cssi/SciSciGPT-SciSciNet huggingface dataset:
Low-mass evolution from he ignition to beyond the horizontal branch

The evolution of an 0.6 m⊙ stellar model during core helium burning is presented. Following the off-center ignition of helium in the “core” flash, the star remains on the red giant branch for > 106 years, undergoing twelve additional flashes. After leaving the giant branch, the star evolves on the horizontal branch for 8.15×107 years before re turning to the giant branch and undergoing strong helium-shell flashes. The implications for horizontal branch and RR Lyrae stars are discussed.
Fourth-generation languages (4GLs) and personal computers

This paper describes how fourth generation languages (4GLs) evolved from enhanced query languages and report generators into applications development tools. Pioneers, such as MAPPER, NOMAD, RAMIS, SQL, and FOCUS are example nonprocedural 4GLs with excellent records. Another area that offers the promise of 4GLs in the next generation of development are the relational databases designed for microcomputers. The third origin of 4GLs is in languages like PRO-IV, SALVO, and REVELATION, which were developed originally as application development tools.The increases in numbers and capabilities of personal computers demonstrate the need for greater understanding of 4GLs since most of them fit on these small machines. Of special note is the upgrade of the IBM Personal Computer XT to an IBM XT/370 and the software becoming available to use on this equipment. This is but one of the many examples where less expensive hardware is changing the entire concept of corporate computing and applications development by users.
White Dwarf Cosmochronology in the Solar Neighborhood

The study of the stellar formation history in the solar neighborhood is a powerful technique to recover information about the early stages and evolution of the Milky Way. We present a new method that consists of directly probing the formation history from the nearby stellar remnants. We rely on the volume complete sample of white dwarfs within 20 pc, where accurate cooling ages and masses have been determined. The well characterized initial-final mass relation is employed in order to recover the initial masses (1 M initial/M ☉ 8) and total ages for the local degenerate sample. We correct for moderate biases that are necessary to transform our results to a global stellar formation rate, which can be compared to similar studies based on the properties of main-sequence stars in the solar neighborhood. Our method provides precise formation rates for all ages except in very recent times, and the results suggest an enhanced formation rate for the solar neighborhood in the last 5 Gyr compared to the range 5 < Age (Gyr) < 10. Furthermore, the observed total age of ~10 Gyr for the oldest white dwarfs in the local sample is consistent with the early seminal studies that have determined the age of the Galactic disk from stellar remnants. The main shortcoming of our study is the small size of the local white dwarf sample. However, the presented technique can be applied to larger samples in the future.
Asymmetric aza-Claisen rearrangement: Synthesis of (+)-dihydropallescensin-2 [(+)-penlanpallescensin].

Abstract Synthetic confirmation of the C(1′)-(S)-configuration of (+)-dihydropallescensin-2 (1) is reported, the key reaction being a chiron-mediated asymmetric aza-Claisen rearrangement (6→7).
True Radix-2 discrete cosine transform algorithm

In this paper we present a true radix-2 discrete cosine transform (DCT) algorithm in both decimation-in-frequency and decimation-in-time forms. To date, there has been strong interest in developing new processing techniques in the DCT domain for the reason that the DCT is popularly used in the current international standards for image, audio, and video compression. One important function in this respect is to merge or split of DCT blocks in the transform domain. Though many fast DCT algorithms have been existed, they are not suitable for such application. Most of the existing fast DCT algorithms are in radix-2 form, of which the DCT matrix is factorized into two half-sized transform matrices. But these two sub-matrices are not the same, at the best only one is the lower order DCT. In other words, the existing fast DCT algorithms are not true radix-2. This in turn has prevented them from direct applications to the transform-domain processing. The true radix-2 DCT algorithm presented in this paper has alleviated the above difficulty, and it may provide new techniques for other potential applications.
Classification of generalized symmetries of the Yang–Mills fields with a semi-simple structure group

Abstract A complete classification of generalized (or local) symmetries of the Yang–Mills equations on four dimensional Minkowski space with a semi-simple structure group is carried out. It is shown that any generalized symmetry, up to a generalized gauge symmetry, agrees with a first order symmetry on solutions of the Yang–Mills equations. Let g = g 1 +⋯+ g n be the decomposition of the Lie algebra g of the structure group into simple ideals. First order symmetries for g -valued Yang–Mills fields are found to consist of gauge symmetries, conformal symmetries for g m -valued Yang–Mills fields, 1⩽m⩽n, and their images under a complex structure of g m .
Modeling and Compensation of Hysteresis in Piezoceramic Transducers for Vibration Control

Hysteretic behavior in piezoceramic transducers is investigated theoretically and experimentally. The applicability of the rate-independent generalized Maxwell resistive capacitor (MRC) hysteresis model is established. Methods for MRC and inverse MRC online model identification are developed by first establishing that the MRC and its inverse are the same particular cases of the classical Preisach hysteresis model. This enables use of the extensive mathematical framework that has been developed for Preisach models. A method of incorporating the MRC model in a feed forward control scheme for hysteresis compensation is also presented. Experimental studies on a 1-3 piezoceramic composite support the theoretical developments and their applicability to piezoceramics.
High-sensitivity analysis of buprenorphine, norbuprenorphine, buprenorphine glucuronide, and norbuprenorphine glucuronide in plasma and urine by liquid chromatography–mass spectrometry

A new method using ultra-fast liquid chromatography and tandem mass spectrometry (UFLC–MS/MS) was developed for the simultaneous determination of buprenorphine and the metabolites norbuprenorphine, buprenorphine-3β-glucuronide, and norbuprenorphine-3β-glucuronide in plasma and urine. Sample handling, sample preparation and solid-phase extraction procedures were optimized for maximum analyte recovery. All four analytes of interest were quantified by positive ion electrospray ionization tandem mass spectrometry after solid-phase microextraction. The lower limits of quantification in plasma were 1 pg/mL for buprenorphine and buprenorphine glucuronide, and 10 pg/mL for norbuprenorphine and norbuprenorphine glucuronide. The lower limits of quantitation in urine were 10 pg/mL for buprenorphine, norbuprenorphine and their glucuronides. Overall extraction recoveries ranged from 68–100% in both matrices. Interassay precision and accuracy was within 10% for all four analytes in plasma and within 15% in urine. The method was applicable to pharmacokinetic studies of low-dose buprenorphine.
Relativistic force-free electrodynamic simulations of neutron star magnetospheres

The luminosity and structure of neutron star magnetospheres are crucial to our understanding of pulsar and plerion emission. A solution found using the force-free approximation would be an interesting standard with which any model with more physics could be compared. Prior quasi-analytic force-free solutions may not be stable, while prior time-dependent magnetohydrodynamic models used unphysical model parameters. We use a time-dependent relativistic force-free electrodynamics code with no free parameters to find a unique stationary solution for the axisymmetric rotating pulsar magnetosphere in a Minkowski space–time in the case of no surface currents on the star. The solution is similar to the force-free quasi-analytic solution found in 1999 by Contopoulos, Kazanas & Fendt and the numerical magnetohydrodynamic solution found in 2006 by Komissarov. The magnetosphere structure and the usefulness of the classical y-point in the general dissipative regime are discussed. The pulsar luminosity is found to be L≈ 0.99 ± 0.01 μ2Ω4★/c3 for a dipole moment μ and stellar angular frequency Ω★.
The coupling of elastic, surface-wave modes by a slow, interfacial inclusion

A layer of homogeneous, isotropic, elastic material overlays a substrate of similar material. The shear wavespeed within the layer is less than that of the substrate causing waves to be trapped within the layer. At the interface a long inclusion, that grows gradually until it reaches a constant thickness, is introduced. The inclusion is composed of a material whose shear wavespeed is less than that in the layer; it is described as slow. It is imagined that the lowest surface-wave mode of the structure is incident to the growing inclusion. Numerical calculations show that the growth of the slow inclusion brings the wavenumber of this lowest mode into an interval where it is close to that of the second mode, thus exciting it. This process is repeated when the wavenumber of the second mode is brought close to that of the third. Within these intervals, energy is exchanged among the coupling modes. Outside of these localized intervals, the modes propagate independently of one another and their amplitudes vary such that the flux of energy in each mode is conserved; they are said to propagate adiabatically. Reflections are also excited, but are shown to be very small in magnitude.
An efficient synthesis of alkenyl and alkynyl silyl ethers

Abstract A general synthesis of alkynyl and alkenyl silylethers is described. This involves reaction of alkynyl or alkenyl organometallic reagents, usually the lithio derivatives, with chlorodimethylaminodimethylsilane, followed by reaction of the product with an alcohol.
Deformation quantization of pseudo-symplectic (Poisson) groupoids

We introduce a new kind of groupoid—a pseudo-etale groupoid, which provides many interesting examples of noncommutative Poisson algebras as defined by Block, Getzler, and Xu. Following the idea that symplectic and Poisson geometries are the semiclassical limits of the corresponding quantum geometries, we quantize these noncommutative Poisson algebras in the framework of deformation quantization.
On the critical behavior of D1-brane theories

The authors study renormalization-group of patterns in theories arising on D1-branes in various supersymmetry-breaking backgrounds. The authors argue that the theory of N D1-branes transverse to an orbifold space can be fine-tuned to flow to the corresponding orbifold conformal field theory in the infrared, for particular values of the couplings and {theta} angles which the authors determine using the discrete symmetries of the model. By calculating various nonplanar contributions to the scalar potential in the world volume theory, the authors show that fine-tuning is in fact required at finite N, as would be generically expected. The authors further comment on the presence of singular conformal field theories (such as those whose target space includes a ``throat'' described by an exactly solvable CFT) in the non-supersymmetric context. Throughout the analysis two applications are considered: to gauge theory/gravity duality and to linear sigma model techniques for studying worldsheet string theory.
The principle of symmetric criticality in general relativity

We consider a version of Palais' principle of symmetric criticality (PSC) that is applicable to the Lie symmetry reduction of Lagrangian field theories. Given a group action on a space of fields, PSC asserts that for any group-invariant Lagrangian, the equations obtained by restriction of Euler–Lagrange equations to group-invariant fields are equivalent to the Euler–Lagrange equations of a canonically defined, symmetry-reduced Lagrangian. We investigate the validity of PSC for local gravitational theories built from a metric and show that there are two independent conditions which must be satisfied for PSC to be valid. One of these conditions, obtained previously in the context of transverse symmetry group actions, provides a generalization of the well-known unimodularity condition that arises in spatially homogeneous cosmological models. The other condition seems to be new. These results are illustrated with a variety of examples from general relativity.
Absolute Magnitude Distributions and Light Curves of Stripped-Envelope Supernovae

The absolute visual magnitudes of three Type IIb, 11 Type Ib, and 13 Type Ic supernovae (collectively known as stripped-envelope supernovae) are studied by collecting data on the apparent magnitude, distance, and interstellar extinction of each event. Weighted and unweighted mean absolute magnitudes of the combined sample, as well as various subsets of the sample, are reported. The limited sample size and the considerable uncertainties, especially those associated with extinction in the host galaxies, prevent firm conclusions regarding differences between the absolute magnitudes of supernovae of Types Ib and Ic, and regarding the existence of separate groups of overluminous and normal-luminosity stripped-envelope supernovae. The spectroscopic characteristics of the events of the sample are considered. Three of the four overluminous events are known to have had unusual spectra. Most but not all of the normal-luminosity events have had typical spectra. The light curves of stripped-envelope supernovae are collected and compared. Because SN 1994I in M51 was very well observed, it often is regarded as the prototypical Type Ic supernova, but it has the fastest light curve in the sample. Light curves are modeled by means of a simple analytical technique that, combined with a constraint on E/M from spectroscopy, yields internally consistent values of ejected mass, kinetic energy, and nickel mass.
Atomic Collision Experiments Utilizing Low-Velocity, Highly-Charged Ion Beams

Intense beams of highly-stripped ions are now routinely produced at low velocities using the Brookhaven dual MP-tandems in a unique four-stage accel/decel mode. This mode of operation combines three stages of acceleration, stripping at high energy, and one stage of deceleration to near-zero velocity. To date, experiments have used 10-100 nA beams of bare and few-electron heavy ions at energies as low as 0.2 MeV/amu, and upgrades of the facility should push the lower limit below 0.1 MeV/amu. Recent experiments, such as measurements of charge transfer and x-ray production for S6-16+ on He and Ar at 6-20 MeV and P(b) measurements for MO x-rays produced in Cl16+ + Ar collisions at 20, 10 and 5 MeV have demonstrated the usefulness of highly-stripped, low-velocity projectiles. These experiments and a few possibilities for future experiments are discussed.
Dust and Stellar Populations in the Large Magellanic Cloud

We present an analysis of line-of-sight extinction measurements obtained using data from the Magellanic Clouds Photometric Survey (Zaritsky, Harris, & Thompson), which provides four-filter photometry for millions of stars in the Large Magellanic Cloud. We find that visual extinctions are typically larger by several tenths of a magnitude for stars with effective temperatures greater than 12,000 K than for stars with effective temperatures between 5500 and 6500 K. Several repercussions of this population-dependent extinction are discussed. In particular, LMC distance measurements that utilize old stellar populations, but use extinctions derived from OB stars, may be biased low. As a specific example, we show that the LMC distance modulus derived from field red clump stars is revised upward relative to published measurements by ~0.2 mag if one uses the extinction measured for a matched stellar population. Conversely, measurements that utilize the youngest stars are subject to greater, and more variable, extinction leading preferentially to results that may be biased high. Population-dependent extinction affects the interpretation of color-magnitude diagrams and results in an effective absorption law that is steeper than that intrinsic to the dust for unresolved stellar systems. We further explore the relation between the stellar populations and dust by comparing our extinction map to the 100 μm image of the region and identifying potential heating sources of the dust. We find that although regions of high 100 μm flux are associated with young stars, young stars are not necessarily associated with regions of high 100 μm flux and that ~50% of the 100 μm flux is emitted beyond the immediate regions of high OB stellar density. We conclude that 100 μm flux should be used with caution as a star formation tracer, particularly for studies of star formation within galaxies. Finally, we reproduce the observed extinction variation between the hot and cold stellar populations with a simple model of the distribution of the stars and dust in which the scale height of the cooler stars is much greater than that of the dust (which is twice that of the OB stars; Harris, Zaritsky, & Thompson).
Distressed Properties: Valuation Bias and Accuracy

Using New Orleans foreclosure data, where each property has three appraisals (borrower, lender, and referee), we are able to investigate the factors affecting appraisal bias and accuracy for distressed properties. Unconditional analysis shows that on average lender appraisals are higher than referee appraisals, while borrower appraisals are lower than referee appraisals. Much of the bias could be explained by various client and appraiser characteristics. The relation between the client and the appraiser affects valuation bias. Customer employed appraisers tend to give more client friendly valuations than their court appointed counterparts. However, experienced and licensed appraisers render less biased valuations. The appraisal bias does not appear to depend on neighborhood and demographic characteristics. In addition, experienced and licensed appraisers provide materially more accurate valuations. Unlicensed, inexperienced appraisers have an error rate approximately four times worse than licensed, experienced appraisers.
The dayside ionosphere of Venus

Ionic and thermal structure model of daytime Venus ionosphere with solar wind heating based on Mariner 5 flyby mission
Discrete Adjoint-Based Design for Unsteady Turbulent Flows on Dynamic Overset Unstructured Grids

A discrete adjoint-based design methodology for unsteady turbulent flows on three-dimensional dynamic overset unstructured grids is formulated, implemented, and verified. The methodology supports both compressible and incompressible flows and is amenable to massively parallel computing environments. The approach provides a general framework for performing highly efficient and discretely consistent sensitivity analysis for problems involving arbitrary combinations of overset unstructured grids that may be static, undergoing rigid or deforming motions, or any combination thereof. General parent–child motions are also accommodated, and the accuracy of the implementation is established using an independent verification based on a complex-variable approach. The methodology is used to demonstrate aerodynamic optimizations of a wind-turbine geometry, a biologically inspired flapping wing, and a complex helicopter configuration subject to trimming constraints. The objective function for each problem is successful...
Self-Excited Limit Cycles in an Integral-Controlled System With Backlash

In this technical note, we study the properties of self-excited limit cycles in an integral-controlled system containing a play operator. A Newton-Raphson algorithm is formulated to calculate the limit cycles, and we prove that the amplitude and period of these limit cycles have linear relationships to system parameters. These results are confirmed in simulation, where we demonstrate the ability to predict the properties of the limit cycles.
Corrosion of Aluminum Nitride (AlN) in Aqueous Cleaning Solutions

The corrosion of aluminum nitride (AlN) in aqueous solutions has been evaluated in situ, using an ammonium/ammonia ion-selective electrode. The corrosion behavior of AlN over a pH range of 5.5–12 indicates that the corrosion products that are formed act as a protective barrier layer in the pH regime where they have the lowest stability. An insoluble barrier layer is formed via the oxidation of the AlN surface in air at a temperature of 750°C for 10 min. This oxynitride layer, which is 200 A thick, prevents the corrosion of the AlN in a pH 9.5 aqueous solution; however, the thermal conductivity is reduced by 6.6%.
Rh(III)-catalyzed regioselective synthesis of pyridines from alkenes and α,β-unsaturated oxime esters.

α,β-Unsaturated O-pivaloyl oximes are coupled to alkenes by Rh(III) catalysis to afford substituted pyridines. The reaction with activated alkenes is exceptionally regioselective and high-yielding. Mechanistic studies suggest that heterocycle formation proceeds via reversible C–H activation, alkene insertion, and a C–N bond formation/N–O bond cleavage process.
The enumerability of P collapses P to NC

We show that one cannot rule out even a single possibility for the value of an arithmetic circuit on a given input using an NC algorithm, unless P collapses to NC (i.e., unless all problems with polynomial-time sequential solutions can be efficiently parallelized). In other words, excluding any possible solution in this case is as hard as actually finding the solution. The result is robust with respect to NC algorithms that err (i.e., exclude the correct value) with small probability. We also show that P collapses all the way down to NC1 when the characteristic of the field that the problem is over is sufficiently large (but in this case under a stronger elimination hypothesis that depends on the characteristic).
Maintenance of multiple corpora lutea in superovulated-prepubertal heifers following hysterectomy

Abstract Fourteen 6-mo-old crossbred heifers were used to study the effects of hysterectomy on corpora lutea (CL) function in prepubertal heifers. A series of follicle stimulating hormone (FSH) injections were given to induce multiple ovulations. Five d after the last injection of FSH, all animals were laparotomized, number of CL were recorded and the uteri were removed from six heifers. Blood samples were taken from all 14 animals at 28-d intervals over a 224-d period and serum progesterone concentrations were measured. Signs of behavioral estrus were not observed in the superovulated-hysterectomized (SO-H) heifers but estrous avtivity was observed in all superovulated-intact (SO-I) heifers. All heifers were slaughtered at 13 to 14 mo of age and ovaries were collected and observed for multiple corpora lutea (MCL). Four of six SO-H heifers had MCL, while the SO-I heifers had no more than one CL per ovary. In the SO-I heifers, MCL present at surgery regressed within 28 d as indicated by lack of serum progesterone at this time. The overall mean serum progesterone of SO-H heifers was higher (P
On optimizing discrete Morse functions

In 1998, Forman introduced discrete Morse theory as a tool for studying CW complexes by producing smaller, simpler-to-understand complexes of critical cells with the same homotopy types as the original complexes. This paper addresses two questions: (1) under what conditions may several gradient paths in a discrete Morse function simultaneously be reversed to cancel several pairs of critical cells, to further collapse the complex, and (2) which gradient paths are individually reversible in lexicographic discrete Morse functions on poset order complexes. The latter follows from a correspondence between gradient paths and lexicographically first reduced expressions for permutations. As an application, a new partial order on the symmetric group recently introduced by Remmel is proven to be Cohen-Macaulay.
Iodosobenzoate-functionalized surfactant vesicles: adjustable reactivity in reactive phosphate cleavage

Abstract The reactivity of vesicular iodosobenzoate surfactant 3 toward p-nitrophenyldiphenyl phosphate is strongly potentiated in covesicles with dihexadecyldimethylammonium bromide, 2 .
The vinylogous conia rearrangement: A masked ene reaction

Abstract A novel carbocyclic thermal rearrangement of 4-substituted 2-cyclohexen-1-ones is suggested to involve a 'masked' ene reaction and provides a facile route to spirocyclic cyclohexenone systems.
A manifesto for the computational method

We promote the much maligned computational method. The computational method is a paradigm for proving mathematical results where the burden of doing the "grunt work" is given to our able research assistant, the computer. We assert that proofs using the computational method, also known as computer aided proofs, are here to stay. In fact, the use of a computer can make the analysis of complicated algorithms fun. We illustrate the usefulness of the method by analyzing a randomized algorithm for multi-processor scheduling with rejection. More specifically, we present a randomized algorithm which is 1.44127-competitive. The best previously known result is a 1.5-competitive algorithm.
General solution for the optimal trajectory of an AFE-type spacecraft

The Aeroassisted Flight Experiment (AFE) involves the Space Shuttle-based launch and subsequent recovery of an experimental spacecraft, simulating a transfer from GEO to LEO. One such AFE transfer is presently considered under assumed conditions of identical orbital planes, circular initial and final orbits, and given initial phase angle in conjunction with a free final phase angle. The aeroassisted trajectory involves preatmospheric, GEO-to-entry, postatmospheric, and exit-to-LEO phases; the optimal trajectory is obtained by minimizing the total characteristic velocity.
Endocrine maturation and lung function in premature neonates of women with diabetes

Because respiratory distress syndrome may result, in part, from a hormonal deficiency in the developing fetus, we investigated the endocrine milieu of 28 infants of women with diabetes who were delivered prematurely (34 to 37 weeks of gestation). The umbilical serum concentrations of estrone, estradiol, estriol, cortisol, and prolactin in infants of women with diabetes who developed respiratory distress syndrome ( n = 6) were lower than those in infants of women with diabetes who had normal lung function. Serum hormone levels in age-matched newborns of normal women were higher than those in the infants of women with diabetes with respiratory distress syndrome but were not different than those in the infants of women with diabetes with normal lung function. Plasma glucose levels were highest in women whose neonates developed respiratory distress syndrome. An inverse correlation existed between maternal glucose levels and lecithin-sphingomyelin ratios in amniotic fluid. Thus diabetes occasionally results in significantly delayed maturation of the fetal endocrine milieu. In these instances, delayed fetal lung maturation is a frequent occurrence. Moreover, both phenomena may be related to the extent of diabetic control during pregnancy.
Do Small Classes Reduce the Achievement Gap between Low and High Achievers? Evidence from Project STAR

Abstract Given that previous findings on the social distribution of the effects of small classes have been mixed and inconclusive, in the present study I attempted to shed light on the mechanism through which small classes affect the achievement of low- and high-achieving students. I used data from a 4-year, large-scale, randomized experiment (project STAR) to examine the effects of small classes on the achievement gap. The sample consisted of nearly 11,000 elementary school students who participated in the experiment from kindergarten to grade 3. Meta-analysis and quantile regression methods were employed to examine the effects of small classes on the achievement gap in mathematics and reading SAT scores. The results consistently indicated that higher-achieving students benefited more from being in small classes in early grades than other students. The findings also indicated that, although all types of students benefited from being in small classes, reductions in class size did not reduce the achievemen...
Virtual Commercial Vehicle Compliance Stations: A Review of Legal and Institutional Issues

In the past 5 years, commercial vehicle travel has increased 60% on California's highways, without a corresponding increase in compliance inspection station capacity or enforcement officers. Commercial vehicles that do not comply with regulations impose significant costs on the public (e.g., costs due to pavement and structural damage to roads and catastrophic crashes). In response to these problems, the California Department of Transportation is investigating the potential application of detection and communication technology in virtual compliance stations (VCS) to improve enforcement of commercial vehicle regulations cost-effectively. This study begins with a description of the fledgling VCS research programs in North America as well more advanced international programs. Next, the results of expert interviews with key officials involved in the North American VCS programs in Kentucky, Florida, and Indiana in the United States and in Saskatchewan, Canada, are reported. This is followed by an analysis of institutional barriers to VCS implementation based on the evaluation literature on commercial vehicle electronic prescreening and red-light and speeding automated enforcement programs. The paper concludes with some key recommendations to address legal and institutional barriers to VCS deployment in the United States.
A simple proof of the unconditional security of quantum key distribution

Quantum key distribution is the best known application of quantum cryptography. Previously proposed proofs of security of quantum key distribution contain various technical subtleties. Here, a conceptually simpler proof of security of quantum key distribution is presented. The new insight is the invariance of the error rate of a teleportation channel: we show that the error rate of a teleportation channel is independent of the signals being transmitted. This is because the non-trivial error patterns are permuted under teleportation. This new insight is combined with the recently proposed quantum-to-classical reduction theorem. Our result shows that assuming that Alice and Bob have fault-tolerant quantum computers, quantum key distribution can be made unconditionally secure over arbitrarily long distances even against the most general type of eavesdropping attacks and in the presence of all types of noises.
Political Power and Aid-Tying Practices in the Development Assistance Committee Countries

This paper uses a panel of 22 OECD Development Assistance Committee countries to examine whether fragmentation of executive power and the degree of competition from the legislative branch of government increased the amount of tied aid over the period 1979–2009. Fragmentation is defined as the degree to which the costs of a dollar of aid expenditure are internalized by decision-makers and is measured as the number of decision-makers in government. Legislative competition is defined as the relative strength of the government in relation to the legislature. Three variables are used to capture this effect. The empirical results show tied aid, both in levels and as a percentage of total aid, increases as the number of decision-makers within the government increases, and decreases as the proportion of excess seats a governing coalition holds above a simple majority increases.
Structure/function relationships for basic zeolite catalysts containing occluded alkali species

Abstract The basicity and reactivity of alkali-modified zeolites were investigated in order to elucidate the role of occluded species on catalytic activity. To synthesize intrazeolite oxide or metal species, cesium acetate or cesium azide was impregnated into the pores of zeolites and decomposed in situ. To characterize the basicity of the samples, we used adsorption of iodine and carbon dioxide. The blue shift in the UV–visible spectrum of adsorbed iodine was found to increase with increasing electropositivity of the exchangeable cation, indicating greater donor strength of the zeolite framework. Cesium-exchanged zeolite X was an active catalyst for the reaction of ethylene oxide and carbon dioxide to form ethylene carbonate. For a series of faujasite-type zeolites with different loadings of occluded cesium oxide, the CO 2 uptake increased linearly with the amount of occluded Cs. The catalytic activities of the CsO x /CsX samples for the isomerization of 1-butene and dehydrogenation of 2-propanol increased linearly with the amount of excess cesium, consistent with results from the adsorption of CO 2 . A majority of the base sites on these materials exhibited a heat of CO 2 adsorption around 85 kJ mol −1 , which is much lower than the 270 kJ mol −1 seen on bulk cesium oxide. After thermal pretreatment, Na(azide) and Cs(azide) modified X zeolites catalyzed the side-chain alkylation of toluene with ethylene and the side-chain alkenylation of o -xylene with butadiene, whereas occluded cesium oxide was inactive in the reactions.
An insight into the features of the OAO-C thermal design.

The Orbiting Astronomical Observatory (OAO)-C was successfully launched into a 400-nautical mile circular orbit on Aug. 21, 1972. For this spacecraft, a unique sensitivity approach to the thermal design was developed which resulted in a predictable design - the merits of which should be considered for application on future spacecraft. The OAO-C is also serving as a test bed for the evaluation of thermal control hardware. To provide flight data for space program applications, experiments for a new coating and four different heat pipe designs are on this spacecraft. The data derived from OAO-C will be extremely valuable for such future programs as the Large Space Telescope (LST) and the Earth Observation Satellite (EOS).
Proteus mirabilis viability after lithotripsy of struvite calculi.

Purpose: We tested the hypotheses that Proteus mirabilis viability of struvite calculi differs after exposure to different lithotripsy modalities and that the photothermal mechanism of holmium:YAG lithotripsy is antibacterial. Materials and Methods: Human calculi of known struvite composition (greater than 90% magnesium ammonium phosphate hexohydrate) were incubated with P. mirabilis. Calculi were randomly distributed and fragmented with no lithotripsy (controls), or shock wave, intracorporeal ultrasonic, electrohydraulic, pneumatic, holmium:YAG or pulsed dye laser lithotripsy. After lithotripsy fragments were sonicated and specimens were serially plated for 48 hours at 38C. Bacterial counts and the rate of bacterial sterilization were compared. Results: Median bacterial counts (colony-forming units per ml.) were 8 × 10 6 in controls and 3 × 10 6 in shock wave, 3 × 10 7 in ultrasonic, 4 × 10 5 in electrohydraulic, 8 × 10 6 in pneumatic, 5 × 10 4 in holmium:YAG and 1 × 10 6 in pulsed dye laser lithotripsy cases (p Conclusions: P. mirabilis viability varies among lithotrites. The photothermal mechanism of holmium:YAG lithotripsy is antibacterial.
LIGHT-CONE SUPERSPACE AND THE FINITENESS OF THE N=4 MODEL

Superspace in light‐cone co‐ordinates takes a simple form. No auxilliary fields are necessary, and application to extended supersymmetries is straightforward. In a certain form of the light‐cone gauge, the perturbation expansion of the N=4 model is free of ultraviolet divergences. As a consequence, the β‐function vanishes in any order of perturbation theory in any gauge.
Women’s College Decisions: How Much Does Marriage Matter?

This article investigates the sequential college attendance decision of young women and quantifies the effect of marriage expectations on their decision to attend and graduate from college. A dynamic choice model of college attendance, labor supply, and marriage is formulated and structurally estimated using panel data from the NLSY79. The model is used to simulate the effects of no marriage benefits and finds that the predicted college enrollment rate will drop from 58.0% to 50.5%. Using the estimated model, the college attendance behavior for a younger cohort from the NLSY97 is predicted and used to validate the behavioral model.
Overcoming Product Inhibition in Catalysis of the Intramolecular Schmidt Reaction

A method for carrying out the intramolecular Schmidt reaction of alkyl azides and ketones using a substoichiometric amount of catalyst is reported. Following extensive screening, the use of the strong hydrogen-bond-donating solvent hexafluoro-2-propanol was found to be consistent with low catalyst loadings, which ranged from 2.5 mol % for favorable substrates to 25 mol % for more difficult cases. Reaction optimization, broad substrate scope, and preliminary mechanistic studies of this improved version of the reaction are described.
Dark Matter and Synchrotron Emission from Galactic Center Radio Filaments

The inner degrees of the Galactic center contain a large population of filamentary structures observed at radio frequencies. These so-called non-thermal radio filaments (NRFs) trace magnetic field lines and have attracted significant interest due to their hard (S_v ~ -0.1 +/- 0.4) synchrotron emission spectra. The origin of these filaments remains poorly understood. We show that the electrons and positrons created through the annihilations of a relatively light (~5-10 GeV) dark matter particle with the cross section predicted for a simple thermal relic can provide a compelling match to the intensity, spectral shape, and flux variation of the NRFs. Furthermore, the characteristics of the dark matter particle necessary to explain the synchrotron emission from the NRFs is consistent with those required to explain the excess gamma-ray emission observed from the Galactic center by the Fermi-LAT, as well as the direct detection signals observed by CoGeNT and DAMA/LIBRA.
A Brain-Machine Interface for Control of Medically-Induced Coma

Medically-induced coma is a drug-induced state of profound brain inactivation and unconsciousness used to treat refractory intracranial hypertension and to manage treatment-resistant epilepsy. The state of coma is achieved by continually monitoring the patient's brain activity with an electroencephalogram (EEG) and manually titrating the anesthetic infusion rate to maintain a specified level of burst suppression, an EEG marker of profound brain inactivation in which bursts of electrical activity alternate with periods of quiescence or suppression. The medical coma is often required for several days. A more rational approach would be to implement a brain-machine interface (BMI) that monitors the EEG and adjusts the anesthetic infusion rate in real time to maintain the specified target level of burst suppression. We used a stochastic control framework to develop a BMI to control medically-induced coma in a rodent model. The BMI controlled an EEG-guided closed-loop infusion of the anesthetic propofol to maintain precisely specified dynamic target levels of burst suppression. We used as the control signal the burst suppression probability (BSP), the brain's instantaneous probability of being in the suppressed state. We characterized the EEG response to propofol using a two-dimensional linear compartment model and estimated the model parameters specific to each animal prior to initiating control. We derived a recursive Bayesian binary filter algorithm to compute the BSP from the EEG and controllers using a linear-quadratic-regulator and a model-predictive control strategy. Both controllers used the estimated BSP as feedback. The BMI accurately controlled burst suppression in individual rodents across dynamic target trajectories, and enabled prompt transitions between target levels while avoiding both undershoot and overshoot. The median performance error for the BMI was 3.6%, the median bias was -1.4% and the overall posterior probability of reliable control was 1 (95% Bayesian credibility interval of [0.87, 1.0]). A BMI can maintain reliable and accurate real-time control of medically-induced coma in a rodent model suggesting this strategy could be applied in patient care.
Empirical Wind Turbine Load Distributions Using Field Data

In the design of land-based or offshore wind turbines for ultimate limit states, long-term loads associated with return periods on the order of the service life (20 years, usually) must be estimated. This requires statistical extrapolation from turbine load data that may be obtained by simulation or by field tests. The present study illustrates such extrapolation that uses field data from the Blyth offshore wind farm in the United Kingdom, where a 2 MW wind turbine was instrumented, and environment and load data were recorded. From this measurement campaign, the load data available are in two different formats: as 10 min statistics (referred to as "summary" data) or as full time series (referred to as "campaign" data). The characteristics of the site and environment and, hence, that of the turbine response are strikingly different for winds from the sea and winds from the shore. The load data (here, only the mudline bending moment is studied) at the Blyth site are hence separated depending on wind regime. By integrating load distributions conditional on the environment with the relative likelihood of the different environmental conditions, long-term loads associated with specified return periods can be derived. This is achieved here using the peak-over-threshold method based on campaign data but long-term loads are compared with similar estimates based on the summary data. Winds from the shore are seen to govern the long-term loads at the site. Though the influence of wave heights on turbine long-term loads is smaller than that of wind speed, there is possible resonance of tower dynamics induced by the waves; still, to first order, it is largely the wind speed and turbulence intensity that control design loads. Predicted design loads based on the campaign data are close to those based on the summary data discussed in a separate study.
A superconducting tunnel junction receiver for 345 GHz

In this paper we discuss the design, fabrication, and testing of a quasiparticle tunnel junction receiver for use at 345 GHz. The design employs small area Nb/Nb-oxide/PbInAu edge junctions in order to keep the device capacitance small and maintain a modest value for ωRNC. For optimura noise performance and beam properties the mixer is contained in a waveguide mounting structure. Our best sensitivity was obtained at 312 GHz where we measured a double sideband (DSB) noise temperature of 275 K. Noise temperatures of 400 K (DSB) or better were obtained out to 350 GHz.
Curvature sensing from a single defocused image in partially coherent light

Curvature sensing is an intensity-based technique for wavefront reconstruction using two defocused images located on the opposite sides of the focal plane. It requires either one detector placed at two consecutive axial locations or a dual path with a pair of detectors from which the sensor signal is obtained. The method yields a sensitivity comparable to that of the Hartmann test in the adjustment and evaluation of ground-based optical telescopes. We introduce the analytical framework underlying the function of a curvature sensor which operates from a single defocused image. A series of twin images is computed from the propagation law of the mutual intensity along the optical axis. The polynomial decomposition of the wavefront allows retrieval of Zernike coefficients by means of the standard least-squares algorithm. The paper concludes with a review of image sampling requirements and a discussion on the signal-to-noise ratio.
Potential diagnostics for the next-generation light sources ☆

There is continued interest in developing a diffraction-limited soft or hard x-ray source. Candidate paths include the storage-ring-based free-electron laser (FEL) and the linac-based self-amplified spontaneous emission (SASE) FEL for the two regimes, respectively. As previously discussed, target beam parameters are {sigma}{sub x,y} {approximately} 10 {micro}m, {sigma}{sub x{prime},y{prime}} = 1 {micro}rad, and {sigma}{sub t} {approximately} 1 ps (0.1 ps for the linac case). The authors report the use of few- to sub-angstrom radiation emitted by a 7-GeV beam transmitting a 198-period diagnostics undulator and a bending magnet to characterize the particle beam. A particle beam divergence as low as {sigma}{sub y{prime}} = 3.3 {micro}rad was measured using an x-ray monochromator. Additionally, a particle beam size of {sigma}{sub y} < 45 {micro}m and a bunch length of {sigma}{sub t} = 28 ps with 4-ps resolution were measured using an x-ray pinhole camera with a unique synchroscan and dual-sweep x-ray streak camera as the detector. The adjustable pinhole aperture was varied by more than a factor of 100 to assess spatial resolution and dynamic range issues in the system. These diagnostics demonstrations should scale to next-generation applications.
DARK MATTER DENSITIES DURING THE FORMATION OF THE FIRST STARS AND IN DARK STARS

The first stars in the universe form inside ~106 M ☉ dark matter (DM) halos whose initial density profiles are laid down by gravitational collapse in hierarchical structure-formation scenarios. During the formation of the first stars in the universe, the baryonic infall compresses the DM further. The resultant DM density is presented here, using an algorithm originally developed by Young to calculate changes to the profile as a result of adiabatic infall in a spherical halo model; the Young prescription takes into account the noncircular motions of halo particles. The density profiles obtained in this way are found to be within a factor of 2 of those obtained using the simple adiabatic contraction prescription of Blumenthal and colleagues. Our results hold regardless of the nature of the DM or its interactions and rely merely on gravity. If the DM consists of weakly interacting massive particles, which are their own antiparticles, their densities are high enough that their annihilation in the first protostars can indeed provide an important heat source and prevent the collapse all the way to fusion. In short, a "Dark Star" phase of stellar evolution, powered by DM annihilation, may indeed describe the first stars in the universe.
Implicit Numerical Integration of Constrained Equations of Motion Via Generalized Coordinate Partitioning

An implicit, stiffly stable numerical integration algorithm is developed and demonstrated for automated simulation of multibody dynamic systems. The concept of generalized coordinate partitioning is used to parameterize the constraint set with independent generalized coordinates. A stiffly stable, Backward Differentiation Formula (BDF) numerical integration algorithm is used to integrate independent generalized coordinates and velocities. Dependent generalized coordinates, velocities, and accelerations, as well as Lagrange multipliers that account for constraints, are explicitly retained in the formulation to satisfy all of the governing kinematic and dynamic equations. The algorithm is shown to be valid and accurate, both theoretically and through solution of an example.
Fault-signature modeling and detection of inner-race bearing faults

This paper develops a fault-signature model and a fault-detection scheme for using machine vibration to detect inner-race defects. To motivate this research, it is explained and illustrated with experimental results why fault signatures from nonouter-race defects (e.g., inner-race defects) can be less salient than those from outer-race defects. Then, a signal model is presented for the production and propagation of an inner-race fault signature; this model is then used to design an inner-race fault-detection scheme. This scheme examines machine-vibration spectra for peaks with phase-coupled sidebands occurring at a spacing predicted by the model. The proficiency of this fault-detection scheme at detecting inner-race bearing faults is then experimentally verified with results from 12 bearings representing varying degrees of fault severity.