Academic literature on the topic 'Distribution libre'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Distribution libre.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Distribution libre"
1
Vlachou, Evangelia. "Sémantique et distribution des termes de choix libre du français." Langue française 166, no. 2 (2010): 133. http://dx.doi.org/10.3917/lf.166.0133.
Full text
2
Servais, P., P. Laurent, G. Billen, and D. Gatel. "Développement d'un modèle décrivant les variations de CODB et de biomasse bactérienne dans les réseaux de distribution." Revue des sciences de l'eau 8, no. 4 (April 12, 2005): 427–62. http://dx.doi.org/10.7202/705232ar.
Full textAbstract:
Sur la base d'études microbiologiques expérimentales réalisées sur différents réseaux de distribution d'eau potable en France, un modèle de la dynamique des bactéries et du carbone organique biodégradable (CODB) a été développé ( le modèle SANCHO). Les processus suivants ont été pris en compte : - l'hydrolyse bactérienne exoenzymatique de la matière organique et la croissance des bactéries libres et fixées, à partir des produits des hydrolyses ; - la mortalité des bactéries, source de relargage de matière organique ; - les interactions entre les surfaces internes des canalisations et les bactéries avec un processus d'adsorption réversible ; - la consommation de chlore par réaction avec la matière organique et l'effet du chlore libre sur l'activité des bactéries en suspension et fixées qui a été déterminé expérimentalement. Le modèle calcule, en considérant les cinétiques présentées ci-dessus, les variations spatiales à l'état stationnaire du CODB, du résiduel de chlore libre, de la biomasse bactérienne libre et fixée. Ce calcul s'effectue pour une masse d'eau circulant durant des temps connus dans des canalisations de diamètres décroissants. Afin de valider ce modèle, des comparaisons entre les résultats expérimentaux et calculés par le modéle ont été effectuées pour deux réseaux de distribution différents. Un bon accord est observé entre les résultats expérimentaux et ceux calculés pour les situations présentées qui sont caractérisées par des teneurs très différentes en chlore et en CODB dans l'eau alimentant les réseaux. Une fois validé, ce modèle peut être utilisé afin de prédire l'effet de certaines modifications de la qualité de l'eau alimentant un réseau sur la dynamique bactérienne au sein de ce réseau. Il permet de définir la qualité de l'eau requise en sortie de filière afin de respecter une qualité souhaitée dans tout le réseau de distribution.
3
Lavallée, Daniel, and Claude Marche. "Déversements turbulents de matériau granulaire en eau libre. I. Observations en laboratoire." Canadian Journal of Civil Engineering 22, no. 3 (June 1, 1995): 480–87. http://dx.doi.org/10.1139/l95-056.
Full textAbstract:
Capping of contaminated sediment with clean granular material is a commonly used mitigative measure. The capping material is often dispersed from the end of a pipeline or dumped down a chute. Such methods require special equipment that is sometimes costly. The possibility of using a hopper barge to place the material was thus explored. Laboratory tests were conducted to study bottom distribution of granular material placed in this way. Distribution is determined at the moment of impact. To identify the mechanisms at work at the moment of impact, tests were conducted with different bottom slopes. Experimental results indicate that distribution of the granular material can be described by the turbulence created by an impinging jet. This turbulence is estimated, using a digital model, the results described in a second paper. Key words: dredging, capping, seacoast.[Journal translation]
4
Bardiaux, Jean-Bernard, José Vazquez, and Robert Mosé. "Estimation de la distribution tridimensionnelle des vitesses dans un écoulement à surface libre." La Houille Blanche, no. 4 (August 2007): 99–103. http://dx.doi.org/10.1051/lhb:2007053.
Full text
5
Nouiri, Issam, and Féthi Lebdi. "Algorithme Génétique (AG) pour le choix optimal des stations d’appoint de chlore sur les réseaux d’eau potable." Revue des sciences de l'eau 19, no. 1 (March 20, 2006): 47–55. http://dx.doi.org/10.7202/012596ar.
Full textAbstract:
Résumé La chloration sur les réseaux de distribution d’eau potable constitue une tâche délicate. Elle assure la protection contre la reviviscence microbienne et contre la contamination du réseau. Les réactions du chlore avec la matière organique du système entraînent la formation des sous‑produits chlorés, indésirables pour la santé humaine. Ainsi, le maintien du taux de chlore libre à des valeurs admissibles, sur tout le réseau et à tout moment, constitue un objectif principal des gestionnaires des réseaux. Lors de la chloration à partir des sources d’eau, les processus de réaction-transport créent sur les réseaux, caractérisés par des temps de séjours importants, de mauvaises distributions des taux de chlore libre. Les stations d’appoints sur les réseaux constituent une alternative efficace. La détermination de leur nombre et le choix des emplacements optimums constituent les deux difficultés auxquelles sont confrontés les gestionnaires. Le présent travail utilise un algorithme génétique (AG) pour la détermination du nombre et des emplacements optimums des stations d’appoint de chlore sur les réseaux. Deux objectifs ont été fixés : (1) l’amélioration de l’homogénéité spatio-temporelle de la chloration et (2) la minimisation du nombre de stations d’appoint. L’application du modèle développé sur un réseau test a permis d’identifier les emplacements des deux stations d’appoint de chlore. La solution optimale a considérablement amélioré l’homogénéité et a assuré, pour 98 % des noeuds, des taux de chlore libre dans l’intervalle admissible (0,1-0,5) mg/L.
6
Schulz, John T., Gabriel D. Shapiro, Amy Acton, Philip Fidler, Molly E. Marino, Allen Jette, Jeffrey E. Schneider, Lewis E. Kazis, and Colleen M. Ryan. "The Relationship of Level of Education to Social Reintegration after Burn Injury: A LIBRE Study." Journal of Burn Care & Research 40, no. 5 (May 8, 2019): 696–702. http://dx.doi.org/10.1093/jbcr/irz074.
Full textAbstract:
Abstract Social and emotional recovery from burn injury is a complex process impacted by both clinical and social factors. Because level of education (LOE) has been correlated to overall health, health outcomes, and life expectancy, we questioned whether LOE might be associated with successful social recovery after burn injury. The Life Impact Burn Recovery Evaluation (LIBRE) data set served as a novel tool to explore this question. The LIBRE project is a collaborative effort designed to provide a clinical yardstick for social reintegration among burn survivors. After institutional review board approval, 601 burn survivor respondents, aged 18 or over with >5% TBSA burn were surveyed and a six-scale, 126-item LIBRE Profile was derived from their responses. LOE was collapsed into four categories ranging from less than high school equivalency certificate to graduate degree. Impact of burn injury on subsequent LOE was examined by splitting the sample into those burned at age 30 years or less and those burned at greater than 30 years of age. Regression models were run to estimate associations between education and scale scores with adjustment for age at injury, sex, marital status, work status, TBSA, and time since burn. Regression models were run on the entire cohort and then stratified by age at burn injury (≤30 vs >30). Among all subjects, we found an association between LOE and social recovery as measured by LIBRE scale scores. This association was contributed entirely from the cohort burned at age 30 or less: for those burned at greater than age 30, there was no association between LOE and social recovery. Of particular interest, the distribution of LOE among those burned at ≤ 30 was very similar to LOE distribution in both millennials and in the U.S. population at large. LOE appears to be associated with social recovery for those burned at younger ages but not for those burned at over age 30. More importantly, burn injury during schooling may have no impact on a survivor’s educational trajectory since distribution of LOE in our ≤30 cohort mirrors that of the general population. LOE and age at burn injury may provide a quick screen for survivors at risk of difficult social reintegration, allowing providers to target those at risk with additional peer support and counseling.
7
Denis, Jean-Émile, Christine Stavrinidis, and Serge Tessier. "Les incidences sectorielles et régionales du libre-échange Canada-Etats-Unis." Études internationales 17, no. 1 (April 12, 2005): 33–47. http://dx.doi.org/10.7202/701962ar.
Full textAbstract:
The debate on the advantages and disadvantages of free trade between Canada and the U.S. has intensified over the past months. Reluctance towards such an option in trading policy has increased and views differ more and more on the subject, particularly concerning its sector-based and regional consequences. Following a survey of the findings of earlier economic studies, the consequences of free trade between Canada and the U.S. are assessed as regards job distribution in the manufacturing industry. Estimates are derived from studies made by Harris and Cox which allow comparison to be made between the consequences of bilateral and multilateral free trade s. Contrary to the views expressed by the Royal Inquiry Commission, the results lead to the conclusion that bilateral free trade will bring about a marked relocation of the labour force. It turns out that job opportunity in areas with high level of employment would grow, as would the specialization of Quebec in these areas, as compared to Ontario.
8
Piriou, P., S. Dukan, Y. Levi, F. Guyon, and P. Villon. "Modélisation du comportement des biomasses bactériennes libres et fixées dans les réseaux de distribution d'eau potable." Revue des sciences de l'eau 9, no. 3 (April 12, 2005): 381–406. http://dx.doi.org/10.7202/705259ar.
Full textAbstract:
La prolifération bactérienne en réseaux de distribution d'eau potable est un souci majeur des distributeurs d'eau. La complexité des phénomènes impliqués dans la croissance bactérienne en réseaux nécessite une modélisation mathématique pour définir l'impact des différents paramètres de la qualité de l'eau et généraliser ces résultats à l'échelle du réseau de distribution. Une approche déterministe a été choisie pour développer cette modélisation prédictive de la croissance bactérienne dans les systèmes de distribution. Le modèle prend en compte : la croissance de fa biomasse libre et de la biomasse fixée, la consommation en nutriments exprimés par le CODB, l'action bactéricide du chlore sur la flore libre et la dore fixée, la déposition des bactéries en suspension et le détachement des bactéries fixées. Le modèle propose une approche originale pour la modélisation de l'action bactéricide du chlore. Par ailleurs, différentes formulations du détachement ont été testées algébriquement pour définir la modélisation la plus adaptée à notre système d'équations. Ce modèle a été couplé au logiciel de modélisation hydraulique IMCCOI.O développé par la SAFEGE. Utilisant les données hydrauliques et de géométrie générées par PICCOLO, le modèle prédit les numérations bactériennes en chaque noeud et sur chaque arc du réseau de distribution. Utilisant l'interface graphique de PICCOLO, le modèle permet une visualisation de l'évolution de la qualité bactérienne par cartographie. Des simulations ont été réalisées sur de nombreux réseaux présentant des tailles et des niveaux de complexité variables. Le modèle a été validé à partir de campagnes de prélèvements sur sites. Ce modèle permettant de simuler l'évolution de la qualité bactériologique à l'échelle du réseau est un outil unique pour le diagnostic et la gestion qualitative des systèmes de distribution d'eau potable.
9
Turner, Brian. "Liberating the Municipio Libre: The Normalization of Municipal Finance in Yucatan." Mexican Studies/Estudios Mexicanos 18, no. 1 (2002): 101–31. http://dx.doi.org/10.1525/msem.2002.18.1.101.
Full textAbstract:
This article investigates the reform of municipal funding in Yucatáán in the 1990s. At the beginning of this period, the state government had considerable discretion in municipal funding. By 2000, municipal funding practices were considerably constrained by federal law. The article explores whether, and how, political considerations entered into the distribution of these funds at the end of the Zedillo sexenio, despite reforms. After analyzing the data regarding municipal finance, the article concludes that while normalization made municipal finance somewhat less capricious, funding was still a political and partisan process in the state. En este artíículo se investiga la reforma del financiamiento municipal en Yucatáán en los añños noventa. Al principio de este perííodo, el gobierno del estado teníía una injercióón considerable en el manejo del financiamiento municipal. Antes de 2000, las práácticas del financiamiento municipal estaban sujetas considerablemente por ley federal. El artíículo explora tanto si las consideraciones polííticas fueron incorporadas en la distribucióón de estos fondos al final del sexenio de Zedillo, ello a pesar de las reformas, asíí como la manera en que tal hecho se llevóó a cabo. Despuéés de analizar los datos con respecto a las finanzas municipales, se concluye que mientras que la normalizacióón hizo el financiamiento municipal algo menos caprichoso, el financiamiento seguíía siendo un proceso políítico y partisano en el estado.
10
Suárez Rivera, Manuel. "Gent, Basque and book merchant: Tomás Domingo de Acha, his commercial and distribution networks (1771-1814)." Estudios de Historia Novohispana, no. 50 (August 17, 2015): 125. http://dx.doi.org/10.22201/iih.24486922e.2014.50.51390.
Full textAbstract:
El artículo tiene como objetivo mostrar las redes mercantiles de un comerciante de libros en los últimos años del régimen de flotas y las primeras décadas del libre comercio. Para ello utilizo la figura de Tomás Domingo de Acha, comerciante vasco que se estableció en la ciudad de México y que logró ascender a los más altos niveles sociales y económicos. La última parte del artículo describe precisamente la búsqueda de intermediarios que se encargaran de despachar los cajones de libros a la ciudad de México bajo un nuevo sistema mercantil, aunque en esta última etapa no es posible identificar sus redes provenientes de España, sí es posible advertir la construcción de un nuevo sistema de distribución de Veracruz hacia la ciudad de México.
Dissertations / Theses on the topic "Distribution libre"
1
Scheepers, Valérie. "La distribution de la réserve libre avant et au moment de la ruine." Doctoral thesis, Universite Libre de Bruxelles, 2001. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211652.
Full text
2
Disma, Gérald. "L'exploitation compétitive des ressources d'un environnement variable : la distribution libre et idéale chez l'enfant." Amiens, 2006. http://www.theses.fr/2006AMIE0012.
Full textAbstract:
Quand plusieurs individus interagissent, il est important de prendre en compte les paramètres de l’environnement et de moduler ses choix en fonction de ceux des autres. Très jeunes, les enfants peuvent être confrontés à ce type de problème dans leur milieu familial, social ou naturel, avec parfois des conséquences importantes en cas de mauvais choix. Lorsqu’il y a compétition pour l’accès à des ressources limitées et localisées dans l’espace, la Distribution Libre et Idéale permet de prédire comment un groupe doit se répartir spatialement dans son environnement afin de maximiser les gains individuels. Notre hypothèse principale est que les enfants en situation de compétition vont pouvoir disposer de mécanismes permettant d’aboutir à des décisions efficaces. En utilisant la DLI comme outil d’analyse, deux approches sont employées: une première, expérimentale, avec 16 groupes d’enfants âgés de 7 à 11ans ; une seconde, éthologique, basée sur l’observation d’enfants des rues à IstanbulWhen several individuals interact, it is significant to take into account the parameters of the environment and to modulate its choices according to those of the others. Early in life, children can be confronted with this type of problem in their family, social or natural environment, with sometimes significant consequences in case of bad choice. When there is competition for the access to limited and spatially located resources, Ideal Free Distribution can predict how a group must be distributed spatially in its environment in order to maximize the individual profits. Our principal assumption is that the children in situation of competition will be able to have mechanisms allowing to lead to effective decisions. By using the IFD as tool for analysis, two approaches are employed: a first, experimental, with 16 groups of children from 7 to 11 years old; a second, ethologic, based on the observation of street children in Istanbul
3
Pavan, Sara. "Nouveaux schémas de convection pour les écoulements à surface libre." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1011/document.
Full textAbstract:
Cette thèse a pour objectif la construction de schémas d’ordre élevé et peu diffusifs pour le transport d’un scalaire dans les écoulements à surface libre, en deux ou trois dimensions. On souhaite en particulier obtenir des schémas robustes, qui gardent au niveau discret les propriétés mathématiques de l’équation de transport avec une faible diffusion numérique, et les utiliser sur des cas industriels. Dans ce travail deux méthodes numériques sont envisagées : une méthode aux volumes finis (VF) et une méthode aux résidus distribués (RD). Dans les deux cas, l’équation de transport est résolue avec une approche découplée, qui est la solution la plus avantageuse en termes de précision et de coûts de calcul. Pour ce qui concerne la méthode aux volumes finis, les équations de Saint-Venant couplées à l’équation du transport sont d’abord résolues avec un schéma dit vertex-centred où le flux numérique est approximé avec un solveur de Riemann appelé Harten-Lax-Van Leer-Contact [135]. A partir de cette approche, une formulation découplée est proposée. Cette dernière permet de résoudre l’équation du transport avec un pas de temps plus grand que celui de la formulation couplée. Cette idée a été d’abord proposée pour d’autres schémas dans [13]. Pour augmenter l’ordre de précision en espace, la technique MUSCL [89] est utilisée en combinaison avec l’approche découplée. Finalement, la problématique des zones sèches est abordée. Dans le cas de la méthode aux résidus distribués, les équations de Saint-Venant sont résolues avec une méthode éléments finis, et la méthode RD est utilisée seulement pour discrétiser l’équation du transport, en focalisant l’attention sur les problèmes non stationnaires. L’équation de continuité du fluide discrétisée est employée pour garantir la conservation de la masse et le principe du maximum. Pour obtenir des schémas d’ordre deux dans les problèmes non stationnaires, un schéma prédicteur-correcteur [112] est utilisé, en l’adaptant au cas de concentration moyennée sur la verticale. Une version d’ordre 1 mais peu diffusive, est aussi présentée dans ce travail. De plus, un schéma localement implicite, complètement nouveau, est aussi formulé pour pouvoir traiter le problème des bancs découvrant. Les deux techniques sont validées d’abord sur des cas simples, pour évaluer l’ordre de précision des schémas et ensuite sur des cas plus complexes pour vérifier aussi les autres propriétés numériques. Les résultats montrent que les nouveaux schémas sont à la fois précis et conservatifs, tout en gardant la monotonie comme le prévoient les démonstrations. Un cas d’application industriel est aussi présenté en conclusion. Le schéma prédicteur-correcteur RD est adapté aussi au cas 3D, sans aucun problème théorique nouveau, par rapport au cas 2D. Les propriétés de base des schémas sont validées sur des cas test préliminairesThe purpose of this thesis is to build higher order and less diffusive schemes for pollutant transport in shallow water flows or 3D free surface flows. We want robust schemes which respect the main mathematical properties of the advection equation with relatively low numerical diffusion and apply them to environmental industrial applications. Two techniques are tested in this work: a classical finite volume method and a residual distribution technique combined with a finite element method. For both methods we propose a decoupled approach since it is the most advantageous in terms of accuracy and CPU time. Concerning the first technique, a vertex-centred finite volume method is used to solve the augmented shallow water system where the numerical flux is computed through an Harten-Lax-Van Leer-Contact Riemannsolver [135]. Starting from this solution, a decoupled approach is formulated and is preferred since it allows to compute with a larger time step the advection of a tracer. This idea was inspired by [13]. The Monotonic Upwind Scheme for Conservation Law [89], combined with the decoupled approach, is then used for the second order extension in space. The wetting and drying problem is also analysed and a possible solution is presented. In the second case, the shallow water system is entirely solved using the finite element technique and the residual distribution method is applied to the solution of the tracer equation, focusing on the case of time-dependent problems. However, for consistency reasons the resolution of the continuity equation must be considered in the numerical discretization of the tracer. In order to get second order schemes for unsteady cases a predictor-corrector scheme [112] is used in this work. A first order but less diffusive version of the predictor-corrector scheme is also introduced. Moreover, we also present a new locally semi-implicit version of the residual distribution method which, in addition to good properties in terms of accuracy and stability, has the advantage to cope with dry zones. The two methods are first validated on academical test cases with analytical solution in order to assess the order of the schemes. Then more complex cases are addressed to test the robustness of the schemes and their performance under different flow conditions. Finally a real test case for which real data are available is carried out. An extension of the predictor-corrector residual distribution schemes to the 3D case is presented as final contribution. Even in this case the RD technique is completely compatible with the finite element framework used for the Navier-Stokes equations, thus its extension to the 3D case does not present any extra theoretical problem. The method is tested on preliminary cases
4
Chidiac, Chidiac. "Modélisation de la relaxation rotationnelle de CO en jet supersonique libre : effet de la condensation et des phénomènes de glissement." Châtenay-Malabry, Ecole centrale de Paris, 1987. http://www.theses.fr/1987ECAP0069.
Full textAbstract:
Le travail est consacré à l'étude de la relaxation rotationnelle couplée à la détente dans un jet supersonique libre de CO-He. Les sections efficaces de collisions sont calculées pour des énergies allant jusqu'à 60 meV. Deux méthodes sont utilisées : - La méthode CS pour les basses énergies E 10 meV. - La méthode IOS pour les énergies plus élevées (10 meV E 60 meV) afin de préserver le temps de calcul. Deux modèles de potentiel d'interaction sont testés. Les équations de la relaxation rotationnelle couplées aux équations de la détente sont déduites des équations de Boltzmann et résolues numériquement sur une ligne de courant dans deux cas différents : - sans glissement de vitesses ni différence de températures entre les deux espèces. - avec glissement de vitesses et différence de températures. Un modèle de condensation selon la théorie classique de nucléation homogène est aussi considéré. Les résultats théoriques sont comparés aux résultats expérimentaux existants.
5
Boscher, Daniel. "Etudes théorique et expérimentale de l'influence de la détente en jet supersonique libre sur la distribution rovibrationnelle de CO." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37596177c.
Full text
6
Boscher, Daniel. "Études théorique et expérimentale de l'influence de la détente en jet supersonique libre sur la distribution rovibrationnelle de CO." Paris 11, 1986. http://www.theses.fr/1986PA112068.
Full textAbstract:
Le travail théorique et expérimental est consacré à l’influence de la détente en jet supersonique, en particulier l’évolution de la volumique, sur la distribution rotationnelle de la molécule CO. Après avoir utilisé une méthode de fluorescence spontanée infrarouge en jet, rendue possible par une excitation vibrationnelle des molécules dans la chambre génératrice par une décharge électrique continue, deux nouvelles techniques d’investigation locales des jets ont été mises au point. La première associa l’inversion d’Abel à la déviation d’un faisceau laser par effet mirage. La deuxième utilise la technique du laser sonde. Le caractère local est obtenu soit grâce à l’expansion du jet (décalage Doppler), soit par l’inversion d’Abel. Ces différentes méthodes ont permis de mettre en évidence : - l’influence de la géométrie réelle de la tuyère, - les gels progressifs de la rotation et de la vibration, - les déséquilibres rotationnel et vibrationnel, - l’influence de la condensation sur la masse volumique et la température de rotation, - l’excitation du gaz résiduel entourant le jet, - la non symétrie axiale du jet. Enfin, un calcul théorique mené parallèlement a permis de confirmer l’influence de l’évolution de la masse volumique sur les populations rotationnelle et vibrationnelle. Une section efficace globale de rotation de CO est déterminée à des températures voisines de 50 KThis theoretical and experimental work is devoted to the influence of the density evolution in a supersonic free jet, on the rotational populations of CO molecules. First, we used a spontaneous fluorescence method in jets, made possible by a vibrational excitation of the molecules in the stagnation conditions. Afterwards, we developed two new techniques for local measurements in jets. One uses a laser schlieren technique associated to an Abel inversion and gives us the density. The second is based on the probe laser technique and allow us to measure rotational populations. The local measurements are then obtained either by using the Doppler shift associated to the spherical expansion of the molecules or by the Abel inversion. All these methods allow us to show: - the influence of the actual nozzle geometry, - the progressive freezings of rotational and vibrational degrees of freedom, - rotational and vibrational non equilibria, - the influence of clustering on the density and the rotational temperature, - a non-axial symmetry of the jet. Moreover, a theoretical calculation has also shown the influence of the density evolution on the rovibrational populations of CO. The total rotational cross section of CO is determined around 50 Kelvin
7
Frateur, Isabelle. "Incidence de la corrosion des materiaux ferreux sur la demande en chlore libre en reseaux de distribution d'eau potable." Paris 6, 1997. http://www.theses.fr/1997PA066338.
Full textAbstract:
La corrosion des materiaux ferreux constituant les conduites d'eau potable, induit une consommation du chlore libre qui peut etre electrochimique (reaction cathodique couplee a la dissolution du fer) ou chimique (oxydation des ions ferreux). Or la vitesse de disparition chimique apparait proportionnelle a la vitesse de corrosion. Par consequent, l'objectif de ce travail est l'analyse de trois systemes materiaux ferreux / eau potable (fer pur, acier doux et fonte), en vue d'une evaluation fiable de la vitesse de corrosion. L'etude, menee en laboratoire (electrodes a disque tournant de fer pur et de fonte) ou sur site pilote (electrodes en acier doux), fait appel a des techniques electrochimiques (stationnaires, spectroscopie d'impedance ac) et d'analyse de surface (meb, rayons x et spectrometrie raman). Il est montre, a partir d'echantillons de fer recuits ou non, que la corrosion des materiaux ferreux est d'autant plus importante que les impuretes ou defauts du metal sont nombreux. Par ailleurs, l'analyse par impedance ac des electrodes en acier conduit a une critique de l'utilisation d'un corrosimetre comme outil de mesure de la vitesse de corrosion des conduites. Les resultats obtenus avec la fonte, permettent une modelisation physique unique de l'interface fonte / eau potable, en accord avec la theorie de l'electrode poreuse developpee par r. De levie. De plus, ils montrent que le comportement de la fonte ne depend que de la presence ou de l'absence de chlore libre et non de sa concentration. Le traitement prealable des resultats d'impedance par le modele de mesure conduit a l'evaluation de l'erreur stochastique et au rejet des points non stationnaires. Ensuite, l'ajustement du modele physique au donnees experimentales permet d'extraire la resistance de transfert de charge anodique qui s'avere du meme ordre de grandeur que la resistance de polarisation. La comparaison des courants de corrosion ainsi calcules avec les potentiels de corrosion correspondants, mene a la conclusion que la consommation electrochimique du chlore libre est negligeable quel que soit le temps d'immersion. Enfin, le calcul montre que la disparition chimique du chlore induite par la corrosion de la fonte presente une vitesse globalement superieure a celle des decroissances causees par l'eau et le biofilm, tout en restant du meme ordre de grandeur.
8
Marcou, Olivier. "Modélisation et contrôle d’écoulements à surface libre par la méthode de Boltzmann sur réseau." Perpignan, 2010. http://www.theses.fr/2010PERP1001.
Full textAbstract:
Ce travail de thèse traite de la modélisation et la simulation des systèmes complexes et s’inscrit dans la thématique du contrôle et la gestion des ressources en eau. Nous proposons une approche originale basée sur les modèles de Boltzmann sur réseau pour représenter les écoulements au sein des canaux d’irrigation, habituellement décrits par les équations non linéaires de Saint-Venant. Nous avons adapté un modèle bi-fluide et étudié les conditions aux bords qui permettent de reproduire la géométrie d’un canal à surface libre. Des méthodes de détermination des grandeurs hydrauliques d’intérêt ont été développées. Nous nous sommes intéressés au comportement des vannes de fond en régime noyé, et nous démontrons que le modèle permet de décrire celui-ci spontanément dans différentes situations de fonctionnement. Des validations ont été effectuées par le biais d’une comparaison avec des expérimentations menées sur un micro-canal expérimental. Nous avons également introduit dans le modèle des phénomènes de sédimentation et étudié l’influence de la présence d’un dépôt de sédiments sur l’écoulement. Là aussi, les résultats de simulation et d’expérimentation convergentThis PhD work considers the general problem of modelling and simulation of complex systems and deals with the domain of control and management of water resources. We propose here an original approach based on Lattice Boltzmann models (LB) for modelling free surface flows in irrigation canals, usually described with the non-linear shallow water equations. We adapted a bi-fluid model and studied the boundary conditions which allow to reproduce the geometry of a free-surface irrigation canal. Methods for estimating the desired hydraulic quantities were developed. We studied the behavior of submerged underflow gates, and we show that the model is able to spontaneously and correctly describe how the gates function in quite different situations. Validations were realized by comparing results from simulations and experimentations performed on a laboratory micro-canal facility. We also introduced sedimentation phenomena in the model and studied the influence of a sedimentation deposit on the flow. Comparisons between experimental and simulation results were also performed and converged
9
Sandoval, Gabriel. "20 Años De Tlcan: Promesas Vs Realidades." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/cmc_theses/843.
Full textAbstract:
This thesis explores the effects of NAFTA on Mexico’s economy. In 1994, when Mexico first signed the agreement, it expected to boost its economy substantially by increasing trade with two world powers. Mexico stood to benefit the most with a convergence of economies which set high expectations for NAFTA. Twenty years later it is evident that not all goals were met. The success of NAFTA has sparked a debate in which opposing sides tend to project extremists arguments. However, this study reflects that NAFTA has not been a complete success or an absolute failure for Mexico. Rather, it looks at NAFTA as a project with room for improvement given the current results. This conclusion is reached by answering the following questions: In what ways has Mexico’s economy improved since 1994? Can these improvements be attributed to NAFTA? Twenty years later, which expectations have not been met? How does Mexico’s economic growth compare to that of other Latin American countries? And lastly, in what ways can the agreement or Mexican policy be modified to improve results?
10
Lefebvre, Christian. "HPF-Builder : un environnement visuel de placement et distribution dédié à HPF." Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-311.pdf.
Full textAbstract:
L'algorithmique scientifique modelise les phenomenes physiques par des methodes numeriques mettant en uvre d'enormes quantites de calculs. Pour etre capable de venir a bout de tels calculs, l'utilisation des machines paralleles est necessaire. Dans ce contexte, l'utilisation du parallelisme de donnees rend plus accessible la programmation des architectures paralleles. Le langage hpf respecte le modele de programmation a parallelisme de donnees tout en gardant la compatibilite avec le langage fortran, ce qui apporte une plus grande facilite dans le portage d'applications existantes. En parallelisme de donnees, le placement des donnees sur les differents nuds de calcul est d'une importance primordiale sur l'efficacite du programme. C'est pourquoi hpf propose des directives pour l'alignement des donnees entre elles et leur distribution sur une machine cible virtuelle. Nous proposons un modele de representation graphique des placements, afin de guider le programmeur dans le choix de ses directives. Ce modele permet la visualisation des alignements et des distributions a travers differents points de vue, de l'allure generale a la specification detaillee. La mise en uvre de ce modele a ete realisee sous la forme d'une interface graphique de visualisation et d'aide a l'edition de directives hpf : hpf-builder. Cet outil permet de mettre en uvre tous les placements de donnees d'un programme fortran de facon visuelle et interactive. Il libere l'utilisateur des contraintes syntaxiques et verifie la coherence des directives. De plus, nous proposons une extension de ce modele, ayant pour but d'evaluer a priori l'influence du placement sur les performances. Pour cela, nous avons defini un moyen de representer graphiquement les couts de communications et nous proposons plusieurs methodes de calcul permettant une evaluation approchee mais generique ou, au contraire, plus precise mais dediee a une architecture ou un compilateur donnes.
Books on the topic "Distribution libre"
1
Petras, James F. El sistema en crisis: Dinámica del capitalismo de libre mercado. Madrid: Editorial Popular, 2004.
Find full text
2
Pinhas, Luc. Éditer dans l'espace francophone: Législation, diffusion, distribution et commercialisation du livre. Paris: Alliance des éditeurs indépendants, 2005.
Find full text
3
L'Alcorano di Macometto: Storia di un libro del Cinquecento europeo. Bologna: Società editrice Il mulino, 2013.
Find full text
4
Mirucki, Jean. Le marché du livre au Canada: Les lecteurs, les composantes du marché et les réseaux de distribution du livre francophone au Canada : rapport d'étude. Montréal: Université du Québec à Montréal, Dép. des sciences économiques, 1986.
Find full text
5
Mirucki, Jean. Le marché du livre au Canada: Les lecteurs, les composantes du marché et les réseaux de distribution du livre francophone au Canada : rapport d'étude. [Montréal]: Université du Québec à Montréal, Dép. des sciences économiques, 1986.
Find full text
6
Varderi, Alejandro. Estado e industria editorial: ¿Por qué no se vende el libro en Venezuela? Caracas, Venezuela: FUNDARTE, 1985.
Find full text
7
La littérature d'enfance et de jeunesse en Côte-d'Ivoire: Structures de production et de distribution du livre pour enfants. Paris: L'Harmattan, 1996.
Find full text
8
Illusions of prosperity: America's working families in an age of economic insecurity. New York: Oxford University Press, 1999.
Find full text
9
Kast, Fundación Miguel, ed. La probreza en la distribución del ingreso: Libre mercado o estado benefactor? Santiago de Chile: Fundación Miguel Kast, 1997.
Find full text
10
Thalasso, Adolphe. Le Théâtre Libre: Essai Critique, Historique Et Documentaire, Suivi de Notices Biographiques de la Liste de Tous les Ouvrages Avec Leur Distribution ... Scene (Classic Reprint) (French Edition). Forgotten Books, 2018.
Find full textBook chapters on the topic "Distribution libre"
1
Ammannati, Francesco. "La disuguaglianza economica in area marchigiana: uno studio di lungo periodo (1400-1800)." In Disuguaglianza economica nelle società preindustriali: cause ed effetti / Economic inequality in pre-industrial societies: causes and effect, 37–63. Florence: Firenze University Press, 2020. http://dx.doi.org/10.36253/978-88-5518-053-5.08.
Full textAbstract:
The research aimed at bringing new data to the study of inequality in the distribution of wealth in the long run using the fiscal documentation available to many communities of the Marches region over a period covering the late Middle Ages and the full modern age. The political-administrative history of this territory, progressively incorporated into the Papal State, was reflected in an evolution of the methodologies for assessing wealth for tax purposes. Their characteristics have been carefully taken into account and criticized in order to ensure compatibility in time and space. Land registers, “estimi”, "libre", as well as books of “collette”, will be used to describe the fiscal capacity of taxpayers enrolled in these registers and to estimate the dynamics of economic inequality.
2
Feu, Montse. "España Libre, the Antifascist Periodical." In Fighting Fascist Spain, 36–52. University of Illinois Press, 2020. http://dx.doi.org/10.5622/illinois/9780252043246.003.0003.
Full textAbstract:
Franco’s rule had a devastating effect on workers in Spain: not only were workers’ unions suppressed and their leaders either shot or sent to prison or into exile, but their politics were censored and destroyed. España Libre’s editors and contributors had a clear understanding of their role in preserving the diverse legacy of progressive and radical workers, something that was documented in each issue in the form of essays, reviews of books and fundraising events, historical writing, theater, fiction, and poetry. Staff and contributors, nongovernmental institutions, and the global antifascist community published political protest in España Libre, which demonstrates the transnational reach and distribution of the periodical.
3
Thaisy, Laurence. "Chapitre 5. Du monopole à la libre distribution dans les zones occidentales." In La politique cinématographique de la France en Allemagne occupée (1945-1949), 105–22. Presses universitaires du Septentrion, 2006. http://dx.doi.org/10.4000/books.septentrion.76051.
Full text
4
Collantes, Sergio Sánchez. "Spanish Republicanism and the Press." In Writing Revolution, 17–35. University of Illinois Press, 2019. http://dx.doi.org/10.5622/illinois/9780252042744.003.0002.
Full textAbstract:
This chapter examines the important role of freethinking and federal republican publications on the formation of anarchist ideology and social practices. It focuses on the distribution and circulation of Spanish freethinking newspapers in Spanish-speaking progressive and anarchist communities in the United States, presenting a new line of inquiry into Hispanic anarchism and its transnational networks. The freethinking movement that crystalized at the end of the nineteenth century constitutes an excellent example of this confluence of ideas. This movement garnered the sympathies of many republicans, socialists, anarchists, masons, and other dissidents who shared the heterodox theses of its main mouthpiece, the weekly journal Las Dominicales del Libre Pensamiento (The Sunday Supplement of Free Thought). Edited between 1883 and 1909 in Madrid, this paper was well known across Spain.
5
Gonzalez-Barahona, Jesús M., Gregorio Robles, Miguel Ortuno-Perez, Luis Rodero-Merino, José Centeno-Gonzalez, Vicente Matellan-Olivera, Eva Castro-Barbero, and Pedro de-las-Heras-Quirós. "Analyzing the Anatomy of GNU/Linux Distributions." In Free/Open Source Software Development, 27–58. IGI Global, 2005. http://dx.doi.org/10.4018/978-1-59140-369-2.ch002.
Full textAbstract:
GNU/Linux distributions are probably the largest coordinated pieces of software ever put together. Each one is in some sense a snapshot of a large fraction of the libre software development landscape at the time of the release and, therefore, its study is important to understand the appearance of that landscape. They are also the working proof of the possibility of releasing reliable software systems in the range of 50-100 millions of lines of code, even when the components of such systems are built by hundreds of independent groups of developers, with no formal connection to the group releasing the whole system. In this chapter, we provide some quantitative information about the software included in two such distributions: Red Hat and Debian. Differences in policy and organization of both distributions will show up in the results, but some common patterns will also arise. For instance, both are doubling their size every two years, and both present similar patterns in programming language usage and package size distributions. All in all, this study pretends to show how GNU/Linux distributions are with respect to their source code, and how they evolve over time. A methodology of how to make comparable and automated studies on this kind of distributions is also presented.
6
Curry, Nicola, and Susie Shapiro. "Thrombocytopenia and disorders of platelet function." In Oxford Textbook of Medicine, edited by Chris Hatton and Deborah Hay, 5520–32. Oxford University Press, 2020. http://dx.doi.org/10.1093/med/9780198746690.003.0545.
Full textAbstract:
The platelet is the smallest circulating blood cell. In health, it plays a vital role in haemostasis, and in disease contributes to problems of bleeding and/or thrombosis. The number of platelets produced is under tight homeostatic control, regulated by the cytokine thrombopoietin. A normal platelet count lies within the range 150 to 450 × 109/litre. Thrombocytopenia is defined as a reduction in the number of circulating platelets to fewer than the normal reference range (typically <150 × 109/litre). Spontaneous bleeding is uncommon unless the platelet count falls below 10 to 20 × 109/litre or unless there is abnormal platelet function. Thrombocytopenia can be classified according to three main pathologies: (1) increased platelet destruction, (2) reduced platelet production, and (3) increased platelet sequestration. Disorders of increased platelet destruction may be immune mediated or nonimmune. Primary immune thrombocytopenia (ITP) is an acquired disorder affecting both adults and children, characterized by an isolated thrombocytopenia (platelet count <100 × 109 /litre) for which no precipitant can be found. Primary ITP is a diagnosis of exclusion. Corticosteroids are the main first-line therapy for adult ITP, commonly prednisolone. Nonimmune causes of platelet destruction include microangiopathic haemolytic disorders such as thrombotic thrombocytopenic purpura, haemolytic uraemic syndrome, and disseminated intravascular coagulation. Decreased platelet production—most cases are acquired, with common or important causes being toxins (drugs, alcohol), nutritional deficiencies (folate or vitamin B12), bone marrow infiltration, and myelodysplastic syndrome. Disorders of platelet distribution and platelet sequestration include splenomegaly and hypersplenism, haemodilution, and extracorporeal circulation. Disorders of platelet function are usually acquired. The most common causes are medications and toxins, systemic disorders, and haematological diseases. Congenital disorders are a rare cause of symptomatic bleeding.
7
Otayek, Michel. "Keepsakes of the Revolution." In Writing Revolution, 227–44. University of Illinois Press, 2019. http://dx.doi.org/10.5622/illinois/9780252042744.003.0014.
Full textAbstract:
This chapter examines the literature produced by the CNT-FAI during the Spanish Civil War, with a focus on Estampas de la Revolución Española and ¿España? Un libro de imágenes sobre cuentos de miedo y calumnias fascistas. The author shows that the revolutionary narrative had the power to generate considerable media interest and mobilize public support beyond anarchist circles. However, the Foreign Propaganda Office failed to capitalize on the strengths of existing networks across the United States at a time of increased collaboration between Hispanic and non-Hispanic anarchist groups. As head of the Foreign Propaganda Office, Augustin Souchy developed and sought to carry out a propaganda production and distribution strategy that relied heavily on his links to anarchist networks across Europe, particularly in France and Sweden, while all but neglecting the renewed strength of the movement in North America.
8
Contreras Cabrera, Gustavo Antonio, Rosa María Jordá Borrell, and Javier López Otero. "Equidad y efectos distributivos de la política regional de inclusión digital en Andalucía." In Libro Homenaje al Profesor Alfredo Morales Gil, 457–80. Servicio de Publicaciones de la UA, 2016. http://dx.doi.org/10.14198/librohomenajealfredomorales2016-22.
Full text
9
Rouet, François. "4. Diffusion et distribution : place et enjeux pour la filière du livre et l’offre non marchande des bibliothèques." In Les bibliothèques dans la chaîne du livre, 125. Éditions du Cercle de la Librairie, 2004. http://dx.doi.org/10.3917/elec.paye.2004.01.0125.
Full textConference papers on the topic "Distribution libre"
1
Steimes, Johan, François Gruselle, and Patrick Hendrick. "Performance Study of an Air-Oil Pump and Separator Solution." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68895.
Full textAbstract:
Many applications need to extract a certain phase from a multiphase flow like in oil extraction, flow in nuclear power plants, aircraft lubrication systems, etc. The Aero-Thermo-Mechanics (ATM) Department of Universiteé Libre de Bruxelles (ULB) is developing an original system to extract the gas from a liquid-gas flow together with increasing the pressure of the liquid phase. This system will help to reduce the complexity and the oil consumption of aeroengine lubrication systems. This paper will summarise the results of a first air/oil prototype. It will also present the guidelines learned from this prototype and used to design a second version of the integrated pump and separator. A newly developed oil consumption measurement system will also be presented. Based on previous results, on litterature review and on an in-house theoretical model, the paper will explain theoretically how the separation efficiency is affected by the particle distribution at the inlet of the prototype, and by the key parameters identified in different studies. Finally the conclusions will present the lessons learned through the design and tests of these two prototypes and the future work will be presented.
2
Herraiz, Israel, Gregorio Robles, Rafael Capilla, and Jesus M. Gonzalez-Barahona. "Managing Libre Software Distributions under a Product Line Approach." In 2008 32nd Annual IEEE International Computer Software and Applications Conference. IEEE, 2008. http://dx.doi.org/10.1109/compsac.2008.45.
Full text
3
Zhang, Xin, Shenjing Yao, Ronghui Huang, Dan Hou, Weizhao Huang, and Min Zheng. "Oil-immersed transformer online hot spot temperature monitoring and accurate life lose calculation based on liber Bragg grating sensor technology." In 2014 China International Conference on Electricity Distribution (CICED). IEEE, 2014. http://dx.doi.org/10.1109/ciced.2014.6991908.
Full text
4
Ludovisi, Daniele, William M. Worek, and Milton Meckler. "VRA Enhancement of Two Stage LiBr Chiller Performance Improves Sustainability." In ASME 2007 Energy Sustainability Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/es2007-36109.
Full textAbstract:
Multi-effect LiBr absorption chiller must take advantage of higher temperature heat sources to achieve higher COP so as to be competitive with lower first cost comparable commercially available, efficient electric chillers under current market pricing conditions. Yet a nominal conventional double-effect absorption chiller operating at a COP of 1.0 versus a comparable efficient motor driven centrifugal chiller operating at a COP of 7.0 will consume slightly less than twice the amount of prime natural gas (NG) source energy assuming a local 28% NG fired electric utility plant’s annual average efficiency and a 10% gas distribution leakage and 10% electric transmission loss to user’s meter. However if the COP of the above referenced double-effect LiBr absorption chiller were doubled, it would consume approximately the same amount of prime NG source energy and equally sustainable from an environmental impact standpoint. Consequently research to further improve double-effect LiBr absorption chillers beyond the VRA benefits reported to date was investigated in this study. Former simulation studies of a low differential pressure-vapor recompression absorber (VRA) reported in 2001 indicated a 7% COP efficiency gain, while additional simulation studies reported in 2006 indicated a 38% COP efficiency gain with the VRA operating at elevated differential pressures at the same upper stage concentrator temperature previously considered. Double-effect LiBr absorption chillers are limited by corrosion effects, which have been shown to accelerate significantly above 160 °C. In this paper, a reverse series flow, double-effect LiBr absorption chiller employing a VRA is investigated over a wider range of upper stage concentrator and absorber cooling temperatures but operating at the same low and elevated pressure differential levels reported earlier showed significant improvement in COP efficiency, capacity performance and projected hybrid operational cost.
5
Sul, Hea Youn, Jung-Yeul Jung, and Yong Tae Kang. "Thermal Conductivity Enhancement of Binary Nanoemulsions (O/S)." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22556.
Full textAbstract:
Binary nanoemulsions, nano-sized oil-droplet suspensions in binary solution (H2O/LiBr), are developed to enhance the heat and mass transfer performance of absorption refrigeration systems. In this study, a novel four-step method is proposed to prepare the stable oil-in-binary solution (O/S) emulsion. To stabilize the nanoemulsions in a strong electrolyte, a polymeric stabilizer (Gum Arabic) is used as a steric stabilizer. The droplet size and the thermal conductivity of binary nanoemulsions are measured by the dynamic light scattering method and the transient hot-wire method, respectively. It is concluded that the ratio of 2:1 (oil:surfactant) is the best condition for distribution stability. It is also found that the measured thermal conductivity of the oil-in-water nanoemulsion enhances up to 6.4% at 0.1 vol% of oil, and the binary nanoemulsion enhances up to 3.6% at 1.0 vol% of oil in 30 wt% H2O/LiBr compared with the estimated one from the Maxwell’s model. This result is compared with electric conductivity of LiBr solution and it is found both conductivities have similar trend. It is finally proposed that the thermal conductivity of the binary nanoemulsion could be enhanced by adding nano-sized droplets of n-decane oil, which has a lower thermal conductivity than that of the base fluid.
6
Odunfa, K. M., R. O. Fagbenle, and M. O. Oyewola. "Magnetic Field Enhancement in Water-Lithium Bromide Absorption Refrigeration Systems." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-64192.
Full textAbstract:
Absorption refrigeration systems are generally characterized by low Coefficient of Performance (COP). Absorption enhancement is an effective way of improving the COP of refrigeration systems. Literature is sparse on the use of magnetic field for the enhancement of absorption refrigeration systems despite its cheapness and environmental friendliness as compared with other enhancement methods. Although the method has recently been employed on ammonia solution, its influence on lithium bromide (LiBr) solution is yet to be fully studied. In this paper a numerical model for the magnetic field enhancement in water-LiBr absorption systems was developed and evaluated. The flow within the film thickness to the absorber wall was considered as a two-dimensional steady laminar flow. A Finite Difference model was developed based on conservation of mass, momentum, energy equations and mass transport relationship. The model was validated using data from the literature on ammonia solution. Standard parameters including absorber wall length (1 m), film thickness (10–3 m), magnetic field vacuum permeability (1.257 × 10–6 kgmA-2s2), magnetic mass susceptibilities and magnetic induction intensities were used for LiBr solution’ modeling. Changes in their concentrations, both in the direction of falling film and across its thickness, were investigated. Data were analysed using descriptive statistics and Student’s t-test (p = 0.05). The concentration distribution of lithium bromide solution in the direction of falling film was between 54.9% and 60.0% for the magnetic induction range of 0.0 and 3.0 Tesla. Across the film thickness and for the same range of magnetic induction, the concentration distribution was between 0.0 and 0.19. The concentration of the solution increased from 0.0 to 21.7 when magnetic induction was increased from 0.0 to 3.0 Tesla, implying higher cooling effect. The COP of lithium bromide solution absorption refrigeration system was increased by 0.3% for magnetic induction of 3.0 Tesla. Magnetic field enhanced the absorption performance in the lithium bromide solution; hence can be used in typical absorption refrigeration systems.
7
Onan, Cenk, and Derya B. O¨zkan. "Daily Exergy Assessment of LiBr-Water Absorption Chiller Used for Solar Cooling." In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90162.
Full textAbstract:
In today’s society in which energy costs are high, the use of renewable energy sources has gained importance in cooling and heating systems. In recent years, solar cooling, which is a type of renewable energy source, is increasing rapidly in use in Europe. A solar assisted absorption cooling system was designed for acclimatizing villas in Mardin, Turkey, and the performance of the system under different temperatures was analyzed using Matlab. The cooling load of the villas was calculated assuming a cooling season of May 15 to September 15. The cooling capacity was calculated to be 106 kW. Changes in the coefficient of performance, the capacity of the hot water driven absorption cooling system and the exergy destruction values of the system according to our country’s meteorological data were calculated using Matlab. The amounts of inlet and outlet exergy were calculated separately for each component. Calculations were performed for two dead state temperatures: 25 °C and the environmental temperature, which is a more realistic approach. Therefore, the effect of varying the dead state temperature on the results was determined. It is observed that the greatest source of exergy destruction in the system was the solar collectors and the second greatest source of exergy destruction was the generator. The hourly distributions of exergy destruction values are given in a table. The effects of environmental temperature and solar insulation were stated for the optimization of energy and exergy in the combined system, which are planned to be established.
8
Liu, Yunshan, and Ebrahim Al Hajri. "Mass and Heat Transfer Characteristics of a Single-High Aspect Ratio Microchannel Absorber." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-89787.
Full textAbstract:
Recently, study on a microscale-based absorption refrigeration system has sprung up motivated by the need of efficient energy utilization. Heat-driven absorption systems offer a possibility of generating both power and cooling with environment friendly refrigerants, such as ammonia/water and LiBr/water. However, these systems are often large in size and low in COP especially in single stage absorption systems. These characteristics of absorptions systems make them unattractive in most cases. This work introduces the utilization of micro-channel enhanced surfaces as heat exchangers to enhance the component and system performance, to reduce the system size and to reduce the cost of the system as well. In this work, a new concept of enhancing heat and mass transfer processes is applied in the absorber part of the absorption cycle by using a single micro-channel. Due to its merit of high area to volume ratio, microchannel technology has been well theoretically validated to be a very effective and potential choice for enhancing heat transfer performance. But there is a lack of research work on the mass transfer performance in micro-channels. This work investigated simultaneous mass and heat transfer characteristics of a novel microchannel absorber that uses LiBr/water as the working fluid. A microchannel with hydraulic diameter of 0.7mm is employed in this characterization study. Velocity distribution, pressure drop, concentration and temperature profile inside the microchannel as well as effects of the inlet absorbent concentration, flow rate and temperature together with the refrigerant flow rate on the heat/mass transfer are predicted. Investigations on the optimum inlet angle design of a single channel absorber are also presented in the end of this work. Feasibility of this novel absorber design was proved via this numerical simulation as the mass transfer taking place inside the mixing channel was observed to achieve the identical performance but with a size reduction by 1/27 compared to a conventional falling film absorber. A 7 times enhancement of the heat transfer coefficient was also achieved with the comparison of a macro-scale based absorber configuration.
9
Zhao, Jian, Maria José Resende Oliveira, Junfeng Zhao, Kangxu Ren, Leonardo Costa Oliveira, Isabela Oliveira Carmo, Cristiano Camelo Rancan, and Qicai Deng. "Fault Activity and its Influences on Distribution of Igneous Rocks in Libra Block, Santos Basin: Semi-Quantitative to Quantitative Assessment of Fault Activity Based on High-Resolution 3D Seismic Data." In Offshore Technology Conference Brasil. Offshore Technology Conference, 2019. http://dx.doi.org/10.4043/29691-ms.
Full text
10
Cepraga, D. G., G. Cambi, M. Frisoni, and D. Ene. "Cemented Containers Radiological Data From a Disused Uranium Mine Low-Level Waste Repository: A Calculated-Experiment Cross-Check for Data Verification and Validation." In ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4516.
Full textAbstract:
Code validation problems involve calculation of experiments and a comparison experiment-calculation. Experimental data and physical properties of these systems are used to determine the range of applicability of the validation. Once a sequence-code of calculations has been validated, it has to be underlined that the comparison experimental-calculated results involving “complex systems” or “complex experimental measures” permits also a bi-lateral cross-check between the calculation scheme and the experimental procedures. The results of the testing and the validation effort related to the collection of information and measured data and the comparison between code results with experimental data coming from a “low-level waste” repository are presented in this paper. The Baita-Bihor repository, sited into former disused uranium mine in Transylvania, has been considered as the source of experimental data. The study was developed through the following steps: a) collection and processing of measured data (radioactivity content and dose rate), from the cemented containers of the Baita-Bihor repository; b) decay gamma source calculation by the ANITA-2000 code package (the input data for the calculations are the measured isotope activities for each container); c) decay gamma transport calculation by the SCALENEA-1 shielding Sn sequence approach (Nitawl-Xsdrnpm-Xsdose modules of the Scale 4.4a code system, using the Vitenea-J library, based on FENDL/E-2 data) to obtain dose rates on the surfaces and at various points outside the containers; d) comparison experimental-calculated dose rates, taking into account also the measurement uncertainties. The new version of the ANITA-2000 activation code package used makes possible to assess the behaviour of irradiated materials independently from the knowledge of the irradiation scenario but using only data on the isotope radioactive material composition. Radioactive waste disposed of at Baita Bihor repository consists of worn reactor parts, resins and filters, packing materials, mop heads, protective clothing, temporary floor coverings and tools, the sources normally generated during the day-to-day operation of research reactors, the remediation-treatment stations and the medicine and biological activities. The low and intermediate wastes are prepared for shipping and disposal in the treatment stations by confining them in a cement matrix inside 220 litre metallic drums. Each container consists of an iron cladding filled by concrete Portland. Radioisotope composition and radioactivity distributions inside the drum are measured. The gamma spectroscopy has been used for. The calibration technique was based on the assumption of a uniform distribution of the source activity in the drum and also of a uniform sample matrix. Dose rate measurements are done continuously, circularly, in the central plan on the surface of the drum and 1 m from the surface, in the air. A “stuffing factor” model has been adopted to simulate, for the calculation, the spatial distribution of the gamma sources in the concrete region. In order to guarantee a complete Quality Assurance for codes and procedures, a simulation of the radioactive containers to evaluate the dose rates was done also by using the Monte Carlo MCNP-4C code. Its calculation results are in a very good agreement with those obtained by the Sn approach (discrepancies are around 2%, using the spherical approximation).