cssi/SciSciGPT-SciSciNet huggingface dataset:
Development and Validation of Navier-Stokes Procedure for Turbomachinery Unsteady Flow

An unsteady viscous e ow solver based on the Runge ‐Kutta scheme has been developed. Three low-Reynoldsnumber k-" turbulence models have been assessed for their ability to predict unsteady transitional e ow. The k-" model has been modie ed to incorporate leading-edge effects. A pseudo time approach has been used to accelerate the numerical algorithm for unsteady e ows. A sensitivity study has been carried out, including the effects of the artie cial dissipation, the grid density, and the physical and pseudo time steps. The numerical simulation of the unsteady transitional e ow in a compressor cascade has been carried out successfully. Good agreement with the measured data as well as the previous Euler/boundary-layer predictions has been achieved. The numerical solver has been ableto predict major features, associated with the wake-induced transition on a compressorblade (wakeinduced transitional strip, wake-induced turbulent strip, etc. ). An analysis and an interpretation of the results from the unsteady e ow simulation have been carried out to understand additional e ow physics associated with the transitional e ow.
Synthesis, characterization, and magnetic properties of a commensurate and incommensurate phase of Sr3ZnRhO6: zinc in trigonal prismatic coordination

Abstract The new compound Sr 3 ZnRhO 6 has been synthesized as both a commensurate and an incommensurate phase. The commensurate compound was structurally characterized by Rietveld refinement of powder X-ray diffraction data in the space group R 3 c (no. 167), Z =6. The lattice parameters for this compound were found to be a =9.6194(1) A and c =11.1061(1) A. It belongs to a family of pseudo one-dimensional materials and is isostructural with the K 4 CdCl 6 structure. The commensurate structure contains zinc in a highly unusual trigonal prismatic coordination environment. The structure consists of infinite one-dimensional chains of alternating face-shared RhO 6 octahedra and ZnO 6 trigonal prisms. The strontium cations are located between the chains and are coordinated in a distorted square antiprismatic environment. Magnetic measurements were made for both compounds. The data for the commensurate structure shows that the susceptibility of Sr 3 ZnRhO 6 increases rapidly below 20 K without the usual signs of long range ferromagnetic ordering. The magnetic susceptibility of the incommensurate phase of Sr 3 ZnRhO 6 , however, is quite different from the commensurate analog and does not exhibit the rapid increase in magnetization at low temperature and appears much more Curie-like.
Induced-charge electro-osmosis

We describe the general phenomenon of ‘induced-charge electro-osmosis’ (ICEO) – the nonlinear electro-osmotic slip that occurs when an applied field acts on the ionic charge it induces around a polarizable surface. Motivated by a simple physical picture, we calculate ICEO flows around conducting cylinders in steady (DC), oscillatory (AC), and suddenly applied electric fields. This picture, and these systems, represent perhaps the clearest example of nonlinear electrokinetic phenomena. We complement and verify this physically motivated approach using a matched asymptotic expansion to the electrokinetic equations in the thin-double-layer and low-potential limits. ICEO slip velocities vary as $u_s \,{\propto}\,E_0^2 L$, where $E_0$ is the field strength and $L$ is a geometric length scale, and are set up on a time scale $\tau_c \,{=}\,\lambda_D L/D$, where $\lambda_D$ is the screening length and $D$ is the ionic diffusion constant. We propose and analyse ICEO microfluidic pumps and mixers that operate without moving parts under low applied potentials. Similar flows around metallic colloids with fixed total charge have been described in the Russian literature (largely unnoticed in the West). ICEO flows around conductors with fixed potential, on the other hand, have no colloidal analogue and offer further possibilities for microfluidic applications.
TCP Splitter: a TCP/IP flow monitor in reconfigurable hardware

This flow-monitoring circuit delivers an ordered byte stream to a client application for every TCP/IP connection it processes. Using an active flow-processing algorithm, TCP Splitter is a lightweight, efficient design that supports the monitoring of an almost unlimited number of flows at multigigabit line rates.
Radial Color Gradients in K+A Galaxies in Distant Clusters of Galaxies

Galaxies in rich clusters with z 0.3 are observed to have a higher fraction of photometrically blue galaxies than their nearby counterparts. This raises the important question of what environmental effects can cause the termination of star formation between z ≈ 0.3 and the present. The star formation may be truncated because of ram pressure stripping, or the gas in the disk may be depleted by an episode of star formation caused by some external perturbation. To help resolve this issue, surface photometry was carried out for a total of 70 early-type galaxies in the cluster Cl 1358+62, at z ~ 0.33, using two-color images from the Hubble archive. The galaxies were divided into two categories based on spectroscopic criteria: 24 are type K + A (e.g., strong Balmer lines, with no visible emission lines), while the remaining 46 are in the control sample, with normal spectra. Radial color profiles were produced to see whether the K + A galaxies show bluer nuclei in relation to their surrounding disks. Specifically, a linear gradient was fitted to the radial color profile of each galaxy. We find that the K + A galaxies on average tend to have slightly bluer gradients toward the center than the normal galaxies. A Kolmogorov-Smirnov two-sample test has been applied to the two sets of color gradients. The result of the test indicates that there is only a ~2% probability that the K + A and normal samples are drawn from the same parent distribution. There is a possible complication from a trend in the apparent magnitude-versus-color gradient relation, but overall our results favor the centralized star formation scenario as an important process in the evolution of galaxies in dense clusters.
Learning with globally predictive tests

We introduce a new bias for rule learning systems. The bias only allows a rule learner to create a rule that predicts class membership if each test of the rule in isolation is predictive of that class. Although the primary motivation for the bias is to improve the understandability of rules, we show that it also improves the accuracy of learned models on a number of problems. We also introduce a related preference bias that allows creating rules that violate this restriction if they are statistically significantly better than alternative rules without such violations.
On the Rotation Period of (90377) Sedna

We present precise, ~1%, r-band relative photometry of the unusual solar system object (90377) Sedna. Our data consist of 143 data points taken over eight nights in 2004 October and 2005 January 2005. The rms variability over the longest contiguous stretch of five nights of data spanning 9 days is only ~1.3%. This subset of data alone constrains the amplitude of any long-period variations with period P to be A 1%(P/20 days)2. Over the course of any given ~5 hr segment, the data exhibit significant linear trends not seen in a comparison star of similar magnitude, and in a few cases these segments show clear evidence of curvature at the level of a few millimagnitudes per hour squared. These properties imply that the rotation period of Sedna is O(10 hr); it cannot be 5 hr nor can it be 10 days, unless the intrinsic light curve has significant and comparable power on multiple timescales, which is unlikely. A sinusoidal fit yields a period of P = 10.273 ± 0.002 hr and a semiamplitude of A = 1.1% ± 0.1%. There are additional acceptable fits with flanking periods separated by ~3 minutes as well as another class of fits with P ~ 18 hr, although these later fits appear less viable based on visual inspection. Our results indicate that the period of Sedna is likely consistent with typical rotation periods of solar system objects, thus obviating the need for a massive companion to slow its rotation.
A New Mid-Infrared Map of the BN/KL Region Using the Keck Telescope

We present a new mid-infrared (12.5 μm) map of the BN/KL high-mass star-forming complex in Orion using the LWS instrument on Keck I. Despite poor weather we achieved nearly diffraction-limited images (FWHM = 038) over a roughly 25'' × 25'' region centered on IRc2 down to a flux limit of ≈250 mJy. Many of the known IR sources in the region break up into smaller subcomponents. We have also detected six new mid-IR sources. Nearly all of the sources are resolved in our mosaic. The near-IR source "n" is slightly elongated in the mid-IR along a northwest-southeast axis and perfectly bisects the double-peaked radio source "L." Source n has been identified as a candidate for powering the large IR luminosity of the BN/KL region (L = 105 L⊙). We postulate that the 12 μm emission arises in a circumstellar disk surrounding source n. The morphology of the mid-IR emission and the Orion "hot core" (as seen in NH3 emission), along with the location of water and OH masers, is very suggestive of a bipolar cavity centered on source n and aligned with the rotation axis of the hypothetical circumstellar disk. IRc2, once thought to be the dominant energy source for the BN/KL region, clearly breaks into four subsources in our mosaic, as seen previously at 3.8–5.0 μm. The anticorrelation of mid-IR emission and NH3 emission from the nearby hot core indicates that the IRc2 sources are roughly coincident (or behind) the dense hot core. The nature of IRc2 is not clear: neither self-luminous sources (embedded protostars) nor external heating by source "I" can be definitively ruled out. We also report the discovery of a new arclike feature southwest of the BN object and some curious morphology surrounding near-IR source "t."
Synthetic studies on asperparaline A.Synthesis of the spirosuccinimide ring system

A photooxygenation reaction of 2′,2′,4′,4′-tetramethyl tetrahydroindole (9) followed by a pinacoltype rearrangement furnished 2′,2′,4′,4′-tetramethyl-3-spirocyclopentylsuccinimide (11). This transformation constitutes a model study for the synthesis of the spirosuccinimide ring system of asperparaline A.
A data-driven approach to optimized medication dosing: a focus on heparin

To demonstrate a novel method that utilizes retrospective data to develop statistically optimal dosing strategies for medications with sensitive therapeutic windows. We illustrate our approach on intravenous unfractionated heparin, a medication which typically considers only patient weight and is frequently misdosed. We identified available clinical features which impact patient response to heparin and extracted 1,511 patients from the multi-parameter intelligent monitoring in intensive care II database which met our inclusion criteria. These were used to develop two multivariate logistic regressions, modeling sub- and supra-therapeutic activated partial thromboplastin time (aPTT) as a function of clinical features. We combined information from these models to estimate an initial heparin dose that would, on a per-patient basis, maximize the probability of a therapeutic aPTT within 4–8 h of the initial infusion. We tested our model’s ability to classifying therapeutic outcomes on a withheld dataset and compared performance to a weight-alone alternative using volume under surface (VUS) (a multiclass version of AUC). We observed statistically significant associations between sub- and supra-therapeutic aPTT, race, ICU type, gender, heparin dose, age and Sequential Organ Failure Assessment scores with mean validation AUC of 0.78 and 0.79 respectively. Our final model improved outcome classification over the weight-alone alternative, with VUS values of 0.48 vs. 0.42. This work represents an important step in the secondary use of health data in developing models to optimize drug dosing. The next step would be evaluating whether this approach indeed achieves target aPTT more reliably than the current weight-based heparin dosing in a randomized controlled trial.
Very High Energy Colliders

The first particle accelerators were built roughly fifty years ago. These first machines had energies of the order of MeVs and were used to study a world that looked relatively simple. Matter was composed of four basic constituents: protons, neutrons, electrons, and neutrinos. These constituents interacted via four forces: the weak (to account for radioactivity); the electromagnetic (to account for the interaction between charges and currents); the strong (to bind the nucleus together); and the gravitational (to account for the interaction of masses at large distances.) All our attempts at understanding matter were guided by two dynamical principles -- relativity and quantum mechanics.
The master field for 2D QCD on the sphere

Abstract We continue our analysis of the field strength correlation functions of two-dimensional QCD on Riemann surfaces by studying the large N limit of these correlation functions on the sphere for the gauge group U ( N ). Our results allow us to exhibit an explicit master field for the field strength F μν in a “topological gauge”, given by a single master matrix in the Lie algebra of the maximal torus of the gauge group. Field correlators are obtained from the traces of the products of the master field. We also obtain a master field for the gauge potential A μ on the sphere, consistent with the master field for the field strength.
Targeting the Poor: Evidence from a Field Experiment in Indonesia

The brief summarizes the targeting the poor: evidence from a field experiment in Indonesia for the period December 2008 - January 2009. This paper reports an experiment in 640 Indonesian villages on three approaches to target the poor: proxy means tests (PMT), where assets are used to predict consumption; community targeting, where villagers rank everyone from richest to poorest; and a hybrid. Defining poverty based on PPP$2 per capita consumption, community targeting and the hybrid perform somewhat worse in identifying the poor than PMT, though not by enough to significantly affect poverty outcomes for a typical program. Elite capture does not explain these results. Instead, communities appear to apply a different concept of poverty.
Mind the Gap: Using Derivatives Overlays to Hedge Pension Duration

Recent legislation and accounting rule changes motivate defined-benefit pension plans to manage the interest rate risk arising from volatility in their liabilities, as measured by either the accumulated benefit obligation (ABO) or the projected benefit obligation (PBO). For either measure, asset portfolios comprising equity and fixed-income bonds usually have much lower average durations than do liabilities. This article discusses how interest rate derivatives overlay strategies can be used to reduce or eliminate the negative duration gap. A theoretical model is developed to show how to calculate the ABO and PBO measures and their duration statistics.
Highly diastereoselective synthesis of tetrahydropyridines by a C-H activation-cyclization-reduction cascade.

A versatile reaction cascade leading to highly substituted 1,2,3,6-tetrahydropyridines has been developed. It comprises rhodium(I)-catalyzed C–H activation–alkyne coupling followed by electrocyclization and subsequent acid/borohydride-promoted reduction. This one-pot procedure affords the target compounds in up to 95% yield with >95% diastereomeric purity.
Did nature also choose arsenic

All known life requires phosphorus (P) in the form of inorganic phosphate (PO43− or Pi) and phosphate-containing organic molecules. Pi serves as the backbone of the nucleic acids that constitute genetic material and as the major repository of chemical energy for metabolism in polyphosphate bonds. Arsenic (As) lies directly below P on the periodic table and so the two elements share many chemical properties, although their chemistries are sufficiently dissimilar that As cannot directly replace P in modern biochemistry. Arsenic is toxic because As and P are similar enough that organisms attempt this substitution. We hypothesize that ancient biochemical systems, analogous to but distinct from those known today, could have utilized arsenate in the equivalent biological role as phosphate. Organisms utilizing such ‘weird life’ biochemical pathways may have supported a ‘shadow biosphere’ at the time of the origin and early evolution of life on Earth or on other planets. Such organisms may even persist on Earth today, undetected, in unusual niches.
Space-Radiation Effects in Integrated Circuits

Damage mechanism in semiconductors from space radiation and effects on various microcircuits
Spectral estimation of irregularly sampled multidimensional processes by generalized prolate spheroidal sequences

A nonparametric spectral estimation method is presented for bandlimited random processes that have been sampled at arbitrary points in one or more dimensions. The method makes simultaneous use of several weight sequences that depend on the set of sampling point, the signal band, and the frequency band being analyzed. These sequences are solutions to a generalized matrix eigenvalue problem and are termed generalized prolate spheroidal sequences, being extensions of the familiar discrete prolate spheroidal sequences. Statistics of the estimator are derived, and the tradeoff among bias, variance, and resolution is quantified. The method avoids several problems typically associated with irregularly sampled data and multidimensional processes. A related method is suggested that has nearly as good performance while requiring significantly fewer computations. >
Studies on Syntheses of a Novel Anti-Herpetic Nucleoside A-5021 and Related Compounds

A series of conformationally constrained nucleoside analogues with two hydroxymethyl groups mimicking the 3'- and 5'-hydroxyl groups of the 2'-deoxyribose were prepared and evaluated for their antiherpetic activity. Among those, 9- [[cis-1'-, 2'-bis (hydroxylmethyl) cycloprop-1'-yl] methy] guanine showed extremely potent antiviral activity against HSV-1. One of the enantiomers with (1'S), (2'R) -configuration (A-5021) was proved to be the active form. A-5021 was more active than acyclovir (ACV) against HSV-1, HSV-2, VZV, HCMV and showed superior activity over ACV in animal models. An efficient process for preparation of A-5021 including enantioselective hydrolysis of the intermediate is described. An oral prodrug AV-038 and anti-VZV drug AV-100 are also described.
Adult Learner Graduation Rates at Four U.S. Community Colleges by Prior Learning Assessment Status and Method

The completion agenda demands higher community college graduation rates among adult learners, and prior learning assessment (PLA) is a promising solution. PLA permits students to earn credit for college-level learning acquired outside of higher education and is associated with improved student outcomes. However, little is known regarding community college graduation rates among adult learners by prior learning assessment status and method. Therefore, the purpose of the current study was to examine adult learner graduation rates by PLA status and method at four U.S. community colleges. Results from this foundational study confirmed a remarkable difference in graduation rates between adult PLA learners and adult non-PLA learners, uncovered striking differences in the graduation rates of adult PLA learners by PLA method, and identified a relationship between PLA method and graduation. Findings provide community college stakeholders with new insight into adult PLA learners in the community college and a basis...
Synthesis and radioprotective effects of new phosphorothioate esters of WR-2721, WR-3689 and WR-151327

Abstract Three 4-chlorophenyl diaminoalkylthiophasphate esters of WR -2721, WR-3689 and WR-151327 were synthesized and evaluated for in vitro cytotoxicity and in vitro and in vivo radioprotective efficacy against Chinese hamster V-79 cells and CD2F1 male mice, respectively. Three 4-chlorophenyl diaminoalkylthiophasphate esters of WR -2721, WR-3689 and WR-151327 were synthesized and evaluated for in vitro cytotoxicity and in vitro and in vivo radioprotective efficacy against Chinese hamster V-79 cells and CD2F1 male mice, respectively.
Automated Approach to Very High-Order Aeroacoustic Computations

Computational aeroacoustics requires efficient, high-resolution simulation tools. For smooth problems, this is best accomplished with very high-order in space and time methods on small stencils. However, the complexity of highly accurate numerical methods can inhibit their practical application, especially in irregular geometries. This complexity is reduced by using a special form of Hermite divided-difference spatial interpolation on Cartesian grids, and a Cauchy-Kowalewski recursion procedure for time advancement. In addition, a stencil constraint tree reduces the complexity of interpolating grid points that am located near wall boundaries. These procedures are used to develop automatically and to implement very high-order methods (> 15) for solving the linearized Euler equations that can achieve less than one grid point per wavelength resolution away from boundaries by including spatial derivatives of the primitive variables at each grid point. The accuracy of stable surface treatments is currently limited to 11th order for grid aligned boundaries and to 2nd order for irregular boundaries.
Small instantons in string theory

Abstract A long-standing puzzle about the heterotic string has been what happens when an instanton shrinks to zero size. It is argued here that the answer at the quantum level is that an extra SU (2) gauge symmetry appears that is supported in the core of the instanton. Thus in particular the quantum heterotic string has vacua with higher rank than is possible in conformal field theory. When k instantons collapse at the same point, the enhanced gauge symmetry is Sp ( k ). These results, which can be tested by comparison to Dirichlet five-branes of Type I superstrings and to the ADHM construction of instantons, give the first example for the heterotic string of a non-perturbative phenomenon that cannot be turned off by making the coupling smaller. They have applications to several interesting puzzles about string duality.
A model of weak viscoelastic nematodynamics

The paper develops a continuum theory of weak viscoelastic nematodynamics of Maxwell type. It can describe the molecular elasticity effects in mono-domain flows of liquid crystalline polymers as well as the viscoelastic effects in suspensions of uniaxially symmetric particles in polymer fluids. Along with viscoelastic and nematic kinematics, the theory employs a general form of weakly elastic thermodynamic potential and the Leslie–Ericksen–Parodi type constitutive equations for viscous nematic liquids, while ignoring inertia effects and the Frank (orientation) elasticity in liquid crystal polymers. In general case, even the simplest Maxwell model has many basic parameters. Nevertheless, recently discovered algebraic properties of nematic operations reveal a general structure of the theory and present it in a simple form. It is shown that the evolution equation for director is also viscoelastic. An example of magnetization exemplifies the action of non-symmetric stresses. When the magnetic field is absent, the theory is reduced to the symmetric, fluid mechanical case with relaxation properties for both the stress and director. Our recent analyses of elastic and viscous soft deformation modes are also extended to the viscoelastic case. The occurrence of possible soft modes minimizes both the free energy and dissipation, and also significantly decreases the number of material parameters. In symmetric linear case, the theory is explicitly presented in terms of anisotropic linear memory functionals. Several analytical results demonstrate a rich behavior predicted by the developed model for steady and unsteady flows in simple shearing and simple elongation.
Organocatalyzed enantioselective synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carboxylates.

The organocatalyzed enantioselective synthesis of biologically active 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate derivatives was achieved using bifunctional cinchona alkaloids as the catalysts. Using quinine thiourea as the catalyst, the tandem Michael addition–cyclization reaction between 1,3-cyclohexanediones and alkylidenecyanoacetate derivatives gives the desired products in high yields (up to 92%) and good ee values (up to 82%).
Massless D-Branes on Calabi–Yau Threefolds and Monodromy

We analyze the link between the occurrence of massless B-type D-branes for specific values of moduli and monodromy around such points in the moduli space. This allows us to propose a classification of all massless B-type D-branes at any point in the moduli space of Calabi–Yau’s. This classification then justifies a previous conjecture due to Horja for the general form of monodromy. Our analysis is based on using monodromies around points in moduli space where a single D-brane becomes massless to generate monodromies around points where an infinite number become massless. We discuss the various possibilities within the classification.
Fluctuations during melting

Fluctuations which involve the repetitive melting and recrystallization of crystals in equilibrium with their liquid are reported. The experiments were performed at constant volume and temperature inside a diamond anvil cell. The results, which we believe are the first to show the importance of temporal fluctuations during a first order phase transition, are not explained by any theory of Ostwald ripening.
The path for metal complexes to a DNA target

The discovery of cisplatin as a therapeutic agent stimulated a new era in the application of transition metal complexes for therapeutic design. Here we describe recent results on a variety of transition metal complexes targeted to DNA to illustrate many of the issues involved in new therapeutic design. We describe first structural studies of complexes bound covalently and non-covalently to DNA to identify potential lesions within the cell. We then review the biological fates of these complexes, illustrating the key elements in obtaining potent activity, the importance of uptake and subcellular localization of the complexes, as well as the techniques used to delineate these characteristics. Genomic DNA provides a challenging but valuable target for new transition metal-based therapeutics.
CARBON-CHAIN SPECIES IN WARM-UP MODELS

In previous warm-up chemical models of the low-mass star-forming region L1527, we investigated the evolution of carbon-chain unsaturated hydrocarbon species when the envelope temperature is slightly elevated to T 30?K. These models demonstrated that enhanced abundances of such species can be explained by gas-phase ion-molecule chemistry following the partial sublimation of methane from grain surfaces. We also concluded that the abundances of hydrocarbon radicals such as the C n H family should be further enhanced as the temperatures increase to higher values, but this conclusion stood in contrast with the lack of unambiguous detection of these species toward hot core and corino sources. Meanwhile, observational surveys have identified C2H, C4H, CH3CCH, and CH3OH toward hot corinos (especially IRAS 16293?2422) as well as toward L1527, with lower abundances for the carbon-chain radicals and higher abundances for the other two species toward the hot corinos. In addition, the Herschel Space Telescope has detected the bare linear chain C3 in 50?K material surrounding young high-mass stellar objects. To understand these new results, we revisit previous warm-up models with an augmented gas-grain network that incorporated reactions from a gas-phase network that was constructed for use with increased temperature up to 800?K. Some of the newly adopted reactions between carbon-chain species and abundant H2 possess chemical activation energy barriers. The revised model results now better reproduce the observed abundances of unsaturated carbon chains under hot corino (100?K) conditions and make predictions for the abundances of bare carbon chains in the 50?K regions observed by the Herschel HIFI detector.
Lattice-Matched Heteroepitaxy of Wide Gap Ternary Compound Semiconductors

A variety of applications are identified for heteroepitaxial structures of wide gap I-III-VI2 and II-IV-V2 semiconductors, and are assessed in comparison with ternary III-V alloys and other wide gap materials. Non-linear optical applications of the I-III-VI2 and II-IV-V2 compound heterostructures are discussed, which require the growth of thick epitaxial layers imposing stringent requirements on the conditions of heteroepitaxy. In particular, recent results concerning the MOCVD growth of ZnSi(x)Ge(1-x)P2 alloys lattice-matching Si or GaP substrates are reviewed. Also, heterostructures of Cu(z)Ag(1-z)GaS2 alloys that lattice-match Si, Ge, GaP or GaAs substrates are considered in the context of optoelectronic devices operating in the blue wavelength regime. Since under the conditions of MOCVD, metastable alloys of the II-IV-V2 compounds and group IV elements are realized, II-IV-V2 alloys may also serve as interlayers in the integration of silicon and germanium with exactly lattice-matched tetrahedrally coordinated compound semiconductors, e.g. ZnSi(x)Ge(1-x)P2.
Collective alignment of nanorods in thin Newtonian films

In this paper, we provide a complete analytical description of the alignment kinetics of magnetic nanorods in magnetic field. Nickel nanorods were formed by template electrochemical deposition in alumina membranes from a dispersion in a water–glycerol mixture. To ensure uniformity of the dispersion, the surface of the nickel nanorods was covered with polyvinylpyrrolidone (PVP). A 40–70 nm coating prevented aggregation of the nanorods. These modifications allowed us to control alignment of the nanorods in a magnetic field and test the proposed theory. An orientational distribution function of nanorods was introduced. We demonstrated that the 0.04% volume fraction of nanorods in the glycerol–water mixture behaves as a system of non-interacting particles. However, the kinetics of alignment of a nanorod assembly does not follow the predictions of the single-nanorod theory. The distribution function theory explains the kinetics of alignment of a nanorod assembly and shows the significance of the initial distribution of nanorods in the film. It can be used to develop an experimental protocol for controlled ordering of magnetic nanorods in thin films.
Obesity, Weight Loss, and Employment Prospects: Evidence from a Randomized Trial

This study presents credible estimates for the causal effect of BMI growth on employment among the obese. By exploring random assignment of a weight-loss intervention based on monetary rewards, I provide convincing evidence that weight loss positively affects the employment prospects of obese women but not of obese men. Consistent with this, significant effects of weight loss on proxy variables for labor productivity are found only for obese women.
Real-Time Frequency Response Estimation from Flight Data

A nonparametric method for estimating frequency responses in realtime using a method based on recursive least squares in the time domain was developed and studied. The proposed method uses sinusoidal functions at selected frequencies known to be contained in the input in conjunction with recursive least squares to rapidly estimate Fourier series coefficients for input and output time series, and thereby estimate frequency responses. Practical problems that arise when applying the discrete Fourier transform in recursive form were identified using simple examples. A general expression for accurate realtime calculation of the covariance matrix for recursive least squares parameter estimation was developed and used to calculate valid uncertainty bounds for realtime frequency response estimates. Simulation data generated with optimized multisine inputs were used to investigate the accuracy of the proposed method for realtime frequency response estimation, and to validate the calculated error bounds. The approach was also applied in realtime to flight data from a subscale jet transp ort aircraft. Comparisons of realtime frequency response estimates and error bounds with results from conventional postflight batch analysis showed that results from the realti me method were in statistical agreement with postflight batch estimates, with valid error bounds that properly indicated the quality of the realtime frequency response estimates.
Numerical ansatz for solving integro-differential equations with increasingly smooth memory kernels: spin-boson model and beyond

We present an efficient and stable numerical ansatz for solving a class of integro-differential equations. We define the class as integro-differential equations with increasingly smooth memory kernels. The resulting algorithm reduces the computational cost from the usual T^2 to TC(T), where T is the total simulation time and C(T) is some function. For instance, C(T ) is equal to ln T for polynomially decaying memory kernels. Due to the common occurrence of increasingly smooth memory kernels in physical, chemical and biological systems, the algorithm can be applied in quite a wide variety of situations. We demonstrate the performance of the algorithm by examining two cases. Firstly, we compare the algorithm to a typical numerical procedure for a simple integro-differential equation. Secondly, we solve the non-interacting blip approximation equations for the spin-boson model in real time.
Discovering Valuable Growth Opportunities: An Analysis of Equity Alliances with IPO Firms

Firms often use alliances to access external resources and explore new market or technological opportunities, yet they also can face obstacles to discovering these opportunities in the first place. In this paper, we examine how firms can overcome these obstacles and form equity alliances with newly public companies to obtain valuable growth opportunities. Specifically, we build on real options theory and develop the argument that the visibility of firms having an initial public offering (IPO) can shape investors' recognition of the embedded growth opportunities and therefore channel their alliance activities. The evidence shows that firms are more likely to partner with IPO firms possessing more valuable growth opportunities. Furthermore, this relationship is magnified for IPO firms that have obtained more visibility, either through various interorganizational relationships or media coverage on going public.
Spatial epidemics: critical behavior in one dimension

In the simple mean-field SIS and SIR epidemic models, infection is transmitted from infectious to susceptible members of a finite population by independent p-coin tosses. Spatial variants of these models are considered, in which finite populations of size N are situated at the sites of a lattice and infectious contacts are limited to individuals at neighboring sites. Scaling laws for these models are given when the infection parameter p is such that the epidemics are critical. It is shown that in all cases there is a critical threshold for the numbers initially infected: below the threshold, the epidemic evolves in essentially the same manner as its branching envelope, but at the threshold evolves like a branching process with a size-dependent drift. The corresponding scaling limits are super-Brownian motions and Dawson–Watanabe processes with killing, respectively.
Vapor flow into a capillary propellant-acquisition device

An analytical model is described that specifies the conditions needed to cause a flow of vapor through the screens of a start basket. The analytical model is composed of several original submodels that interrelate the evaporation of the liquid in the basket, the bubble-point change of a screen in the presence of wicking, the drying out of a screen through a combination of evaporation and pressure difference, the vapor flow rate across a wet screen as a function of pressure difference, and the effect on wicking of a difference between the static pressure of the liquid reservoir and the vapor surrounding the screen. Most of the interrelations were demonstrated by a series of separate-effects tests, which were also used to determine certain empirical constants. The equations of the model were solved numerically for typical start basket designs. A simplified start basket was constructed and tested to verify these predictions, using both volatile and non-volatile liquids. The test results verified the trends predicted by the model.
Algebraic and dynamic Lyapunov equations on time scales

We revisit the canonical continuous-time and discrete-time matrix algebraic and matrix differential equations that play a central role in Lyapunov-based stability arguments. The goal is to generalize and extend these types of equations and subsequent analysis to dynamical systems on domains other than R or Z, called “time scales”, e.g. nonuniform discrete domains or domains consisting of a mixture of discrete and continuous components. In particular, we compare and contrast a generalization of the algebraic Lyapunov equation and the dynamic Lyapunov equation in this time scales setting.
Selection-free predictions in global games with endogenous information and multiple equilibria

Global games with endogenous information often exhibit multiple equilibria. In this paper, we show how one can nevertheless identify useful predictions that are robust across all equilibria and that cannot be delivered in the commonknowledge counterparts of these games. Our analysis is conducted within a flexible family of games of regime change, which have been used to model, inter alia, speculative currency attacks, debt crises, and political change. The endogeneity of information originates in the signaling role of policy choices. A novel procedure of iterated elimination of nonequilibrium strategies is used to deliver probabilistic predictions that an outside observer—an econometrician—can form under arbitrary equilibrium selections. The sharpness of these predictions improves as the noise gets smaller, but disappears in the complete-information version of the
Surface Chemistry of GaAs(100) after Treatment with Aqueous H3PO4 Solution

The interaction of semiconductor surfaces with aqueous acid solutions is important in chemical cleaning and etching. Wet chemical treatments are advantageous because they cause little damage to the surface and do not usually require high temperatures. The surface chemistry of GaAs after treatment with phosphoric acid was studied using multiple internal reflection infrared spectroscopy. The treatment left behind a thin film containing several types of P x O y bonds. The chemical nature of the film was observed to change with time as new species would form on the surface.
Blade loss transient dynamic analysis of turbomachinery

This paper reports on work completed to develop an analytical method for predicting the transient nonlinear response of a complete aircraft engine system due to the loss of a fan blade, and to validate the analysis by comparing the results against actual blade loss test data. The solution, which is based on the component element method, accounts for rotor-to-casing rubs, high damping, and rapid deceleration rates associated with the blade loss event. A comparison of test results and predicted response show good agreement except for an initial overshoot spike not observed in test. The method is effective for analysis of large systems.
Mapping of forest types in Alaskan boreal forests using SAR imagery

Mapping of forest types in the Tanana river flood-plain, interior Alaska, is performed using a maximum-a-posteriori Bayesian classifier applied on SAR data acquired by the NASA/JPL three-frequency polarimetric AIRSAR system on several dates. Five vegetation types are separated, dominated by 1) white spruce, 2) balsam poplar, 3) black spruce, 4) alder/willow shrubs, and 5) bog/fen/nonforest vegetation. Open water of rivers and lakes is also separated. Accuracy of forest classification is investigated as a function of frequency and polarization of the radar, as well as the forest seasonal state, which includes winter/frozen, winter/thawed, spring/flooded, spring/unflooded, and summer/dry conditions. Classifications indicate that C-band is a more useful frequency for separating forest types than L- or P-bands, and HV polarization is the most useful polarization at all frequencies. The highest classification accuracy, with 90 percent of forest pixels classified correctly, is obtained by combining L-band HV and C-band HV data acquired in spring as seasonal river flooding recedes and before deciduous tree species have leaves. In 17 forest stands for which actual percentages of each tree species are known, the same radar data are capable of predicting tree species composition with less than 10 percent error. From the authors' classification, they predict that current and future spaceborne SAR systems will have limited mapping capabilities when used alone. Yet, RADARSAT combined with J-ERS-1 and ERS-1 could resolve forest types with 80 percent accuracy, separate nonforest areas resulting from commercial logging or forest wildfire, and map river edges. >
A fragmentation-rearrangement sequence of cyclobutylcarbinyl radicals

Abstract The fragmentation of cyclobutylcarbinyl radicals produces primary radicals which can undergo addition to adjacent pi-bonds resulting in ring expansion reactions. This tandem fragmentation-expansion sequence provides a unique entry into some complex carbon skeleta.
The Coronary Angiogram and Its Seminal Contributions to Cardiovascular Medicine Over Five Decades

The selective injection of contrast media into the right coronary artery of a middle-aged male by Dr F. Mason Sones, Jr, on October 30, 1958 (Figure 1) introduced a new era in cardiovascular medicine that was to revolutionize our understanding and management of the cardiac patient for the remainder of the twentieth century.1,2⇓ As the first reliable in vivo marker for the presence of obstructing coronary lesions, the coronary angiogram not only provided objective evidence to support or refute the clinical diagnosis of angina pectoris but, quite importantly, led to our first studies of the natural history of patients with coronary artery disease (CAD). The purpose of this article is to underscore the crucial role this particular technology played in contributing to the epochal events and discoveries that have characterized the march of progress in the field of cardiology over the past 50 years. Figure 1. Cine frame from the first selective coronary arteriogram taken by F. Mason Sones, MD, on October 30, 1958. Reprinted with permission from J Am Coll Cardiol. 1998;31:89B–96B. Sones’ decision to undertake selective visualization of the coronary artery in his patient undergoing catheterization to evaluate mitral regurgitation was, in some measure, the result of a serendipitous event that occurred in his laboratory 2 days earlier. This has been described in detail elsewhere by Dr Willis Hurst3 and entailed a power injection of 40 to 50 cc of contrast media that was intended to be delivered into the aortic root of a patient with aortic regurgitation. Under 10 kg/cm2 of pressure, the catheter whiplashed into the ostia of the right coronary artery, and an estimated 30cc of 90% Hypaque (Nicomed) was selectively delivered as a bolus into the coronary artery before the injection could be aborted. A former fellow of Sones’, Dr …
In Situ Monitoring of III–V Processing

Fabrication of high performance III-V devices and integrated circuits depends on careful control of layer thicknesses and compositions in the as-grown epitaxial layers and in the etching of these layers. The relatively high value of compound semiconductor devices (compared with high-volume Si devices) makes the use of advanced process control (with expensive in situ sensors) potentially advantageous. Considerable attention has been given to the problems of realtime feedback control of MBE growth systems. In this paper, I will discuss experiences with use of both in situ and ex situ monitors for controlling reactive ion etching (RIE) of III-V materials. Specific examples from an electron cyclotron resonance (ECR) RIE base contact etch from an AlInAs/GalnAs HBT process will be given. The relative merits of reflection-based wafer sensors vs. process state sensors (optical emission spectroscopy and mass spectroscopy) will be discussed. The unique opportunities and problems associated with the III-V materials and required etch processes will be contrasted to implementation of advanced wafer state endpoint detection schemes in Si and flat panel display processes. Specific problems and solutions from our research which I will discuss include chamber seasoning effects on the drift of optical emission based endpoint detection schemes and signal processing techniques for accounting for this drift, modeling of the optical dielectric function of the compounds of interest vs. composition, and the effects of surface roughness on optical thickness measurements.
Global managers’ perceptions of cultural competence

Abstract To work effectively in the global business arena, managers need a strong set of intercultural management skills. When dealing with clients, co-workers, and other stakeholders at home or abroad, managers with cross-cultural competence have a distinct competitive advantage in the multicultural marketplace. Although generally accepted as a valuable asset for doing business, cross-cultural competence defies easy definition. This study attempts to conceptualize the complex term from the practitioner's point of view. What does cross-cultural competence mean to global managers? From their perspective, which aspects of culture do business people need to understand? From the universe of cultural beliefs, values, attitudes, and country-specific information, what should an executive, with limited time, focus on to develop a basic level of cultural competence? This study asked Mexican managers what they needed to know about culture to do business with the U.S. In the process, they consistently identified certain basic components of cultural competence. Responses were surprisingly similar among the managers, indicating they had a clear picture of which cultural essentials were most important for global executives to learn. The results of the study reveal a working definition of cultural competence for global managers. This research also provides trainers and business educators a content framework for a short-term training program, based on the global managers’ perceptions of cross-cultural competence.
2MASS J20261584–2943124: AN UNRESOLVED L0.5 + T6 SPECTRAL BINARY

We identify the L dwarf 2MASS J20261584–2943124 as an unresolved spectral binary, based on low-resolution, near-infrared spectroscopy from IRTF/SpeX. The data reveal a peculiar absorption feature at 1.6 μm, previously noted in the spectra of other very low-mass spectral binaries, which likely arises from overlapping FeH and CH4 absorption bands in the blended light of an L dwarf/T dwarf pair. Spectral template matching analysis indicates component types of L0.5 and T6, with relative brightness ΔH = 4.2 ± 0.6. Laser guide star adaptive optics imaging observations with Keck/NIRC2 fail to resolve the source, indicating a maximum separation at the observing epoch of 0".25, or a projected separation of 9 AU assuming a distance of 36 ± 5 pc. With an age that is likely to be relatively older (≳ 5 Gyr) based on the system's large V_(tan) and mass ratio arguments, the relative motion of the potentially "massive" (0.06-0.08 M_⊙) components of 2MASS J2026–2943 may be detectable through radial velocity variations, like its earlier-type counterpart 2MASS J03202839–0446358 (M8+T5), providing dynamical mass measurements that span the hydrogen burning limit.