cssi/SciSciGPT-SciSciNet huggingface dataset:
Introducing sustainability concepts in lower division engineering core courses

Engineers will play a significant role in designing, building and implementing creative solutions to major global challenges that we face. To prepare the 21st century engineer, sustainability concepts needs to be covered systematically throughout the curriculum and in all majors of the engineering departments. This NSF-funded project is integrating fundamental concepts of sustainability into two core lower division engineering courses (Introduction to Engineering and Introduction to Materials). The outcome of the project is three learning modules covering the topics of renewable and non-renewable energy sources, energy conversion and efficiency, water and energy, and product life cycle analysis. The modules include lectures, hands-on laboratories, and interactive Excel spreadsheets. The modules, along with the accompanying equipment and software, are currently being piloted in SJSU courses and will be disseminated to local the community colleges through a hands-on workshop for community college teachers. Preliminary assessment materials have been collected for the past year to determine effectiveness of the modules.
Flows, Fragmentation, and Star Formation. I. Low-Mass Stars in Taurus

The remarkably filamentary spatial distribution of young stars in the Taurus molecular cloud has significant implications for understanding low-mass star formation in relatively quiescent conditions. The large scale and regular spacing of the filaments suggests that small-scale turbulence is of limited importance, which could be consistent with the driving on large scales by flows that produced the cloud. The small spatial dispersion of stars from gaseous filaments indicates that the low-mass stars are generally born with small velocity dispersions relative to their natal gas, of the order of the sound speed or less. The spatial distribution of the stars exhibits a mean separation of about 0.25 pc, comparable to the estimated Jeans length in the densest gaseous filaments, and is consistent with roughly uniform density along the filaments. The efficiency of star formation in filaments is much higher than elsewhere, with an associated higher frequency of protostars and accreting T Tauri stars. The protostellar cores are generally aligned with the filaments, suggesting that they are produced by gravitational fragmentation, resulting in initially quasi-prolate cores. Given the absence of massive stars that could strongly dominate cloud dynamics, Taurus provides important tests of theories of dispersed low-mass star formation and numerical simulations of molecular cloud structure and evolution.
TEMPERATURE CORRELATIONS IN A FINITE UNIVERSE

We study the effect of a finite topology on the temperature correlations of the cosmic microwave background in a flat universe. Analytic expressions for the angular power spectrum are given for all possible finite flat models. We examine the angular correlation function itself, pointing out visible and discrete features that arise from topology. While observations of the power spectrum on large angular scales can be used to place bounds on the minimum topology length, cosmic variance generally restricts us from differentiating one flat topology from another. Schemes that acknowledge anisotropic structures, such as searches for ghosts, circles or geometric patterns, will be needed to further probe topology.
Teacher characteristics and student achievement: evidence from teacher surveys

Teachers and peers are believed to have a strong influence on student achievement, but the specific characteristics that affect student achievement are hard to identify. This paper utilizes teacher survey data to investigate teacher characteristics that are not usually available in administrative data, as well as more readily available attributes such as experience and education. Classroom fixed effects explain a large portion of within-student variation in test score growth, suggesting a potentially important role for teachers and peers. Teacher characteristics are generally insignificant predictors of student achievement, especially for the lower grades.
Clinical experience with routine diode dosimetry for electron beam radiotherapy

Abstract Purpose: Electron beam radiotherapy is frequently administered based on clinical setups without formal treatment planning. We felt, therefore, that it was important to monitor electron beam treatments by in vivo dosimetry to prevent errors in treatment delivery. In this study, we present our clinical experience with patient dose verification using electron diodes and quantitatively assess the dose perturbations caused by the diodes during electron beam radiotherapy. Methods and Materials: A commercial diode dosimeter was used for the in vivo dose measurements. During patient dosimetry, the patients were set up as usual by the therapists. Before treatment, a diode was placed on the patient's skin surface and secured with hypoallergenic tape. The patient was then treated and the diode response registered and stored in the patient radiotherapy system database via our in-house software. A customized patient in vivo dosimetry report showing patient details, expected and measured dose, and percent difference was then generated and printed for analysis and record keeping. We studied the perturbation of electron beams by diodes using film dosimetry. Beam profiles at the 90% prescription isodose depths were obtained with and without the diode on the beam central axis, for 6–20 MeV electron beams and applicator/insert sizes ranging from a 3-cm diameter circular field to a 25 × 25 cm open field. Results: In vivo dose measurements on 360 patients resulted in the following ranges of deviations from the expected dose at the various anatomic sites: Breast (222 patients) −20.3 to +23.5% (median deviation 0%); Head and Neck (63 patients) −21.5 to +14.8% (median −0.7%); Other sites (75 patients) −17.6 to +18.8% (median +0.5%). Routine diode dosimetry during the first treatment on 360 patients (460 treatment sites) resulted in 11.5% of the measurements outside our acceptable ±6% dose deviation window. Only 3.7% of the total measurements were outside ±10% dose deviation. Detailed investigations revealed that the dose discrepancies, overwhelmingly, were due to inaccurate diode orientation and positioning, especially in the regions with rapidly changing contours and/or sloping surfaces. The presence of a diode in the treatment field was found, in some cases, to cause significant dose reduction, most noticeable with smaller fields and lower energy beams. The reduction in dose ranged from 16% (for a 6 MeV beam and a 3 cm diameter circular field) to 4% (for a 12 MeV beam and a 10× 10 cm field). Conclusions: Diode dosimetry was found to be convenient and valuable for verifying in real time the dose delivery accuracy of electron beam treatments, but with some caveats. When treating a small field by low energy electrons, frequent use of diodes is undesirable, because it might result in appreciable reduction of dose to the target volume.
Divergence of Infinite-Variance Nonradial Solutions to the 3D NLS Equation

We consider solutions u(t) to the 3d NLS equation i∂ t u + Δu + |u|2 u = 0 such that ‖xu(t)‖ L 2 = ∞ and u(t) is nonradial. Denoting by M[u] and E[u], the mass and energy, respectively, of a solut...
High-resolution millimeter-wave mapping of linearly polarized dust emission: Magnetic field structure in orion

We present 1.3 and 3.3 mm polarization maps of Orion-KL obtained with the BIMA array at approximately 4'' resolution. Thermal emission from magnetically aligned dust grains produces the polarization. Along the Orion ridge the polarization position angle varies smoothly from about 10° to 40°, in agreement with previous lower resolution maps. In a small region south of the Orion hot core, however, the position angle changes by 90°. This abrupt change in polarization direction is not necessarily the signpost of a twisted magnetic field. Rather, in this localized region, processes other than the usual Davis-Greenstein mechanism might align the dust grains with their long axes parallel with the field, orthogonal to their normal orientation.
Effects of providing total cost of ownership information on consumers’ intent to purchase a hybrid or plug-in electric vehicle

Abstract Energy-saving technologies have a difficult time being widely accepted in the marketplace when they have a high initial purchase price and deferred financial benefits. Consumers might not realize that, in the long-run, the financial benefits from reduced energy consumption offset much or all of the initial price premium. One strategy to address consumer misconception of this advantage is to supply information on the “total cost of ownership”, a metric which accounts for the purchase price, the cost of the fuel, and other costs over the ownership period. In this article, we investigate how providing information on five-year fuel cost savings and total cost of ownership affects the stated preferences of consumers to purchase a gasoline, conventional hybrid, plug-in hybrid, or battery electric vehicle. Through an online survey with an embedded experimental design using distinct labels, we find that respondent rankings of vehicles are unaffected by information on five-year fuel cost savings. However, adding information about total cost of ownership increases the probability that small/mid-sized car consumers express a preference to acquire a conventional hybrid, plug-in hybrid, or a battery-electric vehicle. No such effect is found for consumers of small sport utility vehicles. Our results are consistent with other findings in the behavioral economics literature and suggest that further evaluation of the effects of providing consumers with information on the total cost of vehicle ownership is warranted.
SYNTHESIS OF THERMALLY STABLE MESOPOROUS HEXAGONAL ALUMINOPHOSPHATE MOLECULAR SIEVES

Thermally stable mesoporous hexagonal aluminophosphates (UHM-1) and silicoaluminophosphates (UHM-3) are synthesized based on ion-pair interactions of aluminophosphate species in the presence of tetramethylammonium hydroxide with a cationic surfactant [C 16 H 33 NMe 3 Cl].
Homeownership in the 1980s and 1990s: aggregate trends and racial gaps

Abstract Housing policy under the Clinton and Bush Administrations has sought to boost homeownership while also narrowing racial gaps in owner-occupancy rates. Against that backdrop, homeownership rose sharply in the 1990s, but white-minority gaps remain in excess of 25 percentage points. We analyze these patterns using data from the 1983 to 2001 Survey of Consumer Finances. Results indicate that household characteristics explain most of the increase in homeownership and roughly two-thirds of the white-minority homeownership gap. Credit barriers account for no more than 5 percentage points of the remaining gap. This suggests that policy makers will need to look beyond innovations in mortgage finance if their goal is to further expand homeownership.
CHANGES IN TRADING ACTIVITY FOLLOWING STOCK SPLITS AND THEIR EFFECT ON VOLATILITY AND THE ADVERSE‐INFORMATION COMPONENT OF THE BID‐ASK SPREAD

We examine changes in trading activity around stock splits and their effect on volatility and the adverse-information component of the bid-ask spread. Even after controlling for microstructure biases, we find a significant increase in volatility after the split. Changes in total volatility and in its permanent component are positively related to changes in the number of trades. This suggests that both informed and noise traders contribute to changes in trading activity. Further, while the adverse-information component of the spread increases unconditionally after the split, the change is negatively related to the change in trading activity. The results suggest that a crucial determinant of liquidity changes after a stock split is the success of the split in attracting new trades in the security.
Abundant lipid and protein components of drusen.

Background Drusen are extracellular lesions characteristic of aging and age-related maculopathy, a major retinal disease of the elderly. We determined the relative proportions of lipids and proteins in drusen capped with retinal pigment epithelium (RPE) and in RPE isolated from non-macular regions of 36 human retinas with grossly normal maculas obtained <6 hr after death. Methodology/Principal Findings Druse pellets were examined by light and electron microscopy. Component proteins were extracted using novel methods for preserved tissues, separated, subjected to tryptic digestion and LC-MS(MS)2 analysis using an ion trap mass spectrometer, and identified with reference to databases. Lipid classes were separated using thin layer chromatography and quantified by densitometry. Major druse components were esterified cholesterol (EC), phosphatidylcholine (PC), and protein (37.5±13.7, 36.9±12.9, and 43.0±11.5 ng/druse, respectively). Lipid-containing particles (median diameter, 77 nm) occupied 37–44% of druse volume. Major proteins include vitronectin, complement component 9, apoE, and clusterin, previously seen in drusen, and ATP synthase subunit β, scavenger receptor B2, and retinol dehydrogenase 5, previously seen in RPE. Drusen and RPE had similar protein profiles, with higher intensities and greater variability in drusen. C8, part of the complement membrane attack complex, was localized in drusen by immunofluorescence. Conclusions/Significance At least 40% of druse content is comprised by lipids dominated by EC and PC, 2 components that are potentially accounted for by just one pathway, the secretion of lipoproteins by RPE. Manipulating genes encoding apolipoprotein pathways would be a fruitful approach to producing drusen with high EC content in laboratory animals. Therapies that directly mitigate drusen should prepare for the substantial volume of neutral lipids. The catalog of major druse proteins is nearing completion.
Skeleton simplicial evaluation codes

For a subspace arrangement over a finite field we study the evaluation code defined on the arrangements set of points. The length of this code is given by the subspace arrangements characteristic polynomial. For coordinate subspace arrangements the dimension is bounded below by the face vector of the corresponding simplicial complex. The minimum distance is determined for coordinate subspace arrangements where the simplicial complex is a skeleton. A few examples are presented with high minimum distance and dimension.
Formation of heavily doped n-type layers in GaAs by multiple ion implantation

N-type layers in GaAs with high free electron concentrations have been produced by multiple implantation of Ga, As, or P with dopant species such as Se, Si, or Ge. The implants that have been investigated include Si, Si + P, Ge, Ge + As, Se, and Se + Ga. The multiple implants Si + P, Ge + As, and Se + Ga gave higher peak carrier concentrations, especially at lower anneal temperatures, than did the respective single implants Si, Ge, and Se. In fact, Ge when implanted alone produced a p-type layer while the Ge + As multiple implant produced an n-type layer. Multiple implants with Si and Ge as dopants showed significant thermal diffusion during the anneal. Multiple implants of Ga with Se, on the other hand, resulted in reduced thermal diffusion in comparison with single Se implants.
Interaction of disturbances with an oblique detonation wave attached to a wedge

The linear response of an oblique overdriven detonation to imposed free‐stream disturbances or to periodic movements of the wedge is examined. The free‐stream disturbances are assumed to be steady vorticity waves and the wedge motions are considered to be time periodic oscillations either about a fixed pivot point or along the plane of symmetry of the wedge aligned with the incoming stream. All disturbances are assumed to have wavelengths large compared to the thickness of the detonation so that the detonation is considered to be a region of infinitesimal thickness in which a finite amount of heat is released. The response to the imposed disturbances is a function of the Mach number of the incoming flow, the wedge angle, and the exothermicity of the reaction within the detonation. It is shown that, as the degree of overdrive increases, the amplitude of the response increases significantly; furthermore, a fundamental difference in the dependence of the response on the parameters of the problem is found between the response to a free‐stream disturbance and to a disturbance emanating from the wedge surface.
Study of gas-phase molecular recognition using Fourier transform ion cyclotron resonance mass spectrometry (FTICR/MS)

The application of Fourier transform ion cyclotron resonance (FTICR) mass spectrometry to the quantitative study of molecular recognition in the gas phase is reviewed. Because most quantitative measurements are dependent on accurate determination of the pressure of a neutral reagent, methods for accurate pressure measurement in FTICR, including gauge calibration using a reaction with known rate constants (the traditional method), exothermic proton transfer rate measurement (often the best method when accurate neutral pressures in the trapping cell are desired), and linewidth measurement (a little-used, but generally applicable method) are discussed. The use of rate constant measurements in molecular recognition is illustrated with examples employing natural abundance isotopic labeling to study self-exchange and 2 : 1 ligand:metal complex formation kinetics in crown ether-alkali cation systems. Self-exchange rates do not correlate with alkali cation/crown cavity size relationships, whereas 2 : 1 complex formation kinetics correlate strongly with size relationships. The use of exchange equilibrium constant measurements to characterize molecular recognition is illustrated by alkali cation exchanges between 18-crown-6 and the isomers of dicyclohexano-18-crown-6. These experiments show that the alkyl-substituted ligand binds alkali cations better than unsubstituted 18-crown-6 in the gas phase, in accordance with expectations based on the higher polarizability of the alkyl-substituted ligand. Further, the metal binding thermochemistry differs for the two dicyclohexano-18-crown-6 isomers, with the bowl-shaped cis-syn-cis isomer binding all the alkali cations more strongly than the cis-anti-cis isomer. The measurement of entropies and enthalpies associated with one of the most subtle forms of molecular recognition, enantiomeric discrimination, is illustrated by studies of the discrimination between enantiomers of chiral amines by dimethyldiketopyridino-18-crown-6. This chiral ligand binds chiral primary ammonium cations that have the opposite absolute configuration at their stereocenter more strongly than the enantiomer with the same absolute configuration. Gas-phase studies show that this enantiomeric discrimination is enthalpic in origin, likely related to more favorable pi-pi stacking for the preferred enantiomer. Entropy disfavors binding of the preferred enantiomer.
Vision-guided robotic fabric manipulation for apparel manufacturing

Methods are described for vision-guided robotic control of fabric motion for performing simulated joining operations for apparel manufacturing. The determination of robot motion paths is based on visual information defining the position of the fabric edges in world coordinates. The usefulness of the shape analysis and motion control algorithms is demonstrated by experimentation with an integrated robot and vision fabric-handling system. Results of these tests show that using machine vision for planning robot motion provides an effective solution for implementing automated robotic fabric manipulation. >
Acute Reversibility of Pulmonary Hypertension Predicts Neither Long-Term Hemodynamic Response Nor Outcome in Patients Awaiting Heart Transplantation

For transplant wait-list patients with end-stage congestive heart failure, reversibility of pulmonary hypertension tested with acute administration of vasodilators is a prerequisite to listing for transplantation. We have shown that the magnitude of the initial pulmonary vasodilatory response to nitroprusside predicts neither the extent of the long-term hemodynamic response nor the subsequent need for transplantation versus clinical improvement and removal from transplant consideration.
A Direct Synthesis of 3,5‐Dibromo‐O‐methyl‐L‐tyrosine

Abstract A simple and efficient synthesis of 3,5‐dibromo‐O‐methyl‐L‐tyrosine is described by direct bromination of commercial O‐methyl‐L‐tyrosine with bromine in aqueous hydrochloric acid. MO calculations are presented to explain a difference in the degree of substitution of O‐methyl‐L‐tyrosine in different solvents.
"Your poor boy no father no mother": 'Orphans,' Alienation, and the Perils of Atlantic Child Slave Biography

This article explores the social and political context embedded in Atlantic child slave biography, such as claims about family, parentage, and orphanhood in narratives of child enslavement. I examine the claims of orphanhood and the fictive kinship relations marshaled by James B. Covey, the interpreter during the trials of La Amistad , during his Atlantic passages as examples of the struggle against alienation to “remake” his political and social being. More than adult slaves, children deployed kinship language and idioms as part of a larger struggle to forge and preserve relationships with benefactors. Although kinship claims are an experience common across slave populations, a focus on the difficulties of writing a biography of child claims draws attention to the extreme vulnerability of child slaves and their pressing need for patron/client relationships.
Family Approaches to Treatment for Obsessive Compulsive Disorder

Abstract This article reviews the family constellation of patients with obsessive compulsive disorder (OCD), the presence of OCD symptoms among family members, and familial aspects including parental attachment, expressed emotion (EE), and family accommodation. Some evidence supports a negative effect of hostility, emotional overinvolvement, and criticism perceived by the patient on behavioral treatment outcome. However, actual criticism observed by the relative during an interview was associated with more benefit from therapy. Family accommodation predicted poorer family functioning and more severe OCD symptoms after behavioral treatment. A review of the limited treatment literature indicates no actual tests of the effects of psychoeducational and supportive treatments although several reports suggest they are useful for families and patients. Including relatives in treatment has proved beneficial in some studies, especially with children, but not in others. Multiple family groups that focus on behaviora...
A nested transaction mechanism for LOCUS

Atomic transactions are useful in distributed systems as a means of providing reliable operation in the face of hardware failures. Nested transactions are a generalization of traditional transactions in which transactions may be composed of other transactions. The programmer may initiate several transactions from within a transaction, and serializability of the transactions is guaranteed even if they are executed concurrently. In addition, transactions invoked from within a given transaction fail independently of their invoking transaction and of one another, allowing use of alternate transactions to accomplish the desired task in the event that the original should fail. Thus nested transactions are the basis for a general-purpose reliable programming environment in which transactions are modules which may be composed freely.A working implementation of nested transactions has been produced for LOCUS, an integrated distributed operating system which provides a high degree of network transparency. Several aspects of our mechanism are novel. First, the mechanism allows a transaction to access objects directly without regard to the location of the object. Second, processes running on behalf of a single transaction may be located at many sites. Thus there is no need to invoke a new transaction to perform processing or access objects at a remote site. Third, unlike other environments, LOCUS allows replication of data objects at more than one site in the network, and this capability is incorporated into the transaction mechanism. If the copy of an object that is currently being accessed becomes unavailable, it is possible to continue work by using another one of the replicated copies. Finally, an efficient orphan removal algorithm is presented, and the problem of providing continued operation during network partitions is addressed in detail.
Contact-Dependent Demyelination by Mycobacterium leprae in the Absence of Immune Cells

Demyelination results in severe disability in many neurodegenerative diseases and nervous system infections, and it is typically mediated by inflammatory responses. Mycobacterium leprae, the causative organism of leprosy, induced rapid demyelination by a contact-dependent mechanism in the absence of immune cells in an in vitro nerve tissue culture model and in Rag1-knockout (Rag1-/-) mice, which lack mature B and T lymphocytes. Myelinated Schwann cells were resistant to M. leprae invasion but undergo demyelination upon bacterial attachment, whereas nonmyelinated Schwann cells harbor intracellular M. leprae in large numbers. During M. leprae-induced demyelination, Schwann cells proliferate significantly both in vitro and in vivo and generate a more nonmyelinated phenotype, thereby securing the intracellular niche for M. leprae.
FRICTION FACTOR OF MAGNETO-RHEOLOGICAL FLUID FLOW IN GROOVED CHANNELS

The focus of this work is to study surface effects on the friction factor a magneto-rheological (MR) fluid flowing through a grooved channel under various magnetic fields and volumetric flow rates. Based on the experimental data, a relation is developed for the friction factor of MR fluid in channel flow in terms of Mason number evaluated at the surface, and the depth of the grooves. Using this relation, the pressure loss of a MR fluid flowing through a channel with grooved walls can be determined without implementing a constitutive model for MR fluids or utilizing the concept of shear yield stress. Several grooves with different configurations in channel walls have been considered. From the experimental results it has been demonstrated that under an applied magnetic field, the grooved surface would increase the friction factor of MR fluid flow significantly when comparing to the surface without grooving. The depth of grooves plays an important role in this increment.
Distinguishing Adoption and Entrenchment of Management Practices: A Framework for Analysis

This paper distinguishes two stages of management practices in organizations initial adoption and institutional entrenchment. Adopted practices that are not yet entrenched are referred to as fads, and entrenchment is defined as the embedding of practices such that they are likely to endure and resist pressure for change. Next, the paper proposes five bases that give rise to both adoption and entrenchment: modelling, culture, education, regulation, and technical rationality. Modelling is seen to be operative mostly in the initial adoption phase, while culture and education are characteristic of the entrenchment stage. Based on these, a framework is offered to help researchers assess the extent to which a practice is a fad or has been entrenched. The framework is used in an abbreviated example to illustrate the differences between quality circles (a practice popular in the early 1980s) and total quality management (a complex set of practices indicative of institutionalization). The evidence, once organized ...
From place-based to people-based exposure measures.

An essential task in any study that examines the contextual determinants of health behaviors and outcomes is to identify the appropriate geographic area to be used as the basis for deriving exposure measures. Historically, most studies start from conventional and static notions of place or neighborhood, which is often identified in terms of administrative units such as census tracts, census block groups, or post-code areas. These units are convenient because available data of censuses and surveys that can be used to derive contextual measures are often tied to them.
Facile benzo-ring construction via palladium-catalyzed functionalization of unactivated sp3 C-H bonds under mild reaction conditions.

A practical synthetic method for the annulation of benzo-rings by the intramolecular coupling of an aryl iodide and a methylene C−H bond is described. The palladium-catalyzed C−H functionalization is directed by an aminoquinoline carboxamide group, which can be easily installed and removed. High yields and broad substrate scope were achieved. An additive of ortho-phenyl benzoic acid, identified from a systematic screening, functions as a critical ligand for the catalytic process under mild condition, even at near room temperature.
UNIVERSAL ASPECTS OF TWO-DIMENSIONAL YANG-MILLS THEORY AT LARGE N

We show that the large N partition functions and Wilson loop observables of two-dimensional Yang-Mills theories admit a universal functional form irrespective of the gauge group. We demonstrate that U(N) QCD2 undergoes a large N, third order phase transition on the projective plane at an area coupling product of π2/2. We use this as a lemma to provide a direct transcription for the partition functions and phase portraits of Yang-Mills theory from the U(N) on RP2 at large N to the other classical Lie groups on S2. We compute the expectation value of the Wilson loops in the fundamental representation for SO(N) and Sp(N) on the two-sphere. Finally we compare the strong and weak coupling limit of these expressions with those found elsewhere in the literature.
Spin Related Effects in Transport Properties of "Open" Quantum Dots

We study the interaction corrections to the transport coefficients in open quantum dots (i.e., dots connected to leads of large conductance $G⪢{e}^{2}∕\ensuremath{\pi}\ensuremath{\hbar}$), via a quantum kinetic equation approach. The effects of all the channels of the universal (in the random matrix theory sense) interaction Hamiltonian are accounted for at one-loop approximation. For the electrical conductance we find that even though the magnitude of the triplet channel interaction is smaller than the charging energy, the differential conductance at small bias is greatly affected by this interaction. Furthermore, the application of a magnetic field can significantly change the conductance due to the Zeeman splitting, producing finite bias anomalies. For the thermal conductance we find that the Wiedemann-Franz law is violated by the interaction corrections, and we investigated the effect of magnetic field on the Lorentz ratio for contacts of finite reflection. The charge and triplet channel corrections to the electrical and thermal conductance vanish for reflectionless contacts. In the latter case the temperature and magnetic-field dependence of the conductance is determined by the Maki-Thompson correction in the Cooper channel.
Holographic Studies of Shock Waves Within Transonic Fan Rotors

NASA has funded two separate contracts to apply pulsed laser holographic interferometry to the detection of shock patterns in the outer span regions of high tip speed transonic rotors. The first holographic approach used ruby laser light reflected from a portion of the centerbody just ahead of the rotor. These holograms showed the bow wave patterns upstream of the rotor and the shock patterns just inside the blade row near the tip. Much of the region of interest was in the shadow of the blade leading edge and could not be visualized. The second holographic approach, on a different rotor, used light transmitted diagonally across the inlet annulus past the centerbody. This approach gave a more extensive view of the region bounded by the blade leading and trailing edges, by the part span shroud and by the blade tip. These holograms showed the passage shock emanating from the blade leading edge and a moderately strong conical shock originating at the intersection of the part span shroud leading edge and the blade suction surface. Due to a limited viewing angle, the bow waves upstream of the rotor could not be observed, and only limited details of the trailing edge shocks were obtained. The results of these studies were promising. Reasonable details of the shock patterns were obtained from holograms which were made without extensive rig modifications. These studies indicated several advancements that would give even better results. Larger viewing windows, and holographic plates would permit a wider viewing angle and give much more coverage of the regions of interest. Shorter time delay for double-pulsed holograms is also desirable. This would minimize blade movement and give clearer holograms. With these improvements of technique effective visualization of shock configurations at least outboard of part span shrouds should be possible. Accurate definition of shock configurations will aid in attainment of improved transonic fan and compressor rotors.
Stereocontrolled synthesis of diamines from iodolactams

Abstract Displacement of iodide from iodolactams by azide occurs with retention of configuration if a catalytic amount of NaH is added, due to the intervention of an N-acyl-aziridine. Several diamine equivalents and a spermidine analogue are prepared in this way.
Low-drag airfoils in transonic flow of dense gases

Low-drag airfoils for transonic flow of BZT gases are constructed through a nonlinear small-disturbance theory on this topic. This kind of transonic flow is characterized by the high nonlinearity of the fluid thermodynamic behavior that is closely coupled with its compressible flow dynamics. Utilizing BZT gases may result in low drag exerted on airfoils operating at high transonic speeds. This advantage may be further improved by a proper design of the airfoils' shape. The modified airfoils are characterized by arcs along which the flow is sonic and that connect to a sharp tail. These airfoils may give the highest free stream Mach number for which the flow is nowhere supersonic. Using an analysis in the hodograph (velocity) plane, an analytical formula is derived to describe the sonic arc. Numerical computations using the Euler equations demonstrate that the modified airfoils have significantly lower pressure drag against standard airfoils and their critical Mach number is increased to higher values.
Redetermination of the Newtonian Gravitational Constant G

The universal Newtonian gravitational constant is being redetermined at the National Bureau of Standards with use of the method of Boyes in which the period of a torsion pendulum is altered by the presence of two 10.5-kg tungsten balls. The difference in the squares of the frequencies with and without the balls is proportional to $G$. The resulting value of $G$ is (6.6726\ifmmode\pm\else\textpm\fi{}0.0005)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}11}$ ${\mathrm{m}}^{3}$\ifmmode\cdot\else\textperiodcentered\fi{} ${\mathrm{sec}}^{\ensuremath{-}2}$\ifmmode\cdot\else\textperiodcentered\fi{} ${\mathrm{kg}}^{\ensuremath{-}1}$\ifmmode\cdot\else\textperiodcentered\fi{}
Cytology of Respiratory Epithelium as a Predictor of Respiratory Complications after Operation

A study of 111 patients undergoing elective surgery under general endotracheal anesthesia has shown that the pulmonary complication rate after operation is minimal in nonsmokers (7.9 percent) and that it rises steadily as smoking habit increases, reaching 43 percent in very heavy smokers. Peak expiratory flow rate and timed vital capacity (FEV1) were unaffected before operation except in very heavy smokers. The morphologic integrity of the ciliated tracheobronchial epithelial cells seen in smears obtained within ten minutes of the onset of anesthesia and quantitated by a scoring system, deteriorates progressively with increasing smoking habit and constitutes the most sensitive index for the prediction of diminished resistance to the stress of anesthesia and operation and of incipient chronic obstructive lung disease in smokers.
Neutron electric dipole moment and spontaneous CP breaking

Abstract In a model where CP is spontaneously broken, the aspon model, it is shown by extending previous arguments about B decay and the value of Re ( ϵ ′ / ϵ ) in the kaon system, that the neutron electric dipole moment D n is bounded from below by D n ≥10 −29 e.cm.
A highly active palladium catalyst system for the arylation of anilines

Abstract The chelating ligand bis[2-(diphenylphosphino)phenyl] ether (DPEphos), in combination with palladium acetate, forms a highly active catalyst system for the coupling of anilines with aryl bromides. The bisphosphine is easily prepared in large quantity and at low cost by a known procedure. The catalyst system is effective in coupling reactions involving a variety of substrates, including electron-poor anilines or electron-rich aryl bromides. In addition, it tolerates a high degree of steric congestion at both the aniline and the aryl bromide.
The utility of an in-hospital observation period after discontinuing intravenous antibiotics

Abstract PURPOSE: To determine whether observing patients overnight in the hospital after intravenous antibiotics have been discontinued is a useful way to identify important clinical events. SUBJECTS AND METHODS: We performed a retrospective chart review of patients admitted during a 6-month period to a tertiary care teaching hospital with a primary diagnosis of either pneumonia, urinary tract infection, or cellulitis who were treated with intravenous antibiotics. Charts were abstracted for patient characteristics, including comorbid illnesses and laboratory values, as well as for evidence of recurrent infection or other adverse events. RESULTS: Of the 374 patients in the study, 63 (17%) were discharged on the day intravenous antibiotics were discontinued. These patients were 10 years younger (P = 0.0009) and had fewer comorbid illnesses (P = 0.02) than those who were observed in the hospital. Recurrent infection was noted in 3 (1%; 95% confidence interval 0.2% to 3%) of the 308 patients who were observed. A mild adverse antibiotic reaction was also noted in three observed patients. The readmission rate to the same institution for recurrent infection was 3% for patients with an observation period and 2% for patients without an observation period (P = 0.70). CONCLUSIONS: Observing patients overnight in the hospital after discontinuing intravenous antibiotics is a common clinical practice. There was an extremely low incidence of adverse events during the observation period, and the events that did occur would have been discovered in an outpatient setting. In-hospital observation after discontinuing intravenous antibiotics is unnecessary for most patients with pneumonia, urinary tract infection, or cellulitis and greatly increases health-care costs.
Synthesis and SAR of selective small molecule Neuropeptide Y Y2 receptor antagonists

Highly potent and selective small molecule neuropeptide Y Y2 receptor antagonists are reported. The systematic SAR exploration of a hit molecule N-(4-ethoxyphenyl)-4-[hydroxy(diphenyl)methyl]piperidine-1-carbothioamide, identified from HTS, led to the discovery of highly potent NPY Y2 antagonists 16 (CYM 9484) and 54 (CYM 9552) with IC(50) values of 19 nM and 12 nM respectively.
Endoscopic repair of orbital blow-out fractures

Orbital floor blow-out fractures occur in repeatable patterns that can be classified as either medial or lateral to the infraorbital nerve. Medial fractures are the most common and are amenable to endoscopic repair, while lateral fractures are not. The keys to successful surgical repair of these injuries are adequate exposure, complete visualization of the entire fracture, and anatomic repair of the defect. Visualization of the posterior shelf is often challenging through traditional transconjunctival and subciliary incisions. These approaches also have known risks of postoperative eyelid malposition. The transmaxillary endoscopic approach to orbital blow-out fractures offers excellent visualization of the entire orbital floor. Fracture types can be evaluated and anatomically repaired without the need for an eyelid incision. Although this is a new and evolving technique, early experience suggests that the endoscopic approach is a safe, efficacious technique for orbital blow-out fracture repair. It offers improved visualization, anatomic fracture repair, no risk of postoperative eyelid complications, and good clinical results.
Total synthesis of (+/-)-psychotrimine.

A new process for the union of anilines with tryptamine derivatives has been developed, furnishing C-3 quaternized pyrroloindoline architectures. This chemoselective coupling of a tryptamine with 1.2 equiv of 2-iodoaniline proceeds efficiently on a gram-scale using only the simple reagents N-iodosuccinimide and triethylamine. Using this new reaction, the complex natural product psychotrimine has been fashioned with a rare level of efficiency and practicality. From a readily available bromotryptamine, only four steps (41−45% overall isolated yield) are necessary to procure gram quantities of the natural product. Functional group manipulations, protecting group chemistry, and unnecessary redox fluctuations have been minimized.
A Note on the Sticky Matroid Conjecture

A matroid is sticky if any two of its extensions by disjoint sets can be glued together along the common restriction (that is, they have an amalgam). The sticky matroid conjecture asserts that a matroid is sticky if and only if it is modular. Poljak and Turzik proved that no rank-3 matroid having two disjoint lines is sticky. We show that, for r ≥ 3, no rank−r matroid having two disjoint hyperplanes is sticky. These and earlier results show that the sticky matroid conjecture for finite matroids would follow from a positive resolution of the rank-4 case of a conjecture of Kantor.
Defective neutrophil function in myotonic dystrophy

Abstract Polymorphonuclear leukocytes (PMNs), obtained from 10 patients with myotonic dystrophy and 39 age-matched controls, were tested for chemotactic activity, chemiluminescence (CL), and phagocytosis. PMNs from 8 of the 10 patients had depressed chemotactic indexes (30 ± 23) as compared to controls (61 ± 18) (P
Optimal Compression in Natural Gas Networks: A Geometric Programming Approach

Natural gas transmission pipelines are complex systems whose flow characteristics are governed by challenging nonlinear physical behavior. These pipelines extend over hundreds and even thousands of miles. Gas is typically injected into the system at a constant rate, and a series of compressors is distributed along the pipeline to boost the gas pressure to maintain system pressure and throughput. These compressors consume a portion of the gas, and one goal of the operator is to control the compressor operation to minimize this consumption while satisfying pressure constraints at the gas load points. The optimization of these operations is computationally challenging. Many pipelines simply rely on the intuition and prior experience of operators to make these decisions. Here, we present a new geometric programming approach for optimizing compressor operation in natural gas pipelines. Using models of real natural gas pipelines, we show that the geometric programming algorithm consistently outperforms approaches that mimic the existing state of practice.
Analyticity of strictly static and strictly stationary, inheriting and non-inheriting Einstein–Maxwell solutions

Following the technique of Muller zum Hagen (Proc. Camb. Phil. Soc. 67: 415–421, 1970) we show that strictly static and strictly stationary solutions of the Einstein–Maxwell equations are analytic in harmonic coordinates. This holds whether or not the Maxwell field inherits the symmetry.
UNDERPRICING AND LONG-RUN PERFORMANCE OF SHARE ISSUE PRIVATIZATIONS IN THE EGYPTIAN STOCK MARKET

The underpricing of initial public offerings (IPOs) is documented for 53 share issue privatizations in Egypt between 1994 and 1998. Over several intervals (up to five years), I find mixed results: share issue privatizations sustain their positive performance and provide investors with positive abnormal returns over a one-year period; however, my results document negative abnormal returns over three- and five-year horizons. The initial excess returns are determined by ex ante uncertainty and oversubscription, whereas the aftermarket abnormal returns over a one-year period are driven by ex ante uncertainty and the price-earnings ratio. However, over three- and five-year periods, abnormal returns are significantly affected by initial excess returns, the price-earnings ratio, and, to a lesser extent, oversubscription. The empirical findings are consistent with IPO markets in which investors are overoptimistic about the performance of these issues but grow more pessimistic over time.
A Decade of Natural Gas Development: The Makings of a Resource Curse?

Abstract Many studies find that areas more dependent on natural resources grow more slowly – a relationship known as the resource curse. For counties in the south-central U.S., I find little evidence of an emerging curse from greater natural gas production in the 2000s. Each gas-related mining job created more than one nonmining job, indicating that counties did not become more dependent on mining as measured by employment. Increases in population largely mitigated a rise in earnings per job and crowding out. Furthermore, changes in the adult population by education level reveal that greater production did not lead to a less educated population.
Uniform embeddings of bounded geometry spaces into reflexive Banach space

We show that every metric space with bounded geometry uniformly embeds into a direct sum of l p (N) spaces (p's going off to infinity). In particular, every sequence of expanding graphs uniformly embeds into such a reflexive Banach space even though no such sequence uniformly embeds into a fixed l p (N) space. In the case of discrete groups we prove the analogue of a-T-menability - the existence of a metrically proper affine isometric action on a direct sum of l p (N) spaces.
Optical trapping of nanoparticles in resonant cavities: optical tweezers with single particle selectivity

We present the first theoretical analysis on the opto-mechanical interactions between a nanoparticle and the optical field inside an optical resonant nano-cavity. We illustrate single particle trapping from monodispersed particles based on size-dependent trapping dynamics.
An Algorithm for Unconstrained Quadratically Penalized Convex Optimization

Estimators are often defined as the solutions to data dependent optimization problems. A common form of objective function (function to be optimized) that arises in statistical estimation is the sum of a convex function V and a quadratic complexity penalty. A standard paradigm for creating kernel-based estimators leads to such an optimization problem. This article describes an optimization algorithm designed for unconstrained optimization problems in which the objective function is the sum of a non negative convex function and a known quadratic penalty. The algorithm is described and compared with BFGS on some penalized logistic regression and penalized L 3/2 regression problems.
Global well-posedness of slightly supercritical active scalar equations

The paper is devoted to the study of slightly supercritical active scalars with nonlocal diffusion. We prove global regularity for the surface quasigeostrophic (SQG) and Burgers equations, when the diffusion term is supercritical by a symbol with roughly logarithmic behavior at infinity. We show that the result is sharp for the Burgers equation. We also prove global regularity for a slightly supercritical two-dimensional Euler equation. Our main tool is a nonlocal maximum principle which controls a certain modulus of continuity of the solutions.