cssi/SciSciGPT-SciSciNet huggingface dataset:
Extended adiabatic blast waves and a model of the soft X-ray background

An analytical approximation is generated which follows the development of an adiabatic spherical blast wave in a homogeneous ambient medium of finite pressure. An analytical approximation is also presented for the electron temperature distribution resulting from coulomb collisional heating. The dynamical, thermal, ionization, and spectral structures are calculated for blast waves of energy E sub 0 = 5 x 10 to the 50th power ergs in a hot low-density interstellar environment. A formula is presented for estimating the luminosity evolution of such explosions. The B and C bands of the soft X-ray background, it is shown, are reproduced by such a model explosion if the ambient density is about .000004 cm, the blast radius is roughly 100 pc, and the solar system is located inside the shocked region. Evolution in a pre-existing cavity with a strong density gradient may, it is suggested, remove both the M band and OVI discrepancies.
Incorporation of a Late-forming Chondrule into Comet Wild 2

We report the petrology, O isotopic composition, and Al-Mg isotope systematics of a chondrule fragment from the Jupiter-family comet Wild 2, returned to Earth by NASA's Stardust mission. This object shows characteristics of a type II chondrule that formed from an evolved oxygen isotopic reservoir. No evidence for extinct {sup 26}Al was found, with ({sup 26}Al/{sup 27}Al){sub 0} < 3.0 Multiplication-Sign 10{sup -6}. Assuming homogenous distribution of {sup 26}Al in the solar nebula, this particle crystallized at least 3 Myr after the earliest solar system objects-relatively late compared to most chondrules in meteorites. We interpret the presence of this object in a Kuiper Belt body as evidence of late, large-scale transport of small objects between the inner and outer solar nebula. Our observations constrain the formation of Jupiter (a barrier to outward transport if it formed further from the Sun than this cometary chondrule) to be more than 3 Myr after calcium-aluminum-rich inclusions.
Proplyds and massive disks in the Orion Nebula Cluster imaged with CARMA and SMA

We imaged a 2' × 2' region of the Orion Nebula Cluster (ONC) in 1.3 mm wavelength continuum emission with the recently commissioned Combined Array for Research in Millimeter Astronomy (CARMA) and with the Submillimeter Array (SMA). Our mosaics include >250 known near-IR cluster members, of which 36 are so-called "proplyds" that have been imaged previously with the Hubble Space Telescope. We detected 40 sources in 1 mm continuum emission (one of which is the BN Object), and several of them are spatially resolved with our observations. The emission from most objects arises predominantly from dust, and circumstellar masses inferred for detected sources range from 0.01 to 0.5 M⊙. The average circumstellar mass for undetected sources is estimated to be ~0.001 M⊙, approximately an order of magnitude smaller than the minimum-mass solar nebula. Most stars in the ONC thus do not appear to currently possess sufficient mass in small dust grains to form Jupiter-mass (or larger) planets. Comparison with previous results for younger and older regions indicates that massive disks evolve significantly on ~Myr timescales. We also show that the percentage of stars in Orion surrounded by disks more massive than ~0.01 M⊙ is substantially lower than in Taurus, indicating that environment has an impact on the disk-mass distribution. Disks in Orion may be truncated through photoevaporation caused by the intense radiation field of the Trapezium stars, and we see marginal evidence for such a scenario in the spatial distribution of massive disks within the cluster. Our data show no statistically significant correlation between disk and stellar masses, although we see hints of a higher percentage of massive disks around lower mass stars.
Diffuser augmentation of wind turbines

Abstract One of the more promising advanced concepts for overcoming the economic deterrents to widespread use of windpower is the Diffuser-Augmented Wind Turbine (DAWT). The diffuser controls the expansion of turbine exhaust flow, producing a highly subatmospheric pressure at the turbine exit. The low static pressure induces greater mass flow through the turbine in contrast to a conventional turbine design of the same diameter. Thus, the output power of the DAWT is much larger than for an unshrouded turbine. Our wind tunnel investigation of models of two diffuser design concepts is directed toward unconventional, very short, cost-effective configurations. One approach uses the energetic external wind to prevent separation of the diffuser's internal boundary layer. Another method uses high lift airfoil contours for the diffuser wall shape. Diffuser model tests have indicated almost a doubling of wind power extraction capability for DAWTs compared to conventional turbines. Economic studies of DAWTs have used these test data and recent (1975) cost projections of wind turbines with diameter. The specific power costs ($/kW) for a realistic DAWT configuration are found to be lower than conventional wind turbines for very large size rotors, above 50 m diameter, and for rotor diameters less than about 20 m. The cost-to-benefit assessment for intermediate size rotors is affected by the uncertainty band of cost for these rotor sizes.
The cohomology of the Sylow 2-subgroup of the Higman–Sims group

Abstract In this paper we compute the mod 2 cohomology of the Sylow 2-subgroup of the Higman–Sims group HS, one of the 26 sporadic simple groups. We obtain its Poincare series as well as an explicit description of it as a ring with 17 generators and 79 relations.
Interaction Design and Children

Children are increasingly using computer technologies as reflected ini¾ reports of computer use in schools in the United States. Given thei¾ greater exposure of children to these technologies, it is imperative that they be designed taking into account children's abilities, interests, and developmental needs. This survey aims to contribute toward this goal through a review of research on children's cognitive and motor development, safety issues related to technologies and design methodologies and principles. It also provides and overview of current research trends in the field of interaction design and children and identifies challenges for future research.
Nonperturbative corrections in resummed cross sections

Abstract We show that the resummation of large perturbative corrections in QCD leads to ambiguities in high energy cross sections that are suppressed by powers of large momentum scales. These ambiguities are caused by infrared renormalons, which are a general feature of resummed hardscattering functions in perturbative QCD, even though these functions are infrared safe order-by-order in perturbation theory. As in the case of the operator product expansion, the contributions of infrared renormalons to coefficient functions may be absorbed into the definition of higher-dimensional operators, which induce nonperturbative corrections that are power-suppressed at high energies. The strength of the suppression is determined by the location of the dominant infrared renormalon, which may be identified explicitly in the resummed series. In contrast to the operator product expansion, however, the relevant operators in factorized hadron-hadron scattering and jet cross sections are generally nonlocal in QCD, although they may be expressed as local operators in an effective theory for eikonalized quarks. In this context, we verify and interpret the presence of 1 / Q corrections to the inclusive Drell-Yan cross section with Q the pair mass. In a similar manner, we find exp (- b 2 In Q ) corrections in the impact parameter space of the transverse momentum distributions of the Drell-Yan process and e + 6 - annihilation. We also show that the dominant nonperturbative corrections to cone-based jet cross sections behave as 1 /( Qδ ), with δ the opening angle of the jet and Q the center of mass energy.
Different magnitudes of projected subsurface ocean warming around Greenland and Antarctica

Accurate projections of global sea-level rise require information of future ocean warming in the vicinity of the large ice sheets. An analysis of 19 climate model projections suggests that subsurface ocean warming near both polar ice sheets will be substantial, with the potential to lead to significant increases in ice-mass loss.
Independence, Monotonicity, and Latent Index Models: An Equivalence Result

The selection model and instrumental variable, local average treatment effect (LATE) framework are widely interpreted as alternative, competing frameworks. This note shows that the assumption of an unobserved index crossing a threshold that defines the selection model is equivalent to the independence and monotonicity assumptions at the center of the LATE approach. The underlying assumptions of the two approaches are equivalent.
Electrical Control of Silicon Photonic Crystal Cavity by Graphene

The efficient conversion of an electrical signal to an optical signal in nanophotonics enables solid state integration of electronics and photonics. The combination of graphene with photonic crystals is promising for electro-optic modulation. In this paper, we demonstrate that by electrostatic gating a single layer of graphene on top of a photonic crystal cavity, the cavity resonance can be changed significantly. A ∼2 nm change in the cavity resonance line width and almost 400% (6 dB) change in resonance reflectivity is observed. In addition, our analysis shows that a graphene–photonic crystal device can potentially be useful for a high speed and low power absorptive and refractive modulator, while maintaining a small physical footprint.
Control System for a 373 kW, Intercooled, Two-Spool Gas Turbine Engine Powering a Hybrid Electric World Sports Car Class Vehicle

SatCon Technology Corporation has completed design, fabrication, and the first round of test of a 373 kW (500 hp), two-spool, intercooled gas turbine engine with integral induction type alternators. This turbine alternator is the prime mover for a World Sports Car class hybrid electric vehicle under development by Chrysler Corporation. The complete hybrid electric vehicle propulsion system features the 373 kW (500 hp) turbine alternator unit, a 373 kW (500 hp) 3.25 kW-h (4.36 hp-h) flywheel, a 559 kW (750 hp) traction motor, and the propulsion system control system. This paper presents and discusses the major attributes of the control system associated with the turbine alternator unit. Also discussed is the role and operational requirements of the turbine alternator unit as part of the complete hybrid electric vehicle propulsion svstem.
LED white light visual equivalence

Current white LED color has a wide range of CCT and varying distance to Planckian Loci, which cause different tint in white color. This color variation keeps a number of illumination and indication applications away from LEDs. This article introduces a passive method, adding correction filters, to correct the color and achieve visual equivalence of the LED white light. Efficiency of using correction filters is discussed.
The experimental evidence of the role of surface restructuring during catalytic reactions

Changes of surface structure of transition metals, and oxides were observed to occur on three different time scales. Chemisorption induced restructuring is localized to the proximity of the adsorption site and is likely to take place within less than 10−6 sec. In this regime the coverage dependence of restructuring can also be detected. Surface reconstruction has also been found to occur on the catalytic turnover time scale (10−2–102 sec) and is detectable readily during oscillatory and partial oxidation reactions. Structural changes also occur at oxide-metal interfaces in this time scale under reaction conditions. Surface atom transport controlled restructuring takes place during longer time-periods, 102–104 sec. These diffusion controlled processes can be correlated with catalyst activation and deactivation that are detectable on a similar time scale. Oxidation and reduction of catalyst particles, sulfur or alkali metal adsorption can all lead to restructuring of this type. The results of experiments are reviewed and the need for developing time resolved techniques to detect surface structural changes at high pressures and temperatures is discussed.
Correlations in one-dimensional quantum impurity problems with an external field

Abstract We study response functions of integrable quantum impurity problems with an external field at T = 0 using non-perturbative techniques derived from the Bethe ansatz. We develop the first steps of the theory of excitations over the new, field-dependent ground state, leading to renormalized (or “dressed”) form factors. We obtain exactly the low-frequency behaviour of the dynamical susceptibility χ″ (ω) in the double-well problem of dissipative quantum mechanics (or equivalently the anisotropic Kondo problem), and the low-frequency behaviour of the AC noise S t ( ω ) for tunnelling between edges in fractional quantum Hall devices. We also obtain exactly the structure of singularities in χ″ (ω) and S t ( ω ). Our results differ significantly from previous perturbative approaches.
Sleep in children with autism spectrum disorders

Children with autism spectrum disorders frequently have significant sleep problems, most commonly insomnia. Fortunately, a variety of treatments are available, including behavioral interventions and pharmacotherapy. When establishing a treatment plan, it is imperative to understand the underlying etiology of the sleep problem, which in many cases is multifactorial. Some sleep problems, such as suspected obstructive sleep apnea, should be referred to a sleep specialist. Identifying and treating sleep disorders may not only result in improved sleep but also may favorably affect daytime behavior and family functioning. In general, when treating insomnia, behavioral interventions should be instituted initially, followed by pharmacotherapy if needed.
Comments on papers by Reichert and Wong

Papers of Reichert and Wong (1971) and Reichert (1972) are referred to as erroneous in stating that in their work with cytochrome c sequences they demonstrated that vertebrates have achieved a higher organized genetic message with a higher fidelity in the DNA-to-protein information processing channel. Arguments are given to contest that statement.
Quantitative Analysis of Histone Modifications: Formaldehyde Is a Source of Pathological N6-Formyllysine That Is Refractory to Histone Deacetylases

Aberrant protein modifications play an important role in the pathophysiology of many human diseases, in terms of both dysfunction of physiological modifications and the formation of pathological modifications by reaction of proteins with endogenous electrophiles. Recent studies have identified a chemical homolog of lysine acetylation, N6-formyllysine, as an abundant modification of histone and chromatin proteins, one possible source of which is the reaction of lysine with 3′-formylphosphate residues from DNA oxidation. Using a new liquid chromatography-coupled to tandem mass spectrometry method to quantify all N6-methyl-, -acetyl- and -formyl-lysine modifications, we now report that endogenous formaldehyde is a major source of N6-formyllysine and that this adduct is widespread among cellular proteins in all compartments. N6-formyllysine was evenly distributed among different classes of histone proteins from human TK6 cells at 1–4 modifications per 104 lysines, which contrasted strongly with lysine acetylation and mono-, di-, and tri-methylation levels of 1.5-380, 5-870, 0-1400, and 0-390 per 104 lysines, respectively. While isotope labeling studies revealed that lysine demethylation is not a source of N6-formyllysine in histones, formaldehyde exposure was observed to cause a dose-dependent increase in N6-formyllysine, with use of [13C,2H2]-formaldehyde revealing unchanged levels of adducts derived from endogenous sources. Inhibitors of class I and class II histone deacetylases did not affect the levels of N6-formyllysine in TK6 cells, and the class III histone deacetylase, SIRT1, had minimal activity (<10%) with a peptide substrate containing the formyl adduct. These data suggest that N6-formyllysine is refractory to removal by histone deacetylases, which supports the idea that this abundant protein modification could interfere with normal regulation of gene expression if it arises at conserved sites of physiological protein secondary modification.
Sensitivity of Teacher Value-Added Estimates to Student and Peer Control Variables.

AbstractTeacher value-added models (VAMs) must isolate teachers’ contributions to student achievement to be valid. Well-known VAMs use different specifications, however, leaving policymakers with little clear guidance for constructing a valid model. We examine the sensitivity of teacher value-added estimates under different models based on whether they include student and peer background characteristics, and a double-lagged achievement score. We also consider two previously unexplored model variations: (a) replacing classroom peer characteristics with teacher-level averages, and (b) allowing demographics to influence the relationship between current and prior achievement. Using data from a northern state, we find that teacher effectiveness estimates are highly correlated across specifications. However, up to 26% of teachers in the bottom quintile using one specification are ranked higher using another specification. Differences between VAMs have direct implications for which estimates change. In particula...
Twisted representation rings and Dirac induction

Abstract Extending ideas of twisted equivariant K-theory, we construct twisted versions of the representation rings for Lie superalgebras and Lie supergroups, built from projective Z 2 -graded representations with a given cocycle. We then investigate the pullback and pushforward maps on these representation rings (and their completions) associated to homomorphisms of Lie superalgebras and Lie supergroups. As an application, we consider the Lie supergroup Π ( T * G ) , obtained by taking the cotangent bundle of a compact Lie group and reversing the parity of its fibers. An inclusion H ↪ G induces a homomorphism from the twisted representation ring of Π ( T * H ) to the twisted representation ring of Π ( T * G ) , which pulls back via an algebraic version of the Thom isomorphism to give an additive homomorphism from K H ( pt ) to K G ( pt ) (possibly with twistings). We then show that this homomorphism is in fact Dirac induction, which takes an H-module U to the G-equivariant index of the Dirac operator / ∂ ⊗ U on the homogeneous space G / H with values in the homogeneous bundle induced by U.
COMBINATORICS OF MATRIX FACTORIZATIONS AND INTEGRABLE SYSTEMS

We study relations between the eigenvectors of rational matrix functions on the Riemann sphere. Our main result is that for a subclass of functions that are products of two elementary blocks it is possible to represent these relations in a combinatorial–geometric way using a diagram of a cube. In this representation, vertices of the cube represent eigenvectors, edges are labeled by differences of locations of zeroes and poles of the determinant of our matrix function, and each face corresponds to a particular choice of a coordinate system on the space of such functions. Moreover, for each face this labeling encodes, in a neat and efficient way, a generating function for the expressions of the remaining four eigenvectors that label the opposing face of the cube in terms of the coordinates represented by the chosen face. The main motivation behind this work is that when our matrix is a Lax matrix of a discrete integrable system, such generating functions can be interpreted as Lagrangians of the system, and ...
Chaos in the Mixed Even-Spin Models

We consider a disordered system obtained by coupling two mixed even-spin models together. The chaos problem is concerned with the behavior of the coupled system when the external parameters in the two models, such as, temperature, disorder, or external field, are slightly different. It is conjectured that the overlap between two independently sampled spin configurations from, respectively, the Gibbs measures of the two models is essentially concentrated around a constant under the coupled Gibbs measure. Using the extended Guerra replica symmetry breaking bound together with a recent development of controlling the overlap using the Ghirlanda–Guerra identities as well as a new family of identities, we present rigorous results on chaos in temperature. In addition, chaos in disorder and in external field are addressed.
Stereo image compression with disparity compensation using the MRF model

In coming years there will be an increasing demand for realistic 3-D display of scenes using such popular approaches as stereo or multi-view images. As the amount of information displayed increases so does the need for digital compression to ensure efficient storage and transmission of the sequences. In this paper, we introduce a new approach to stereo image compression based on the MRF model and MAP estimation. The basic strategy will be to encode the right image as a reference, then estimate the disparity between blocks in the right and left images and transmit the disparity and the error between the disparity compensated left image and the original. This approach has been used in the literature and is akin to the block matching technique used for motion compensation in video coders. The main drawback in this approach is that as the block size becomes smaller the overhead required to transmit the disparity map becomes too large. Also, simple block matching algorithms frequently fail to provide good matching results because the correspondences are locally ambiguous due to noise, occlusion, and repetition or lack of texture. The novelty in our work is that to compute the disparity map we introduce an MRF model with its corresponding energy equation. This allow us to incorporate smoothness constraints, to take into account occlusion, and to minimize the effect of noise in the disparity map estimation. Obtaining a smooth disparity is beneficial as it reduces the overhead required to transmit the disparity map. It is also useful for video coding since the robustness against noise ensures that disparity maps in successive frames will be very similar. We describe this new formulation in detail and provide compression results.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The Blue Straggler and Main-Sequence Binary Population of the Low-Mass Globular Cluster Palomar 13*

We present high-precision VI photometry of stars from the middle of the giant branch to about 5 mag below the main-sequence turnoff in the globular cluster Palomar 13 based on images obtained with the Keck II 10 m telescope. We tabulate a complete sample of blue stragglers in the cluster out to about 18 core radii. The blue straggler population is significantly more centrally concentrated than the giant-star sample, which is in turn significantly more centrally concentrated than the main-sequence–star sample. Pal 13 has one of the highest specific frequencies of blue stragglers of any known globular cluster, but the specific frequency of blue stragglers in the outskirts of the cluster does not increase, as has been seen in denser clusters. We also identify a group of faint blue stragglers (bluer than the turnoff but having about the same magnitude) that outnumbers the brighter stragglers by more than a factor of 2. The cluster's color-magnitude diagram shows a large excess of stars to the red of the main sequence, indicating that the cluster's binary fraction is at least 30% ± 4%, which appears to be similar to that of the low-mass cluster E3 but significantly higher than that of the more massive clusters Pal 5 and NGC 288.
A proof of the positive density conjecture for integer Apollonian circle packings

A bounded Apollonian circle packing (ACP) is an ancient Greek construction which is made by repeatedly inscribing circles into the triangular interstices in a Descartes configuration of four mutually tangent circles. Remarkably, if the original four circles have integer curvature, all of the circles in the packing will have integer curvature as well. In this paper, we compute a lower bound for the number $\kappa(P,X)$ of integers less than $X$ occurring as curvatures in a bounded integer ACP $P$, and prove a conjecture of Graham, Lagarias, Mallows, Wilkes, and Yan that the ratio $\kappa(P,X)/X$ is greater than 0 for $X$ tending to infinity.
Twisted bundle on quantum torus and BPS states in matrix theory

Abstract Following the recent work of Connes, Douglas and Schwarz, we study the M(atrix) model compactified on a torus with a background of the three-form field. This model is given by a super Yang-Mills theory on a quantum torus. To consider twisted gauge field configurations, we construct twisted U ( n ) bundles on the quantum torus as a deformation of its classical counterpart. By properly taking into account membranes winding around the light-cone direction, we derive from the M(atrix) model the BPS spectrum which respects the full SL(2, Z )×SL(2, Z ) U-duality in M theory.
Asymmetric epoxidation of functionalized cis-olefins catalyzed by chloroperoxidase

Abstract Chloroperoxidase catalyzes the asymmetric epoxidation of functionalized cis-2-alkenes with excellent enantioselectivity and good yields, using tert-butyl hydroperoxide as the terminal oxidant.
Ambient carboxylation on a supported reversible CO2 carrier: ketone to β-keto ester

A reversible CO2 carrier (RCC) has been developed to perform carboxylation of ketone to β-ketoester under ambient CO2 pressure and temperature. RCC has been synthesized by immobilizing 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) on methylhydrosiloxane support and reacting with CO2 with 100% degree of functionalisation. RCC is found to be recyclable and shows retention of activity in 5 recycles. CO2 absorption under ambient temperature and desorption at 120 °C renders the material suitable for carrying out carboxylation reactions at 25 °C with excellent yields. The yield of the reaction can reach up to 100% with TON 200 in 4 h. The extent of the reaction primarily depends upon enol content of the substrate. β-Ketoacid produced during the reaction can be isolated and converted to its corresponding methyl ester derivative by reacting with methyl iodide.
Standby supply voltage minimization for deep sub-micron SRAM

Abstract Suppressing the leakage current in memories is critical in low-power design. By reducing the standby supply voltage (VDD) to its limit, which is the data retention voltage (DRV), leakage power can be substantially reduced. This paper models the DRV of a standard low leakage SRAM module as a function of process and design parameters, and analyzes the SRAM cell stability when VDD approaches DRV. The DRV model is verified using simulations as well as measurements from a 4 KB SRAM chip in a 0.13 μm technology. Due to a large on-chip variation, DRV of the 4 KB SRAM module ranges between 60 and 390 mV. Measurements taken at 100 mV above the worst-case DRV show that reducing the SRAM standby VDD to a safe level of 490 mV saves 85% leakage power. Further savings can be achieved by applying DRV-aware SRAM optimization techniques, which are discussed at the end of this paper.
The co-operative, transformative organization of human action and knowledge

Abstract Focusing on a range of features that are central to the constitution of action, this article is an empirically based theoretical contribution to the field of research attempting to understand how human sociality is established and sustained. Human action is intensely, perhaps uniquely, co-operative. Individual actions are constructed by assembling diverse materials, including language structure, prosody, and visible embodied displays. Semiotically charged objects, such as maps, when included within local action, incorporate ways of knowing and acting upon the world that have been inherited from predecessors. New action is built by performing systematic, selective operations on these public configurations of resources. The way in which a single action encompasses different kinds of resources makes possible 1) distinctive forms of co-operative social organization as alternatively positioned actors contribute different kinds of structure to a single shared action (e.g., the talk of a speaker and the silent visible displays of hearer work together to construct a turn-at-talk and the utterance emerging within it); and 2) the accumulation and differentiation through time within local co-operative transformation zones of dense substrates that create a multiplicity of settings for action. Each setting for action must be inhabited by competent members who have mastered the culturally specific practices required to perform the activities that animate the lifeworld of a particular community. Through the progressive development of, and apprenticeship within, diverse epistemic ecologies, communities invest their members with the resources required to understand each other in just the ways that make possible the accomplishment of ongoing, situated action. Human beings inhabit each other's actions.
Ovals and Hyperovals in Desarguesian Nets

We determine the Desarguesian planes which hold r-nets with ovals and those which hold r-nets with hyperovals for every r≤7.
Flexible Object Architectures for Hybrid Neural Processing Systems

This paper introduces an initial object architecture and prototype for the flexible, hybrid genetic-neural processing environment called ELYSE, the Evolving, Life-like Yielding, Symbiotic Environment. This architecture will allow the system to dynamically adapt its structure as it evolves and learns more about the types of environments it must deal with. The architecture accommodates a variety of memory classes and algorithm methods. The basic building blocks of ELYSE, the fuzzy, genetic perceptron, may be added or deleted from the system, depending on the complexity of the classes of information the system must process. Presented will be a theoretical description of dynamic adaptation along with the object architecture and high-level requirements for the system.
An Efficient Preparation of (+)-trans-2-(α-Cumyl)cyclohexanol ((+)-TCC): A practical alternative to (+)-8-phenylmenthol☆

Abstract An efficient synthesis and resolution of trans-2-(α-cumyl)cyclohexanol gives the (+)-enantiomer in three steps from cyclohexene oxide.
Emission of Positron Annihilation Line Radiation by Clusters of Galaxies

Clusters of galaxies are enriched with positrons from jets of active galactic nuclei (AGNs) or from the interaction of cosmic rays with the intracluster gas. We follow the cooling of these positrons and show that their eventual annihilation with cluster electrons yields a narrow annihilation line. Unlike annihilation in the interstellar medium of galaxies, the line produced in clusters is not smeared by three-photon decay of positronium because positronium formation is suppressed at the high (1 keV) temperature of the cluster electrons. We show that if AGN jets are composed of e+e- pairs, then the annihilation line from rich clusters within a distance of 100 Mpc might be detectable with future space missions, such as the International Gamma-Ray Astrophysical Laboratory or the Energetic X-Ray Imaging Survey Telescope.
Iodine(III)-promoted synthesis of oxazolines from N-allylamides

Abstract PhI(OAc)2 (activated by BF3·OEt2) has been used to promote the oxidative cyclization of N-allylamides to give oxazolines. The reaction products are formed in high yield and, when a branched allylic amine is used, high diastereoselectivity. Initial mechanistic experiments suggest that the final C–O bond is formed from a reactive tight ion pair, rather than a neutral external nucleophile.
Migration and Social Change: Some Conceptual Reflections

Examining the multiple ways in which migration relates to social change is a daunting task. It requires, first of all, defining what social change is and, secondarily, delimiting the scope of analysis to certain types of migration and not others. The greatest dangers that I envision in this enterprise are, first, getting lost in generalities of the ‘social change is ubiquitous’ kind and, second, attempting to cover so much terrain as to lose sight of analytic priorities and of major, as opposed to secondary, causal linkages. I seek to avoid these dangers by first discussing the concept of social change, second identifying the types of migration to be considered, and third examining the major factors that link one to another. I conclude the paper with four theoretical and methodological considerations that may guide future work in this field.
A breaker-oriented, three-phase IEEE 24-substation test system

Accurate bus-oriented, three-phase modeling of power systems is desirable for advanced applications and has become practical due to increased computational capability. To assist research activities in this area, this paper presents a benchmark three-phase test system. The proposed system is based on the 24-bus IEEE Reliability test system that has been converted into a 24-substation, breaker-oriented, three-phase model. The model is available in electronic form at the site: http://pscal.ece.gatech.edu/testsys/. The proposed model is in-tended for use in research for three-phase power flow analysis, reliability analysis, fault analysis, transient stability, evaluation of fault currents through specific breakers, risk assessment of breaker failures and other applications.
The Chemical Nature of Buckminsterfullerene (C60) and the Characterization of a Platinum Derivative

Little is known about the chemical nature of the recently isolated carbon clusters (C60, C70, C84, and so forth). One potential application of these materials is as highly dispersed supports for me...
Prospective capabilities in hardware

Today we can look back over the past thirty years and view the entire history of the electronic digital computer! In addressing the topic of prospective capabilities in hardware, this paper first attempts to extrapolate, from today's state-of-the-art and vantage point, general industry-wide trends and likely achievements. Then, an effort is made to cover in more detail specific areas of interest to the ERDA community. Subjects discussed include available large-scale computers---their architecture and viability. The microprocessor's impact on computer systems is considered, and potential applications of the microcomputer are identified. Then mass storage offerings and their role in predicted memory hierarchies is assessed; progress in the development of alternate storage technologies is reviewed. New products and anticipated innovations in peripheral and input-output equipment, probably the most lethargic segment of the dynamic hardware market, are described, and a survey of network and communications activity examines future directions this rapidly-expanding field might be expected to follow.Whenever possible in each of these areas, examples with descriptive characteristics, accompanied by cost and performance statistics, are presented in support of the initially-forecast broad technological trends. These examples, chosen for illustration, represent new hardware products, advanced technologies in the developmental stages, or planned enhancements of existing product lines.
Muon acceleration using fixed field, alternating gradient (FFAG) rings

Given their 2.2 μs lifetime, muons must be accelerated fairly rapidly for a neutrino factory or muon collider. Muon bunches tend to be large. Progress in fixed field, alternating gradient (FFAG) lattices to meet these challenges are reviewed. FFAG magnets are naturally wide; low momentum muons move from the low field side of a gradient magnet to the high field side as they gain energy. This can be exploited to do double duty and allow a large beam admittance without unduly increasing the magnetic field volume. If the amount of RF must be reduced to optimize cost, an FFAG ring can accommodate extra orbits. I describe scaling FFAGs in which the bends in each magnet are energy independent and non-scaling FFAGs in which the bends in each magnet do vary with muon energy. In all FFAG designs the sum of the bends in groups of magnets are constant; otherwise orbits would not close. Ways of keeping the accelerating beam in phase with the RF are described. Finally, a 1 MeV proof of principle scaling FFAG has been built at KEK and began accelerating protons in June 2000 with a 1 kHz repetition rate.
Clinical outcome of transcatheter closure of patent ductus arteriosus in small children weighing 10 kg or less

【Purpose: Transcatheter closure has become an effective therapy in most patients with patent ductus arteriosus (PDA). However, there are difficulties in transcatheter closure of PDA in small children. We reviewed clinical outcomes of transcatheter closure of PDA in children weighing less than 10 kg in a single center. Methods: Between January 2003 and December 2009, 314 patients with PDA underwent transcatheter closure in our institute. Among them, 115 weighed less than 10 kg. All of these patients underwent transcatheter closure of PDA using either COOK Detachable $Coil^{(R)}$ , PFM Nit- $Occlud^{(R)}$ , or Amplatzer duct $occluder^{(R)}$ . A retrospective review of the treatment results and complications was performed. Results: The mean age of patients was $9.1{\pm}5.9$ months (median, 8 months), and mean weight was $7.6{\pm}1.8kg$ (median, 7.8 kg). The mean diameter of PDA was $3.2{\pm}1.4mm$ (median, 3 mm). Complete occlusion occurred in 113 patients (98%). One patient was sent to surgery because of a failed attempt at device closure, and another patient had a small residual shunt after device placement. The average mean length of hospital stay was $3.0{\pm}3.3$ days, and mean follow-up duration was $21.0{\pm}19.6$ months. There were no major complications in any of the patients. Conclusion: Transcatheter closure of PDA is considered safe and efficacious in infants weighing less than 10 kg. With sufficient experience and further effort, transcatheter closure of PDA can be accepted as the gold standard of treatment for this group of patients.】
A Portable Slurry Wear Test for the Field

A new portable slurry wear test apparatus developed by the Bureau of Mines, U.S. Department of the Interior, makes it possible to gather materials wear and corrosion data at a mineral processing site
Two diverse constituents of the cephalaspidean mollusk Smaragdinella calyculata

Abstract Isolation of an aminoalkylpyridine, naloamine (4), and a cytotoxic polypropionate, nalodionol (5), from Smaragdinella calyculata is described. The structures were determined by interpretation of spectral data.
Preparative liquid chromatography

Historically, liquid chromatography has been a preparative technique. Its applications have been limited, however, until a decade ago. The needs of modern chemical, pharmaceutical and biochemical industries have motivated this period of phenomenal growth which is being witnessed now. Novel packing materials, new packing technologies, and advancements in instrumentation and process technologies have appeared in rapid succession. Instruments using columns with diameters ranging from a few inches to a few feet, can be packed with efficiencies comparable or better than analytical columns having the same packing material. This permits the development of new applications covering a wide variety of problems. The empirical approach, followed until recently for the development of new applications, is being improved by insights derived from a better understanding of the theory of large concentration chromatography. With increased computer power and a greater comprehension of the theoretical aspects, a fundamental approach to design and optimization of the operating parameters is being developed. Investigation of the components of the cost of industrial production is also in its early stages. Historical trends, theoretical treatments, column technologies, operating modes and guidelines for optimization will be discussed and reviewed.
Synthesis of 2,6-difluorodopamine and 3-(2,6-difluoro-3,4-dihydroxyphenyl)alanine

Abstract 2,6-Difluorodopamine and 3-(2,6-difluoro-3,4-dihydroxyphenyl)alanine were prepared by side-chain elaboration of 2,6-difluoroveratraldehyde, followed by removal of protecting groups.
Biomedical applications of thermally activated shape memory polymers

Shape memory polymers (SMPs) are smart materials that can remember a primary shape and can return to this primary shape from a deformed secondary shape when given an appropriate stimulus. This property allows them to be delivered in a compact form via minimally invasive surgeries in humans, and deployed to achieve complex final shapes. Here we review the various biomedical applications of SMPs and the challenges they face with respect to actuation and biocompatibility. While shape memory behavior has been demonstrated with heat, light and chemical environment, here we focus our discussion on thermally stimulated SMPs.
Angle‐resolved photoemission measurements of band discontinuities in the GaAs‐Ge heterojunction

The conduction- and valence-band discontinuities for the (110) GaAs-Ge heterojunction have been measured as ΔE c = 0.50 eV and ΔE v = 0.25 eV by the angle-resolved ultraviolet photoemission (ARUPS) technique. These values are in good agreement with the theoretical predictions of Pickett et al.
Higher-order unCurrying

We present a formal specification of unCurrying for a higherorder, functional language with ML-style let-polymorphism. This specification supports the general unCurrying of functions, even for functions which are passed as arguments or returned as values. The specification also supports partial unCurrying of any consecutive parameters of a function, rather than only unCurrying all of a function's parameters. We present the specification as a deductive system which axiomatizes a judgment relating a source term with an unCurried form of the term. We prove that this system relates only typable terms and that it is correct with respect to an operational semantics. We define a practical algorithm, based on algorithm W, which implements the unCurrying and prove this algorithm sound and complete with respect to the deductive system. This algorithm generates maximally unCurried forms of source terms. These results provide a declarative framework for reasoning about unCurrying and support a richer form of unCurrying than is currently found in compilers for functional languages.
Lattice Codes for the Gaussian Relay Channel: Decode-and-Forward and Compress-and-Forward

Lattice codes are known to achieve capacity in the Gaussian point-to-point channel, achieving the same rates as i.i.d. random Gaussian codebooks. Lattice codes are also known to outperform random codes for certain channel models that are able to exploit their linearity. In this paper, we show that lattice codes may be used to achieve the same performance as known i.i.d. Gaussian random coding techniques for the Gaussian relay channel, and show several examples of how this may be combined with the linearity of lattices codes in multisource relay networks. In particular, we present a nested lattice list decoding technique in which lattice codes are shown to achieve the decode-and-forward (DF) rate of single source, single destination Gaussian relay channels with one or more relays. We next present two examples of how this DF scheme may be combined with the linearity of lattice codes to achieve new rate regions which for some channel conditions outperform analogous known Gaussian random coding techniques in multisource relay channels. That is, we derive a new achievable rate region for the two-way relay channel with direct links and compare it to existing schemes, and derive a new achievable rate region for the multiple access relay channel. We furthermore present a lattice compress-and-forward (CF) scheme for the Gaussian relay channel which exploits a lattice Wyner-Ziv binning scheme and achieves the same rate as the Cover-El Gamal CF rate evaluated for Gaussian random codes. These results suggest that structured/lattice codes may be used to mimic, and sometimes outperform, random Gaussian codes in general Gaussian networks.
Cosmological constraints on MFV SUSY

We study cosmological constraints in the context of R-parity violating MFV SUSY and find it is driven to tan(β) ≈ 1. These constraints are from two sources: first from the requirement that baryon number violation not undo baryogenesis and second that the flux of decay products from gravitino dark matter not exceed that observed by experiments such as PAMELA and Fermi LAT. The latter discussion favors relatively low gravitino masses of a few GeV.
A contribution to the Al-Pb-Zn ternary system

The liquidus curve projection of the Al-Pb-Zn ternary system is the only experimental result for the Al-Pb-Zn ternary system in the existing literature. Due to the lack of other experimental data, thermodynamic calculations based on the extrapolation of its binary systems are performed in the present paper. The ternary interaction parameters used in this work are obtained by Chou's general solution model, which, in the absence of experimental data, offers a reasonable guide for the phase diagram calculation. As a result, a set of isothermal sections, isopleth sections and liquidus curve projections of the Al-Pb-Zn system, especially the liquidus curve projection of the Pb-rich corner, have been obtained.
Thermolysis of Acylazo O-Trimethylsilyl Cyanohydrins: Azoalkanes Yielding Captodatively Substituted Radicals

A new synthetic method has been developed for preparing azoalkanes bearing geminal α-cyano and α-trimethylsiloxy groups. While the symmetrical compound 5 decomposes near room temperature to afford, almost entirely, the C−C dimers, the unsymmetrical azoalkane 3 requires heating to 75 °C. The thermolysis activation parameters of 3 and 5 can be rationalized on steric grounds without invoking captodative radical stabilization. A 13C NMR product study of photolyzed 3 in the presence of TEMPO at 21 °C shows that the fate of caged [tert-butyl, 1-trimethylsiloxy-1-cyanoethyl (14)] radical pairs is disproportionation, 17%, cage recombination, 20%, and cage escape, 63%.
Isolation and spectral characteristics of Ferric Iodide

Ferric iodide is isolated pure for the first time as a dark purple solid when a hexane solution of diiodotetracarbonyliron(II) and diiodine is exposed to actinic radiation. Its identity is confirmed by elemental analysis and quantitative conversion to the known tetraiodoferrate(III) by treatment with tetra-n-butylammonium iodide. Although persistent in the solid state, ferric iodide is readily decomposed in solution to ferrous iodide and 0.5 mol diiodine quantitatively. Isolierung und spektrale Charakterisierung von Eisen(III)-iodid Eisen(III)-iodid wurde zum ersten Mal in reiner Form als dunkelvioletter Feststoff aus einer Losung in n-Hexan durch Bestrahlung von Fe(CO)4I2 und I2 mit Tageslicht erhalten. Seine Zusammensetzung wurde durch Elementaranalyse und quantitative Umsetzung mit n-Bu4N+I− zu dem bekannten n-Bu4N+FeI4− bestatigt. Obwohl die Verbindung im festem Zustand stabil ist, zersetzt sich FeI3 quantitativ in Losung zu FeI2 und 0,5 mol I2.