cssi/SciSciGPT-SciSciNet huggingface dataset:
Challenges for Precision Cosmology with X-Ray and Sunyaev-Zeldovich Effect Gas Mass Measurements of Galaxy Clusters

We critically analyze the measurement of galaxy cluster gas masses, which is central to cosmological studies that rely on the galaxy cluster gas mass fraction. Using synthetic observations of numerically simulated clusters viewed through their X-ray emission and thermal Sunyaev-Zeldovich effect (SZE), we reduce the observations to obtain measurements of the cluster gas mass. We quantify the possible sources of uncertainty and systematic bias associated with the common simplifying assumptions used in reducing real cluster observations, including isothermality and hydrostatic equilibrium. We find that intrinsic variations in clusters limit the precision of observational gas mass estimation to ~10% to 1 σ confidence, excluding instrumental effects. Gas mass estimates show surprisingly little trending in the scatter as a function of cluster redshift. For the full cluster sample, methods that use SZE profiles out to roughly the virial radius are the simplest, most accurate, and unbiased way to estimate cluster mass. X-ray methods are systematically more precise mass estimators than are SZE methods if merger and cool-core systems are removed, but slightly overestimate (5%-10%) the cluster gas mass on average. We find that cool-core clusters in our samples are particularly poor candidates for observational mass estimation, even when excluding emission from the core region. The effects of cooling in the cluster gas alter the radial profile of the X-ray and SZE surface brightness even outside the cool-core region. Finally, we find that methods using a universal temperature profile estimate cluster masses to higher precision than those assuming isothermality.
Global risk bounds and adaptation in univariate convex regression

We consider the problem of nonparametric estimation of a convex regression function \(\phi _0\). We study the risk of the least squares estimator (LSE) under the natural squared error loss. We show that the risk is always bounded from above by \(n^{-4/5}\) modulo logarithmic factors while being much smaller when \(\phi _0\) is well-approximable by a piecewise affine convex function with not too many affine pieces (in which case, the risk is at most \(1/n\) up to logarithmic factors). On the other hand, when \(\phi _0\) has curvature, we show that no estimator can have risk smaller than a constant multiple of \(n^{-4/5}\) in a very strong sense by proving a “local” minimax lower bound. We also study the case of model misspecification where we show that the LSE exhibits the same global behavior provided the loss is measured from the closest convex projection of the true regression function. In the process of deriving our risk bounds, we prove new results for the metric entropy of local neighborhoods of the space of univariate convex functions. These results, which may be of independent interest, demonstrate the non-uniform nature of the space of univariate convex functions in sharp contrast to classical function spaces based on smoothness constraints.
Performance analysis and optimization on a parallel atmospheric general circulation model code

An analysis is presented of the primary factors influencing the performance of a parallel implementation of the UCLA atmospheric general circulation model (AGCM) on distributed memory, massively parallel computer systems. Several modifications to the original parallel AGCM code aimed at improving its numerical efficiency, load balance and single node code performance are discussed. The impact of these optimization strategies on the performance on two of the state of the art parallel computers, the Intel Paragon and Cray T3D, is presented and analyzed. It is found that implementation of a load balanced FFT algorithm results in a reduction in overall execution time of approximately 45% compared to the original convolution based algorithm. Preliminary results of the application of a load balancing scheme for the physics part of the AGCM code suggest additional reductions in execution time of 15-20% can be achieved. Finally, several strategies for improving the single node performance of the code are presented, and the results obtained thus far suggest reductions in execution time in the range of 30-40% are possible.
The preparation of aromatic NLO amine and diamine monomers for polymerization: A mild Mitsunobu coupling technique for the tethering of sensitive NLO chromophores

Abstract Polymerizable NLO monomers, including those containing highly nonlinear, reagent sensitive chromophores, are prepared under very mild conditions using a deprotection strategy, coupled with Mitsunobu chemistry.
Rotation of the Coronal Magnetic Field

The coronal magnetic field rotates differently than the photosphere. The field configuration of the corona can be calculated from the observed photosphpere field using a potential field model. Correlation of the field patterns at different latitudes with a lag near one solar rotation shows much less differential rotation than observed in the photospheric field; however, the peak is very broad and determines the rotation rate rather poorly. Consideration of longer lags reveals a more complex rotational structure and indicates different rotation rates in the Northern and Southern Hemispheres. Spectral analysis of the equatorial dipole component of the coronal field reveals an organization into just a few discrete rotation frequencies which are apparently present simultaneously. Spectral analysis of the field at different latitudes shows that the frequencies are present simultaneously. Spectra analysis of the field at different latitudes shows that the frequencies are present simultaneously, but in different hemispheres, and that the Southern Hemisphere fields rotate more slowly than those in the north in solar cycle 21.
Vapor Pressures of Chlorinated Dioxins and Dibenzofurans

Abstract The subcooled liquid vapor pressures of five polychlorinated dibenzo- p -dioxins (PCDD) and nine polychlorinated dibenzofurans (PCDF) were determined by a gas chromatographic (GC) method. The experimentally determined vapor pressures are highly correlated with published GC retention indices. Using this correlation, vapor pressures were calculated for all chlorinated dioxins and dibenzofurans; these predicted vapor pressures correlate with vapor pressures determined or predicted by other methods.
Second language acquisition, applied linguistics and the teaching of foreign languages

Given the current popularity of second language acquisition (SLA) as a research base for the teaching and learning of foreign languages in educational settings, it is appropriate to examine the relationship of SLA to other relevant areas of inquiry, such as foreign language education, foreign language methodology, and applied linguistics. This article makes the argument that applied linguistics, as the interdisciplinary field that mediates between the theory and the practice of language acquisition and use, is the overarching field that includes SLA and SLA-related domains of research. Applied linguistics brings to all levels of foreign language study not only the research done in SLA proper, but also the research in stylistics, language socialisation, and critical applied linguistics that illuminates the teaching of a foreign language as sociocultural practice, as historical practice, and as social semiotic practice.
Semigroups of matrices with dense orbits

We give examples of n × n matrices A and B over the field &#x1d542; = ℝ or ℂ such that for almost every column vector x ∈ &#x1d542; n , the orbit of x under the action of the semigroup generated by A and B is dense in &#x1d542; n .
The chemical vapor synthesis of inorganic nanopowders

Chemical vapor synthesis (CVS) is a process for making fine solid particles by the vapor-phase chemical reactions of precursors. At the University of Utah, this process has been applied to the synthesis of the aluminides of titanium and nickel, other metallic and intermetallic powders, and subsequently aluminum nanopowder and WC-Co nanocomposite powder. This work has demonstrated that it is possible to prepare fine particles of 5–200 nm size by CVS. Further, it has been shown that this technique has a unique capability to produce uniformly mixed powders of different solids. This is possible because the reactants are perfectly mixed in the gas phase. More recently, the CVS process has been carried out in a plasma reactor. This system has shown considerable promise for many applications as a method of producing nanosized powders.
An adamantane-like [Ge4Te10]4− anion: synthesis and single crystal structure determination of (Et4N)4[Ge4Te10]

Abstract The extraction of the alloy of composition K4Ge4Te10 in ethylenediamine (en) in the presence of Et4NBr afforded black cubic crystals of (Et4N)4[Ge4Te10], 1, in 72% yield. The X-ray diffraction data revealed two crystallographically independent [Ge4Te10]4− clusters each having approximate 4 3m point symmetry. The Ge4+ based tetrahedra share three corners to form an adamantane-like (Ge4Te6) unit with the fourth site occupied by a terminal Te2− ligand.
Bend, break and count

This paper gives a formula for the number of members of a given ‘nice’ family of rational curves on a surface passing through the appropriate number of general points, expressing this number in terms of reducible members of the family. Similar formulae have been obtained previously using methods of quantum cohomology, but the present method is by contrast completely elementary, relying merely on some simple geometry on ruled surfaces.
Construction of higher order accurate vortex and particle methods

The standard point vortex method has recently been shown to be of high order of accuracy for problems on the whole plane, when using a uniform initial subdivision for assigning the vorticity to the points. If obstacles are present in the flow, this high order deteriorates to first or second order. This paper introduces new vortex methods which are of arbitrary accuracy (under regularity assumptions) regardless of the presence of bodies and the uniformity of the initial subdivision.
Transformation of an Agulhas eddy near the continental slope

Abstract. The transformation of Agulhas eddies near the continental slope of southern Africa and their subsequent self-propagation are analyzed in both observational data and numerical simulations. Self-propagation results from a net dipole moment of a generalized heton structure consisting of a surface-intensified anticyclonic eddy and deep cyclonic pattern. Such Agulhas vortical structures can form near the retroflection region and further north along the western coast of southern Africa. We analyze nonlinear topographic wave generation, vortex deformations, and filament production as an important part in water mass exchange. Self-propagating structures provide a conduit for exchange between the deep ocean and shelf regions in the Benguela upwelling system.
An analysis of the congestion effects of link failures in wide area networks

The authors present the results of a study to determine the effects of link failures on the performance of a network in terms of the occurrence of congestion due to traffic restoration after a failure. The network studied is a virtual circuit based packet switched wide area network. A generic queueing framework is developed to study the effect of failures and the subsequent traffic restoration on network performance. In general, the congestion resulting after a failure is a transient phenomenon. Hence, a numerical methods based nonstationary queueing analysis is conducted in order to quantify the effects of failures in terms of the transient behavior of queue lengths and packet loss probabilities. A bounding relationship is developed whereby a network node can determine whether or not congestion will occur as the result of traffic restoration after a failure. >
Efficient Message Passing Interface (MPI) for Parallel Computing on Clusters of Workstations

Parallel computing on clusters of workstations and personal computers has very high potential, since it leverages existing hardware and software. Parallel programming environments offer the user a convenient way to express parallel computation and communication. In fact, recently, a Message Passing Interface (MPI) has been proposed as an industrial standard for writing “portable” message-passing parallel programs. The communication part of MPI consists of the usual point-to-point communication as well as collective communication. However, existing implementations of programming environments for clusters are built on top of a point-to-point communication layer (send and receive) over local area networks (LANs) and, as a result, suffer from poor performance in the collective communication part. In this paper, we present an efficient design and implementation of the collective communication part in MPI that is optimized for clusters of workstations. Our system consists of two main components: the MPI-CCL layer that includes the collective communication functionality of MPI and a User-Level Reliable Transport Protocol (URTP) that interfaces with the LAN Data-Link Layer and leverages the fact that the LAN is a broadcast medium. Our system is integrated with the operating system via an efficient kernel extension mechanism that we developed. The kernel extension significantly improves the performance of our implementation as it can handle part of the communication overhead without involving user space. We have implemented our system on a collection of IBM RS/6000 workstations connected via a 10-Mbit Ethernet LAN. Our performance measurements are taken from typical scientific programs that run in a parallel mode by means of the MPI. The hypothesis behind our design is that the system's performance will be bounded by interactions between the kernel and user space rather than by the bandwidth delivered by the LAN Data-Link Layer. Our results indicate that the performance of our MPI Broadcast (on top of Ethernet) is about twice as fast as a recently published software implementation of broadcast on top of ATM.
Considerations of Television Holography

Television holography systems are considered with particular emphasis on the resolution requirements of the camera and reproducer. Methods are shown whereby conventional cameras and reproducers can...
Influence of atmospheric intraseasonal oscillations on seasonal and interannual variability in the upper Indian Ocean

[1] An ocean general circulation model, the Hybrid Coordinate Ocean Model (HYCOM), is used to examine the rectification of atmospheric intraseasonal oscillations (ISOs) on the mean and seasonal-to-interannual sea surface temperature (SST), mixed layer thickness (hm) and upper ocean heat content in the Indian Ocean. Existing studies have shown that ISOs rectify on seasonal and interannual equatorial surface currents and on cross-equatorial transport, suggesting that they may also have important impacts on upper ocean variability. To evaluate these impacts, a hierarchy of HYCOM experiments isolates the ocean response to forcing by atmospheric ISO events. Other experiments isolate the ocean response to a range of intraseasonal forcing fields including shortwave radiation, precipitation, and winds. Results indicate that rectification of ISOs onto seasonal and interannual upper ocean variability does occur, and that it is important in some regions. The regions displaying maximum rectification vary between SST, hm, and upper ocean heat content, and from seasonal to interannual timescales. Strong seasonal SST rectification occurs in the Arabian Sea and in the Bay of Bengal. Because SSTs in the Arabian Sea are already warm (28°C), the ISO-forced seasonal cycle peak of 0.6°C in May can affect convection there. Intraseasonal wind speed and stress have a much larger impact on seasonal and interannual SST, hm, and upper ocean heat content than either intraseasonal shortwave radiation or precipitation. The relative importance of entrainment and turbulent heat flux due to intraseasonal wind speed, and of upwelling, horizontal advection, and vertical mixing due to intraseasonal wind stress, varies with region.
Throughput scaling in wireless networks with restricted mobility

We study throughput scaling in an ad-hoc wireless network where the communication domain is divided into overlapping neighborhoods and n mobile nodes are restricted to move within their assigned neighborhood. In our model, when a node is located in a region not shared with any other neighborhood, it transmits to nodes of its own neighborhood only; when it is in an area that overlaps with another neighborhood, it transmits to nodes of the overlapping neighborhood. Communication between source-destination pairs is subject to interference from other nodes. By adopting a deterministic approach, we obtain an achievable throughput which is a function of properties of the node locations and neighborhood dimensions. As special cases of our neighborhood model, the results of P. Gupta and P.R. Kumar (2000) and M. Grossglauser and D. Tse (2002) can be recovered. We then study the case of random placement of nodes with nalpha neighborhoods, where 0 les alpha les 1, and achieve a throughput of Omega (n1-alpha/2). Hence our model captures every order of growth for the throughput, encompassing the results from both P. Gupta and P.R. Kumar (2000) and M. Grossglauser and D. Tse (2002) as extreme situations
Organization of the Mitotic Chromosome

Mitotic chromosomes are among the most recognizable structures in the cell, yet for over a century their internal organization remains largely unsolved. We applied chromosome conformation capture methods, 5C and Hi-C, across the cell cycle and revealed two distinct three-dimensional folding states of the human genome. We show that the highly compartmentalized and cell type–specific organization described previously for nonsynchronous cells is restricted to interphase. In metaphase, we identified a homogenous folding state that is locus-independent, common to all chromosomes, and consistent among cell types, suggesting a general principle of metaphase chromosome organization. Using polymer simulations, we found that metaphase Hi-C data are inconsistent with classic hierarchical models and are instead best described by a linearly organized longitudinally compressed array of consecutive chromatin loops.
Characterizing and reasoning about probabilistic and non-probabilistic expectation

Expectation is a central notion in probability theory. The notion of expectation also makes sense for other notions of uncertainty. We introduce a propositional logic for reasoning about expectation, where the semantics depends on the underlying representation of uncertainty. We give sound and complete axiomatizations for the logic in the case that the underlying representation is (a) probability, (b) sets of probability measures, (c) belief functions, and (d) possibility measures. We show that this logic is more expressive than the corresponding logic for reasoning about likelihood in the case of sets of probability measures, but equi-expressive in the case of probability, belief, and possibility. Finally, we show that satisfiability for these logics is NP-complete, no harder than satisfiability for propositional logic.
Error analysis of semidiscrete finite element methods for inhomogeneous time-fractional diffusion

We consider the initial boundary value problem for the inhomogeneous time-fractional diu- sion equation with a homogeneous Dirichlet boundary condition and a nonsmooth right hand side data in a bounded convex polyhedral domain. We analyze two semidiscrete schemes based on the standard Galerkin and lumped mass nite element methods. Almost optimal error estimates are obtained for right hand side data f(x; t)2 L 1 (0; T ; _ H q ()), 1 < q 1, for both semidiscrete schemes. For lumped mass method, the optimal L 2 ()-norm error estimate requires symmetric meshes. Finally, numerical experiments for one- and two-dimensional examples are presented to verify our theoretical results.
The CO Tully-Fisher Relation and Implications for the Host Galaxies of High-Redshift Quasars

The integrated line width derived from CO spectroscopy provides a powerful tool to study the internal kinematics of extragalactic objects, including quasars at high redshift, provided that the observed line width can be properly translated to more conventionally used kinematical parameters of galaxies. We show, through the construction of a Ks-band CO Tully-Fisher relation for nearby galaxies spanning a wide range in infrared luminosity, that the CO line width measured at 20% of the peak intensity, when corrected for inclination and other effects, successfully recovers the maximum rotation velocity of the disk. The line width at 50% of the peak intensity performs much more poorly, in large part because CO lines have a wide range of profiles, which are shown to vary systematically with infrared luminosity. We present a practical prescription for converting observed CO line widths into the stellar velocity dispersion of the bulge (σ*) and then apply it to a sample of low-redshift (z 0.2) and high-redshift (1.4 z 6.4) quasars to study their host galaxies. Nearby quasars roughly fall on the correlation between black hole mass and bulge stellar velocity dispersion established for inactive galaxies, but the host galaxies of the high-z quasars systematically deviate from the local M•-σ* relation. At a given σ*, high-z quasars have black hole masses larger by a factor of ~4 relative to local galaxies, suggesting that early in the life cycle of galaxies the development of the bulge lags behind the growth of the central black hole. An alternative explanation for these observations, which currently cannot be ruled out rigorously, is that high-redshift quasars are preferentially viewed at face-on orientations.
Natural Food Folate and Late-Life Depression

Low folate status has been linked to depression, but findings have been inconsistent. The authors sought to examine the association between folate intake and late-life depression. This cross-sectional study included individuals age 60 and older (n = 111 depression, n = 136 comparison). Depression participants received psychiatric care. Folate and kilocalorie intakes were assessed with a Block 1998 food frequency questionnaire. Naturally occurring food folate was inversely associated with depression after controlling for age, sex, race, education, and total energy (P = 0.0047). All other folate variables including total dietary folate and folic acid were non-significant for depression. These findings may indicate that the naturally occurring form of folate is uniquely protective for depression and perhaps brain health. Alternatively, natural folate may be a surrogate for other nutrients or overall dietary quality.
The Local Bubble and Interstellar Material Near the Sun

The properties of interstellar matter at the Sun are regulated by our location with respect to a void in the local matter distribution, known as the Local Bubble. The Local Bubble (LB) is bounded by associations of massive stars and fossil supernovae that have disrupted dense interstellar matter (ISM), driving low density intermediate velocity ISM into the void. The Sun appears to be located in one of these flows of low density material. This nearby interstellar matter, dubbed the Local Fluff, has a bulk velocity of ∼19 km s−1 in the local standard of rest. The flow is coming from the direction of the gas and dust ring formed where the Loop I supernova remnant merges into the LB. Optical polarization data suggest that the local interstellar magnetic field lines are draped over the heliosphere. A longstanding discrepancy between the high thermal pressure of plasma filling the LB and low thermal pressures in the embedded Local Fluff cloudlets is partially mitigated when the ram pressure component parallel to the cloudlet flow direction is included.
Alkylation of amines using trivalent bismuth derivatives

Mixed alkylaryl BiIII derivatives have been prepared by both anionic and free radical methods. The thermal stability of these compounds permits them to be used in the presence of cupric acetate for the alkylation of amines. Trialkylbismuth compounds can also be used in the same way.
Improved quantum hypergraph-product LDPC codes

We suggest several techniques to improve the toric codes and the finite-rate generalized toric codes (quantum hypergraph-product codes) recently introduced by Tillich and Zemor. For the usual toric codes, we introduce the rotated lattices specified by two integer-valued periodicity vectors. These codes include the checkerboard codes, and the family of minimal single-qubit-encoding toric codes with block length n = t2 + (t+1)2 and distance d = 2t + 1, t = 1, 2, … We also suggest several related algebraic constructions which increase the rate of the existing hypergraph-product codes by up to four times.
Three-dimensional computed tomography from interferometric measurements within a narrow cone of views

A theory to determine the properties of a fluid from measurements of its projections was developed and tested. Viewing cones as small as 10 degrees were evaluated, with the only assumption being that the property was space limited. The results of applying the theory to numerical and actual interferograms of a spherical discontinuity of refractive index are presented. The theory was developed to test the practicality and limits of using three-dimensional computer tomography in internal fluid dynamics.
The stellar populations of M33's outer regions - IV. Inflow history and chemical evolution

We have modelled the observed colour–magnitude diagram (CMD) at one location in M33’s outskirts under the framework of a simple chemical evolution scenario which adopts instantaneous and delayed recycling for the nucleosynthetic products of Type II and Ia supernovae. In this scenario, interstellar gas forms stars at a rate modulated by the Kennicutt–Schmidt relation and gas outflow occurs at a rate proportional to the star formation rate (SFR). With this approach, we put broad constraints on the role of gas flows during this region’s evolution and compare its [α/Fe] versus [Fe/H] relation with that of other Local Group systems. We find that models with gas inflow are significantly better than the closed-box model at reproducing the observed distribution of stars in the CMD. The best models have a majority of gas inflow taking place in the last 7 Gyr, and relatively little in the last 3 Gyr. These models predict most stars in this region to have [α/Fe] ratios lower than the bulk of the Milky Way’s halo. The predictions for the present-day SFR, gas mass and oxygen abundance compare favourably to independent empirical estimates. Our results paint a picture in which M33’s outer disc formed from the protracted inflow of gas over several Gyr with at least half of the total inflow occurring since z ∼ 1.
Practical management of anticoagulation in patients with atrial fibrillation.

Anticoagulation for atrial fibrillation has become more complex due to the introduction of new anticoagulant agents, the number and kinds of patients requiring therapy, and the interactions of those patients in the matrix of care. The management of anticoagulation has become a “team sport” involving multiple specialties in multiple sites of care. The American College of Cardiology, through the College’s Anticoagulation Initiative, convened a roundtable of experts from multiple specialties to discuss topics important to the management of patients requiring anticoagulation and to make expert recommendations on issues such as the initiation and interruption of anticoagulation, quality of anticoagulation care, management of major and minor bleeding, and treatment of special populations. The attendees continued to work toward consensus on these topics, and present the key findings of this roundtable in a state-of- the-art review focusing on the practical aspects of anticoagulation care for the patient with atrial fibrillation. (J Am Coll Cardiol
Electron-Nuclear Double-Resonance Study of the Self-Trapped Hole Associated with Lithium in NaF

A new ESR center has been produced in NaF crystals containing lithium impurities by producing ${V}_{K}$ centers and warming the crystal to 150\ifmmode^\circ\else\textdegree\fi{}K so that the self-trapped holes can migrate until they associate with the impurities. The complex consisting of the self-trapped hole associated with a ${\mathrm{Li}}^{+}$ impurity ion has been named the "${V}_{\mathrm{KA}}$ center." The ESR spectrum can be interpreted in terms of a "bent-bond" $\mathrm{F}_{2}^{}{}_{}{}^{\ensuremath{-}}$ molecule ion. An electron-nuclear double-resonance (ENDOR) study of the ${V}_{\mathrm{KA}}$ center has provided definite confirmation of the assumed model. The difference in the ENDOR spectra of different ESR lines has been explained by a diagonalization of the complete spin Hamiltonian matrix which includes the hyperfine interactions of the unpaired electron with both the molecular nuclei and the lattice nuclei.
Evaluation of a pH-Sensitive Polymer for Gravel-Packing Operations

Rheological data is presented for a type of polyacrylic acid polymer as a function of polymer concentration, pH, shear rate, and temperature. It was found that the viscosity of the polymer is strongly dependent on the pH of the solution. Compatibility tests showed that the polymer was compatible with most brines (NaCI, NH 4 Cl, and KCl) used for field applications. Core-flow results indicated that the filtration rate was low compared to that of hydroxethylcellusose (HEC). Our evaluation study shows that this anionic polymer would be an excellent nondamaging carrier fluid for gravel packing. It has excellent rheological and suspension properties and is easily broken down with a mild acid wash before flowback.
Expanding the crystal chemistry of actinyl peroxides: open sheets of uranyl polyhedra in Na5[(UO2)3(O2)4(OH)3](H2O)13.

A uranyl peroxide, Na5[(UO2)3(O2)4(OH)3](H2O)13, with an open sheet of uranyl polyhedra has been synthesized under ambient conditions and structurally characterized. The structure (orthorombic, Cmca, a = 23.632(1) A, b = 15.886(1) A, c = 13.952(1) A, V = 5237.7 A3, and Z = 8) consists of sheets composed of two symmetrically unique uranyl (UO2)2+ ions that are coordinated equatorially by two peroxide groups and two OH- groups, forming distorted uranyl hexagonal bipyramids of composition (UO2)(O2)2(OH)24-. The uranyl bipyramids are connected into sheets with openings with dimensions 13.7 A along [010] and 15.9 A along [100]. The shortest dimension of the cavity is 8.08 A. Sheets of two-dimensionally polymerized uranyl polyhedra are the most common structural type of inorganic uranyl phases; however, such an open topology has never been observed.
Localized Structures in Indented Shells: A Numerical Investigation

We present results from a numerical investigation of the localization of deformation in thin elastomeric spherical shells loaded by differently shaped indenters. Beyond a critical indentation, the deformation of the shell ceases to be axisymmetric and sharp structures of localized curvature form, referred to as “s-cones,” for “shell-cones.” We perform a series of numerical experiments to systematically explore the parameter space. We find that the localization process is independent of the radius of the shell. The ratio of the radius of the shell to its thickness, however, is an important parameter in the localization process. Throughout, we find that the maximum principal strains remain below 6%, even at the s-cones. As a result, using either a linear elastic (LE) or hyperelastic constitutive description yields nearly indistinguishable results. Friction between the indenter and the shell is also shown to play an important role in localization. Tuning this frictional contact can suppress localization and increase the load-bearing capacity of the shell under indentation.
A Separate Universe Approach to Quintessence Perturbations

There is some observational evidence that the dark energy may not be smooth on large scales. This makes it worth while to try and get as simple and as intuitive a picture of how dark energy perturbations behave so as to be able to better constrain possible models of dark energy and the generation of large scale perturbations. The separate Universe method provides an easy way to evaluate cosmological perturbations, as all that is required is an understanding of the background behavior. Here, this method is used to show how the size of the dark energy perturbations preferred by observations is larger than would be expected, and so some mechanism may be required to amplify them.
CMB signatures of extended reionization

Abstract I comment on the challenges and opportunities presented by an extended period of reionization.
Test Experiment for Time-Reversal Symmetry Breaking Superconductivity

A new experiment is proposed to probe the time-reversal symmetry of a superconductor. It is shown that a time-reversal symmetry breaking superconductor can be identified by the observation of a fractional flux in connection with a Josephson junction in a special geometry.
On the role of waveform diversity in MIMO radar

MIMO radar employs multiple antennas to simultaneously transmit diverse waveforms, as well as multiple antennas to receive the radar returns. This paper studies the role of waveform diversity in MIMO radar as separate and distinct from the role of the multiple transmit antennas. This is done by comparing a MIMO radar system to a scanning phased array radar which uses the same transmit and receive arrays but only a single waveform. The performance characteristics of the two systems, in terms of the ambiguity function and the spatial response, are compared for single pulse operation as well as multi-pulse operation with coherent integration. Both element-space and beam-space systems are considered.
Precision Radial Velocities of Double-lined Spectroscopic Binaries with an Iodine Absorption Cell

A spectroscopic technique employing an iodine absorption cell (I2) to superimpose a reference spectrum onto a stellar spectrum is currently the most widely adopted approach to obtain precision radial velocities of solar-type stars. It has been used to detect ~80 extrasolar planets out of ~130 known. Yet in its original version, it only allows us to measure precise radial velocities of single stars. In this paper, we present a novel method employing an I2 absorption cell that enables us to accurately determine radial velocities of both components of double-lined binaries. Our preliminary results, based on the data from the Keck I telescope and HIRES spectrograph, demonstrate that 20-30 m s-1 radial velocity precision can be routinely obtained for early type binaries (F3-F8). For later type binaries, the precision reaches ~10 m s-1. We discuss applications of the technique to stellar astronomy and searches for extrasolar planets in binary systems. In particular, we combine the interferometric data collected with the Palomar Testbed Interferometer with our preliminary precision velocities of the spectroscopic double-lined binary HD 4676 to demonstrate that with such a combination one can routinely obtain masses of the binary components accurate at least at the level of 1.0%.
Metal Absorption Profiles from the Central Star of the Planetary Nebula M27 (NGC 6853, PN G060.8-03.6, the Dumbbell): Photospheric and Nebular Line Identifications

High-resolution spectra of the hot central star of the planetary nebula (CSPN) M27, acquired with the Far Ultraviolet Spectroscopic Explorer (FUSE), have revealed an unusually rich set of narrow molecular hydrogen absorption features. This object is also unique in that the velocity of nebular absorption features are cleanly separated from the velocity of the intervening interstellar medium. These features blend with and in many cases obscure atomic features. We have developed a continuum model of the CSPN including atomic and molecular hydrogen absorption. Using this model we have identified and tabulated the metal lines as arising from either photospheric, nebular and/or nonnebular velocity systems. We find the nebular outflow and ionization balance to be stratified with high ionization states favored at low velocity and low ionization states favored at high velocity. Neutrals and molecules are found at a velocity that marks the transition between these two regimes. These observations are a challenge to the interacting wind model of PN evolution. Mappings at high resolution of the line profiles for C I-IV, N I-III, O I, O VI, Si II-IV, P II-V, S II-IV, Ar I-II, and Fe II-III within the FUSE and STIS bandpasses are presented. The digital spectra of the stars and the model are freely available on the H2ools Web site. They will be useful for photospheric analyses seeking to determine the metallicity of the central star and for absorption line based atomic and molecular abundance determination of the nebular outflow.
Nickel-catalyzed cyclizations and couplings with vinylzirconium reagents.

1,3-Dienes were prepared by a variety of nickel-catalyzed couplings and cyclization processes. Intermolecular or partially intramolecular couplings of alkynes, vinylzirconium reagents, and either aldehydes or enones efficiently proceeded to generate a broad range of functionalized dienes.
Fractional Diffusion in Gaussian Noisy Environment

We study the fractional diffusion in a Gaussian noisy environment as described by the fractional order stochastic heat equations of the following form: \(D_t^{(\alpha)} u(t, x)=\textit{B}u+u\cdot \dot W^H\), where \(D_t^{(\alpha)}\) is the Caputo fractional derivative of order \(\alpha\in (0,1)\) with respect to the time variable \(t\), \(\textit{B}\) is a second order elliptic operator with respect to the space variable \(x\in\mathbb{R}^d\) and \(\dot W^H\) a time homogeneous fractional Gaussian noise of Hurst parameter \(H=(H_1, \cdots, H_d)\). We obtain conditions satisfied by \(\alpha\) and \(H\), so that the square integrable solution \(u\) exists uniquely.
Weakly Infinite Dimensional Subsets of R N

Abstract The Continuum Hypothesis implies an Erdos–Sierpinski like duality between the ideal of first category subsets of R N , and the ideal of countable dimensional subsets of R N . The algebraic sum of a Hurewicz subset – a dimension theoretic analogue of Sierpinski sets and Lusin sets – of R N with any compactly.
Operational characteristics of a 1000 MVA superconducting power transmission system

Over the last three years, the power transmission project at Brookhaven National Laboratory has been testing two flexible superconducting cables for the transmission of ac electric power. These cables are each 115 m long and are rated at 80 kV, 4100 A single-phase for a power rating of 333 MVA- (1000 MVA, 138 kV, 3 phase). They have been operated over the range of 7-12 K in supercritical helium at 14-15 atm. The cables have been tested at currents and voltages above their ratings and have also been operated with no coolant flow to study the effects of loss of refrigeration on cable performance. The insights gained from the operating of the system over this extended period will be presented. Finally, we will delineate those areas which will require further research before this technology can be integrated into the U.S. electrical power delivery system.
The Seventeenth Amendment, Senate ideology and the growth of government

The Seventeenth Amendment disturbed the existing electoral system in the United States by requiring direct elections for state Senators. Scholars have argued this made the Senate more populist and contributed to the growth of government in the US post-1913. We employ econometric tools to investigate whether the mean ideology of the Senate and its winning policies experienced a structural change around the time of the enactment. We find no compelling evidence of a structural break at that time but do find some evidence for a change in the mid-to-late 1890s.
Transport of chloride ion through phospholipid bilayers mediated by synthetic ionophores

Chloride has emerged as one of the most vigorously studied ions that occur in nature. A continuing motivation for the study of chloride transport lies in the pathological conditions that relate to or involve chloride transport. The goal of the organic, biological, or supramolecular chemist, thus, is to understand binding strength, binding dynamics, binding selectivity, transport selectivity and dynamics of chloride transporters. Various successful anion transporters or channels are now known, although detailed characterization and elaboration in most cases is ongoing. Several of these synthetic systems will be discussed in this review as we focus our discussion on the efforts to develop artificial transporters for chloride anions.
Sharp kernel clustering algorithms and their associated Grothendieck inequalities

In the kernel clustering problem we are given a (large) n × n symmetric positive semidefinite matrix A = (aij) with and a (small) k × k symmetric positive semidefinite matrix B = (bij). The goal is to find a partition {S1,…,Sk} of {1,…n} which maximizes . We design a polynomial time approximation algorithm that achieves an approximation ratio of , where R(B) and C(B) are geometric parameters that depend only on the matrix B, defined as follows: if bij = 〈vi,vj〉 is the Gram matrix representation of B for some then R(B) is the minimum radius of a Euclidean ball containing the points {v1,…,vk}. The parameter C(B) is defined as the maximum over all measurable partitions {A1,…,Ak} of of the quantity , where for i∈{1,…,k} the vector is the Gaussian moment of Ai, i.e., . We also show that for every e > 0, achieving an approximation guarantee of is Unique Games hard. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2013
Research and Application of Rule Engine in Scheduled Outage Management

With the rapid development of economy, the requirement for electricity supply is growing dramatically, and the consumers are claiming for higher power supply quality with less outage. Scheduled outage makes a major part of power outage, and it is mainly caused by power grid construction and power equipment maintenance. Scheduled outage has a lot of concerns, such as grid structure, potential outage loss, critical consumers or important occasions, and such factors are changing rapidly with the quick development of distribution network. As a result, the validation and optimization of scheduled outage becomes complicated. Rule engine [1] can describe business rules by pre-defined language, separate such rules from functional code [2], and execute them when trigger condition is satisfied. The application of rule engine can increase system adaptability to business variation, and decrease the system coupling and maintenance cost. With the application of rule engine in scheduled outage management, outage plan can be effectively validated and flexibly optimized, and the outage loss and consumer complaints could be significantly decreased.
An iterative growing and pruning algorithm for classification tree design

A critical issue in classification tree design-obtaining right-sized trees, i.e. trees which neither underfit nor overfit the data-is addressed. Instead of stopping rules to halt partitioning, the approach of growing a large tree with pure terminal nodes and selectively pruning it back is used. A new efficient iterative method is proposed to grow and prune classification trees. This method divides the data sample into two subsets and iteratively grows a tree with one subset and prunes it with the other subset, successively interchanging the roles of the two subsets. The convergence and other properties of the algorithm are established. Theoretical and practical considerations suggest that the iterative free growing and pruning algorithm should perform better and require less computation than other widely used tree growing and pruning algorithms. Numerical results on a waveform recognition problem are presented to support this view. >
Accuracy of frozen-section (intraoperative consultation) diagnosis of ovarian tumors

Objective: Frozen-section evaluation of ovarian tumors can be used to establish a histopathologic diagnosis and guide the surgeon to perform the appropriate surgical procedure. A retrospective study was conducted to determine the accuracy of frozen-section diagnosis of ovarian tumors. Study Design: Frozen- and permanent-section diagnoses were divided into three categories (benign, borderline, and malignant). The sensitivity, specificity and predictive values, and 95% percent confidence intervals of each frozen-section diagnosis were determined. Results: Three hundred eighty-three ovarian tumors that underwent frozen-section evaluation between June 1983 and June 1993 were studied. The final histopathologic diagnosis was 61.1 % benign, 7.6% borderline, and 31.3% malignant. Frozen section was accurate in 92.7% of all cases and inaccurate in 7.3%. The sensitivity for malignant tumors was 92.5% tumors (95% confidence intervals 87.7% to 97.2%), the sensitivity for borderline tumors was 44.8% (95% confidence interval 26.4% to 63.2%). The specificity for benign tumors was 92.0% (95% confidence interval 88.6% to 95.4%) but increased to 97.9% (95% confidence interval 96.1 % to 99.7%) if borderline tumors were excluded. The positive predictive value and 95% confidence intervals were 92.0% (88.6% to 95.4%) for benign tumors, 65% (43.6% to 86.5%) for borderline tumors, and 99.1% (97.3% to 100.0%) for malignant tumors. Thirteen of 16 (81 %) ovarian lymphomas and tumors metastatic to the ovary were correctly identified by intraoperative frozen section. The sensitivity for borderline serous tumors was 64.3% and for borderline mucinous tumors 30.8% (p = 0.48). Conclusion: With the exception of borderline tumors, the sensitivity and specificity of frozen-section diagnosis of ovarian tumors are high. Borderline tumors remain difficult to accurately diagnose at frozen section because of the extensive sampling required. Frozen-section diagnoses have important implications regarding the type and extent of surgery performed at the initial operation.
On Deriving Space–Time from Quantum Observables and States

We prove that, under suitable assumptions, operationally motivated quantum data completely determine a space–time in which the quantum systems can be interpreted as evolving. At the same time, the dynamics of the quantum system is also determined. To minimize technical complications, this is done in the example of three-dimensional Minkowski space.
Design and Mechanics of Multi-Lay Wire Strands

Wire strands and ropes have been used extensively for many years. However, the method for designing these elements remains highly dependent on the designer’s experience. In recent years, capabilities for the analysis of wire rope have progressed to a level where a reevaluation of wire rope design is appropriate. Recently, a linearized theory has been developed that allows a relatively simple method for analyzing complex strands and wire ropes. This theory, through substantiation with experiment, is felt to be reasonably accurate for most wire rope behavior. The present paper considers multi-lay wire strands and adds generality to the linearized theory to account for strands with any number and direction of wire lays. The geometry of wire strands is investigated in detail and a design methodology for strand geometry, including sizing the wires, is devised. The theory is then utilized to examine the effects of various design parameters on strand properties.