Search results for "PIP"
showing 10 items of 1156 documents
Thermal conductivity of disperse insulation materials and their mixtures
2017
Development of new, more efficient thermal insulation materials is a key to reduction of heat losses and contribution to greenhouse gas emissions. Two innovative materials developed at Thermeko LLC are Izoprok and Izopearl. This research is devoted to experimental study of thermal insulation properties of both materials as well as their mixture. Results show that mixture of 40% Izoprok and 60% of Izopearl has lower thermal conductivity than pure materials. In this work, material thermal conductivity dependence temperature is also measured. Novel modelling approach is used to model spatial distribution of disperse insulation material. Computational fluid dynamics approach is also used to est…
A computational framework for low-cycle fatigue in polycrystalline materials
2021
Abstract A three-dimensional framework for low-cycle fatigue analysis of polycrystalline aggregates is proposed in this work. First, a cohesive law coupling plasticity and damage is developed for modelling cycle-by-cycle degradation of material interfaces up to complete de-cohesion and failure. The law may model both quasi-static degradation under increasing monotonic load and degradation under cyclic loading, through a coupled plasticity-damage model whose activation and flow rules are formulated in a thermodynamically consistent framework. The proposed interface laws have been then implemented and coupled with a multi-region boundary element formulation, with the aim of analysing low-cycl…
Experimental characterization of a novel configuration of thermoelectric refrigerator with integrated finned heat pipes
2021
Abstract Thermoelectric refrigerating systems (TER) are environment-friendly technologies. They have several advantages such as low maintenance costs, are less cumbersome and long lifetime. However, these systems have low coefficient of performance and are limited in achieving low temperature levels. This study investigates a new configuration of TE refrigerator employing a novel arrangement of heat sinks with integrated flat and finned heat pipes. A mathematical model is firstly developed to predict transient temperatures and cooling limit time. An experimental characterization is then performed and it includes optimization of energy consumption, cooling time, temperature levels and TE ref…
RNACache: Fast Mapping of RNA-Seq Reads to Transcriptomes Using MinHashing
2021
The alignment of reads to a transcriptome is an important initial step in a variety of bioinformatics RNA-seq pipelines. As traditional alignment-based tools suffer from high runtimes, alternative, alignment-free methods have recently gained increasing importance. We present a novel approach to the detection of local similarities between transcriptomes and RNA-seq reads based on context-aware minhashing. We introduce RNACache, a three-step processing pipeline consisting of minhashing of k-mers, match-based (online) filtering, and coverage-based filtering in order to identify truly expressed transcript isoforms. Our performance evaluation shows that RNACache produces transcriptomic mappings …
User-oriented evaluation of mechanical single-channel axial pipettes.
2013
Hand tools should be designed so that they are comfortable to use, fit the hand and are user-oriented. Six different manual, single-channel axial pipettes were evaluated for such objective outcomes as muscular activity, wrist postures and efficiency, as well as for subjective outcomes concerning self-assessed features of pipette usability and musculoskeletal strain. Ten experienced laboratory employees volunteered for the study. The results showed that light and short pipettes with better tool comfort resulted in reduced muscular activity and perceived musculoskeletal strain when they were compared with a long and heavy pipette. There were no differences in the efficiency between the differ…
Sildenafil protects epithelial cell through the inhibition of xanthine oxidase and the impairment of ROS production
2009
Recent reports suggest that xanthine oxidase (XO), a modified form of the native xanthine dehydrogenase enzyme, plays an important role in various forms of ischemic and vascular injuries, inflammatory diseases, and chronic heart failure. The XO inhibitors allopurinol and its oxidation product oxypurinol held considerable promises in the treatment of these conditions both in experimental animals and in human clinical trials. More recently, an endothelium-based protective effect of sildenafil, a well-known type-5 phosphodiesterase inhibitor, has been reported in preconditioning prior to ischemia/reperfusion in healthy human subjects. Based on the structural similarities between allopurinol an…
The effect of excipients on the stability and phase transition rate of xylazine hydrochloride and zopiclone
2015
The compatibility of thermodynamically unstable polymorph of two active pharmaceutical compounds (xylazine hydrochloride form X and zopiclone form C) with different excipients was investigated. The effects of the excipient and its amount in the sample on the thermal properties and possible chemical interactions were studied. The most commonly used excipients in the pharmaceutical industry - calcium carbonate, lactose hydrate, cellulose, magnesium stearate hydrate and calcium stearate hydrate were selected for this study. The dependence of the phase transition rate from an unstable to a more stable polymorph on the excipients and their amounts in the initial sample was analysed at 80°C, and …
Cytotoxicity and modes of action of four Cameroonian dietary spices ethno-medically used to treat cancers: Echinops giganteus, Xylopia aethiopica, Im…
2013
Abstract Ethnopharmacological relevance. Echinops giganteus , Imperata cylindrica , Piper capense and Xylopia aethiopica are four medicinal spices used in Cameroon to treat cancers. Aim of the study The above plants previously displayed cytotoxicty against leukemia CCRF-CEM and CEM/ADR5000 cell lines as well as human pancreatic MiaPaCa-2 cells. The present study aims at emphasizing the study of the cytotoxicity and the modes of action of the above plants on a panel of ten cancer cell lines including various sensitive and drug-resistant phenotypes. The study has been extended to the isolation of the bioactive constituents from Echinops giganteus . Materials and methods The cytotoxicity of th…
Smart camera design for realtime High Dynamic Range imaging
2011
International audience; Many camera sensors suffer from limited dynamic range. The result is that there is a lack of clear details in displayed images and videos. This paper describes our approach to generate high dynamic range (HDR) from an image sequence while modifying exposure times for each new frame. For this purpose, we propose an FPGA-based architecture that can produce a real-time high dynamic range video from successive image acquisition. Our hardware platform is build around a standard low dynamic range CMOS sensor and a Virtex 5 FPGA board. The CMOS sensor is a EV76C560 provided by e2v. This 1.3 Megapixel device offers novel pixel integration/readout modes and embedded image pre…
Asserting the Precise Position of 3D and Multispectral Acquisition Systems for Multisensor Registration Applied to Cultural Heritage Analysis
2012
International audience; We present a novel method to register multispectral acquisitions on a 3D model. The method is based on the external tracking of the acquisition systems using close-range photogrammetric techniques: multiple calibrated cameras simultaneously observe the successive acquisition systems in use. The views from these cameras are used to precisely determine the position of each acquisition system. All datasets can then be projected in the same coordinate system. The registration is thus independent from the quality and content of the data. This method is well suited to the study of cultural heritage or any other application where we do not wish to place targets on the objec…