cssi/SciSciGPT-SciSciNet huggingface dataset:
Selective chemisorption and oxidation/reduction kinetics of supported copper oxide catalysts prepared from copper(II) acetylacetonate

Copper(II) oxide catalysts, prepared by non-aqueous adsorption of Cu(acac)2 on Cab-O-Sil followed by thermal decomposition, were titrated by NO and N20 to characterize the dispersion of the copper ions. These catalysts showed molar ratios of NO/Cu close to unity when the Cu loadings were less than 2.5 wt%. For samples having loadings greater than 3.8 wt% Cu, the NO/Cu molar ratios were near 0.7. The NO/Cu molar ratio also depended upon the catalyst preparation technique subsequent to the initial impregnation with Cu(acac)2 when the Cu loadings were ≥ 3.5 wt%. Samples washed with fresh acetonitrile showed NO/Cu ratios close to unity, whereas, those not so washed showed NO/Cu ratios near 0.7. IR spectra of NO sorbed on partially decomposed samples showed only “bent” CuNO, whereas, NO sorbed to the sample which was totally decomposed showed both linear and bent CuNO. Selected samples (3.8 and 8.6 wt% Cu) were reacted with N2O to determine the dispersion of the Cu. The sample having 8.6 wt% Cu reacted with the N2O to give a dispersion of 0.43; whereas the other sample (3.8 wt%) did not react with the N2O. This dispersion determined by N2O agreed with that calculated from NO titration (0.47) if the NO/Cu stoichiometry was assumed equal to unity. Subsequently, these catalysts were reduced in H2 and reoxidized in O2 to determine the oxidation and reduction kinetics as a function of copper loading. The 3.8 wt% Cu sample lost 1 O/Cu upon reduction in H2 and gained l O/Cu for reoxidation in O2 for up to five redox cycles; whereas, the 8.6 wt% Cu sample showed a stoichiometry of O/Cu which decreased from 1.00 to 0.57 after five redox cycles.
A HIGH YIELDING PROCEDURE FOR PREPARATION OF MONO-CARBOXYLATE SURROGATES OF ALLENIC DICARBOXYLATES AND DIESTERS

A high yielding procedure for preparation of various allenyl mono-carboxylates is presented.
Protonation and dimerization reactions of cyclopentadienylrhodiumcarbonylphosphine and phosphite derivatives

Abstract Eight cyclopentadienylrhodiumcarbonylphosphine and phosphite complexes have been prepared and their IR, 1H, and 31P NMR spectra recorded. A good correlation between carbonyl stretching frequencies and rhodium-phosphorous coupling constants has been observed. Reaction of these compounds with trifluorosulfonic acid, HCF3SO3, forms the expected cationic rhodium-hydride species which were examined using 1H and 31P NMR spectroscopy. Similar reactions between trifluoroacetic acid, HCF3CO2, and the phosphine compounds gave evidence of rapid proton exchange at the metal. Reaction between trifluoroacetic acid and cyclopentadienylrhodiumcarbonylphosphite compounds yielded new sets of rhodium-hydride resonances which were shown to be due to the formation of dinuclear rhodium complexes and cyclopentadienylrhodiumbis(phosphite) complexes which arise under the reaction conditions. A Scheme for the formation of these reaction products is presented which is consistent with all of the experimental data.
On-line extraction efficiency analyses for the Los Alamos free electron laser

Abstract The on-line extraction efficiency analysis procedures for the Los Alamos free electron laser are described. The analyses are based on the measurement of the electron beam's energy spectra as a function of time under lasing and nonlasing conditions. In the nongraphic, tuneup mode the procedure takes about 6 s, so at a 1 Hz repetition rate for the laser we can analyze one out of every six shots. If graphics output is desired, it is produced at a 20-s repetition rate. The tapered wiggler result for extraction efficiency, η ∼ 2% is presented as an example.
MESON2006 SUMMARY: THEORY

This is a summary of theoretical plenary contributions to the biennial hadron physics conference Meson2006, which was the ninth in this series. The topics covered in the meeting include low energy pion-pion and pion-nucleon interactions, photoproduction and hadronic production of light mesons and baryons, in-medium effects, recent developments in charmed mesons, charmonia and B mesons, the status of exotica, and some related topics such as final state interactions. In this contribution we review and summarize the plenary talks presented by theorists at the meeting, and emphasize some of the main points of their presentations. Where appropriate we will add brief comments on some aspects of QCD spectroscopy. Finally, following tradition, we conclude with a new Feynman story.
Flame advection and propagation algorithms

We present a simple algorithm for approximating the motion of a thin flame front of arbitrary shape and variable connectivity, which is advected by a fluid and which moves with respect to the fluid in the direction of its own normal. As an application, we examine the wrinkling of a flame front by a periodic array of vortex structures.
Channelization architecture for wide-band slow light in atomic vapors

We propose a "channelization" architecture to achieve wide-band electromagnetically induced transparency (EIT) and ultra-slow light propagation in atomic Rb-87 vapors. EIT and slow light are achieved by shining a strong, resonant "pump" laser on the atomic medium, which allows slow and unattenuated propagation of a weaker "signal" beam, but only when a two-photon resonance condition is satisfied. Our wideband architecture is accomplished by dispersing a wideband signal spatially, transverse to the propagation direction, prior to entering the atomic cell. When particular Zeeman sub-levels are used in the EIT system, then one can introduce a magnetic field with a linear gradient such that the two-photon resonance condition is satisfied for each individual frequency component. Because slow light is a group velocity effect, utilizing differential phase shifts across the spectrum of a light pulse, one must then introduce a slight mismatch from perfect resonance to induce a delay. We present a model which accounts for diffusion of the atoms in the varying magnetic field as well as interaction with levels outside the ideal three-level system on which EIT is based. We find the maximum delay-bandwidth product decreases with bandwidth, and that delay-bandwidth product 1 should be achievable with bandwidth 50 MHz (5 ns delay). This is a large improvement over the 1 MHz bandwidths in conventional slow light systems and could be of use in signal processing applications.
Phase separation in polymer solutions from a Born–Green–Yvon lattice theory

Abstract Phase separation in mixtures of polymers and alkanes is investigated with the aid of a recently developed lattice model, based on the Born–Green–Yvon (BGY) integral equation approach to fluids. The system-dependent parameters of the BGY lattice model for binary mixtures are deduced from those of its pure components, which in turn are determined from a comparison with experimental data. The lower critical solution temperatures (LCSTs) for polyethylene (PE) in various n -alkanes were predicted from the BGY lattice model and compared with experimental data. While the model underestimates the LCSTs for the smaller alkanes, it reproduces the experimental values very well for the higher alkanes (decane through tridecane). The effect of the chain length of the polymer on the solubility is investigated for the case of decane as a solvent.
Anion Catalyzed Addition of γ-Silylallenyl Esters to Aldehydes: A New Entry into [3.2.1] Bicyclic Natural Products

A significant improvement in the generality and reactivity of MBH-type reactions is made possible by anion catalysis and a 1,3-Brook rearrangement. In this new reaction, both aliphatic and aromatic aldehydes are rapidly added to silylallenes, leading to γ-carbinol allenoates at low temperatures. The utility of these reaction products is demonstrated by a fast-tracked synthesis of a [3.2.1] bisoxa bicycle that makes up the framework of many biologically active natural products, including vitisinol D, an antithrombotic agent.
Predictors of mortality amongst recipients of implantable cardioverter defibrillators for secondary prevention of cardiac arrest

BACKGROUND: Implantable Cardioverter-defibrillators (ICD) reduce mortality in survivors of cardiac arrest (CA). We investigated the predictors of mortality after ICD implantation in survivors of CA. METHODS: Retrospective review of clinical records and social security death index of all patients who received an ICD in a preexisting database of survivors of CA at the University of Pittsburgh Medical Center was performed. Multivariate analyses using the Cox proportional hazard model were performed with backward elimination to identify independent predictors of the time to death, and Kaplan-Meier curves were plotted. RESULTS: Eighty patients (64 men) with a mean age of 64.4+/-12.5 years were followed for 4.7+/-2.3 years after ICD implantation. Survival rates were 93.8%, 65% and 50% at 1, 5, and 10 years, respectively. Independent predictors of time to death were determined to include age (hazard ratio (HR) = 1.91 per 10-year increase, p = 0.003), serum creatinine > or = 1.3 mg/dL (HR = 2.56, p = 0.004), and QRS width >120 ms (HR = 5.14, p = 0.012). CONCLUSIONS: In this sample of ICD recipients secondary to CA, older age, elevated serum creatinine, and wider QRS duration were independent predictors of mortality. The presence of more than one risk factor in the same patient was associated with higher mortality rates. Whether interventions such as biventricular pacing can offset this increase risk of death warrants further investigation.
Cubanes : starting materials for the chemistry of the 1990s and the new century

The study of non-natural products has led to a broad understanding of bonding and reactivity in organic chemistry. Many times, compounds thought impossible have been realized in the course of such studies. Cubane, a landmark in the world of “impossible” compounds, has been found to have a rich chemistry, full of the unexpected. The recent renaissance of cubane chemistry, triggered by potential applications of the system to the production of high-energy fuels and the like, has led to many discoveries including the first methods for systematic substitution on strained, saturated systems and a new process for the metalation of arenes, ortho magnesiation. Reactive intermediates with exceptional bonding parameters have been uncovered and characterized including 1(9)-homocubene, the most twisted olefin; cubene, the most pyramidalized olefin; cubyl cation, once the “least likely” cation; cubylmethyl radical, a saturated radical that rearranges on the picosecond timescale; and many other extraordinary species. There is certainly good reason to believe that future work in the cubane arena will be at least as productive (probably more so), and that it will help develop a deeper understanding of chemistry.
ASLIC: a low power CMOS analog circuit design automation

This paper proposes an efficient automation platform that provides fast and reliable path to analog circuit design for desired specifications. Circuit heuristics and hierarchy are employed to aid efficient design flow. As a synthesis method, procedural planning of design equations is developed to improve accuracy. To cope with the low power requirements of recent analog design trend, automation flow of subthreshold analog circuit is developed based on weak inversion model. The proposed and developed tool is applied to several test cases. The results show that design time is reduced from weeks to seconds, and at the same time, a significantly accurate circuit behavior for the desired performance specification is obtained.
Evidence for a Geometrically Thick Self-Gravitating Accretion Disk in NGC 3079

We have mapped, for the first time, the full velocity extent of the water maser emission in NGC 3079. The largely north-south distribution of emission, aligned with a kiloparsec-scale molecular disk, and the segregation of blueshifted and redshifted emission on the sky are suggestive of a nearly edge-on molecular disk on parsec scales. Positions and line-of-sight velocities of blueshifted and redshifted maser emission are consistent with a central mass of ~2 × 106 M☉ enclosed within a radius of ~0.4 pc. The corresponding mean mass density of 106.8 M☉ pc-3 is suggestive of a central black hole, which is consistent with the detection of hard X-ray excess (20-100 keV) and an Fe Kα line from the nucleus. Because the rotation curve traced by the maser emission is flat, the mass of the parsec-scale disk is significant with respect to the central mass. Since the velocity dispersion of the maser features does not decrease with radius and constitutes a large fraction of the orbital velocity, the disk is probably thick and flared. The rotation curve and the physical conditions necessary to support maser emission imply a Toomre Q-parameter that is 1. Thus, the disk is most likely clumpy, and we argue that it is probably forming stars. Overall, the accretion disk in NGC 3079 stands in contrast to the compact, thin, warped, differentially rotating disk in the archetypal maser galaxy NGC 4258. We have also mapped radio continuum emission in the vicinity of the disk and identify a new, time-variable, nonthermal component (E) that is not collinear with the previously imaged putative jet. Based on the large luminosity and the unusually steep spectrum (α < -2.1), we exclude a radio supernova as the progenitor of E. However, because its spectrum is consistent with an aging electron energy distribution, E might be a rapidly cooling remnant, which may indicate that the jet axis wobbles. Alternatively, considering its location, the component might mark a shock in a wide-angle outflow that is interacting with a dense ambient medium. In this context, masers at high latitudes above the disk, mapped in this and previous studies, may be tracing an inward extension of the kiloparsec-scale bipolar wide-angle outflow previously observed along the galactic minor axis.
Large-time behavior of the weak solution to 3D Navier–Stokes equations

Abstract The weak solution to the Navier–Stokes equations in a bounded domain D ⊂ R 3 with a smooth boundary is proved to be unique provided that it satisfies an additional requirement. This solution exists for all t ≥ 0 . In a bounded domain D the solution decays exponentially fast as t → ∞ if the force term decays at a suitable rate.
The Impact of hydrodynamic mixing on supernova progenitors

Recent multidimensional hydrodynamic simulations have demonstrated the importance of hydrodynamic motions in the convective boundary and radiative regions of stars to transport of energy, momentum, and composition. The impact of these processes increases with stellar mass. Stellar models that approximate this physics have been tested on several classes of observational problems. In this Letter, we examine the implications of the improved treatment for supernova progenitors. The improved models predict substantially different interior structures. We present presupernova conditions and simple explosion calculations from stellar models with and without the improved mixing treatment at 23 M☉. The results differ substantially.
Nuclear effects on open charm production in p+A reactions

We calculate and resum the nuclear enhanced power corrections from the final state partonic scattering in nuclear matter to open charm production and correlations. In p+A reactions, we find that single and double inclusive D mesons can be suppressed as much as the neutral pions from the dynamical high twist shadowing. Effects of initial state energy loss in p+A collisions are also investigated and may lead to significantly weaker transverse momentum dependence of the nuclear suppression.
Inlet Stagnation Pressure Loss Estimate for a Simplified Thrust Model

In a previous work, the author presented a simplified thrust model to be used in predicting the performance of high-speed aircraft. That model contained an ad hoc estimate of the stagnation pressure loss in the inlet/diffuser of the engine. The current analysis attempts to capture some of the actual physics of the flow, modeling the incoming flow as a single oblique shock followed by a single normal shock, and including frictional losses in the subsonic portion of the diffuser. The result is a polynomial function of Mach number that captures much of the actual physics of the flow. Results using the new model are compared to the previous model and the data on which that model was based. A sample calculation of cruise Mach number for a jet aircraft is also included.
Quantifying End-Use Energy Intensity of the Urban Water Cycle

AbstractThe water end-use segment (WES), consisting of activities that utilize water in homes and buildings, has been identified as a major component of energy use in the urban water supply system. In this paper, an analytical framework is presented which can be used at the planning stages of new urban developments to assess future building-level water demands and associated energy requirements. The framework is applied to Masdar City, a new urban area in the United Arab Emirates, which has been targeted in its design to be a future zero-carbon and zero-waste city. Results show that the energy intensity (in electric kWh) in WES for Masdar City may range from 2.6 to 4 kWh/m3. The dominant use of energy in this segment is attributed to water heating requirements, and the total energy use for obtaining hot water is estimated to range from approximately 20 to 50 million kWh annually. It is found that the residential sector in the city can have the greatest impact in affecting energy requirements associated w...
OPTICAL COLORS OF INTRACLUSTER LIGHT IN THE VIRGO CLUSTER CORE

We continue our deep optical imaging survey of the Virgo cluster using the CWRU Burrell Schmidt telescope by presenting B-band surface photometry of the core of the Virgo cluster in order to study the cluster's intracluster light (ICL). We find ICL features down to {mu}{sub B} {approx}29 mag arcsec{sup -2}, confirming the results of Mihos et al., who saw a vast web of low surface brightness streams, arcs, plumes, and diffuse light in the Virgo cluster core using V-band imaging. By combining these two data sets, we are able to measure the optical colors of many of the cluster's low surface brightness features. While much of our imaging area is contaminated by galactic cirrus, the cluster core near the cD galaxy, M87, is unobscured. We trace the color profile of M87 out to over 2000'', and find a blueing trend with radius, continuing out to the largest radii. Moreover, we have measured the colors of several ICL features which extend beyond M87's outermost reaches and find that they have similar colors to the M87's halo itself, B - V {approx}0.8. The common colors of these features suggest that the extended outer envelopes of cD galaxies, such as M87, may bemore » formed from similar streams, created by tidal interactions within the cluster, that have since dissolved into a smooth background in the cluster potential.« less
Three particles in a finite volume: The breakdown of spherical symmetry

Lattice simulations of light nuclei necessarily take place in finite volumes, thus affecting their infrared properties. These effects can be addressed in a model-independent manner using Effective Field Theories. We study the model case of three identical bosons (mass m with resonant two-body interactions in a cubic box with periodic boundary conditions, which can also be generalized to the three-nucleon system in a straightforward manner. Our results allow for the removal of finite-volume effects from lattice results as well as the determination of infinite-volume scattering parameters from the volume dependence of the spectrum. We study the volume dependence of several states below the break-up threshold, spanning one order of magnitude in the binding energy in the infinite volume, for box side lengths L between the two-body scattering length a and L = 0.25a. For example, a state with a three-body energy of −3/(ma 2) in the infinite volume has been shifted to −10/(ma 2) at L = a. Special emphasis is put on the consequences of the breakdown of spherical symmetry and several ways to perturbatively treat the ensuing partial-wave admixtures. We find their contributions to be on the sub-percent level compared to the strong volume dependence of the S-wave component. For shallow bound states, we find a transition to boson-diboson scattering behavior when decreasing the size of the finite volume.
Static Colored SU(2) Sources in (1+1) Dimensions — AN Analytic Solution in the Electric Representation

Within the Schrodinger electric representation, we analytically calculate the complete set of wave functionals obeying Gauss' law with static sources in a general representation of SU(2) in (1+1) dimensions. The effective potential is found to be linear in the distance between the sources with the string tension depending on the polarization of the solution.
Aeroelastic effects of spoiler surfaces on a low-aspect-ratio rectangular wing

An experimental research study to determine the effectiveness of spoiler surfaces in suppressing flutter onset for a low-aspect-ratio, rectangular wing has been conducted in the Langley Transonic Dynamics Tunnel (TDT). The wing model used in this flutter test consisted of a rigid wing mounted to the wind-tunnel wall by a flexible, rectangular beam. The flexible beam was connected to the wing root and cantilever mounted to the wind-tunnel wall. The wing had a 1.5 aspect ratio based on wing semispan and a NACA 64AGIO airfoil shape. The spoiler surfaces consisted of thin, rectangular aluminum plates that were vertically mounted to the wing surface. The spoiler surface geometry and location on the wing surface were varied to determine the effects of these parameters on the classical flutter of the wing model. Subsonically, the experiment showed that spoiler surfaces increased the flutter dynamic pressure with each successive increase in spoiler height or width. This subsonic increase in flutter dynamic pressure was approximately 15% for the maximum height spoiler configuration and for the maximum width spoiler configuration. At transonic Mach numbers, the flutter dynamic pressure conditions were increased even more substantially than at subsonic Mach numbers for some of the smaller spoiler surfaces. But for larger spoiler sizes (in terms of either height or width) the spoilers forced a torsional instability in the transonic regime that was highly Mach number dependent. This detrimental torsional instability was found at dynamic pressures well below the expected flutter conditions. Variations in the span wise location of the spoiler surfaces on the wing showed little effect on flutter. Flutter analysis was conducted for the basic configuration (clean wing with all spoiler surface mass properties included). The analysis correlated well with the clean wing experimental flutter results.
One-step formation and characterization of Zn(II)-Cr(III) layered double hydroxides, Zn2Cr(OH)6X (X = Cl, 1/2SO4).

Titration curves show that the layered double hydroxide Zn2Cr(OH)6Cl, unlike Zn2Fe(OH)6Cl (shown) or Zn2Al(OH)6Cl (not shown) forms directly from solution, without the intermediacy of “MIII(OH)3”, when a mixture of metal chlorides is treated with base. Co(II), Ni(II), and Cu(II) behave similarly. Spectroscopic and titrimetric data show that Zn2Cr(OH)6Cl is formed initially from mixed solutions of various stoichiometries and suggest that the Zn(II) and Cr(III) ions may be locally ordered.
Linear Control of Neuronal Spike Timing Using Phase Response Curves

We propose a simple, robust, and linear method to control the spike timing of a periodically firing neuron. The control scheme uses the neuron’s phase response curve to identify an area of optimal sensitivity for the chosen stimulation parameters. The spike advance as a function of current pulse amplitude is characterized at the optimal phase, and a linear least-squares regression is fit to the data. The inverted regression is used as the control function for this method. The efficacy of this method is demonstrated through numerical simulations of a Hodgkin–Huxley style neuron model as well as in real neurons from rat hippocampal slice preparations. The study shows a proof of concept for the application of a linear control scheme to control neuron spike timing in vitro. This study was done on an individual cell level, but translation to a tissue or network level is possible. Control schemes of this type could be implemented in a closed loop implantable device to treat neuromotor disorders involving pathologically neuronal activity such as epilepsy or Parkinson’s disease.
Radiation and scattering from electrically small conducting bodies of arbitrary shape

A simple moment solution is given for low frequency electromagnetic scattering and radiation problems. The problem is reduced to the corresponding electrostatic and magnetostatic problems. Each static problem is solved using the Method of Moments. The surface of the perfectly conducting scatterer is modeled by a set of planar triangular patches. Pulse expansion functions and point matching testing are used to compute the charge density in the electrostatic problem. For the magnetostatic current a set of charge-free vector expansion functions is used. The problem is formulated assuming the scatterer to be in an unbounded homogeneous region. Scatterers of various shapes, such as the circular disc, the sphere, and the cube are studied. Special attention is paid to a conducting box with a narrow slot. The computed results are the scattered fields, the induced charge and current distributions, and the induced electric and magnetic dipole moments. These are in close agreement with whatever published data are available.
Prediction of environmental and strain-rate effects on the stress corrosion cracking of austenitic stainless steels

The stress corrosion cracking (SCC) susceptibility of austenitic stainless steels in high-temperature water is controlled by environmental variables (e.g., dissolved oxygen, corrosion potential, impurities), microstructure (e.g., degree of sensitization), and strain rate. A phenomenological model based on the slip-dissolution mechanism and elastic-plastic fracture mechanics is presented to quantitatively describe the effects of both environment-related parameters and strain rate on SCC in constant extension rate tests. The model predictions are in good agreement with the results of tests performed on Types 304, 316, and 316NG stainless steel at different strain rates in a wide variety of environments relevant to boiling-water reactors.
NMDA-sensitive glutamate antagonism: A human model for psychosis

The use of animal models for the study of psychosis and new treatment development is inadequate in assessing target psychotic symptoms because animals lack an ability to use language. Despite this deficiency, new antidopaminergic antipsychotic drugs have still become available. However, even these new antipsychotics, although substantially better than the conventional compounds, do not “cure” psychosis or normalize schizophrenic symptoms. The need for new treatment strategies is apparent. The value of a human model, where language is available to describe target symptoms, is clear. Currently, there is an opportunity to use the mild psychotomimetic symptoms induced by a minimal dose of ketamine in normal humans as a model of psychosis. The mental symptoms in this model resemble some of the symptoms of schizophrenia, suggesting the additional possibility that parallel mechanisms of psychosis may occur in schizophrenia and in a ketamine state, creating a potentially viable psychosis model for pathophysiology. This paper includes arguments in support of this human model's application. Several potential outcome measures that can be used to evaluate potentially novel antipsychotics are described. This model has the potential for identifying novel therapeutics because it does not primarily utilize the dopaminergic system. Further delineation of ketamine pharmacology in humans is pivotal to the eventual application of this ketamine model in drug development.
Organometallic photonucleases: A novel class of DNA-cleaving agents

The first demonstration of DNA cleavage by an organic radical generated via homolysis of a metal-alkyl bond in a Cp-metal complex is presented. Irradiation of CpW(CO)3CH3 (1.5 molecules/base pair) produced methyl radical, giving single-strand cleavage of pBR322 DNA. This process was inhibited by the general radical trap cysteine and by TEMPO, which traps carbon radicals but not oxygen-centered radicals.
Hook-lengths and pairs of compositions

The monomial basis for polynomials in N variables is labeled by compositions. To each composition there is associated a hook-length product, which is a product of linear functions of a parameter. The zeroes of this product are related to "critical pairs" of compositions; a concept defined in this paper. This property can be described in an elementary geometric way; for example: consider the two compositions (2, 7, 8, 2, 0, 0) and (5, 1, 2, 5, 3, 3), then the respective ranks, permutations of the index set {1,2,...,6} sorting the compositions, are (3, 2, 1, 4, 5, 6) and (1, 6, 5, 2, 3, 4), and the two vectors of differences (between the compositions and the ranks, respectively) are (-3, 6, 6, -3, -3, -3) and (2, -4, -4, 2, 2, 2), which are parallel, with ratio -3/2. For a given composition and zero of its hook-length product there is an algorithm for constructing another composition with the parallelism property and which is comparable to it in a certain partial order on compositions, derived from the dominance order. This paper presents the motivation from the theory of nonsymmetric Jack polynomials and the description of the algorithm, as well as the proof of its validity.
Isospin dependence of nucleon correlations in ground-state nuclei

The dispersive optical model (DOM) as presently implemented can investigate the isospin (nucleon asymmetry) dependence of the Hartree-Fock-like potential relevant for nucleons near the Fermi energy. Data constraints indicate that a Lane-type potential adequately describes its asymmetry dependence. Correlations beyond the mean field can also be described in this framework, but this requires an extension that treats the non-locality of the Hartree-Fock-like potential properly. The DOM has therefore been extended to properly describe ground-state properties of nuclei as a function of nucleon asymmetry in addition to standard ingredients like elastic nucleon scattering data and level structure. Predictions of nucleon correlations at larger nucleon asymmetries can then be made after data at smaller asymmetries constrain the potentials that represent the nucleon self-energy. A simple extrapolation for Sn isotopes generates predictions for increasing correlations of minority protons with increasing neutron number. Such predictions can be investigated by performing experiments with exotic beams. The predicted neutron properties for the double closed-shell 132Sn nucleus exhibit similar correlations as those in 208Pb . Future relevance of these studies for understanding the properties of all nucleons, including those with high momentum, and the role of three-body forces in nuclei are briefly discussed. Such an implementation will require a proper treatment of the non-locality of the imaginary part of the potentials and a description of high-momentum nucleons as experimentally constrained by the (e, e′ p) reactions performed at Jefferson Lab.
Altair Navigation During Trans-Lunar Cruise, Lunar Orbit, Descent and Landing

The Altair lunar lander navigation system is driven by a set of requirements that not only specify a need to land within 100 m of a designated spot on the Moon, but also be capable of a safe return to an orbiting Orion capsule in the event of loss of Earth ground support. These requirements lead to the need for a robust and capable on-board navigation system that works in conjunction with an Earth ground navigation system that uses primarily ground-based radiometric tracking. The resulting system relies heavily on combining a multiplicity of data types including navigation state updates from the ground based navigation system, passive optical imaging from a gimbaled camera, a stable inertial measurement unit, and a capable radar altimeter and velocimeter. The focus of this paper is on navigation performance during the trans-lunar cruise, lunar orbit, and descent/landing mission phases with the goal of characterizing knowledge and delivery errors to key mission events, bound the statistical delta V costs for executing the mission, as well as the determine the landing dispersions due to navigation. This study examines the nominal performance that can be obtained using the current best estimate of the vehicle, sensor, and environment models. Performance of the system under a variety sensor outages and parametric trades is also examined.
Investigating a Stream Synchronization Middleware for the NEES MAST System

This paper describes the streaming synchronization middleware research conducted while investigating how to provide a collaborative experimentation system for the NEES Multi-Axial Sub-Assemblage Testing (MAST) Experimental setup at the University of Minnesota. Continuous multimedia streams such as those produced by MAST experiments are characterized by well-defined temporal relationships between subsequent media units (MUs). The information present in these streams can only be presented correctly when these time-dependent relationships are maintained during presentation time. Even if these relationships change during transportation (e.g. due to network delays), they need to be reconstructed at the client (sink) before playout. Whereas most previous work addresses synchronization at the application level by modifying the end system, Our goal is to leave the endsystem largely unchange and simply add a new synchronization middleware application control system. This paper presents our three proposed algorithms that ensure the continuous and synchronous playback of distributed stored multimedia streams across a communications network via a middleware controlled commercial media player.
Dynamic analysis of large-scale mechanical systems and animated graphics

This paper presents a computer-based method for formulation and solution of coupled differential and algebraic equations describing large-scale mechanical systems, including feedback control, aerodynamic forces, and other multidisciplinary effects that interact with the mechanical system. A Euler parameter repersentation of the configuration of the mechanical system is employed to obtain singularity free solution for generalized coordinates and a much simplified algebraic formulation of the governing system of equations, compared with the more classical Euler angle generalized coordinate formulation. A generalized coordinate partitioning algorithm is employed to identify independent generalized coordinates automatically and reduce the dimension of the numerical integration problem. Animated graphics output is employed to assist in visualization of dynamic performance of several systems—a parachute descending in air, an aircraft landing on a damaged runway, and a truck with flexible chassis.
Helicopter noise prediction : the current status and future direction

Abstract The current status of helicopter noise prediction is examined in this paper. A brief history is given, followed by a discussion of the status of prediction for each source mechanism. The acoustic analogy approach, and specifically, theories based on the Ffowcs Williams-Hawkings equations are the most widely used for deterministic noise sources. Thickness and loading noise can be routinely predicted given good blade motion and blade loading inputs. Blade-vortex interaction (BVI) noise can also be predicted well with measured input data, but prediction of airloads with the high spatial and temporal resolution required for BVI is still difficult. No efficient prediction method for high speed impulsive noise is currently available, but much progress has been made. The best broadband noise prediction currently depends on semi-empirical methods.
Forked Temperley–Lieb algebras and intermediate subfactors

We consider noncommuting pairs P, Q of intermediate subfactors of an irreducible, finite-index inclusion N⊂M of II1 factors such that P and Q are supertransitive with Jones index less than 4 over N. We show that up to isomorphism of the standard invariant, there is a unique such pair corresponding to each even value [P:N]=4cos2π2n but none for the odd values [P:N]=4cos2π2n+1. We also classify the angle values which occur between pairs of intermediate subfactors with small index over their intersection: if [P:N],[Q:N]<4, then the unique nontrivial angle value is always cos−11[P:N]−1.
High Order Maximum-Principle-Preserving Discontinuous Galerkin Method for Convection-Diffusion Equations

In this paper, we propose to apply the parametrized maximum-principle-preserving (MPP) flux limiter in [T. Xiong, J.-M. Qiu, and Z. Xu, J. Comput. Phys., 252 (2013), pp. 310--331] to the discontinuous Galerkin (DG) method for solving the convection-diffusion equations. The feasibility of applying the proposed MPP flux limiters is based on the fact that cell averages of the DG solutions are updated in a conservative fashion (by using flux difference). Compared with the earlier approach in preserving the MPP property of DG solutions for convection-diffusion problems [Y. Zhang, X. Zhang, and C.-W. Shu, J. Comput. Phys., 234 (2012), pp. 295--316], we avoid the difficulty of rewriting cell averages as a convex combination of point values in the presence of diffusion terms for DG schemes of higher than second order accuracy. As a result, our proposed parametrized MPP flux limiter can be applied to DG methods of arbitrary high order. We theoretically prove that up to the third order accuracy can be preserved for...
The Investment Performance of Real Estate Limited Partnerships

Real estate limited partnerships have become an increasingly popular form of investment over the past decade. Many investors have been drawn to these investment vehicles because of the high claimed rates of return earned by investors in previous partnerships. However, there has been little analysis of the historical rates of return on these investments other than that provided by the syndicators in offering prospectuses. This paper examines the returns earned by investors in real estate limited partnerships over the past decade. These results are compared with previous studies of the investment performance of real estate. Because of the importance of the tax shield aspects of these investments, we calculate the after-tax rate of return for investors in several marginal tax brackets.
A masked-alkene metathesis-based synthesis of isopulo’upone

A metathesis-based formal synthesis of (±)-isopulo’upone has been completed featuring a masked olefin metathesis/elimination sequence followed by an intramolecular Diels–Alder reaction to construct the 5,6-fused bicyclic core.
Homogeneous mixed-metal catalyst systems: new and effective routes to N-acyl-α-amino acids via carbonylations

Abstract New homogeneous mixed metal catalyst systems for the synthesis of N-acyl-α-amino acids directly from allylic alcohols, oxiranes or olefins are described. The new catalytic processes include (a) the isomerization-amido-carbonylation of allylic alcohols catalyzed by Co2(CO)8-Group VIII transition metal complex combinations, (b) the isomerization-amido-carbonylation of oxiranes promoted by Co2(CO)8-Lewis acid systems, and (c) the hydroformylation-amidocarbonylation of fluoro-olefins catalyzed by Co2(CO)8-rhodium carbonyl systems which proceeds with excellent regio-selectivity. It is found that the hydroformylation-amidocarbonylation process includes a unique Co-Rh mixed metal cluster, CoRh(CO)7, as an active catalyst species. The mechanism of this novel mixed cluster-catalyzed process is discussed. Possible mechanisms for the isomerization-amidocarbonylations are also proposed.
Doppler tomography of accretion in binaries

Since its conception, Doppler tomography has matured into a versatile and widely used tool. It exploits the information contained in the highly-structured spectral line-profiles typically observed in mass-transferring binaries. Using inversion techniques akin to medical imaging, it permits the reconstruction of Doppler maps that image the accretion flow on micro-arcsecond scales. I summarise the basic concepts behind the technique and highlight two recent results; the use of donor star emission as a means to system parameter determination, and the real-time movies of the evolving accretion flow in the cataclysmic variable WZ Sge during its 2001 outburst. I conclude with future opportunities in Doppler tomography by exploiting the combination of superior data sets, second generation reconstruction codes and simulated theoretical tomograms to delve deeper into the physics of accretion flows.
Compact Hankel Operators on Generalized Bergman Spaces of the Polydisc

Let \({\vartheta}\) be a measure on the polydisc \({\mathbb{D}^n}\) which is the product of n regular Borel probability measures so that \({\vartheta([r,1)^n\times\mathbb{T}^n) >0 }\) for all 0 < r < 1. The Bergman space \({A^2_{\vartheta}}\) consists of all holomorphic functions that are square integrable with respect to \({\vartheta}\). In one dimension, it is well known that if f is continuous on the closed disc \({\overline{\mathbb{D}}}\), then the Hankel operator Hf is compact on \({A^2_\vartheta}\). In this paper we show that for n ≥ 2 and f a continuous function on \({{\overline{\mathbb{D}}}^n}\), Hf is compact on \({A^2_\vartheta}\) if and only if there is a decomposition f = h + g, where h belongs to \({A^2_\vartheta}\) and \({\lim_{z\to\partial\mathbb{D}^n}g(z)=0}\).
RECENT PROGRESS IN AdS/CFT

The study of AdS/CFT (or gauge/gravity) duality has been one of the most active and illuminating areas of research in string theory over the past decade. The scope of its relevance and the insights it is providing seem to be ever expanding. In this talk I briefly describe some of the attempts to explore how the duality works for maximally supersymmetric systems.
Depression and ambulatory care sensitive hospitalizations among Medicare beneficiaries with chronic physical conditions.

Abstract Objective We examined the association between depression and hospitalizations for Ambulatory Care Sensitive Conditions (H-ACSC) among Medicare beneficiaries with chronic physical conditions. Methods We used a retrospective longitudinal design using multiple years (2002–2009) of linked fee-for-service Medicare claims and survey data from Medicare Current Beneficiary Survey to create six longitudinal panels. We followed individuals in each panel for a period of 3-years; first year served as the baseline and subsequent 2-years served as the follow-up. We measured depression, chronic physical conditions and other characteristics at baseline and examined H-ACSC at follow-up. We identified chronic physical conditions from survey data and H-ACSC and depression from fee-for-service Medicare claims. We analyzed unadjusted and adjusted relationships between depression and the risk of H-ACSC with chi-square tests and logistic regressions. Results Among all Medicare beneficiaries, 9.3% had diagnosed depression. Medicare beneficiaries with depression had higher rates of any H-ACSC as compared to those without depression (13.6% vs. 7.7%). Multivariable regression indicated that, compared to those without depression, Medicare beneficiaries with depression were more likely to experience any H-ACSC. Conclusions Depression was associated with greater risk of H-ACSC, suggesting that health care quality measures may need to include depression as a risk-adjustment variable.
Asymmetric Synthesis of Both Antipodes of β-Hydroxy Nitriles and β-Hydroxy Carboxylic Acids via Enzymatic Reduction or Sequential Reduction/Hydrolysis

Use of isolated carbonyl reductases in the reduction of aromatic β-ketonitriles have completely eliminated the competing α-ethylation, which is often observed with whole cell biocatalysts. By choosing suitable recombinant carbonyl reductase, the reduction of β-ketonitriles afforded (R)- or (S)-β-hydroxy nitriles with excellent optical purity and yield. Subsequently, nitrilase-catalyzed hydrolysis of the obtained optically pure β-hydroxy nitriles led to the corresponding β-hydroxy carboxylic acids in high yields. More importantly, the sequential enzymatic reduction and hydrolysis could be carried out in “two-step-one-pot” fashion without the isolation of intermediates β-hydroxy nitriles, lowering the cost and minimizing the environmental impact. This allows ready access to both antipodes of chiral β-hydroxy nitriles and β-hydroxy carboxylic acids of pharmaceutical importance with excellent optical purity.
Synthesis, structure and superconductivity in the Ba1-xKxBiO3-y system

The recent discovery of superconductivity near 30 K in Ba1−xKxBiO3−y (x≈0.4)1,2 is remarkable for two reasons. It is the first copper-free oxide superconductor that has a transition temperature (Tc) above that for the best intermetallic superconductor; and the structure is reported to be cubic, which excludes a two-dimensional metal–oxygen sublattice analogous to the CuO2 planes believed to be responsible for superconductivity in the copper-oxide-based superconductors. Cava et al.1 described a synthesis technique which involved starting with a 100% excess of KO2. At least part of the excess potassium was found to be present in the final sample (in a form not detectable by X-ray diffraction), resulting in samples that were not suitable for resistivity measurements and making a precise determination of the potassium and oxygen content in the superconducting phase impossible. Here we describe a two-step synthesis technique starting with a stoichiometric oxide composition, which yields single-phase samples suitable for transport measurements. Neutron powder diffraction studies of samples with varying potassium concentration show that superconductivity in Ba1−xKxBiO3−y, occurs only in a cubic perovskite phase which is stable at ≲600°C and which forms only for x > 0.25. Within this cubic phase, Tc is highest for compositions near the structural phase transition (x ≈ 0.25) and decreases with increasing x.
Too much mobility limits the capacity of wireless ad hoc networks

We show that for highly mobile ad hoc networks, the benefits of mobility are overshadowed by the cost of mobility in terms of the increased channel uncertainty and network homogeneity. We assume a block-fading channel model with jointly isotropic fading. We allow relays which can transmit and receive simultaneously. Under fairly general assumptions for the users' channel fades and additive noise distributions we show that increasing the number of transmit antennas M at any node beyond the channel coherence time Tc (measured in units of channel uses) does not affect the capacity region of the ad hoc network. For a fast-fading (coherence time TclesM) homogeneous network, we determine the exact capacity region of the ad hoc network for any partition of the nodes into source, destination, and relay nodes. The optimal strategy is such that only one pair of source-destination nodes is active at a time while all the other nodes are inactive. There is no benefit from relaying and at high signal-to-noise ratio (SNR) the total throughput grows at most double-logarithmically with the number of nodes. Even for the case of slow fading, where the channel variations are slow enough that the receiver can track the channel perfectly, the inability of the transmitter to track the network topology limits the total throughput growth rate to no more than logarithmic in the number of nodes. Spatial correlation is shown to enhance the capacity region of the Rayleigh-fading ad hoc network