cssi/SciSciGPT-SciSciNet huggingface dataset:
The determination of the prognosis of pregnancy in rheumatic heart disease.

Abstract In determining the prognosis in pregnancy of 142 women with rheumatic heart disease, the following factors were considered: duration of rheumatic fever, age, functional capacity, history of previous failure, type of valvular damage, size of heart, nature of earlier rheumatic manifestations, and parity. It was found that the important signs were those which helped prognosticate congestive failure. That failure is the governing feature in prognosis is supported by the observations (1) that it is the most common cause of death in pregnancy complicated by rheumatic heart disease and (2) that the infant mortality rate for our group of patients with congestive heart failure was three times as high as for patients who had heart disease without failure and four times as high as for normal pregnant women delivered on the same obstetrical service. The factors found to be important in prognosticating failure and in estimating the risk involved in pregnancy form integral parts of a basic principle, which consists of establishing the patient's position in the natural course of her rheumatic heart disease. This principle gains validity when data collected under wellcontrolled conditions indicate that pregnancy per se does not alter the course of this disease. The application of this principle for determining prognosis led to interruption (per vagina) of only eleven of 142 pregnancies. No hysterotomies were performed after the patient was permitted to pass through the first trimester of pregnancy. There were no deaths from congestive heart failure among the 129 patients who remained under our care through pregnancy and parturition.
Fast geometric approximation techniques and geometric embedding problems

Abstract Given an undirected n-vertex graph G and a set of n points in R d, we wish to embed the vertices of G onto the points so as to minimize the total embedded edge length. Important special cases of this geometric embedding problem as those in which G is a binary tree, a cycle, or a star. We give fast approximation algorithms for embedding these graphs on the line and in the plane in several metrics. Our principal techniques are: a notion of “approximate geometric sorting” that can be computed in linear time, and fast approximation schemes for the minimum spanning tree problem in the plane. We expect that these approximation techniques can be applied to many geometric problems besides the embedding problem. We give the example of approximating the convex hull of a set of points in the plane.
Attracting structures in volcanic ash transport

Abstract Volcanic ash clouds are a natural hazard that poses direct threats to aviation safety. Many volcanic ash transport and dispersion (VATD) models have been developed to forecast trajectories of volcanic ash clouds and to plan safety measures in the events of eruptions. Predictions based on these models are heavily dependent on accuracy of wind fields and initial parameters of ash plumes. However, these data of high accuracy are usually difficult to obtain, leading to possible inaccurate predictions of ash clouds trajectories using VATD models. In this study, a new method is developed to predict volcanic ash transport. In contrast to many existing VATD models that simulate the evolution of volcanic ash clouds, the new method focuses on the overall properties of the wind field in which volcanic particles are transported and correlates particle motion to the attracting structures that dictate the transport. As demonstrated in the study of Eyjafjallajokull eruption in Iceland in April, 2010, these structures act as attractors in the atmosphere towards which volcanic ash particles are transported. These attracting structures are associated with hazard zones with high concentrations of volcanic ash. The advantages of the method are that the attracting structures are independent of particle source parameters and are less prone to inaccuracy in the wind field than particle trajectories. The new approach provides the hazard maps of volcanic ash, and is able to help improve long-term predictions and to plan flight route diversions and ground evacuations.
Newton solution of inviscid and viscous problems

The application of Newton iteration to inviscid and viscous airfoil calculations is examined. Spatial discretization is performed using upwind differences with split fluxes. The system of linear equations which arises as a result of linearization in time is solved directly using either a banded matrix solver or a sparse matrix solver. In the latter case, the solver is used in conjunction with the nested dissection strategy, whose implementation for airfoil calculations is discussed. The boundary conditions are also implemented in a fully implicit manner, thus yielding quadratic convergence. Complexities such as the ordering of cell nodes and the use of a far field vortex to correct freestream for a lifting airfoil are addressed. Various methods to accelerate convergence and improve computational efficiency while using Newton iteration are discussed. Results are presented for inviscid, transonic nonlifting and lifting airfoils and also for laminar viscous cases.
Eugene Wigner, Nuclear Engineer

Wigner led the design of the Hanford nuclear reactors and founded a school to teach reactor physics to people working in industry.
1000°C Phase Relations and Superconductivity in the (Nd‐Ce‐Cu)‐O Ternary System

The phase relations involving the 24 K n-type Nd2-xCexCuO4 superconductor were investigated at 1000°C in air. The terminal solid solubility was confirmed to be x= 0.2. This solid solution is the only ternary phase in the Nd2O3–CeO2–CuO diagram. A binary (1 −y)CeO2–yNdO1.5 solid solution exists out to y= 0.4. Phase diagrams for NdO1.5–CeO2–CuO (1000°C) and NdO1.5–CeO2 (900° to 1500°C) are presented.
2-Amino-4,6-diarylpyridines as novel ligands for the estrogen receptor.

Abstract We have prepared a novel series of 2-amino-4,6-diarylpyridines that function as ligands of estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). These compounds bind to both ERα and ERβ with a modest selectivity for the alpha subtype. The most potent of these analogues, compound 19, has a Ki=20 nM at ERα. These molecules represent a novel template for designing potentially useful ligands for the estrogen receptor.
Norms extremal with respect to the Mahler measure

Abstract In this paper, we introduce and study several norms which are constructed in order to satisfy an extremal property with respect to the Mahler measure. These norms are a natural generalization of the metric Mahler measure introduced by Dubickas and Smyth. We show that bounding these norms on a certain subspace implies Lehmerʼs conjecture and in at least one case that the converse is true as well. We evaluate these norms on a class of algebraic numbers that include Pisot and Salem numbers, and for surds. We prove that the infimum in the construction is achieved in a certain finite dimensional space for all algebraic numbers in one case, and for surds in general, a finiteness result analogous to that of Samuels and Jankauskas for the t -metric Mahler measures.
Spin transport and relaxation in graphene

Abstract We review our recent work on spin injection, transport and relaxation in graphene. The spin injection and transport in single layer graphene (SLG) were investigated using nonlocal magnetoresistance (MR) measurements. Spin injection was performed using either transparent contacts (Co/SLG) or tunneling contacts (Co/MgO/SLG). With tunneling contacts, the nonlocal MR was increased by a factor of ∼1000 and the spin injection/detection efficiency was greatly enhanced from ∼1% (transparent contacts) to ∼30%. Spin relaxation was investigated on graphene spin valves using nonlocal Hanle measurements. For transparent contacts, the spin lifetime was in the range of 50–100 ps. The effects of surface chemical doping showed that for spin lifetimes in the order of 100 ps, charged impurity scattering (Au) was not the dominant mechanism for spin relaxation. While using tunneling contacts to suppress the contact-induced spin relaxation, we observed the spin lifetimes as long as 771 ps at room temperature, 1.2 ns at 4 K in SLG, and 6.2 ns at 20 K in bilayer graphene (BLG). Furthermore, contrasting spin relaxation behaviors were observed in SLG and BLG. We found that Elliot–Yafet spin relaxation dominated in SLG at low temperatures whereas Dyakonov–Perel spin relaxation dominated in BLG at low temperatures. Gate tunable spin transport was studied using the SLG property of gate tunable conductivity and incorporating different types of contacts (transparent and tunneling contacts). Consistent with theoretical predictions, the nonlocal MR was proportional to the SLG conductivity for transparent contacts and varied inversely with the SLG conductivity for tunneling contacts. Finally, bipolar spin transport in SLG was studied and an electron–hole asymmetry was observed for SLG spin valves with transparent contacts, in which nonlocal MR was roughly independent of DC bias current for electrons, but varied significantly with DC bias current for holes. These results are very important for the use of graphene for spin-based logic and information storage applications.
The propagation and growth of whistler mode waves generated by electron beams in earth's bow shock

In this study, the propagation and growth of whistler mode waves generated by electron beams within earth's bow shock is investigated using a planar model for the bow shock and a model electron distribution function. Within the shock, the model electron distribution function possesses a field-aligned T greater than T beam that is directed toward the magnetosheath. Waves with frequencies between about 1 and 100 Hz with a wide range of wave normal angles are generated by the beam via Landau and anomalous cyclotron resonances. However, because the growth rate is small and because the wave packets traverse the shock quickly, these waves do not attain large amplitudes. Waves with frequencies between about 30 and 150 Hz with a wide range of wave normal angles are generated by the beam via the normal cyclotron resonance. The ray paths for most of these waves are directed toward the solar wind although some wave packets, due to plasma convection travel transverse to the shock normal. These wave packets grow to large amplitudes because they spend a long time in the growth region. The results suggest that whistler mode noise within the shock should increase in amplitude with increasing upstream theta sub Bn. The study provides an explanation for the origin of much of the whistler mode turbulence observed at the bow shock.
Latitudinal variation of middle atmospheric density and temperature

Abstract Profiles of the latitudinal distribution of middle atmospheric density and temperature have been obtained from a ground based remote sensing instrument. A two color Rayleigh/Raman lidar, built at Penn State University, was part of the LADIMAS (Latitudinal Distribution of Middle Atmospheric Structure) campaign. The goal was to measure density, temperature, and trace constituents from the troposphere to the thermosphere on a global scale. Measurements were taken from 70° North to 65° South latitude during a three month period between September 1991 and January 1992. The data provides a unique opportunity to study the latitudinal variations of the mean temperature and the variability in the atmospheric structure. Comparisons of the atmospheric conditions to models, such as the CIRA atmospheric model, were made to study the deviations.
On the adaptive elastic-net with a diverging number of parameters

We consider the problem of model selection and estimation in situations where the number of parameters diverges with the sample size. When the dimension is high, an ideal method should have the oracle property (Fan and Li, 2001; Fan and Peng, 2004) which ensures the optimal large sample performance. Furthermore, the high-dimensionality often induces the collinearity problem which should be properly handled by the ideal method. Many existing variable selection methods fail to achieve both goals simultaneously. In this paper, we propose the adaptive Elastic-Net that combines the strengths of the quadratic regularization and the adaptively weighted lasso shrinkage. Under weak regularity conditions, we establish the oracle property of the adaptive Elastic-Net. We show by simulations that the adaptive Elastic-Net deals with the collinearity problem better than the other oracle-like methods, thus enjoying much improved finite sample performance.
Obliquity Tides on Hot Jupiters

Obliquity tides are a potentially important source of heat for extrasolar planets on close-in orbits. Although tidal dissipation will usually reduce the obliquity to zero, a nonzero obliquity can persist if the planet is in a Cassini state, a resonance between spin precession and orbital precession. Obliquity tides might be the cause of the anomalously large size of the transiting planet HD 209458b.
Silicate Emission Profiles from Low-Mass Protostellar Disks in the Orion Nebula: Evidence for Growth and Thermal Processing of Grains

We present 8-13 μm low-resolution spectra (R ≈ 100) of eight low-mass protostellar objects ("proplyds") in the Orion Nebula using the Long Wavelength Spectrometer at the W. M. Keck Observatory. All but one of the sources in our sample show strong circumstellar silicate emission, with profiles that are qualitatively similar to those seen in some T Tauri and Herbig Ae/Be stars. The silicate profile in all cases is significantly flattened compared with the profile for typical interstellar dust, suggesting that the dominant emitting grains are significantly larger than those found in the interstellar medium. The 11.3-to-9.8 μm flux ratio—often used as an indicator of grain growth—is in the 0.8-1.0 range for all of our targets, indicating that the typical grain size is around a few microns in the surface layers of the attendant circumstellar disk for each object. Furthermore, the silicate profiles show some evidence of crystalline features, as seen in other young stellar objects. The results of our analysis show that the grains in the photoevaporating protostellar disks of Orion have undergone significant growth and perhaps some annealing, suggesting that grain evolution for these objects is not qualitatively different from other young stellar objects.
Study on structure formation of short polyethylene chains via dynamic Monte Carlo simulation

Abstract Monte Carlo (MC) simulations of structure formation for short polyethylene chains at low temperature are performed based on a recent developed method that uses coarse-grained chains on a high coordination lattice. Local short-range interactions based on rotational isomeric state (RIS) model and long-range interactions obtained from Lennard–Jones (LJ) potential are introduced during the simulation. Properties evaluated from the simulations are the mean square dimensions, anisotropy of the radius of gyration tensor, local conformation determined by the occupancy of trans state and orientation correlation functions, energy of the system, and chain packing reflected by the pair correlation functions and structure factors. All of these parameters reveal an ordering process that produces an approximation to a hexagonal crystal phase. The hexagonal structure is imposed by the presence of a diamond lattice underlying the high coordination lattice on which the simulation is performed. Folding of the chains in the crystal is mandatory, because they have fully extended lengths in excess of the dimension of the simulated periodic box. Nevertheless, the simulations demonstrate that a high degree of crystallinity can be achieved in reasonable computer time. The simulation technique should be applicable to other choices of periodic boundary conditions that do not affect the results as strongly as in the present case.
Studies of defects and surfaces by channeling

Uses of channeling to study defects and surfaces are reviewed briefly with emphasis on ways in which they are currently evolving. Consideration is first given to normalization of yields for channeling directions to the yield for a random direction, this normalization being important to the accuracy of both defect and surface studies. The discussion of atom location concentrates on the use that can be made of quantitative calculations of flux peaking. The treatment of surfaces includes accurate determination of the area of the surface peak as well as basic ways of extracting from experiments information on the positions of surface atoms.
Total Synthesis of Enantiopure Phalarine via a Stereospecific Pictet−Spengler Reaction: Traceless Transfer of Chirality from l-Tryptophan

An appropriately constructed 2-substituted derivative of l-tryptophan undergoes conversion to a prephalarine structure in a single step. The reaction occurs in a diastereoselective fashion, leading shortly thereafter to the naturally occurring version of the alkaloid phalarine.
Effect of Regret on Post-choice Valuation: The Case of More Than Two Alternatives

The author examines the influence of experienced regret on the selection of the reference point used in post-choice valuation. He incorporates two reference points, expected performance and performance of the forgone alternative, the former affecting the amount of satisfaction and the latter affecting the amount of regret experienced by a decision maker. Prior research on regret has assumed only a two-alternative choice set with the forgone alternative being the reference point for measuring regret. The author relaxes that assumption and develops hypotheses to examine the selection of the reference point in cases that more closely represent real-life experience (i.e., choice sets with more than two alternatives). Two studies are reported. The results from the first study support most of the hypotheses. The second study further investigated the selection of a reference point. Several theoretical and managerial implications are discussed and future research directions are suggested.
Are the Virial Masses of Clusters Smaller than We Think

The constraints that the available X-ray spectral and imaging data place on the mass distribution and mass to light ratio of rich clusters are considered. It was found for the best determined cases that the mass to light ratio is less than 125 h sub 50 at radii exceeding 1 h sub 50 Mpc. The mass to light ratio is approximately constant at radii exceeding 1 h sub 50 Mpc but may rise to values of roughly 200 h sub 50 in the central regions. The fraction of the total mass that is in baryons, primarily the hot X-ray emitting gas, is roughly 30% thus setting the mass to light ratio of the dark material to roughly 70. The model that fits the X-ray data for Coma is in good agreement with the observed optical velocity dispersion vs. radius data.
The effects of PtxSi growth on the redistribution of p-type dopants in silicon

Abstract The redistribution of p-type dopants (boron and indium) during Pt x Si growth was studied as a function of annealing time using secondary ion mass spectrometry. It was found that both boron and indium atoms redistribute into the silicide during a thermal anneal. Initially, the dopant becomes trapped at the Pt x SiSi interface and concomitantly getters to defect sites located at the moving PtPt x Si interface. Even after silicide formation is complete, the dopant continues to out-diffuse to the surface via an enhanced mechanism due to defects and/or grain boundaries. Finally, no evidence for a “snowplow” effect was observed for either boron or indium at the implant dose of 2 × 10 13 ions cm −2 .
Diels–Alder and ene reactions of singlet oxygen, nitroso compounds and triazolinediones: transition states and mechanisms from contemporary theory

Singlet oxygen, nitroso compounds and triazolinediones have similar electronic structures: they share a low lying LUMO, making them powerful electrophiles, and a high lying HOMO, orthogonal to the LUMO and consisting of an antibonding combination of lone pairs. This bestows some nucleophilic character on these species. We describe a number of studies employing the best levels of theory currently available for systems of this size and demonstrate that the Diels–Alder and ene reactions of these three species are calculated to show subtle changes in mechanism. The calculations have been calibrated, wherever possible, by comparison to experimental observations including measured activation and reaction energies, regio- and stereo-selectivities, intermediates observed either spectroscopically or by trapping, and kinetic isotope effects.
Automatic Derivation of the Irrationality of e

As part of a project on automatic generation of proofs involving both logic and computation, we have automatically generated a proof of the irrationality of e. The proof involves inequalities, bounds on infinite series, type distinctions (between real numbers and natural numbers), a subproof by mathematical induction, and significant mathematical steps, including correct simplification of expressions involving factorials and summing an infinite geometrical series. Metavariables are instantiated by inference rules embodying mathematical knowledge, rather than only by unification. The proof is generated completely automatically, without any interactive component.
S986 in M67: A Totally Eclipsing Binary at the Cluster Turnoff

We have discovered that the star S986 in the old open cluster M67 has detectable total eclipses of depth 0.08 mag for the primary eclipse and 0.011 mag for the secondary eclipse (in I only). We confirm the detection of a third star in spectra contributing (11.5 ± 1.5)% of the total light in V band. The radial velocity of the third star indicates that it is a cluster member, but it is unclear whether it is physically associated with the eclipsing binary. Using spectroscopic and photometric data, we deconvolve the photometry of the three stars and find that the primary star in the eclipsing binary is significantly hotter than the turnoff. The two most likely explanations are that the primary star is in a rapid phase of evolution near core hydrogen exhaustion (associated with the turnoff gap in M67's color-magnitude diagram) or that it is a blue straggler created during a stellar collision earlier in the cluster's history. Our detection of Li in the primary star tightly constrains possible formation mechanisms in the blue straggler explanation. Because S986 is often used to constrain tidal dissipation models, this may imply that the strength of tidal effects is underestimated.
The Bulletin of the Geological Society of America and Charles Doolittle Walcott

Charles Doolittle Walcott, who became the third Director of the U.S. Geological Survey and the fourth Secretary of the Smithsonian Institution, was author of a paper in volume 1, number 1, of the Bulletin of the Geological Society of America . From 1890 through 1906, he published six scientific papers, one abstract, eight discussions, and a presidential address in that journal. Examination of these four categories of publication helps trace the history of the Society and the Bulletin through their early years. Walcott made a very few errors of fact and of judgment in the six papers. Notwithstanding those, the quality and breadth of the papers demonstrate that he was a geologist of wide-ranging interests and confirm his importance in American geology; only part of his scientific activities during this 16-year interval were published in the Bulletin . The subsequent impact of Walcott9s scientific papers is included in this historical review.
A muon collider scenario based on stochastic cooling

Abstract The most severe limitation to the muon production for a large-energy muon collider is the short time allowed for cooling the beam to dimensions small enough to provide reasonably high luminosity. The limitation is caused by the short lifetime of the particles that, for instance, at the energy of 100 GeV is of only 2.2 ms. Moreover, it appears to be desirable to accelerate the beam quickly, with very short bunches of about a millimeter so it can be made immediately available for the final collision. This paper describes the requirements of single-pass, fast stochastic cooling for very short bunches. Bandwidth, amplifier gain and Schottky power do not seem to be of major concern. Problems do arise with the ultimate low emittance that can be achieved, the value of which is seriously affected by the front-end thermal noise. Since mixing within the beam bunches is completely absent, methods are required for the regeneration of the beam signal with external and powerful magnetic lenses. The feasibility of these methods are crucial for the development of the muon collider. These methods will be studied in a subsequent report.
Forests, frames, and games: Algorithms for matroid sums and applications

This paper presents improved algorithms for matroid-partitioning problems, such as finding a maximum cardinality set of edges of a graph that can be partitioned intok forests, and finding as many disjoint spanning trees as possible. The notion of a clump in a matroid sum is introduced, and efficient algorithms for clumps are presented. Applications of these algorithms are given to problems arising in the study of the structural rigidity of graphs, the Shannon switching game, and others.
The Littlewood-Offord problem and invertibility of random matrices

Abstract We prove two basic conjectures on the distribution of the smallest singular value of random n × n matrices with independent entries. Under minimal moment assumptions, we show that the smallest singular value is of order n − 1 / 2 , which is optimal for Gaussian matrices. Moreover, we give a optimal estimate on the tail probability. This comes as a consequence of a new and essentially sharp estimate in the Littlewood–Offord problem: for i.i.d. random variables X k and real numbers a k , determine the probability p that the sum ∑ k a k X k lies near some number v . For arbitrary coefficients a k of the same order of magnitude, we show that they essentially lie in an arithmetic progression of length 1 / p .
Sand Production Management

Sand production may be inevitable in many fields that have a relatively low formation strength. Sand erosion and settling predictions and sand monitoring are important elements of any effective sand production management strategy. Sand erosion predictions are used to establish tolerable sand production rates, and, thus, well productivity, and to develop cost-effective inspection frequency for critical components. Prediction of critical flow rate to prevent sand settling is important for flowlines that are not designed for pigging. Quantitative sand monitoring is essential in verifying the effectiveness of sand control procedures and in generating an important input parameter for erosion and sand settling predictions. This paper presents equations for predicting sand erosion rate and sand settling flow rate, and assesses the accuracy of these equations In addition, the paper presents an assessment of the sensitivity of commercially available nonintrusive acoustic and intrusive electrical resistance sand monitors.
The role of an information analysis center in software engineering technology transfer

As software engineering advances into its second decade, the ideas, principles and practices conceived in its first decade need to be assimilated into a workable set of tools and techniques that can be dispersed to software developers for their use in the production of software. The need for this technology transfer is clear and immediate. Without the proper transfer of software engineering technology from software engineering researcher to developer, the software world will be unable to extricate itself from its present predicament. This predicament has been characterized by Meyers as follows:"The general character of the software predicament can be seen clearly, although consistent numbers with which to characterize it more precisely are hard to come by. Because less expensive hardware is bringing more applications within economic reach, the amount of software to be developed is increasing. Also because more software is already in existence, there is more to be maintained. But the productivity of programmers is improving rather slowly, especially by the standards of hardware price/performance, with the result that the overall cost of software development is tending to increase".
Low-State Gamma-Ray Emission from Blazars and the Gamma-Ray Background

We examine the contribution of flat spectrum radio sources (FSRSs), or blazars, to the diffuse gamma-ray background (DGRB), prompted by the association of the extragalactic γ-ray sources detected by the EGRET instrument aboard the Compton Gamma Ray Observatory (CGRO) with this class of objects by using their well-studied log N-log S distribution. The basic assumption of our study are that (1) there exists steady state γ-ray emission at the EGRET energy band from the entire population of FSRSs with γ-ray luminosity that is proportional to their radio luminosity, i.e., (νFν)100 MeV = f(νFν)5 GHz; (2) the ensemble of blazars produce the DGRB. Under these assumptions, the estimated average value of the proportionality constant is f 70, compared to a mean observed value of fobs 750 seen among the EGRET-detected blazars. We explore the implications of this result for AGN models and address the results that should be achieved by the next generation of γ-ray satellites.
Membership On Editorial Boards And Finance Department Rankings

We examine membership on editorial boards of sixteen leading finance journals in 1985, 1990, 1995, and 2000. Membership on a board of a high-quality journal is highly selective. Editors and members of editorial boards of quality journals are trusted by their peers who submit their research for publication consideration. Thus, the number of faculty represented on editorial boards of quality journals should provide a quality indication of the finance department. We use membership representation to provide a ranking of finance departments adjusted for department size and journal quality.
Design Method for Buckling Amplified Piezoelectric Actuator Using Flexure Joint and its Application to an Energy Efficient Brake System

This paper shows a practical design method for a displacement amplification mechanism for a piezoelectric actuator which employs a buckling-like phenomenon. This mechanical singularity realizes a substantial displacement magnification, at least 50 times, within a simple structure. An SMA preload mechanism essentially provides potential for full range push-pull actuation to the piezoelectric actuator. This integrated actuator performs a high energy transfer ratio and is suitable for brake mechanisms due to their requirement of high force, specific displacement and energy efficiency. A practical design method is shown and is evaluated by comparing the analytical model with finite element analysis and experimental hardware performance. The actuator properties obtained by these methods fit well each other with errors less than 13%.The experimental actuators are applied to a brake for a commercial motor and its properties are evaluated. The brake can produce more than 2.5Nm in the displacement range of 0.5mm. These experimental results suggest that this novel piezoelectric actuator has potential for use in a wide range of applications.Copyright © 2012 by ASME
Hadamard products of product operators and the design of gradient-diffusion experiments for simulating decoherence by NMR spectroscopy

An extension of the product operator formalism of NMR is introduced, which uses the Hadamard matrix product to describe many simple spin 1/2 relaxation processes. The utility of this formalism is illustrated by deriving NMR gradient-diffusion experiments to simulate several decoherence models of interest in quantum information processing, along with their Lindblad and Kraus representations.
New β-linked pyrrole monomers: approaches to highly stable and conductive electrochromic polymers☆

An efficient synthetic route to β-linked dipyrrole monomers has been developed. Electrochemical polymerization of these monomers leads to the incorporation of polycyclic aromatic residues into a polymer backbone. The resulting conjugated polymer films are electroactive, robust electrochromic materials that are highly delocalized in their oxidized forms.
TAU 98 conference summary

Abstract I very briefly review the highlights of the fifth workshop on the physics of the tau lepton and its neutrino. There has been much progress in many sub-fields, which I touch upon in this review: the couplings of the tau to the Z 0 and W ± ; the leptonic branching fractions, lifetime, and tests of universality; the Lorentz structure of tau decays; searches for neutrinoless decays; limits on weak and electromagnetic dipole moments and CP violation; inclusive semi-hadronic decays, spectral functions, sum rules, QCD, and applications; substructure in tau decays to three pseudoscalars; tau decays to kaons; limits on the mass of the tau neutrino; tau neutrinos from solar, atmospheric, and AGN sources; accelerator searches for neutrino oscillations; and prospects for the future.
New Collections of p-Subgroups and Homology Decompositions for Classifying Spaces of Finite Groups

We define new collections of p-subgroups for a finite group G and p a prime dividing its order. We study the homotopy relations among them and with the standard collections of p-subgroups and determine their ampleness and sharpness properties.
Super-resolution imaging via spatiotemporal frequency shifting and coherent detection

Diffraction limit is manifested in the loss of high spatial frequency information that results from decay of evanescent waves. As a result, conventional far-field optics yields no information about an object's subwavelength features. Here we propose a novel approach to recovering evanescent waves in the far field, thereby enabling subwavelength-resolved imaging and spatial spectroscopy. Our approach relies on shifting the frequency and the wave vector of near-field components via scattering on acoustic phonons. This process effectively removes the spatial frequency cut-off for unambiguous far field detection. This technique can be adapted for digital holography, making it possible to perform phase-sensitive subwavelength imaging. We discuss the implementation of such a system in the mid-IR and THz bands, with possible extension to other spectral regions.
Eptifibatide: a potent inhibitor of the platelet receptor integrin glycoprotein IIb/IIIa

The platelet glycoprotein (GP) IIb/IIIa integrin plays a key role in mediating platelet aggregation. Blockade of the platelet GP IIb/IIIa receptor prevents arterial thrombosis in animal models much better than does aspirin. Among the most specific inhibitors in this class of drugs is eptifibatide (Integrilin(TM), Millennium Pharmaceuticals, Inc.), a cyclic heptapeptide based on a peptide recognition sequence found in snake venom. Peptide inhibitors, such as eptifibatide, bind competitively to GP IIb/IIIa and have a short half-life, allowing the effect to be rapidly reversible and providing a favourable overall safety profile. Eptifibatide has been studied in a broad range of ischaemic coronary conditions including percutaneous coronary intervention (PCI), ST-segment and non-ST-segment acute myocardial infarction (MI) and unstable angina. In PCI and non-ST-segment MI, therapy with eptifibatide has been shown to reduce acute ischaemic complications without any increased risk of life-threatening adverse events. In the recently reported Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy (ESPRIT) trial, two 180 microg/kg boluses of eptifibatide, 10 min apart, followed by an 18 - 24 h infusion at 2 microg/kg/min given as adjunctive therapy in non-urgent PCI reduced the 30-day composite of death, MI and need for urgent target vessel revascularisation from 10.4 to 6.8% compared with placebo. These results were achieved under conditions of typical contemporary PCI, namely the implantation of second- and third-generation stents deployed at high balloon pressures along with modern adjunctive pharmacological treatment, particularly the universal use of thienopyridines and lower-dose heparin. Few significant pharmacological effects other than inhibition of platelet aggregation and the effect on bleeding time have been reported. Future research will focus on alternative clinical applications and combinations with other therapies to further improve cardiovascular outcomes.
Constraining the Beaming of Gamma-Ray Bursts with Radio Surveys

The degree of beaming in gamma-ray bursts (GRBs) is currently unknown. The uncertainty in the γ-ray-beaming angle, θb, leaves the total energy release ( ∝ θ2b) and the event rate per galaxy ( ∝ θ−2b) unknown to within orders of magnitude. Since the delayed radio emission of GRB sources originates from a mildly relativistic shock and receives only weak relativistic beaming, the rate of radio-selected transients with no GRB counterparts can be used to set an upper limit on θ−2b. We find that a VLA survey with a sensitivity of ~0.1 mJy at 10 GHz could identify 2 × 104(θb/10°)−2 radio afterglows across the sky if each source is sampled at least twice over a period of 1 month or longer. From the total number of 0.1 mJy sources observed at 8.44 GHz and the fraction of fading sources at 1.44 GHz, we get the crude limit θb 6°.
Robust adaptive control of linearizable nonlinear single input systems with guaranteed error bounds

In this paper, a nonlinear robust adaptive control algorithm is designed and analyzed for a class of single-input nonlinear systems with unknown nonlinearities. The controller employs a single layer neural network to estimate the unknown plant nonlinearities on-line. The proposed controller is continuous and guarantees closed-loop semi-global stability and convergence of the tracking error to a small residual set. Furthermore, it handles the situation where the estimated plant becomes uncontrollable without any restrictive assumptions. In contrast to previous work on the same subject, the size of the residual tracking error can be specified a priori and is guaranteed by choosing certain design parameters. A procedure for choosing these parameters is presented. An example is used to demonstrate the performance and properties of the proposed scheme.
HCN synthesis from CH4, NH3, and O2 on clean Pt☆

Abstract Rates of reactions in HCN synthesis were measured between 0.01 and 10 Torr on clean Pt foils between 600 and 1500 K in a steady state flow reactor attached to an analysis system equipped with AES for surface analysis. Addition of O2 to a 1:1 CH4:NH3 mixture at foil temperatures between 1000 and 1400 K caused the HCN production to fall while NO rose to become the dominant product. The CO production rate was lower than that of NO, and very small amounts of CO2 were formed. AES showed that addition of O2 produces a reduction of surface carbon from approximately a monolayer to a small coverage. Oxygen appears to react with NH3 to form NO faster than with CH4 to form CO. However, NO is capable of reacting with CH4 to produce HCN so that NH3 does not oxidize totally to N2. The rates of CH4 oxidation and the rate of formation of HCN from CH4 and NO were also examined. Individual rates are fit to Langmuir-Hinshelwood models, and the rates and selectivities predicted by the rate equations agree well with experiments. These results indicate that under the conditions of industrial HCN synthesis HCN is produced mostly by the NH3 + CH4 and CH4 + NO reactions.
INFORMATION-PRESERVING BLACK HOLES STILL DO NOT PRESERVE BARYON NUMBER AND OTHER EFFECTIVE GLOBAL QUANTUM NUMBERS

It has been claimed recently that the black hole information-loss paradox has been resolved: the evolution of quantum states in the presence of a black hole is unitary and information preserving. We point out that, contrary to some claims in literature, information-preserving black holes still violate the baryon number and any other quantum number which follows from an effective (and thus approximate) or anomalous symmetry.
Matrix Multiplication Using Coherent Optical Techniques

A method for real-time matrix multiplication is presented. This paper describes the geometrical interpretation of the mathematical manipulations between the two matrices. Three coherent optical astigmatic systems are developed based on the analysis. Each system is essentially composed of two subsystems that are con-nected in series. The first one performs multiplications between the corresponding elements of the matrices coded in the amplitude transmittance of the transparencies. The results are received by the second subsystem that performs the necessary summation operations to give the calculated rise to each element in the final result, the product of the two matrices. In these processes, no preparation of a hologram or intermediate memory is required. The operations are done in parallel. The multiplication between an N x N matrix and an N x 1 vector is presented in detail. The possibility of multiplication between N x N and N x N matrices is also discussed.© (1977) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Catalytic iron-mediated ene carbocyclizations: formal [4+4]-ene reactions of triene esters☆

Abstract 2-Substituted-2,7,9-decatrienoates undergo an iron-catalyzed carbocyclization to yield trans -disubstituted cyclopentanes in moderate-to-good chemical yields. The cyclization products are formally the result of a [4+4]-ene reaction in which cis -propenyl and 2-acroyl functionalities are introduced as appendages to the newly formed cyclopentane ring by the cyclization. Triene ester substrates bearing an alkyl substituent at the 4- or 6-positions cyclize with high 1,2-stereoinduction to yield trisubstituted cyclopentanes in which the relative stereochemistry between three contiguous stereocenters is controlled.
Optimal Charging Profiles with Minimal Intercalation-Induced Stresses for Lithium-Ion Batteries Using Reformulated Pseudo 2-Dimensional Models

aDepartment of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, Missouri 63130, USA bCFD Research Corporation, Biomedical and Energy Technologies, Huntsville, Alabama 35806, USA cDepartment of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA dDepartment of Chemical Engineering, Clean Energy Institute, University of Washington, Seattle, Washington 98195, USA
Effect of Hydrostatic Pressure on Indentation Modulus

The high pressures generated at a contact during nanoindentation have a quantifiable effect on the measured indentation modulus. This effect can be accounted for by invoking a Murnaghan equation of state-based analysis where the measured indentation modulus is a function of the hydrostatic component of the stress state which is generated beneath the indenter tip. This approach has implications pertinent to a range of mechanical characterization techniques that include instrumented indentation and quantitative atomic force microscopy (AFM) since these techniques traditionally consider only zero-pressure modulus values during data interpretation. To demonstrate the validity of this approach, the indentation modulus of four materials (fused quartz, sapphire, rutile and silicon) is evaluated using a 1 μm radius conospherical diamond tip to maximum contact depths of 30 nm. The tip area function is independently determined via AFM while the unloading stiffness from the load-displacement data is determined using standard Oliver-Pharr analysis.
Spatial Impact of a Slender Beam

In this paper the dynamics of the spatial impact of a slender beam is analyzed. The equations of motion are calculated using Kane's impact method. The generalized momentum and generalized impulse of the beam are considered to find the equations of motion of the beam. The frictional phenomenon at the contact point is analyzed. For the case of impact without slipping, it is used the assumption that the tangential component of the velocity of separation is null. In the case with slipping, the tangential impulse (at the plane of impact) is computed. The sliding direction after impact is calculated. A simulation of the impact of beam with a surface is developed and the velocity of separation, force of impact and kinetic energy of the beam after impact are studied for different incident angles of the beam. The incident angle is varied from 0 deg to 57 deg. The results are function of the incident angle of impact.
The catalytic action of adsorbed thiocyanate ions and thiourea in the electron transfer from glassy carbon to solid copper(I) selenide and copper(I) sulfide particles

Abstract Thiocyanate ions and thiourea molecules enhance the reversibility of the reduction of copper(I) selenide Cu 2 Se and copper(I) sulfide Cu 2 S which are immobilised on a glassy carbon electrode. This behaviour is explained by the adsorption of SCN − ions and thiourea on the surface of copper(I) chalcogenites and their bridging function in an inner-sphere electron transfer reaction from the solid glassy carbon to the solid sample particles. Model calculations show that both electrocatalysts decrease the resistance for the electron transfer across the glassy carbon/Cu 2 Se (Cu 2 S) interface and simultaneously increase the rate constant of this process. This is the first example of an inner-sphere solid-to-solid electron transfer reaction.
Particle heating by Alfvenic turbulence in hot accretion flows

Recent work on Alfvenic turbulence by Goldreich & Sridhar (GS) suggests that the energy cascades almost entirely perpendicular to the local magnetic field. As a result, the cyclotron resonance is unimportant in dissipating the turbulent energy. Motivated by the GS cascade, we calculate the linear collisionless dissipation of Alfven waves with frequencies much less than the proton cyclotron frequency, but with perpendicular wavelengths of order the Larmor radius of thermal protons. In plasmas appropriate to hot accretion flows (proton temperature much greater than electron temperature), the dissipated Alfven wave energy primarily heats the protons. For a plasma with β 5, however, where β is the ratio of the gas pressure to the magnetic pressure, the MHD assumptions utilized in the GS analysis break down before most of the energy in Alfven waves is dissipated; how the cascade then proceeds is unclear. Hot accretion flows, such as advection-dominated accretion flows (ADAFs), are expected to contain significant levels of MHD turbulence. This work suggests that, for β 5, the Alfvenic component of such turbulence primarily heats the protons. Significant proton heating is required for the viability of ADAF models. We contrast our results on particle heating in ADAFs with recent work by Bisnovatyi-Kogan & Lovelace.
Core domains of shared decision-making during psychiatric visits: scientific and preference-based discussions

Shared decision-making (SDM) is imperative to person-centered care, yet little is known about what aspects of SDM are targeted during psychiatric visits. This secondary data analysis (191 psychiatric visits with 11 providers, coded with a validated SDM coding system) revealed two factors (scientific and preference-based discussions) underlying SDM communication. Preference-based discussion occurred less. Both provider and consumer initiation of SDM elements and decision complexity were associated with greater discussions in both factors, but were more strongly associated with scientific discussion. Longer visit length correlated with only scientific discussion. Providers’ understanding of core domains could facilitate engaging consumers in SDM.
Nitroxide synthesis using the methyltrioxorhenium/hydrogen peroxide system

Some secondary amines of varying structural type have been oxidized by the methyltrioxorhenium/hydrogen peroxide system to the corresponding nitroxides in excellent yield. These results, coupled with our earlier work using this system, indicate the striking parallel between this chemistry and that of the dioxiranes. While the yields in the dioxirane and methyltrioxorhenium/hydrogen peroxide methods are comparable, the latter method must be regarded as superior since it is catalytic. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:347–350, 1998