gebhart/patrepeval huggingface dataset:
Asymmetric Synthesis of A-240610.0 via a New Atropselective Approach for Axially Chiral Biaryls with Chirality Transfer (2002)

A new approach for atropselective preparation of axially chiral biaryl was developed. This process proceeded through a chirality transfer from a stereogenic center of a secondary alcohol to the stereogenic axis via regioselective intramolecular silyl group migration. This methodology allowed for the preparation of a single atropisomer 2 in good yield (85%) with high diastereoselectivity (99:1), which subsequently led to the successful development of an efficient asymmetric synthesis of A-240610.0, 1.
Gas Turbine Cooling: Moving From Macro to Micro Cooling (2013)

Up to the present time, virtually all production gas turbine engines utilize high-pressure turbine components that are cooled by various modes of bulk, or macro, internal flow passages and networks, many of which are then linked to external film cooling by holes through the walls. Typical examples of macro cooling include serpentine passages, swirl chambers, pin banks, and impingement jets. All cooled turbine airfoils in commercial operation today utilize cooling channels and film holes that are considered to be macroscopic in physical magnitude. The conventional delimiters between macro and micro cooling are (1) whether the feature (internal passages and holes) can be repeatedly manufactured via investment casting methods, and (2) whether the flow passage (film hole, impingement orifice, dust hole) may become plugged by particles in the cooling fluid. The acceptable sizes are relative to the turbine size and the operating environment. This study examines the limitations and weaknesses inherent in macro cooling and the reasoning that demands gas turbine cooling change to micro cooling methods. A brief history of the developments in micro cooling for turbine airfoils is presented, including the reasons why it has not yet become commercially viable. A simple cooling study is used to demonstrate the very significant performance gains that can be obtained with micro cooling, such as cooling flow reductions approaching 40%, and thermal stress (gradient) reductions of 50%. The key to realizing these gains in full lies in cost effective manufacturing and durability in operation.
Functional Polymers. 61. Ultraviolet Spectral Behavior of Selected 2(2-Hydroxyphenyl)2<i>H</i>-Benzotriazoles (1995)

Abstract Ultraviolet spectra of a number of 2(2-hydroxyphenyl)2H-benzotriazoles were studied in nonpolar, polar, and hydrogen bonding solvents. The effect of substituents located in the 4-position of the benzotriazole ring was investigated, and the effect on the UV absorption characteristics of 2(2-hydroxyphenyl)2H-benzotriazoles was determined. Substituted resorcinol or phloroglucinol-based 2(2-hydroxyphenyl)2H-benzotriazole derivatives were investigated with special emphasis on UV absorption characteristics that were expected to be useful as polymerbound UV stabilizers in optical lens applications.
Asynchronous Maximum Likelihood (ML) Detection Of Servo Repeatable Run Out (RRO) Data (2006)

A servo sector contains a preamble, servo address mark (SAM), Gray data, burst demodulation fields, a DC erase section and then repeatable run out (RRO) field. The RRO field consists of a RRO address mark (RROAM, same for every sector) and RRO data. The servo controller processes the RRO field to compensate for effects such an off center spindle rotation. We discuss the detection reliability of the RRO field, not how it is used for RRO compensation. We (i) propose a maximum likelihood (ML)asynchronous detection technique for coded servo RRO data (ii) quantify the detection.
Real-Time Reed-Solomon Decoder (1985)

RS decoder uses dedicated hardware and data pipelining for high-speed operation. Parallel processing techniques provide equivalent of over one billion operations per second at one step in decoding. Decoder finds commercial application in data encoding/decoding, telemetry, and radio communications.
View segmentation and static/dynamic summary generation for echocardiogram videos (2001)

No abstract available.
Material Characterization and Flaw Detection, Sizing, and Location by the Differential Gamma Scattering Spectroscopy Technique. Part II: Experiment (1990)

AbstractThe differential gamma scattering spectroscopy technique is a novel means of nondestructive testing using Compton scattering to determine local density perturbations in a test sample. A narrow collimated beam of gamma rays irradiates a test sample, and the scattered radiation field is detected in a transversely placed high-purity germanium detector. This detector provides excellent energy resolution so that a detailed energy spectrum can be obtained. This spectrum is then subtracted from a reference spectrum that was collected from a well-known, unflawed sample to obtain the differential spectrum. This differential spectrum contains information characterizing the flaw. Using the relationship between scattering angle and scattering energy that characterizes Compton scattering, the single-scattered spectrum can be used to determine the location of scattering and, consequently, the density distribution along the portion of the primary beam path that passes through the sample.An attractive feature of this technique that distinguishes it from other Compton scattering techniques is the ability to detect flaws both on and off the primary beam path. A series of experiments was conducted to assess the sensitivity of the detection system for different sizes and shapes of flaws located throughout the sample. The results of these experiments are analyzed.
Inflatable-Seal Assembly For Cryogenic Fluids (1989)

Connector for cryogenic fluid lines quickly joined or separated, seals tightly, and reduces transfer of heat to fluid. Features redundant sealing rings inflated after joining so they wedge tightly against connector base, preventing leakage. Cylinder of FEP inflatable. Pair of threaded stainless-steel rings - one at each end of cylinder - secure cylinder in quick-disconnect assembly.
Quantum well optical tri-state devices (1990)

We demonstrate quantum well tri-state logic devices for possible use in optical bus architectures. These optical devices are analogous to the tri-state devices often used in electronic buses, where each device can be actively on, actively off, or disabled with at most one device on the bus active at a time. We show two methods of generating these tri-state data, one using tri-state quantum well modulators and one using optical tri-state self-electrooptic effect devices, and we demonstrate a simple optical bus consisting of two such devices. Finally, we comment on the limitations on the number of devices that can be connected to a bus of this type.
<title>Automatic key-frame selection for content-based video indexing and access</title> (1999)

This paper addresses key-frame selection for content-based video indexing and access. The proposed key-frame selection method is aimed to operate in real-time irrespective of the available computation resources and memory. Hence, we provide three solutions to content-based key-frame selection with different costs, and suggests three operation levels. The suggested key-frame selection method has two major parts: (i) segmentation of the video into shots; (ii) analysis of the motion and color activity within each video shot to selected additional frames. We also prove a new color based approach to key-frame selection and discuss how to fuse color and motion based key-frame selection results.
Inversion of borehole dispersions for formation stresses (2002)

Horizontal tectonic stresses in vertical boreholes, and overburden and tectonic stresses in horizontal wells cause stress-induced azimuthal anisotropy in shear wave logging. It has been reported that a dipole dispersion crossover is an indicator of stress-induced anisotropy dominating over other possible sources of shear anisotropy. This paper describes a method of estimating the difference between the maximum and minimum stresses in the azimuthal plane perpendicular to the borehole from the stress-induced flexural and Stoneley dispersions. This method consists of analyzing the flexural dispersions for dipole sources aligned parallel and perpendicular to the maximum azimuthal stress direction together with the Stoneley wave dispersion derived from a monopole source. In the presence of formation and borehole stresses above and beyond those in an assumed isotropic reference state, the borehole flexural and Stoneley velocity dispersions are also functions of the formation stresses and nonlinear constants. A multifrequency inversion of the flexural and Stoneley velocity dispersions over a selected frequency band is performed to determine the differential or uniaxial stress magnitude S, and the quantities Sc/sub 111//c/sub 66/, Sc/sub 112//c/sub 66/, and Sc/sub 123//c/sub 66/, where c/sub 66/ is the formation shear modulus; and c/sub 111/, c/sub 112/, and c/sub 123/ are the formation nonlinear constants in the assumed isotropic reference state. The optimal frequency band for multifrequency inversion is obtained from sensitivity analyses of flexural and Stoneley dispersions to the stress magnitude and nonlinear constants.
Pyrolyzed Polysiloxanes for Use as Anode Materials in Lithium‐Ion Batteries (1997)

More than sixty siloxane polymers containing various organofunctional siloxane units were synthesized. The synthesized siloxane polymers were pyrolyzed in inert gas at 1000°C. Chemical analysis showed that the products of pyrolysis were distributed over a well‐defined region in the Si‐C‐O Gibbs phase diagram. The electrochemical and structural properties of these materials were measured using coin‐type test cells and x‐ray powder diffraction, respectively. The most interesting materials are found near the line in the Si‐C‐O Gibbs triangle connecting carbon to . Materials with the largest reversible specific capacity for lithium (about 900 mAh/g) are on this line and were at about 43% carbon, 32% oxygen, and 25% silicon (atomic percent). Materials which were almost pure carbon showed diffraction patterns characteristic of disordered carbons. Along the line from carbon to the sample structure can be described as a mixture of single or small groups of graphene sheets mixed with regions of Si‐C‐O amorphous glass. The amount and composition of the glass changed according to the overall sample composition. Moving from carbon to , the reversible capacity first rises from about 340 mAh/g for pure carbon, to a maximum of 900 mAh/g near 50% carbon, and then falls to near zero mAh/g at 0% carbon. This suggests that the amorphous glass can reversibly react with lithium, provided the carbon is present to provide a path for electrons and Li ions. However, the hysteresis in the voltage profile (difference between charge and discharge voltages) and the irreversible capacity increase almost linearly along this line. There is a clear correlation between both the irreversible capacity and hysteresis in these materials with their oxygen content. Along the line connecting carbon to silicon, the reversible capacity rises from 340 mAh/g for pure carbon to about 600 mAh/g for samples with about 15 atomic percent Si. It then decreases to near zero as the composition nears SiC. Along the C‐SiC line, the irreversible capacities remain below about 200 mAh/g. We are quite convinced that optimized silicon‐containing carbons can be good alternatives to pure carbons as anode materials in lithium‐ion batteries.
Nanoparticle-Stabilized Capsules for the Treatment of Bacterial Biofilms (2015)

Bacterial biofilms are widely associated with persistent infections. High resistance to conventional antibiotics and prevalent virulence makes eliminating these bacterial communities challenging therapeutic targets. We describe here the fabrication of a nanoparticle-stabilized capsule with a multicomponent core for the treatment of biofilms. The peppermint oil and cinnamaldehyde combination that comprises the core of the capsules act as potent antimicrobial agents. An in situ reaction at the oil/water interface between the nanoparticles and cinnamaldehyde structurally augments the capsules to efficiently deliver the essential oil payloads, effectively eradicating biofilms of clinically isolated pathogenic bacteria strains. In contrast to their antimicrobial action, the capsules selectively promoted fibroblast proliferation in a mixed bacteria/mammalian cell system making them promising for wound healing applications.
Evolution of the Single-Nanocrystal Photoluminescence Linewidth with Size and Shell: Implications for Exciton–Phonon Coupling and the Optimization of Spectral Linewidths (2015)

The optimization of photoluminescence spectral linewidths in semiconductor nanocrystal preparations involves minimizing both the homogeneous and inhomogeneous contributions to the ensemble spectrum. Although the inhomogeneous contribution can be controlled by eliminating interparticle inhomogeneities, far less is known about how to synthetically control the homogeneous, or single-nanocrystal, spectral linewidth. Here, we use solution photon-correlation Fourier spectroscopy (S-PCFS) to measure how the sample-averaged single-nanocrystal emission linewidth of CdSe core and core/shell nanocrystals change with systematic changes in the size of the cores and the thickness and composition of the shells. We find that the single-nanocrystal linewidth at room temperature is heavily influenced by the nature of the CdSe surface and the epitaxial shell, which have a profound impact on the internal electric fields that affect exciton-phonon coupling. Our results explain the wide variations, both experimental and theoretical, in the magnitude and size dependence in previous reports on exciton-phonon coupling in CdSe nanocrystals. Moreover, our findings offer a general pathway for achieving the narrow spectral linewidths required for many applications of nanocrystals.
Why Are Short Pulses More Efficient in Tissue Erosion Using Pulsed Cavitational Ultrasound Therapy (Histotripsy)? (2010)

Histotripsy produces mechanical tissue fractionation through controlled cavitation. The histotripsy induced tissue erosion is more efficient with shorter (i.e., 3–6 cycles) rather than longer (i.e. 24 cycles) pulses. In this study, we investigated the reasons behind this observation by studying dynamics of the cavitating bubble clouds and individual bubbles during and after a therapy pulse. Bubble clouds were generated at a gel‐water interface using 5 to 30‐cycle 1 MHz pulses at P−/P+>19/125‐MPa pressure and 1‐kHz pulse repetition frequency. The evolution of the overall bubble cloud and individual bubbles were studied using high speed photography. Results show that: 1) within the first 10–15 cycles, the overall cloud grew to its maximum size; the individual bubbles underwent violent expansion and collapse, and grew in size with each cycle of ultrasound; 2) between the 15th cycle and the end of the pulse, the overall cloud size did not change even if further cycles of ultrasound were delivered; the individual bubbles no longer underwent violent collapse; 3) after the pulse, the overall cloud gradually dissolved; the individual bubbles may coalesce into larger bubbles for 0–40 μs, and then gradually dissolved. These observations suggest that violent growth and collapse of individual bubbles occur within the first few cycles of ultrasound pulse most often. This may explain why extremely short pulses are more energy efficient in histotripsy‐induced tissue erosion.
Hydrogen and elemental sulfur by photochemical redox reaction of hydrogen sulfide and sulfides (1982)

L'hydrogène et le soufre élémentaire sont produits par irradiation par la lumière visible de solutions d'hydrogène sulfuré ou de sulfure de métaux en presence d'un catalyseur consistant en une matière semiconductrice, telle que le sulfure de cadmium, recouverte d'une couche transparente d'oxyde de ruthénium.
26-hydroxycholesterol: regulation of hydroxymethylglutaryl-CoA reductase activity in Chinese hamster ovary cell culture. (1983)

The effect of 26-hydroxycholesterol and other intermediates in bile acid synthesis on HMG-CoA reductase activity was studied in Chinese hamster ovary (CHO) cell culture. Incubation of CHO cells for 5 hr in 0.25 microM 26-hydroxycholesterol caused a 40% inhibition of HMG-CoA reductase activity. All other intermediates tested including 3 beta-hydroxy-5-cholenoic acid and cholest-5-ene-3 beta,7 alpha,26-triol, oxidation products of 26-hydroxycholesterol, had little or no inhibitory effect. It is proposed that 26-hydroxycholesterol has a selective biological role in the regulation of cholesterol synthesis.
Polymeric nanostructured material for high-density three-dimensional optical memory storage (2001)

The unique properties of a polymer photonic crystal are examined with respect to applications as a medium for high-density three-dimensional optical data storage media. The nanocomposite material was produced from core-shell latex particles, in which the latex cores contained dye-labeled polymer. Nonfluorescent latex shells were attached to the core particles. Upon annealing, the close-packed core-shell particles formed a nanostructured material with the fluorescent particles periodically embedded into the optically inert matrix in a hexagonal close-packed structure. A two-photon laser scanning microscope was used to write bits of information into the material by photobleaching the optically sensitive particles and, under much lower fluence, read out the resulting image. Relative to conventional homogeneous storage media, the nanostructured periodic material is shown to increase the effective optical storage density by at least a factor of 2 by spatially localizing the optically active region and imposing an optically inactive barrier to cross-talk between bits. This polymer photonic crystal has the potential to dramatically improve performance further through the improved capabilities to optimize the photochemical processes and more fully exploiting the periodic nature of the information domains in the image processing.
Configuration Design of Mechanical Assemblies using an Estimation of Distribution Algorithm and Constraint Programming (2019)

A configuration design problem in mechanical engineering involves finding an optimal assembly of components and joints that realizes some desired performance criteria. Such a problem is a discrete, constrained, and black-box optimization problem. A novel method is developed to solve the problem by applying Bivariate Marginal Distribution Algorithm (BMDA) and constraint programming (CP). BMDA is a type of Estimation of Distribution Algorithm (EDA) that exploits the dependency knowledge learned between design variables without requiring too many fitness evaluations, which tend to be expensive for the current application. BMDA is extended with adaptive chi-square testing to identify dependencies and Gibbs sampling to generate new solutions. Also, repair operations based on CP are used to deal with infeasible solutions found during search. The method is applied to a vehicle suspension design problem and is found to be more effective in converging to good solutions than a genetic algorithm and other EDAs. These contributions are significant steps towards solving the difficult problem of configuration design in mechanical engineering with evolutionary computation.
Imidodisulfamides. 1. A novel class of antagonists of slow-reacting substance of anaphylaxis (1982)

A series of N',N"-bis(aryl)- and N',N"-(aralkyl)imidodisulfamides was prepared and evaluated as antagonists of slow-reacting substance of anaphylaxis (SRS-A) induced contractions of isolated guinea pig ileum. Some of these compounds, notably N',N"-bis(4-phenylbutyl)-, N',N"-bis[2-(4-chlorophenyl)ethyl]-, and N',N"-bis[2-(4-bromophenyl)ethyl]imidodisulfamides (16, 22, and 26), were moderately potent and selective antagonists of SRS-A. The influence of lipophilic (pi) and electronic (sigma) factors on SRS-A antagonist activity appears to be of considerable importance to the derivation of potent and selective SRS-A antagonists.
Porphyromonas gingivalis htrA is involved in cellular invasion and in vivo survival (2008)

HtrA is a heat-stress protein that functions both as a chaperone and as a serine protease. HtrA has been shown in several organisms to be involved in responses to stressful environmental conditions and involvement of HtrA in virulence has been reported in pathogenic species. A Porphyromonas gingivalis htrA mutant demonstrated no significant difference to the W83 parent strain when subjected to high temperature and pH values from 3 to 11. However, the htrA mutant showed increased sensitivity to H(2)O(2). Cell invasion assays indicated that the total interaction (adherence) with KB cells, human coronary artery endothelial cells and gingival epithelial cells (GEC) was the same for both the wild-type and the htrA mutant. However, the htrA mutant showed increased invasion in KB cells and GEC. Microarray experiments indicated that a total of 253 genes were differentially regulated in the htrA mutant, including a group of stress-related genes, which might be responsible for the observed decreased resistance to H(2)O(2). In animal experiments, a competition assay showed that the htrA mutant did not survive as well as the wild-type. In another in vivo assay, fewer mice infected with the htrA mutant died than mice infected with W83, suggesting that the htrA gene is virulence-related. These data indicate that the htrA gene in P. gingivalis does not relate to stress conditions such as high temperature and pH, but rather to H(2)O(2) stress. The htrA gene also appears to be important for virulence and survival in in vivo animal models.
Limits on the Traffic Carrying Capacity of Optical Networks With an Arbitrary Topology (2004)

The letter examines the limits on the traffic carrying capacity of a dense wavelength-division multiplexing (DWDM)-based network of arbitrary topology. It also presents a technique to maximize the traffic carrying capacity of such networks.
Sub-voltage Graphene-Plasmon Based Electro-absorption Modulator (2017)

We experimentally show a sub-volt graphene-based hybrid plasmonic waveguide-integrated electro-absorption modulator showing an extinction ratio (0.25 dB/µm) compact footprint (5 µm2) enabled by improved both electrostatics and mode overlap factor.
Scaling laws for soliton pulse compression by cascaded quadratic nonlinearities (2007)

We present a detailed study of soliton compression of ultrashort pulses based on phase-mismatched second-harmonic generation (SHG) (i.e., the cascaded quadratic nonlinearity) in bulk quadratic nonlinear media. The single-cycle propagation equations in the temporal domain including higher-order nonlinear terms are presented. The balance between the quadratic (SHG) and the cubic (Kerr) nonlinearity plays a crucial role; we define an effective soliton number—related to the difference between the SHG and the Kerr soliton numbers—and show that it has to be larger than unity for successful pulse compression to take place. This requires that the phase mismatch be below a critical level, which is high in a material where the quadratic nonlinearity dominates over the cubic Kerr nonlinearity. Through extensive numerical simulations we find dimensionless scaling laws, expressed through the effective soliton number, that control the behavior of the compressed pulses. These laws hold in the stationary regime, in which group-velocity mismatch effects are small, and they are similar to the ones observed for fiber soliton compressors. The numerical simulations indicate that clean compressed pulses below two optical cycles can be achieved in a β-barium borate crystal at appropriate wavelengths, even for picosecond input pulses.