cssi/SciSciGPT-SciSciNet huggingface dataset:
POSSIBLE NEW BUBBLE PHASES OF TWO-DIMENSIONAL ELECTRONS IN HIGHER LANDAU LEVELS

We argue that, due to the specific form of the interaction potential between electronic guiding centers, a bubble crystal (BC) with basis may be energetically more favorable than the usual bubble solid. This new BC has well-defined normal eigenmodes, and remains energetically favorable when the effects of finite sample thickness and of screening by electrons in lower LLs are taken into account.
Influence of Coolant Density on Turbine Platform Film-Cooling With Stator–Rotor Purge Flow and Compound-Angle Holes

A detailed parametric study of film-cooling effectiveness was carried out on a turbine blade platform. The platform was cooled by purge flow from a simulated stator-rotor seal combined with discrete hole film-cooling. The cylindrical holes and laidback fan-shaped holes were accessed in terms of film-cooling effectiveness. This paper focuses on the effect of coolant-to-mainstream density ratio on platform film-cooling (DR = 1 to 2). Other fundamental parameters were also examined in this study — a fixed purge flow of 0.5%, three discrete-hole film-cooling blowing ratios between 1.0 and 2.0, and two freestream turbulence intensities of 4.2% and 10.5%. Experiments were done in a five-blade linear cascade with inlet and exit Mach number of 0.27 and 0.44, respectively. Reynolds number of the mainstream flow was 750,000 and wad based on the exit velocity and chord length of the blade. The measurement technique adopted was conduction-free pressure sensitive paint (PSP) technique. Results indicated that with the same density ratio, shaped holes present higher film-cooling effectiveness and wider film coverage than the cylindrical holes, particularly at higher blowing ratios. The optimum blowing ratio of 1.5 exists for the cylindrical holes, whereas the effectiveness for the shaped holes increases with increase of blowing ratio. Results also show that the platform film-cooling effectiveness increases with density ratio but decreases with turbulence intensity.Copyright © 2013 by ASME
A group-specific measure of intergenerational persistence

Abstract I describe a method for comparing intergenerational mobility for different groups, taking account of both within- and between-group effects. When group means differ, this method yields results that are more informative than is the comparison of within-group estimates alone.
Polynomial-time algorithm for computing translocation distance between genomes

With the advent of large-scale DNA physical mapping and sequencing, studies of genome rearrangements are becoming increasingly important in evolutionary molecular biology. From a computational perspective, study of evolution based on rearrangements leads to rearrangement distance problem, i.e., computing the minimum number of rearrangement events required to transform one genome into another. Different types of rearrangement events give rise to a spectrum of interesting combinatorial problems. The complexity of most of these problems is unknown. Multichromosomal genomes frequently evolve by a rearrangement event called translocation which exchanges genetic material between different chromosomes. In this paper we study the translocation distance problem, modeling evolution of genomes evolving by translocations. Translocation distance problem was recently studied for the first time by Kececioglu and Ravi, who gave a 2-approximation algorithm for computing translocation distance. In this paper we prove a duality theorem leading to a polynomial algorithm for computing translocation distance for the case when the orientation of the genes are known. This leads to an algorithm generating a most parsimonious (shortest) scenario, transforming one genome into another by translocations.
Synchronization of Nonlinear Circuits in Dynamic Electrical Networks With General Topologies

Sufficient conditions are derived for global asymptotic synchronization in a system of identical nonlinear electrical circuits coupled through linear time-invariant (LTI) electrical networks. In particular, the conditions we derive apply to settings where: i) the nonlinear circuits are composed of a parallel combination of passive LTI circuit elements and a nonlinear voltage-dependent current source with finite gain; and ii) a collection of these circuits are coupled through either uniform or homogeneous LTI electrical networks. Uniform electrical networks have identical per-unit-length impedances. Homogeneous electrical networks are characterized by having the same effective impedance between any two terminals with the others open circuited. Synchronization in these networks is guaranteed by ensuring the stability of an equivalent coordinate-transformed differential system that emphasizes signal differences. The applicability of the synchronization conditions to this broad class of networks follows from leveraging recent results on structural and spectral properties of Kron reduction-a model-reduction procedure that isolates the interactions of the nonlinear circuits in the network. The validity of the analytical results is demonstrated with simulations in networks of coupled Chua's circuits.
LOCALIZATION OF WAVE PROPAGATION IN DISORDERED PERIODIC STRUCTURES

A structure designed to be spatially periodic in its configuration cannot be exactly periodic due to material, geometric, and manufacturing variabilities. Such variabilities are random, and their presence (often referred to as disorder) can reduce the ability of the structure to transmit waves from one location to another. The phenomenon is known as vibration confinement or localization. A new perturbation scheme is developed in this paper on the basis of probability theory to calculate the average exponential decay rate of wave transmission with respect to the distance of transmission, called the localization factor. Account is also taken of structural damping. The new scheme permits successive improvement of accuracy, making it applicable to either weak, strong, or moderate localization. Moreover, the analysis is based on a generic periodic structure; thus, it is not restricted to a specific set of governing equations. These are achieved by taking into account reflections from nearby disordered cell-units successively and substituting the ensemble average for the sequential average of certain statistical properties of the cell units on the basis of spatial ergodicity. Application of the method is illustrated by an example, and the results are compared with Monte Carlo simulations.
Consequences of Proposed Changes To Clean Water Act Thermal Discharge Requirements

This paper summarizes three studies that examined the economic and environmental impact on the power industry of: a) limiting thermal mixing zones to 1,000 feet (∼305 m), and b) eliminating the Clean Water Act (CWA) §316(a) variance. Both of these proposed changes were included in S. 1081, a 1991 Senate bill to reauthorize the CWA. The bill would not have provided for grandfathering plants already using the variance or mixing zones larger than 305 m. Each of the two changes to the existing thermal discharge requirements were independently evaluated. Power companies were asked what they would do if these two changes were imposed. Most plants affected by the proposed changes would retrofit cooling towers and some would retrofit diffusers. Assuming that all affected plants would proportionally follow the same options as the surveyed plants, the estimated capital cost of retrofitting cooling towers or diffusers at all affected plants ranges from $21.4 to 24.4 billion. Both cooling towers and diffusers exert a 1%–5.8 % energy penalty on a plant's output. Consequently, the power companies must generate additional power if they install those technologies. The estimated cost of the additional power ranges from $10 to 18.4 billion over 20 years. Generation of the extra power would emit over 7.3 billion kg per year of additional carbon dioxide. Operation of the new cooling towers would cause more than 94.5 m3 per second of additional evaporation. Neither the restricted mixing zone size nor the elimination of the §316(a) variance was adopted into law. More recent proposed changes to the Clean Water Act have not included either of these provisions, but in the future, other Congresses might attempt to reintroduce these types of changes.
The Meyer–Schuster rearrangement for the synthesis of α,β-unsaturated carbonyl compounds

The Meyer–Schuster rearrangement is the conversion of propargyl alcohols into α,β-unsaturated carbonyl compounds via a formal 1,3-hydroxyl shift and tautomerization. The major challenge associated with the Meyer–Schuster reaction is that of selectively promoting the desired rearrangement over the myriad other reaction pathways available to propargyl alcohols. This Perspective Article features recent advances in the Meyer–Schuster reaction, including several demonstrated techniques for improving the scope. Strengths and weaknesses of each technique are discussed, and outstanding problems that warrant further study are highlighted. The primary motivation for research and development of the Meyer–Schuster rearrangement is as a means of preparing α,β-unsaturated carbonyl compounds as part of a two-stage olefination strategy.
A Comprehensive Theory of Yielding and Failure for Isotropic Materials

A theory of yielding and failure for homogeneous and isotropic materials is given. The theory is calibrated by two independent, measurable properties and from those it predicts possible failure for any given state of stress. It also differentiates between ductile yielding and brittle failure. The explicit ductile-brittle criterion depends not only upon the material specification through the two properties, but also and equally importantly depends upon the type of imposed stress state. The Mises criterion is a special (limiting) case of the present theory. A close examination of this case shows that the Mises material idealization does not necessarily imply ductile behavior under all conditions, only under most conditions. When the first invariant of the yield/failure stress state is sufficiently large relative to the distortional part, brittle failure will be expected to occur. For general material types, it is shown that it is possible to have a state of spreading plastic flow, but as the elastic-plastic boundary advances, the conditions for yielding on it can change over to conditions for brittle failure because of the evolving stress state. The general theory is of a three-dimensional form and it applies to full density materials for which the yield/failure strength in uniaxial tension is less than or at most equal to the magnitude of that in uniaxial compression.
Synthesis of (−)-Quinocarcin by Directed Condensation of α-Amino Aldehydes

An enantioselective synthesis of the natural antiproliferative agent quinocarcin was achieved by the directed condensation of optically active α-amino aldehyde intermediates. Condensation of the N-protected α-amino aldehyde 1, prepared in eight steps (19% yield) from (R,R)-pseudoephedrine glycinamide, with the C-protected α-amino aldehyde derivative 2, prepared in seven steps (34% yield) from (R,R)-pseudoephedrine glycinamide, afforded the corresponding imine in quantitative yield. Without isolation, direct treatment of this imine intermediate with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and hydrogen cyanide led to cleavage of the fluorenylmethoxycarbonyl (Fmoc) protective group followed by addition of cyanide (Strecker reaction) to form the bis-amino nitriles 3 as a mixture of diastereomers, in 91% yield. Treatment of the diastereomers 3 with trimethylsilyl cyanide and zinc chloride in 2,2,2-trifluoroethanol at 60 °C led to stepwise cyclization to form the tetracyclic product 4 (42% yield from 1 and 2)....
Baxter Algebras and Shuffle Products

In this paper we generalize the well-known construction of shuffle product algebras by using mixable shuffles, and prove that any free Baxter algebra is isomorphic to a mixable shuffle product algebra. This gives an explicit construction of the free Baxter algebra, extending the work of Rota and Cartier.
A counterexample in congestion control of wireless networks

This paper studies the interaction between TCP congestion control and wireless interference. One of the triumphs of wireline network research of the last decade has been the casting of the Internet congestion control problem within an optimization framework based on utility functions. Such an approach has provided a sound theoretical understanding of the underlying stability and fairness issues, as well as a post-facto justification of the scalability and stability of TCP-like additive-increase multiplicative-decrease (AIMD) algorithms. This paper provides counterexamples showing that the same result cannot be extended to wireless networks, at least not in a straightforward manner. The fundamental difference is that wireless networks are of a broadcast nature. There is no strict notion of a 'link', since transmissions from nearby nodes interfere with each other. We consider a fairly general model of interference in wireless networks, and present a counterexample of a wireless network in which the congestion control mechanism has an unstable equilibrium point at the desired fair solution. ns-2 simulations of this counterexample manifest an oscillatory throughput behaviour that is orders of magnitude worse than the corresponding wired networks. Surprisingly, this oscillatory throughput behaviour appears to be fairly typical of simulations in wireless networks, with almost all randomly chosen network simulation examples manifesting it. This loss of stability leads us to suggest that perhaps TCP should be modified for use in wireless networks, and that a cross-layer redesign of wireless TCP and MAC is needed to explicitly account for the effects of the wireless nature of interference.
Analytical Modeling of Cracked Thin-Walled Beams Under Torsion

We present an analytical model, derived using the principle of virtual work, for closed and open thin-walled beams subjected to torsion. Non-classical effects like primary and secondary torsional warping are taken into account. A closed-form expression for Mode II stress intensity factor for thin-walled beams with a longitudinal crack is derived. We start by finding analytical solutions based on the Vlasov’s torsional beam theory for thin-walled beams with any cross-sections. We then use the calc ulated stress of a rectangular thin-walled beam to determine an analytical expression for Mode II stress intensity factor. Finally, we add a correction factor to account for complex beha vior of long cracks. Examples are presented to illustrate the effectiveness of the cu rrent model, and it is validated by comparison with detailed finite element results obt ained using the ABAQUS TM .
Thermoplastic Coated Carbon Fibers for Textile Preforms

A continuous process for producing prepreg from carbon fiber and thermoplastic matrix is described. After the tow has been spread using a pneumatic device, the process utilizes a fluidized bed to apply thermoplastic powder to the bun dle. Finally, direct electrical heating of the coated fiber tow melts the polymer on the individual fibers, creating a uniform and extremely flexible prepreg. The efficiency of the process was evaluated during initial trials in which a thermoplastic polyimide, LaRC-TPI, was applied to T-300, 3K (3000 filament) carbon fiber tow. The physical properties of unidirectional composite specimens fabricated from this prepreg were measured, and the matrix uniformity and void content of the samples was deter mined The results of these evaluations are detailed and discussed
Gold(I)-catalyzed enantioselective synthesis of benzopyrans via rearrangement of allylic oxonium intermediates.

The first transition metal catalyzed asymmetric carboalkoxylation reaction of propargyl esters is described. The (R)-MeO-DTBM-BIPHEP(AuCl)2-catalyzed reactions allow for the construction of benzopyrans containing quaternary stereocenters with excellent enantioselectivity. Experimental evidence supports a mechanism proceeding via the generation of a stabilized carbocation from an allylic oxonium intermediate and subsequent trapping by a chiral allylgold(I) spieces.
Glass Formation in Microgravity

Containerless glass forming experiments conducted aboard the space shuttle STS-61A in October 1985, which used a single axis acoustic levitator/furnace (SAAL) are described. A total of eight spherical samples =6±1 mm diameter were used. Each sample had one or more of the following objectives; (1) obtain quantitative evidence for the suppression of heterogeneous nucleation/crystallization in containerless melts in micro-g, (2) study melt homogenization in the absence of gravity driven convection, (3) develop procedures for preparing precursor samples suitable for space experiments, (4) perform comparative property analysis of glasses melted on earth and in micro-g, (5) determine the feasibility of preparing glass shells in micro-g for use as laser fusion targets, and (6) assess the operational performance of the SAAL for processing multicomponent, glass forming melts in micro-g. Depending upon their composition, the samples were melted between 900 and 1500°C for about 5 to 12 minutes. Motion pictures of solid and liquid samples showed that the levitator/furnace operated as planned. A ternary calcia-gallia-silica glass prepared in micro-g was reasonably homogeneous and provided evidence for 2 to 3 fold increase in the tendency for glass formation in space. Melt homogenization in space was reasonably fast for this calcia-gallia-silica melt and hot-pressing appeared to be a feasible way of preparing precursor samples for use in micro-g flight experiments. Valuable information for the technology of materials processing in space was obtained.
A Broad Search for Counterrotating Gas and Stars: Evidence for Mergers and Accretion

We measure the frequency of bulk gas-stellar counterrotation in a sample of 67 galaxies drawn from the Nearby Field Galaxy Survey, a broadly representative survey of the local galaxy population down to MB ~ -15. We detect four counterrotators among 17 E/S0's with extended gas emission (24 %). In contrast, we find no clear examples of bulk counterrotation among 38 Sa–Sbc spirals, although one Sa does show peculiar gas kinematics. This result implies that, at 95% confidence, no more than 8% of Sa–Sbc spirals are bulk counterrotators. Among types Sc and later, we identify only one possible counterrotator, a Magellanic irregular. We use these results together with the physical properties of the counterrotators to constrain possible origins for this phenomenon.
Hot White Dwarf Donors in Ultracompact X-Ray Binaries

The discovery of two accreting millisecond X-ray pulsars in binaries with ≈43 minute orbital periods allows for a new probe of the donor's structure. For XTE J1751-305, only a hot white dwarf (WD) can fill the Roche lobe. A cold He WD is a possible solution for XTE J0929-314, although I will show that evolutionary arguments make a hot WD more likely. In addition to being larger than the T = 0 models, these finite entropy, low-mass (Mc < 0.03 M☉) WDs have a minimum mass for a fixed core temperature. If they remain hot as they lose mass and expand, they can "evaporate" to leave an isolated millisecond radio pulsar. They also adiabatically expand upon mass loss at a rate faster than the growth of the Roche radius if the angular momentum deposited in the disk is not returned to the donor. If the timescale of the resulting runaway mass transfer is shorter than the viscous timescale in the outer disk, then the mass transfer instability of Ruderman & Shaham for He WDs would be realized. However, my estimates of these timescales still make the instability unlikely for adiabatic responses. I close by noting the possible impact of finite temperature WDs on our understanding of AM CVn binaries.
The amorphous-to-gamma transformation in ion implanted Al2O3☆

Abstract Amorphous surface layers, free of implanted impurities, were produced on single crystal α-Al 2 O 3 substrates by implantation at − 185 °C with 2 × 10 16 Al/cm 2 at 90 keV and 3 × 10 16 O/cm 2 at 55 keV. The response of these amorphous layers to post-implantation annealing in the temperature range from 700 to 800 ° C was investigated by in situ transmission electron microscopy (TEM) and conventional TEM of specimens annealed in bulk form. It was found that the amorphous Al 2 O 3 transformed to the cubic transitional γ phase along an irregular front. The recrystallized material is columnar with the individual columns or domains being irregular in size and shape. The γ-Al 2 O 3 is composed of two variants which are twin related and have the following orientation relationship with the substrate: 〈110〉) γ ∥〈1010〉 α and {111} γ ∥{0001} α . The temperature-dependent velocity of the amorphous-to-γ transformation front was measured by in situ TEM. Assuming a thermally activated process, the activation energy has been determined from an Arrhenius plot of velocity versus T −1 . These results are discussed in terms of possible rate controlling processes of the transformation.
Tunable frequency comb generation from a microring with a thermal heater

We demonstrate a novel comb tuning method for microresonator-based Kerr comb generators. Continuously tunable, low-noise, and coherent comb generation is achieved in a CMOS-compatible silicon nitride microring resonator.
Study of layered and coevaporated V(Mo)N and (V/Si)N films

Layered and coevaporated V/Mo samples were nitrided and their T c 's and spin-orbit scattering rates were compared. This is of Interest because of the close lattice match of VN with the postulated high T c of cubic MoN. In no case was a T c higher than that of VN obtained. The spin-orbit scattering rate was found to be larger in the layered (V/Mo)N samples than in the coevaporated ones. We have compared (V/Mo)N and similarly made (V/Si)N multilayer films with theories for the critical field of such structures. Evidence for dimensional crossover was seen in the parallel critical field curve of (V/Mo)N films. Also, the T c of thin (V/Si)N multilayers was found to be dependent on the Si layer thickness.
Multiscale stochastic dynamics in finance

Abstract Semimartingale probabilistic setups lead to very useful volatility estimation. The integrated volatility can be consistently estimated by the realized one according to the quadratic variation principle, even if the convergence speed can result relatively slow, depending on noise and market microstructure effects. We show, experimentally, that scale transforms based on wavelets and the corresponding cumulative periodogram estimators may offer comparable numerical performance in measuring the quadratic variation limit, thus minimizing the discrepancy between realized and integrated volatility.
Estimating Uncertainty in Computations of Two-Dimensional Separated Flows

The present paper investigates sources of uncertainties in two-dimensional flow computations and presents methods for estimating them. A sample problem is used for illustration. The following categories are explored in detail: (1) Uncertainty due to truncation error in numerical schemes; (2) Uncertainty due to discretization error; (3) Uncertainty due to outflow boundary conditions; (4) Uncertainty due to incomplete iterative convergence; (5) Uncertainty due to computational grid aspect ratio. The error estimates are based on requirements for internal consistencies in computed results. Therefore, they provide better judgment of the numerical solution integrity than comparisons to experimental data or benchmark'' solutions whose reliability may sometimes be questionable. Ideally, both approaches should by employed. A new method is presented for estimating the optimum grid-cell aspect ratio for computational accuracy and efficiency.
Improved preparation of phosphinate esters for palladium-catalyzed cross-coupling

Abstract The reaction between phosphinic acid and trimethyl orthoformate to yield methyl phosphinate shows a pronounced solvent dependence. Conditions are defined to improve ester purity. t-Butyl phosphinate is also prepared cleanly, and its palladium-catalyzed reaction with aryl iodide is reported.
The Origin of the Magellanic Stream and its Leading Arm

We explore the Magellanic Stream (MS) using a Gaussian decomposition of the H I velocity proles in the Leiden-Argentine-Bonn (LAB) all-sky H I survey. This decomposition exposes the MS to be composed of two laments distinct both spatially (as rst pointed out by Putman et al.) and in velocity. Using the velocity coherence of the laments, one can be traced back to its origin in what we identify as the SouthEast H I Overdensity (SEHO) of the Large Magellanic Cloud (LMC), which includes 30 Doradus. Parts of the Leading Arm (LA) can also be traced back to the SEHO in velocity and position. Therefore, at least one-half of the trailing Stream and most of the LA originates in the LMC, contrary to previous assertions that both the MS and the LA originate in the Small Magellanic Cloud (SMC) and/or in the Magellanic Bridge. The two MS laments show strong periodic, undulating spatial and velocity patterns that we speculate are an imprint of the LMC rotation curve. If true, then the drift rate of the Stream gas away from the Magellanic Clouds is 49 km s 1 and the age of the MS is 1.74 Gyr. The Staveley-Smith et al. high-resolution H I data of the LMC show gas outows from supergiant shells in the SEHO that seem to be creating the LA and LMC lament of the MS. Blowout of LMC gas is an eect not previously accounted for but one that probably plays an important role in creating the MS and LA. Subject headings: Galaxies: interactions { Galaxies: kinematics and dynamics { Galaxies: Local Group { Galaxy: halo { Intergalactic Medium { Magellanic Clouds { Radio Lines: general
Albedos and densities of the inner satellites of Saturn

Broad-band radiometry at 20 microns is presented for Rhea and Dione; the measured flux densities, together with visual photometry, indicate that both satellites have geometric albedos near 0.6 and that their radii are, respectively, 800 plus or minus 125 and 575 plus or minus 100 km. The density of Dione is 1.4 plus or minus 0.6 g per cu cm; for Tethys, Enceladus, and Mimas, whose densities have not been measured, a 'photometric density' is defined from the available data, and it is shown that their densities are probably near unity. These satellites must therefore all be composed primarily of ices.
Point mass insertion on the real line and non‐exponential perturbation of the recursion coefficients

We present the construction of a probability measure dγ with compact support on such that adding a discrete pure point results in changes in the recursion coefficients without exponential decay.
Physical activity, physical fitness and longevity

Numerous studies consistently have shown that higher levels of physical activity are associated with decreased risks of coronary heart disease, cerebrovascular disease, hypertension, non-insulin-dependent diabetes mellitus, colon and, possibly, breast cancer, as well as osteoporosis. The biological processes proposed to explain these inverse associations are highly plausible. If physical activity does reduce the risk of developing these chronic diseases, we also would expect physical activity to delay mortality and enhance longevity. In this article, we review the major epidemiological studies worldwide that have examined the association between physical activity or physical fitness and all-cause mortality. The data from these studies indicate that physical activity is effective in postponing mortality and enhancing longevity. Public health professionals worldwide should emphasize the need to increase activity levels during leisure time, as well as the need to incorporate physical activity into the daily activities of life.
The Effect of Multiple Scattering on the Polarization from Binary Star Envelopes. I. Self- and Externally Illuminated Disks

We present the results of a Monte Carlo radiative transfer code that calculates the polarization produced by multiple Thomson scattering and variable absorptive opacity in a circumstellar disk around one component of a close detached binary system. We consider in detail the polarization variations over the binary cycle that result from the disk's illumination both by the external star and by its own volume emission. We identify key features of these polarization phase curves and investigate their behavior as functions of optical depth, albedo, and inclination for geometrically thin and thick disks. The polarization due to disk self-illumination is sensitive to the internal optical characteristics of the disk, while the polarization arising from external illumination is sensitive mainly to the disk's geometrical thickness. With appropriate flux weighting, these results, combined with those for an internally illuminated disk, allow simulation of the polarization signature from an arbitrary binary-disk system.
Clay catalyzed synthesis of imines and enamines under solvent-free conditions using microwave irradiation

Abstract The reactions of primary and secondary amines with aldehydes and ketones, respectively, are accelerated by microwaves under solvent-free conditions in the presence of montmorillonite K 10 clay to afford a high yield synthesis of imines and enamines.
Spontaneous magnetization in Lorentz invariant theories

Abstract In a class of three-dimensional Abelian gauge theories with both light and heavy fermions, heavy chiral fermions can trigger dynamical generation of a magnetic field, leading to the spontaneous breaking of the Lorentz invariance. Finite masses of light fermions tend to restore the Lorentz invariance.
Weak coin flipping with small bias

This paper presents a quantum protocol that demonstrates that weak coin flipping with bias ≈ 0.239, less than 1/4, is possible. A bias of 1/4 was the smallest known, and followed from the strong coin flipping protocol of Ambainis in [33rd STOC, 2001] (also proposed by Spekkens and Rudolph [Phys. Rev. A 65 (2002) 012310]). Protocols with yet smaller bias ≈ 0.207 have independently been discovered by Ambainis (2001) and Spekkens and Rudolph [Phys. Rev. Lett. 89 (2002) 227901]. We also present an alternative Strong coin flipping protocol with bias 1/4 with analysis simpler than that of Ambainis [33rd STOC, 2001].
Thermal considerations in inferring frictional heating from vitrinite reflectance and implications for shallow coseismic slip within the Nankai Subduction Zone

Abstract Frictional properties within the upper few kilometers of subduction zones are generally thought to inhibit rupture propagation. Understanding whether large rapid slip propagates to the surface during megathrust earthquakes is important for characterizing tsunami hazard. Recent vitrinite reflectance analysis by Sakaguchi et al. (2011) on cores from the NanTroSEIZE drilling transect at the Nankai Trough, Japan, has been interpreted to suggest that these faults reached temperatures ∼380 °C, considerably larger than background temperature values, implying they hosted coseismic slip at shallow depths. Analysis of other temperature proxies on the megasplay by Hirono et al. (2009) , however, suggests temperatures have not exceeded 300 °C and is inconclusive as to whether the fault slipped at high velocity. We evaluate the effects of frictional heat generation on the spatial distribution of vitrinite reflectance, its sensitivity to slip zone thickness and slip duration, and the cumulative effects of numerous events. We build on the analysis of Sakaguchi et al. (2011) by estimating frictional heating scenarios that are consistent with both the peak and spatial extent of anomalous vitrinite reflectance data. Our results imply coseismic slip magnitudes of several 10s of meters. Peak temperature estimates from the vitrinite reflectance data can be reconciled with the other geochemical constraints only by assuming the vitrinite reflectance results from the cumulative effects of multiple earthquakes. However, this results in unrealistically large estimates of total displacement. Our results imply that current understanding of how vitrinite reflectance is affected by fault slip is incomplete.
THEORY OF DENDRITIC GROWTH—I. ELEMENTS OF A STABILITY ANALYSIS

Abstract We propose that the maximum-velocity principle previously used in theories of dendritic crystal growth be replaced by a stability criterion of the form υρ 2 = constant, where υ is the growth rate and ρ the tip radius of a dendrite. This form of the stability criterion is valid for small Peclet numbers (ρ much smaller than the diffusion length). A direct evaluation of the relevant constant of proportionality yields values of υ and ρ, as functions of undercooling, which are in substantial agreement with the measurements of Glicksman et al. [3] on dendritic growth of succinonitrile crystals. In this paper, we summarize our basic ideas and describe qualitatively our theoretical results. Mathematical details are presented in two subsequent papers.
Model and simulations of the epitaxial growth of graphene on non-planar 6H?SiC surfaces

We study step flow growth of epitaxial graphene on 6H–SiC using a one-dimensional kinetic Monte Carlo model. The model parameters are effective energy barriers for the nucleation and propagation of graphene at the SiC steps. When the model is applied to graphene growth on vicinal surfaces, a strip width distribution is used to characterize the surface morphology. Additional kinetic processes are included to study graphene growth on SiC nano-facets. Our main result is that the original nano-facet is fractured into several nano-facets during graphene growth. This phenomenon is characterized by the angle at which the fractured nano-facet is oriented with respect to the basal plane. The distribution of this angle across the surface is found to be related to the strip width distribution for vicinal surfaces. As the terrace propagation barrier decreases, the fracture angle distribution changes continuously from two-sided Gaussian to one-sided power law. Using this distribution, it will be possible to extract energy barriers from experiments and interpret the growth morphology quantitatively.
The neuroendocrinology of human sleep

Abstract Sleep consists of several distinct patterns of CNS activation, including synchronized or slow wave of sleep and desynchronized or rapid eye movement sleep. Specific areas of the brain as well as specific biogenic amine neurotransmitters appear to be responsible for the periodic shifts between sleep stages. Hypothalamic regulation of the anterior pituitary gland also is influenced by the same biogenic amine neurotransmitters, and the episodic release patterns of the anterior pituitary hormones suggest prominent CNS influences. This review considers the relationship of these hormone release patterns to the circadian sleep-wake cycle and to sleep staging within the sleep period itself.
Monopoles as big as a universe

Abstract We show that, contrary to the standard belief, primordial monopoles expand exponentially during inflation in the new inflationary universe scenario. Moreover, inflation of monopoles continues without end even when inflation ends in the surrounding space. Therefore primordial monopoles (as well as other topological defects produced during inflation) can serve as seeds for the process of eternal self-reproduction of inflationary universe.
Corrections for atmospheric refractivity in satellite laser ranging

The range correction calculated from ground-level meteorological measurements is shown to consist of a series of terms. The zeroth order term of this series corresponds to the correction obtained under the assumption of a spherically symmetric refractivity profile. The higher order terms arise due to departures from the spherical-symmetry assumption. The range correction is also shown to have residual errors, and an analytic expression for these errors is derived. Pertinent surface data are analyzed to obtain the magnitudes of the higher order corrections and the residual errors.
Electrochemical properties of iron(III)-substituted heteropolytungstate anions

Abstract The electrochemical behavior of a series of heteropolytungstate anions in which one of the W 6+ cations is replaced by Fe 3+ is described. The anions investigated were FeXW 11 O m − 39 (X = P, As, m = 4; X = Ge, Si, m = 5). All of the anions exhibit a reversible, one-electron couple associated with the Fe 3+ center and a pair of two-electron waves attributed to electron addition and removal from the tungsten-oxo framework that comprises each anion's structure. The dependence of the formal potentials of the couples on pH and ionic strength is interpreted in terms of competition between protonation and ion-pairing of the reduced forms of the couples. The results are contrasted with the apparently less intricate behavior of the unsubstituted anions, SiW 12 O 5− 40 and PW 12 O 4− 40 , that was described recently (B. Keita and L. Nadjo, J. Electroanal. Chem., 227 (1987) 77).
Non-self-averaging and the statistical mechanics of endogenous macroeconomic fluctuations

Abstract Strong fluctuation phenomena are an endogenous feature of economic systems if they are non-self-averaging. We show that an important consequence of non-self-averaging is that current forms of economic policy can be rendered useless. We also find non-self-averaging both to exist in microeconomic models of cluster development within economies and to be consistent with observed economic power laws. These results suggest the need for straightforward identification of non-self-averaging in economic systems and to this end we present a sufficient condition for non-self-averaging in terms familiar to financial risk management.
Perceptions and truth: a mechanism design approach to crowd-sourcing reputation

We consider a distributed multiuser system where individual entities possess observations or perceptions of one another, while the truth is only known to themselves and they might have an interest in withholding or distorting the truth. We ask the question whether it is possible for the system as a whole to arrive at the correct perceptions or assessment of all users, referred to as their reputation, by encouraging or incentivizing the users to participate in a collective effort without violating private information and self-interest. In this paper, we investigate this problem using a mechanism design theoretic approach. We introduce a number of utility models representing users' strategic behavior, each consisting of one or both of a truth element and an image element, reflecting the user's desire to obtain an accurate view of others and an inflated image of itself. For each model, we either design a mechanism that achieves the optimal performance (solution to the corresponding centralized problem), or present individually rational suboptimal solutions. In the latter case, we demonstrate that even when the centralized solution is not achievable, by using a simple punish-reward mechanism, not only does a user have the incentive to participate and provide information, but also that this information can improve the system performance.
COLOR-MAGNITUDE DIAGRAMS OF RESOLVED STARS IN VIRGO CLUSTER DWARF GALAXIES

The Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST) has been used to image two fields in the core of the Virgo Cluster that contain a number of dwarf elliptical galaxies. The combined F555W and F814W images have resolved red giant stars in these galaxies, down to 1 mag below the giant branch tip. Two of the galaxies were targeted because of their extremely low central surface brightnesses (Bo > 27.0); thus, the successful resolution into stars confirms the existence of such tenuous galaxies. Red giant stars were also found that are not ostensibly associated with any galaxy. Color-magnitude diagrams in V and I have been derived for the five dwarfs, as well as the halo of a nearby spiral galaxy and the intracluster stars in the two fields. These diagrams were used to derive distances and metallicities via the magnitude of the red giant branch tip, and the mean color of the giant branch. The mean abundances of stars in the dwarfs range from -1.2 < [Fe/H] < -2.4, and fall along the relation between galaxy luminosity and metallicity found for Local Group and M81 group dwarf elliptical galaxies. [Fe/H] does not appear to be well-correlated with galaxy surface brightness, as the two extremely low surface brightness galaxies do not have extreme abundances. The mean distance modulus of the six Virgo galaxies is 31.0 ± 0.05, or 16.1 ± 0.4 Mpc, whereas that for the intracluster stars in those fields is 31.2 ± 0.09 (17.4 ± 0.7 Mpc).
Falling fertility rates: new challenges to the European welfare state

One of the biggest issues currently plaguing many advanced industrialized countries is the persistence of below-replacement fertility rates (fewer than 2.1 children per woman). Decreasing fertility rates threaten economic growth, while government budgets have to accommodate more pension and health services, as the number of adults of working age who contribute to older generations' pensions diminishes. In addressing the dilemma of low fertility in Europe, we are inevitably confronted with a combination of institutional and human factors: while governments can attempt to put into place institutions and policies that will encourage childbirth (such as subsidies for children, family leave policies, and day care facilities), population reproduction is fundamentally a micro-level decision. The crux of the matter is that women and men must choose to have children; no number of institutional configurations will by themselves result in the birth of babies. Rather, it is the combination of systems of welfare provision, people's ability to provide for their well-being, and the choice of women and men to conceive children, that will likely result in increased fertility rates across Europe. This article examines several factors that influence the makeup of state, market, and family decisions, surveying literature in the field of work and family reconciliation and fertility decisions. The article concludes by highlighting several issues of societal polarization that are related to family policy and indicates avenues for future research on fertility and government policies.
Counting substructures I: color critical graphs

Let F be a graph which contains an edge whose deletion reduces its chromatic number. We prove tight bounds on the number of copies of F in a graph with a prescribed number of vertices and edges. Our results extend those of Simonovits [8], who proved that there is one copy of F , and of Rademacher, Erd} os [1, 2] and Lov asz
Quadrupolar particles in a nematic liquid crystal: effects of particle size and shape.

We investigate the effects of particle size and shape on the quadrupolar (Saturn-ring-like) defect structures formed by a nematic liquid crystal around nm-sized and $\ensuremath{\mu}\mathrm{m}$-sized particles with spherical and spherocylindrical shapes. We also report results for the potentials of mean force in our systems, calculated using a mesoscale theory for the tensor order parameter $\mathbf{Q}$ of the nematic. Our results indicate that for pairs of nm-sized particles in close proximity, the nematic forms ``entangled hyperbolic'' defect structures regardless of the shape of the nanoparticles. In our calculations with nanoparticles we did not observe any other entangled or unentangled defect structures, in contrast to what was reported for pairs of $\ensuremath{\mu}\mathrm{m}$-sized spherical particles. Such a finding suggests that the ``entangled hyperbolic'' defect structures are the most stable for pairs of nanoparticles in close proximity. For pairs of $\ensuremath{\mu}\mathrm{m}$-sized particles, our results indicate that the nematic forms entangled ``figure-of-eight'' defect structures around pairs of spheres and spherocylinders. Our results suggest that the transition between ``entangled hyperbolic'' and figure-of-eight defect structures takes place when the diameter of the particle is between $D=100\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ and $1\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$. We have also calculated the torques that develop when pairs of spherocylindrical nanoparticles in a nematic approach each other. Our calculations suggest that the nematic-mediated interactions between the nm-sized particles are fairly strong, up to 5700 ${k}_{B}T$ for the case of pairs of spherocylindrical nanoparticles arranged with their long axis parallel to each other. Furthermore, these interactions can make the particles to bind together at specific locations, and thus could be used to assemble the particles into ordered structures with different morphologies.
Test methodology to evaluate the safety of materials using spark incendivity

For many years scientists and engineers have been searching for the proper test method to evaluate an electrostatic risk for materials used in hazardous environments. A new test standard created by the International Electrotechnical Commission is a promising addition to conventional test methods used throughout the industry. The purpose of this paper is to incorporate this test into a proposed new methodology for the evaluation of materials exposed to flammable environments. However, initial testing using this new standard has uncovered some unconventional behavior in materials that conventional test methods were thought to have reconciled. For example some materials tested at higher humidities were more susceptible to incendive discharges than at lower humidity even though the surface resistivity was lower.
Approximate and exact cone-beam reconstruction with standard and non-standard spiral scanning

The long object problem is practically important and theoretically challenging. To solve the long object problem, spiral cone-beam CT was first proposed in 1991, and has been extensively studied since then. As a main feature of the next generation medical CT, spiral cone-beam CT has been greatly improved over the past several years, especially in terms of exact image reconstruction methods. Now, it is well established that volumetric images can be exactly and efficiently reconstructed from longitudinally truncated data collected along a rather general scanning trajectory. Here we present an overview of some key results in this area.
Generalization bounds for learning with linear, polygonal, quadratic and conic side knowledge

In this paper, we consider a supervised learning setting where side knowledge is provided about the labels of unlabeled examples. The side knowledge has the effect of reducing the hypothesis space, leading to tighter generalization bounds, and thus possibly better generalization. We consider several types of side knowledge, the first leading to linear and polygonal constraints on the hypothesis space, the second leading to quadratic constraints, and the last leading to conic constraints. We show how different types of domain knowledge can lead directly to these kinds of side knowledge. We prove bounds on complexity measures of the hypothesis space for quadratic and conic side knowledge, and show that these bounds are tight in a specific sense for the quadratic case.
Endogenous Policy Choice: The Case of Pollution and Growth

What determines the relationship between pollution and growth? Are the forces that explain the behavior over time of these quantities potentially useful for understanding more generally the relationship between policies and growth? In this paper we make a first attempt to analyze the equilibrium behavior of two quantities—the level of pollution and the level of income— in a setting in which societies choose, via voting, how much to regulate pollution. Our major finding is that, consistent with the evidence, the relationship between pollution and growth need not be monotone, and that the precise equilibrium nature of the relationship between the two variables depends on whether individuals vote over effluent charges or directly restrict the choice of technology. Moreover, our analysis of the pollution problem suggests that, more generally, endogenous policy choices should be taken seriously as potential sources of heterogeneity when cross-country differences in economic performance are studied. Journal of Economic Literature Classification Numbers: E2, O1, O2, Q2.