gebhart/patrepeval huggingface dataset:
Review of Organic Friction Modifiers - Contribution to Fuel Efficiency? (2000)

<div class="htmlview paragraph">Friction modifiers have been around for many years. Originally, the application was for limited slip gear oils, automatic transmission fluids and multipurpose tractor fluids.</div> <div class="htmlview paragraph">Since fuel economy became an international issue, initially to reduce crude oil consumption, friction modifiers have been introduced into automotive crankcase lubricants as well. The current emphasis is to improve the fuel efficiency through the engine lubricant and to reduce emissions to the environment.</div> <div class="htmlview paragraph">This paper describes the chemistry of the various organic friction modifiers as well as the non-organic types. A basic understanding is given on the mechanisms how and why these products work as friction modifiers and what is known about structure - activity relationships.</div> <div class="htmlview paragraph">Definitions are given about the various lubrication regimes as well as figures to what extend these regimes are present in current engine tests measuring fuel economy. In addition, it is described which type of friction modifiers is most active in the various lubrication regimes.</div> <div class="htmlview paragraph">Factors influencing the friction reducing properties, like base fluid characteristics and competing additives, are covered and appropriate tests to measure frictional properties are described. Finally, some recent work regarding the effect of some friction modifiers on frictional levels, determined with a pin-on-ring tribometer, is shown.</div>
Path MTU Discovery Considered Harmful (2018)

Path MTU Discovery (PMTUD) allows to optimize the performance in the Internet by identifying the maximal packet size that can be transmitted through a network. Despite the central role that PMTUD plays in the Internet communication, it has a long history of software bugs, failures and misconfigurations. In this work we explore the benefits versus drawbacks of PMTUD in the Internet from the clients and servers perspective. First, we examine the fraction of clients that use PMTUD. To that end we analyse ICMP PTB messages in CAIDA Internet Traces and show that the fraction of networks using PMTUD is negligible and that this number is further decreasing over the period of 2008 - 2016. Second, we evaluate the fraction of popular web servers that support the PMTUD mechanism and show that a large number of the servers block "ICMP packet too big" messages. On the other hand, we show easy and efficient - even though well-known - degradation of service attacks that exploit the availability of PMTUD. Since the benefit of PMTUD is questionable, and in contrast it exposes to degradation of service attacks, we advocate to stop using it. As with any new change in the Internet, the implications of our recommendation should be carefully evaluated and gradually implemented. In the meanwhile, we provide recommendations for mitigations against the degradation of service attacks.
Coulometric Titrations with Externally Generated Reagents (1950)

Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.
<b>The Chemistry of Carbonyl Fluoride. II. Synthesis of Perfluoroisopropyl Ketones</b> (1962)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Chemistry of Carbonyl Fluoride. II. Synthesis of Perfluoroisopropyl KetonesR. D. Smith, F. S. Fawcett, and D. D. CoffmanCite this: J. Am. Chem. Soc. 1962, 84, 22, 4285–4288Publication Date (Print):November 1, 1962Publication History Published online1 May 2002Published inissue 1 November 1962https://pubs.acs.org/doi/10.1021/ja00881a018https://doi.org/10.1021/ja00881a018research-articleACS PublicationsRequest reuse permissionsArticle Views561Altmetric-Citations35LEARN 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
Specificities of Eleven Different DNA Methyltransferases of <i>Helicobacter pylori</i> Strain 26695 (2001)

Methyltransferases (MTases) of procaryotes affect general cellular processes such as mismatch repair, regulation of transcription, replication, and transposition, and in some cases may be essential for viability. As components of restriction-modification systems, they contribute to bacterial genetic diversity. The genome of Helicobacter pylori strain 26695 contains 25 open reading frames encoding putative DNA MTases. To assess which MTase genes are active, strain 26695 genomic DNA was tested for cleavage by 147 restriction endonucleases; 24 were found that did not cleave this DNA. The specificities of 11 expressed MTases and the genes encoding them were identified from this restriction data, combined with the known sensitivities of restriction endonucleases to specific DNA modification, homology searches, gene cloning and genomic mapping of the methylated bases m(4)C, m(5)C, and m(6)A.
Ten-Year Follow-Up Evaluation of a School Screening Program for Scoliosis (1999)

The Adams forward-bending test cannot be considered a safe diagnostic criterion for the early detection of scoliosis (especially when it is used as the only screening tool) because it results in an unacceptable number of false-negative findings. For the early detection of scoliosis, a combination of back-shape analysis methods can be safely used with the introduction of cutoff limits for referral being a useful procedure. The incidence of significant scoliosis is low, and its natural history seems to be independent of early detection. The wide-spread use of school scoliosis screening with the use of the forward-bending test must be questioned.
The Molecular Weight Distribution of Succinoglycan Produced by <i>Sinorhizobium meliloti</i> Is Influenced by Specific Tyrosine Phosphorylation and ATPase Activity of the Cytoplasmic Domain of the ExoP Protein (2001)

It is thought that in the gram-negative soil bacterium Sinorhizobium meliloti the protein ExoP is involved in biosynthesis of the acidic exopolysaccharide succinoglycan (EPS I). The amounts and compositions of EPS I produced by mutants expressing ExoP proteins characterized by specific amino acid substitutions in the C-terminal cytoplasmic domain were analyzed. The cytoplasmic domain of the ExoP protein was shown to have ATPase activity. Mutations in the highly conserved Walker A ATP-binding motif prevented ATPase activity of the ExoP protein. Phenotypically, these mutations resulted in much lower levels of succinoglycan which consisted only of monomers of the octasaccharide repeating unit. The ExoP protein has similarities to proteins with autophosphorylating protein tyrosine kinase activity. We found that ExoP was phosphorylated on tyrosine and that site-directed mutagenesis of specific tyrosine residues in the cytoplasmic domain of ExoP resulted in an altered ratio of low-molecular-weight succinoglycan to high-molecular-weight succinoglycan.
Turbo Pascal: A Problem Solving Approach (1986)

Turbo Pascal: a problem solving approach , Turbo Pascal: a problem solving approach , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
Essential Factors for Control of the Equilibrium in the Reversible Rearrangement of M<sub>3</sub>N@<i>I<sub>h</sub></i>‐C<sub>80</sub> Fulleropyrrolidines: Exohedral Functional Groups versus Endohedral Metal Clusters (2014)

The effects of exohedral moieties and endohedral metal clusters on the isomerization of M3N@I(h)-C80 products from the Prato reaction through [1,5]-sigmatropic rearrangement were systematically investigated by using three types of fulleropyrrolidine derivatives and four different endohedral metal clusters. As a result, all types of derivatives provided the same ratios of the isomers for a given trimetallic nitride template (TNT) as the thermodynamic products, thus indicating that the size of the endohedral metal clusters inside C80 was the single essential factor in determining the equilibrium between the [6,6]-isomer (kinetic product) and the [5,6]-isomer. In all the derivatives, the [6,6]- and [5,6]-Prato adducts with larger metal clusters, such as Y3N and Gd3N, were equally stable, which is in good agreement with DFT calculations. The reaction rate of the rearrangement was dependent on both the substituent of exohedral functional groups and the endohedral metal-cluster size. Further DFT calculations and (13)C NMR spectroscopic studies were employed to rationalize the equilibrium in the rearrangement between the [6,6]- and [5,6]-fulleropyrrolidines.
A Bayesian approach to identification of gaseous effluents in passive LWIR imagery (2009)

Typically a regression approach is applied in order to identify the constituents present in a hyperspectral image, and the task of species identification amounts to choosing the best regression model. Common model selection approaches (stepwise and criterion based methods) have well known multiple comparisons problems, and they do not allow the user to control the experimet-wise error rate, or allow the user to include scene-specific knowledge in the inference process. A Bayesian model selection technique called Gibbs Variable Selection (GVS) that better handles these issues is presented and implemented via Markov chain monte carlo (MCMC). GVS can be used to simultaneously conduct inference on the optical path depth and probability of inclusion in a pixel for a each species in a library. This method flexibly accommodates an analyst's prior knowledge of the species present in a scene, as well as mixtures of species of any arbitrary complexity. A series of automated diagnostic measures are developed to monitor convergence of the Markov chains without operator intervention. This method is compared against traditional regression approaches for model selection and results from LWIR data from the Airborne Hyperspectral Imager (AHI) are presented. Finally, the applicability of this identification framework to a variety of scenarios such as persistent surveillance is discussed.
Hydraulic Fracturing for Reservoir Management: Production Enhancement, Scale Control and Asphaltine Prevention (2001)

Abstract Productivity in the Scott reservoir, located in the Central North Sea, is subject to impairment by scale and asphaltine disposition in the near wellbore region. Several intervention options have been attempted to restore the production potential (ie. re-perforation, fractured re-perforation, scale dissolution). These techniques have proved largely unsuccessful since due to the severity of the damage mechanism. This left hydraulic fracturing as the final option to bypass the damage and reconnect the wellbore to the productive sands. A technical and economic success was particularly desirable given the high operating costs associated with offshore operations and was achieved through a combination of well analysis and novel enabling technologies which are described in detail within this paper. The target well identified (J9) was selected based on criteria of production potential, drainage, pressure support and wellbore access. The fracture orientation plane was identified using existing open hole imaging logs allowing perforations to be oriented along the preferred fracture azimuth to minimize near wellbore effects during proppant placement and production. Specialized scale inhibitor impregnated proppant was employed to ensure deep and long term productivity protection for the fracture and tubulars. Placing a fracture in the reservoir also assisting in mitigating the effect of asphaltine disposition within the formation matrix. The large production string necessitated a new approach to lifting out the excess proppant within the wellbore. This was accomplished by reverse flow up a coiled tubing string in a process which was engineered to be a safe and effective.
Light Beam Deflector Performance: a Comparative Analysis (1974)

The performance of various types of analog light beam deflectors is summarized, and their relative positions in a deflector hierarchy are defined. The three types of deflectors considered are (1) mechanical (galvanometer) mirror deflectors, (2) acoustooptic deflectors, and (3) analog electrooptic deflectors. Material figures of merit are defined and compared, and the theoretical trade-off between speed and resolution is given for each type of deflector.
Ontology reuse and application (1998)

In this paper, we describe an investigation into the reuse and application of an existing ontology for the purpose of specifying and formally developing software for aircraft design. Our goals were to clearly identify the processes involved in the task, and assess the cost-effectiveness of reuse. Our conclusions are that (re)using an ontology is far from an automated process, and instead requires significant effort from the knowledge engineer. We describe and illustrate some intrinsic properties of the ontology translation problem and argue that fully automatic translators are unlikely to be forthcoming in the foreseeable future. Despite the effort involved, our subjective conclusions are that in this case knowledge reuse was cost-effective, and that it would have taken significantly longer to design the knowledge content of this ontology from scratch in our application. Our preliminary results are promising for achieving larger-scale knowledge reuse in the future.
Pulse compression acoustic microscopy at 750 MHz (1983)

A pulse compression acoustic microscope working at a centre frequency of 750 MHz is reported. The pulse expansion and compression is achieved by SAW dispersive delay lines. The transmitted chirp has a bandwidth of 150 MHz and a dispersion of 1 MHz/ns. A processing gain in excess of 10 dB has been achieved.
Hes6 Promotes Cortical Neurogenesis and Inhibits Hes1 Transcription Repression Activity by Multiple Mechanisms (2003)

Hes1 is a mammalian basic helix-loop-helix transcriptional repressor that inhibits neuronal differentiation together with corepressors of the Groucho (Gro)/Transducin-like Enhancer of split (TLE) family. The interaction of Hes1 with Gro/TLE is mediated by a WRPW tetrapeptide present in all Hairy/Enhancer of split (Hes) family members. In contrast to Hes1, the related protein Hes6 promotes neuronal differentiation. Little is known about the molecular mechanisms that underlie the neurogenic activity of Hes6. It is shown here that Hes6 antagonizes Hes1 function by two mechanisms. Hes6 inhibits the interaction of Hes1 with its transcriptional corepressor Gro/TLE. Moreover, it promotes proteolytic degradation of Hes1. This effect is maximal when both Hes1 and Hes6 contain the WRPW motif and is reduced when Hes6 is mutated to eliminate a conserved site (Ser183) that can be phosphorylated by protein kinase CK2. Consistent with these findings, Hes6 inhibits Hes1-mediated transcriptional repression in cortical neural progenitor cells and promotes the differentiation of cortical neurons, a process that is normally inhibited by Hes1. Mutation of Ser183 impairs the neurogenic ability of Hes6. Taken together, these findings clarify the molecular events underlying the neurogenic function of Hes6 and suggest that this factor can antagonize Hes1 activity by multiple mechanisms.
<i>In vitro</i> effects of NIPRISAN (Nix‐0699): a naturally occurring, potent antisickling agent (2002)

Among the various potential antisickling agents tested, hydroxyurea (HU) has been the most effective compound used for the treatment of patients with sickle cell disease (SCD). Although HU is effective in many patients, not all patients respond to this drug. In addition, some patients reveal adverse effects, including myelosuppression. In an attempt to find other effective agents with less adverse effects, we investigated the antisickling effect of NIPRISAN (Nix-0699). We found that Nix-0699, an ethanol/water extract from indigenous plants, has a strong antisickling effect. The concentration of Nix-0699 required to inhibit 50% of erythrocyte sickling was about 0.05 mg/ml. As for the kinetics of polymerization, addition of 0.05 microg/ml Nix-0699 caused a sixfold prolongation of the delay time prior to deoxy-Hb S polymerization when compared with that of untreated Hb S samples. The solubility of deoxy-Hb S significantly increased upon treatment with Nix-0699. Analysis of the effect of Nix-0699 on the Hb S oxygen affinity indicated that the drug slightly shifted the oxygen-dissociation curve of Hb S toward the left without any apparent change in the Hill coefficient. These results suggest that the antisickling properties of Nix-0699 may involve direct interaction with Hb molecules. Incubation of red blood cell (RBC) suspensions with various concentrations of Nix-0699 did not dehydrate RBCs, cause haemolysis, increase the amount of denatured Hb, nor form met-Hb. In view of the outcome of this study, Nix-0699 may be a promising option for the treatment of patients with SCD.
A Bismuth Germanate-Shielded Mercuric Iodide X-Ray Detector for Space Applications (1982)

Mercuric iodide (HgI2) solid state X-ray detectors have many unique advantages in their application to X-ray astronomy. HgI2 detectors operate at or near room temperature so that bulky and massive cryogenic coolers are not required. HgI2 detectors also combine a high quantum efficiency wish good room temperature energy resolution. Because of the excellent quantum efficiency (due to the high effective atomic number of HgI2), background contributions that scale as the volume of the detector (e.g. those due to neutrons and gamma rays) are lower than for other hard X-ray detectors with equivalent stopping power (e.g. germanium). To measure the actual background counting rates of HgI2 that can be achieved in a space-like environment, we have constructed an instrument containing a HgI2 detector shielded by a bismuth germanate (BGO) scintillator to be flown on a high altitude balloon (40 km altitude). The first flight of this instrument is planned later this year. In June 1980 an array of 11 HgI2 detectors shielded with sodium iodide was flown in a balloon experiment to observe the black hole candidate Cygnus X-1. The results from this flight have been previously reported.
Efficient Protection of the Register File in Soft-Processors Implemented on Xilinx FPGAs (2017)

Soft-processors implemented on SRAM-based FPGAs are increasingly being adopted in on-board computing for space and avionics applications due to their flexibility and ease of integration. However, efficient component-level protection techniques for these processors against radiation-induced upsets are necessary otherwise as system failures could manifest. A register file is one of the critical structures that stores vital information the processor uses related to user computations and program execution. In this paper, we present a fault tolerance technique for the register file of a microprocessor implemented in Xilinx SRAM-based FPGAs. The proposed scheme leverages the inherent implementation redundancy created by the FPGA design automation tools when mapping the register file to on-chip distributed memory. A parity-based error detection and switching logic are added for fault masking against single-bit errors. The proposed scheme has been implemented and evaluated in lowRISC, a RISC-V ISA soft-processor implementation. The effectiveness of the proposed scheme was tested using fault injection. The fault masking overhead required in terms of FPGA resources was much lower than a traditional Triple Modular Redundancy protection. Therefore, the proposed scheme is an interesting option to protect the register file of soft processors that are implemented in Xilinx FPGAs.
One Approach to Cyclic Carbonates via a Three-Component Cyclization of Phenacyl Bromide, CO<sub>2</sub>, and Aldehyde (2011)

A three-component cyclization reaction was designed for synthesizing cyclic carbonates in a single operation from phenacyl bromide, CO(2), and aldehyde in the presence of lithium diisopropylamide (LDA). These novel reactions were achieved under extremely mild conditions to generate the target products in moderate to good yields within 10 min.
Extremely Stable Thorium(IV) Dialkyl Complexes Supported by Rigid Tridentate 4,5-Bis(anilido)xanthene and 2,6-Bis(anilidomethyl)pyridine Ligands (2007)

A new NON-donor ligand, 4,5-bis(2,6-diisopropylanilino)-2,7-di-tert-butyl-9,9-dimethylxanthene (H2[XA2], 1), was prepared by palladium-catalyzed coupling of 2,6-diisopropylaniline with the appropriate dibromoxanthene precursor. Stable K2(dme)2[XA2] (2) and Na2[XA2] (3) salts were accessible by deprotonation of H2[XA2] with KH in dme or NaH in toluene. The thermally unstable lithium salt of McConville's 2,6-bis(2,6-diisopropylanilidomethyl)pyridine ligand (Li2[BDPP], 4) was isolated by deprotonation with nBuLi or LiCH2SiMe3 in hexanes at low temperature. Reaction of [ThCl4(dme)2] with Li2[BDPP] or M2(dme)n[XA2] resulted in the formation of pentagonal bipyramidal [LThCl2(dme)] complexes (L = BDPP, 5; XA2, 6). Subsequent reaction of 5 or 6 with LiCH2SiMe3 gave base- and salt-free dialkyl complexes, [LTh(CH2SiMe3)2] (L = BDPP, 7; XA2, 8), which are stable for days in solution at 90 and 70 °C, respectively. Complexes 5, 7, and 8 were also accessible by initial combination of 2 or 4 equiv of LiCH2SiMe3 with [ThCl4(dme)2], followed by addition of H2L. These reactions likely proceed by alkane elimination, but dialkyl or tetraalkyl thorium intermediates were not identified. The X-ray crystal structure of 8 suggests the presence of α-agostic C−H−Th interactions for both alkyl groups. In solution, 7 and 8 exhibit temperature-dependent 1JC,H coupling constants for ThCH2, demonstrating the presence of α-agostic interactions which become increasingly favored at lower temperature. Reaction of 5 with Li2[BDPP] at 0 °C or 7 with H2[BDPP] at 100 °C resulted in the formation of extremely sterically encumbered [Th(BDPP)2] (9), which adopts a highly distorted six-coordinate geometry with the four anilido groups arranged in an approximate tetrahedron around thorium. Bis-ligand complexes were not accessible with the XA2 platform, presumably due to increased ligand rigidity.
Microwave-Stimulated Drug Release from Liposomes (1985)

Microwaves (2450 MHz) are shown to stimulate the release of an aqueous chemotherapeutic drug from phospholipid vesicles. This effect occurs at temperatures below the membrane phase transition temperature of 41 degrees C where these liposomes are normally not leaky. In buffered saline, microwave exposure (60 mW/g) triggers the onset of drug release at 33 degrees C, whereas in plasma a near maximal release is observed as low as 27 degrees C. Significantly, this drug release is enhanced by oxygen and is attenuated by antioxidants. These results demonstrate that phospholipids in artificial membranes devoid of protein are influenced by nonionizing electromagnetic radiation, and that this interaction can be modulated by two physiologically important factors, plasma and oxygen. Such a permeability effect may provide a means for investigating microwave interactions with ordered membrane bilayers.