cssi/SciSciGPT-SciSciNet huggingface dataset:
Finite element modeling of a finite piezoelectric sensor/actuator embedded in a fluid-loaded plate

The sensor response of a piezoelectric transducer embedded in a fluid loaded structure is modeled using a hybrid numerical approach. The structure is excited by an obliquely incident acoustic wave. Finite element modeling in the structure and fluid surrounding the transducer region is used and a plane wave representation is exploited to match the displacement field at the mathematical boundary. On this boundary, continuity of field derivatives is enforced by using a penalty factor. Numerical results are presented for the sensor response and it is found that the sensor at that location is not only non-intrusive but also sensitive to the characteristic of the structure.
The impact of deep cumulus reflection on the ground-level global irradiance

The magnitude of solar irradiance reflected from deep cumulus clouds to the ground was evaluated using observations along the Front Range of Colorado. Solar-irradiance reflection around noon was found to cause increases of up to about 250 W/m sq. Enhancements of the global irradiance measured at the surface were observed to persist for 15-30 min. Occasionally, the increased global irradiance prevailed for a period of about 1 h. Model simulations implied similar patterns. It was evaluated that in some locations cloud reflection of solar irradiance may have a seasonal nonrandom pattern, thus increasing its significance. Estimation of the applied impact of cloud-reflected solar irradiance in several relevant situations is provided.
Restricted Ramsey configurations

In recent years there has been great development in the area becoming known as Ramsey Theory. In this paper we explore some restricted Ramsey theorems, best illustrated by the following beautiful result of NeSetIil and RodI. We begin with the first nontrivial example of the original theorem of Ramsey: Given any two-coloring of the edges of KB there exists a monochromatic triangle. Let us use the notation H--f (G), if any c-coloring of the edges of a graph H yields a monochromatic G. In this instance we write K, -+ (K& . It was asked, by P. Erdos, what graphs H have the property H--f (K& , and whether such H exist if you restrict the clique number w(H). In an elegant, though complex, paper Folkman [4] showed that there exist H satisfying H---f (K& , where w(H) = 3. A full generalization, using a totally different method, was given by NeSetIil and Rod1 [6], who showed that for all G, c there exists a graph H so that H -+ (G), and w(H) = w(G).
Balance and coordination for road and rail

Abstract The concern here is with coordination and investment balance between road and rail, especially in the next half century in North America. There may now be some overdevelopment of road in relation to rail and an associated technological lag in rail, where necessary system-wide standards make changes difficult. Coordination should be closer and possibly include more use of dual-mode (road-rail) vehicles. Rail might well expand into the very large market share now held by road and air. In view of this possibility, some suggestions on technology and public policy are discussed. It would appear that rail should shift somewhat out of feeder service and expand in linehaul service.
The Economics of Managing Scarce Water Resources

AbstractThis article surveys the literature on the economics of water scarcity and water demand. We examine demand estimation in diverted uses (urban, agricultural, and industrial), as well as the ...
Residue Cover and Surface-Sealing Effects on Infiltration

Surface sealing of bare soils often reduces rain infiltration, and crop-residue cover is commonly used to reduce surface sealing. We conducted numerical experiments to quantify effects of the percentage and distribution of residue cover on infiltration, and to provide guidelines for residue management. Residue cover was simulated over the soil surface in circular patches. Excess surface water from the bare surface-sealed areas was available for infiltration in nonsealed areas. Numerical simulations were conducted for combinations of (i) soil type, either a clay loam or loamy sand soil; (ii) percentage residue cover (P rc ); (iii) saturated hydraulic conductivity of the surface seal (K c ) relative to bulk soil (K,); (iv) residue-patch size with a constant P re ; and (v) rainfall intensity. The K c values had the greatest influence on infiltration as a function of P rc , This influence increased with rainfall intensity. For a given P rc , smaller patches gave greater relative infiltration due to differences in the lateral redistribution of infiltrated water. The target values of P rc that provided 95% relative infiltration varied from 40 to 80% for most combinations. Changing the geometry of the residues made no significant difference. We also tested a one-dimensional model with a spatially averaged saturated hydraulic conductivity (K ce ) for both covered and surface-sealed areas, and found that infiltration into a partially residue-covered soil could be estimated by the one-dimensional model for all cases of this study, when K c > 0. Finally, simulated infiltration qualitatively agreed with data sets of two independent field experiments under similar soil and rainfall conditions.
Dimensions of polyelectrolyte chains and concentration fluctuations in semidilute solutions of sodium–poly(styrene sulfonate) as measured by small-angle neutron scattering

Abstract We have measured the radius of gyration (Rg) of labeled polymer chains and the correlation length (ξ) for semidilute solutions of sodium–poly(styrene sulfonate) using small-angle neutron scattering (SANS). This is the first measurement of both length scales as the system is advanced to an unstable phase boundary by adding barium chloride salt. The Rg decreases from 80±2 to 54±2 A as the salt concentration is increased. Simultaneously, ξ is found to crossover from ξ≪Rg to ξ≫Rg. This crossover signals the enhancement of concentration fluctuations. In addition to extracting these length scales a crossover from mean-field to Ising criticality is observed. This conclusion is made within the context of a mean-field model, which supports temperature and salt-induced phase separation.
Wearing Union T-Shirts Undocumented Women Farm Workers and Gendered Circuits of Political Power

Numerous scholars have analyzed the political victimization of undocumented Mexican (im)migrant women. A study of women farm workers and state legislative politics in the Salinas Valley reveals gendered circuits of power that link undocumented women to Latino elected officials through their participation in electoral mobilizations led by the United Farm Workers union and facilitated by Latina organizers. Power flows from politicians to immigrant women and circulates in the reverse direction through the organizing efforts of undocumented activists. The political agency of these women farm workers is severely limited, however, by the mutual reinforcement of their immigration status and their economic marginalization.
Pneumatosis intestinalis in association with sigmoid volvulus: Value of lung windows during abdominal computed tomography

An 80-year-old man presented with progressive left-sided abdominal pain and distention. His abdominal plain radiograph revealed a focally dilated, redundant loop of sigmoid colon, having a mottled appearance. A computed tomographic (CT) scan with soft tissue settings showed no evidence of pneumatosis; however, with lung window settings [mean, —600 Hounsfield units (HU); width, 1000 HU], intramural pockets of air were seen in the bowel wall. The pneumatosis was presumed secondary to recurrent sigmoid volvulus. The utility of CT lung windows to evaluate the gastrointestinal tract in patients with acute abdominal conditions cannot be overemphasized.
MR Imaging-guided Percutaneous Tumor Ablation1

RATIONALE AND OBJECTIVES The purpose of this study is to compare the feasibility and precision of renal artery angioplasty and stent placement using two different MR scanners. MATERIALS AND METHODS MR imaging-guided angioplasty and stent placements were performed on seven pigs using 0.2 and 1.5 T scanners (Magnetom Open and Magnetom Sonata, Siemens Medical Solutions, Erlangen, Germany). For guidance of catheters, guide wires and stents susceptibility artifact-based tracking was used. The end point of each intervention was to position a stent in the renal artery with its proximal end at the level of the aortic wall. Procedure time and stent position were evaluated. RESULTS Catheterization, angioplasty, and stent placement were feasible using MRI guidance at both 0.2 and 1,5 Tesla. At 1.5 T all catheter manipulations and interventions were performed in less than 30 minutes. At 0.2 T the interventions took up to 90 minutes. No significant difference in the stent deviation was noted between the two scanners. CONCLUSION The use of a high-performance 1.5 T scanner helped to reduce the procedure time to half of that of a low-field system. Since no difference in stent placement precision was noted, a dedicated MR-stent might be mandatory for more precise stent placement.
Classical Magnetoresistance Measurements in AlxGa1-Xas/GaAs MODFET Structures - Determination of Mobilities

Abstract Classical magnetoresistance techniques have proven to be quite useful for obtaining mobility profiles in GaAs MESFET structures. Here we extend these techniques to AlxGa1−xAs/GaAs MODFET structures, which are more complicated because of multi-band conduction effects. A multi-band geometric-magnetoresistance (GMR) theory is developed in the relaxation-time approximation, and average and differential mobility expressions are defined. The magnetic-field dependences of these quantities permit determination of the mobilities associated with the various conducting bands. We apply this analysis to an Al0.3Ga0.7As/GaAs MODFET structure and obtain results for μ0, the lowest subband mobility, μ1–3, a combination of higher-subband mobilities, and μAlG, the mobility in the heavily doped Al0.3Ga0.7As layer. Complicating factors such as finite Hall field, energy-dependent relaxation time, parasitic resistance and gate current are also considered.
The role of the united nations in promoting international cooperation in peaceful uses of outer space

Abstract The Committee on the Peaceful Uses of Outer Space (COPUOS) was established in 1959 by the United Nations General Assembly in order to review and foster international cooperation in the peaceful uses of outer space and to consider legal issues arising from the exploration of outer space. Since its establishment, the Committee has addressed such issues as benefits from space activities, the definition and delimitation of outer space and the use of the geostationary orbit, implications of remote sensing, space sciences, space-based communications, navigation and meteorological systems, as well as use of nuclear power sources in outer space, space debris and spin-off benefits of space technology. At its session in 1996, a symposium on the ‘Utilization of micro- and small satellites for the expansion of low-cost space activities, taking into particular account the needs of developing countries’ was organized by COSPAR and IAF to complement discussions on this theme. It was noted at the symposium that the increasing number of small satellites, in particular the proposed introduction of multi-satellite ‘constellations’ at low orbits, would result in concentrations of satellite mass at certain regions of space around the Earth. Special provisions would be needed to minimize the probability of satellite breakups and collisions which might create more space debris and compromise the future of spaceflight.
Followup in Psychoanalysis: Clinical and Research Values

Data are presented from the Menninger project dealing specifically with the impact of routine planned followup on issues of treatment termination and resolution and on the nature of the post-treatment period
Automated Sensor Selection and Fusion for Monitoring and Diagnostics of Plunge Grinding

This paper deals with the development of an online monitoring system based on feature-level sensor fusion and its application to OD plunge grinding. Different sensors are used to measure acoustic emission, spindle power, and workpiece vibration signals, which are used to monitor three of the most common faults in grinding-workpiece burn, chatter, and wheel wear. Although a number of methods have been reported in recent literature for monitoring these faults, they have not found widespread application in industry as no single method or feature has been shown to be successful for all setups and for all wheel-workpiece combinations. This paper proposes a systematic approach, which allows the development and deployment of process-monitoring systems via automated sensor and feature selection combined with parameter-free model training, both of which are especially crucial for implementation in industry. The proposed algorithm makes use of "sparsity-promoting" penalty terms to encourage sensor and feature selection while the "hyperparameters" of the algorithm are tuned using an approximation of the leave-one-out error. Experimental results obtained for monitoring burn, chatter, and wheel wear from a plunge grinding test bed show the effectiveness of the proposed method.
Numerical Simulations of Bow Echo Formation Following a Squall Line–Supercell Merger

AbstractOutput from idealized numerical simulations is used to investigate the storm-scale processes responsible for squall-line evolution following a merger with an isolated supercell. A simulation including a squall line–supercell merger is compared to one using the same initial squall line and background environment without the merger. These simulations reveal that while bow echo formation is favored by the strongly sheared background environment, the merger produces a more compact bowing structure owing to a locally enhanced rear-inflow jet. The merger also represents a favored location for severe weather production relative to other portions of the squall line, with surface winds, vertical vorticity, and rainfall all being maximized in the vicinity of the merger.An analysis of storm-scale processes reveals that the premerger squall line weakens as it encounters outflow from the preline supercell, and the supercell becomes the leading edge of the merged system. Subsequent localized strengthening of th...
Top Quark FB Asymmetry And Flavor Physics

Abstract CDF and D0 have reported a deviation from the predicted SM forward-backward asymmetry in t t ¯ production at the Tevatron. BSM models that accommodate this observation must incorporate flavor physics and can lead to unacceptable levels of FCNC. We describe recent work on incorporating flavor naturally into these models, both for new physics mediated by scalars and by vectors, using the Minimal Flavor Violation principle. We then describe a new class of models that address the asymmetry, that use derivatively coupled spin-2 mediators. This type of interaction naturally suppresses FCNC.
Seasonal variability of salt transport during the Indian Ocean monsoons

[1] The seasonal variability of salinity transport in the Indian Ocean is investigated using the high-resolution global HYbrid Coordinate Ocean Model (HYCOM). Mechanisms and physical parameters that control the salinity budget are examined. Results show the influence of freshwater forcing and zonal advection as the dominant mechanisms of sea surface salinity (SSS) variability. Precipitation is highest in the eastern Bay of Bengal (BoB), where it shows seasonal variation, and in the south equatorial eastern Indian Ocean (EIO), where it was consistently high year-round. These patterns result in significant seasonal variation in the SSS in the BoB and almost no variation in the EIO. Zonal SSS transport was higher than meridional SSS transport with the strongest seasonality observed along the Sri Lankan region. Results of depth-integrated transport show northward salt transport in the bottom layers and a southward salt transport in the surface layers. The 4 year mean net flux of depth-integrated salt transport was southward (−154.8 × 106 kg/s to −552.4 × 106 kg/s) at all latitudes except at 20°N, where it was northward (396 × 106 kg/s). Transport generally increases southward with the highest transports occurring in the south (10°S–35°S) and a maximum at 30°S. Analyses of meridional Ekman volume and salt transport show a predominantly southward transport, an indication of the strong influence of SW monsoonal winds. It is anticipated that this study will be useful in computing salt transport using satellite-derived salinity data from the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) and NASA Aquarius salinity missions.
Copper(I) tert-Butyl 3-Oxobutanoate Complexes as Precursors for Chemical Vapor Deposition of Copper

Copper(I) complexes, (btac)CuL, where btac = tert-butyl 3-oxobutanoate and L = trimethylvinylsilane (TMVS), bistrimethylsilylacetylene (BTMSA), 1,5-cyclooctadiene (COD), 1,5-dimethyl-1,5-cyclooctadiene (DMCOD), 2-butyne, 1-trimethylsilyl-1-propyne (TMSP), trimethylphosphine (PMe3), and trimethyl phosphite [P(OMe)3], were synthesized. They produce copper metal via a thermally induced disproportionation reaction. (Btac)Cu[P(OMe)3] is especially attractive as a CVD precursor since it is a volatile liquid with high thermal stability. High-purity Cu films were deposited on TiN substrates at temperatures as low as 120 °C using (btac)Cu[P(OMe)3], while no deposition was observed on SiO2, even at 200 °C.
Engineers as Problem-Solving Leaders: Embracing the Humanities

As you develop the concept of a new curriculum and new pedagogy, as you try to attract and interest students in nanoscale science, large complex systems, product development, sustainability, and business realities, don't be tempted to crowd the humanities, arts, and social sciences out of the curriculum. The integral role of these subjects in US engineering education differentiates us from much of the rest of the world. Using problem solving as a backdrop leads to insights about what it takes to move beyond engineering competence to engineering leadership.
Reversible Switching of Magnetism in Thiolate-Protected Au25 Superatoms

We report reversible switching of paramagnetism in a well-defined gold nanoparticle system consisting of atomically monodisperse nanoparticles containing 25 gold atoms protected by 18 thiolates [abbreviated as Au25(SR)18]. The magnetism in these nanoparticles can be switched on or off by precisely controlling the charge state of the nanoparticle, that is, the magnetic state of the Au25(SR)18 nanoparticles is charge-neutral while the nonmagnetic state is an anionic form of the particle. Electron paramagnetic resonance (EPR) spectroscopy measurements establish that the magnetic state of the Au25(SR)18 nanoparticles possess one unpaired spin per particle. EPR studies also imply an unusual electronic structure of the Au25(SR)18 nanoparticle. Density functional theory calculations coupled with the experiments successfully explain the origin of the observed magnetism in a Au25(SR)18 nanoparticle as arising from one unpaired spin having distinct P-like character and delocalized among the icosahedral Au13 core of...
Determination of the Product Branching Fraction for HNF in the Reaction of HN3 with F

The reaction of F atoms with HN3 forms the products HF (+N3) or HNF (+N2). The product branching fraction for this reaction has been investigated in a room-temperature flow reactor using laser-induced fluorescence to monitor the concentration of HNF. A microwave discharge applied to a dilute flow of CF4 in argon served as the F atom source. Using reactant concentrations of (0.7−3.0) × 1012 and (1.7−20.0) × 1012 molecules cm-3 for CF4 and HN3, respectively, the rate constant for formation of HNF from HN3 + F was determined to be (6.3 ± 3.5) × 10-12 cm3 molecule-1 s-1. The average product branching fraction for formation of HNF was determined to be . The quenching rate constant of electronically excited HNF by Ar was determined to be (3.0 ± 0.3) × 10-11 cm3 molecule-1 s-l. In addition, secondary reactions between HNF and HN3, F, and H2S were examined. No reaction was observed to occur between HNF and HN3. The reaction of HNF + F was observed to occur with an estimated rate constant of 2.0 × 10-10 cm3 molecu...
Analyticity, and lack thereof, of thermo-elastic semigroups

We consider (linear) thermo-elastic plate equations under five sets of canonical B.C., including two cases where the mechanical and the thermal variables are coupled on the boundary. The challenging so-called free B.C. case of [Lag], [A-L] is included. The main results are as follows. If rotational forces are not accounted for, then the resulting s.c. contraction semigroup is, moreover, analytic on the natural (energy) space under all such canonical B.C. By contrast, if rotational forces are accounted for, then the corresponding s.c. contraction semigroup has a structural property that makes it more akin to a s.c. group (at least in the mechanical part); a fortiori, it is neither compact, nor differentiable, nor uniformly continuous for all t > 0. Analyticity of the s.c. thermo-elastic semigroup, particularly in the difficult case of free B.C., has been an open problem for some time in specialized circles. Similarly, a general description of the cases where analyticity fails has been the object of inquiries.
Synthesis of the 13-vertex rhodacarborane anion [4-(1,2:5,6-η-cod )-closo -4,1,6-RhC2B10H12]- and its reactions with electrophiles

Reduction of closo-1,2-C2B10H12, with sodium naphthalide in THF (THF = tetrahydrofuran), followed by addition of [Rh2(μ-Cl)2(cod)2] (cod = 1,2:5,6-η-cyclooctadiene) and [N(PPh3)2]Cl, affords the mo...
Equilibria for economies with production: constant-returns technologies and production planning constraints

We consider the computation of equilibria in two economic models that generalize the exchange model by including production. In the constant returns model, each producer has a convex, constant-returns-to-scale, technology. In particular, this means that if the technology can output a certain quantity of a good using as input certain quantities of other goods, then scaling all these quantities by a common, non-negative, number also results in a technologically feasible plan. The technology also accomodates the no-free-lunch property, which says that it is not possible to produce something from nothing. At a given price, the producer picks a technologically feasible plan that maximizes her profit. Associated with each consumer is an initial endowment of goods and a utility function that describes her preferences between various bundles of goods. At a given price, the consumer sells her initial endowment, thus obtaining a certain income, and demands the bundle of goods maximizing her utility among all bundles that she can afford at the given price with her income.
The excess enthalpies of (carbon dioxide+toluene) at 390.15, 413.15, 470.15 and 508.15 K from 7.60 to 17.50 MPa

Abstract The excess molar enthalpies HmE{xCO2 + (1 − x)C6H5CH3} were measured in the vicinity of the critical locus. Large changes in HmE were observed with changes in the compositions, temperatures, and pressures of the mixtures. Characteristic features of HmE(x) and HmE(T) for this binary mixture were examined. Two interpolating methods were compared in an effort to best-fit the results. The Soave equation of state was used to correlate extensive HmEs from this study and three previous studies over a temperature range of 308.15 to 573.15 K and a pressure range of 7.50 to 17.50 MPa. The fit ranged from fair to good depending upon the pressures and temperatures.
Land suitability analysis for the upper Gila River watershed.

In the United States, federal management agencies, such as the U.S. Forest Service and the U.S. Bureau of Land Management are required to assess the capability of land for future use. In addition, Arizona law now requires local jurisdictions to prepare comprehensive and general plans. Suitability analysis can be used for compliance with several elements of these plans. Here, a framework for land suitability analysis is presented for the upper Gila River watershed in Arizona and New Mexico. The framework is based on a thorough ecological inventory of the watershed. A goal of suitability analysis is to explicitly identify constraints and opportunities for future land conservation and development. This is accomplished by determining the fitness of a given tract of land for a defined use. Four land uses were targeted by local officials for analysis: low-density housing, commercial development, industrial development, and recreation. The framework can be useful for natural resource management as well as town, city, county, and federal planning in the watershed.
Total energy expenditure and carbohydrate oxidation are increased in the human immunodeficiency virus lipodystrophy syndrome.

To determine whether total energy expenditure (TEE) is increased in the human immunodeficiency virus (HIV) lipodystrophy syndrome, we compared energy expenditure (EE) and substrate oxidation rates in 12 HIV-infected men with lipodystrophy, 7 HIV-infected men without lipodystrophy, and 14 healthy controls. TEE and nutrient oxidation rates were assessed by whole-room indirect calorimetry. Resting energy expenditure (REE) was measured by indirect calorimetry using the open-circuit technique. Body composition was assessed by dual-energy x-ray absorptiometry (DEXA). Insulin sensitivity was measured using the insulin-modified frequently sampled intravenous glucose tolerance test. TEE adjusted for lean body mass (LBM) was significantly higher in the HIV-infected group with lipodystrophy compared to HIV-infected patients without lipodystrophy (2,873.3 +/- 69 v 2,573.9 +/- 92 kcal/d, P =.02) and compared to healthy controls (2,873.3 +/- 69 v 2,404.0 +/- 64 kcal/d, P <.001). REE and sleeping metabolic rate (SMR) adjusted for LBM were also significantly higher in the HIV-infected group with lipodystrophy compared to both HIV-infected and healthy controls. Carbohydrate oxidation rates adjusted for LBM were higher in men with HIV lipodystrophy as compared to healthy controls (362.5 +/- 23 v 250.0 +/- 22 g/d, P = <.01) and tended to be higher as compared to HIV-infected controls (362.5 +/- 23.6 v 297.3 +/- 31 g/d, P =.1). In conclusion, TEE and carbohydrate oxidation are increased in the HIV lipodystrophy syndrome. The increase in TEE appears to be due to increases in REE. The pathogenesis of elevated EE in HIV lipodystrophy and other forms of lipodystrophy remains to be determined.
Immunoassay of Aflatoxin in Food and Human Tissue

AbstractAn enzyme-linked immunosorbent assay (ELISA) developed to determine aflatoxin in food was adapted to analyse rapidly human serum for aflatoxin.Sera from subjects in the U.K., Nigeria and Nepal were studied. No aflatoxin was found in U.K. sera, whilst 76% and 100% respectively of Nigerian and Nepalese samples were found positive for aflatoxin.Study was also made of maternal and cord sera from Thai subjects. Only 6% of maternal blood had detectable aflatoxin whilst 49% of cord sera were found positive for aflatoxin. This is evidence of trans-placental transfer of aflatoxin in humans and possibly of concentration of aflatoxin by the feto-placental unit.
Plato’s Crito On the Nature of Persuasion and Obedience

The Crito dramatizes the impossibility, and the indispensability, of persuasion sby locating it between two extremes, Socrates and the Laws, the truths of philosophy and the force of politics. The question is whether those two limits are themselves inside or outside rhetoric. Can philosophy persuade, ormust it always be an alternative sto persuasion? Socrates insists on ignoring the opinion, and the power, of the many, and so the Laws have to show themselves as different from the opinion of the many in order for him to obey. If Socrates and the Laws cannot talk to each other, it is because philosophy and politics are incommensurable. If there is common ground, it is because persuasion can make the two, philosophy and politics, commensurable to each other. Socrates exhibits the philosopher’s task as transforming himself from a universal thinker into a particular agent, while the Laws face the opposite challenge, aspiring to a generality that makes them rational and normative, and so open to discourse and persuasion. The many whom Socrates constantly denigrates have the particularity of being fickle and changeable, while the Laws look rigid. Socrates, as he says in the Apology, is always the same. Both sides look to the flexibility and adaptability to circumstances central to rhetoric.
Radioautography of cerebral tumors employing P32.

SummaryRadioautographs of human brain tumors and of normal brain, employing P32, have been made in 18 cases. A frozen section technic, without fixation, has been found necessary in order to prevent redistribution of the isotope within the tissues. Autographic blackening has been consistently much higher in tumor tissue than in brain, but is subject to considerable variation within certain tumors. These variations, reflecting differences in uptake of radioactive phosphate ion by various portions of the tumor, may be correlated with certain histologic features in the stained sections. Quantitative microdensitometric measurements have been made, and relative P32 uptake determined from these data. Attempt is being made to correlate radioautographic features, especially in the gliomas, with histologic appearance and with prognosis.
Analytical solutions for bacterial energy taxis (chemotaxis): Traveling bacterial bands

Motile bacteria may form bands that travel with a constant speed of propagation through a medium containing a dissolved substrate, to which they respond energy tactically. We generalize the analytical solution by Keller and Segel for such bands by accounting for (1) the presence of a porous medium, (2) substrate consumption described by a Monod kinetics model, and (3) an energy tactic response model derived by Rivero et al. Specifically, we determine the concentration profiles of the bacteria and the substrate. We also derive various expressions for the band velocity. The band velocity is also shown to equal the energy tactic velocity at the bacterial peak divided by tortuosity.
Strained interface of lattice-mismatched wafer fusion

A model has been developed for the periodic strain field near the wafer-fusion interface of lattice-mismatched single crystals. A solution has been found that satisfies the elastic mechanical equilibrium and the boundary conditions. It reveals a wavy interface with the amplitude of the atomic displacement rapidly decaying a short distance from the interface. The model is consistent with the experimental observations of nearly defect-free material except at the interface. The strong alternating strains along the interface have implications for its electronic energy-band structure and electrical characteristics.
Central difference TVD schemes for time dependent and steady state problems

We use central differences to solve the time dependent Euler equations. The schemes are all advanced using a Runge-Kutta formula in time. Near shocks, a second difference is added as an artificial viscosity. This reduces the scheme to a first order upwind scheme at shocks. The switch that is used guarantees that the scheme is locally total variation diminishing (TVD). For steady state problems it is usually advantageous to relax this condition. Then small oscillations do not activate the switches and the convergence to a steady state is improved. To sharpen the shocks, different coefficients are needed for different equations and so a matrix valued dissipation is introduced and compared with the scalar viscosity. The connection between this artificial viscosity and flux limiters is shown. Any flux limiter can be used as the basis of a shock detector for an artificial viscosity. We compare the use of the van Leer, van Albada, mimmod, superbee, and the 'average' flux limiters for this central difference scheme. For time dependent problems, we need to use a small enough time step so that the CFL was less than one even though the scheme was linearly stable for larger time steps. Using a total variation bounded (TVB) Runge-Kutta scheme yields minor improvements in the accuracy.
Redistribution of Ti and Al in deuterium charged TiAl

The redistribution of titanium and aluminum in a single-phase TiAl alloy that has been exposed to a high pressure of deuterium gas at high temperature is studied. The microstructure in the as-received, uncharged condition consisted of single-phase gamma TiAl grains and a random distribution of precipitates. Precipitates were distributed throughout the matrix and along the grain boundaries. The chemistry of the precipitates varied considerably; some were rich in Al, while other were mostly Ti with some Si and Al. The dislocation density in most grains was low, although in a few grains a high dislocation density was observed. FCC deuterides with a lattice parameter of 0.45 nm form in a Ti-52.1Al-2.1Ta (at. pct) alloy after exposure to 1.38 MPa of deuterium gas at 650 C for 213 hr. The structure and lattice parameter are consistent with the formation of Ti(l)D2. The deuterides that form in this alloy are enriched in Ti and deficient in Al and Ta compared to the deuteride-free matrix. Regions of the matrix contiguous with the deuterides have a correspondingly enhanced aluminum and tantalum concentration.
Improving organic light-emitting diode performance with patterned structures

The influence nano- and micro- structures on light extraction and carrier injection characteristics in organic light-emitting diodes (OLEDs) is examined. The results demonstrate device enhancement from two distinctive patterning scales: embedded microstructure arrays for improved light extraction and imprinted nanostructures for carrier injection enhancement. Further, based on these results, a two-level imprinting stamp is designed which simultaneously produces a micron-sized pattern for facilitating light extraction and a nanometer-sized pattern to improve carrier injection. Additionally, this scalable patterning technology circumvents imprinting misalignment while preserving its compatibility with rollto- roll technology.
QCD corrections to top quark pair production in association with a photon at hadron colliders

We compute QCD corrections to the production of a $t\overline{t}$ pair in association with a hard photon at the Tevatron and the LHC. This process allows a direct measurement of the top quark electromagnetic couplings that, at the moment, are only loosely constrained. We include top quark decays, treating them in the narrow width approximation, and retain spin correlations of final-state particles. Photon radiation off top quark decay products is included in our calculation and yields a significant contribution to the cross section. We study next-to-leading-order QCD corrections to the $p\overline{p}\ensuremath{\rightarrow}t\overline{t}\ensuremath{\gamma}$ process at the Tevatron for the selection criteria used in a recent measurement by the CDF collaboration. We also discuss the impact of QCD corrections to the $pp\ensuremath{\rightarrow}t\overline{t}\ensuremath{\gamma}$ process on the measurement of the top quark electric charge at the 14 TeV LHC.
The phase space of (2 + 1)-dimensional gravity in the Ashtekar formulation

Abstract The Ashtekar formulation of 2+1 gravity differs from the geometrodynamical and Witten descriptions when the two-metric is degenerate. We study the phase space of 2+1 gravity in the Ashtekar formulation to understand these degenerate solutions to the field equations. In the process we find two new systems of first-class constraints which describe part of the degenerate sectors of the Ashtekar formulation. One of them also generalizes the Witten constraints. Finally we argue that the Ashtekar formulation has an arbitrarily large number of degrees of freedom in contrast to the usual descriptions.
Performance of Coated Concrete in Wastewater Environment

Polyurethane based coatings are used to protect concrete facilities against corrosive environments. The performances of two commercially available polyurethane coatings were evaluated under sulfuric acid environment for over five years. Both a dry application (representing new construction) and a wet application (representing rehabilitation) concrete were used in this study. It was necessary to use a combination of full-scale, bonding and chemical resistance tests for evaluating coatings to protect concrete structures below groundwater. Full-scale test facilities were used to evaluate the performance of coatings under hydrostatic pressure and to simulate underground concrete structures below groundwater. Visual inspections and in-situ bonding tests were performed. Test results showed that bonding strength of one coating was affected by the moisture condition and hydrostatic water pressure in the full-scale test. Coated cement concrete specimens with pinholes were used to study the chemical resistance of the coated concrete under acidic environment to represent the worst sewer condition. Change in weight of coated concrete specimens was measured at regular intervals. Types of failures in coated concrete under acidic environment have been identified. Test results showed that the performances of the two coatings were noticeably different and one coating with pinholes extended the service life by 14 times while the other by 57 times. There was no direct correlation between bonding strength and chemical resistance of coated materials. Although both coatings were polyurethane based, their performances were different under the testing conditions adopted in the study.
Reaction of Methyl 2-[2ʹ,2ʹ-Bis(carbethoxy)vinylamino]benzoate with Hydrazine

Abstract Previous workers incorrectly assigned the 1,3,4-benzo- triazepine-5-one structure to the product resulting from the reaction of methyl 2-[2ʹ,2ʹ-bis(carbethoxy)vinylamino]benzoate with hydrazine. Spectral data and independent synthesis show that the product is actually 3-amino-4-quinazolone.
Assessment of methoxyfenozide exposure on the sexual attractiveness and responsiveness of adult codling moth, Cydia pomonella L., in small orchard blocks

BACKGROUND: The sexual attractiveness of female and the responsiveness of male codling moth, Cydia pomonella L., exposed to surfaces treated with the ecdysteroid agonist methoxyfenozide were investigated in small orchard block experiments. The main purpose of the study was to determine whether the reported sublethal effects of methoxyfenozide affecting moth behavior also occur under field conditions. RESULTS: Data from the first experiment showed that in some trials untreated females were significantly more attractive to wild males than methoxyfenozide-treated females. The second experiment revealed that some released methoxyfenozide-treated males were not as responsive to calling females as untreated males, and that some untreated females were more attractive to males than methoxyfenozide-treated females. The third experiment revealed that wild males exposed to treated tree surfaces were significantly less responsive to traps than were wild males exposed to untreated trees. However, there were no significant differences in mean recaptures of released males between the untreated and treated orchard blocks. CONCLUSION: Exposure of adult C. pomonella to methoxyfenozide-treated surfaces resulted in a negative impact on male responsiveness to calling females and synthetic pheromone lures. However, the level of impact on the sexual attractiveness of treated females did not appear to be as explicit. Copyright © 2008 Society of Chemical Industry
The effects of some synthetic quinones on the hill reaction in spinach chloroplasts

Abstract The Hill reaction activity of spinach chloroplasts has been measured spectrophotometrically by photoreduction of 2,6-dichlorophenol indophenol. Tetrachlorobenzoquinone, 2,3-dichloronaphthoquinone, and 1,2-dihydroxyanthraquinone (alizarin) were found to inhibit the reaction rate, while 2,5-diphenylbenzoquinone and1,8-dihydroxyanthraquinone were stimulatory.
Life expectancy in Eastern Europe.

In his News Focus article “Stress: The invisible hand in Eastern Europe's death rates” (9 June, p. 1732), Richard Stone highlights the potentially important role that psychosocial stress plays in cardiovascular disease mortality and suggests that this factor, at least in part, explains the
Injury in the developing world.

Injury is the commonest cause of death for children and young adults in developed and middle-income countries. In low-income countries, deaths in this age group are most often due to infectious disease, but there is a rising rate of deaths from injury.1 The Global Burden of Disease Study highlighted the overall toll from injury in the developing world.2 The table shows the major causes of death for the 2 main age groups affected by injury.3 Injury-related causes account for 3 of the top 6 killers of older children and 4 of the top 6 killers of young adults. Road traffic accidents alone are second only to AIDS as a killer of young adults. Other major causes include nonintentional or accidental causes (such as drowning, fires and burns, poisoning, falls, and home injuries) and intentional causes (such as violence and suicide). In addition to mortality, disability is often due to injury, especially with the success of the global efforts to control polio. Injury is also a leading contributor to health-related economic losses. Despite the toll from injury, scarce attention has been paid to the problem. Although a tremendous amount of resources are consumed caring for injured patients at hospitals throughout the developing world, minimal attention has been directed toward better understanding of injury, prevention efforts, or organized efforts to improve trauma treatment systems. The amount of funding devoted to such efforts is a small percentage of that devoted to other health problems in developing countries.4 Table 1 Major causes of death in developing countries (both low and middle-income) in 1998* Rank 5-14 yr Rate† 15-44 yr Rate† 1 Respiratory infections 19.7 HIV/AIDS 67.0 2 Malaria 19.4 Road traffic injuries‡ 21.9 3 Road traffic injuries‡ 14.5 Interpersonal violence‡ 20.2 4 Drowning‡ 14.5 Self-inflicted injuries‡ 19.0 5 Diarrheal diseases 12.4 Tuberculosis 17.8 6 War injuries‡ 5.3 War injuries‡ 15.5 View it in a separate window *Source: Krug et al.3 †Rates of death expressed as deaths per 100,000 per year. ‡Injury-related causes. Part of the reason for such neglect may be that many of the solutions to the problem lay outside the usual domain of health professionals. For example, possible solutions include road engineering and road use legislation. Another reason for the neglect may be a sense of futility. Injuries are conceptualized by much of the public around the world as due to bad luck or to carelessness, with little that can be done to prevent them.
Alterations in prepyriform evoked potential in relation to stimulus intensity.

Abstract The single-shock prepyriform evoked potential may be described as a sinusoidal transient having the four parameters of frequency spectrum, amplitude, phase of onset, and Q . At threshold for the single-shock evoked potential averaged by computer summation, frequency and Q are maximal and amplitude and phase are minimal. With increasing stimulus intensity there is progressive increase in amplitude of the initial peak and phase of onset, and reduction in frequency and Q . Related changes take place in frequency-response curves. Up to 2 × threshold, the wave forms of evoked and spontaneous activity may be very similar. Above 2.5 × threshold, which roughly corresponds to threshold for the evoked potential in an ink tracing, there is progressive decrease in resemblance. Definitive comparisons of wave forms in different behavioral states are shown to require the use of families of evoked potentials taken over a range of stimulus intensity.
Automated CD SEM tilt—ready for primetime: a fast in-line methodology for differentiating lines vs. spaces

One of many challenges the process or metrology engineers face is incorrect flagging on the process control chart. It could either be a result of an un-optimized recipe that measures the wrong feature (a space instead of line) or a feature placement error due to tool limitation. This can be a costly problem in the fab where processes are put on hold, feedback loops are corrupted and backlogs are built up unnecessarily. Often many hours must be spent by operators re-inspecting lots and process or metrology engineers re-qualifying the recipes. Most CD SEMs use algorithms employing pattern matching and contrast difference to differentiate between line and space. However, the shrinking node requirement, limited contrast between line and space images and the 1:1 line and space ratios have revealed limitations of these algorithms. Recently, a metrology solution using beam tilt on the KLA-Tencor ECD-2 has been developed to tackle the problem of dense line or dense trench array measurements. This methodology is a line vs. space detection mechanism that precedes the metrology measurement. This application is quick and oblivious to low contrast differences between line/space and to systematic errors that occur with narrow feature positioning. Whether or not the specified feature type for measurement is centered in the field of view, it always detects the requested feature type and sets the metrology measurement to be made accordingly and therefore significantly reducing false negatives and false positives. This application also allows for greater tolerance in recipe setup and placement error, and thus lightens the burden of recipe creation on the novice user. This technique can also be incorporated into waferless design based metrology where limited prior knowledge of the wafer is one of the requirements. Future potential of this metrology solution will also be discussed. This could include detecting undercut situations and possibly even correcting bottom CD based on undercut angular detection.
Relationship of δ-Aminolevulinic Acid-Induced Protoporphyrin IX Levels to Mitochondrial Content in Neoplastic Cells in Vitro

Protoporphyrin IX, induced by the exogenous addition of δ-aminolevulinic acid, reaches different levels in different tumor cells. Because many of the steps in heme biosynthesis, of which protoporphyrin IX is penultimate, are located in the mitochondria, we surmised that the mitochondrial content of cells may relate to the amount of protoporphyrin IX synthesized in response to excess δ-aminolevulinic acid. We observed that accumulation of MitoTracker, a fluorescent mitochondrial probe, δ-aminolevulinic acid-induced protoporphyrin IX levels, and porphobilinogen deaminase activity all presented with the same cell-line-dependent rank order among the four different neoplastic cells. This rank order, however, differed for cytochrome c oxidase activity, the final enzyme in mitochondrial electron transport, and for accumulation of radioactive label from [14C]δ-aminolevulinic acid. The data demonstrate that enzymes involved in heme biosynthesis, in general, display a rank order associated with mitochondrial content. These data imply that such parameters may have value as prognosticators of cells to produce δ-aminolevulinic acid-induced protoporphyrin IX, a photosensitizer for photodynamic therapy of cancer.