cssi/SciSciGPT-SciSciNet huggingface dataset:
Evidence for melt injection in the crust of northern California

Abstract The occurrence of an earthquake sequence near Lake Pillsbury, California during a 6-month period in mid-2000 can be linked to magma transport in the crust; this activity is potentially a pre-cursor to future volcanism. The position of Cenozoic volcanism in the crust of the northern California Coast Ranges is directly linked to the northward migration of the Mendocino triple junction (MTJ) and the formation of a slab window beneath North American crust. The most recent manifestation of this is the Clear Lake volcanics, which began erupting ∼ 2 Ma. With the continued migration of the triple junction, volcanic activity is expected to occur to the north of Clear Lake in the future. These volcanic centers erupt in areas where the crust is undergoing significant modification as a result of slab window processes, and reflect important components in the development of the San Andreas plate boundary system. When precisely relocated, the earthquake sequence defines a streak of seismicity at ∼ 8 km depth. This sequence demonstrates a local time–space migration over a distance of ∼ 10 km in two major pulses of activity in the 6-month time period. Stress modeling allows us to infer that these earthquakes may be the result of several dike injections. In combination with evidence for lower crustal melts in the same region from other seismological studies, we propose that these earthquakes help map the occurrence of melt injection in the mid-crust to depths of ∼ 10 km, and present evidence that MTJ-related melt in the crust of northern California has migrated north of the Clear Lake volcanic center.
A NICMOS Survey of Early-Type Galaxy Centers*: The Relation Between Core Properties, Gas and Dust Content, and Environment

We present a NICMOS 1.6 μm imaging isophotal study of 27 early-type galaxies. Core galaxies have reduced ellipticity and boxiness near and within their core or break radius. This supports a core formation mechanism that mixes or scatters stars such as scattering caused by a binary black hole. We find the same trends between central surface brightness and luminosities as the WPFC studies. We find no correlation between core properties and dust mass or X-ray luminosity, suggesting that processes determining the current gas content (e.g., such as minor mergers and cooling flows) are unrelated to processes occurring during core formation. Core galaxies exist in a variety of environments ranging from poor groups to large clusters. A combined sample suggests that galaxy groups may harbor more luminous power-law galaxies than clusters such as Virgo and Fornax.
Estimating the Probability Distribution of von Mises Stress for Structures Undergoing Random Excitation

The von Mises stress is often used as the metric for evaluating design margins, particularly for structures made of ductile materials. For deterministic loads, both static and dynamic, the calculation of von Mises stress is straightforward, as is the resulting calculation of reliability. For loads modeled as random processes, the task is different; the response to such loads is itself random process and its properties must be determined in terms of those of both the loads and the system. This has been done in the past by Monte Carlo sampling of numerical realizations that reproduce the second order statistics of the problem. Here, we present a method that provides analytic expressions for the probability distributions of von Mises stress which can be evaluated efficiently and with good numerical precision. Further, this new approach has the important advantage of providing the asymptotic properties of the probability distribution.
Real-Gas and Surface-Ablation Effects on Hypersonic Boundary-Layer Instability over a Blunt Cone

There has been little research into surface-ablation effects on hypersonic boundary-layer instability, and the current understanding of real-gas effects on hypersonic boundary-layer instability still contains uncertainties. The objective of the current work was to analyze the hypersonic boundary-layer transition process using linear-stability theory, in which surface ablation, as well as real-gas effects, is present, and the second mode is the dominant instability mode. A thermochemical nonequilibrium linear-stability-theory code with a gas-phase model that includes multiple carbon species, as well as a linearized surface graphite-pseudoablation model, is developed and validated. It is validated with previously published linear-stability analysis and direct-numerical-simulation results. A high-order method for discretizing the linear-stability equations is used, which can easily include high-order boundary conditions. The developed linear-stability code, with mean-flow solutions produced from a high-order...
Hybrid strategic groups

The notion of strategic groups has recently emerged as a critical perspective for uncovering firms' strategic postures/recipes and competitive market structures. Firms within strategic groups generally adopt similar strategic recipes and compete more intensely than firms across strategic groups. Building on recent research, the authors develop the concept of hybrid strategic groups, which blend the strategic recipes of more than one group, in contrast to existing conceptualizations of strategic groups, where either firms tightly follow the recipes of a strategic group (i.e., core firms) or firms loosely follow the recipes of a strategic group (i.e., secondary firms). Thus, competition among firms depends not only on the strategic group but also on the overlap of that strategic group with other strategic groups. The authors devise a combinatorial optimization-based classification procedure utilizing a bilinear model that accommodates multiple variable batteries that can estimate hybrid strategic groups. The proposed methodology is illustrated by using archival data on public banks. For this illustration, the hybrid strategic group solution outperforms ordinary cluster analyses and offers critical insights into the nature of competition among firms. Copyright © 2007 John Wiley & Sons, Ltd.
Stability of individual loudness functions obtained by magnitude estimation and production

A correlational analysis of individual magnitude estimation and production exponents at the same frequency was perfor.med, as well as an analysis of individual exponents produced in different sessions by the same procedure across frequency(250, 1, 000, and 3, 000 Hz). Taken together, results show, first, that individual exponent differences do not decrease by counterbalancing magnitude estimation with magnitude production, and, second, that individual exponent differences remain stable over time despite changes in stimulus frequency. Further results disclose that although individual magnitude estimation and production exponents do not necessarily obey the .6 power law, it is possible to predict the slope (exponent) of an equal-sensation function averaged for a group of listeners from individual magnitude estimation and production data. Assuming that individual listeners with sensorineural hearing loss also produce stable and reliable magnitude functions, it is also shown that the slope of the loudness-recruitment function measured by magnitude estimation and production can be predicted for individuals with bilateral losses of long duration. Thus, results obtained in normal and in pathological ears suggest that individual listeners can produce loudness judgments that reveal, albeit indirectly, the input-output characteristic of the auditory system.
Neutrinoless double beta decay can constrain neutrino dark matter

Abstract We examine how constraints can be placed on the neutrino component of dark matter by an accurate measurement of neutrinoless double beta (0 νββ ) decay and the solar oscillation amplitude. We comment on the alleged evidence for 0 νββ decay.
Au(III) in Borate Medium: Electrochemical Behavior and Application to Electroplating

A well-defined steady-state current for the reduction of gold on a glassy carbon microdisk electrode is obtained from borate medium. Coulometric experiments show that this current is due to the reduction of gold(III) to gold(0). This current is proportional to the concentration of gold(III) and suitable for analytical purposes. Gold(III) is more stable in borate electrolytes than in solutions of an indifferent electrolyte at the same ionic strength and pH. However, UV-vis spectrometry and pH-metric titrations suggest that borate does not form stoichiometric complexes with gold(III). This medium yields an excellent quality of deposit on test masks with feature size in the range of 5 to 250 μm and highest aspect ratio 1 :1
Diagnostics for Respondent-driven Sampling

Respondent-driven sampling (RDS) is a widely used method for sampling from hard-to-reach human populations, especially populations at higher risk for HIV. Data are collected through peer-referral over social networks. RDS has proven practical for data collection in many difficult settings and is widely used. Inference from RDS data requires many strong assumptions because the sampling design is partially beyond the control of the researcher and partially unobserved. We introduce diagnostic tools for most of these assumptions and apply them in 12 high risk populations. These diagnostics empower researchers to better understand their data and encourage future statistical research on RDS.
Decaying turbulence in the presence of a shearless uniform kinetic energy gradient

The decay of turbulent kinetic energy in nearly isotropic grid turbulence has been studied extensively as a fundamental point of reference for turbulence theories and numerical simulations. Most studies have focused on nearly homogeneous turbulence characterised by power-law decay. Other studies have focused on so-called shearless mixing layers, in which two regions with the same mean velocity but distinctly different kinetic energy levels slowly diffuse into each other downstream thus providing information about spatial transport of turbulence. Here, we introduce and study another type of shearless turbulent flow. It has initially a nearly uniform spatial gradient of kinetic energy of the form k ∼ β(y − y0), where y is the spanwise position. In the experiments, this gradient is generated with the use of an active grid and screens mounted upstream of the wind-tunnel’s test section, iteratively designed to produce a uniform gradient of turbulent kinetic energy without mean velocity shear. Data are acquired...
Regularization for effective field theory with two heavy particles

A regularization for effective field theory with two propagating heavy particles is constructed. This regularization preserves the low-energy analytic structure, implements a low-energy power counting for the one-loop diagrams, and preserves symmetries respected by dimensional regularization.
Identification of vibrating flexible structures

This paper presents novel identification schemes to determine model parameters of vibrating structures. A time-domain identification method using transient response is discussed first. Next, a steady-state response method using nonresonant harmonic excitations is considered. An especially attractive method for uniquely identifying the parameters of a structure using both free and forced response is also discussed. Numerical results show that the methods are relatively immune to the presence of damping and many low-frequency modes with repeated or closely spaced frequencies.
The mobility of zirconium and other "immobile" elements during hydrothermal alteration

Abstract Development of zircon and other Zr phases in hydrothermal deposits indicates that Zr can be highly mobile in these systems. Mobility is most common in, but not restricted to, F-rich hydrothermal systems related to alkalic, F-rich igneous suites; these suites can range from peralkaline through metaluminous to peraluminous. A few examples are neither alkalic nor F rich. Three locations in the Trans-Pecos Magmatic Province, Texas, U.S.A., demonstrate this hydrothermal Zr mobility. All three igneous systems are alkalic and F rich but vary in alkali/Al ratios. Peralkaline rhyolites and trachytes in the Christmas Mountains contain as much as 2100 ppm Zr, mostly in aegirine or arfvedsonite; zircon is rare or absent. Fluorspar replacement deposits in limestone at contacts with the rhyolites contain as much as 38,000 ppm Zr, occurring as small, disseminated zircons. The deposits also are enriched in a variety of incompatible elements, including Be, rare-earth elements (REE), Y, Nb, Mo, Hf, Pb, Th and U. The Sierra Blanca intrusions, a series of mildly peraluminous, F-rich rhyolite laccoliths, contain as much as 1000 ppm Zr, mostly as zircon. Hydrothermal zircon occurs as overgrowths on magmatic grains, as veinlets connected to overgrowths, and in fluorspar replacement bodies in adjacent limestone. The highest Zr concentrations in fluorspar are ∼200 ppm. Metaluminous quartz monzonite from the Infiernito caldera contains 400–600 ppm Zr, mostly as zircon. Euhedral zircon in quartz-fluorite veins in the quartz monzonite indicates mobility of Zr. Zirconium concentrations in the veins are unknown, but the paucity of zircon suggests little Zr enrichment relative to the host. Zircon and, more rarely, zirconolite, occur in skarn in the Ertsberg District of Irian Jaya, Indonesia. Unlike in Texas, related igneous rocks are metaluminous, and the hydrothermal system was F poor. Worldwide, hydrothermal zircon, other Zr phases, and Ti- and Al-bearing phases occur in skarn, epithermal precious metal veins, volcanogenic massive-sulfide deposits and mylonites. We propose that differences in Zr mineralogy of igneous source rocks is an important factor in determining the availability of Zr to hydrothermal fluids. Although Zr concentrations in the Sierra Blanca and Christmas Mountains rhyolites are similar, Zr enrichment in fluorspar was much greater in the Christmas Mountains. We suggest that hydrothermal solutions could easily break down aegirine and arfvedsonite to release Zr, but that zircon was only moderately attacked. Therefore, far more Zr was available for transport and subsequent deposition in the Christmas Mountains than at Sierra Blanca. Availability of other trace elements probably is also governed by their mineral host. Although Zr mobility is most common in F-rich hydrothermal systems related to alkalic and F-rich igneous systems, mobility at Ertsberg may have been promoted by sulfate complexing.
Photodissociation of RNCS and RSCN (R=H, CH3, C2H5) : Evidence for an excited state isomerization and energy deposition in the NCS product

The 248 and 193 nm photodissociation of the series of molecules RNCS and RSCN (R=H, CH3, C2H5) has been investigated. Laser‐induced fluorescence of the radical NCS was used to probe the energy deposition in the R+NCS channel of this dissociation, however excitation to many vibrational states of NCS caused spectral congestion which prohibited direct measurement of populations of individual levels. A single‐photon dissociation channel leading to RS and CN was observed for both isomers of all of the precursor molecules. While this was expected for the thiocyanate species, no direct channel to these products is available for the isothiocyanates. This observation is discussed in terms of an excited state isomerization of these molecules. Measured ratios of CN to NCS production for all compounds provide additional support for this mechanism and suggest a significant barrier to the process. Comparison of nascent laser‐induced fluorescence (LIF) spectra of NCS with spectra obtained following different amounts of collisional relaxation suggests that all three vibrational modes were equally excited with a vibrational temperature of roughly 4500 K. The rotational temperature was estimated to be less than 1000 K. A spin–orbit population inversion was observed for all vibrational levels with approximately 75% of the population in the upper spin–orbit component of the vibrationless and low lying bending excited levels. No simple model is found to explain the photodissociation dynamics or the isomerization.
Quasi-Polynomial Time Approximation Scheme for Sparse Subsets of Polygons

We describe how to approximate, in quasi-polynomial time, the largest independent set of polygons, in a given set of polygons. Our algorithm works by extending the result of Adamaszek and Wiese [1, 2] to polygons of arbitrary complexity. Surprisingly, the algorithm also works for computing the largest subset of the given set of polygons that has some sparsity condition. For example, we show that one can approximate the largest subset of polygons, such that the intersection graph of the subset does not contain a cycle of length 4 (i.e., K2,2).
A study of intermittent faults in digital computers

Definition of intermittent faults in digital computer systems and their possible causes are given. The effects of intermittent faults on the performance of systems and alternatives to overcome these effects have been examined. Present attempts to cope with the intermittent failures and future research areas have been explored.
Two-loop computation of a running coupling in lattice Yang-Mills theory

Abstract We compute the two-loop coefficient in the relation between the lattice bare coupling and the running coupling defined through the Schrodinger functional for the case of pure SU(2) gauge theory. This result is needed as one computational component to relate the latter to the MS coupling, and it allows us to implement O(a) improvement of the Schrodinger functional to two-loop order. In addition, the two-loop β-function is verified in a perturbative computation on the lattice, and the behavior of an improved bare coupling is investigated beyond one loop.
Conservation Errors and Convergence Characteristics of Iterative Space-Marching Algorithms

The new iterative space-marching algorithms for numerical solution of the parabolized Navier-Stokes equations are critically examined. It is shown by analysis and numerical examples that employing parabolized flux difference splitting in the marching direction can lead to serious conservation errors even though a finite-volume formulation is employed. Schemes employing parabolized flux vector splitting in the marching direction are shown to be conservative. The structure of the iterative algorithm is examined to determine what factors play important roles in the convergence of the local iteration.
Iron abundance profiles of 12 clusters of galaxies observed with BeppoSAX

We have derived azimuthally averaged radial iron-abundance profiles of the X-ray gas contained within 12 clusters of galaxies with redshift 0.03 ≤ z ≤ 0.2 observed with BeppoSAX. We find evidence for a negative metal-abundance gradient in most of the clusters, particularly significant in clusters that possess cooling flows. The composite profile from the 12 clusters resembles that of cluster simulations of Metzler & Evrard. This abundance gradient could be the result of the spatial distribution of gas-losing galaxies within the cluster being more centrally condensed than the primordial hot gas. Both inside and outside the core region we find a higher abundance in cooling-flow clusters than in non-cooling-flow clusters. Outside of the cooling region this difference cannot be the result of more efficient sputtering of metals into the gaseous phase in cooling-flow clusters but might be the result of the mixing of low-metallicity gas from the outer regions of the cluster during a merger.
Nanocatalyst doping of Zn(BH4)2 for on-board hydrogen storage

Abstract In this work, we report the synthesis and characterization of Zn(BH4)2, a new class of complex borohydrides for on-board hydrogen storage. The thermal decomposition of Zn(BH4)2 comprises of not only the evolution of H2, but also an appreciable amount of B–H (borane) compounds. Lowering the decomposition temperature by catalytic doping may lead to negligible release of boranes. An amount of 1.5 mol% nanoNi was estimated and found to be the optimum concentration for nanocatalyst doping of Zn(BH4)2. Significance of the nanoNi doping, lowers the melting and thermal decomposition temperatures (at least 20–40 °C) of Zn(BH4)2 as evidenced from the calorimetric analysis. At these low temperatures, the nanocatalyzed Zn(BH4)2 exhibits reduction in the amount of borane gases released by a factor of 20 as compared to the undoped sample.
Is Deuterium in High-Redshift Lyman Limit Systems Primordial?

Detections of deuterium in high-redshift Lyman limit absorption systems along the line of sight to QSOs promise to reveal the primordial deuterium abundance. At present, the deuterium abundances (D/H) derived from the very few systems observed are significantly discordant. Assuming the validity of all the data, if this discordance does not reflect intrinsic primordial inhomogeneity, then it must arise from processes operating after the primordial nucleosynthesis epoch. We consider processes that might lead to significant deuterium production or destruction and yet allow the cloud to mimic a chemically unevolved system. These processes include, for example, anomalous/stochastic chemical evolution and D/4He photodestruction. In general, we find it unlikely that these processes could have significantly altered D/H in Lyman limit clouds. We argue that chemical evolution scenarios, unless very finely tuned, cannot account for significant local deuterium depletion since they tend to overproduce 12C, even when allowance is made for possible outflow. Similarly, D/4He photodestruction schemes engineered to locally produce or destroy deuterium founder on the necessity of requiring an improbably large γ-ray source density. Future observations of D/H in Lyman limit systems may provide important insight into the initial conditions for the primordial nucleosynthesis process, early chemical evolution, and the galaxy formation process.
Stochastic Taylor expansions and heat kernel asymptotics

These notes focus on the applications of the stochastic Taylor expansion of solutions of stochastic differential equations to the study of heat kernels in small times. As an illustration of these methods we provide a new heat kernel proof of the Chern–Gauss–Bonnet theorem.
Reionization and structure formation with ARCADE

Abstract Structure formation in the early universe is expected to produce a cosmological background of free–free emission. The Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) will measure the spectrum of the cosmic microwave background at centimeter wavelengths to detect this signature of structure formation. I describe the ARCADE instrument and the cryogenic engineering required to achieve millikelvin accuracy at such long wavelengths.
General Modal Properties of Optical Resonances in Subwavelength Nonspherical Dielectric Structures

Subwavelength dielectric structures offer an attractive low-loss alternative to plasmonic materials for the development of resonant optics functionalities such as metamaterials and optical antennas. Nonspherical-like rectangular dielectric structures are of the most interest from the standpoint of device development due to fabrication convenience. However, no intuitive fundamental understanding of the optical resonance in nonspherical dielectric structures is available, which has substantially delayed the development of dielectric resonant optics devices. Here, we elucidate the general fundamentals of the optical resonance in nonspherical subwavelength dielectric structures with different shapes (rectangular or triangular) and dimensionalities (1D nanowires or 0D nanoparticles). We demonstrate that the optical properties of nonspherical dielectric structures are dictated by the eigenvalue of the structure's leaky modes. Leaky modes are defined as optical modes with propagating waves outside the structure. We also elucidate the dependence of the modal eigenvalue on physical features of the structure. The eigenvalue shows scale invariance with respect to the size of the structure, weak dependence on the refractive index, but linear dependence on the size ratio of different sides of the structure. We propose a modified Fabry-Perot model to account for the linear dependence. The knowledge of leaky modes, including the role in optical responses and the dependence on physical features, can serve as a powerful guide for the rational design of devices with desired optical resonances. It may open up a pathway to design devices with functionality that has not been explored due to the lack of intuitive understanding, for instance, imaging devices able to sense incident angle or superabsorbing photodetectors.
Pressure and Ionization Balances in the Circum-Heliospheric Interstellar Medium and the Local Bubble

A disconcerting mismatch of thermal pressures for two media in contact with each other, (1) the warm, Circum-Heliospheric Interstellar Medium (CHISM) and (2) the very hot material within a much larger region called the Local Bubble (LB), has troubled astronomers for over two decades. A possible resolution of this problem, at least in part, now seems possible. We now understand that earlier estimates for the average electron density in the very hot LB plasma were inflated by an unrecognized foreground contamination to the low energy diffuse X-ray background measurements. This foreground illumination arises from photons emitted by charge exchange reactions between solar wind ions and neutral atoms from the interstellar medium that enter into the heliosphere. However, with the resolution of this problem comes a new one. The high ionization fraction of helium in the CHISM, relative to that of hydrogen, could be understood in terms of the effects from a strong flux of EUV and X-ray radiation coming from both the Local Bubble and a conductive interface around the CHISM. A revision of this interpretation may now be in order, now that the photoionization rate from radiation emitted by hot gas the Local Bubble is lower than previously assumed.
Instantons and the chiral phase transition

Abstract We examine the role of instantons in the zero-temperature chiral phase transition in an SU(N) gauge theory. For a range of Nf (the number of fermion flavors) depending on N, the theory exhibits an infrared fixed point at coupling α ∗ . As Nf decreases, α ∗ increases, and it eventually exceeds a critical value sufficient to trigger chiral symmetry breaking. For the case N = 2, we estimate the critical values of Nf and α ∗ due to instantons by numerically solving a gap equation with an instanton-generated kernel. We find instanton effects of strength comparable to that of gluon exchange.
Optimizing a solid rocket motor boosted ramjet powered missile using a genetic algorithm

This paper describes an effort in which the design of an entire missile system consisting of a ramjet powered sustainer and an associated solid rocket booster is considered. The design process is controlled by a genetic algorithm optimizer which directs and controls other system performance prediction codes. The optimizer used in the present process is the IMPROVE^(C) code, a genetic algorithm (GA) with many advanced features including a pareto option and nicheing. The paper contains limited discussion of the methodology and shows results for several design scenarios. The results are to be interpreted as a ''proof of concept'' effort and are not directed toward a specific design problem.
Baseline body mass index among children and adults undergoing allogeneic hematopoietic cell transplantation: clinical characteristics and outcomes

Obesity is an important public health problem that may influence the outcomes of hematopoietic cell transplantation (HCT). We studied 898 children and adults receiving first-time allogeneic hematopoietic SCTs between 2004 and 2012. Pretransplant body mass index (BMI) was classified as underweight, normal weight, overweight or obese using the WHO classification or age-adjusted BMI percentiles for children. The study population was predominantly Caucasian, and the median age was 51 years (5 months–73 years). The cumulative 3-year incidence of nonrelapse mortality (NRM) in underweight, normal weight, overweight and obese patients was 20%, 19%, 20% and 33%, respectively. Major causes of NRM were acute and chronic GVHD. The corresponding incidence of relapse was 30%, 41%, 37% and 30%, respectively. Three-year OS was 59%, 48%, 47% and 43%, respectively. Multivariate analysis showed that obesity was associated with higher NRM (hazard ratio (HR) 1.43, P=0.04) and lower relapse (HR 0.65, P=0.002). Pretransplant plasma levels of ST2 and TNFR1 biomarkers were significantly higher in obese compared with normal weight patients (P=0.04 and P=0.05, respectively). The increase in NRM observed in obese patients was partially offset by a lower incidence of relapse with no difference in OS.
Capacity Constrained Firms and Expansion Subsidies: Should Governments Avoid Generous Subsidies?

This paper examines entry deterrence and signaling when an incumbent firm experiences capacity constraints. Our results show that if the costs that constrained and unconstrained incumbents incur when expanding their facilities are substantially different, separating equilibria can be supported under large parameter values whereby information is perfectly transmitted to the entrant. If, in contrast, both types of incumbent face similar expansion costs, subsidies that reduce expansion costs can help move the industry from a pooling to a separating equilibrium with associated efficient entry. Nonetheless, our results demonstrate that if subsidies are very generous entry patterns remain unaffected, suggesting a potential disadvantage of policies that significantly reduce firms’ expansion costs.
Speculations on ALEPH's Dijet Enhancement

Abstract We interpret the dijet enhancement reported by the ALEPH collaboration in the process e + e − →4 jets as being due to the production of a pair of bottom squarks, followed by their R-parity violating decays into pairs of light quarks. Constraints on this speculative interpretation are examined. Some of the consequences of our hypothesis are drawn within the context of softly broken supersymmetry.
Cationic copper(I) complexes as efficient precatalysts for the hydrosilylation of carbonyl compounds

Novel cationic copper complexes bearing two N-heterocyclic carbenes (NHCs) have been synthesized and fully characterized. These air- and moisture-stable complexes were found to be highly active toward the hydrosilylation of ketones with varying steric congestion, aldehydes (even enolizable ones), and esters.
Enumeration of hybrid domino-lozenge tilings

We solve and generalize an open problem posted by James Propp (Problem 16 in New Perspectives in Geometric Combinatorics, Cambridge University Press, 1999) on the number of tilings of quasi-hexagonal regions on the square lattice with every third diagonal drawn in. We also obtain a generalization of Douglas? theorem on the number of tilings of a family of regions of the square lattice with every second diagonal drawn in.
Mid-Infrared Images of Stars and Dust in Irregular Galaxies*

We present mid-IR to optical properties of 22 representative irregular galaxies: 18 irregular (Im) galaxies, 3 blue compact dwarfs, and 1 Magellanic-type spiral galaxy. The mid-IR is based on images from the Spitzer Space Telescope archives. The 3.6 and 4.5 ?m bands and the UBVJHK images are used to examine disk morphology and the integrated and azimuthally averaged magnitudes and colors of stars. The nonstellar contribution to the 4.5 ?m images is used to trace hot dust. The 5.8 and 8.0 ?m images reveal emission from hot dust and polycyclic aromatic hydrocarbons (PAHs), and both may contribute to these passbands, although we refer to the nonstellar emission as PAH emission. We compare the 8.0 ?m images to H?. Im galaxies have no hidden bars, and those with double-exponential optical light profiles have the same at mid-IR. Most galaxies have similar optical and mid-IR scale lengths. Four galaxies have super star clusters that are not visible at optical bands. Galaxies with higher area-normalized star formation rates have more dust and PAH emission relative to starlight. Hot dust and PAH emission is found mostly in high surface brightness H?II regions, implying that massive stars are the primary source of heating. Galaxies with intense, widespread star formation have more extended PAH emission. The ratio of PAH to H? emission is not constant on small scales. PAHs are associated with shells and giant filaments, so they are not destroyed during shell formation.
Alkylation of 2-azaallyl anions; a versatile primary amine synthesis

Abstract Imines from primary amines and mesityl 2-pyridyl ketone react with LDA followed by treatment with an alkyl halide and hydrolysis to give the original amine alkylated at the alpha-position.
Manufacturing process control at IBM

IBM manufacturing facilities in both the United States and Europe have installed computer systems of essentially identical design to aid in the control of many types of manufacturing processes. The basic structure of the system is depicted in Figure 1. One or two central computer systems (IBM System 360) are attached to several satellite computers (IBM 1130, 1800 and 360 processors) via a high speed Transmission Control Unit (multiplexor).
Structural characterization of silicon orthophosphate

Abstract Silicon phosphate samples have been synthesized at low temperature (200–300 °C) and characterized using various physico-chemical methods. The crystal structure of the silicon phosphate prepared at low temperature and the sample heated at 1000 °C was studied by the Rietveld method. The crystals belong to the hexagonal space group R 3 with a ⋍ 7.8 and c ⋍ 24.0 A. The structure of silicon phosphate in both of these samples is found to be Si5O(PO4)6. The asymmetric unit consist of three crystallographically independent silicon atoms of which one is in a tetrahedral environment and the other two have octahedral coordination.
A Wind-Tunnel Technique for Measuring Frequency-Response Functions for Gust Load Analyses

Wind tunnel technique for measuring frequency response of flexible airplane to vertical sinusoidal gusts
Compton Scattering by Static and Moving Media. I. The Transfer Equation and Its Moments

Compton scattering of photons by nonrelativistic particles is thought to play an important role in forming the radiation spectrum of many astrophysical systems. Here we derive the time-dependent photon kinetic equation that describes spontaneous and induced Compton scattering, as well as absorption and emission by static and moving media, the corresponding radiative transfer equation, and their zeroth and first angular moments, both in the system frame and in the frame comoving with the medium. We show that it is necessary to use the correct relativistic differential scattering cross section in order to obtain a photon kinetic equation that is correct to first order in e/me, Te/me, and V, where e is the photon energy, Te and me are the electron temperature and rest mass, and V is the electron bulk velocity in units of the speed of light. We also demonstrate that the terms in the radiative transfer equation that are second order in V should usually be retained, because if the radiation energy density is sufficiently large, compared to the radiation flux, the effects of bulk Comptonization described by the terms that are second order in V can be as important as the effects described by the terms that are first order in V, even when V is small. The system- and fluid-frame equations that we derive are correct to first order in e/me. Our system-frame equations, which are correct to second order in V, may be used when V is not too large. Our fluid-frame equations, which are exact in V, may be used when V → 1. Both sets of equations are valid for systems of arbitrary optical depth and can therefore be used in both the free-streaming and diffusion regimes. We demonstrate that Comptonization by the electron bulk motion occurs whether or not the radiation field is isotropic or the bulk flow converges and that it is more important than thermal Comptonization if V2 > 3Te/me.
Moral dilemmas, thought experiments, and conflict vagueness

L'A. vise a montrer comment la cas traditionnel contre les «dilemmes moraux» peut avoir pour complement la notion de «vague» du conflit. L'A. s'interroge ainsi sur la rationalite des devoirs moraux en soulignant l'interet des experiences de pensee pour se representer dans tous les cas l'indetermination psychologique liee au dilemme, la difficulte d'etablir une balance pour choisir le mieux face a l'incommensurabilite des obligations ethiques
The origin of tektites.

Origin of Moung Nong type tektities detached by meteoritic impact, considering lunar origin based on diffusion rates in silicates
Simulation of a Biological System On an Analog Computer

The purpose of this paper is to discuss a method for the construction of a mathematical model of a large biological system. This method, based on Gibbs' free energy hypothesis, uses the format of mathematical programming, while the actual computation is ac complished by the method of steepest descent. The biological system chosen to exemplify the mathe matical method was the respiratory function of the blood in the human lung. This method is based on the postulate that chemical mixtures tend toward a reaction equilibrium which minimizes the potential, or free energy, of the system. We may thus write down the classical Gibbs free energy function for each chemical species, and require that total free energy relative to some standard state be minimized under the conditions of the experiment. The solution of the equilibrium problem consists of a set of mole numbers which minimizes the free energy function, subject to equations for conservation of mass and nonnegativity.The analog computer solution of the resp...
The Variability of Sagittarius A* at Centimeter Wavelengths

We present the results of a 3.3 yr project to monitor the flux density of Sagittarius A* at 2.0, 1.3, and 0.7 cm with the Very Large Array. Between 2000.5 and 2003.0, 119 epochs of data were taken with a mean separation between epochs of 8 days. After 2003.0, observations were made roughly once per month for a total of nine additional epochs. Details of the data calibration process are discussed, including corrections for opacity and elevation effects, as well as changes in the flux density scales between epochs. The fully calibrated light curves for Sgr A* at all three wavelengths are presented. Typical errors in the flux density are 6.1%, 6.2%, and 9.2% at 2.0, 1.3, and 0.7 cm, respectively. There is preliminary evidence for a bimodal distribution of flux densities, which may indicate the existence of two distinct states of accretion onto the supermassive black hole. At 1.3 and 0.7 cm, there is a tail in the distribution toward high flux densities. Significant variability is detected at all three wavelengths, with the largest amplitude variations occurring at 0.7 cm. The rms deviation of the flux density of Sgr A* is 0.13, 0.16, and 0.21 Jy at 2.0, 1.3, and 0.7 cm, respectively. During much of this monitoring campaign, Sgr A* appeared to be relatively quiescent compared with results from previous campaigns. At no point during the monitoring campaign did the flux density of Sgr A* more than double its mean value. The mean spectral index of Sgr A* is α = 0.20 ± 0.01 (where Sν ∝ να), with a standard deviation of 0.14. The spectral index appears to depend linearly on the observed flux density at 0.7 cm with a steeper index observed during outbursts. This correlation is consistent with the expectation for outbursts that are self-absorbed at wavelengths of 0.7 cm or longer and inconsistent with the effects of simple models for interstellar scintillation. Much of the variability of Sgr A*, including possible time lags between flux density changes at the different wavelengths, appears to occur on timescales less than the time resolution of our observations (8 days). Future observations should focus on the evolution of the flux density on these time-scales.
Extensional collapse modes of structural members

Attenuation of the load transmitted to a vehicle occupant by the structure, either by modifying structural assembly, changing geometry of its elements, or adding specific load limiting devices to help dissipate kinetic energy was studied. General aviation aircraft have fuselage subfloors of a built up structure which are generally very stiff perpendicular to the floor of the cabin. The subfloor structure, designed to crush at an appropriate force level, can be used to advantage in a crash by dissipating energy through plastic buckling of the floor beams and frames. Simple closed form solutions to predict the mean crushing force levels of subfloor designs is useful in engineering practice. The crushing process of thin walled, plate formed, open structures with particular emphasis on L and cruciform shapes was analyzed. Lower and upper bound solutions for the mean crushing strength of cruciforms are obtained by considering modes of deformation which account for both bending and extensional deformation. It is the importance of extensional deformation to the energy absorption process, representing at least one third of the dissipated energy is shown. Previously announced in STAR as N82-33765
Perturbative bosonic end anyon spectra and contact interactions

Abstract Bosonic end perturbative calculations for quantum mechanical anyon systems require a regularization. I regularize by adding a specific δ-function potential to the Hamiltonian. The reliability of this regularization procedure is verified by comparing its results for the 2-anyon in harmonic potential system with the known exact solutions. I then use the δ-function regularized bosonic end perturbation theory to test some recent conjectures concerning the unknown portion of the many-anyon spectra.
Magnitude dependence of radiated energy spectra: Far-field expressions of slip pulses in earthquake models

[1] We examine the radiated waves emitted by events on a model fault. The model deterministically produces a complex sequence of events, with a wide range of sizes, from a uniform frictional instability. The spontaneous rupture events emit a rich spectrum of radiated waves as they nucleate, propagate, and decelerate within the complex stress field left by previous events. Two model innovations, a new driving boundary condition on the fault and a new radiating boundary condition which allows a spatially varying prestress away from the fault, allow us to directly measure the radiation without problems from boundary reflections in our two-dimensional model. We quantify the radiation by first measuring the energy spectral density and then averaging over events of a similar size to examine the magnitude dependence. Assuming only a physics of the tractions on the fault, we obtain a full spectra of radiated waves for a complex population of events with a wide range of sizes. To quantify the resulting spectra, we consider two different spectral measures. One, the peak amplitude of the spectral energy density, occurs at a period which scales with the rupture length and corresponds with the classical corner frequency measurement. The other, the peak amplitude of the spectral average acceleration or the low-frequency corner in the case of a flat acceleration spectrum, occurs at a period that scales with the duration of slip of points on the fault. The period of the peak spectral acceleration saturates for large events. Looking at the rupture motions on the fault, we find that this spectral behavior corresponds with the behavior of slip pulses in the model. Intense narrow pulses of slip develop for very long rupture events. We quantify this by measuring the mean slip duration as a function of rupture length and show that it is has the same behavior as the peak period of spectral acceleration. Thus the duration of the slip pulses in these ruptures is directly expressed in their radiated spectra. Moreover, we find that these corner periods exhibit a nontrivial dependence on event magnitude for the different frictional instabilities that we have examined, suggesting that any observed dependence of these corner periods on earthquake magnitude might provide insight into the frictional instability of earthquakes.
Read/write amplifier design considerations for MR heads

This paper presents a number of considerations that have to be taken into account when read/write amplifiers for magnetoresistive-read/inductive-write recording heads. It discusses various concepts for implementation of magnetoresistive (MR) pre-amplifiers, the noise and bandwidth obtainable, different techniques for biasing the MR sensor and a number of alternative signal sensing schemes. Different forms of required sensor protection are dealt with as well. The flagging of a number of possible mis-operations is reviewed and, finally, the write amplifier design for these MR/inductive heads is briefly touched upon. >
Lack of BV bounds for approximate solutions to the p-system with large data

We consider front tracking approximate solutions to the p-system of isentropic gas dynamics. At interaction times, the outgoing wave fronts have the same strength as in the exact solution of the Riemann problem, but some error is allowed in their speed. For large BV initial data, we construct examples showing that the total variation of these approximate solutions can become arbitrarily large, or even blow up in finite time. This happens even if the density of the gas remains uniformly positive.
Tracking Agricultural Economics Professionals

In 1998, a survey of the American Agricultural Economics Association was conducted by the Committee on Women in Agricultural Economics. The survey was the first in an ongoing tracking system, funded by the American Agricultural Economics Association Foundation, designed to track the progress of agricultural economics professionals over time, examine factors that influence their professional development, and investigate changes over time in the composition of the profession and issues influencing change. This study provides the background and objectives of the tracking system, the survey procedure, and basic demographics of the American Agricultural Economics Association and survey respondents.
A path algorithm for affine Kazhdan-Lusztig polynomials

We develop an algorithm for computing affine Kazhdan-Lusztig polynomials, for all Lie types. This generalizes our previously published algorithm for type A, which in turn is a faster version of an algorithm due to Lascouz, Leclerc and Thibon (proposed in the setting of Hecke algebras of type A, at roots of unity.)