cssi/SciSciGPT-SciSciNet huggingface dataset:
X-RAY IMAGES OF HOT ACCRETION FLOWS

We consider the X-ray emission due to bremsstrahlung processes from spherically symmetric, low radiative efficiency hot accretion flows around supermassive and galactic black holes. We calculate surface brightness profiles and Michelson visibility functions for a range of density profiles, ? ~ r-3/2+p, with 0 < p < 1, to allow for the presence of outflows. We find that although the 1?keV emitting region in these flows can always extend up to 106 Schwarzschild radii (RS), their surface brightness profiles and visibility functions are strongly affected by the specific density profile. The advection-dominated solutions with no outflows (p = 0) lead to centrally peaked profiles with characteristic sizes of only a few tens of RS. Solutions with strong outflows (p ~ 1) lead to flat intensity profiles with significantly larger characteristic sizes of up to 106RS. This implies that low-luminosity galactic nuclei, such as M87, may appear as extended X-ray sources when observed with current X-ray imaging instruments. We show that X-ray brightness profiles and their associated visibility functions may be powerful probes for determining the relevant mode of accretion and, in turn, the properties of hot accretion flows. We discuss the implications of our results for observations with the Chandra X-Ray Observatory and the proposed X-ray interferometer MAXIM.
Black Hole Accretion Disks on the Edge

The local axisymmetric stability of hydrodynamical and magnetized, nearly Keplerian gaseous accretion disks around nonrotating black holes is examined in the vicinity of the classical marginally stable orbit (at radii ~Rms). An approximate Paczynski-Wiita pseudo-Newtonian potential is used. Hydrodynamical disks are linearly unstable inside a radius that differs slightly from the classical Rms value because of finite pressure and radial stratification effects. Linear stresses associated with unstable hydrodynamical modes vanish exactly at the radius of marginal stability and are generally positive inside of that radius. When a magnetic field is introduced, however, the concept of a radius of marginal stability becomes largely irrelevant because there are linearly unstable magnetorotational modes everywhere. Associated linear stresses are positive and continuous across the region of hydrodynamical marginal stability, even for large-scale "hydro-like" modes subject only to weak magnetic tension. This conclusion is valid for arbitrarily thin disks (in ideal MHD) and it does not require a large-scale "radially connecting" magnetic field. Results on hydrodynamical diskoseismic modes trapped in deep relativistic potential wells should be revised to account for the short-wavelength Alfven-like behavior of inertio-gravity waves in magnetized disks.
Effects of Distributed Suction on an Airfoil at Low Reynolds Number

A suction distribution was designed based on Thwaites’ criterion of separation. The effectiveness of the designed suction distribution in controlling the size of the laminar separation bubble on a LA2573a airfoil was investigated. The suction distribution was capable of maintaining an unseparated laminar boundary up to the original transition location. The effects of applying different suction rates on the drag were tested. Drag reductions between 14 and 24 % were achieved. The penalty for utilizing suction was estimated by introducing an equivalent suction drag. The analysis showed that the penalty for using suction to reduce the drag was relatively small.
Decoherence, chaos, the quantum and the classical

The key ideas of the environment-induced decoherence approach are reviewed. Application of decoherence to the transition from quantum to classical in open quantum systems with chaotic classical analogs is described. The arrow of time is, in this context, a result of the information loss to the correlations with the environment. The asymptotic rate of entropy production (which is reached quickly, on the dynamical time scale) isindependent of the details of the coupling of the quantum system to the environment, and is set by the Lyapunov exponents. We also briefly outline theexistential interpretation of quantum mechanics, justifying the slogan «No information without representation».
Expanding Pd-catalyzed C-N bond-forming processes: the first amidation of aryl sulfonates, aqueous amination, and complementarity with Cu-catalyzed reactions.

The first general method for the Pd-catalyzed amination of aryl tosylates and benzenesulfonates was developed utilizing ligand 1, which belongs to a new generation of biaryl monophosphine ligands. In addition, the new catalyst system for the first time enables amidation of aryl arenesulfonates and aqueous amination protocols that do not necessitate the use of cosolvents. The substrate scope has been significantly expanded to include aryl halides containing primary amides and free carboxylic acid groups. In the case of multifunctional substrates, the Pd-catalyzed amination can provide selectivity that is complementary to the Cu-catalyzed C−N bond-forming processes.
A census of the Carina Nebula — I. Cumulative energy input from massive stars

The Carina Nebula (NGC 3372) is our richest nearby laboratory in which to study feedback through ultraviolet radiation and stellar winds from very massive stars during the formation of an OB association, at an early phase in the evolution of the surrounding proto-superbubble before supernova explosions have influenced the environment. This feedback is triggering successive generations of new star formation around the periphery of the nebula, while simultaneously evaporating the gas and dust reservoirs out of which young stars are trying to accrete material. This paper takes inventory of the combined effect from all the known massive stars that power the Carina Nebula through their total ionizing flux and integrated mechanical energy from their stellar winds. Carina is close enough and accessible enough that spectral types for individual stars are available, and many close binary and multiple systems have recently been spatially resolved, so that one can simply add them. Adopting values from the literature for corresponding spectral types, the present-day total ionizing photon luminosity produced by the 65 O stars and three WNL stars in Carina is Q H ≃ 10 51 s -1 , the total bolometric luminosity of all stars earlier than B2 is 2.5 x 10 7 L ⊙ , and the total mechanical luminosity of stellar winds is L SW ≃ 10 5 L ⊙ . The total Q H was about 25 per cent higher when η Carinae was on the main sequence, before it and its companion were surrounded by its obscuring dust shell; for the first 3 Myr, the net ionizing flux of the 70 O stars in Carina was about 150 times greater than in the Orion Nebula. About 400-500 M ⊙ has been contributed to the H II region by stellar wind mass-loss during the past 3 Myr. Values for Q H and Lsw are also given for the individual clusters Trl4, 15 and 16, and BolO and 11, which are more relevant on smaller spatial scales than the total values for the whole nebula.
The thermodynamics of ternary palladium-based solid solutions containing nickel and hydrogen

Abstract The solubility of hydrogen in Pd-Ni-H ternary solutions in equilibrium with H gas at atmospheric pressure has been measured in the temperature range 625–1250 K and in Pd-Ni “binary solvents” containing up to 80 at.% of Ni. Concomitant elastic measurements have provided data which enable the partial thermodynamic functions of the H-atoms, deduced from the solubility measurements, to be converted so as to refer to a hypothetical Pd-Ni lattice of constant specific volume. The resulting “volume corrected” functions have been discussed in terms of the cell model for ternary solutions and have been shown to vary with temperature and Ni-concentration in a manner in accord with this mode. The usual linear form of cell interaction energy spectrum has been modified by including supplemental contributions to the cell interaction energy which occur when substitutional solute atoms occupy adjacent sites on the f.c.c. Pd-Ni lattice.
Bridgehead dienes. Thermal generation of the bicyclo[3.3.1]nona-1(2),4(5)-diene (ZZ) ring system

Abstract The bicyclo[3.3.1]nona-1(1),4(5)-diene (ZZ) ring system has been generated by intramolecular Diels-Alder cycloaddition of methyl 7-methylene-non-2-yn-8-enoate. This highly strained bridgehead diene undergoes a homo 1,5-hydrogen shift to yield a [3.3.1] propellane product.
W ′ signatures with odd Higgs particles

We point out that W ′ bosons may decay predominantly into Higgs particles associated with their broken gauge symmetry. We demonstrate this in a renormalizable model where the W ′ and W couplings to fermions differ only by an overall normalization. This “meta-sequential” W ′ boson decays into a scalar pair, with the charged one subsequently decaying into a W boson and a neutral scalar. These scalars are odd under a parity of the Higgs sector, which consists of a complex bidoublet and a doublet. The W ′ and Z ′ bosons have the same mass and branching fractions into scalars, and may show up at the LHC in final states involving one or two electroweak bosons and missing transverse energy.
Sunfall: a collaborative visual analytics system for astrophysics

Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.
ELECTROSYNTHESIS OF RES4. XAS ANALYSIS OF RES2, RE2S7, AND RES4

Solutions of ReS4- undergo electro-oxidation at 0.5 V vs Ag|AgCl to give black, amorphous ReS4 via a process that can be reversed at −0.9 V. The oxidative polymerization can also be effected chemically using either I2 or ferrocenium as oxidants. X-ray absorption spectroscopy (XAS) suggests that the phases Re2S7 and ReS4 are closely related structurally. The XAS data were calibrated with studies on [ReS4]- and crystalline ReS2. For both ReS4 and Re2S7 XAS data show the presence of both S2- and S22-, with S2- being less abundant than S22-. The presence of terminal sulfides (rReS ∼ 2.14 A) was ruled out by the EXAFS analysis. Variable temperature EXAFS studies showed that ReS4 and Re2S7 convert to ReS2 as anticipated from the results of TGA experiments. These considerations, when taken together with literature precedents, led to the reformulation of Re2S7 as ReV(S)1.5(S2)1, and correspondingly ReS4 is formulated as ReV(S)1(S2)1.5. These two materials are proposed to be members of a continuum of Re(S)1.5-1(S2...
Analysis of Streamline Curvature Effects on Wall-Bounded Turbulent Flows

We deal with numerical analysis for the effects of surface curvature, particularly the concave curvature; on turbulent duct flows and boundary layers. A compressible Navier-Stokes code incorporating Reynolds stress models has been developed using a four-stage Runge-Kutta scheme. Numerical computations have been carried out for curved flows in 180-deg and 90-deg turning ducts and a turbulent boundary layer using Reynolds stress models with/without modifications to the dissipation rate (e) equation. Various modifications to the e equation are discussed. A quantitative relationship has been established between two seemingly different modifications to the e equation. It is observed that the modeling of concave curvature effect is qualitatively different from the modeling of convex curvature effect. Detailed comparisons between computations and data indicate that, to capture the strong amplification of turbulence near a concave wall, the standard e equation needs to be modified.
Novel preparation of functionalized iodotetrahydronaphthyridine, iodoazaindoline, and iodotetrahydropyridoazepine systems

Abstract A novel method, which utilizes a key halogen dance step for the preparation of iodotetrahydronaphthyridine, iodoazaindoline, and iodotetrahydropyridoazepine ring-systems is described. A variety of transformations of the iodo-functional group are also reported to demonstrate the utility of this method.
Economic insecurity in the new wave of globalization: offshoring and the labor share under varieties of capitalism

Countries subject to the same degree of exposure to globalization may experience very different levels of economic insecurity depending on social support or employment protections provided by the state or even due to insurance obtained by households. We identify five varieties of industrialized countries, characterized by national levels of ‘labor support’ and ‘strictness of employment protection,’ and analyze the importance of the role of the state in mediating the impact of globalization on economic security by estimating the relation between offshoring and the labor share of income across the OECD. We find that the effect of offshoring varies across countries depending on their regulatory structure and in particular on the degree of labor market support provided by governments. Regression analysis shows that for the countries providing ‘more support’, offshoring has a less unfavorable or more favorable effect on the labor share of national income.
Alignment of Dust with Magnetic Inclusions: Radiative Torques and Superparamagnetic Barnett and Nuclear Relaxation

We consider grains with superparamagnetic inclusions and report two new condensed matter effects that enhance the internal relaxation of the energy of a wobbling grain, namely, superparamagnetic Barnett relaxation, and an extension of the range where nuclear relaxation is important to higher frequencies. In addition, we report a new effect related to grain rotation: in situations where grains otherwise rotate subthermally subject to radiative torques, they get into a state of fast rotation in the presence of superparamagnetic inclusions. This effect enhances alignment, as fast rotating grains, unlike slowly rotating ones, exhibit the perfect alignment of grain axes with respect to the ambient astrophysical, e.g., interstellar, magnetic fields. Thus measurements of the polarization degree provide a possibility of testing whether grains have superparamagnetic inclusions.
Intermittency in branching processes

We study the intermittency properties of two branching processes, one with a uniform and another with a singular splitting kernel. The asymptotic intermittency indices, as well as the leading corrections to the asymptotic linear regime are explicitly computed in an analytic framework. Both models are found to possess a monofractal spectrum with ϕq =q − 1 and inverse logarithmic corrections. Relations with previous results are discussed.
Silica sol–gel chemistry: creating materials and architectures for energy generation and storage

There is widespread recognition that the use of energy in the twenty-first century must be sustainable. Because of its extraordinary flexibility, silica sol–gel chemistry offers the opportunity to create the novel materials and architectures which can lead to significant advances in renewable energy and energy storage technologies. In this paper, we review some of the significant contributions of silica sol–gel chemistry to these fields with particular emphasis on electrolytes and separators where sol–gel approaches to functionalization and encapsulation have been of central importance. Examples are presented in the areas of dye-sensitized solar cells, biofuel cells, proton exchange membrane fuel cells, redox flow batteries and electrochemical energy storage. Original work is also included for the sol–gel encapsulation of a room temperature ionic liquid to create a solid state electrolyte for electrochemical capacitors. In view of the critical importance of energy and the versatility of the sol–gel process, we expect the sol–gel field to play an increasingly important role in the development of sustainable energy generation and storage technologies.
The Monte Carlo—Library Least-Squares approach for energy-dispersive x-ray fluorescence analysis

Abstract A new analysis principle called Monte Carlo—Library Least-Squares (MCLLS) approach has been identified and investigated for quantitative energy dispersive x-ray fluorescence analyses. The feasibility of the MCLLS principle has been investigated with a radioisotope source excited EDXRF analytical system for several standard samples of known composition. With good initial elemental composition guesses, the MCLLS results showed excellent agreement with the elemental compositions in the standard samples. Furthermore, by taking the ratio of the photoelectric peak counts in the sample experimental spectra as approximate initial guesses, the proposed iterative MCLLS algorithm works quite well, converging to the correct elemental compositions. Only one iteration was needed for the analysis of all major elements. For trace elements a second iteration was needed in some cases. Other possible applications of the MCLLS approach and future work are also discussed.
Consolidating Corporate Control: Divisional Versus Whole-Company Leveraged Buyouts

We examine the empirical relation between firm characteristics and the likelihood of choosing a restructuring choice between two types of leveraged buyouts: a whole-company leveraged buyout (WLBO) and a divisional leveraged buyout (DLBO). Our findings suggest that firm characteristics such as volatility of cash flow and growth potential play an important role in determining a firm's restructuring choice between a WLBO and a DLBO. In particular, firms with greater volatility of cash flow and/or greater future growth potential are more likely to adopt a DLBO than a WLBO as their restructuring choice. These results are consistent with the notion that although low-growth, high-cash-flow firms would create the most value for stockholders by paying out cash and tying future cash flows to the firm's debt service through a WLBO, high-growth, low-cash-flow firms would be better off by selling assets if those assets would be better managed under a DLBO.
A check on the energy method of predicting blade transonic stall flutter

An improved structural dynamic model of an oscillating blade in two degrees of freedom is combined with an unsteady aerodynamic model for the transonic flow about a cascade with separation, which results in a coupled system. The system is solved in an iterative way between the two models. As a check on the current energy methods, the stall flutter boundaries for two real rotors are predicted by using the present method and the results are compared with the experiments and those predicted by using an energy method.
Properties of Gluons in Color Superconductors

I give an introduction to color superconductivity in cold, dense quark matter. I focus in particular on how the solution to the gap equation is qualitatively different in ordinary BCS theory with local four-fermion interactions, in theories with non-local, but screened boson exchange, and in QCD, where magnetic gluon exchange is not screened at zero temperature. I argue that a reliable computation of the gap parameter requires knowledge of the gluon self-energy in a color superconductor. As a first step to determine the gluon self-energy, I report calculations of the Debye and Meissner masses in two- and three-flavor color superconductors.
Hybrid density functional calculations of redox potentials and formation energies of transition metal compounds

We compare the accuracy of conventional semilocal density functional theory (DFT), the DFT+U method, and the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional for structural parameters, redox react ...
Optimization of a point-focusing, distributed receiver solar thermal electric system

This paper presents an approach to optimization of a solar concept which employs solar-to-electric power conversion at the focus of parabolic dish concentrators. The optimization procedure is presented through a series of trade studies, which include the results of optical/thermal analyses and individual subsystem trades. Alternate closed-cycle and open-cycle Brayton engines and organic Rankine engines are considered to show the influence of the optimization process, and various storage techniques are evaluated, including batteries, flywheels, and hybrid-engine operation.
Mild oxidation of tosylmethylisocyanide to tosylmethylisocyanate: utility in synthetic and medicinal chemistry

A convenient and efficient (one-step) oxidation is reported of commercially available tosylmethylisocyanide (TOSMIC) to form tosylmethylisocyanate, making this highly reactive bifunctional molecule a readily available synthetic reagent. Besides engaging in nucleophilic addition reactions with alcohols, amines, and thiols, tosylmethylisocyanate also reacts with carboxylic acids to form tosylmethylamides, which undergo substitution reactions in the presence of organocopper and organomagnesium reagents.
Thermal aggregation of almond protein isolate.

Abstract Almond protein isolate (API) formed a gel at 90 °C in 5 min at a concentration of 4% (w/v) in distilled deionized water adjusted to pH 8.2. The rate of API aggregation was dependent on the composition of the heating medium. Adding NaCl, NaBr, NaI, NaF, or NaSCN (each at 0.25, 0.5, 0.75, and 1 M) to the heating medium decreased the rate of thermal aggregation of API, while addition of 1 M CaCl 2 promoted it. Hydrophobic interactions helped stabilize the API against thermal aggregation. Hydrogen bonds, ionic interactions, and disulfide exchange promoted the API thermal aggregation. Contribution of disulfide exchange to the API thermal aggregation was more than that made by the hydrogen and ionic bonds.
On the Aging of Comets

This study is based primarily on the calculations of comet orbits over ~ 106 years for 160 short-period comets by Harold F. Levison and Martin J. Duncan from which there are calculated “ablation AGES”. There are positive statistical correlations (having many deviations) with radial nongravitational forces, comet activity measures, and dust-to-gas ratios in the spectra, in the sense that comets of greater “AGES” tend to be less active and to show less dust in their spectra than comets of lesser “AGES”.
Blazar 3C 454.3 in Outburst and Quiescence During 2005-2007: Two Variable Synchrotron Emission Peaks

We monitored the flaring blazar 3C 454.3 during 2005 June-July with the Spitzer Infrared Spectrograph (IRS: 15 epochs), Infrared Array Camera (IRAC: 12 epochs), and Multiband Imaging Photometer (MIPS: 2 epochs). We also made Spitzer IRS, IRAC, and MIPS observations from 2006 December to 2007 January when the source was in a low state, the latter simultaneous with a single Chandra X-ray observation. In addition, we present optical and submillimeter (sub-mm) monitoring data. The 2005-2007 period saw three major outbursts. We present evidence that the radio-optical spectral energy distribution (SED) actually consists of two variable synchrotron peaks, the primary at IR and the secondary at sub-mm wavelengths. The lag between the optical and sub-mm outbursts may indicate that these two peaks arise from two distinct regions along the jet separated by a distance of 0.9-3 pc. The flux at 5-35 μm varied by a factor of 40 and the IR peak varied in frequency from 4 × 10^(12) Hz to 4 × 10^(13) Hz between the highest and lowest states in 2005 and 2006, respectively. Variability was well correlated across the mid-IR band, with no measurable lag. Flares that doubled in flux occurred on a timescale of ~5 days, yielding a variability size of <0.05 pc. The IR SED peak moved to higher frequency as a flare brightened, then returned to lower frequency as it decayed. The fractional variability amplitude increased with frequency, which we attribute to decreasing synchrotron self-absorption optical depth. Mid-IR flares may signal the re-energization of a shock that runs into inhomogeneities along the pre-existing jet or in the external medium. The synchrotron peak frequencies during each major outburst may depend upon both the distance from the jet apex and the physical conditions in the shocks. Variation of the Doppler parameter along a curved or helical jet is another possibility. Frequency variability of the IR synchrotron peak may have important consequences for the interpretation of the blazar sequence, and the presence of a secondary peak may give insight into jet structure.
Gas permeability through thin-foil x-ray filters

We have measured the permeation rates of helium and water through thin-foil UV-blocking filters used in the ASTRO-E/X-Ray Spectrometer (XRS) instrument. In the XRS program, there is a concern that outgassed contaminants such as water could permeate through the outermost filter, which will be at room temperature, and freeze on the inner filters, which will be at cryogenic temperatures. The filters tested consisted of ~ 1000 A Al on ~ 1000 A of either Lexan or polyimide. Results discussed include the permeation rate as a function of pressure difference across a filter, the ratio of helium to water permeation rate, and the effect of the aluminum layer thickness on permeation.
Parliament as a wealth-maximizing institution: The right to the residual and the right to vote

What could explain the emergence of parliament and its ascendancy? I argue that dictatorial kings encountered difficulties in securing the cooperation of their subjects because they could not commit not to confiscate subjects' gains. Where the gain from cooperation increased and kings were more secure, they deliberately gave up some of their power to be able to commit themselves to keep their promises.
Diagnosability Analysis of Multi-Station Manufacturing Processes

Variation propagation in a multi-station manufacturing process (MMP) is described by the theory of "Stream of Variation. " Given that the measurements are obtained via ertai sensor distribution scheme, the problem of whether the stream of variation of an MMP is diagnosable is of great interest to both academia and industry. We present a comprehensive study of the diagnosability of MMPs in this paper It is based on the state space model and is parallel to the concept of observability in control theory. Analogous to the observability matrix and index, the diagnosability matrix and index are first defined and then derived for MMP systems. The result of diagnosability study is applied to the evaluation of sensor distribution strategy. It can also be used as the basis to develop an optimal sensor distribution algorithm. An example of a three-station assembly process with multifixture layouts is presented to illustrate the methodology.
Classification of personal information for privacy protection purposes

Laws now in effect require protection of individual privacy in personal information record-keeping systems maintained by the federal government and by several states. These requirements will be extended to the private sphere in the future. It is necessary for their implementation in record-keeping systems to establish a standard sensitivity scale and classification system for personal information. This paper surveys several classification systems that have been discussed in the literature, examines the criteria for setting up such systems, proposes a new sensitivity scale and corresponding classification system, discusses the information integrity and security provisions that should be adequate for each classification level, and examines the problems that arise in assigning sensitivity and classification levels to personal information items, records, and record-keeping systems.
The role of gravity concentration in modern processing plants

Abstract Next to hand picking, gravity concentration is the oldest of all forms of mineral processing. While, in the twentieth century gravity concentration has been partially replaced by other processes, notably flotation and magnetic separation, they have not made it obsolete. That such an ancient and inherently simple process has not only survived, but thrived, is in part due to its very simplicity. Not only is gravity concentration the process of choice in small, remote, artisanal plants, it also continues to play a major role in larger, “modern” plants for the concentration of many minerals, literally from A (andelusite) to Z (zircon). This paper will review some of the advances in gravity concentration equipment and technology, that has allowed it to keep pace with, and grow, in what is becoming an increasingly competitive world. Various examples of modern equipment, and their potential application will be given. The paper will serve to challenge the mineral processing engineer to ask himself: “can gravity concentration solve my problem too?”
Chern classes of Schubert cells and varieties

We give explicit formulas for the Chern-Schwartz-MacPherson classes of all Schubert varieties in the Grassmannian of d-planes in a vector space, and conjecture that these classes are effective. We prove this is the case for d ≤ 2.
Copper-catalyzed Hiyama coupling of (hetero)aryltriethoxysilanes with (hetero)aryl iodides.

A CuI-catalyzed Hiyama coupling was achieved, which proceeds in the absence of an ancillary ligand for aryl–heteroaryl and heteroaryl–heteroaryl couplings. A P,N-ligand is required to obtain the best product yields for aryl–aryl couplings. In addition to facilitating transmetalation, CsF is also found to function as a stabilizer of the [CuAr] species, potentially generated as an intermediate after transmetalation of aryltriethoxysilanes with CuI-catalysts in the absence of ancillary ligands.
Analysis of Crossed Wires in a Plane-Wave Field

The currents and charges induced in a pair of electrically thin crossed wires by a normally incident plane electromagnetic wave are derived by analytical methods. The boundary conditions at the ends and at the junction are explained. The solution of a new integro-differential equation for the currents is obtained in terms of trigonometric and integral-trigonometric functions. Depending on the electrical lengths of the crossed elements and location of their junction a variety of quite different distributions of current and charge obtain. These determine the scattered near and far fields. Graphs of computed currents and charges per unit length on the four arms of several important cases are displayed. The accurate determination of the induced currents and charges on a mathematically tractable structure-the thin-wire cross-is an early step in a study that will proceed to electrically thick cylinders, wide strips, and their junctions in crossed configurations in an effort to gain a meaningful approximate understanding of the currents and charges induced on an aircraft by an electromagnetic pulse.
A Finite Element Analysis For Stiffness of Fixture Units

This paper presents a systematic finite element model to predict the fixture unit stiffness by introducing nonlinear contact elements on the contact surface between fixture components. The contact element includes three independent springs: two in tangential directions and one in the normal direction of the contact surface. Strong nonlinearity is caused by possible separation and sliding between two fixture components. The problem is formulated by the penalty function method and is solved by the Newton-Raphson procedure. The model was validated by two cases of analysis of a linear cantilever beam and a simple fixture unit with two components. The results are in agreement with the corresponding analytical solution of beams and the previous experimental results for fixture in the literature.
On the Relationship Between Comets and Minor Planets

Although the majority of the minor planets evidently arose as the result of fragmentation of larger planetary objects through collisions, there is a certain amount of evidence that some of them may be defunct cometary nuclei. Opik (e.g. 1963) has long felt that the Apollo asteroids, with their perihelia inside the orbit of the earth, are especially likely to be ex-comets. Their aphelia are well inside the orbit of Jupiter (unlike those of the short-period comets), but this could be explained by the action of nongravitational forces when they were comets, just as the secular acceleration of P/Encke has apparently caused that comet’s aphelion distance to decrease to the present 4.1 AU. The radii of these objects, 1 to 5 km or so, are quite comparable with those of cometary nuclei (Roemer, 1966); further, Wetherill (1968, 1969) has shown that large meteoroids, and in particular chondritic meteorites, apparently come from typically cometary orbits with perihelia near the orbit of the earth and aphelia near that of Jupiter.
A novel key management scheme using biometrics

Key management is one of the most important issues in cryptographic systems. Several important challenges in such a context are represented by secure and efficient key generation, key distribution, as well as key revocation. Addressing such challenges requires a comprehensive solution which is robust, secure and efficient. Compared to traditional key management schemes, key management using biometrics requires the presence of the user, which can reduce fraud and protect the key better. In this paper, we propose a novel key management scheme using iris based biometrics. Our newly proposed scheme outperforms traditional key management schemes as well as some existing key-binding biometric schemes in terms of security, diversity and/or efficiency.
Leptonic Fritzsch matrices and neutrino oscillations

Abstract It was recently shown by the authors that the Fritzsch Ansatz for the quark mass matrices prescribed at the supersymmetric grand unified scale is compatible with a moderately heavy top quark ( m t ⋍ 120–150 GeV ) . Here we extend the Ansatz to incorporate the charged leptons and the neutrinos. It is found that the ν e − ν μ mixing angle is small and consistent with the MSW solution of the solar neutrino puzzle. Furthermore, the model predicts observable ν μ − ν τ oscillations with sin 2 2θ μτ ⋍ 0.1 and ν τ mass in the 1–3 eV range.
Some thoughts on saddle-point conditions and information structures in zero-sum differential games

For a very simple two-stage, linear-quadratic, zero-sum difference game with dynamic information structure, we show that (i) there exist nonlinear saddle-point strategies which require the same existence conditions as the well-known linear, closed-loop, no-memory solution and (ii) there exist both linear and nonlinear saddle-point strategies which require more stringent conditions than the unique open-loop solution. We then discuss the implication of this result with respect to the existence of saddle points in zero-sum differential games for different information patterns.
The Extent of Repeated Migration: An Analysis Based on the Danish Population Register

Abstract Migration and duration of residence data in the continuous population registers of Copenhagen, Denmark, have been analyzed to ascertain the extent to which repeated migration is a factor in accounting for high mobility rates. The findings, based on the period 1950–1961, support the view suggested by several American studies that stability of residence is characteristic of a large majority of the population. Stability is most typical of the young and the older age groups and least common among those 25–44 years of age, both male and female. But even for the middle age range, at least 70 per cent of the population was stable. The findings also emphasize that the pattern of repeated mobility is most characteristic of a limited segment of the population, a group which shows a particularly strong tendency to move several times over relatively short time spans. This pattern is particularly characteristic of those in the 25–44 year age group. These data emphasize, therefore, that a high degree of reside...
Convection cells induced by spontaneous symmetry breaking

Ubiquitous in nature, convection cells are a clear signature of systems out-of-equilibrium. Typically, they are driven by external forces, like gravity (in combination with temperature gradients) or shear. In this article, we show the existence of such cells in possibly the simplest system, one that involves only a temperature gradient. In particular, we consider an Ising lattice gas on a square lattice, in contact with two thermal reservoirs, one at infinite temperature and another at T. When this system settles into a non-equilibrium stationary state, many interesting phenomena exist. One of these is the emergence of convection cells, driven by spontaneous symmetry breaking when T is set below the critical temperature.
Three-body systems with attractive 1/r potentials

We have used the hyperspherical adiabatic representation to describe the system of three identical bosons in a spin stretched state interacting through an attractive $1∕r$ potential. A proposal has been forwarded to enable the experimental realization of such a system in cold trapped atoms using extremely off-resonant laser fields [Phys. Rev. Lett., 84, 5687 (2000)]. We have obtained the effective potentials, channel functions, and nonadiabatic couplings for this gravitylike interaction, allowing us to calculate the ground-state energy with accuracy that substantially improves upon previous results. We have similarly calculated the energies for the first four ${0}^{+}$ excited states. These results show that the simple adiabatic hyperspherical approximation offers an accurate description for such a system. Further, since the effective potentials have a long-range $1∕R$ attraction, the properties of the excited states follow from the well-known results for Rydberg states. We have also analyzed the possible geometries and vibrational modes for this system.
Constructing Lefschetz-type fibrations on four-manifolds

We show how to construct broken, achiral Lefschetz fibrations on arbitrary smooth, closed, oriented 4‐manifolds. These are generalizations of Lefschetz fibrations over the 2‐sphere, where we allow Lefschetz singularities with the non-standard orientation as well as circles of singularities corresponding to round 1‐handles. We can also arrange that a given surface of square 0 is a fiber. The construction is easier and more explicit in the case of doubles of 4‐manifolds without 3‐ and 4‐handles, such as the homotopy 4‐spheres arising from nontrivial balanced presentations of the trivial group. 57M50; 57R17
Implantable hemodynamic monitors.

The evaluation and management of volume status in patients with heart failure is a challenge for most clinicians. In addition, such an evaluation is possible only during a personal clinician–patient interface. The ability to acquire hemodynamic data continuously with the help of implanted devices with remote monitoring capability can provide early warning of heart failure decompensation and thus may aid in preventing hospitalizations for heart failure. The data obtained also may improve the understanding of the disease process. It is important for the clinician treating patients who have heart failure to become acquainted with this type of technology and learn to interpret and use these data appropriately. This article reviews the implantable hemodynamics monitors currently available.
The directed reduction of β-hydroxy ketones employing Me4NHB(OAc)3

Abstract The diastereoseiective reduction of a range of acyclic β-hydroxy ketones with triacetoxyborohydride is described. In all cases, the anti 1,3-diol diastereomer is the principal product (eq 1).
Homo-Roche Ester Derivatives By Asymmetric Hydrogenation and Organocatalysis

Asymmetric hydrogenation routes to homologues of The Roche ester tend to be restricted to hydrogenations of itaconic acid derivatives, that is, substrates that contain a relatively unhindered, 1,1-disubstituted alkene. This is because in hydrogenations mediated by RhP2 complexes, the typical catalysts, it is difficult to obtain high conversions using the alternative substrate for the same product, the isomeric trisubstituted alkenes (D in the text). However, chemoselective modification of the identical functional groups in itaconic acid derivatives are difficult; hence, it would be favorable to use the trisubstituted alkene. Trisubstituted alkene substrates can be hydrogenated with high conversions using chiral analogs of Crabtree’s catalyst of the type IrN(carbene). This paper demonstrates that such reactions are scalable (tens of grams) and can be manipulated to give optically pure homo-Roche ester chirons. Organocatalytic fluorination, chlorination, and amination of the homo-Roche building blocks was p...
Algols as limits on binary evolution scenarios

Evolutionary scenarios must account for Algol binaries surviving their first phase of mass transfer. The outcome of this phase is dependent upon the rapidity of the initial mass transfer, which can be estimated by calculating the radial reponse of potential progenitors to mass loss. Limits on the donor’s evolutionary state, and its companion mass, can be placed on systems which would transfer mass on a thermal or dynamical timescale. Slower mass transfer rates are necessary for the successful transition to an Algol. Considering 1.5 and 5.0 M⊙ models, the former succeed in case A and Br systems, while the latter can do so only in case A systems. To evolve into an Algol binary, all systems seem to require initial mass ratios near one.
EXACT FORMULAS FOR PRICING BONDS AND OPTIONS WHEN INTEREST RATE DIFFUSIONS CONTAIN JUMPS

I develop Heath-Jarrow-Morton extensions of the Vasicek and Jamshidian pure-diffusion models, extend these models to incorporate Poisson-Gaussian interest rate jumps, and obtain closed-form models for valuing default-free, zero-coupon bonds and European call and put options on default-free, zero-coupon bonds in a market where interest rates can experience discontinuous information shocks. The jump-diffusion pricing models value the instrument as the probability-weighted average of the pure-diffusion model prices, each conditional on a specific number of jumps occurring during the life of the instrument. I extend the models to coupon-bearing instruments by applying Jamshidian's serial-decomposition technique.
Are REIT IPOs Unique? The Global Evidence

Previous studies of real estate investment trust (REIT) IPOs have focused primarily on REITs listed in the U.S. These studies in general find that, unlike industrial firm IPOs, REIT IPOs in the U.S. exhibit an abnormally low initial-day return and mixed long-run performance. Our study examines this puzzle using a large sample of 370 REIT IPOs from four continents (14 different countries) during the 1996–2010 period. We find that (1) the newly-established REITs in other countries exhibit similar initial-day return pattern as in the U.S., (2) the low initial-day return might be caused by the fund-like structure of REITs and the re-deployable assets (real estate) they hold, (3) the slightly positive initial-day return is offset by the poor performance in the 190 days subsequent to the IPO, and (4) the change in U.S. REIT IPO performance before and after 1990 is likely due to a change in the REIT structure.
Sedation and Sleep Disturbances in the ICU

Sedation in the ICU is, paradoxically, both a cause and a potential treatment for the sleep disruption almost universally observed in the critically ill. A patient-focused sedation strategy that minimizes unnecessary medication, avoids medication withdrawal, addresses the specific impediments to sleep, and serves as an adjunct to attentive environmental control may ultimately serve patients best.
On the origin of stellar masses

It has been a longstanding problem to determine, as far as possible, the characteristic masses of stars in terms of fundamental constants; the almost complete invariance of this mass as a function of the star-forming environment suggests that this should be possible. Here I provide such a calculation. The typical stellar mass is set by the characteristic fragment mass in a star-forming cloud, which depends on the cloud's density and temperature structure. Except in the very early universe, the latter is determined mainly by the radiation released as matter falls onto seed protostars. The energy yield from this process is ultimately set by the properties of deuterium burning in protostellar cores, which determines the stars' radii. I show that it is possible to combine these considerations to compute a characteristic stellar mass almost entirely in terms of fundamental constants, with an extremely weak residual dependence on the interstellar pressure and metallicity. This result not only explains the invariance of stellar masses, it resolves a second mystery: why fragmentation of a cold, low-density interstellar cloud, a process with no obvious dependence on the properties of nuclear reactions, happens to select a stellar mass scale such that stellar cores can ignite hydrogen. Finally, the weak residual dependence on the interstellar pressure and metallicity may explain recent observational hints of a smaller characteristic mass in the high-pressure, high-metallicity cores of giant elliptical galaxies.
Pair Production From Nuclear Collisions and Cosmic Ray Transport

Modern cosmic ray transport codes, that are capable of use for a variety of applications, need to include all significant atomic, nuclear and particle reactions at a variety of energies. Lepton pair production from nucleus–nucleus collisions has not been included in transport codes to date. Using the methods of Baur, Bertulani and Baron, the present report provides estimates of electron–positron pair production cross sections for nuclei and energies relevant to cosmic ray transport. It is shown that the cross sections are large compared to other typical processes such as single neutron removal due to strong or electromagnetic interactions. Therefore, lepton pair production may need to be included in some transport code applications involving MeV electrons.
Cohen-Macaulay quotients of normal semigroup rings via irreducible resolutions

Every quotient R/I of a semigroup ring R by a radical monomial ideal I has a unique minimal injective-like resolution by direct sums of quotients of R modulo prime monomial ideals. The quotient R/I is Cohen-Macaulay if and only if every summand in cohomological degree $i$ has dimension exactly dim(R/I) - i. This Cohen-Macaulay characterization reduces to the Eagon-Reiner theorem by Alexander duality when R is a polynomial ring. The proof exploits a graded ring-theoretic generalization of the Zeeman spectral sequence, thereby also providing a combinatorial topological version for polyhedral cell complexes, involving no commutative algebra.
Stereoselective oligomerizations catalyzed by lipases in organic solvents

Abstract Lipases have been found to act as stereoselective catalysts in polycondensation reactions between racemic diesters and achiral diols (or vice versa) in organic solvents. Optically active trimers andpentamers have been formed as a result.