cssi/SciSciGPT-SciSciNet huggingface dataset:
Simple randomized mergesort on parallel disks

Abstract We consider the problem of sorting a file of N records on the D-disk model of parallel I/O in which there are two sources of parallelism. Records are transferred to and from disk concurrently in blocks of B contiguous records. In each I/O operation, up to one block can be transferred to or from each of the D-disks in parallel. We propose a simple, efficient, randomized mergesort algorithm called SRM that uses a forecast-and-flush approach to overcome the inherent difficulties of simple merging on parallel disks. SRM exhibits a limited use of randomization and also has a useful deterministic version. Generalizing the technique of forecasting, our algorithm is able to read in, at any time, the ‘right’ block from any disk and using the technique of flushing, our algorithm evicts, without any I/O overhead, just the ‘right’ blocks from memory to make space for new ones to be read in. The disk layout of SRM is such that it enjoys perfect write parallelism, avoiding fundamental inefficiencies of previous mergesort algorithms. By analysis of generalized maximum occupancy problems we are able to derive an analytical upper bound on SRM's expected overhead valid for arbitrary inputs. The upper bound derived on expected I/O performance of SRM indicates that SRM is provably better than disk-striped mergesort (DSM) for realistic parameter values D, M and B. Average-case simulations show further improvement on the analytical upper bound. Unlike previously proposed optimal sorting algorithms, SRM outper-forms DSM even when the number D of parallel disks is small.
Spectral and Electrochemical Investigations on the "Tail-On" and "Tail-Off" Mechanism in Pyridine Covalently Bound Zinc(II) Porphyrins.

(Tetraphenylporphyrinato)zinc(II) covalently linked with pyridine at the ortho position of one of the four phenyl rings exists as a stable pentacoordinated complex while a temperature dependent “tail-on” and “tail-off” binding mechanism is operative for the meta-substituted derivative. The axially bound pyridine does not participate in secondary chemical reactions during the electrochemical oxidation of the ortho derivative while for the meta derivative, additional chemical reactions occur between the zinc(II) porphyrin dication and the appended pyridyl entity leading to the formation of a pyrrole β-substituted isoporphyrin.
Spin dependence of D0-brane interactions

Abstract The long-range, spin-dependent forces between D0-branes are related to long-range fundamental string interactions using duality. These interactions can then be computed by taking the long distance non-relativistic expansion of string four-point amplitudes. The results are in accord with the general constraints of Matrix Theory.
Dynamic control schemes for a packet switched multi-access broadcast channel

Domestic satellites are emerging as an exciting alternative to satisfying the communications requirements of data users, providing both flexibility and economy. Two attributes of satellites are especially advantageous for the transmission of data in large geographically distributed computer networks. They are (i) the availability of wide transmission bandwidths over long distances and (ii) the multi-access broadcast capability inherent in radio communications which permits transmission to, and reception from, all points in a satellite connected network. These considerations also apply (on a smaller geographical scale) to the use of ground radio channels in a terminal access computer-communication network exemplified by the ALOHA System at the University of Hawaii.
A Tool to Integrate Design for Assembly During Product Platform Design

To survive in the current market, many companies are moving toward design and development of product families using a platform approach. To effectively develop a family of products, companies have to consider both component and assembly perspectives. The assembly perspective has many issues associated with it for developing common platforms, which includes assemblability evaluation for the entire family. Application of Design for Assembly techniques to evaluate product family will require modifications to the current single product DFA method. In this paper a product family DFA tool and guidelines are presented. The application of this product family DFA tool is illustrated using Walkman® and Coffeemaker product family.Copyright © 2008 by ASME
Photovoltaic module performance and durability following long‐term field exposure

Our investigations of both new and field-aged photovoltaic modules have indicated that, in general, today's commercially available modules area highly reliable product. However, by using new test procedures, subtle failure mechanisms have also been identified that must be addressed in order to achieve 30-year module lifetimes. This paper summarizes diagnostic test procedures, results, and implications of in-depth investigations of the performance and durability characteristics of commercial modules after long-term field exposure. A collaborative effort with U.S. module manufacturers aimed at achieving 30-year module lifetimes is also described.
Dinitrogen functionalization with bis(cyclopentadienyl) complexes of zirconium and hafnium.

The rich chemistry of substituted bis(cyclopentadienyl)zirconium and hafnium complexes bearing side-on coordinated dinitrogen ligands is highlighted in this Perspective. Our studies in this area were initially motivated by the desire to understand side-on vs. end-on dinitrogen coordination in bimetallic zirconocene and hafnocene N2 compounds. In the cases where η2,η2-dinitrogen compounds were isolated, both structural and computational data have established significant imido character in the metal–nitrogen bonds. This additional bonding interaction, which is diminished in end-on complexes bearing both terminal and bridging N2 ligands, facilitates dinitrogen functionalization by non-polar reagents including dihydrogen, carbon–hydrogen bonds and weak Bronsted acids such as water and ethanol. In hafnocene chemistry, where unwanted side-on, end-on isomerization is suppressed, cycloaddition of phenylisocyanate to coordinated N2 has also been accomplished. For N–H bond forming reactions involving H2, kinetic measurements, in addition to isotopic labelling and computational studies, are consistent with dinitrogen functionalization by 1,2-addition involving a highly ordered, four-centred transition structure.
Transport properties of small polarons

Abstract A qualitative discussion of the essentials of small-polaron motion is presented. After a very brief description of the notion of a small polaron and the situation under which it is formed, the principal physical features and predictions of the theory of small-polaron transport is addressed. Specifically, small-polaron band and hopping motion are both initially considered with the discussion thereafter being restricted to hopping motion. First quantum-mechanical treatments of small-polaron hopping motion are considered. Then the semiclassical approach to the calculation of the high-temperature (κT ≳ħωDebye) adiabatic and nonadiabatic jump rate is described with the question of correlated hopping motion also being addressed. After this, the high-frequency absorption associated with small-polaron motion is considered. Finally, a review of the Hall-mobility calculations and some comments about the thermoelectric power are presented.
Efficacy of Nonsurgical Therapy for Urinary Incontinence

OBJECTIVE : To assess the efficacy of aggressive nonsurgical therapy for urinary incontinence in women and to determine if it is advantageous to perform invasive urodynamic testing prior to initiating treatment. STUDY DESIGN : We subjectively assessed 202 incontinent women three months to four years following nonsurgical therapy for urinary incontinence. Therapy in all patients included behavioral modification in the form of timed voiding and pelvic floor exercises. Depending on the suspected diagnosis and menopausal state, patients were also treated with various combinations of pharmacologic agents and estrogen replacement therapy. Based on initial evaluation, patient preference and referring physician preference, 100 women were started on therapy after a minimal evaluation, while 102 women were treated based on invasive urodynamic testing. A subjective assessment of treatment outcome was made via a telephone interview in which patients were asked standardized questions. RESULTS : One hundred nineteen cases (59%) were subjectively improved or cured with nonsurgical therapy. Performing urodynamic testing prior to initiating therapy did not increase the overall success rate : 69 of 100 patients (69%) treated on the basis of history, physical examination and a minimal office evaluation were improved or cured, while only 50 of 102 patients (49%) having electronic multichannel urodynamic testing were improved or cured. CONCLUSION : All women with urinary incontinence should be initially offered nonsurgical therapy since a large percentage will obtain satisfactory results. It is not beneficial or cost-effective to perform electronic urodynamic testing prior to initiating therapy.
Testing the no-hair theorem with observations of black holes in the electromagnetic spectrum

Abstract According to the no-hair theorem, astrophysical black holes are uniquely described by their mass and spin. In this paper, we review a new framework for testing the no-hair hypothesis with observations in the electromagnetic spectrum. The approach is formulated in terms of a Kerr-like spacetime containing a quadrupole moment that is independent of both mass and spin. If the no-hair theorem is correct, then any deviation from the Kerr metric quadrupole has to be zero. We show how upcoming VLBI imaging observations of Sgr A∗ as well as spectroscopic observations of iron lines from accreting black holes with IXO may lead to the first astrophysical test of the no-hair theorem.
The Operator Gap

This paper continues investigations pertaining to recursive bounds on computing resources (such as time or memory) and the amount by which these bounds must be increased if new computations are to occur within the new bound. The paper proves that no recursive operator can increase every recursive bound enough to reach new computations. In other words, given any general recursive operator F[], there is an arbitrarily large recursive t() such that between bound t() and bound F[t()]() there is a gap in which no new computation runs. This demonstrates that the gap phenomenon first discovered by Borodin for composition is a deeply intrinsic property of computational complexity measures. Moreover, the Operator Gap Theorem proved here is shown to be the strongest possible gap theorem for general recursive operators. The proof involves a priority argument but is sufficiently self-contained that it can easily be read by a wide audience. The paper also discusses interesting connections between the Operator Gap Theorem and McCreight & Meyer''s important result that every complexity class can be named by a function from a measured set.
Análisis cualitativo de un modelo de pesquerías de acceso abierto

Un analisis cualitativo de un modelo bioeconomico de pesqueria de una sola especie es desarrollado usando una funcion de captura mas realista que la usada en la hipotesis de Schaefer. Se discute la existencia de bifurcaciones en los puntos de equilibrio y su estabilidad. Se comenta el comportamiento de este modelo de pesqueria de acceso abierto bajo el cambio de los parametros. Una variedad de situaciones tanto biologicas como economicas son discutidas considerando el equilibrio bioeconomico y niveles de extincion, agotamiento del recurso, como tambien la autorregulacion de la pesqueria. Se presentan diversas curvas del espacio de fase del sistema usando el programa PHASER.
Deposit Liquidity and Bank Monitoring

Abstract Why do banks fund loans embodying considerable borrower-specific information with liquid deposits? I address this question by examining the disciplinary effect of liquid deposits in a framework where banks' production of nontransferable borrower information is explicitly considered. I show that deposit liquidity motivates banks to provide greater monitoring of their loan applicants despite the general lack of observability of bank monitoring and bank loan quality. The analysis provides an important link between the two activities in which banks are viewed as “special”—their liquidity provision through demand deposits and their lending to information-intensive borrowers.Journal of Economic LiteratureClassification Numbers: G21, G28.
Searching for Planets in the Hyades. IV. Differential Abundance Analysis of Hyades Dwarfs

We present a differential abundance analysis of Hyades F–K dwarfs in search for evidence of stellar enrichment from accreted hydrogen-deficient disk material. Metallicities and relative abundance ratios of several species have been determined. We derive a cluster mean [Fe/H] = 0.13 ± 0.01. Two stars show abundances ~0.2 dex larger than the cluster mean. In addition, one star, which was added by a recent study as a cluster member, shows significantly lower abundances than the cluster mean. These three stars have questionable membership characteristics. The remaining stars in the survey have an rms of 0.04 dex in the differential [Fe/H] values. The Hyades cluster members have apparently not been significantly chemically enriched. The abundance ratios of Si, Ti, Na, Mg, Ca, and Zn with respect to Fe are in their solar proportions.
Walking technicolor and electroweak radiative corrections

Abstract We examine the effect of walking technicolor dynamics on the electroweak S -parameter and contrast it with the effect of QCD-like technicolor dynamics. Our main tools are the operator product expansion for the high-momentum behavior of the electroweak gauge boson vacuum polarizations and the analyticity of these polarizations which relate their low and high momentum behaviors. We show that whereas in large QCD-like technicolor models S is large and positive, in walking technicolor models a negative contribution is emphasized, related to the large anomalous dimension of the technifermion condensate. Thus in walking technicolor S is determined by a large cancellation of two competing effects. This may result in much smaller values of S than in QCD-like technicolor, although considerable uncertainties are involved. We conclude that it is impossible to rule out walking technicolor based on the present experimental limits on S and the present theoretical technology.
Supervised training of neural networks via ellipsoid algorithms

In this paper we show that two ellipsoid algorithms can be used to train single-layer neural networks with general staircase nonlinearities. The ellipsoid algorithms have several advantages over other conventional training approaches including (1) explicit convergence results and automatic determination of linear separability, (2) an elimination of problems with picking initial values for the weights, (3) guarantees that the trained weights are in some "acceptable region," (4) certain "robustness" characteristics, and (5) a training approach for neural networks with a wider variety of activation functions. We illustrate the training approach by training the MAJ function and then by showing how to train a controller for a reaction chamber temperature control problem.
Waveform Design for Secure SISO Transmissions and Multicasting

Wireless physical-layer security is an emerging field of research aiming at preventing eavesdropping in an open wireless medium. In this paper, we propose a novel waveform design approach to minimize the likelihood that a message transmitted between trusted single-antenna nodes is intercepted by an eavesdropper. In particular, with knowledge first of the eavesdropper's channel state information (CSI), we find the optimum waveform and transmit energy that minimize the signal-to-interference-plus-noise ratio (SINR) at the output of the eavesdropper's maximum-SINR linear filter, while at the same time provide the intended receiver with a required pre-specified SINR at the output of its own max-SINR filter. Next, if prior knowledge of the eavesdropper's CSI is unavailable, we design a waveform that maximizes the amount of energy available for generating disturbance to eavesdroppers, termed artificial noise (AN), while the SINR of the intended receiver is maintained at the pre-specified level. The extensions of the secure waveform design problem to multiple intended receivers are also investigated and semidefinite relaxation (SDR) -an approximation technique based on convex optimization- is utilized to solve the arising NP-hard design problems. Extensive simulation studies confirm our analytical performance predictions and illustrate the benefits of the designed waveforms on securing single-input single-output (SISO) transmissions and multicasting.
Fluoromethanol: Synthesis, microwave spectrum, and dipole moment

Abstract The microwave spectrum of the new molecular species CH2FOH has been observed and analyzed. The molecule exhibits a gauche conformation which is in accord with previous ab initio calculations. This is also the conformation that is predicted based on anomeric effect arguments. The rotational transitions are split by the tunneling of the molecule between equivalent gauche conformations. A simultaneous fit of both tunneling states allows the determination of perturbation free rotational parameters as well as the tunneling frequency and a tunneling distortion parameter. A dipole moment analysis yields values of all three dipole moment components and the μbμc term which indicates that μb and μc have opposite signs.
ASTROPHYSICAL CONSTRAINTS ON LARGE EXTRA DIMENSIONS

In the Kaluza-Klein (KK) scenario with n large extra dimensions where gravity propagates in the 4+n dimensional bulk of spacetime while gauge and matter fields are confined to a four dimensional subspace, the light graviton KK modes can be produced in the Sun, red giants and supernovae. We study the energy-loss rates through photon-photon annihilation, electron-positron annihilation, gravi-Compton-Primakoff scattering, gravi-bremsstrahlung and nucleon-nucleon bremsstrahlung, and derive lower limits to the string scale MS. The most stringent lower limit obtained from SN1987A leads to MS>30–130 TeV (2.1–9.3 TeV) for the case of two (three) large extra dimensions.
Determinants of Disclosure Noncompliance and the Effect of the SEC Review: Evidence from the 2006 Mandated Compensation Disclosure Regulations

ABSTRACT We investigate the economic forces that influence noncompliance with mandatory compensation disclosures and the effect of a subsequent focused enforcement action. We utilize SEC evaluations of compensation disclosures mandated by rules adopted in 2006 to examine whether noncompliance is associated with excess CEO compensation, proprietary costs, or previous media attention. We further test whether subsequent CEO compensation declines after the SEC publicly identifies noncompliance. We construct measures of defective disclosures from SEC critiques and find that disclosure defects are positively associated with excess CEO compensation and media criticism of CEO compensation during the previous year. We find no evidence supporting the contention that compensation disclosure defects are associated with proprietary costs. Furthermore, we are unable to document that the level of disclosure defects identified by the SEC is associated with a reduction in excess CEO compensation in the subsequent year. Da...
Scaling of cross sections for K-electron capture by high-energy protons and alpha-particles from the multielectron atoms

Electron capture by protons from H, He, and the K shell of Ar, and electron capture by alpha particles from He are considered. Using the experimental data, a function of the capture cross section is formed. It is shown that when this function is plotted versus the inverse of the collision energies, at high energies a straight line is obtained. At lower energies the line is concave up or down, depending on the charge of the projectile and/or the effective charge and the ionization potential of the electron that is being captured. The plot can be used to predict cross sections where experimental data are not available, and as a guide in future experiments. High-energy scaling formulas for K-electron capture by low-charge projectiles are given.
MIGRATION OF SMALL MOONS IN SATURN's RINGS

The motions of small moons through Saturn's rings provide excellent tests of radial migration models. In theory, torque exchange between these moons and ring particles leads to radial drift. We predict that moons with Hill radii r {sub H} {approx} 2-24 km should migrate through the A ring in 1000 yr. In this size range, moons orbiting in an empty gap or in a full ring eventually migrate at the same rate. Smaller moons or moonlets-such as the propellers-are trapped by diffusion of disk material into corotating orbits, creating inertial drag. Larger moons-such as Pan or Atlas-do not migrate because of their own inertia. Fast migration of 2-24 km moons should eliminate intermediate-size bodies from the A ring and may be responsible for the observed large-radius cutoff of r {sub H} {approx} 1-2 km in the size distribution of the A ring's propeller moonlets. Although the presence of Daphnis (r {sub H} Almost-Equal-To 5 km) inside the Keeler gap challenges this scenario, numerical simulations demonstrate that orbital resonances and stirring by distant, larger moons (e.g., Mimas) may be important factors. For Daphnis, stirring by distant moons seems the most promising mechanism to halt fast migration. Alternatively, Daphnis may be amore » recent addition to the ring that is settling into a low inclination orbit in {approx}10{sup 3} yr prior to a phase of rapid migration. We provide predictions of observational constraints required to discriminate among possible scenarios for Daphnis.« less
Multifrequency HF radar observations of currents and current shears

Techniques have been developed for using high-frequency (HF) surface-wave radar to measure ocean currents and vertical current shears in the upper 1 or 2 m of the ocean surface. An HF radar can precisely measure the phase velocity and direction of propagation of ocean waves whose wavelength is one.half the radar wavelength. In the absence of a current, the speed of the waves is given by the still-water dispersion relation. An underlying current will modify this speed. The radar measures the actual phase velocity through a Doppler shift, and the wavelength of the ocean wave is known through the first-order Bragg scattering relation, so a difference between observed and theoretical stillwater phase velocity can be calculated. In addition, longer ocean waves are affected by currents at deeper depths than are shorter ocean waves. By measuring the phase velocity at several different wavelengths, it is possible to measure a vertical current shear in the top 1 or 2 m of the ocean surface. This is a measurement that is very difficult to make by any other means. A portable coherent pulsed-Doppler HF radar system was developed at Stanford and used in several experiments, both on land on the California coast and on board a ship during the Joint Air-Sca Interaction (JASIN) experiment. The land-based experiments demonstrated that a current could be measured by an HF radar, and that its value agreed well with that measured by in-situ drifting spar buoys. In addition, there was evidence of a vertical current shear, both from the radar measurements and from the buoy measurements. The JASIN experiment was an attempt to apply these techniques to the measurement of surface current and current shear in the open ocean. The radar system was installed on board a ship, along with a receiving antenna consisting of a steerable phased array of eight wide-band loops. The steerable antenna was quite rugged and performed as expected. It produced antenna patterns consistent with the physical aperture of the array. The wind velocity during the JASIN experiment was quite low, so wind- and wave-generated currents were quite small. Nevertheless, there is some evidence of a current shear. Its magnitude is small and near the resolution limit of the radar, but it appears to be somewhat higher than estimates based on either the wind or wave conditions alone, but less than the estimates based on the sum of the two components.
Tobacco industry use of judicial seminars to influence rulings in products liability litigation

Objectives: This paper examines the tobacco industry’s efforts to influence litigation by sponsoring judicial seminars. Methods: Thousands of internal tobacco documents were examined, including memos, reports, presentations, and newsletters. Connections to outside organisations were corroborated by examining tobacco industry financial records, budgets, and letters pledging funds. Facts about outside organisations were triangulated through examining their websites and publicly-filed financial records, and verifying facts through their representatives’ statements in newspaper and law review articles. Results: There are direct financial ties between the tobacco industry and groups that organise judicial seminars in an effort to influence jurisprudence, and judges who attend these seminars may be breaching judicial ethics either by not inquiring about the source of funding or by ignoring funding by potential litigants. Conclusions: The tobacco industry’s attempts to clandestinely influence judges’ decisions in cases to which they are a party endangers the integrity of the judiciary.
Atomic and Molecular Opacities for Brown Dwarf and Giant Planet Atmospheres

We present a comprehensive description of the theory and practice of opacity calculations from the infrared to the ultraviolet needed to generate models of the atmospheres of brown dwarfs and extrasolar giant planets. Methods for using existing line lists and spectroscopic databases in disparate formats are presented, and plots of the resulting absorptive opacities versus wavelength for the most important molecules and atoms at representative temperature/pressure points are provided. Electronic, rovibrational, bound-free, bound-bound, free-free, and collision-induced transitions and monochromatic opacities are derived, discussed, and analyzed. The species addressed include the alkali metals, iron, heavy metal oxides, metal hydrides, H2, H2O, CH4, CO, NH3, H2S, PH3, and representative grains. Once monochromatic absorption cross sections for all constituents have been derived, chemical abundances have to be obtained before the resulting product can be summed to obtain total opacities. Hence, we include a review of the thermochemistry, techniques, and databases needed to derive equilibrium abundances and provide some sample results.
Baryons as Solitons in Three-Dimensional Quantum Chromodynamics

We show that baryons of three-dimensional quantum chromodynamics can be understood as solitons of its effective Lagrangian. In the parity-preserving phase we study, these baryons are fermions for odd Nc and bosons for even Nc, never anyons. We quantize the collective variables of the solitons and thereby calculate the flavor quantum numbers. magnetic moments and mass splittings of the baryon. The flavor quantum numbers are in agreement with naive quark model for the low-lying states. The magnetic moments and mass splittings are smaller in the soliton model by a factor of logFπ/Ncmπ. We also show that there is a dibaryon solution that is an analog of the deuteron. These solitons can describe defects in a quantum antiferromagnet.
An ultracool Star's Candidate Planet

We report here the discovery of the first planet around an ultracool dwarf star. It is also the first extrasolar giant planet astrometrically discovered around a main-sequence star. The statistical significance of the detection is shown in two ways. First, there is a 2 × 10–8 probability that the astrometric motion fits a parallax-and-proper-motion-only model. Second, periodogram analysis shows a false alarm probability of 3 × 10–5 that the discovered period is randomly generated. The planetary mass is M 2 = 6.4 (+2.6,–3.1) Jupiter-masses (M J), and the orbital period is P = 0.744 (+0.013,–0.008) yr in the most likely model. In less likely models, companion masses that are higher than the 13 M J planetary mass limit are ruled out by past radial velocity (RV) measurements unless the system RV is more than twice the current upper limits and the near-periastron orbital phase was never observed. This new planetary system is remarkable, in part, because its star, VB 10, is near the lower mass limit for a star. Our astrometric observations provide a dynamical mass measurement and will in time allow us to confront the theoretical models of formation and evolution of such systems and their members. We thus add to the diversity of planetary systems and to the small number of known M-dwarf planets. Planets such as VB 10b could be the most numerous type of planets because M stars comprise >70% of all stars. To date they have remained hidden since the dominant RV planet-discovery technique is relatively insensitive to these dim, red systems.
Bismuth(III) oxide perchlorate promoted rearrangement of epoxides to aldehydes and ketones

Abstract Aryl-substituted epoxides and aliphatic epoxides with a tertiary epoxide carbon undergo smooth rearrangement in the presence of 10–50 mol% bismuth(III) oxide perchlorate, BiOClO 4 ·×H 2 O, to give carbonyl compounds. The rearrangement is regioselective with aryl substituted epoxides and a single carbonyl compound arising from cleavage of benzylic C–O bond is formed. BiOClO 4 ·×H 2 O is relatively non-toxic, insensitive to air and inexpensive, making this catalyst an attractive alternative to more corrosive and toxic Lewis acids such as BF 3 ·Et 2 O or InCl 3 currently used to effect epoxide rearrangements.
The Ethical Implications of Using Genetic Information in Personnel Selection

Biology, during the last decade in particular, is making substantial headway into our social theories of business and behavior. While the social sciences rush to keep up with the advancement of knowledge, we highlight the need for an ethics discussion to also keep pace. Although the implications to theory are important, our focus is on how new knowledge has the capacity to alter the formulation and practice of business policy, which we believe is potentially profound. Furthermore, the ethicality of a set of issues can depend heavily on one’s perspective, and differing views may not always be compatible. With this in mind, we discuss the ways in which one area of emerging biological knowledge—behavioral genetics—invites a rethinking of the nuances of four long-standing topic areas of business ethics surrounding personnel selection; and we do so from two perspectives—that of the employer and of the job seeker. The four ethical topics are (a) the static (mostly) nature of genetic information that is out of a...
List-Barbas-Mannich reaction catalyzed by modularly designed organocatalysts.

The List–Barbas–Mannich reaction of ethyl (p-methoxyphenylimino)acetate (p-methoxyphenyl = PMP) with unmodified aldehydes or ketones catalyzed by modularly designed organocatalysts (MDOs) that are self-assembled from proline and cinchona alkaloid thioureas (such as a quinidine-derived thiourea) produces the corresponding γ-oxo-α-amino acid derivatives in high yields and excellent stereoselectivities. No solvent is necessary for this reaction. Aldehydes are especially good substrates for this reaction: The reaction takes only a few minutes to yield the corresponding List–Barbas–Mannich products in excellent dr (up to >99:1) and ee values (up to >99% ee).
Choose-your-own-adventure routing: Lightweight load-time defect avoidance

Aggressive scaling increases the number of devices we can integrate per square millimeter but makes it increasingly difficult to guarantee that each device fabricated has the intended operational characteristics. Without careful mitigation, component yield rates will fall, potentially negating the economic benefits of scaling. The fine-grained reconfigurability inherent in FPGAs is a powerful tool that can allow us to drop the stringent requirement that every device be fabricated perfectly in order for a component to be useful. To exploit inherent FPGA reconfigurability while avoiding full CAD mapping, we propose lightweight techniques compatible with the current single bitstream model that can avoid defective devices, reducing yield loss at high defect rates. In particular, by embedding testing operations and alternative path configurations into the bitstream, each FPGA can avoid defects by making only simple, greedy decisions at bitstream load time. With 20p additional tracks above the minimum routable channel width, routes can tolerate 0.01p switch and wire defect rates, raising yield from essentially 0p to near 100p.
Brownian Motion in a Weyl Chamber, Non-Colliding Particles, and Random Matrices

Abstract Let n particles move in standard Brownian motion in one dimension, with the process terminating if two particles collide. This is a specific case of Brownian motion constrained to stay inside a Weyl chamber; the Weyl group for this chamber is An−1, the symmetric group. For any starting positions, we compute a determinant formula for the density function for the particles to be at specified positions at time t without having collided by time t. We show that the probability that there will be no collision up to time t is asymptotic to a constant multiple of t −n(n−1) 4 as t goes to infinity, and compute the constant as a polynomial of the starting positions. We have analogous results for the other classical Weyl groups; for example, the hyperoctahedral group Bn gives a model of n independent particles with a wall at x = 0. We can define Brownian motion on a semisimple Lie algebra, viewing it as a vector space with the Killing form. Since the Killing form is invariant under the adjoint, the motion induces a process in the Weyl chamber of the Lie algebra, giving a Brownian motion conditioned never to exit the chamber. If there are m roots in n dimensions, this shows that the radial part of the conditioned process is the same as the n + 2m-dimensional Bessel process. The conditioned process also gives physical models, generalizing Dyson's model for An−1 corresponding to un of n particles moving in a diffusion with a repelling force between two particles proportional to the inverse of the distance between them.
THE INTERSTELLAR BUBBLES OF G38.9–0.4 AND THE IMPACT OF STELLAR FEEDBACK ON STAR FORMATION

We present a study of the star formation (SF) region G38.9–0.4 using publicly available multiwavelength Galactic plane surveys from ground- and space-based observatories. This region is composed of four bright mid-IR bubbles and numerous infrared dark clouds. Two bubbles, N 74 and N 75, each host a star cluster anchored by a single O9.5V star. We identified 162 young stellar objects (YSOs) and classify 54 as stage I, 7 as stage II, 6 as stage III, and 32 as ambiguous. We do not detect the classical signposts of triggered SF, i.e., star-forming pillars or YSOs embedded within bubble rims. We conclude that feedback-triggered SF has not occurred in G38.9–0.4. The YSOs are preferentially coincident with infrared dark clouds. This leads to a strong correlation between areal YSO mass surface density and gas mass surface density with a power law slope near 1.3, which closely matches the Schmidt-Kennicutt Law. The correlation is similar inside and outside the bubbles and may mean that the SF efficiency is neither enhanced nor suppressed in regions potentially influenced by stellar feedback. This suggests that gas density, regardless of how it is collected, is a more important driver of SF than stellar feedback. Larger studies should be able to quantify the fraction of all SF that is feedback-triggered by determining the fraction SF, feedback-compressed gas surrounding H II regions relative to that already present in molecular clouds.
Goodwill Impairment Charges and Analyst Forecast Properties

SYNOPSIS: We examine the association between goodwill impairment charges and analysts' forecast accuracy and dispersion. We compare a test sample of firm-quarters with reported goodwill impairment charges during 2003–2007, and two control samples (matched on propensity scores and performance) of firm-quarters that do not report impairment charges. We find that analysts' forecasts are less accurate and more dispersed for the impairment sample than for the control samples. The magnitude of impairment charges is also negatively associated with forecast accuracy and positively associated with forecast dispersion. However, two forms of monitoring, auditor industry specialization and institutional ownership, reduce the adverse effect of goodwill impairments on analyst forecast dispersion. JEL Classifications: G14; M41; M44
Design and functionality of colloidal-crystal-templated materials—chemical applications of inverse opals

Templating with colloidal crystals composed of monodisperse spheres is a convenient chemical method to obtain porous materials with well-ordered periodicity and interconnected pore systems. The three-dimensionally ordered macroporous (3DOM) products or inverse opals are of interest for numerous applications, both for the optical properties related to structural color of these photonic crystal materials and because of their bicontinuous nanostructure, i.e., a continuous nanostructured skeleton with large interfacial area and a three-dimensionally interconnected pore system with low tortuosity. This review outlines various synthetic methods used to control the morphology of 3DOM materials with different compositions. It highlights aspects of the choice of colloidal particles, assembly of the colloidal crystal template, infiltration and processing, template removal, and other necessary modifications to enhance the functionality of the materials. It also considers syntheses within the confinement of 3DOM materials and summarizes characterization methods that are particularly useful in the analysis of 3DOM materials. The review then discusses chemical applications of 3DOM materials, namely sorption and controlled release, optical and electrochemical sensors, solar cells, lithium ion batteries, supercapacitors, fuel cells, and environmental and chemical fuel catalysis. A focus is on structural features and materials properties that enable these applications.
Assessment of Two- and Three-Scale k–ε Models for Rotating Cavity Flows

A three-scale {kappa}-{epsilon} turbulence model was recently developed for complex flows such as the rotor-rotor and rotor-stator cavities found in gas turbine engines. The three-scale model is a logical extension of the previous two-scale {kappa}-{epsilon} model of Ko and Rhode (1990). Both multiscale turbulence models are presented and assessed via comparison with measurements for possible adoption in future cavity computations. A single computer code solving the two-dimensional axisymmetric Navier-Stokes equations with a switch for selecting among the various turbulence models being compared was used. It was found for both cavity cases that the three-scale model gives a marginal improvement over the two-scale model. Further, both multiscale models give a substantial improvement over the standard {kappa}-{epsilon} model for the rotor-stator case, especially in the near-wall region where different eddy sizes are found. However, the feasibility of using a multiscale model for the rotor-rotor case is unclear since it gives improved values over the standard high-Re model in some regions but worse values in other regions. In addition, the solutions provide enhanced insight concerning the large changes in flow pattern previously photographed in the rotor-rotor case as rotation increases. In particular, it is shown how: (a) the number of recirculation zones increasemore » with increasing rotation rate and (b) the recirculation zones decrease in size with a decreasing G ratio.« less
Multi-lepton signals from the top-prime quark at the LHC

We analyze the collider signatures of models with a vector-like top-prime quark and a massive color-octet boson. The top-prime quark mixes with the top quark in the Standard Model, leading to richer final states than ones that are investigated by experimental collaborations. We discuss the multi-lepton final states, and show that they can provide increased sensitivity to models with a top-prime quark and gluon-prime. Searches for new physics in high multiplicity events are an important component of the LHC program and complementary to analyses that have been performed.
How Auctions Work for Wine and Art

interview auctioneers, and even to buy a little wine.' In the meantime I have also had the opportunity (with John Abowd, 1988) to observe and collect data on the auction sale of impressionist and contemporary paintings. This paper reports on some of the empirical regularities that I and others have observed in the actual operation of the auction markets for these items. In view of the rich and diverse array of theoretical literature on auctions it seems high time economists began to spell out precisely what facts it is meant to explain.2
Optimized readout system for cooled optically stimulated luminescence

Abstract Cooled optically stimulated luminescence (COSL) in CaF2:Mn is an ionizing radiation dosimetry method recently developed at Pacific Northwest Laboratory (1,2,3,4). The new method is thought to be an example of a highly sensitive phototransfer technique that could form the basis for future radiation dosimetry applications. Measurements to date have shown high potential for measuring gamma exposures as low as 10 μR. Along with the potential for a system that is more sensitive than thermoluminescent (TL) dosimetry, multiple COSL readouts may be possible with minimal reduction of the COSL intensity. The multiple readout capability can serve as a possible permanent dosimetry record, thus allowing a questionable reading to be re-analyzed. A new readout system is being developed in an attempt to optimize the sensitivity and to improve the reproducibility of the COSL method. This paper presents details of the new readout system, the COSL process, and recent data obtained with an older manual system.
From molecular dynamics to coarse self-similar solutions: a simple example using equation-free computation

Abstract In the context of the recently developed “equation-free” approach to the computer-assisted analysis of complex systems, we illustrate the computation of coarsely self-similar solutions. Dynamic renormalization and fixed point algorithms for the macroscopic density dynamics are applied to the results of short bursts of appropriately initialized molecular dynamics in a simple diffusion simulation. The approach holds promise for locating coarse self-similar solutions and the corresponding exponents in a variety of multiscale computational contexts.
Synthesis and Enhanced Intercalation Properties of Nanostructured Vanadium Oxides

Nanomaterials lie at the heart of the fundamental advances in efficient energy storage/conversion and other types of nanodevices in which the surface process and transport kinetics play determining roles. This review describes some recent developments in the synthesis and characterizations of various vanadium oxide nanostructures including nanowires, nanorolls, nanobelts, and ordered arrays of nanorods, nanotubes, and nanocables for significantly enhanced intercalation properties. The major topic of this article is to highlight the lithium ion intercalation properties of nanostructured vanadium oxides for energy storage as well as other applications in sensors, actuators, and transistors.
Examples of Unsteady Combustion in Non-Metallized Propellants

For over thirty years the T-Burner has been the de facto standard for determining the unstable response of solid propellants. This paper reviews some of the different approaches that have been used, and briefly summarizes advantages and disadvantages of the different techniques. Data from a variety of sources have been reviewed and summarized showing the effect of various test conditions and propellant formulation variations. Much of the data taken in the 60's and early 70's were with so-called research propellants, with relatively low solids loading and usually monomodal AP as the oxidizer. Later data were obtained with propellants containing solids loading more typical and practical propellants. Several distinct differences were observed in the data for the different types of propellants. Data varying AP particle size distributions indicate that either additional fine AP or finer AP usually increases the propellant response. A significant reduction in the response can be achieved by reducing the amount of fine AP, while holding burning rate constant either by adding a catalyst or by varying the overall AP size distribution. A significant amount of data has been obtained for reduced smoke propellants containing stability additives. The data indicate that the additives provide significant particle damping, and most often, also reduce the propellant response. Data from double base propellants indicate a much broader response over a wide frequency range. This implies that double base propellants should be more unstable in tangential modes than composite propellants. This trend seems to be consistent with observed motor data. Measuring the response of metallized propellants has been a challenge due to the large damping due to metal oxide particles in the gas. Data from metallized propellants are not presented here, but will be summarized in a future paper.
The Main Injector Particle Physics Experiment (MIPP FNAL E-907) at Fermilab – status and plans

We describe the status of the Main Injector particle production Experiment (MIPP) at Fermilab which has to date acquired 18 million events of particle interactions using ( 5 GeV / c – 120 GeV / c ) π ± , K ± and p ± beams on various targets. We describe plans to upgrade the data acquisition speed of MIPP to make it run 100 times faster which will enable us to obtain particle production data of unprecdented quality and statistics on a wide variety of nuclear targets including nitrogen which is of importance to cosmic ray physics.
Fitting hyperbolic pants to a three-body problem

Consider the three-body problem with an attractive 1/r2 potential. Modulo symmetries, the dynamics of the bounded zero-angular-momentum solutions is equivalent to a geodesic flow on the thrice-punctured sphere, or ‘pair of pants’. The sphere is the shape sphere. The punctures are the binary collisions. The metric generating the geodesics is the Jacobi–Maupertuis metric. It is complete, has infinite area, and its ends, the neighborhoods of the punctures, are asymptotically cylindrical. Our main result is that when the three masses are equal then the metric has negative curvature everywhere except at two points (the Lagrange points). A corollary of this negativity is the uniqueness of the 1/r2 figure-eight, a complete symbolic dynamics for encoding the collision-free solutions, and the fact that collision solutions are dense within the bound solutions.