cssi/SciSciGPT-SciSciNet huggingface dataset:
Nonlinear crack growth monitoring

Oak Ridge National Laboratory has developed (Welch et al. 1999. Nonlinear Crack Growth Monitoring, Oak Ridge National Laboratory, Oak Ridge, TN, 1999) a new technique to monitor the growth of cracks in structural members, and to predict at what point failure due to this damage is imminent, requiring structure repair or replacement, in those cases where predictions based on conventional design techniques are difficult. This will allow greater confidence in continued operation of structures with known flaw sites, and will provide a quantifiable means of assessing when structure failure is imminent.
The Strategy and Consistency of Federal Reserve Monetary Policy, 1924–1933

List of figures List of tables Preface 1. Introduction 2. The objectives of monetary policy, 1924-33 3. Member bank borrowing and the Fed's policy strategy 4. Policy disagreements within the Federal reserve system: the effects of institutional change 5. Conclusion References Index.
Nanocluster with one missing core atom: A three-dimensional hybrid superlattice built from dual-sized supertetrahedral clusters

通讯作者地址: Feng, PY (通讯作者), Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA 地址: 1. Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA 2. Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA
Manure Applications and Nutrient Standards

Because of environmental concerns, many states are regulating animal manure applications to crops. A conceptual model is presented to describe manure demand for crop nutrient application under alternative regulatory standards. Demand relationships are incorporated into a spatial equilibrium model to estimate welfare costs of phosphorus and nitrogen regulatory standards for manure applications. Model estimates for Virginia indicate that regulatory standards for manure application achieve large reductions in excess nitrogen and phosphorus and result in 5–15% welfare losses excluding nonmarket environmental valuation.
Optimum corner reflectors for calibration of imaging radars

Trihedral corner reflectors are widely used as calibration targets for imaging radars because of their large radar cross section (RCS) and extremely wide RCS pattern. An important source of uncertainty in the RCS of a trihedral sitting on a ground plane is the coherent interaction of the ground plane with the trihedral. At UHF and low microwave frequencies the large physical size of corner reflectors become a limiting factor in regard to difficulties in field deployment and deviation of their RCS from the expected values. In this paper, a general class of corner reflectors with high-aperture efficiency referred to as self-illuminating corner reflectors, is introduced whose coherent interaction with the surrounding terrain is minimized and their total surface area is two-thirds of that of a triangular corner reflector having the same maximum RCS. Analytical expressions based on geometrical optics and a new numerical solution based on near-field physical optics for the RCS of two simple self-illuminating corner reflectors are presented and compared with backscatter measurements. Also the panel geometry for an optimum corner reflector which has the shortest edge length among polygonal self-illuminating corner reflectors is obtained. High-aperture efficiency is achieved at the expense of azimuth and elevation beamwidth. It is shown that the 1-dB RCS beamwidths of the optimal corner reflectors, both in azimuth and elevation directions, are about 16/spl deg/. RCS measurements of corner reflectors in the presence of a ground plane show that the RCS of self-illuminating corner reflectors are less affected by the coherent ground interaction.
Design, synthesis and biological evaluation of 3-amino-3-phenylpropionamide derivatives as novel μ opioid receptor ligands

Abstract 3-Amino-3-phenylpropionamide derivatives were produced as small molecule mimics of the cyclic octapeptide octreotide from readily available imine 1 Download : Download high-res image (51KB) Download : Download full-size image Scheme 1 . Preparation of 3-amino-3-phenylpropionamide derivatives. 18 (a) TiCl4, CH2Cl2, rt., 10 h; 88%; (b) n-BuLi, R1NH2, THF, 0 °C; 15 min then add 3; 85–98% yield; (c) BBr3, CH2Cl2, −78 °C to rt; 80–95% yield; (d) RxCHO, NaBH(OAc)3, AcOH, CH2Cl2, rt; 10 h; 65–95% yield. . The compounds exhibit high affinity for the μ opioid receptor.
A Comparison of Reverse Leveraged Buyouts and Original Initial Public Offers: Factors Impacting their Issuance in the IPO Market

The purpose of this paper is to assess the factors that affect the returns earned by investors in early trading of reverse LBOs and compare those results to factors affecting original IPOs which are matched by size, industry, and issue date. A mean excess return of 7.64% is observed for the sample of reverse LBOs during the period 1987 to 1998. This return is uniformly lower than returns earned by investing in original IPOs. These results support the information asymmetry hypothesis. The results also show that factors such as number of months the LBO was privately held, the over-allotment, or greenshoe option, the size of the issue, insider ownership, and gross spread impact the returns earned by investors in reverse LBOs. Other factors which are known to affect returns on original IPOs, such as lead underwriter, whether the deal was syndicated, the number of managers, the listing exchange, lockup agreements, and auditor, are shown to have no impact on the returns in reverse LBOs for the sample in question. We find that the level of insider participation and the over-allotment option are more important to original IPOs than to reverse LBOs in explaining the excess returns earned by shareholders in early trading. We find, however, that the size of the offering has more impact on excess returns for reverse LBOs than for original IPOs.
The Mechanics of Fast-Start Performance of Pike Studied Using a Mechanical Fish

A northern pike (Esox lucius) is capable of achieving a maximum instantaneous acceleration of 25g, far greater than that achieved by any manmade vehicle. In order to understand the physical mechanisms behind achieving such high accelerations, we have built a mechanical fish to emulate the motion of a pike, a fast-start specialist. A live pike bends its body into either a C-shaped or an S-shaped curve and then uncoils it very quickly to send a traveling wave along its body in order to achieve high acceleration. We have designed a mechanical fish whose motion is accurately controlled by servo motors, to emulate the fast-start by bending its body to a curve from its original straight position, and then back to its straight position. Furthermore, this mechanical fish is designed to be adjustable in swimming pattern, tail shape, tail rigidity, and body rigidity, making it possible to study the influence of all of these parameters on the fast-start performance. Peak accelerations of 2.0 m/s2 and peak velocities of 0.09 m/s are measured. Although the maximum accelerations and velocities observed in our mechanical fish are smaller than those of live fish, the form of the measured acceleration signal as function of time is quite similar to that of a live fish. The hydrodynamic efficiencies are observed to be around 12%, and it is shown that the majority of the thrust is produced at the rear part of the mechanical fish — similarly to the live fish.© 2011 ASME
André–Quillen homology of algebra retracts

Abstract Given a homomorphism of commutative noetherian rings ϕ :R→S , Daniel Quillen conjectured in 1970 that if the Andre–Quillen homology functors Dn(S∣R;−) vanish for all n⪢0, then they vanish for all n⩾3. We prove the conjecture under the additional hypothesis that there exists a homomorphism of rings ψ :S→R such that ϕ∘ψ=idS. More precisely, in this case we show that ψ is a complete intersection at ϕ −1 ( n ) for every prime ideal n of S. Using these results, we describe all algebra retracts S→R→S for which the algebra Tor•R(S,S) is finitely generated over Tor0R(S,S)=S.
Synthesis of aldehydes from synthesis gas over Na-promoted Mn-Ni catalysts

Abstract The synthesis of acetaldehyde and propionaldehyde from CO hydrogenation over NaMnNi catalysts has been studied. Coprecipitated NaMnNi catalysts exhibited high activities for the synthesis of acetaldehyde from CO hydrogenation and the synthesis' of propionaldehyde from addition of ethylene to CO hydrogenation. In contrast, NaMnNi/SiO2 catalysts prepared from coimpregnation showed mainly methanation and ethylene hydrogenation activities. The selectivities to acetaldehyde in CO hydrogenation were found to parallel the selectivities to propionaldehyde in ethylene addition. X-ray photoelectron spectroscopic studies revealed that reduction of the coprecipitated NaMnNi catalyst at 350°C led to the migration of Na ions onto the surface of the catalyst resulting in the suppression of hydrogen chemisorption on the catalyst.
Phthalimide resin reagent for efficient mitsunobu amino-dehydroxylation

Abstract A phthalimide-containing resin has been designed and prepared from trimellitic anhydride. It provides an efficient route to primary amines from corresponding alcohols via Mitsunobu coupling with subsequent hydrazine-induced cleavage.
Dynamic properties of high-purity beryllium

Tests were conducted on high-purity beryllium plate to determine the Hugoniot equation of state and shock wave profile up to 50 kbar, and the spall threshold for elastic pulse widths of 0.2, 0.4, and 0.8 jusec, using flat-plate impact techniques. Tests were carried out at material temperatures of 22°C and 260°C. This beryllium was found to have a two-wave elasticplastic structure with a highly ramped transition from the elastic precursor to the plastic wave. No change in the material equation of state was observed for a temperature increase of 22°C to 260°C. The spall threshold (as defined by the onset of microcracking) was found to be time dependent, with impact velocity required for spall increasing with decreasing pulse width, and temperature dependent, with velocity increasing with increasing temperature.
Visual and linguistic information in gesture classification

Classification of natural hand gestures is usually approached by applying pattern recognition to the movements of the hand. However, the gesture categories most frequently cited in the psychology literature are fundamentally multimodal; the definitions make reference to the surrounding linguistic context. We address the question of whether gestures are naturally multimodal, or whether they can be classified from hand-movement data alone. First, we describe an empirical study showing that the removal of auditory information significantly impairs the ability of human raters to classify gestures. Then we present an automatic gesture classification system based solely on an n-gram model of linguistic context; the system is intended to supplement a visual classifier, but achieves 66% accuracy on a three-class classification problem on its own. This represents higher accuracy than human raters achieve when presented with the same information.
Classical physics and the Church--Turing Thesis

Would physical laws permit the construction of computing machines that are capable of solving some problems much faster than the standard computational model? Recent evidence suggests that this might be the case in the quantum world. But the question is of great interest even in the realm of classical physics. In this article, we observe that there is fundamental tension between the Extended Church--Turing Thesis and the existence of numerous seemingly intractable computational problems arising from classical physics. Efforts to resolve this incompatibility could both advance our knowledge of the theory of computation, as well as serve the needs of scientific computing.
SCATHA conductive spacecraft materials development

The development of new or modified spacecraft materials that would limit, control, and/or prevent spacecraft charging was included as part of the cooperative, interdependent Air Force/NASA Spacecraft Charging/ Spacecraft Charging at High Altitudes (SCATHA) program. Materials of interest included conductive polymers, paints, transparent f i lms and coatings, as well as fabric coatings and interweaves. The evaluation of materials charging/discharging properties in ihe laboratory as well as under simulated and actual space substorm charging conditions were included in the overall integrated SCATHA program. Conductive inorganic thermal control paints with a range of thermo-optical properties were developed and have been successfully applied to operational spacecraft. Conductive transparent indium oxide and indium tin oxide spacecraft charging control coatings have been developed to control the charging of flexible Kapton and FEP Teflon polymeric thermal control materials, OSR and solar cell covers, and other nonconductive dielectric surfaces. A conductive glass for application as OSR and solar ceil cover glasses lhas been prepared. Fabric spacecraft charging control materials have been developed and evaluated. Conductive adhesives for use in conjunction with conductive antistatic spacecraft charging materials have been developed.
Recent Departures in the Synthesis of Peptides and Glycopeptides

In this account, we describe the results of a research program directed to the proposition that chemical synthesis can play a valuable role in identifying biologic level molecules worthy of pharma level development. We recount our journey towards the chemical synthesis of homogeneous erythropoietin, the challenges we encountered, and our efforts to address deficiencies in the current "state of the art" of glycopeptide synthesis. Here we describe new methods for the synthesis of glycopeptides that have emerged from the erythropoietin adventure, including the development of unique C-terminal acyl donors, novel amide bond forming methods, and new ligation and coupling strategies.
General Relativistic Self-Similar Waves That Induce an Anomalous Acceleration into the Standard Model of Cosmology

The authors prove that the Einstein equations for a spherically symmetric spacetime in Standard Schwarzschild Coordinates (SSC) close to form a system of three ordinary differential equations for a family of self-similar expansion waves, and the critical ($k=0$) Friedmann universe associated with the pure radiation phase of the Standard Model of Cosmology is embedded as a single point in this family. Removing a scaling law and imposing regularity at the center, they prove that the family reduces to an implicitly defined one-parameter family of distinct spacetimes determined by the value of a new acceleration parameter $a$, such that $a=1$ corresponds to the Standard Model. The authors prove that all of the self-similar spacetimes in the family are distinct from the non-critical $k\neq0$ Friedmann spacetimes, thereby characterizing the critical $k=0$ Friedmann universe as the unique spacetime lying at the intersection of these two one-parameter families. They then present a mathematically rigorous analysis of solutions near the singular point at the center, deriving the expansion of solutions up to fourth order in the fractional distance to the Hubble Length. Finally, they use these rigorous estimates to calculate the exact leading order quadratic and cubic corrections to the redshift vs luminosity relation for an observer at the center.
Most nephrologists are primary care providers for chronic dialysis patients: results of a national survey

The medical care of end-stage renal disease (ESRD) patients includes not only dialysis-related medical care but preventive and general medical care as well as the care of minor acute illnesses. There is little information about nephrologists' interpretation of their potential role as a primary health care provider for the general medical needs of chronic dialysis patients. To characterize nephrologists' primary care practice patterns related to the care of chronic dialysis patients, we surveyed a randomly selected group of practicing nephrologists and asked questions about preventive medicine guidelines followed, treatment of minor acute illnesses, and management of chronic medical problems in ESRD patients. The results of 233 questionnaires (46% response rate) were analyzed. Most of the responding nephrologists were men (91%), were board certified in internal medicine (96%) and nephrology (83%), were out of nephrology practice for a mean of 16 years, had a mean age of 48 +/- 7 years, and were in private practice (65%). The average percentage of time spent with chronic dialysis patients was reported as 30%; 38% of that time was devoted to the general medical care of those patients. Ninety percent of nephrologists reported that they provided primary care to their dialysis patients, and only 21% said a nurse practitioner or physician assistant worked with them. Age and number of years in practice were the only demographic factors increasing the likelihood of nephrologist-provided primary care, with older, more experienced practitioners more likely to be providing primary care to dialysis patients. Most nephrologists reported that they managed minor acute illnesses and comorbid conditions (diabetes mellitus, cardiac disease, and gastrointestinal disease) in their dialysis patients. Nephrology fellowship training programs and recertification programs may need to address issues of primary general health care of ESRD patients. Plans under development for health care programs and reimbursement criteria also need to recognize and consider the primary medical care role practiced by nephrologists caring for ESRD patients.
Hot phonon effects in heterolayers

Abstract The theory of hot phonon effects in heterolayers is presented, in particular for electrons in gallium arsenide. The acoustic mode and optical mode cases are distinct. For the former, at low temperature, a phonon flux is radiated out of the heterolayer, and can be partially absorbed in a neighboring layer. For the latter, the phonon excitation buffers the electron energy dissipation and reduces the power scale in the dependence of electron temperature on power input. Also it adds appreciably to the total energy per electron and lengthens the thermalization ttime. Theoretical results are compared with experimental data.
Preparation of α-fluorophosphonates

Abstract Two approaches to the preparation of α-fluorohosphonates are described. The first approach involved the free radical addition of (EtO) 2 P(O)CFBr 2 to alkenes followed by reduction of the addition adducts with Bu 3 SnH. The second approach utilized the Pd(PPh 3 ) 4 or Cu(O) catalyzed addition of (RO) 2 P(O)CFHl to alkenes followed by Zn/NiCl 2 ·6H 2 O reduction of the addition adduct.
Black ring deconstruction

We present a sample microstate for a black ring in four and five dimensional language. The microstate consists of a black string microstate with an additional D6-brane. We show that with an appropriate choice of parameters the piece involving the black string microstate falls down a long AdS throat, whose M-theory lift is AdS_3 x S2. We wrap a spinning dipole M2-brane on the S2 in the probe approximation. In IIA, this corresponds to a dielectric D2-brane carrying only D0-charge. We conjecture this is the firstapproximation to a cloud of D0-branes blowing up due to their non-abelian degrees of freedom and the Myers effect.
The manipulation of massive ro-vibronic superpositions using time–frequency-resolved coherent anti-Stokes Raman scattering (TFRCARS): from quantum control to quantum computing

Abstract Molecular ro-vibronic coherences, joint energy-time distributions of quantum amplitudes, are selectively prepared, manipulated, and imaged in time–frequency-resolved coherent anti-Stokes Raman scattering (TFRCARS) measurements using femtosecond laser pulses. The studies are implemented in iodine vapor, with its thermally occupied statistical ro-vibrational density serving as initial state. The evolution of the massive ro-vibronic superpositions, consisting of 10 3 eigenstates, is followed through two-dimensional images. The first- and second-order coherences are captured using time-integrated frequency-resolved CARS, while the third-order coherence is captured using time-gated frequency-resolved CARS. The Fourier filtering provided by time-integrated detection projects out single ro-vibronic transitions, while time-gated detection allows the projection of arbitrary ro-vibronic superpositions from the coherent third-order polarization. A detailed analysis of the data is provided to highlight the salient features of this four-wave mixing process. The richly patterned images of the ro-vibrational coherences can be understood in terms of phase evolution in rotation–vibration–electronic Hilbert space, using time-circuit diagrams. Beside the control and imaging of chemistry, the controlled manipulation of massive quantum coherences suggests the possibility of quantum computing. We argue that the universal logic gates necessary for arbitrary quantum computing – all single qubit operations and the two-qubit controlled-NOT (CNOT) gate – are available in time-resolved four-wave mixing in a molecule. The molecular rotational manifold is naturally “wired” for carrying out all single qubit operations efficiently, and in parallel. We identify vibronic coherences as one example of a naturally available two-qubit CNOT gate, wherein the vibrational qubit controls the switching of the targeted electronic qubit.
The Structure of the Local Interstellar Medium. III. Temperature and Turbulence

We present 50 individual measurements of the gas temperature and turbulent velocity in the local interstellar medium (LISM) within 100 pc. By comparing the absorption line widths of many ions with different atomic masses, we can satisfactorily discriminate between the two dominant broadening mechanisms, thermal broadening and macroscopic nonthermal, or turbulent, broadening. We find that the successful use of this technique requires a measurement of a light ion, such as D I, and an ion at least as heavy as Mg II. However, observations of more lines provide an important consistency check and can also improve the precision and accuracy of the measurement. Temperature and turbulent velocity measurements are vital to understanding the physical properties of the gas in our local environment and can provide insight into the three-dimensional morphological structure of the LISM. The weighted mean gas temperature in the LISM warm clouds is 6680 K and the dispersion about the mean is 1490 K. The weighted mean turbulent velocity is 2.24 km s-1 and the dispersion about the mean is 1.03 km s-1. The ratio of the mean thermal pressure to the mean turbulent pressure is PT/Pξ ~ 26. Turbulent pressure in LISM clouds cannot explain the difference in the apparent pressure imbalance between warm LISM clouds and the surrounding hot gas of the Local Bubble. Pressure equilibrium among the warm clouds may be the source of a moderately negative correlation between temperature and turbulent velocity in these clouds. However, significant variations in temperature and turbulent velocity are observed. The turbulent motions in the warm partially ionized clouds of the LISM are definitely subsonic, and the weighted mean turbulent Mach number for clouds in the LISM is 0.19 with a dispersion of 0.11. These measurements provide important constraints on models of the evolution and origin of warm partially ionized clouds in our local environment.
Using Visual Range Data For Highway Operations In Blowing Snow

This paper describes characteristics of visual range attenuation in blowing snow in relation to motorist vision. Visual range V is related to wind speed U according to V = AU-5 with the A coefficient changing in response to snow availability. A lower limit for visual range is described with A =1.1 X108 m6 s-5. An operational monitoring system used on Interstate Highway 80 in Wyoming demonstrates how real-time computer analysis of photometric data can be used to determine the A value, interpret visual range in terms of vehicle operation, and provide automated traffic operations decisions.
Palladium-Catalyzed Carbonylative Cyclization/Arylation Cascade for 2-Aroylindolizine Synthesis

An efficient synthesis of densely substituted 2-aroylindolizines via the palladium-catalyzed carbonylative cyclization/arylation is reported. This transformation proceeds via the 5-endo-dig cyclization of 2-propargylpyridine triggered by an aroyl Pd complex. It produced diversely substituted 2-aroylindolizines in good to excellent yields.
Novae with Long-lasting Supersoft Emission that Drive a High Accretion Rate

We identify a new class of novae characterized by the post-eruption quiescent light curve being more than roughly a factor of 10 brighter than the pre-eruption light curve. Eight novae (V723 Cas, V1500?Cyg, V1974?Cyg, GQ Mus, CP Pup, T Pyx, V4633 Sgr, and RW UMi) are separated out as being significantly distinct from other novae. This group shares a suite of uncommon properties, characterized by the post-eruption magnitude being much brighter than before eruption, short orbital periods, long-lasting supersoft emission following the eruption, a highly magnetized white dwarf (WD), and secular declines during the post-eruption quiescence. We present a basic physical picture which shows why all five uncommon properties are causally connected. In general, novae show supersoft emission due to hydrogen burning on the WD in the final portion of the eruption, and this hydrogen burning will be long-lasting if new hydrogen is poured onto the surface at a sufficient rate. Most novae do not have adequate accretion for continuous hydrogen burning, but some can achieve this if the companion star is nearby (with short orbital period) and a magnetic field channels the matter onto a small area on the WD so as to produce a locally high accretion rate. The resultant supersoft flux irradiates the companion star and drives a higher accretion rate (with a brighter post-eruption phase), which serves to keep the hydrogen burning and the supersoft flux going. The feedback loop cannot be perfectly self-sustaining, so the supersoft flux will decline over time, forcing a decline in the accretion rate and the system brightness. We name this new group after the prototype, V1500?Cyg. V1500?Cyg stars are definitely not progenitors of Type Ia supernovae. The V1500?Cyg stars have similar physical mechanisms and appearances as predicted for nova by the hibernation model, but with this group accounting for only 14% of novae.
The EITC, Tax Refunds, and Unemployment Spells

The Earned Income Tax Credit generates large average tax refunds for low-income parents, and these refunds are distributed in a narrow time frame. I rely on this plausibly exogenous source of variation in liquidity to investigate the effect of cash-on-hand on unemployment duration. Among EITC-eligible women, unemployment spells beginning just after tax refund receipt last longer than unemployment spells beginning at other times of year. There is no evidence that tax refund receipt is associated with longer unemployment duration for men, or that the longer durations for women are associated with higher-quality subsequent job matches. The Earned Income Tax Credit (EITC) has grown to be an important part of the safety net for low-income families. In 2003, EITC-recipient households received payments averaging $150 per family per month, while the average TANF-recipient household received $140 in monthly welfare benefits and the average food stamp participant got benefits of $80 per month (Congressional Budget Office 2005). Although most transfer programs deliver benefits in periodic payments spread over time, EITC payments typically arrive in one annual lump sum. Beverly, Schneider, and Tufano (2006) point out that for many EITC recipients, their federal tax refund will be the single largest payment received during the year. As a result, EITC recipients tend to have temporarily high levels of liquid assets just after tax refunds are distributed. Building on recent evidence showing that higher levels of liquid assets are associated with longer unemployment spells, this paper uses refund-related variation to investigate the sensitivity of unemployment duration to cash-on-hand among low-income parents. The distinctive pattern of EITC-related tax refunds received by low-income parents provides the foundation for my empirical strategy. Low income families with children receive tax refunds that are large relative to their annual income. Averaged over 1993 to 2007, filers with children and with income in the EITC range received refunds equal to 30% of their annual adjusted gross income. Payment of tax refunds is more temporally concentrated for low-income filers than for the population as a whole. In recent years more than half of EITC payments have
Resonance Raman and surface- and tip-enhanced Raman spectroscopy methods to study solid catalysts and heterogeneous catalytic reactions

Resonance Raman (RR) spectroscopy has several advantages over the normal Raman spectroscopy (RS) widely used for in situ characterization of solid catalysts and catalytic reactions. Compared with RS, RR can provide much higher sensitivity and selectivity in detecting catalytically-significant surface metal oxides. RR can potentially give useful information on the nature of excited states relevant to photocatalysis and on the anharmonic potential of the ground state. In this critical review a detailed discussion is presented on several types of RR experimental systems, three distinct sources of so-called Raman (fluorescence) background, detection limits for RR compared to other techniques (EXAFS, PM-IRAS, SFG), and three well-known methods to assign UV-vis absorption bands and a band-specific unified method that is derived mainly from RR results. In addition, the virtues and challenges of surface-enhanced Raman spectroscopy (SERS) are discussed for detecting molecular adsorbates at catalytically relevant interfaces. Tip-enhanced Raman spectroscopy (TERS), which is a combination of SERS and near-field scanning probe microscopy and has the capability of probing molecular adsorbates at specific catalytic sites with an enormous surface sensitivity and nanometre spatial resolution, is also reviewed (300 references).
Molecular dynamics simulations of reactive wetting

Abstract Liquid Ag drops spreading on a Cu(1 0 0) surface are studied with molecular dynamics simulations. Results for reactive wetting by which a Cu/Ag alloy is formed are compared to a frozen substrate for which there is no alloying. The radius of the Ag wetting layer increases initially as t1/2 for both cases but drops spread faster in reactive systems. A crossover to slower wetting kinetics is observed at later t.
Calabi–Yau Black Holes and (0,4) Sigma Models

When an M-theory fivebrane wraps a holomorphic surface ? in a Calabi–Yau 3-fold X the low energy dynamics is that of a black string in 5 dimensional ? =1 supergravity. The infrared dynamics on the string worldsheet is an ? = (0,4) 2D conformal field theory. Assuming the 2D CFT can be described as a nonlinear sigma model, we describe the target space geometry of this model in terms of the data of X and ?. Variations of weight two Hodge structures enter the construction of the model in an interesting way.
High Resolution Cryogenic Spark Chambers

A cluster of four narrow gap (2.5 mm) spark chambers containing 8 wires per millimeter has been built and operated at low temperatures (as low as 118°K). Results obtained from these chambers indicate that the width of the spark column is reduced at lower temperatures due to the increased gas density. Electron diffusion and deviation of the spark column from the true particle trajectory are greatly reduced at lower temperatures with narrow gap spark chambers. Space resolutions less than ? = 70 microns (HWHM) has been achieved and even better resolutions are predicted from the observed temperature dependence.
Potatoes, milk, and the Old World population boom

Abstract This paper explores the role of two foods, potatoes and milk, in explaining the increase in economic development experienced throughout the Old World in the 18th and 19th centuries. Nunn and Qian (2011) show the introduction of the potato from the New World has a significant explanatory role for within country population and urbanization growth over this period. I expand on this by considering the role of milk consumption, which is hypothesized to be a complement in diet to potatoes due to a differential composition of essential nutrients. Using a country-level measure for the suitability of milk consumption, the frequency of lactase persistence, I show that the marginal effect of potatoes on post-1700 population and urbanization growth is positively related to milk consumption. As the frequency of milk consumption approaches unity, the marginal effect of potatoes more than doubles in magnitude compared to the baseline estimate of Nunn and Qian.
The challenge of environmental education

in the naive state, living within limits which he cannot control, is better company to the world than man the technologist. His power to bring his house down in ruins is not the power of a savage or a brute. It has the strength that only the deepest knowledge of art and science can give to those who seek it with diligence and wisdom. The finger on the trigger of the machine of doom is the finger of a man, bursting with pride in the sensation of his own power, shouting his slogan of righteousness, but conscious through it all of his fragility as a tenant in the house of nature. Thus, if everything falls to pieces, we shall be more than culprit or victim or witness. We shall understand the outcome as the
Scale and performance in a distributed file system

The Andrew File System is a location-transparent distributed tile system that will eventually span more than 5000 workstations at Carnegie Mellon University. Large scale affects performance and complicates system operation. In this paper we present observations of a prototype implementation, motivate changes in the areas of cache validation, server process structure, name translation, and low-level storage representation, and quantitatively demonstrate Andrews ability to scale gracefully. We establish the importance of whole-file transfer and caching in Andrew by comparing its performance with that of Sun Microsystems NFS tile system. We also show how the aggregation of files into volumes improves the operability of the system.
Phosphine-Mediated Reductive Condensation of γ-Acyloxy Butynoates: A Diversity Oriented Strategy for the Construction of Substituted Furans

Exposure of gamma-acyloxy butynoates to stoichiometric quantities of triphenylphosphine results in reductive condensation to afford substituted furans, by way of allenic ester intermediates. As gamma-acyloxy butynoates are readily obtained through condensation of ethyl propiolate with aldehydes followed by acylation, this method represents a powerful and mechanistically novel protocol for the convergent three-component construction of substituted furans.
Oil and Conflict: What Does the Cross Country Evidence Really Show?

This paper re-examines the effect of oil wealth on political violence. Using a unique historical panel dataset of oil discoveries, we show that simply controlling for country fixed effects removes the statistical association between the value of oil reserves and civil war onset. Other macro-political violence measures, such as coup attempts, are also uncorrelated with oil wealth. To further address endogeneity concerns, we exploit changes in oil reserves due to randomness in the success of oil explorations. We find little robust evidence that oil discoveries increase the likelihood of political violence. Rather, oil discoveries increase military spending in nondemocratic countries. (JEL D74, H56, O17, Q34, Q41) D oes oil wealth corrupt or strengthen regimes? The conventional wisdom dating back to at least Malthus is that resource scarcity triggers conflict. Since the end of the Cold War, however, resource abundance—particularly when that resource is oil—has been blamed for many civil wars in developing countries, and for political instability in the Middle East. If civil strife is caused by resource scarcity and poverty, why should oil revenues weaken states by fueling separatism and causing political instability? The puzzle is intensified by another popular argument for the oil curse—oil wealth enhances the stability and durability of authoritarian regimes because it strengthens dictators by funding patronage and repressive apparatuses. This paper uses data on historical oil explorations and discoveries to provide new evidence on the effect of oil wealth on political violence. In particular, we re-examine the “oil-fuels-war” hypothesis, and provide the first systematic analysis of the impact of oil wealth on coup attempts, irregular leadership transitions, and military spending, using a unique industrial dataset describing worldwide oil explorations, discoveries, extractions, and endowments since 1930.
Evaluating the solubility of powdered food ingredients using dynamic nuclear magnetic resonance (NMR) relaxometry

Abstract Dynamic nuclear magnetic resonance (NMR) relaxometry was used to monitor hydration and solubility of powdered food ingredients (glucose, cellulose, β-lactoglobulin, and zein) and the effects of stirring rate on the hydration of powdered soy protein. A low-field (15 MHz) NMR spectrometer was used to measure the transverse relaxation times (T2) of stirred dilute aqueous mixtures (0.105 g/3.5 ml) of the powdered food ingredients for up to 50 min. The soluble and insoluble fractions of aqueous mixtures subjected to the same mixing treatment were determined by physically separating the soluble and insoluble components using filtration followed by freeze-drying and gravimetric measurements. Although the absolute value of T2 may not be useful for comparing solubilities of different ingredients, sequential low-field NMR measurements of T2 values can be used for monitoring changes in ingredient solubility over various mixing times, these results showed no significant differences ( α = 0.05 ) from the filtration and freeze-drying results, and data can be collected in situ. It is proposed that this approach be used by the food industry for optimizing mixing processes.
Sensitivity study for long term reliability

This paper illustrates using Markov models to establish system and maintenance requirements for small electronic controllers where the goal is a high probability of continuous service for a long period of time. The system and maintenance items considered are quality of components, various degrees of simple redundancy, redundancy with reconfiguration, diagnostic levels, periodic maintenance, and preventive maintenance. Markov models permit a quantitative investigation with comparison and contrast. An element of special interest is the use of conditional probability to study the combination of imperfect diagnostics and periodic maintenance.
High Energy Physics Horizons

A horizon is a boundary beyond which we cannot see. But one can speculate on what lies beyond it, and I shall try to do so for three aspects of high‐energy physics: its technology, its need for support and planning, and—what makes the other two parts worth caring about—the prospects for significant new discoveries.
Anxiolytic activity of analogues of 4-benzylamino-2-methyl-7H-pyrrolo[2,3-d]pyrimidines

Abstract An extensive series of analogues of the lead anxiolytic 4-benzylamino-2-methylpyrrolo[2,3-d]pyrimidine 1 was synthesized and evaluated in the Geller-Seifter conflict test for anxiolytic activity to discover a less toxic derivative. Analysis of the SAR revealed that the most potent compounds were those with meta substituents on the benzylamino ring. In this group the most promising derivatives were 4-[bis(3,5-dimethylamino)]benzylamino-2-methyl-7H-pyrrolo[2,3-d]pyrimidine 12 and 4-(3,5-dimethylbenzyl-amino)-2-rnethyl-7H-pyrrolo[2,3-d]pyrimidine 24. Potential metabolites of 12 were synthesized and checked for their anxiolytic activity. Less toxic analogues of the second lead 24 were prepared by extending the alkyl groups attached to the benzene ring moiety. The addition of a fluoro substituent to the benzene moiety in the extended alkyl chain analogue 4-(3,5-diethyl-2-fluorobenzylamino)-2-methyl-7H-pyrrolo[2,3-d]pyrimidine 34 resulted in a compound with a longer duration of activity relative to its analogue 4-(3,5-diethylbenzylamino)-2-methyl-7H-pyrrolo[2,3-d]pyrimidine 26.
Measuring Implementation of Evidence-Based Programs Targeting Young Children at Risk for Emotional/Behavioral Disorders: Conceptual Issues and Recommendations.

Young children with and at risk for emotional/behavioral disorders (EBD) present challenges for early childhood teachers. Evidence-based programs designed to address these young children’s behavior problems exist, but there are a number of barriers to implementing these programs in early childhood settings. Advancing the science of treatment integrity measurement can assist researchers and consumers interested in implementing evidence-based programs in early childhood classrooms. To provide guidance for researchers interested in assessing the integrity of implementation efforts, we describe a conceptual model of implementation of evidence-based programs designed to prevent EBD when applied in early childhood settings. Next, we describe steps that can be used to develop treatment integrity measures. Last, we discuss factors to consider when developing treatment integrity measures with specific emphasis on psychometrically strong measures that have maximum utility for implementation research in early childh...
Correlations in the impenetrable electron gas

Abstract We consider non-relativistic electrons in one dimension with infinitely strong repulsive delta function interaction. We calculate the long-time, large-distance asymptotics of field-field correlators in the gas phase. The gas phase at low temperatures is characterized by the ideal gas law. We calculate the exponential decay, the power law corrections and the constant factor of the asymptotics. Our results are valid at any temperature. They simplify at low temperatures, where they are easily recognized as products of free fermionic correlation functions with corrections arising due to the interaction.
Detection of airway obstruction in exercise-induced asthma.

Pulmonary function test results were evaluated in 24 bronchodilator-dependent asthmatic boys before treadmill exercise (baseline) and at 7 and 30 minutes afterward. The following pulmonary function parameters were measured: forced vital capacity, forced expiratory volume in one second, maximal midexpiratory flow, peak expiratory flow rate, thoracic gas volume, airway resistance, specific airway conductance, and closing volume. A clinical scoring system based on auscultatory findings was also used to determine the degree of wheezing and respiratory effort before, during, and after exercise. Results showed that specific airway conductance, maximal midexpiratory flow, and closing volume were the most sensitive parameters reflecting changes in airway caliber. Less significant changes also appeared in the forced expiratory volume in one second and in the forced vital capacity. Determination of closing volume, although a sensitive technique, could be achieved in only a minority of severely asthmatic children (25 percent of our patients). It was also evident that a normal peak flow reading and normal auscultatory findings did not necessarily imply a normally functioning lung. It was observed that the degree of exercise-induced asthma (EIA) depended on workload. Judged by the changes in maximal midexpiratory flow rate, airway resistance, and specific conductance, the incidence of EIA was 75 percent for workload 1, corresponding to 1.26 watts/kg of body weight and 100 percent for work load 2, corresponding to 1.75 watts/kg of body weight. Correlation coefficients calculated from absolute values between individual pulmonary function tests were lower for workload 1 but markedly higher in the case of workload 2.
Reverse mathematics and properties of finite character

Abstract We study the reverse mathematics of the principle stating that, for every property of finite character, every set has a maximal subset satisfying the property. In the context of set theory, this variant of Tukey’s lemma is equivalent to the axiom of choice. We study its behavior in the context of second-order arithmetic, where it applies to sets of natural numbers only, and give a full characterization of its strength in terms of the quantifier structure of the formula defining the property. We then study the interaction between properties of finite character and finitary closure operators, and the interaction between these properties and a class of nondeterministic closure operators.
Vita: Friedrich Wilhelm Wiener

We report on the life and work of F. Wiener, whom we confused with N. Wiener in a previous article.
Optimal wiring in the cortex and neuronal degree of separation

Abstract Experimental allometric laws for cortical neurons, synapses and axons are used to study an optimal wiring of the cortex. It is argued that the optimal wiring principle should take into account minimization of both axonal length and energy cost required in the long distance communication between areas. The latter quantity is proportional to an average degree of separation between neurons. Using scaling arguments, it is shown that this principle leads to a trade-off between saving axons and saving energy used in the communication.
Effective capacity-based quality of service measures for wireless networks

An important objective of next-generation wireless networks is to provide quality of service (QoS) guarantees. This requires a simple and efficient wireless channel model that can easily translate into connection-level QoS measures such as data rate, delay and delay-violation probability. To achieve this, in Wu and Negi (IEEE Trans. on Wireless Communications 2(4) (2003) 630-643), we developed a link-layer channel model termed effective capacity, for the setting of a single hop, constant-bit-rate arrivals, fluid traffic, and wireless channels with negligible propagation delay. In this paper, we apply the effective capacity technique to deriving QoS measures for more general situations, namely, (1) networks with multiple wireless links, (2) variable-bit-rate sources, (3) packetized traffic, and (4) wireless channels with non-negligible propagation delay.
Improved Nonlinear Model for Electrode Voltage–Current Relationship for More Consistent Online Battery System Identification

An improved nonlinear model for the electrode voltage-current relationship for online battery system identification is proposed. In contrast to the traditional linear-circuit model, the new approach employs a more accurate model of the battery electrode nonlinear steady-state voltage drop based on the Butler-Volmer (BV) equation. The new form uses an inverse hyperbolic sine approximation for the BV equation. Kalman-filter-based system identification is proposed for determining the model parameters based on the measured voltage and current. Both models have been implemented for lead-acid batteries and exercised using test data from a Corbin Sparrow electric vehicle. A comparison of predictions for the two models demonstrates the improvements that can be achieved using the new nonlinear model. The results include improved battery voltage predictions that provide the basis for more accurate state-of-function readings.
Existence and symmetry of minimizers for nonconvex radially symmetric variational problems

We study functionals of the form $$E(u):=\int_{B_R(0)} W(\nabla u)+G(u)\,dx,$$ where u is a real valued function over the ball \(B_R(0)\subset {\mathbb{R}}^N\) which vanishes on the boundary and W is nonconvex. The functional is assumed to be radially symmetric in the sense that W only depends on \(|{\nabla u}|\) . Existence of one and radial symmetry of all global minimizers is shown with an approach based on convex relaxation. Our assumptions on G do not include convexity, thus extending a result of A. Cellina and S. Perrotta.