cssi/SciSciGPT-SciSciNet huggingface dataset:
Generation of Motion of Drops with Interfacial Contact

A liquid drop moves on a solid surface if it is subjected to a gradient of wettability or temperature. However, the pinning defects on the surface manifested in terms of a wetting hysteresis, or first-order nonlinear friction, limit the motion in the sense that a critical size has to be exceeded for a drop to move. The effect of hysteresis can, however, be mitigated by an external vibration that can be either structured or stochastic, thereby creating a directed motion of the drop. Many of the well-known features of rectification, amplification, and switching that are generic to electronics can be engineered with such types of movements. A specific case of interest is the random coalescence of drops on a surface that gives rise to self-generated noise. This noise overcomes the pinning potential, thereby generating a random motion of the coalesced drops. Randomly moving coalesced drops themselves exhibit a directed diffusive flux when a boundary is present to eliminate them by absorption. With the presence of a bias, the coalesced drops execute a diffusive drift motion that can have useful applications in various water and thermal management technologies.
Measurement of the Lamb Shift in Hydrogen, n=2

A measurement based on the fast-atomic-beam separated-oscillatory-field method of sub-natural-linewidth spectroscopy gives, for the Lamb shift in hydrogen, $\mathcal{S}(n=2)=1057.845(9)$ MHz. The result is not in good agreement with theory.
Review of Chemical Reactions in the NO Reduction by CO on Platinum/alumina Catalysts

The emissions of nitric oxide and carbon monoxide from internal combustion engines generate a large impact on the environment and on people's health. Catalytic reduction of these species using platinum group metals has already shown significant potential for emissions control. Since catalysts often use carbon monoxide to reduce nitric oxide in these devices, accurate models of their interaction are required to advance catalyst simulations in order to meet increasingly stringent emissions regulations. As a result, this paper reviews the literature of the NO–CO reaction over platinum in order to develop more precise detailed and global reaction mechanisms for use in exhaust after-treatment modeling activities. Moreover, it is found that the reaction between NO and CO over platinum yields carbon dioxide and nitrogen as main products and nitrous oxide as an important side product. Hence, this paper additionally describes the mechanism for nitrous oxide production in advance of greenhouse gas regulations.
KINEMATIC, MICROPHYSICAL, AND ELECTRICAL ASPECTS OF AN ASYMMETRIC BOW-ECHO MESOSCALE CONVECTIVE SYSTEM OBSERVED DURING STEPS 2000

[1] Five hours of detailed observations of the asymmetric bow-echo mesoscale convective system on 11–12 June 2000 during the STEPS project are presented. Data sources included polarimetric and Doppler radars, a VHF lightning mapper, and the National Lightning Detection Network. Nearly every (99%) VHF lightning source occurred within 10 km of the convective line. Charge identification within the much of the convective line revealed evolution during the first 3 h from a normal polarity dipole (upper positive charge near 9 km MSL/−30°C, over mid-level negative charge near 7 km/−16°C) to a normal polarity tripole with the addition of lower positive charge near 4 km (1°C). During the final 2 h, the charge structure resembled an inverted dipole, with negative charge overlaying positive. When the bow echo occurred during hour 2, part of the cells associated with severe winds developed an inverted tripolar charge structure and produced predominantly positive cloud-to-ground lightning. Stratiform lightning was infrequent, normally initiating in the convective line and propagating rearward along two pathways: a downward-sloping upper pathway near 9 km, and a more common constant-altitude lower pathway near 6 km (−10°C). Some flashes initiated within the stratiform region during this time, but only after stratiform reflectivities increased significantly in the mixed-phase region. These flashes initiated near the bright band (4 km), and tapped negative charge above and positive charge below. Possible mechanisms to explain the observations are discussed.
Cyclic Descents and P-Partitions

Louis Solomon showed that the group algebra of the symmetric group $$\mathfrak{S}_{n}$$ n has a subalgebra called the descent algebra, generated by sums of permutations with a given descent set. In fact, he showed that every Coxeter group has something that can be called a descent algebra. There is also a commutative, semisimple subalgebra of Solomon's descent algebra generated by sums of permutations with the same number of descents: an "Eulerian" descent algebra. For any Coxeter group that is also a Weyl group, Paola Cellini proved the existence of a different Eulerian subalgebra based on a modified definition of descent. We derive the existence of Cellini's subalgebra for the case of the symmetric group and of the hyperoctahedral group using a variation on Richard Stanley's theory of P-partitions.
Improved gluonic actions on anisotropic lattices

Abstract The use of novel perturbatively-improved gluonic actions on anisotropic lattices in which the temporal spacing is much smaller than that in the spatial directions is discussed. Such actions permit more efficient measurements of noisy correlation functions, such as glueball correlators, on coarse lattices. A derivation of these actions at tree-level is outlined; mean-field link renormalization plays a crucial role in their construction. Results for the low-lying glueball masses and the heavy-quark potential are presented.
Synthesis of Polycyclic Benzofused Nitrogen Heterocycles via a Tandem Ynamide Benzannulation/Ring Closing Metathesis Strategy. Application in a Formal Total Synthesis of (+)-FR900482

A two-stage "tandem strategy" for the synthesis of benzofused nitrogen heterocycles is described that is particularly useful for the construction of systems with a high level of substitution on the benzenoid ring. The first stage in the strategy involves a benzannulation based on the reaction of cyclobutenones with ynamides. This cascade process proceeds via a sequence of four pericyclic reactions and furnishes a multiply substituted aniline derivative which can bear a variety of functionalized substituents at the position ortho to the nitrogen. In the second stage of the tandem strategy, ring-closing metathesis generates the nitrogen heterocyclic ring. This two-step sequence provides efficient access to highly substituted dihydroquinolines, benzazepines, benzazocines, and related benzofused nitrogen heterocyclic systems. The application of this chemistry in a concise formal total synthesis of the anticancer agents (+)-FR900482 and (+)-FR66979 is described.
Bayesian Energy Landscape Tilting: Towards Concordant Models of Molecular Ensembles

Predicting biological structure has remained challenging for systems such as disordered proteins that take on myriad conformations. Hybrid simulation/experiment strategies have been undermined by difficulties in evaluating errors from computational model inaccuracies and data uncertainties. Building on recent proposals from maximum entropy theory and nonequilibrium thermodynamics, we address these issues through a Bayesian energy landscape tilting (BELT) scheme for computing Bayesian hyperensembles over conformational ensembles. BELT uses Markov chain Monte Carlo to directly sample maximum-entropy conformational ensembles consistent with a set of input experimental observables. To test this framework, we apply BELT to model trialanine, starting from disagreeing simulations with the force fields ff96, ff99, ff99sbnmr-ildn, CHARMM27, and OPLS-AA. BELT incorporation of limited chemical shift and 3J measurements gives convergent values of the peptide’s α, β, and PPII conformational populations in all cases. As a test of predictive power, all five BELT hyperensembles recover set-aside measurements not used in the fitting and report accurate errors, even when starting from highly inaccurate simulations. BELT’s principled framework thus enables practical predictions for complex biomolecular systems from discordant simulations and sparse data.
The “Race Card” Revisited: Assessing Racial Priming in Policy Contests

In The Race Card (2001), Mendelberg finds support for her theory that implicit racial appeals, but not explicit ones, prime racial resentment in opinion formation. She argues that citizens reject explicit appeals, rendering them ineffective, because they violate widespread egalitarian norms. Mendelberg’s innovative research, however, suffers from several limitations. We remedy these deficiencies using two randomized experiments with over 6,300 respondents. We confirm that individuals do tend to reject explicit appeals outright, but find that implicit appeals are no more effective than explicit ones in priming racial resentment in opinion formation. In accounting for the differences between previous research and our own, we show that education moderates both the accessibility of racial predispositions and message acceptance. This suggests that the necessary assumptions of Mendelberg’s theory hold only for different and exclusive subsets of the general population.
Iron uptake and transport in plants: the good, the bad, and the ionome.

Fe is essential for plant growth. At the same time, Fe is highly reactive and toxic via the Fenton reaction. Consequently, plants tightly control Fe homeostasis and react to Fe deficiency as well as Fe overload. The ability of plants to respond to Fe availability ultimately affects human nutrition, both in terms of crop yield and the Fe concentration of edible tissues. Thus, elucidating the mechanisms of Fe uptake and transport is essential for the breeding of crops that are more nutrient rich and more tolerant of Fe-limited soils.This review covers Fe transport and homeostasis in plants, focusing on the research published in the past five years. Because Fe transporters often have a broad range of substrates, we also examine the relationship between Fe and the toxic metals that often accompany Fe uptake, namely Cd, Co, and Ni. We begin by discussing Fe uptake into the root, then long-distance transport to the shoot, and finally, the loading of Fe into seeds. And, as Fe is essential to the metabolism of the mitochondria and chloroplast, we also look at the recent discoveries in Fe transport and homeostasis at the intracellular level. We do not cover the regulation of these transporters asmore » this topic has been recently reviewed.« less
Linkage analysis in a large kindred with autosomal dominant transmission of polyglandular autoimmune disease type II (Schmidt syndrome).

Schmidt syndrome (PGA syndrome type II) is a rare condition characterized by polyglandular failure. It is an autosomal dominant trait with variable expressivity that was inherited over four generations in an Indiana kindred. Association of HLA-B8 has been reported with Schmidt syndrome. Our proband is a 12-year-old boy with Addison disease, insulin dependent diabetes mellitus (IDDM), and vitiligo. Two of his eight sibs had either IDDM (sister) or vitiligo and hyperthyroidism (brother). His mother had hypothyroidism. Seven members of earlier generations apparently were also affected. We obtained peripheral blood for HLA and genetic analysis from 21 relatives in a family with 8 Schmidt syndrome individuals in three generations. HLA studies on 15 affected and unaffected relatives showed only 2 of 7 persons with B8-containing haplotypes. Therefore, no association exists between the B8-containing haplotype and the syndrome. We identified informative marker loci. No evidence for linkage of the Schmidt locus to any of the 14 markers was found and close linkage to esterase D and adenylate kinase and possibly properdin factor B was excluded.
Instability Due to Interacting Hydraulic and Mechanical Dynamics in Backhoes

A backhoe is a tractor-like vehicle that has a hydraulically actuated bucket loader at the front and a hydraulically actuated backhoe shovel at the rear The operator sits inside a canopy or cab that is mounted to the tractor chassis, and operates the hydraulic controls. The cab is typically isolated somewhat from the chassis using cab mounts. There are instances when the bucket is raised or lowered or wrapped that an instability of the entire machine is excited. In this mode, a frequency oscillation of the vehicle occurs and the operator is unable to keep his hands on the controls. This instability is investigated here and demonstrated through simulation. The instability described here is due to an interaction between the mechanical dynamics and hydraulic dynamics of the machine. All instabilities require an energy source, and, in this case, the energy comes from the fuel. It turns out that the hydromechanical interaction has positive feedback components and produces an instability. In order to expose the fundamental cause of the instability, a model is needed that allows the interaction of mechanical and hydraulic components. Bond graphs are a logical choice for development of the model. Bond graphs are a concise pictorial representation of the interactive dynamics of all types of energetic systems. They allow the model to be developed in pieces and then put together into an overall computational model. This procedure is demonstrated for the system here. The end result is a reasonably low order model that exposes the fundamental cause of the instability in backhoes. It also allows assessment of cures for the problem, some requiring redesign of components, and some requiring an automatic stabilization control system.
The Bright Ages Survey. I. Imaging Data

This is the first paper in a series presenting and analyzing data for a K-selected sample of galaxies collected in order to identify and study galaxies at moderate to high redshift in rest-wavelength optical light. The sample contains 842 objects over 6 separate fields covering 75.6 arcmin 2 down to K=20-20.5. We combine the K-band with UBVRIzJH multi-band imaging, reaching depths of R�26. Two of the fields studied also have deep HST WFPC2 imaging, totaling more than 60 hours in the F300W, F450W, F606W, and F814W filters. Using artificial galaxy modeling and extraction we measure 85% completeness limits down to K=19.520, depending on the field examined. The derived K-band number counts are in good agreement with previous studies. We find a density for Extremely Red Objects (EROs; R-K>5) of 1.55±0.16 arcmin −2 for K<19.7, dominated by the 1714+5015 field (centered on 53w002), with an ERO number density more than 3 times that of the other sample fields. If we exclude the counts for 1714+5015, our density is 0.95+/- 0.14 arcmin. Both ERO densities are consistent with previous measurements due to the significant known cosmic variance of these red sources. Keck spectroscopic redshifts were obtained for 18 of the EROs, all but one of which are emission galaxies. None of the EROs in the 1714+5015 field for which we obtained spectroscopic redshifts are associated with the known z=2.39 overdensity, although there are three different galaxy redshift pairs (z=0.90, z=1.03, z=1.22). Subject headings: galaxies: evolution, galaxies: high-redshift, infrared: galaxies
Economic Reform, Growth and Convergence in China

Summary In this paper, we propose a new concept of convergence which is based on the metric entropy measure recently proposed by Granger et al. (2004, Journal of Time Series Analysis 25, 649–69) to investigate economic convergence in China. This entropy measure compares whole distributions of growth rates across individual provinces. Separately, based on this same entropy measure, we also implement cluster analysis to identify any convergence clubs. Our four main conclusions are: (1) while we certainly reject the null hypothesis that there exists a nationwide convergence, we do find that there exist convergence clubs for both the pre- and post-reform periods, (2) we find a number of very small convergence clubs. In particular, there are eleven and six convergence clubs for the pre- and post-reform periods, respectively, (3) in comparing the number and size of convergence clubs for both the pre- and post-reform periods, it could be argued that the extent of convergence is more prevalent during the post-reform period than during the pre-reform period and (4) convergence groups cannot be simply characterized by such unique features as region or the extent of policy preference level that are commonly used in the literature.
Pressure-Dependence of the Crystal-Structures and EPR-Spectra of Potassium Hexaaquacopper(II) Sulfate and Deuterated Ammonium Hexaaquacopper(II) Sulfate

The crystal structures of (ND4)2[Cu(D2O)6](SO4)2 at 295 K, determined by X-ray diffraction at pressures of 1 bar, ∼1.5 kbar and ∼3.0 kbar, are reported. Between 1 bar and 1.5 kbar, the crystal structure changes to one almost identical to that of the corresponding hydrogenous compound at 1 bar. The structural change involves a 90° switch in the direction of the long bonds of the Cu(D2O)62+ ion, accompanied by a change in the hydrogen-bonding interactions of the ammonium cations. Comparison of these two structures with those at ∼15 K shows that at room temperature, for both the high (H) and low (L) pressure phases, the Cu complexes are in thermal equilibrium with the other structural isomer. Though one of these is energetically preferred in the H and the other in the L phase, the variation of the powder EPR spectrum with pressure indicates a continuous transition between both within ∼1 kbar and suggests that at ∼0.5 kbar the two orientations of the copper complex are similar in energy. However, the underlyi...
Stroboscopic image capture: Reducing the dose per frame by a factor of 30 does not prevent beam-induced specimen movement in paraffin

Beam-induced specimen movement may be the major factor that limits the quality of high-resolution images of organic specimens. One of the possible measures to improve the situation that was proposed by Henderson and Glaeser [Ultramicroscopy 16 (1985) 139-150], which we refer to here as "stroboscopic image capture", is to divide the normal exposure into many successive frames, thus reducing the amount of electron exposure--and possibly the amount of beam-induced movement--per frame. The frames would then be aligned and summed. We have performed preliminary experiments on stroboscopic imaging using a 200-kV electron microscope that was equipped with a high dynamic range Charge-coupled device (CCD) camera for image recording and a liquid N2-cooled cryoholder. Single-layer paraffin crystals on carbon film were used as a test specimen. The ratio F(g)/F(0) of paraffin reflections, calculated from the images, serves as our criterion for the image quality. In the series that were evaluated, no significant improvement of the F(image)(g)/F(image)(0) ratio was found, even though the electron exposure per frame was reduced by a factor of 30. A frame-to-frame analysis of image distortions showed that considerable beam-induced movement had still occurred during each frame. In addition, the paraffin crystal lattice was observed to move relative to the supporting carbon film, a fact that cannot be explained as being an electron-optical effect caused by specimen charging. We conclude that a significant further reduction of the dose per frame (than was possible with this CCD detector) will be needed in order to test whether the frame-to-frame changes ultimately become small enough for stroboscopic image capture to show its potential.
Comparisons of Supergranule Characteristics During the Solar Minima of Cycles 22/23 and 23/24

Supergranulation is a component of solar convection that manifests itself on the photosphere as a cellular network of around 35 Mm across, with a turnover lifetime of 1 – 2 days. It is strongly linked to the structure of the magnetic field. The horizontal, divergent flows within supergranule cells carry local field lines to the cell boundaries, while the rotational properties of supergranule upflows may contribute to the restoration of the poloidal field as part of the dynamo mechanism, which controls the solar cycle. The solar minimum at the transition from cycle 23 to 24 was notable for its low level of activity and its extended length. It is of interest to study whether the convective phenomena that influence the solar magnetic field during this time differed in character from periods of previous minima. This study investigates three characteristics (velocity components, sizes and lifetimes) of solar supergranulation. Comparisons of these characteristics are made between the minima of cycles 22/23 and 23/24 using MDI Doppler data from 1996 and 2008, respectively. It is found that whereas the lifetimes are equal during both epochs (around 18 h), the sizes are larger in 1996 (35.9 ± 0.3 Mm) than in 2008 (35.0 ± 0.3 Mm), while the dominant horizontal velocity flows are weaker (139 ± 1 m s−1 in 1996; 141 ± 1 m s−1 in 2008). Although numerical differences are seen, they are not conclusive proof of the most recent minimum being inherently unusual.
Abstracting abstract machines

We describe a derivational approach to abstract interpretation that yields novel and transparently sound static analyses when applied to well-established abstract machines. To demonstrate the technique and support our claim, we transform the CEK machine of Felleisen and Friedman, a lazy variant of Krivine's machine, and the stack-inspecting CM machine of Clements and Felleisen into abstract interpretations of themselves. The resulting analyses bound temporal ordering of program events; predict return-flow and stack-inspection behavior; and approximate the flow and evaluation of by-need parameters. For all of these machines, we find that a series of well-known concrete machine refactorings, plus a technique we call store-allocated continuations, leads to machines that abstract into static analyses simply by bounding their stores. We demonstrate that the technique scales up uniformly to allow static analysis of realistic language features, including tail calls, conditionals, side effects, exceptions, first-class continuations, and even garbage collection.
New methods for the synthesis of fluoroolefins via the palladium catalyzed cross-coupling reaction of 1-fluorovinyl halides with organoboranes and organostannanes

Abstract The palladium catalyzed cross-coupling reaction of 1-fluorovinyl halides with organoboranes and organostannanes provide two new facile methods to 1-substituted 1-fluoroolefins. The reactions proceed with retention of configuration in good to excellent yields.
Observations of the cosmic microwave background

The properties of the cosmic microwave background radiation provide unique constraints on cosmological models, i.e. on the content, history, and evolution of the Universe. I discuss the latest measurements of the spectral and spatial properties of the cosmic microwave background radiation. Recent measurements from NASA's Cosmic Background Explorer ( COBE ) satellite, and from balloon-borne and ground-based platforms, are summarized and their cosmological implications are discussed.
Parallel dynamics and computational complexity of the Bak–Sneppen model

The parallel computational complexity of the Bak–Sneppen evolution model is studied. It is shown that Bak–Sneppen histories can be generated by a massively parallel computer in a time that is polylogarithmic in the length of the history. In this parallel dynamics, histories are built up via a nested hierarchy of avalanches. Stated in another way, the main result is that the logical depth of producing a Bak–Sneppen history is exponentially less than the length of the history. This finding is surprising because the self-organized critical state of the Bak–Sneppen model has long range correlations in time and space that appear to imply that the dynamics is sequential and history dependent. The parallel dynamics for generating Bak–Sneppen histories is contrasted to standard Bak–Sneppen dynamics. Standard dynamics and an alternate method for generating histories, conditional dynamics, are both shown to be related to P-complete natural decision problems implying that they cannot be efficiently implemented in parallel.
Synthesis and antiviral evaluation of 1-O-hexadecylpropanediol-3-P-acyclovir: efficacy against HSV-1 infection in mice.

Abstract We synthesized, 1-O-hexadecylpropanediol-3–P-acyclovir, an orally bioavailable lipid prodrug of acyclovir and evaluated it for in vitro and in vivo activity against herpes simplex virus infections. Although 1-O-hexadecylpropanediol-3–P-acyclovir was less active in vitro than acyclovir, on a molar basis it was 2.4 times more active orally in preventing mortality from acute HSV-1 infection in mice. In vitro, 1–O-hexadecylpropanediol-3–P-acyclovir was also more active than acyclovir in a thymidine kinase negative mutant strain of HSV-1 (DM21) and had somewhat higher activity in cytomegalovirus infection in vitro due to it's ability to bypass thymidine kinase.
Learning-Based Auditory Encoding for Robust Speech Recognition

This paper describes an approach to the optimization of the nonlinear component of a physiologically motivated feature extraction system for automatic speech recognition. Most computational models of the peripheral auditory system include a sigmoidal nonlinear function that relates the log of signal intensity to output level, which we represent by a set of frequency dependent logistic functions. The parameters of these rate-level functions are estimated to maximize the a posteriori probability of the correct class in training data. The performance of this approach was verified by the results of a series of experiments conducted with the CMU S phinx-III speech recognition system on the DARPA Resource Management, Wall Street Journal databases, and on the AURORA 2 database. In general, it was shown that feature extraction that incorporates the learned rate-nonlinearity, combined with a complementary loudness compensation function, results in better recognition accuracy in the presence of background noise than traditional MFCC feature extraction without the optimized nonlinearity when the system is trained on clean speech and tested in noise. We also describe the use of lattice structure that constraints the training process, enabling training with much more complicated acoustic models.
Phonon wave heat conduction in thin films and superlattices

Heat conduction in thin films and superlattices is important for many engineering applications such as thin-film based microelectronic, photonic, thermoelectric, and thermionic divides. Past modeling efforts on the thermal conductivity of thin films were based on solving the Boltzmann transport equation that treats phonons as particles. The effects of phonon interference and tunneling on the heat conduction and the thermal conductivity of thin films and superlattices remain to be explored. In this work, the wave effects on the heat conduction in thin films and superlattices are studied based on the consideration of the acoustic wave propagation in thin film structures and neglecting the internal scattering. A transfer matrix method is used to calculate the phonon transmission and heat conduction through these structures. The effects considered in this work include the phonon interference, tunneling, and confinement. The phonon dispersion is considered by introducing frequency-dependent Lamb constants. A ray-tracing method that treats phonons as particles is also developed for comparison. Sample calculations are performed on double heterojunction structures resembling Ge/Si/Ge and n-period superlattices similar to Ge/Si/n(Si/Ge)/Ge. It is found that phonon confinements caused by the phonon spectra mismatch and by the total internal reflection create a dramatic decrease of the overall thermalmore » conductance of thin films. The phonon interference in a single layer does not have a strong effect on its thermal conductance but for superlattice structures, the stop bands created by the interface effects can further reduce the thermal conductance. Tunneling of phonon waves occurs when the constituent layers are 1--3 monolayer thick and causes a slight recovery in the thermal conductance when compared to thicker layers. The thermal conductance obtained from the ray tracing and the wave methods approaches the same results for a single layer. For superlattices, however, the wave method leads to a finite thermal conductance even for infinitely thick superlattices while the ray tracing method gives a thermal conductance that decreases with increasing number of layers. Implications of these results on explaining the recent thermal conductivity data of superlattices are explored.« less
String Network from M-theory

Abstract We study the three-string junctions and string networks in Type IIB string theory by explicitly constructing the holomorphic embeddings of the M-theory membrane that describe such configurations. The main feature of them such as supersymmetry, charge conservation and balance of tensions are derived in a more unified manner. We calculate the energy of the string junction and show that there is no binding energy associated with the junction.
Materials characterization of the effect of mechanical bending on area array package interconnects

Abstract The mechanical integrity of solder joint interconnects in PWB assemblies with micro-BGA, chip scale, and land grid array packages is being questioned as the size and pitch decrease. Some consumer products manufacturers have mechanically reinforced fine pitch package interconnects with an adhesive underfill, and others are evaluating the need for underfill on a case-by-case basis. Three-point cyclic bend testing provides a useful tool for characterizing the expected mechanical cycling fatigue reliability of PWB assemblies. Cyclic bend testing is useful for characterizing bending issues in electronic assemblies such as repetitive keypad actuation in cell phone products. This paper presents the results of three-point bend testing of PWB assemblies with fine pitch packages. The solder joints on ceramic components performed better than a laminate interposer component in bend testing, because of the stiffening effect of the ceramic packaging materials. The methodology of materials analyses of the metallurgy of solder interconnects following mechanical bending and thermal cycle testing is described. The microstructure and fracture surfaces of solder joint failures in bend test samples differed significantly from thermal cycle test samples.
Design considerations for an X-ray microprobe☆

Abstract The optical design of a fluorescent microprobe covering the X-ray region from 2 to 16 keV is considered for the NSLS X-ray ring. The limit on detectability is from total (photons/μm2) and several design choices are considered to match the optical system to the storage ring to maximize throughput. The tradeoffs in image quality and energy resolution of these designs have been considered and within these constraints two firm proposals are presented.
Modes of shock-wave oscillations on spike-tipped bodies

The phenomenon of self-excited shock oscillations on a spike-tipped body at Mach 3 is investigated. Various modes of shock oscillations are observed. For some spike lengths, the shock oscillations are symmetric. For other spike lengths, the shock structure oscillates asymmetrically with respect to the spike's axis. In this case, experimental evidence confirms the presence of standing rotational waves on the body face and spike. Spike configurations resulting in stable shock systems are also observed. Holography and interferometry are used to obtain a detailed flow visualization.
Near‐tail reconnection as the cause of cometary tail disconnections

In a cometary tail disconnection event the plasma tail appears to separate from the coma and to accelerate away from it. As this occurs a new tail begins to form. It is proposed that these disconnections arise in a manner analogous to geomagnetic substorms, i.e., by the formation of a strongly reconnecting region in the near tail that forms a magnetic island in the coma and ejects the plasma tail by strengthening the magnetic 'slingshot' within the tail. This reconnection process may be triggered by several different processes, such as interplanetary shocks or variations in the Alfven Mach number.
AN ANALYTIC MODEL OF THE PHYSICAL PROPERTIES OF GALAXY CLUSTERS

We introduce an analytic model of the diffuse intergalactic medium in galaxy clusters based on a polytropic equation of state for the gas in hydrostatic equilibrium with the cluster gravitational potential. This model is directly applicable to the analysis of X-ray and Sunyaev-Zel'dovich effect observations from the cluster core to the virial radius, with five global parameters and three parameters describing the cluster core. We validate the model using Chandra X-ray observations of two polytropic clusters, MS 1137.5+6625 and CL J1226.9+3332, and two cool core clusters, 1835 and A2204. We show that the model accurately describes the spatially resolved spectroscopic and imaging data, including the cluster core region where significant cooling of the plasma is observed.
PLATO'S FIRE AND THE NEUTRINO MASS MATRIX

With the accumulation of many years of solar and atmospheric neutrino oscillation data, the approximate form of the 3 × 3 neutrino mixing matrix is now known. The theoretical challenge is to understand where this mixing matrix comes from. Recently, a remarkable fact was discovered that for a specific pattern of the neutrino mass matrix at a high scale, any flavor-changing radiative correction will automatically lead to the desired mixing matrix. It was also discovered that the required specific pattern at the high scale can be maintained by the non-Abelian discrete symmetry A4 which is also the symmetry group of the regular tetrahedron, one of the five perfect geometric solids known to Plato who associated it with the element "fire". We discuss this recent development and add to it a new and very simple mechanism for the implementation of the flavor-changing radiative correction.
Laser chemical synthesis of clusters and ultrafine particles using organometallics

Gas-phase synthesis of clusters and ultrafine particles using lasers and organometallics is reviewed. The general field of laser chemistry is introduced in the context of using organometallics as reactants. Examples of particle and cluster synthesis in flowing gases and in bulk gases, and during laser chemical vapor deposition, are given. A brief introduction to the general field of random irreversible fractal coagulation provides a basis for describing how powders, clusters and ultrafine particles are synthesized. References to applications and characterization methods are given.
Is Farm Real Estate The Next Bubble

The recent increase in farmland prices leads many to conjecture that a price bubble exists. A dataset of Iowa farmland prices for three grades of quality over the last 60 years is examined to address the question whether the conditions for a rational expectations bubble are evident. An abnormal component in the change in farmland prices is found during the most recent sub-period of the sample. A novel valuation model that measures the speculative component of farmland value as a function of cash rents shows no speculative component is present. An additional test of the time series characteristics of the data provides no evidence of negative duration dependence. However, analysis of transition probabilities shows asymmetry exists most notably in the low quality farmland data series. Finally, time irreversibility is shown to be present at different lags for only the lowest farmland quality grade. Overall, the results imply that the low quality grade farmland is the most likely candidate to exhibit the conditions necessary to support a rational expectations bubble. In general, however, the data offer weak support of a bubble in farmland prices.
Rhodium(II) catalyzed intramolecular reactions between vinyldiazomethanes and pyrroles. Novel synthesis of fused 7-azabicyclo[4.2.0]octadienes

Abstract Intramolecular capture by pyrroles of vinylcarbenoids generated by rhodium(II) carboxylate catalyzed decomposition of vinyldiazomethanes results in the formation of fused 7-azabicyclo[4.2.0]octadienes or fused tropanes.
Studying transient mobility and energy loss using scanning tunneling microscopy

Abstract We show how scanning tunneling microscopy can be used to determine aspects of transient mobility in the adsorption process, in chemical reactions, and energy transfer processes at surfaces. For adsorption from the gas phase both the mean accommodation length and the promptness of energy loss can be elucidated using real space imaging.
PRIMORDIAL BLACK HOLES, HAWKING RADIATION AND THE EARLY UNIVERSE

The 511 keV gamma emission from the galactic core may originate from a high concentration (~ 1022) of primordial black holes (PBHs) in the core, each of whose Hawking radiation includes ~ 1021 positrons per second. The PBHs we consider are taken as near the lightest with longevity greater than the age of the universe (mass ~ 1012kg; Schwarzschild radius ~ 1 fm). These PBHs contribute only a small fraction of cold dark matter, ΩPBH ~ 10-8. This speculative hypothesis, if confirmed implies the simultaneous discovery of Hawking radiation and an early universe phase transition.
S and U-duality constraints on IIB S-matrices

Abstract S- and U-duality dictate that graviton scattering amplitudes in IIB superstring theory be automorphic functions on the appropriate fundamental domain which describe the inequivalent vacua of (compactified) theories. A constrained functional form of graviton scattering is proposed using Eisenstein series and their generalizations compatible with: (a) two-loop supergravity, (b) genus one superstring theory, (c) the perturbative coupling dependence of the superstring, and (d) with the unitarity structure of the massless modes. The form has a perturbative truncation in the genus expansion at a given order in the derivative expansion. Comparisons between graviton scattering S-matrices and effective actions for the first quantized superstring are made at the quantum level. Possible extended finiteness properties of maximally extended quantum supergravity theories in different dimensions is implied by the perturbative truncation of the functional form of graviton scattering in IIB superstring theory.
Robust autothermal microchannel reactors

Abstract Autothermal microchannel reactors are intensified process units that bring significant energy efficiency benefits over their conventional counterparts. Efficiency gains are obtained, however, at the cost of operational challenges. These stem from the loss of control handles that is inherent to combining several unit operations in a single physical device. In this paper, we investigate the impact of two recently proposed reactor design concepts (a segmented catalyst macromorphology and an embedded layer of phase change material) aimed at improving the steady state energy distribution and, respectively, preventing the advent of hotspots during transient operation, on reactor dynamics and control. Using an autothermal microchannel reactor coupling steam methane reforming with methane catalytic combustion as a prototype system, we demonstrate through rigorous simulations that these design innovations have a synergistic effect, resulting in superior steady-state performance and excellent disturbance rejection ability.
Anatomy of a State/Tribal Tax Dispute: Legal Formalism, Shifting Incidence, Potatoes, and the Idaho Motor Fuel Tax

ABSTRACT: The law regarding state taxation in Indian country is one of the last bastions of legal formalism in tax law jurisprudence. The ability of a state to tax in Indian country turns on the legal incidence of the tax: in general, a tax on the tribe or tribal members is not allowed; a tax on nonmembers doing business with the tribes or tribal members is allowed. In a world where legal formalism governs and there is no overarching mechanism for reconciling the competing interests of state and tribal governments, state/tribal tax disputes can quickly become contentious. A recent battle between the state of Idaho and the tribes within its borders over fuel tax revenue exemplifies the truculence of state/tribal tax disputes, but also shows that amicable resolution is possible when the courts take small steps away from legal formalism. This article provides an overview of the tax landscape in Indian country and then analyzes the dispute over the Idaho motor fuel tax and what it reveals about resolving stat...
ADAM: an adaptive beamforming system for multicasting in wireless LANs

We present the design and implementation of ADAM, the first adaptive beamforming-based multicast system and experimental framework for indoor wireless environments. ADAM addresses the joint problem of adaptive beamformer design at the PHY layer and client scheduling at the MAC layer by proposing efficient algorithms that are amenable to practical implementation. ADAM is implemented on a field programmable gate array (FPGA) platform, and its performance is compared against that of omnidirectional and switched beamforming based multicast. Our experimental results reveal that: 1) switched multicast beamforming has limited gains in indoor multipath environments, whose deficiencies can be effectively overcome by ADAM to yield an average gain of threefold; 2) the higher the dynamic range of the discrete transmission rates employed by the MAC hardware, the higher the gains in ADAM's performance, yielding up to ninefold improvement over omni with the 802.11 rate table; and 3) finally, ADAM's performance is susceptible to channel variations due to user mobility and infrequent channel information feedback. However, we show that training ADAM's signal-to-noise ratio (SNR)-rate mapping to incorporate feedback rate and coherence time significantly increases its robustness to channel dynamics.
On K3 Surfaces with Large Complex Structure

Abstract We discuss a notion of large complex structure for elliptic K3 surfaces with section inspired by the eight-dimensional F-theory/heterotic duality in string theory. This concept is naturally associated with the Type II Mumford partial compactification of the moduli space of periods for these structures. The paper provides an explicit Hodge-theoretic condition for the complex structure of an elliptic K3 surface with section to be large. We also establish certain geometric consequences of this large complex structure condition in terms of the Kodaira types of the singular fibers of the elliptic fibration.
Explanation-based auditing

To comply with emerging privacy laws and regulations, it has become common for applications like electronic health records systems (EHRs) to collect access logs, which record each time a user (e.g., a hospital employee) accesses a piece of sensitive data (e.g., a patient record). Using the access log, it is easy to answer simple queries (e.g., Who accessed Alice's medical record?), but this often does not provide enough information. In addition to learning who accessed their medical records, patients will likely want to understand why each access occurred.In this paper, we introduce the problem of generating explanations for individual records in an access log. The problem is motivated by user-centric auditing applications, and it also provides a novel approach to misuse detection. We develop a framework for modeling explanations which is based on a fundamental observation: For certain classes of databases, including EHRs, the reason for most data accesses can be inferred from data stored elsewhere in the database. For example, if Alice has an appointment with Dr. Dave, this information is stored in the database, and it explains why Dr. Dave looked at Alice's record. Large numbers of data accesses can be explained using general forms called explanation templates.Rather than requiring an administrator to manually specify explanation templates, we propose a set of algorithms for automatically discovering frequent templates from the database (i.e., those that explain a large number of accesses). We also propose techniques for inferring collaborative user groups, which can be used to enhance the quality of the discovered explanations. Finally, we have evaluated our proposed techniques using an access log and data from the University of Michigan Health System. Our results demonstrate that in practice we can provide explanations for over 94% of data accesses in the log.
On the value of the Curie temperature in doped manganites

Abstract We have verified that the variational mean field theory approach suggested by Narimanov and Varma (preprint cond-mat/0002191) being applied to the realistic two-band model provides a good agreement with experimental data for the Curie temperature in doped manganites A 1− x B x MnO 3 ( x ≃0.3). We have also considered the problem of an interplay between the ferromagnetic and antiferromagnetic interactions by using the same approach.
The Division of Labor, Coordination Costs, and Knowledge

This paper considers specialization and the division of labor. A more extensive division of labor raises productivity because returns to the time spent on tasks are usually greater to workers who concentrate on a narrower range of skills. The traditional discussion of the division of labor emphasizes the limitations to specialization imposed by the extent of the market. We claim that the degree of specialization is more often determined by other considerations. Especially emphasized are various costs of "coordinating" specialized workers who perform complementary tasks, and the amount of general knowledge available.
Anti-Markovnikov hydroamination and hydrothiolation of electron-deficient vinylarenes catalyzed by well-defined monomeric copper(I) amido and thiolate complexes

Monomeric Cu(I) amido and thiolate complexes that are supported by the N-heterocyclic carbene ligand 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) catalyze the hydroamination and hydrothiolation of electron-deficient vinylarenes with reactivity patterns that are consistent with an intermolecular nucleophilic addition of the amido/thiolate ligand of (IPr)Cu(XR) (X = NH or S; R = Ph, CH2Ph) to free vinylarene.
The theory and practice of bipartisan constitutional computer-aided redistricting

The theory behind bipartisan constitutional computer-aided redistricting essentially consists of three normative criteria which any systematic legislative redistricting scheme probably ought to seek to achieve. First, the redistricting system ought to be feasible such that it keeps computer time and other costs down to a minimum. Second, the system ought to provide legislative districts that will be approximately equal in population per representative so as to satisfy the Supreme Court's equality criterion, and the districts should be so shaped as to satisfy other legal requirements that relate to contiguity. Third, the system should consider the impact of the resulting districting on incumbents and on party balance so as to minimize the unhappiness which redistricting might otherwise produce for political leaders and for diverse political viewpoints.
GUT, neutrinos, and baryogenesis

Abstract It is an exciting time for flavor physics. In this talk, I discuss recent topics in baryogenesis and leptogenesis in light of new data, and implications in B and neutrino physics. I also discuss current situation of grand unified theories concerning coupling unification, proton decay, and indirect consequences in lepton flavor violation and B physics. I explain attempts to understand the origin of flavor based on flavor symmetry, in particular “anarchy” in neutrinos.