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Regional Drought Severity Assessment at a Basin Scale in the Limpopo Drainage System

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journal of Water Resource and Protection 2013年第11期5卷 1110-1116页

作者： Berhanu F. Alemaw j. m. Kileshye-Onema D. Love Department of Geology University of Botswana Gaborone Botswana WaterNet University of Zimbabwe Harare Zimbabwe

A spatial analysis of drought characteristics in the Limpopo basin is undertaken to evaluate its regional implications to water management challenges. In this study, drought duration, frequency and severity are investigated. In addition drought Severity-Area-Frequency (SAF) curves were constructed. The entire Limpopo River Basin is subdivided into four homogeneous regions based on topographic and climate variations in the basin, which was constructed with the K-means Clustering algorithm. Using the medium range time series of the Standardized Precipitation Index (SPI) as an indicator of drought for each homogeneous region, monthly and annual SAF curves and maps of probability of drought occurrence were produced. The results indicated localized severe droughts in higher frequencies compared to moderate to severe low frequency droughts spread over wider areas in the basin. The approach can be used to develop improved drought indicators to assess the relationship between drought hazard and vulnerability and to enhance the performance of methods currently used for drought forecasting. In general, this preliminary investigation reveals that the western part of the basin will face a higher risk of drought when compared to other regions of the Limpopo Basin in terms of the medium-term drought patterns. The Limpopo Basin is water stressed and livelihood challenges remain high, thus impacts of droughts and related resilience options should be taken into account in the formulation of regional sustainable water resources development strategies.

关键词： Drought Standardized Precipitation Index Drought Severity Drought Severity-Area-Frequency (SAF) Curves Limpopo Basin

Twenty years of experience with the rabbit model,a versatile model for tracheal transplantation research

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Plastic and Aesthetic Research 2016年第1期3卷 223-230页

作者： margot Den Hondt Bart m.Vanaudenaerde Pierre Delaere jan j.Vranckx Department of Plastic and Reconstructive Surgery KU Leuven University Hospitals3000 LeuvenBelgium Department of Clinical and Experimental medicine Laboratory of PulmonologyLung Transplant UnitKU LeuvenUniversity of Leuven3000 LeuvenBelgium Department of Otolaryngology Head and Neck SurgeryKU Leuven University Hospitals3000 LeuvenBelgium

Pathologies comprising more than half the length of the trachea are a challenge to the reconstructive *** tracheal transplantation techniques aim to offer the patient a curative solution with a sustained improvement in quality of *** review summarizes the authors’experience with the rabbit as a versatile model for research regarding tracheal *** of the segmental blood supply of the trachea,it is not feasible to transplant the organ together with a well-defined vascular *** such,the key element of successful tracheal transplantation is the creation of a new blood *** vascularized construct is created by prelaminating the rabbit trachea heterotopically,within the lateral thoracic *** prelamination,the construct and its vascular pedicle are transferred to the orthotopic position in the *** model has become gold standard because of the advantages of working with rabbits,the anatomy of the rabbit trachea,and the reliability of the lateral thoracic artery *** this paper,the key elements of surgery in the rabbit are discussed,as well as the tracheal anastomosis and the harvest of the lateral thoracic artery *** tips and tricks are *** data described in this review represent the fundaments of ongoing translational research in the center over the past twenty years.

关键词： Trachea transplantation rabbit lateral thoracic artery flap prelamination prefabrication

Development of aluminum rheo-extrusion process using semi-solid slurry at low solid fraction

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Transactions of Nonferrous metals Society of China 2010年第9期20卷 1763-1768页

作者： T.RATTANOCHAIKUL S.jANUDOm N.mEmONGKOL j.WANNASIN Department of mining and materials Engineering Faculty of EngineeringPrince of Songkla University Department of Industrial Engineering Faculty of EngineeringPrince of Songkla University

An aluminum extrusion process is mainly used to fabricate long tubes, beams and rods for various applications. However, this process has a high production cost due to the need for investment of high-pressure machinery. The objective of this work is to develop a new semi-solid extrusion process using semi-solid slurry at low solid fractions. A laboratory extrusion system was used to fabricate aluminum rods with the diameter of 12 ram. The semi-solid metal process used in this study was the gas induced semi-solid （GISS） technique. To study the feasibility of the GISS extrusion process, the effects of extrusion parameters such as plunger speed and solid fi-action on the extrudability, microstructure, and mechanical properties of extruded samples were investigated. The results show that the plunger speed and solid fraction of the semi-solid metal need to be carefully controlled to produce complete extruded parts.

关键词： aluminum alloys extrusion semi-solid metal rheo-extrusion gas induced semi-solid (GISS)

Escherichia coli-host macrophage interactions in the pathogenesis of inflammatory bowel disease

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World journal of Gastroenterology 2014年第27期20卷 8751-8763页

作者： Ahmed Tawfik Paul K Flanagan Barry j Campbell Department of Gastroenterology Institute of Translational Medicine University of Liverpool

multiple studies have demonstrated alterations in the intestinal microbial community (termed the microbiome) in Crohn’s disease (CD) and several lines of evidence suggest these changes may have a significant role in disease pathogenesis. In active and quiescent disease, both the faecal and mucosa-associated microbiome are discordant with matched controls with reduced biodiversity, changes in dominant organisms and increased temporal variation described. mucosa-associated adherent, invasive Escherichia coli (E. coli) (AIEC), pro-inflammatory and resistant to killing by mucosal macrophages, appear to be particularly important. AIEC possess several virulence factors which may confer pathogenic potential in CD. Type-1 pili (FimH) allow adherence to intestinal cells via cell-surface carcinoembryonic antigen-related cell adhesion molecules and possession of long polar fimbrae promotes translocation across the intestinal mucosa via microfold (m)-cells of the follicle-associated epithelium. Resistance to stress genes (htrA, dsbA and hfq) and tolerance of an acidic pH may contribute to survival within the phagolysosomal environment. Here we review the current understanding of the role of mucosa-associated E. coli in Crohn’s pathogenesis, the role of the innate immune system, factors which may contribute to prolonged bacterial survival and therapeutic strategies to target intracellular E. coli.

关键词： Crohn's disease Inflammatory bowel disease Escherichia coli Intra-macrophage survival and replication Phagolysosome Autophagy

Review of Obstetrics and Perinatal Outcome of multiple Pregnancies with Vanishing and Selective Embryo Reduction in an Oocyte Donation Program

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journal of Reproduction and Contraception 2005年第2期16卷 73-82页

作者： Rodríguez-González m García-Velasco jA Remohí j Pellicer A Serra V Instituto Valenciano de Infertilidad of Castellón Spain Instituto Valenciano de Infertilidad of madrid. Instituto Valenciano de Infertilidad of Valencia Spain Departmen of Pediatrics Obstetrics and Gynaecology Valencia University School of Medicine Spain

To check previous findings of the most common complications among pregnancies with vanishing embryo（VE） in another actual study retropective and in group of patiens with selective embryo reduction （SER） methods We defined vanishing phenomenon as the spontaneous loss of one or more embryos after visualizing heart activity at the first trimester of pregnancy. Selective embryo reduction was performed between 8th-12th pregnancy week, through vaginal punction and aspiration of embryonic mass. Results Vanishing embryo was observed in 86 patients （18.0%）. In 61 patients （70.9%） this phenomenom happened before 9th pregnancy week. The incidence of VE increased with higher number of gestational sacs initially visualized （P〈0.03）. First trimester bleeding was more common among pregnancies with VE than in the control （P〈0.005）. The incidence of pregnancy induced hypertension was lower in pregnancies with VE than in the controls （P〈0.03）. In contrast, preterm spontaneous rupture of membranes was higher, although without statistical significance. Gestational age at delivery, mode of delivery and birth weight was similar in the group of VE and the controls （P=NS）. Conclusion All these informations may be useful in counselling patients on the prognosis and outcome of pregnancies achieved by oocyte donation.

关键词： vanishing embryo spontaneous embryo reduction selective embryo reduction outcome

Bayesian Estimation for GEV-B-Spline model

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Open journal of Statistics 2013年第2期3卷 118-128页

作者： Bouchra Nasri Salaheddine El Adlouni Taha B. m. j. Ouarda Center Eau Terre Environnement Institut national de la Recherche Scientifique Québec Canada Département de mathématique et de Statistique Université de Moncton Moncton Canada

The stationarity hypothesis is essential in hydrological frequency analysis and statistical inference. This assumption is often not fulfilled for large observed datasets, especially in the case of hydro-climatic variables. The Generalized Extreme Value distribution with covariates allows to model data in the presence of non-stationarity and/or dependence on covariates. Linear and non-linear dependence structures have been proposed with the corresponding fitting approach. The objective of the present study is to develop the GEV model with B-Spline in a Bayesian framework. A markov Chain monte Carlo (mCmC) algorithm has been developed to estimate quantiles and their posterior distributions. The methods are tested and illustrated using simulated data and applied to meteorological data. Results indicate the better performance of the proposed Bayesian method for rainfall quantile estimation according to BIAS and RmSE criteria especially for high return period events.

关键词： GEV Bayesien B-Spline Nonlinearity Covariate Non-Stationarity

Determination of Young Olive-Tree Water Consumption with Drainage Lysimeters

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journal of Water Resource and Protection 2014年第9期6卷 841-851页

作者： L.Puppo C.García j.Girona m.García-Petillo Grupo Disciplinario de Ingeniería Agrícola Unidad de HidrologíaDepartamento de Suelos y Aguas-Facultad de AgronomíaUniversidad de la RepúblicaMontevideoUruguay Instituto Nacional de Investigacion Agropecuaria(INIA) Las BrujasCanelonesUruguay Institut de Recerca i Tecnologia Agroalimentaries(IRTA) Programa Uso Eficiente del AguaCentre UdL-IRTA Parc de GardenyEdifici FruitcentreLleidaCatalunyaEspana

Information about olive-tree irrigation in sub-humid climates, as in Uruguay, is scarce. Water consumption of young olive trees, Arbequina variety, was measured for two years with six drainage lysimeters, protected from rain by an automatic rain-out shelter. Irrigation water volume and drainage of each lysimeter were measured daily and soil moisture was registered twice a week with neutron probe at four depths. Evapotranspiration (ETc) was calculated by volume balance. Data periods when available water descended below 50% or increased over 100% were eliminated, as those in which the stem water potential was below -1.5 mPa. Water consumption values were averaged within 7- to 14-day periods, expressed in mm·d-1, and referred to a 2.5 × 5.5 m plantation framework without vegetation cover. There was a positive linear relation of the summer crop coefficient (Kc mid) with age, canopy cover percentage and canopy volume. Canopy cover percentage was the parameter which explained most of the variation of Kc mid, which ranged between 0.13 and 0.24, with 5% and 46% canopy cover, respectively. Full irrigation, associated to a good drainage resulted in a rapid growth of the young plants, bringing forward the start of full production period. This represents useful information for the adjustment of irrigation in olive-tree orchards, to accelerate growth with a rational and sustainable use of both water and energy in Uruguay.

关键词： Evapotranspiration Crop Coefficients Irrigation Requirements Olea europea L.

Thermal, mechanical and Rheological Properties of Low Density/Linear Low Density Polyethylene Blend for Packing Application

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journal of materials Science and Chemical Engineering 2018年第1期6卷 32-38页

作者： F. Al-Attar m. Alsamhan A. Al-Banna j. Samuel Polymeric Products and Customization Program Petroleum Research Center Kuwait Institute for Scientific Research Kuwait City Kuwait

Packaging is the subject of considerable commercial development by a variety of organizations around the world. In this study the mechanical, thermal and rheological properties were investigated for different blend ratios of low density polyethylene (LDPE) and linear low density polyethylene (LLDPE). The weight percent of the LDPEs used in the blends were 50, 60, 70, 80 and 90. The polymer blends were prepared in a twin screw extruder to produce a thin sheet (1-mm thickness) similar to the packaging grade. Tensile results showed that the 50/50 composition exhibited the highest stress at break, where the differential scanning calorimetry results indicated a co-crystalline phase in some blends. The results produced by the rheometer revealed the LLDPE effect over the complex viscosity and consequently blend easy processing. The present study conclusively demonstrates that at low weight percent of linear low density polyethylene in the blend displays better properties for packaging application.

关键词： PE Blend Packaging Tensile Properties morphology

Experimental and CFD Simulations of Pressure Loss through Perforated Plates

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journal of Energy and Power Engineering 2011年第2期5卷 112-121页

作者： j.A. Barros Filho m.A. Navarro A. dos Santos E. jordao Brazilian Nuclear Energy Commission （CNEN/CDTN） Av. Pres. Antonio Carlos 6627-UFMG-Pampulha 30123-970 Belo Horizonte Minas Gerais Brazil Federal University of minas Gerais （UFA4G/DEMEC） Av. Pres. Antonio Carlos 662-UFMG-Pampulha 31270-901 Belo Horizonte Minas Gerais Brazil FEQ/UNICAmP Cidade Universitoria ＂Zeferino Vaz＂ Av. Albert Einstein 500 13083-852 Campinas SP Brazil

This paper presents the experimental pressure loss of water flow through perforated plates with geometry similar to the ones of the bottom end piece of a Pressurized Water Reactors （PWR） fuel element. Geometric features like the number, pattern and diameter of holes were evaluated as well as different inlet chamfers. The recovering pressure profile downstream of the plates was also measured. The experimental results were compared with numerical modeling performed with the commercial Computational Fluid Dynamics （CFD） code CFX 11.0. The analysis of the results shows that the standard k-e turbulence model presents the best compromise between computing time and accuracy for the calculation of the total pressure loss through the perforated plates tested.

关键词： Computational fluid dynamics (CFD) pressurized water reactors-PWR pressure drop perforated plates