cssi/SciSciGPT-SciSciNet huggingface dataset:
On the distribution of imaginary parts of zeros of the Riemann zeta function, II

We continue our investigation of the distribution of the fractional parts of αγ, where α is a fixed non-zero real number and γ runs over the imaginary parts of the non-trivial zeros of the Riemann zeta function. We establish some connections to Montgomery’s pair correlation function and the distribution of primes in short intervals. We also discuss analogous results for a more general L-function.
High-resolution measurements of the bands of carbonyl sulfide between 2510 and 3150 cm−1

Abstract The four strongest absorption bands of OCS in the region from 2500 to 3150 cm−1 have been measured with FTS spectrometers with effective resolutions of about 0.010 cm−1 or better. A total of 25 different vibrational transitions have been identified in the spectrum and have been analyzed to obtain improved band centers and rovibrational constants. Included in the bands identified are a few transitions due to the less abundant isotopomers, 16O12C34S, 16O12C33S, 16O13C32S, and 18O12C32S. Relative values are given for the transition moments of some of the overlapping bands.
The impact of private provision of public education : empirical evidence from Bogota's concession schools

In 1999 the city of Bogota, Colombia launched the concession school program designed to broaden the coverage and quality of basic education. It consists of a contract between a group of private schools and the public educational system such that private agents provide education for low-income students. This paper tests three main hypotheses concerning the impact of concessions on the quality of education: first, dropout rates are lower in concession schools than in similar public schools; second, other public schools nearby the concession schools have lower dropout rates in comparison with other public schools outside the area of influence; and third, test scores from concession schools are higher than scores in similar public schools. The paper presents evidence in favor of the three hypotheses using propensity score and matching estimators.
Mispricing and Arbitrage in CDS Auctions

Credit default swaps were a major addition to the array of financial instruments available in the market. But as is typical for a fundamentally new product, the early designs had to be tweaked. First, it was necessary to eliminate ambiguity over what constitutes a credit event, and more recent changes enhanced liquidity by standardizing the contract terms and regularized how the payoff is determined following a default. This is now accomplished through a rather complicated twostage auction process. In this article, Gupta and Sundaram describe how the auction works and establish the existence of a striking and somewhat troubling pattern exhibited by prices of the underlying bonds at the time of the auction. In auctions where the first round shows an imbalance of selling over buying orders, the market price is higher on the day prior to the auction, drops sharply at the auction, and then shoots upward the next day. The reverse pattern happens in a buy auction. These patterns produce significant profits for simple trading rules, such as buying (selling) immediately after a sell (buy) auction.
Quark Masses: An Environmental Impact Statement

We investigate worlds that lie on a slice through the parameter space of the standard model over which quark masses vary. We allow as many as three quarks to participate in nuclei, while fixing the mass of the electron and the average mass of the lightest baryon flavor multiplet. We classify as congenial worlds that satisfy the environmental constraint that the quark masses allow for stable nuclei with charge one, six, and eight, making organic chemistry possible. Whether a congenial world actually produces observers capable of measuring those quark masses depends on a multitude of historical contingencies, beginning with primordial nucleosynthesis and including other astrophysical processes, which we do not explore. Such constraints may be independently superimposed on our results. Environmental constraints such as the ones we study may be combined with information about the a priori distribution of quark masses over the landscape of possible universes to determine whether the measured values of the quark masses are determined environmentally, but our analysis is independent of such an anthropic approach. We estimate baryon masses as functions of quark masses via first-order perturbation theory in flavor SU(3) breaking. We estimate nuclear masses as functions of the baryon masses using two separatemore » tools: for a nucleus made of two baryon species, when possible we consider its analog in our world, a nucleus with a similar binding energy, up to Coulomb contributions. For heavy nuclei or nuclei made of more than two baryons, we develop a generalized Weizsaecker semiempirical mass formula, in which strong kinematic flavor symmetry violation is modeled by a degenerate Fermi gas . We check for the stability of nuclei against fission, strong particle emission (analogous to {alpha} decay), and weak nucleon emission. For two light quarks with charges 2/3 and -1/3 , we find a band of congeniality roughly 29 MeV wide in their mass difference, with our own world lying comfortably away from the edges. We also find another, less robust region of congeniality with one light, charge -1/3 quark, and two heavier, approximately degenerate quarks with charges -1/3 and 2/3. No other assignment of light quark charges yields congenial worlds with two baryons participating in nuclei. We identify the region in quark mass space where nuclei would be made from three or more baryon species. We discuss issues relevant to the congeniality of such worlds, but a full characterization of them is left for future investigation.« less
Nonhematopoietic NADPH oxidase regulation of lung eosinophilia and airway hyperresponsiveness in experimentally induced asthma.

Pulmonary eosinophilia is one of the most consistent hallmarks of asthma. Infiltration of eosinophils into the lung in experimental asthma is dependent on the adhesion molecule vascular cell adhesi...
Note on the derivative of the hyperbolic cotangent

In a letter to Nature (Ford G W and O'Connell R F 1996 Nature 380 113) we presented a formula for the derivative of the hyperbolic cotangent that differs from the standard one in the literature by an additional term proportional to the Dirac delta function. Since our letter was necessarily brief, shortly after its appearance we prepared a more extensive unpublished note giving a detailed explanation of our argument. Since this note has been referenced in a recent article (Estrada R and Fulling S A 2002 J. Phys. A: Math. Gen. 35 3079) we think it appropriate that it now appear in print. We have made no alteration to the original note.
Anionic σ-complexes from sulfite ion attack on n-methyl-N-β-hydroxyethyl picramide and its spiro complex. Search for geometric isomerism in 1:2 complexes. An instructive example of complex kinetics†

N-Methyl-N-β-hydroxyethyl picramide (PH) forms a 1:1 (PHS2−) and a 1:2 (PHS) anionic σ-complex with sulfite ion. In alkaline solution PH is present mainly in the form of its spiro Meisenheimer complex (M−) which also adds sulfite ion to form a complex MS3−. Rate and equilibrium constants for the various reactions which interrelate the five species PH, PHS2−, PHS, M−, and MS3− (scheme I) were determined. PHS and MS3− can, in principle, exist in the form of two geometric isomers. Despite a careful search by nuclear magnetic resonance and kinetic techniques, no experimental manifestation of this isomerism could be found. Various limiting situations are discussed under which the absence of experimental evidence does or does not exclude the presence of two isomers. Our preferred but unproven interpretation is that in the case of PHS one isomer (trans?) is thermodynamically strongly favored over the other, whereas in the case of MS3− both isomers are of similar thermodynamic stability and have also similar rates. This latter feature would make the isomerism kinetically undetectable. Several other features of scheme I make it an instructive example in complex chemical kinetics.
The impact of multiplexing on the dynamic requirements of analog-to-digital converters

In data acquisition applications where the signals being digitized are produced in a time-division multiplexed system, the required dynamic performance of the analog-to-digital converter (ADC) is no longer bound by the conditions set forth in the sampling theorem. This results from the introduction of very high-frequency information by the multiplexing process which, while not necessarily containing information of interest, must be processed by the input circuitry of the ADC. In this situation, signal bandwidths and slew rates can greatly exceed those produced in a Nyquist limited system and can surpass the capability of the ADC, thus degrading overall system performance. This paper examines two common multiplexing schemes and their impact on ADC dynamic requirements. First, the authors examine a simple voltage multiplexing scheme typically found in state-of-health or data-logging applications and develop the necessary equations to show how the ADC dynamic requirements are affected. Then, the analysis is extended to a multiplexed photodiode array readout to see how this application further challenges the dynamic performance of the ADC. Finally, the issues associated with developing dynamic test methodologies for assessing ADC performance in multiplexed systems are discussed.
Neural acceleration for general-purpose approximate programs

As improvements in per-transistor speed and energy efficiency diminish, radical departures from conventional approaches are needed to continue improvements in the performance and energy efficiency of general-purpose processors. One such departure is approximate computing, where error in computation is acceptable and the traditional robust digital abstraction of near-perfect accuracy is relaxed. Conventional techniques in energy-efficient computing navigate a design space defined by the two dimensions of performance and energy, and traditionally trade one for the other. General-purpose approximate computing explores a third dimension---error---and trades the accuracy of computation for gains in both energy and performance. Techniques to harvest large savings from small errors have proven elusive. This paper describes a new approach that uses machine learning-based transformations to accelerate approximation-tolerant programs. The core idea is to train a learning model how an approximable region of code---code that can produce imprecise but acceptable results---behaves and replace the original code region with an efficient computation of the learned model. We use neural networks to learn code behavior and approximate it. We describe the Parrot algorithmic transformation, which leverages a simple programmer annotation ("approximable") to transform a code region from a von Neumann model to a neural model. After the learning phase, the compiler replaces the original code with an invocation of a low-power accelerator called a neural processing unit (NPU). The NPU is tightly coupled to the processor pipeline to permit profitable acceleration even when small regions of code are transformed. Offloading approximable code regions to NPUs is faster and more energy efficient than executing the original code. For a set of diverse applications, NPU acceleration provides whole-application speedup of 2.3× and energy savings of 3.0× on average with average quality loss of at most 9.6%. NPUs form a new class of accelerators and show that significant gains in both performance and efficiency are achievable when the traditional abstraction of near-perfect accuracy is relaxed in general-purpose computing.
Sheath Physics and Boundary Conditions for Edge Plasmas

The boundary conditions of mass, momentum, energy, and charge appropriate for fluid formulations of edge plasmas are surveyed. We re-visit the classic problem of 1-dimensional flow, and note that the Bohm sheath criterion is requirement of connectivity of the interior plasma with the external world, not the result of termination of the plasma by a wall. We show that the nature of the interior plasma solution is intrinsically different for ion sources that inject above and below the electron sound speed. We survey the appropriate conditions to apply, and resultant fluxes, for a magnetic field obliquely incident on a wall, including the presence of drifts and radial transport. We discuss the consequences of toroidal asymmetries in wall properties, as well as experimental tests of such effects. Finally, we discuss boundary-condition modifications in the case of rapidly varying plasma conditions.
A constrained sequential-lamination algorithm for the simulation of sub-grid microstructure in martensitic materials

We present a practical algorithm for partially relaxing multiwell energy densities such as pertain to materials undergoing martensitic phase transitions. The algorithm is based on sequential lamination, but the evolution of the microstructure during a deformation process is required to satisfy a continuity constraint, in the sense that the new microstructure should be reachable from the preceding one by a combination of branching and pruning operations. All microstructures generated by the algorithm are in static and configurational equilibrium. Owing to the continuity constraint imposed upon the microstructural evolution, the predicted material behavior may be path-dependent and exhibit hysteresis. In cases in which there is a strict separation of micro- and macrostructural lengthscales, the proposed relaxation algorithm may effectively be integrated into macroscopic finite-element calculations at the sub-grid level. We demonstrate this aspect of the algorithm by means of a numerical example concerned with the indentation of a Cu–Al–Ni shape memory alloy by a spherical indenter.
VIRTUE ETHICS, THE ANALECTS, AND THE PROBLEM OF COMMENSURABILITY

In support of the thesis that virtue ethics allows for a more comprehensive and consistent interpretation of the Analects than other possible models, the author uses a structural outline of a virtue ethic (derived from Alasdair MacIntyre's account of the Aristotlelian tradition) to organize a discussion of the text. The resulting interpretation focuses attention on the religious aspects of Confucianism and accounts for aspects of the text that are otherwise difficult to explain. In addition, the author argues that the structural similarities between the Aristotelian and Confucian conceptions of self-cultivation indicate a dimension of commensurability between the two traditions, despite very real variations in specific content. Finally, the author suggests how crosscultural commensurability, in general, can be understood on a theoretical level.
Unpackaging Demand for Water Service Quality: Evidence from Conjoint Surveys in Sri Lanka

In the early 2000s, the Government of Sri Lanka considered engaging private sector operators to manage water and sewerage services in two separate service areas: one in the town of Negombo (north of Colombo), and one stretching along the coastal strip (south from Colombo) from the towns of Kalutara to Galle. Since then, the government has abandoned the idea of setting up a public-private partnership in these two areas. This paper is part of a series of investigations to determine how these pilot private sector transactions (forming part of the overall water sector reform strategy) could be designed in such a manner that they would benefit the poor. This paper describes the results of a conjoint survey evaluating the factors that drive customer demand for alternative water supply and sanitation services in Sri Lanka. We demonstrate how conjoint surveys can be used to un-package household demand for attributes of urban services and improve the design of infrastructure policies. We present conjoint surveys as a tool for field experiments and source of valuable empirical data. In our study of three coastal towns in southwestern Sri Lanka the conjoint survey allows us to compare household preferences for four water supply attributes – price, quantity, safety, and reliability. Sub-populations of poor and non-poor households are examined to determine if demand is heterogeneous. Our case study suggests that households care about service quality (not just price). In general, we find that households have diverse preferences in terms of quantity, safety, and service options, but not with regard to hours of supply. In particular we find that the poor have lower ability to tradeoff income for services, a finding that has significant equity implications in terms of allocating scarce public services and achieving universal water access.
Capital Taxation During the U.S. Great Depression

Previous studies of the U.S. Great Depression find that increased government spending and taxation contributed little to either the dramatic downturn or the slow recovery. These studies include only one type of capital taxation: a business profits tax. The contribution is much greater when the analysis includes other types of capital taxes. A general equilibrium model extended to include taxes on dividends, property, capital stock, excess profits, and undistributed profits predicts patterns of output, investment, and hours worked that are more like those in the 1930s than found in earlier studies. The greatest effects come from the increased taxes on corporate dividends and undistributed profits. JEL Codes: E13, E32, H25 Copyright 2012, Oxford University Press.
Characteristic parameters of drift vortices coupled to Alfvén waves in an inhomogeneous space plasma.

We present detailed measurements of ion scale vortices of drift type coupled to Alfven waves in an inhomogeneous and collisionless space magnetoplasma. The two free parameters of a dipolar vortex, intensity and spatial radius, are measured. The vortices are driven by a strong density gradient on a boundary layer with scale size of the same order as the vortex diameter. Observations of vortices off the gradient show that symmetry-breaking conditions in a real inhomogeneous plasma can lead not only to cross-field but also to cross-boundary anomalous transport of particles and energy.
Electronic and optical properties of body-centered-tetragonal Si and Ge

We present a first-principles calculation of the quasiparticle and optical excitation spectra of recently predicted silicon and germanium polytypes in the body-centered-tetragonal (bct) structure. The quasiparticle spectra calculated within the $GW$ approximation predict that both silicon and germanium in the bct structure are small band gap materials with indirect gaps of 0.86 and 0.38 eV, respectively. The optical spectra is evaluated by solving the Bethe-Salpeter equation taking into account electron-hole interactions. We then make comparison to the cubic phases of Si and Ge which suggest the possible utility of the silicon bct phase in photovoltaic applications.
GOVERNMENT POLICY IN MONETARY ECONOMIES

I study how the specic details of a micro founded monetary economy aect the determination of government policy. I consider three variants of the Lagos-Wright monetary framework: a benchmark were all markets are competitive; a case which allows for nancial intermediaries; and a case with trading frictions. Although intitutions/frictions are shown to have a signicant structural impact in the determination of policy, the calibrated articial economies are observationally equivalent in steady state. The policy response to aggregate shocks is qualitatively similar in the variants considered. However, there are signicant quantitative dierences in the response of government policy to productivity shocks, mainly due to the idiosyncratic behavior of money demand. The variants with no trading frictions display the best t to U.S. post-war data.
Recent studies of FFAGs in the USA

Muon acceleration is one of the most difficult stages to develop for a Neutrino Factory or Muon Collider. The large transverse and longitudinal admittances which must be designed into the system and the rapidity with which acceleration must take place because of muon decay preclude the use of conventional synchrotron design. The current baseline is a recirculating linac (RLA) in the shape of a racetrack with separate fixed-field arcs for each acceleration turn. However, RLAs have proved costly and are a potential bottleneck, at least with respect to the storage ring. Therefore, another approach, the fixed-field alternating gradient (FFAG) accelerator, is being actively pursued. This paper discusses the FFAG option and progress.
Characteristics of tropospheric scattered fields

Experimental results obtained with transmissions at wavelengths of 3.2, 9.3, and 24 cms over a 46.3-mile path are presented. With low terminal heights the scattered field was dominant on this path. Tests with a narrow beam antenna indicate that the scattered field arrives at the receiver spread over an appreciable angle. This angle is some five to seven times as large as the Booker-Gordon theory predicts on the assumption that the scale of turbulence is large compared to the wavelength. Loss in ability to receive power in proportion to antenna gain was encountered for antennas with aperture diameters greater than about 20 wavelengths. This loss occurs for aperture sizes considerably smaller than the Booker-Gordon theory predicts. The speed of fading of the scattered field signal increases almost linearly with frequency. This agrees fairly well with the concept (due to Ratcliffe and applied to tropospheric scattering by Booker and Gordon) that fading is due to beating between various scattered field components whose frequencies differ by a fractional Doppler shift due to motion of the scatterers. The speed of fading always increases, during the day, with time of day and does not correlate with mean upper wind speed. This increase with time of day is probably connected with the repetitive diurnal meteorological cycle prevalent in Arizona.
A direct synthesis of 2-arylpropenoic acid esters having nitro groups in the aromatic ring: a short synthesis of (±)-coerulescine and (±)-horsfiline †

Abstract A short synthesis of 2-arylpropenoic acid esters that possess nitro groups in their phenyl ring using common and less expensive reagents is described. The usefulness of this methodology is substantiated by the efficient total syntheses of (±)-coerulescine and (±)-horsfiline from the 2-arylpropenoic acid esters obtained.
Studies of the sea using HF radio scatter

Radio signals of decameter wavelength resonantly scattered from waves on the sea surface are used to measure precisely the wave. length, frequency, and direction of travel of those waves. These measurements are not only important in themselves, but are also used to deduce currents, winds, and perhaps wind stress at the sea surface. Techniques for obtaining these measurements, as well as experiments to evaluate these techniques are discussed. Finally, scatter has been used to produce the first high-resolution measurements of the directional distribution of large ocean waves, measurements of ocean surface currents at ranges of 20 km, and of surface winds at ranges of 3000 km.
Title IX and the Allocation of Resources to Women’s and Men’s Sports

As a result of Title IX, there has been a large increase in participation of women in college sports, while men’s participation has remained roughly constant. Using a standard contest success function, we analyze the resource allocation decision between women’s and men’s sports before and after the Title IX regulation is imposed. If the number of women’s and men’s sports is held constant, the model predicts an increase in resources devoted to women’s sports which is matched by a one-for-one decrease in resources devoted to men’s sports after Title IX is implemented. Since this prediction is counterfactual, we next consider the possibility that women’s sports are added and men’s sports dropped. We find that one possible response to Title IX is an increase in resources devoted to women’s sports with no change in resources devoted to men’s sports.
A simple, general synthesis of 1-alkynyldiisopropoxyboranes

Abstract A representative selection of 1-alkynyldiisopropoxyboranes has been prepared in high yields from the reaction of 1-lithio-1-alkynes and triisopropoxyboranes at −78° C, followed by treatment with hydrogen chloride.
Specificity and promiscuity in membrane helix interactions.

Transmembrane a-helices can associate with one another in lipid bilayers. This association is important in the folding and oligomerization of many integral membrane proteins, and may also play a role in their function. The interactions between helices may be highly specitic or relatively non-specific, and their roles may differ accordingly. These two cases are discussed. Key woruk Membrane protein; Transmembrane a-helix; Protein-protein interaction; Oligomerization; Folding 1. Helix-helix interactions in membrane folding and oligomerization between sets of dynamically accessible states of particular helices [16]. In some cases, these interactions are mediated in part by prosthetic groups. The membrane-spanning portions of many integral membrane proteins consist of one or a number of transmembrane a-helices, which are expected to be independently stabilized by hydrophobic interactions with the bilayer and by main chain hydrogen bonds. Side-by-side interactions between these transmembrane a-helices are important in the folding and assembly of such integral membrane proteins and their complexes [14]. The establishment of independently stable transmembrane a-helices, and their self-association without rearrangement of secondary structure comprise two stages in a conceptual model for the thermodynamics of integral membrane protein folding [2]. This concept is supported by a body of experimental evidence [5-l 11, so an understanding of the factors involved in helix-helix interactions within lipid bilayers could yield useful biological insights. Portions of the protein outside the lipid bilayer also contribute to the folding and oligomerization energies of integral membrane proteins, and have the capacity to define specificity. Extramembraneous contributions may include the effects of helix-connecting polypeptide loops, the ligation of extramembraneous domains to other molecules, as well as interactions between extramembraneous domains of adjacent proteins in an oligomer.
Development of head-mounted projection displays for distributed, collaborative, augmented reality applications

Distributed systems technologies supporting 3D visualization and social collaboration will be increasing in frequency and type over time. An emerging type of head-mounted display referred to as the head-mounted projection display (HMPD) was recently developed that only requires ultralight optics (i.e., less than 8 g per eye) that enables immersive multiuser, mobile augmented reality 3D visualization, as well as remote 3D collaborations. In this paper a review of the development of lightweight HMPD technology is provided, together with insight into what makes this technology timely and so unique. Two novel emerging HMPD-based technologies are then described: a teleportal HMPD (T-HMPD) enabling face-to-face communication and visualization of shared 3D virtual objects, and a mobile HMPD (M-HMIPD) designed for outdoor wearable visualization and communication. Finally, the use of HMPD in medical visualization and training, as well as in infospaces, two applications developed in the ODA and MIIND labs respectively, are discussed.
Resistance and lifetime measurements of polymer solar cells using glycerol doped poly[3,4-ethylenedioxythiophene]: poly[styrenesulfonate] hole injection layers

We have performed resistivity measurements of poly[3,4-ethylenedioxythiophene]: poly[styrenesulfonate] (PEDOT:PSS) films with varying concentrations of glycerol. Resistivity is seen to decrease exponentially from roughly 3 Ω-cm for pure PEDOT:PSS to 3 × 10-2 Ω-cm for 35 mg/cm3 glycerol in PEDOT:PSS. Beyond this concentration adding glycerol does not significantly change resistivity. Bulk heterojunction polymer solar cells using these variously doped PEDOT:PSS layers as electrodes were studied to characterize the effects on efficiency and lifetime. Although our data display significant scatter, lowering the resistance of the PEDOT:PSS layers results in lower device resistance and higher efficiency as expected. We also note that the lifetime of the devices tends to be reduced as the glycerol content of PEDOT:PSS is increased. Many devices show an initial increase in efficiency followed by a roughly exponential decay. This effect is explained based on concomitant changes in the zero bias conductance of the samples under dark conditions.
High Performance Fortran Compilation Techniques for Parallelizing Scientific Codes

With current compilers for High Performance Fortran (HPF), substantial restructuring and hand- optimization may be required to obtain acceptable performance from an HPF port of an existing Fortran application. A key goal of the Rice dHPF compiler project is to develop optimization techniques that can provide consistently high performance for a broad spectrum of scientific applications with minimal restructuring of existing Fortran 77 or Fortran 90 applications. This paper presents four new optimization techniques we developed to support efficient parallelization of codes with minimal restructuring. These optimizations include computation partition selection for loop nests that use privatizable arrays, along with partial replication of boundary computations to reduce communication overhead; communication- sensitive loop distribution to eliminate inner-loop communications; interprocedural selection of computation partitions; and data availability analysis to eliminate redundant communications. We studied the effectiveness of the dHPF compiler, which incorporates these optimizations, in parallelizing serial versions of the NAS SP and BT application benchmarks. We present experimental results comparing the performance of hand-written MPI code for the benchmarks against code generated from HPF using the dHPF compiler and the Portland Group's pghpf compiler. Using the compilation techniques described in this paper we achieve performance within 15% of hand-written MPI code on 25 processors for BT and within 33% for SP. Furthermore, these results are obtained with HPF versions of the benchmarks that were created with minimal restructuring of the serial code (modifying only approximately 5% of the code).
Gratitude A Tool for Reducing Economic Impatience

The human mind tends to excessively discount the value of delayed rewards relative to immediate ones, and it is thought that "hot" affective processes drive desires for short-term gratification. Supporting this view, recent findings demonstrate that sadness exacerbates financial impatience even when the sadness is unrelated to the economic decision at hand. Such findings might reinforce the view that emotions must always be suppressed to combat impatience. But if emotions serve adaptive functions, then certain emotions might be capable of reducing excessive impatience for delayed rewards. We found evidence supporting this alternative view. Specifically, we found that (a) the emotion gratitude reduces impatience even when real money is at stake, and (b) the effects of gratitude are differentiable from those of the more general positive state of happiness. These findings challenge the view that individuals must tamp down affective responses through effortful self-regulation to reach more patient and adaptive economic decisions.
Periodic Electrodynamic Field of Dielectric Barrier Discharge

The periodic electrodynamic field of a dielectric barrier discharge is investigated via a physical-based model and solved by rigorous boundary conditions associated with the Maxwell equations for electromagnetics in the time domain. The global motion of charged particles in the form of a succession of random micro discharges is described by the drift-diffusion theory. The plasma generation process of the dielectric barrier discharge is still mainly the result of avalanche growth of electrons produced by the secondary emission on the cathode. This phenomenon together with the charged particles accumulation on the electrode will be demonstrated in a two-dimensional simulation as the principal mechanism for generating the so-called electric wind. Through the present approach, the self-limiting characteristic of dielectric barrier discharge for preventing corona-to-spark transition is convincingly demonstrated
Reference modulation for calibrated measurements of tag backscatter

This paper presents an approach for calibrating backscattering measurements from 860–960 MHz Ultra-High Frequency Radio Frequency Identification (UHF RFID) tags. An S-parameter model is formulated to relate diode switch and antenna input circuit parameters with the scattering performance of the calibration device. Measurements of modulated backscattered power agree with the model to within ±0.1 dB. Tag backscatter measurements can then be calibrated by comparing them to the reference signal. In an example testbed, the expanded uncertainty of these measurements is estimated to be ±0.4 dB, compared with uncertainties worse than −0.9 dB, +1.2 dB for methods that calibrate against radar cross section (RCS) standards in the same testbed.
Pin assignment for multi-FPGA systems

Multi-FPGA systems have tremendous potential, providing a high-performance computing substrate for many different applications. One of the keys to achieving this potential is a complete, automatic mapping solution that creates high-quality mappings in the shortest possible time. In this paper, we consider one step in this process, the assignment of inter-FPGA signals to specific I/O pins on the FPGAs in a multi-FPGA system. We show that this problem can neither be handled by pin assignment methods developed for other applications nor standard routing algorithms. Although current mapping systems ignore this issue, we show that an intelligent pin assignment method can achieve both quality and mapping speed improvements over random approaches. Intelligent pin assignment methods already exist for multi-FPGA systems, but are restricted to topologies where logic-bearing FPGAs cannot be directly connected. In this paper, we provide three new algorithms for the pin assignment of multi-FPGA systems with arbitrary topologies. We compare these approaches on several mappings to current multi-FPGA systems, and show that the force-directed approach produces better mappings, in significantly shorter time, than any of the other approaches.
Microstructural design of toughened ceramics

On discute des mecanismes de renforcement des ceramiques par pontage des fissures a l'aide de trichites et d'autres types de renforcants discontinus. On montre que le renforcement par pontage des fissures peut etre combine avec d'autres mecaniques de renforcement (par exemple par transformation de phase) et que l'on peut obtenir des effets de synergie. La conception des materiaux renforces repose fortement sur le controle des proprietes des materiaux et des constituants microstructuraux
The effect of ion irradiation on inert gas bubble mobility

Abstract The effect of Al ion irradiation on the mobility of Xe gas bubbles in Al thin films was investigated. Transmission electron microscopy was used to determine bubble diffusivities in films irradiated and/or annealed at 673,723 and 773 K. Irradiation increased bubble diffusivity by a factor of 2–9 over that due to thermal annealing alone. The Arrhenius behavior and dose rate dependence of bubble diffusivity are consistent with a radiation enhanced diffusion phenomenon affecting a volume diffusion mechanism of bubble transport.
On the Origin of Nuclear Star Clusters in Late-Type Spiral Galaxies

A large fraction of bulgeless disk galaxies contain young compact stellar systems at their centers, in spite of the local gravitational stability of these disks. We evaluate two contrasting hypotheses for the origin of the nuclear star clusters in late-type disk galaxies. The clusters could not have migrated from distant eccentric locations in the disk. Instead they must have formed in situ, requiring radial transport of gas toward the center of the disk. This transport could be a consequence of the development of the magnetorotational instability in the differentially rotating warm neutral medium. We evaluate the rate of gas transport into the disk center and find that it is sufficient to support continuous star formation in that location. Enhanced stellar surface brightness in the inner few hundred parsecs and the formation of a compact stellar system in the central few parsecs are unavoidable in dark matter halos with divergent density profiles. We illustrate our conclusions on a model of the nearest late-type disk galaxy M33.
Navier-Stokes Solutions for an Axisymmetric Nozzle

Numerical solutions of the Navier-Stokes equations are obtained for an axisymmetric nozzle in a supersonic external flowfield (M^ =1.94, My =3.0, Re^ =2.2xl0). Five jet pressure ratio conditions ranging from a highly overexpanded case that exhibits a Mach disk shock formation to a slightly underexpanded case are solved computationally. MacCormack's explicit finite-difference algorithm, an adaptive grid scheme, and locally dependent eddy viscosity modeling are utilized to obtain the numerical solutions. The computational results accurately reproduce the experimentally observed viscous effects on the nozzle base pressure and shock locations resulting from a thick base annulus on the nozzle. Correct transition from regular shock reflection to Mach disk reflection in the jet core was achieved numerically.
A semi-empirical model for the therapeutic range shift estimation caused by inhomogeneities in proton beam therapy.

The purpose of this study was to devise a simple semi-empirical model to estimate the range shift in clinical practices with high-Z inhomogeneity in proton beam. A semi-empirical model utilizing the logarithmic dependence on Z in stopping power from Bohr’s classical approach has been developed to calculate the range shift due to the presence of inhomogeneity. Range shift from metallic plates of atomic number Z of various thicknesses were measured in water using a parallel plate ionization chamber and calculated with the FLUKA Monte Carlo code. The proton range shifts for bone and polymethyl methacrylate (PMMA) were estimated using the semi-empirical model and compared with Monte Carlo calculation. The semi-empirical equation to determine range shift and water equivalent thickness is presented. The model predicts a shift of the therapeutic range to within 2.5% accuracy for initial proton energies of 50 to 250 MeV and atomic numbers from 3.3 (effective Z for water) to 82. This equation is independent of beam energy, and thus provides range shift from high-Z materials without the knowledge of proton energy. The proposed method of calculating the therapeutic range shift accurately requires only knowledge of the effective or actual atomic number of the inhomogeneity and the thickness of the inhomogeneity along the beam direction. The model generalizes the range shift calculation for any material based on its effective atomic number, and permits reliable prediction of the range shift for material combinations where no data is currently available. The proposed model can be readily implemented in routine clinical practice for proton range shift estimation and quality assurance on the treatment planning.
Evolution and Yields of Extremely Metal-poor Intermediate-Mass Stars

Intermediate-mass stellar evolution tracks from the main sequence to the tip of the AGB for five initial masses (2-6 M☉) and metallicity Z = 0.0001 have been computed. The detailed one-dimensional structure and evolution models include exponential overshooting, mass loss, and a detailed nucleosynthesis network with updated nuclear reaction rates. The network includes a two-particle heavy neutron sink for approximating neutron density in the He-shell flash. It is shown how the neutron-capture nucleosynthesis is important in models of very low metallicity for the formation of light neutron-heavy species, like sodium or the heavy neon and magnesium isotopes. The models have high resolution, as required for modeling the third dredge-up. All sequences have been followed from the pre-main sequence to the end of the AGB when all envelope mass is lost. Detailed structural and chemical model properties as well as yields are presented. This set of stellar models is based on standard assumptions and updated input physics. It can be confronted with observations of extremely metal-poor stars and may be used to assess the role of AGB stars in the origin of abundance anomalies of some globular cluster members of correspondingly low metallicity.
Radar Signal Processing: Digital, Charge-Coupled Device (CCD), Or Surface Acoustic Wave (SAW)?

Recent emphasis placed upon real-time coherent radar signal processing has fostered competition between digital, charge-coupled device (CCD) and surface acoustic wave (SAW) technologists. In that this stimulates and encourages technological advances, this competition is a healthy one; to the extent that the complementary rather than competitive properties of the technologies are not effectively utilized, the competition is counterproductive. The application of the various technologies to ground radar signal processors is investigated. The emergent theme emphasizes the fact that all signal processor tasks must be considered to properly assess the applicability of the various technologies; it is insufficient to compare signal processor implementations on the basis of a filtering function alone. To illustrate this viewpoint, examples of digital, CCD, and SAW signal processors are given.
Comparison of two esmolol bolus doses on the haemodynamic response and seizure duration during electro-convulsive therapy

Twelve ASA physical status I-III patients were enrolled in a double-blind, prospective, randomized, three-way, within-patient crossover study designed to determine the effect of two standard esmolol bolus doses (100 and 200 mg) on the haemodynamic response and seizure duration during electro-convulsive therapy (ECT). Esmolol or placebo was administered one minute prior to induction of anaesthesia and exactly two minutes before ECT. Both the 100 and 200 mg bolus doses significantly blunted the maximum increase in heart rate (HR) and mean arterial pressure (MAP) following ECT in comparison with placebo. Compared with placebo, esmolol 100 mg decreased maximum HR by 23 +/- 3%, maximum MAP by 17 +/- 7% and maximum rate-pressure product (RPP) by 40 +/- 9%. Esmolol 200 mg decreased maximum HR by 25 +/- 3%, maximum MAP by 19 +/- 3% and maximum RPP by 42 +/- 5%. No significant difference was found between the two esmolol doses at corresponding measurement points before and after ECT. Treatment with esmolol 200 mg resulted in a significantly shorter mean seizure duration than with placebo. As the 200 mg dose caused a shorter seizure duration and the haemodynamic effects of 100 mg and 200 mg doses were similar, it was concluded that the 100 mg esmolol bolus dose was the better dose for ECT.
An anomalous case of diastereofacial selectivity in the addition of chiral allylstannanes to benzaldehyde: is the “inside alkoxy” effect involved?

Abstract The “inside alkosy” effect has been found to be important in the addition of α-(alkoxy) allylstannanes to aldehydes in the presence of BF3·Et2O.
Endogenous RhoG is dispensable for integrin-mediated cell spreading but contributes to Rac-independent migration.

Rac activation by integrins is essential for cell spreading, migration, growth and survival. Based mainly on overexpression of dominant-negative mutants, RhoG has been proposed to mediate integrin-dependent Rac activation upstream of ELMO and Dock180. RhoG-knockout mice, however, display no significant developmental or functional abnormalities. To clarify the role of RhoG in integrin-mediated signaling, we developed a RhoG-specific antibody, which, together with shRNA-mediated knockdown, allowed analysis of the endogenous protein. Despite dramatic effects of dominant-negative constructs, nearly complete RhoG depletion did not substantially inhibit cell adhesion, spreading, migration or Rac activation. Additionally, RhoG was not detectably activated by adhesion to fibronectin. Using Rac1 –/– cells, we found that constitutively active RhoG induced membrane ruffling via both Rac-dependent and -independent pathways. Additionally, endogenous RhoG was important for Rac-independent cell migration. However, RhoG did not significantly contribute to cell spreading even in these cells. These data therefore clarify the role of RhoG in integrin signaling and cell motility.
Multiple-Input Multiple-Output Gaussian Broadcast Channels With Common and Confidential Messages

This paper considers the problem of the multiple-input multiple-output (MIMO) Gaussian broadcast channel with two receivers (receivers 1 and 2) and two messages: a common message intended for both receivers and a confidential message intended only for receiver 1 but needing to be kept asymptotically perfectly secure from receiver 2. A matrix characterization of the secrecy capacity region is established via a channel enhancement argument. The enhanced channel is constructed by first splitting receiver 1 into two virtual receivers and then enhancing only the virtual receiver that decodes the confidential message. The secrecy capacity region of the enhanced channel is characterized using an extremal entropy inequality previously established for characterizing the capacity region of a degraded compound MIMO Gaussian broadcast channel.
White is green

Green is the center of the visible spectrum and the hue to which we are most sensitive. In RGB color, green is 60 percent of white. When we look through a prism at a white square, as Goethe did, we see white between yellow and cyan, just where green appears in the spectrum of Newton. Additional arguments were published previously and appear at www.csulb.edu/-percept, along with the Percept color chart of the hue/value relationships. A new argument, derived from the perception of leaves, is presented here. The Percept color chart transformed into a color wheel is also presented.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Channel state feedback schemes for multiuser MIMO-OFDM downlink

Channel state feedback schemes for the MIMO broadcast downlink have been widely studied in the frequency flat case. This work focuses on the more relevant frequency selective case, where some important new aspects emerge. We consider a MIMO-OFDM broadcast channel and compare achievable ergodic rates under three channel state feedback schemes: analog feedback, direction quantized feedback and "time-domain" channel quantized feedback. The first two schemes are direct extensions of previously proposed schemes. The third scheme is novel, and it is directly inspired by rate-distortion theory of Gaussian correlated sources. For each scheme we derive the conditions under which the system achieves full multiplexing gain. The key difference with respect to the widely treated frequency-flat case is that in MIMO-OFDM the frequency domain channel transfer function is a Gaussian correlated source. The new time-domain quantization scheme takes advantage of the channel frequency correlation structure and outperforms the other schemes. Furthermore, it is by far simpler to implement than complicated spherical vector quantization. In particular, we observe that no structured codebook design and vector quantization is actually needed for efficient channel state information feedback.