gebhart/patrepeval huggingface dataset:
Improved method of preparing composite superconducting wire (1979)

An improved method of preparing composite multifilament superconducting wire of Nb/sub 3/Sn in a copper matrix which eliminates the necessity of coating the drawn wire with tin is described. A generalized cylindrical billet of an alloy of copper containing at least 15 weight percent niobium, present in the copper as discrete, randomly distributed and oriented dendritic-shaped particles, is provided with at least one longitudinal opening which is filled with tin to form a composite drawing rod. The drawing rod is then drawn to form a ductile composite multifilament wire containing a filament of tin. The ductile wire containing the tin can then be wound into magnet coils or other devices before heating to diffuse the tin through the wire to react with the niobium forming Nb/sub 3/Sn. Also described is an improved method for making large billets of the copper-niobium alloy by consumable-arc casting.
Reversible Ion Exchange-Membrane (RIX-M) Process for Fouling Free and Energy Efficient Desalination of Seawater (2011)

Reversible ion exchange-membrane (RIX-M) is a hybrid process of desalination in which scale formation potentials of seawater can be eliminated by changing the chemistry of the feed water through the introduction of a reversible cation exchange step before the membrane based desalination step. In this process, scale forming di- or other poly-valent cations like calcium, barium, strontium, etc. are exchanged for equivalent concentrations of magnesium ions when the saline water is passed through a bed of cation exchanger pre-saturated in magnesium form. Near-complete replacement of scale forming cations by non-scale forming magnesium ions allows for obtaining a higher permeate flux compared to the conventional RO process. Addition of anti-scaling agent can be avoided altogether. Also, the exchange of magnesium ions for monovalent sodium ions, either partly or fully, reduces the osmotic pressure of the resultant feed solution to the membrane. Thus, the membrane process can operate with high permeate water recovery and enhanced energy efficiency for natural saline water like sea and brackish water and other industrial saline water effluents. The concentrated return from the membrane process is used as a regenerant for the exhausted ion exchanger. Thus, once started, the process can be sustained without requiring any external addition of regenerant chemicals.
Hard x-ray phase imaging and tomography with a grating interferometer (2004)

We have developed a two-grating interferometer for hard X rays that can be used for phase imaging and tomography. A silicon phase grating positioned just downstream of the object under study splits the distorted wavefront into essentially a positive and a negative first-order beam. At a given distance from this beam-splitter grating, where the two beams still mostly overlap, they form a pattern of interference fringes that is distorted according to the wavefront distortions. The fringes may be finer than the resolution of an area detector used to record the signal, but an absorption grating with suitable pitch, put in front of the detection plane, allows the detection of intensity variations that correspond to the derivative of the wavefront phase taken along the direction perpendicular to the grating lines. A combination of this technique with the phase-stepping method, in which several exposures are made which differ in the phase of the fringe pattern, allows to eliminate effects of non-uniform intensity due to inhomogeneous illumination and edge-enhancing inline phase contrast. Several examples of tomograms taken under different experimental conditions are shown, including a polychromatic "pink-beam" setup.
128×10.66 Gbit/s transmission over 840 km standard SMF with 140 km optical repeater spacing (30.4 dB loss) employing dual-band distributed Raman amplification (2002)

We present the first demonstration of a high-capacity (1.28 Tbit/s), long-haul (6/spl times/140 km) WDM transmission employing dual-band (C/L-band) distributed Raman amplification (DRA). The DRA improved OSNR and enabled an extra-long repeater spacing of 140 km.
Analysis of SAW properties in ZnO/Al/sub x/Ga/sub 1-x/N/c-Al/sub 2/O/sub 3/ structures (2005)

Piezoelectric thin films on high acoustic velocity nonpiezoelectric substrates, such as ZnO, AlN, or GaN deposited on diamond or sapphire substrates, are attractive for high frequency and low-loss surface acoustic wave devices. In this work, ZnO films are deposited on AlxGa1-xN/c-Al2O3 (0 < or = chi < or = 1) substrates using the radio frequency (RF) sputtering technique. In comparison with a single AlxGa1-xN layer deposited on c-Al2O3 with the same total film thickness, a ZnO/AlxGa1-xN/c-Al2O3 multilayer structure provides several advantages, including higher order wave modes with higher velocity and larger electromechanical coupling coefficient (K2). The surface acoustic wave (SAW) velocities and coupling coefficients of the ZnO/AlxGa1-xN/c-Al2O3 structure are tailored as a function of the Al mole percentage in AlxGa1-xN films, and as a function of the ZnO (h1) to AlxGa1-xN (h2) thickness ratio. It is found that a wide thickness-frequency product (hf) region in which coupling is close to its maximum value, K(2)max, can be obtained. The K(2)max of the second order wave mode (h1 = h2) is estimated to be 4.3% for ZnO/GaN/c-Al2O3, and 3.8% for ZnO/AlN/c-Al2O3. The bandwidth of second and third order wave modes, in which the coupling coefficient is within +/- 0.3% of K(2)max, is calculated to be 820 hf for ZnO/GaN/c-Al2O3, and 3620 hf for ZnO/AlN/c-Al2O3. Thus, the hf region in which the coupling coefficient is close to the maximum value broadens with increasing Al content, while K(2)max decreases slightly. When the thickness ratio of AlN to ZnO increases, the K(2)max and hf bandwidth of the second and third higher wave modes increases. The SAW test devices are fabricated and tested. The theoretical and experimental results of velocity dispersion in the ZnO/AlxGa1-xN/c-Al2O3 structures are found to be well matched.
Energy and Electron Transfer Cascade in Self-Assembled Bilayer Dye-Sensitized Solar Cells (2016)

Current high efficiency dye-sensitized solar cells (DSSCs) rely on the incorporation of multiple chromophores, via either codeposition or preformed assemblies, as a means of increasing broad band light absorption. These strategies have some inherent limitations including decreased total light absorption by each of the dyes, low surface loadings, and complex synthetic procedures. In this report, we introduce an alternative strategy, self-assembled bilayers, as a simple, stepwise method of incorporating two complementary chromophores into a DSSC. The bilayer devices exhibit a 10% increase in J<sub>sc</sub>, V<sub>oc</sub>, and η over the monolayer devices due to increased incident photon-to-electron conversion efficiency across the entire visible spectrum and slowed recombination losses at the interface. Directional energy and electron transfer toward the metal oxide surface are key steps in the bilayer photon-to-current generation process. These results are important as they open the door to a new architecture for harnessing broadband light in dye-sensitized devices.
Theoretical study of integrated magnetic heads for high recording densities (1974)

The structure of integrated heads offers better possibilities of optimization than conventional heads. The length of the gap and the thickness of the pole tips can be optimized in order to obtain the best efficiency of the head during the writing process. This optimization relies on the magnetization distribution of a single transition. We will here study three transitions the separation of which is adjustable. The purpose of this paper is to show that the optimization of the write process is not always really convenient for high density recording. We use an iterative method the principle of which is identical to the one used for the calculation of a single transition. This method extended to three transitions reflects the magnetic history of the magnetization as faithfully as possible. During the computations, the magnetization varies on the major B-H loop or on the minor cycles taking into account the transition interactions and the demagnetizing fields. After the third position, the head is translated faraway. In order to understand better the method, a detailed diagram will be given. Results show us the density limitation of an integrated head with a given medium. In conclusion, this study shows that the pole tip thickness of integrated heads is an important parameter for magnetic peak-shift.
Performance enhancement by narrow-beam quad-sector cell and interleaved channel assignment in wireless networks (2003)

We propose an improved sectorization scheme for cellular networks, called narrow beam quad-sector cell (NBQC), in which each cell is divided into 4 sectors and each sector is covered by a 60/spl deg/ antenna. The NBQC architecture has a better coverage performance than the current 3-sector cellular architecture. More importantly, the NBQC architecture allows easy implementation of the powerful interleaved channel assignment (ICA) scheme. Because of taking full advantage of the antenna directivity, the NBQC architecture with the ICA scheme can improve the signal to interference ratio (SIR) performance, thereby increasing the system capacity significantly. Our results show that in a typical radio environment, the NBQC system with the ICA scheme can achieve a reuse factor N=2 with the 90 percentile of SIR as high as 11 dB, which represents 3 to 5 dB SIR improvement or about at least 40 percent system capacity improvement over current cellular networks.
High-gain, free-electron laser amplifiers: Design considerations and simulation (1981)

The design and performance of variable-wiggler, free-electron laser (FEL) amplifiers was studied by using a one-dimensional computer model which incorporated separate sections for design and simulation. Resonant-particle equations were used in the design phase. The variation of the wiggler parameters was not predetermined (linear, exponential, etc.) but was carefully tailored to match the electron energy throughout the FEL amplifier. The simulation section of the model self-consistently tracked the phase-space trajectories of 500 particles for the length of the amplifier. In this way the designs were tested not only for overall gain and efficiency but also for resistance to irregularities in laser input power, electron-beam power, electron-beam-energy spread, and wiggler construction. High-current-density electron beams (electron-beam power > laser-beam power) were found to be essential for stable and efficient amplifiers. Some designs demonstrated better performance under conditions of nonresonant input particles.
The 3'tsRNAs are aminoacylated: Implications for their biogenesis (2020)

Abstract Emerging evidence indicates that tRNA-derived small RNAs (tsRNAs) are involved in fine-tuning gene expression and become dysregulated in various cancers. We recently showed that the 22nt LeuCAG tsRNA from 3’ end of tRNA Leu is required for efficient translation of a ribosomal protein mRNA and ribosome biogenesis. Inactivation of this tsRNA induced apoptosis in rapidly dividing cells and suppressed the growth of a patient derived orthotopic hepatocellular carcinoma in mice. The mechanism involved in the generation of the 3’-tsRNAs remains elusive and it is unclear if the 3’-ends of 3’-tsRNAs are aminoacylated. Here we report an enzymatic method utilizing exonuclease T to determine the 3’charging status of tRNAs and tsRNAs. Our results showed that the LeuCAG 3’-tsRNA is fully charged and originated solely from charged mature tRNA. When the leucyl-tRNA synthetase was knocked down, less tsRNA was generated while the mature tRNA was not reduced further supporting that tsRNA generation is regulated. The fact that the 3’-tsRNA is aminoacylated has implications for their biogenesis and provides additional insights into their biological role in post-transcriptional gene regulation.
Laser-induced chemistry of the allyl halides (1986)

The continuous wave CO2 laser‐induced chemistry of several allyl halides has been studied at various pressures and laser powers. The majority of products observed in these reactions are also reported in gas phase pyrolysis. From the kinetic studies of allyl chloride and bromide, overall reaction orders were determined. New reaction mechanisms for formation of cyclic products based upon results obtained in these reactions have been proposed.
NMR spectroscopy of coin cell batteries with metal casings (2021)

Battery cells with metal casings are commonly considered incompatible with nuclear magnetic resonance (NMR) spectroscopy because the oscillating radio-frequency magnetic fields (“rf fields”) responsible for excitation and detection of NMR active nuclei do not penetrate metals. Here, we show that rf fields can still efficiently penetrate nonmetallic layers of coin cells with metal casings provided “<bold>B</bold><sub>1</sub> damming” configurations are avoided. With this understanding, we demonstrate noninvasive high-field in situ <sup>7</sup>Li and <sup>19</sup>F NMR of coin cells with metal casings using a traditional external NMR coil. This includes the first NMR measurements of an unmodified commercial off-the-shelf rechargeable battery in operando, from which we detect, resolve, and separate <sup>7</sup>Li NMR signals from elemental Li, anodic β-LiAl, and cathodic Li<i><sub>x</sub></i>MnO<sub>2</sub> compounds. Real-time changes of β-LiAl lithium diffusion rates and variable β-LiAl <sup>7</sup>Li NMR Knight shifts are observed and tied to electrochemically driven changes of the β-LiAl defect structure.
High repetition rate figure eight laser with extracavity feedback (1992)

The operation of an erbium figure eight all-fibre laser with a fundamental repetition rate of 28.5 MHz is reported. The feedback of light rejected by the nonlinear amplifying loop mirror back into the laser is found to stabilise mode locking enhance startup, shorten the pulse lenght to 275fs, and provide a simple means of multiplying the repetition rate.
WE‐G‐108‐02: Oncospace: A Database Designed for Personalized Medicine in Radiation Oncology (2013)

Purpose: The Oncospace database aggregates treatment planning and clinical information about prior patients facilitating extraction of knowledge from prior courses of care. The goal is to use this knowledge to influence clinical decisions, quality and safety of care for new patients. Methods: The Oncospace website, built in C# and ASP.NET, accesses the MS SQLServer database for analysis. The data tables are designed to support patient geometry, targets and organs at risk (OAR) and their spatial relationships, dose distributions, toxicities, diagnosis and disease progression, chemotherapy and medications, laboratory values, patient histories and demographics. Data is collected directly from the treatment planning system and the oncology information system (OIS). Point of service data collection is facilitated with tablet (iPad) forms linked to the OIS. Results: Web pages have been built to answer the following: A) For a selected toxicity and OAR, display the dose volume histogram (DVH) and colorize them by the maximum toxicity grade of the patient while identifying a selected patients DVH B) For a selected OAR and percent volume (%V), find the lowest dose achieved from all patients whose %V is closer to the selected target volume? C) For a given diagnosis, toxicity and treatment, display the aggregate trend in toxicity from start of treatment (acute) through several year follow‐up (late)? Oncospace currently supports: and a full H&N database, a multi‐institutional pancreatic stereotactic trial, and shape database for automated planning pancreas cancer. Conclusion: Oncospace can provide fast access to large amounts of data through complex queries designed to answer specific clinical questions to influence the safety and quality of care for new patients. This system can be used in the clinical setting to assess both plan quality and outcome expectations for new patients based on the data of prior patients. Funding for this research was provided by the Commonwealth Foundation, Elekta/IMPAC Medical Systems, Inc., Philips Radiation Oncology Sytems, and the Johns Hopkins University.
Adaptive optics-optical coherence tomography for in vivo retinal imaging: comparative analysis of two wavefront correctors (2006)

Adaptive optics-optical coherence tomography (AO-OCT) has the potential to improve lateral resolution for OCT retinal imaging. Several reports have already described the successful combination of AO with a scanning confocal Fourier-domain OCT instrument to permit real-time three-dimensional (3D) imaging with high resolution (in all three dimensions). One of the key components that sets the performance limit of AO is the wavefront corrector. Several different wavefront correctors have been used in AO-OCT systems so far. In this paper we compare two commercially available wavefront correctors: an AOptix Bimorph deformable mirror (DM) and a Boston Micromachines Micro- Electro Mechanical System (MEMS) DM (used for the first time in an AO-OCT system). To simplify the analysis, we tested their performance for the correction of low-amplitude high-order aberrations (with minimal defocus and astigmatism). Results were obtained with an AO-OCT instrument constructed at UC Davis that combines state-of-the-art Fourier-domain OCT and an AO design to allow simultaneous testing of both mirrors without the need to modify the optical system.
Highly Sensitive Peptide‐Based Probes for Protein Tyrosine Phosphatase Activity Utilizing a Fluorogenic Mimic of Phosphotyrosine. (2006)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Temperature dependence of 4.1 <i>μ</i>m mid-infrared type II “W” interband cascade lasers (2011)

The thermal properties of 5-stage “W” Interband-Cascade Lasers emitting at 4.1 μm at room temperature (RT) are investigated by measuring the lasing and spontaneous emission properties as a function of temperature and hydrostatic pressure up to 1 GPa. Experiments show that at RT more than 90% of threshold current of these devices is due to non-radiative loss processes. We also find that the threshold current density dependence on temperature can be fitted with a single exponential function over a wide temperature range with a characteristic temperature, T0, of 45 K. The relatively high temperature sensitivity in these devices is attributable to the large non-radiative current contribution coupled with non-pinning of the carrier density above threshold.
Filament-Wrapped Cotton Yarn Made from Card Web (1986)

Two mechanical drafting devices have been developed for drafting and aligning fibers in a strip of card web for the purpose of producing filament-wrapped yarns. Both devices, one an apron drafter, and the other a roller drafter, are fully described in this report. Yarns ranging from 25 to 48 tex were made at production rates ranging from 21 to 48 m/min. Yarns produced from the two drafters were compared and analyzed. The apron drafter made yarns with higher strength, elongation, and better uniformity and appearance than the roller drafter.
<title>X-ray microscopy with high-resolution zone plates: recent developments</title> (1995)

In order to expand the applications of x-ray microscopy, developments in the fields of zone plate technology, specimen preparation and imaging techniques have been made. A new cross- linked polymer chain electron beam resist allows us to record zone plate pattern down to 19 nm outermost zone width. High resolution zone plates in germanium with outermost zone widths down to 19 nm have been developed. In addition, phase zone plates in nickel down to 30 nm zone width have been made by electroplating. In order to enhance the image contrast for weak absorbing objects, the phase contrast method for x-ray microscopy was developed and implemented on the Gottingen x-ray microscope at BESSY. The effects of x ray absorption on the structure of biological specimen limits the maximum applicable radiation dose and therefore the achievable signal to noise ratio for an artifact-free x-ray image. To improve the stability especially of biological specimen, a cryogenic object chamber has been developed and tested. It turns out that at the operating temperature T less than or equal to 130 K unfixed biological specimen can be exposed to a radiation dose of 10<SUP>9</SUP> - 10<SUP>10</SUP> Gy without any observable structural changes. A multiple-angle viewing stage allows us to take stereoscopic images with the x-ray microscope, giving a 3D-impression of the object. As an example for the applications of x-ray microscopy in biology, erythrocytes infected by malaria parasite have been examined. Studies of the aggregation of hematite by sodium sulfate gives an example for the application of x-ray microscopy in the field of colloid research.
General method for incorporation of modified N.omega.-cyanoguanidino moieties on selected amino functions during solid-phase peptide synthesis (1990)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGeneral method for incorporation of modified N.omega.-cyanoguanidino moieties on selected amino functions during solid-phase peptide synthesisPaula Theobald, John Porter, Carl Hoeger, and Jean RivierCite this: J. Am. Chem. Soc. 1990, 112, 26, 9624–9626Publication Date (Print):December 1, 1990Publication History Published online1 May 2002Published inissue 1 December 1990https://pubs.acs.org/doi/10.1021/ja00182a024https://doi.org/10.1021/ja00182a024research-articleACS PublicationsRequest reuse permissionsArticle Views70Altmetric-Citations6LEARN 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
Optimizing the precision in T1 relaxation estimation using limited flip angles (1987)

In this article we describe the precision in the estimation of the spin-lattice relaxation time T1 from MRI signals acquired for various flip angles with the repetition time TR held constant. We review the estimation procedure itself and present a model for the propagation of noise in the signal into the calculated T1. This model is verified by both Monte Carlo simulations and experimental data taken on image phantoms. Based on this model, we find that for a given TR/T1 there exist two optimal flip angles that will minimize the uncertainty in the estimated T1. We also show how two optimal angles can be selected for a given range of TR/T1 values. In addition, T1 estimation using the two optimal angles can be comparable to or better than using multiple evenly spaced angles. Finally, in an initial comparison with the two-point saturation recovery method of calculating T1, results for equal total scanning time TRTot suggest that for T1 greater than 0.5 TRTot, the limited flip angle approach gives better T1 precision whereas for T1 less than 0.5 TRTot the saturation recovery approach is better.