57 research outputs found

    Evaluation of the thermal and hydraulic performances of a very thin sintered copper flat heat pipe for 3D microsystem packages

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    The reported research work presents numerical studies validated by experimental results of a flat micro heat pipe with sintered copper wick structure. The objectives of this project are to produce and demonstrate the efficiency of the passive cooling technology (heat pipe) integrated in a very thin electronic substrate that is a part of a multifunctional 3-D electronic package. The enhanced technology is dedicated to the thermal management of high dissipative microsystems having heat densities of more than 10W/cm2. Future applications are envisaged in the avionics sector. In this research 2D numerical hydraulic model has been developed to investigate the performance of a very thin flat micro heat pipe with sintered copper wick structure, using water as a refrigerant. Finite difference method has been used to develop the model. The model has been used to determine the mass transfer and fluid flow in order to evaluate the limits of heat transport capacity as functions of the dimensions of the wick and the vapour space and for various copper spheres radii. The results are presented in terms of liquid and vapour pressures within the heat pipe. The simulated results are validated by experiments and proved that the method can be further used to predict thermal performance of the heat pipe and to optimise its design.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/EDA-Publishing

    Innovative Laboratories for Teaching on Photovoltaic Generation in Higher Education

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    The production of energy from Photovoltaic technology is becoming more and more relevant. Therefore, it is essential that academic world focuses attention on this topic in order to properly teach and transmit knowledge, skills and abilities. These ones are very useful in work activities. The academic course 'Photovoltaic Power Generation' aims to better explain theoretical aspects by practical activities which require the implementation of innovative laboratories for learning. This paper presents the guidelines for replication of laboratory practices (twin labs), already offered to Italian students, in the context of the project EU-MONG

    Innovative teaching on photovoltaic generation

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    One of the most important technologies for the renewable energy production is the Photovoltaic (PV) one. In the last decades, the enormous growth in the world of Photovoltaic installation capacity, and future trends, makes the knowledge of this topic fundamental for engineers working in the energy field with this competence, and not only. Thus, for students enrolled in industrial engineering courses, appropriate and innovative teaching methods are necessary. This paper aims to describe the structure of the course 'Photovoltaic Power Generation' in which solar resource and the photovoltaic generators, including power electronics, are explained. The topics of traditional theoretical lectures are presented, with the links to practical exercises and laboratories

    ANTIMICROBIAL ACTIVITY OF LACTOBACILLUS PLANTARUM AGAINST PATHOGENIC AND FOOD SPOILAGE MICROORGANISMS: A REVIEW

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    One of the most important properties of probiotic bacteria is their antimicrobial activity against many species of microorganisms which could be useful to prevent food spoilage caused by certain sensitive bacteria and fungi as well as to control the speed of propagation of potentially pathogenic bacteria by probiotic application. Lactobacillus plantarum is considered one of the probiotic bacteria with broad-est spectrum of antibacterial activity which makes it useful in veterinary, human medicine and food industry. According to a number of studies Lactobacillus plantarum exerts inhibitory activity against ma¬ny Gram-positive and Gram-negative bacteria – Escherichia coli (including E. coli 0157:H7), Pseudomonas aeruginosa, Helicobacter pylori, Yersinia enterocolitica, Campylobacter jejuni, Lis-teria monocytogenes, Staphylococcus aureus, Klebsiella, Salmonella, Shigella, Bacillus, Clostridium, Enterococcus, Lactobacillus spp., etc. as well as a number of moulds and yeasts – Aspergillus, Fusa-rium, Mucor, Candida spp., etc. The main antibacterial compounds of Lactobacillus plantarum are the bacteriocins and organic acids whereas the antifungal compounds are the organic acids, hydroxy fatty acids and cyclic dipeptides. Because of the high antifungal activity of some L. plantarum strains against food spoilage microorganisms they can be used as effective biopreservatives in food industry. Also, some L. plantarum strains could be applied as supporting therapeutic agents in treatment of infections caused by the corresponding susceptible microorganisms

    Anaesthetic considerations of adults with Morquio's syndrome - a case report

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    <p>Abstract</p> <p>Background</p> <p>The anaesthetic management of patients with Morquio syndrome is complicated by a number of factors including odontoid hypoplasia, atlantoaxial instability, thoracic kyphosis, and deposition of mucopolysaccharides in the soft tissue of the oropharnyx.</p> <p>Case presentation</p> <p>Herein we describe the anaesthetic considerations and management of a 26 year old adult with Morquio syndrome, who presented for an elective hip replacement.</p> <p>Conclusion</p> <p>This report details an awake fiberoptic intubation in an adult with Morquio syndrome. We recommend that this approach be considered in patients with Morquio syndrome undergoing general anaesthesia.</p

    A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin

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    We produced a composite depth scale and chronology for Site U1385 on the SW Iberian Margin. Using log(Ca/Ti) measured by core scanning XRF at 1-cm resolution in all holes, a composite section was constructed to 166.5 meters composite depth (mcd) that corrects for stretching and squeezing in each core. Oxygen isotopes of benthic foraminifera were correlated to a stacked δ^18O reference signal (LR04) to produce an oxygen isotope stratigraphy and age model. Variations in sediment color contain very strong precession signals at Site U1385, and the amplitude modulation of these cycles provides a powerful tool for developing an orbitally-tuned age model. We tuned the U1385 record by correlating peaks in L* to the local summer insolation maxima at 37^oN. The benthic δ^18O record of Site U1385, when placed on the tuned age model, generally agrees with other time scales within their respective chronologic uncertainties. The age model is transferred to down-core data to produce a continuous time series of log(Ca/Ti) that reflect relative changes of biogenic carbonate and detrital sediment. Biogenic carbonate increases during interglacial and interstadial climate states and decreases during glacial and stadial periods. Much of the variance in the log(Ca/Ti) is explained by a linear combination of orbital frequencies (precession, tilt and eccentricity), whereas the residual signal reflects suborbital climate variability. The strong correlation between suborbital log(Ca/Ti) variability and Greenland temperature over the last glacial cycle at Site U1385 suggests that this signal can be used as a proxy for millennial-scale climate variability over the past 1.5 Ma. Millennial climate variability, as expressed by log(Ca/Ti) at Site U1385, was a persistent feature of glacial climates over the past 1.5 Ma, including glacial periods of the early Pleistocene (‘41-kyr world’) when boundary conditions differed significantly from those of the late Pleistocene (‘100-kyr world’). Suborbital variability was suppressed during interglacial stages and enhanced during glacial periods, especially when benthic δ^18O surpassed ~ 3.3-3.5‰. Each glacial inception was marked by appearance of strong millennial variability and each deglaciation was preceded by a terminal stadial event. Suborbital variability may be a symptomatic feature of glacial climate or, alternatively, may play a more active role in the inception and/or termination of glacial cycles.This research was supported by the Natural Environmental Research Council Grant NE/K005804/1 to DH and LS and NE/J017922/1 to DH.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.gloplacha.2015.07.00

    A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin

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    Variations in sediment color contain very strong precession signals at Site U1385, and the amplitude modulation of these cycles provides a powerful tool for developing an orbitally-tuned age model. We tuned the U1385 record by correlating peaks in L* to the local summer insolation maxima at 37°N. The benthic δ18O record of Site U1385, when placed on the tuned age model, generally agrees with other time scales within their respective chronologic uncertainties. The age model is transferred to down-core data to produce a continuous time series of log(Ca/Ti) that reflect relative changes of biogenic carbonate and detrital sediment. Biogenic carbonate increases during interglacial and interstadial climate states and decreases during glacial and stadial periods. Much of the variance in the log(Ca/Ti) is explained by a linear combination of orbital frequencies (precession, tilt and eccentricity), whereas the residual signal reflects suborbital climate variability. The strong correlation between suborbital log(Ca/Ti) variability and Greenland temperature over the last glacial cycle at Site U1385 suggests that this signal can be used as a proxy for millennial-scale climate variability over the past 1.5 Ma. Millennial climate variability, as expressed by log(Ca/Ti) at Site U1385, was a persistent feature of glacial climates over the past 1.5 Ma, including glacial periods of the early Pleistocene (‘41-kyr world’) when boundary conditions differed significantly from those of the late Pleistocene (‘100-kyr world’). Suborbital variability was suppressed during interglacial stages and enhanced during glacial periods, especially when benthic δ18O surpassed ~ 3.3–3.5‰. Each glacial inception was marked by appearance of strong millennial variability and each deglaciation was preceded by a terminal stadial event. Suborbital variability may be a symptomatic feature of glacial climate or, alternatively, may play a more active role in the inception and/or termination of glacial cycles
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