cssi/SciSciGPT-SciSciNet huggingface dataset:
Reactivity control schemes for fast spectrum space nuclear reactors

Abstract Several reactivity control schemes are considered for future space nuclear reactor power systems. Each of these control schemes uses a combination of boron carbide absorbers and/or beryllium oxide reflectors to achieve sufficient reactivity swing to keep the reactor subcritical during launch and to provide sufficient excess reactivity to operate the reactor over its expected 7–15 year lifetime. The size and shape of the control system directly impacts the size and mass of the space reactor's reflector and shadow shield, leading to a tradeoff between reactivity swing and total system mass. This paper presents a trade study of drum, shutter, slat, and petal control schemes based on reactivity swing and mass effects for a representative fast-spectrum, gas-cooled reactor. For each control scheme, the dimensions and composition of the core are constant, and the reflector is sized to provide $5 of cold-clean excess reactivity with each configuration in its most reactive state. Reactivity insertion behavior is analyzed for each control scheme, along with the submersion behavior following a launch abort. The advantages and disadvantages of each configuration are discussed, along with optimization techniques and novel geometric approaches for each scheme.
The Arousal-Performance Relationship Revisited

Abstract William P. Morgan reviews the arguments associated with trait psychology, in particular in the field of sport psychology. He describes the existing research including several models and their ability to predict behavior, emphasizing the viability of a mental health model. In addition, Morgan discusses a role of perception and cognition in sports and physical activity. Finally, trait theory is placed in a realistic perspective, to be applied in a multidimensional framework in studying prediction of behavior. The article by Daniel M. Landers involves a reexamination of the arousal-performance relationship. The role of attention in performing most sports skills is discussed, with particular emphasis on the attentional narrowing phenomenon. In addition, Landers discusses the measurement of anxiety, recommending that it be viewed as a multidimensional construct consisting of physical, behavioral, and cognitive components.
Active memory: a new abstraction for memory system simulation

This paper describes the active memory abstraction for memory-system simulation. In this abstraction---designed specifically for on-the-fly simulation, memory references logically invoke a user-specified function depending upon the reference's type and accessed memory block state. Active memory allows simulator writers to specify the appropriate action on each reference, including "no action" for the common case of cache hits. Because the abstraction hides implementation details, implementations can be carefully tuned for particular platforms, permitting much more efficient on-the-fly simulation than the traditional trace-driven abstraction.Our SPARC implementation, Fast-Cache, executes simple data cache simulations two or three times faster than a highly-tuned trace-driven simulator and only 2 to 7 times slower than the original program. Fast-Cache implements active memory by performing a fast table look up of the memory block state, taking as few as 3 cycles on a SuperSPARC for the no-action case. Modeling the effects of Fast-Cache's additional lookup instructions qualitatively shows that Fast-Cache is likely to be the most efficient simulator for miss ratios between 3% and 40%.
Model of genetic variation in human social networks.

Socialnetworksexhibitstrikinglysystematicpatternsacrossawide range of human contexts. Although genetic variation accounts for a significant portion of the variation in many complex social behaviors, the heritability of egocentric social network attributes is unknown. Here, we show that 3 of these attributes (in-degree, transitivity, and centrality) are heritable. We then develop a ‘‘mirrornetwork’’methodtotestextantnetworkmodelsandshow that none account for observed genetic variation in human social networks. We propose an alternative ‘‘Attract and Introduce’’ model with two simple forms of heterogeneity that generates significant heritability and other important network features. We show that the model is well suited to real social networks in humans. These results suggest that natural selection may have played a role in the evolution of social networks. They also suggest that modeling intrinsic variation in network attributes may be important for understanding the way genes affect human behaviors and the way these behaviors spread from person to person. evolution of cooperation heritability twins
Improve peer cooperation using social networks

Due to the dynamic nature of peer-to-peer (P2P) systems, it is impossible to keep an accurate history of the transactions that take place while avoiding security attacks such as whitewashing and collusion, and abuse such as freeriding. This is why it is important to develop a mechanism that both rewards cooperative peers and punishes misbehaving peers. Modelling P2P networks as social structures can allow incentive mechanisms to be developed that prevent the negative behaviours mentioned. In a social structure, peers make and receive payments for services provided to and from each other. In this paper, we extend a social network algorithm to include the transfer of credit between peers to reduce the path length in queries. We also develop a selection strategy that involves different aspects of peer interactions in P2P networks and a credit transfer mechanism that helps to discourage misbehaving peers by taking away credits that they have with good peers and transferring them to more cooperative ones. The simulation results show that our algorithm is effective in reducing the amount of debt between peers, meaning that peers become more cooperative, and shortening the average path length to a satisfied query, while increasing delivery ratio.
On the galactic chemical evolution of sulfur

Department of Astronomy, University of Texas, Austin, TX 78712-1083, USAe-mail: ryde@astro.uu.seReceived ; acceptedAbstract. Sulfur abundances have been determined for ten stars to resolve a debate in the literature on theGalactic chemical evolution of sulfur in the halo phase of the Milky Way. Our analysis is based on observationsof the Si lines at 9212.9, 9228.1, and 9237.5 ˚A for stars for which the S abundance was obtained previously frommuch weaker Si lines at 8694.0 and 8694.6 ˚A. In contrast to the previous results showing [S/Fe] to rise steadilywith decreasing [Fe/H], our results show that [S/Fe] is approximately constant for metal-poor stars ([Fe/H]<∼−1)at [S/Fe] ≃ +0.3. Thus, sulfur behaves in a similar way to the other α elements, with an approximately constant[S/Fe] for metallicities lower than [Fe/H] ≃ −1. We suggest that the reason for the earlier claims of a rise of [S/Fe]is partly due to the use of the weak Si 8694.0 and 8694.6˚A lines and partly uncertainties in the determinationof the metallicity when using Fei lines. The Si 9212.9, 9228.1, and 9237.5˚A lines are preferred for an abundanceanalysis of sulfur for metal-poor stars.
Embedded constant mean curvature surfaces in Euclidean three-space

In this paper we refine the construction and related estimates for complete constant mean curvature surfaces in Euclidean three-space developed in Kapouleas (Ann Math 131:239–330, 1990) by adopting the more precise and powerful version of the methodology which was developed in Kapouleas (Invent Math 119(3):443–518, 1995). As a consequence we remove the severe restrictions in establishing embeddedness for complete Constant Mean Curvature surfaces in Kapouleas (Ann Math 131:239–330, 1990) and we produce a very large class of new embedded examples of finite topology.
Type-2 fuzzy sets and bichains

This paper is a continuation of the study of the variety generated by the truth value algebra of type-2 fuzzy sets. That variety and some of its reducts were shown to be generated by finite algebras, and in particular to be locally finite. A basic question remaining is whether or not these algebras have finite equational bases, and that is our principal concern in this paper. The variety generated by the truth value algebra of type-2 fuzzy sets with only its two semilattice operations in its type is generated by a four element algebra that is a bichain. Our initial goal is to understand the equational properties of this particular bichain, and in particular whether or not it has a finite equational basis.
Adaptive Arrays for Multiple Simultaneous Desired Signals

Steered beam adaptive arrays for multiple simultaneous desired signals are discussed. It is shown that the performance of a steered beam adaptive array depends upon the range of input signal strengths and the choice of the steering vector. Optimum steering vectors for various input signal strengths are given. All choices of steering vectors are equally effective in the rejection of jammers.
Improved Synthesis of Trans-4-Diethylaminocinnamaldehyde

Abstract The title compound was prepared from diisobuty1 aluminum hydride reduction of 4-diethylaminocinnamonitrile, which in turn was obtained by condensing 4-diethylaminobenzaldehyde and cyanoacetic acid.
Lead diffusion in titanite and preliminary results on the effects of radiation damage on Pb transport

Lead diffusion has been measured in natural titanite using two different methods to introduce the diffusant: (1) implantation of Pb ions; and (2) immersion of the crystals in a PbS powder reservoir. In both sets of experiments, Rutherford backscattering spectrometry (RBS) was used to obtain concentration profiles, which were then fit with appropriate solutions to the diffusion equation. Experiments using the PbS powder source, run over the temperature range 650–1027°C, define the Arrhenius relationship: D=1.11+1.18−0.57exp−78.5±2.7 (kcal mol−1)RT(cm2s−1) for diffusion parallel to the (100) plane. Diffusivities are not significantly affected by orientation or differences in preannealing treatment. The ion implantation experiments, in contrast, deviate from simple linear Arrhenius behavior, with the high-temperature data (850–950°C) displaying good agreement with the above relation but the lower-temperature data (600–800°C) exhibiting enhanced diffusivities and a lowered activation energy (19 kcal mol−1). These results suggest that radiation damage induced by the ion implantation is repaired at high temperatures, thus leading to agreement of the two data sets. At lower temperatures, lattice repair proceeds much more slowly in relation to the duration of the diffusion anneal, resulting in elevated diffusion coefficients typical of materials that have become amorphous. A comparison with earlier work on apatite and zircon places the rate of repair of implantation-induced damage in titanite between these minerals, with apatite exhibiting a more rapid rate of repair and zircon a much slower rate for the same implant dose and similar annealing conditions. This difference is largely a function of structural and compositional characteristics that affect the rate of accumulation and repair of damage in each mineral. The results presented here may have important implications for Pb transport and interpretation of isotope ratios in naturally radiation-damaged minerals, as ion implantation produces damage comparable to that resulting from α-recoil.
The Anatomy of Star Formation in NGC 300

The Spitzer Space Telescope was used to study the mid- to far-infrared properties of NGC 300 and to compare dust emission to Hα to elucidate the heating of the interstellar medium (ISM) and the star formation cycle at scales smaller than 100 pc. The new data allow us to discern clear differences in the spatial distribution of 8 μm dust emission with respect to 24 μm dust and to H II regions traced by Hα light. The 8 μm emission highlights the rims of H II regions, and the 24 μm emission is more strongly peaked in star-forming regions than 8 μm. We confirm the existence and approximate amplitude of interstellar dust emission at 4.5 μm, detected statistically in Infrared Space Observatory (ISO) data, and conclude it arises in star-forming regions. When averaging over regions larger than ~1 kpc, the ratio of Hα to aromatic feature emission in NGC 300 is consistent with the values observed in disks of spiral galaxies. The mid- to far-infrared spectral energy distribution of dust emission is generally consistent with pre-Spitzer models.
Constraints on Dirac neutrinos from SN 1987A

Abstract The Livermore Supernova Explosion Code was used to calculate the effect of a massive Dirac neutrino on neutrino emission from SN 1987A in a self-consistent manner. Spin-flip interactions involving neutrino-nucleon, nucleon-nucleon and pion-nucleon collisions lead to the copious emission of sterile, right-handed neutrinos and cool the core faster than the observed neutrino emission time for Dirac masses exceeding about 3 keV. These limits are compared with the previous limits of Burrows et al.
Micropillar fabrication on bovine cortical bone by direct-write femtosecond laser ablation

We investigated fabrication of cylindrical micropillars on bovine cortical bone using direct-write femtosecond laser ablation. The ablation threshold of the material was measured by single-pulse ablation tests, and the incubation coefficient was measured from linear scanned ablation tests. A motion system was programmed to apply multiple layers of concentric rings of pulses to machine pillars of various diameters and heights. The diameter of the top surface of the pillar was found to steadily decrease due to incubation of damage from successive layers of pulses during the machining process. Pillar top diameter was predicted based on a paraxial beam fluence approximation and single-pulse ablation threshold and incubation coefficient measurements. Pillar diameters predicted as successive layers of pulses were applied were well-matched to experiments, confirming that femtosecond laser ablation of the cortical bone was well-modeled by single-pulse ablation threshold measurements and an incubation coefficient.
Fate of the false vacuum: Semiclassical theory

It is possible for a classical field theory to have two homogeneous stable equilibrium states with different energy densities. In the quantum version of the theory, the state of higher energy density becomes unstable through barrier penetration; it is a false vacuum. This is the first of two papers developing the qualitative and quantitative semiclassical theory of the decay of such a false vacuum for theories of a single scalar field with nonderivative interactions. In the limit of vanishing energy density between the two ground states, it is possible to obtain explicit expressions for the relevant quantities to leading order in $h$; in the more general case, the problem can be reduced to solving a single nonlinear ordinary differential equation.
The Effect of Environment on Shear in Strong Gravitational Lenses

Using new photometric and spectroscopic data in the fields of nine strong gravitational lenses that lie in galaxy groups, we analyze the effects of both the local group environment and line-of-sight (LOS) galaxies on the lens potential. We use Monte Carlo simulations to derive the shear directly from measurements of the complex lens environment, providing the first detailed independent check of the shear obtained from lens modeling. We account for possible tidal stripping of the group galaxies by varying the fraction of total mass apportioned between the group dark matter halo and individual group galaxies. The environment produces an average shear of γ = 0.08 (ranging from 0.02 to 0.17), significant enough to affect quantities derived from lens observables. However, the direction and magnitude of the shears do not match those obtained from lens modeling in three of the six four-image systems in our sample (B1422, RXJ1131, and WFI2033). The source of this disagreement is not clear, implying that the assumptions inherent in both the environment and lens model approaches must be reconsidered. If only the local group environment of the lens is included, the average shear is γ = 0.05 (ranging from 0.01 to 0.14), indicating that LOS contributions to the lens potential are not negligible. We isolate the effects of various theoretical and observational uncertainties on our results. Of those uncertainties, the scatter in the Faber-Jackson relation and error in the group centroid position dominate. Future surveys of lens environments should prioritize spectroscopic sampling of both the local lens environment and objects along the LOS, particularly those bright (I< 21.5) galaxies projected within 5' of the lens.
Moral-hazard credit cycles with risk-averse agents

Abstract We consider a simple overlapping-generations model with risk-averse financial agents subject to moral hazard. Efficient contracts for such financial intermediaries involve back-loaded late-career rewards. Compared to the analogous model with risk-neutral agents, risk aversion tends to reduce the growth of agents' responsibilities over their careers. This moderation of career growth rates can reduce the amplitude of the widest credit cycles, but it also can cause small deviations from steady state to amplify over time in rational-expectations equilibria. We find equilibria in which fluctuations increase until the economy enters a boom/bust cycle where no financial agents are hired in booms.
The scalar quarkonium spectrum and quarkonium-glueball mixing

Abstract We evaluate the valence approximation to the mass of scalar quarkonium and to the mixing energy between scalar quarkonium and the lightest scalar glueball for a range of different lattice sizes and quark masses. Our results support the identification of f0(1710) as the lightest scalar glueball.
Majority-Vote Cellular Automata, Ising Dynamics, and P-Completeness

We study cellular automata where the state at each site is decided by a majority vote of the sites in its neighborhood. These are equivalent, for a restricted set of initial conditions, to nonzero probability transitions in single spin-flip dynamics of the Ising model at zero temperature. We show that in three or more dimensions these systems can simulate Boolean circuits of AND and OR gates, and are therefore P-complete. That is, predicting their state t time-steps in the future is at least as hard as any other problem that takes polynomial time on a serial computer. Therefore, unless a widely believed conjecture in computer science is false, it is impossible even with parallel computation to predict majority-vote cellular automata, or zero-temperature single spin-flip Ising dynamics, qualitatively faster than by explicit simulation.
Flammability Characteristics of Treated Coals

In this paper the effects of two processes used to treat coal on the flammability characteristics of the coal are presented. Experiments were conducted on an Entrained Dust Flow Facility which supports a stationary premixed coal dust and air flame. The facility is designed to provide access for thermocouple so that detailed axial and radial temperature profiles of the coal flames can be used to investigate the flame structure. Flame speeds of the coal and air mixtures were determined based on the inlet velocity of the flow and the temperature maps. Flame speed increases of over 35 percent were observed as a direct result of an aggregate flotation process which reduced the ash content and the average size of the coal and increased the volatile content and heating value. Partially devolatilized chars were burned to simulate the use of a low-volatile solid by-product of a gasification process.
Some issues in the loop variable approach to open strings and an extension to closed strings

Abstract Some issues in the loop variable renormalization group approach to gauge-invariant equations for the free fields of the open string are discussed. It had been shown in an earlier paper that this leads to a simple form of the gauge transformation law. We discuss in some detail some of the curious features encountered there. The theory looks a little like a massless theory in one higher dimension that can be dimensionally reduced to give a massive theory. We discuss the origin of some constraints that are needed for gauge invariance and also for reducing the set of fields to that of standard string theory. The mechanism of gauge invariance and the connection with the Virasoro algebra is a little different from the usual story and is discussed. It is also shown that these results can be extended in a straightforward manner to closed strings.
Dust Outflows and Inner Gaps Generated by Massive Planets in Debris Disks

Main-sequence stars are commonly surrounded by debris disks, formed by cold far-IR-emitting dust that is thought to be continuously replenished by a reservoir of undetected dust-producing planetesimals. We have investigated the orbital evolution of dust particles in debris disks harboring massive planets. Small dust grains are blown out by radiation pressure, as is well known; in addition, gravitational scattering by the giant planets also creates an outflow of large grains. We describe the characteristics of this large-particle outflow in different planetary architectures and for different particle sizes. In addition, the ejection of particles is responsible for the clearing of dust inside the orbit of the planet. We study the efficiency of particle ejection and the resulting dust density contrast inside and outside the orbit of the planet as a function of the planet's mass and orbital elements and the particle size. We discuss its implications for exoplanetary debris disks and for the interpretation of in situ dust detection experiments on space probes traveling in the outer solar system.
Coulomb potentials in two and three dimensions under periodic boundary conditions.

A method to sum over logarithmic potential in two-dimensions (2D) and Coulomb potential in three dimensions (3D) with periodic boundary conditions in all directions is given. We consider the most general form of unit cells, the rhombic cell in 2D and the triclinic cell in 3D. For the 3D case, this paper presents a generalization of Sperb’s work [R. Sperb, Mol. Simulation 22, 199 (1999)]. The expressions derived in this work converge extremely fast in all region of the simulation cell. We also obtain results for slab geometry. Furthermore, self-energies for both 2D as well as 3D cases are derived. Our general formulas can be employed to obtain Madelung constants for periodic structures.
Phase-gradient microscopy in thick tissue with oblique back-illumination

Phase-contrast techniques, such as differential interference contrast microscopy, are widely used to obtain morphological images of unstained biological samples. The transillumination geometry required for these techniques restricts their application to thin samples. We introduce oblique back-illumination microscopy, a method of collecting en face phase-gradient images of thick scattering samples, enabling near-video-rate in vivo phase imaging with a miniaturized probe suitable for endoscopy.
Error detection in data base systems

Incorrect data poses a serious impediment to the effective use of computerized data bases. Conventional approaches to the design and implementation of automated data error detection systems are inadequate for large and complex data bases. Partly, this derives from the inherent intricacy of the problem, with decisions being required as to what checks to perform, how and when to do the checking, and how to respond should an error be found; writing procedures to accomplish these functions is a difficult programming task. Also at fault is the unrealistic and overly simplistic view of data correctness embodied in most contemporary systems."Intelligent" data checking systems are required, which possess more extensive knowledge of the data base environment. They will need to understand the structure of the world which the data base models; the way the data base is used, and the relative importance of its various components; the sources of the errors that might occur and the costs of detecting them; and the patterns and rates of errors that actually do occur. Such a system would then be in a position to detect a wide range of errors, allocating its resources in a systematic fashion and responding appropriately to different error situations.
Characterization of the viscosity of blends of dimethyl ether with various fuels and additives

Dimethyl ether (DME) is a potential ultra clean diesel fuel. Dimethyl ether burns without producing the smoke associated with diesel combustion and can be manufactured from synthesis gas or methanol. However, DME has a low viscosity compared to diesel fuel and has insufficient lubricity to prevent excessive wear in fuel injection systems. One strategy to utilize DME is to blend it with diesel fuel to obtain cleaner burning fuels that retain satisfactory fuel properties. In the present work, the viscosity of blends of DME and various fuels and additives was characterized, including a federal low-sulfur diesel fuel, soybean oil, biodiesel, and various lubricity additives, over a range of blend ratios. A methodology was developed to utilize a high-pressure capillary viscometer to measure the viscosity of pure DME and blends of DME and other compounds in varying proportions and at pressures up to 3500 psig. While DME is miscible in diesel fuel at any mixture fraction when the blend is held under pressures of 75 psi or above, the viscosity of the blends is below the ASTM diesel fuel specification for even a 25 wt % blend of DME in diesel fuel. None of the additives or fuels provides adequate viscosity when blended with DME unless the blend contains less than 50% DME. Viscosity, rather than lubricity, may be the limiting factor in utilizing DME.
Synthesis, structure and properties of Mn1.5Mo8O11, a unique structure type among compounds having infinite chains of Trans-Edge-Shared Octahedral Cluster Units

Abstract The compound Mn1.5Mo8O11 is prepared in single phase form by reaction of intimate mixtures of MnMoO4, MoO3 and molybdenum powders in the mole ratio 9:10:29 in sealed molybdenum tubing at 1450 °C for 4 days. The thin, hair-like needles crystallize in the monoclinic system, space group P2 1 a , a = 9.8463(8) A , b = 16.896(1) A , c = 2.8462(3) A , β = 94.95(1)°, Z = 2 . The structure, solved and refined to R = 0.038, consists of infinite chains of trans-edge-shared octahedral cluster units coupled together through MoOMo interchain linkages. The unique mode of interchain linking provides channels in which the manganese atoms reside and impose unusual square planar and teeter-toter geometry for the interchain bridging oxygen atoms. Magnetic susceptibility measurements show that manganese is present as high spin Mn2+ and resistivity data on single crystals parallel to the infinite chain axis demonstrate metallic behavior. The octahedral cluster repeat units in the infinite chains, Mo4O5.51.5−, each have 14.5 electrons for MoMo bonding and bond order sums indicate that these electrons are utilized efficiently for this purpose.
Minimizing the Energy Spread within a Single Bunch by Shaping Its Charge Distribution

When electrons or positrons in a bunch pass through the periodic structure of a linear accelerator, they leave behind them energy in the form of longitudinal wake fields. The wakefields thus induced by early particles in a bunch offset the energy of later particles. For a linear collider, the energy spread introduced within the bunches by this beam loading effect must be minimized because it limits the degree to which the particles can be focused to a small spot due to chromatic effects in the final focus system. For example, for the SLC, the maximum allowable energy spread is + or - 0.5%. It has been known for some time that partial compensation of the longitudinal wake field effects can be obtained for any bunch by placing it ahead of the accelerating crest (in space), thereby letting the positive rising sinusoidal field offset the negative beam loading field. The work presented in this paper shows that it is possible to obtain complete compensation, i.e., to reduce the energy spread essentially to zero by properly shaping the longitudinal charge distribution of the bunch and by placing it at the correct position on the wave.
Goals and achievement orientations of anglo and mexican-american adolescents in sport and the classroom☆

Abstract The purpose of this study was to analyze the definitions of success and failure (achievement goals) and preferred means to goal attainment (achievement orientations) among male and female Anglo and Mexican-American high school students I athletes in sport and the classroom. Based on a recent conceptualization of achievement motivation, it was assumed that definitions of success and failure could be equated to personal characteristics, behaviors, or outcomes and reflect an emphasis on either effort or ability. Further, it was assumed that there are two major achievement orientations: In one, the means to goal attainment entail social comparison; in the second, goal attainment is processed according to mastery criteria. Results revealed cultural and sex differences in athletic goals. Anglo males were more likely to define sport success in terms of ability while Anglo females and Mexican-American athletes tended to equate athletic success to the demonstration of effort. The reverse was true for sport failure—Anglo males emphasized low effort while the other groups stressed low ability. Variations in preferred achievement orientations were also revealed. For example, in the athletic setting, females showed the least preference for sport success which reflected on the individual and involved social comparison. Males indicated the least preference for individual-oriented, social comparison-based athletic failure.
Parent stars of extrasolar planets – VIII. Chemical abundances for 18 elements in 31 stars

We present the results of detailed spectroscopic abundance analyses for 18 elements in 31 nearby stars with planets (SWPs). The resulting abundances are combined with other similar studies of nearby SWPs and compared to a sample of nearby stars without detected planets. We find some evidence for abundance differences between these two samples for Al, Si and Ti. Some of our results are in conflict with a recent study of SWPs in the SPOCS data base. We encourage continued study of the abundance patterns of SWPs to resolve these discrepancies.
The short-run impacts of Connecticut’s paid sick leave legislation

In 2012, Connecticut became the first state to enact paid sick leave legislation. Using a difference-in-differences framework, we find the law had modest but negative effects on the labour market, particularly on the likelihood of working in the past week.
Magnetoresistive random access memory (MRAM) and reliability

This paper provides an overview of the design and operation of, and materials used in, magnetoresistive random access memory (MRAM) with emphasis from a reliability engineering perspective. The speaker will provide background information on MRAM architectures and discuss novel reliability problems inherent to MRAM. Reliability issues and concerns will be discussed and illustrated with examples wherever possible. The intention of the paper is to give attendees a basic and broad introduction to the potential reliability issues and challenges raised by this new memory form.
Courts as Coordinators Endogenous Enforcement and Jurisdiction in International Adjudication

Why do states build international courts, submit cases, and enforce court judgments? This article examines the role of a court that is neither a “decider” nor an “information provider.” Litigation is costly and does not reveal private information. The court’s ruling is not binding and bargaining can occur before and after the court has ruled. Nevertheless, an alternative dispute resolution mechanism emerges: court rulings can coordinate endogenous multilateral enforcement. Disinterested states will enforce to ensure that they can profitably use the court in the future. Accepting jurisdiction of the court allows a state to make efficiency-enhancing “trades,” winning high-value disputes in exchange for losing low-value disputes. This is possible because litigation is a screening device: states only sue when they derive relatively high value from the disputed asset. The use of the court as a coordination device for multilateral enforcement allows for the existence of a court with endogenous enforcement and j...
Evolution of domain walls in the early Universe.

The evolution of domain walls in the early universe is studied via 2-D computer simulation. The walls are initially configured on a triangular lattice and then released from the lattice, their evolution driven by wall curvature and by the universal expansion. The walls attain an average velocity of about 0.3c and their surface area per volume (as measured in comoving coordinates) goes down with a slope of -1 with respect to conformal time, regardless of whether the universe is matter or radiation dominated. The additional influence of vacuum pressure causes the energy density to fall away from this slope and steepen, thus allowing a situation in which domain walls can constitute a significant portion of the energy density of the universe without provoking an unacceptably large perturbation upon the microwave background.
Appraising cross-national income inequality databases : an introduction

In response to a growing interest in comparing inequality levels and trends across countries, several cross-national inequality databases are now available. These databases differ considerably in purpose, coverage, data sources, inclusion and exclusion criteria, and quality of documentation. A special issue of the Journal of Economic Inequality, which this paper introduces, is devoted to an assessment of the merits and shortcomings of eight such databases. Five of these sets are microdata-based: CEPALSTAT, Income Distribution Database, Luxembourg Income Study, PovcalNet, and Socio-Economic Database for Latin America and the Caribbean. Two are based on secondary sources: All the Ginis and the World Income Inequality Database; and one is generated entirely through multiple-imputation methods: the Standardized World Income Inequality Database. Although there is much agreement across these databases, there is also a nontrivial share of country/year cells for which substantial discrepancies exist. In some cases, different databases would lead users to radically different conclusions about inequality dynamics in certain countries and periods. The methodological differences that lead to these discrepancies often appear to be driven by a fundamental trade-off between a wish for broader coverage on the one hand, and for greater comparability on the other hand. These differences across databases place considerable responsibility on both producers and users: on the former, to better document and explain their assumptions and procedures, and on the latter, to understand the data they are using, rather than merely taking them as true because available.
Nonlinear filtering of multiplied and convolved signals

An approach to some nonlinear filtering problems through a generalized notion of superposition has proven useful In this paper this approach is investigated for the nonlinear filtering of signals which can be expressed as products or as convolutions of components. The applications of this approach in audio dynamic range compression and expansion, image enhancement with applications to bandwidth reduction, echo removal, and speech waveform processing are presented.
MINIMUM RADII OF SUPER-EARTHS: CONSTRAINTS FROM GIANT IMPACTS

The detailed interior structure models of super-Earth planets show that there is degeneracy in the possible bulk compositions of a super-Earth at a given mass and radius, determined via radial velocity and transit measurements, respectively. In addition, the upper and lower envelopes in the mass-radius relationship, corresponding to pure ice planets and pure iron planets, respectively, are not astrophysically well motivated with regard to the physical processes involved in planet formation. Here we apply the results of numerical simulations of giant impacts to constrain the lower bound in the mass-radius diagram that could arise from collisional mantle stripping of differentiated rocky/iron planets. We provide a very conservative estimate for the minimum radius boundary for the entire mass range of large terrestrial planets. This envelope is a readily testable prediction for the population of planets to be discovered by the Kepler mission.
Dirichlet duality and the nonlinear Dirichlet problem

We study the Dirichlet problem for fully nonlinear, degenerate elliptic equations of the form F(Hess u) = 0 on a smoothly bounded domain Ω ⋐ ℝn. In our approach the equation is replaced by a subset F ⊂ Sym2(ℝn) of the symmetric n × n matrices with ∂F ⊆ {F = 0}. We establish the existence and uniqueness of continuous solutions under an explicit geometric “F-convexity” assumption on the boundary ∂Ω. We also study the topological structure of F-convex domains and prove a theorem of Andreotti-Frankel type. Two key ingredients in the analysis are the use of “subaffine functions” and “Dirichlet duality.” Associated to F is a Dirichlet dual set F that gives a dual Dirichlet problem. This pairing is a true duality in that the dual of F is F, and in the analysis the roles of F and F are interchangeable. The duality also clarifies many features of the problem including the appropriate conditions on the boundary. Many interesting examples are covered by these results including: all branches of the homogeneous Monge-Ampere equation over ℝ, ℂ, and ℍ; equations appearing naturally in calibrated geometry, Lagrangian geometry, and p-convex Riemannian geometry; and all branches of the special Lagrangian potential equation. © 2008 Wiley Periodicals, Inc.
IgE and FcεRI Regulation

A central feature of allergic reactions is the aggregation of the high-affinity IgE receptor, FcepsilonRI, to initiate a change in the behavior of the cell expressing the receptor. It is now clear that a number of cell types can express this receptor, which broadens the biology that revolves around IgE antibody. It is also quite clear that the presence of monomeric IgE antibody alters the expression of FcepsilonRI. There remains considerable uncertainty about the importance of independent regulation of the FcepsilonRIbeta subunit or its splice variant beta(T), in terms of regulating both expression and function of FcepsilonRI. There is also only primitive understanding of the role of various polymorphisms in the subunit genes on the atopic phenotype. There are, however, many efforts being made to resolve these issues and to discover other factors that regulate expression of this receptor. Of particular interest for understanding the variation in expression in atopy among patients, the role of this receptor on non-mast cell/basophils will be important to elucidate.
Matching Matters in 401(k) Plan Participation

This study offers new evidence on the effects of the matching contributions made by employers to 401(k) plan accounts on plan participation rates, exploiting microdata from the National Compensation Survey, a large, nationally representative, establishment dataset. It addresses the potential endogeneity of the matching contributions by employing coworker and labor market characteristics as instruments. The results indicate that employer matches have substantial effects. They also indicate that higher match rates tend to be correlated with workers having lower propensities to save; correcting for this endogeneity produces estimates that are bigger than those seen through direct crosssectional comparisons.
Do Temporary Help Jobs Improve Labor Market Outcomes for Low-Skilled Workers? Evidence from 'Work First'

Temporary-help jobs offer rapid entry into paid employment, but they are typically brief and it is unknown whether they foster longer term employment. We utilize the unique structure of Detroit's welfare-to-work program to identify the effect of temporary-help jobs on labor market advancement. Exploiting the rotational assignment of welfare clients to numerous nonprofit contractors with differing job placement rates, we find that temporary-help job placements do not improve and may diminish subsequent earnings and employment outcomes among participants. In contrast, job placements with direct-hire employers substantially raise earnings and employment over a seven quarter follow-up period.
Energy and Momentum of a Stationary Beam of Light

The energy–momentum complexes of Einstein, Landau–Lifshitz, Papapetrou, and Weinberg give the same and meaningful results for the energy and momentum of the Bonnor space–time describing the gravitational field of a stationary beam of light. The results support the Cooperstock hypothesis.
Improved Upper Bounds on Stopping Redundancy

For a linear block code with minimum distance d, its stopping redundancy is the minimum number of check nodes in a Tanner graph representation of the code, such that all nonempty stopping sets have size d or larger. We derive new upper bounds on stopping redundancy for all linear codes in general, and for maximum distance separable (MDS) codes specifically, and show how they improve upon previous results. For MDS codes, the new bounds are found by upper-bounding the stopping redundancy by a combinatorial quantity closely related to Turan numbers. (The Turan number, T(v,k,t), is the smallest number of t-subsets of a v-set, such that every k-subset of the v-set contains at least one of the t-subsets.) Asymptotically, we show that the stopping redundancy of MDS codes with length n and minimum distance d >1 is T(n,d-1,d-2)(1+O(n-1)) for fixed d, and is at most T (n,d-1,d-2)(3+O(n-1)) for fixed code dimension k=n-d+1. For d=3,4, we prove that the stopping redundancy of MDS codes is equal to T(n,d-1,d-2), for which exact formulas are known. For d=5, we show that the stopping redundancy of MDS codes is either T(n,4,3) or T(n,4,3)+1
Bispectral and Trispectral Characterization of Transition to Chaos in the Duffing Oscillator

Higher-order spectral (bispectral and trispectral) analyses of numerical solutions of the Duffing equation with a cubic stiffness are used to isolate the coupling between the triads and quartets, respectively, of nonlinearly interacting Fourier components of the system. The Duffing oscillator follows a period-doubling intermittency catastrophic route to chaos. For period-doubled limit cycles, higher-order spectra indicate that both quadratic and cubic nonlinear interactions are important to the dynamics. However, when the Duffing oscillator becomes chaotic, global behavior of the cubic nonlinearity becomes dominant and quadratic nonlinear interactions are weak, while cubic interactions remain strong. As the nonlinearity of the system is increased, the number of excited Fourier components increases, eventually leading to broad-band power spectra for chaos. The corresponding higher-order spectra indicate that although some individual nonlinear interactions weaken as nonlinearity increases, the number of nonlinearly interacting Fourier modes increases. Trispectra indicate that the cubic interactions gradually evolve from encompassing a few quartets of Fourier components for period-1 motion to encompassing many quartets for chaos. For chaos, all the components within the energetic part of the power spectrum are cubically (but not quadratically) coupled to each other.
An expeditious solvent-free route to ionic liquids using microwaves

A microwave-assisted preparation of a series of ambient temperature ionic liquids, 1-alkyl-3-methylimidazolium (AMIM) halides, that proceeds via efficient reaction of 1-methylimidazole with alkyl halides/terminal dihalides under solvent-free conditions, is described.
Dynamic Effects among Movie Ratings, Movie Revenues, and Viewer Satisfaction:

Abstract This research investigates how movie ratings from professional critics, amateur communities, and viewers themselves influence key movie performance measures (i.e., movie revenues and new movie ratings). Using movie-level data, the authors find that high early movie revenues enhance subsequent movie ratings. They also find that high advertising spending on movies supported by high ratings maximizes the movie's revenues. Furthermore, they empirically show that sequel movies tend to reap more revenues but receive lower ratings than originals. Using individual viewer–level data, this research highlights how viewers' own viewing and rating histories and movie communities' collective opinions explain viewer satisfaction. The authors find that various aspects of these ratings explain viewers' new movie ratings as a measure of viewer satisfaction, after controlling for movie characteristics. Furthermore, they find that viewers' movie experiences can cause them to become more critical in ratings over time...
EHD flow visualization in the wire-plate and barbed plate electrostatic precipitator

A barbed-plate discharge electrode has been designed to reduce the size of current inhomogeneities within a precipitator flow channel. Consequently, the scale of the corona-induced eddies and thus the particle mixing are decreased. It is shown that visualization of the interelectrode flow gives physical insight into the structure of the electrohydrodynamic flow. Still photographs of the flow are interpreted in the light of measured current-voltage relationships, turbulence intensities, integral length scales, and eddy diffusivities. Results confirm that the scale of the electrically induced flow is reduced by the barbed-plate discharge electrode. However, turbulence levels increase, so that gas diffusivities are slightly diminished. >
DNA methylation dynamics of the human preimplantation embryo

In mammals, cytosine methylation is predominantly restricted to CpG dinucleotides and stably distributed across the genome, with local, cell-type-specific regulation directed by DNA binding factors. This comparatively static landscape is in marked contrast with the events of fertilization, during which the paternal genome is globally reprogrammed. Paternal genome demethylation includes the majority of CpGs, although methylation remains detectable at several notable features. These dynamics have been extensively characterized in the mouse, with only limited observations available in other mammals, and direct measurements are required to understand the extent to which early embryonic landscapes are conserved. We present genome-scale DNA methylation maps of human preimplantation development and embryonic stem cell derivation, confirming a transient state of global hypomethylation that includes most CpGs, while sites of residual maintenance are primarily restricted to gene bodies. Although most features share similar dynamics to those in mouse, maternally contributed methylation is divergently targeted to species-specific sets of CpG island promoters that extend beyond known imprint control regions. Retrotransposon regulation is also highly diverse, and transitions from maternally to embryonically expressed elements. Together, our data confirm that paternal genome demethylation is a general attribute of early mammalian development that is characterized by distinct modes of epigenetic regulation.