gebhart/patrepeval huggingface dataset:
Three-dimensional superhydrophobic structures printed using solid freeform fabrication tools (2013)

Superhydrophobic surfaces are of fundamental and commercial interest as water does not wet the surface, leading to unique properties such as low slip angle, high contact angle, and icephobicity. These behaviours are achieved through a combination of low surface energy materials and high surface roughness. Two printing techniques were used to fabricate hydrophobic polymers into superhydrophobic surfaces. In one approach, a commercially available multi-jet modelling rapid prototyping machine was used to fabricate 3D superhydrophobic objects including helical conduits and porous membranes, using the standard printer resins. A robotic dispensing tool was also developed that enables greater freedom of material selection and feature shape. Both approaches were used to fabricate arrays of high aspect ratio surface features on which water assumes a nearly spherical shape and easily rolls off the surface at low tilt angles. The fabrication and wetting properties of surfaces made using these two techniques will be discussed.
The Laser-Induced Nitrations of Several Hydrocarbons (1989)

The Army uses nitrated compounds as explosives and propellants. The ability to selectively nitrate materials is a much-needed process. Laser-induced chemistry possesses the potential to drive some reactions in an efficient and selective manner. Laser-induced chemistry may be useful in driving nitration reactions toward specific products. Reported herein are the results of several successful attempts to laser-induce the reaction of nitrogen dioxide with hydrocarbons of 3, 4, and 5 carbons. Specifically, the tunable continuous wave (cw) infrared laser was used to drive the reaction between nitrogen dioxide, NO 2 , and propane, n-butane, isobutane, and n-pentane. The major products of the reactions were secondary (tertiary in the isobutane reaction) nitrohydrocarbons, of the same chain length as the reacting hydrocarbon. Some short-chain nitrated compounds were also identified. The yield of 2-nitrobutane observed in the nitration of butane is ∼20% on the basis of the depletion of NO 2 . The propane reacted with NO 2 to produce mostly 2-nitropropane with a smaller yield of 5–9%. The analogous reaction of pentane produced ∼9% of the major product, which is believed to be 2-nitropentane. The isobutane nitration resulted in approximately a 10% yield of 2-methyl-2-nitropropane. The results of these laser-induced reactions are contrasted to the corresponding thermal reactions. The reaction mechanism is also discussed for these two processes.
Genome‐scale model for <i>Clostridium acetobutylicum</i>: Part I. Metabolic network resolution and analysis (2008)

A genome-scale metabolic network reconstruction for Clostridium acetobutylicum (ATCC 824) was carried out using a new semi-automated reverse engineering algorithm. The network consists of 422 intracellular metabolites involved in 552 reactions and includes 80 membrane transport reactions. The metabolic network illustrates the reliance of clostridia on the urea cycle, intracellular L-glutamate solute pools, and the acetylornithine transaminase for amino acid biosynthesis from the 2-oxoglutarate precursor. The semi-automated reverse engineering algorithm identified discrepancies in reaction network databases that are major obstacles for fully automated network-building algorithms. The proposed semi-automated approach allowed for the conservation of unique clostridial metabolic pathways, such as an incomplete TCA cycle. A thermodynamic analysis was used to determine the physiological conditions under which proposed pathways (e.g., reverse partial TCA cycle and reverse arginine biosynthesis pathway) are feasible. The reconstructed metabolic network was used to create a genome-scale model that correctly characterized the butyrate kinase knock-out and the asolventogenic M5 pSOL1 megaplasmid degenerate strains. Systematic gene knock-out simulations were performed to identify a set of genes encoding clostridial enzymes essential for growth in silico.
Long-life leak standard assembly. [Patent application] (1980)

The present invention is directed to a portable leak standard assembly which is capable of providing a stream of high-purity reference gas at a virtually constant flow rate over an extensive period of time. The leak assembly comprises a high pressure reservoir coupled to a metal leak valve through a valve-controlled conduit. A reproducible leak valve useful in this assembly is provided by a metal tube crimped with a selected pressure loading for forming an orifice in the tube with this orifice being of a sufficient size to provide the selected flow rate. The leak valve assembly is formed of metal so that it can be baked-out in a vacuum furnace to rid the reservoir and attendent components of volatile impurities which reduce the efficiency of the leak standard.
Manipulation of spin states by dipole polarization switching (2007)

A ferromagnetic/ferroelectric hybrid double quantum disk structure is proposed, capable of manipulating spin states. Switching of spontaneous electric polarization of the ferroelectric quantum disk changes the potential profile of the system and induces ground state transition. Two carrier spin states are separated into ferroelectric semiconductor and diluted magnetic semiconductor disks via asymmetric Zeeman splitting of the coupled quantum disks. The proof of the spin separation resulting from the dipole polarization switching is shown by the probability density change of the lowest energy subband. Evolution of the spin state is also predicted from the subband energy diagram as a function of the bias voltage.
Enzymatische Regeneration von 3′-Phosphoadenosin-5′-phosphosulfat mit Aryl-Sulfotransferase zur präparativen enzymatischen Synthese von sulfatierten Kohlenhydraten (1999)

Preiswerter als zuvor können Oligosaccharide jetzt präparativ enzymatisch sulfatiert werden. Ausgehend von Adenosin-3′,5′-diphosphat (PAP) kann jetzt der als Sulfatgruppen-Donor dienende, teure Cofaktor 3′-Phosphoadenosin-5′-phosphosulfat (PAPS) 1 mit einer neuen Methode unter Verwendung einer rekombinanten Aryl-Sulfotransferase und p-Nitrophenylsulfat regeneriert werden. Dieses System unterliegt nicht der Produkthemmung durch PAP und kann als kontinuierlicher spektrophotometrischer Assay für die kinetische Analyse von Sulfotransferasen eingesetzt werden.
New optical effects in liquid crystals: self-organization and dynamic characteristics of fullerene-doped nematic mesophase (2005)

As a new way to create promising LC network, the charge-transfer complexes (CTC) between an organic donor (monomer, polymer, nanoparticles) and fullerenes can be used. The new complex has a high dipole moment and hence it increases the polarizability of the compound. This effect improves the control of the NLC structure. The re-orientation of the NLC dipoles under light or field action can be observed with high speed. Thus, new principle of the speed enhancement of self-organized fullerene-doped nematic liquid crystal has been demonstrated. The switching time in the microsecond range has been obtained for all nematic LC devices.
Lyrics-to-Audio Alignment and its Application (2012)

Automatic lyrics-to-audio alignment techniques have been drawing attention in the last years and various studies have been made in this field. The objective of lyrics-to-audio alignment is to estimate a temporal relationship between lyrics and musical audio signals and can be applied to various applications such as Karaoke-style lyrics display. In this contribution, we provide an overview of recent development in this research topic, where we put a particular focus on categorization of various methods and on applications.
Recent results with coupled opto-electronic oscillator (1998)

We present experimental results of coupled opto-electronic oscillators (COEO) constructed with a semiconductor optical amplifier based ring laser, a semiconductor Fabry-Perot laser, and a semiconductor colliding pulse mode-locked laser. Each COEO can simultaneously generate short optical pulses and spectrally pure RF signals. With these devices, we obtained optical pulses as short as 6 picoseconds and RF signals as high in frequency as 18 GHz with a spectral purity comparable with a HP8561B synthesizer. These experiments demonstrate that COEOs are promising compact sources for generating low jitter optical pulses and low phase noise RF/millimeter wave signals.
Growth of Large Diamond Crystals by Reduction of Magnesium Carbonate with Metallic Sodium (2003)

Diamonds in the rough: Crystals as large as 510 μm in diameter were formed at a temperature as low as 500 °C by the reduction of magnesium carbonate with metallic sodium (see picture). The product mixture was found to contain cubic diamonds by X-ray diffraction and micro-Raman spectrum analysis. The yield of diamond is about 6.6 % with respect to carbonate carbon. Magnesium carbonate is nontoxic, cheap, and abundant, and the temperature of this process is much lower than that of traditional methods. Therefore, the results of these studies could be applied in the production of industrial low-cost diamonds.
SARS-CoV-2 D614G Variant Exhibits Enhanced Replication <i>ex vivo</i> and Earlier Transmission <i>in vivo</i> (2020)

Abstract The D614G substitution in the S protein is most prevalent SARS-CoV-2 strain circulating globally, but its effects in viral pathogenesis and transmission remain unclear. We engineered SARS-CoV-2 variants harboring the D614G substitution with or without nanoluciferase. The D614G variant replicates more efficiency in primary human proximal airway epithelial cells and is more fit than wildtype (WT) virus in competition studies. With similar morphology to the WT virion, the D614G virus is also more sensitive to SARS-CoV-2 neutralizing antibodies. Infection of human ACE2 transgenic mice and Syrian hamsters with the WT or D614G viruses produced similar titers in respiratory tissue and pulmonary disease. However, the D614G variant exhibited significantly faster droplet transmission between hamsters than the WT virus, early after infection. Our study demonstrated the SARS-CoV2 D614G substitution enhances infectivity, replication fitness, and early transmission.
Low fluorescence background electroblotting membrane for DNA sequencing (1992)

A low fluorescence background polypropylene (PP) membrane has been developed for ultimate use as an electroblotting membrane in DNA sequencing based on fluorescence detection. The DNA binding capacity of this membrane is improved by a surface modification using radio frequency plasma discharge (RFPD) in ammonia gas. The RFPD operational parameters are evaluated both in terms of membrane nitrogen content and in terms of the product's capacity for binding radioisotope-labeled DNA fragments. The surface morphologies of the derivatized membranes are examined by scanning electron microscopy; their mechanical and electrical properties, which are important for the subsequent sequencing procedures, are likewise established. Due to the goal of developing a membrane suitable for multiplex processing, in which the electroblotted DNA must withstand dozens of hybridization/stripping cycles, special attention is given the covalent attachment of DNA to the membrane. The modified PP membrane is evaluated in a multiplex sequencing application using radioisotope-labeled DNA probes, and found to yield somewhat better binding of a given amount of electroblotted DNA than the commonly used GeneScreen membrane. A tenfold repetition of the probing indicates little loss of signal; the membrane-bound DNA is stable upon storage and shows no detectable loss in probing efficiency after one month.
A new cephalosporin. SCE-963: 7-[2-(2-aminothiazol-4-yl)-acetamido]-3-[[[1-(2-dimethylaminoethyl)-1H-tetrazol-5-yl]-thio]methyl]ceph-3-em-4-carboxylic acid. Chemistry and structure-activity relationships. (1978)

The synthesis and the in vitro and in vivo antimicrobial activities of a series of 7-[2-(2-aminothiazol-4-yl)acetamido]cephalosporins (1) having varied 3-substituents, such as methyl, hydroxymethyl, acetoxymethyl, pyridiniomethyl and heterocyclicthiomethyls, are described. The derivatives having five membered heterocyclicthiomethyls exhibited strong inhibitory activities against Gram-negative organisms including some strains of Escherichia coli and Proteus morganii which are insensitive to cefazolin and cephaloridine. Pronounced activities were noted with 7-[2-(2-aminothiazol-4-yl)-acetamido]-3-[[[1-(2-dimethylaminoethyl)-1H-tetrazol-5-yl]thio]methyl]ceph-3-em-4-carboxylic acid (1y; SCE-963).
SELECTIVE ETHYLENE ADSORBENTS COMPOSED OF COPPER(I) CHLORIDE AND POLYSTYRENE RESINS HAVING AMINO GROUPS (1985)

Abstract A selective adsorbent for ethylene is prepared by stirring 15 g of copper (I) chloride and 10 g of polystyrene resin having primary and secondary amino groups in 1:1 (v/v) acetonitrile–water mixture, followed by removal of the liquid phase. The adsorbent adsorbs 15.0 mmol of ethylene at 20 °C, 1 atm, which is 7.9 fold larger than the value (1.9 mmol) for ethane.
Floating-point implementation of complex multiplication (2009)

This paper extends the consideration of fused floating-point arithmetic to complex multiplication, an operation that is frequently used in DSP. There are two basic approaches to complex multiplication: (1) the conventional method that uses 4 real multiplies and 2 real adds and (2) Golub's method that uses 3 real multiplies and 5 real additions. This paper compares discrete implementations using individual floating-point adders and multipliers with implementations that use fused operations (fused dot product, fused add-subtract and combinations of the two).
Structural Robustness Affects the Engineerability of Aminoacyl-tRNA Synthetases for Genetic Code Expansion (2021)

The ability to engineer the substrate specificity of natural aminoacyl-tRNA synthetase/tRNA pairs facilitates the site-specific incorporation of noncanonical amino acids (ncAAs) into proteins. The <i>Methanocaldococcus jannaschii</i>-derived tyrosyl-tRNA synthetase (MjTyrRS)/tRNA pair has been engineered to incorporate numerous ncAAs into protein expressed in bacteria. However, it cannot be used in eukaryotic cells due to cross-reactivity with its host counterparts. The <i>Escherichia coli</i>-derived tyrosyl-tRNA synthetase (EcTyrRS)/tRNA pair offers a suitable alternative to this end, but a much smaller subset of ncAAs have been genetically encoded using this pair. Here we report that this discrepancy, at least partly, stems from the structural robustness of EcTyrRS being lower than that of MjTyrRS. We show that the thermostability of engineered TyrRS mutants is generally significantly lower than those of their wild-type counterparts. Derived from a thermophilic archaeon, MjTyrRS is a remarkably sturdy protein and tolerates extensive active site engineering without a catastrophic loss of stability at physiological temperature. In contrast, EcTyrRS exhibits significantly lower thermostability, rendering some of its engineered mutants insufficiently stable at physiological temperature. Our observations identify the structural robustness of an aaRS as an important factor that significantly influences how extensively it can be engineered. To overcome this limitation, we have further developed chimeras between EcTyrRS and its homologue from a thermophilic bacterium, which offer an optimal balance between thermostability and activity. We show that the chimeric bacterial TyrRSs show enhanced tolerance for destabilizing active site mutations, providing a potentially more engineerable platform for genetic code expansion.
Electrooptical image shifting for particle image velocimetry (1988)

The direction of fluid motion can be determined in particle image velocimetry (and laser speckle velocimetry) if the image field is spatially shifted between the first and second exposures, so that the most negative fluid velocity still produces a positive particle image displacement. Two new techniques are described which accomplish very fast accurate image shifting using electrooptical hardware. These methods involve regulating the polarization of light scattered from the seeding particles by switching the polarization of the illuminating beam, and placing a birefringent unaxial plate in front of the photographing lens to displace the particle image between illuminating pulses.
Supramolecular hydrogels formed by the conjugates of nucleobases, Arg-Gly-Asp (RGD) peptides, and glucosamine (2012)

Here we report the generation of a novel class of supramolecular hydrogelators based on the integration of nucleobase, Arg-Gly-Asp (RGD) peptides, and glucosamine in a single molecule. These novel small molecule hydrogelators self-assemble in water to form stable supramolecular nanofibers/hydrogels and exhibit useful biostability. This approach provides a new opportunity for systematic exploration of the self-assembly of small biomolecules by varying any individual segment to generate a large array of supramolecular hydrogels for biological functions and for biomedical applications.
Superconducting microbolometer with controllable coordinate sensitivity: an alternative approach to FPA design (2005)

A method of controlling the coordinate sensitivity in a high temperature superconducting microbolometer is described. A laser beam, precisely focused on the patterned superconducting structure, was used to nucleate a resistive area that is sensitive to external thermal effects. The electron beam lithography and wet chemical etching were applied as pattern transfer processes in epitaxial Y-Ba-Cu-O films. Two different sensor designs were tested: (i) 3 millimeters long and 40 micrometers wide stripe and (ii) 1.25 millimeters long, and 50 micron wide meander -like structure. It is shown experimentally that scanning the laser beam along the stripe leads to physical displacement of the sensitive area and, therefore may be used as a basis for imaging over a broad spectral range. Our approach, by which the coordinate sensitivity of a microfabricated superconducting stripe is controlled, is an alternative solution to Focal Plane Array (FPA) design. For example, patterning the superconducting film into a meander structure is equivalent to a two-dimensional detector array. In additional to the simplicity of the detector fabrication sequence (one step mask transfer), a clear advantage of this approach is the simplicity of the read-out process: an image is formed by registering the signal with only two electrical terminals. The proposed approach can be extended for imaging over a wide spectral range; the limiting factor is the wavelength-dependent efficiency of thermal conversion in the film/substrate system.
Performance analysis of double suction centrifugal pumps with a novel impeller configuration (2022)

Pumps are largely used in domestic, civil, industrial and agricultural systems. It is estimated that they are responsible of about 10% of the world energy consumption. To favor sustainability and reduce carbon footprint of pumps, it is required to improve their efficiency. In recent years, the authors proposed a novel impeller configuration (cross-vaned, with a completely new design of the vanes) for double suction centrifugal pumps with higher efficiency and reduced blade loading compared to conventional back-to-back impellers. Given the good results, herein a second version of the prototype has been designed by means of a one-dimensional (1D) in-house code with the purpose to increase the blade loading by reducing the number of blades. The new 5-bladed crossed-vaned prototype was studied numerically, then constructed and experimentally tested showing a good agreement between numerics and experiments in terms of head coefficient and efficiency. Through numerical simulations, pressure, velocity and vorticity fields at the outlet of the impeller have been investigated; besides, a new slip factor correlation is proposed for this new generation of pumps. Moreover, the new configuration confirms its benefit in term of reduction of the slip factor and increase of the global efficiency, proving to be useful for retrofitting of old impellers, with a higher efficiency and smaller overall dimensions. Finally, an example of conventional impellers retrofitting in a real pumped-storage system is presented and its impact in terms of global efficiency and carbon footprint is discussed.
Cardiac muscle patches containing four types of cardiac cells derived from human pluripotent stem cells improve recovery from cardiac injury in mice (2023)

Collectively, these observations suggest that the inclusion of hPSC-CFs during hCMP manufacture promotes hPSC-CM maturation and increases the potency of implanted hCMPs for improving cardiac recovery in mice model of MI.
Design and Operation of a Signal Comparator to Increase Efficiency of Continuous-Flow Analyzers (1974)

Abstract Design features and operation of a signal comparator are described. The efficiency of continuous-flow analyzers is improved by allowing the bubbled stream to remain intact as it passes through the colorimeter flow cell. The signal comparator eliminates the bubble artifact from the photodetector signal while allowing the signal produced from the fluid segment to remain intact. The instrument is reliable, easy to use, and does not require any adjustments by a technician.
Photoluminescence Imaging of Silicon Bricks (2013)

Photoluminescence imaging techniques have recently been extended to silicon bricks for early production quality control and electronic characterisation in photovoltaics and microelectronics. This contribution reviews the state of the art of this new method which is fundamentally based on spectral luminescence analyses. We present highly resolved bulk lifetime images that can be rapidly extracted from the side faces of directionally solidified or Czochralski grown silicon bricks. It is discussed how detailed physical modelling and experimental verification give good confidence of the best practice measurement errors. It is also demonstrated that bulk lifetime imaging can further be used for doping and interstitial iron concentration imaging. Additionally, we show that full spectrum measurements allow verification of the luminescence modelling and are, when fitted to the theory, another accurate method of extracting the absolute bulk lifetime.
Infrared photoconductivity via deep copper acceptors in silicon-doped, copper-compensated gallium arsenide photoconductive switches (1993)

Silicon-doped, copper-compensated, semi-insulated gallium arsenide of various doping parameters was studied with respect to infrared photoconductivity. This material is used as a photoconductive switch, the bistable optically controlled semiconductor switch (BOSS). One limitation was the relatively low conductivity of the device during the on-state. Typically, silicon-doped gallium arsenide is converted to semi-insulating gallium arsenide by the thermal diffusion of copper into the GaAs:Si. It is shown that variation of the diffusion parameters can improve the on-state conductivity by the enhancement of the concentration of a copper center known as Cu/sub B/. The conductivity of the device 150 ns after irradiation from a 20-ns FWHM laser pulse ( lambda =1.1 mu m) is recorded for various incident energies. This on-state conductivity saturates at a value that is predicted by the densities of the copper levels and the mobility.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Chirosorb™ as an invisible medium (1989)

Using electromagnetic chirality, we propose a novel material, Chirosorb™, which is invisible to incident electromagnetic energy by virtue of its zero reflectance. To achieve zero reflectivity, certain conditions on constitutive parameters must be met that are difficult to obtain for conventional radarabsorbing materials. Chirosorb™ has the potential to overcome this difficulty.