3,238 research outputs found

    Information and Communication Technologies and Informal Scholarly Communication: A Review of the Social Oriented Research

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    This article reviews and analyzes findings from research on computer mediated informal scholarly communication. Ten empirical research papers, which show the effects and influences of information & communication technologies (ICTs), or the effects of social contexts on ICTs use in informal scholarly communication, were analyzed and compared. Types of ICTs covered in those studies include e-mails, collaboratories, and electronic forums. The review shows that most of the empirical studies examined the ICTs use effects or consequences. Only a few studies examined the social shaping of ICTs and ICT uses in informal scholarly communication. Based on comparisons of the empirical findings this article summarizes the ICT use effects/consequences as identified in the studies into seven categories and discusses their implications

    Design, fabrication and characterization of monolithic embedded parylene microchannels in silicon substrate

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    This paper presents a novel channel fabrication technology of bulk-micromachined monolithic embedded polymer channels in silicon substrate. The fabrication process favorably obviates the need for sacrifical materials in surface-micromachined channels and wafer-bonding in conventional bulk-micromachined channels. Single-layer-deposited parylene C (poly-para-xylylene C) is selected as a structural material in the microfabricated channels/columns to conduct life science research. High pressure capacity can be obtained in these channels by the assistance of silicon substrate support to meet the needs of high-pressure loading conditions in microfluidic applications. The fabrication technology is completely compatible with further lithographic CMOS/MEMS processes, which enables the fabricated embedded structures to be totally integrated with on-chip micro/nano-sensors/actuators/structures for miniaturized lab-on-a-chip systems. An exemplary process was described to show the feasibility of combining bulk micromachining and surface micromachining techniques in process integration. Embedded channels in versatile cross-section profile designs have been fabricated and characterized to demonstrate their capabilities for various applications. A quasi-hemi-circular-shaped embedded parylene channel has been fabricated and verified to withstand inner pressure loadings higher than 1000 psi without failure for micro-high performance liquid chromatography (µHPLC) analysis. Fabrication of a high-aspect-ratio (internal channel height/internal channel width, greater than 20) quasi-rectangular-shaped embedded parylene channel has also been presented and characterized. Its implementation in a single-mask spiral parylene column longer than 1.1 m in a 3.3 mm × 3.3 mm square size on a chip has been demonstrated for prospective micro-gas chromatography (µGC) and high-density, high-efficiency separations. This proposed monolithic embedded channel technology can be extensively implemented to fabricate microchannels/columns in high-pressure microfludics and high-performance/high-throughput chip-based micro total analysis systems (µTAS)

    The Revelation of Foreign Carbon Emission Policies for Developing China Low-Carbon Economy

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    In present, developing the low-carbon economy is common recognized by the world. In order to achieve the aim of low-carbon economy, to reduce the carbon dioxide emissions is one of the most important measures. Nowadays, because of the large population, high energy intensity and the unreasonable energy structure based on fossil fuel, our country has faced an enormous pressure during the reducing carbon emissions process. Based on the current international applying carbon emission reduction proposals, we discussed the developed countries carbon emission reduction policies in detailed which includes the United States, Britain and Japan and etc. and in the meantime. Based on the above overseas developed countries experiences, the paper analyses  our country’s present situation of carbon emission reduction, finds the existing problems and put forward relevant recommendations. In brief, the research will provide some reference to build a low-carbon economy society of our country.Keywords:  low-carbon economy; CO2 emission; home and abroad carbon emission reduction policy; questions and measures Résumé:  A l'heure actuelle, le développement de l'économie à bas-carbone est généralement reconnu par le monde. Afin d'atteindre l'objectif de l'économie à bas-carbone, la réduction des émissions de dioxyde de carbone est l'une des mesures les plus importantes. De nos jours, en raison d'une population nombreuse, d'une intensité énergétique élevée et d'une structure énergétique déraisonnable basée sur les combustibles fossiles, notre pays a fait face à une pression énorme au cours du processus de réduction des émissions de carbone. Sur la base des propositions internationales de la réduction de l'émission de carbone actuellement appliquées, nous avons étudié les politiques de réduction des émissions de carboneles des pays développés en détail, qui comprend les États-Unis, la Grande-Bretagne, le Japon etc, et en même temps,  basé sur les expériences de ces pays développés ci-dessus, le document analyse la situation actuelle de notre pays en matière de la réduction des émissions de carbone, trouve des problèmes existants et propose des recommandations pertinentes. En bref, cette recherche fournira des références à la construction d'une société de l'économie bas-carbone dans notre pays.Mots-Clés:  économie à bas-carbone; émissions de CO2; politiques de la réduction de l'émission de carbone domestiques et étrangères; problèmes et mesure

    Parylene-strengthened thermal isolation technology for microfluidic system-on-chip applications

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    Here we reported a novel technology using parylene-cross-linking structure to achieve on-chip air-gap thermal isolation for microfluidic system-on-chip (SOC) applications. Two applications based on this technology, on-chip continuous-flow polymerase chain reaction (PCR) and on-chip temperature gradient liquid chromatography (LC) were successfully demonstrated. Device thermal performance in each example was characterized. Results showed that our technology not only provides excellent on-chip thermal isolation but also its simplicity of integration with other on-chip components makes versatile microfluidic SOC applications feasible

    Resonance-induced sensitivity enhancement method for conductivity sensors

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    Methods and systems for improving the sensitivity of a variety of conductivity sensing devices, in particular capacitively-coupled contactless conductivity detectors. A parallel inductor is added to the conductivity sensor. The sensor with the parallel inductor is operated at a resonant frequency of the equivalent circuit model. At the resonant frequency, parasitic capacitances that are either in series or in parallel with the conductance (and possibly a series resistance) is substantially removed from the equivalent circuit, leaving a purely resistive impedance. An appreciably higher sensor sensitivity results. Experimental verification shows that sensitivity improvements of the order of 10,000-fold are possible. Examples of detecting particulates with high precision by application of the apparatus and methods of operation are described

    Yield strength of thin-film parylene-C

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    For the first time, the yield strength of thin-film parylene-c is measured from membrane load-deflection experiments and surface profile analysis. To do so, the onset pressure which causes plastic deformation of the membrane is first experimentally measured. Then a new 2-step displacement model, together with the energy minimization technique, is developed to convert the onset pressure to the yield strength on the pre-stressed parylene membrane under a uniform pressure loading. The results depict a Yield Strength of 59 MPa (or 0.012 of strain) for thin-film parylene-c in comparison to 55 MPa reported by parylene vendor (measured from large samples). To double check with the result, the balloon model is further used to compare with the stress value from our model at the center of parylene membranes and good agreements are obtained

    Predicting protein-protein interactions in unbalanced data using the primary structure of proteins

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    <p>Abstract</p> <p>Background</p> <p>Elucidating protein-protein interactions (PPIs) is essential to constructing protein interaction networks and facilitating our understanding of the general principles of biological systems. Previous studies have revealed that interacting protein pairs can be predicted by their primary structure. Most of these approaches have achieved satisfactory performance on datasets comprising equal number of interacting and non-interacting protein pairs. However, this ratio is highly unbalanced in nature, and these techniques have not been comprehensively evaluated with respect to the effect of the large number of non-interacting pairs in realistic datasets. Moreover, since highly unbalanced distributions usually lead to large datasets, more efficient predictors are desired when handling such challenging tasks.</p> <p>Results</p> <p>This study presents a method for PPI prediction based only on sequence information, which contributes in three aspects. First, we propose a probability-based mechanism for transforming protein sequences into feature vectors. Second, the proposed predictor is designed with an efficient classification algorithm, where the efficiency is essential for handling highly unbalanced datasets. Third, the proposed PPI predictor is assessed with several unbalanced datasets with different positive-to-negative ratios (from 1:1 to 1:15). This analysis provides solid evidence that the degree of dataset imbalance is important to PPI predictors.</p> <p>Conclusions</p> <p>Dealing with data imbalance is a key issue in PPI prediction since there are far fewer interacting protein pairs than non-interacting ones. This article provides a comprehensive study on this issue and develops a practical tool that achieves both good prediction performance and efficiency using only protein sequence information.</p
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