gebhart/patrepeval huggingface dataset:
Integration of a UV curable polymer lens and MUMPs structures on a SOI optical bench (2007)

This work presents the design concept of integrating a polymer lens, poly-Si MUMPs and single-crystal-silicon HARM structures on a SOI wafer to form a silicon optical bench. This approach enables the monolithic integration of various optical components on the wafer so as to improve the design flexibility of the silicon optical bench. Fabrication processes, including surface and bulk micromachining on the SOI wafer, have been established to realize bi-convex spherical polymer lenses with in-plane as well as out-of-plane optical axes. In addition, a micro device consisting of an in-plane polymer lens, a thick fiber holder and a mechanical shutter driven by an electrothermal actuator is also demonstrated using the present approach. In summary, this study significantly improves the design flexibility as well as the functions of SiOBs.
A fingerprint based bio‐cryptographic security protocol designed for client/server authentication in mobile computing environment (2010)

Abstract With fast evolution of mobile devices and mobile network, the need of protecting user sensitive information locally and performing secure user authentication remotely become evermore increasing. Bio‐cryptography is emerging as a powerful solution which can combine the advantages of conventional cryptography and biometric security. In this paper, we present an efficient bio‐cryptographic security protocol designed for client/server authentication in current mobile computing environment, with a reasonable assumption that server is secure. In this protocol, fingerprint biometric is used in user verification, protected by a computationally efficient Public Key Infrastructure (PKI) scheme, Elliptic Curve Cryptography (ECC). The genuine fingerprint information is hidden in the feature vault which is the mixture of genuine and chaff features. Fingerprint features are not only used for biometric verification but also for cryptographic key generation. Our security analysis shows that the proposed protocol can provide a secure and trustworthy authentication of remote mobile users over insecure network. Experimental results on public domain database show an acceptable verification performance. We also tested the computational costs and efficiency of our protocol on the CLDC emulator using Java ME (previous J2ME) programming technology. The simulation results prove that the proposed protocol suits current mobile environment. Copyright © 2010 John Wiley & Sons, Ltd.
Morphological study of supported chromium polymerization catalysts. 1. Activation (1987)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMorphological study of supported chromium polymerization catalysts. 1. ActivationE. L. Weist, Ahmed H. Ali, and W. C. ConnerCite this: Macromolecules 1987, 20, 3, 689–693Publication Date (Print):March 1, 1987Publication History Published online1 May 2002Published inissue 1 March 1987https://doi.org/10.1021/ma00169a039RIGHTS & PERMISSIONSArticle Views74Altmetric-Citations-LEARN 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 InReddit PDF (2 MB) Get e-Alerts Get e-Alerts
Mast Cells and Inflammatory Heart Disease: Potential Drug Targets (2008)

Inflammation underlies the pathogenesis of many common cardiovascular diseases (CVD) such as myocardial infarction, atherosclerosis, myocarditis and dilated cardiomyopathy. Allergic disorders like allergic rhinitis and asthma, both chronic inflammatory conditions, have recently been linked to increased CVD and death. Studies have found that increased IgE levels, eosinophilia, positive skin-prick tests, self-reported asthma and enzymes that regulate leukotriene synthesis (5-lipoxygenase) predict a high risk for atherosclerosis, stroke and myocardial infarction. Mast cells (MCs), cells involved in the pathogenesis of allergy and asthma, are emerging as key players in the regulation of inflammation and fibrosis in the heart and vasculature. Our laboratory has found that MC numbers are increased in mice susceptible to developing chronic dilated cardiomyopathy. The fibrosis associated with chronic heart disease is increased by MC degranulation. MCs can also act as antigen-presenting cells increasing inflammation in the heart through Toll-like receptor-4 signaling and increased proinflammatory cytokine production. Similar inflammatory mechanisms are observed for myocarditis and atherosclerosis. Many of the drugs currently used to reduce heart disease act on mediators/ pathways downstream of MC degranulation. An improved understanding of the role of MCs in regulating inflammation and fibrosis will enable researchers and clinicians to better treat heart disease.
Patterns of electroconvection in a nematic liquid crystal (1998)

We present a survey of pattern formation in electroconvection of the nematic liquid crystal 4-ethyl-2-fluoro-4${}^{\ensuremath{'}}$-[2-(trans-4-pentylcyclohexyl)-ethyl] biphenyl (I52) as a function of three control parameters: the applied voltage, applied frequency, and electrical conductivity of the sample. The patterns are dominated by oblique-roll states. Over the lower range of conductivity, the initial transition is a supercritical Hopf bifurcation which leads to four degenerate modes: right- and left-traveling zig and zag rolls. For higher values of the conductivity, the primary instability is a subcritical bifurcation to a single set of stationary oblique rolls. The convecting states exhibit a rich variety of patterns as a result of the interactions between the four modes, including states of spatiotemporal chaos and localized states.
Best Practices and Lessons Learned from more than 1,000 Treatments: Revival of Mature Fields by Hydraulic Fracturing in Khalda Ridge, Egypt's Western Desert (2016)

Abstract Most of Egypt's Western Desert reservoirs are characterized to have low permeability and heterogeneous, poor rock quality. In the early development stages only layers with high permeability were produced, while the low-permeability, low-porosity layers were not considered economic. As these high-permeability layers became more mature and declined in production, tight layers became the operator's alternative choice to unlock the enormous amounts of hydrocarbons still present in these rocks and achieve economical production targets from these marginal fields. Hydraulic fracturing technology enabled us to unlock the potential of these challenging layers that were previously considered uneconomical. Hydraulic fracturing is now a common practice, even pushing extremes such as deeper, high-temperature and high-pressure wells in the Western Desert. The incremental production gains from these challenging layers have encouraged operators to invest. Currently, hydraulic fracturing is routinely conducted for all new production and injection wells and is reconsidered for the old wells. Completion practices, candidate selection criteria, perforation and design strategies, and workflows were revised to address these new challenging conditions and reservoir complexities with hydraulic fracturing technology. For example, vertical completions were replaced by horizontal multistage fracturing completions to increase the reservoir contact. State-of-the-art software was used to simplify decisions on fracture initiation points across heterogeneous reservoirs. Different technologies, alternative to conventional perforating, were introduced to enhance the proppant placement, post-fracturing production, and operational efficiency. This paper provides a review of hydraulic fracturing in Egypt's Western Desert. The hydraulic fracturing technique has been used to develop mature fields and challenging formations of Egypt since the early 1990s. More than 1,000 treatments targeting low- to medium- permeability rocks were pumped in Khalda Ridge. Correlation between mechanical properties, reservoir properties, essential fracturing design, completions, and operational parameters were established over time to help other operators that intend to apply hydraulic fracturing to their assets. Case histories are also provided, demonstrating different fracturing techniques for extreme conditions. In this paper we detail the progress related to completion practices and technologies to revive the mature fields of Egypt.
Synaptic Cysteine Sulfhydryl Groups as Targets of Electrophilic Neurotoxicants (2006)

Many structurally diverse chemicals (e.g., acrylamide, 2,4-dithiobiuret, methylmercury) are electrophiles and cause synaptic dysfunction by unknown mechanisms. The purpose of this Forum review is to discuss the possibility that highly nucleophilic cysteine thiolate groups within catalytic triads of synaptic proteins represent specific and necessary targets for electrophilic neurotoxicants. Most of these toxicants share the ability to adduct or otherwise modify nucleophilic sulfhydryl groups. It is also now recognized that synaptic activity is regulated by the redox state of certain cysteine sulfhydryl groups on proteins. Electrophilic neurotoxicants might, therefore, produce synaptic toxicity by modifying these thiols. Because most proteins contain cysteine residues, target specificity is an issue that significantly detracts from the mechanistic validity of this hypothesis. However, recent research indicates that these thiolates are receptors for the endogenous nitric oxide (NO) pathway and that subsequent reversible S-nitrosylation finely regulates a broad spectrum of synaptic activities. We hypothesize that electrophilic neurotoxicants selectively adduct/derivatize NO-receptor thiolates in catalytic triads and that the resulting loss of fine gain control impairs neurotransmission and produces neurotoxicity. This proposal has mechanistic implications for a large class of electrophilic chemicals used in the agricultural and industrial sectors. In addition, research based on this hypothesis could provide mechanistic insight into neurodegenerative conditions such as Parkinsonism and Alzheimer's disease that presumably involve endogenous production of neurotoxic electrophiles (e.g., acrolein, 4-hydroxy-2-nonenal). The proposed mechanism of electrophilic neurotoxicants represents a new and exciting experimental framework for mechanistic research in human neuropathological conditions associated with toxicant exposure or disease-based processes.
Phase-Transition Temperatures and Piezoelectric Properties of (Bi 1/2 Na 1/2 )TiO 3 - (Bi 1/2 Li 1/2 )TiO 3 -(Bi 1/2 K 1/2 )TiO 3 Lead-Free (2007)

The phase-transition temperatures and piezo- electric properties of (Bi1 2Na1 2)TiO3- (Bi1 2Li1 2) TiO3- (Bi1 2K1 2)TiO3 ( + + = 1) (abbreviated as BNLKT100 -100 ) ceramics were investigated. These ceramics were prepared using a conventional ceramic fabrication process. The phase-transition temperatures such as depolarization temperatures ,r hombohedral- tetragonal phase transition temperature ,a nd dielectric-maximum temperature were determined us- ing electrical measurements such as dielectric and piezo- electric properties. The X-ray powder diffraction patterns of BNLKT100 -100 show the morphotropic phase bound- ary (MPB) between rhombohedral and tetragonal at ap- proximately =0 20, and the piezoelectric properties show the maximum at the MPB. The electromechanical coupling factor 33, piezoelectric constant 33 and of BNLKT4- 20 and BNLKT8-20 were 0.603, 176 pC/N, and 171 C, and 0.590, 190 pC/N, and 115 C, respectively. In addition, the relationship between 33 and of tetragonal side and rhombohedral side for BNLKT4-100 and BNLKT8-100 were presented. Considering both high and high 33, the tetragonal side of BNLKT4-100 is thought to be the superior composition. The 33 and of BNLKT4-28 were 135 pC/N and 218 C, respectively. Moreover, this study revealed that the variation of is related to the varia- tion of lattice distortion such as rhombohedrality 90- and tetragonality .
Digital cash and the surveillance society : negotiating identification in new consumer payment systems (1998)

Transaction generated information is a primary resource in identification, classification, and discrimination. New consumer payment systems offer different possibilities of personal information generation. Social construction of technology theory suggests that the frames through which groups understand technological systems constrain and structure use of those systems. Interested actors will attempt to mobilize particular frames, hence particular practices. This dissertation uses discourse analysis and interview analysis to study the framing tactics of activists as they attempt to influence understandings of three new consumer payment systems. It finds four framing strategies. Each is analyzed according to its use of two cultural resources--existing understandings of cash as an exemplar and the issue of privacy as a mobilizing concern. The first strategy, coherent segregation, extends the existing frames of target groups without linking those frames or significantly altering them. Activists using this tactic exploit multiple, even contradictory, understandings of cash and privacy. This tactic requires an awareness of the ambiguity of the object system, surveillance capacity over the target groups, faculty with the discursive structures of the target social groups, and the ability to segregate messages--to ensure strategic silences. The second tactic, globalization, creates a new technological frame which subsumes and transforms existing frames. Activists using this tactic address multiple understandings of cash and privacy, but link those understandings within a global frame to clarify and reconcile their contradictions. The new global frame must include a strong motivation for its acceptance, such as the correction of a hitherto insoluble injustice. The research suggests that privacy issues may be inadequate to provide such motivation. The third tactic, domination, creates a new frame or amplifies an existing frame and attempts to replace or dominate other frames. Actors using this tactic may depend less on discursive power and more on other forms of power: for example, market forces, technical efficiency, or adoption by dominant groups. Actors using this tactic may be vulnerable to oppositional power dynamics, both discursive and structural. The fourth tactic, silence, maintains status quo and relies for its success primarily on existing, non-discursive power structures.
From Alcohols to Hyperbranched Polymers:  The Influence of Differently Branched Additives on the Vapor−Liquid Equilibria of Selected Azeotropic Systems (2003)

Ternary vapor−liquid equilibria (VLE) of selected aqueous azeotropic systems in the presence of differently branched hydroxyl functional components (additives) have been measured. Three azeotropic mixtures, ethanol + water, 2-propanol + water, and tetrahydrofuran + water, were chosen. The additives used were nonvolatile hyperbranched polymers such as polyesters, polyesteramides, and polyethers as well as low-volatility alcohols (1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, 1,12-dodecanediol, 1,2,3-propanetriol, 1,2,3,4-butanetetrol, and 2,4-dimethyl-3-pentanol). The experimental results show the influence of differently structured additives, that is, their degree of branching, molecular weight, and number of functionalities, on the VLE of the respective azeotropic system. For the investigated polymer solutions, the extent of inter- and intramolecular hydrogen bond formation has a dominant impact on the solvent activity and therefore determines the partition coefficients and the relative volatilities. Due to their remarkable solution properties, hyperbranched polymers such as hyperbranched polyesteramides or hyperbranched polyglycerols can be used for the separation of azeotropic mixtures by means of extractive distillation.
Optimized Lentiviral Vectors for HIV Gene Therapy: Multiplexed Expression of Small RNAs and Inclusion of MGMTP140K Drug Resistance Gene (2014)

Gene therapy with hematopoietic stem and progenitor cells is a promising approach to engineering immunity to human immunodeficiency virus (HIV) that may lead to a functional cure for acquired immunodeficiency syndrome (AIDS). In support of this approach, we created lentiviral vectors with an engineered polycistronic platform derived from the endogenous MCM7 gene to express a diverse set of small antiviral RNAs and a drug resistance MGMT(P140K) marker. Multiple strategies for simultaneous expression of up to five RNA transgenes were tested. The placement and orientation of each transgene and its promoter were important determinants for optimal gene expression. Antiviral RNA expression from the MCM7 platform with a U1 promoter was sufficient to provide protection from R5-tropic HIV in macrophages and resulted in reduced hematopoietic toxicity compared with constructs expressing RNA from independent RNA polymerase III promoters. The addition of an HIV entry inhibitor and nucleolar TAR RNA decoy did not enhance antiviral potency over constructs that targeted only viral RNA transcripts. We also demonstrated selective enrichment of gene-modified cells in vivo using a humanized mouse model. The use of these less toxic, potent anti-HIV vectors expressing a drug selection marker is likely to enhance the in vivo efficacy of our stem cell gene therapy approach in treating HIV/AIDS.
Synthesis of thiazolidinones from 1,4-dithiocyanatobut-2-enes and their use as masked 2-amino-1-mercaptobut-3-enes (1987)

1,4-Dithiocyanatobut-2-enes can be readily prepared from either the appropriate buta-1,3-diene or 1,4-dihalogenobut-2-ene, and give, on heating in methanol, thiazolidinones via[3,3]-sigmatropic rearrangement. The initial products of this rearrangement, vicinal isothiocyanatothiocyanates, can be trapped with other nucleophiles: in benzene, amines react to afford dihydrothiazoles. The thiazolidinones are readily transformed to 2-amino-1-mercaptobut-3-enes, the corresponding carbamate esters and to the analogous disulphides. Reaction of these aminothiols with aldehydes and ketones, and with methyl bromoacetate afford respectively thiazolidines and thiomorpholinones.
Gate stack resistance and limits to CMOS logic performance (2013)

The input resistance of CMOS circuits is a measurable limit on the performance of typical static CMOS logic gates. A survey of measured data from five generations of CMOS technology including polysilicon oxynitride gate first stacks (P-SiON) high-K metal gate first stacks (GF) and high-K replacement metal gate stacks (RMG) shows a trend of increasing gate resistance. We show DC and RF measurements may be analyzed to determine horizontal and vertical components of gate resistance in terms of scalable parameters and the sum of these components may be represented by a compact scalable equation representing total gate resistance. Gate resistance increases at advanced nodes and affects typical logic performance of a 20nm replacement gate technology.
An ultra low power CMOS motion detector (2009)

This paper proposes a CMOS motion detector which consumes extremely low power. CMOS image sensor pixels in this motion detector senses image and image data are converted into just one-bit by using clocked comparators. Because using one-bit data makes additional processing units simple, total power consumption of this CMOS motion detector can be reduced. That is, internal memory which is composed of the clocked gating schemes based on the flip-flop and XOR function which compares a current image with a previous one in order to detect a difference are main features for the simple structure. However one-bit data process has a critical problem that it is hard to detect a motion when image inclines to white or block. For solving this problem, reference voltage controller which makes about the same proportion of white and block is implemented. We have made a test module of the proposed CMOS motion detector and tested it by using FPGA. According to the measurement result, total power consumption is about 32 ¿W at 3.3 V. Therefore, this motion detector can be useful for portable battery-operated devices.
The effect of release-etch holes on the electromechanical behaviour of MEMS structures (2002)

When wet etches are used to release a large microstructural element, it is common practice to distribute small holes in the microstructure to promote under-etching and release, and for reduction of squeezed-film damping. In this paper, we demonstrate that while the mechanical properties are strongly affected by the presence of etch holes, because of fringing-field effects at the edges of the etched holes, the electrostatic-force behaviour of structural elements with an array of small etched holes is nearly that of an unetched element. This leads to an "effective medium" approximation for the mechanical material that can then be used with standard electrostatic actuation models to give good predictions of electromechanical behaviour. Comparison with experimental device behaviour shows the validity of this approach.
Charging in the IP Multimedia Subsystem: A Tutorial (2007)

The IP multimedia subsystem enables a service-rich communication landscape and the convergence of mobile and fixed networks. However, IMS solutions can succeed only when charging for these new services is supported in a flexible and efficient manner. To meet the new challenges, the 3GPP recently introduced a generic charging framework. In this article we give a short overview of the 3GPP charging framework and then describe how IMS charging works with in this framework. To illustrate IMS charging, we discuss an IMS scenario in which three persons with different payment methods conduct a teleconference.