cssi/SciSciGPT-SciSciNet huggingface dataset:
Analysis of a bounding box heuristic for object intersection

Bounding boxes are commonly used in computer graphics and other fields to improve the performance of algorithms that should process only the intersecting objects. A bounding-box-based heuristic avoids unnecessary intersection processing by eliminating the pairs whose bounding boxes are disjoint. Empirical evidence suggests that the heuristic works well in many practical applications, although its worst-case performance can be bad for certain pathological inputs. What is a pathologi- cal input, however, is not well understood, and consequently there is no guarantee that the heuristic will always work well in a specific application. In this paper, we analyze the performance of bounding box heuristic in terms of two natural shape parameters, aspect ratio and scale factor. These parameters can be used to realistically measure the degree to which the objects are pathologically shaped. We derive tight worst-case bounds on the performance for bounding box heuristic. One of the significant contributions of our paper is that we only require that objects be well shaped on average. Somewhat surprisingly, the bounds are significantly different from the case when all objects are well shaped.
Electronic functionalization of the surface of organic semiconductors with self-assembled monolayers

Self-assembled monolayers (SAMs) are widely used in a variety of emerging applications for surface modification of metals and oxides. Here, we demonstrate a new type of molecular self-assembly: the growth of organosilane SAMs at the surface of organic semiconductors. Remarkably, SAM growth results in a pronounced increase of the surface conductivity of organic materials, which can be very large for SAMs with a strong electron-withdrawing ability. For example, the conductivity induced by perfluorinated alkyl silanes in organic molecular crystals approaches 10(-5) S per square, two orders of magnitude greater than the maximum conductivity typically achieved in organic field-effect transistors. The observed large electronic effect opens new opportunities for nanoscale surface functionalization of organic semiconductors with molecular self-assembly. In particular, SAM-induced conductivity shows sensitivity to different molecular species present in the environment, which makes this system very attractive for chemical sensing applications.
National and international information networks in science and technology

The 20th Century has been variously called the atomic age; the age of the second industrial revolution and the century of the computer. However the historians choose to label this period, it is clear that science and technology has had a central role and a significant impact on our society. Research and engineering are no longer considered esoteric disciplines, for their products are clearly visible. Although the importance of science has been recognized and accepted for many years, only now are we becoming concerned with the results of these scientific activities. It is not enough to produce new knowledge; the information must be made available so that it can be tested, evaluated, and applied for the benefit of the community.
Adaptive control using neural networks and approximate models

The NARMA model is an exact representation of the input-output behavior of finite-dimensional nonlinear discrete-time dynamical systems in a neighborhood of the equilibrium state. However, it is not convenient for purposes of adaptive control using neural networks due to its nonlinear dependence on the control input. Hence, quite often, approximate methods are used for realizing the neural controllers to overcome computational complexity. In this paper, we introduce two classes of models which are approximations to the NARMA model, and which are linear in the control input. The latter fact substantially simplifies both the theoretical analysis as well as the practical implementation of the controller. Extensive simulation studies have shown that the neural controllers designed using the proposed approximate models perform very well, and in many cases even better than an approximate controller designed using the exact NARMA model. In view of their mathematical tractability as well as their success in simulation studies, a case is made in this paper that such approximate input-output models warrant a detailed study in their own right.
Laser-Assisted Machining of Reaction Sintered Mullite Ceramics

The present study focuses on the evaluation of the laser-assisted machining (LAM) of pressureless sintered mullite ceramics. Due to mullite's low thermal diffusivity and tensile strength, a new method for applying laser power is devised to eliminate cracking and fracture of the workpiece during laser heating. The LAM process is characterized in terms of cutting force, surface temperature, chip morphology, tool wear, surface roughness and subsurface damage for a variety of operating conditions. Estimated material removal temperatures and the ratio of the feed force to the main cutting force are used to determine material removal mechanisms and regimes for brittle fracture and semi-continuous and continuous chip formation. Surface roughness and subsurface damage are compared between typical parts produced by LAM and grinding. Tool wear characteristics are investigated for variations in laser power, and hence material removal temperature, during LAM of mullite with carbide tools.
Amorphous silicon technology: Coming of age

Abstract This paper describes the current status of hydrogenated amorphous silicon (a-Si:H) based solar cell technology and the evolution to its “coming of age”. Several features which are unique to the a-Si:H technology are reviewed as well as the advances in concurrently improving materials, cell design and manufacturing. Future developments in this technology, whose impact is not only felt in the photovoltaic field but also in the huge market of liquid crystal displays, are also discussed.
Monte Carlo Simulations of Light Scattering by Composite Particles in a Planetary Surface

Abstract Composite particles containing internal scatterers have been proposed as an explanation for the fact that most photometric studies of planetary surfaces based on Hapke's bidirectional reflectance model have found the planetary particles to exhibit moderately backscattering phase functions. However, an implicit assumption made in this explanation is that the scattering by composite particles containing multiple internal inclusions in a planetary surface can still be adequately computed using standard radiative transfer theory assuming the composite particles to be the fundamental scattering unit even though the particles are necessarily in close proximity to each other. This assumption was explored by J. K. Hillier (1997, Icarus 130 , 328–335) using a Monte Carlo routine. However, in this initial study several simplifying assumptions were made. The internal scatterers were assumed to be isotropic and scattering off of the surface and absorption within the composite particle were ignored. While these assumptions are not very realistic, it was believed that the study could still provide insight into the light scattering by such surfaces. Here we relax these assumptions in order to examine the light scattering by more realistic particles. Almost all of the conclusions reached in the earlier paper remain valid. As before, we find that classical radiative transfer (assuming a random distribution of scattering particles) coupled with the assumption that the composite particle is the fundamental scatterer provides a good approximation in the high porosity limit. However, even for porosities as high as 90% the effects of close packing are clearly seen with the radiative transfer calculation underestimating the scattering by ∼10% at high phase angles. In contrast to the earlier study we find that the radiative transfer calculation tends to overestimate, not underestimate, the scattering at high emission but moderate phase angles. As the porosity is lowered further, the discrepancy becomes more severe and can reach 100% or greater. In particular, our main conclusion remains intact: the parameters derived using the classical radiative transfer theory will yield results intermediate between those of the composite as a whole and those of the internal scatterers and thus one should exercise caution in interpreting the results of models based on classical radiative transfer theory in terms of the physical properties of the surface particles.
Exchange Interaction in Alloys with Cerium Impurities

Starting with the Anderson model for the $4{f}^{1}$ configuration of cerium, the transformation of Schrieffer and Wolff is performed, taking into account combined spin and orbit exchange scattering. The resultant interaction Hamiltonian differs qualitatively from the conventional $s\ensuremath{-}f$ exchange interaction. The Kondo effect, the spin-disorder resistivity, the Ruderman-Kittel interaction, and the depression of the super-conducting transition temperature with impurity concentration are worked out for alloys containing cerium impurities on the basis of this new interaction.
Stereoselective SN2′ additions to chiral acyclic vinyloxiranes

Abstract Additions of LiMe2Cu to acyclic vinyloxiranes 4, 5, 6, and 7 proceed predominately anti SN2′to afford the (E)-allylic alcohol products.
HI/acetic acid reduction of peracetylated N-acetyl neuraminic acid esters to stereoselectively provide α-2-deoxy-2-hydrido derivatives

Abstract Peracetylated ester derivatives of N -acetyl neuraminic acid were reacted with hydrogen iodide in acetic acid to stereoselectively provide α-2-deoxy-2-hydrido analogs. The reaction proceeds through formation of an anomeric iodide which, in the presence of excess HI, is reduced to give an enol intermediate. Kinetic protonation of the intermediate enol gives a 3.4:1 α:β mixture of 2-deoxy-2-hydrido derivatives. Under thermodynamic conditions the α-anomer is formed exclusively.
The effect of the administration of estrogens upon the production of cervical mucus in castrated women.

OF THE various functions that have been assigned to the cervical mucus, that of protection of the uterine cavity against infection (3, 4) would appear to rank high in importance. Whereas clinical evidence seems to support the contention that the mucus possesses this property, actual proof that it exercises this function through a bactericidal substance seems wanting. The protection given the uterus by the cervix and its constant secretion of mucus may appear to have a physical rather than a chemical basis. It has however been reported that secretions associated with chronic cervicitis exert a hostile, if not a lethal, effect upon spermato-zoa in vivo (2, 8, 14). Seguy et al. (9, 10) reported that an increase in the amount of cervical mucus occurs between the 10th and 15th days of the menstrual cycle, and correlated this observation with an increase in urinary estrogen and with visual evidence of ovulation.
Debye Shielding and Particle Correlations in Strongly Coupled Dusty Plasmas

A particle-in-cell simulation method is shown effective in modeling strongly coupled plasmas, exhibiting good energy conservation properties and good resolution of the dust-particle interaction. For coupling parameters of order unity, the simulation dust particles exhibit Debye shielding on the spatial scale of the dust Debye length. When initialized with a large coupling parameter, the dust particles do not organize themselves into a crystalline structure as expected, but instead are scattered by the presence of substantial electrostatic wave activity. Liquid-like or crystal-like correlations among the dust particles occur only when annealing is imposed. {copyright} {ital 1997} {ital The American Physical Society}
ON THE VIBRATION OF AN ELASTIC PLATE ON AN ELASTIC FOUNDATION

Abstract The forced vibration of an elastic plate under a time harmonic point force is studied. The plate is infinite in extent and supported by an elastic foundation. This study is made on the basis of the improved (Timoshenko) plate theory. The mathematical problem is to seek a fundamental solution (the Green's function) of the time-reduced plate equation of the improved plate theory. Such a fundamental solution is constructed by the distributional Fourier transform method. From the explicit expressions of the fundamental solution, the behavior of the fundamental singularity as a function of the vibration frequency and the foundation stiffness is examined. Conditions under which plate resonance occurs are also determined.
Matrix metalloproteinase-9 is increased in obese subjects and decreases in response to pioglitazone.

Context: The study investigated the regulation of matrix metalloproteinases (MMP)-9 in obesity-associated insulin resistance in humans. Objectives: The objectives of the investigation were to study MMP-9 regulation by insulin resistance and pioglitazone treatment in impaired glucose tolerant subjects using adipose tissue biopsies and study the mechanism of MMP-9 regulation by pioglitazone in adipocyte cultures. Research Design: 86 nondiabetic, weight-stable subjects between 21 and 66 yr of age were recruited in a university hospital research center setting. All subjects underwent a sc adipose tissue incisional biopsy from the lower abdominal wall and insulin sensitivity testing using a frequently sampled iv glucose tolerance test. Impaired glucose-tolerant subjects were randomized to receive metformin or pioglitazone for 10 wk. To study the mechanism of MMP-9 regulation in adipocytes, cells were treated with pioglitazone or protein kinase Cα antisense oligomers, and MMP-9 levels were examined. Results: Th...
Subgap states in dirty superconductors and their effect on dephasing in Josephson qubits

We present a theory of the subgap tails of the density of states in a diffusive superconductor containing magnetic impurities. We show that the subgap tails have two contributions: one arising from mesoscopic gap fluctuations, previously discussed by Lamacraft and Simons, and the other associated to the long-wave fluctuations of the concentration of magnetic impurities. We study the latter both in small superconducting grains and in bulk systems $[d=1,2,3]$, and establish the dimensionless parameter that controls which of the two contributions dominates the subgap tails. We observe that these contributions are related to each other by dimensional reduction. We apply the theory to estimate the effects of a weak concentration of magnetic impurities $[\ensuremath{\approx}1\phantom{\rule{0.3em}{0ex}}\mathrm{ppm}]$ on the phase coherence of Josephson qubits. We find that at these typical concentrations, magnetic impurities are relevant for the dephasing in large qubits, designed around a $10\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$ scale, where they limit the quality factor to be $Ql{10}^{4}\ensuremath{-}{10}^{5}$.
Comparing National Innovation Systems in Japan and the United States: Push, Pull, Drag and Jump Factors in the Development of New Technology

What jump-starts technology commercialization, venture capital investment, and new firm formation in new technology industries? What are the most effective ways to encourage start-ups and to connect fledgling firms to critical resources? National policies targeting life science (for example, biotechnology and medical devices) in Japan and the USA are compared in the context of their national innovation systems (NIS) supporting (and hindering) new technology-based entrepreneurship as a whole. Japan has embarked on an unprecedented bet on the future potential of life science, investing nationally and locally in building up R&D and commercialization infrastructure and stimulating new business creation through its Cluster Initiative and other policies. At the same time, while the USA until now has been at the forefront in new technology entrepreneurship, national policy is currently faltering. Through an analysis of best practices in national and regional innovation systems one can get a sense of important pu...
Yang-Mills inspired solutions for general relativity

Abstract Several exact, stationary axisymmetric solutions to Einstein's vacuum equations are given. These solutions were found using the connection between Yang-Mills theory and general relativity. Taking known solutions of the Yang-Mills equations (e.g. the topological BPS monopole solutions) it is possible to construct exact solutions to the general relativistic field equations. Although the general relativistic solutions were found starting from known solutions of Yang-Mills theory they have different physical characteristics.
Light's bending angle due to black holes: From the photon sphere to infinity

The bending angle of light is a central quantity in the theory of gravitational lensing. We develop an analytical perturbation framework for calculating the bending angle of light rays lensed by a Schwarzschild black hole. Using a perturbation parameter given in terms of the gravitational radius of the black hole and the light ray’s impact parameter, we determine an invariant series for the strong-deflection bending angle that extends beyond the standard logarithmic deflection term used in the literature. In the process, we discovered an improvement to the standard logarithmic deflection term. Our perturbation framework is also used to derive as a consistency check, the recently found weak deflection bending angle series. We also reformulate the latter series in terms of a more natural invariant perturbation parameter, one that smoothly transitions between the weak and strong deflection series. We then compare our invariant strong deflection bending-angle series with the numerically integrated exact formal bending angle expression, and find less than 1% discrepancy for light rays as far out as twice the critical impact parameter. The paper concludes by showing that the strong and weak deflection bending angle series together provide an approximation that is within 1% of the exact bending angle value for light rays traversing anywhere between the photon sphere and infinity.
Time-Resolved Ellipsometry and Reflectivity Measurements of the Optical Properties of Silicon During Pulsed Excimer Laser Irradiation

Several advances in time-resolved optical measurement techniques have been made, which allow a more detailed determination of the optical properties of silicon immediately before, during, and after pulsed laser irradiation. It is now possible to follow in detail the time-resolved reflectivity signal near the melting threshold; measurements indicate that melting occurs in a spatially inhomogeneous way. The use of time-resolved ellipsometry allowed us to accurately measure the optical properties of the high reflectivity (molten) phase, and of the hot, solid silicon before and after the laser pulse. We obtain n = 3.8, k = 5.2 (±10.1) at λ = 632.8 nm for the high reflectivity phase, in minor disagreement with the published values of Shvarev et al. for liquid silicon. Before and after the high reflectivity phase, the time-resolved ellipsometry measurements are entirely consistent with the known optical properties of crystalline silicon at temperatures up to its melting point.
SCATTERING OF 190-MEV DEUTERONS ON PROTONS

A measurement of the total $d\ensuremath{-}p$ scattering cross section is reported. Because of the divergence of Coulomb scattering at small angles, a small angle cutoff has been applied to the elastic scattering. The result may be stated as follows: The cross section for elastic scattering to angles greater than 10 degrees in the c.m. system, plus the total inelastic scattering cross section, is (${94}_{\ensuremath{-}5}^{+7}$)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}27}$ ${\mathrm{cm}}^{2}$.Measurements are also reported of those inelastic scattering processes in which both protons suffer significant momentum changes. We have termed these events "inelastic $p\ensuremath{-}p$ type collisions." The differential cross sections for these events appear to be smaller than would be expected in view of the theoretical considerations of others.
A new regiospecific preparation of xanthones.

Condensation of a benzopyranonphthalide with Michael acceptors provides an efficient, general method for regiospecific preparation of xanthones as well as linear and angular polycyclic aromatic systems containing a xanthone fragment.
Acyl derivatives of hydroxamic acids as a source of carbon radicals

Abstract Acyl derivatives of a number of hydroxamic acids are smoothly reduced by tributyltin hydride with initiation by AIBN to give the corresponding nor-hydrocarbons in a new radical chain reaction.
Theoretical constraints on true polar wander

[1] For the present geologic epoch, true polar wander (TPW) is relatively small, but simple theoretical considerations suggest that it could have been larger in other epochs. In this work, we use scaling arguments to assess the qualitative behavior of TPW and a simple Maxwell model to analytically describe how changes in mass anomalies translate into TPW. Unlike previous work, we derive simple analytical estimates of TPW based on the characteristic amplitudes and timescales for changes in the moment of inertia. We find estimates for both the amplitude and speed of TPW as a function of Earth properties. The following four main factors influence how large the maximum TPW can be: the (geological) timescale over which the desired TPW occurs τTPW, the viscosity structure of the mantle which yields a weighted average viscosity η, the characteristic amplitude of the nonhydrostatic changes in the moment of inertia δC, and the added moment of inertia due to the equatorial bulge (C − A). For the nominal values η = 3 × 1022 Pa s and δC/(C − A) = 0.003, the maximum TPW is 61° over 100 Myr and 8° over 10 Myr. The maximum TPW speed is only sensitive to η, δC, and (C − A), and is 2.4° Myr-1 for the nominal values. TPW is shown to act as a low-pass filter; rapid changes in moment of inertia produce smaller and delayed TPW. A consequence of this is that inertial interchange TPW does not have a different character than TPW. TPW can have an important contribution to plate motions over relatively long timescales but not over shorter timescales. Our simple approach allows us to assess whether multiple TPW events are possible but the major uncertainty continues to be the mantle viscosity structure.
Evidence for multiple magma ocean outgassing and atmospheric loss episodes from mantle noble gases

Abstract The energy associated with giant impacts is large enough to generate global magma oceans during Earth's accretion. However, geochemical evidence requiring a terrestrial magma ocean is scarce. Here we present evidence for at least two separate magma ocean outgassing episodes on Earth based on the ratio of primordial 3 He to 22 Ne in the present-day mantle. We demonstrate that the depleted mantle 3 He/ 22 Ne ratio is at least 10 while a more primitive mantle reservoir has a 3 He/ 22 Ne ratio of 2.3 to 3. The 3 He/ 22 Ne ratios of the mantle reservoirs are higher than possible sources of terrestrial volatiles, including the solar nebula ratio of 1.5. Therefore, a planetary process must have raised the mantle's 3 He/ 22 Ne ratio. We show that long-term plate tectonic cycling is incapable of raising the mantle 3 He/ 22 Ne ratio and may even lower it. However, ingassing of a gravitationally accreted nebular atmosphere into a magma ocean on the proto-Earth explains the 3 He/ 22 Ne and 20 Ne/ 22 Ne ratios of the primitive mantle reservoir. Increasing the mantle 3 He/ 22 Ne ratio to a value of 10 in the depleted mantle requires at least two episodes of atmospheric blow-off and magma ocean outgassing associated with giant impacts during subsequent terrestrial accretion. The preservation of a low 3 He/ 22 Ne ratio in a primitive reservoir sampled by plumes suggests that the later giant impacts, including the Moon-forming giant impact, did not generate a whole mantle magma ocean. Atmospheric loss episodes associated with giant impacts provide an explanation for Earth's subchondritic C/H, N/H, and Cl/F elemental ratios while preserving chondritic isotopic ratios. If so, a significant proportion of terrestrial water and potentially other major volatiles were accreted prior to the last giant impact, otherwise the fractionated elemental ratios would have been overprinted by the late veneer.
Charge changing cross sections of relativistic uranium

We report equilibrium charge state distributions of uranium at energies of 962 MeV/nucleon, 437 MeV/nucleon and 200 MeV/nucleon in low Z and high Z targets and the cross sections for U/sup 92 +/ reversible U/sup 91 +/ and U/sup 91 +/ reversible U/sup 90 +/ at 962 MeV/nucleon and 437 MeV/nucleon. Equilibrium thickness Cu targets produce approx. = 5% bare U/sup 92 +/ at 200 MeV/nucleon and 85% U/sup 92 +/ at 962 MeV/nucleon. 7 references, 5 figures.
Solution- and Solid-Phase Synthesis of Triazole Oligomers That Display Protein-Like Functionality

We recently developed a new class of oligomers that contain alpha-amino acid residues linked by 1,2,3-triazole groups [Angelo, N. G.; Arora, P. S. J. Am. Chem. Soc. 2005, 127, 17134-17135]. Synthesis of these oligomers involves an iterative sequence consisting of diazotransfer and Huisgen 1,3-dipolar cycloaddition steps. In this contribution, we describe an efficient one-pot, two-step sequence for the preparation of triazoles from the corresponding amino acid-derived amines and alkynes in solution. The one-pot sequence affords the desired products in significantly higher yields than our original method. We also outline a highly effective protocol for the synthesis of these triazole-based biomimetic oligomers on the solid phase. We find that amino acid derivatives and iterative formation of triazole rings require nontraditional reaction conditions for high yields.
Phase Coherent Timing of RX J0806.3+1527 with ROSAT and CHANDRA

RX 50806.3+1527 is an ultra-compact, double degenerate binary with the shortest known orbital period (321.5 s). Hakala et.al., have recently reported new optical measurements of the orbital frequency of the source which indicate that the frequency has increased over the approx.= 9 years since the earliest ROSAT observations. They find two candidate solutions for the long term change in the frequency; nu approx. = 3 or 6 x 10(exp -16)Hz/s. Here we present the results of a phase coherent timing study of the archival ROSAT and Chandra data for RX 50806.3+1527 in the light of these new constraints. We find that the ROSAT - Chandra timing data are consistent with both of the solutions reported by Hakala et al., but that the higher nu = 6.1 x 10(exp -16)Hz/s solution is favored at the approx. 97% level. This large a nu can be accomodated by an approx. = 1 solar mass detached double degenerate system powered in the X-ray by electrical energy. With such a large nu the system provides a unique opportunity to explore the interaction of gravitational radiation and electromagnetic torques on the evolution of an ultracompact binary.
Stereotype Threat in Criminal Interrogations:Why Innocent Black Suspects are at Risk for Confessing Falsely

© 2009 by American Psychological Association; Psychology, Public Policy, and Law. This article may not exactly replicate the final version published in the APA journal. It is not the copy of record. DOI: 10.1037/a0023741
Short-term planning and the life-cycle consumption puzzle

Abstract We develop a new life-cycle consumption model where the individual has a short planning horizon. Standard life-cycle consumers with perfect foresight and ‘hand-to-mouth’ consumers are both special (limiting) cases of our model, where the length of the planning horizon is set to the entire lifetime and zero, respectively. We derive an analytical solution to the (time inconsistent) short-term planning problem, which reveals the inner workings of the model and facilitates its use in other settings. We also show that the short-term planning mechanism is powerful enough to generate a consumption hump with the right size and location.
Supported Single-Site Organometallic Catalysts for the Synthesis of High-Performance Polyolefins

Single-site organometallic catalysts supported on solid inorganic or organic substrates are making an important contribution to heterogeneous catalysis. Early and late transition metal single-site catalysts have changed the polyolefin manufacturing industry and research with their ability to produce polymers with unique properties. Moreover, several of these catalysts have been commercialized on a large scale. Their heterogenization for slurry or gas phase olefin polymerization is important to produce polyolefin as beads and to avoid reactor fouling. The large majority of supports currently used in industry are inorganic materials (SiO2, Al2O3, MgCl2), with silica being the most important. Single-site supported catalysts are most commonly prepared by molecular-level anchoring/chemisorption, in which a molecular precursor undergoes reaction with the surface while maintaining most of the ligand sphere of the parent molecule. Chemisorption of discrete organometallic complexes on solid supports yields catalysts with well-defined active sites, greater thermal stability than the homogeneous analogues, and decreased reactor fouling versus the homogeneous analogues. This review presents a detailed account of the synthesis, characterization and polymerization properties of single-site catalysts supported on metal oxides and metal sulfated oxides, primarily carried out at Northwestern University. Early and late transition metal single-site catalysts supported on inorganic surfaces have changed the polyolefin research and production with their unique ability to produce polymeric materials with unique architectures. This review presents a detailed account of the synthesis, characterization, and polymerization properties of single-site catalysts supported on metal oxide surfaces.
PACOL: A parallel control language

An Extended Parallel Program Scheme (EPPS) and a higher level Parallel Control Language (PACOL) are defined. They are suitable for describing and programming parallel programs, intended for execution by a LSI modular, highly parallel processing system. PACOL provides for the definition of the sequencing of task-executions and of the related data transfers. To define the computations associated with the tasks, however, any one of the usual programming languages has to be used. These program statements are interwoven with the PACOL statements, to form a complete parallel program. PACOL uses ternary control variables but, for convenience, the task entry-functions are “quasi boolean”. It allows for very flexible sequencing schemes, including reentrant and recursive executions, lock, unlock and waiting actions. A programming example and the description of a part of the PACOL-semantics follow the definitions of its syntax and of the EPPS.
Solvent Sniffing: A Continuing Problem Among Youth.

The catalog of agents that have been used to produce subjective changes is impressive, and each generation not only adds a few new substances but seems impelled to re-evaluate the old [1].
Uranium-Thorium-Lead Isotope Relations in Lunar Materials

The lead isotopic compositions and uranium, thorium, and lead concentrations have been measured on six samples of material from the Sea of Tranquillity. The leads are moderately to very radiogenic; the initial lead concentrations are very low; the uranium and thorium levels are 0.26 to 0.88 and 0.87 to 3.35 parts per million, respectively. The Th/U ratios cluster about a 3.6 value. Apparent ages calculated for four rocks are 4.1 to 4.2 x 10^9 years. Dust and breccia yield apparent ages of 4.60 to 4.63 x 10^9 years. The uranium-lead ages are concordant, or nearly so, in all cases. The lunar surface is an ancient region with an extended record of events in the early history of the solar system. The discrepancy between the rock ages and dust ages poses a fundamental question about rock genesis on the moon.
A model of the balance of payments

Abstract A model of the balance of payments is presented in this paper in which stock and flow effects are completely integrated. The model accounts for all flows of funds in the system and allows for the endogenous determination of the exchange rate. The model is first outlined in general terms and then a particular ‘quasi-empirical’ version of it is analyzed by means of simulation techniques. The results of analyzing this version show the likely importance of accounting for capital flows and price linkages among countries in the construction of multicountry econometric models.
Compact and low delay routing labeling scheme for Unit Disk Graphs

In this paper, we propose a new compact and low delay routing labeling scheme for Unit Disk Graphs (UDGs) which often model wireless ad hoc networks. We show that one can assign each vertex of an n-vertex UDG G a compact O(log^2n)-bit label such that, given the label of a source vertex and the label of a destination, it is possible to compute efficiently, based solely on these two labels, a neighbor of the source vertex that heads in the direction of the destination. We prove that this routing labeling scheme has a constant hop route-stretch (= hop delay), i.e., for each two vertices x and y of G, it produces a routing path with h(x,y) hops (edges) such that h(x,y)=<3@?d"G(x,y)+12, where d"G(x,y) is the hop distance between x and y in G. To the best of our knowledge, this is the first compact routing scheme for UDGs which not only guaranties delivery but has a low hop delay. Furthermore, our routing labeling scheme has a constant length route-stretch and a constant power route-stretch. To obtain this result, we establish a novel balanced separator theorem for UDGs, which mimics the well-known Lipton and Tarjan@?s planar balanced shortest paths separator theorem. We prove that, in any n-vertex UDG G, one can find two hop-shortest paths P(s,x) and P(s,y) such that the removal of the 3-hop-neighborhood of these paths (i.e., N"G^3[P(s,x)@?P(s,y)]) from G leaves no connected component with more than 2/3n vertices. This new balanced shortest-paths-3-hop-neighborhood separator theorem allows us to build, for any n-vertex UDG G, a system T(G) of at most 2log"3"2n+2 spanning trees of G such that, for any two vertices x and y of G, there exists a tree T in T(G) with d"T(x,y)=<3@?d"G(x,y)+12. That is, the distances in any UDG can be approximately represented by the distances in at most 2log"3"2n+2 of its spanning trees.
Critical Current of a Quasi-One-Dimensional Superconducting Wire

We solve the Bogoliubov\char21{}de Gennes equations self-consistently to obtain the critical current ${\mathit{I}}_{\mathit{c}}$ versus Fermi energy \ensuremath{\mu} for a ballistic quasi-one-dimensional superconducting wire. Instead of the ``discretized'' critical current ${\mathit{I}}_{\mathit{c}}$(\ensuremath{\mu})=Ne${\mathrm{\ensuremath{\Delta}}}_{\mathrm{bulk}}$/\ensuremath{\Elzxh} predicted for a superconducting point contact, we find ${\mathit{I}}_{\mathit{c}}$(\ensuremath{\mu})=[4e${\mathrm{\ensuremath{\Delta}}}_{\mathrm{wire}}$(\ensuremath{\mu})/h][n(\ensuremath{\mu})/${\mathit{n}}_{1}$(\ensuremath{\mu})] for the superconducting wire. The normalized electron density n(\ensuremath{\mu})/${\mathit{n}}_{1}$(\ensuremath{\mu})=${\ensuremath{\sum}}_{\mathit{i}=1}^{\mathit{N}}$(${\mathit{k}}_{\mathit{Fi}}$/${\mathit{k}}_{\mathit{F}1}$)\ensuremath{\leqslant} N is a slowly increasing function of \ensuremath{\mu}. The superconducting order parameter ${\mathrm{\ensuremath{\Delta}}}_{\mathrm{wire}}$(\ensuremath{\mu}) must be obtained self-consistently for each value of the Fermi energy. We find ${\mathrm{\ensuremath{\Delta}}}_{\mathrm{wire}}$(\ensuremath{\mu}) follows the normal-metal quasi-one-dimensional density of states N(\ensuremath{\mu}) of the wire, as does the critical current ${\mathit{I}}_{\mathit{c}}$(\ensuremath{\mu}) . \textcopyright{}1996 The American Physical Society.
Synthesis, structure, and properties of four ternary compounds: CaSrTt, Tt=Si, Ge, Sn, Pb

Abstract The title compounds were synthesized and characterized by structural measurements and electronic structure calculations. Single-crystal X-ray diffraction analyses established that they all have the orthorhombic inverse -PbCl 2 -type structure ( Pnma , Z =4, a =8.108(2), 8.124(2), 8.421(2), 8.509(2) A; b =4.944(1), 4.949(1), 5.168(1), 5.189(1) A; c =9.170(2), 9.184(2), 9.685(2), 9.740(2) A, respectively). The tetrel ( Tt ) atoms are situated in tricapped trigonal prisms of ordered Sr and Ca atoms in which the smaller Ca atoms play a distinctive role. The structure is distinguishable from the Co 2 Si type by its more nearly ideal 6+3 (TCTP) environment about Tt rather than a higher coordination by cations. Other representations of the two structural types are also considered. Electronic band structure calculations suggest that the compounds are semiconductors, in agreement with literature data on their Ae 2 Tt analogues.
New backgrounds in trilepton, dilepton and dilepton plus tau jet SUSY signals at the tevatron

Abstract We determine the Tevatron's reach in supersymmetric parameter space in trilepton, like-sign dilepton, and dilepton plus tau-jet channels, taking all relevant backgrounds into account. We show results for the minimal supergravity model. With a standard set of cuts we find that the previously unaccounted for Wγ ∗ background is larger than all other backgrounds combined. We include cuts on the dilepton invariant mass and the W -boson transverse mass to reduce the Wγ ∗ background to a reasonable level. We optimize cuts at each point in supersymmetry parameter space in order to maximize signal-to-noise.
Bargaining, Communication, and Limited War*

Limited war requires limits; so do strate? gic maneuvers if they are to be stabilized short of war. But limits require agreement or at least some kind of mutual recognirion and acquiescence. And agreement on limits is difficult to reach, not only because of the uncertainties and the acute divergence of interests but because negoriation is severely inhibited both during war and before it begins and because communication becomes difficult between adversaries in time of war.
The Torelli geometry and its applications

Let S be a closed orientable surface of genus g. The mapping class group Mod(S) of S is defined as the group of isotopy classes of orientationpreserving diffeomorphisms S → S. We will need also the extended mapping class group Mod±(S) of S which is defined as the group of isotopy classes of all diffeomorphisms S → S. Let us fix an orientation of S. Then the algebraic intersection number provides a nondegenerate, skew-symmetric, bilinear form on H = H1(S,Z), called the intersection form. The natural action of Mod(S) on H preserves the intersection form. If we fix a symplectic basis in H, then we can identify the group of symplectic automorphisms of H with the integral symplectic group Sp(2g,Z) and the action of ModS on H leads to a natural surjective homomorphism
Mass transfer limitations in protein separations using ion-exchange membranes

Abstract Sorption of bovine serum albumin to commercial 150-μm pore size membranes was measured in batch and flow experiments. For residence times of 2–40 min, early and broad breakthrough curves and broad asymmetric elution peaks were observed that depended strongly on flow-rate. System dispersion could not explain the flow-rate dependence. Breakthrough and elution curves were analyzed using new models that included Langmuir sorption, convection and diffusion. From the analysis, film mass transfer resistance was found to be the rate-limiting factor. The maximum allowable pore size that eliminates this limitation was calculated for different molecular weight solutes.
Efficient implementation of a variable projection algorithm for nonlinear least squares problems

Nonlinear least squares problems frequently arise for which the variables to be solved for can be separated into a linear and a nonlinear part. A variable projection algorithm has been developed recently which is designed to take advantage of the structure of a problem whose variables separate in this way. This paper gives a slightly more efficient and slightly more general version of this algorithm than has appeared earlier.
Hot Corrosion Resistance of Nickel‐Chromium‐Aluminum Alloys

The hot corrosion resistance of nickel-chromium-aluminum alloys was examined by cyclically oxidizing sodium sulfate-coated specimens in still air at 900, 1000, and 1100 C. The compositions tested were within the ternary region: Ni, Ni-50 at.% Cr, and Ni-50 at.% Al. At each temperature the corrosion data were statistically fitted to a third order regression equation as a function of chromium and aluminum contents. From these equations corrosion isopleths were prepared. Compositional regions with the best hot corrosion resistance were identified.
A concordance invariant from the Floer homology of double branched covers

Ozsvath and Szabo defined an analog of the Froyshov invariant in the form of a correction term for the grading in Heegaard Floer homology. Applying this to the double cover of the 3-sphere branched over a knot K, we obtain an invariant δ of knot concordance. We show that δ is determined by the signature for alternating knots and knots with up to nine crossings, and conjecture a similar relation for all H-thin knots. We also use δ to prove that for all knots K with τ(K) > 0, the positive untwisted double of K is not smoothly slice.
Greatest lower bounds on Ricci curvature for toric Fano manifolds

Abstract In this short note, based on the work of Wang and Zhu (2004) [8] , we determine the greatest lower bounds on Ricci curvature for all toric Fano manifolds.
Computation of vectoring nozzle performance

As an initial step toward greater application of computational fluid dynamics to airframe/exhaust nozzle integration efforts, Euler codes were applied to numerically evaluate the internal performance of three advanced thrust vectoring nozzles developed for aircraft control. Nozzle geometry parameters included: pitch and yaw vector angles, sidewall length, sidewall deflection, and thrust reverser position. Computed pressure distributions and nozzle thrust and vectoring performance were compared to experimental data; agreement was excellent for vectoring configurations, and marginal for a reversing configuration.
Galaxy-QSO correlation induced by weak gravitational lensing arising from large-scale structure

Observational evidence shows that gravitational lensing induces an angular correlation between the distribution of galaxies and much more distant QSOs. We use weak gravitational lensing theory to calculate this angular correlation, updating previous calculations and presenting new results exploring the dependence of the correlation on the large-scale structure. We study the dependence of the predictions on a variety of cosmological models, such as cold dark matter models, mixed dark matter models, and models based on quintessence. We also study the dependence on the assumptions made about the nature of the primordial fluctuation spectrum: adiabatic, isocurvature and power spectra motivated by the cosmic string scenario are investigated. Special attention is paid to the issue of galaxy biasing, which is fully incorporated. We show that different mass power spectra imply distinct predictions for the angular correlation, and therefore the angular correlation provides an extra source of information about cosmological parameters and mechanisms of structure formation. We compare our results with observational data and discuss their potential uses. In particular, it is suggested that the observational determination of the galaxy-QSO correlation may be used to give an independent measurement of the mass power spectrum.
Soil Endowments, Female Labor Force Participation, and the Demographic Deficit of Women in India

Differences in relative female employment by soil texture are used to explain the heterogeneous deficit of female children across districts within India. Soil texture varies exogenously and determines the depth of land tillage. Deep tillage, possible in loamy but not in clayey soil textures, reduces the demand for labor in agricultural tasks traditionally performed by women. Girls have a lower economic value where female labor opportunities are fewer. Consistently, higher relative female employment in agriculture improves the ratio of female to male children in districts that have a smaller fraction of loamy relative to clayey soils.
Spatial Distribution of Ca2+ Signals during Repetitive Depolarizing Stimuli in Adrenal Chromaffin Cells

Exocytosis in adrenal chromaffin cells is strongly influenced by the pattern of stimulation. To understand the dynamic and spatial properties of the underlying Ca2+ signal, we used pulsed laser Ca2+ imaging to capture Ca2+ gradients during stimulation by single and repetitive depolarizing stimuli. Short single pulses (10–100 ms) lead to the development of submembrane Ca2+ gradients, as previously described (F. D. Marengo and J. R. Monck, 2000, Biophysical Journal, 79:1800–1820). Repetitive stimulation with trains of multiple pulses (50 ms each, 2Hz) produce a pattern of intracellular Ca2+ increase that progressively changes from the typical Ca2+ gradient seen after a single pulse to a Ca2+ increase throughout the cell that peaks at values 3–4 times higher than the maximum values obtained at the end of single pulses. After seven or more pulses, the fluorescence increase was typically larger in the interior of the cell than in the submembrane region. The pattern of Ca2+ gradient was not modified by inhibitors of Ca2+-induced Ca2+ release (ryanodine), inhibitors of IP3-induced Ca2+ release (xestospongin), or treatments designed to deplete intracellular Ca2+ stores (thapsigargin). However, we found that the large fluorescence increase in the cell interior spatially colocalized with the nucleus. These results can be simulated using mathematical models of Ca2+ redistribution in which the nucleus takes up Ca2+ by active or passive transport mechanisms. These results show that chromaffin cells can respond to depolarizing stimuli with different dynamic Ca2+ signals in the submembrane space, the cytosol, and the nucleus.
A Critical Test of Topological Defect Models: Spatial Clustering of Clusters of Galaxies

Gaussian cosmological models, typified by the inflationary cold dark matter models, and non-Gaussian topological defect-based cosmological models such as the texture-seeded model, differ regarding the origin of large-scale cosmic structures. In the former it is believed that high peaks at appropriate scales in the initial density field are the sites onto which matter accretes and collapses to form galaxies and clusters of galaxies, whereas in the latter these structures form around the density perturbation seeds (which are textures in the texture model). Textures initially are randomly distributed on scales larger than their size, in sharp contrast to the initial high-density peaks in the Gaussian models, which are already strongly clustered before any gravitational evolution has occurred. One thus expects that the resultant correlation of large cosmic objects such as clusters of galaxies in the texture model should be significantly weaker than its Gaussian counterpart. We show that an Ω0 = 1, biased b = 2 (as required by cluster abundance observations) texture model (or any random-seed model) predicts a two-point correlation length of ≤6.0 h-1 Mpc for rich clusters, independent of richness. On the other hand, the observed correlation length for rich clusters is ≥10.0 h-1 Mpc at a confidence level of approximately 2 σ. It thus appears that the global-texture cosmological model or any random-seed cosmological model is ruled out at a very high confidence (>3 σ).