cssi/SciSciGPT-SciSciNet huggingface dataset:
Quarks and Leptons Beyond the Third Generation

Abstract The possibility of additional quarks and leptons beyond the three generations already established is discussed. The make-up of this Report is (1) Introduction : the motivations for believing that the present litany of elementary fermions is not complete; (2) quantum numbers : possible assignments for additional fermions; (3) masses and mixing angles : mass limits from precision electroweak data, vacuum stability and perturbative gauge unification; empirical constraints on mixing angles; (4) lifetimes and decay modes : their dependence on the mass spectrum and mixing angles of the additional quarks and leptons; the possibility of exceptionally long lifetimes; (5) dynamical symmetry breaking : the significance of the top quark and other heavy fermions for alternatives to the elementary Higgs Boson; (6) CP violation : extensions to more generations and how strong CP may be solved by additional quarks; (7) experimental searches : present status and future prospects; (8) conclusions .
Color sonagrams: A new dimension in seismic data interpretation

We have developed a computer-graphic-photographic system which uses color mimicry to display the frequency spectra of seismic events simultaneously with their time-varying waveforms. Mimicking the visible light spectrum, we have used red for the low frequencies and violet for the highs. The output of our system is a variable-area-wiggletrace seismic cross-section. The waveforms are the same as those on a conventional section; however, the variable-area part of the section appears in color. The color represents the frequency spectrum of the wavelets. Lateral changes in rock attenuation show up as color shifts on this type of display. Faults often stand out as interrupted color bands. Fault diffractions sometimes have a characteristic color signature. The cancellation of high frequencies due to misalignment of events on constant-velocity stacks can show up in color. Loss of high frequencies due to slight lateral changes in moveout velocity, and consequent trace misalignment, is often indicated by a shift toward red on a color seismic section.
Polarized light propagation in biologic tissue and tissue phantoms

Imaging through biologic tissue relies on the discrimination of weakly scattered from multiply scattered photons. The degree of polarization can be used as the discrimination criterion by which to reject multiply scattered photons. Polarized light propagation through biologic tissue is typically studied using tissue phantoms consisting of dilute aqueous suspensions of microspheres. We show that, although such phantoms are designed to match the macroscopic scattering properties of tissue they do not accurately represent biologic tissue for polarization-sensitive studies. In common tissue phantoms, such as dilute Intralipid and dilute 1-micrometers -diameter polystyrene microsphere suspensions, we find that linearly polarized light is depolarized more quickly polarized light. In dense tissue, however, where scatterers are often located in close proximity to one another, circularly polarized light is depolarized similar to or more quickly than linearly polarized light. We also demonstrate that polarized light propagates differently in dilute versus densely packed microsphere suspensions, which may account for the differences seen between polarized light propagation in common dilute tissue phantoms versus dense biologic tissue.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
DUST EMISSION FROM UNOBSCURED ACTIVE GALACTIC NUCLEI

We use mid-infrared (MIR) spectroscopy of unobscured active galactic nuclei (AGNs) to reveal their native dusty environments. We concentrate on Seyfert 1 galaxies, observing a sample of 31 with the Infrared Spectrograph aboard the Spitzer Space Telescope, and compare them with 21 higher luminosity quasar counterparts. Silicate dust reprocessing dominates the MIR spectra, and we generally measure the 10 and 18 {mu}m spectral features weakly in emission in these galaxies. The strengths of the two silicate features together are sensitive to the dust distribution. We present numerical radiative transfer calculations that distinguish between clumpy and smooth geometries, which are applicable to any central heating source, including stars as well as AGNs. In the observations, we detect the obscuring 'torus' of unified AGN schemes, modeling it as compact and clumpy. We also determine that star formation increases with AGN luminosity, although the proportion of the galaxies' bolometric luminosity attributable to stars decreases with AGN luminosity.
Montmorillonite clay-catalyzed cyclotrimerization and oxidation of aliphatic aldehydes

A temperature-dependent equilibrium is observed for the cyclotrimerization of aliphatic aldehydes in the presence of Montmorillonite K10 clay, while aerobic oxidation of aliphatic aldehydes to the corresponding carboxylic acids is favored at room temperature in the presence of Montmorillonite KSF clay.
The Anthropology of Online Search Strategy Formation: A Study of Four Countries.

This paper discusses the results of a survey sent to online searchers in four countries: the United Kingdom, the United States, Australia and Canada. The survey form provided a sample question and asked searchers to prepare a preliminary strategy for a search in the Sociological Abstracts database. American searchers depend on controlled vocabulary much more than British searchers. Australian searchers have created their own search pattern, while Canadian searchers have blended the American and British patterns. In reviewing results of the searches, over half of the citations retrieved were retrieved by more than one search. Australian searchers were more likely to retrieve items that no other search retrieved, while Canadian searchers had the highest overlap rate.
How deep cells feel: Mean-field Computations and Experiments

Most cells in solid tissues exert contractile forces that mechanically couple them to elastic surroundings and that significantly influence cell adhesion, cytoskeletal organization, and even cell differentiation. However, strains within the depths of matrices are often unclear and are likely relevant not only to the fact that some matrices such as so-called basement membranes are thin relative to cell dimensions but also to defining how far cells can ‘feel’. Here we present experimental results for cell spreading on thin, ligand-coated gels and for prestress in stem cells in relation to gel stiffness. Spread area on thin and soft gels was found to resemble cells on thick and stiff gels. Matrix thickness also affects focal adhesions and cytoskeleton organization in stem cells, which we will compare to differentiated cells. We introduce a finite element computation in which a cell is placed on an elastic matrix, while matrix elasticity and thickness are varied in order to compute and compare elastostatic deformations within the matrix. Average interfacial strains between cell and matrix show large deviations only when soft matrices are a fraction of the height and width of a cell, proving consistent with experiments. Three-dimensional (3D) cell morphologies that model stem cell-derived neurons, myoblasts, and osteoblasts show that a cylinder-shaped myoblast induces the highest strains, consistent with the prominent contractility of muscle. Groups of such cells show a weak crosstalk in matrix strains, but the cells must be much closer than a cell-width - experimental tests of this are emerging. Cells thus feel on length scales closer to that of adhesions than on cellular scales or larger.
Efficient optimistic parallel simulations using reverse computation

In optimistic parallel simulations, state-saving techniques have traditionally been used to realize rollback. In this article, we propose reverse computation as an alternative approach, and compare its execution performance against that of state-saving. Using compiler techniques, we describe an approach to automatically generate reversible computations, and to optimize them to reap the performance benefits of reverse computation transparently. For certain fine-grain models, such as queuing network models, we show that reverse computation can yield significant improvement in execution speed coupled with significant reduction in memory utilization, as compared to traditional state-saving. On sample models using reverse computation, we observe as much as a six-fold improvement in execution speed over traditional state-saving.
Combinatorial Reciprocity Theorems

A common theme of enumerative combinatorics is formed by counting functions that are polynomials evaluated at positive integers. In this expository paper, we focus on four families of such counting functions connected to hyperplane arrangements, lattice points in polyhedra, proper colorings of graphs, and P-partitions. We will see that in each instance we get interesting information out of a counting function when we evaluate it at a negative integer (and so, a priori the counting function does not make sense at this number). Our goals are to convey some of the charm these “alternative” evaluations of counting functions exhibit, and to weave a unifying thread through various combinatorial reciprocity theorems by looking at them through the lens of geometry, which will include some scenic detours through other combinatorial concepts.
Flow Analysis of X-34 Main Propulsion System Feedlines

This viewgraph presentation reviews the flow analysis of the propulsion feedlines in the X-34. The objective of the analysis was to determine the flow development at the engine interface, and to predict the pressure drop in the feedline. The presentation shows the design of the feedlines, and the computational grids. It reviews the numerical method, which included solving the curvilinear coordinate transport equations. Line graphs review the computational fluid dynamic results. The results and conclusions are also presented.
Very Large Format Back Illuminated CCDs

The University of Arizona Imaging Technology Laboratory has processed several types of very large format (> 4K×4K pixel) charge coupled devices for low light level scientific applications. These back illuminated devices were produced from frontside die fabricated by or for Fairchild Imaging Systems, Semiconductor Technology Associates, the Jet Propulsion Laboratory, and Kodak. A Philips 7K×9K frontside device has also been processed using similar techniques. The backside sensors yield >90% quantum efficiency (QE). All devices show excellent charge transfer efficiency (CTE>0.999997) at operating temperatures (typically −100 °C). Devices specifically designed for low signal applications have been demonstrated with less than 4 electrons read noise.
Rf and space-charge effects in laser-driven rf electron guns

Abstract The evolution of the electron-beam phase space distribution in laser-driven rf guns is studied by taking into account both the time variation of the rf field and space-charge effects. In particular, simple formulas are derived for the transverse and longitudinal emittances at the exit of the gun. The results are compared and found to agree well with those from simulation.
Measurement-noise maximum as a signature of a phase transition

We propose that a maximum in measurement noise can be used as a signature of a phase transition. As an example, we study the energy and magnetization noise spectra associated with first- and second-order phase transitions by using Monte Carlo simulations of the Ising model and 5-state Potts model in two dimensions. For a finite size system, the total noise power and the low frequency white noise $S(fl{f}_{\mathrm{knee}})$ increase as ${T}_{c}$ is approached. In the thermodynamic limit, $S(fl{f}_{\mathrm{knee}})$ diverges but ${f}_{\mathrm{knee}}\ensuremath{\rightarrow}0$ and the total noise power vanishes. ${f}_{\mathrm{knee}}^{\ensuremath{-}1}$ is approximately the equilibration time.
Metal Abundance Calibration of the Ca II Triplet Lines in RR Lyrae Stars

The Gaia satellite is likely to observe thousands of RR Lyrae Stars with a small spectral range, between 8470 A to 8750 A, at a resolution of 11,500. In order to derive metallicity from Gaia, we have obtained numerous spectra of RR Lyrae stars at a resolution of 35,000 with the Apache Point Observatory 3.5 m echelle spectrograph. We have correlated Ca(II) triplet line strengths with metallicity as derived from Fe(II) abundances, analogous to Preston (Astrophys. J., 130:507, 1959) use of the Ca(II) K line to estimate metallicity in RR Lyrae Stars.
Income inequality and the business cycle: A threshold cointegration approach

Abstract This paper investigates the impact of various socio-economic variables on various cohorts of the income distribution. We use asymmetric cointegration tests to show that unemployment and immigration shocks have real impacts on income inequality. In addition, using threshold test results we are able to show that positive and negative shocks to the economy do not have symmetric effects nor do the impacts of these shocks impact income quintiles uniformly.
The Economics of American Sports Leagues

Player mobility in North American sports leagues is limited by labour market constraints designed ostensibly to allow teams to recoup player development costs and to maintain competitive balance within leagues. Theory holds that the distribution of talent will be invariant under any institutional configuration, and that while rules to constrain movement will serve to enhance monopsonistic exploitation of talent, they will have no effect on competitive balance. This paper reprises a general theory through which the effects of the labour market constraints can be comparatively analysed for American sports leagues. The economics of sports has been relegated to the realm of labour theory by the unnecessarily limiting assumption that owners of sports clubs are single-minded profit maximisers. This paper also presents a theory that seeks to unify capital market decisions of financial leverage and ownership syndication with operational labour market decisions for athletic talent and an owner’s desire to win.
The Real Exchange Rate and Real Interest Differentials: The Role of the Trend-Cycle Decomposition

We propose an alternative model and method to reconcile the puzzling feature in the relationship between the real exchange rate and real interest rate differentials. Our simple two-country model with preset prices, along with firms’ misperception about the future exchange rate, implies that the real exchange rate follows an ARIMA(0,1,p) process. This allows us to compute the exact Beveridge-Nelson decomposition, which is a model-consistent decomposition. In accordance with our model, unit roots in the real exchange rates are found; and statistical inference is partially found to be affirmative regarding the link between the real exchange rate detrended by the Beveridge-Nelson decomposition and corresponding real interest differentials.
Management of febrile children with urinary tract infections

Abstract This study of the management of children with fever and urinary tract infection (UTI) was conducted to identify factors associated with initial admission, outpatient treatment, and outpatient treatment failure. A retrospective chart review identified children 3 months to 16 years of age with an emergency department (ED) diagnosis of cystitis, pyelonephritis, or UTI, a positive urine culture, and an ED temperature of >38°C. Sixty-nine patients (90% female) were studied; 19% were admitted initially. Age younger than 2 years was associated with admission ( P v 39.2°C, P = .03, Mann-Whitney U ) but was unrelated to age, initial white blood cell count, or use of parenteral antibiotics. These results indicate that most children with fever and UTI do not require hospital admission; those with temperatures of ≥40°C are at increased risk for outpatient failure.
DESIGN OF DEEP STALL PROTECTION FOR THE C-17A

The design of the C-17 angle-of-attack limiter system is presented. TheC-17, because of its T-tail, has a locked-in deep stall potential in some aft center of gravity con gurations. The angle-of-attack system uses alpha measurements from three pairs of vanes for precise angle-of-attack control and to prevent excursion into the deep stall region. The vanes, because of their locations, are sensitive to sideslip angle excursions in varyingdegrees, therefore, requiring sideslip angle information for proper failure monitoring.A method of synthesizing sideslip and angle of attack using the information from the vanes was developed. With the synthesized angle of attack and sideslip, it was possible to provide a minimumof fail-operational-fail-operationalcapabilitywith tight failure tolerance. After over 2000 stall tests and assaults to alpha limit, the pilot community has gained the con dence that the system will protect the C-17 from entering the locked-in deep stall region.
The gravitational lens as an intergalactic communication tool

Abstract The gravitational lens, a consequence of general relativistic light bending with perfect or near-perfect observer-bender-object alignment, is now a well-studied natural phenomenon. Primarily an astrophysical tool for galactic and dark matter mass estimation, it may also have applications to SETI via gain enhancement of the ETI signal (a “gravity lens gain system”, or GLGS). It has been shown that gains of up to 80 dB may be achieved, making a GLGS a superior gain system for all save the most large-scale reflection systems. A “typical” application of a gravity lens may be realized through a special type of microlensing, where the transmitter (or receiver) orbits a compact or collapsed star. One or more satellites may sweep out a “lensing cone” which will result in an intense, transient signal at the observer sight. Unlike normal stars, collapsed stars afford very small (⪡ 1 AU) orbits which allow for repetitive sweeps of the lensing cone across a region of sky. Steady-state alignment, although imaginable, may be impossible to achieve over interstellar or intergalactic distances. It is much more likely that the swept-gain orbiting system would be used in SETI. The gravitational lens may not be necessary for interstellar spans since sufficient EIRP can be achieved in other ways. However, it may be a method of choice for intergalactic transmissions since only Type III civilizations would be able to route sufficient EIRP's otherwise. Less advanced civilizations may use gravity lenses as a method of achieving very large EIRP's with their available technology. The signature of a lensed signal is a transient (less than 1 millisecond at peak) signal. For any degree of information to be conveyed the bandwidth must be large. Any inherent phase-frequency-amplitude modulation will be affected by the dynamics of the lens amplification and appropriate encoding/decoding schemes ae discussed. High time resolution/broad bandwidth modes are suggested as a scenario for extragalactic SETI. VLBI is suggested for it allows for automatic bit checking of the extraterrestrial transmission.
A subwavelength plasmonic metamolecule exhibiting magnetic-based optical Fano resonance

We demonstrate that a subwavelength plasmonic metamolecule consisting of four nanoparticles supports a magnetic response spectrally overlapped with the electric dipole resonance. Small structural asymmetries lead to interference and thus a Fano resonance in scattering.
Detecting the Rapidly Expanding Outer Shell of the Crab Nebula: Where to Look

We present a range of steady-state photoionization simulations, corresponding to different assumed shell geometries and compositions, of the unseen postulated rapidly expanding outer shell to the Crab Nebula. The properties of the shell are constrained by the mass that must lie within it, and by limits to the intensities of hydrogen recombination lines. In all cases the photoionization models predict very strong emissions from high ionization lines that will not be emitted by the Crab's filaments, alleviating problems with detecting these lines in the presence of light scattered from brighter parts of the Crab. The near-NIR [Ne VI] λ7.652 μm line is a particularly good case; it should be dramatically brighter than the optical lines commonly used in searches. The C IV λ1549 doublet is predicted to be the strongest absorption line from the shell, which is in agreement with Hubble Space Telescope observations. We show that the cooling timescale for the outer shell is much longer than the age of the Crab, due to the low density. This means that the temperature of the shell will actually "remember" its initial conditions. However, the recombination time is much shorter than the age of the Crab, so the predicted level of ionization should approximate the real ionization. In any case, it is clear that IR observations present the best opportunity to detect the outer shell and so guide future models that will constrain early events in the original explosion.
Metrics for Matrix-valued Measures via Test Functions

It is perhaps not widely recognized that certain common notions of distance between probability measures have an alternative dual interpretation which compares corresponding functionals against suitable families of test functions. This dual viewpoint extends in a straightforward manner to suggest metrics between matrix-valued measures. Our main interest has been in developing weakly-continuous metrics that are suitable for comparing matrix-valued power spectral density functions. To this end, and following the suggested recipe of utilizing suitable families of test functions, we develop a weakly-continuous metric that is analogous to the Wasserstein metric and applies to matrix-valued densities. We use a numerical example to compare this metric to certain standard alternatives including a different version of a matricial Wasserstein metric developed in [1], [2].
Boundary conformal field theories, limit sets of Kleinian groups and holography

Abstract In this paper, based on the available mathematical works on geometry and topology of hyperbolic manifolds and discrete groups, some results of Friedman et al. (Nuclear Phys. B 456 (1999) 96–118) are reproduced and broadly generalized. Among many new results, the possibility of extension of work of Belavin, Polyakov and Zamolodchikov to higher dimensions is investigated. Objections known in the physical literature against such an extension are removed and the possibility of an extension is convincingly demonstrated.
Capital use intensity and productivity biases

Measures of productivity growth are often pro-cyclical. This paper focuses on measurement errors in capital inputs, associated with unobserved variations in capital utilization rates, as an explanation for the existence of pro-cyclical patterns in measures of productivity. Recently constructed national and state-specific indexes of inputs, outputs, and productivity in U.S. agriculture for 1949–2002 are used to estimate production functions that include proxy variables for changes in the utilization of durable inputs. The proxy variables include an index of farmers’ terms of trade and an index of local seasonal growing conditions. We find that utilization responses by farmers are significant and bias measures of productivity growth in a pro-cyclical pattern. We quantify the bias, adjust the measures of productivity for the estimated utilization responses, and compare the adjusted and conventional measures.
Coloring H-free hypergraphs

Fix r ≥ 2 and a collection of r-uniform hypergraphs $\cal{H}$. What is the minimum number of edges in an $\cal{H}$-free r-uniform hypergraph with chromatic number greater than k? We investigate this question for various $\cal{H}$. Our results include the following: An (r,l)-system is an r-uniform hypergraph with every two edges sharing at most l vertices. For k sufficiently large, there is an (r,l)-system with chromatic number greater than k and number of edges at most c(kr-1 log k)l-(l-1), where $$c=2\left( {100(r)^{2}_{l} \over {l!}}\right)^{1/(l-1)} \left( {10(r-1) \over {l-1}}\right)^{l/(l-1)}.$$This improves on the previous best bounds of Kostochka et al. (Random Structures Algorithms 19 (2001), 87–98). The upper bound is sharp apart from the constant c as shown in (Random Structures Algorithms 19 (2001) 87–98). The minimum number of edges in an r-uniform hypergraph with independent neighborhoods and chromatic number greater than k is of order kr+1-(r-1) log O(1)k as k → ∞. This generalizes (aside from logarithmic factors) a result of Gimbel and Thomassen (Discrete Mathematics 219 (2000), 275–277) for triangle-free graphs. Let T be an r-uniform hypertree of t edges. Then every T-free r-uniform hypergraph has chromatic number at most 2(r - 1)(t - 1) + 1. This generalizes the well-known fact that every T-free graph has chromatic number at most t. Several open problems and conjectures are also posed. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2010
TOO BIG TO FAIL IN BANKING: WHAT DOES IT MEAN?

Abstract Interest in too big to fail (TBTF) resolutions of insolvent large complex financial firms has intensified in recent years. TBTF resolutions protect some in-the-money counterparties of a targeted insolvent firm from losses that they would suffer if the usual bankruptcy resolution regimes used in resolving other firms in the industry were applied. Although special TBTF resolution regimes may reduce the collateral spill-over costs of the failure, the combined direct and indirect costs from such “bailouts” may be large and often financed in part or in total by taxpayers. Thus, TBTF has become a major public policy issue that has not been resolved in part because of disagreements about definitions and thereby the estimates of the benefits and costs. This paper explores these differences and develops a framework for standardizing the definitions and evaluating the desirability of TBTF resolutions more accurately.
Ring opening of sialyllactones with glycine esters: Synthesis of selectively protected glycinyl-NeuAc saccharopeptides

Abstract Two different classes of sialyllactones were prepared as potential substrates for ring opening reactions with naturally occurring amino acids. The sialyllactones underwent reaction with glycine ethyl ester hydrochloride salt to afford selectively protected glycine-NeuAc adducts. The reactions could be performed on NeuAc derivatives capable of serving as glycosylation donors. These compounds represent a new class of saccharopeptides, composed of sugar amino acids and naturally occurring amino acids.Two different classes of sialyllactones were prepared as potential substrates for ring opening reactions with naturally occurring amino acids. The sialyllactones underwent reaction with glycine ethyl ester hydrochloride salt to afford selectively protected glycine-NeuAc adducts. The reactions could be performed on NeuAc derivatives capable of serving as glycosylation donors. These compounds represent a new class of saccharopeptides, composed of sugar amino acids and naturally occurring amino acids.
SOFIA: Stratospheric Observatory for Infrared Astronomy

SOFIA is a planned 2.5 meter telescope to be installed in a Boeing 747 aircraft and operated at altitudes from 41,000 to 46,000 feet. It will provide astronomers with routine access to infrared wavelengths unavailable from the ground, and with the means to observe astronomical objects and transient events from anywhere in the world. The concept is based on 17 years of experience with NASA’s Kuiper Airborne Observatory (KAO), which SOFIA would replace. The facility would be developed and operated by NASA and the German Space Agency DARA.
First-principles theory of structural phase transitions for perovskites: Competing instabilities

Abstract We extend our previous first-principles theory for perovskite ferroelectric phase transitions to treat also antiferrodistortive phase transitions. Our approach involves construction of a model Hamiltonian from a Taylor expansion, first-principles calculations to determine expansion parameters, and Monte-Carlo simulations to study the resulting system. We apply this approach to three cubic perovskite compounds, SrTiO3, CaTiO3 and NaNbO3, that are known to undergo antiferrodistortive phase transitions. We calculate their transition sequences and transition temperatures at the experimental lattice constants. For SrTiO3, we find our results agree well with experiment. For more complicated compounds like CaTiO3 and NaNbO3. which can have many different structures with very similar energy, the agreement is somewhat less satisfactory.
THE PHOTOIONIZED ACCRETION DISK IN HER X-1

We present an analysis of several high-resolution Chandra grating observations of the X-ray binary pulsar Her X-1. With a total exposure of 170 ks, the observations are separated by years and cover three combinations of orbital and superorbital phases. Our goal is to determine distinct properties of the photoionized emission and its dependence on phase-dependent variations of the continuum. We find that the continua can be described by a partial covering model which above 2 keV is consistent with recent results from Rossi X-Ray Timing Explorer studies and at low energies is consistent with recent XMM-Newton and BeppoSAX studies. Besides a power law with fixed index, an additional thermal blackbody of 114 eV is required to fit wavelengths above 12 A (~1 keV). We find that likely all the variability is caused by highly variable absorption columns in the range (1-3) × 1023 cm–2. Strong Fe K line fluorescence in almost all observations reveals that dense, cool material is present not only in the outer regions of the disk but interspersed throughout the disk. Most spectra show strong line emission stemming from a photoionized accretion disk corona (ADC). We model the line emission with generic thermal plasma models as well as with the photoionization code XSTAR and investigate changes of the ionization balance with orbital and superorbital phases. Most accretion disk coronal properties such as disk radii, temperatures, and plasma densities are consistent with previous findings for the low state. We find that these properties change negligibly with respect to orbital and superorbital phases. A couple of the higher energy lines exhibit emissivities that are significantly in excess of expectations from a static ADC.
Synthesis and Structure Revision of Nakiterpiosin

This manuscript describes a convergent synthesis and the revision of the relative stereochemistry of nakiterpiosin, a marine C-nor-D-homosteroid. Our synthesis features a late-stage carbonylative Stille cross-coupling reaction and a photo-Nazarov cyclization reaction that deliver the complete nakiterpiosin skeleton efficiently.
The effects of dissolved methane upon liquid argon scintillation light

In this paper we report on measurements of the effects of dissolved methane upon argon scintillation light. We monitor the light yield from an alpha source held 20 cm from a cryogenic photomultiplier tube (PMT) assembly as methane is injected into a high-purity liquid argon volume. We observe significant suppression of the scintillation light yield by dissolved methane at the 10 part per billion (ppb) level. By examining the late scintillation light time constant, we determine that this loss is caused by an absorption process and also see some evidence of methane-induced scintillation quenching at higher concentrations (50-100 ppb). Using a second PMT assembly we look for visible re-emission features from the dissolved methane which have been reported in gas-phase argon methane mixtures, and we find no evidence of visible re-emission from liquid-phase argon methane mixtures at concentrations between 10 ppb and 0.1%.
Detection of solar wind at synchronous orbit

The detection of unshocked solar wind by the plasma detector on the ATS-5 synchronous satellite is reported. The fact that solar wind particles were detected means that the flow vector must have been nearly perpendicular to the spin axis of the spacecraft. Comparisons of fluxes and protons before and after the event tend to indicate that the flow vector in the magnetosheath is inclined not more than 20 deg to the equatorial plane.
Water and the thermal evolution of carbonaceous chondrite parent bodies

Two hypotheses are proposed for the aqueous alteration of carbonaceous chondrites within their parent bodies, in which respectively the alteration occurs (1) throughout the parent body interior, or (2) in a postaccretional surface regolith; both models assume an initially homogeneous mixture of ice and rock that is heated through the decay of Al-26. Water is seen to exert a powerful influence on chondrite evolution through its role of thermal buffer, permitting substitution of a low temperature aqueous alteration for high temperature recrystallization. It is quantitatively demonstrated that liquid water may be introduced by either hydrothermal circulation, vapor diffusion from below, or venting due to fracture.
Terrestrial measurement of the performance of high-rejection optical baffling systems.

Spatial rejection is critical when exo-atmospheric or in situ radiometric measurements of faint sources, such as air glow emissions, are made in the presence of relatively intense sources such as the sun, moon, or earth. Scattering from atmospheric molecules and aerosols during evaluation in an earth-bound laboratory makes the high-rejection baffle appear to be less effective than it actually is in the measurement situation. A Monte Carlo computer program SCAT was written to predict the effects of atmospheric scattering upon field-of-view calibration measurements of optical baffling systems. It was found that Mie scattering could be reduced in a clean room environment and Rayleigh scattering was determined to be the limiting mechanism in a special chamber designed for off-axis measurements. The background flux at 40° off axis was found to be 1 x 10-9 of the on-axis incident flux for a 5° full-angle baffle when illuminated by a 10.2 cm diameter collimated beam. A two-step process was used to measure a baffle response at 40° off axis down to 1 x 10-11 of the on-axis incident flux.
Use of personal computing technology by deaf-blind individuals

This paper describes a system that enables deaf-blind people to work with micro-computers. This system utilizes the International Morse Code as a general communication medium. The deaf-blind person "hears" Morse Code via a vibrotactile device to "see" the computer's screen. This technique enables deaf-blind individuals to receive immediate feedback of their typing and scan the screen, thus making it possible for them to use the keyboard and screen in much the normal manner of seeing persons. A side benefit is that it provides a means for deaf-blind people to communicate with the sighted through a common medium: the sighted person can see the screen while the deaf-blind feels it. Hardware cost to equip a standard personal computer with this interface is negligible. Vibrotactile Morse Code is particularly viable because it can be adapted fro the individual's particular tactile sensitivities. Morse encoded tactile communication fits well in a social facilitation context for learning. It is technologically simple and standard. This work can significantly improve the quality of life for dear-blind individuals because it provides new opportunities for communication and vocation.
A Data Filter for Identifying Steady-State Operating Points in Engine Flight Data for Condition Monitoring Applications

Abstract This paper presents an algorithm that automatically identifies and extracts steady-state engine operating points from engine flight data. It calculates the mean and standard deviation of select parameters contained in the incoming flight data stream. If the standard deviation of the data falls below defined constraints, the engine is assumed to be at a steady-state operating point, and the mean measurement data at that point are archived for subsequent condition monitoring purposes. The fundamental design of the steady-state data filter is completely generic and applicable for any dynamic system. Additional domain-specific logic constraints are applied to reduce data outliers and variance within the collected steady-state data. The filter is designed for on-line real-time processing of streaming data as opposed to post-processing of the data in batch mode. Results of applying the steady-state data filter to recorded helicopter engine flight data are shown, demonstrating its utility for engine condition monitoring applications.
From non-Hermitian effective operators to large-scale no-core shell model calculations for light nuclei

No-core shell model (NCSM) calculations using ab initio effective interactions are very successful in reproducing experimental nuclear spectra. The main theoretical approach is the use of effective operators, which include correlations left out by the truncation of the model space to a numerically tractable size. We review recent applications of the effective operator approach, within a NCSM framework, to the renormalization of the nucleon-nucleon interaction, as well as scalar and tensor operators.
Solution-mediated effect of bioactive glass in poly (lactic-co-glycolic acid)–bioactive glass composites on osteogenesis of marrow stromal cells

A previous study demonstrated that the incorporation of bioactive glass (BG) into poly (lactic-co-glycolic acid) (PLGA) can promote the osteoblastic differentiation of marrow stromal cells (MSCs) on PLGA by promoting the formation of a calcium-phosphate-rich layer on its surface. To further understand the mechanisms underlying the osteogenic effect of PLGA-BG composite scaffolds, whether solution-mediated factors derived from composite scaffolds/hybrids can promote osteogenesis of marrow stromal cells was tested. The dissolution product from PLGA-30%BG scaffold stimulated osteogenesis of MSCs, as was confirmed by increased mRNA expression of osteoblastic markers such as osteocalcin (OCN), alkaline phosphatase (ALP), and bone sialoprotein (BSP). The three-dimensional structure of the scaffolds may contribute to the production of cell-derived factors that promoted distant MSC differentiation. Thus PLGA-BG composites demonstrate significant potential as a bone-replacement material.
The Gauss-Bonnet theorem for vector bundles

We give a short proof of the Gauss-Bonnet theorem for a real oriented Riemannian vector bundle E of even rank over a closed compact orientable manifold M. This theorem reduces to the classical Gauss-Bonnet-Chern theorem in the special case when M is a Riemannian manifold and E is the tangent bundle of M endowed with the Levi-Civita connection. The proof is based on an explicit geometric construction of the Thom class for 2-plane bundles.
Nuclear electron capture in a plasma

We consider the electron density at the position of an ion of charge Ze in a plasma under conditions approximating those in the core of the Sun. Numerical calculations have shown that the plasma effects on the density, over and above the ordinary Coulomb factor for a single electron in the vicinity of the ion, are well represented by a reduction factor, exp (-Ze2βκD), where β is the inverse temperature and κD is the Debye wavelength. Although this factor is the direct analog of the Salpeter enhancement factor for the fusion rates in stars, the elementary considerations that establish it in the fusion case are not applicable to the determination of the electron density and the resulting electron-capture rates. We show analytically, through a sum rule that leads to a well-defined perturbative approach, that in the limit of Boltzmann statistics, the Salpeter factor indeed provides the leading correction. We estimate residual effects both from Fermi statistics and from short-range terms.
Glueballs and hybrids (gluons as constituents)

Abstract After a brief introduction to hybrid and glueball source operators, I summarize recent lattice results for these particles.
Modeling of sudden hydrogen expansion from cryogenic pressure vessel failure

Abstract We have modeled sudden hydrogen expansion from a cryogenic pressure vessel. This model considers real gas equations of state, single and two-phase flow, and the specific “vessel within vessel” geometry of cryogenic vessels. The model can solve sudden hydrogen expansion for initial pressures up to 1210 bar and for initial temperatures ranging from 27 to 400 K. For practical reasons, our study focuses on hydrogen release from 345 bar, with temperatures between 62 K and 300 K. The pressure vessel internal volume is 151 L. The results indicate that cryogenic pressure vessels may offer a safety advantage with respect to compressed hydrogen vessels because i) the vacuum jacket protects the pressure vessel from environmental damage, ii) hydrogen, when released, discharges first into an intermediate chamber before reaching the outside environment, and iii) working temperature is typically much lower and thus the hydrogen has less energy. Results indicate that key expansion parameters such as pressure, rate of energy release, and thrust are all considerably lower for a cryogenic vessel within vessel geometry as compared to ambient temperature compressed gas vessels. Future work will focus on taking advantage of these favorable conditions to attempt fail-safe cryogenic vessel designs that do not harm people or property even after catastrophic failure of the inner pressure vessel.
Nonequilibrium thermal transport and its relation to linear response

We study the real-time dynamics of spin chains driven out of thermal equilibrium by an initial temperature gradient ${T}_{L}\ensuremath{\ne}{T}_{R}$ using density matrix renormalization group methods. We demonstrate that the nonequilibrium energy current saturates fast to a finite value if the linear-response thermal conductivity is infinite, i.e., if the Drude weight $D$ is nonzero. Our data suggest that a nonintegrable dimerized chain might support such dissipationless transport ($Dg0$). We show that the steady-state value ${J}_{E}$ of the current for arbitrary ${T}_{L}\ensuremath{\ne}{T}_{R}$ is of the functional form ${J}_{E}=f({T}_{L})\ensuremath{-}f({T}_{R})$, i.e., it is completely determined by the linear conductance. We argue for this functional form, which is essentially a Stefan-Boltzmann law in this integrable model; for the XXX ferromagnet, $f$ can be computed via the thermodynamic Bethe ansatz in good agreement with the numerics. Inhomogeneous systems exhibiting different bulk parameters as well as Luttinger liquid boundary physics induced by single impurities are discussed briefly.
Star Formation in a Crossing Time

Observations suggest that star formation occurs in only one or two crossing times for a range of scales spanning a factor of ~1000. These observations include (1) measurements of embedded cluster ages in comparison with the cloud core dynamical times, (2) measurements of the age difference versus separation for clusters in the Large Magellanic Clouds in comparison with the crossing time versus size correlation for molecular clouds, (3) the hierarchical structure of embedded young clusters, and (4) the high fraction of dense clouds that contain star formation. Such a short overall timescale for star formation implies that sources of turbulent energy or internal feedback are not required to explain or extend cloud lifetimes and that star and protostar interactions cannot be important for the stellar initial mass function. Stars appear in a cloud as if they freeze out of the gas, preserving the turbulent-driven gas structure in their birth locations. The Galaxy-wide star formation rate avoids the Zuckerman-Evans catastrophe, which has long been a concern for molecular clouds that evolve this quickly, because the multifractal structure of interstellar gas ensures that only a small fraction of the mass is able to form stars. Star formation on large scales operates more slowly than on small scales, but in most cases the whole process is over in only a few dynamical times.
Augmented thrust and mass flow associated with two-dimensional jet reattachment

Etude experimentale de l'augmentation de debit massique et de poussee associee a l'ecoulement d'un jet bidimensionnel incompressible sortant parallelement a une paroi adjacente
Obtain a Simulation Model of a Pedestrian Collision Imminent Braking System Based on the Vehicle Testing Data

Forward pedestrian collision imminent braking (CIB) systems have proven to be of great significance in improving road safety and protecting pedestrians. Since pedestrian CIB technology is not mature, the performance of different pedestrian CIB systems varies significantly. Therefore the simulation of a CIB system needs to be vehicle specific. The CIB simulation can be based on the component sensor parameters and decision making rules. Since these parameters and decision rules for on the market vehicles are not available outside of vehicle manufacturers, it is difficult for the general research communities to develop a good CIB simulation model based on this approach. To solve this problem, this study presents a new method for developing a pedestrian CIB simulation model using pedestrian CIB testing data. The implementation was in PreScan. The simulation results demonstrate that a pedestrian CIB simulation model developed using this methodology could reflect the behavior of a real vehicle equipped with a pedestrian CIB system.
Imbalanced Feshbach-resonant Fermi gases

We present an overview of recent developments in species-imbalanced ('polarized') Feshbach-resonant Fermi gases. We summarize the current status of thermodynamics of these systems in terms of a phase diagram as a function of the Feshbach resonance detuning, polarization and temperature. We review instabilities of the s-wave superfluidity across the Bose–Einstein condensation-to-Bardeen–Cooper–Schrieffer crossover to phase separation, Fulde–Ferrell–Larkin–Ovchinnikov states, polarized molecular superfluidity and the normal state, driven by the species imbalance. We discuss different models and approximations of this system and compare their predictions with current experiments.
Structural and Mechanical Design of Tokamaks

The UWMAK series of reactor studies have assessed the technological problems associated with the design and construction of a working power reactor. A procedure has been developed to evaluate the quality of magnet design by a comparison to a minimum mass system established by the virial theorem. Failure and fault analyses and material selection for the many diverse environments are critical for long term reliability. Overall structural compatibility and multipurpose use of structural components are also emphasized.
Pushing Scientists into the Marketplace: Promoting Science Entrepreneurship:

The need to play catch-up in biotechnology has led Germany and Japan to adopt novel technology policies. While policies to assist domestic industries have traditionally been geared toward incumbent firms, current trends revolve around "science entrepreneurship"—reforms in the national R&D system and targeted incentives for biotechnology scientists to file patents and start up their own firms. Japan in particular has recognized that catching up with the U.S. in basic science and in the commercialization of scientific research represents a kind of final frontier.
Evaluation and Management of the Elderly Patient at Risk for Postoperative Delirium

Geriatric patients are at a high risk for the development of postoperative delirium. By recognizing predisposing and precipitating risk factors, preventive measures can be undertaken to reduce this risk. Accurate and timely diagnosis is essential, and we offer therapeutic strategies to help reduce the high morbidity and mortality of this important condition.
Photoassisted, iron-catalyzed allylic amination of olefins with nitroarenes

Abstract Olefins react with nitroarenes and carbon monoxide photochemically in the presence of [Cp*Fe(CO) 2 ] 2 (Cp*=η 5 -C 5 Me 5 ) to produce N -aryl- N -allyl amines in moderate to good yields. Unsymmetrical olefins react highly regioselectively with N -functionalization at the less substituted vinylic carbon. Mechanistic probes using 2′-nitrobiphenyl, 2,3-dimethylbutadiene and nitrosobenzene suggest that neither aryl nitrenes nor nitrosoarenes are the active aminating agents in these reactions.