gebhart/patrepeval huggingface dataset:
Heterocyclic compounds from urea derivatives. Part XII. Ethoxycarbonylhydrazine as a source of 1,2,4-triazoles (1967)

Interaction of equimolar quantities of carbodi-imides and ethoxycarbonylhydrazine in dimethylformamide yields 1-(NN′-diarylamidino)-2-ethoxycarbonylhydrazines, which are readily cyclised, with loss of ethanol, to 4-aryl-3-arylamino-5-hydroxy-1,2,4-triazoles. Ring-closure to the corresponding 5-ethoxy-heterocycles, with loss of water, occurred in one case. S-Alkyl 1-ethoxycarbonyl-4-phenyl-3-isothiosemicarbazides, obtained from ethoxycarbonylhydrazine and phenyl isothiocyanate, and subsequent S-alkylation, are similarly convertible into 3-alkylthio-5-hydroxy-4-phenyl-1,2,4-triazoles.Addition of aroyl isothiocyanates to ethoxycarbonylhydrazine yields 4-aroyl-1-ethoxycarbonyl-3-thiosemicarbazides. These are ring-closed in alkaline media, with loss of carbon dioxide and ethanol, to 3-aryl-5-mercapto-1,2,4-triazoles. The isolation of 1-ethoxycarbonyl-3-methylthio-5-phenyl-1,2,4-triazole in one example suggests that compounds of this type are formed intermediately in this cyclisation.
A generalized Maxwell-slip friction model appropriate for control purposes (2004)

Under the increasing demand for more accurate high-performance motion systems, various friction models appropriate for control purpose of mechanical systems have been proposed. Most of these friction models formulate a heuristic dynamical model based on a few observed typical friction properties (e.g. a Stribeck curve for constant velocities and a hysteresis behaviour in presliding regime). This paper presents a novel friction model, called the generalized Maxwell-slip (GMS) model, appropriate for control purpose, based on a physically motivated friction model, i.e. a generic friction model which simulates the contact physics at asperity level. This paper compares the GMS model with some well-known existing models and shows that the novel model is capable of predicting accurately not only the presliding regime and Stribeck effect, but also friction lag, transition behavior, break-away force and the non-drifting ('stiction') property.
An Inherently Monotonic 7-Bit CMOS ADC for Video Applications (1986)

This paper describes a CMOS 7-bit flash analog-to-digital converter capable of operation at sample rates in excess of 30 megasamples per second (MSPS) with an analog bandwidth to /spl plusmn/1/2 least significant bit (Isb) of 5 MHz. The device has been realized on a 2-/spl mu/m double-layer metal CMOS process and takes advantage of the low power consumption available from CMOS logic. Circuit techniques have been employed to overcome most of the major problems inherent in flash converters and to guarantee a completely monotonic transfer function.
An environment for maintaining computation dependency in XML documents (2005)

In the domain of XML authoring, there have been many tools to help users to edit XML documents. These tools make it easier to produce complex documents by using such technologies as syntax-directed or presentation-oriented editing, etc. However, when an XML document contains data with some computation dependency among them, these tools cannot free users from the burden of maintaining this dependency relationship. By computation dependency, we mean that some data are gotten by computing from other data in the same document.In this paper, we present an environment for authoring XML document, in which users can express the data dependency relationship in one document explicitly rather than implicitly in their minds. Under this environment, the dependent parts of the document are represented as expressions, which in turn can be evaluated to generate the dependent data. Therefore, users need not to compute the dependent data first and then input them manually, as required by the current authoring tools.
Promising feedback methods for transmit beamforming in broadband mobile OFDM (2006)

This paper details three methods for closed-loop operation in the downlink of a broadband mobile OFDM system: uplink sounding, codebook feedback, and direct channel feedback (DCFB). Uplink sounding is intended for TDD systems and works by the base translating the uplink channel estimates into downlink channel estimates. DCFB is a means of obtaining full channel knowledge in either FDD or TDD systems. In DCFB, the mobile replaces normal transmitted symbols with a DCFB waveform constructed from downlink channel estimates to multiple base antennas. Another feedback method for TDD or FDD is codebook feedback where the mobile chooses a best transmit weight out of a codebook of 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sup> vectors and then signals this weight back to the base. To track the frequency-selective channel, multiple codebook vectors are sent back corresponding to different parts of the band. Simulation results show that uplink sounding is the best method for obtaining channel information for transmit beamforming, but sounding is only effective in TDD systems. For FDD, DCFB is more flexible, computationally efficient (at the mobile), and effective than codebook feedback for broadband transmit beamforming at the base
Practical spot size definition for single higher-order rectangular-mode laser beams (1981)

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text James T. Luxon and David E. Parker, "Practical spot size definition for single higher-order rectangular-mode laser beams," Appl. Opt. 20, 1728-1729 (1981) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article
Geometric blur for template matching (2005)

We address the problem of finding point correspondences in images by way of an approach to template matching that is robust under affine distortions. This is achieved by applying "geometric blur" to both the template and the image, resulting in a fall-off in similarity that is close to linear in the norm of the distortion between the template and the image. Results in wide baseline stereo correspondence, face detection, and feature correspondence are included.
In Ga As ∕ Al As Sb quantum cascade detectors operating in the near infrared (2007)

The authors report on short-wavelength In0.53Ga0.47As∕AlAs0.56Sb0.44 quantum cascade detectors (QCDs). At room temperature, one device detects at 505meV (2.46μm) with a responsivity of 2.57mA∕W, while a second QCD is sensitive at 580meV (2.14μm) with a responsivity of 0.32mA∕W.
Optical constants of CH_3NH_3PbBr_3 perovskite thin films measured by spectroscopic ellipsometry (2016)

The lack of optical constants information for hybrid perovskite of CH3NH3PbBr3 in thin films form can delay the progress of efficient LED or laser demonstration. Here, we report on the optical constants (complex refractive index and dielectric function) of CH3NH3PbBr3 perovskite thin films using spectroscopic ellipsometry. Due to the existence of voids, the refractive index of the thin films is around 8% less than the single crystals counterpart. The energy bandgap is around 2.309 eV as obtained from photoluminescence and spectrophotometry spectra, and calculated from the SE analysis. The precise measurement of optical constants will be useful in designing optical devices using CH3NH3PbBr3 thin films.
Demonstration of fully Ni-silicided metal gates on HfO/sub 2/ based high-k gate dielectrics as a candidate for low power applications (2004)

We have fabricated fully Ni-silicided metal gate (FUSI) CMOS devices with HfO2-based gate dielectrics for the first time. We demonstrate that full silicidation eliminates the Fermi level pinning at the polySi-HfO2 dielectric interface in pFETs. For nMOS devices, a 5 orders of magnitude reduction in short channel sub-threshold leakage is obtained with similar drive current compared to the poly gate devices. In addition, the FUSI process does not degrade the hysterisis nor the dielectric breakdown. This result makes FUSI on high-K a strong candidate for scaled low power technologies.
Thermal Compensation of Low-Cost MEMS Accelerometers for Tilt Measurements (2018)

Low-cost MEMS accelerometers have the potential to be used in a number of tilt-based monitoring applications but have the disadvantage of being very sensitive to temperature variation (thermal drift). In this paper, we analyze the thermal behavior of a low-cost sensor in the range -10 to +45 °C in order to provide a simple compensation strategy to mitigate this problem. For sensor analysis, we have developed a miniaturized thermal chamber, which was mounted on a tilting device to account for tilt angle variation. The obtained raw data were used to construct low degree polynomial equations that by relating the measurement error induced by thermal drift (i.e., acceleration residuals) to temperature and inclination (of each specific axis), can be used for thermal compensation. To validate our compensation strategy, we performed a field monitoring test and evaluated the compensation performance by calculating RMS errors before and after correction. After compensation, the RMS errors calculated for both the X and Y axes decreased by 96%, indicating the potential of using a simple set of equations to solve common drawbacks that currently make low-cost MEMS sensors unsuitable for tilt-based monitoring applications.
Meta Web Service based Distributed Model Management and Composition Approach (2010)

To satisfy the requirement of making scientific decision quickly and correctly in distributed network environment, a Meta Web Service based Distributed Model Management and Composition Approach is proposed. The Overall framework of Meta web service is designed, and each component is analyzed. An improved model service matching algorithm is given. Utilizing backward reasoning technique to compose model services dynamically and automatically, a process is then given which uses several model services to compose to make a single service. Compared with traditional model management approach, the approach provided here has the functions of model remote calling and running, automatic composing and executing etc., which provide a new approach to build model system for decision support system solving complex problems.
Application of Intelligent Structure and Intelligent Control in Active Vibration Control (2004)

The structure frame and the control algorithm are the main study objects of active vibration control. In this paper,the nature,development and current state of intelligent structure and intelligent control are reviewed in detail.Their application in active vibration controlis also discussed.This will give a good reference for the concerning issues.Finally some problems that should be solved in the future and the possible methods that can be used to solve them are presented.
Performance and modeling of active metal-matrix composites manufactured by ultrasonic additive manufacturing (2011)

This paper presents the development and characterization of active aluminum-matrix composites manufactured by Ultrasonic Additive Manufacturing (UAM), an emerging rapid prototyping process based on ultrasonic metal welding. The primary benefit of UAM over other metal-matrix fabrication processes is the low process temperatures, as low as 25 °C. UAM thus provides unprecedented opportunities to develop adaptive structures with seamlessly embedded smart materials and electronic components without degrading the properties that make these materials and components attractive. The objective of this research is to develop UAM composites with aluminum matrices and embedded shape memory NiTi, magnetostrictive Galfenol (FeGa), and polyvinylidene fluoride (PVDF) phases. The paper is focused on the thermally induced strain response and stiffness behavior of NiTi-Al composites, the actuation properties of FeGa-Al composites, and the embedded sensing capabilities of PVDF-Al composites. We observe up to a 10% increase over room temperature stiffness for NiTi-Al composites and a magnetomechanical response in the FeGa-Al composite up to 52.4 με. The response of the PVDF-Al composite to harmonic loads is observed over a frequency range of 10 to 1000 Hz.
Direct graphene growth on MgO(111) by physical vapor deposition: interfacial chemistry and band gap formation (2011)

Graphene can be grown directly on MgO(111) by industrially practical and scalable methods: free radical-assisted chemical vapor deposition (CVD), and physical vapor deposition (PVD). Single layer and double layer films can be produced by PVD, with a ~ 2 monolayer (ML) thick film as the apparent limiting thickness. C(1s) x-ray photoemission spectra (XPS) indicate that in both layers, carbon atoms are in two different oxidation states. Low energy electron diffraction (LEED) data are consistent with this, showing unequal graphene A site/B site intensities for both single and double layer graphene, yielding C<sub>3V</sub> symmetry. This lifts the A site/B site chemical equivalence in the graphene lattice, and therefore also the HOMO/LUMO degeneracy at the Dirac point. Consistent with this, a band gap of ~ 0.5 -1 eV has been observed for the two layer film. The XPS, LEED and band gap findings indicate that the graphene/MgO interface is commensurate, and that the MgO surface layer is reconstructed, resulting in carbon→MgO charge transfer. In addition, graphene growth by PVD is self-limiting at 2 monolayers thickness. These findings have implications for graphene growth on other (111) oxide surfaces. The ability to grow MgO(111) films on Si(100)-reported in the literature- points to a direct path to the development of graphene-based field effect transistors (FETs) and spin-FETs on MgO(111)/Si(100).
A monolithic DC-1.6 GHz digital attenuator (2003)

A 5-bit attenuator with integral TTL-compatible switch drivers is described. The unit has a 15.5 dB attenuation range in 0.5 dB increments, 3 dB insertion loss, operating frequency range from DC to 1.6 GHz, and 1.4:1 input/output VSWR (voltage standing-wave ratio) over that frequency range. The unit uses GaAs MESFET integrated circuit technology. The performance is typified by its integral and differential linearity (<0.25 dB at 1.6 GHz and <0.1 dB below 1.6 GHz) and 15-ns RF switching time. The power performance is typified by its <250-mW power consumption and 20-dBm maximum RF input power level.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Homocysteine Metabolism in ZDF (Type 2) Diabetic Rats (2005)

Mild hyperhomocysteinemia is a risk factor for many diseases, including cardiovascular disease. We determined the effects of insulin resistance and of type 2 diabetes on homocysteine (Hcy) metabolism using Zucker diabetic fatty rats (ZDF/Gmi fa/fa and ZDF/Gmi fa/?). Plasma total Hcy was reduced in ZDF fa/fa rats by 24% in the pre-diabetic insulin-resistant stage, while in the frank diabetic stage there was a 59% reduction. Hepatic activities of several enzymes that play a role in the removal of Hcy:cystathionine beta-synthase (CBS), cystathionine gamma-lyase, and betaine:Hcy methyltransferase (BHMT) were increased as was methionine adenosyltransferase. CBS and BHMT mRNA levels and the hepatic level of S-adenosylmethionine were also increased in the ZDF fa/fa rats. Studies with primary hepatocytes showed that Hcy export and the transsulfuration flux in cells from ZDF fa/fa rats were particularly sensitive to betaine. Interestingly, liver betaine concentration was found to be significantly lower in the ZDf fa/fa rats at both 5 and 11 weeks. These results emphasize the importance of betaine metabolism in determining plasma Hcy levels in type 2 diabetes.
Cell Saver Versus Hemofilter for Concentration of Oxygenator Blood after Cardiopulmonary Bypass (1987)

Concentration of superfluous blood in the oxygenator after the termination of a cardiopulmonary bypass was studied in 46 aortocoronary bypass patients. 15 patients were treated with a centrifugation system, the Haemonetics Cell Saver, 16 patients were treated with the Gambro Hollow Fibre Hemofilter and the remaining 15 patients received as much as possible from the untreated oxygenator contents and served as controls in a coagulation study. Both methods functioned well, the time consumption for operation of the two systems was similar. The products differed greatly as centrifugation revealed highly concentrated red cells in saline solution while hemofiltration produced protein-rich concentrated whole blood. A coagulation study of the patients who had received the concentrated products showed no signs of activation of the coagulation factors nor of the fibrinolytic system.
Increased hepatic Δ6‐Desaturase activity with growth hormone expression in the MG101 transgenic mouse (1996)

Growth hormone (GH) has many metabolic effects, but its mechanism(s) of action are not fully understood. We studied the short-term effects of endogenously produced GH on liver delta 6-desaturase activity and adipose and liver lipid fraction fatty acid composition in transgenic mice. MG101 transgenic mice ages 73-114 d received zinc to activate the ovine GH transgene for 7 d. Nontransgenic littermates, used as controls, also received zinc. Liver lipids were fractionated into phospholipids (PL), cholesteryl esters, and triglycerides (TG), and retroperitoneal adipose fractionated into PL and TG for fatty acid analysis. Liver microsomes were assayed for delta 6-desaturase activity. Animals expressing the ovine growth hormone transgene had a 2.5-fold higher liver delta 6-desaturase activity than controls. Arachidonate and docosahexaenoate were significantly higher in liver PL of GH transgenic animals compared to controls, but both were decreased in adipose PL in the GH animals. We conclude that increased production of GH affects both production and organ distribution of highly unsaturated fatty acids. The changes in arachidonate in various lipid pools following transgene expression may mediate the systemic actions of GH.
Dip-pen microarraying of molecular beacon probes on microgel thin-film substrates (2014)

The integration of microarray-based nucleic acid detection technologies and microfluidics is attractive, because the combination of small sample volumes, relatively short diffusion distances, and solid-phase detection enhances the development of multiplexed assays with improved sensitivity and minimal sample size. However, traditional microarray spotting methods typically create probe spot sizes of ∼50-100 μm diameter, comparable to the dimensions of many microfluidic channels. In addition, detection of hybridization events typically requires a post-hybridization labeling step. We address both issues by exploring the use of dip-pen nanolithography (DPN) to pattern linear oligonucleotides and self-reporting molecular beacon (MB) probes on streptavidin-functionalized poly(ethylene glycol) microgel thin-film substrates. In contrast to many systems involving DPN deposition, the fluorescence of the labeled probes enables their amount and spatial distribution to be characterized by optical microscopy. Their deposition rate decreases with increasing DPN dwell time, consistent with a Langmuir adsorption model, but the linear relationship between spot diameter and time(1/2) indicates that spot size is diffusion controlled. We then use DPN to pattern MB probes for the mecA and spa genes in Staphylococcus aureus as a 2-column array with 1 μm spot sizes and 5 μm spot spacings, and we use this array to differentiate targets characteristic of methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus. This duplexed self-reporting gel-tethered MB microarray not only shows high specificity but also a high signal-to-background ratio.
Genetic diversity of field populations of the cat flea, Ctenocephalides felis, and the human flea, Pulex irritans, in the South Central United States (2008)

The cat flea, Ctenocephalides felis, and the human flea, Pulex irritans, are species of significant human and veterinary health concerns. Genetic analysis of these species may provide insight into the dispersal of these insects and the spread of insecticide resistance. For this study, a total of 58 fleas were collected from Texas and Arkansas from both dwellings and pet animals. A total of 52 fleas collected were identified as C. felis, and 6 were identified as P. irritans. Samples were subjected to PCR and DNA sequencing using two markers, a portion of the mitochondrial DNA 16S rRNA gene and the nuclear rRNA first internal transcribed spacer region. For both species, no genetic variation was observed in either the nuclear or mitochondrial markers. Based on this observed lack of genetic variation, C. felis and P. irritans possibly underwent a genetic bottleneck in the United States.
Low-resolution mass spectrometric determination of aromatic fractions from petroleum (1969)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLow-resolution mass spectrometric determination of aromatic fractions from petroleumCharles John. Robinson and Glenn Leon. CookCite this: Anal. Chem. 1969, 41, 12, 1548–1554Publication Date (Print):October 1, 1969Publication History Published online1 May 2002Published inissue 1 October 1969https://pubs.acs.org/doi/10.1021/ac60281a005https://doi.org/10.1021/ac60281a005research-articleACS PublicationsRequest reuse permissionsArticle Views95Altmetric-Citations27LEARN 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
Study on Freezing Process of Killifish Egg: Utilizing the Undercooled State for Cryopreservation (1994)

The purpose of this study is to find the feasibility of preservation of large cell and tissue by maintaining the undercooled state in a freezing process, leading to avoiding the growth of ice crystals in the intracellular space, which causes destruction of cell and tissue. The fertilized killifish egg was employed to test biological tissue. The cooling system was equipped with Peltier devices and able to decrease the temperature of the test section to -50 degrees C. The cooling rate could be regulated by the electric current supplied to the Peltier devices. In the temperature range 0 to -40 degrees C, the morphology of fertilized killifish egg was observed under a microscope with a cooling rate from 0.1 to 10 degrees C/min. The damage rate to the egg in the intracellular undercooled state was evaluated by hatching rate. As a result, intracellular undercooled states were observed in the freezing process with the extracellular undercooling and the extracellular freezing. Extracellular undercooling proves to preserve the egg, and extracellular freezing frequently damages the egg. Thus the cryopreservation of biological material is achieved by maintaining the undercooled state until the temperature of -40 degrees C, then is instantly frozen by the liquid nitrogen to avoid the growth of ice crystals. The maintaining of the stable undercooled state of biological material is requisite for the initial phase in the freezing process. Therefore, dehydration or maintaining the extracellular stable undercooled state should be desirable to maintain the intracellular undercooled state for cryopreservation of biological material.