gebhart/patrepeval huggingface dataset:
Quantum Detection Efficiency in Geiger Mode Avalanche Photodiodes (2008)

The fabrication of silicon shallow junction photodiodes is a relevant topic for the detection of blue and near ultraviolet weak photon fluxes. In this paper we present a simple model to calculate the quantum detection efficiency (QDE) of a Geiger mode avalanche photodiode (GMAP) as a function of the dead layer thickness above the junction depletion layer. A comparison between calculated and experimental data is also presented. Moreover, by using the same model, an analysis of the QDE at 420 nm wavelength of conventional GMAPs based on shallow N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -P and P <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> -N junctions is given.
Chemical compatibility of ceramics for directionally solidifying Ni-base eutectic alloys. [Compatibility between 1700/sup 0/-1850/sup 0/ C] (1979)

The chemical compatibility of 14 oxides with the Ni-base eutectic alloy NiTaC-13 was experimentally evaluated between 1700/sup 0/ and 1850/sup 0/C using 1-h sessile drop tests and 20-h immersion tests. Of the 14, Al/sub 2/O/sub 3/, Y/sub 3/Al/sub 5/O/sub 12/, YAlO/sub 3/, Y/sub 4/Al/sub 2/O/sub 9/, Al/sub 2/O/sub 3/--rich spinel (MgAl/sub 6/O/sub 10/), LaAlO/sub 3/, LaAl/sub 11/O/sub 18/, and probably NdAlO/sub 3/ were found not to react appreciably with NiTaC-13 at 1800/sup 0/C other than forming CO, which can be prevented by adding CO to the Ar atmosphere. Therefore, on the basis of bulk thermodynamic criteria, these oxides can be made to be chemically compatible with NiTaC-13 at 1800/sup 0/C and thus may be potential casting ceramics for this family of alloys. Y/sub 2/O/sub 3/ was found to react slightly with NiTaC-13 at 1800/sup 0/C by forming a thin, apparently protective reaction layer. Thus, Y/sub 2/O/sub 3/ may also be a potential casting ceramic for this family of alloys.
VDM-based UAV Attitude Determination in Absence of IMU Data (2018)

The capability of a previously proposed VDM (vehicle dynamic model) based navigation method for UAVs is assessed in attitude determination without IMU data. This method utilizes the VDM as main process model within the navigation filter and treats data from IMU (if available) and other sensors as observations. Experimental results from a test flight and a Monte Carlo simulation are presented to compare the performance of the VDM-based navigation against the conventional INS-based navigation. While the attitude estimation performance of VDM/GNSS integration is comparable to that of INS/GNSS in simulations, experimental results reveal the need for improved VDM parameter calibration.
An efficient bit-loading algorithm for DMT applications (2000)

This letter describes an efficient bit allocation algorithm for digital subscriber loop modems that use discrete multi-tone technology. The algorithm computes the optimum bit allocation profile within all constraints and requires fewer computations than the conventional "water-filling" approach. Conventional algorithms are unable to assign data bits to higher frequency bins over long loops with high level of interference due to the power spectrum mask limitation, even if the total power budget is not expended. We propose a novel scheme to distribute data over multiple bins at correspondingly reduced power in these, otherwise unpopulated bins.
Carbohydrate Modifications in Antisense Oligonucleotide Therapy: New Kids on the Block (1999)

Abstract Chemical modifications to improve the efficacy of an antisense oligonucleotide are designed to increase the binding affinity to target RNA, to enhance the nuclease resistance, and to improve cellular delivery. Among the different sites available for chemical modification in a nucleoside building block, the 2′-position of the carbohydrate moiety1 has proven to be the most valuable for various reasons: (1) 2′-modification can confer an RNA-like 3′-endo conformation to the antisense oligonucleotide. Such a preorganization for an RNA like conformation2,3,4,5 greatly improves the binding affinity to the target RNA; (2) 2′-modification provides nuclease resistance to oligonucleotides; (3) 2′-modification provides chemical stability against potential depurination conditions pharmacology evaluations and correlation with pharmacokinetic changes are emerging from these novel chemical modifications. Analytical chemistry of modified oligonucleotides before and after biological administration of antisense oligonucleotides with techniques such as capillary gel electrophoresis (CGE) and mass spectrometry help to determine the purity as well as the in vivo fate of these complex molecules. Large-scale synthesis is becoming a tangible reality for antisense oligonucleotides. Nucleic acid chemists and biologists alike are beginning to understand the structure-biological activity in terms of basic physical-organic parameters such as the gauche effect, the charge effect and conformational constraints. Synthesis of chimeric designer oligonucleotides bringing the attractive features of different modifications to a given antisense oligonucleotide sequence to generate synergistic interactions is forthcoming30. These advances along with the potential availability of complete human genome sequence information promise a bright future for the widespread use of nucleic acid based therapeutics.
Flight test validation of sideslip estimation using inertial accelerations (2000)

This paper demonstrates the feasibility of using INS derived accelerations to estimate the sideslip angle of aircraft. This is validation of earlier work [1], a paper proposing an avionics system architecture that, by sensing both the Ny and Nz acceleration components of the aircraft, can analytically derive both the angle-of-attack, a, and the sideslip angle, p, in the presence of gusts and turbulence. Results from U-2S aircraft flight test are used to show that the system will work for sideslip calculation.
CW-powered squegging micromechanical clock generator (2017)

A mechanical circuit has been demonstrated that harnesses squegging to convert -50dBm of input continuous-wave (CW) energy into a local 1-kHz clock output while consuming three orders less local battery power than a typical real-time clock (RTC). Unlike a previous clock receiver that relied on a modulated RF input, this clock generator converts a CW input-no modulation needed-to a clock output via squegging of an impacting micromechanical resonant switch (“resoswitch”). Here, impact-induced disruption compels the device's resonating element to lose oscillation amplitude (hence stop impacting), then recover to impact again, only to again lose amplitude, in a periodic and repeatable fashion. The resulting time domain waveform, with periodic peaks and valleys, then provides a stable frequency that serves as a local on-board clock for low data rate applications. By dispensing with the need for a positive feedback sustaining amplifier, this CW-powered mechanical clock generator operates with only 0.8nW of battery power when outputting a triangle-wave into 0.8pF, which is 1250× lower than the μW of a typical RTC.
New compact TEM-type deflecting and crabbing rf structure (2009)

A new type of rf structure for the deflection and crabbing of particle beams is presented. The structure is comprised of a number of parallel TEM resonant lines operating in opposing phase from each other. One of its advantages is its compactness compared to conventional crabbing cavities operating in the ${\mathrm{TM}}_{110}$ mode, thus allowing low frequency designs. This geometry would also be effective for the deflection of beams propagating at velocities substantially less than that of light.
The Identification of 2-(1<i>H</i>-Indazol-4-yl)-6-(4-methanesulfonyl-piperazin-1-ylmethyl)-4-morpholin-4-yl-thieno[3,2-<i>d</i>]pyrimidine (GDC-0941) as a Potent, Selective, Orally Bioavailable Inhibitor of Class I PI3 Kinase for the Treatment of Cancer (2008)

Phosphatidylinositol-3-kinase (PI3K) is an important target in cancer due to the deregulation of the PI3K/ Akt signaling pathway in a wide variety of tumors. A series of thieno[3,2-d]pyrimidine derivatives were prepared and evaluated as inhibitors of PI3 kinase p110alpha. The synthesis, biological activity, and further profiling of these compounds are described. This work resulted in the discovery of 17, GDC-0941, which is a potent, selective, orally bioavailable inhibitor of PI3K and is currently being evaluated in human clinical trials for the treatment of cancer.
GMS Guardrail Mini Spacer Releasable Fastener: Improving Performance and Reliability of Conventional Strong-Post Guardrail (2008)

This paper describes a cost-effective and versatile strong-post W-beam guardrail called the GMS Guardrail. Only the guardrail mounting fastener is changed to implement unprecedented performance, reliability, and cost benefits in strong post guardrails. This robust releasable fastener is interchangeably called a “Gregory Mini Spacer” or simply a “Mini Spacer”. The Mini Spacer succeeds in leveraging independently-funded, synergistic, ground-breaking research and advanced proprietary nonlinear crash analysis solutions to overcome decades-old problems and paradigms, to more effectively manage barrier system loads. For example, release loads are only now more systematically and appropriately selected in relation to cross section and material properties of standard posts to completely redefine and improve load-transfer interactions between posts and the rail or an impacting vehicle. In addition, major sources of variability in release of the rail are directly circumvented, and thus entirely eliminated. The rail-to-post mounting connection of this tapered fastener is strong in shear and weak in tension. Among other benefits, elimination of release variability means that splices may now be confidently placed at posts without fear of compromising performance. Finally, several mechanisms of major guardrail failure modes are systematically scrutinized, dismantled, and defused. The resulting performance improvements are quite dramatic- yet they do not require (cost penalties related to) the alteration of rail height, weakening of steel posts, alteration of end anchors, use of backup plates, deeper blockouts- or even any blockouts at all. Cost benefits include the use of unaltered, un-weakened, standard posts and unaltered guardrail panels- i.e. no added rail slots or end adapters to accommodate mid-span splice placement. The GMS Guardrail is both innovative and pragmatic, since these kinds of extra hardware items may significantly burden State DOT’s that must stock and inventory them. Successful NCHRP 350 Update Test 3-11 crash tests of a Modified G4 (1S) guardrail with unaltered standard 12 gage W-Beam rail at 6 ft 3 inch post spacing of unaltered standard 6 ft long W6x8.5 steel-posts, without blocks or backup-plates at posts, confirm the GMS Guardrail's ability to contain heavier, high center-of-gravity light trucks at nominal top-of-rail heights of 27 inches and 31 inches. More recent successful crash tests include repetition of the above test- changing only the post spacing to a wider 12 ft 6 inch post spacing at a nominal 27 inch top-of-rail height. This paper highlights individual technology breakthroughs that enable the Mini Spacer to significantly upgrade existing strong-post guardrails.
One-Step Deposition of Catalyst Layers for High Temperature Proton Exchange Membrane Fuel Cells (PEMFC) (2014)

Catalyst-coated membranes (CCMs) for use in high temperature proton exchange membrane fuel cells (PEMFC) were successfully fabricated by a one-step jet-flame direct deposition process using reactive spray deposition technology (RSDT). The as-deposited catalyst layer (CL) was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and electrochemical measurements. Pt nanoparticles averaging 2.6 nm in diameter formed a good dispersion with a Pt content of 47.5 wt% on the carbon. The Pt/C catalyst had a specific activity and a mass activity of 277 μA/cmPt2 and 0.155 A/mgPt, respectively. Polybenzimidazole (PBI) was employed as the membrane, and the membrane electrode assemblies (MEAs) were tested in temperatures ranging from 140°C to 160°C. Power densities of 375 mW/cm2 in oxygen and 135 mW/cm2 in air were achieved with a total Pt loading of 0.8 mg/cm2.
Reconstruction by weighted correlation for MRI with time-varying gradients (1988)

A general reconstruction algorithm for magnetic resonance imaging (MRI) with gradients having arbitrary time dependence is presented. This method estimates spin density by calculating the weighted correlation of the observed free induction decay signal and the phase modulation function at each point. A theorem which states that this method can be derived from the conditions of linearity and shift invariance is presented. Since these conditions are general, most of the MRI reconstruction algorithms proposed so far are equivalent to the weighted correlation method. An explicit representation of the point spread function (PSF) in the weighted correlation method is given. By using this representation, a method to control the PSF and the static field inhomogeneity effects is studied. A correction method for the inhomogeneity is proposed, and a limitation is clarified. Some simulation results are presented.
Population inversion and gain measurements for soft X-ray laser development in a magnetically confined plasma column (1983)

We present population inversion and gain measurements from an experimental investigation of possibilities to obtain high gain and lasing action in the soft X-ray region. Our approach to soft X-ray laser development is based on rapid plasma cooling after the laser pulse by radiation losses, leading to fast recombination and collisional cascade into upper excited levels of CVI, for example, while the lower excited levels depopulate rapidly by radiative transitions, thus creating population inversions and gain. A ≈ 0.5 kJ CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> laser was focused onto a target of solid carbon or teflon; or CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> , O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> , Ne gas, and the resulting plasma confined in a 50-90 kG magnetic field. Spectroscopic diagnostics with absolute intensity calibration were used to measure level populations. Population inversions were observed between the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4d</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3d</tex> levels in the lithium sequence ions: CIV, OVI, FVII, and NeVIII, and a gain of 0.1 (10 percent) was estimated for the OVI <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4f-3d</tex> transition at 520 Å. In experiments with a solid carbon target, we observe relatively high CVI 182 Å emission in the axial direction compared to the transverse direction, which, if due to stimulated emission, would correspond to a gain of 4. Extension of these results to potential lasing transitions below 100 Å will be discussed.
Differentiation of Infectious Bursal Disease Viruses Directly from Infected Tissues with Neutralizing Monoclonal Antibodies: Evidence of a Major Antigenic Shift in Recent Field Isolates (1988)

Two neutralizing monoclonal antibodies (MCAs), R63 and B69, were used in antigen-capture enzyme immunoassays to verify the presence of infectious bursal disease virus (IBDV) in infected bursal tissues. The intra-serotype-common neutralization site defined by the R63 MCA was present on all IBDV isolates and laboratory strains tested. However, the neutralization site defined by the B69 MCA was found on only classic or older IBDV strains; it was not found on recently isolated variants of IBDV or on a majority of recent field viruses examined. The data suggest that a major antigenic shift in IBDV has occurred in the field and that this shift involves, at a minimum, the deletion or alteration of one of two neutralization sites previously found on classic IBDV strains.
Using prime-and-switch phasing to reduce model bias in molecular replacement (2004)

Atomic models are commonly used to calculate phases in macromolecular crystallography. When combined with measured amplitudes, model-based phases yield electron-density maps with features of the correct structure but with a significant bias towards features of the model. The present contribution shows applications of the technique of prime-and-switch phasing to reduce this bias. An atomic model is used to generate phases that are close to the correct set but that may be biased. An unbiased source of phase information, an estimate of the probability that the electron-density map corresponds to a macromolecule, is then used to select a set of phases that are near the biased set, without further reference to the biased phases. The probability that the electron-density map corresponds to a macromolecule is based on agreement of the map with expectations such as a flat solvent region. Prime-and-switch phasing can be useful even for crystals with low solvent content and may reduce errors in interpretation of electron density in a wide range of applications of macromolecular crystallography, including molecular replacement, model building, ligand-binding and conformation-change studies, refinement and structure validation.
Surface roughness and slope measurements using polarimetric SAR data (2002)

In this paper, the circular polarization coherence, /spl rho//sub RRLL/, is investigated as a potential estimator of terrain surface roughness and small-scale slopes. The studies utilize microwave backscatter collected from 1) dielectric surfaces in an anechoic chamber and 2) a desert test site using P-, L-, and C-band NASA/JPL AIRSAR data. These experimental studies and supporting theory, indicate a sensitive decrease of |/spl rho//sub RRLL/| with increasing surface roughness ks over a range 0 /spl les/ ks /spl les/ 1. For the present studies this decrease is caused largely by the depolarizing effects of small-scale surface slopes in the azimuth direction rather than by volume, or multiple scatter. For cases when the scatter is reflection symmetric, the value of |/spl rho//sub RRLL/| depends on the surface roughness and on the local incidence angle. The dependence of |/spl rho//sub PRRLL/| on the local incidence angle is supported by theory and experimental results. For these same scattering cases, however, |/spl rho//sub PRRLL/| is independent of the surface dielectric constant. Estimation of the functional dependency of |/spl rho//sub PRRLL/| versus ks, for a mid-range incidence angle, has been carried out using roughness estimates derived from an empirical model.
ChemInform Abstract: Synthesis and Biological Evaluation of Highly Potent Analogues of Epothilones B and D. (2001)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
In-line fiber etalon (ILFE) fiber-optic strain sensors (1995)

This paper describes an optical fiber interferometer that uses a short segment of silica hollow-core fiber spliced between two sections of single-mode fiber to form a mechanically robust in-line optical cavity. The hollow-core fiber is specifically manufactured to have an outer diameter that is equal to the outer diameter of the single mode lead fibers, thereby combining the best qualities of existing intrinsic and extrinsic Fabry-Perot sensors. Uniaxial tension and pure bending strength tests are used to show that the new configuration does not diminish the axial strength of bare fiber and reduces the bending strength by 17% at most. Similar tests confirm that the fiber sensor has 1.96% strain to failure. Axisymmetric finite element analysis is used to investigate the reliability of the in-line etalon when it is embedded in a typical thermoset composite, and parametric studies are performed to determine the mechanically optimal cavity length. The fiber optic sensor is tested using low coherence interferometry with pseudo-heterodyne demodulation under strain and temperature fields. The strain response compares well with resistance strain gages, and the temperature tests confirm the low thermal apparent strain of this sensor.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Isolation of Streptomyces sp. KK565 as a producer of β-amyloid aggregation inhibitor (2003)

β-amyloid (Aβ) peptides from the proteolytic processing of β-amyloid precursor protein (β-APP) aggregates in the brain to form senile plaques, and their aggregation plays a key role in pathogenesis of Alzheimer's disease (AD). To isolate an active compound that has an Aβ aggregation-inhibitory activity, 2,000 microbial metabolite libraries were screened based on their ability to inhibit Aβ aggregation by using both Congo red and thioflavin T assays. As a result, a water-soluble fraction of a soil microorganism. KK565, showed a potent Aβ aggregation-inhibitory activity. The strain was identified as Streptomyces species, based on the cultural and morphological characteristics, the presence of diaminopimelic acid in the cell wall, and the sugar patterns for the whole-cell extract. In addition, the purification of active principle resulted in identifying a heat-unstable protein responsible for the Aβ aggregation-inhibitory activity.
3D Metallo-Dielectric Photonic Crystals with Strong Capacitive Coupling between Metallic Islands (1998)

We introduce a new type of metallo-dielectric photonic band gap structure (PBG), intentionally incorporating very strong capacitive interactions between the periodic metallic islands. The band gaps become huge, with the lower band edge frequency being pushed down by the capacitive interaction between metallic islands, while the upper band edge frequency continues to depend primarily on the lattice constant, as in normal PBG's. With this new type of photonic crystal, the spatial periodicity can be much smaller than the corresponding electromagnetic wavelength, allowing PBG structures to play a role at radio frequencies.
Evolution of surface morphology in the initial stage of nitridation of the Si(111)-7×7 surface by nitrogen ions (1997)

The evolution of surface morphology in the initial stage of nitridation of Si(111)-7×7 has been investigated by using a scanning tunneling microscope (STM) and low energy electron diffraction (LEED). The STM and LEED measurements were done on the Si(111) surface nitrided under different experimental conditions including the variations in the nitrogen ion energy, nitrogen ion dose, nitridation temperature, and the postannealing temperature. A growth mechanism of the silicon nitride layer in the initial stage was proposed based upon a comparison of the surface morphology obtained under different nitridation conditions. For the growth of uniform and large silicon nitride islands, it was necessary to have proper heat treatment of the surface. In particular, the surface postannealed at 980 °C after nitridation at 950 °C produced dramatically enlarged flat silicon nitride islands compared to that postannealed at the same temperature after nitridation at room temperature, and is probably due to improved mobilities of the reacting species with elevation of the nitridation temperature.