models can markedly reduce a numewrical problem's execution time.
Chiral-symmetry breakdown in large-N chromodynamics

Chromodynamics with $n$ flavors of massless quarks is invariant under chiral $\mathrm{U}(n)\ensuremath{\bigotimes}\mathrm{U}(n)$. It is shown that in the limit of a large number of colors, under reasonable assumptions, this symmetry group must spontaneously break down to diagonal $\mathrm{U}(n)$.
Effect of input pulse shape on FSK optical coherent communication system

Directly modulated semiconductor lasers exhibit a dynamic wavelength shift arising from the gain-induced variations of the laser refractive index. It is an accepted fact that the input current pulse shape plays an important role in the frequency chirping (wavelength shift) of directly modulated semiconductor lasers. This paper gives large signal analysis of the dynamic frequency chirping due to the gain-induced variation of the laser refractive index for four different input current pulse shapes. The laser is biased above threshold for the analysis. The rate equations are solved numerically and the frequency chirping and carrier density variations for the four input current pulse shapes are compared.
Reactions of inorganic high polymers as a route to tailored solids

Abstract A new class of reactive inorganic polymers - the polyphosphazenes - can be used as macromolecular intermediates for the synthesis of a wide range of inorganic-organic solids. By reactions that change the polymer side groups, it is possible to bias the properties toward elastomers or microcrystalline polymers, liquid crystalline materials, bioerodable solids, solids with bioactive surfaces, solid electrolytes, semiconductors or ultrastructures.
Pattern recognition and modern computers

We consider the process we call Pattern Recognition. By this we mean the extraction of the significant features of data from a background of irrelevant detail. What we are interested in is simulating this process on digital computers. We give examples on three levels of complexity corresponding to the subjects of the other three speakers here today. We examine in detail the problem on the second level, visual recognition of simple shapes.
Unification of Evidence Theoretic Fusion Algorithms: A Case Study in Level-2 and Level-3 Fingerprint Features

This paper formulates an evidence-theoretic multimodal unification approach using belief functions that take into account the variability in biometric image characteristics. While processing nonideal images, the variation in the quality of features at different levels of abstraction may cause individual classifiers to generate conflicting genuine-impostor decisions. Existing fusion approaches are nonadaptive and do not always guarantee optimum performance improvements. We propose a contextual unification framework to dynamically select the most appropriate evidence-theoretic fusion algorithm for a given scenario. In the first approach, the unification framework uses deterministic rules to select the most appropriate fusion algorithm; while in the second approach, the framework intelligently learns from the input evidences using a 2nu-granular support vector machine. The effectiveness of the unification approach is experimentally validated by fusing match scores from level-2 and level-3 fingerprint features. Compared to existing fusion algorithms, the proposed unification approach is computationally efficient, and the verification accuracy is not compromised even when conflicting decisions are encountered.
Ultracold Atom-Atom Collisions in a Nonresonant Laser Field

Using a recently developed approach for treating the three-dimensional anisotropic scattering we find considerable influence of a nonresonant laser field with intensity I> or =10(5) W/cm(2) on the Cs-Cs ultracold collisions. Strong dependence on the laser wavelength lambda(L) is shown at the optical region as lambda(L) becomes shorter than the critical value lambda(0) approximately 3000 nm (of the atomic de Broglie wave lambda) defining the region lambda(0)< or =lambda of the s-wave domination in the absence of the external field. Dependence on the laser polarization is also essential. The found effect can be applicable for controlling atom-atom interactions at ultralow temperatures.
Robust control for manipulators with uncertain dynamics

Abstract The increase in applications of manipulators in industry and automated manufacturing systems calls for more robust manipulator controllers. A major problem for most of the present control schemes is the inability to deal with dynamic uncertainties associated with a manipulator or its working environment. This paper considers such uncertainties and presents a robust control scheme for industrial manipulators. To illustrate the feasibility of this controller, it has been applied to a General Electric P50 robot. The control design procedure and the implementation results on the GE-P50 robot are presented.
Efficient syntheses of l-ribose and 2-deoxy l-ribose from d-ribose and l-arabinose

Abstract Interconversion of the ends of d -ribose 2 afforded in 6 steps and 45% overall yield l -ribose 1, from which 2-deoxy l -ribose 12 was easily prepared. In addition, the inexpensive l -arabinose 13 was also converted into 2-deoxy l -ribose 12 via a reductive radical rearrangement of the arabinopyranosyl bromide 14.
Denouement of a Wormhole-Brane Encounter

Higher-dimensional black holes have long been considered within the context of brane worlds. Recently, it was shown that the brane-world ethos also permits the consideration of higher-dimensional wormholes. When such a wormhole, pre-existing in the bulk, impinges upon our universe, taken to be a positive-tension three-brane, it can induce the creation in our universe of a wormhole of ordinary dimensionality. The throat of this wormhole might fully constrict, pinch off, and thus birth a baby universe. Alternatively, the induced wormhole might persist. I show that persistence is more likely and note that the persistent wormhole manifests itself as a particle-like object whose interaction with cosmic matter is purely gravitational. I consider the viability of this object as a dark matter candidate.
The downshift of electron plasma oscillations in the electron foreshock region

Electron plasma oscillations in the earth's electron foreshock region are observed to shift above and below the local electron plasma frequency. As plasma oscillations shift downward from the plasma frequency, their bandwidth increases and their wavelength decreases. Observations of plasma oscillations well below the plasma frequency are correlated with times when ISEE 1 is far downstream of the electron foreshock boundary. Although wavelengths of plasma oscillations below the plasma frequency satisfy k x lambda-De approximately 1 the Doppler shift due to the motion of the solar wind is not sufficient to produce the observed frequency shifts. A beam-plasma interaction with beam velocities on the order of the electron thermal velocity is suggested as an explanation for plasma oscillations above and below the plasma frequency. Frequency, bandwidth, and wavelength changes predicted from the beam-plasma interaction are in good agreement with the observed characteristics of plasma oscillations in the foreshock region.
Community Mobilization and Credit: The Impact of Nonprofits and Social Capital on Community Reinvestment Act Lending*

Objective. Recent trends in urban research emphasize the importance of local nonprofits and social capital in the revitalization of poor and minority neighborhoods. This article tests the idea that urban communities able to mobilize themselves by establishing development nonprofits and overcoming collective action problems will be better able to make use of urban-development policies. Methods. Measures operationalizing nonprofit presence and social capital are used in an empirical test to see if they can, through the medium of the Community Reinvestment Act, increase the number of mortgage and business loans in Washington, D.C. Results. These variables show only weak effects on mortgage lending, but very strong results for small-business lending in all types of communities. Conclusions. The results suggest that nonprofits and social capital may have only limited benefit in the revitalization of urban neighborhoods and researchers and practitioners should be careful when relying on them.
Intergalactic Extinction of High Energy Gamma-Rays

We discuss the determination of the intergalactic pair-production absorption coefficient as derived by Stecker and De Jager by making use of a new empirically based calculation of the spectral energy distribution of the intergalactic infrared radiation field as given by Malkan and Stecker. We show that the results of the Malkan and Stecker calculation agree well with recent data on the infrared background. We then show that previous spectral data from observations of Mrk 421 and Mrk 501 are consistent with the amount of intergalactic absorption predicted by Stecker and De Jager and that the new HEGRA observations of the flaring spectrum of Mrk 501 presented at this conference actually appear to show the amount of intergalactic absorption which we predict. As a further test for intergalactic absorption, we give a predicted spectrum, with absorption included, for PKS 2155-304. This XBL lies at a redshift of 0.12, the highest redshift source yet observed at an energy above 0.3 TeV. This source should have its spectrum steepened by ∼ 1 in its spectral index between ∼ 0.3 and ∼ 3 TeV and should show an absorption cutoff above ∼ 6 TeV. We also discuss the determination of the γ-ray opacity at higher redshifts (out to z = 3), following the treatment of Salamon and Stecker.
Micro/Nanotransport Phenomena in Renewable Energy and Energy Efficiency

This article introduces a series of papers presented in a special issue entitled: “Micro/Nanotransport Phenomena in Renewable Energy and Energy Efficiency.” The papers in this issue address some of the basic aspects of renewable energy harvest/conversion, emission control, and optimization of energy. The first article describes a new method based on Femtosecond laser that can be used to fabricate high-quality metallic light absorbers. These artificially made surfaces can be used to improve the energy conversion efficiency such as thermophotovoltaics and solar energy absorbers. Articles on fuel cells cover the experimental and numerical study of cold startup of Proton Exchange Membrane (PEM) fuel cell, development of a continuum model for water transport in the Ionomer-phase of catalyst-coated membranes for PEM, and mesoscopic modeling based on the lattice Boltzmann method for water management in fuel cells. In the area of emission control, the next article discuss the use of nanosized cerium oxide particles as additives on biodiesel, reporting that these additives can appreciably reduce the emission levels of hydrocarbon and NOx through enhancing hydrocarbon oxidation and promoting complete combustion. Another article found that mesoscopic modeling of multiphysicochemical transport phenomena in porous media based on the lattice Boltzmann method (LBM) is especially effective to model the dissolving process of supercritical CO2 into geologic formations such as limestone rock. This may provide a comprehensive numerical tool to simulate the long-term fate of CO2 after injection into the geologic formations. Additional articles discuss thermal management and its role in solar technology, the use of flat-plate oscillating heat pipes for cooling photovoltaic cells with high concentration ratios, the use of nanoparticles to improve the convective heat transfer at high Reynolds number, the optimization of energy in the end use, and the “field synergy principle” as an effective tool to optimize the energy and mass flow in energy systems.
Deal Size, Bid Premium, and Gains in Bank Mergers: The Impact of Managerial Motivations

Do mergers with greater target relative to acquirer size create more value than mergers with smaller relative sized targets? Do larger bid amounts represent wealth transfers from acquirers or do they signal greater expected merger gains? We hypothesize that the relations among aggregate merger gains, relative size, and bid premiums are asymmetric across mergers made by value-enhancing versus value-reducing managers. We use a large sample of bank mergers to test these predictions and find that the value response to different explanatory variables is asymmetric. Our findings provide new insights into how the market values merger bids.
Anomalous effects in measurements of rotational barriers in formamidinium ions. Influence of solvent, counter‐ion and concentration

Chemical exchange studies on the tetramethylformamidinium ion lead to anomalous values for the Arrhenius parameters of internal rotation when apolar solvents, high concentrations and nucleophilic anions are used. The deviations cannot be ascribed to ion-pairing, and might be due to covalent bonding.
Influence of the ground state spin of target nuclei on the anomalous behavior of fission fragment anisotropies

The angular distributions of fission fragments have been measured over a range of near- and sub-barrier energies for reactions involving {sup 12}C projectiles on {sup 235,236,238}U targets. For the reactions involving the zero spin targets, the discrepancies between the experimental fission anisotropies and the transition state model increase dramatically as the beam energy decreases through the region of the fusion barriers. However, the {sup 12}C+(I=7/2){sup 235}U fission anisotropies exhibit a much less dramatic departure from the transition state model. {copyright} {ital 1997} {ital The American Physical Society}
On the political economy of means-tested education vouchers

Abstract We use computational experiments to study the impact of means-tested education vouchers on the level and distribution of educational expenditures. Our benchmark is a regime where public and private schools coexist. Our means-tested voucher regime is one where households with lower incomes receive a larger voucher. Both the level of funding and the allocation of vouchers by income are endogenously determined by sequential majority voting. We examine the effect on educational expenditures of switching from a mixed public/private education regime to a means-tested voucher regime or to a uniform voucher regime where all households receive the same voucher. We find that: (i) Under means-tested vouchers, public funding for education is the smallest but average educational expenditure is the largest; (ii) inequality of educational resources is smaller under means-tested than that under uniform vouchers or the mixed regime; (iii) the ‘poor’ and the ‘rich’ households prefer means testing to either the mixed or uniform regime.
CONCERNING THE SLOPE OF THE CEPHEID PERIOD-LUMINOSITY RELATION

We discuss the impact of possible differences in the slope of the Cepheid period-luminosity (PL) relation on the determination of extragalactic distances in the context of recent studies that suggest changes in this slope. We show that the Wesenheit function W = V – R × (V – I), widely used for the determination of the Cepheid distances, is expected to be highly insensitive to changes in the slope of the underlying (monochromatic) PL relations. This occurs because the reddening trajectories in the color-magnitude plane are closely parallel to lines of constant period. As a result W-based PL relations have extremely low-residual dispersion, which is because differential (and the total line of sight) reddening is eliminated in the definition of W and the residual scatter due to a star's intrinsic color/position within the Cepheid is also largely insensitive to W. Basic equations are presented and graphically illustrated, showing the insensitivity of W to changes in the monochromatic PL relations.
Neutron radii in mean field models

Abstract Bulk nuclear observables such as charge radii and binding energies are well described by both nonrelativistic and covariant mean-field models. However, predictions of neutron radii, which are not tightly constrained by reliable data, vary significantly. The nature of this variation is investigated using correlations between basic properties of the models and the neutron skin thickness in lead. The results suggest that conventional covariant models are too limited. The study is guided by principles and insights of effective field theory (EFT), such as power counting, and the relation of mean-field models to a more general EFT approach to nuclei is discussed.
Vortex-mediated microwave absorption in superclean layered superconductors

In the superclean case the spectrum of vortex core excitations in the presence of disorder is not random but consists of two series of equally spaced levels [Phys. Rev. B, 57, 5457 (1997)]. The $I\ensuremath{-}V$ characteristics of such superconductors displays many interesting phenomena. A series of resonances is predicted at frequencies commensurate with the spacing of the vortex excitations. These resonances reveal an even-odd anomaly. In the presence of one weak impurity the excitation levels can approach each other and almost cross. Absorption at low frequencies is identified with the resonances arising in this case. The results of such microscopic theory coincide up to the order of magnitude with both the theory employing kinetic equation [JETP Lett. 23, 578 (1976)] and the experiment [Phys. Rev. B 49, 4380 (1994)]. The nonlinear effects associated with Zener transitions in such crossings are studied. These phenomena can be used as a probe of vortex core excitations.
A Wick rotation for spinor fields: the canonical approach

Abstract Recently we proposed a new Wick rotation for Dirac spinors which resulted in a hermitean action in Euclidean space. Our work was in a path integral context, however, in this note, we provide the canonical formulation of the new Wick rotation along the lines of the proposal of Osterwalder and Schrader.