cssi/SciSciGPT-SciSciNet huggingface dataset:
The far field hubble constant

We used the Hubble Space Telescope to obtain surface brightness fluctuation (SBF) observations of four nearby brightest cluster galaxies (BCGs) to calibrate the BCG Hubble diagram of Lauer & Postman. This BCG Hubble diagram contains 114 galaxies covering the full celestial sphere and is volume-limited to 15,000 km s-1, providing excellent sampling of the far-field Hubble flow. The SBF zero point is based on the Cepheid calibration of the ground IKC method as extended to the WFPC2 F814W filter by Ajhar and coworkers. The BCG globular cluster luminosity functions give distances essentially identical to the SBF results. Using the velocities and SBF distances of the four BCGs alone gives H0 = 82 ? 8 km s-1 Mpc-1 in the CMB frame, valid on ~4500 km s-1 scales; the error includes both systematic and random contributions. Use of BCGs as photometric redshift estimators allows the BCG Hubble diagram to be calibrated independently of recession velocities of the four nearby BCGs, yielding a far-field H0 = 89 ? 10 km s-1 Mpc-1 with an effective depth of ~11,000 km s-1. The larger error in this case is due to the photometric cosmic scatter in using BCGs as redshift estimators; this H0 is not significantly different from the more local value. The concordance of the present results with other recent H0 determinations and a review of theoretical treatments on perturbations in the near-field Hubble flow argue that going to the far field removes an important source of uncertainty, but that there is not a large systematic error to be corrected for to begin with. Further improvements in H0 depend more on understanding nearby calibrators than on improved sampling of the distant flow.
Function-oriented investigations of a peptide-based catalyst that mediates enantioselective allylic alcohol epoxidation.

We detail an investigation of a peptide-based catalyst (6) that is effective for the site- (>100 : 1 : 1) and enantioselective epoxidation (86% ee) of farnesol. Studies of the substrate scope exhibited by the catalyst are included, along with an exploration of optimized reaction conditions. Mechanistic studies are reported, including relative rate determinations for the catalyst and propionic acid, a historical perspective, truncation studies, and modeling using NMR data. Our compiled data advances our understanding of the inner workings of a catalyst that was identified through combinatorial means.
One formulation for both lineal gravities through a dimensional reduction

Abstract The two lineal gravities - based on the de Sitter group or a central extension of the Poincare group in 1 + 1 dimension - are shown to derive classically from a unique topological gauge theory. This one is obtained after a dimensional reduction of a Chern-Simons model, which describes pure gravity in 2 + 1 dimensions, the gauge symmetry being given by an extention if ISO (2, 1).
Self-interference of a single Bose-Einstein condensate due to boundary effects

A simple model wavefunction, consisting of a linear combination of two free-particle Gaussians, describes many of the observed features seen in the interactions of two isolated Bose–Einstein condensates (BECs) as they expand, overlap and interfere. It is shown that a simple extension of this idea can be used to predict the qualitative time-development of a single expanding BEC produced near an infinite wall boundary, giving similar interference phenomena. Other possible time-dependent behaviours of single BECs in restricted geometries, such as wave packet revivals are also briefly discussed.
On Nonlinear Quantum Mechanics, Noncommutative Phase Spaces, Fractal-Scale Calculus and Vacuum Energy

A (to our knowledge) novel Generalized Nonlinear Schrodinger equation based on the modifications of Nottale-Cresson’s fractal-scale calculus and resulting from the noncommutativity of the phase space coordinates is explicitly derived. The modifications to the ground state energy of a harmonic oscillator yields the observed value of the vacuum energy density. In the concluding remarks we discuss how nonlinear and nonlocal QM wave equations arise naturally from this fractal-scale calculus formalism which may have a key role in the final formulation of Quantum Gravity.
Practical preparation and deblocking conditions for N-α-2-(p-biphenylyl)-2-propyloxycarbonyl)-amino acid(N-α-Bpoc-Xxx-OH) derivatives

Reproducible preparations are given for salts of the following L-amino acid derivatives: Bpoc-Ala-OH, Bpoc-Arg(Mtr)-OH, Bpoc-Asn-OH, Bpoc-Asp(OtBu)-OH, Bpoc-Cys(Acm)-OH, Bpoc-Cys(S-tBu)-OH, Bpoc-Gln-OH, Bpoc-Glu(OtBu)-OH, Bpoc-Gly-OH, Bpoc-Ile-OH, Bpoc-Leu-OH, N-alpha-Bpoc-Lys(epsilon-Boc)-OH, Bpoc-Met-OH, Bpoc-Phe-OH, Bpoc-Pro-OH, Bpoc-Ser(OtBu)-OH, Bpoc-Thr(OtBu)-OH, Bpoc-Tyr-OH, Bpoc-Val-OH. A study of the deblocking of N-alpha-Bpoc peptides in dichloromethane containing 0.5% trifluoroacetic acid revealed that a rapid equilbrium is established between the first-formed monomeric alkene 2-p-biphenylylpropene and the hindered dimer 2,4-bis(p-biphenylyl)-4-methyl-1-pentene. Thioethers were found to be inefficient carbocation scavengers for the deblocking reaction. The most efficient scavengers were found to be thiophenol and benzyl mercaptan, and the following approximate reactivity order was established: benzyl mercaptan approximately thiophenol greater than indole much greater than 1,3-dimethoxybenzene approximately resorcinol greater than 1,3,5-trimethoxybenzene approximately dimethyl sulfide approximately thioanisole.
Data mining the NCI60 to predict generalized cytotoxicity

Elimination of cytotoxic compounds in the early and later stages of drug discovery can help reduce the costs of research and development. Through the application of principal components analysis (PCA), we were able to data mine and prove that approximately 89% of the total log GI 50 variance is due to the nonspecific cytotoxic nature of substances. Furthermore, PCA led to the identification of groups of structurally unrelated substances showing very specific toxicity profiles, such as a set of 45 substances toxic only to the Leukemia_SR cancer cell line. In an effort to predict nonspecific cytotoxicity on the basis of the mean log GI 50, we created a decision tree using MACCS keys that can correctly classify over 83% of the substances as cytotoxic/noncytotoxic in silico, on the basis of the cutoff of mean log GI 50 = -5.0. Finally, we have established a linear model using least-squares in which nine of the 59 available NCI60 cancer cell lines can be used to predict the mean log GI 50. The model has R (2) = 0.99 and a root-mean-square deviation between the observed and calculated mean log GI 50 (RMSE) = 0.09. Our predictive models can be applied to flag generally cytotoxic molecules in virtual and real chemical libraries, thus saving time and effort.
Very High Energy Heavy-Ion Accelerators

A review is given of various programs for building heavy ion accelerators. Topics discussed are (1) options of reaching very high energies with heavy ions; (2) present performance of the superHILAC and the Bevalac; (3) heavy ion sources; (4) applications of heavy ion accelerators outside of basic research; and (5) reliability and operating costs of heavy ion sources. (PMA)
A note on contestation-based tournament solutions

In tournaments, one alternative contests another if is a “winner” among only alternatives that beat it. This paper examines the consequences and limitations of the contestation relation by considering a procedure in which alternatives that are contested are iteratively eliminated from consideration. In doing so, a new family of tournament solutions are introduced and related to existing refinements of the Banks set. Findings show that iterated removal of contested alternatives a limited device for choosing from tournaments. These results contrast with results regarding the top-set of the contestation relation. Results highlight the role of the top-set operator for choice from tournaments.
The Abstract Lace Expansion

David Brydges and Thomas Spencer's lace expansion is abstracted and it is shown how it sometimes gives rise to sieves.
Bargaining over productivity and wages when technical change is induced: implications for growth, distribution, and employment

I study a model of growth and income distribution in which workers and firms bargain a la Nash (Econometrica 18(2):155–162, 1950) over wages and productivity gains, taking into account the trade-offs faced by firms in choosing factor-augmenting technologies. The aggregate environment resulting from self-interested, objective function-maximizing decision rules on wages, productivity gains, savings and investment, is described by a two-dimensional dynamical system in the employment rate and output/capital ratio. The economy converges cyclically to a long-run equilibrium involving a Harrod-neutral profile of technical change, a constant rate of employment of labor, and constant input shares. The type of oscillations predicted by the model is qualitatively consistent with the available data on the United States (1963–2003), replicates the dynamics found in earlier models of growth cycles such as Goodwin (A growth cycle, in C.H. Feinstein (ed). Socialism, Capitalism and Economic Growth. Cambridge University Press, Cambridge 1967. Cambridge University Press, Cambridge, 1967); Shah and Desai (Econ J 91:1006–1010, 1981); van der Ploeg (J Macroecon 9:1–12, 1987); Flaschel (J Econ: Zeitschrift fur Nationalokonomie 44:63–69, 1984) and Sportelli (J Econ: Zeitschrift fur Nationalokonomie 61(1):35–64, 1995), and can be verified numerically in simulations. Institutional change, as captured by variations in workers’ bargaining power, has a positive effect on the long-run rate of growth of output per worker but a negative effect on long-run employment. Economic policy can also affect the growth and distribution pattern through changes in the unemployment compensation, which also have a positive long-run impact on labor productivity growth but a negative long-run impact on employment. In both cases, employment can overshoot its new equilibrium value along the transitional dynamics.
On cosmological string backgrounds with toroidal isometries

Abstract A large class of cosmological solutions (of the Einstein equations) in string theory, in the presence of Maxwell fields, is obtained by O(d, d) transformations of simple backgrounds with d toroidal isometries. In all examples in which we find a (closed) expanding universe, such that the universe admits a smooth, complete initial value hypersurface, a naked singularity may form only at the time when the universe collapses. The discrete symmetry group O (d, d, Z ) identifies different cosmological solutions with a background corresponding to a (relatively) simple CFT, and therefore, may be useful in understanding the properties of naked singularities in string theory.
Implications of the ultrahigh-energy cosmic-ray spectrum observed by the Fly's Eye detector.

We discuss the potential implications of the recent results of the Fly's Eye detector on the ultrahigh-energy cosmic-ray spectrum. The data suggest that the observed slope flattening immediately prior to the cutoff appears to be a recoil-proton pileup associated with an ${E}^{\mathrm{\ensuremath{-}}2.5\ifmmode\pm\else\textpm\fi{}.3}$ injection spectrum. We discuss the induced neutrino spectrum and its detectability in Fly's Eye and DUMAND detectors.
Laser Systems For High Peak-Power Applications

LASER SYSTEMS FOR HIGH PEAK -POWER APPLICATIONSCharles FenstermacherLos Alamos Scientific LaboratoryLos Alamos, New Mexico 87545AbstractLarge scale programs are underway at major laboratories to study the feasibility oflaser- induced fusion. The laser requirements for this investigation are formidable andit is estimated that powers in the range of 100 terrawatts with total energies of 105 to106 joules may be needed. A major fraction of the effort has been directed toward thedevelopment of high- energy short -pulse lasers which can meet these requirements. Theparameters of the CO2 laser system have been extensively studied and it appears that theefficiency, energy density, bandwidth, and optical damage limits are compatible with therequirements. The scaling laws are also now well understood. Based upon these results,several large carbon dioxide systems have been developed by the Los Alamos ScientificLaboratory. The first system has been in operation for several years at a power of 0.2terrawatt with a focused intensity of 5 x 1014 W /cm2. A second system with power andenergy outputs increased by an order of magnitude will be operating presently. Succeed-ing systems are being planned and developed to extend this performance to the range ofinterest for laser fusion energy production.IntroductionOne of the many properties of the laser is its ability to generate optical energy ona short time scale (- 10 -9 sec) which can be focused to very high intensity. Almost fromthe time of the realization of the first laser in 1960 the possibility of taking advantageof this property to produce thermonuclear fusion has attracted wide interest and serious
Theory and Experiment of Low Transitions in CO Discharge Lasers

A self-consistent model, which couples the kinetics of the electrons and heavy particles with the optical and fluid dynamic processes, has been employed to identify the various parameters and explain the mechanism responsible for producing low-lying transitions in slow-flowing CO lasers. Both theory and experiment indicate that lasing on low-lying transitions can be achieved at low temperatures for low pressures (or low-flow rates) together with high partial pressures of He and N/sub 2/. The role of N/sub 2/ has been identified as an additive responsible for reducing the electron temperature to a range at which the transfer of electrical power to the lower vibrational modes of CO is optimum.
An Agent-Based Approach to Inference Prevention in Distributed Database Systems

We propose an inference prevention agent as a tool that enables each of the databases in a distributed system to keep track of probabilistic dependencies with other databases and then use that information to help preserve the confidentiality of sensitive data. This is accomplished with minimal sacrifice of the performance and survivability gains that are associated with distributed database systems.
College Majors and the Knowledge Content of Jobs

Abstract College students select majors for a variety of reasons, including expected returns in the labor market. This paper demonstrates an empirical method linking a census of US degrees and fields of study with measures of the knowledge content of jobs. The study combines individual wage and employment data from the Current Population Survey (CPS) with ratings on 27 knowledge content areas from the Occupational Information Network (O*NET), thus providing measures of the economy-wide knowledge content of jobs. Fields of study and corresponding BA degree data from the Digest of Education Statistics for 1976–1977 through 2001–2002 are linked to these 27 content areas. We find that the choice of college major is responsive to changes in the knowledge composition of jobs and, more problematically, the wage returns to types of knowledge. Women's degree responsiveness to knowledge content appears to be stronger than men's, but their response to wage returns is weak.
IMPROVED ACCURACY AND ACCELERATION OF VARIATIONAL ORDER-N ELECTRONIC-STRUCTURE COMPUTATIONS BY PROJECTION TECHNIQUES

Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801~Received 27 January 1998; revised manuscript received 7 August 1998!We have performed minimizations of the order-N energy functional of Ordejo´n et al. @Phys. Rev. B 51, 1456~1995!# in models of fourfold-coordinated amorphous carbon containing 512 and 4096 atoms using the ﬁrst-principle local-orbital Hamiltonian of Sankey and Niklewski. The total time for performing the minimizationcan be signiﬁcantly reduced by directly projecting the initial functions to the occupied subspace of the Hamil-tonian before applying a conjugate-gradients minimization. In addition, the energies achieved in the minimi-zation can be signiﬁcantly lowered by dynamically optimizing the localization regions of the projected func-tions using a population rather than distance criterion. Furthermore, the projection method also provides anefﬁcient scheme for the linear-scaling computation of the Fermi energy in semiconductors, which is needed forthe computation of the projected functions as well as for the evaluation of several other order-N functionals.@S0163-1829~98!01344-7#I. INTRODUCTION
Jumping numbers on algebraic surfaces with rational singularities

In this article, we study the jumping numbers of an ideal in the local ring at rational singularity on a complex algebraic surface. By understanding the contributions of reduced divisors on a fixed resolution, we are able to present an algorithm for finding of the jumping numbers of the ideal. This shows, in particular, how to compute the jumping numbers of a plane curve from the numerical data of its minimal resolution. In addition, the jumping numbers of the maximal ideal at the singular point in a Du Val or toric surface singularity are computed, and applications to the smooth case are explored.
Ion trapping in dusty plasmas

Summary form only given. A model is developed that includes charge-exchange collisons between ions and neutral gas atoms. The number of trapped ions is computed by assuming a steady state between collisional trapping and detrapping. The trapping rate is the product of a capture cross section and the incoming flux of ions, while detrapping occurs at random times due to collisions with a finite probability per unit time. The results show that the number of trapped ions is independent of the mean free path, and proportional to the plasma ion density. In low-density astrophysical plasmas, it is found that there is no significant number of trapped ions, but in laboratory plasmas, ion trapping can be a major effect that must be accounted for in any dusty plasma theory.
Copper-Catalyzed Aerobic Oxidative Amidation of Terminal Alkynes: Efficient Synthesis of Ynamides

A copper-catalyzed method for the preparation of ynamides has been identified that proceeds via aerobic oxidative coupling of terminal alkynes with various nitrogen nucleophiles, including cyclic carbamates, amides and ureas, and N-alkyl-arylsulfonamides and indoles.
On the Deformation of UHP Eclogite: From Laboratory to Nature

We present in this paper a side-by-side comparison of deformation microstructures, fabrics, and seismic properties between naturally deformed and experimentally deformed eclogites synthesized from ...
Photoisomerization in different classes of azobenzene

Azobenzene undergoes trans → cisisomerization when irradiated with light tuned to an appropriate wavelength. The reverse cis →transisomerization can be driven by light or occurs thermally in the dark. Azobenzene's photochromatic properties make it an ideal component of numerous molecular devices and functional materials. Despite the abundance of application-driven research, azobenzene photochemistry and the isomerization mechanism remain topics of investigation. Additional substituents on the azobenzene ring system change the spectroscopic properties and isomerization mechanism. This critical review details the studies completed to date on the 3 main classes of azobenzene derivatives. Understanding the differences in photochemistry, which originate from substitution, is imperative in exploiting azobenzene in the desired applications.
1D-to-3D transition of phonon heat conduction in polyethylene using molecular dynamics simulations

The thermal conductivity of nanostructures generally decreases with decreasing size because of classical size effects. The axial thermal conductivity of polymer chain lattices, however, can exhibit the opposite trend, because of reduced chain-chain anharmonic scattering. This unique feature gives rise to an interesting one-dimensional-to-three-dimensional transition in phonon transport. We study this transition by calculating the thermal conductivity of polyethylene with molecular dynamics simulations. The results are important for designing inexpensive high thermal-conductivity polymers.
Discovering REIT Price Discovery: A New Data Setting

This study decomposes real estate investment trust (REIT) returns into two components: (1) real returns, and (2) public returns. The real returns are based on the changes in the private, appraisal-based net asset values of REITs, whereas the public returns are measured by the variations in REITs’ premiums/discounts. This study then investigates the price discovery of REIT prices. The results indicate that lagged public returns are useful in predicting real returns. In addition, the study documents concurrent factor exposures for public returns and lagged factor exposures for private returns under a variety of asset pricing models. Overall, the results are consistent with the notion that public markets are more efficient in processing information.
Gradient-based aerodynamic shape optimization using alternating direction implicit method

A gradient-based shape optimization methodology that is intended for practical three-dimensional aerodynamic applications has been developed. It is based on the quasianalytical sensitivities. The flow analysis is rendered by a fully implicit, finite volume formulation of the Euler equations. The aerodynamic sensitivity equation is solved using the alternating direction implicit algorithm for memory efficiency. A flexible wing geometry model that is based on surface parameterization and planform schedules is utilized. The present methodology and its components have been tested via several comparisons. Initially, the flow analysis for a wing is compared with those obtained using an unfactored, preconditioned conjugate gradient approach (PCG) and an extensively validated computational fluid dynamics code. Then, the sensitivities computed with the present method have been compared with those obtained using the finite difference and PCG approaches. Effects of grid refinement and convergence tolerance on the analyses and the shape optimization have been explored. Finally, the new procedure has been demonstrated in the design of a cranked arrow wing at Mach 2.4.
EUV SPECTRAL LINE FORMATION AND THE TEMPERATURE STRUCTURE OF ACTIVE REGION FAN LOOPS: OBSERVATIONS WITH HINODE/EIS AND SDO/AIA

With the aim of studying active region fan loops using observations from the Hinode EUV Imaging Spectrometer (EIS) and Solar Dynamics Observatory Atmospheric Imaging Assembly (AIA), we investigate a number of inconsistencies in modeling the absolute intensities of Fe VIII and Si VII lines, and address why spectroheliograms formed from these lines look very similar despite the fact that ionization equilibrium calculations suggest that they have significantly different formation temperatures: log(Te /K) = 5.6 and 5.8, respectively. It is important to resolve these issues because confidence has been undermined in their use for differential emission measure (DEM) analysis, and Fe VIII is the main contributor to the AIA 131 A channel at low temperatures. Furthermore, the strong Fe VIII 185.213 A and Si VII 275.368 A lines are the best EIS lines to use for velocity studies in the transition region, and for assigning the correct temperature to velocity measurements in the fans. We find that the Fe VIII 185.213 A line is particularly sensitive to the slope of the DEM, leading to disproportionate changes in its effective formation temperature. If the DEM has a steep gradient in the log(Te /K) = 5.6-5.8 temperature range, or is strongly peaked, Fe VIII 185.213 A and Si VII 275.368 A will be formed at the same temperature. We show that this effect explains the similarity of these images in the fans. Furthermore, we show that the most recent ionization balance compilations resolve the discrepancies in absolute intensities. With these difficulties overcome, we combine EIS and AIA data to determine the temperature structure of a number of fan loops and find that they have peak temperatures of 0.8-1.2 MK. The EIS data indicate that the temperature distribution has a finite (but narrow) width < = 5.5 which, in one detailed case, is found to broaden substantially toward the loop base. AIA and EIS yield similar results on the temperature, emission measure magnitude, and thermal distribution in the fans, though sometimes the AIA data suggest a relatively larger thermal width. The result is that both the Fe VIII 185.213 A and Si VII 275.368 A lines are formed at log(Te /K)~ 5.9 in the fans, and the AIA 131 A response also shifts to this temperature.
Almost Sure Frequency Independence of the Dimension of the Spectrum of Sturmian Hamiltonians

We consider the spectrum of discrete Schrodinger operators with Sturmian potentials and show that for sufficiently large coupling, its Hausdorff dimension and its upper box counting dimension are the same for Lebesgue almost every value of the frequency.
Magnetic and structural characterization of sputtered FeN multilayer films

The magnetic and structural properties of ferromagnetic FeN thin films. FeN/FeN (ferromagnetic/paramagnetic) and FeN/SiO2 multilayers deposited in a rotational dc magnetron sputter system were investigated. Monolithic films containing ⋍ 2at% N2had 4πMs, values ⋍ 25 kG magnetostriction (λs) has been related to N2 content and film thickness. λs could be varied significantly over a range of compositions where 4πMs was > 22 kG by adjusting thickness and nitrogen. content. Lamination reduced easy- and hard-axis coercivity to < Oe. Lorentz microscopy indicated that the ferromagnetic FeN layers in the FeN/FeN films were exchanged coupled while those in the FeN/SiO2 films were magnetostatically coupled.
One flavor QCD

Abstract One flavor QCD is a rather intriguing variation on the underlying theory of hadrons. In this case quantum anomalies remove all chiral symmetries. This paper discusses the qualitative behavior of this theory as a function of its basic parameters, exploring the non-trivial phase structure expected as these parameters are varied. Comments are made on the expected changes to this structure if the gauge group is made larger and the fermions are put into higher representations.
Pd-catalyzed alkyl to aryl migration and cyclization: an efficient synthesis of fused polycycles via multiple C-H activation.

A novel palladium migration methodology for the synthesis of complex fused polycycles has been developed. This process involves 1,4-palladium alkyl to aryl migrations via through-space C−H activation, followed by intramolecular arylation or an intermolecular Heck reaction providing a very efficient way to synthesize fused ring systems.
SO2-Rich Equatorial Basins and Epeirogeny of Io

Abstract The most concentrated deposits of SO 2 frost on Io occur within a series of large equatorial basins. About 30% of the surface is covered by SO 2 outside of the basins, increasing to more than 50% within the basins. This pattern is poorly expressed in the region from longitude 240° to 360° where bright areas are frequently buried by the fallout from the large Pele-type plumes. The fourfold pattern of alternating basins and swells in Io's equatorial region is similar to the heat-flow pattern predicted from tidal heating in a thin, partially molten asthenosphere. However, the topographic pattern is offset from the predicted heat-flow pattern; thus it is unclear whether topographic highs correspond to regions of higher or lower predicted heat flow. These two possibilities imply two very different models for Io's highlands: a thermal-uplift model or a continental-crust model. In the thermal-uplift model, the regions of enhanced asthenospheric heating cause lithospheric thinning and isostatic uplift, perhaps accompanied by uplift due to penetrative magmatism or basaltic underplating. In the continental-crust model, "continents" of differentiated crust float on low-density roots, the crust and lithosphere are approximately one and the same, and basal melting controls its thickness. Although both models are plausible, the thermal-uplift model best explains the SO 2 distribution. Cold trapping must be important for concentrating SO 2 frost in optically thick patches; thus either cold traps are preferentially initiated over large basin areas or they are preferentially removed from the highlands. The patchy distribution and approximately 30% SO 2 coverage of the highlands show that cold traps are abundant here, but not extensive; thus the SO 2 must be preferentially removed and/or buried. Higher heat flows in the highlands should lead to increased volatilization of SO 2 frost, and a greater frequency of relatively SO 2 -poor volcanism should tend to bury frost patches. This model links asthenospheric tidal heating, large-scale heat flow and topography, volcanic activity, and the global distribution of surface SO 2 , and it leads to several specific predictions for future observations.
Transverse heating due to nonadiabatic propagation of cold atoms in an atomic guide

We study propagation of cold atoms along a curved atomic guide following an arbitrary trajectory in space. Transverse energy of the atomic beam increases as the beam propagates along the guide. Our model explains results of recent experiments on optical and magnetic guiding of cold atoms.
Neural network point detection using a coning scan imager

A very compact and inertially pointed imaging device can be constructed by combining the functions of a telescope and a gyroscope into a single assembly. However, the image resulting from this device is not easily processed owing to scan-induced geometric distortions. We have devised a method for adaptively processing the imager outputs to facilitate detection of bright points in a cluttered background. Pseudo-image neighborhoods are vectorized and have scan angle bits appended, allowing a neural net to learn the best matched filter for each scan configuration. We present the results of testing this filter using both synthetic and measured solar sea glint clutter.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Nonlocal potentials in independent‐electron models

Density functional theory, exact for ground states, is commonly assumed to imply an independent-electron model in which only local potential functions appear. It has recently been shown that several paradoxes in different aspects of the theory can be resolved if this locality hypothesis is abandoned. However, the locality hypothesis itself appears to be implied by rigorous variational theory. This conflict is discussed and resolved here. The resolution involves embedding the density functional theory in an orbital functional theory whose functional derivatives are not confined to normalized ground states. The orbital Euler–Lagrange equations of this extended theory in general contain effective potentials that are linear operators acting on orbital wave functions. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 81: 384–388, 2001
Conical shock-wave turbulent boundary-layer interaction including suction effects

Conical shock wave-turbulent boundary layer interaction data obtained for adiabatic wall conditions at supersonic free stream Mach numbers, including suction effects
A combined experimental and analytical approach for interface fracture parameters of dissimilar materials in electronic packages

This study concerns the development of a combined experimental and analytical technique to determine the critical values of fracture parameters for interfaces between dissimilar materials in electronic packages. This technique utilizes specimens from post-production electronic packages. The mechanical testing is performed inside a scanning electron microscope while the measurements are achieved by means of digital image correlation. The measured displacements around the crack tip are used as the boundary conditions for the analytical model to compute the energy release rate. The critical energy release rate values obtained from post-production package specimens are obtained to be lower than those laboratory specimens.
RENORMALIZATION OF BLACK HOLE ENTROPY AND OF THE GRAVITATIONAL COUPLING CONSTANT

Abstract The quantum corrections to black hole entropy, variously defined, suffer quadratic divergences reminiscent of the ones found in the renormalization of the gravitational coupling constant (Newton constant). We consider the suggestion, due to Susskind and Uglum, that these divergences are proportional, and attempt to clarify its precise meaning. We argue that if the black hole entropy is identified using a Euclidean formulation, including the necessary surface term as proposed by Gibbons and Hawking, then the proportionality is, up to small identifiable corrections, a fairly immediate consequence of basic principles - a low-energy theorem. Thus in this framework renormalizing the Newton constant renders the entropy finite, and equal, in the limit of large mass, to its semiclassical value. As a partial check on our formal arguments we compare the one loop determinants, calculated using heat kernel regularization. An alternative definition of black hole entropy relates it to behavior at conical singularities in two dimensions, and thus to a suitable definition of geometric entropy. A definition of geometric entropy, natural from the point of view of heat kernel regularization, permits the same renormalization, but it does not yield an intrinsically positive quantity. The possibility, for scalar fields, of non-minimal coupling to background curvature allows one to consider test the framework in a continuous family of theories, and crucially involves a subtle sensitivity of geometric entropy to curved space couplings. Fermions and gauge fields are considered as well. Their functional determinants are closely related to the determinants for non-minimally coupled scalar fields with specific values for the curvature coupling, and pose no further difficulties.
Some new equivalences of Anderson’s paving conjectures

Anderson's paving conjectures are known to be equivalent to the Kadison-Singer problem. We prove some new equivalences of Anderson's conjectures that require the paving of smaller sets of matrices. We prove that if the strictly upper triangular operators are paveable, then every 0 diagonal operator is paveable. This result follows from a new paving condition for positive operators. In addition, we prove that if the upper triangular Toeplitz operators are paveable, then all Toeplitz operators are paveable.
Highly Convergent Total Synthesis of (+)-Acutiphycin

An enantioselective, convergent, total synthesis of (+)-acutiphycin (18 steps, longest linear sequence from commercial materials) features the first application of an alkynyl ether as a macrolactone precursor in total synthesis, as well as the first example of an intermolecular, SmI2-mediated, Reformatsky fragment coupling reaction. The high convergence, efficiency, and modular nature of this synthesis make it amenable to the synthesis of structurally related compounds.
Discovery of a Wide, Low-Mass Binary System in Upper Scorpius

Using the near-infrared spectrometer SpeX and its slit-viewing camera at the Infrared Telescope Facility, I have resolved a low-mass member of the Upper Scorpius OB association into a double star. From K-band images of the pair, DENIS-P J161833.2-251750.4 A and B, I measure a separation of 096 and a magnitude difference of ΔK = 0.42 mag. I present resolved 0.8-2.5 μm spectroscopy of the two objects, both of which exhibit signatures of youth in the shape of their H- and K-band continua, demonstrating that both are members of Upper Scorpius, rather than field stars. In addition, through a comparison with optically classified pre-main-sequence objects, I derive a spectral type near M5 for each component, corresponding to a mass of ~0.15 M☉ with the evolutionary models of Chabrier & Baraffe. The probability that this pair is composed of unrelated M-type members of Upper Scorpius is ~10-5. When added to the recent discoveries of other wide, easily disrupted low-mass binaries, this new system further establishes that the formation of low-mass stars and brown dwarfs does not require ejection from multiple systems. These observations also indicate that wide, low-mass binaries can form in OB associations as well as in smaller clusters where the previously known wide pairs have been found. Thus, the available data show no perceptible effect of star-forming environment on the prevalence of loosely bound low-mass systems.
Energy Landscape and Isotropic Tensile Strength of n-Alkane Glasses

We report results from a systematic simulational study of the ultimate mechanical strength of n-alkane glasses for carbon numbers n ) 1, 2, 3, 4, 6, 8, 16, 24, and 48. The ultimate isotropic tensile strength was determined by constructing the equation of state of energy landscape for this homologous series. The tensile strength depends nonmonotonically on carbon number, exhibiting a maximum at n ) 3. The mass density at which fracture occurs initially increases with chain length and then reaches a plateau value for n > 8. The predictions of the landscape equation of state are entirely consistent with results generated by a direct inherent structure deformation procedure. Although the ultimate isotropic tensile strength maximum at n ) 3 would seem to contradict physical intuition regarding chain entanglement, we present a simple mean-field theory that reveals the underlying physics responsible for the tensile strength maximum, namely the simple competition between intermolecular interactions and intramolecular packing effects.
Characterization of polymer electrolytes for fuel cell applications

Abstract We review here our recent work on polymer electrolyte fuel cells emphasizing membrane transport issues. Transport parameters measured at 30°C for several available perfluorosulfonic acid membranes are compared. The diffusion coefficient and conductivity of each of these membranes were determined as functions of membrane water content. Data on water sorption and conductivity are reported for an experimental membrane which is a modified form of NAFION®. Contact angle measurements indicate that the surface of a perfluorosulfonic acid membrane exposed to water vapor is quite hydrophobic, even in the presence of saturated water vapor. Modeling of water distribution in PEFCs based on the uptake and transport data shows that membrane thickness contributes in a nonlinear fashion to performance in PEM fuel cells.
Keynesian Conundrum: Multiplicity and Time Consistent Stabilization

Abstract This paper identifies a novel form of dynamic inconsistency of stabilization policy in increasing returns models that generate multiple equilibria. We present a two-period model with externalities and derive closed-form solutions for all endogenous variables in every perfect foresight equilibrium. We provide conditions under which the stabilization policy that maximizes time-zero consumer welfare is not time consistent. Furthermore, we characterize the time consistent stabilization policy. Our results cast doubts on the usefulness of government coordination of economic activity when the government lacks a commitment mechanism. Without commitment, a benevolent government can rule out multiplicity only by ensuring that a Pareto dominated equilibrium obtains.
Cell sorting by deterministic cell rolling

This communication presents the concept of “deterministic cell rolling”, which leverages transient cell-surface molecular interactions that mediate cell rolling to sort cells with high purity and efficiency in a single step.
Modeling and Measurement of Toroidal Currents in the HSX Stellarator

A set of magnetic diagnostics, including Rogowski coils, diamagnetic loops and two poloidal ‘belts’ of 3-axis pick-up coils measure the magnetic field at several locations around HSX. The two belts are separated by ≈1/3 of a field period and measure the local magnetic field vector at 16 poloidal locations at the two toroidal angles. With the VMEC [1] and PENTA [2] codes, a calculation of the Pfirsch-Schluter (PS) and bootstrap currents is performed. The 3-D equilibrium reconstruction code V3FIT [3] is then used to calculate the expected response of the magnetic diagnostics. The sensitivity of the diagnostic set to features in both the PS and bootstrap current is explored. Because of the lack of toroidal curvature, the dipole PS current has a helical rotation and nearly reverses at the two toroidal locations. The bootstrap current in HSX is in the opposite direction compared to that in a tokamak. Compared to a tokamak, the relative magnitude of each current is reduced by a factor of the effective transform (≈3) [4]. The PS current reaches steady state quickly, whereas the bootstrap current rises throughout the discharge on a 50-500 ms timescale. In most cases, the toroidal current is still rising at the end of the discharge, reaching 0.4-0.6 kA. A 3-D model that relies on the calculation of the susceptance matrix [5] is used to calculate the time evolution of the toroidal current (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Strategies for ansamycin antibiotics. asymmetric synthesis of the C(3)–C(21) subunit of herbimycin A

Abstract The asymmetric synthesis of 25, which constitutes the C(3)–C(21) segment of the stereochemically complex ansa chain of herbimycin A (2) has been achieved. The approach features the furan-hydropyran transformations 7→5 and 8→6 and the fragment coupling of 5 and 6 to produce the trisubstituted alkene 4 with high stereoselectivity. Stereoselective addition of the aryl anion derived from 24, which possesses the novel BIPSOP protecting group for the primary amine function, to the lactol 22 then delivered 25 as the major product.
Current Large Deviations in a Driven Dissipative Model

We consider lattice gas diffusive dynamics with creation-annihilation in the bulk and maintained out of equilibrium by two reservoirs at the boundaries. This stochastic particle system can be viewed as a toy model for granular gases where the energy is injected at the boundary and dissipated in the bulk. The large deviation functional for the particle currents flowing through the system is computed and some physical consequences are discussed: the mechanism for local current fluctuations, dynamical phase transitions, the fluctuation-relation.
Radical Evil in the Lockean State: The Neglect of the Political Emotions

All modern liberal democracies have strong reasons to support an idea of toleration, understood as involving respect, not only grudging acceptance, and to extend it to all religious and secular doctrines, limiting only conduct that violates the rights of other citizens. There is no modern democracy, however, in which toleration of this sort is a stable achievement. Why is toleration, attractive in principle, so difficult to achieve? The normative case for toleration was well articulated by John Locke in his influential A Letter Concerning Toleration , although his attractive proposal thus rests on a fragile foundation. Kant did much more, combining a Lockean account of the state with a profound diagnosis of ‘radical evil’, the tendencies in all human beings to militate against stable toleration and respect. But Kant proposed no mechanism through which the state might mitigate the harmful influence of ‘radical evil’, thus rendering toleration stable. One solution to this problem was proposed by Rousseau, but it has deep problems. How, then, can a respectful pluralistic society shore up the fragile human basis of toleration, especially in a world in which we need to cultivate toleration not only within each state, but also among peoples and states, in this interlocking world?
Separability and topology control of quasi unit disk graphs

A deep understanding of the structural properties of wireless networks is critical for evaluating the performance of network protocols and improving their designs. Many protocols for wireless networks--routing, topology control, information storage/retrieval and numerous other applications--have been based on the idealized unit-disk graph (UDG) network model. The significant deviation of the UDG model from many real wireless networks is substantially limiting the applicability of such protocols. A more general network model, the quasi unit-disk graph (quasi-UDG) model, captures much better the characteristics of wireless networks. However, the understanding of the properties of general quasi-UDGs has been very limited, which is impeding the designs of key network protocols and algorithms. In this paper, we present results on two important properties of quasi-UDGs: separability and the existence of power efficient spanners. Network separability is a fundamental property leading to efficient network algorithms and fast parallel computation. We prove that every quasi-UDG has a corresponding grid graph with small balanced separators that captures its connectivity properties. We also study the problem of constructing an energy-efficient backbone for a quasi-UDG. We present a distributed local algorithm that, given a quasi-UDG, constructs a nearly planar backbone with a constant stretch factor and a bounded degree. We demonstrate the excellent performance of these auxiliary graphs through simulations and show their applications in efficient routing.
Relative Geometric Invariant Theory and Universal Moduli Spaces

We expose in detail the principle that the relative geometric invariant theory of equivariant morphisms is related to the GIT for linearizations near the boundary of the G-effective ample cone. We then apply this principle to construct and reconstruct various universal moduli spaces. In particular, we constructed the universal moduli space over of Simpson’s p-semistable coherent sheaves and a canonical rational morphism from the universal Hilbert scheme over to a compactified universal Picard.
Geometry for palindromic automorphism groups of free groups

We examine the palindromic automorphism group $ \Pi A(F_n) $ , of a free group F n , a group first defined by Collins in [5] which is related to hyperelliptic involutions of mapping class groups, congruence subgroups of $ SL_n({\Bbb Z}) $ , and symmetric automorphism groups of free groups. Cohomological properties of the group are explored by looking at a contractible space on which $ \Pi A(F_n) $ acts properly with finite quotient. Our results answer some conjectures of Collins and provide a few striking results about the cohomology of $ \Pi A(F_n) $ , such as that its rational cohomology is zero at the vcd.
Shape optimization with p adaptivity

The p method of analysis, when used with shape optimization, has certain advantages over the h method. The method of h adaptivity results in fine meshes with small elements in areas of stress concentration. The presence of these small elements prevents the shape from changing significantly during optimization due to mesh distortion. The p-adaptive method uses relatively large sized elements, and adaptivity is achieved by increasing the polynomial order of the shape functions rather than by introducing small elements as in the h method. Thus, the p-adaptive method allows for greater shape changes without sacrificing the accuracy of the analysis. A methodology is developed in this paper to integrate p-adaptive analysis with shape optimization for general velocity fields. The key contributions lie in an easily implementable shape update strategy and an adaptive scheme to locally increase the polynomial order based on error indicators. Numerical results show that significant shape change is achievable prior to serious mesh distortion. In addition, need for an h-p adaptive strategy rather than a pure p-adaptive strategy is also highlighted.