cssi/SciSciGPT-SciSciNet huggingface dataset:
A multi-source full spectrum k-distribution method for 1-D inhomogeneous media

The k-distribution method for treating the spectral properties of an absorbing–emitting medium represents an alternative to line-by-line calculations. It reduces the number of RTE evaluations from the order of a million to the order of ten without any significant loss of accuracy. For problems where an appropriate reference temperature can be defined, the k-distribution method is formally exact. However, when no appropriate reference temperature can be defined, the method results in errors. There have been several attempts to implement corrections to the k-distribution method to extend its application to inhomogeneous media by modeling the effects of temperature, pressure, and concentration gradient. Some of these techniques are effective at reducing these errors, but none successfully extend the k-distribution method to inhomogeneous media in a way that retains the analytical guarantee of line-by-line accuracy. The Multi-Source Full Spectrum K-Distribution Method (MSFSK) introduced here manages to attain this goal for 1-dimensional domains with piecewise constant temperature distributions by applying the superposition principle to the original RTE before applying the k-distribution transformation to decompose the problem into a set of sub-problems each of which is able to be solved exactly via the ordinary or modified full spectrum k-distribution method.
An analysis of a coupled-ring rotary joint design

A theoretical and experimental analysis of a coupled-ring rotary joint design is described. A rotary joint of this type is commonly used for mechanically scanned, multichannel radars. The main goal of the analysis is to develop a better understanding for the transfer of energy through the joint's highly coupled rings. The author considers the geometry of a typical single channel and then describes a coupled transmission line model for the coupled-ring network. Using the model, the author determines the type of ring network needed for low channel loss and small rotational variations of this loss. Measurements on some test models support the predictions of the analysis. >
A solvolysis route to a macrobicyclic allene

Abstract One of our objectives was to develop further access to large bicyclic tetrasubstituted olefins by cationic rearrangement. Among other things, such olefins can serve as valuable precursors to bicyclic tetrasubstituted allenese, and we report one such conversion by a new route that provided the first symmetrical member of this rare class of compounds. We synthesized the bicyclic trisubstituted olefins(Z)-bicyclo [10.5.0]heptadec-1(17)-ene (11) and (Z)-bicyclo[10.6.0]octadec-1(18)-ene (17) via an intramolecular Wittig reaction and a titanium mediated intramolecular reductive coupling, respectively. Olefins 11 and 17 were isomerized under acidic conditions to their tetrasubstituted counterparts (Z)-bicyclo[10.5.0]heptadec-1(12)-ene (12) and (Z)-bicyclo[10.6.0]octaladec-1(12)-ene (18). respectively. The previously reported tetrasubstituted olefin (Z)-bicyclo[11.11.0]tetracos-1(13)-ene (19) was further elaborated in a three step sequence to the allene bicyclo[11.11.0]pentacosa-1(25).13(25)-diene (22). Our approach involved dichlorocyclopiopanation of olefin 19 to cyclopropyl adduct 25,25-dichloro-tricyclo[11.11.1.0]pentacosane (20), silver assisted solvolysis of 20 to 25-chloro-1-methoxy-bicyclo[11.11.1]pentacos-13(25)-ene (21), and reductive elimination of 21 with zinc to allene 22.
Left Ventricular Noncompaction in a Family with Lamin A/C Gene Mutation

Left ventricular noncompaction is a rare type of cardiomyopathy, the genetics of which are poorly understood to date. Lamin A/C gene mutations have been associated with dilated cardiomyopathy and diseases of the conduction system, but rarely in left ventricular noncompaction cardiomyopathy. This report describes the cases of 4 family members with a lamin A/C gene mutation, 3 of whom had phenotypic expression of left ventricular noncompaction.
Molecular Catalysts for Multielectron Redox Reactions of Small Molecules: The “Cofacial Metallodiporphyrin” Approach

The role of metalloenzymes in important biological transformations has attracted increasing attention over the past several decades. Of the many chemical transformations mediated by enzymes, few are as challenging as multielectron redox reactions. Recent studies have revealed a partial structural and mechanistic description of these redox-active metalloenzymes, but there is much still to be learned regarding the mechanisms of substrate transformation. Due to the complexity of the metalloenzyme systems, simplified model systems are employed to mimic structural or functional features of the enzyme. In multielectron redox enzymes, several metals are probably in-volved in both substrate binding and the subsequent redox reactions. Thus, functional mimics of multielectron redox enzymes might also need two or more metal centers to be efficacious. The roles of multiple metal centers are to (1) increase the substrate's affinity for the catalyst, (2) increase the rate of electron transfer to the bound substrate, (3) increase the reactivity of the bound substrate, and (4) inhibit deleterious side reactions. Deter-mining the importance of each factor may help in the development of these catalysts. Cofacial metallodiporphyrins, because of the control they provide over the geometric and electronic properties of the synthetic reaction center, are ideal bimetallic model complexes. The knowledge gained from model studies will help in understanding the mechanisms of metalloenzymes and can be used to design new homogeneous catalysts to effect multielectron transformations.
Coverage-aware connectivity restoration in mobile sensor networks

Mobile sensor networks rely heavily on inter-sensor connectivity for collection of data. Nodes in these networks monitor different regions of an area of interest and collectively present a global overview of some monitored activities or phenomena. A failure of a sensor leads to loss of connectivity and may cause partitioning of the network into disjoint segments. A number of approaches have been recently proposed that pursue node relocation in order to restore connectivity. However, these approaches tend to ignore the possible loss of coverage in some areas, either due to the failure itself or due to the connectivity-limited focus of the recovery. This paper fills this gap by addressing the connectivity and coverage concerns in an integrated manner. A novel coverage conscious connectivity restoration (C^3R) algorithm is presented. C^3R involves one or multiple neighbors of the failed node to recover from the failure. Each neighbor temporarily relocates to substitute the failed node, one at a time, and then returns back to its original location. This leads to intermittent connectivity and monitoring of all the originally covered spots. This paper also presents energy-centric optimized recovery algorithm (ECR), an optimized version of C^3R that is geared for energy efficiency. Both C^3R and ECR are validated through simulation. The simulation results confirm the effectiveness of these approaches.
Cu(I)-Catalyzed C−H α-Amination of Aryl Ketones: Direct Synthesis of Imidazolinones

This paper describes an α-amination process of aryl ketones using CuCl as catalyst and di-tert-butyldiaziridinone as the nitrogen source. A variety of imidazolinone derivatives are prepared in moderate yields under mild conditions. A possible catalytic cycle is proposed for this reaction.
PTSD Symptoms and Self-Rated Recovery Among Adult Sexual Assault Survivors: The Effects of Traumatic Life Events and Psychosocial Variables

Prior research has demonstrated that self-blame is predictive of more posttraumatic stress disorder (PTSD) symptoms and poorer recovery (Frazier, 2003; Koss, Figueredo, & Prince, 2002), and perceived control over recovery is associated with less distress (Frazier, 2003) in adult sexual assault (ASA) survivors. A structural equation model was tested to examine the role of traumatic events, self-blame, perceived control over recovery, and coping strategies on PTSD symptoms and self-rated recovery in women ASA survivors. Adaptive coping partially mediated the effects of other traumas, self-blame, and perceived control over recovery on PTSD symptoms and showed a small positive association with increased PTSD symptoms. As hypothesized, maladaptive coping partially mediated the effects of other traumas, self-blame, and perceived control over recovery on both PTSD symptoms and self-rated recovery; greater maladaptive coping was associated with increased PTSD symptoms and lower self-rated recovery. Implications and directions for future research are discussed.
Recent advances in the development of high average power induction accelerators for industrial and environmental applications

Short-pulse accelerator technology developed during the early 1960`s through the late 1980`s is being extended to high average power systems capable of use in industrial and environmental applications. Processes requiring high dose levels and/or high volume throughput will require systems with beam power levels from several hundreds of kilowatts to megawatts. Beam accelerating potentials can range from less than 1 MeV to as much as 10 MeV depending on the type of beam, depth of penetration required, and the density of the product being treated. This paper addresses the present status of a family of high average power systems, with output beam power levels up to 200 kW, now in operation that use saturable core switches to achieve output pulse widths of 50 to 80 nanoseconds. Inductive adders and field emission cathodes are used to generate beams of electrons or x-rays at up to 2.5 MeV over areas of 1000 cm{sup 2}. Similar high average power technology is being used at {le} 1 MeV to drive repetitive ion beam sources for treatment of material surfaces over 100`s of cm{sup 2}.
Is Copyright Property? -- The Debate in Jewish Law

Is copyright a property right? Common law and civil law jurists have debated that issue for over three centuries. It remains at the heart of battles over copyright’s scope and duration today, even if its import lies principally in the rhetorical force of labeling a right as "property," not in any doctrinal consequence flowing directly from that label. In parallel to their common law and civil law counterparts, presentday rabbinic jurists engage in lively debate about whether Jewish law recognizes copyright as a property right. And, as in secular law but for different reasons, that issue has significant repercussions in Jewish law. As discussed in rabbinic court decisions and writings, whether Jewish law accords authors a right of ownership in their works impacts such issues as whether it is permissible, without license from the author or publisher, to copy and distribute software and sound recordings, perform music in wedding halls, make copies for private and classroom use, and download songs from the Internet. There are numerous, and at times profound, differences in the terminology, form of argument, doctrinal specifics, and overarching legal framework of Jewish and secular law. Nonetheless, the arguments within the Jewish law debate have some intriguing parallels with those of secular copyright law. In fact, one finds the direct, if largely unstated, influence of secular copyright just below the surface in the debate in Jewish law about whether copyright is property.
Revealing the electroweak properties of a new scalar resonance

One or more new heavy resonances may be discovered in experiments at the CERN Large Hadron Collider. In order to determine if such a resonance is the long-awaited Higgs boson, it is essential to pin down its spin, CP, and electroweak quantum numbers. Here we describe how to determine what role a newly-discovered neutral CP -even scalar plays in electroweak symmetry breaking, by measuring its relative decay rates into pairs of electroweak vector bosons: W+W−, ZZ, γγ, and Zγ. With the data-driven assumption that electroweak symmetry breaking respects a remnant custodial symmetry, we perform a general analysis with operators up to dimension five. Remarkably, only three pure cases and one nontrivial mixed case need to be disambiguated, which can always be done if all four decay modes to electroweak vector bosons can be observed or constrained. We exhibit interesting special cases of Higgs look-alikes with nonstandard decay patterns, including a very suppressed branching to W+W− or very enhanced branchings to γγ and Zγ. Even if two vector boson branching fractions conform to Standard Model expectations for a Higgs doublet, measurements of the other two decay modes could unmask a Higgs imposter.
Explicitly real form of the Wilson-Dirac matrix for SU(2)

Abstract The Wilson-Dirac matrix for SU(2) with I= 1 2 fermions is written in an explicitly real form. The basis change relating it to the conventional form in which the matrix has complex entries is also given. Some applications are presented.
Synthesis of 4(S)-(3,4-dichlorophenyl)-3,4-dihydro-1(2H)-naphthalenone by SN2 cuprate displacement of an activated chiral benzylic alcohol

Abstract Two routes for the preparation of 4(S)-(3,4-dichlorophenyl)-3,4-dihydro-1(2H)-naphthalenone are reported. The most efficient route generates a chiral benzylic alcohol by catalytic asymmetric oxazaborolidine reduction of a γ-ketoester that is subsequently activated and displaced in an SN2 manner with a higher order cuprate. Intramolecular Friedel-Crafts cyclization of the resulting t-butylester affords the title compound.
A Comparison of Naive and Experienced Bidders in Common Value Offer Auctions: A Laboratory Analysis

Laboratory economics experiments typically use financially motivated students as subjects. An ongoing issue is whether this is an appropriate subject pool since the students are typically inexperienced in the types of decision-making required of them in the lab. This paper addresses this issue in the context of common value offer auctions as we compare the -behaviour of experienced business executives in the construction contract industry ('experts') with that of ('naive') student subjects. Results of previous research of this sort have been equivocal; in some cases experts make the same errors as novices, in other cases they do not (Hogarth and Reder, I987). A series of sealed-bid, common value offer auctions in which bidders compete for the right to supply an item of unknown cost were conducted. Inherent to common value auctions (CVAs) is an adverse selection problem which may result in below normal or negative profits (the winner's curse). Experimental studies have documented the presence of the winner's curse with financially motivated student subjects in high price demand-side auctions (Kagel et al., I986; Kagel and Levin, I986). The experiments reported here generalise these earlier studies from bid to offer auctions. Also, in employing offer auctions we establish a setting with which our 'experts' are familiar, thus allowing their experience the best chance to manifest itself.'
Synthesis, dopamine and serotonin transporter binding affinities of novel analogues of meperidine

A series of meperidine analogues was synthesized and the binding affinities for the dopamine and serotonin transporters were determined. The substituents on the phenyl ring greatly influenced the potency and selectivity of these compounds for the transporter binding sites. In general, meperidine (3) and its analogues were more selective for serotonin transporter binding sites and the esters 9 were more potent than the corresponding nitriles 8. The 3,4-dichloro derivative 9e was the most potent ligand of the series for dopamine transporter binding sites while the 2-naphthyl derivative 9g exhibited the most potent binding affinity and was highly selective for serotonin transporter binding sites.
Stereospecific synthesis of (E)-α,β-difluorostyrenes

Abstract Isomerically pure (Z)-HFCCFZnI undergoes Pd(PPh3)4/CuBr co-catalyzed cross-coupling reactions with aryl iodides in DMAC to give the title compounds in good yields, under mild conditions. In the absence of CuBr, the reaction is sluggish, requires more vigorous reaction conditions, and gives lower yields.
In situ scanning tunneling microscopy of the anodic oxidation of highly oriented pyrolytic graphite surfaces

We report here studies of the surface of highly oriented pyrolytic graphite (HOPG) at atomic resolution with the scanning tunneling microscope (STM) with the sample immersed in an aqueous solution and under potential control. We also describe the effect of anodic oxidation of the HOPG sample in dilute sulfuric acid on the surface topography and composition.
Physical Activity Patterns in the National Weight Control Registry

Objective: The National Weight Control Registry (NWCR) was established in 1993 to examine the characteristics of those who are successful at weight loss: individuals maintaining a 13.6-kg weight loss for >1 year. The size of the registry has increased substantially since the early descriptions of this group a decade ago. The purpose of this study was to describe in detail the weekly physical activity habits of NWCR members, to examine the relationship between amount of activity and demographic characteristics, and to determine if changes in activity parameters have occurred over time. Methods and Procedures: Participants were 887 men and 2,796 women who enrolled in the NWCR between 1993 and 2004. Physical activity was evaluated at registry entry using the Paffenbarger Physical Activity Questionnaire. Results: NWCR entrants report an average of 2,621 ± 2,252 kcal/week in physical activity. There is considerable variability in the amount of activity reported: 25.3% report 3,000 kcal/week. Activity level on registry entry is related to the magnitude but not the duration of weight loss. The amount of activity reported by men has decreased over time while no significant change was observed in women. Changes in the types of activities most frequently reported were also observed. Discussion: Overall, NWCR participants are an extremely physically active group. However, the amount of activity reported is highly variable, making it difficult to develop a single recommendation for the optimum amount of physical activity for weight loss maintenance. A better understanding of individual-specific determinants of how much activity is required for weight loss maintenance ought to be a high research priority.
Hypophosphorous acid and its salts: New reagents for radical chain deoxygenation, dehalogenation and deamination

Abstract Thionocarbonates and xanthates of alcohols, bromides, iodides and isonitriles can be transfromed to the corresponding hydrocarbons with hypophosphorous acid or its salts in radical chain reactions.
Alkynes as Synthetic Equivalents to Stabilized Wittig Reagents: Intra- and Intermolecular Carbonyl Olefinations Catalyzed by Ag(I), BF3, and HBF4

The first use of cationic silver (AgSbF4) as a catalyst for intra- and intermolecular alkyne−carbonyl coupling to form conjugated enones is described, and a comparison to corresponding Bronsted acid (HBF4) and Lewis acid (BF3) catalyst systems is made. Notably, intermolecular coupling proceeds stereoselectively to afford the corresponding trisubstituted enones as single geometrical isomers. This transformation represents a completely atom economical alternative to the use of stabilized Wittig reagents in carbonyl olefination and may be viewed as a formal alkyne−carbonyl metathesis.
Valuable oxygenates by aerobic oxidation of polymers using metal/bromide homogeneous catalysts

A method of plastics recycling by selectively oxidizing 10 different polymers is demonstrated using homogeneous, liquid phase aerobic oxidation in acetic acid with metal/bromide catalysts and in water using vanadium/bromide catalysts. Some examples are the conversion of polystyrene to benzoic acid in 88% yield, polypropylene to acetic acid in 63% yield, polylethylene to a mixture of succinic, glutaric, and adipic acid in 47% yield, poly(butylene)terephthalic acid to terephthalic acid and succinic acid, the latter in 37% yield, and poly(vinyl)chloride to succinic acid in 38% yield.
Zinc-Mediated Palladium-Catalyzed Formation of Carbon―Sulfur Bonds

A catalytic amount of zinc chloride in combination with a palladium catalyst ligated by a monodentate phosphine allows the coupling of aryl and alkyl thiols with aryl bromides in high yields. The addition of zinc chloride to a palladium catalyst system that reportedly failed to promote sulfide formation allows this once ineffective catalyst system to provide the sulfide product in good yield. This paper describes a high-yielding and general monodentate phosphine-ligated palladium catalyst for biaryl and alkyl aryl sulfide formation.
Universal extra dimensions and the muon magnetic moment

Abstract We analyze the muon anomalous magnetic moment in the context of universal extra dimensions. Our computation shows that the bound from electroweak data on the size of these dimensions allows only a small shift in the muon magnetic moment given by Kaluza–Klein modes of standard model fields. In the well-motivated case of two universal extra dimensions, additional contributions arising from physics at scales where the effective 6-dimensional standard model breaks down, given by dimension-ten operators, have a natural size comparable to the sensitivity of the muon ( g −2) experiment at BNL.
Palladium-catalyzed coupling of aldehyde-derived hydrazones: practical synthesis of triazolopyridines and related heterocycles.

Mild and selective coupling of 2-chloropyridines with arylhydrazones, followed by oxidation of the resulting hydrazono pyridines offers an efficient entry to triazolopyridines (IV).
Gas chromatography/mass spectroscopy for plastics failure analysis ☆

Abstract Gas chromatography/mass spectroscopy is particularly useful as an analytical method for plastics failure analysis in cases where detection of an unknown contaminant or other compositional factor may be the cause or a contributor to failure. It takes advantage of the fact that GC is a method of separating compounds in a mixture, permitting their identification and possibly quantification. MS is not only a very sensitive detector but also gives mass spectra of GC peaks, permitting their identification in many cases. In thermal desorption GC/MS compounds are transferred from the sample to the GC with heat. Completely nonvolatile materials are not detected. Using desorption temperatures up to 300–350 °C, many components of plastics can be analyzed. In pyrolysis GC/MS the sample is decomposed at temperatures up to 900 °C; GC/MS analyzes the pyrolyzate. Examples are given of causes of plastics failures that have been determined by GC/MS.
Quantifying the Eddy Feedback and the Persistence of the Zonal Index in an Idealized Atmospheric Model

An idealized atmospheric model is employed to quantify the strength of the eddy feedback and the persistence of the zonal index. The strength of the surface frictional damping on the zonal index is varied, and an external zonal momentum forcing is included to compensate for the momentum change associated with the friction change such that the climatological jet latitude and shape are unchanged. The model can generate a nearly identical climatology and leading mode of the zonal mean zonal wind for different frictional damping rates, except when the jet undergoes a regime transition. For those experiments without a regime transition, as the surface friction is increased, the strength of eddy feedback is enhanced but the zonal index becomes less persistent. A simple feedback model suggests that the e-folding decorrelation time scale of the zonal index can be determined by the frictional damping rate and the strength of eddy feedback. The strength of eddy feedback is found to be related to the instantaneous vertical wind shears near the surface controlled by the frictional damping. Furthermore, the climate response to an external zonal torque is proportional to the decorrelation time scale, although the simple prediction used here overestimates the climate response by a factor of 2.
Recent progress in the development of diesel surrogate fuels

Abstract There has been much recent progress in the area of surrogate fuels for diesel. In the last few years, experiments and modeling have been performed on higher molecular weight components of relevance to diesel fuel such as n-hexadecane (n-cetane) and 2,2,4,4,6,8,8-heptamethylnonane (iso-cetane). Chemical kinetic models have been developed for all the n-alkanes up to 16 carbon atoms. Also, there has been experimental and modeling work on lower molecular weight surrogate components such as n-decane and n-dodecane that are most relevant to jet fuel surrogates, but are also relevant to diesel surrogates where simulation of the full boiling point range is desired. For two-ring compounds, experimental work on decalin and tetralin recently has been published. For esters, kinetic mechanisms for compounds of lower molecular weights but similar to those found in typical biodiesel blendstocks also have been published. For multi-component surrogate fuel mixtures, recent work on modeling of these mixtures and comparisons to real diesel fuel is reviewed. Detailed chemical kinetic models for surrogate fuels are very large in size, so it is noteworthy that significant progress also has been made in improving the mechanism reduction tools that are needed to make these large models practicable in multi-dimensional reacting flow simulations of diesel combustion. Nevertheless, major research gaps remain. In the case of iso-alkanes, there are experiments and modeling work on only one of relevance to diesel: iso-cetane. Also, the iso-alkanes in diesel are lightly branched and no detailed chemical kinetic models or experimental investigations are available for such compounds. More components are needed to fill out the iso-alkane boiling point range. For the aromatic class of compounds, there has been little work for compounds in the boiling point range of diesel. Most of the new work has been on alkyl aromatics that are of the range C7–C9, below the C10–C20 range that is needed. For the chemical classes of cycloalkanes and esters, experiments and modeling on higher molecular weight components are warranted. Finally for multi-component surrogates needed to treat real diesel, the inclusion of higher molecular weight components is needed in models and experimental investigations.
N-Heterocyclic Carbene-Catalyzed Redox Amidations of α-Functionalized Aldehydes with Amines

A catalytic method for the direct synthesis of carboxylic acid amides from amines and α-functionalized aldehydes is possible through the synergistic role of a N-heterocyclic carbene catalyst and imidazole, affording amides via activated carboxylates catalytically generated via an internal redox reaction of the aldehyde substrates. The use of imidazole or other N-heterocycles as an additive is essential to overcoming imine formation and serves as a uniquely reactive substrate for the generation of an acyl imidazolium intermediate that is converted to the final amide product.
The Impact of PCAOB AS5 and the Economic Recession on Client Portfolio Characteristics of the Big 4 Audit Firms

SUMMARY: We examine the impact of PCAOB Auditing Standard No. 5 (AS5) and the economic recession on risk characteristics and degree of auditor/client misalignment in the publicly traded client portfolios of Big 4 firms. AS5 and the economic recession both likely resulted in an increase in audit firm personnel capacity as well as a decline in current and future revenue prospects, leading to concerns that the Big 4 firms may pursue clients that present greater risk to the portfolio. We find that the overall portfolio in 2009 presents greater financial risk, attributable to the impact of the recession on continuing clients. A net decrease in audit and auditor business risks is also attributable to continuing clients over this period, as increases for new clients are offset by reductions due to departing clients. Overall, the results, which should be of interest to regulators, indicate that Big 4 firms continued to balance their portfolio with risk in mind. Data Availability: Data are publicly available from ...
A p-adic proof of Hodge symmetry for threefolds

Abstract We give a p -adic proof of Hodge symmetry for smooth and projective varieties of dimension three over the field of complex numbers. To cite this article: K. Joshi, C. R. Acad. Sci. Paris, Ser. I 338 (2004).
If at first you don’t succeed: applying for and staying on the Supplemental Nutrition Assistance Program

We examine households’ applications to and participation in the Supplemental Nutrition Assistance Program using administrative records from South Carolina. We model application resolutions with multinomial logit (MNL) specifications where the possible outcomes are acceptance, denial due to income ineligibility, denial due to a failure to provide sufficient information and denial due to other reasons. For cases with successful applications, we model the durations of participation spells using competing risk hazard specifications that distinguish among exits that result from missed recertifications, financial ineligibility, incomplete or missing information and other reasons. The application and hazard outcomes depend on past programme behaviour and observed characteristics. The results indicate that a household’s application and participation history affect its subsequent application success and programme tenure.
Heterotic Coset Models

A description is given on how to construct (0, 2) supersymmetric conformal field theories as coset models. These models may be used as non-trivial backgrounds for heterotic string theory. They are realized as a combination of an anomalously gauged Wess–Zumino–Witten model, right-moving supersymmetric fermions, and left-moving current algebra fermions. Requiring the sum of the gauge anomalies from the bosonic and fermionic sectors to cancel yields the final model. Applications discussed include exact models of extremal four-dimensional charged black holes and Taub–NUT solutions of string theory. These coset models may also be used to construct important families of (0, 2) supersymmetric heterotic string compactifications. The Kazama–Suzuki models are the left-right symmetric special case of these models.
A Helical Gear Pair Pocketing Power Loss Model

A new fluid dynamics model is proposed to predict the power losses due to pocketing of air, oil, or an air-oil mixture in the helical gear meshes. The proposed computational procedure treats a helical gear pair as combination of a number of narrow face width spur gear segments staggered according to the helix angle and forms a discrete, fluid dynamics model of the medium being pocketed in the gear mesh. Continuity and conservation of momentum equations are applied to each coupled control volume filled with a compressible fluid mixture to predict fluid pressure and velocity distributions from, which the instantaneous pocketing power loss is calculated. The proposed model is exercised in order to investigate fluid pressure and velocity distributions in time, as well as pocketing power loss as a function of speed, helix angle and oil-to-air ratio.Copyright © 2013 by ASME
Shell model Monte Carlo methods

We review quantum Monte Carlo methods for dealing with large shell model problems. These methods reduce the imaginary-time many-body evolution operator to a coherent superposition of one-body evolutions in fluctuating one-body fields; resultant path integral is evaluated stochastically. We first discuss the motivation, formalism, and implementation of such Shell Model Monte Carlo methods. There then follows a sampler of results and insights obtained from a number of applications. These include the ground state and thermal properties of pf-shell nuclei, thermal behavior of {gamma}-soft nuclei, and calculation of double beta-decay matrix elements. Finally, prospects for further progress in such calculations are discussed. 87 refs.
Selectivity Patterns in Alkane Oxidation over Mg3(VO4)2-MgO, Mg2V2O7, and (VO)2P2O7

Abstract The catalytic oxidation of ethane, propane, 2-methylpropane, butane, pentane, and cyclohexane has been studied over Mg3(VO4)2-MgO, Mg2V2O7, and (VO)2P2O7. These reactions produced a wide range of products ranging from alkenes, dienes, anhydrides, acids, and carbon oxides. Broadly speaking, the major products were dehydrogenation products over Mg3(VO4)2, combustion products over Mg2V2O7, and oxygen-containing organic products over (VO)2P2O7, although there are exceptions to this broad generalization. From the product selectivities, the moles of oxygen consumed per mole of alkane reacted could be calculated. These were the average oxygen stoichiometries for the reactions. They had values of about unity for ethane oxidation over VPO, about two when oxidative dehydrogenation was the predominant reaction, and about four for the other reactions studied. The selectivity patterns in terms of the formation of dehydrogenation products versus oxygen-containing products including carbon oxides were explained by assuming that there existed a selectivity-determining step, which could be the reaction of the surface alkyl species or the adsorbed alkene before its desorption. The formation of oxygen-containing products would be facilitated if the surface alkyl or adsorbed alkene could interact with the vanadium ions in two adjacent VOx units such that it could easily react with the reactive oxygen in the V-O-V bridge. The results of ethane oxidation, however, could not be explained simply by this model, and other factors needed to be considered.
Surface-dependent pathways for formaldehyde oxidation and reduction on TiO2(001)

The reactions of formaldehyde on differently prepared surfaces of a TiO2(001) single crystal were investigated by temperatureprogrammed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Surfaces which had been ion-bombarded and annealed at low temperature, up to ca. 650 K, were oxygen deficient and contained Ti cations in lower oxidation states than + 4, in addition to Ti4+ cations. TPD after formaldehyde adsorption on these surfaces showed coincident desorption of methanol and formaldehyde in two temperature domains, at ca. 370 K and ca. 550 K. In contrast on fully oxidized surfaces (obtained by annealing at 750 K and above), formaldehyde and methanol desorbed only at ca. 370 K. Formaldehyde reacted on TiO2(001) surfaces via two different routes. The first was direct reduction of formaldehyde to methanol on the reduced surfaces, as evidenced by the presence of methoxide species at 286.3 eV in the C(1s) spectrum at 250 K following formaldehyde adsorption. Part of the formaldehyde was totally decomposed to C(a), H(a), and O(a); H(a) was involved in the reduction of formaldehyde to methanol, C(a) was oxidized to CO and CO2 while O(a) oxidized reduced titanium sites as indicated by the decrease of the XPS Ti(2p32) lines corresponding to Tix+ (x < 4). The second principal pathway for reaction of formaldehyde involved a Cannizzaro-type reaction and was only observed on fully oxidized surfaces. This reaction was responsible for the coincident formation of methoxide (286.3 eV) and formate (289.5–289.7 eV) species observed by XPS at room temperature.
A retrospective on the LBNL PEM project

We present a retrospective on the LBNL Positron Emission Mammography (PEM) project, looking back on our design and experiences. The LBNL PEM camera utilizes detector modules that are capable of measuring depth of interaction (DOI) and places them into 4 detector banks in a rectangular geometry. In order to build this camera, we had to develop the DOI detector module, LSO etching, Lumirror-epoxy reflector for the LSO array (to achieve optimal DOI), photodiode array, custom IC, rigid-flex readout board, packaging, DOI calibration and reconstruction algorithms for the rectangular camera geometry. We will discuss the high-lights (good and bad) of these developments.
Carbon nanotubes for potential electronic and optoelectronic applications

Carbon nanotubes (CNTs) are novel quasi-one-dimensional materials with excellent electrical properties in addition to their remarkable mechanical strength, thermal conductivity and chemical inertness. Moreover, semiconducting CNTs are direct-gap semi-conductors that directly absorb and emit light. This offers the possibility of developing a CNT-based electric and optoelectronic technology.
The Hubble Constant from the Gravitational Lens B1608+656

We present a refined gravitational lens model of the four-image lens system B1608+656 based on new and improved observational constraints: (1) the three independent time delays and flux ratios from Very Large Array observations, (2) the radio-image positions from Very Large Baseline Array observations, (3) the shape of the deconvolved Einstein ring from optical and infrared Hubble Space Telescope images, (4) the extinction-corrected lens-galaxy centroids and structural parameters, and (5) a stellar velocity dispersion, σap = 247 ± 35 km s-1, of the primary lens galaxy (G1), obtained from an echelle spectrum taken with the Keck II Telescope. The lens-mass model consists of two elliptical mass distributions with power-law density profiles and an external shear, totaling 22 free parameters, including the density slopes that are the key parameters for determining the value of H0 from lens time delays. This has required the development of a new lens code that is highly optimized for speed. The minimum-χ2 model reproduces all observations very well, including the stellar velocity dispersion and the shape of the Einstein ring. A combined gravitational lens and stellar dynamical analysis leads to a value of the Hubble constant of H0 = 75 km s- 1 Mpc -1 (68% CL; Ωm = 0.3, ΩΛ = 0.7). The nonlinear error analysis includes correlations between all free parameters, in particular the density slopes of G1 and G2, yielding an accurate determination of the random error on H0. The lens galaxy G1 is ~5 times more massive than the secondary lens galaxy (G2) and has a mass density slope of γ = 2.03 ± 0.03 (68% CL) for ρ ∝ r, very close to isothermal (γ' = 2). After extinction correction, G1 exhibits a smooth surface brightness distribution with an R1/4 profile and no apparent evidence for tidal disruption by interactions with G2. Given the scope of the observational constraints and the gravitational lens models, as well as the careful corrections to the data, we believe this value of H0 to be little affected by known systematic errors (5%).
The structure of wages during the economic transition in Romania

Abstract I use cross-sectional individual data from the 1994 Integrated Household Survey (IHS) of Romania to analyze the determinants of male and female wages in public and private enterprises. Using quantile regression I estimate the rate of return to education and experience at different quantiles of the wage distribution. Higher levels of education are significantly associated with higher wages for both males and females in public firms. In private firms, only college education is correlated with significantly higher wages. I also find that there are no significant differences in the returns to human capital at the median and at the upper and lower tail of the distribution of gender-specific wages in each sector. Differences in individual characteristics are found to explain the highest portion of the male–female wage differential in Romania in both sectors.
Women, Alcoholics Anonymous, and Related Mutual Aid Groups: Review and Recommendations for Research

Recent literature reviews and meta-analyses have supported the effectiveness of Alcoholics Anonymous (AA) in helping members stop drinking and maintain sobriety. Despite the extensive body of research on AA, less attention has focused on differences in the efficacy of the program for and experiences of women as compared to men. Such a focus is warranted given that there are significant gender differences in the development and progression of alcoholism, impact of drinking, and response to treatment. This review synthesizes results of extant research on women in AA and similar mutual aid groups focused on problem drinking to describe the state of knowledge and make suggestions for future research. Critiques of the ability of AA and 12-Step programs to address women's needs are also reviewed, as are attempts to respond to those critiques. Understudied issues, including the role of victimization histories (which are more prevalent in women who abuse alcohol), are also discussed.
Pump Design for a Portable Renal Replacement System

This work proposes a small, light, valve-less pump design for a portable renal replacement system. By analyzing the working principle of the pump and exploring the design space using an analytical pump model, we developed a novel design for a cam-driven finger pump. Several cams sequentially compress fingers, which compress flexible tubes, thus eliminating valves. Either changing the speed of the motor or size of the tube can control the flow rate. In vitro experiments conducted with whole blood using the pump measured Creatinine levels over time, and the results verify the design for the portable renal replacement system. The proposed pump design is smaller than 153 cm3 and consumes less than 1W while providing a flow rate of more than 100ml/min for both blood and dialysate flows. The smallest pump of a portable renal replacement system in the literature uses check valves, which considerably increase the overall manufacturing cost and possibility of blood clotting. Compared to that pump, the proposed pump design achieved reduction in size by 52% and savings in energy consumption by 89% with the removal of valves. This simple and reliable design substantially reduces the size requirements of a portable renal replacement system.Copyright © 2010 by ASME
Population-Based Input Function Modeling for [18F]FMPEP-d2, an Inverse Agonist Radioligand for Cannabinoid CB1 Receptors: Validation in Clinical Studies

Background Population-based input function (PBIF) may be a valid alternative to full blood sampling for quantitative PET imaging. PBIF is typically validated by comparing its quantification results with those obtained via arterial sampling. However, for PBIF to be employed in actual clinical research studies, its ability to faithfully capture the whole spectrum of results must be assessed. The present study validated a PBIF for [18F]FMPEP-d2, a cannabinoid CB1 receptor radioligand, in healthy volunteers, and also attempted to utilize PBIF to replicate three previously published clinical studies in which the input function was acquired with arterial sampling. Methods The PBIF was first created and validated with data from 42 healthy volunteers. This PBIF was used to assess the retest variability of [18F]FMPEP-d2, and then to quantify CB1 receptors in alcoholic patients (n = 18) and chronic daily cannabis smokers (n = 29). Both groups were scanned at baseline and after 2–4 weeks of monitored drug abstinence. Results PBIF yielded accurate results in the 42 healthy subjects (average Logan-distribution volume (VT) was 13.3±3.8 mL/cm3 for full sampling and 13.2±3.8 mL/cm3 for PBIF; R2 = 0.8765, p<0.0001) and test-retest results were comparable to those obtained with full sampling (variability: 16%; intraclass correlation coefficient: 0.89). PBIF accurately replicated the alcoholism study, showing a widespread ∼20% reduction of CB1 receptors in alcoholic subjects, without significant change after abstinence. However, a small PBIF-VT bias of −9% was unexpectedly observed in cannabis smokers. This bias led to substantial errors, including a VT decrease in regions that had shown no downregulation in the full input function. Simulated data showed that the original findings could only have been replicated with a PBIF bias between −6% and +4%. Conclusions Despite being initially well validated in healthy subjects, PBIF may misrepresent clinical protocol results and be a source of variability between different studies and institutions.
GPU-based fast low-dose cone beam CT reconstruction via total variation

X-ray imaging dose from serial Cone-beam CT (CBCT) scans raises a clinical concern in most image guided radiation therapy procedures. The goal of this paper is to develop a fast GPU-based algorithm to reconstruct high quality CBCT images from undersampled and noisy projection data so as to lower the imaging dose. The CBCT is reconstructed by minimizing an energy functional consisting of a data fidelity term and a total variation regularization term. We develop a GPU-friendly version of a forward-backward splitting algorithm to solve this problem. A multi-grid technique is also employed. We test our CBCT reconstruction algorithm on a digital phantom and a head-and-neck patient case. The performance under low mAs is also validated using physical phantoms. It is found that 40 x-ray projections are sufficient to reconstruct CBCT images with satisfactory quality for clinical purposes. Phantom experiments indicate that CBCT images can be successfully reconstructed under 0.1 mAs/projection. Comparing with the widely used head-and-neck scanning protocol of about 360 projections with 0.4 mAs/projection, an overall 36 times dose reduction has been achieved. The reconstruction time is about 130 sec on an NVIDIA Tesla C1060 GPU card, which is estimated ∼ 100 times faster than similar regularized iterative reconstruction approaches.
MODELING A HIGH-MASS TURN-DOWN IN THE STELLAR INITIAL MASS FUNCTION

Statistical sampling from the stellar initial mass function (IMF) for all star-forming regions in the Galaxy would lead to the prediction of ~1000 M☉ stars unless there is a rapid turn-down in the IMF beyond several hundred solar masses. Such a turn-down is not necessary for dense clusters because the number of stars sampled is always too small. Although no upper mass limits to star formation have ever been observed, a theory for the IMF should be able to explain the lack of ~1000 M☉ stars in normal galaxy disks. Here we explore several mechanisms for an upper mass cutoff, including an exponential decline of the star formation probability after a turbulent crossing time. The results are in good agreement with the observed IMF over the entire stellar mass range, and they give a gradual turn-down compared to the Salpeter function above ~100 M☉ for the normal thermal Jeans mass, MJ. However, they cannot give both the observed power-law IMF out to the high-mass sampling limit in dense clusters and the observed lack of supermassive stars in whole galaxy disks. The exponential decline is too slow for this. Either there is a sharp upper mass cutoff in the IMF, perhaps from self-limitation, or the IMF is different for dense clusters than for the majority of star formation that occurs at lower density. In the latter case, dense clusters would have to form an overabundance of massive stars relative to the average IMF in a galaxy. Evidence for a difference in the cluster and field IMFs supports this picture, but systematic effects could mimic this evidence even with a universal IMF. Within the framework of the sampling model, the upper mass turn-down should shift toward higher mass when MJ shifts upward, as might be the case in some starburst galaxies, and shift toward lower mass when MJ is lower, as might be the case in ultracold or high-pressure regions. Supermassive stars may therefore be possible in starburst galaxies, while in low surface brightness regions, where ultracold gas might exist at normal pressures, or in galactic cluster cooling flows, where cold gas could have extremely high pressures, a high fraction of the star formation could end up as brown dwarfs.
Computer simulation of cathode heating by back-bombardment in the microwave electron gun

Abstract An electron beam with low normalized emittance, 2 π mm mrad, has been achieved by using a microwave electron gun as the injector for an rf linac. However, cathode heating caused by back-bombarding electrons causes a ramp in the macropulse current. A transverse magnetic field can be applied at the cathode to reduce this effect. The simulation is an effort to find the optimum magnetic field.