cssi/SciSciGPT-SciSciNet huggingface dataset:
Model structures on modules over Ding-Chen rings

An n-FC ring is a left and right coherent ring whose left and right self-FP-injective dimension is n. The work of Ding and Chen shows that these rings possess properties which generalize those of n-Gorenstein rings. In this paper we call a (left and right) coherent ring with finite (left and right) self-FP-injective dimension a Ding-Chen ring. In the case of Noetherian rings, these are exactly the Gorenstein rings. We look at classes of modules we call Ding projective, Ding injective and Ding flat which are meant as analogs to Enochs' Gorenstein projective, Gorenstein injective and Gorenstein flat modules. We develop basic properties of these modules. We then show that each of the standard model structures on Mod-R, when R is a Gorenstein ring, generalizes to the Ding-Chen case. We show that when R is a commutative Ding-Chen ring and G is a finite group, the group ring R[G] is a Ding-Chen ring.
An openmath content dictionary for tensor concepts

We introduce a new OpenMath content dictionary named "tensor1" containing symbols for the expression of tensor formulas. These symbols support the expression of non-Cartesian coordinates and invariant, multilinear expressions in the context of coordinate transformations. While current OpenMath symbols support the expression of linear algebra formulas using matrices and vectors, we find that there is an underlying assumption of Cartesian, or standard, coordinates that makes the expression of general tensor formulas difficult, if not impossible. In introducing these new OpenMath symbols for the expression of tensor formulas, we attempt to maintain, as much as possible, consistency with prior OpenMath symbol definitions for linear algebra.
Nonlinear Steepest Descent Asymptotics for Semiclassical Limit of Integrable Systems: Continuation in the Parameter Space

The initial value problem for an integrable system, such as the Nonlinear Schrodinger equation, is solved by subjecting the linear eigenvalue problem arising from its Lax pair to inverse scattering, and, thus, transforming it to a matrix Riemann-Hilbert problem (RHP) in the spectral variable. In the semiclassical limit, the method of nonlinear steepest descent ([4,5]), supplemented by the g-function mechanism ([3]), is applied to this RHP to produce explicit asymptotic solution formulae for the integrable system. These formule are based on a hyperelliptic Riemann surface \({\mathcal {R} = \mathcal {R}(x,t)}\) in the spectral variable, where the space-time variables (x, t) play the role of external parameters. The curves in the x, t plane, separating regions of different genuses of \({\mathcal {R}(x,t)}\), are called breaking curves or nonlinear caustics. The genus of \({\mathcal {R}(x,t)}\) is related to the number of oscillatory phases in the asymptotic solution of the integrable system at the point x, t. The evolution theorem ([10]) guarantees continuous evolution of the asymptotic solution in the space-time away from the breaking curves.
A short, stereospecific route to chiral trans-2,6-disubstituted quinuclidines

Abstract An efficient six-step stereospecific synthesis of trans-2,6-diphenylquinuclidine (1) is described together with an effective resolution of 1 into pure enantiomers. A key step in the synthesis is a highly efficient, catalyzed Diels-Alder reaction.
Taylor expansion for the solution of a stochastic differential equation driven by fractional Brownian motions

We study the Taylor expansion for the solution of a differential equation driven by a multi-dimensional Holder path with exponent $H> 1/2$. We derive a convergence criterion that enables us to write the solution as an infinite sum of iterated integrals on a non empty interval. We apply our deterministic results to stochastic differential equations driven by fractional Brownian motions with Hurst parameter $H > 1/2$. We also study the convergence in L2 of the stochastic Taylor expansion by using L2 estimates of iterated integrals and Borel-Cantelli type arguments.
Saturn V launch vehicle digital computer and data adapter

This paper describes the IBM Space Guidance Center's part in the Saturn V Program and the digital computer and data adapter being developed for the Saturn V booster. This work is being performed under contract to NASA under direction of the Marshall Space Filight Center, Huntsville, Alabama.
Trellis pruning for peak-to-average power ratio reduction

This paper introduces a new trellis pruning method which uses nonlinear convolutional coding for peak-to-average power ratio (PAPR) reduction of filtered QPSK and 16-QAM modulations. The Nyquist filter is viewed as a convolutional encoder that controls the analog waveforms of the filter output directly. Pruning some edges of the encoder trellis can effectively reduce the PAPR. The only tradeoff is a slightly lower channel capacity and increased complexity. The paper presents simulation results of the pruning action and the resulting PAPR, and also discusses the decoding algorithm and the capacity of the filtered and pruned QPSK and 16-QAM modulations on the AWGN channel. Simulation results show that the pruning method reduces the PAPR significantly without much damage to capacity
Great earthquakes of variable magnitude at the Cascadia subduction zone

Comparison of histories of great earthquakes and accompanying tsunamis at eight coastal sites suggests plate-boundary ruptures of varying length, implying great earthquakes of variable magnitude at the Cascadia subduction zone. Inference of rupture length relies on degree of overlap on radiocarbon age ranges for earthquakes and tsunamis, and relative amounts of coseismic subsidence and heights of tsunamis. Written records of a tsunami in Japan provide the most conclusive evidence for rupture of much of the plate boundary during the earthquake of 26 January 1700. Cascadia stratigraphic evidence dating from about 1600 cal yr B.P., similar to that for the 1700 earthquake, implies a similarly long rupture with substantial subsidence and a high tsunami. Correlations are consistent with other long ruptures about 1350 cal yr B.P., 2500 cal yr B.P., 3400 cal yr B.P., 3800 cal yr B.P., 4400 cal yr B.P., and 4900 cal yr B.P. A rupture about 700–1100 cal yr B.P. was limited to the northern and central parts of the subduction zone, and a northern rupture about 2900 cal yr B.P. may have been similarly limited. Times of probable short ruptures in southern Cascadia include about 1100 cal yr B.P., 1700 cal yr B.P., 3200 cal yr B.P., 4200 cal yr B.P., 4600 cal yr B.P., and 4700 cal yr B.P. Rupture patterns suggest that the plate boundary in northern Cascadia usually breaks in long ruptures during the greatest earthquakes. Ruptures in southernmost Cascadia vary in length and recurrence intervals more than ruptures in northern Cascadia.
Electron energy relaxation in the presence of magnetic impurities.

We study inelastic electron-electron scattering mediated by the exchange interaction of electrons with magnetic impurities and find the kernel of the corresponding two-particle collision integral. In a wide region of parameters, the kernel $K$ is proportional to the inverse square of the transferred energy, $K\ensuremath{\propto}{J}^{4}/{E}^{2}$. The exchange constant $J$ is renormalized due to the Kondo effect. At small energy transfers, the $1/{E}^{2}$ divergence is cut off; the cutoff energy is determined by the dynamics of the impurity spins. The obtained results may provide a quantitative explanation of the experiments of Pothier et al. [Phys. Rev. Lett. 79, 3490 (1997)] on anomalously strong energy relaxation in short metallic wires.
Topical Mosquito Repellents XI: Carbamates Derived from N,N′-Disubstituted Diamines

Carbamates derived from various N,N′-disubstituted diamines were synthesized and evaluated as repellents for Aedes aegypti mosquitoes with an in vitro blood-feeding test system. Several compounds were more effective than diethyltoluamide.
Interpretation of ~35 Hz QPO in the Atoll Source 4U 1702–42 as a Low Branch of the Keplerian Oscillations under the Influence of the Coriolis Force

The recent model of quasi-periodic oscillations in neutron star binaries has suggested the existence of two branches of QPOs due to the influence of Coriolis force on the linear Keplerian oscillator: one branch with frequencies ~400-1200 Hz and another branch with frequencies an order of magnitude lower. The frequencies of the high branch νh hold a hybrid frequency relation with the Keplerian frequency νK: ν = ν + Ω2/π2, where Ω is the rotational frequency of the star's magnetosphere. The frequency of the low branch is νL = (Ω/π)(νK/νh) sin δ, where δ is a small angle between Ω and the vector normal to the plane of Keplerian oscillations. The observations of the source 4U 1702-42 have shown that the centroid of the ~35 Hz QPO tracks the frequency of the kilohertz oscillations. We interpret the ~35 Hz oscillations as νL and find δ = 39 ± 02. Our results make 4U 1702-42 the second source (after Sco X-1) for which the theoretically derived lower branch is identified (within our model) and δ is calculated. The inferred angle δ stays approximately the same over the significant range of νK (650-900 Hz), as expected from the model. Based on our model, we present a classification of QPO frequencies in the source 4U 1702-42 observed above and below νL.
Chronic pain in individuals with spinal cord injury: a survey and longitudinal study.

Cross-sectional and longitudinal postal survey. To (1) compare the severity of pain in persons with spinal cord injury (SCI) to national norms, (2) examine the association between pain and measures of (a) psychological functioning, (b) community integration and (c) pain interference with daily activities, and (3) examine the change in the prevalence and intensity of pain over time. Community. A total of 147 adults with SCI were surveyed twice, 2–6 years apart. Main outcome measures included presence/absence of pain in general and at specific body sites, 0–10 numerical rating scale of average pain intensity, modified Brief Pain Inventory Pain Interference scale, SF-36 Bodily Pain scale, SF-36 Mental Health scale, Community Integration Questionnaire. Pain was more severe, on average, in this sample of patients with SCI than it is in normative samples. The presence of pain was associated with trends towards poorer psychological functioning and social integration, and the intensity of pain was associated with interference with a number of important basic activities of daily living. Little systematic change was found in pain over a 2–6-year-period, although there was evidence that the prevalence of shoulder pain increases over time. The current findings underscore the serious nature of pain in persons with SCI and provide additional support for the need to identify effective treatments for SCI-related pain.
Effects of Behavioral and Drug Therapy on Nocturia in Older Incontinent Women

Objectives: To examine changes in nocturia from a multicomponent behavioral training program or drug therapy in older women with urge or mixed (urge-predominant) urinary incontinence. Design: A secondary analysis of data from a prospective, randomized clinical trial. Setting: Parent trial was an outpatient research protocol in Alabama. Participants: One hundred ninety-seven women (aged 55–92) with incontinence and urodynamic evidence of bladder dysfunction. At baseline, 131 women (66% of participants) had nocturia. Intervention: In the parent study, participants received behavioral training, including four sessions of biofeedback-assisted pelvic floor muscle exercises, drug treatment (oxybutynin IR titrated from 2.5 mg per day to 5.0 mg three times a day), or placebo. Measurements: Participant-completed bladder diaries were used to calculate changes in nocturia. Results: Behavioral training reduced nocturia by a median 0.50 episodes per night and was significantly more effective than drug treatment (median reduction=0.30 episodes; P=.02) and placebo (median reduction=0.00 episodes; P<.001). Also, drug treatment was more effective than control (P=.007). Conclusion: Both behavioral training and drug treatment reduced nocturia more than placebo, but behavioral training was the most effective.
Triply periodic level surfaces as models for cubic tricontinuous block copolymer morphologies

The domains of microphase separated block copolymers develop interfacial surfaces of approximately constant mean curvature in response to thermodynamic driving forces. Of particular recent interest are the tricontinuous triply periodic morphologies and their mathematical representations. Level surfaces are represented by certain real functions which satisfy the expression F ( x,y,z ) = t , where t is a constant. In general, they are non-self-intersecting and smooth, except at special values of the parameter t . We construct periodic level surfaces according to the allowed reflections of a particular cubic space group; such triply periodic surfaces maintain the symmetries of the chosen space group and make attractive approximations to certain recently computed triply periodic surfaces of constant mean curvature. This paper is a study of the accuracy of the approximations constructed using the lowest Fourier term of the Pm 3 m , Fd 3 m and I 4 1 32 space groups, and the usefulness of these approximations in analysing experimentally observed tricontinuous block copolymer morphologies at a variety of volume fractions. We numerically compare surface area per unit volume of particular level surfaces with constant mean curvature surfaces having the same volume fraction. We also demonstrate the utility of level surfaces in simulating projections of tricontinuous microdomain morphologies for comparison with actual transmission electron micrographs and determination of block copolymer microstructure.
A Framework for the Sound Specification of Cryptographic Tasks

Nowadays it is widely accepted to formulate the security of a protocol carrying out a given task via the “trustedparty paradigm,” where the protocol execution is compared with an ideal process where the outputs are computed by a trusted party that sees all the inputs. A protocol is said to securely carry out a given task if running the protocol with a realistic adversary amounts to “emulating” the ideal process with the appropriate trusted party. In the Universal Composability (UC) framework the program run by the trusted party is called an ideal functionality. While this simulation-based security formulation provides strong security guarantees, its usefulness is contingent on the properties and correct specification of the ideal functionality, which, as demonstrated in recent years by the coexistence of complex, multiple functionalities for the same task as well as by their “unstable” nature, does not seem to be an easy task. In this paper we address this problem, by introducing a general methodology for the sound specification of ideal functionalities. First, we introduce the class of canonical ideal functionalities for a cryptographic task, which unifies the syntactic specification of a large class of cryptographic tasks under the same basic template functionality. Furthermore, this representation enables the isolation of the individual properties of a cryptographic task as separate members of the corresponding class. By endowing the class of canonical functionalities with an algebraic structure we are able to combine basic functionalities to a single final canonical functionality for a given task. Effectively, this puts forth a bottom-up approach for the specification of ideal functionalities: first one defines a set of basic constituent functionalities for the task at hand, and then combines them into a single ideal functionality taking advantage of the algebraic structure. In our framework, the constituent functionalities of a task can be derived either directly or, following a translation strategy we introduce, from existing game-based definitions; such definitions have in many cases captured desired individual properties of cryptographic tasks, albeit in less adversarial settings. Our translation methodology entails a sequence of steps that systematically derive a corresponding canonical functionality given a game-based definition, effectively “lifting” the game-based definition to its composition-safe version. We showcase our methodology by applying it to a variety of basic cryptographic tasks, including commitments, digital signatures, zero-knowledge proofs, and oblivious transfer. While in some cases our derived canonical functionalities are equivalent to existing formulations, thus attesting to the validity of our approach, in others they differ, enabling us to “debug” previous definitions and pinpoint their shortcomings.
Transient response of Ge:Be and Ge:Zn FIR photoconductors under low background photon flux conditions

An experimental study of the transient behavior of Ge:Be and Ge:Zn photoconductors to changes in photon flux rates has been performed under the low background flux conditions (10 to the 8th photon/s) typical of astronomy and astrophysics applications. A characteristic transient behavior with time constants ranging from 0.1 to greater than 5 s has been observed in both materials when the shallow levels are very closely compensated. The detector response consists of both a fast and a slow component. The amplitude of the slow component can be up to 10 times greater than the initial fast component. It has been established that this phenomenon cannot be explained by current models of carrier sweep-out or dielectric relaxation. The transient behavior has been characterized as a function of temperature, electric field, photoconductive gain and material parameters.
Microbial activities in deep subsurface environments

Abstract Activities of microorganisms residing in terrestrial deep subsurface sediments were examined in 46 sediment samples from three boreholes. Radiolabeled time course experiments assessing in situ microbial activities were initiated within 30 min of core recovery. [1‐C4] Acetate incorporation into lipids, [ methyl‐3H] thymidine incorporation into DNA, [2‐14C]acetate, and [U‐14C]glucose mineralization in addition to microbial enrichment and enumeration studies were examined in surface and subsurface sediments. Surface soils contained the greatest biomass and activities, followed by the shallow aquifer zones. Water‐saturated subsurface sands exhibited three to four orders of magnitude greater activity and culturable microorganisms than the dense clay zones, which had low permeability. Regardless of depth, sediments that contained more than 20% clays exhibited the lowest activities and culturable microorganisms.
Intramolecular photocycloaddition reactions of 1-acyl-3-oxa-1,5-hexadienes

Abstract The regioselectivity of the intramolecular [2+2] photocycloadditions of 1-Acyl-3-oxa-1,5-hexadienes appears, in general, to follow “rule of five” closure and give annelated 2-oxa-bicyclo[2.1.1]hexanes.
Social choice and resource allocation: a topological perspective

This volume brings together a collection of papers in an area which has evolved rapidly in recent years. This is the area of continuous or topological approaches to the study of social choice, and the analysis of what have come to be known as “Chichilnisky rules”. Initiated by Chichilnisky in a paper in Advances in Mathematics in 1980 [14], the field has quickly evolved from a separate and distinct area of social choice to one which is integrated into the mainstreams of both social choice and the general equilibrium approach to markets, and which in turn has come to integrate and bridge these previously disparate areas, revealing deep and unexpected connections between them. Many of the papers in this volume were first presented either at a conference on “Ethics, Economics and Business” held at Columbia Business School in March 1993, or at a workshop on “Geometry, Topology and Markets” held at the Fields Institute for Mathematical Sciences in July 1994. These two meetings were important in catalyzing the growth of this area. My aim in this introduction is to place the papers in this volume in the context of the development of the area in general, and then to give some personal reflections and observations on the growth of this area, its future, and its role in economic theory. Three of the sections of this introduction, “Topological Social Choice”, “Incentives”, “Infinite Populations”, match the three sections into which the papers that follow have been organized. Section 2 of this introduction, on “Social Choice and Resource Allocation”, surveys recent results on the relationship between social choice theory and resource allocation theory, a field covered in more detail in Chichilnisky’s paper [18] in Sect. 1.
Who merits financial aid? Massachusetts' Adams scholarship

Abstract Most states now fund merit-based financial aid programs, the effects of which depend on how strongly students react to changes in college costs. I estimate such reactions using quasi-experimental aspects of a recent Massachusetts merit scholarship program intended to attract talented students to the state's public colleges. Despite its small monetary value, the Adams Scholarship induced 6% of winners to choose four-year public colleges instead of four-year private colleges, suggesting an elasticity of demand for public college enrollment above unity. Nonetheless, most funds flowed to students who would have enrolled in public colleges absent the scholarship and the aid had no effect on winners' overall college enrollment rate, which already exceeded 90%. Regression discontinuity estimates are larger than those from difference-in-difference specifications because winners with relatively low academic skill, and thus nearest the treatment threshold, reacted much more strongly to the price change than did highly skilled winners. Conditional on academic skill, low-income winners reacted similarly to their higher income peers, suggesting that previous research may have mistaken income heterogeneity for skill heterogeneity.
Pressure effects in the microwave plasma growth of polycrystalline diamond

Microwave plasma deposition of polycrystalline diamond is investigated over the pressure range 1 to 100 kPa. The conditions of growth, microstructure, and spectroscopic properties of the resulting materials are compared. A phenomenological description of the dependence of diamond microstructure upon growth conditions is developed.
Algebraic factor analysis: tetrads, pentads and beyond

Factor analysis refers to a statistical model in which observed variables are conditionally independent given fewer hidden variables, known as factors, and all the random variables follow a multivariate normal distribution. The parameter space of a factor analysis model is a subset of the cone of positive definite matrices. This parameter space is studied from the perspective of computational algebraic geometry. Grobner bases and resultants are applied to compute the ideal of all polynomial functions that vanish on the parameter space. These polynomials, known as model invariants, arise from rank conditions on a symmetric matrix under elimination of the diagonal entries of the matrix. Besides revealing the geometry of the factor analysis model, the model invariants also furnish useful statistics for testing goodness-of-fit.
Passive thermal energy storage in refrigerated warehouses

Abstract This paper investigates operational strategies that use stored products as thermal mass to shift refrigeration loads to more favorable operational periods (low energy cost periods, lower outdoor air conditions, etc.) allowing an opportunity to reduce system operating costs. An integrated model of the stored product, warehouse air, and warehouse structure is developed and thermal response characteristics are predicted for a selected warehousing facility. Simulated results are validated with experimental measurements. Food quality impacts associated with the temperature cycling caused by potential operating strategies are discussed. Results from this investigation indicated that a full load-shifting control strategy would save $82,000 (US) ($0.40/ft 2 /year or $4.28/m 2 /year) annually over the test facility's current operational strategy, representing 53% of the total cooling cost. Predicted maximum warehouse temperature variation is 5.6°C, which is not expected to cause significant product quality changes in the temperature range (below−18°C) studied.
Pyridoxine: a potential local antidote for mitomycin-C extravasation

Two cases are presented which suggest that pyridoxine injected into a Mitomycin-C extravasation site may slow or prevent necrosis, and may decrease the pain associated with the chronic ulceration of extravasation.
Local debris congestion in the geosynchronous environment with population augmentation

Abstract Forecasting of localized debris congestion in the geostationary (GEO) regime is performed to investigate how frequently near-miss events occur for each of the longitude slots in the GEO ring. The present-day resident space object (RSO) population at GEO is propagated forward in time to determine current debris congestion conditions, and new probability density functions that describe where GEO satellites are inserted into operational orbits are harnessed to assess longitude-dependent congestion in “business-as-usual” launch traffic, with and without re-orbiting at end-of-life. Congestion forecasting for a 50-year period is presented to illustrate the need for appropriately executed mitigation measures in the GEO ring. Results indicate that localized debris congestion will double within 50 years under current 80% re-orbiting success rates.
Constraints on the Formation Age of Cometary Material from the NASA Stardust Mission

We measured the 26 Al- 26 Mg isotope systematics of a ~5-μm refractory particle, Coki, returned from comet 81P/Wild 2 in order to relate the time scales of formation of cometary inclusions to their meteoritic counterparts. The data show no evidence of radiogenic 26 Mg and define an upper limit to the abundance of 26 Al at the time of particle formation of 26 Al/ 27 Al −5 . The absence of 26 Al indicates Coki formed >1.7 Ma after the oldest solar system solids, Ca-Al-rich inclusions (CAIs). The data presented here suggest that high temperature inner solar system material formed, was subsequently transferred to the Kuiper Belt, and incorporated into comets several million years following CAI formation.
Particle-in-cell/Monte Carlo simulation of ion back bombardment in a high average current RF photo-gun

Abstract In this paper, we report on study of ion back bombardment in a high average current radio-frequency (RF) photo-gun using a particle-in-cell/Monte Carlo simulation method. Using this method, we systematically studied effects of gas pressure, RF frequency, RF initial phase, electric field profile, magnetic field, laser repetition rate, different ion species on ion particle line density distribution, kinetic energy spectrum, and ion power line density distribution back bombardment onto the photocathode. These simulation results suggest that effects of ion back bombardment could increase linearly with the background gas pressure and laser repetition rate. The RF frequency significantly affects the ion motion inside the gun so that the ion power deposition on the photocathode in an RF gun can be several orders of magnitude lower than that in a DC gun. The ion back bombardment can be minimized by appropriately choosing the electric field profile and the initial phase.
Unexpected affects of Me3Si-X on reactions of higher order cyanocuprates

Abstract The assumed compatibility of Me3SiCl with higher order cyanocuprates has been studied by both chemical and spectroscopic (1H, 7Li, 29Si NMR) means. Both types of experiments confirm that Me3Si-X significantly alters the composition of both homo (R2Cu(CN)Li2) and mixed (RR′Cu(CN)Li2) reagents.
Time-varying Correlations and Optimal Allocation in Emerging Market Equities for the US Investors

Low correlations between asset returns increase the portfolio diversification benefits and for US investors emerging market equities are one such class of assets. Several studies indicate that the correlations between asset returns are time varying and using unconditional estimates of correlation in a portfolio optimization model can result in misallocation of assets. To overcome this problem we use multivariate Generalized Autoregressive Conditional Heteroskedasticity (GARCH) models to estimate the time-varying correlations and use the same in portfolio optimization models. Ex-post return calculations show that unrestricted portfolios created with emerging stock indices and S&P 500 index outperform the S&P 500 index by itself. Since investors exhibit strong home bias in their portfolio choice, restricted optimization models are tested. Results indicate that if the total investment in emerging markets is restricted, a minimum investment of 20% in emerging markets is required to obtain significant diversification benefit. With investments in each of the emerging market restricted to less than 3%, there was no significant diversification benefit. Copyright © 2007 John Wiley & Sons, Ltd.
Future intelligent Earth observing satellites

This paper presents a simulated architecture of an envisioned future intelligent Earth observing satellite system (FIEOS). The proposed system is a space-based architecture for dynamic and comprehensive on-board integration of Earth observing sensors, data processors and communication systems. It is intended to enable simultaneous, global measurements and timely analyses of Earth's environment for a variety of users. This paper also reports our progress of initial research in on-board image database management, including data structure, data model, and query. The intelligence of EO satellite system lies in that common users would access data directly, and in a manner similar to selecting a TV channel. The imagery viewed would most likely be obtained directly from the satellite system. The future of this system is promising for Earth observation. Real-time information systems are key to solving the challenges associated with this innovative architecture. Realization of such a technologically complex system will require contributions of scientists and engineers from many disciplines. Hopefully, this revolutionary concept will impact dramatically how future Earth observing satellite's development in the next few decades.
A SHORT PROOF OF GROMOV'S FILLING INEQUALITY

We give a very short and rather elementary proof of Gromov's filling volume inequality for n-dimensional Lipschitz cycles (with integer and Z 2 -coefficients) in L∞-spaces. This inequality is used in the proof of Gromov's systolic inequality for closed aspherical Riemannian manifolds and is often regarded as the difficult step therein.
Welfare impacts of a non-profit firm in mixed commercial markets

Abstract Utilizing a model that allows for the welfare of the commercial NPO’s stakeholders directly in terms of their consumer surplus, and indirectly in terms of NPO profits, we explore the impact of changes in the NPO’s “social concern” for consumers on market efficiency. Three separate Cournot mixed market scenarios are analyzed: competition between the NPO and a private for-profit firm, competition between the NPO and a public firm, and a market scenario that includes all three firms. We find that the technical efficiency of the NPO vis-a-vis the profit maximizer is crucial in determining whether social welfare rises or falls as the NPO places more weight on their stakeholders’ surplus. In particular, if the NPO is less technically efficient than the profit maximizer or public firm, somewhat paradoxically social welfare may fall as the NPO shows a greater social concern for consumers. In other words, a movement away from pure profit maximizing behavior by a NPO may well be detrimental in these mixed commercial markets. We also show the additional sources of revenue available to a NPO may decrease the overall welfare in these mixed market situations.
Kinematics of the Galactic Globular Cluster System: New Radial Velocities for Clusters in the Direction of the Inner Galaxy

The High-Resolution Echelle Spectrometer (HIRES) on the Keck I telescope has been used to measure the first radial velocities for stars belonging to 11 heavily reddened globular clusters in the direction of the inner Galaxy. The sample consists of the clusters Terzan 3, NGC 6256, IC 1257, NGC 6380 (=Ton 1), Ton 2 (=Pismis 26), Djorg 1, NGC 6540 (=Djorg 3), IC 1276 (=Pal 7), Terzan 12, NGC 6749, and Pal 10. Candidate cluster members were selected from a combination of previously published color-magnitude diagrams (CMDs) and new instrumental CMDs obtained with the Palomar 1.5 m telescope. The systemic velocities of Djorg 1 and Pal 10 should be considered provisional, since velocities are available for only two stars. For the remaining nine clusters, we have measured radial velocities for three to nine member stars. Using our HIRES spectra, we estimate metallicities of [Fe/H] -0.75 for both Terzan 3 and IC 1276, two clusters lacking previous metallicity estimates. The question of kinematic substructuring among the Galactic globular clusters is investigated using an updated catalog of globular cluster distances, metallicities, and velocities. It is found that the population of metal-rich globular clusters shows significant rotation at all Galactocentric radii. For the metal-rich clusters within 4 kpc of the Galactic center, the measured rotation velocity and line-of-sight velocity dispersion are similar to those of bulge field stars. We investigate claims that the metal-rich clusters are associated with the central Galactic bar by comparing the kinematics of the innermost clusters to that of the atomic hydrogen in the inner Galaxy. The longitude-velocity diagram of both metal-rich and metal-poor clusters bears a remarkable similarity to that of the gas, including the same noncircular motions that have traditionally been interpreted as evidence for a Galactic bar, or, alternatively, a nonaxisymmetric bulge. However, uncertainties in the existing three-dimensional Galactocentric positions for most of the clusters do not yet allow an unambiguous discrimination between the competing scenarios of membership in a rigidly rotating bar or in a bulge that is an oblate isotropic rotator. We conclude that the majority of metal-rich clusters within the central ~4 kpc of the Galaxy are probably associated with the bulge/bar, and not the thick disk.
Electron acceleration and synchrotron radiation in decelerating plasmoids

Abstract An equation is derived to calculate the dynamics of relativistic magnetized plasma which decelerates by sweeping up matter from the ISM. Reduction to the non-radiative and radiative regimes is demonstrated for the general case of a collimated plasmoid whose area increases as a power of distance x from the explosion, and in the specific case of a blast-wave geometry where the area increases quadratically with x. An equation for the evolution of the electron momentum distribution function in the comoving fluid frame is used to calculate the observed synchrotron radiation spectrum. The central uncertainty involves the mechanism for transfering energy from the non-thermal protons to the electrons. The simplest prescription is to assume that a fixed fraction of the comoving proton power is instantaneously transformed into a power-law, “shock”-like electron distribution function. This permits an analytic solution for the case of a relativistic plasmoid with a constant internal magnetic field. Effects of parameter changes are presented. Breaks in the temporal behavior of the primary burst emission and long wavelength afterglows occur on two time scales for external ISM density distributions nextαx−η. The first, as emphasized by Meszaros & Rees, represents the time when the outflow sweeps up ≈ M th/Γ0 of material from the ISM, where M this the mass in the outflow ejecta and Γ0 is the initial Lorentz factor of the plasmoid. The second represents the time when synchrotron cooling begins strongly to regulate the number of nonthermal electrons that are producing radiation which is observed at a given energy. Results are applied to GRB and blazar variability. The slopes of the time profiles of the X-ray and optical light curves of the afterglows of GRB 970228 and GRB 970508 are explained by injection of hard electron spectra with indices s
Modeling clear-air turbulence with vortices using parameter-identification techniques

A vortex model of winds associated with clear-air turbulence is shown to be useful for characterizing actual airline encounters with severe turbulence. The model consists of an array of vortices with solid-body cores embedded in a potential flowfield. Parameters such as the size and strength of the vortices and their locations are identified using a modified Newton-Raphson algorithm. A manual identification startup scheme is used to minimize errors in the initial parameter estimates, and the identification algorithm is found to be robust in regard to the remaining errors. The analysis of a turbulence experience involving a commercial airliner demonstrates the success of the model and estimation procedure. The analysis finds vortices with core diameters of 1000 ft and tangential velocities of 87 ft/s in this encounter. LEAR-air turbulence (CAT) is a little-understood phenomenon that occurs in the mid to upper troposphere and the lower stratosphere and that poses a safety hazard to aircraft. The most severe cases are characterized by sudden, violent disturbances with definite periodicity. This problem is being investigated by the NASA Ames Research Center in con- junction with the National Transportation Safety Board. Because of the small scale in both duration and distance over which CAT occurs, it has been a difficult phenomenon to study. However, in the recent past, wide-bodied commercial aircraft equipped with digital flight-data recorders have had a few encounters with CAT, and the data from these recorders, along with additional data from air-traffic control (ATC) radar records, have made it possible to obtain a detailed description of the winds associated with CAT encounters. A model of the wind environment during CAT has been developed using these wind data and previous theoretical studies of CAT. These studies1'6 predict that CAT is a result of the breakdown of stably stratified shear layers in the at- mosphere, a condition known as Kelvin-Helmholtz instability. The shear layers roll up into a vortex array which forms in a Kelvin "cat's eyes" pattern (Fig. 1). The direction of rotation of the vortices depends on the way the shear layer breaks down, as discussed in Ref. 7. To compare /theory with data from actual encounters, parameter-identification techniques have been used to match the winds produced by a vortex-array model to the data. This has been done successfully with two actual encounters and is reported in a previous paper.7 A similar technique had been used earlier to study an airplane's traling vortices.8 The pur- pose of this paper is to describe the vortex model and the parameter-identification techniques used to match the model to the winds found in a CAT encounter. First, a vortex model and its relation to an aircraft flight path is described. Next, the algorithm used to determine the model parameters is discussed briefly, followed by an explana-
Insulin Resistance Is a Sufficient Basis for Hyperandrogenism in Lipodystrophic Women with Polycystic Ovarian Syndrome

Context: The lipodystrophies (LD) are characterized by metabolic abnormalities (insulin resistance, hypertriglyceridemia, and diabetes) and a polycystic ovarian syndrome (PCOS) phenotype. Therapeutic administration of leptin improves insulin sensitivity and the metabolic features. Objective: The objective of the study was to investigate whether the PCOS features are corrected by increasing insulin sensitivity as a function of leptin treatment. Design: This was a prospective, open-label trial using leptin replacement in various forms of lipodystrophy. Setting: The study was performed at the Clinical Center at the National Institutes of Health. Patients or Other Participants: Twenty-three female patients with LD were enrolled in a leptin replacement trial from 2000 to the present. Different parameters were assessed at baseline and after 1 yr of therapy. Intervention(s): Patients were treated with leptin for at least 1 yr. Main Outcome Measure(s): We evaluated free testosterone, SHBG, and IGF-I at baseline a...
THE FORMATION OF CRYSTALLINE DUST IN AGB WINDS FROM BINARY-INDUCED SPIRAL SHOCKS

As stars evolve along the asymptotic giant branch (AGB), strong winds are driven from the outer envelope. These winds form a shell, which may ultimately become a planetary nebula. Many planetary nebulae are highly asymmetric, hinting at the presence of a binary companion. Some post-AGB objects are surrounded by tori of crystalline dust, but there is no generally accepted mechanism for annealing the amorphous grains in the wind to crystals. Here, we show that the shaping of an AGB wind by a binary companion provides a possible mechanism for forming crystalline dust in the orbital plane.
A New Multicomponent Reaction Catalyzed by a [Lewis Acid]+[Co(CO)4]- Catalyst: Stereospecific Synthesis of 1,3-Oxazinane-2,4-diones from Epoxides, Isocyanates, and CO

The use of mechanistic information to develop a new, catalytic multicomponent reaction is described. The complex [(salph)Al(THF)2+[co(CO)4]-(1, salph = N,N-o-phenylenebis(3,5-di-tert-butylsalicylid ...
Light quark distributions in the proton sea

We use the meson cloud model to calculate $\bar{d}(x) - \bar{u}(x)$ and $ \bar{d}(x)/\bar{u}(x)$ in the proton. We show that a modification of the symmetric, perturbative part of the light quark sea provides better agreement with the ratio $ \bar{d}(x)/\bar{u}(x).
D-branes in orbifold singularities and equivariant K-theory

Abstract The study of brace-antibrane configurations in string theory leads to the understanding of supersymmetric D p -branes as the bound states of higher dimensional branes. Configurations of pairs of brane-antibranes admit in a natural way a description in terms of K-theory. We analyze configurations of brane-antibranes at fixed point orbifold singularities in terms of equivariant K-theory as recently suggested by Witten. Type I and IIB fivebranes and small instantons on ALE singularities are described in K-theoretical terms and their relation to the Kronheimer-Nakajima construction of instantons is also provided. Finally the D-brane charge formula is reexamined in this context.
Spin-Orbit Misalignment in Close Binaries with Two Compact Objects

Spin-orbit misalignment in coalescing compact binaries affects their gravitational radiation waveforms. When the misalignment angles are large (30°), the detection efficiency of the coalescence events can decrease significantly if the misalignment effects are not modeled. In this paper, we consider the formation of close compact binaries and calculate the expected misalignment angles after the second core collapse event. Depending on the progenitor parameters and the assumptions made about supernova kicks, we find that 30%-80% of binaries containing a black hole and a neutron star that coalesce within 1010 yr have misalignment angles larger than 30°, and a significant fraction of them could remain undetected. The calculations allow us to place strong constraints on the progenitors of such binaries and the kick magnitudes required for their formation. We also discuss the formation of close binaries with two black holes and the effect of nonisotropic kicks.
Friction and wear of polyimide thin films

Abstract The friction and wear of thin polyimide films were measured as functions of the polyimide structure, the sliding speed and the temperature in a pin-on-disk machine. A 5 N load pressed a stationary 52100 steel ball against the rotating polyimide film 50 μm thick which was solvent cast on an AISI 410 stainless steel disk. The wear rates were significantly affected by structural differences which resulted from the different dianhydrides and diamines from which the polyimides were synthesized. The wear rates were lowest for the most flexible molecular chains as indicated by the glass transition temperatures. A positive correlation was found for a power law relationship between the wear rate and the elastic modulus (the correlation coefficient was 0.997) for tests at 24 and 130°C. The power law relationship is suggested by the fatigue model of wear.
Performance of High-Speed Ball Bearings With Lead and Lead-Alloy-Plated Retainers in Liquid Hydrogen at 1.2 Million DN

Ball bearings with lead- and lead-alloy-coated retainers were operated in liquid hydrogen at 30,000 rpm under a thrust load of 400 lb. Bearing lives were compared using different: (1) lead- and lead-alloy coatings, (2) coating thicknesses, (3) substrate materials, (4) retainer locating surfaces, and (5) plating techniques. Longer bearing run times were achieved using retainers with a lead-tin-copper alloy coating electroplated onto a leaded-bronze material and an aluminum-bronze alloy. Thirty percent of the bearings tested achieved the desired objective of 10 hours. All of the lead-alloy coated retainers exceeded this objective. A coating thickness of at least 0.0014 in. was used for all bearings exceeding the 10-hour goal.
Hierarchically Parallelized Constrained Nonlinear Solvers with Automated Substructuring

This paper develops a parallelizable multilevel multiple constrained nonlinear equation solver. The substructuring process is automated to yield appropriately balanced partitioning of each succeeding level. Due to the generality of the procedure,_sequential, as well as partially and fully parallel environments can be handled. This includes both single and multiprocessor assignment per individual partition. Several benchmark examples are presented. These illustrate the robustness of the procedure as well as its capability to yield significant reductions in memory utilization and calculational effort due both to updating and inversion.
Adjoint optimization of one-dimensional hyperbolic equations with constrained periodic boundary conditions

Abstract This paper presents a continuous adjoint-based optimization theory for a general closed-loop transport hyperbolic model controlled via a periodic boundary control to minimize a cost functional. The periodic boundary control is subject to a nonlinear differential equation constraint, thus resulting in a coupling between the hyperbolic equation and the ordinary differential equation. Variational principles are used to derive the Pontryagin’s minimum principle for optimality that results in a dual adjoint system. A numerical optimization method is implemented using the adjoint-based second-order gradient method to solve for the optimal trajectory of the control. Numerical methods for solving the hyperbolic equation using an explicit scheme, wave splitting method and for solving the adjoint equation using an implicit scheme and a quasi-steady state method are described.
Collapsing D-branes in Calabi–Yau moduli space I

Abstract We study the quantum volume of D-branes wrapped around various cycles in Calabi–Yau manifolds, as the manifold's moduli are varied. In particular, we focus on the behaviour of these D-branes near phase transitions between distinct low energy physical descriptions of the resulting string theory. Whereas previous studies have solely considered quantum volumes in the context of two-cycles in perturbative string theory or D-branes in the specific example of the quintic hypersurface, we work more generally and find qualitatively new features. On the mathematical side, as we briefly note, our work has some interesting implications for certain issues in arithmetic.