gebhart/patrepeval huggingface dataset:
Defects in liquid crystals: homotopy theory and experimental studies (1988)

The fundamental concepts of the homotopy theory of defects in liquid crystals and the results of experimental studies in this field are presented. The concepts of degeneracy space, homotopy groups, and topological charge, which are used for classifying the topologically stable inhomogeneous distributions in different liquid-crystalline phases are examined (uni and biaxial nematics, cholesterics, smectics, and columnar phases). Experimental data are given for the different mesophases on the structure and properties of dislocations, disclinations, point defects in the volume (hedgehogs) and on the surface of the medium (boojums), monopoles, domain formations, and solitons. Special attention is paid to the results of studies of defects in closed volumes (spherical drops, cylindrical capillaries), and to the connection between the topological charges of these defects and the character of the orientation of the molecules of the liquid crystal at the surface. A set of fundamentally new effects that can occur in studying the topological properties of defects in liquid crystals is discussed.
Catalytic synthesis of methanethiol from CO/H2/H2S mixtures using α-Al2O3 (2004)

Sustained synthesis of methanethiol from the reaction of CO/H2/H2S mixtures is reported and discussed. Surprisingly, unmodified α-Al2O3 gives the best results for this reaction and methanethiol selectivities of >98% at CO conversions of ca. 6% can be readily obtained (CO∶H2∶H2S = 4∶5∶1, 340 °C, total pressure = 20 bar, 200 h−1). Reaction of CO + H2 (CO∶H2 = 1∶1) in the absence of H2S using α-Al2O3 under comparable conditions gives a lower CO conversion (ca. 1.3%) with significant selectivities to methane (20%), methanol (28.5%) and ethanol (21.1%). When H2S is added to the synthesis gas feedstock, the product selectivity switches to sulfur-containing products, almost exclusively methanethiol, but some by-product thiophene is also observed. A range of other catalysts were also investigated (e.g., γ-Al2O3, Cr2O3, Cr2O3/Al2O3, Cu/Cr2O3) but all give inferior catalytic performance when compared with α-Al2O3. The mechanism of the synthesis of methanethiol is discussed, based on a modification of chain propagation in the Fischer–Tropsch synthesis reaction.
IC‐P2‐099: Systematics of the ADNI phantom (2008)

The Alzheimer's Disease Neuroimaging Initiative (ADNI) employs a fleet of 66 phantoms (photo below) for MRI scanner characterization and to insure the integrity of data pre-processing steps. Eighty-four different scanners are used in ADNI. The ADNI phantom is scanned along with the subject for every ADNI MRI exam. Geometric fidelity is assessed by comparing the design with observed locations of 160 small spherical fiducial markers. Differences in expected and observed positions are plotted versus observed positions below. SNR and relative contrast are estimated from larger spheres containing solutions of known copper sulfate concentration. Phantom images are acquired with the same MP-RAGE pulse sequence used for human imaging. The phantom scan analysis is fully automated and provides estimates of gradient calibration (proportional to an object's size as measured by MRI), non-linear geometric distortion, SNR and contrast properties. Estimates of within phantom measurement stability were obtained by repeated scanning. Estimates of phantom to phantom variability were obtained by comparing all phantoms to single phantom. Repeatability was assessed by scanning a single phantom multiple times; between scans the phantom was removed and replaced. Coefficients of variation (CV) for SNR and contrast measures were found in the 2–4% range. Gradient calibration CV's were in the range of 3x10–4 to 5x10–4, the larger CV in the scan frequency encoding direction. The phantom construction is a stacked plate design. Phantom to phantom variation is smallest parallel to the plates. Observed CV's parallel to the plate are essentially the same as the within phantom measurement error (i.e. within-plate the manufacturing variability is likely smaller than the measurement error). The CV perpendicular to the plate is 15x10–4 (3X to 5X larger than measurement error), and is assumed to be due to variation in the plate stacking during manufacturing. The leading source of potential error in gradient measurements using the ADNI phantom is phantom-to-phantom variability. Owing to the phantom design, that variability is anisotropic. Given a multi-year study, with thousands of MRI studies, phantoms will occasionally be damaged (dropped) and must be replaced introducing a confound in the consistency of calibration measurements.
(Invited) Generation and Evolution of Materials in the Anode Solid Electrolyte Interphase (SEI) of Lithium Ion Batteries (2019)

A solid electrolyte interphase is generated on the anode of lithium ion batteries during the first few charging cycles. The presence and stability of the solid electrolyte interphase (SEI) is critical to the performance of the battery. Despite thorough investigation of the SEI for over 20 years, the mechanism of formation and function are still relatively poorly understood. We have investigated the structure of the initial SEI on graphite and silicon electrodes along with changes which occur to the SEI upon additional cycling via a combination of ex-situ surface analysis techniques. The investigation of SEI provides significant insight into the structure and properties of the anode SEI. The one electron reducing agent, lithium napthalenide has been used to independently prepare the reduction products which constitute the SEI. The initial reduction product of ethylene carbonate is lithium ethylene dicarbonate (LEDC). However, the thermal decomposition of LEDC and related lithium alkyl carbonates in the presence of LiPF6 generates a intricate mixture of compounds which greatly complicates the structure of the SEI. The reduction products and their subsequent thermal decomposition products have been thoroughly investigated via a combination of NMR, XPS, IR-ATR, TGA, and GC-MS. Mechanisms for the generation of the complicated mixture of products will be discussed. Thermal behavior of the SEI on a silicon electrode for Lithium ion batteries has been investigated by TGA. In order to provide a better understanding of the thermal decomposition of the SEI on silicon, the thermal decomposition behavior of independently synthesized lithium ethylene dicarbonate (LEDC) was investigated as a model SEI. The model SEI (LEDC) has three stages of thermal decomposition. Over the temperature range of 50~300oC, LEDC decomposes to evolve CO2 and C2H4 gasses leaving lithium propanoate (CH3CH2CO2Li) and Li2CO3 as solid residues. The lithium propanoate decomposes over the temperature range of 300~600oC to evolve pentanone leaving Li2CO3 as a residual solid. Finally, the Li2CO3 decomposes over 600oC to evolve CO2 leaving Li2O as a residual solid. A very similar thermal decomposition process is observed for the SEI generated on cycled silicon electrodes. However, two additional thermal decomposition reactions were observed characteristic of LixPOyFz at 300oC and the polyimide binder at 550oC. TGA measurements of Si electrodes after various numbers of cycles suggest that the LEDC on Si electrodes thermally decomposes during cycling to form lithium propanoate and Li2CO3, resulting in increased complexity of the SEI.
Dehydroabietic Acid Induces Regeneration of Collagen Fibers in Ultraviolet B-Irradiated Human Dermal Fibroblasts and Skin Equivalents (2019)

Our results suggest that DAA could be a useful agent for improving skin photoaging through the protection and regeneration of collagen fibers in skin.
ADLOC: An Aptamer‐Displacement Assay Based on Luminescent Oxygen Channeling (2010)

Functional nucleic acids, such as aptamers and allosteric ribozymes, can sense their ligands specifically, thereby undergoing structural alterations that can be converted into a detectable signal. The direct coupling of molecular recognition to signal generation enables the production of versatile reporters that can be applied as molecular probes for various purposes, including high-throughput screening. Here we describe an unprecedented type of a nucleic acid-based sensor system and show that it is amenable to high-throughput screening (HTS) applications. The approach detects the displacement of an aptamer from its bound protein partner by means of luminescent oxygen channeling. In a proof-of-principle study we demonstrate that the format is feasible for efficient identification of small drug-like molecules that bind to a protein target, in this case to the Sec7 domain of cytohesin. We extended the approach to a new cytohesin-specific single chain DNA aptamer, C10.41, which exhibits a similar binding behavior to cytohesins but has the advantage of being more stable and easier to synthesize and to modify than the RNA-aptamer M69. The results obtained with both aptamers indicate the general suitability of the aptamer-displacement assay based on luminescent oxygen channelling (ADLOC) for HTS. We also analyzed the potential for false positive hits and identified from a library of 18,000 drug-like small molecules two compounds as strong singlet-oxygen quenchers. With full automation and the use of commercially available plate readers, we estimate that the ADLOC-based assay described here could be used to screen at least 100,000 compounds per day.
Surface-plasmon-enhanced GaN-LED based on a multilayered M-shaped nano-grating (2013)

A multilayered metallic M-shaped nano-grating is proposed to enhance the internal quantum efficiency, light extraction efficiency and surface-plasmon (SP) extraction efficiency of the gallium nitride-based light emitting diodes. This structure is fabricated by the low-cost nano-imprint lithography. The suitable grating based on quasi-symmetrical-waveguide structure has a high transmission in the visible region. The properties of SP mode and the Purcell effect in this type of LED is investigated. The experimental results demonstrate that its peak photoluminescence intensity of the proposed LED is over 10 times greater than that from a naked GaN-LED without any nanostructure.
A common period four-satellite continuous global coverage constellation (1986)

Nomenclature A = semimajor axis of satellite orbit, in units of the Earth's equatorial radius r a = semimajor axis, n.mi. e = eccentricity h = satellite altitude, n.mi. J2 coefficient of the second harmonic of the Earth's potential function i = inclination, deg M =mean anomaly, deg P = semiparameter, = a ( 1 e) p = perpendicular distance from Earth center to satellite plane, n.mi. r = satellite radius, n.mi. Re =mean radius of Earth, =3442 n.mi. Amax = radial perturbation, ft Sl9S2,S3,S4 = satellite designator Si ,$2,£3,£4 = satellite surborbital points T = constellation period, h a = satellite visibility angle (look angle) above horizon, deg co = argument of perigee, deg cb = rotation of perigee, deg/yr Q = right ascension of ascending node, deg Q = regression of line of nodes, deg/yr H = Earth's gravitational constant, = 1.4077xl0ftVs
THE INCIDENCE AND IMPLICATIONS OF RENAL CELL CARCINOMA IN CADAVERIC RENAL TRANSPLANTS AT THE TIME OF ORGAN RECOVERY (1999)

Renal cell carcinoma is rarely found during renal recovery from a cadaveric donor. However, because the kidneys are usually recovered after the intrathoracic and intraabdominal organs, careful palpation of the kidneys and exploration of any abnormalities is mandated to avoid transplanting any organs from a donor with a known renal malignancy.
Optical Strain Measurement and Tear-Out Behavior of Sutured Porcine Small Intestine Tissue Using a Standarized Procedure (2011)

Some of the major complications leading to high morbidity and mortality rates in intestine surgery are caused by anastomotic insufficiencies. As the suture represents a crucial factor for the successful treatment of intestine anastomosis, it is of critical importance to investigate the tearing of sutured tissue. The goal of this study consists in examining the tear-out characteristics of stitched porcine small intestinal tissue as a function of the position of the stitch, using an optical strain measurement system. Furthermore, the hole formation of two different suture materials (monofilament and braided) with a single stitch is examined and compared. A clear trend for strain characteristic cannot be found for all number of stitches. In the case of four stitches however, it can be observed that for four out of six samples the outer stitches show a higher strain distribution than the inner ones. The comparison of the hole formation indicates that tissue stitched with monofilament PDS II tears by exhibiting a broader deformation pattern than tissue stitched with braided Vicryl.
Influence of Paint Baking Exposure on the Lap-Shear Properties of a Polymer-Cored Laminated Steel (1995)

Abstract Effect of thermal aging on the lap-shear properties of an acrylic-cored laminated steel was investigated by shear testing of specimens following exposure in air to the paint bake temperature of 180°C. The laminated steel consists of two thin steel layers bonded to a polymer core. It was found that thermal aging caused an increase in shear modulus and a decrease in ductility. Shear strength initially decreased, but then increased with aging time. Fractographic, thermal gravimetric, and differential scanning calorimetric analyses indicated that the decrease in shear strength and ductility is likely caused by void formation resulting from evaporation of the volatiles in the acrylic. These voids increased the local stresses. The subsequent increase in shear strength is attributed to the increase in adhesive cross-linking from thermal curing which hardens the adhesive. The increase in shear modulus with increase in aging time is ascribed primarily to thermal curing.
Evolution of glassy gratings with variable aspect ratios under surface diffusion (2011)

The structural evolution of surface gratings on a glassy material is investigated by means of molecular simulations. The gratings provide a means to probe surface diffusion in the vicinity of the glass transition temperature. A theory by Mullins [J. Appl. Phys. 30, 77 (1959)] is used to extract qu-antitative measures of surface diffusivity that rely on calculation of grating amplitude as a function of time. The simulations are implemented in the context of a model binary glass mixture [S. S. Ashwin and S. Sastry, J. Phys.: Condens. Matter 15, S1253 (2003)]. We find that surface diffusion is faster than bulk diffusion by several orders of magnitude, consistent with recent experimental data for an organic glass former. The diffusivities extracted by the grating-decay approach are consistent with those estimated on the basis of mean-squared particle displacements. The grating-decay approach, however, is more efficient than traditional techniques based on Einstein's diffusion equation. Grating decay is also more versatile and is shown to be applicable in a variety of sample geometries.
A Meta-analysis of Randomized Clinical Trials (2008)

Background: Perioperative pathologic microvascular bleeding is associated with increased morbidity and mortality and could be reduced by hemostatic drugs. At the same time, safety concerns regarding existing hemostatic agents include excess mortality. Numerous trials investigating desmopressin have lacked power to detect a beneficial effect on transfusion of blood products. The authors performed a meta-analysis of 38 randomized, placebo-controlled trials (2,488 patients) investigating desmopressin in surgery and indicating at least perioperative blood loss or transfusion of blood products. Methods: Pertinent studies were searched in BioMed Central, CENTRAL, and PubMed (updated May 1, 2008). Further hand or computerized searches involved recent (2003‐2008) conference proceedings. Results: In most of the included studies, 0.3 g/kg desmopressin was used prophylactically over a 15- to 30-min period. In comparison with placebo, desmopressin was associated with reduced requirements of blood product transfusion (standardized mean difference 0.29 [0.52 to 0.06] units per patient; P 0.01), which were more pronounced in the subgroup of noncardiac surgery and were without a statistically significant increase in thromboembolic adverse events (57/1,002 5.7% in the desmopressin group vs. 45/979 4.6% in the placebo group; P 0.3). Conclusions: Desmopressin slightly reduced blood loss (almost 80 ml per patient) and transfusion requirements (almost 0.3 units per patient) in surgical patients, without reduction in the proportion of patients who received transfusions. This meta-analysis suggests the importance of further large, randomized controlled studies using desmopressin in patients with or at risk of perioperative pathologic microvascular bleeding.
J. L. Austin. How to do things with words. The William James Lectures delivered at Harvard University in 1955. The Clarendon Press, Oxford1962, vii + 166 pp., and Harvard University Press, Cambridge, Mass., 1962, ix + 167 pp. - Jon Wheatley. Austin on implication and entailment. Philosophical studies (Minneapolis), vol. 15 (1964), pp. 46–48. - Bill MathewsJr., Austin on implication and entailment: A reply to Mr. Wheatley. Philosophical studies (Minneapolis), vol. 15 (1964), pp. 88–89. (1971)

J. L. Austin. How to do things with words. The William James Lectures delivered at Harvard University in 1955. The Clarendon Press, Oxford1962, vii + 166 pp., and Harvard University Press, Cambridge, Mass., 1962, ix + 167 pp. - Jon Wheatley. Austin on implication and entailment. Philosophical studies (Minneapolis), vol. 15 (1964), pp. 46–48. - Bill MathewsJr., Austin on implication and entailment: A reply to Mr. Wheatley. Philosophical studies (Minneapolis), vol. 15 (1964), pp. 88–89. - Volume 36 Issue 3
System Distortion Model for the Cross-Validation of Millimeter-Wave Channel Sounders (2019)

Because millimeter-wave directional channel measurements are time-consuming and expensive to collect, there is considerable interest in combining measurement data obtained with different channel sounders in order to yield more comprehensive datasets. The simplest way to verify that the results obtained with these different instruments in a given environment are comparable would be to transport the channel sounders to that environment, collect and process measurement data, and then compare the results. Because this is rarely feasible, we propose an alternative method that is much more practical. It involves: 1) Generating an ideal three-dimensional channel impulse response that corresponds to a scenario of interest, 2) Degrading the ideal response by applying a distortion model that capture the factors that limit the spatio-temporal resolution and dynamic range of each channel sounder, and 3) Applying the multipath component (MPC) extraction techniques used by the channel sounder to the distorted response. After the last step, one will observe: a) correctly estimated, b) incorrectly estimated, c) missing, and d) spurious MPCs. Discrepancies between the ideal and distorted responses will be readily apparent and the performance of the channel sounders can be easily compared in a given environment. The effort required to fully characterize the three-dimensional patterns of the transmitting and receiving antennas is considerable and further work is required to determine the corresponding accuracy requirements.
BiF(A+, v′) radiative lifetimes and rate coefficients for V↔T transfer and electronic quenching (1986)

The radiative lifetime for several vibrational states (v′=0–3) was measured for electronically excited BiF(A0+). The measured radiative lifetime is 1.4 μs and does not vary for the v′ levels investigated. Also measured for those v′ levels are the electronic quenching and V–T rate coefficients for the rare gases He and Ar at an experimental temperature of ∼485 K. The results indicate Ar is slightly more efficient in electronic quenching than is He. For both gases the quenching rate constants increases with v′, with these rates becoming competitive with the radiative decay rate only for pressures in excess of 40 Torr. The vibrational relaxation (V–T) rate constant for all levels studied are found to be at least an order of magnitude greater than those for electronic quenching. The reported V–T rate coefficients scale as V1.7 for both He and Ar for v′=0, to v′=3, a result which is contrary to the behavior predicted by the classical harmonic oscillator model.
Recent Progress of Transparent Ceramic Scintillators (2016)

Recent progress of transparent ceramic scintillators is reviewed. The present work reports the research and development of oxide transparent ceramic materials such as garnet, sesquioxide, complex perovskite and some other kinds. Some representative scintillation properties such as scintillation emission spectra and decay times under X-ray irradiation are presented. Gamma-ray induced scintillation detector properties including pulse height spectrum, energy resolution, and light yield nonproportionality are also shown.
The Effect of Reactor Conditions on High‐Impact Polypropylene Properties and Gas Phase Polymerization Kinetics (2018)

Abstract High impact polypropylene (hiPP) powders are made in a 2.5 L semi‐batch gas‐phase reactor using a Ziegler–Natta catalyst and two sequential polymerization steps. The amount of copolymer, reactor temperature and pressure, the relative amounts of ethylene and propylene, and the presence of hydrogen are varied systematically to understand their impact on the copolymerization kinetics, hiPP properties, and on rubber distribution. Examples of discoveries are that the presence of hydrogen can reduce copolymerization activity, depending on the catalyst system, and that the fraction of crystalline copolymer decreases with 1) copolymer content in hiPP; and 2) copolymerization activity. The last implies a resistance to mass transfer of ethylene during copolymerization. To understand this phenomenon, atomic force microscopy analyses of hiPP samples with distinct morphology of the polypropylene matrix (isotactic polypropylene, iPP) and copolymer ethylene/propylene ratios are performed after microtoming. It is found that mesoparticles are the determining structure for the copolymer distribution, and that powders with more ethylene in the copolymer or an iPP matrix better suited for mass transfer had more rubber in the center of the mesoparticles. This indicates that the length scales of the mesoparticles that control transfer limitations for ethylene also impact the properties of the final impact copolymer.