cssi/SciSciGPT-SciSciNet huggingface dataset:
Factors Influencing the Adoption and Effective Use of Creativity Techniques in Business Settings: An Exploratory Study

Abstract:Using creativity techniques is a common way to promote innovation in engineering; however, little is known about the factors influencing the adoption and use of creativity techniques by individuals. This study explores this topic through interviews with four professionals who are knowledgeable and experienced in using creativity techniques in the real business world. Factors influencing the adoption and effective use of creativity techniques are identified. These factors should be managed for better innovation outcomes, while some factors lead to research questions that deserve further investigation.
New parametrization for differences between plasma kinetic codes

Abstract Validation and verification of plasma kinetics codes requires the development of quantitative methods and techniques for code comparisons. We describe two parameters that can be used for characterization of differences between such codes. It is shown that these parameters, which are determined from the most general results of kinetic codes, can provide important information on the differences between the basic rate coefficients employed. Application of this method is illustrated by comparisons of some results from the 3rd NLTE Code Comparison Workshop for carbon, germanium, and gold plasmas.
Asymmetric Oxidation of o-Alkylphenols with Chiral 2-(o-Iodoxyphenyl)-oxazolines

A new class of chiral iodine(V) derivatives has been prepared. These compounds have been found to transform ortho-alkylphenols into ortho-quinol Diels−Alder dimers with significant levels of asymme...
Habitat utilization by Hawaiian stream fishes with reference to community structure in oceanic island streams

Much of the freshwater biota on high Pacific islands is derived from marine ancestors. Traces of this marine origin are seen in the amphidromous life history patterns of these species. Investigation of the habitat utilization of an assemblage of freshwater gobies in the Hawaiian Islands indicates some resource partitioning within this group. The three major stream species appear to exhibit distinct habitat preferences, which in conjunction with their longitudinal zonation in streams may have served to facilitate their colonization or co-existence.
Bargaining and Bargaining Sets

Abstract We argue that, in exchange economies, various versions of the bargaining set cannot be implemented in Nash equilibrium. We then propose an extensive form mechanism that exactly implements the Aumann–Davis–Maschler bargaining set in subgame perfect equilibrium. The mechanism corresponds closely to the description of the bargaining set and respects feasibility in and out of equilibrium. Journal of Economic Literature Classification Numbers: C71, C72, C78, D51.
Selection practices for Web-based government publications in state depository library programs: Comparing active and passive approaches

Abstract This paper describes a comparative case study of the capture and selection practices used to populate electronic depositories of born-digital state government publications. The three case sites illustrate differences in collection building approaches, technological infrastructures, and statutory contexts. The findings reveal two basic modes of selection practices—active selection and passive selection, and three selection models based on the loci of selection control—library selection, liaison selection, and creator selection. Also, the findings suggest the power of defining and selecting government publications for state depositories is shifting from government agencies to state libraries in the active selection model. The authors argue for the need to attend to Web publications in non-traditional formats (e.g., an interactive HTML document) and to include common publications produced for lay citizens (e.g., brochures, fact sheets, FAQs, etc.) in the permanent collections in order to fully document government activities for the historical record.
Nonlinear Resonances with a Potential: Multilinear Estimates and an Application to NLS

This paper considers the question of global in time existence and asymptotic behavior of small-data solutions of nonlinear dispersive equations with a real potential $V$. The main concern is treating nonlinearities whose degree is low enough as to preclude the simple use of classical energy methods and decay estimates. In their place, we present a systematic approach that adapts the space-time resonance method to the non-Euclidean setting using the spectral theory of the Schroedinger operator $-\Delta+V$. We start by developing tools of independent interest, namely multilinear analysis (Coifman-Meyer type theorems) in the framework of the corresponding distorted Fourier transform. As a first application, this is then used to prove global existence and scattering for a quadratic Schroedinger equation.
Rejecting "Conventional" Wisdom: Estimating the Economic Impact of National Political Conventions

This paper provides an empirical examination of the economic impact of the Democratic and Republican National Conventions on local economies. Our analysis from 1970-2005 of the 50 largest metropolitan areas in the country, including all cities that have hosted one of the national conventions during this time period, finds that the presence of the Republican or the Democratic National Convention has no discernable impact on employment, personal income, or personal income per capita in the cities where the events were held confirming the results of other ex post analyses of mega-events.
Highly Enantioselective, Catalytic Conjugate Addition of Cyanide to α,β-Unsaturated Imides

(Salen)Al−Cl complex 1a catalyzes the asymmetric conjugate addition of hydrogen cyanide to α,β-unsaturated imides in high yields and enantioselectivities. The cyanide adducts can readily be converted into a variety of useful chiral building blocks, including α-substituted-β-amino acids and β-substituted-γ-aminobutyric acids. Mechanistic data obtained thus far point to a cooperative bimetallic mechanism for nucleophile and electrophile activation.
Alkyne competition in the benzannulation reaction with chromium carbene complexes.

The benzannulation reaction of Fischer carbene complexes is investigated under conditions where the reaction of the carbene complex is occurring in the presence of two different alkynes. A series of competition experiments are examined where the effects of various structural factors are explored by pitting 10 different carbene complexes with 11 different alkynes. Terminal alkynes will react selectively over internal alkynes in all cases examined including both aryl and alkenyl complexes. Aryl carbene complexes with methoxy substituents do not give quite as high selectivity for terminal alkynes over internal alkynes (∼95:5) as do isopropoxy substituents (>99:1), whereas most alkenyl complexes give high selectivity with both substituents (>99:1). Competition experiments between two different terminal alkynes or between two different internal alkynes did not result in anything more than very modest selectivities at best (∼2:1). Excellent selectivities were realized between two different terminal acetylenes i...
Dendritic encapsulation-roles of cores and branches

Examples of new dendrimers are presented. In the first, the effect on electron transfer rate attenuation is investigated for two dendrimer isomers that differ only in the linkage (ortho- versus meta-linked) of the phenyl ether units within one generation of the structure. Second, the effect of encapsulation on electrochemical and luminescence behavior of a new type of rhenium selenide cluster core dendrimer is illustrated.
3D articulated object recognition: a case study

A simple method for visualizing, understanding, interpreting, and recognizing 3D objects from 2D images is presented. It extended the linear combination methods, uses parallel pattern matching and can handle 3D rigid concave objects as well as convex objects, yet, needs only a very small number of learning samples. Some real images are illustrated, with future research discussed including more complicated images such as 3D concave and articulated objects.
Lamb shift in muonic hydrogen—I. Verification and update of theoretical predictions

Abstract In view of the recently observed discrepancy of theory and experiment for muonic hydrogen [R. Pohl et al., Nature 466 (2010) 213], we reexamine the theory on which the quantum electrodynamic (QED) predictions are based. In particular, we update the theory of the 2P–2S Lamb shift, by calculating the self-energy of the bound muon in the full Coulomb + vacuum polarization (Uehling) potential. We also investigate the relativistic two-body corrections to the vacuum polarization shift, and we analyze the influence of the shape of the nuclear charge distribution on the proton radius determination. The uncertainty associated with the third Zemach moment 〈r3〉2 in the determination of the proton radius from the measurement is estimated. An updated theoretical prediction for the 2S–2P transition is given.
Families of four-dimensional manifolds that become mutually diffeomorphic after one stabilization

Abstract In this paper, we will introduce a cut and paste move, called a geometrically null log transform, and prove that any two manifolds related by a sequence of these moves become diffeomorphic after one stabilization. To motivate the cut and paste move, we will use the symplectic fiber sum, and a construction of Fintushel and Stern to construct several large families of 4-manifolds. We will then proceed to prove that the members of any one of these families become diffeomorphic after one stabilization. Finally, we will compute the Seiberg–Witten invariants of each member of each of the families.
A Fuzzy Dead Reckoning Algorithm for a Personal Navigator

: A concept design of a fuzzy Dead Reckoning (DR) algorithm for a personal navigator (PN) is introduced here. The PN system prototype includes a range of self-contained sensors such as GPS, accelerometer, gyroscope, magnetometer, digital barometer, and step sensors. In addition, a human locomotion model is considered as a navigation sensor, with the step length (SL) and step direction (SD) as primary parameters. The major focus of this paper is on DR navigation supported by human dynamics during GPS signal blockages. It is demonstrated that in the absence of GPS, the other sensors can sense the body locomotion in terms of its dynamics and geometry that represent an implicit function of SL and SD. A practical implementation of the DR system based on human dynamics is a fuzzy logic Knowledge-Based System (KBS). This paper discusses the design and implementation of the KBS, followed by its performance evaluation in the indoor environments.
The Nature of the Aesthetic and Human Values

"When one's environment is arranged with the sole goal of making it beautiful, the results are likely to be dull, just as the search for pleasure and fun turns out to be so pointless and dis appointing. What is at fault in our American environment is not that it is unbeautiful, but that it is so uniform."
Making BPEL flexible: adapting in the context of coordination constraints using WS-BPEL

Although WS-BPEL is emerging as the prominent language for modeling executable business processes, its support for designing flexible processes is limited.An important need of many adaptive processes is for concurrent activities in the process to respect coordination constraints. These require that concurrent activities coordinate their behaviors in response to exogenous events.We show how coordination inducing constraints may be represented in WS-BPEL, and use generalized adaptation and constraint enforcement models to transform the traditional BPEL process to an adaptive one. The final outcome is an executable WS-BPEL process without extensions, able to adapt to events while respecting coordination constraints between activities.
Parton momentum and helicity distributions in the nucleon

We review the current status of spin-averaged and spin-dependent parton distribution functions (PDFs) of the nucleon. After presenting the formalism used to fit PDFs in modern global data analyses, we discuss constraints placed on the PDFs by specific data types. We give representative examples of unpolarized and polarized PDFs and their errors, and list open questions in global quantum chromodynamics fitting. Finally, we anticipate how future facilities, with fixed-target and collider experiments, may impact our knowledge of PDFs and reduce their uncertainties.
Control of integrated process networks—A multi-time scale perspective

Abstract In this work, we consider a generic class of process networks that feature large material recycle streams and in which impurities are present, and are removed by a small purge stream. We show that such networks exhibit a dynamic behavior featuring three time scales. Employing a nested application of singular perturbation arguments, we propose a method for deriving non-linear, non-stiff, reduced order models for the dynamics in each time scale. Subsequently, we propose a hierarchical controller design framework that takes advantage of the identified time scale multiplicity. The developed concepts are exemplified through a case study on the dynamics and control of a reactor–single-stage separator network core, and illustrative numerical simulation results are provided.
A Semiparametric Model for Randomly Truncated Data

Abstract For randomly censored data, it is known that the maximum likelihood estimate (MLE) of the survival curve is not affected by parametric assumption on the censoring variable. The Kaplan-Meier (1958) estimate is the MLE for both nonparametric and semiparametric models. For randomly truncated data, the truncation product-limit estimate is the MLE for nonparametric models. This is not the case if the truncation mechanism is parameterized, however. Specifically, let X be a generic random variable and T be the truncation variable. If the distribution of T is parameterized and the distribution of X is left unspecified, it can be shown that the truncation product-limit estimate is not the MLE for this semiparametric model, even though it is for the fully nonparametric model. In this article the MLE is characterized for the semiparametric model, and the large-sample properties of the estimate are established. The results show that, unlike censoring, the parametric information from the truncation mechanism ...
Boratabenzene Zirconium Complexes

1-Substituted boratabenzenes (1) are six π-electron aromatic anions which can serve as surrogates for cyclopentadienyl in important organometallic compounds. The reaction of 1 with ZrCl4 produces bis(boratabenzene) zirconium(IV) dichlorides 3, which when activated by excess methylaluminoxane react with ethylene to produce either high molecular weight polyethylene or smaller ethylene oligomers, depending upon the substituents at boron. The reaction of 3 with BuLi in the presence of PMe3 affords the corresponding zirconium(II) complexes (4). The reaction of 4 with acetylene involves an unprecedented ring annulation to afford complexes which contain the novel ligand lOH-5-boratanaphthalene.
Protonation constants and metal ion binding constants of N,N′-bis(2-hydroxyphenyl)-N,N′ -ethylenediaminediacetic acid

The study of a recently reported sexadentate ligand, N,N′-bis(2-hydroxyphenyl)-N,N′-ethylenediaminediacetic acid (HPED), and its hydrogen ion and metal ion affinities is described. The ligand has two phenolate donors directly attached to the aliphatic nitrogens of an N,N-ethylenediaminediacetic acid backbone to impart specificity for trivalent metal ions such as those of Fe(III), Ga(III) and In(III). Potentiometric and spectrophotometric studies of the protonation constants of the ligand and its metal chelates are reported. The log stability constants for the Fe(III), Ga(III) and In(III) chelates, which are 31.81, 32.02 and 26.25, respectively, are compared with those previously reported, and with those of analogous ligands.
Growth of TiN/AlN Superlattice by Pulsed Laser Deposition

TiN-AlN binary-components have attracted a lot of interests in coatings of high speed cutting tools, due to their higher oxidation resistance, higher hardness, lower internal stresses and better adhesion. Especially, nanometer-scale multilayer structures of AlN/TiN show superior structural and mechanical properties due to their tremendous interface area and become one of the promising candidates for superhard coatings. Here we present a novel method to grow highly aligned TiN/AlN superlattice by pulsed laser deposition. In this method TiN and AlN targets are arranged in a special configuration that they can be ablated in sequence, giving alternate layer by layer growth of TiN(1nm)/AlN(4nm). X-ray diffraction and transmission electron microscopy (TEM) analysis showed the structure to be cubic for both TiN and AlN in the nanoscale multilayers. Microstructure and uniformity for the superlattice structure were studied by TEM and Scanning transmission electron microscopy with Z-contrast (STEM). Nanoindentation results indicated a higher hardness for this new structure than pure AlN and rule-of-mixtures value. Four point probe electrical resistivity measurements showed overall insulating behavior.
Mass Spectrometric Studies of the Nitridation of Silicon

The nitridation of silicon was examined by analyzing the nitriding atmosphere with a mass spectrometer. Silicon monoxide vapor was found throughout the entire temperature range of the process in amounts of the order of 10−3 of the volume of the nitriding agent. Controversial results obtained in previous investigations of nitridation kinetics are explained in terms of the SiO vapor and the O2 partial pressure of the system. The effects of H2 and H2O on nitridation are also discussed.
Carleman estimates for the regularization of ill-posed Cauchy problems

This work is a survey of results for ill-posed Cauchy problems for PDEs of the author with co-authors starting from 1991. A universal method of the regularization of these problems is presented here. Even though the idea of this method was previously discussed for specific problems, a universal approach of this paper was not discussed, at least in detail. This approach consists in constructing of such Tikhonov functionals which are generated by unbounded linear operators of those PDEs. The approach is quite general one, since it is applicable to all PDE operators for which Carleman estimates are valid. Three main types of operators of the second order are among them: elliptic, parabolic and hyperbolic ones. The key idea is that convergence rates of minimizers are established using Carleman estimates. Generalizations to nonlinear inverse problems, such as problems of reconstructions of obstacles and coefficient inverse problems are also feasible.
Trajectories to Jupiter via Gravity Assists from Venus, Earth, and Mars

Gravity-assist trajectories to Jupiter, launching between 1999 and 2031, are identi ed using patched-conic techniques. The classical trajectories, such as the Venus–Earth–Earth gravity assist, and many less conventional paths, such as Venus–Mars–Venus–Earth, are examined. Flight times of up to about seven years are considered. The D V-optimized results con rm thatVenus–Earth–Earth is themosteffective gravity-assisttrajectory type,with launch opportunities occurring almost every year and launch vis viva for ballistic trajectories as low as 9 km2 /s2. If the Earth is excluded as a  yby body, Venus–Venus–Venus gravity assists are typically the best option,with launch vis viva for ballistic trajectories as low as 30 km2 /s2, although in some years nonconventionalpaths are better, such as a ballistic Venus–Mars–Venus–Venus trajectory in 2012, with a launch vis viva of 16 km2/s2 . Nonconventional paths, such as Venus–Mars–Venus–Earth with a 3.7-year  ight-time trajectory in 2021, can occasionally decrease the time of  ight signi cantly, at very minor D V cost, when compared with the classical types.
Continuous interval exchange actions

The dynamics of interval exchanges were first studied in the late seventies by Keane [9; 10], Katok [8], Rauzy [16], Veech [17] and others. This initial stage of research culminated in the independent proofs by Masur [12] and Veech [18] that almost every interval exchange is uniquely ergodic. See the recent survey of Viana [19] for a unified presentation of these results. There is currently much interest and activity in the dynamics of interval exchanges. This is due in part to the recent resolution of certain long-standing problems in this area; one important example is the work of Avila and Forni [1] in which they prove that almost every interval exchange is weakly mixing. Much of the study of interval
Categoricity in abstract elementary classes with no maximal models

Abstract The results in this paper are in a context of abstract elementary classes identified by Shelah and Villaveces in which the amalgamation property is not assumed. The long-term goal is to solve Shelah’s Categoricity Conjecture in this context. Here we tackle a problem of Shelah and Villaveces by proving that in their context, the uniqueness of limit models follows from categoricity under the assumption that the subclass of amalgamation bases is closed under unions of bounded, ≺ K -increasing chains.
Gauge theory high-energy behavior from J-plane unitarity

Abstract In a non-abelian gauge theory the t-channel multiparticle unitarity equations continued in the complex j -plane can be systematically expanded around j = 1 and t = 0. The combination of Ward identity constraints with unitarity is sufficient to produce directly many of the results obtained by Regge limit leading-log and next-to-leading log momentum-space calculations. The O ( g 2 ) BFKL kernel is completely determined. O ( g 4 ) infrared contributions to this kernel are also obtained, including the leading contribution of a new partial-wave amplitude—previously identified as a separate forward component with a holomorphically factorizable spectrum. For this amplitude the only scale ambiguity is the overall normalization and it is anticipated to be a new conformally invariant kernel. While scale-dependent non-leading reggeon interactions can not be derived by the techniques developed, it is conjectured that all conformally invariant interactions may be determined by t -channel unitarity.
A Closed-Form Analysis of Rotor Blade Flap-Lag Stability in Hover and Low-Speed Forward Flight in Turbulent Flow

An approximate, closed-form analysis of the stability of coupled flap-lag motion of a helicopter rotor blade in the presence of turbulence is presented. The longitudinal, lateral, and vertical components of turbulence are modeled as uncorrelated physical white noise processes and a special case of the stochastic averaging method is applied to obtain the equations governing the first moments of the stochastic system. A closed-form first moment stochastic stability criterion is obtained using approximations based on realistic rms values of turbulence velocities. This closed form analysis is a generalization of a previous analysis by Peters for the deterministic case. Based on the stability criterion obtained, an interpretation is given for the result, previously obtained by the authors, that in hover the turbulence increases the stability of the coupled flap-lag motion. The interpretation is that the turbulence increases the damping in the least-stable, lead-lag mode by providing the same stabilizing effect as an increase in the profile drag coefficient in both hover and low-speed forward flight. Of the three turbulence components, the vertical turbulence is shown to have the dominant effect on this increase in stability. Numerical results are presented for the hover case and comparison with the more stringent case of second moment stability is made.
On the existence of consistent rules to adjudicate conflicting claims: a constructive geometric approach

For the problem of adjudicating conflicting claims, a rule is consistent if the choice it makes for each problem is always in agreement with the choice it makes for each “reduced problem” obtained by imagining that some claimants leave with their awards and reassessing the situation from the viewpoint of the remaining claimants. We develop a general technique to determine whether a given two-claimant rule admits a consistent extension to general populations, and to identify this extension if it exists. We apply the technique to a succession of examples.
Assembly Configurations and Branches of Planar Single-Input Dyadic Mechanisms

This paper examines the problem of enumerating the assembly configurations (ACs), also called circuits, and branches of planar single-input dyadic (SID) mechanisms which have links with pin joints and sliding joints. An SID mechanism is a multiloop mechanism which can be defined by adding one loop at a time such that the mechanism has one degree of freedom after each loop is added. A method is given to find the ACs of such a mechanism. The emphasis is on using graphical interpretation to determine the mobility regions of the mechanism which are preserved when each new loop is added to the mechanism. This method of interpretation is readily automated. Each AC can be represented as a set of instructions for the input link to follow, along with a list of dyad configurations for each instruction. Each instruction corresponds to a branch of the mechanism. Examples are given to demonstrate the use of this method.
Passivation of Iron in Sulfate, Perchlorate, and Borate Solutions: Role of Borate in the Passivation Process

The anodic passivation of Fe has been investigated in borate buffer, sulfate, and perchlorate solutions. In sulfate and perchlorate solutions of either pH 3.0 or 8.4, the passivation process is highly inefficient with very large amounts of anodic charge passing before a substantial decrease in current is observed. In these solutions, passivation appears to be associated with precipitation of a salt film and/or changes in the solution pH near the surface which permits the formation of a passive oxide. The efficiency for potential‐step passivation cannot be significantly increased by changing the concentration of the supporting electrolyte, the pH of the solution from 3.0 to 8.4, or the potential of anodization. However, the addition of <5% pH 8.4 borate buffer to the neutral sulfate or perchlorate solutions results in a dramatic increase in the efficiency, with the anodic passiyation charge decreasing by as much as two orders of magnitude. Similar trends are observed in pH 8.4 solutions with previously passivated Fe electrodes which were cathodically reduced to different extents prior to anodization. The more of the prior film that remains on the surface before the anodic potential step in sulfate, the more efficient is the passivation process. The marked similarity of these results suggests that the beneficial action of borate towards Fe passivation is due to its ability to assist in the formation of the surface oxide film. While the pH buffering capacity of the borate can be playing a role, it is possible that borate buffer contains strongly interacting anions which give it an inhibiting capability. The interaction of these anions with the Fe surface is believed to stimulate formation of a surface oxide film, and this could explain the results in the present work. Passivation of Fe in sulfate and perchlorate solutions would be inefficient because these anions, unlike those derived from borate, do not have inhibitive abilities, nor do their solutions have buffering capacity. The results indicate the important role played by prior oxide films, and the need for well‐defined starting surface conditions in passivation experiments.
The Gromov invariant and the Donaldson-Smith standard surface count

Simon Donaldson and Ivan Smith recently studied symplectic surfaces in symplectic 4{manifolds X by introducing an invariant DS associated to any Lefschetz bration on blowups of X which counts holomorphic sections of a relative Hilbert scheme that is constructed from the bration. Smith has shown that DS satises a duality relation identical to that satised by the Gromov invariant Gr introduced by Cliord Taubes, which led Smith to conjecture that DS = Gr provided that the bration has high enough degree. This paper proves that conjecture. The crucial technical ingredient is an argument which allows us to work with curves C in the blown-up 4{manifold that are made holomorphic by an almost complex structure which is integrable near C and with respect to which the bration is a pseudoholomorphic map. AMS Classication numbers Primary: 53D45 Secondary: 57R17
Discretionary Caching for I/O on Clusters

I/O bottlenecks are already a problem in many large-scale applications that manipulate huge datasets. This problem is expected to get worse as applications get larger, and the I/O subsystem performance lags behind processor and memory speed improvements. At the same time, off-the-shelf clusters of workstations are becoming a popular platform for demanding applications due to their cost-effectiveness and widespread deployment. Caching I/O blocks is one effective way of alleviating disk latencies, and there can be multiple levels of caching on a cluster of workstations. Previous studies have shown the benefits of caching--whether it be local to a particular node, or a shared global cache across the cluster--for certain applications. However, we show that while caching is useful in some situations, it can hurt performance if we are not careful about what to cache and when to bypass the cache. This paper presents compilation techniques and runtime support to address this problem. These techniques are implemented and evaluated on an experimental Linux/Pentium cluster running a parallel file system. Our results using a diverse set of applications (scientific and commercial) demonstrate the benefits of a discretionary approach to caching for I/O subsystems on clusters, providing as much as 48% savings in overall execution time over indiscriminately caching everything in some applications.
Rayleigh-Taylor Instability in a Relativistic Fireball on a Moving Computational Grid

We numerically calculate the growth and saturation of the Rayleigh-Taylor (RT) instability caused by the deceleration of relativistic outflows with Lorentz factor Γ = 10, 30, and 100. The instability generates turbulence whose scale exhibits strong dependence on Lorentz factor, as only modes with angular size smaller than 1/Γ can grow. We develop a simple diagnostic to measure the kinetic energy in turbulent fluctuations, and calculate a ratio of turbulent kinetic energy to thermal energy of e{sub RT} = .03 in the region affected by the instability. Although our numerical calculation does not include magnetic fields, we argue that small-scale turbulent dynamo amplifies magnetic fields to nearly this same fraction, giving a ratio of magnetic to thermal energy of e{sub B} ∼ 10{sup –2}, to within a factor of two. The instability completely disrupts the contact discontinuity between the ejecta and the swept up circumburst medium. The reverse shock is stable, but is impacted by the RT instability, which strengthens the reverse shock and pushes it away from the forward shock. The forward shock front is unaffected by the instability, but RT fingers can penetrate of the order of 10% of the way into the energetic region behind the shockmore » during the two-shock phase of the explosion. We calculate afterglow emission from the explosion and find the reverse shock emission peaks at a later time due to its reduced Lorentz factor and modified density and pressure at the shock front. These calculations are performed using a novel numerical technique that includes a moving computational grid. The moving grid is essential as it maintains contact discontinuities to high precision and can easily evolve flows with extremely large Lorentz factors.« less
Molecular dynamics simulation study of nanoscale passive oxide growth on Ni-Al alloy surfaces at low temperatures

Oxidation kinetics of Ni-Al (100) alloy surface is investigated at low temperatures (300--600 K) and at different gas pressures using molecular dynamics (MD) simulations with dynamic charge transfer between atoms. Monte Carlo simulations employing the bond order simulation model are used to generate the surface segregated minimum energy initial alloy configurations for use in the MD simulations. In the simulated temperature-pressure-composition regime for Ni-Al alloys, we find that the oxide growth curves follow a logarithmic law beyond an initial transient regime. The oxidation rates for Ni-Al alloys were found to decrease with increasing Ni composition. Structure and dynamical correlations in the metal/oxide/gas environments are used to gain insights into the evolution and morphology of the growing oxide film. Oxidation of Ni-Al alloys is characterized by the absence of Ni-O bond formation. Oxide films formed on the various simulated metal surfaces are amorphous in nature and have a limiting thickness ranging from $\ensuremath{\sim}1.7\text{ }\text{nm}$ for pure Al to 1.1 nm for 15% Ni-Al surfaces. Oxide scale analysis indicates significant charge transfer as well as variation in the morphology and structure of the oxide film formed on pure Al and 5% Ni-Al alloy. For oxide scales thicker than 1 nm, the oxide structure in case of pure Al exhibits a mixed tetrahedral $({\text{AlO}}_{4}\ensuremath{\sim}37%)$ and octahedral $({\text{AlO}}_{6}\ensuremath{\sim}19%)$ environment, whereas the oxide scale on Ni-Al alloy surface is almost entirely composed of tetrahedral environment $({\text{AlO}}_{4}\ensuremath{\sim}60%)$ with very little ${\text{AlO}}_{6}$ $(l1%)$. The oxide growth kinetic curves are fitted to Arrhenius-type plots to get an estimate of the activation energy barriers for metal oxidation. The activation energy barrier for oxidation on pure Al was found to be 0.3 eV lower than that on 5% Ni-Al surface. Atomistic observations as well as calculated dynamical correlation functions indicate a layer by layer growth on pure Al, whereas a transition from an initial island growth mode $(l75\text{ }\text{ps})$ to a layer by layer mode $(g100\text{ }\text{ps})$ occurs in case of 5% Ni-Al alloy. The oxide growth on both pure Al and Ni-Al alloy surfaces occurs by inward anion and outward cation diffusions. The cation diffusion in both the cases is similar, whereas the anion diffusion in case of 5% Ni-Al is 25% lower than pure Al, thereby resulting in reduced self-limiting thickness of oxide scale on the alloy surface. The simulation findings agree well with previously reported experimental observations of oxidation on Ni-Al alloy surface.
NATIONAL SCIENCE FOUNDATION VISION IN PARTICLE AND NUCLEAR ASTROPHYSICS

The NSF has made investments in searches for dark matter, in ultrahigh energy cosmic rays and gamma rays, in neutrino physics and astrophysics, and in nuclear astrophysics. We expect the future to witness the expansion of these efforts, along with efforts to refine the measurements of the cosmic microwave background. In some of these efforts the Deep Underground Science and Engineering Laboratory is expected to play a major role.
Promotion of calvarial cell osteogenesis by endothelial cells

Bone development and remodeling are associated with changes in the pattern of vascularization. Here we show that endothelial cells isolated from rat liver or bovine aorta can greatly enhance bone formation when implanted in diffusion chambers with rat fetal calvarial cells. The latter cells are unable to form bone when implanted alone at low initial cell density. The amount of mineralization measured by calcium deposition was 70 times higher in chambers containing calvarial cells mixed with endothelial cells from isologous liver or bovine aorta than in chambers containing endothelial or calvarial cells alone. Alkaline phosphatase activity was increased 20-fold. Calvarial cells in the presence of demineralized bone matrix powder did not form bone when implanted under similar conditions. Endothelial cells implanted alone seemed to enhance neovascularization around the Millipore diffusion chambers.
Exact determination of the phase in neutron reflectometry.

We show that by using a known reference layer having three tunable values of scattering density, an exact determination of the complex amplitude R=ReR+i ImR for neutron specular reflection can be made for any unknown real potential (i.e., no absorption). This straightforward yet remarkable general result is valid even in the dynamical regime (where the conventional Born approximation fails) and makes it feasible to consider direct inversion methods for obtaining the scattering length density profile normal to the reflecting surface.
Thermodynamics of a higher-order phase transition: Scaling exponents and scaling laws

Abstract The well-known scaling laws relating critical exponents in a second-order phase transition have been generalized to the case of an arbitrarily higher-order phase transition. In a higher-order transition, such as suggested for the superconducting transition in Ba0.6K0.4BiO3 and in Bi2Sr2CaCu2O8, there are singularities in higher-order derivatives of the free energy. A relation between exponents of different observables has been found, regardless of whether the exponents are classical (mean-field theory; no fluctuations; integer order of a transition) or not (fluctuation effects included). We also comment on the phase transition in a thin film.
Characteristics of Women and Men Corporate Inside Directors in the US

This study examines the qualifications of women and men corporate inside directors of Fortune 1000 firms. Our results indicate that women insiders differ significantly from a random set of men insiders on several characteristics relevant to their dual positions as directors and officers of the corporation. While they do not differ on the experience-based qualifications of board tenure or corporate tenure, women insiders hold fewer directorships of other corporations, hold less powerful corporate titles, occupy disproportionately more staff functions, are less likely to be top earners of the corporation, and earn considerably less than men inside directors. Implications are drawn for women executives’ under utilisation in the executive suite and corporate governance.
In Search of the Largest Velocity Dispersion Galaxies

We present Hobby-Eberly Telescope (HET) observations for galaxies at redshift z 500 km s−1 by the local M•-σ* relationship. This suggests either that QSO black hole masses are overestimated or that the black hole-bulge relationship changes at high black hole mass. The latter option is consistent with evidence that the increase in σ* with luminosity levels off for the brightest elliptical galaxies.
Methylborane - a remarkable unhindered monoalkylborane which achieves the controlled sequential hydroboration of representative alkenes

Abstract Methylborane, MeBH 2 , the simplest of the monoalkylboranes, possesses extraordinary hydroboration characteristics in tetrahydrofuran. In this solvent, methylborane is capable of monohydroborating the usual classes of alkenes, hindered and unhindered, to provide the simple alkylmethylboranes, RMeBH. The addition of a second equivalent of another alkene to the alkylmethylborane formed initially produces the sequential hydroboration product, RR′MeB. In all cases there is no evidence of redistributed products.
Monte Carlo simulation of ferroelectric domain structure and applied field response in two dimensions

A two-dimensional, lattice-Monte Carlo approach, based upon the energy minimization of an ensemble of electric dipoles, was developed to simulate ferroelectric domain behavior. The model utilizes a Hamiltonian for the total energy based upon electrostatic terms involving dipole–dipole interactions, local polarization gradients, and the influence of applied electric fields. The impact of boundary conditions on the domain configurations obtained was also examined. In general, the model exhibits domain structure characteristics consistent with those observed in a tetragonally distorted ferroelectric. The model was also extended to enable the simulation of ferroelectric hysteresis behavior. Simulated hysteresis loops were found to be very similar in appearance to those observed experimentally in actual materials. This qualitative agreement between the simulated hysteresis loop characteristics and real ferroelectric behavior was also confirmed in simulations run over a range of simulation temperatures and appl...
The evolution of cuspy triaxial galaxies harboring central black holes

We use numerical simulations to study the evolution of triaxial elliptical galaxies with central black holes. In contrast to earlier studies which used galaxy models with central density "cores," our galaxies have steep central cusps, as observed in real ellipticals. As a black hole grows in these cuspy triaxial galaxies, the inner regions become rounder owing to chaos induced in the orbital families that populate the model. At larger radii, however, the models maintain their triaxiality, and orbital analyses show that centrophilic orbits there resist stochasticity over many dynamical times. While black hole-induced evolution is strong in the inner regions of these galaxies and reaches out beyond the nominal "sphere of influence" of a black hole, our simulations do not show evidence for a rapid global transformation of the host. The triaxiality of observed elliptical galaxies is therefore not inconsistent with the presence of supermassive black holes at their centers.
Synthetic studies toward verrucosidin: Synthesis of (±)verrucosal

Abstract Verrucosal, 3 , a major degradation product of verrucosidin was synthesized in racemic form by a short and direct route from 4,5-dimethyl-2-furoic acid.
A note on heterotic/type I' duality and D0 brane quantum mechanics

In the note a simple calculation of one loop threshold corrections for the SO(32) heterotic string is performed. In particular the compactification on T2 with a Wilson line breaking the gauge group to SO(16) × SO(16) is considered. Using heterotic type I duality, these corrections can be related to quantities appearing in the quantum mechanics of type I' D0 particles.
Information systems and technology sourcing strategies of e-Retailers for value chain enablement

Abstract In the e-Retail industry, a well-designed IT infrastructure is essential in creating a tightly integrated value chain and delivering high quality service. With intense competition for market share and profits, information systems and technology (IST) sourcing decisions are becoming increasingly important to e-Retail firms to support continued growth and market responsiveness. Drawing on the contingency theory , we examine organizational and environmental factors that influence an e-Retailer's IST sourcing strategy of make versus buy in enabling its value chain activities, and we also look at firm-level performance impacts of IST sourcing decisions that involve bundling across value chain activities. We test the proposed model and hypotheses using a panel data set of 307 firms over the period of 2006–2010. The results show that firms that make transformative IT investments tend to source a smaller portion of IST for their e-Retail value chain activities than firms that pursue automate or informate as their strategic role for IT investment. Capabilities are positively associated with IST sourcing. Firms experienced in e-Retail are more likely to build rather than buy their IST. In addition, we find mimicking behavior for IST sourcing among firms in the same merchandizer category. We find that IT strategic role is strongly associated with growth metric, whereas sourcing decisions predominantly impact operational performance measures. There is partial evidence that alignment between IT strategic role and IST sourcing decisions results in better performance effects. Moreover, complementary IST sourcing of synergistic marketing and sales activities positively impacts Web sales and conversion rate, but the sourcing combination of logistics, operations, and sales activities is associated with lower Web sales and conversion rate.
Multidimensional Unstructured-Grid Liquid Rocket Engine Nozzle Performance and Heat Transfer Analysis

The objective of this study is to conduct a unified computational analysis for computing design parameters such as axial thrust, convective and radiative wall heat fluxes for regeneratively cooled liquid rocket engine nozzles, so as to develop a computational strategy for computing those parameters through parametric investigations. The computational methodology is based on a multidimensional, finite-volume, turbulent, chemically reacting, radiating, unstructured-grid, and pressure-based formulation, with grid refinement capabilities. Systematic parametric studies on effects of wall boundary conditions, combustion chemistry, radiation coupling, computational cell shape, and grid refinement were performed and assessed. Under the computational framework of this study, it is found that the computed axial thrust performance, flow features, and wall heat fluxes compared well with those of available data and calculations, using a strategy of structured-grid dominated mesh, finite-rate chemistry, and cooled wall boundary condition.
Operator split methods in the numerical solution of the finite deformation elastoplastic dynamic problem

Abstract The spatial formulation of the elastoplastic dynamic problem for finite deformations is considered. A thermodynamic argument leads to an additive decomposition of the spatial rate of deformation tensor and allows an operator split of the evolutionary equations of the problem into “elastic” and “plastic” parts. This operator split is taken as the basis for the definition of a global product algorithm. In the context of finite element discretization the product algorithm entails, for every time step, the solution of a nonlinear elastodynamic problem followed by the application of plastic algorithms that operate on the stresses and internal variables at the integration points and bring in the plastic constitutive equations. Suitable plastic algorithms are discussed for the cases of perfect and hardening plasticity and viscoplasticity. The proposed formalism does not depend on any notion of smoothness of the yield surface and is applicable to arbitrary convex elastic regions, with or without corners. The stability properties of the global product algorithm are shown to be identical to those of the algorithm used for the integration of the nonlinear elastodynamic problem. Numerical examples illustrate the accuracy of the method.
TIME-INTEGRATED GAMMA-RAY BURST SYNCHROTRON SPECTRA FROM BLAST-WAVE/CLOUD INTERACTIONS

We show that the spectral shape of the low-energy tails found for the time-integrated spectra of gamma-ray bursts, even in the absence of strong synchrotron cooling, can be significantly softer than the νFν∝ν4/3 asymptote predicted by synchrotron shock models. As we have noted in a previous work, blast-wave deceleration via interaction with ambient material causes the characteristic electron injection energy to decrease in proportion to the bulk Lorentz factor of the blast wave, and under certain conditions, this effect will at least partially account for the observed increase in pulse widths with decreasing energy. This spectral softening can also be reflected in the time-integrated pulse spectrum. Using a simple model for the blast-wave interaction with a dense cloud of material, we show that just below the νFν spectral peak the integrated spectrum behaves as νFν~ν½ and rolls over to a ν4/3 dependence at lower energies, and thus a spectral shape arises that is similar to that predicted for the spectrum of a strongly synchrotron-cooled electron population. We discuss the implications of this work in the context of models of burst light-curve variability that are based on blast-wave/cloud interactions.