cssi/SciSciGPT-SciSciNet huggingface dataset:
Experimental testing of a hypersonic inlet with rectangular-to-elliptical shape transition

Wind-tunnel testing of a hypersonic inlet with rectangular-to-elliptical shape transition has been conducted at Mach 6.2. These tests were performed to validate the use of a recently developed design methodology for fixed-geometry hypersonic inlets suitable for airframe integrated scramjets. Results indicated that flow features within the inlet were similar to design and that the inlet typically captured 96% of the available airflow. Typical mass-flow-weighted total pressure recoveries of 55% were obtained for compression ratios of 14.8 throughout the test program. Assessment of the inlet starting characteristics indicated that the inlet self-started at Mach 6.2 despite the fact that it had an internal contraction ratio well above the Kantrowitz limit (Kantrowitz, A,, and Donaldson, C., "Preliminary Investigation of Supersonic Diffusers," NACA WR L-713, 1945). These results demonstrate that high-performance, fixed-geometry inlets can be designed to combine a nearly rectangular capture with a smooth transition to an elliptical throat.
Decoupled Conflict-Resolution Procedures for Decentralized Air Traffic Control

This paper addresses the challenge of designing provably safe conflict-resolution procedures (CRPs) that are decentralized and decoupled from each other. The main contribution of this paper is identifying necessary and sufficient conditions to decouple CRPs. Additionally, this paper demonstrates the existence of decentralized en-route CRPs that satisfy the identified decoupling conditions for each local conflict and, thereby, guarantee global conflict resolution. An advantage of the proposed CRPs is that they do not require a reduction in the aircraft flow levels in the intersecting routes for conflict resolution, which can aid in increasing the efficiency of en-route air traffic control.
Magnetic instabilities and phase diagram of the double-exchange model in infinite dimensions

Dynamical mean-field theory is used to study the magnetic instabilities and phase diagram of the double-exchange (DE) model with Hund's coupling JH > 0 in infinite dimensions. In addition to ferromagnetic (FM) and antiferromagnetic (AF) phases, the DE model also supports a broad class of short-range ordered (SRO) states with extensive entropy and short-range magnetic order. For any site on the Bethe lattice, the correlation parameter q of an SRO state is given by the average q = sin2 (θi/2), where θi is the angle between any spin and its neighbours. Unlike the FM (q = 0) and AF (q = 1) transitions, the transition temperature of an SRO state with 0 < q < 1 cannot be obtained from the magnetic susceptibility. But a solution of the coupled Green's functions in the weak-coupling limit indicates that an SRO state always has a higher transition temperature than the AF for all fillings p below 1 and even has a higher transition temperature than the FM for 0.26 ≤ p ≤ 0.39. For 0.39 < p < 0.73, where both the FM and AF phases are unstable for small JH, an SRO phase has a nonzero transition temperature except close to p = 0.5. As JH increases, the SRO transition temperature eventually vanishes and the FM phase dominates the phase diagram. For small JH, the T = 0 phase diagram of the DE model is greatly simplified by the presence of the SRO phase. An SRO phase is found to have lower energy than either the FM or AF phases for 0.26 ≤ p < 1. Phase separation (PS) disappears as JH → 0 but appears for any nonzero coupling. For fillings near p = 1, PS occurs between an AF with p = 1 and either an SRO or a FM phase. The stability of an SRO state at T = 0 can be understood by examining the interacting density-of-states, which is gapped for any nonzero JH in an AF but only when JH exceeds a critical value in an SRO state.
Allenyl azide cycloaddition chemistry. 2,3-cyclopentennelated indole synthesis through indolidene intermediates.

The thermal, photochemical, and photochemical/CuI-mediated cascade cyclizations of a range of substituted 1-(2-azidophenyl)-3-alkenylallenes are described. These reactions provide both 1,2- and 2,3-cyclopentennelated indole products in varying ratios. In most cases, high regioselectivity for the 2,3-annelated isomer can be achieved under the hν/CuI conditions. Computational studies of this multistep reaction support the intermediacy of indolidene intermediates whose electrocyclizations (with or without copper present) define the regioselectivity branch point in the sequence.
Stability for Time-Dependent Inverse Transport

This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from full knowledge of the albedo operator at the boundary of a bounded domain of interest. We present optimal stability results on the reconstruction of the absorption and scattering parameters for a given error in the measured albedo operator.
Margulis numbers for Haken manifolds

For every closed orientable hyperbolic Haken 3-manifold and, more generally, for any orientable hyperbolic 3-manifold M which is homeomorphic to the interior of a Haken manifold, the number 0.286 is a Margulis number. If H1(M;ℚ) ≠ 0, or if M is closed and contains a semi-fiber, then 0.292 is a Margulis number for M.
The evolution of spontaneous and coherent radiation in the free electron laser oscillator

An analysis of the free electron laser (FEL) oscillator start-up problem in the linear regime is presented. The model is spatially one dimensional, though many important three dimensional effects are included heuristically. The electron beam consists of pulses of arbitrary shape separated by approximately twice the radiation transit time. The small gain/pass approximation is employed in deriving an energy rate equation, which describes the evolution of the radiation pulses within the resonator. The wiggler field is assumed to occupy a portion of the finite Q resonator. In the energy rate equation, the spontaneous (incoherent) radiation term is represented by a source matrix, while the stimulated (coherent) radiation term is represented by a gain matrix. The effects of small variations in the mirror separation are investigated in the context of laser lethargy. Our analysis suggests possible methods which could substantially shorten the start-up times in FEL oscillators. Finally, our results are compared with the FEL oscillator experiments performed at Stanford University.
Numerical simulation of long-duration blast wave evolution in confined facilities

The objective of this research effort was to investigate the quasi-steady flow field produced by explosives in confined facilities. In this effort we modeled tests in which a high explosive (HE) cylindrical charge was hung in the center of a room and detonated. The HEs used for the tests were C-4 and AFX 757. While C-4 is just slightly under-oxidized and is typically modeled as an ideal explosive, AFX 757 includes a significant percentage of aluminum particles, so long-time afterburning and energy release must be considered. The Lawrence Livermore National Laboratory (LLNL)-produced thermo-chemical equilibrium algorithm, “Cheetah”, was used to estimate the remaining burnable detonation products. From these remaining species, the afterburning energy was computed and added to the flow field. Computations of the detonation and afterburn of two HEs in the confined multi-room facility were performed. The results demonstrate excellent agreement with available experimental data in terms of blast wave time of arrival, peak shock amplitude, reverberation, and total impulse (and hence, total energy release, via either the detonation or afterburn processes.
In vitro evaluation of surfactants with eucalyptus oil for respiratory distress syndrome

Abstract The effects of low doses of eucalyptus oil (EO) were studied on the surface properties of phospholipid suspensions as exogenous surfactants, by in vitro analysis using a pulsating bubble surfactometer and a Wilhelmy balance. Survanta, ALEC and Exosurf, commonly used surfactants in therapy of respiratory distress syndrome were used as controls for comparison. The test surfactants, in Ringer's lactate at 1%, were pulsated at 40cpm in the surfactometer. EO caused a significant improvement of adsorption of the surfactants. In the case of the binary mixture of dipalmitoylphosphatidylcholine and phosphatidylethanolamine (2:3), EO significantly improved the adsorption, stability and minimum surface tension obtained. This combination performed better than ALEC and Exosurf and was comparable to Survanta with respect to minimum surface tension attained. The re-spreading of a surface excess film of this mixture in a Wilhelmy balance was higher than that of ALEC and Exosurf. The ultrastructure of the EO enriched surfactants using cryogenic scanning electron microscopy showed easy facturability and formation of open membranous structures, which could have been associated with the improved surface activity.
Faraday effect current sensor with improved sensitivity - bandwidth product.

We report a new design for a Faraday effect current sensor based on yttrium iron garnet that has substantially greater bandwidth than previous designs and is much easier to fabricate. The measured sensitivity is 0.7°/A, with a −3-dB bandwidth of 500 MHz, which gives an improvement in sensitivity–bandwidth product of approximately 45. A noise-equivalent current of 840 nA/Hz1/2 was measured at 1.8 kHz by difference-over-sum processing. The use of turning prisms with phase-preserving coatings greatly simplifies construction, improves electrical isolation, and increases sensitivity through proximity effects.
Exploratory Procedures with Carbon Nanotube-based Sensors for Propellant Degradation Determinations

Exploratory research is conducted at the US Army Aviation & Missile Research, Development, and Engineering Center (AMRDEC) in order to perform assessments of the degradation of solid propellant used in rocket motors. Efforts are made to discontinue and/or minimize destructive methods and utilize nondestructive techniques to assure the quality and reliability of the weaponry's propulsion system. Collaborative efforts were successfully made between AMRDEC and NASA-Ames for potential add-on configurations to a previously designed sensor that AMRDEC plan to use for preliminary detection of off-gassing. Evaluations were made in order to use the design as the introductory component for the determination of shelf-life degradation rate of rocket motors. Previous and subsequent sensor designs utilize functionalized single-walled carbon nano-tubes (SWCNTs) as the key sensing element. On-going research is conducted to consider key changes that can be implemented (for the existing sensor design) such that a complete wireless sensor system design can be realized. Results should be a cost-saving and timely approach to enhance the Army's ability to develop methodologies for measuring weaponry off-gassing and simultaneously detecting explosives. Expectations are for the resulting sensors to enhance the warfighters' ability to simultaneously detect a greater variety of analytes. Outlined in this paper are the preliminary results that have been accomplished for this research. The behavior of the SWCNT sensor at storage temperatures is outlined, along with the initial sensor response to propellant related analytes. Preparatory computer-based programming routines and computer controlled instrumentation scenarios have been developed in order to subsequently minimize subjective interpretation of test results and provide a means for obtaining data that is reasonable and repetitively quantitative. Typical laboratory evaluation methods are likewise presented, and program limitations/barriers are outlined.
Precision electroweak constraints on top-color assisted technicolor

Using precision electroweak data, we put limits on “natural” top-color assisted technicolor models. Generically the new U(1) gauge bosons in these models must have masses larger than roughly 2 TeV, although in certain (seemingly unrealistic) models the bound can be much lower.
Perceptual learning of vowels in a neuromorphic system

Abstract Linear neuromorphic systems assume that neurally encoded stimuli are mapped through linear combinations of a set of underlying features (represented as the eigenvectors of the matrix of learned associations) onto perceptual categories. Learning in this type of system may be through an auto-associative process that induces prototypes that represent the central tendency of each perceptual category. It has been proposed that human listeners learn vowel categories through just this type of computational mechanism. To investigate this claim, we trained an auto-associative network on a set of American English vowels averaged over talkers. We examined performance of this network for learning and classifying vowels produced by the average of tokens from several male talkers. In addition, we compared the effects of different auditory coding representations on recognition performance for the male vowels. Since, for these models it is necessary for the stimulus set to be linearly independent, the perceptual representation of the vowels can affect learning. Furthermore, we investigated the extent to which the underlying feature space learned from a set of vowels is shared between talkers. For this type of network to be a plausible model of vowel perception, it must be capable of perceptual constancy across talkers. Finally, we compared the effects of different learning algorithms on the development of vowel categories in perceptual space, and investigated the ability of a paired-associate model to develop vowel categories. We will discuss the results of these studies and their implications for simple, network models of speech perception and talker normalization.
Plasma-etched neural probes

Abstract A new method is presented for microfabricating silicon-based neural probes that are designed for neurobiology research. Such probes provide unique capabilities to record high-resolution signals simultaneously from multiple, precisely defined locations within neural tissue. The fabrication process utilizes a plasma etch to define the probe outline, resulting in sharp tips and compatibility with standard CMOS processes. A low-noise amplifier array has been fabricated through the MOSIS service to complete a system that has been used in multiple successful physiological experiments.
Integrated optoelectronic silicon devices for optical signal processing and communications

Integrated optoelectronic devices will be considered in which optical fibers are coupled to optical channel waveguides and in which both optical slab and channel waveguides are coupled to detectors. Use of Si02/Si substrates allows formation of low loss waveguides, smooth V-groove channels for both channel waveguides and fiber support channels and sophisticated detector configurations such as charge-coupled device (CCD) linear arrays. We will discuss a slab waveguide-CCD detector coupling structure which has been experimentally characterized by a high degree of uniformity along the linear array, minimal excessive optical scattering and very low charge transfer inefficiency. Coupling of light from optical fibers to channel waveguides and from an array of channel waveguides to a CCD linear array is demonstrated. Applications of the various device structures considered to integrated optical spectrum analysis, optical transversal filtering, and time multiplexing of a number of fiber optical communication channels are discussed.
Non-stretchable pseudo-visibility graphs

We exhibit a family of graphs which can be realized as pseudo-visibility graphs of pseudo-polygons, but not of straight-line polygons. The example is based on the characterization of vertex-edge pseudo-visibility graphs of O'Rourke and Streinu [Proc. ACM Symp. Comput. Geometry, Nice, France, 1997, pp. 119-128] and extends a recent result of the author [Proc. ACM Symp. Comput. Geometry, Miami Beach, 1999, pp. 274-280] on non-stretchable vertex-edge visibility graphs. We construct a pseudo-visibility graph for which there exists a unique compatible vertex-edge visibility graph, which is then shown to be non-stretchable. The construction is then extended to an infinite family.
Searching for Planets in the Hyades. I. The Keck Radial Velocity Survey

We describe a high-precision radial velocity search for Jovian-mass companions to main-sequence stars in the Hyades. The Hyades provides an extremely well controlled sample of stars of the same age, the same metallicity, and a common birth and early dynamical environment. This sample allows us to explore the dependence of the process of planet formation on only a single independent variable: the stellar mass. In this paper, we describe the survey and summarize results for the first 5 years.
Polar coronal plumes

Polar coronal plumes are modeled using concentrations of magnetic flux at 1.01R⊙, and assuming the field is current-free, or a potential field. Identifying the density enhancement of plumes with magnetic flux concentration produces good agreement between 1.01R⊙ and 1.10R⊙, for model conditions of a large background magnetic field and a plume separation of 50 000 to 70 000 km at the base. Beyond 1.10R⊙, both plumes and the potential field diverge very nearly as r2.
Exogenous progestogen and estrogen implicated in birth defects

A five-year study of the possible teratogenicity of exogenous female sex hormones included three case-control studies and one cohort study. The first case-control study disclosed an estimated relative risk of 8.41 and a highly significant difference in maternal hormonal exposure ( P P =.017) and 3.35 ( P ( JAMA 240:837-843, 1978)
Superconducting properties of polycrystalline Nb nanowires templated by carbon nanotubes

Continuous Nb wires, 7–15 nm in diameter, have been fabricated by sputter-coating single fluorinated carbon nanotubes. Transmission electron microscopy revealed that the wires are polycrystalline, having grain sizes of about 5 nm. The critical current of wires thicker than ∼12 nm is very high (107 A/cm2) and comparable to the expected depairing current. The resistance versus temperature curves measured down to 0.3 K are well described by the Langer–Ambegaokar–McCumber–Halperin theory of thermally activated phase slips. Quantum phase slips are suppressed.
Wind-tunnel measurements of dynamic reefing line force in ribbon parachutes

This paper presents the results of a series of wind-tunnel tests conducted to measure the force in ribbon parachute reefing lines. Three-foot diameter ribbon parachute models with porosities of 10-25% were tested in the Vought Systems Low-Speed Wind Tunnel. Simultaneous measurement of parachute axial force and reefing line force allowed the latter to be expressed either as a percent of axial force or as a dimensionless force coefficient. Maximum reefing line forces for 15, 20, and 25% porosity chutes were 4-5% of the axial force. Forces for the 10% porosity chute were considerably higher. The 10% porosity chute also showed a significant dynamic effect, with maximum values considerably higher than those in steady state.
Observation of d-orbital aromaticity.

While main group clusters can give rise to s- and p-aromaticity, transition-metal-containing clusters can exhibitd-orbitalaromaticityor,moreinterestingly,d-aromaticitydueto d bonding interactions. However, d-orbital aromaticityrequiressignificantd–dbondinginteractions.Unlikevalentsor p orbitals, d orbitals are spatially more contracted, andtheir tendency to participate in chemical bonding dependsstrongly on the position of the transition metals in theperiodic table and their coordination environments. ThepredictedaromaticityinthecyclicCu-containingspecies,
Ferric ion assisted photooxidation of haloacetates

Aqueous solutions containing ferric ions and chloro- or fluoroacetates were photolyzed by light with wavelengths greater than 300 nm. Significant variation in the extent of reaction was observed, with the totally halogenated acetates degraded very little in the course of the experiments. The relative rates of degradation were found to correlate very well with the relative rates of reaction of the haloacetate with the hydroxyl radical.
Relationships between nitrous acid and other nitrogen oxides in urban air

Abstract Nitrous acid (HNO2), nitric acid (HNO3), nitric oxide (NO) and nitrogen dioxide (NO2) were measured over a four day period in Clairmont, CA. Concentrations of each nitrogen oxide (NOx) compound varied diurnally during the study period HNO3, NO2, and NO generally reached maxima during daylight hours. Conversely, HNO2 concentrations were highest at night. HNO3 and HNO2 concentrations increased with increasing NO and NO2. HNO3 dependance became limited at high NO2 and NO. HNO2 concentrations declined when high NO and NO2 concentrations were present. The decline in HNO2 is postulated to result from direct photolysis during the time periods of NO and NO2 maxima or from reactions to form HNO3.
Spectral structure of pressure measurements made in a combustion duct

The spectral structure of pressure measurements made in a ducted combustion test facility are studied. Dispersion and attenuation of acoustic plane waves may occur in the duct at low frequencies due to combustor emissions and affect the spectral structure. A model that considers the propagation of plane waves through a cloud of particles in a flowing gas and which includes heat transfer between soot particles and the gas is discussed. Experimental results are compared with theory.
Spin states and climates of eccentric exoplanets

Abstract The known extrasolar planets exhibit a wide range of orbital eccentricities e. This has a profound influence on their rotations and climates. Because of tides in their interiors, mostly solid exoplanets are expected eventually to despin to a state of spin-orbit resonance, where the orbital period is some integer or half-integer times the rotation period. The most important of these resonances is the synchronous state, where the planet's spin period exactly equals its orbital period (like Earth's Moon, and indeed most of the regular satellites in the Solar System). Such planets seem doomed to roast on one side and freeze on the other. However, synchronous planets rock back and forth by an angle of ∼ 2 Arcsin e with respect to the sub-stellar point. For e = 0.055 (as for the Moon), this optical libration amounts to only ∼6°; but for a synchronous planet with e = 0.50 , for example, it would rise to ∼59°. This greatly expands the temperate “twilight zone” near the terminator and considerably improves the planet's prospects for habitability. For e ≳ 0.72389 , the optical libration exceeds 90°; for such planets, the sector of permanent night vanishes, while the sunniest region splits in two. Furthermore, the synchronous state is not the only possible spin resonance. For example, Mercury (with e ≈ 0.206 ) has an orbital period exactly 1.5 times its rotation period. A terrestrial exoplanet with e = 0.40 , say, is liable to have an orbital period of 2.0, 2.5, or 3.0 times its spin period. The corresponding insolation patterns are generally complicated, and all different from the synchronous state. Yet these non-synchronous resonances also protect certain longitudes from the worst extremes of temperature and solar radiation, and improve the planet's habitability, compared to non-resonant rotation. These results also have implications for the direct detectability of extrasolar planets, and the interpretation of their thermal emissions.
Low-cost, low-input RNA-seq protocols perform nearly as well as high-input protocols

Recently, a number of protocols extending RNA-sequencing to the single-cell regime have been published. However, we were concerned that the additional steps to deal with such minute quantities of input sample would introduce serious biases that would make analysis of the data using existing approaches invalid. In this study, we performed a critical evaluation of several of these low-volume RNA-seq protocols, and found that they performed slightly less well in per-gene linearity of response, but with at least two orders of magnitude less sample required. We also explored a simple modification to one of these protocols that, for many samples, reduced the cost of library preparation to approximately $20/sample.
Universality and complexity in cellular automata

Abstract Cellular automata are discrete dynamical systems with simple construction but complex self-organizing behaviour. Evidence is presented that all one-dimensional cellular automata fall into four distinct universality classes. Characterizations of the structures generated in these classes are discussed. Three classes exhibit behaviour analogous to limit points, limit cycles and chaotic attractors. The fourth class is probably capable of universal computation, so that properties of its infinite time behaviour are undecidable.
Stochastic sensitivity analysis using fuzzy influence diagrams

The practice of stochastic sensitivity analysis described in the decision analysis literature is a testimonial to the need for considering deviations from precise point estimates of uncertainty. We propose the use of Bayesian fuzzy probabilities within an influence diagram computational scheme for performing sensitivity analysis during the solution of probabilistic inference and decision problems. Unlike other parametric approaches, the proposed scheme does not require resolving the problem for the varying probability point estimates. We claim that the solution to fuzzy influence diagrams provides as much information as the classical point estimate approach plus additional information concerning stochastic sensitivity. An example based on diagnostic decision making in microcomputer assembly is used to illustrate this idea. We claim that the solution to fuzzy influence diagrams provides as much information as the classical point estimate approach plus additional interval information that is useful for stochastic sensitivity analysis.
Micron‐sized dust particles detected in the outer solar system by the Voyager 1 and 2 plasma wave instruments

During the Voyager 1 and 2 flybys of the outer planets it has been demonstrated that the plasma wave instrument can detect small dust particles striking the spacecraft. In this paper, we examine the Voyager plasma wave data for dust impacts in the interplanetary medium at heliocentric radial distances ranging from 6 to 60 astronomical units (AU). The results show that a small but persistent level of dust impacts exists out to at least 30 to 50 AU. The average number density of these particles is about 2 x 10(exp -8)/cu m, and the average mass of the impacting particles is believed to be a few times 10(exp -11) g, which corresponds to particle diameters in the micron range. Possible sources of these particles are planets, moons, asteroids, comets, and the interstellar medium. Of these, comets appear to be the most likely source. ne number densities are only weakly dependent on ecliptic latitude, which indicates that the particles probably do not originate from planets, moons, or asteroids. Comparisons with interstellar dust fluxes measured in the inner regions of the solar system by the Ulysses spacecraft indicate that the particles are not of interstellar origin.
Proofs of two conjectures related to the thermodynamic Bethe ansatz

We prove that the solution to a pair of nonlinear integral equations arising in the thermodynamic Bethe Ansatz can be expressed in terms of the resolvent kernel of the linear integral operator with kernel $$\frac{{e^{ - (u(\theta ) + u(\theta \prime ))} }}{{\cosh ^{\frac{{\theta - \theta \prime }}{2}} }}$$ .
Active Vibration Control of the Axially Moving String by Wave Cancellation

Active vibration control of an axially moving string by wave cancellation is presented. The control problem is formulated in the frequency domain. An exact, closed-form expression for the transfer function of the controlled system, consisting of the flexible structure, a feedback control law and the dynamics of the sensing and actuation devices, is derived. It is shown that all vibration modes can be stabilized and that the controlled system has no resonance. Moreover, the designed controller is applicable to the control of the string transverse vibration under various kinds of loading and constraint conditions. Results for the response of the controlled string under different excitations are presented and discussed along with the wave propagation and cancellation characteristics
Optical Spectroscopy of 2MASS Color-selected Ultracool Subdwarfs

We present Gemini GMOS and Magellan LDSS-3 optical spectroscopy for seven ultracool subdwarf candidates color-selected from the Two Micron All Sky Survey. Five are identified as late-type subdwarfs, including the previously reported sdM9.5 SSSPM 1013-1356 and L subdwarf 2MASS 1626+3925, and a new sdM8.5 2MASS 0142+0523. 2MASS 1640+1231 exhibits spectral features intermediate between a late-type M dwarf and subdwarf, similar to the previously identified high proper motion star SSSPM 1444-2019, and we classify both sources as mild subdwarfs, d/sdM9. 2MASS 1227-0447 is a new ultracool extreme subdwarf, spectral type esdM7.5. Spectral model fits yield metallicities that are consistent with these metallicity classifications. Effective temperatures track with numerical subtype within a metallicity class, although they are not equivalent across metallicity classes. As a first attempt to delineate subtypes in the L subdwarf regime we classify 2MASS 1626+3925 and the previously identified 2MASS 0532+8246 as sdL4 and sdL7, respectively, to reflect their similarity to equivalently classified, solar metallicity L-type field dwarfs over the 7300-9000 A region. We also detail preliminary criteria for distinguishing L subdwarf optical spectra as a road map for defining this new spectral class. The strong TiO bands and Ca I and Ti I lines in the spectrum of 2MASS 1626+3925 provide further evidence that condensate formation may be inhibited in metal-deficient L subdwarfs. We conclude with a compendium of currently known, optically classified ultracool subdwarfs.
Theoretical study of band offsets at semiconductor interfaces

We present a first-principles approach to deriving the relative energies of valence and conduction bands at semiconductor interfaces, along with a model which permits a simple interpretation of these band offsets. Self-consistent density-functional calculations, using ab initio nonlocal pseudo-potentials, allow us to derive the minimum-energy structure and band offsets for specific interfaces. Here we report results for a large number of lattice-matched interfaces, which are in reasonable agreement with reported experimental values. In addition, our systematic analysis leads to the important conclusions that, for the cases considered, the offsets are independent of interface orientation and obey the transitivity rule, to within the accuracy of our calculations. These are necessary conditions for the offsets to be expressible as differences between quantities which are intrinsic to each of the materials. Based on the information obtained from the full interface calculations, we have developed a new and simple approach to derive such intrinsic band offsets. We define a reference energy for each material as the average (pseudo)potential in a “model solid,” in which the charge density is constructed as a superposition of neutral (pseudo)atomic densities. This reference depends on the density of each type of atom and the detailed form of the atomic charge density, which must be chosen consistently for the different materials. The bulk band structures of the two semiconductors are then aligned according to these average potential positions. For many cases, these model lineups yield results close to those obtained from full self-consistent interface calculations. We discuss the comparison with experiments and with other model theories.
Intentionality and its Place in Nature

Intentionality is that feature of certain mental states and events that consists in their (in a special sense of these words) being directed at, being about, being of, or representing certain other entities and states of affairs. If, for example, Robert has the belief that Ronald Reagan is President, then his belief is an intentional state because in the appropriate sense his belief is directed at, or about, or of, or represents Ronald Reagan and the state of affairs that Ronald Reagan is President. In such a case Ronald Reagan is the intentional object of Robert’s belief, and the existence of the state of affairs that Ronald Reagan is President is the condition of satisfaction of his belief. If there is not anything that a belief is about, then it does not have an intentional object; and if the state of affairs it represents does not obtain, it is not satisfied.
Allylic coupling between electrophilic molybdenum and nucleophilic iron allyl complexes

Abstract Allylic coupling between [CpMo(CO)(NO)(η 3 -allyl)]+ and CpFe(CO) 2 (η 1 -allyl) gives equal amounts of two stereoisomers of a 1,5-hexadiene in which the double bonds are complexed to different metals. Removal of the iron moiety yields a single diastereomer of a molybdenum - olefin complex. Investigation of the coupling with the crotyl molybdenum complex shows that it occurs regiospecifically at the unsubstituted terminus of the crotyl ligand.
On the oscillations of multiplicative functions taking values ±1

For multiplicative functions f(n), which take on the values ±1, we show that under certain conditions on f(n), for all x sufficiently large, there are at least xexp(−7(loglogx)logx) values of n⩽x for which f(n(n+1))=−1.
How Does A Single Mother Choose Kin and Welfare Support

Abstract The number of female-headed families has increased dramatically in the past two decades and the importance of external support from private and public sources has drawn increasing research attention. This paper proposes a one-decision model to examine the determinants of kin and welfare support. Using data on single mothers from the National Longitudinal Survey of Youth, the study has found: (1) greater kin economic resources substitute for public aid, (2) intact parents discourage their daughters′ participation in AFDC, (3) government aid crowds out kin contributions to their daughters and grandchildren, (4) higher wage rates of single mothers and larger amount of child support promote leaving welfare programs, and (5) single mothers with higher income resources still demand kin support.
Goertler instability and hypersonic quiet nozzle design

A concept for nozzle design which incorporates slow expansion rates and a radial flow region is developed for use on a hypersonic (Mach 6) nozzle. It is shown that the boundary-layer suction slot upstream of the nozzle throat is necessary to remove upstream turbulent boundary layers and to initialize a new laminar boundary layer on the downstream nozzle wall. In effect, the laminar boundary-layer flow can be extended more effectively farther downstream by a slow expansion contour based on the present design concept than by a rapid expansion contour used in previous pilot quiet nozzles.
Distributed Classifier Based on Genetically Engineered Bacterial Cell Cultures

We describe a conceptual design of a distributed classifier formed by a population of genetically engineered microbial cells. The central idea is to create a complex classifier from a population of weak or simple classifiers. We create a master population of cells with randomized synthetic biosensor circuits that have a broad range of sensitivities toward chemical signals of interest that form the input vectors subject to classification. The randomized sensitivities are achieved by constructing a library of synthetic gene circuits with randomized control sequences (e.g., ribosome-binding sites) in the front element. The training procedure consists in reshaping of the master population in such a way that it collectively responds to the "positive" patterns of input signals by producing above-threshold output (e.g., fluorescent signal), and below-threshold output in case of the "negative" patterns. The population reshaping is achieved by presenting sequential examples and pruning the population using either graded selection/counterselection or by fluorescence-activated cell sorting (FACS). We demonstrate the feasibility of experimental implementation of such system computationally using a realistic model of the synthetic sensing gene circuits.
Interannual variability in North American grassland biomass/productivity detected by SeaWinds scatterometer backscatter

[1] We analyzed 2000–2004 growing-season SeaWinds Ku-band microwave backscatter and MODIS leaf area index (LAI) data over North America. Large anomalies in mid-growing-season mean backscatter and LAI, relative to 5-year mean values, occurred primarily in the western Great Plains; backscatter and LAI anomalies had similar spatial patterns across this region. Backscatter and LAI time series data for three ∼103 km2 regions in the western Great Plains were strongly correlated (r2 ∼ 0.6–0.8), and variability in mid-growing season values was well-correlated with annual precipitation (October through September). The results indicate that SeaWinds backscatter is sensitive to interannual variability in grassland biomass/productivity, and can provide an assessment that is completely independent of optical/near-infrared remote sensing instruments.
Assessing Callous-Unemotional Traits in Preschool Children With Disruptive Behavior Problems Using Peer Reports

The goal of this study was to examine the extent to which preschoolers with externalizing behavior problems (EBP) can identify behaviors indicative of callous-unemotional (CU) traits among their peers. Participants for this study included 86 preschool children (69% boys; Mage = 5.07 years) with at-risk or clinically elevated levels of EBP who were attending a summer treatment camp. Data collected from the children, their peers, and the counselors who worked at the summer camp examined preschoolers’ social preference, likability, and behaviors indicative of CU. Parents and preschool teachers also reported on children's CU traits and severity of behavioral impairment, as well as school readiness. Peer nominations of CU traits showed (a) excellent factor structure as evidenced by clear CU items (e.g., “don't feel bad when they do something wrong”) versus more prosocial items (“share,” “cooperate”); (b) moderate construct validity when compared to counselor reports of the CU factor as well as preschool teache...
Neutral carbon in the Egg Nebula (AFGL 2688)

A search for sub-mm C I emission from seven stars that are surrounded by dense molecular gas shells led to the detection, in the case of the "Egg Nebula' (AFGL 2688), of an 0.9 K line implying a C I/CO value greater than 5. The material surrounding this star must be extremely carbon-rich, and it is suggested that the apparently greater extent of the C I emission region may be due to the effects of the galactic UV field on the shell's chemistry, as suggested by Huggins and Glassgold (1982).
RAM: a Relativistic Adaptive Mesh Refinement Hydrodynamics Code

The authors have developed a new computer code, RAM, to solve the conservative equations of special relativistic hydrodynamics (SRHD) using adaptive mesh refinement (AMR) on parallel computers. They have implemented a characteristic-wise, finite difference, weighted essentially non-oscillatory (WENO) scheme using the full characteristic decomposition of the SRHD equations to achieve fifth-order accuracy in space. For time integration they use the method of lines with a third-order total variation diminishing (TVD) Runge-Kutta scheme. They have also implemented fourth and fifth order Runge-Kutta time integration schemes for comparison. The implementation of AMR and parallelization is based on the FLASH code. RAM is modular and includes the capability to easily swap hydrodynamics solvers, reconstruction methods and physics modules. In addition to WENO they have implemented a finite volume module with the piecewise parabolic method (PPM) for reconstruction and the modified Marquina approximate Riemann solver to work with TVD Runge-Kutta time integration. They examine the difficulty of accurately simulating shear flows in numerical relativistic hydrodynamics codes. They show that under-resolved simulations of simple test problems with transverse velocity components produce incorrect results and demonstrate the ability of RAM to correctly solve these problems. RAM has been tested in one, two and three dimensions andmore » in Cartesian, cylindrical and spherical coordinates. they have demonstrated fifth-order accuracy for WENO in one and two dimensions and performed detailed comparison with other schemes for which they show significantly lower convergence rates. Extensive testing is presented demonstrating the ability of RAM to address challenging open questions in relativistic astrophysics.« less
Dangerous Liouville Wave - Exactly marginal but non-conformal deformation

We give a non-trivially interacting field theory example of scale invariant but non-conformal field theory. The model is based on the exactly solvable Liouville field theory coupled with free scalars deformed by an exactly marginal operator. We show non-vanishing of the trace of the energy-momentum tensor by using the quantum Schwinger-Dyson equation for the Liouville field theory, which is a sophistication of the quantum higher equations of motion for the Liouville field theory introduced by Alyosha Zamolodchikov. Possibly dangerous implications for the super-critical string theory will be discussed.
Municipal publications: A bibliographic guide to library literature

Abstract The following bibliography, which draws together the reported writings relating to municipal publications in the United States, suggests that many of the historical writings have value for presently debated issues.
Voluntary Euthanasia: A Utilitarian Perspective

Belgium legalised voluntary euthanasia in 2002, thus ending the long isolation of the Netherlands as the only country in which doctors could openly give lethal injections to patients who have requested help in dying. Meanwhile in Oregon, in the United States, doctors may prescribe drugs for terminally ill patients, who can use them to end their life--if they are able to swallow and digest them. But despite President Bush's oft-repeated statements that his philosophy is to 'trust individuals to make the right decisions' and his opposition to 'distant bureaucracies', his administration is doing its best to prevent Oregonians acting in accordance with a law that its voters have twice ratified. The situation regarding voluntary euthanasia around the world is therefore very much in flux. This essay reviews ethical arguments regarding voluntary euthanasia and physician-assisted suicide from a utilitarian perspective. I shall begin by asking why it is normally wrong to kill an innocent person, and whether these reasons apply to aiding a person who, when rational and competent, asks to be killed or given the means to commit suicide. Then I shall consider more specific utilitarian arguments for and against permitting voluntary euthanasia.
Direct computation of the sound generated by vortex pairing in an axisymmetric jet

The sound generated by vortex pairing in axisymmetric jets is determined by direct solution of the compressible Navier–Stokes equations on a computational grid that includes both the near field and a portion of the acoustic far field. At low Mach number, the far-field sound has distinct angles of extinction in the range of 60°–70° from the jet's downstream axis which can be understood by analogy to axisymmetric, compact quadrupoles. As the Mach number is increased, the far-field sound takes on a superdirective character with the dominant sound directed at shallow angles to the jet's downstream axis. The directly computed sound is compared to predictions obtained from Lighthill's equation and the Kirchhoff surface method. These predictions are in good agreement with the directly computed data. The Lighthill source terms have a large spatial distribution in the axial direction necessitating the introduction of a model to describe the source terms in the region downstream of the last vortex pairing. The axial non-compactness of the quadrupole sources must be adequately treated in the prediction method.
Simulation of simplicity: a technique to cope with degenerate cases in geometric algorithms

This paper describes a general-purpose programming technique, called Simulation of Simplicity, that can be used to cope with degenerate input data for geometric algorithms. It relieves the programmer from the task of providing a consistent treatment for every single special case that can occur. The programs that use the technique tend to be considerably smaller and more robust than those that do not use it. We believe that this technique will become a standard tool in writing geometric software.
A new particle identifier technique for Z = 1 and Z = 2 particles in the energy range > 10 MeV

Abstract Protons, deuterons, tritons, helium-3 and α particles produced in nuclear reactions have previously been identified by use of ΔE and E counters to determine dE/dx and E. Multiplying these together produces an output that is dependent on the type of particle. This technique is based on the theoretical relationship between dE/dx, E and the mass and charge of the particle. Unfortunately there is an obvious restriction on the technique, since dE/dx changes as the particle passes through the ΔE counter. For the E(dE/dx) product to have any real meaning, the ΔE counter must be thin and absorb only a small part of the total energy. This limits the use of this technique in a given experiment to small energy ranges and to selected types of particle. The new identifier also uses a ΔE (thickness T) and E counter, but employs the empirical relationship: Range = aE1.73, where a depends on the type of particle. Using the relationship, one can show T/a = (E+ΔE) 1.73 −E 1.73 . The identifier employs logarithmic elements to calculate this quantity and to produce an output that has a fixed value for each type of particle. The thickness of the ΔE counter is not limited to a very small value, and the identifier can cope with mixtures of all five types of particle, each covering a fairly wide energy range. Experimental results using this identifier and lithium drifted silicon detectors are presented and illustrate the clear separation between He3 and He4 particles (difficult to achieve with the multiplier type of identifier).
Formation of trans-3-hydroxy-4-phenylbutyrolactone from trans-styrylacetic acid and aqueous KHSO5

Abstract The formation of trans-3-hydroxy-4-phenylbutyrolactone from trans-styrylacetic acid mediated by aqueous KHSO5 is described. The lactone is proposed to arise via an epoxide intermediate directly formed by the monopersulfate.
A Theory of Monetary Exchange

The transactions cost for alternative exchange mechanisms for the household exchange problem can be characterized by the computational complexity of the exchange process. The computational complexity for any exchange mechanism is at least nH, where n is the number of goods and H is the number of households. Imposing the conditions of conservation, nonnegativity and quid pro quo results in a command exchange mechanism whose computational complexity is nH. Multiparty barter exchange, formalized using graph theory, has computational complexity
Quinone methide initiated cyclization reactions: Studies toward the synthesis of (+)-pancratistatin

Abstract The synthesis of highly functionalized cyclohexenone 15 , a possible precursor for (+)-pancratistatin, was accomplished in 15 steps (10% yield) from aldehyde 4 via a quinone methide initiated cyclization reaction.