Analysis of a Hybrid Solar Collector Photovoltaic Thermal (PVT)

AbstractA solar hybrid photovoltaic thermal (PVT) is a set of combined solar collector, which consists of a photovoltaic module (PV) for the conversion of electrical energy and solar plan for the high efficiency thermal energy conversion, in the same frame.An attempt made to analyze the hybrid solar collector using Computational Fluid Dynamics (CFD) to simulate the PVT solar collector to a better understanding of heat transfer capabilities in this type of systems. In the present work, the fluid flow and heat transfer in the module are studied using the ANSYS14 software. The heat transfer phenomenon conjugate between the photovoltaic cells and the coolant is modeled using the FLUENT software. The transfer of heat by the solar radiation is not modeled; however, the effects of radiation are taken for consideration when calculating the conditions for heat flux limit for the collector region. The geometric model and fluid domain for the CFD analysis is generated using ANSYS software DesingModeler, mesh geometry is carried out by ANSYS Meshing Software

Thermal Performance of Hybrid PVT Collector with Natural Circulation

Hybrid photovoltaic thermal (PVT) collectors allow simultaneous production of electrical energy thus heat energy. There are several configurations of hybrid collectors (to produce water or air). For hybrids water collectors, there are several configurations that differ by the nature of the absorber (serpentine, tubes...). In this paper, an absorber tank is studied. The circulation of the coolant is natural (we do not use the pump). We present the obtained results in our experimental study and we analyzed the data, and then we compare the results with the theory practices. The electrical performances of the hybrid collector are compared with those of conventional photovoltaic module mounted on the same structure and measured under the same conditions. We conducted experiments with natural circulation of the coolant (Thermosyphon), for a flow rate of 0.025kg/m²

Étude de la contamination parasitologique des cultures irriguées par les eaux usées dans le Maroc Oriental (Oujda)

Cette étude a pour objectif d’évaluer le risque potentiel lié aux helminthes parasites pour la population humaine et le cheptel dans la région d'Oujda. Les analyses parasitologiques montrent que les cultures irriguées par les eaux usées du collecteur principal (Cp) présentent les teneurs moyennes les plus élevées avec 19,89 oeufs/100 g de sol, 27,68 oeufs/100 g de racines et 9,21 oeufs/100 g de feuilles, suivies de celles irriguées par les eaux usées du collecteur secondaire (Cs) avec 6,57 oeufs/100 g de sol, 5,73 oeufs/100 g de racines et 4,15 oeufs/100 g de feuilles et enfin celles irriguées par les eaux usées de l’Oued Bounaïm avec 1,33 oeufs/100 g de sol, 5,26 oeufs/100 g de racines et 2,96 oeufs/100 g de feuilles. Les principaux parasites identifiés sont: Ascaris sp, Strongles, Trichuris sp, Ankylostoma sp, Strongyloides sp pour la classe des nématodes, Hymenolepis sp, Taenia sp and Moniezia sp pour la classe des cestodes

Caractérisation parasitologique des eaux usées réutilisées en agriculture dans le Maroc Oriental (Oujda)

Les eaux usées de la ville d’Oujda sont utilisées en totalité pour l’irrigation de 518 hectares. Les superficies irriguées sont composées de 43% de cultures fourragères, 23% de céréaliculture, 24% d’arboriculture et 10% de cultures maraîchères ou cultures à risque. L’objectif de cette étude est d’évaluer le risque potentiel lié aux oeufs d’helminthes auquel les populations humaines et animales peuvent être exposées lors de la réutilisation des eaux usées en agriculture. Les analyses parasitologiques montrent que les teneurs moyennes en oeufs d’helminthes (Nématodes et Cestodes) sont de 21,01 oeufs/l pour le canal principal (Cp), 9,81 oeufs/l pour le collecteur secondaire (Cs) et de 2,53 oeufs/l pour l’Oued Bounaim avec des taux d’échantillons positifs respectifs de 97%, 80% et 75%. Les oeufs identifiés sont dominés par les nématodes et en particulier par le genre Ascaris. Les principaux genres identifiés sont: Ascaris, Trichuris, Ankylostoma, Strongyloides pour la classe des nématodes, Hymenolepis et Tænia pour les cestodes

TUMEUR FIBREUSE SOLITAIRE DE L’ORBITE A PROPOS D’UN CAS AVEC REVUE DE LITTERATURE

Background: the solitary fibrous tumor (SFT) is a spindle-cell tumor that very rarely involves the orbit. We report a case that we compare to reports in the literature. Case: a 43 year old man presented a conjunctival inflammation of the left eye developing over 14 months with progressive proptosis. Magnetic resonance imaging revealed a retroocular mass, which showed isointensity on T1 and hyperintensity on T2. Histological examination of the lesion confirmed the diagnosis of the SFT of the orbit. The patient was doing well without recurrence after 12 months. Discussion: The diagnosis of SFT is histological. It is a mesenchymal tumor. Immunohistochemically, the tumor cells are strongly positive for CD34 and vimentin. Conclusion: The SFT of the orbit is a very rare and generally benign tumor. immunohisochemically differentiated from other spindle-cell tumors of the orbit . The treatment is a complete surgical excision, and long-term follow-up is necessary because recurrence may appear long after treatment.(TFS) est une tumeur mésenchymateuse ubiquitaire exceptionnellement retrouvée dans l’orbite. Nous rapportons un nouveau cas que nous  confrontons aux données de la littérature. Observation: Un homme âgé de 43 ans, présentait une inflammation conjonctivale de l’oeil gauche évoluant depuis 14 mois, avec apparition progressive d’une exophtalmie axile irréductible et indolore aggravée d’une ophtalmoplégie et d’une cécité gauche. L’IRM orbitaire a mis en évidence une masse tissulaire retro-oculaire iso intense en T1, hyper signal en T2. L’examen anatomopathologique de la pièce opératoire obtenue par voie fronto-orbitaire gauche a permis de poser le diagnostic de TFS orbitaire. L’évolution est favorable avec un recul d’un an. Discussion: Le diagnostic de TFS est anatomopathologique. Il s’agit d’une tumeur de nature mésenchymateuse. On note une forte expression de l’antigène CD34 et de la vimentine en immunohistochimie. Conclusion: La TFS de l’orbite est une tumeur rare habituellement bénigne. Elle doit être différenciée imunohistochimiquement des autres types mésenchymateuses de l’orbite. Sa prise en charge repose sur l’exérèse chirurgicale complète, et un suivi clinique prolongé est proposé car des récidives peuvent survenir à long terme et il existe des formes malignes

Ubiquitous [Na+]i/[K+]i-Sensitive Transcriptome in Mammalian Cells: Evidence for Ca2+i-Independent Excitation-Transcription Coupling

Stimulus-dependent elevation of intracellular Ca2+ ([Ca2+]i) affects the expression of numerous genes – a phenomenon known as excitation-transcription coupling. Recently, we found that increases in [Na+]i trigger c-Fos expression via a novel Ca2+i-independent pathway. In the present study, we identified ubiquitous and tissue-specific [Na+]i/[K+]i-sensitive transcriptomes by comparative analysis of differentially expressed genes in vascular smooth muscle cells from rat aorta (RVSMC), the human adenocarcinoma cell line HeLa, and human umbilical vein endothelial cells (HUVEC). To augment [Na+]i and reduce [K+]i, cells were treated for 3 hrs with the Na+,K+-ATPase inhibitor ouabain or placed for the same time in the K+-free medium. Employing Affymetrix-based technology, we detected changes in expression levels of 684, 737 and 1839 transcripts in HeLa, HUVEC and RVSMC, respectively, that were highly correlated between two treatments (p<0.0001; R2>0.62). Among these Na+i/K+i-sensitive genes, 80 transcripts were common for all three types of cells. To establish if changes in gene expression are dependent on increases in [Ca2+]i, we performed identical experiments in Ca2+-free media supplemented with extracellular and intracellular Ca2+ chelators. Surprisingly, this procedure elevated rather than decreased the number of ubiquitous and cell-type specific Na+i/K+i-sensitive genes. Among the ubiquitous Na+i/K+i-sensitive genes whose expression was regulated independently of the presence of Ca2+ chelators by more than 3-fold, we discovered several transcription factors (Fos, Jun, Hes1, Nfkbia), interleukin-6, protein phosphatase 1 regulatory subunit, dual specificity phosphatase (Dusp8), prostaglandin-endoperoxide synthase 2, cyclin L1, whereas expression of metallopeptidase Adamts1, adrenomedulin, Dups1, Dusp10 and Dusp16 was detected exclusively in Ca2+-depleted cells. Overall, our findings indicate that Ca2+i-independent mechanisms of excitation-transcription coupling are involved in transcriptomic alterations triggered by elevation of the [Na+]i/[K+]i ratio. There results likely have profound implications for normal and pathological regulation of mammalian cells, including sustained excitation of neuronal cells, intensive exercise and ischemia-triggered disorders

Regional microbial signatures positively correlate with differential wine phenotypes: evidence for a microbial aspect to terroir

Many crops display differential geographic phenotypes and sensorial signatures, encapsulated by the concept of terroir. The drivers behind these differences remain elusive, and the potential contribution of microbes has been ignored until recently. Significant genetic differentiation between microbial communities and populations from different geographic locations has been demonstrated, but crucially it has not been shown whether this correlates with differential agricultural phenotypes or not. Using wine as a model system, we utilize the regionally genetically differentiated population of Saccharomyces cerevisiae in New Zealand and objectively demonstrate that these populations differentially affect wine phenotype, which is driven by a complex mix of chemicals. These findings reveal the importance of microbial populations for the regional identity of wine, and potentially extend to other important agricultural commodities. Moreover, this suggests that long-term implementation of methods maintaining differential biodiversity may have tangible economic imperatives as well as being desirable in terms of employing agricultural practices that increase responsible environmental stewardship