792 research outputs found

    CFD Simulation of Heat and Mass Transfer for Climate Control in Greenhouses

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    Greenhouse plant production involves a number of processes such as transpiration, condensation, photosynthesis, and climate control. Such processes, in turn, set off mass and heat transfer phenomena that influence not only the quality and quantity of crop production but also its environmental cost. While these processes have considerably been analyzed in separate, they strongly interact with one another. For instance, increased radiation (mainly thermal infrared) increases temperature, reduces humidity, consequently increases transpiration, and affects CO2 exchange as well as other reaction rates. Computational fluid dynamics (CFD) is a numerical tool with a solid physical basis which allows, through the construction of a computational model, to simulate the fluid flow environment. Heating, ventilation, and condensation have been analyzed in the greenhouse environment with CFD techniques. The current challenge is the interaction of these processes and their impact on the production system. The present work summarizes some CFD investigations carried out in this topic, in order to analyze the processes of heat and mass transfer in a greenhouse for agronomic purposes

    Ciencias Sociales: EconomĂ­a y Humanidades HANDBOOK T-I

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    Se presenta un breve examen de la producciĂłn y comercializaciĂłn de rosa en MĂ©xico; un estudio en MĂ©xico sobre el ingreso mĂ­nimo de las familias que identifica la lĂ­nea de pobreza alimentaria en el ĂĄrea rural del sur de MĂ©xico, 2012; un pequeño estudio donde hablarĂĄ sobre el anĂĄlisis comparado del Sector Gubernamental y la EconomĂ­a Mexicana desde la perspectiva de los eslabonamientos productivos Hirshman-Rasmuss; un estudio sobre los canales de comercializaciĂłn de limĂłn persa en el municipio de MartĂ­nez de la Torre, Veracruz; una anĂĄlisis del comercio estratĂ©gico en el TLCAN: El Estado en la polĂ­tica agrĂ­cola de biocombustibles; tambiĂ©n se expresan acerca de la importancia de la comercializaciĂłn del cafĂ© en MĂ©xico; un diagnĂłstico, retos del comercio electrĂłnico en el Sector Agroindustrial Mexicano; trabajo nos muestra y habla sobre la inversiĂłn extranjera directa y su impacto en crecimiento de MĂ©xico, un anĂĄlisis en prospectiva: 1999-2010; un estudio acerca sobre la importancia de la Banca en MĂ©xico; un trabajo acerca de la competitividad de la producciĂłn agrĂ­cola en MĂ©xico, un anĂĄlisis regional; se analizan todo acerca de el SIAL productor de quesos en Poxtla, competividad y territorio; se habla acerca de la intermediaciĂłn financiera al servicio de la comunidad indĂ­gena: el fondo regional indĂ­gena Tarhiata Keri; ademas un estudio acerca de la demanda de Importaciones de durazno (Prunus pĂ©rsica L. Batsch) en MĂ©xico procedentes de Estados Unidos de AmĂ©rica (1982-2011); Loera y SepĂșlveda analizan los parĂĄmetros de la productividad forestal en la producciĂłn de madera en rollo; un anĂĄlisis de factores sociales, ambientales y econĂłmicos del territorio rural cercano a la ciudad de MĂ©xico; un estudio acerca de la crisis econĂłmica mundial y su efecto sobre los flujos migratorios de AmĂ©rica Latina; MagadĂĄn, HernĂĄndez y Escalona presentan la tipologĂ­a de los sujetos sociales que intervienen en el mercado campesino de OcotlĂĄn Oaxaca; la normalizaciĂłn del proceso de compostaje: una opciĂłn para desarrollar el mercado de la composta; acerca de la reestructuraciĂłn del capitalismo y crisis polĂ­tica en MĂ©xico; la rentabilidad de la producciĂłn de miel en el municipio de LeĂłn, Guanjuato; la economĂ­a del maĂ­z en la regiĂłn metropolitana, Chiapas, 2014; anĂĄlisis de los centros de educaciĂłn y cultura ambiental, necesidad de profesionalizaciĂłn PedagĂłgica de facilitadores ambientales; los Costos y competitividad de la producciĂłn del limĂłn persa en el municipio de MartĂ­nez de la Torre, Veracruz

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Search for stop and higgsino production using diphoton Higgs boson decays

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    Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass

    Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

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    Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia

    Search for anomalous production of events with three or more leptons in pp collisions at √s = 8TeV

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    Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.A search for physics beyond the standard model in events with at least three leptons is presented. The data sample, corresponding to an integrated luminosity of 19.5fb-1 of proton-proton collisions with center-of-mass energy s=8TeV, was collected by the CMS experiment at the LHC during 2012. The data are divided into exclusive categories based on the number of leptons and their flavor, the presence or absence of an opposite-sign, same-flavor lepton pair (OSSF), the invariant mass of the OSSF pair, the presence or absence of a tagged bottom-quark jet, the number of identified hadronically decaying τ leptons, and the magnitude of the missing transverse energy and of the scalar sum of jet transverse momenta. The numbers of observed events are found to be consistent with the expected numbers from standard model processes, and limits are placed on new-physics scenarios that yield multilepton final states. In particular, scenarios that predict Higgs boson production in the context of supersymmetric decay chains are examined. We also place a 95% confidence level upper limit of 1.3% on the branching fraction for the decay of a top quark to a charm quark and a Higgs boson (t→cH), which translates to a bound on the left- and right-handed top-charm flavor-violating Higgs Yukawa couplings, λtcH and λctH, respectively, of |λtcH|2+|λctH|2<0.21

    Measurement of B-c(2S)(+) and B-c*(2S)(+) cross section ratios in proton-proton collisions at root s=13 TeV

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    Measurement of associated W plus charm production in pp collisions at √s=7 TeV

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    Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

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    This paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the dat
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