cssi/SciSciGPT-SciSciNet huggingface dataset:
Interaction of surface radiation with convection in crystal growth by physical vapor transport

Growth of single crystals from vapor in closed ampoules is governed by an intricate interplay between mass, momentum and heat transfer processes. The objective of this study is to examine and isolate the effects of surface radiation heat transfer on the vapor transport process using a mathematical model. The model consists of a set of coupled nonlinear partial differential equations for conservation of mass, momentum, energy and species, and the integrodifferential equations which represent radiative exchange. It depends on five important physical parameters. These are Grashof number, Prandtl number, Schmidt number, aspect ratio and the radiation-conduction number. The effects of these dimensionless groupings are systematically investigated. From the cases examined, it is concluded that surface radiation can change the flow structure appreciably. This is especially true in microgravity environment where radiation competes primarily with conduction in modifying the thermal profiles. The numerical results also show that in the presence of radiation, the top heating configuration (source on top) is no longer stable and that near the growing crystal, radiation-induced vortices can introduce significant nonuniformities in the growth flux.
Adjusted Earnings Yields and Real Rates of Return

An accurate forecast of real return requires that accounting and debt adjustments be made to reported earnings. This article presents methodologies that investors can use to estimate the accounting and debt adjustments for individual companies and offers evidence, derived from a predictive regression model, that investors should consider these adjustments important. The article also reviews the use of nonfinancial corporate debt and makes the case that investors should view the use of debt by nonfinancial companies more positively than they currently do.
Model structures on exact categories

Abstract We define model structures on exact categories, which we call exact model structures. We look at the relationship between these model structures and cotorsion pairs on the exact category. In particular, when the underlying category is weakly idempotent complete, we get Hovey’s one-to-one correspondence between model structures and complete cotorsion pairs. We classify the right and the left homotopy relation in terms of the cotorsion pairs and look at examples of exact model structures. In particular, we see that given any hereditary abelian model category, the full subcategories of cofibrant, fibrant and cofibrant–fibrant subobjects each has natural exact model structures equivalent to the original model structure. These model structures each has interesting characteristics. For example, the cofibrant–fibrant subobjects form a Frobenius category, whose stable category is the same as the homotopy category of its model structure.
Effects of Mergers and Core Structure on the Bulk Properties of Nearby Galaxy Clusters

We use X-ray morphological measurements and the scatter of clusters about observed and simulated scaling relations to examine the impact of merging and core-related phenomena on the structure of galaxy clusters. We use a range of X-ray and near-infrared (near-IR) scaling relations; all observed scaling relations constructed from emission-weighted mean temperature and intracluster medium mass, X-ray luminosity, isophotal size, and near-IR luminosity show a separation between clusters identified as cool core (CC) and those identified as non-cool core (NCC). We attribute this partially to a simple temperature bias in CC clusters and partially to other cool core-related structural changes. Scaling relations constructed from observables that are largely independent of core structure show smaller separation between CC and NCC populations. We attempt to minimize CC-related separation in scaling relations via two methods: by applying a uniform scale factor to CC cluster temperatures and determining the scale factor for each relation that minimizes the separation between CC and NCC populations, and by introducing cluster central surface brightness as a third parameter in observable-temperature scaling relations. We find an average temperature bias factor of 1.07 ± 0.02 between the CC and NCC populations; the three-parameter approach reduces scatter in scaling relations more than a simple CC temperature scaling. We examine the scatter about the best-fit observable-temperature-brightness scaling relations and compare the intrinsic scatter within subsamples split by CC/NCC and four different morphological merger indicators. CC clusters and clusters with less substructure generally exhibit higher scatter about scaling relations. The larger structural variations in CC clusters are present well outside the core, suggesting that a process more global than core radiative instability is at work. Simulations without cooling mechanisms also show no correlation between substructure and larger scatter about scaling relations, indicating that any merger-related scatter increases are subtle. Taken together, the observational and simulation results indicate that cool core-related phenomena—not merging processes—are the primary contributor to scatter in scaling relations. Our analysis does not appear to support the scenario in which clusters evolve cool cores over time unless they experience major mergers.
Earnings Predictability, Information Asymmetry, and Market Liquidity

We investigate the relation between earnings predictability, information asymmetry and the behavior of the adverse selection cost component of the bid-ask spread around quarterly earnings announcements for NASDAQ firms. While we find an increase in the adverse selection component of the bid-ask spread on the day of and the day prior to quarterly earnings announcements for firms with less predictable earnings, we find no evidence of such changes for firms with more predictable earnings. During a non-announcement period, we find that firms with relatively less predictable earnings have consistently higher total bid-ask spreads than firms with more predictable earnings. This finding suggests that firms with relatively less predictable earnings have a higher cost of equity capital than comparable firms with more predictable earning streams, ceteris paribus. Hence, earnings predictability may be a legitimate concern of managers who wish to minimize their cost of equity capital at least as it pertains to bid-ask spreads.
Variable Powder Flow Rate Control in Laser Metal Deposition Processes

This paper proposes a novel method, called variable powder flow rate control (VPFRC), for the regulation of powder flow rate in laser metal deposition processes. The idea of VPFRC is to adjust the powder flow rate to maintain a uniform powder deposition per unit length even when disturbances occur (e.g., the motion system accelerates and decelerates). Dynamic models of the powder delivery system motor and the powder transport system (i.e., 5 m pipe, powder dispenser, and cladding head) are constructed. A general tracking controller is then designed to track variable powder flow rate references. Since the powder flow rate at the nozzle exit cannot be directly measured, it is estimated using the powder transport system model. The input to this model is the dc motor rotation speed, which is estimated online using a Kalman filter. Experiments are conducted to examine the performance of the proposed control methodology. The experimental results demonstrate that the VPFRC method is successful in maintaining a uniform track morphology, even when the motion system accelerates and decelerates.
Top decay in topcolor-assisted technicolor☆

Abstract Conventional technicolor models with light charged technipions ( π T ± ) lead to an unacceptably large contribution to t → π T + b decay rate. Topcolor-assisted technicolor models also have additional PGBs called top-pions ( π t +- ) which may contribute to this decay. We study the potentially dangerous mixing of charged top-pion and technipions in toy models of ‘natural’ topcolor-assisted technicolor. We find that the t → π t , T + b decay rate in such models can be within experimental limits due to a combination of heavy top-pion and small π t - π T mixing.
Intercepted Decarboxylative Allylations of Nitroalkanoates

Using palladium-catalyzed decarboxylation, several cascade reactions of allyl and prenyl nitroalkanoates that lead to nitro-containing chemical building blocks are described. A nitronate Michael addition/Tsuji-Trost allylation cascade was developed, leading to functionally dense chemical building blocks. Likewise, a Tsuji-Trost/decarboxylative protonation sequence was developed for the synthesis of orthogonally functionalized 2° nitroalkanes. The latter method provides rapid access to the indolizidine core.
Synthesis of fused imidazoles, pyrroles, and indoles with a defined stereocenter α to nitrogen utilizing Mitsunobu alkylation followed by palladium-catalyzed cyclization.

Nitrogen-containing fused heterocycles comprise many compounds that demonstrate interesting biological activities. A new synthetic approach involving Mitsunobu alkylation of imidazoles, pyrroles, a...
Communication With Disturbance Constraints

Motivated by the broadcast view of the interference channel, the new problem of communication with disturbance constraints is formulated. The rate-disturbance region is established for the single constraint case and the optimal encoding scheme turns out to be the same as the Han-Kobayashi scheme for the two user-pair interference channel. This result is extended to the Gaussian vector (MIMO) case. For the case of communication with two disturbance constraints, inner and outer bounds on the rate-disturbance region for a deterministic model are established. The inner bound is achieved by an encoding scheme that involves rate splitting, Marton coding, and superposition coding, and is shown to be optimal in several nontrivial cases. This encoding scheme can be readily applied to discrete memoryless interference channels and motivates a natural extension of the Han-Kobayashi scheme to more than two user pairs.
Pioneer Venus Multiprobe Entry Telemetry Recovery

The Entry Phase of the Pioneer Venus Multiprobe Mission involved data transmission over only a two-hour span. The criticality of recovery of those two hours of data, coupled with the fact that there were no radio signals from the Probes until their arrival at Venus, dictated unique telemetry recovery approaches on the ground. The result was double redundancy, use of spectrum analyzers to aid in rapid acquisition of the signals, and development of a technique for recovery of telemetry data without the use of real-time coherent detection which is normally employed by all other NASA planetary missions.
Isonucleosides: Design and Synthesis of New Isomeric Nucleosides with Antiviral Potential

Isonucleosides discovered in our laboratory have been found to have interesting antiviral activity. The design, development of methodology, and stereochemical synthesis of new isonucleosides of anti-HCV interest are described. Antiviral results are cited.
Quantum symmetric pairs and their zonal spherical functions

We study the space of biinvariants and zonal spherical functions associated to quantum symmetric pairs in the maximally split case. Under the obvious restriction map, the space of biinvariants is proved isomorphic to the Weyl group invariants of the character group ring associated to the restricted roots. As a consequence, there is either a unique set, or an (almost) unique two-parameter set of Weyl group invariant quantum zonal spherical functions associated to an irreducible symmetric pair. Included is a complete and explicit list of the generators and relations for the left coideal subalgebras of the quantized enveloping algebra used to form quantum symmetric pairs.
Quasar Proximity Zones and Patchy Reionization

Lyα forest absorption spectra toward quasars at z ~ 6 show regions of enhanced transmission close to their source. Several authors have argued that the apparently small sizes of these regions indicate that quasar ionization fronts at z 6 expand into a largely or partly neutral IGM. Assuming that the typical region in the IGM is reionized by z ≤ 6, as is suggested by Lyα forest observations, we argue that at least 50% of the volume of the IGM was reionized before the highest redshift quasars turned on. Further, even if the IGM is as much as ~50% neutral at quasar turn-on, the quasars are likely born into large galaxy-generated H II regions. The H II regions during reionization are themselves clustered, and using radiative transfer simulations, we find that long skewers through the IGM toward quasar progenitor halos pass entirely through ionized bubbles, even when the IGM is half-neutral. These effects have been neglected in most previous analyses of quasar proximity zones, which assumed a spatially uniform neutral fraction. We model the subsequent ionization from a quasar and construct mock Lyα forest spectra. Our mock absorption spectra are more sensitive to the level of small-scale structure in the IGM than to the volume-averaged neutral fraction and suggest that existing proximity zone size measurements are compatible with a fully ionized IGM. However, we mention several improvements in our modeling that are necessary to make more definitive conclusions.
Regional Economic Effects of Higher Education Institutions.

Abstract The paper describes five economic linkages by which a university might promote regional development. Both theory and empirical evidence are considered In general, the benefits of a university are found to dissipate too quickly outside of a local region to have very decisive local effects; however, there are exceptions which suggest ways to make the university a more powerful agent of regional development. Major attention is given to the possibility of enhancing the ‘amenity’ effects and the ‘expenditure’ effects of a university. Basic issues of cause-and-effect are also reviewed in light of their policy implications.
The Origin of Low-energy Anomalous Cosmic Rays at the Solar-wind Termination Shock

We address the origin of the enhancement of ~40 keV to 5 MeV ions at the solar wind termination shock. Using self-consistent two-dimensional hybrid simulations (kinetic proton, fluid electron) of a shock moving through a plasma similar to that observed in the outer heliosphere, we conclude that the observed ion enhancements are consistent with accelerated "core" interstellar pickup ions (those that have not previously undergone any significant energization) by the termination shock via a combination of shock drift acceleration and particle scattering in meandering magnetic fields in the vicinity of the shock. In addition to the consequences for our understanding of anomalous cosmic rays, this work is also relevant to the more-general long-standing problem of accelerating low-energy particles by shocks that move nearly normal to a mean magnetic field.
The Long and Short on Long-Short

By balancing long positions in equity with short positions of roughly equal dollar amount and market sensitivity, it is possible to construct a portfolio whose return is neutralized against overall market moves. Properly constructed, using an integrated optimization process, a long-short portfolio offers advantages over long-only portfolios in enhanced flexibility to pursue return, control risk, and allocate assets. Any additional costs do not outweigh the benefits of such a strategy.
The surface chemistry of hydrocarbon partial oxidation catalysis

Abstract The catalytic oxidation of simple alkyl moieties and alcohols on nickel surfaces has been studied by a combination of surface-science and catalytic techniques on increasingly more complex model systems. Initial work was carried out on oxygen-treated nickel single-crystal surfaces under ultrahigh vacuum conditions. The emulation of sub-stoichiometric nickel oxides was corroborated by a number of physical and chemical means, in particular by the use of carefully chosen probe molecules. The mechanism for partial oxidation was then determined. In the case of alkyl groups, an initial facile oxygen insertion was determined to lead to the formation of surface alkoxides, and to a subsequent dehydrogenation of those intermediates at the beta position to yield aldehydes or ketones. Alcohols were found to dehydrogenate by the same β-hydride elimination step, and surface OH groups to enhance that partial oxidation pathway. High selectivity towards dehydrogenation was observed on most nickel-based catalysts, except when alumina was used as a support, where the new acid sites favored dehydration instead. Total oxidation appears to be a secondary reaction on the initial dehydrogenation products, not a parallel pathway.
Frey's syndrome: treatment with topical glycopyrrolate

Gustatory sweating and flushing of the facial skin, or Frey's syndrome, is fairly common after parotidectomy. The most likely mechanism is aberrant reinnervation of the sweat glands of the face by the severed parotid parasympathetic nerve fibers. A survey of 61 patients having undergone parotidectomy yielded 29 (47.5%) with gustatory sweating. Twenty-three percent (14 patients) considered the symptoms severe. In a double-blind study, five of those 14 patients were alternately treated with topically applied placebo and with glycopyrrolate (an anticholinergic agent) as 0.5% lotion, 2% lotion, and 2% cream. All five patients showed some improvement with the test preparations, but had longer lasting and more effective lessening of symptoms with the 2% glycopyrrolate preparations. There were no adverse side effects. We therefore believe that the topical application of a 2% glycopyrrolate preparation is a safe and effective treatment for severe gustatory sweating following parotidectomy.
Succession and interrelationships of microorganisms on painted surfaces

Abstract This paper relates a series of experiments designed to elucidate the interrelationships of microorganisms on painted surfaces. Evidence is given to support the conclusion that bacteria are the earliest colonizers on painted surfaces. Bacterial capsules appear to enhance the later settlement of fungi and their continued growth. Evidence is given to support the hypothesis that bacteria condition painted surfaces and through extracellular enzymes convert paint components to fungal metabolites. Observations were made relative to the influence of proprietary mildewcides on microbial succession on painted surfaces.
A Statistical Method for Constructing Transcriptional Regulatory Networks Using Gene Expression and Sequence Data

Transcriptional regulation is one of the most important means of gene regulation. Uncovering transcriptional regulatory networks helps us to understand the complex cellular process. In this paper, we describe a statistical approach for constructing transcriptional regulatory networks using data of gene expression, promoter sequence, and transcription factor binding sites. Our simulation studies show that the overall and false positive error rates in the estimated transcriptional regulatory networks are expected to be small if the systematic noise in the constructed feature matrix is small. Our analysis based on 658 microarray experiments on yeast gene expression programs and 46 transcription factors suggests that the method is capable of identifying significant transcriptional regulatory interactions and uncovering the corresponding regulatory network structures.
On the Use of Empirical Bolometric Corrections for Stars

When making use of tabulations of empirical bolometric corrections for stars (BC V ), a commonly overlooked fact is that while the zero point is arbitrary, the bolometric magnitude of the Sun (M bol,☉) that is used in combination with such tables cannot be chosen arbitrarily. It must be consistent with the zero point of BC V so that the apparent brightness of the Sun is reproduced. The latter is a measured quantity, for which we adopt the value V ☉ = –26.76 ± 0.03. Inconsistent values of M bol,☉ are listed in many of the most popular sources of BC V . We quantify errors that are introduced by failure to pay attention to this detail. We also take the opportunity to reprint the BC V coefficients of the often used polynomial fits by Flower, which were misprinted in the original publication.
EQCM studies of the electrodeposition and corrosion of tin–zinc coatings

Abstract A 70% Sn–30% Zn layer is deposited from a neutral non-cyanide bath. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) show that it is composed of Sn and Zn phases. By use of an electrochemical quartz crystal microbalance (EQCM), the plating current efficiency is determined. When the plated sample is exposed to a 0.5 M Na2SO4 (pH 3.6) solution at open circuit potential (OCP), the EQCM measures the corrosion rate. The open circuit potential shows that the Zn dissolution reaction is the major reaction occurring at OCP. A linear potential scanning experiment shows that the anodic polarization current of this system is rather small in a wide range of potentials until it reaches the anodic dissolution potential of pure Sn in the same solution.
Urban neighborhood context and mortality in late life.

Objective: To examine the contextual effects of urban neighborhood characteristics on mortality among older adults. Method: Data are from the Study of Assets and Health Dynamics Among the Oldest Ol...
CORRELATION AND LOCALIZATION OF 2-D ELECTRONS IN A STRONG MAGNETIC FIELD

An overview is given of some recent experiments on the localization‐delocalization transition in the integral quantum Hall effect and the new quantum liquid ground states giving rise to the fractional quantum Hall effect.
Studying Governance and Public Management: Challenges and Prospects

How can public-sector regimes, agencies, programs, and activities be organized and managed to achieve public purposes? This question, of fundamental importance in the fields of politics, policy implementation, public administration, and public management, motivates the systematic study of governance. In this article, we present a logic of governance, based in political economy literatures, that might be used as a first step toward framing theory-based governance research. We also describe a methodological approach that is more likely to appropriately identify and explain relationships in governance regimes that involve activities and interactions that span more than one level of an organization or systemic structure. In addition, we explore the potential of various sources of data for governance research, recognizing that governance researchers will inevitably have to make simplifying assumptions or measure crudely things that we know are much more complex. We argue that when appropriately framed and interpreted through a logic of governance that acknowledges limitations attributable to the models, methods, and data employed, governance research is more likely to produce enduring knowledge about how, why, and with what consequences public-sector activity is structured and managed.
Effects of Hierarchical Architecture on Electronic and Mechanical Properties of Nanocast Monolithic Porous Carbons and Carbon−Carbon Nanocomposites

This study compares the effects of meso- and macroporosity and the influence of nanocomposite structure on textural, electronic, and mechanical properties of monolithic carbon samples. Glassy carbon monoliths with three-dimensionally ordered macropores and walls containing mesopores (3DOM/m C) were synthesized by nanocasting from monolithic silica with hierarchical pore structure. The porous silica monoliths (3DOM/m SiO2) were prepared by combining colloidal crystal templating with surfactant templating. These preforms were infiltrated with a phenolic resin through a gas-phase process. After carbonization and HF extraction of silica, the resulting carbon monoliths maintained the open, interconnected macropore structure of the preform and the mesoporosity of the skeleton, which provided a high surface area >1200 m2/g to the material. Subsequent introduction of more graphitic, nitrogen-doped carbon into the mesopores by chemical vapor deposition produced a monolithic nanocomposite material (3DOM/m C/C). The...
The Nambu-Jona-Lasinio model of QCD on the lattice

Abstract In an effort to obtain insights on the behavior of an interacting theory of fermions on the lattice that posseesses the QCD chiral symmetry, the two flavor Nambu-Jona-Lasinio model with SU (2) × SU (2) chiral symmetry is studied on the four-dimensional hypercubic lattice using large N techniques and numerical simulations. Naive and Wilson fermions are considered and transparent results are obtained regarding the following: the approach to the zero quark and zero pion mass limits, the size of the 1/ N corrections, the effects of the zero momentum fermionic modes on finite lattices, and the scalar and pseudoscalar spectrum. Some interesting observations are made by viewing the model as the low energy approximation to QCD, as well as an embedding theory of the Higgs sector.
Successful virtual screening of a chemical database for farnesyltransferase inhibitor leads.

Virtual screening of chemical databases is an emerging approach in drug discovery that uses computers to dock chemicals into the active site of a drug target to identify leads through evaluation of binding affinities of the chemicals. However, there are concerns about the validity and scope of the reported virtual screens due to lack of studies to show that randomly selected chemicals are not equally active and due to the fact that metalloproteins were rarely used as drug targets. We have performed a virtual screening of a chemical database to identify prototypic inhibitors of farnesyltransferase (FT) with zinc present in the active site. Among the 21 compounds identified by computers, four inhibited FT in vitro with IC50 values in the range from 25 to 100 μM. The most potent inhibitor also inhibited FT in human lung cancer cells. In contrast, none of 21 randomly selected compounds have an IC50 lower than 100 μM. The results demonstrate the validity of virtual screening and the feasibility of applications...
Buoyant Bubbles in Intracluster Gas: Effects of Magnetic Fields and Anisotropic Viscosity

Recent observations by Chandra and XMM-Newton indicate that there are complex structures at the cores of galaxy clusters, such as cavities and filaments. One plausible model for the formation of such structures is the interaction of radio jets with the intracluster medium (ICM). To investigate this idea, we use three-dimensional magnetohydrodynamic simulations including anisotropic (Braginskii) viscosity to study the effect of magnetic fields on the evolution and morphology of buoyant bubbles in the ICM. We investigate a range of different initial magnetic field geometries and strengths, and study the resulting X-ray surface brightness distribution for comparison to observed clusters. Magnetic tension forces and viscous transport along field lines tend to suppress instabilities parallel, but not perpendicular, to field lines. Thus, the evolution of the bubble depends strongly on the initial field geometry. We find that toroidal field loops initially confined to the interior of the bubble are best able to reproduce the observed cavity structures.
The dynamical evolution of massive black hole binaries I. Hardening in a fixed stellar background

Abstract The stellar ejection rate and the rates of change of the binary semimajor axis and eccentricity are derived from scattering experiments for the restricted three-body problem. They are used to study the evolution of binaries in simple models for galactic nuclei, starting soon after the black holes become bound and continuing until the evolution is dominated by the emission of gravitational radiation or until the ejected mass is too large for the galaxy to be considered fixed. The eccentricity growth is found to be unimportant unless the binary forms with a large eccentricity. The scattering results suggest that a binary with masses m1 ≥ m2 should not be considered hard until its orbital velocity exceeds the background velocity dispersion by a factor that scales as (1 +m1/m21/2). The results are compared with predictions from Chandrasekhar's dynamical-friction formula and with previous work on the capture and scattering of comets by planetary systems.
FREYA—A New Monte Carlo Code for Improved Modeling of Fission Chains

A new simulation capability for modeling individual fission events and chains and the transport of fission products in materials is presented. The fission yield event yield algorithm (FREYA) is a Monte Carlo code for generating fission events providing correlated kinematic information for prompt neutrons, gammas, and fragments. For each fission event, FREYA generates multiplicity, energy, and the direction of neutrons and gammas while conserving energy and momentum at each step. To study materials with multiplication, shielding effects, and detectors, we have integrated FREYA into the general-purpose Monte Carlo code MCNP. This new tool will allow more accurate modeling of detector responses including correlations and the development of SNM detectors with increased sensitivity.
Dynamic Modeling and Statistical Analysis of Event Times

This review article provides an overview of recent work in the modelling and analysis of recurrent events arising in engineering, reliability, public health, biomedical, and other areas. Recurrent event modelling possesses unique facets making it different and more difficult to handle than single event settings. For instance, the impact of an increasing number of event occurrences needs to be taken into account, the effects of covariates should be considered, potential association among the inter-event times within a unit cannot be ignored, and the effects of performed interventions after each event occurrence need to be factored in. A recent general class of models for recurrent events which simultaneously accommodates these aspects is described. Statistical inference methods for this class of models are presented and illustrated through applications to real data sets. Some existing open research problems are described.
Disturbing extremal behavior of spot rate dynamics

Abstract This paper presents a study of extreme interest rate movements in the US federal funds market over almost a half century of daily observations from the mid 1950s through the end of 2000. We analyze the fluctuations of the maximal and minimal changes in short-term interest rates and test the significance of time-varying paths followed by the mean and volatility of extremes. We formally determine the relevance of introducing trend and serial correlation in the mean and of incorporating the level and GARCH effects in the volatility of extreme changes in the federal funds rate. The empirical findings indicate the existence of volatility clustering in the standard deviation of extremes and a significantly positive relationship between the level and the volatility of extremes. The results point to the presence of an autoregressive process in the means of both local maxima and local minima values. The paper proposes a conditional extreme value approach to calculating value at risk (VaR) by specifying the location and scale parameters of the generalized Pareto distribution (GPD) as a function of past information. Based on the estimated VaR thresholds, the statistical theory of extremes is found to provide more accurate estimates of the rate of occurrence and the size of extreme observations.
Center symmetry and abelian projection at finite temperature

Abstract At finite temperature, there is an apparent conflict between Abelian projection and critical universality. For example, should the deconfinement transition of an SU(2) gauge theory projected to U(1) lie in the Z(2) universality class of the parent SU(2) theory or in the U(1) universality class? I prove that the projected theory lies in the universality class of the parent gauge theory. The mechanism is shown to be non-local terms in the projected effective action involving Polyakov loops. I connect this to the recent work by Dunne et al. on the deconfinement transition in the 2+1 dimensional Georgi-Glashow model, leading to a discussion of the role of renormalization group fixed points in Abelian projection.
Projected shell model study on nuclei near the N = Z line

Study of the \(N \approx Z\) nuclei in the mass-80 region is not only interesting due to the existence of abundant nuclear-structure phenomena, but also important in understanding the nucleosynthesis in the rp-process. It is difficult to apply a conventional shell model due to the necessary involvement of the g 9/2 sub-shell. In this paper, the projected shell model is introduced to this study. Calculations are systematically performed for the collective levels as well as the quasi-particle excitations. It is demonstrated that calculations with this truncation scheme can achieve a comparable quality as the large-scale shell model diagonalizations for 48 Cr, but the present method can be applied to much heavier mass regions. While the known experimental data of the yrast bands in the \(N \approx Z\) nuclei (from Se to Ru) are reasonably described, the present calculations predict the existence of high-K states, some of which lie low in energy under certain structure conditions.
Looking at distance learning through both ends of the camera

Abstract This case study follows an instructor and her students (thirty‐three elementary teachers) as they experience for the first time a graduate‐level science course delivered via compressed video technology. The study focuses on teacher learning and coping strategies. Data were gathered from videotaped records of classes, informal interviews with students and site facilitators, open‐ended student surveys, and instructor and student journals. Findings are reported in the discussion section of the study.
Predicting Risk as a Function of Risk Factors

In previous research, we showed that risk factors have a significant negative effect on reliability (e.g., failure occurrence). In this research, we show that it is feasible to predict risk (i.e., the probability that risk factors are related to discrepancy reports occurring on a software release). This is an important advance over the previous research because discrepancy reports are available in the requirements phase - when the cost and labor required to correct faults is low, whereas failure data only becomes available in the test phase - when the cost and labor required to correct faults is high. Although using historical failure data to drive traditional software reliability models would produce greater prediction accuracy, the opportunity to provide early prediction of reliability, using risk factors, outweighs this advantage
Asymmetric WIMP dark matter

In existing dark matter models with global symmetries the relic abundance of dark matter is either equal to that of anti-dark matter (thermal WIMP), or vastly larger, with essentially no remaining anti-dark matter (asymmetric dark matter). By exploring the consequences of a primordial asymmetry on the coupled dark matter and anti-dark matter Boltzmann equations we find large regions of parameter space that interpolate between these two extremes. Interestingly, this new asymmetric WIMP framework can accommodate a wide range of dark matter masses and annihilation cross sections. The present-day dark matter population is typically asymmetric, but only weakly so, such that indirect signals of dark matter annihilation are not completely suppressed. We apply our results to existing models, noting that upcoming direct detection experiments will constrain a large region of the relevant parameter space.
Electron-Hole Asymmetry is the Key to Superconductivity

In a solid, transport of electricity can occur via negative electrons or via positive holes. In the normal state of superconducting materials experiments show that transport is usually dominated by dressed positive hole carriers. Instead, in the superconducting state experiments show that the supercurrent is always carried by undressed negative electron carriers. These experimental facts indicate that electron-hole asymmetry plays a fundamental role in superconductivity, as proposed by the theory of hole superconductivity.
A multi-threaded fast convolver for dynamically parallel image filtering

2D convolution is a staple of digital image processing. The advent of large format imagers makes it possible to literally "pave" with silicon the focal plane of an optical sensor, which results in very large images that can require a significant amount computation to process. Filtering of large images via 2D convolutions is often complicated by a variety of effects (e.g., non-uniformities found in wide field of view instruments) which must be compensated for in the filtering process by changing the filter across the image. This paper describes a fast (FFT based) method for convolving images with slowly varying filters. A parallel version of the method is implemented using a multi-threaded approach, which allows more efficient load balancing and a simpler software architecture. The method has been implemented within a high level interpreted language (IDL), while also exploiting open standards vector libraries (VSIPL) and open standards parallel directives (OpenMP). The parallel approach and software architecture are generally applicable to a variety of algorithms and has the advantage of enabling users to obtain the convenience of an easy operating environment while also delivering high performance using a fully portable code.
Cognitive Trajectories after Postoperative Delirium

BACKGROUND Delirium is common after cardiac surgery and may be associated with long-term changes in cognitive function. We examined postoperative delirium and the cognitive trajectory during the first year after cardiac surgery. METHODS We enrolled 225 patients 60 years of age or older who were planning to undergo coronary-artery bypass grafting or valve replacement. Patients were assessed preoperatively, daily during hospitalization beginning on postoperative day 2, and at 1, 6, and 12 months after surgery. Cognitive function was assessed with the use of the Mini– Mental State Examination (MMSE; score range, 0 to 30, with lower scores indicating poorer performance). Delirium was diagnosed with the use of the Confusion Assessment Method. We examined performance on the MMSE in the first year after surgery, controlling for demographic characteristics, coexisting conditions, hospital, and surgery type. RESULTS The 103 participants (46%) in whom delirium developed postoperatively had lower preoperative mean MMSE scores than those in whom delirium did not develop (25.8 vs. 26.9, P<0.001). In adjusted models, those with delirium had a larger drop in cognitive function (as measured by the MMSE score) 2 days after surgery than did those without delirium (7.7 points vs. 2.1, P<0.001) and had significantly lower postoperative cognitive function than those without delirium, both at 1 month (mean MMSE score, 24.1 vs. 27.4; P<0.001) and at 1 year (25.2 vs. 27.2, P<0.001) after surgery. With adjustment for baseline differences, the between-group difference in mean MMSE scores was significant 30 days after surgery (P<0.001) but not at 6 or 12 months (P = 0.056 for both). A higher percentage of patients with delirium than those without delirium had not returned to their preoperative baseline level at 6 months (40% vs. 24%, P = 0.01), but the difference was not significant at 12 months (31% vs. 20%, P = 0.055). CONCLUSIONS Delirium is associated with a significant decline in cognitive ability during the first year after cardiac surgery, with a trajectory characterized by an initial decline and prolonged impairment. (Funded by the Harvard Older Americans Independence Center and others.)
Faster information dissemination in dynamic networks via network coding

We use network coding to improve the speed of distributed computation in the dynamic network model of Kuhn, Lynch and Oshman [STOC '10]. In this model an adversary adaptively chooses a new network topology in every round, making even basic distributed computations challenging.Kuhn et al. show that n nodes, each starting with a d-bit token, can broadcast them to all nodes in time O(n2) using b-bit messages, where b > d + log n. Their algorithms take the natural approach of token forwarding: in every round each node broadcasts some particular token it knows. They prove matching Ω(n2) lower bounds for a natural class of token forwarding algorithms and an Ω(n log n) lower bound that applies to all token-forwarding algorithms.We use network coding, transmitting random linear combinations of tokens, to break both lower bounds. Our algorithm's performance is quadratic in the message size b, broadcasting the n tokens in roughly d/b2 * n2 rounds. For b = d = Θ(log n) our algorithms use O(n2/log n) rounds, breaking the first lower bound, while for larger message sizes we obtain linear-time algorithms. We also consider networks that change only every T rounds, and achieve an additional factor T2 speedup. This contrasts with related lower and upper bounds of Kuhn et al. implying that for natural token-forwarding algorithms a speedup of T, but not more, can be obtained. Lastly, we give a general way to derandomize random linear network coding, that also leads to new deterministic information dissemination algorithms.
Limited Attention and Income Distribution

Economists have long been interested in the idea that there is a direct circular relation between poverty and low productivity, and not just one that is mediated by market failures, usually in asset markets. The nutrition-based efficiency wage model (Partha Dasgupta and Debraj Ray, 1987) is the canonical example of models where this happens: However it has been variously suggested (see for example T. N. Srinivasan, 1994) that the link from nutrition to productivity and especially the link from productivity to nutrition is too weak to be any more than a small part of the story. Partha Dasgupta himself acknowledges this when he writes "nutrition-productivity construct provides a metaphor,..., for ... an economic environment harboring poverty traps" (Partha Dasgupta, 1997, page 5). We propose an alternative approach to this question based on the idea that attention is a scarce resource that is important for productivity. Specifically, people may not be able to fully attend to their jobs if they are also worrying about problems at home and being distracted in this way reduces productivity. But not paying attention at home is also costly: early symptoms of a child's sickness may go unnoticed; water may run out at the end of the day; kerosene for lighting lamps at home might run out and make it hard to do homework; etc. Finally, the extent to which home life distracts depends on the nature of home life. Specifically, certain goods (e.g. a good baby sitter, a 24-hour piped water supply, a connection to a power supply grid) can reduce the extent of home life distraction. These three assumptions generate an interesting relation between income and productivity that is at the core of our model. The non-poor in this model, by virtue of owning distraction-saving goods and services at home, are able to focus more on their work. Hence they will be more productive at work and will be able to afford more distraction-saving goods. This simple two-way relationship between in(This abstract was borrowed from another version of this item.)
Antimony: annual survey covering the year 1986

Ce rapport est une synthese des etudes portant sur les composes organiques de l'antimoine en 1986
Preparation and Characterization of Barium Titanate Electrolytic Capacitors from Porous Titanium Anodes

BaTiO 3 is widely used as the dielectric in ceramic chip capacitors and multilayer capacitors, because of its high dielectric constant and ferroelectric properties. Multilayer capacitors provide fairly high capacitance per unit volume (volumetric efficiency); however, processing difficulties in the preparation of ultrathin layers limit further enhancement. Tantalum solid electrolytic capacitors, on the other hand, provide very high volumetric efficiencies, because of the large surface area of the sintered, porous tantalum anode on which the dielectric Ta 2 O 5 is electrochemically deposited. Recent developments in electrochemical methods to deposit BaTiO 3 on titanium substrates provide an opportunity to fabricate barium titanate electrolytic capacitors using sintered, porous titanium anodes. The high dielectric constant of BaTiO 3 and the high surface area of the sintered, porous anode provide a good combination to achieve larger volumetric efficiencies. Current work involves the fabrication and characterization of barium titanate electrolytic capacitors. Effects of electrochemical processing parameters on the formation of BaTiO 3 on the surface of sintered titanium anodes are described. Influence of the purity of titanium powder, the porosity of the sintered anode, and the post-deposition heat treatment on the dielectric properties of the fabricated capacitors is discussed. Complete penetration of the electrolyte solution and a thin uniform coating of TaTiO 3 over the entire titanium surface was achieved using high-porosity (35%-40% of theoretical density) sintered titanium anodes. Samples treated for 8 h in 0.5M Ba(OH) 2 .8H 2 O electrolyte solutions at 100°C with an applied cell voltage of 12 V show the formation of a dense, uniform BaTiO 3 coating on the surface of the titanium anode. High-purity, chloride-free titanium powder provides smaller dissipation factors at low frequencies. Heat treatment at 400°C significantly increases the capacitance at all frequencies, whereas the heat treatment lowers the dissipation factors at low frequencies. Calculated volumetric efficiencies are comparable to those typically obtained for tantalum solid electrolytic capacitors but are not as high as expected for barium titanate electrolytic capacitors. Penetration of the colloidal-carbon (external) electrode was limited to a depth of -300 μm, which might have caused the lower volumetric efficiencies.
Amorphous and Nanocrystalline Oxide Electrodes for Rechargeable Lithium Batteries

Oxo ions (MO{sub 4}){sup n-} (M = V, Cr, Mn and Mo) have been reduced in aqueous solutions with potassium borohydride to obtain the binary oxides MO{sub 2+{delta}}. While the vanadium and manganese oxides are nanocrystalline, the chromium and molybdenum oxides are amorphous. The nanocrystalline VO{sub 2} having a metastable structure and the amorphous CrO{sub 2} and MoO{sub 2.3} transform to the thermodynamically more stable phases upon heating above 300--400 C. These metastable oxides after heating in vacuum at 200--300 C to remove water show good electrode performance in lithium cells. VO{sub 2}, CrO{sub 2} and MoO{sub 2.3} show a reversible capacity of, respectively, 290 mAh/g in the range 4--1.5 V, 180 mAh/g in the range 3.3--2.3 V, and 220 mAh/g in the range 3--1 V. MnO{sub 2} obtained by this process does not show good electrode properties.
Generic pronouns and sexist language: The oxymoronic character of masculine generics

This experiment investigated the propensity of the generic he to evoke images of males relative to he/she and the plural they. Undergraduates read sentences aloud and verbally described the images that came to mind. The results provide strong support for the hypothesis that the generic he evokes a disproportionate number of male images. Results also suggest that while the plural they functions as a generic pronoun for both males and females, males may comprehend he/she in a manner similar to he. Theoretical implications for a critique of sexist language and prescribing generic pronoun usage are considered.