cssi/SciSciGPT-SciSciNet huggingface dataset:
Measurement Scheme Synthesis in Multi-Station Machining Systems

Different sets of measurements carry different amounts of information about the root causes of quality problems in machining. The selection of measurements in multi-station machining systems is currently a slow and error-prone process based on expert human knowledge. In this paper, we propose systematic procedures for synthesizing measurement schemes that carry the most information about the root causes of dimensional machining errors. The amount of root cause information conveyed by a given set of measurements was assessed using the recently introduced formal methods for quantitative characterization of measurement schemes in multi-station machining systems. The newly proposed measurement scheme synthesis procedures were applied to devising measurement schemes in an automotive cylinder head machining process. It was observed that the measurement scheme synthesis procedure based on a genetic algorithm robustly outperformed the synthesis procedures based on the heuristics of successive measurement removal.
From Glasma to Quark Gluon Plasma in heavy ion collisions

When two sheets of color glass condensate collide in a high-energy heavy-ion collision, they form matter with very high energy densities called the glasma. We describe how this matter is formed, its remarkable properties and its relevance for understanding the thermalization of the quark–gluon plasma in heavy-ion collisions. Long-range rapidity correlations contained in the near-side ridge measured in heavy-ion collisions may allow one to directly infer the properties of the glasma.
Medium Resolution Transmission Measurements of Water Vapor at High Temperature

Medium-resolution transmissivities of water vapor were measured at temperatures between 600 and 1550 K for all-important vibration-rotation bands as well as part of the purely rotational band. Measurements were made with an improved drop tube design, which ensures a relatively isothermal high-temperature gas column. Data were collected with a Fourier-transform-infrared-spectrometer, allowing for much better spectral resolution than most previous high-temperature measurements. The measured data were compared to the HITEMP database, as well as with the data of Phillips for the 2.7 μm band of H 2 O. The data show minor discrepancies with the high-resolution database, particularly at higher temperatures, but, in general, agreement is acceptable.
Near-infrared transit photometry of the exoplanet HD 149026b

The transiting exoplanet HD 149026b is an important case for theories of planet formation and planetary structure, for the planet's relatively small size has been interpreted as evidence for a highly metal-enriched composition. We present observations of four transits with the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) on the Hubble Space Telescope within a wavelength range of 1.1-2.0 {mu}m. Analysis of the light curve gives the most precise estimate yet of the stellar mean density, {rho}{sub *} = 0.497{sup +0.042} {sub -0.057} g cm{sup -3}. By requiring agreement between the observed stellar properties (including {rho}{sub *}) and stellar evolutionary models, we refine the estimate of the stellar radius: R {sub *} = 1.541{sup +0.046} {sub -0.042} R {sub sun}. We also find a deeper transit than has been measured at optical and mid-infrared wavelengths. Taken together, these findings imply a planetary radius of R{sub p} = 0.813{sup +0.027} {sub -0.025} R {sub Jup}, which is larger than earlier estimates. Models of the planetary interior still require a metal-enriched composition, although the required degree of metal enrichment is reduced. It is also possible that the deeper NICMOS transit is caused by wavelength-dependent absorption by constituents in the planet's atmosphere, although simplemore » model atmospheres do not predict this effect to be strong enough to account for the discrepancy. We use the four newly measured transit times to compute a refined transit ephemeris.« less
The Eigenvalue Problem of Singular Ergodic Control

We consider the problem of finding a real numberand a functionu satisfying the PDE maxf� � �uf; jDu j� 1 gD 0; x 2 R n : Heref is a convex, superlinear function. We prove that there is a unique� � such that the above PDE has a viscosity solutionusatisfying limjxj!1u.x/=jx jD 1. Moreover, we show that associated to� � is a convex solutionuwithD 2 u � 2 L 1 .R n / and give two min-max formulae for� � . � � has a probabilistic interpre- tation as being the least, long-time averaged (ergodic) cost for a singular control problem involvingf . © 2011 Wiley Periodicals, Inc.
Characterization of radiation pressure and thermal effects in a nanoscale optomechanical cavity

Optical forces in guided-wave nanostructures have recently been proposed as an effective means of mechanically actuating and tuning optical components. In this work, we study the properties of a photonic crystal optomechanical cavity consisting of a pair of patterned Si3N4 nanobeams. Internal stresses in the stoichiometric Si3N4 thin-film are used to produce inter-beam slot-gaps ranging from 560-40 nm. A general pump-probe measurement scheme is described which determines, self-consistently, the contributions of thermo-mechanical, thermo-optic, and radiation pressure effects. For devices with 40 nm slot-gap, the optical gradient force is measured to be 134 fN per cavity photon for the strongly coupled symmetric cavity supermode, producing a static cavity tuning greater than five times that of either the parasitic thermo-mechanical or thermo-optic effects.
Controlled foam laundry formulations

Heavy duty laundry systems are complex formulations containing a large number of ingredients. They can be formulated to produce a variety of foam profiles. This work has demonstrated that laundry detergent systems, which consist principally of biodegradable nonionic active components, may be formulated to exhibit low and moderate controlled foam profiles under typically American and European working conditions. In addition these formulations demonstrate excellent detergency properties when compared to currently distributed commercial brands.
A priori pre-equilibrium decay models☆

Abstract Intranuclear transition rates for a priori calculations of pre-equilibrium decay have been calculated using both the imaginary optical potential and a nucleon-nucleon scattering approach which is improved over earlier results used in the geometry dependent hybrid model. Spectra calculated using these intranuclear transition rates in several formulations of the hybrid model are compared with each other and with experimental results for the reactions 209 Bi(p, p') and 54 Fe(p, p') at incident proton energies of 39 and 62 MeV. Results calculated in several ways are found to be in reasonable agreement with data in view of the uncertainties of the calculation. It is shown that the initial target-projectile interaction may be treated as a direct reaction term for which it is essential to consider the geometry of the reaction with respect to the nuclear density distribution but, based on estimated nucleon mean free paths, higher order pre-equilibrium terms may be treated in a non-localized fashion. It is also shown that the relative lifetime dependences assumed in many exciton model calculations are in reasonable agreement with results from nucleon-nucleon scattering calculations at excitation energies below 25 MeV, but get progressively poorer at higher excitations.
Designing a System for Patients Controlling Providers’ Access to their Electronic Health Records: Organizational and Technical Challenges

BACKGROUND Electronic health records (EHRs) are proliferating, and financial incentives encourage their use. Applying Fair Information Practice principles to EHRs necessitates balancing patients’ rights to control their personal information with providers’ data needs to deliver safe, high-quality care. We describe the technical and organizational challenges faced in capturing patients’ preferences for patient-controlled EHR access and applying those preferences to an existing EHR.
Nitro- para- and meta- substituted 2-phenylindolizines as potential antimicrobial agents

Abstract Some para- and meta -substituted nitro-2-phenylindolizines were prepared and tested as potential antimicrobial agents. The syntheses were accomplished via the Chichibabin-Stepanow synthesis, using the properly substituted α -picoline and phenacyl bromides followed by direct nitration.
Vision at the workplace: Part I — Guidelines for the practitioner

Visual problems at the workplace are unlikely to affect the worker's health although they may cause unnecessary stress on the visual system, sometimes resulting in headache and fatigue. Visual performance may be affected, resulting in increased errors and time/unit. Visual problems can be due to deficiencies in the individual, the lighting, or the task. In most cases, visual deficiencies can be corrected with corrective lenses, either spectacles or contact lenses. Lighting deficiencies will be divided into quantity and quality. There are two basic approaches to lighting workstations—uniform lighting and nonuniform (task) lighting. In addition to light color and light orientation and variability, glare also affects the quality of light. Glare reduction techniques include (1) reducing brightness of the glare source and (2) reducing size of the glare source. Indirect (reflected) glare reduction techniques include (1) reducing amount of light from the source and (2) reorientation of the reflecting surface.
Adam Smith and Three Theories of Altruism

Smith a propose une vision particuliere de l’altruisme qui devrait etre pertinente pour la recherche contemporaine sur le sujet. Celle-ci constitue le socle sur lequel repose sa critique de trois differentes theories. On retrouve ces theories dans trois approches modernes : l’approche « egoiste » de Robert Axelrod, « egocentrique » de Gary Becker et « altercentrique » de Robert Franck. L’approche de Axelrod reproduit l’erreur que Smith a decelee chez Mandeville, la theorie de Becker celle qu’il a identifiee chez Hobbes et la vision de Mead/Franck celle qu’il a mise en evidence dans l’approche de Francis Hutcheson ou d’autres figures du courant ecossais des Lumieres.
Nested Variant of Urothelial Carcinoma: A Clinicopathologic and Immunohistochemical Study of 12 Cases

Nested variant of urothelial carcinoma is characterized by confluent small nests and abortive tubules of mildly atypical neoplastic cells infiltrating the lamina propria and/or muscularis propria of the bladder. Despite its deceptively bland histomorphologic appearance, the lesion is reported to have an aggressive behavior. The collective immunohistochemical expression of suppressor genes, growth factor, and proliferation activity marker has not been previously studied in this disease. Formalin-fixed, paraffin-embedded archival tissues from 12 cases of nested variant of urothelial carcinoma were stained with monoclonal antibodies to p21, p27, p53, EGF-R, and bcl-2, as well as the proliferation marker MIB-1. The area of predominant immunoreactivity was also evaluated. The pattern of immunostaining was compared with the clinical parameters. p21 was positive in 10 of 12 cases and located at the deepest portion of the tumor in 5 of 10 positive cases. Immunoreactivity for p27 was seen in 11 of 12 cases and limited to the superficial portion of the tumor in 9 of 11 positive cases. Only 3 and 2 of 12 cases were positive for p53 and bcl-2, respectively. MIB-1 immunoreactivity ranged from 2 to 35% of the neoplastic cells, with most tumors showing a proliferation index of >15%. Follow-up ranged from 3 to 30 months (mean, 17.6 mo). All patients except one were alive, although three patients developed metastases. Nested variant of urothelial carcinoma is a deceptively benign-appearing neoplasm with potential of deep invasion and metastases. Immunohistochemically, nested variant of urothelial carcinoma shares some features with high-risk conventional urothelial carcinomas, such as loss of p27 expression and high proliferation index. Nevertheless, p53, bcl-2, or EGF-r immunoreactivity is not frequently seen.
Mathematical Models of the Transient Heat Flow to Fuel Droplets.

Two models for the preheat stage of conventional liquid fuel droplets and of emulsified fuel droplets in combustion gases are analyzed theoretically. These models contain the effects of transient heat conduction to the droplets. In the first model, the droplet and gas temperatures vary temporally hut only the gas temperature varies spatially; i.e., the droplet temperature is spatially uniform. Numerical examples, computed from this model, for both the droplet and gas temperatures are given. In the second model, both the droplet and gas temperatures vary spatially and temporally. Numerical examples computed from this second model for the surface and average temperature of the droplet are given. These analyses show that the temperature gradients inside droplets of oil and water are small compared to those in the combustion gases near the droplet; that temperature profiles given by both models are very similar. In particular, the predicted times at which micro-explosions are expected to occur agree within 10 percent of each other.
DEGREE THEORETIC METHODS IN OPTIMAL CONTROL

Publisher Summary This chapter focuses on degree theoretic methods in optimal control and presents some problems of optimal control and presents an analysis of a coincidence degree for (L, N). Though the notion of coincidence degree has been extended to multivalued functions by Pruszko and Tarafdar and Suat Khoh Teo, the ill-definition ∂l creates some difficulties because it is usually required that N(x, p) be nonempty for all (x, p) in some open bounded set. However, the definition of coincidence degree may be extended to this case by approximating l by a sequence of well-behaved convex functions {ln}. The chapter also focuses on the existence theorem.
An Algorithm to Compact a VLSI Symbolic Layout with Mixed Constraints

A popular algorithm to compact a VLSI symbolic layout is to use a graph algorithm similar to finding the 'longest-path' in a network. The algorithm assumes that the spacing constraints on the mask elements are of the lower-bound type. However, to enable the user to have close control over the compaction result, a desired symbolic layout system should allow the user to add either the equality or the upper-bound constraints on selected pairs of mask elements as well. This paper proposes an algorithm which uses a graph-theoretic approach to solve efficiently the compaction problem with mixed constraints.
Divergent pathways of acetaldehyde and ethanol decarbonylation on the Rh(111) surface

Abstract The decomposition reactions of acetaldehyde and ethanol on the Rh(111) surface were compared in temperature-programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) experiments. The decarbonylation of acetaldehyde produced methane at 267 K in TPD. The selectivity to methane was dependent on the initial coverage of acetaldehyde. For acetaldehyde coverages less than 0.05 monolayer, no methane was desorbed, but for a coverage that saturated the first layer, methane was produced with 50% selectivity. Coadsorbing deuterium with a low coverage of acetaldehyde resulted in the enhancement of methane production. This result indicates that the selectivity to methane was partially controlled by the availability of hydrogen atoms on the surface required to hydrogenate the hydrocarbon species produced by acetaldehyde decarbonylation. Monodeuterated methane was the primary methane product observed after these coadsorption experiments. Thus it was concluded that acetaldehyde decarbonylates via a methyl migration mechanism on the Rh(111) surface. Decarbonylation of ethanol did not produce methane. The absence of methane production indicated that the decomposition of ethanol on the Rh(111) surface did not proceed via dehydrogenation to adsorbed acetaldehyde, but instead, ethanol appeared to dehydrogenate by methyl hydrogen abstraction resulting in the formation of an oxametallacycle. Since this proposed intermediate rapidly dehydrogenated to carbon monoxide and surface carbon, it was difficult to characterize spectroscopically. The existence of an ethanol decomposition pathway that does not include acetaldehyde intermediates indicates that ethanol formation on supported Rh catalysts may not be the result of acetaldehyde hydrogenation. Support for ethanol synthesis pathways that both do and do not include acetaldehyde can be found in previous studies of ethanol formation on supported Rh catalysts. This surface science study has allowed the identification of some of the factors that may control the selectivity of higher oxygenate decomposition/synthesis pathways.
Dispersion and alignment of carbon nanotubes in polycarbonate

Dispersion and alignment of carbon nanotubes in thermoplastic polymers such as polycarbonate have been studied. Dispersion was accomplished by mixing in a conical twin-screw extruder and alignment was carried out using a fiber-spinning apparatus. The effects of mixing time and fiber draw rates on dispersion and alignment were investigated. Uniform dispersions were produced with relatively short residence times in the extruder. Excellent alignment of carbon nanotubes in nanocomposite filaments was obtained when the fiber draw rate was greater than 70 m/min. The ability to closely control the dispersion and alignment of carbon nanotubes in polymers is expected to lead to the development of nanocomposites with desirable electronic and structural properties.
Nuclear reactions in inhomogeneous cosmologies

Abstract This paper presentes revised and additional nuclear reactions rates originally published in [G.R. Caughlan and W.A. Fowler, At. Data Nucl. Data Tables 40 (1988) 283; W.A. Fowler, Baryonic Dark Matter (Kluwer, Deventer, 1990) pp. 257–264]. Also presented are the reactions rates associated with these new reactions. The use of these rates may help remove the ambiguity of whether results reported by different groups are, to some extent, an artifact of the different reaction networks employed. It is stressed that many of these reactions play important roles in the nucleosynthesis, but their rates are poorly determined and thus deserve further experimental study. Using the reaction network of Malaney and Fowler supplemented by the reactions presented here, it is shown that the production of 9 Be in inhomogeneous models is strongly dependent on the density contrast R , and on the high-density volume fraction f v . Consequently, observations of 9 Be in stars could lead to vital information on the value of these crucial, but poorly determined, parameters. It is concluded that 9 Be may be used as a possible indicator of inhomogeneity at the time of nucleosynthesis only for a certain range of f v R . For an ohm b =1 universe the appropriate range would be f v R ≳10. ohm b is the ratio of the universal baryon (b) density to the “critical” density between an open and closed universe which can be calculated from Hubble's constant ( H 0 ). For H 0 =58 km s −1 Mpc −1 the critical density now is 6.3 × 10 −30 g cm −3 [W.A. Fowler, Q.J.R. Astr. Soc. 28 (1987) 87].
Synchronous and Resonant Satellite Orbits Associated With Equatorial Ellipticity

for rarefied gases," Rarefied Gas Dynamics, edited by F. M. Devienne (Pergamon Press, London, 1960), pp. 161-191. 42 Street, R. E., "Shock wave structure based on Ikenberry-Truesdell approach to kinetic theory of gases," NASA TN D-365 (1960). 43 Talbot, L. and Scala, S. M., "Shock wave structure in a relaxing diatomic gas," Rarefied Gas Dynamics, edited by L. Talbot (Academic Press, New York, 1961), pp. 603-622. 44 Talbot, L. and Sherman, F. S., "Structure of weak shock waves in a monatomic gas," NASA Memo. 12-14-58W (1958). 45 Van Dyke, M., "Second-order compressible boundary layer theory with application to blunt bodies in hypersonic flow," Hypersonic Flow Research, F. R. Riddell, Ed. (Academic Press, New York, 1962), pp. 37-76. 46 White, D. R., "Turbulent structure of gaseous detonation," Phys. Fluids 4, 465-480 (1961). 47 Wood, W. W., "Existence of detonations for small values of the rate parameter," Phys. Fluids 4, 46-60 (1961). 48 Wray, K. L., "Chemical kinetics of high temperature air," Hypersonic Flow Research, F. R. Riddell, Ed. (Academic Press, New York, 1962), pp. 181-204. 49 Ziering, S. and Ek, F., "On the mean free path definition in the Mott-Smith shock wave solution," Phys. Fluids 4, 765-766 (1961). 50 Ziering, S., Ek, F. and Koch, P., "Two fluid model for the structure of neutral shock waves," Phys. Fluids 4, 975-987 (1961).
Irreducibility testing and factorization of polynomials

It is shown that under certain hypotheses, irreducibility testing and factorization of polynomials with integer coefficients are polynomial time reducible to primality testing and factorization of integers, respectively. Combined with recently discovered fast primality tests, this yields an almost polynomial time irreducibility algorithm. The assertions of irreducibility produced by this algorithm are always certain and yield short proofs of irreducibility.
Evaluating a vector of the Fed’s forecasts

Abstract In this paper we present a multivariate analysis of the Federal Reserve’s forecasts. First, we use existing univariate methods to evaluate each of the Fed’s forecasts of the ten major expenditure categories of real GDP which have not previously been evaluated in the literature. Second, we apply a recently developed methodology to evaluate jointly the vector of these forecasts. Finally, we use the same methodology to determine whether the Fed’s forecasts of GDP growth, inflation, and unemployment, taken together, present an accurate overall view of the economic situation, and compare the Fed’s forecasts to those of the Survey of Professional Forecasters. We find that the Fed’s forecasts were generally consistent with the overall conditions that actually occurred. We also find that the Fed’s forecasts and those of the Survey of Professional Forecasters are quite similar overall.
Brillouin actuation of whispering-gallery modes on microfluidic optomechanical oscillators

We experimentally actuate mechanical whispering-gallery modes and wineglass modes in ultra-high-Q microfluidic optomechanical resonators by means of the electrostrictive Brillouin scattering nonlinearity. These devices mechanically oscillate at frequencies ranging over several orders-of-magnitude (7.4 MHz–11 GHz). We test the devices with sucrose solutions to determine sensitivity of the mechanical frequency to various liquid parameters.
Global map building and look-ahead implementation on an outdoor autonomous vehicle

In autonomous mobile robot applications, local obstacle avoidance methods are frequently coupled with an initialized global map in order to achieve a complete navigation scheme. Unfortunately, global map information is often unavailable for global map initialization. In these situations, the designer must develop a navigation scheme such that the mobile robot either doesn't need a global map to achieve its goal or it builds the global map autonomously. This work presents a simple algorithm for developing a quasi-free space global map. The algorithm is based on the premise that the robot will be given multiple attempts at a particular goal. During early attempts, the mobile robot explores using solely local obstacle avoidance. While exploring, the robot records where it has been and uses this information on subsequent attempts. Further, this paper also outlines the look-ahead method by which the global map is implemented. Finally, both simulated and experimental results are presented. Testing of this algorithm was performed on an outdoor mobile robot, known as Navigator, which was developed at Virginia Tech.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Development of a Gas Turbine Combustor Dilution Zone Design Analysis

Recent advancements in developing an analytical technique applicable to gas turbine combustion design problems is presented. A three-dimensional mathematical model defines the trajectories of a system of dilution jets within a combustor dilution zone and transition section. Interactions of jets with each other and confining walls are included. The analytical simulation and solution techniques are detailed due to the uniqueness of modeling the multijet trajectories and interactions in a confined environment. Comparisons of the analytical predictions with available experimental data are shown. Results illustrating practical combustor flow problems show that progress has been made toward the realization of a useful combustor design capability.
Metabolic Engineering: The Ultimate Paradigm for Continuous Pharmaceutical Manufacturing

Research and development (R&D) expenditures by pharmaceutical companies doubled over the past decade, yet candidate attrition rates and development times rose markedly during this period. Understandably, companies have begun downsizing their pipelines and diverting investments away from R&D in favor of manufacturing. It is estimated that transitioning to continuous manufacturing could enable companies to compete for a share in emerging markets. Accordingly, the model for continuous manufacturing that has emerged commences with the conversion of late-stage intermediates into the active pharmaceutical ingredient (API) in a series of continuous flow reactors, followed by continuous solid processing to form finished tablets. The use of flow reactions for API synthesis will certainly generate purer products at higher yields in shorter times compared to equivalent batch reactions. However, transitioning from batch to flow configuration simply alleviates transport limitations within the reaction milieu. As the catalogue of reactions used in flow syntheses is a subset of batch-based chemistries, molecules such as natural products will continue to evade drug prospectors. Also, it is uncertain whether flow synthesis can deliver improvements in the atom and energy economies of API production at the scales that would achieve the levels of revenue growth targeted by companies. Instead, it is argued that implementing metabolic engineering for the production of oxidized scaffolds as gateway molecules for flow-based addition of electrophiles is a more effective and scalable strategy for accessing natural product chemical space. This new paradigm for manufacturing, with metabolic engineering as its engine, would also permit rapid optimization of production variables and allow facile scale-up from gram to ton scale to meet material requirements for clinical trials, thus recasting manufacturing as a tool for discovery.
Sub-optimality of the Friedman rule in Townsend's turnpike and stochastic relocation models of money: do finite lives and initial dates matter?

Abstract The Friedman rule, a widely studied prescription for monetary policy, is optimal in Townsend's turnpike model of money; it is not so in the overlapping generations version of his stochastic relocation model of money. We investigate these monetary models in the light of this disparity. To this end, we create a modified version of the turnpike model that generates the same stationary monetary equilibria as does the two-period overlapping generations model with random relocation. We exploit this equivalence to explain the aforementioned disparity. We also discuss the importance of whether or not the economy has an initial date.
(1+p)-dimensional open D (p−2) brane theories

The dynamics of a Dp-brane can be described either by an open string ending on this brane or by an open D(p−2)-brane ending on the same Dp-brane. The ends of the open string couple to a Dp-brane worldvolume gauge field while the boundary of the open D(p−2)-brane couples to a (p−2)-form worldvolume potential whose field strength is Poincare dual to that of the gauge field on the Dp-brane worldvolume. With this in mind, we find that the Poincare dual of the fixed rank-2 magnetic field used in defining a (1+p)-dimensional noncommutative Yang-Mills (NCYM) gives precisely a near-critical electric field for the open D(p−2)-brane. We therefore find (1+p)-dimensional open D(p−2)-brane theories along the same line as for obtaining noncommutative open string theories (NCOS), OM theory and open Dp-brane theories (ODp) from NS5 brane. Similarly, the Poincare dual of the near-critical electric field used in defining a (1+p)-dimensional NCOS gives a fixed magnetic-like field. This field along with the same bulk field scalings defines a (1+p)-dimensional noncommutative field theory. In the same spirit, we can have various (1 + 5)-dimensional noncommutative field theories resulting from the existence of ODp if the description of open D(4−p)-brane ending on the NS5 brane is insisted.
Double blind randomized trial of sucralfate vs placebo during radical radiotherapy for head and neck cancers.

Background This study sought to determine whether sucralfate prophylaxis during a course of high dose radiation therapy (RT) for head and neck cancer decreases acute side effects. Methods Patients receiving curative intent RT for advanced head and neck cancers participated in a single institution double-blind randomized trial comparing sucralfate to placebo. Patients were stratified according to fractionation, use of concurrent chemotherapy, Karnofsky performance status (KPS), age, and pretreatment presence of a feeding gastrostomy. Patients were prospectively evaluated during weekly treatment checks, and analyzed with regard to time (measured in terms of dose) until development of the following: weight loss, mucositis, pain, nutritional intake, and need for a treatment break. After completion of RT, time until healing was similarly compared. Results Fifty-two patients received sucralfate and 50 received placebo. The mean (±SD) prescribed dose was 69 ± 7 Gy. Sixty-nine patients received BID fractionation and 27 received concurrent chemotherapy. No difference was detected in any outcome measure in the direct comparison between the two groups. On multivariate analysis, weight loss >5% or >10% occurred more frequently in patients receiving chemotherapy (p < 0.01 and p = 0.05, respectively). Grade 3 mucositis was more common in patients receiving chemotherapy (p = 0.05) or BID fractionation (p = 0.04) or having a poor KPS (p = 0.02). Interval to healing was not associated with any of the pretreatment- or treatment-related factors. Sucralfate did not result in any additional toxicity. Conclusions Prophylactic treatment with sucralfate during high-dose head and neck RT did not decrease acute treatment side effects. Other modalities should be investigated. © 1999 John Wiley & Sons, Inc. Head Neck 21: 760–766, 1999.
Stereoselective synthesis of cembranolide precursors via macrocyclization of α-alkoxyallylstannane aldehydes

Abstract An efficient route to the MOM-protected α-hydroxylallylstannane propargylic aldehyde 15 starting from geraniol is described. Cyclization of 15 to the 14-membered cembranolide intermediate 16 , a 7:1 mixture of cis and trans isomers, is effected in 80% yield with BF 3 ·OEt 2 at −78°C.
Resonances on Some Geometrically Finite Hyperbolic Manifolds

Abstract We first prove the meromorphic extension to ℂ for the resolvent of the Laplacian on a class of geometrically finite hyperbolic manifolds with infinite volume and we give a polynomial bound on the number of resonances. This class notably contains the quotients Γ\ n+1 with rational nonmaximal rank cusps previously studied by Froese-Hislop-Perry.
Boundary-layer receptivity due to distributed surface imperfections of a deterministic or random nature

Acoustic receptivity of a Blasius boundary layer in the presence of distributed, two-dimensional surface irregularities is investigated analytically. It is shown that, out of the entire spatial spectrum of the surface irregularities, only a narrow band of Fourier components can lead to an efficient conversion of the acoustic input at any given frequency to an unstable eigenmode of the boundary-layer flow. The location and the width of this most receptive band of wave numbers is fixed by the requirement of a relative detuning of O(Rinf1.b.sup−3/8) or less with respect to the instability wave number at the lower-branch station for the frequency under consideration. Surface imperfections in the form of discrete-mode waviness in this range of wave numbers then lead to initial instability amplitudes which are larger by a factor of O(Rinf1.b.sup3/8) than the amplitudes resulting from a single, isolated roughness element of streamwise extent comparable with the instability wavelength at the lower-branch location. In contrast, random irregularities which are spatially homogeneous in nature, and also possess a continuous spectrum in the streamwise direction, lead to instability amplitudes that are intermediate to those caused by the periodic and isolated irregularities, respectively, being, in fact, of the same order as the geometrical mean of the amplitudes in the latter two cases. A physical explanation for these asymptotic scalings is given, in addition to providing an analytical expression for the expected value of the instability amplitude for an ensemble of statistically irregular surfaces with random phase distributions. The duality between the localized and distributed receptivity analyses is also discussed.
N-body collisions in high-energy nuclear reactions

Abstract We study the effect of many-body collisions in simulations of nuclear dynamics. First, for elastic three-nucleon processes, the simplest pion-exchange diagrams are calculated and the ensuing scattering amplitude is used in a schematic calculation illustrating the evolution in momentum space. Then the collision integral in the BUU model is generalized to include many-body collisions. The number of baryons involved in a given collision is determined on the basis of the energy-dependent binary interaction range and their energy is shared microcanonically. This leads to a general treatment of N -body scattering (both elastic and inelastic) that can easily be incorporated into existing BUU codes. We study a variety of experimental observables, for the case of Ca + Ca at bombarding energies of 200–1000 MeV per nucleon, such as anisotropy, flow angle, sidewards momentum, and backwards yield. The treatment is subsequently extended to include particle production and the production of kaons is especially considered. Overall, the results of the standard BUU model are affected relatively little by the incorporation of N -body collisions.
Numerical simulation of hole pressure for a Johnson-Segalman fluid

Abstract The elastic hole pressure for plane, steady, creeping shear flow over a transverse slot of a Johnson-Segalman fluid is studied numerically. To correctly apply the theory of Higashitani, Pritchard, Baird and Lodge (HPBL), we start with a modified hole-pressure relation (MHPR) and simulate the hole-pressure measurement using the finite element method and the multiple-mesh extrapolation technique. The path integrals in MHPR and HP are evaluated to check the error cancellation phenomenon and a full instrument simulation is conducted to predict N1. The agreement between numerical simulation and analytical prediction is satisfactory, within the range of De⩽ 1. This study suggests that N1 can be predicted via the hole-pressure measurement to a sufficient approximation for the Johnson-Segalman model.
One- and two-dimensional wave fronts in diffusive systems with discrete sets of nonlinear sources

Abstract We study the dynamics of one-and two-dimensional diffusion systems with sets of discrete nonlinear sources. We show that wave fronts propagating in such systems are pinned if the diffusion constant is below a critical value which corresponds to a saddle-node bifurcation of the dynamics. In two dimensions we find that the dissipation is enhanced and moving plain and circular fronts are stable with respect to any perturbations.
Probing the epoch of reionization with Milky Way satellites

While the connection between high-redshift star formation and the local Universe has recently been used to understand the observed population of faint dwarf galaxies in the Milky Way (MW) halo, we explore how well these nearby objects can probe the epoch of first light. We construct a detailed, physically motivated model for the MW satellites based on the state-of-the-art Via Lactea II dark-matter simulations. Our model incorporates molecular hydrogen (H 2 ) cooling in low-mass systems and inhomogeneous photoheating feedback during the internal reionization of our own Galaxy. We find that the existence of MW satellites fainter than M V ≈ -5 is strong evidence for H 2 cooling in low-mass haloes, while satellites with ―5 > M v > -9 were affected by hydrogen cooling and photoheating feedback. The age of stars in very low-luminosity systems and the minimum luminosity of these satellites are key predictions of our model. Most of the stars populating the brightest MW satellites could have formed after the epoch of reionization. Our models also predict a significantly larger dispersion in M 300 values than observed and a number of luminous satellites with M 300 as low as 10 6 M ⊙ .
Analysis of welding-induced residual stresses with the ADINA system

Abstract The welding-induced residual stresses analysis procedure (WIRSAP), based on the ADINA system of nonlinear finite element software, is described and the results of several WIRSAP analyses are discussed. Several two-dimensional (2D) axisymmetric WIRSAP analyses have been performed for pipe girth welds and for several multi-pass girth-like welds attaching small nozzles to large, thick-walled pressure vessels. The analytical methodology follows closely the basic techniques outlined by Rybicki et al., enhanced by the use of several specialized modeling techniques available in the ADINA system. For example, the element birth option is used to simulate the addition of weld metal, and the mixed pressure/ displacement element formulation is used, in conjunction with the temperature-dependent bi-linear plasticity material model. Some of the welds analyzed involve backing rings, which were subsequently ‘machined off’ via use of the element death option. The auto-time-stepping algorithm and the matrix update iteration scheme are used in the structural solutions. WIRSAP involves, in general, a pass-by-pass analysis of the uncoupled thermal and structural problems, but some analyses have been performed with an ‘enveloping’ technique for grouping several weld passes together to study the feasibility of modeling multi-pass welds on a layer-by-layer basis. The analyses discussed here are all 2D, but most are large problems ( > 5000 nodes and > 5000 four-noded elements, with a large number of solution steps). As such, they pose significant challenges to both software and hardware resources. Pre- and post-processing operations are performed on a network of Silicon Graphics workstations, and ADINA and ADINA-T are executed on a 64 MW, eight-processor CRAY Y/MP. Nominally 50 solution steps are utilized for each weld pass, and weld joints involving as many as 31 individual weld passes have been analyzed on a pass-by-pass basis. Results from several of these WIRSAP analyses are discussed, and the potential use of WIRSAP in a hypothetic attachment weld design optimization study is illustrated.
Progress in mitral and aortic regurgitation

Abstract Over the past 15 years there has been rapid and dramatic change in the therapy for valvular heart disease. When mitral and aortic regurgitation are severe, they inevitably cause left ventricular damage, eventually resulting in death. However, when surgical correction of these lesions is timed appropriately, longevity can approach that of a normal population after surgery. As surgical techniques have improved, surgery is now indicated earlier in the course of these diseases. It is clear that some patients with mitral and aortic regurgitation require surgery even though they are entirely asymptomatic. However, it must be emphasized that mitral and aortic regurgitation are quite different from one another. These different lesions result in different loading conditions, different pathophysiologies, and have different means for surgical correction. All of these issues impact on the proper timing of surgery and are discussed.
Direct synthesis of methanol, dimethyl ether, and paraffins from syngas over Pd/zeolite Y catalysts

Abstract CO hydrogenation has been studied over Pd/NaY and Pd/HY catalysts prepared by ion exchange. By controlling the calcination program, Pd/NaY catalysts can be tuned to selectively produce either branched C4+ hydrocarbons or CH3OH and CH3OCH3. On Pd/HY catalysts, C2H6 and C3H8 predominate. Dissociative adsorption of CO over small Pd particles leads to formation of methane and an interstitial PdC0.13 compound, detected by XRD. Reduction with H2 converts PdC0.13 to Pd and methane. During CO hydrogenation catalysis, palladium particles grow, leading to local collapse of the zeolite lattice. Pd migration is also manifest from changes in the Pd/Si ratio detected by XPS. The reaction network reveals bifunctional catalysis: formation of CH3OH on Pd particles is followed by its conversion to CH30CH3 and hydrocarbons over acid sites. Readsorption of hydrocarbons on the Pd particles results in hydrogenation of unsaturated compounds and to changes in the activity, selectivity, and deactivation behavior of the catalysts.
Oxidation-chlorination of binary Ni-Cr alloys in flowing Ar-O2-Cl2 gas mixtures at 1200 K

Nickel-chromium alloys are resistant to oxidation because of the selective oxidation of chromium to form a protective Cr2O3 scale. In chlorine-containing environments, volatile corrosion products can also be formed. The mixed oxidation-chlorination of Ni-4.5Cr, Ni-13.8Cr, and Ni-26.5Cr (by weight) alloys in Ar-O2-Cl2 gas mixtures is investigated using thermogravimetric analysis and atmospheric-pressure-sampling mass spectrometry, followed by examination of the corrosion products using scanning electron microscopy and X-ray diffraction analysis. The overall kinetics of the corrosion are affected by the relative amounts of oxides and chlorides formed and the composition of the oxide corrosion products.
Measurement of knowledge structures acquired through instruction, experience, and decision aid use

Abstract This study investigates a method for measuring knowledge structure development in novice accountants by extending Bonner and Walker [Bonner, S. and P. Walker. 1994. The effects of instruction and experience on the acquisition of auditing knowledge. The Accounting Review 69: 157–178.], which examined the effects of instruction and experience on the acquisition of declarative and procedural knowledge. We employ Pathfinder network scaling, a recently developed and validated measure of knowledge structure acquisition, to determine whether the combinations of instruction and experience previously found to be effective in promoting declarative and procedural knowledge acquisition result in the development of expert-like knowledge structures. Further, we examine the effectiveness of a simple decision aid in promoting the acquisition of expert-like knowledge structures through experience with the decision aid. Results from two laboratory experiments indicate that Pathfinder-based measures of knowledge structure can effectively capture the effects of training and decision aid use on the development of expertise. The findings suggest that assessments of knowledge structures are valuable tools for measuring the effectiveness of training programs, and such assessments can be applied in decision domains where traditional measures of knowledge acquisition are insufficient or infeasible. Finally, the results indicate that properly designed decision aids can impart expert-like knowledge structures to novice decision makers, and these knowledge structures are the key to expertise.
Asymmetric allylation of aldehydes catalyzed by substoichiometric amounts of chiral phosphoramides

Abstract The asymmetric allylation and crotylation of aromatic aldehydes with allylic trichlorosilanes catalyzed by substoichiometric quantities of chiral phosphoramides were carried out with good enantiomeric excess (up to 88% ee). Phosphoramides 3 and 4 , prepared from (S)-proline, gave chiral homoallylic alcohols 6 and their enantiomers 7 , respectively, with similar levels of enantioselectivity.
Thiopurine methyltransferase: mouse kidney and liver assay conditions, biochemical properties and strain variation

Thiopurine methyltransferase (TPMT) catalyzes the S-methylation of aromatic and heterocyclic thiol compounds including drugs such as 6-mercaptopurine (6-MP) and 6-thioguanine. In humans, the level of TPMT activity is inherited in a monogenic fashion. It would be important to develop an experimental animal model in which the genetic regulation of TPMT could be studied. Therefore, TPMT activity was measured in kidney and liver homogenates from A/J inbred mice. Apparent Michaelis (Km) constants for the two cosubstrates for the reaction, 6-MP and S-adenosyl-L-methionine (Ado-Met), in mouse kidney were 7.0 X 10(-4) M and 2.4 X 10(-6) M respectively. Apparent Km constants for 6-MP and Ado-Met in mouse liver were 5.4 X 10(-4) M and 2.1 X 10(-6) M respectively. The pH optimum for the reaction was 6.7 in both tissues, and over 95% of the TPMT activity in both mouse liver and kidney was "soluble" after centrifugation at 100,000 g for 1 hr. 3,4-Dimethoxy-5-hydroxybenzoic acid, an inhibitor of human kidney TPMT, decreased mouse kidney and liver enzyme activities by more than 95% at a concentration of 1 mM. TPMT activities were then measured in liver and kidney tissue from nine additional inbred strains of mice aged 7-8 weeks. Six of the nine inbred strains had TPMT activities very similar to those found in A/J animals. However, three strains, the C57BL/6J, C57BL/6ByJ and AKR/J, had significantly lower levels of activity in both liver and kidney than did any of the seven other strains. Liver TPMT activities in these three strains were only 23-32% of the average activity in A/J mouse liver. Kidney enzyme activities in the same three strains averaged 49-62% of the average activity in A/J mouse kidneys. These striking differences in TPMT activity among inbred mouse strains will make it possible to test the hypothesis that inheritance regulates variations in TPMT activity in this experimental animal.
Bimolecular 4+2-cycloaddition reactions of cross conjugated betaines with Electron rich π-systems

Abstract Bicyclic anhydro-2-oxo-4-hydroxy-1,3-thiazinium hydroxides undergo 1,4-dipolar cycloadditions with various electron rich π-systems to give 4+2-cycloadducts which on further heating, extrude carbonyl sulfide producing substituted α-pyridones.
Quantum cohomology of the Hilbert scheme of points in the plane

We determine the ring structure of the equivariant quantum cohomology of the Hilbert scheme of points of ℂ2. The operator of quantum multiplication by the divisor class is a nonstationary deformation of the quantum Calogero-Sutherland many-body system. A relationship between the quantum cohomology of the Hilbert scheme and the Gromov-Witten/Donaldson-Thomas correspondence for local curves is proven.