gebhart/patrepeval huggingface dataset:
Oilfield Performance in the Presence of Asphaltene Using a Dynamic Flow Simulation (2019)

Abstract This paper discusses a method for optimizing production and operation for onshore/offshore wells. Optimizing the production of oil and gas fields necessitates the use of accurate predication techniques to minimize uncertainties associated with day-to-day operational challenges related to serious operational problems caused by asphaltene deposition. It involves the use of a dynamic flow simulator for modeling oil and gas production systems and reservoir management to determine the feasibility of its economic development. Many studies have focused on relating asphaltene precipitation flocculation and deposition in oil reservoirs and flow assurance in the wellbores. Experimental techniques and theoretical models have been developed trying to understand and predict asphaltene behavior. Nevertheless, some ambiguities still remain with regard to the characterization asphaltene in crude oil and its stability during the primary, secondary, and tertiary recovery stages within the near-wellbore regions. A synthetic onshore full-field scale that is based on a heterogeneous three-dimensional Cartesian single-well model is considered in this paper. Two wells (a producer and an injector) and one reservoirs are considered to evaluate the dynamic properties under the influence of asphaltene. The size of the reservoir is 25 ft × 25ft × 20 ft and is represented by grid numbers of 50 columns × 50 rows × 5 layers with 12 hydrocarbon components constituting the constant crude composition of this model. The model comprised a total of 12,500 grid blocks. The three-dimensional simulation employed 5-layers, incorporating all relevant production and reservoir data. Different production scenarios were investigated to define the most appropriate and efficient production strategy. This paper provides a method to assess the effect of asphaltene precipitation, flocculation, and deposition in the well productivity and the economic impacts related to it and investigating prevention techniques and other related in-situ pore level flow assurance parameters. The results will include a comparison of production rates with and without asphaltene precipitation, flocculation, and deposition. In addition, it provides a comparison of asphaltene precipitation, flocculation, and deposition at different times using varying bottomhole and production rate constraints. Several cases (i.e., WAG cycles, completion, target layers of injection, etc.) are tested to help in selection of the optimum completion and operating strategy in the presences asphaltene. The paper will provide insight into factors affecting the flow assurance of oil and gas reservoirs.
<title>Dry etching processes for fabrication of QWIPs and other detector structures</title> (1997)

The fabrication of QWIPs and various grating structures for detectivity improvements requires the ability to selectively or non-selectively or non-selectively etch GaAs/AlGaAs, GaAs/InGaP, AlInAs/InGaAs and other heterostructure systems with high resolution. For selective etching of GaAs over ALGaAs, plasma chemistries involving BCl<SUB>3</SUB> or SiCl<SUB>4</SUB> with additions of SF<SUB>6</SUB> or CF<SUB>4</SUB> can provide selectivities over 600:1 when the ion energies and fluxes in the plasma are relatively low. The selectivity is severely reduced when the ion energy exceeds approximately 150 eV, because of sputter-enhanced removal of the AlF<SUB>3</SUB> which provides the etch-stop reaction. Fluorine-free, chlorine- based chemistries provide equi-rate etching of Al<SUB>x</SUB>Ga<SUB>1-x</SUB>As across the entire composition range as long as water vapor is excluded from the reactor chamber. This is readily achievable in load-locked systems, and BCl<SUB>3</SUB> is an attractive choice as the plasma chemistry because of its ability to get water vapor and to attack the native oxide on III-V materials. The CH<SUB>4</SUB>/H<SUB>2</SUB> plasma chemistry is selective for InGaAs over AlInAs at low ion energies, and also provides smooth controlled etching of II-VI compounds such as HgCdTe and related materials. ECR plasma sources have a number of advantages over conventional RIE systems, including higher etch rates, but typically display lower etch selectivities because of the very high ion fluxes. We also describe new etch processes developed for the III-N materials such as GaN, AlN and InN. Their high bond energies relative to the more common compound semiconductors have generally led to reports of low etch rates and the need for very high dc self-biases, but we show it is possible to use new plasma chemistries such as ICl under ECR conditions which produce efficient etching of these materials.
Aqueous Extract of Kotahla Himbutu (Salacia reticulata) Stems Promotes Oxygen Comsumption and Supresses Body Fat Accumulation in Mice (2008)

Kothala himbutu (KT) is a traditional medicinal plant used in treating diabetes in Ayurvedic medicine. We investigated the effect of the aqueous extract of KT stems (KTE) on energy expenditure in normal mice. Male C57BL/6J mice (n=28) were divided into 4 groups depending on the type of diet they were fed for 9 weeks: normal (N) diet group (N: 13.8% energy in the form of fat), high-fat (HF) diet group (HF: 53.0% energy in the form of fat), 0.1% freeze-dried KTE (KTED)-supplemented N diet group (N+KTED), and 0.1% KTED-supplemented HF diet group (HF+KTED). KTED intake significantly reduced body weight gain in mice in the N and HF groups. Although it did not affect the plasma levels of glucose, triglyceride, and nonesterified fatty acid, KTED significantly decreased the HF diet-induced increased plasma insulin level. The epididymal and perirenal white adipose tissue (WAT) weights were significantly lower in the HF+KTED group than in the HF group. The oxygen consumption (VO2), measured by indirect calorimetry, of the mice in the KTED-supplemented groups was significantly higher than that of the mice in the N and HF control groups. Moreover, KTED significantly reduced the size of epididymal WAT adipocytes in the N and HF groups. Thus, KTED promoted VO2 and suppressed WAT accumulation in the mice on the N and HF diets. Therefore, KTE is beneficial in reducing N diet- and HF diet-induced obesity, which may be partly attributable to the stimulation of whole body energy metabolism.
[Identification of Rad51 protein from Chlamydomonas reinhardtii: recombinational characteristics]. (2005)

The unicellular green microalga Chlamydomonas reinhardtii is a perspective model object for basic and applied research. However, its homologous recombination (HR) system which lies in the basis of double-strand DNA break repair have still not been studied. Last years the program of C. reinhardtii nuclear genome sequence is realized and different nucleotide repeats in the genome structure have been revealed that can explain a low level of HR relative to nonhomologous recombination events. Analyses of the C. reinhardtii EST (Expressed Sequence Tag)--and genome libraries permitted us to reconstruct and clone cDNA of the RAD51 gene. In present work, the cDNA was expressed, its product was purified and some basal biochemical activities were studied. The results show that Rad51C protein from lower eukaryote C. reinhardtii is identified as typical representative of the Rad51C-like subfamily of higher eukaryotes.
Compact high-voltage generator of primary power based on shock wave depolarization of lead zirconate titanate piezoelectric ceramics (2004)

The design and performance of a compact explosive-driven high-voltage primary power generator is presented. The generator utilizes a fundamental physical effect—depolarization of ferroelectric materials under longitudinal shock wave impact, when the shock wave is initiated along the polarization vector P. These primary power sources, containing energy-carrying elements made of lead zirconate titanate poled piezoelectric ceramics, with the volume from 0.35 to 3.3 cm3, are capable of producing pulses of high voltage with amplitudes up to 21.4 kV. The amplitude and full width at half-maximum of the high-voltage pulses are directly proportional to the thickness of the energy-carrying element, with coefficients of proportionality of 3.42±0.12 kV/mm (amplitude) and 0.125±0.01 μs/mm (width). The specific energy density of these ferroelectric energy-carrying elements reaches 76 mJ/cm3.
Microfluidic‐Generated Seeds for Gold Nanotriangle Synthesis in Three or Two Steps (2023)

Nanoparticle synthesis has drawn great attention in the last decades. The study of crystal growth mechanisms and optimization of the existing methods lead to the increasing accessibility of nanomaterials, such as gold nanotriangles which have great potential in the fields of plasmonics and catalysis. To form such structures, a careful balance of reaction parameters has to be maintained. Herein, a novel synthesis of gold nanotriangles from seeds derived with a micromixer, which provides a highly efficient mixing and simple parameter control is reported. The impact of the implemented reactor on the primary seed characteristics is investigated. The following growth steps are studied to reveal the phenomena affecting the shape yield. The use of microfluidic seeds led to the formation of well-defined triangles with a narrower size distribution compared to the entirely conventional batch synthesis. A shortened two-step procedure for the formation of triangles directly from primary seeds, granting an express but robust synthesis is further described. Moreover, the need for a thorough study of seed crystallinity depending on the synthesis conditions, which - together with additional parameter optimization - will bring a new perspective to the use of micromixers which are promising for scaling up nanomaterial production is highlighted.
Simulation of Mechanical Environment in Active Lead Fixation: Effect of Fixation Helix Size (2011)

The risk of myocardial penetration due to active-fixation screw-in type pacing leads has been reported to increase as the helix electrodes become smaller. In order to understand the contributing factors for lead penetration, we conducted finite element analyses of acute myocardial micro-damage induced by a pacemaker lead screw-in helix electrode. We compared the propensity for myocardial micro-damage of seven lead designs including a baseline model, three modified designs with various helix wire cross-sectional diameters, and three modified designs with different helix diameters. The comparisons show that electrodes with a smaller helix wire diameter cause more severe micro-damage to the myocardium in the early stage. The damage severity, represented by the volume of failed elements, is roughly the same in the middle stage, whereas in the later stage the larger helix wire diameter generally causes more severe damage. The onset of myocardial damage is not significantly affected by the helix diameter. As the helix diameter increases, however, the extent of myocardial damage increases accordingly. The present findings identified several of the major risk factors for myocardial damage whose consideration for lead use and design might improve acute and chronic lead performance.
Stabilographic analysis of unconstrained standing (2000)

Natural standing is characterized by postural changes and several hypotheses have been proposed to explain these changes. In this paper, four hypotheses were investigated by quantifying the number of postural changes in the centre of pressure data from unconstrained standing in different experimental conditions, studying the effects of mechanical loading, visual conditions, and type of support surface and sole of the shoes. The subjects stood for 30 min with no specific instructions other than not to step off a force plate. There were no significant effects on the number of centre of pressure patterns associated with the postural changes due to load, vision, surface and shoes during standing; on average, approximately two centre of pressure patterns per minute were observed in all conditions. The analysis of the centre of pressure data by the commonly used statistical parameters (standard deviation, velocity, and mean frequency of the centre of pressure displacement and area of the stabilogram) also did not reveal any effect of the different conditions.
Association Between Colorectal Cancer Mortality and Gradient Fecal Hemoglobin Concentration in Colonoscopy Noncompliers (2016)

After a positive fecal immunochemical test, colonoscopy can reduce by about half the number of deaths from CRC. Among colonoscopy noncompliers, higher f-Hb is associated with an increased risk of mortality from CRC in a dose-response manner.
Potency and selectivity of inhibition of human immunodeficiency virus protease by a small nonpeptide cyclic urea, DMP 323 (1994)

DMP 323 is a potent inhibitor of the protease of human immunodeficiency virus (HIV), with antiviral activity against both HIV type 1 and HIV type 2. This compound is representative of a class of small, novel, nonpeptide cyclic urea inhibitors of HIV protease that were designed on the basis of three-dimensional structural information and three-dimensional database searching. We report here studies of the kinetics of DMP 323 inhibition of the cleavage of peptide and HIV-1 gag polyprotein substrates. DMP 323 acts as a rapidly binding, competitive inhibitor of HIV protease. DMP 323 is as potent against both peptide and viral polyprotein substrates as A-80987, Q8024, and Ro-31-8959, which are among the most potent inhibitors of HIV protease described in the literature to date. Incubation with human plasma or serum did not decrease the effective potency of DMP 323 for HIV protease, suggesting that plasma protein binding is of a low affinity relative to that of HIV protease. DMP 323 was also assessed for its ability to inhibit the mammalian proteases renin, pepsin, cathepsin D, cathepsin G, and chymotrypsin. No inhibition of greater than 12% was observed for any of these enzymes at concentrations of DMP 323 that were 350 to 40,000 times higher than that required to inhibit the viral protease 50%.
Behavioral Approach to Nondyskinetic Dopamine Antagonists:  Identification of Seroquel (2001)

A great need exists for antipsychotic drugs which will not induce extrapyramidal symptoms (EPS) and tardive dyskinesias (TDs). These side effects are deemed to be a consequence of nonselective blockade of nigrostriatal and mesolimbic dopamine D2 receptors. Nondyskinetic clozapine (1) is a low-potency D2 dopamine receptor antagonist which appears to act selectively in the mesolimbic area. In this work dopamine antagonism was assessed in two mouse behavioral assays: antagonism of apomorphine-induced climbing and antagonism of apomorphine-induced disruption of swimming. The potential for the liability of dyskinesias was determined in haloperidol-sensitized Cebus monkeys. Initial examination of a few close cogeners of 1 enhanced confidence in the Cebus model as a predictor of dyskinetic potential. Considering dibenzazepines, 2 was not dyskinetic whereas 2a was dyskinetic. Among dibenzodiazepines, 1 did not induce dyskinesias whereas its N-2-(2-hydroxyethoxy)ethyl analogue 3 was dyskinetic. The emergence of such distinctions presented an opportunity. Thus, aromatic and N-substituted analogues of 6-(piperazin-1-yl)-11H-dibenz[b,e]azepines and 11-(piperazin-1-yl)dibenzo[b,f][1,4]thiazepines and -oxazepines were prepared and evaluated. 11-(4-[2-(2-Hydroxyethoxy)ethyl]piperazin-1-yl)dibenzo[b,f][1,4]thiazepine (23) was found to be an apomorphine antagonist comparable to clozapine. It was essentially nondyskinetic in the Cebus model. With 23 as a platform, a number of N-substituted analogues were found to be good apomorphine antagonists but all were dyskinetic.
Robust control design with real-parameter uncertainty and unmodeled dynamics (1990)

This paper presents a design methodology for the synthesis of a robust controller that accounts for both unmodeled dynamics and structured real-parameter uncertainty for multiple-input/multiple-output systems. The unmodeled dynamics are assumed to be characterized as a single block dynamic uncertainty at a point in the closed-loop system. In a design aimed at constraining both the H^ norm of a certain disturbance transfer matrix and a quadratic Gaussian performance index under their respective bounds, a surrogate system may be formed by modeling the structured real-parameter uncertainty as additional noise inputs and additional weights at the existing noise inputs and measurement outputs of the system. Application of a Riccati equation approach to this surrogate system then yields a robust controller that, when used in the actual system, will result in a closed-loop system that has the same H^ bound and quadratic Gaussian performance index bound as the surrogate system, even in the presence of given real-parameter variations.
Lineage Tracing Reveals Lgr5 + Stem Cell Activity in Mouse Intestinal Adenomas (2012)

The concept that tumors are maintained by dedicated stem cells, the so-called cancer stem cell hypothesis, has attracted great interest but remains controversial. Studying mouse models, we provide direct, functional evidence for the presence of stem cell activity within primary intestinal adenomas, a precursor to intestinal cancer. By "lineage retracing" using the multicolor Cre-reporter R26R-Confetti, we demonstrate that the crypt stem cell marker Lgr5 (leucine-rich repeat-containing heterotrimeric guanine nucleotide-binding protein-coupled receptor 5) also marks a subpopulation of adenoma cells that fuel the growth of established intestinal adenomas. These Lgr5(+) cells, which represent about 5 to 10% of the cells in the adenomas, generate additional Lgr5(+) cells as well as all other adenoma cell types. The Lgr5(+) cells are intermingled with Paneth cells near the adenoma base, a pattern reminiscent of the architecture of the normal crypt niche.
A novel stereoselective access to des-A B-aromatic corticosteroids via intramolecular cycloaddition reaction—potential intermediates for the synthesis of corticosteroids (1987)

A short and stereoselective synthesis of protected des-A B-aromatic corticosteroids (3) and (23)via trans- 2,3,3a,4,5,9b-hexahydro-3β-isopropenyl-7-methoxy-3aβ-methyl-1H-benz[e]inden-3α-ol (13) and its methoxymethyl ether derivative (20), which were prepared by thermolysis of 3-[2-(1,2-dihydro-4-methoxybenzocyclobuten-1-yl)ethyl]-2,4-dimethylpenta-1,4-dien-3-ol (11) and its methoxymethyl ether (19), respectively, is described.
Programmable CRC circuit architecture (2007)

This paper presents the design and implementation of a fully programmable Cyclic Redundancy Check (CRC) computation circuit for System on a Chip (SoC) network processing applications. The presented architecture provides flexibly whilst maintaining gigabit throughput rates for frame/packet processing using standard cell technology.
High-sensitivity far-ultraviolet imaging spectroscopy with the SPRITE Cubesat (2019)

The SPRITE cubesat is a recently selected NASA astrophysics mission designed to measure ionizing radiation escape from star-forming galaxies, and to map far-ultraviolet (1000 - 1750 Å) emission from shocked regions in supernova remnants. The instrument leverages a number of new technologies identified for future large mission concepts, including the LUVOIR surveyor, to achieve the required performance. These include high broadband reflectivity mirror coatings and an ultra-low background photon counting microchannel plate detector with an anti-coincidence particle rejection system. SPRITE will serve as a flight testbed for these technologies, employing a robust calibration program as part of the principal science mission to advance the technology readiness level (TRL) to 7+ and provide heritage for future Explorer-class and larger missions. SPRITE is a 6U class cubesat funded through NASA ROSES with an anticipated launch date in 2022. The science data products will be archived on the Mikulski Archive for Space Telescopes (MAST). This proceedings describes the instrument science program, optical design, preliminary performance projections, and project timeline.
Three-dimensional echocardiography (2009)

Over the past two to three decades echocardiography has come a considerable distance from the early M-mode machines, and has become an indispensable diagnostic tool in any cardiovascular department. It has long been proved to be safe and cost-effective, and its clinical versatility has steadily increased with the continued integration of newer techniques, such as two-dimensional and harmonic imaging, Doppler and much more. One of the more recent developments in the field is three-dimensional echocardiography (3DE). 3DE, in various forms, has been used as a research tool for many years now, but lately improvements in software and transducer technology have begun to facilitate its integration into clinical practice. As with any technique, 3DE has its strengths and weaknesses, and these must be fully appreciated if it is to be utilised effectively.
Unsaturated heterocyclic systems. LXIV. Synthesis and photoisomerization of homo-1H-azepine derivatives (1970)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUnsaturated heterocyclic systems. LXIV. Synthesis and photoisomerization of homo-1H-azepine derivativesLeo A. Paquette and Robert J. HaluskaCite this: J. Org. Chem. 1970, 35, 1, 132–135Publication Date (Print):January 1, 1970Publication History Published online1 May 2002Published inissue 1 January 1970https://pubs.acs.org/doi/10.1021/jo00826a029https://doi.org/10.1021/jo00826a029research-articleACS PublicationsRequest reuse permissionsArticle Views136Altmetric-Citations16LEARN 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
[Growth feature of biomass of Lemna aequinoctialis and Spirodela polyrrhiza in medium with nutrient character of wastewater]. (2004)

Duckweeds have an important potential in nutrient recovery from wastewater because of their rapid multiplication and high protein content in biomass. The growth rate of duckweed biomass has a direct relationship with nutrient removal and recovery. With laboratory experiments of batch culture and continuous culture, the growth curves of two duckweed species, Lemna aequinoctialis and Spirodela polyrrhiza, cultivated in different media were gotten and fitted by Logistic model. The effect of nitrogen on growth of duckweed was evaluated. Experimental results indicated that the growth curve had characteristic of sigmoidal shape and the growth rate had density-dependent characteristic. Results of statistical analysis demonstrated that Logistic model is suitable to describe the growth of single duckweed specie. The maximal growth rate from regression in medium with ammonia nitrogen was lower than those in medium with nitrate nitrogen. The maximal growth rate of Lemna aequinoctialis was higher than Spirodela polyrrhiza The paper also discussed the application of Logistic model in harvesting of duckweed biomass from wastewater.