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Investigation of grain mass flow in a mixed flow dryer

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Particuology 2014年第1期12卷 33-39页

作者： fab.an weigler Jochen Mellmann Department of Post-harvest Technology Leibniz Institute for Agricultural Engineering Potsdam-Bornim

The numerical modeling of grain drying is a topic of great relevance to post-harvest engineering. The required type of drying process depends on the quantity of grain to be dried and the required quality of the grain. The choice of the drying system depends on the operating parameters of the drying process. The granular flow pattern of the material exerts a significant influence on the drying process. Post-harvest drying of grain is essential for better storage, handling, and processing. Therefore, it is important to know the material behavior that controls the particle flow patterns of grain in the drying equipment to guarantee the product quality and to optimize the drying process conditions. The discrete element method （DEM） was applied to investigate the particle flow pattern of wheat through a mixed-flow dryer （MFD） without airflow, and the findings were compared with experimental results in this work. The investigations were performed using dry wheat with 14 wb% moisture content.

关键词： Keywords:Mixed-flow dryerGrain mass flowDiscrete element method

Influence of the number of flights on the dilute phase ratio in flighted rotating drums by PTV measurements and DEM simulations

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Particuology 2021年第3期19卷 171-182页

作者： Lanyue Zhang Zhaochen Jiang Jochen Mellmann fab.an weigler fab.an Herz Andreas Bück Evangelos Tsotsas Department of Postharvest Technology Leibniz Institute for Agricultural Engineering and BioeconomyMax-Eyth-Allee 100Potsdam 14469Germany Thermal Process Engineering Otto von Guericke University MagdeburgUniversitaetsplatz 239106 MagdeburgGermany Institute of Particle Technology(LFG) FAU Erlangen-NurembergCauerstr.491058 ErlangenGermany Department of Applied Biosciences and Process Engineering Anhalt University of Applied SciencesBernburgerStr.5506366 KoethenGermany

Particle distribution in the cross-section of the flighted rotating drum(FRD)is critical to the analysis of heat and mass transfer between gas and *** this work,the particle tracking velocimetry(PTV)method is applied to study the influence of the number of flights on the particle motion in *** drum,installed with 1,4,8,or 12 rectangular flights,is filled with plastic balls to 15%and operated at various rotating speeds ranging from 10 rpm to 30 *** results show that the number of flights has different effects on the holdup ratio and cascading rate of single flight and active *** 8 and 12 flights,the FRD produces a larger and more stable particle ratio of the dilute ***,DEM simulations agree with PTV measurements,whereas literature models show significant deviations.

关键词： Flighted rotating drum Number of flights Dilute phase PTV DEM

Determination of the Electrical Parameters of a Solar Cell in Steady State

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Open Journal of Applied Sciences 2023年第10期13卷 1834-1843页

作者： Omar Diallo Sadio Mamadou Kouyaté Papa Touty Traoré fabé Idrissa Barro Department of Physics Semiconductors and Solar Energy Laboratory Faculty of Science and Technique Cheikh Anta Diop University Dakar Senegal

Photovoltaic solar energy can be obtained by using several types of technologies, including silicon solar cells. The characterization of its solar cells makes it possible to know them better. This article presents, on the one hand, the work that has been carried out on these cells. On the other hand, a theoretical study of the cell under illumination using Lambert’s W function. On the basis of the electrical parameters provided by the manufacturer, the parameters such as the series and shunt resistances and the electrical quantities such as the photocurrent and the photovoltage, are determined and studied according to the ideality factor of the diode. From the results obtained the shunt resistance increases when the ideality factor increases, the series resistance decreases very weakly.

关键词： Solar Cell Series Resistance Shunt Resistance Ideality Factor Lambert Function

分析矩形瓣用于大鼠胆道闭锁术对肠造瘘肠液引流及肠道菌群的影响

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贵州医科大学学报 2024年第7期49卷 1018-1025页

作者：樊珈榕梁鹏周南南马柱刘辉艾尼娃·克然木梁挺李万富新疆医科大学第一附属医院小儿普外科新疆乌鲁木齐830054

目的研究矩形瓣用于SD大鼠胆道闭锁术对肠造瘘肠液引流及肠道菌群的影响。方法选取SPF级级SD大鼠30只,随机将SD大鼠均分为矩形瓣组和非矩形瓣组,两组各15只;矩形瓣组SD大鼠均行肝门空肠Roux.Y吻合,矩形瓣组行空肠胆支防返流瓣成形术、... 详细信息

目的研究矩形瓣用于SD大鼠胆道闭锁术对肠造瘘肠液引流及肠道菌群的影响。方法选取SPF级级SD大鼠30只,随机将SD大鼠均分为矩形瓣组和非矩形瓣组,两组各15只;矩形瓣组SD大鼠均行肝门空肠Roux.Y吻合,矩形瓣组行空肠胆支防返流瓣成形术、非矩形瓣组不做改良矩形瓣,两组均做近端空肠造瘘造口接引流管,收集反流液,比较两组术后30 d引流量;于术后第30天时取胆支段肠壁组织采用16S rDNA扩增子测序技术分析肠道菌群特征,采用RDP Classifier贝叶斯算法对测序数据包括物种的多样性、组成和样本比较进行分析,并根据香浓指数和观测物种指数分析细菌群落多样性、种类和丰度,比较两组肠道菌群种类、多样性及相对丰度的差异;大鼠胆支段肠壁组织切片采用苏木精-伊红(HE)染色观察组织学变化。结果矩形瓣组每日引流量及30 d总引流量均显著低于非矩形瓣组(t=9.918,P<0.001;t=14.212,P<0.001);矩形瓣组厚壁菌门丰度、梭菌纲丰度、梭菌目丰度、链球菌科丰度高于非矩形瓣组,差异有统计学意义(P<0.05);矩形瓣组肠道变形菌门、放线菌门丰度、腈基降解菌目、立克次体目、消化球菌科低于非矩形瓣组,差异有统计学意义(P<0.05);矩形瓣组弯曲菌属、厌氧螺菌属丰度高于非矩形瓣组,差异有统计学意义(P<0.05)。结论矩形瓣可明显减少SD大鼠胆道闭锁术中肠造瘘肠液引流量,并影响肠道菌群丰度,对预防术后肠内容物反流具有一定的临床价值。

关键词：胆道闭锁矩形瓣肝门空肠吻合术肠造瘘肠道菌群

Soil attributes structure plant assemblages across an Atlantic forest mosaic

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Journal of Plant Ecology 2018年第4期11卷 613-622页

作者： Maria fabíola Barros Bruno X.Pinho Tarciso Leão Marcelo Tabarelli Programa de Pós-Graduação em Biologia Vegetal Departamento de BotânicaUniversidade Federal de PernambucoPE 50670-901Brazil Department of Forest Resources University of MinnesotaSt.PaulMN 55108USA

Aims Community assembly persists as a key topic in ecology due to the complex variation in the relative importance of assembly forces and mechanisms across spatio-temporal scales and *** we address a forest-savanna vegetation mosaic in the Brazilian Atlantic forest to examine the role played by soil attributes as determinants of community assembly and organiza-tion at a landscape spatial *** We examined soil and plant assemblage attributes across 23 plots of forest and savanna in a 1600 km2 landscape exposed to the same climatic conditions in the Atlantic forest region of northeast *** attributes included species richness,taxonomic and functional composition(community weighted mean,CWM)and functional diversity(quadratic diversity;Rao’s quadratic entropy index)relative to plant leaf area,specific leaf area,leaf dry matter content,thickness and *** Findings Our results suggest that forest and savanna patches exposed to the same climatic conditions clearly differ in terms of soil attributes,plant assemblage structure,taxonomic and functional *** selecting particular plant strategies relative to resource economy,soil potentially affects community structure,with forest assemblages bear-ing more acquisitive resource-use strategies,while conservative plant strategies are more frequent in ***,savanna-forest mosaics in the Atlantic forest region represent spatially organized plant assemblages in terms of taxonomic and functional features,with a sig-nal of trait convergence in both vegetation ***-mediated filter-ing thus emerges as a potential deterministic assembly force affecting the spatial organization of savanna-forest boundaries and mosaics.

关键词： community assembly habitat filtering plant functional traits savanna vegetation tropical forest

Drivers of the Chemical Quality of Market Gardening Soils in the Urban and Peri-Urban Environment of Bobo-Dioulasso (Burkina Faso): Impact of Fertilizers Sources and Sites Location

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Journal of Agricultural Chemistry and Environment 2023年第1期12卷 1-15页

作者： fabèkourè Cédric Kambire Sheick Ahmed Khalil S. B. Sangare R. Adèle Ouedraogo Adama Zanga Ouattara Institute for Research in Applied Sciences and Technologies (IRSAT)/National Centre for Scientific and Technological Research (CNRST) Bobo-Dioulasso Burkina Faso Nazi Boni University/Laboratory of Study and Research on Soil Fertility (LERF) Bobo-Dioulasso Burkina Faso

Urban and peri-urban agriculture plays a key role by providing many goods and services. In particular, it provides diversified food and employment for vulnerable groups (youth and women). However, it often involves negative externalities due to non-conventional soils fertility management practices. This study aimed to investigate the chemical quality of soils over six (06) sites of the market gardening area of Bobo-Dioulasso (Burkina Faso) as affected by fertilizers uses and sites location. Thirty (30) representative market gardening farms, located in urban, semi-urban and rural areas, were randomly selected from a baseline survey database. Within each farm, composite soil samples made up of 3 individual cores were taken over the 0 - 15 cm soil depth for determining soils carbon, total nitrogen, available phosphorus contents and pH-water. These data were normalized and summarized to compute a synthetic Soil Fertility Index (SFI). The data processing was focused on a Principal Component Analysis and an Ascendant Hierarchical Classification in order to make a typology of the vegetable farms. Fertilizers management effects on soils quality were compared through Variance Analysis (ANOVA) following a GLM procedure in Rstudio software. As main results, soils chemical parameters, except for available K, were affected by the location of the sites. Soils in urban farms are less acidic (on average pH = 6.9), while semi-urban and rural sites (Samadeni, Nakaguana) have more acidic soils. However, the latter site had the highest values of C and N. Moreover, the long-term application of organic matter sources results in improving of the chemical quality of the market garden soil. The SFI is positively correlated with the rate of applied organic fertilizers, and the cultivation duration. On the other hand, soil quality tends to decrease with the expansion of the area, due to a dilution effect of the organic fertilizer doses. All these results suggest that there is a real scope to

关键词： Gardening Soil Fertility Index Chemical Fertility Bobo-Dioulasso

Microbiological biostimulant promotes rooting of olive cuttings

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International Journal of Agricultural and Biological Engineering 2021年第6期14卷 207-212页

作者： Giovana Ritter fabíola Villa Daniel Fernandes da Silva Odair Alberton Fernanda Jaqueline Menegusso Tatiane Eberling Joyce Dória Western ParanáState University(Unioeste) Campus Marechal Cândido Rondon.Marechal Cândido RondonPR85960-000Brazil Paranaense University(UNIPAR) UmuaramaPR87502-210Brazil Federal University of Lavras LavrasMG37200-000Brazil

The most widely used method of olive propagation is cutting,although for some cultivars the technique is still *** objective of this work was to evaluate the use of plant growth promoter bacteria and arbuscular mycorrhizal fungi in the rooting of olive *** experiments were conducted from October 2017 to January 2018 with cuttings from 4 olive cultivars(Ascolano 315,Koroneiki,Maria da Féand Picual)from four-year-old *** first experiment consisted of 4 olive cultivars and 3 mycorrhizal species plus the control and the second experiment of 3 concentrations of commercial inoculant(Nitro1000®),containing Azospirillum brasilense plus *** cuttings were treated with 3000 mg/L of indolebutyric acid(IBA).The experimental design used in the two experiments was randomized blocks,in a 4×4 factorial scheme,containing 25 stakes per replicate and 3 *** cuttings were kept under weaver conditions and within a low rooting *** 75 d,the percentage of rooted cuttings,callus and sprouts,length of the largest root,number and length of shoots were *** use of FMA in Maria da Féand Picual has a positive response to cutting rooting and the fungi benefit the quality of the seedlings by the higher number of shoots and larger root *** relation of Azospirillum brasilense cultivar is specific,being that,the cultivar Picual does not respond to inoculation of the bacterium having less viability in the propagation by *** da Féand Koroneiki have the best percentages of rooting with the use of 75.00 and 52.00 mL/L of inoculant,respectively.

关键词： Azospirillum brasilense Arbuscular mycorrhizal fungi Propagation Olea europaea L. microorganism

Silicon Solar Cell Space Charge Region and Capacitance Behavior under Electric Field

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Energy and Power Engineering 2021年第1期13卷 41-50页

作者： Bernard Zouma fabé Idrissa Barro Prince Abdoul Aziz Honadia Department of Physics Thermal Renewable Energies Laboratory Training and Research Unit in Exact and Applied Sciences Joseph Ki-Zerbo University Ouagadougou Burkina Faso Department of Physics Semiconductors and Solar Energy Laboratory Faculty of Science and Technique Cheikh Anta Diop University Dakar Senegal

This paper investigates theoretically the behavior of the space charge region of a silicon solar cell and its associated capacitance under the effect of an external electric field. The purpose of this work is to show that under illumination the solar cell’s space charge region width varies with both operating point and the external induced electric field and how the solar cell capacitance varies with the space charge region width. Based on a 1D modelling of the quasi-neutral p-base, the space charge region width is determined and the associated capacitance is calculated taking into account the external electric field and the junction dynamic velocity. Based on the above calculations and simulations conducted with Mathcad, we confirmed the linear dependence of the inverse capacitance with space charge region width for thin space charge region and we exhibit an exponential dependence for large space charge region.

关键词： Solar Cell Electric Field Space Charge Region Capacitance

Performance Analysis of a Boost Converter with Components Losses

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Energy and Power Engineering 2018年第9期10卷 399-413页

作者： Prince Abdoul Aziz Honadia fabé Idrissa Barro Moustapha Sané Department of Physics Semiconductors and Solar Energy Laboratory Faculty of Science and Technique Cheikh Anta Diop University Dakar Senegal

A theoretical study of a conventional boost converter is presented. Based on the real behavior of the components, two models of the boost converter are introduced: one dealing only with losses through inductor and capacitor and another taking into account switching losses in addition to resistive ones. From these two models, the detailed analytical expressions of both voltage gain factor and conversion efficiency are established taking into account the losses through parasitic resistances and switching losses. The behavior of the converter is then analyzed for each model by simulation for the voltage gain factor and the conversion efficiency.

关键词： Boost Gain Factor Efficiency ESR