gebhart/patrepeval huggingface dataset:
Omnidirectional Optical Communicator (2019)

We are developing an inter-satellite omnidirectional optical communicator (ISOC) that will enable cross-link communications between spacecraft at Gbps data rates over distances of up to thousands of kilometers in free space. The ISOC will allow superfast cross-links and will be a technology enabler for swarms and formation flying spacecraft. The ISOC under development features a truncated dodecahedron geometry that can hold an array of fast photodiode detectors and gimbal-less MEMS scanning mirrors. The main goals of the ISOC development include: 1) full sky coverage, 2) Gbps data rates and 3) the ability to maintain multiple simultaneous links. We have developed two omnidirectional communicator prototypes capable of full-duplex operation. We are using advanced single-mode laser diodes operating at 850 nm capable of producing hundreds of milliwatts of laser radiation. We are also employing MEMS-based beam steering mirrors, and fast PIN photodiodes to achieve long-range communications. The ultimate goal of the project is to achieve full duplex operation at 1 Gbps data rates over 200 km and slightly lower data rates at longer distances. In this paper we describe the overall ISOC architecture and present the design tradeoffs for gigabit data-rate operation. We also present preliminary NRZ On-Off Keying communications simulation results obtained using our optical link budget model. The ISOC is ideally suited for crosslink communications among small spacecraft, especially for those forming a swarm and/or a constellation. Small spacecraft furnished with ISOC communications systems, should be able to communicate at gigabit per second rates over long distances. This data rate enhancement can allow real-time, global science measurements and/or ultra-high fidelity observations from tens or hundreds of Earth-orbiting satellites, or permit high-bandwidth, direct-to-earth communications for planetary missions.
Excellent corrosion resistance and hardness in Al alloys by extended solid solubility and nanocrystalline structure (2017)

Development of ultra-high strength and corrosion-resistant aluminum (Al) alloys is demonstrated by a combination of suitable alloying elements and processing technology able to cause extended solid solubility and nanocrystalline structure. Binary Al-transition metal (M: Cr, Ni, Mo, Si, Ti, Mn, V, Nb) alloys, produced by high-energy ball milling and subsequent cold compaction, have exhibited significantly high hardness and corrosion resistance compared to any commercial Al alloy. The cyclic potentiodynamic polarization tests revealed a significant improvement in pitting and repassivation potentials. X-ray diffraction analysis revealed the grain refinement <100 nm and extended solid solubility.
Superior NDA ML Delay and Gain Estimators for UWB Channels (2009)

Novel non-data-aided maximum likelihood estimators for the delays and the attenuations in an ultra-wide bandwidth channel are proposed. Numerical results show that these new estimators outperform the previous non-data-aided maximum likelihood channel estimators derived in the literature. Moreover, in some cases, the performances of the new non-data-aided estimators approach those of the data-aided estimators, enabling us to reduce the overhead expense of pilot symbols.
Lucentamycins A−D, Cytotoxic Peptides from the Marine-Derived Actinomycete <i>Nocardiopsis </i><i>lucentensis</i> (2007)

Four new 3-methyl-4-ethylideneproline-containing peptides, lucentamycins A-D (1-4), have been isolated from the fermentation broth of a marine-derived actinomycete identified by phylogenetic methods as Nocardiopsis lucentensis (strain CNR-712). The planar structures of the new compounds were assigned on the basis of 1D and 2D NMR spectroscopic techniques, while the absolute configurations of the amino acid residues were determined by application of the advanced Marfey method. Lucentamycins A (1) and B (2) showed significant in vitro cytotoxicity against HCT-116 human colon carcinoma.
Small Footprint Barium Titanate Photonic Crystal Modulators for Photonic Integrated Circuits (2015)

We report on the design, fabrication, and characterization of photonic crystal phase modulators on epitaxial barium titanate thin films. Modeling indicates that >50 GHz bandwidth and 0.25 V·cm voltage-length product are achievable in sub-millimeter long devices.
Localized Bathless Metal-Composite Plating via Electrostamping (2020)

Composite plating with particles embedded into the metal matrix can enhance the properties of the metal coating to make it more or less conductive, hard, durable, lubricated or fluorescent. However, it can be more challenging than metal plating, because the composite particles are either 1) not charged so they do not have a strong electrostatic attraction to the cathode, 2) are hygroscopic and are blocked by a hydration shell, or 3) too large to remain stagnate at the cathode while stirring. Here, we describe the details of a bathless plating method that involves anode and cathode nickel plates sandwiching an aqueous concentrated electrolyte paste containing large hygroscopic phosphorescent particles and a hydrophilic membrane. After applying a potential, the nickel metal is deposited around the stagnant phosphor particles, trapping them in the film. The composite coatings are characterized by optical microscopy for film roughness, thickness and composite surface loading. In addition, fluorescence spectroscopy can be used to quantify the illumination brightness of these films to assess the effects of various current densities, coating duration and phosphor loading.
Insertion compounds and composites made by ball milling for advanced sodium-ion batteries (2016)

Sodium-ion batteries have been considered as potential candidates for stationary energy storage because of the low cost and wide availability of Na sources. However, their future commercialization depends critically on control over the solid electrolyte interface formation, as well as the degree of sodiation at the positive electrode. Here we report an easily scalable ball milling approach, which relies on the use of metallic sodium, to prepare a variety of sodium-based alloys, insertion layered oxides and polyanionic compounds having sodium in excess such as the Na4V2(PO4)2F3 phase. The practical benefits of preparing sodium-enriched positive electrodes as reservoirs to compensate for sodium loss during solid electrolyte interphase formation are demonstrated by assembling full C/P'2-Na1[Fe0.5Mn0.5]O2 and C/'Na3+xV2(PO4)2F3' sodium-ion cells that show substantial increases (>10%) in energy storage density. Our findings may offer electrode design principles for accelerating the development of the sodium-ion technology.
<title>Lateral-electric-field diffraction mode LCD for projection display systems</title> (1996)

A new liquid crystal display (LCD) mode based on diffraction effects, which result from the application of lateral electric fields on the liquid crystal (LC) layer, is proposed in order to realize bright and high-contrast images in projection displays. The LC cell structure and its electro-optical characteristics are presented and its performance is compared to several other conventional liquid crystal display modes. In the new LCD, the upper and lower substrates support striped transparent electrodes which have a width and a pitch of 7 micrometers and 22 micrometers , respectively, for a typical case. The upper and lower electrodes are positioned parallel to each other and shifted by a half pitch, i.e. the upper electrodes are aligned with the spacings separating the lower electrodes. We refer to this design as the staggered inter-digital electrode configuration. Both substrates are coated with a polyimide layer rubbed in the direction perpendicular to the striped electrodes resulting in an anti-parallel LC alignment. In a typical cell, a nematic LC material with a positive dielectric anisotropy and a thickness of 5 micrometers are used. Lateral electric fields are generated between the upper and lower substrates and we therefore call this LC mode the Lateral Electric Field Diffraction (LEFD) mode. The transmission-voltage (T-V) curves of the LEFD liquid crystal cell were measured by using a polarized and unpolarized He-Ne laser beam ((lambda) equals 632.8 nm). The plane of incidence of the laser was set to be parallel or perpendicular to the longitudinal axis of the striped electrode and the transmitted light (zeroth order diffraction light) was measured by a photometer. The T-V curves did not show any dependence on the polarization of the incident light and no hysteresis was observed. The transmission was found to be about 80% when no voltage was applied. The threshold voltage was found to be about 1.8 volts and the voltage at which the minimum transmission occurred was 4.5 volts. The contrast ratio was calculated to be about 200:1. In the LEFD LCD, the effective indices of refraction in the directions both perpendicular and parallel to the striped electrodes are modified by the lateral electric field. Diffraction effects occur for all polarizations and it is therefore possible to obtain a high contrast ratio for unpolarized light. This means that the LEFD LCD does not require any polarizer. By combining this LEFD design with a schlieren optical system, it would be possible to create bright and high contrast images in projection displays. We think that the use of LEFD LCD is one of the most promising solutions to realize a very high performance in projection display systems.
Core/Shell Fluorescent Silica Nanoparticles for Chemical Sensing: Towards Single‐Particle Laboratories (2006)

A fluorescent chemical sensor based upon a core/shell architecture of silica nanoparticles (see figure) is introduced. By covalent attachment of organic reference dyes within the core and sensor dyes in the outer shell, optimal sensor architectures can be realized. This paves the way for the development of highly functional particles with catalytic or synthetic abilities. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2296/2006/z600017_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Among substituted 9,10-dihydro-9,10-[1,2]benzenoanthracene-1,4,5,8-tetraones, the lead antitumor triptycene bisquinone TT24 blocks nucleoside transport, induces apoptotic DNA fragmentation and decreases the viability of L1210 leukemic cells in the nanomolar range of daunorubicin in vitro (2002)

In contrast to their inactive parent compound triptycene (code name TT0), several new synthetic analogs (TT code number) have antileukemic activities and remain effective in daunorubicin (DAU)-resistant tumor sublines in vitro. Among variously substituted 9,10-dihydro-9,10-[1,2]benzenoanthracene-1,4,5,8-tetraones, a total of six lead antitumor compounds have been identified, and their code names are TT2, TT13, TT16, TT19, TT21 and TT24. These active antitumor triptych structures have bisquinone functionality, and various bromo, methoxy, methylamino and/or dimethylamino substitutions with or without longer alkyl chains on the amino function. Like the anthracycline quinone antibiotic DAU, these triptycene (TT) bisquinones also inhibit DNA synthesis and induce DNA cleavage in relation with their cytotoxic activities, but have the additional advantage of blocking the cellular transport of purine and pyrimidine nucleosides, an effect which DAU cannot do. As demonstrated by intact chromatin precipitation and agarose gel electrophoresis, the ability of TT bisquinones and DAU to induce DNA fragmentation is biphasic with a peak that shifts to lower concentrations with increasing times of drug exposure. The most effective lead antitumor compound, TT24, induces DNA cleavage in the same concentration-dependent manner as DAU at 24 h (similar peak in response to 1.6 microM) and is nearly equipotent to DAU against L1210 tumor cell viability at day 4 (IC50 values of TT24 and DAU: 48 and 25 nM, respectively). The mechanism by which TT24 induces DNA fragmentation is inhibited by actinomycin D, cycloheximide, benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone, benzyloxycarbonyl-Ile-Glu-Thr-Asp-fluoromethyl ketone, N-tosyl-L-phenylalanine chloromethyl ketone and ZnSO4, suggesting that TT bisquinones trigger apoptosis by caspase and endonuclease activation. Since TT24 is cytotoxic in the nanomolar range of DAU, but might have a more versatile mechanism of action than DAU in wild-type and multidrug-resistant tumor cells, this new class of DNA-damaging quinone antitumor drugs inhibiting nucleoside transport might be valuable to develop new means of polychemotherapy.
DEVELOPMENT AND TESTING OF A SEISMIC PAVEMENT ANALYZER (1993)

The Seismic Pavement Analyzer (SPA) is an instrument designed and constructed to monitor conditions associated with pavement deterioration. It measures voids or loss of support under a rigid pavement, moisture infiltration in asphalt concrete pavement, fine cracking in pavements delamination of overlays, and aging of asphalt. The SPA detects these pavement conditions by estimating Young's and shear moduli from the following wave propagation measurements: impact echo; impulse response; spectral analysis of surface waves; ultrasonic surface waves; and ultrasonic body wave velocity. The SPA records the pavement response produced by high- and low-frequency pneumatic hammers on 5 accelerometers and 3 geophones. A computer controls data acquisition, instrument control, and interpretation; measurements and interpretations are reported in both screen and database formats. This report describes the device and summarizes the usefulness of the equipment in maintenance activities. The operation of the SPA to determine different types of distress precursors is briefly illustrated. This report discusses results from several field tests. The specifications and design of different components of the device and a manual of operation are presented in a companion report.
Comparison of unconfined compression and spatially modulated ultrasound radiation force estimates of shear modulus. (2009)

Spatially modulated ultrasound radiation force (SMURF) [S. McAleavey et al., Ultrason. Imag. 29, 87–104, (2007)] is a novel method for ultrasonic estimation of the low-frequency shear modulus properties of elastic media. In this approach, radiation force with a known lateral magnitude variation is applied impulsively within a region of interest using short (∼30 μs) bursts of ultrasound. The spatial frequency k of the radiation force intensity variation is selectable and determined through beamforming. Application of the radiation force impulse gives rise to a low-frequency (500–2000 Hz) shear wave. The temporal frequency ω of this wave is measured using Doppler ultrasound methods. The modulus is estimated from the relationship G=ρ(ωk)2, where ρ is the material density. To validate this method, the moduli of five samples of Zerdine (CIRS, Incorporated), an ultrasonically tissue-equivalent elastic material, were measured using conventional unconfined cyclic compression and SMURF implemented on a Siemens Antares scanner. The samples were cylindrical with diam 54 mm and height 25 mm. The shear modulus of the samples ranged from 2.5–35 kPa. For all samples, the two methods agreed to within the estimated variation. An intrasample variation of 8% was observed for SMURF in the (assumed uniform) samples. [Work supported by NIH/NIBIB.]
<title>Overview of the Optical Communications Demonstrator</title> (1994)

The Optical Communications Demonstrator is a laboratory-based lasercom demonstration instrument designed to validate effective beacon acquisition, high bandwidth tracking, precision beam pointing, and point ahead compensation functions. The instrument is designed using an array detector for both spatial acquisition and high bandwidth tracking, and a fiber coupled laser transmitter. The array detector tracking concept provides wide field of view acquisition as well as high update rate using a single output channel device. At the same time, it permits effective platform jitter compensation and point ahead control using only one steering mirror. The use of fiber coupled transmitter further modularizes transmitter design and decouples the thermal management problem. The reduction in design complexity can lead to a reduced system cost and an improved system reliability. Furthermore, it can permit the implementation of a new generation of lasercom instruments capable of realizing the inherent advantages of optical frequency communication systems.
SALSA: improved protein database searching by a new algorithm for assembly of sequence fragments into gapped alignments. (1998)

torbjorn.rognes@labmed.uio.no
Improved direct specific determination of serum iron and total iron-binding capacity. (1980)

Serum iron is released from transferrin and reduced at pH 1.7 by treating serum with a 10 g/L ascorbic acid solution in 0.1 mol/L HCl. When ferrozine is added to this reagent, it forms a complex with iron that is as intensely colored as at higher pH values, and under these conditions no turbidity is produced. The second major interference, that from copper, is eliminated by adding 1 g of thiosemicarbazide per liter, which at a low pH forms a stable, uncolored complex with copper without affecting the reaction of ferrozine with iron.
Molecular basis for the resistance of an insect chymotrypsin to a potato type II proteinase inhibitor (2010)

Plants produce a variety of proteinase inhibitors (PIs) that have a major function in defense against insect herbivores. In turn, insects have developed strategies to minimize the effect of dietary PIs on digestion. We have discovered that Helicoverpa larvae that survive consumption of a multidomain serine PI from Nicotiana alata (NaPI) contain high levels of a chymotrypsin that is not inhibited by NaPI. Here we describe the isolation of this NaPI-resistant chymotrypsin and an NaPI-susceptible chymotrypsin from Helicoverpa larvae, together with their corresponding cDNAs. We investigated the mechanism of resistance by mutating selected positions of the NaPI-susceptible chymotrypsin using the corresponding amino acids of the NaPI-resistant chymotrypsin. Four critical residues that conferred resistance to NaPI were identified. Molecular modeling revealed that a Phe-->Leu substitution at position 37 in the chymotrypsin results in the loss of important binding contacts with NaPI. Identification of the molecular mechanisms that contribute to PI resistance in insect digestive proteases will enable us to develop better inhibitors for the control of lepidopteran species that are major agricultural pests worldwide.
Interprocedural slicing using dependence graphs (1990)

The notion of a program slice , originally introduced by Mark Weiser, is useful in program debugging, automatic parallelization, and program integration. A slice of a program is taken with respect to a program point p and a variable x ; the slice consists of all statements of the program that might affect the value of x at point p . This paper concerns the problem of interprocedural slicing—generating a slice of an entire program, where the slice crosses the boundaries of procedure calls. To solve this problem, we introduce a new kind of graph to represent programs, called a system dependence graph , which extends previous dependence representations to incorporate collections of procedures (with procedure calls) rather than just monolithic programs. Our main result is an algorithm for interprocedural slicing that uses the new representation. (It should be noted that our work concerns a somewhat restricted kind of slice: rather than permitting a program to b e sliced with respect to program point p and an arbitrary variable, a slice must be taken with respect to a variable that is defined or used at p .) The chief difficulty in interprocedural slicing is correctly accounting for the calling context of a called procedure. To handle this problem, system dependence graphs include some data dependence edges that represent transitive dependences due to the effects of procedure calls, in addition to the conventional direct-dependence edges. These edges are constructed with the aid of an auxiliary structure that represents calling and parameter-linkage relationships. This structure takes the form of an attribute grammar. The step of computing the required transitive-dependence edges is reduced to the construction of the subordinate characteristic graphs for the grammar's nonterminals.
A direct surface silyl modification of acid-synthesized mesoporous silica (2000)

A surface silyl modification and surfactant removal of acid-synthesized mesoporous silica process in a single step is investigated; the surfactant–silyl exchange process allows a large amount of surface attachments of silane.
High flux compact neutron generators (2001)

Compact high flux neutron generators are developed at the Lawrence Berkeley National Laboratory.The neutron production is based on D-D or D-T reaction.The deuterium or tritium ions are produced from plasma using either a 2 MHz or 13.56 MHz radio frequency (RF) discharge.RF-discharge yields high fraction of atomic species in the beam which enables higher neutron output.In the first tube design, the ion beam is formed using a multiple hole accelerator column.The beam is accelerated to energy of 80 keV by means of a threeelectrode extraction system.The ion beam then impinges on a titanium target where either the 2.4 MeV D-D or 14 MeV D-T neutrons are generated.The MCNP computation code has predicted a neutron flux of ~10 11 n/s for the D-D reaction at beam intensity of 1.5 A at 150 kV.The neutron flux measurements of this tube design will be presented.Recently new compact high flux tubes are being developed which can be used for various applications.These tubes also utilize RF-discharge for plasma generation.The design of these tubes and the first measurements will be discussed in this presentation.
Synthesis of 7β-Sulfur Analogues of Paclitaxel Utilizing a Novel Epimerization of the 7α-Thiol Group (2001)

Paclitaxel analogues with a sulfur group at the 7beta position were required for SAR studies. Attempts to generate these compounds by displacing a 7alpha leaving group with sulfur nucleophiles were unsuccessful. Instead, these compounds were successfully prepared from a 7beta-thiol intermediate that was obtained by a base-catalyzed epimerization of the 7alpha-thiol derivative. The epimerization presumably proceeds through a thioaldehyde intermediate and exhibits the opposite stereochemical preference of its oxygen counterpart.
Resistive Switching Driven by Electric Field in the Mott Insulators AM4X8 (A = Ga, Ge; M= V, Nb, Ta; X = S, Se): Towards a New Class of Non-Volatile RRAM Memory (2011)

We report here on a new type of non volatile resistive switching that we discovered in the whole class of Mott Insulator compounds AM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> X <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sub> (A = Ga, Ge; M= V, Nb, Ta; X = S, Se). The mechanism of this resistive switching differs from the thermochemical or electrochemical effects reported so far to explain the resistive switching in other materials. We found that this resistive switching is related to an electric field effect which induces an electronic phase change in the AM4X8 compounds from the Mott insulating state to a metallic-like state. This new type of resistive switching is observed both on crystals and on polycrystalline thin films with fast writing/erasing times (50 ns to 10 μs) and resistance ratios (ΔR/R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">low</sub> ) higher than 33% at room temperature. These results appear very promising at developing a new class of Resistive Random Access Memory (RRAM).