gebhart/patrepeval huggingface dataset:
Screening Considerations for Curable Resin-Coated Proppants (1996)

Abstract Curable resin-coated proppants (RCP) have been used to minimize proppant flowback from propped hydraulic fractured oil and gas wells for years, yet proppant backproduction is still reported to be a major operational problem. The industry cannot currently explain why some hydraulic fractures propped with curable RCP produce proppant back while others containing only uncoated proppant do not produce any proppant back. This paper presents results of a study done to help determine screening considerations for curable resin-coated proppants. The study involved curing and crushing proppant plugs under a variety of conditions ranging from frac-and-pack applications in shallow wells to fracturing applications in deep horizontal wells. These tests were conducted to identify suitable RCPs for given applications. The unconfined compressive strength (UCS) of proppant plugs cured in the treatment fluid at reservoir temperature with closure stress applied, is currently used as the screening criterion for curable RCP. The UCS needs to be as high as possible while the same resin coating should not consolidate the proppant while left in the well after a treatment without closure stress applied. This study demonstrates that at least six data points are needed to obtain a representative value for the unconfined compressive strength (UCS) of proppant for any one set of conditions. Although several studies of factors affecting the performance of RCPs have been presented in the literature, the conclusions in these studies are generally based on limited data for one set of conditions and are, therefore, often questionable. In addition, the effect of cooldown and subsequent heatup on RCPs after a treatment has not been considered previously as a factor in proppant backproduction. This paper demonstrates that this temperature effect is an important parameter to consider. Stress cycling has been identified as one of the failure mechanisms for RCP in experiments. These experiments were conducted at ambient temperature with proppant packs cured at temperatures between 160 and 200°F (71 and 93°C). We conducted similar experiments at simulated in-situ conditions to verify whether the mechanism was still effective for these conditions. We found that the addition of thermoplastic film material to RCP cured at 300°F (149°C) increased its resistance to stress cycling.
9-Bromo-9-borabicyclo[3.3.1]nonane (2001)

[22086-45-9] C8H14BBr (MW 200.91) (selective reagent for the cleavage of ethers2 and deoxygenation of sulfoxides;3 adds regioselectively and stereoselectively to terminal alkynes;4 undergoes conjugate addition to α,β-unsaturated ketones;5 converts vinyltins to vinylboranes10) Alternate Name: Br-9-BBN. Physical Data: colorless liquid; bp 54–59 °C/0.3–0.4 mmHg; mp −17 °C; d 1.315 g cm−3. Solubility: sol pentane, CH2Cl2; dec ethers, alcohols. Form Supplied in: 1.0 M solution in CH2Cl2. Analysis of Reagent Purity: the reagent exhibits a single resonance in its 11B NMR (neat) spectrum at δ 83.9 (s) ppm.2 Handling, Storage, and Precautions: the reagent is pyrophoric and reacts violently with moisture and protic solvents. Individuals should thoroughly familiarize themselves with the special handling techniques required for such reagents prior to use.1 Use in a well-ventilated fume hood.
Deformation behavior of low-carbon Co-Cr-Mo alloys for low-friction implant applications (1996)

The plastic flow behavior of wrought Co-27Cr-5Mo-0.05C alloy was investigated at 298 K as a function of grain size using uniaxial tension testing. The microstructures produced by deformation were characterized using X-ray diffraction, reflected light, and scanning electron microscopy. This study revealed that material with initially coarse face-centered cubic (fcc) grains exhibits larger uniform ductility than material with fine grain size. Typically, increasing the grain size from 7 to 70 μm reduces the yield strength by about 50% and increases the elongation to fracture from 12 to 30% with a small effect on the tensile strength. The material is capable of deforming uniformly to large strains without developing plastic instabilities until the point of fracture. This effect was found to be associated with the occurrence of transformation-induced plasticity (TRIP) in the coarse-grained material. TRIP enhances the material's ability to deform uniformly by maintaining a high rate of strain hardening during deformation. Smaller fcc initial grain size inhibits the transformation kinetics of the fcc-hexagonal close-packed phase transition according to the Olson-Cohen model. © 1996 John Wiley & Sons, Inc.
IF system design for the Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO) (2018)

We present the design, and prototype phases of the intermediate frequency (IF) system for the upcoming balloon borne observatory, Galactic/Extragalactic Ultra-Long Duration Balloon (ULDB) Spectroscopic Terahertz Ob- servatory (GUSTO). GUSTO is a multi-organizational project whose goal is to address several key unanswered questions concerning all of the phases of the stellar life cycle within the Interstellar Medium (ISM). Using the NASA ULDB system for its platform, GUSTO will employ on-the-fly mapping techniques to scan a total of 124 square degrees of the Milky Way and Large Magellanic Cloud (LMC). GUSTO will survey the three brightest cooling lines in the Milky Way and the LMC. These lines are [CII], [OI], and [NII] corresponding to the three wavelengths of 158, 63, and 205 micron respectively. The completed survey will provide higher angular, and velocity resolution than that of previous surveys of [CII], [OI], and [NII]. These lines will be measured using three 8-pixel heterodyne arrays, each one dedicated to an individual cooling line, and all working together to make a 24-pixel focal plane. The GUSTO IF system is being designed to operate at low power consumption and high sensitivity all in a compact and lightweight package. The IF system will include a wideband 0.3 - 5 GHz, cryogenic, low noise amplifier (LNA), which will boost the IF output of a superconducting hot electron bolometer (HEB) mixer. The LNA was designed with commercial, off the shelf SiGe heterojunction bipolar transistors, and surface mount passive components. The LNA design has been optimized for low power consumption, and for sensitivity. The input impedance of the LNA is matched to the output impedance of the mixer over a wide range of frequencies to reduce reflections, and standing waves. Warm IF electronics have also been designed using commercial, off the shelf, surface mount SiGe transistors in order to achieve a high, and at gain (>50dB) over the entire bandwidth. These components provide variable gain and deliver an optimum signal level to the analog to digital converter of the backend spectrometer. The warm IF components were optimized for wide bandwidth, low power consumption, as well as reliability, and fit in a compact package. Commercially fabricated custom flexible printed circuit boards are being used for multi-channel stripline-based transmission lines, instead of the traditional stainless steel cryogenic semi-rigid coaxial cables. Replacing coaxial cables with the flexible printed circuit boards allows us to transmit through up to 16 lines on a single flex circuit, without losing performance, and furthering the design goal of providing a compact/lightweight solution. Each of the components used in this IF system will undergo rigorous qualification testing, and documentation in accordance with a NASA Class-D balloon mission. We discuss the design challenges in adapting cryogenic, and warm IF electronics to operate for an ultra long duration balloon mission.
The role of the specialist nurse in pelvic floor dysfunction (2003)

Pelvic floor dysfunction can have a devastating effect on people's lives. The specialist nurse can play a vital role within the multidisciplinary team to help improve the quality of life for these patients by offering conservative management and support through surgical treatment options.
Perceptual cues for consonant identification. (2008)

This research quantitatively explores the perceptual cues of initial consonants by using psychoacoustical methods. Speech sounds are encoded by across-frequency temporal onsets called events. To determine the time-frequency importance function of the consonant sounds, speech stimuli (16 nonsense CVs from the LDC-2005S22 database) are high-pass or low-pass filtered and time-truncated before being presented to normal hearing listeners. Databases of speech perception under various signal to noise ratio (SNR) conditions are constructed to investigate the effect of noise on speech recognition. A visualization tool that simulates the auditory peripheral processing, called the AI-gram, is used for the analysis of the speech events under various SNR conditions. To verify the nature of the events, a special software has been developed to convert one sound into another, starting from real speech sounds, by removing primary noise robust cues. In pilot studies with a hearing-impaired subject, it is shown that feature boosting improves the robustness of select speech consonants to noise.
A general, high-yielding synthesis of b-diamides and b-amidoesters (2000)

A new and efficient synthetic route to malonamides and malonamic acid esters is described. S-tert-Butyl acetothioacetate monoanion reacted with aryl or alkyl isocyanates to give tricarbonyl compounds, which spontaneously deacetylated to the corresponding b-amidothioesters. Treatment of the latter with aliphatic or aromatic amines or alcohols at room temperature in the presence of silver trifluoroacetate provided malonamides or malonamic acid esters, respectively, in excellent overall yields.
Controlled growth of epitaxial BiFeO3 films using self-assembled BiFeO3-CoFe2O4 multiferroic heterostructures as a template (2012)

The growth mechanism of a BiFeO3 layer deposited on self assembled (0.65) BiFeO3-(0.35) CoFe2O4 (BFO-CFO) composite thin films was studied. Epitaxial and self-assembled BFO-CFO thin films were deposited on SrTiO3 (111) substrates by pulsed laser deposition and were subsequently used as a seed layer for the deposition of an additional BFO layer. x-ray line scans showed the heterostructures were highly epitaxial. Cross-sectional scanning electron microscopy and focused ion beam images revealed the top BFO layer grew preferentially from BFO nanopillars in the BFO-CFO thin films, thus, demonstrating controlled growth. The multiferroic properties of this new nanostructure were then studied.
Effects of sample handling and storage on quantitative lipid analysis in human serum (2009)

There is sparse information about specific storage and handling protocols that minimize analytical error and variability in samples evaluated by targeted metabolomics. Variance components that affect quantitative lipid analysis in a set of human serum samples were determined. The effects of freeze-thaw, extraction state, storage temperature, and freeze-thaw prior to density-based lipoprotein fractionation were quantified. The quantification of high abundance metabolites, representing the biologically relevant lipid species in humans, was highly repeatable (with coefficients of variation as low as 0.01 and 0.02) and largely unaffected by 1-3 freeze-thaw cycles (with 0-8% of metabolites affected in each lipid class). Extraction state had effects on total lipid class amounts, including decreased diacylglycerol and increased phosphatidylethanolamine in thawed compared with frozen samples. The effects of storage temperature over 1 week were minimal, with 0-4% of metabolites affected by storage at 4 degrees C, -20 degrees C, or -80 degrees C in most lipid classes, and 19% of metabolites in diacylglycerol affected by storage at -20 degrees C. Freezing prior to lipoprotein fractionation by density ultracentrifugation decreased HDL free cholesterol by 37% and VLDL free fatty acid by 36%, and increased LDL cholesterol ester by 35% compared with fresh samples. These findings suggest that density-based fractionation should preferably be undertaken in fresh serum samples because up to 37% variability in HDL and LDL cholesterol could result from a single freeze-thaw cycle. Conversely, quantitative lipid analysis within unfractionated serum is minimally affected even with repeated freeze-thaw cycles.
The Performance of a Wireless Sensor Network for Structural Health Monitoring (2004)

An issue associated with agricultural irrigation using reclaimed wastewater is the potential threat to underlying groundwater quality. A prime example is nitrate, which serves as a fertilizing agent but has the potential to leach into groundwater. In order to balance water reuse and groundwater protection, intelligent irrigation management and monitoring systems are required for such water reuse systems. In this work, a nonlinear programming-based control algorithm is proposed to optimize irrigation scheduling subject to contaminant transport constraints. In support of the algorithmic developments, a networked sensor array is being designed for deployment at an agricultural research plot. This array will supply real-time field information about water infiltration and distribution, nitrate propagation, and heat transport, to the irrigation scheduling algorithm. The control scheme (measurement, decision, and action) will be continuously updated using on-line feedback from sensors. The simulator on which the management algorithm depends is a one-dimensional form of the Richards equation coupled to energy and solute transport mass balances.
ChemInform Abstract: SYNTHETIC AND MECHANISTIC ASPECTS ON THE WITTIG REACTION. A YIELD INCREASING MODIFICATION (1981)

Abstract Bei der Wittig‐Reaktion zwischen einem enolisierbaren Keton und Methylentriphenylphosphoran in Ether wird die Ausb. an Olefin in vielen Fällen infolge der Enolbildung stark verringert.
A nonlinear viscoelastic - plastic model for electrorheological fluids (1997)

A nonlinear dynamic model is presented that characterizes electrorheological material behavior in terms of its shear stress versus shear strain behavior. The ER fluid model is essentially a nonlinear combination of linear shear flow mechanisms. These linear shear flow mechanisms, a three-parameter viscoelastic fluid element and a viscous fluid element, are used to describe shear flow behavior in the pre-yield and the post-yield regimes, respectively. In order to capture the material behavior in the transition through the yield point, a nonlinear combination of these linear shear flow mechanisms is used. The model, which relates the shear strain input to the shear stress output, is represented by a simple network that consists of two parallel linear mechanisms whose outputs are combined using nonlinear weighting functions. The weighting functions are dependent on the strain rate in the material. A system identification technique is developed to estimate the model parameters from experimental data, which consists of shear stress versus shear strain hysteresis loops at different levels of electric field. The results of this system identification approach indicate that the model parameters are smooth monotonic functions of the electric field. The experimental hysteresis loops are reconstructed using the estimated model parameters and the results show that the model accurately predicts material response. It is shown that the Coulomb friction-like behavior at high field strengths, which is characteristic of ER fluids, can be captured by this nonlinear mechanism-based model.
USING ULTRASONIC METHODS TO DETERMINE COOKING DEGREE OF DONENESS IN BEEFSTEAKS (2008)

ABSTRACT Imaging and piezoelectric ultrasound were used independently in two separate experiments to determine cooking degree of doneness (DOD) in beefsteaks. Six 2.54‐cm steaks were cut from central portions of frozen United States Department of Agriculture Select strip loins ( n = 18), and were assigned DOD corresponding with very rare, rare, medium rare, medium, well and very well, respectively. Steaks were scanned both before and after cooking. Cooking loss and Warner‐Bratzler shear force (WBSF) were determined. As DOD increased, WBSF and cooking loss increased (P < 0.05). Image intensities were analyzed and comparisons were made between steaks cooked to similar DOD (P > 0.05). Results indicated an observable, although not significant, trend from very rare to medium rare for imaging ultrasound. A linear trend from medium to very well, although not significant, was observed using direct piezoelectric methods. Results of the image intensity analysis were ultimately deemed inconclusive. PRACTICAL APLICATIONS Ultrasonic methods are rapid, noninvasive means of measuring changes in material density and water content. Because meat changes in density and water content during cooking, these methods may be appropriate for measuring internal meat temperature without causing a physical change to the meat. The ability to determine the internal cooking temperature of meat has implications for customer satisfaction as well as food safety.
MATERIAL PROPERTY CHARACTERIZATION AND SPECIFICATIONS FOR IMPROVED RAIL STEELS (2002)

This article reports on efforts to isolate and measure the elements of steel rails that are most important to long, trouble-free service under specific conditions and to also measure the characteristics of steel that best meet those demands. Railroads already apportion different hardnesses of rail to different types of track, with the highest quality going into the track with the greatest curvature. Key considerations are resistance to wear and rolling-contact fatigue, which researchers can show at the microscopic level. Shear yield strength seems important, but only at the cold-worked and work- hardened surface, not as-manufactured. When research is completed, railroad operators will be able to set their specifications for rail so that manufacturers can produce steel that fits their needs more closely. Another goal is to identify stresses that weaken rails.
Improved RF Performance Characteristics of Cascaded Ferroelectric Varactor Shunt Switches (2006)

Our group has been investigating properties of nanostructured barium strontium titanate (BST) thin-films for use in a number of microwave/millimetre wave applications in collaboration with the Air Force Research Laboratory. Currently, a ferroelectric varactor shunt switch which can be useful for low power, low voltage microwave/millimeterwave switching is under investigation. A coplanar waveguide (CPW) based design provides Si MMIC compatible shunt switches for microwave and millimeterwave applications. The cascaded shunt switch consists of two ferroelectric varactor shunt switches with varactor area of 5times5 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> in cascade, separated by a section of a CPW line. The measured isolation of the device (at 0 V dc bias) was better than 35 dB at 35 GHz. The insertion loss of the device was below 4.5 dB up to 35 GHz. The useful bandwidth of operation for the cascaded switch is between 25 and 35 GHz as one can obtain a minimum isolation of 20 dB and maintain insertion loss below 4.5 dB. A single varactor shunt switch of 5times5 mum <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> fabricated on the same chip, exhibited an isolation of ~15 dB at 30 GHz, and insertion loss of ~4 dB at 30 GHz. The experimental results confirmed the simulation results that cascaded shunt switch provides improved isolation, with insertion loss remaining closer to the single shunt switch.
INTERPRETACION DE PRUEBAS DE INYECCION EN YACIMIENTOS NATURALMENTE FRACTURADOS (2008)

Este estudio presenta un nuevo método para determinar la transmisibilidad en yacimientos naturalmente fracturados usando el análisis del flujo radial en pruebas de calibración. El método se basa en el análisis del comportamiento de la derivada de la presión con el tiempo. El objetivo es simplificar y facilitar la identificación del flujo radial y la â€œgargantaâ€ característica que se observa en la derivada cuando se tienen yacimientos naturalmente fracturados. El método propuesto no requiere el conocimiento previo de la presión de yacimiento. Un grafico logarítmico es usado para determinar la permeabilidad, la presión promedio, el almacenamiento y el coeficiente que relaciona las permeabilidades s de la matriz y de las fracturas en el yacimiento.
Metall-Katalysierte Enantioselektive Synthese von Propargylaminen und ihre Anwendungen in der Synthese (2005)

Im Rahmen der Dissertation "Metall-katalysierte enantioselektive Synthese von Propargylaminen und ihre Anwendungen in der Synthese" wurde eine Kupfer-katalysierte enantioselektive Additionsreaktion von Alkinen an in situ generierte Iminium-Ionen untersucht. Zunächst wurde eine neuartige Eintopf-Synthese entwickelt, die eine besonders atomökonomische und synthetisch wertvolle Methode zur Darstellung der Propargylamne darstellt. Dabei wurden equimolare Mengen von terminalen Alkinen, Aldehyden und sekundären Aminen in Gegenwart von katalytischen Mengen Kupferbromid und Quinap als chiralem Ligand umgesetzt. Die Methode toleriert Variationen und die Einführung von funktionellen Gruppen in alle drei Komponenten. Insbesondere die Ausweitung der Synthese auf aromatische Aldehyde ist erwähnenswert. Die auf diesem Wege erhaltenen Propargylamine wurden weiter funktionalisiert und so in synthetisch nützliche Derivate überführt. Unter anderem wurde die synthetische Anwendbarkeit in der enantioselektiven Totalsynthese des Alkaloids Coniin demonstriert. Im zweiten Teil der Dissertation wurde der Einfluß der Stickstoff-Schutzgruppen auf die Enantioselektivität der Reaktion untersucht. Dabei wurden verschiedene neue Schutzgruppen entwickelt. Der Einsatz von Di(2-phenallyl)amin in der Propargylaminsynthese erlaubte nach einer Palladium-katalysierten allylischen Substitution an den allyl-geschützten Propargylaminen die Darstellung primärer Propargylamine, die bis dahin nicht in guten Enantioselektivitäten zugänglich waren. Im abschließenden Teil der Dissertation wurde ein neuartiger, chiraler P,N-Ligand ausgehend von chiralen Propargylalkoholen entwickelt und in der asymmetrischen Synthese (Palladium-katalysierte allylische Substitution) getestet.
1,10-Phenanthrolin-1-ium hydrogen<scp>D</scp>,<scp>L</scp>-tartrate dihydrate (2011)

In the title hydrated molecular salt, C(12)H(9)N(2) (+)·C(4)H(5)O(6) (-)·2H(2)O, the cation is almost planar (r.m.s. deviation = 0.014 Å); the carbon skeleton of the anion assumes a trans conformation [C-C-C-C torsion angle = -179.86 (14)°]. The carboxyl end of one hydrogen tartrate anion forms a short hydrogen bond to the carboxyl-ate end of another anion [O⋯O = 2.508 (2) Å] in a head-to-tail manner, forming a chain; the chains and water mol-ecules inter-act, generating an O-H⋯O hydrogen-bonded layer. The cation binds to the layer by an N-H⋯O hydrogen bond.
A new species of characid fish of the genus Nematobrycon from the Rio Calima of Colombia (Pisces, Characoidei, Characidae) (1971)

The systematic status of three nominal forms of the Colombian characid genus Nematobrycon is herein treated. All forms are illustrated and their interrelationships discussed. One species, Nematobrycon lacortei is described as new. Nematobrycon palmeri Eigenmann, a species from the northern headwaters of the Rio San Juan is compared with Nematobrycon amphiloxus Eigenmann & Wilson from the adjacent headwaters of the Rio Atrato. It is suggested that N. amphiloxus is probably a subspecies of N. palmeri. N. lacortei from the headwaters of the Rio Calima, a large southern tributary of the Rio San Juan, is considered specifically distinct from N. palmeri at the present time. Judgement on the systematic status of all forms of Nematobrycon must await collection of population samples from the headwaters of many uncollected tributaries of the Rio San Juan and Rio Atrato. Finally, forms of Nematobrycon being bred and/or imported by aquarists in the United States are identified.