cssi/SciSciGPT-SciSciNet huggingface dataset:
Hyperspectral Imaging-Based Classification and Wavebands Selection for Internal Defect Detection of Pickling Cucumbers

Hyperspectral imaging is useful for detecting internal defects of pickling cucumbers. The technique, however, is not yet suitable for high-speed online implementation due to the challenges in analyzing large-scale hyperspectral images. This research aimed to select the optimal wavebands from the hyperspectral image data, so that they can be deployed in either a hyperspectral or multispectral imaging-based inspection system for the automatic detection of internal defects of pickling cucumbers. Hyperspectral reflectance (400–700 nm) and transmittance (700–1,000 nm) images were acquired, using an in-house developed hyperspectral imaging system running at two conveyor speeds of 85 and 165 mm/s, for 300 “Journey” pickling cucumbers before and after internal damage was induced by mechanical load. Minimum redundancy–maximum relevance (MRMR) was used for optimal wavebands selection, and the loadings of principal component analysis (PCA) were also applied for qualitatively identifying the important wavebands that are related to the specific features. Discriminant analysis with Mahalanobis distance classifier was performed for the two-class (i.e., normal and defective) and three-class (i.e., normal, slightly defective, and severely defective) classifications using the mean spectra and textural features (energy and variance) from the regions of interest in the spectral images at selected waveband ratios. The classification results based on MRMR wavebands selection were generally better than those from PCA-based classifications. The two-band ratio of 887/837 nm from MRMR gave the best overall classification results, with the accuracy of 95.1 and 94.2 % at the conveyor speeds of 85 and 165 mm/s, respectively, for the two-class classification. The highest classification accuracies for the three-class classification based on the optimal two-band ratio of 887/837 nm were 82.8 and 81.3 % at the conveyor speeds of 85 and 165 mm/s, respectively. The mean spectra-based classification achieved better results than the textural feature-based classification, except in the three-class classification for the higher conveyor speed. The overall classification accuracies for all selected waveband ratios at the low conveyor speed were slightly higher than those at the higher conveyor speed, since the low speed resulted in more scan lines, thus higher spatial resolution hyperspectral images. The identified two-band ratio of 887/837 nm in transmittance mode could be applied for fast real-time internal defect detection of pickling cucumbers.
Some aspects of separability

Abstract We present three necessary separability criteria for bipartite mixed states; the violation of each of these conditions is a sufficient condition for entanglement. Some ideas on the issue of finding a necessary and sufficient criterion of separability are also discussed.
Multiple separations facilitate identification of protein variants by mass spectrometry

Identification of variant proteins from complex biological samples promises to contribute much to our understanding of the etiology of pathological states. Characterization of variants, due either to genetic mutations in protein sequences or to post-translational mod ifications, is considerably more difficult than the simple protein identifications typical of most current proteomic investigations. Iden tification of a few peptides by database retrieval is not adequate when the goal is to have a complete understanding of the modifications of the protein. Although one advantage of mass spectrometry is its ability to obtain specific responses to several compo nents, the complexity of biological samples is often overwhelming, resulting in spectra lacking useful information. For complex mix tures, isolation procedures before mass spectrometric analysis may need to include a variety of chromatographic and electrophoretic separation techniques. In this report, we illustrate how several preparative steps were essential for obtaininginformation about modified human lens -crystallins. The preparative techniques prior to mass spectrometry included size-exclusion chromatography, reversed-phase chromatography, two-dimensional gel electrophoresis, in situ digestion of the proteins and peptide trapping and washing before a final reversed-phase high-performance liquid chromatographic separation on-line to the mass spectrometer. This approach for isolation and analysis, when customized for other proteins, should find application in many studies where protein variants of complex mixtures are to be identified.
An efficient preparation of tetrahydropyran-(3R)-carboxaldehyde, a key intermediate for the synthesis of a novel 5-lipoxygenase inhibitor.

Abstract A novel process based on the efficient resolution of rac-2 and suitable for preparing kilogram quantities of the chemically sensitive aldehyde tetrahydropyan-3R-carboxaldehyde R-2 of >-98% ee is described.
The stability of two‐dimensional wakes and shear layers at high Mach numbers

This study is concerned with the stability properties of laminar free‐shear‐layer flows, and in particular symmetric two‐dimensional wakes, for the supersonic through the hypersonic regimes. Emphasis is given to the use of proper wake profiles that satisfy the equations of motion at high Reynolds numbers. In particular the inviscid stability of a developing two‐dimensional wake is studied as it accelerates at the trailing edge of a splitter plate. The nonparallelism of the flow is a leading‐order effect in the calculation of the basic state, which is obtained numerically. Neutral stability characteristics are computed and the hypersonic stability is obtained by increasing the Mach number. It is found that the stability characteristics are altered significantly as the wake develops. Multiple modes (secondary modes) are found in the near wake that are closely related to the corresponding Blasius ones, but as the wake develops mode multiplicity is delayed to higher and higher Mach numbers. At a distance of about one plate length from the trailing edge, there is only one mode in a Mach number range of 0–20. The dominant mode emerging at all wake stations, and for high enough Mach numbers, is the so‐called vorticity mode that is centered around the generalized inflection point layer. The structure of the dominant mode is also obtained analytically for all streamwise wake locations and it is shown how the far‐wake limit is approached. Asymptotic results for the hypersonic mixing layer given by a tanh and a Lock distribution are also given.
Unsteady radial transport in a transonic compressor stage

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1989.
The effects of self-induction and distributed static capacity in a conductor

(1892). The effects of self-induction and distributed static capacity in a conductor. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 34, No. 211, pp. 528-530.
A model of residential change and neighborhood tipping

Abstract This paper applies the theory of probabilistic consumer demand to an analysis of residential change at the urban neighborhood scale. By developing the profit maximizing pricing behavior of housing suppliers, it is shown that neighborhood transitions from high income to low income and from white to black can be explained on purely economic grounds without involving prejudicial preferences. The analytical model explains two types of transition. In the first, a neighborhood's social mix changes gradually in response to gradual exogenous changes. In the second, a neighborhood “tips” suddenly in response to similar exogenous changes. The two transitions can occur depending on the characteristics of the demand functions for the two competing groups.
Analytical Approximations for Calculating the Escape and Absorption of Radiation in Clumpy Dusty Environments

We present analytical approximations for calculating the scattering, absorption, and escape of nonionizing photons from a spherically symmetric two-phase clumpy medium, with either a central point source of isotropic radiation, a uniform distribution of isotropic emitters, or uniformly illuminated by external sources. The analytical approximations are based on the mega-grains model of two-phase clumpy media, as proposed by Hobson & Padman, combined with escape and absorption probability formulae for homogeneous media. The accuracy of the approximations is examined by comparison with three-dimensional Monte Carlo simulations of radiative transfer, including multiple scattering. Our studies show that the combined mega-grains and escape/absorption probability formulae provide a good approximation of the escaping and absorbed radiation fractions for a wide range of parameters characterizing the clumpiness and optical properties of the medium. A realistic test of the analytic approximations is performed by modeling the absorption of a starlike source of radiation by interstellar dust in a clumpy medium and by calculating the resulting equilibrium dust temperatures and infrared emission spectrum of both the clumps and the interclump medium. In particular, we find that the temperature of dust in clumps is lower than in the interclump medium if the clumps are optically thick at wavelengths at which most of the absorption occurs. Comparison with Monte Carlo simulations of radiative transfer in the same environment shows that the analytic model yields a good approximation of dust temperatures and the emerging UV-FIR spectrum of radiation for all three types of source distributions mentioned above. Our analytical model provides a numerically expedient way to estimate radiative transfer in a variety of interstellar conditions and can be applied to a wide range of astrophysical environments, from clumpy star-forming regions to starburst galaxies.
Enzymatic synthesis of 7-deoxy-N-acetylneuraminic acid and 7-O-methyl-N-acetylneuraminic acid

Abstract 7-Deoxy- N -acetylneuraminic Acid and 7- O -methyl- N -acetylneuraminic acid were synthesized through the sialic acid aldolase-catalyzed aldol addition reactions of 4-deoxy- N -acetyl-D-mannosamine and 4- O -methyl- N -acetyl-D-mannosamine, respectively, with pyruvate. The obtained sialic acids will be used as probes for the investigation of the unusual mechanism of a novel sialidase from leech.
Characterization of cathode keeper wear by surface layer activation

In this study, the erosion rates of the discharge cathode keeper in a 30 cm NSTAR configuration ion thruster were measured using a technique known as Surface Layer Activation (SLA). This diagnostic technique involves producing a radioactive tracer in a given surface by bombardment with high energy ions. The decrease in activity of the tracer material may be monitored as the surface is subjected to wear processes and correlated to a depth calibration curve, yielding the eroded depth. Analysis of the activities was achieved through a gamma spectroscopy system. The primary objectives of this investigation were to reproduce erosion data observed in previous wear studies in order to validate the technique, and to determine the effect of different engine operating parameters on erosion rate. The erosion profile at the TH 15 (23 kw) setting observed during the 8200 hour Life Demonstration Test (LDT) was reproduced. The maximum keeper erosion rate at this setting was determined to be 0.085 pm/hr. Testing at the TH 8 (1.4 kw) setting demonstrated lower erosion rates than TH 15, along with a different wear profile. Varying the keeper voltage was shown to have a significant effect on the erosion, with a positive bias with respect to cathode potential decreasing the erosion rate significantly. Accurate measurements were achieved after operating times of only 40 to 70 hours, a significant improvement over other erosion diagnostic methods.
Equivalent curves in surfaces

We consider various notions of equivalence for homotopy classes of curves on hyperbolic surfaces based on topological, algebraic, and geometric structures, and find the relationships between these equivalences.
Inventories under Joint Production: An Empirical Analysis of Petroleum Refining

This study examines the determinants of inventory investment under joint production. We simultaneously estimate a set of optimal sales relations, variable input demands, and a set of Euler equations for capital and inventories of raw materials, work in process, and final products in the petroleum refining industry. The Euler conditions provide a model for the convenience yield discussed in the returns-to-storage literature. The cost savings from holding inventories and expected changes in marginal production costs are important components of the convenience yield. We also find significant cost and stock interactions that may affect short-run price and inventory dynamics in petroleum product markets.
Experimental analysis of a GPSS simulation of a student health center

Abstract Simulation was found to be a useful device in studying the effects of varying service capacity in a medical clinic. The intuitive expectation of an inverse relationship between service capability and waiting time was confirmed. The anticipated main effects were supported while all but one of the interaction effects were negligible. A non-linear relationship between service capacity and waiting time was estimated by regression. This relationship was used to construct a decision table with alternatives and cost effects which can be used for decision-making under many conditions and constraints within the Health Center administration's decision space.
[2 + 1] Versus [4 + 2] cycloadditions of Fischer carbene complexes with 1,3-dienes. Evidence for a zwitterionic intermediate in a cyclopropanation reaction

Reactions des complexes pentacarbonyles d'α-methoxy benzylidene tungstene et chrome avec le methyl trimethylsiloxy-3 butadiene-1,3yl ether pour donner des cyclopropanes et le methyl phenyl-1 vinyl ether
Effects of whole-body heat acclimation on cell injury and cytokine responses in peripheral blood mononuclear cells

To test the hypothesis that whole-body heat acclimation (HA) would increase peripheral blood mononuclear cells’ (PBMC) tolerance to heat shock (HS) and/or alter the release of cytokines (IL-1β, IL-6, IL-10 and TNF-α) to bacterial lipopolysaccharide (LPS), we heat acclimated nine subjects by exercising them for 100 min in a hot environment for 10 days. The subjects’ PBMC were separated and cultured on days 1 and 10 of HA pre- and post-exercise. Pre-exercise PBMC were allocated to three treatments: control (PRE, 37°C), HS (42.5°C for 2 h), or LPS (1 ng mL−1 for 24 h). Post-exercise samples were incubated at 37°C. PBMC lactate dehydrogenase release increased (p 0.05) between days 1 and 10 (0.100 ± 0.012 and 0.102 ± 0.16 abs., respectively). LPS treatment induced an increased (p 0.05). Pre-exercise intracellular heat shock protein 72 (Hsp72) was higher (p < 0.05) on day 10 compared to day 1 of HA (13 ± 5 and 8 ± 5 ng mL−1, respectively). HS treatment caused a greater increase (p < 0.05) in Hsp72 than the exercise sessions on HA days 1 and 10. In addition, after HA, the Hsp72 response to HS was reduced (day 1, 129 ± 46; day 10, 80 ± 32 ng mL−1, p < 0.05). In conclusion, HA increases PBMC Hsp72 but it does not reduce cellular damage to HS or alter cytokine response to LPS. We speculate that the stress applied during HA is not sufficient to modify the PBMC response.
Remote atmospheric sensing with an airborne laser absorption spectrometer.

A laser absorption spectrometer, using an IR laser transmitter and a heterodyne radiometer, can be used from an aircraft or spacecraft to measure altitude profiles of air pollutants and other atmospheric constituents. The technique involves measurement of differential absorption at several wavelengths, using the diffusely reflecting earth's surface to provide a return signal. The pressure broadening of absorption lines allows one to discriminate between high and low altitude absorbers. Application of the technique to measurements of ozone, nitric oxide, and water vapor are presented. CO2 and CO lasers are considered as transmitters. The discussion includes altitude resolution limitations, atmospheric temperature dependence, and frequency stability requirements of the instrument.
A Comparative Study of Three Finite Element-Based Explicit Numerical Schemes for Solving Maxwell's Equations

Three finite element-based explicit numerical algorithms, named the dual-field domain decomposition at the element level (DFDD-ELD), the discontinuous Galerkin time-domain method with upwind fluxes (DGTD-Upwind), and the discontinuous Galerkin time-domain method with central fluxes (DGTD-Central), are investigated and compared in terms of accuracy and efficiency. All three algorithms can perform an efficient domain decomposition and avoid the inversion of a global system matrix, yet the study shows that they differ from each other in terms of accuracy and efficiency. Hybrid implicit-explicit schemes, which can relax the restriction on the time step size imposed by the smallest elements in the computational domain, are also investigated for both DFDD and DGTD and compared in terms of efficiency.
Supernova constraints on a superlight gravitino

In supergravity models with low supersymmetry-breaking scale, the gravitinos can be superlight, with mass in the ${10}^{\ensuremath{-}6}\mathrm{eV}$ to a few keV range. In such a case, gravitino emission provides a new cooling mechanism for protoneutron stars and therefore can provide constraints on the mass of a superlight gravitino. This happens because the coupling to matter of superlight gravitinos is dominated by its Goldstino component, whose coupling to matter is inversely proportional to the scale of supersymmetry breaking and increases as the gravitino mass decreases. Present observations therefore provide lower limits on the gravitino mass. Using the recently revised Goldstino couplings, we find that the two dominant processes in supernova cooling are ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{G}\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{G}$ and $\ensuremath{\gamma}{+e}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{\ensuremath{-}}\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{G}\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{G}.$ They lead to a lower limit on the supersymmetry-breaking scale ${\ensuremath{\Lambda}}_{S}$ from 160 to 500 GeV for core temperatures 30 to 60 MeV and electron chemical potentials 200 to 300 MeV. The corresponding lower limits on the gravitino mass are 0.6 to $6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}\mathrm{eV}.$
Interaction of organic surfaces with active species in the high-vacuum environment

Using single-crystal organic field-effect transistors with the conduction channel exposed to environmental agents, we have observed generation of electronic defects at the organic surface in the high-vacuum environment. Rapid decrease of the source–drain current of an operating device is observed upon exposure of the channel to the species generated by high-vacuum gauges. We attribute this effect to interaction of the organic surface with electrically neutral free radicals produced in the process of hydrocarbon cracking on hot filaments with a relatively low activation energy Ea∼2.5eV (240kJ∕mol). The reported results might be important for optimizing the high-vacuum processes of fabrication and characterization of a wide range of organic and molecular electronic devices.
Developing chiral phosphorus ligands for asymmetric hydrogenations

Chiral rigid and electron-donating phosphocyclic phosphine ligands and modular atropisomeric biaryl phosphine ligands were designed and synthesized. The performance of these chiral ligands in the asymmetric hydrogenations of prochiral dehydroamino acid deriv- atives, enamides, imines, keto esters, and ketones has been demonstrated to be excellent.
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone-catalyzed reactions employing MnO2 as a stoichiometric oxidant.

Several oxidative reactions can be effected with MnO2 in the presence of substoichiometric quantities of DDQ. These transformations include oxidative cyclization, deprotection, and dehydrogenation reactions. The use of MnO2 as a terminal oxidant for DDQ-mediated reactions is attractive based on economical and environmental factors.
The field-effect transistor — An old device with new promise

Fabrication by evaporation, insulated-gate construction, and predictable performance are contributing to the emergence from obscurity of the unipolar field-effect transistor
Oscillatory Natural Convection in Rectangular Enclosures Filled With Mercury

Lately, natural convection in low Prandtl number (Pr) fluids has gained importance because of growing interest in the transport phenomena in crystal growth processes. It is known that some of the undesirable striations encountered in crystals grown from the melt are caused by thermal instabilities associated with natural convection in the melt. In a typical crystal growth configuration the container aspect ratio Ar (depth/length ratio) is not very small (typically 0.1 to 1) nor is the width ratio Wr (width/depth ratio) very large (typically 1 to 10), so the instability is expected to be influenced by the parameters Ar and Wr. Thus the objective of the present work is to investigate experimentally the effects of Ar and Wr on the onset of thermal instability and the oscillation phenomenon.
School Quality, House Prices and Liquidity

This paper develops an empirical framework for taking into account the effects of endogenous liquidity on price capitalization estimates. Changes in school attendance zones in the East Baton Rouge Parish public school district provide a natural experiment for studying how changes in school characteristics affect house prices and liquidity. House price and selling time, or liquidity, are simultaneously determined in search markets. The empirical model exploits variation in the surrounding neighborhood market conditions pertinent to each house to identify the system of price and liquidity equations. The estimates are consistent with search-market theory in that liquidity absorbs part of the capitalization of school quality.
Oxidation of isoxazolines by peracids - a useful route to β-hydroxy ketones and acylated diols

Abstract A method for bringing about the ring cleavage of isoxazolines by the use of peracids is described.
Symplectic Numerical Integrators in Constrained Hamiltonian Systems

Recent work reported in the literature suggests that for the long-time integration of Hamiltonian dynamical systems one should use methods that preserve the symplectic (or canonical) structure of the flow. Here we investigate the symplecticness of numerical integrators for constrained dynamics, such as occur in molecular dynamics when bond lengths are made rigid in order to overcome stepsize limitations due to the highest frequencies. This leads to a constrained Hamiltonian system of smaller dimension. Previous work has shown that it is possible to have methods which are symplectic on the constraint manifold in phase space. Here it is shown that the very popular Verlet method with SHAKE-type constraints is equivalent to the same method with RATTLE-type constraints and that the latter is symplectic and time reversible. (This assumes that the iteration is carried to convergence.) We also demonstrate the global convergence of the Verlet scheme in the presence of SHAKE-type and RATTLE-type constraints. We perform numerical experiments to compare these methods with the second-order backward differentiation method, commonly recommended for ordinary differential equations with constraints.
Inhibition of Calcium Oxalate Urolithiasis in a Rat Model of Lithogenesis Using Bisphosphonates

Bisphosphonates bind renal calculi and inhibit calcium oxalate crystal growth in vitro. We evaluated their ability to inhibit calcium oxalate urolithiasis in a lithogenic rat model. Male Sprague-Dawley rats (four groups, eight rats each) were fed 1.0% ethylene glycol in their drinking water for 6 weeks. All rats had implantation of a 50- to 60-mg zinc pellet in their urinary bladder at the beginning of the 6-week period. The control group received no treatment. The other three groups received six weekly intraperitoneal injections of one of three bisphosphonates: pamidronate (APD), clodronate (CLO), or methylene diphosphonate (MDP). At the end of 6 weeks, the zinc pellet was retrieved and weighed; the kidneys were sectioned and stained to evaluate inflammation, tubular dilation, and crystal deposition; and blood and urine samples were analyzed for calcium and creatinine. There were no detectable biochemical differences between the control and the treatment groups. Zinc pellets removed from control animals had a significantly greater increase in weight secondary to crystal deposition than those from the treatment groups (mean 28.4% for control v 18.9%, 15.3%, and 18.6%, respectively, for animals given APD, CLO, and MDP). The control animals also had significantly higher scores for inflammation, tubular dilation, and crystal deposition than animals treated with MDP and CLO. Older and newer-generation bisphosphonates have an inhibitory effect on calcium oxalate urolithiasis that is demonstrable at relatively infrequent dosing intervals in vivo. More frequent dosing or higher doses may allow greater inhibition of stone formation.
Interstellar polycyclic aromatic hydrocarbons and carbon in interplanetary dust particles and meteorites

Raman spectra of interplanetary dust particles (IDPs) and meteorites containing material similar to polycyclic aromatic hydrocarbons (PAHs) show features that are similar in position and relative strength to interstellar IR emission features attributable to vibrational transitions in free molecular-sized PAHs. In addition, these spectra sometimes show red photoluminescence that has elsewhere been attributed to PAHs, and a part of the carbonaceous phase in IDPs and meteorites contain a degree of deuterium enrichment anticipated in small, free PAHs that are exposed to ISM UV radiation. These observations suggest that some of the IDPs' carbonaceous material may have been produced in circumstellar dust shells, and only slightly modified in interstellar space.
Counting triangle crossings and halving planes

Every collection oft?2n2 triangles with a total ofn vertices in ?3 has Ω(t4/n6) crossing pairs. This implies that one of their edges meets Ω(t3/n6) of the triangles. From this it follows thatn points in ?3 have onlyO(n8/3) halving planes.
Experimental studies on the lip shock.

Lip shock from separation edge of half angle wedge and resultant static pressure recovery distribution along wake
A C^0-Weak Galerkin Finite Element Method for the Biharmonic Equation

A \(C^0\)-weak Galerkin (WG) method is introduced and analyzed in this article for solving the biharmonic equation in 2D and 3D. A discrete weak Laplacian is defined for \(C^0\) functions, which is then used to design the weak Galerkin finite element scheme. This WG finite element formulation is symmetric, positive definite and parameter free. Optimal order error estimates are established for the weak Galerkin finite element solution in both a discrete \(H^2\) norm and the standard \(H^1\) and \(L^2\) norms with appropriate regularity assumptions. Numerical results are presented to confirm the theory. As a technical tool, a refined Scott-Zhang interpolation operator is constructed to assist the corresponding error estimates. This refined interpolation preserves the volume mass of order \((k+1-d)\) and the surface mass of order \((k+2-d)\) for the \(P_{k+2}\) finite element functions in \(d\)-dimensional space.
Taxation and leverage in international banking

This paper explores how corporate taxes affect the capital structure of multinational banks. Guided by a theory of optimal capital structure, it tests whether (i) corporate tax rates induce subsidiary banks to raise leverage in light of traditional debt bias; and (ii) cross-country corporate tax differences affect a subsidiary’s leverage through international debt shifting. Using a novel data set for 756 commercial bank subsidiaries of 91 largest multinational banks in the world, we find that taxes matter significantly through both channels.
Nucleon-nucleon effective field theory without pions

Abstract Nuclear processes involving momenta much below the mass of the pion may be described by an effective field theory in which the pions do not appear as explicit degrees of freedom. The effects of the pion and all other virtual hadrons are reproduced by the coefficients of gauge-invariant local operators involving the nucleon field. Nucleon-nucleon scattering phase shift data constrains many of the coefficients that appear in the effective Lagrangean but at some order in the expansion coefficients enter that must be constrained by other observables. We compute several observables in the two-nucleon sector up to next-to-next-to leading order in the effective field theory without pions, or to the order at which a counterterm involving four-nucleon field operators is encountered. Effective range theory is recovered from the effective field theory up to the order where relativistic corrections enter or where four-nucleon-external current local operators arise. For the deuteron magnetic moment, quadrupole moment and the np → dγ radiative capture cross section a four-nucleon-one-photon counterterm exists at next-to-leading order. The electric polarizability and electric charge form factor of the deuteron are determined up to next-to-next-to-leading order, which includes the first appearance of relativistic corrections.
A plan for the development and demonstration of optical communications for deep space

A development history, current status, and prospective development account are given for deep-space optical communications, giving attention to overall systems-related activities and to the generic technology developments required for their implementation. An account is given of the progression envisioned from laboratory subsystems demonstrations to the full-scale flight experiment for the Mars Communications Relay Orbiter missions.
Measurements of D-Region Electron Densities Utilizing the Partial Reflection Technique

The partial reflection technique measures Z>-region electron densities as a function of height by transmitting rf pulses vertically and receiving the partially reflected echoes. The rf frequency is approximately 2 MHz, and rightand left-hand circular polarization is employed. Electron densities are derived from the ratio of the amplitudes of the extraordinary and ordinary echoes. Results from a partial reflection experiment conducted in New Mexico are presented, and comparisons are made with in-situ probe measurements and with theoretical predictions from an atmospheric model. The good agreement obtained in these comparisons provides evidence to support the validity of the partial reflection technique.
Particle acceleration in supernova-remnant shocks

It has been known for over 50 years that the radio emission from shell supernova remnants (SNRs) indicates the presence of electrons with energies in the GeV range emitting synchrotron radiation. The discovery of nonthermal X-ray emission from supernova remnants is now 30 years old, and its interpretation as the extension of the radio synchrotron spectrum requires electrons with energies of up to 100 TeV. SNRs are now detected at GeV and TeV photon energies as well. Strong suggestions of the presence of energetic ions exist, but conclusive evidence remains elusive. Several arguments suggest that magnetic fields in SNRs are amplified by orders of magnitude from their values in the ambient interstellar medium. Supernova remnants are thus an excellent laboratory in which to study processes taking place in very high Mach-number shocks. I review the observations of high-energy emission from SNRs, and the theoretical framework in which those observations are interpreted.
A variational problem arising in financial economics

Abstract We provide sufficient conditions for a dynamic consumption–portfolio problem in continuous time to have a solution. When the price processes satisfy a regularity condition, all utility functions that are continuous, increasing, concave, and are dominated by a strictly concave power function admit a solution.
Order and Fashion in Clothes: The King, His Household, and the City of London at the End of the Fifteenth Century

The general attitude toward excess in apparel in 15th-century England was one of disapproval. The king, however, was expected to adorn himself, which inspired respect for the government. Subjects in the lower ranks wore apparel that defined their social position. Sumptuary legislation was even passed to reinforce this behavior. Documents of the Great Wardrobe, the Corporation of London, and the Mercers' and Merchant Taylors' Companies, as well as wills, inventories, and letters, have been used to examine dress in this ordered society. The Great Wardrobe was the storehouse and manufactory of the royal household. Apparel supplied to the kings (Henry VI, Edward IV, Henry VII) and their households and to groups who wore social or professional dress during the 15th century is detailed.
Time and output warping of control systems: Comparing and imitating motions

The problem of making one system ''mimic'' a motion generated by another is studied. To address this, an optimal tracking problem is introduced that, in addition to tracking, optimizes over functions that deform or ''warp'' the time axis and the output space. Parametric and nonparametric versions of the time-warped tracking problem are presented and reduced to standard Bolza problems. The output warping problem is treated for affine and piecewise affine output warping functions. Example applications are given, including that of controlling a marionette to mimic a human dancer.
Physical, adsorptive, and catalytic properties of platinum supported on silica modified with europium oxide

Abstract The physical, chemisorptive, and catalytic properties of platinum on a europium oxide-silica support were studied by Mossbauer spectroscopy, volumetric reduction, chemisorption, and ethane hydrogenolysis experiments. The Mossbauer spectroscopy and volumetric reduction experiments showed that 40% of the silica-supported Eu3+ cations could be reduced to Eu2+ at 773 K; and the reducibility of the europium cations was enhanced to about 50% by the addition of platinum to the europium oxide-silica support. The primary reduction process was the formation of surface hydroxyl groups. The platinum particle sizes determined by hydrogen and carbon monoxide chemisorption, and confirmed by X-ray diffraction and electron microscopy, were substantially smaller for platinum on the mixed-oxide support than for platinum on silica. There was no evidence of suppressed H2or CO chemisorption on platinum. The rate of ethane hydrogenolysis was an order of magnitude lower over platinum on the mixed-oxide support. This decreased activity may be explained in geometric terms; e.g., the Pt particles are smaller on the mixed-oxide support and ethane hydrogenolysis is a structure-sensitive reaction.
A SIMULATION STUDY OF INTERFACES IN Ni, Al AND Ni3Al WITH AND WITHOUT BORON

Presentation des simulations des structures atomiques des surfaces libres et des joints de grains de flexion symetrique [001] dans Ni, Al et dans le compose intermetallique Ni 3 Al avec ou sans bore. La dilatation totale ou le volume en exces associes aux joints de grains sont proportionnels a l'energie des joints de grains. Analyse de la structure atomique des joints simules en terme d'un modele d'unite structurale. On observe une segregation du bore plus importante aux joints de grains qu'aux surfaces libres. Cette segregation a peu d'influence sur la structure des joints de grains
Weak Extinction Limits of Large-Scale Flameholders

Weak extinction data obtained from an experimental apparatus designed to simulate the characteristics of practical afterburner combustion systems are presented. The apparatus supplies mixtures of varied composition (equivalence ratio and degree of vitiation), temperature and velocity to Vee-gutter flame holders of various widths and shapes similar to those found in jet engine systems. The fuel employed is a liquid hydrocarbon whose chemical composition and physical properties correspond to those of aviation kerosine, JP5. An equation for predicting weak extinction limits which accounts for upstream vitiation and the chemical characteristics of the fuel is derived from stirred reactor theory. The correlation between the predictions and experimental results indicates that the stirred reactor approach can provide a framework for predicting the lean blowout limits of practical flameholders over wide ranges of engine operating conditions.Copyright © 1991 by ASME
Some congruences for traces of singular moduli

Abstract We address a question posed by Ono [Ken Ono, The Web of Modularity: Arithmetic of the Coefficients of Modular Forms and q-Series, CBMS Reg. Conf. Ser. Math., vol. 102, Amer. Math. Soc., Providence, RI, 2004, Problem 7.30], prove a general result for powers of an arbitrary prime, and provide an explanation for the appearance of higher congruence moduli for certain small primes. One of our results overlaps but does not coincide with a recent result of Jenkins [Paul Jenkins, p-Adic properties for traces of singular moduli, Int. J. Number Theory 1 (1) (2005) 103–107]. This result essentially coincides with a recent result of Edixhoven [Bas Edixhoven, On the p-adic geometry of traces of singular moduli, preprint, 2005, math.NT/0502213 v1], and we hope that the comparison of the methods, which are entirely different, may reveal a connection between the p-adic geometry and the arithmetic of half-integral weight Hecke operators.
Complete r-partite subgraphs of dense r-graphs

Extending a classical result of Erdos, we derive the following concise statement: Let r>=3 and (lnn)^-^1^/^(^r^-^1^)@[email protected]@?r^-^3. Then every r-uniform graph on n vertices with at least @an^r/r! edges contains a complete r-partite subgraph with r-1 classes of size @[email protected](lnn)^1^/^(^r^-^1^)@? and one class of size @?n^1^-^@a^^^r^^^-^^^[email protected]?. Our main result is a similar, but stronger statement about directed hypergraphs.
Atomic configuration of segregated B on Si(001) surface

The atomic configurations of segregated B atoms on a highly B-doped Si(001) surface is investigated with scanning tunneling microscopy (STM) observation and first-principle cluster calculation, on which characteristic comb-shape step structures are observed. The characteristic features in the STM image are (1) dark regions in the occupied state, and (2) paired protrusions in the unoccupied state. The calculation shows that models of a B dimer on the top surface and B atoms bonded to two neighboring Si atoms in a dimer row can reproduce STM images well for (1) and (2), respectively.
Chern-Simons classes and the Ricci flow on 3-manifolds

In 1974, S.-S. Chern and J. Simons published a paper where they defined a new type of characteristic class - one that depends not just on the topology of a manifold but also on the geometry. The goal of this paper is to investigate what kinds of geometric information is contained in these classes by studying their behavior under the Ricci flow. In particular, it is shown that the Chern- Simons class corresponding to the first Pontryagin class is invariant under the Ricci flow on the warped products $S^2\times_f S^1$ and $S^1 \times_f S^2$ but that this class is not invariant under the Ricci flow on a generalized Berger sphere.
Equivariant Chow cohomology of nonsimplicial toric varieties

For a toric variety X_P determined by a rational polyhedral fan P in a lattice N, Payne shows that the equivariant Chow cohomology of X_P is the Sym(N)--algebra C^0(P) of integral piecewise polynomial functions on P. We use the Cartan-Eilenberg spectral sequence to analyze the associated reflexive sheaf on Proj(N), showing that the Chern classes depend on subtle geometry of P and giving criteria for the splitting of the sheaf as a sum of line bundles. For certain fans associated to the reflection arrangement A_n, we describe a connection between C^0(P) and logarithmic vector fields tangent to A_n.
The kinematics of Abell clusters

Velocity histograms, galaxy positions, and velocity dispersions are presented for 69 nearby Abell clusters. The shape of the cumulative distribution for R = 1 or more clusters does not match the predictions of standard CDM models for any biasing parameter b. The only models consistent with the median and maximum dispersions of the sample are those of b about 1.6-2.0 and in which clusters are identified in three dimensions. Velocity dispersions of high-redshift systems appear fundamentally different from those of nearby clusters. The median dispersion of the subset of 25 cD clusters is similar to that of non-cD systems. A substantial fraction of the cD galaxies have velocities significantly different from the mean of their parent clusters. Three of these have 4 s or more measured redshifts. These last two results suggest that the formation of cD galaxies is dominated by the local, rather than global, cluster environment.
Lengths of edges in carrier graphs

We show that if X is a minimal length carrier graph in a hyperbolic 3-manifold, M, then if X contains a sufficiently short edge, it must contain a short circuit, as well. The meaning of “short” depends only on the rank of π1(M). We also expand the class of manifolds which are known to have minimal length carrier graphs.
Synthesis of ethyl 2‐[(1‐aryl‐1H‐1,2,4‐triazol‐3‐yl)oxy]propionates and related derivatives

Alkylation of 1-aryl-1H-1,2,4-triazol-3-ols with ethyl 2-bromopropionate under basic conditions resulted in the formation of 2-[(1-aryl-1H-1,2,4-triazol-3-yl)oxy]propionic acid, ethyl esters. No N-alkylated products were detected. Similar alkylation of 2-oxo-5-phenyl-1,3,4-thiazole and the corresponding 1,3,4-oxadiazole gave only N-alkylated derivatives. With 4-hydroxy-6-phenylpyrimidine and 2-oxo-4-phenylthiazole, both O- and N-alkylation occurred. Structure assignments were based on ir and 13C nmr spectral data.
Development of an improved model for runback water on aircraft surfaces

A computer simulation for 'running wet' and evaporative aircraft anti-icing systems is developed. The model is based on the analysis of the liquid water film which forms in the regions of direct impingement and, then, breaks up near the impingement limits into rivulets. The wetness factor distribution resulting from the film breakup and the rivulet configuration on the surface are predicted using a stability analysis theory and the laws of mass energy conservation. The solid structure is modeled as a multiple layer wall. The anti-icing system modeled is of the thermal type utilizing hot air and/or electrical heating elements embedded within the wall layers. Experimental observations revealing some of the basic physics of the water flow on the surface are presented. Detailed qualitative documentation of the tests are given. Several numerical examples are considered, and the effect of some of the involved parameters on the system performance are investigated.
Sequential catalytic asymmetric Heck-iminium ion cyclization: enantioselective total synthesis of the Strychnos alkaloid minfiensine.

A catalytic asymmetric method for the chemical synthesis of alkaloids containing the 1,2,3,4-tetrahydro-9a,4a-(iminoethano)-9H-carbazole (1) moiety is reported and verified by the enantioselective total synthesis of (+)-minfiensine (4). The central step in this total synthesis is the sequential catalytic asymmetric Heck−N-acyliminium ion cyclization of dienyl carbamate triflate 10, prepared in six steps from 1,2-cyclohexanedione, to give enantiopure 3,4-dihydro-9a,4a-(iminoethano)-9H-carbazole (12) in 75% yield. Iminoethano-9H-carbazole 12 is transformed in six steps to dienyl iodide 17, which undergoes diastereoselective intramolecular Heck cyclization to form pentacyclic intermediate 18. In eight additional steps, this latter intermediate is transformed to (+)-minfiensine (4).
Should physicians be permitted to 'balance bill' patients?

Abstract This paper studies the efficiency effects of physician fees when the insurer (possibly the government) pays a fee for each procedure, and the doctor may supplement the fee by an extra charge to the patient, a practice known as ‘balance billing.’ Monopolistically competitive physicians can discriminate among patients on the basis of both price and quality. Equilibria with and without balance billing are compared. The paper analyzes and recommends a new fee policy, a form of payer ‘fee discrimination.’
Continuum description of profile scaling in nanostructure decay

The relaxation of axisymmetric crystal surfaces with a single facet below the roughening transition is studied via a continuum approach that accounts for step energy ${g}_{1}$ and step-step interaction energy ${g}_{3}g0.$ For diffusion-limited kinetics, free-boundary, and boundary-layer theories are used for self-similar shapes close to the growing facet. For long times and ${g}_{3}{/g}_{1}l1,$ (a) a universal equation is derived for the shape profile, (b) the layer thickness varies as ${(g}_{3}{/g}_{1}{)}^{1/3},$ (c) distinct solutions are found for different ${g}_{3}{/g}_{1},$ and (d) for conical shapes, the profile peak scales as ${(g}_{3}{/g}_{1}{)}^{\ensuremath{-}1/6}.$ These results compare favorably with kinetic simulations.
Rethinking the Virtual.

The author builds theoretically off an alternative conception of the virtual, through a series of steps. First, he explores four processes of engagement through which immersion happens (interest, involvement, imagination and interaction); these will prove especially important for understanding the educational potential of virtuality. Second, he applies this conception of the virtual to a discussion of virtual space and time, suggesting that as virtual spaces become familiar and significant, they become virtual places. Two ways in which this transformation can take place are architecture and mapping, and the author suggests that in educational contexts these processes broadly relate to the perspectives of teacher and learner, respectively. Architecture and mapping represent the structures or design elements in which the four aspects of immersion are guided towards learning goals; when these structures are successful, the process of immersion involves students strongly in the activities of learning. In this...
TRAVEL TRENDS USING THE PUGET SOUND PANEL SURVEY: A GENERALIZED ESTIMATING EQUATIONS APPROACH

Abstract This paper examines longitudinal mode use trends using four waves of the Puget Sound Transportation Panel. The analysis is conducted using generalized estimating equations for model estimation. In addition to examining mode use frequencies over time, we also consider mode use trends conditioning on household income and lifecycle stage. As expected, results indicate an overall increase in the number of worktrips made between 1989 and 1993 and these trips were marked by increasing use of single occupancy vehicles. The full parameters of the model were also to estimate the rate of increase in terms of percentage increase and their confidence intervals. Results indicate that the mean number of worktrips made by driving alone significantly increased from wave 1 to wave 4; with a 95% C.I. the rate of percent increase was estimated between 8.2 and 24.5%. The ranges for rates of change in high occupancy vehicle modes and non-motorized worktrip frequencies overlap with the range for single occupancy vehicle rate of change, and thus, it cannot be said that rate of change for the high occupancy modes was significantly different from the single occupancy rates of change. The rate of change in the mean frequency for the high occupancy–transit mode is not only below the range for single occupancy vehicle trips but also suggests, with 95% confidence, the rate of percent decrease was between 2.88 and 44.0%.