gebhart/patrepeval huggingface dataset:
Wireless Impact and Leak Detection and Location Systems for the ISS and Shuttle Wing Leading Edge (2005)

A wireless data acquisition, processing, and communications system for continuous monitoring of critical aerospace structures for potentially damaging impacts and resulting air leaks to vacuum has been developed. The system was initially developed under a NASA SBIR Phase II program to monitor the International Space Station (ISS) for atmospheric leaks due to micrometeor or orbital debris (MMOD) impacts. The system acquires data from multiple ultrasonic transducers and determines approximate leak location through a triangularization routine based on angle of arrival. Subsequently, the system was modified to monitor the shuttle wing leading edge RCC panels during ascent and on-orbit phases for potentially damaging impacts from foam, ice, ablator, and MMOD objects. The wing leading edge impact monitoring system is being installed within the shuttle wings for the return to flight mission, STS-114, and subsequent missions to assist in detecting, locating, and characterizing the severity of impact events similar to the debris impact that caused the Columbia disaster. Resulting data from this system will be used in conjunction with various video systems to determine likely impact locations requiring further inspections, and potentially repairs, on-orbit. Each battery operated unit interfaces with high-speed accelerometers and temperature sensors, records data internally, performs detection algorithms, and transfers data through Shuttle or ISS systems for analysis by ground personnel. The design of both system architectures are discussed in this paper, including sensor interfaces, hardware design, embedded software leak and impact detection algorithms, system operations, and Shuttle/ISS integration methods
Identification and Control of Critical Process Impurities: An Improved Process for the Preparation of Dolutegravir Sodium (2016)

A four-stage manufacturing route for the preparation of dolutegravir sodium (1) was assessed and optimized leading to a higher yielding, simpler and scalable process. Key improvements in the process include the development of mild workup procedure by selective derivatization of a difficult to remove a process impurity using tert-butyldimethylsilyl chloride. Metal-based hydrogenation-free O-debenzylation is optimized, and the critical isomeric impurity formed was identified and eliminated from the process by the establishment of a proper control strategy.
NV Countermeasure Technology for a Cylinder-On-Demand Engine – Development of Active Control Engine Mount (2004)

<div class="htmlview paragraph">Active control engine mount system has been developed as a noise and vibration countermeasure technology in a completed vehicle powered by a 3-liter V6 cylinder-on-demand engine. In general, engine vibration is generated by torque fluctuation from its combustion under three-cylinder operation with low rpm. The research described in this paper focuses on the fact that engine vibration is estimated from a fluctuation in crank rotation, and feedforward control algorithm without an exclusive sensor for load or acceleration is established. Then a linear solenoid actuator with high response and low heat generation is specially developed and shows high reliability due to its unique coupling structure between an excitation plate within the hydraulic engine mount and a linear solenoid. Test results from the mount installed on a vehicle show that noise and vibration performance during three-cylinder drive is similar to those at full-cylinder drive.</div>
David against Goliath? Group size and bystander effects in virtual knowledge sharing (2008)

Knowledge management has been identified as a key factor for sustaining a competitive advantage in today's corporate world. A fundamental aspect of knowledge management in a global economy is the sharing of information in online groups. Most researchers and practitioners have so far assumed that a large knowledge sharing group increases response rates, velocity of receiving a response and quality. However, psychological research under the umbrella of the so-called bystander effect suggests counter-intuitively that, with an increase in group size, the likelihood of helping decreases. This study provides empirical support for the fact that a) the bystander effect is also present in virtual (knowledge sharing) environments, b) that group size influences response quality and c) that the negative impact of social inhibition might decrease again in very large groups. The practical trade-offs that managers have to take into account when designing knowledge sharing forums are discussed.
Bidirectional, Raman Extended GPON with 50 km Reach and 1:64 Split Using Wavelength Stabilised Pumps (2011)

We present an experimental demonstration of GPON reach extension to 50 km with a 1:64 PON split using Raman amplification of the upstream signal with wavelength stabilised pump lasers and class C+ transceivers.
Investigation of Polar Transmitters for WCDMA Handset Applications (2006)

The polar transmitter is an attractive architectural solution for high-efficiency multi-mode handset applications. For the polar transmitter the design of a wide-band phase modulator is a challenging task especially for WCDMA signals. In this work the WCDMA signal is analyzed and based on this a method for solving the frequency jump problem is proposed. This method makes it possible to use a two-point SigmaDelta controlled fractional-N PLL as the phase modulator in polar transmitters for WCDMA. Simulation results in Matlab and ADS show that the proposed pre-processing can reduce the frequency dynamic range and solve the frequency jump problem. This pre-processing degrades the ideal WCDMA signal by a 26dB APCR degradation. There is still 17dB margin to spectral mask requirements
Resonance fluorescence in Re187 (1964)

The excited states of Re187+, populated in the decay of W187, have been investigated by the resonance fluorescence method. Using the centrifuge technique, five resonantly scattered {gamma}-lines of 773, 686, 620, 552, and 479 keV energy, originating from the excitation of levels at 773, 686 and very probably 618 keV, have been observed.
Hail, robo-taxi! [Top Tech 2017] (2017)

Take a short walk through Singapore’s city center and you’ll cross a helical bridge modeled on the structure of DNA, pass a science museum shaped like a lotus flower, and end up in a towering grove of artificial Supertrees that pulse with light and sound. It’s no surprise, then, that this is the first city to host a fleet of autonomous taxis.
Mutations Defining the Operator-binding Sites of Bacteriophage   Repressor (1983)

We have characterized about 50 different amino acid substitutions in the aminoterminal domain of lambda repressor. Sixteen of these substitutions alter external side chains of the repressor and cause a substantial reduction in the affinity of the mutant repressor for operator DNA. Seven of these mutant repressors were purified and were shown to be stably folded. The strong, external repressor mutations occur near the aminoterminal end of alpha helix 2, throughout alpha helix 3, and in the aminoterminal-arm region of the repressor. These results suggest that these regions of lambda repressor are close to operator DNA in the protein-DNA complex and thus that these regions comprise the DNA-binding sites of the repressor. Our genetic results support and are completely consistent with more-detailed models of the repressor-operator interaction based on model-building (Pabo and Lewis 1982; Lewis et al. this volume) and biochemical studies (Pabo et al. 1982).
Effect of cyclodextrins on the solubilization of lignoceric acid, ceramide, and cerebroside, and on the enzymatic reactions involving these compounds. (1983)

alpha-Cyclodextrin at concentrations of 1-8 mM helps dissolve, in aqueous solution, fatty acids such as lignoceric, stearic, and palmitic, and complex lipids such as ceramide and cerebroside that contain these acids. Formation of an inclusion complex was indicated on examination of the solution by gel filtration. alpha-Cyclodextrin strikingly increased synthesis of ceramide from sphingosine and either free lignoceric or stearic acid by rat brain preparations. These results suggest the further use of alpha-cyclodextrin in lipid enzymology, especially in relation to sphingolipid metabolism.
Optimal Cycle Scheme of Direct Cycle Supercritical CO2 Gas Turbine for Nuclear Power Generation Systems (2008)

A supercritical CO2 turbine cycle can achieve a considerably high cycle thermal efficiency at medium turbine inlet temperatures of 500-650°C at high pressure such as 20 MPa, which is too high to produce a reactor pressure vessel within the existing fabrication limits. To solve this problem, a dual expansion turbine cycle is effective; its application was examined for both the fast reactor (FR) of 527°C and 12.5 MPa and a high-temperature gas-cooled reactor (HTGR) of 650°C and 8 MPa. Results showed that, in the case of FR, the cycle thermal efficiency became 42.6%, 44.0%, and 45.1%, respectively, for the 12.5 MPa cycle, the dual expansion cycle, and the 20 MPa cycle. Therefore, the dual expansion cycle is effective. On the other hand, for HTGR, the cycle thermal efficiency became 47.5%, 48.5%, and 50.3%, respectively, for the 8 MPa cycle, the dual expansion cycle, and 20 MPa cycle. In this case, the cycle efficiency advantage becomes smaller than that for the FR, but a 1.0% advantage is obtainable.
Fish Passage Can Be Improved by Introducing Hydraulic Refuge: Can the Effects Be Quantified? (2009)

Design methods that account for the ability of fish to swim upstream through culverts are based on tests describing how fast and for how long different fish species can swim. These methods are based on an average water velocity but fail to recognize that fish can take advantage of resting places and non-uniform flow in culverts. Culverts that are designed using this average velocity are likely larger than is necessary. Current design methods could be greatly improved by accounting for the non-uniform velocity distributions in culverts, especially those with roughness elements. In order to better quantify the benefits associated with in-culvert hydraulic refuge, fish tests have been performed in a laboratory flume. This project has focused on one species of fish native to Utah—longnose dace—and the ability to ascend the flume with and without roughness elements—cylinders—in place. Results suggest that the cylinders did allow fish to navigate upstream more successfully than fish attempting to ascend the flume without cylinders at nearly identical average velocities. It is suggested that further testing be conducted by adapting this protocol to key variables affecting fish passage, producing probability distributions for fish performance applicable to culvert design.
Processing of PDGF gene products determines interactions with glycosaminoglycans (1999)

The platelet derived growth factor (PDGF), a mitogen for mesenchymal cells, may be bound to and inhibited by heparin and other glycosaminoglycans. PDGF is a homo- or heterodimer of A- and B-chains. They occur as short (A109 and B110) and long (A125 and B160) isoforms. The latter contain basic carboxyl-terminal extensions. Dimeric A125 binds to heparin through its basic extension in a two-step reaction. The mechanism involves a conformational change and is consistent with a Monod-Wyman-Changeux allosteric model. Previous indirect experiments suggested that three critical amino acids (basic R111, K116 and polar T125) might be involved. Here, direct binding experiments using dimeric full-length mutants in surface plasmon resonanse analysis showed that all three critical amino acids in an R(X)4K(X)8T-motif contributed in a concerted manner to the high affinity binding. Mutations of these amino acids to alanine resulted in large thermodynamic changes, loss of the allosteric mechanism and order(s) of magnitude lower binding affinity. The binding mechanism and affinity of long dimeric rB were similar to the mutants. Short dimeric rA109 and rB110 showed 100 times lower binding affinity than rA125. Consequently, interactions with glycosaminoglycans in tissues varies between PDGF isoforms and may influence their local accumulation and activity.
mRNA expression of somatostatin receptor subtypes SSTR-2, SSTR-3, and SSTR-5 and its significance in pancreatic cancer (2015)

We propose that SSTR-2 plays an important role in clinical implications for patients with pancreatic cancer undergoing somatostatin or its analog therapy.
Generating higher-order quantum dissipation from lower-order parametric processes (2017)

Stabilization of quantum manifolds is at the heart of error-protected quantum\ninformation storage and manipulation. Nonlinear driven-dissipative processes\nachieve such stabilization in a hardware efficient manner. Josephson circuits\nwith parametric pump drives implement these nonlinear interactions. In this\narticle, we propose a scheme to engineer a four-photon drive and dissipation on\na harmonic oscillator by cascading experimentally demonstrated two-photon\nprocesses. This would stabilize a four-dimensional degenerate manifold in a\nsuperconducting resonator. We analyze the performance of the scheme using\nnumerical simulations of a realizable system with experimentally achievable\nparameters.\n
Synthesis and Properties of TRANSDIP, a Rigid Chelator Built upon a Cyclodextrin Cavity: Is TRANSDIP an Authentic <i>trans‐</i>Spanning Ligand? (2007)

The C2-symmetrical diphosphane TRANSDIP was obtained in high yield by treating 6A,6B,6D,6E-tetramesylated, permethylated alpha-cyclodextrin with PPhLi2 in excess. The double cascade cyclisation thus produced is regioselective as phosphinidene capping involves only adjacent glucose units. It is also stereospecific, as both lone pairs on the phosphorus atoms are orientated towards the cyclodextrin axis. The restricted flexibility of the phosphorus atoms, which are part of nine-membered heterocyclic rings, is responsible for JP,C spin-spin couplings with the eight-bond distant CH2OMe carbon atoms of glucose units C and F. The treatment of TRANSDIP with Group 10 metal dihalides quantitatively gave square-planar chelate complexes, in which a M--X bond points towards the centre of the cavitand. The favourable P...P separation and the directional control of the lone pairs on the phosphorus atoms rule out the possibility of forming binuclear complexes or higher oligomers. Further, in all the complexes, the phosphorus atoms are in a trans arrangement. TRANSDIP may therefore be regarded as an authentic trans-spanning diphosphane. In the complex [NiBr2TRANSDIP], the cavity provides effective protection of the encapsulated M--X bond towards nucleophilic attack by MeLi. The same complex, upon activation with methylaluminoxane, efficiently dimerises ethene and propene.
A Thermosensitive and Biodegradable Physical Gel with Chemically Crosslinked Nanogels as the Building Block (2008)

Abstract A triblock copolymer, poly(ethylene glycol)–poly(propylene glycol)–poly(ethylene glycol) was end‐capped by acryloyl groups using a biodegradable oligolactide as spacer, and such biodegradable amphiphilic macromers could form micelles in water. A nanogel was prepared via polymerizing macromers in a micelle, and a macroscopic physical gelation was found upon heating a concentrated aqueous nanogel suspension. Such a sol–gel transition with a chemically crosslinked nanogel as the building block was thermoreversible. While the hydrogel affords a promising injectable biomaterial; this research reveals new physics of the thermogelling mechanism of amphiphilic block copolymers. magnified image
Formation of Oligopeptide-Based Polymeric Membranes at Interfaces between Aqueous Phases and Thermotropic Liquid Crystals (2006)

We report a method for the synthesis of oligopeptide-based polymeric membranes at interfaces between aqueous phases and immiscible liquid crystals. The polymeric membrane was generated by contacting an aqueous solution of the oligopeptide SNKTRIDEANQRATK{Nle}L with a thermotropic liquid crystal, 4-cyano-4‘-pentylbiphenyl, doped with adipoyl chloride (cross-linking reagent). We report characterization of the membrane by scanning electron microscopy and measurements of the permeability of the membrane to phospholipids. The permeability of the polymeric membrane to phospholipids was evaluated by monitoring the orientational response of the liquid crystal upon contact with an aqueous dispersion of vesicles of l-α-dilauroyl phosphatidylcholine. We measured incubation of the membrane in an aqueous solution of trypsin to cause an increase in the permeability of the polymeric membrane to the phospholipids. In contrast, polymeric membranes incubated in aqueous solutions of α-chymotrypsin and bovine serum albumin did not exhibit enhanced permeability, as revealed by the orientational response of the liquid crystals. These results suggest new materials and methods for reporting the presence of enzymes.
Reactions of diborane with aromatic heterocycles. 3. Diborane-catalyzed polymerization of imidazole-borane (1985)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReactions of diborane with aromatic heterocycles. 3. Diborane-catalyzed polymerization of imidazole-boranePhilip C. Keller, Kraig K. Knapp, and John V. RundCite this: Inorg. Chem. 1985, 24, 15, 2382–2383Publication Date (Print):July 1, 1985Publication History Published online1 May 2002Published inissue 1 July 1985https://pubs.acs.org/doi/10.1021/ic00209a013https://doi.org/10.1021/ic00209a013research-articleACS PublicationsRequest reuse permissionsArticle Views171Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
3-D Thin film interposer based on TGV (Through Glass Vias): An alternative to Si-interposer (2010)

Interposers for SiP will become more and more important for advanced electronic systems. But through substrate vias are essential for the 3-D integration. Being a standard for laminate based materials this is much more complex for Si-wafers: High speed etching has to be combined with complex electrical isolation, diffusion barriers and void-free Cu-filling. Without doubt this can be solved in lab-scale but for high production scale cost is a tremendous barrier. Glass wafers with W-plugs have been intensively investigated in this paper. A new acronym has been posted to high-light this technology: TGV for Through Glass Vias. The results of modeling and simulation of TGV at RF/Microwave frequencies showed a very good compromise between wafer thickness, TGV-shape and via diameter for vertical metal plugs with 100 μm diameters in 500 μm thick glass wafer still very stable for thin film wafer processing without costly temporary wafer bonding processes. Therefore the HermeS <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> from Schott was chosen as the basis for a prototype of a bidirectional 4 × 10 Gbps electro-optical transceiver module. Thin film RDL and bumping of these wafers was possible without any modifications to Si-wafer. First thermal cycles showed very promising results for the reliability of this concept.
Diboron-Catalyzed Dehydrative Amidation of Aromatic Carboxylic Acids with Amines (2018)

Tetrakis(dimethylamido)diboron and tetrahydroxydiboron are herein reported as new catalysts for the synthesis of aryl amides by catalytic condensation of aromatic carboxylic acids with amines. The developed protocol is both simple and highly efficient over a broad range of substrates. This method thus represents an attractive approach for the use of diboron catalysts in the synthesis of amides without having to resort to stoichiometric or additional dehydrating agents.
Cyclic boronates in the mass spectrometry of ecdysteroids (1993)

Abstract For the structural elucidation of ecdysteroids a reaction with phenylboronic acid has been employed. This reaction takes place exclusively on the C20,C22 diol moiety, thus facilitating fast and easy detection of this moiety in the molecule od ecdysteroid. This derivatization also redirects fragmentation to C17/C20 bond cleavage with charge retention on both fragments enabling assessment of the structure both of the steroid nucleus and of the side‐chain. Possible reaction of phenylboronic acid with the diol moiety of the glycosyl group of the glycoside od ecdysteroid, producing di‐adduct, is demonstrated; participation of the 5β‐hydroxy group of 5β,20‐dihydroxyecdysone in the formation of such a di‐adduct is discussed; and the role of theenol form of the 6‐carbonyl group is proved.
Crossed Intermolecular [2+2] Cycloadditions of Acyclic Enones via Visible Light Photocatalysis (2009)

Efficient [2+2] heterodimerizations of dissimilar acyclic enones can be accomplished upon visible light irradiation in the presence of a ruthenium(II) photocatalyst. Similar cycloadditions under standard UV photolysis conditions are inefficient and unselective. Nevertheless, a diverse range of unsymmetrical tri- and tetrasubstituted cyclobutane structures can be produced in good yields and excellent diastereoselectivities using this new method. The reaction is promoted by any visible light source, and efficient, gram-scale cycloadditions can be conducted upon irradiating with ambient sunlight.
Biosurfactant production: emerging trends and promising strategies (2018)

Biosurfactants are economically most sought after biotechnological compounds of the 21st century. However, inefficient bioprocessing has mitigated the economical commercial production of these compounds. Although much work is being done on the use of low-cost substrates for their production, a paucity of literature exists on the upcoming bioprocess optimization strategies and their successes and potential for economical biosurfactant production. This review discusses some of the latest developments and most promising strategies to enhance and economize the biosurfactant production process. Recent market analysis, developments in the field of optimally formulated cost credit substrates for enhanced product formation and subsequent process economization are few of the critical aspects highlighted here. Use of nanoparticles and coproduction of biosurfactant along with other commercially important compounds like enzymes, are other upcoming bioprocess intensification strategies. The recent developments discussed here would not only give an overview of pertinent parameters for economic biosurfactant production but would also bring to fore multiple strategies that would open up new avenues of research on biosurfactant production. This would go a long way in making biosurfactants a commercially successful compound of the current century.