Contribution à l’étude théorique du comportement d’un système hybride (éolien- photovoltaïque- diesel) de production d’électricité sans interruption

Actuellement, Le générateur diesel est la technique la plus utilisée pour l’électrification des sites isolés. Néanmoins, l’accès à ces sites étant généralement long et difficile, les coûts de maintenance et d’approvisionnement en carburant sont très élevés. En conséquence, nous avons envisagé de coupler – au sein d’un système hybride - un générateur diesel avec deux sources d’énergies renouvelables (éolien-photovoltaïque) qui représente alors souvent l’option la plus économique. Cependant, notre étude porte sur l’alimentation d’une habitation, qui peut être situe sur différents sites Algériens, par le système hybride avec stockage électrochimique. Dans un premier temps, nous nous sommes basés sur la modélisation détaillée des composantes du système, puis sur l’ensemble du système. Ainsi, nous avons appliqué les modèles et dimensionner le système ce qui nous a permis d’aboutir aux meilleures performances.Mots-clés : système éolien, système photovoltaïque, générateur diesel, systèmehybride, système de stockage, la charge, dimensionnement

Erratum

Evolution des teneurs en polyamines dans les boutons floraux, les fleurs et les jeunes baies de Vitis villifera L. (cv. Cabernet Sauvignon) atteints d'eutypioseVitis 43 (3), 139-144 (2004

Les teneurs en acides gras, en eau et en acide abscissique des feuilles de vigne (Vitis vinifera L. var. Cabernet Sauvignon) infectées par Eutypa lata

Water, fatty acids and abscisic acid contents of grapevine leaves (Vitis vinifera, cv. Cabernet Sauvignon) infected by Eutypa lataEytypiose of grapevines led to a lowering of the water content and to an accumulation of abscisic acid (ABA) in the leaves of Cabernet Sauvignon known to be susceptible to Eutypiose. The accumulation of ABA in the leaves of infected plants possibly causes changes in the composition of fatty acids, in partiular by reducing their degree of insaturation and by elongating their aliphatic chains. These changes may lower the permeability of membranes and, as a consequence, exchanges with the environment, which possibly intensifies dehydration of infected leaves during their development.

Comparaison de la teneur en amidon, en glucides solubles et en acide abscissique des bourgeons latents et des entre-noeuds au cours du cycle végétatif de la vigne

Au cours du cycle annuel, l'évolution des teneurs des différents sucres solubles et de l'amidon des bourgeons et des entre-noeuds du Merlot noir est comparable. Les teneurs en glucides solubles totaux (GST), généralement plus faibles dans les bourgeons, diminuent de juillet à la mi-octobre avant de s'accumuler intensément jusqu'au mois de décembre pour chuter jusqu'au débourrement. Selon les périodes du cycle, les teneurs en hexoses des bourgeons sont soit plus élevées, soit pratiquement identiques à celles des entrenoeuds. Un phénomène inverse est observé pour le saccharose, sucre soluble le plus abondant pendant presque tout le cycle. L' accumulation du raffinose, comme celle du saccharose, dès le mois d'octobre semble en relation avec la diminution des températures journalières moyennes, ce qui paraît confirmer leur rôte cryoprotecteur face au froid hivernal. Les teneurs en raffinose des bourgeons, moins élevées que celles des entre-noeuds, diminuent ensuite à partir de la mi-novembre alors que celles des entre-noeuds ne diminuent qu'à l'approche du débourrement.Les teneurs en amidon, généralement moins élevées dans les bourgeons, évoluent la plupart du temps à l'inverse des GST. En présence des feuilles, l'ABA (acide abscissique) des bourgeons semble contrôler cette évolution en agissant comme inhibiteur de son accumulation. Peu avant la chute des feuilles et jusqu'a la mi-février, a diminution des teneurs en amidon des bourgeons paraît être favorisée par la diminution des teneurs en ABA certainement par la levée de l'inhibition de la synthese de l'α-amylase. L'ABA semble agir aussi, de juillet au début février, comme inhibiteur de l'accumulation du saccharose. Enfin, à l'approche du débourrement, la diminution des teneurs en ABA laisse apparaître une évolution inverse à celle de l'amidon mais parallèle à celle du saccharose.Comparison of the contents of starch, soluble carbohydrates and abscisic acid of latent buds and internodes during the vegetative cycle of grapevineIn the course of the annual cycle the contents of various soluble sugars and of starch were determined in buds and internodes of cv. Merlot. In general, the total soluble carbohydrate content was lower in buds compared to internodes; it decreased from July to mid-October, increased intensely until December and decreased again until bud burst. The content of hexoses corresponded to this cycle; in buds they were either higher or equal to those of the internodes. Sucrose behaved inversely. Starting in October, the accumulation of raffinose and sucrose was obviously related to the decrease of the daily average temperatures which possibly confirms their role as cryoprotectors in winter. The contents of raffinose in buds which were lower compared to those of internodes decreased after mid-November while in internodes they decreased only at the onset of bud burst. Generally, the starch content was lower in buds compared to internodes, its alterations were inversely related to the total soluble carbohydrates. In the presence of leaves the abscisic acid (ABA) content of buds appeared to affect this development by inhibiting the accumulation of starch. The decrease of the starch content of buds appears to be associated with the decrease of the ABA content; a decreasing ABA content is assumed to suspend the inhibition of the a-amylase synthesis. From July to the onset of February ABA is suggested to inhibit the accumulation of sucrose. Before bud burst decreasing amounts of ABA indicate a development which is inversely related to starch but runs parallel to the development of sucrose

Prognostic value of the ratio between prothesis area and indexed annulus area measured by multiSlice-CT for transcatheter aortic valve implantation procedures

Background Postprocedural aortic regurgitations following transcatheter aortic valve implantation (TAVI) procedures remain an is- sue. Benefit of oversizing strategies to prevent them isn’t well established. We compared different level of oversizing in our cohort of con- secutive patients to address if severe oversizing compared to normal sizing had an impact on post-procedural outcomes. Methods From January 2010 to August 2013, consecutive patients were referred for TAVI with preoperative Multislice-CT (MSCT) and the procedures were achieved using Edwards Sapien® or Corevalve devices®. Retrospectively, according to pre-procedural MSCT and the valve size, pa- tients were classified into three groups: normal, moderate and severe oversizing; depending on the ratio between the prosthesis area and the annulus area indexed and measured on MSCT. Main endpoint was mid-term mortality and secondary endpoints were the Valve Academic Research Consortium (VARC-2) endpoints. Results Two hundred and sixty eight patients had a MSCT and underwent TAVI procedure, with mainly Corevalve®. While all-cause and cardiovascular mortality rates were similar in all groups, post-procedural new pacemaker (PM) implantation rate was significantly higher in the severe oversizing group (P = 0.03), while we observed more in-hospital congestive heart-failure (P = 0.02) in the normal sizing group. There was a trend toward more moderate to severe aortic regurgitation (AR) in the normal sizing group (P = 0.07). Conclusions Despite a higher rate of PM implantation, oversizing based on this ratio reduces aortic leak with lower rates of post-procedural complications and a similar mid-term survival

Client Characteristics related Critical Success Factors for Public-Private Partnerships in South Africa

The implementation of the Public-Private Partnership (PPP) projects in South Africa has grown steadily since the late 1990s. However, these partnerships do not realise their potential with a decline in PPP transactions over the past decade. The drivers of success for PPP projects have become a subject of investigation to understand the downward trend. This study evaluates the different critical success factors pertinent to client characteristics that influence PPP projects in South Africa. The study followed a qualitative research inquiry that employs a grounded theory (G.T.) approach involving semi-structured interviews with nine professionals involved in PPP projects selected using a snowball sampling technique. Interviews were conducted on video conferencing and through phone calls. Seven responses were considered relevant to the research, and two were considered irrelevant and were disregarded. An in-depth analysis of the data gathered was conducted through a selective coding process using NVivo. The analysis revealed the research’s emergent themes: client experience and in-house technical capabilities; client risk attitude; client willingness to be involved and trust in the private sector, available financial markets, and political support and stability. By applying the framework established, the chances of success and decline in the use of PPP projects can be considerably improved in South Africa through greater engagement between the public and private sectors in infrastructure investment and delivery. The study’s main limitation is the smallness of the sample size and the use of the snowball sampling technique in which the initial respondents are likely to refer to other respondents who share similar points of view and beliefs. To counter this limitation, the researchers ensured that the convenient sample of initial subjects comprised professionals from different backgrounds

Evolution des teneurs en polyamines dans les boutons floraux, les fleurs et les jeunes baies de Vitis vinifera L. (cv. Cabernet Sauvignon) atteints d’eutypiose

Development of polyamine levels in flower buds, flowers and young berries of Vitis vinifera L. (cv. Cabernet Sauvignon) infected by eutypiosis fungus, Eutypa lata Effects of eutypiosis on polyamines (PAs) and tyramine contents in flower buds, flowers and young berries of grapevine were studied to determine the relationship between these components and disease development. The study was performed using organs (1) from healthy vines, (2) healthy appearing organs from vines with one symptomless arm and one diseased arm, and (3) diseased organs. Free PAs, conjugated polyamines ( PAs-fpm) and wall-bound polyamines (PAs-mm) were analysed in Vitis vinifera L. cv. Cabernet Sauvignon which is sensitive to eutypiosis. An increase of PAs-mm and a decrease of free PAs were observed in diseased organs; particularly putrescine and diaminopropane were concerned. On the other hand these substances were not affected by eutypiosis in the healthy appearing organs. Alterations of free PAs and PAs-mm in diseased organs were correlated with alteration of the flowering process. In contrast, the PAsfpm levels decreased in diseased organs in response to eutypiosis whereas they increased in healthy appearing organs. This group of PAs seems to play an important role in the response to Eutypa lata attacks to prevent the expression of symptoms. Accumulation of the conjugated tyramine in diseased and healthy appearing organs as a response to eutypiosis might be used as marker of Eutypa lata infection

Transient parkinsonism in isolated extrapontine myelinolysis

Extrapontine myelinolysis (EPM) is a rare cause of parkinsonism. In this case report, we describe a 63-year-old woman with parkinsonism due to EPM after correction of hyponatremia. During a 4-year follow-up, both the clinical features of parkinsonism and the changes on magnetic resonance imaging resolved. Parkinsonism due to EPM should be recognized as it has a good prognosis

Toolbox from the EC FP7 HOSANNA project for the reduction of road and rail traffic noise in the outdoor environment

yesThis paper offers a brief overview of innovative methods for road and rail traffic noise reduction between source and receiver. These include using new barrier designs, planting of trees, treatments of ground and road surfaces and greening of building façades and roofs using natural materials, like vegetation, soil and other substrates in combination with recycled materials and artificial elements. The abatements are assessed in terms of numerically predicted sound level reductions, perceptual effects and cost–benefit analysis. Useful reductions of noise from urban roads and tramways are predicted for 1-m-high urban noise barriers and these are increased by adding inter-lane barriers. A 3 m wide 0.3 m high lattice ground treatment, a carefully planted 15-m-wide tree belt and replacing 50 m of paved areas by grassland are predicted to give similar reductions. Tree belts are shown to be very cost-effective and combining tall barriers with a row of trees reduces the negative impact of wind. Green roofs may significantly reduce the noise at the quiet side of buildings