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盾牌δ型变星HD213534的多重频率

天文学报 1992年第3期33卷 327-336页

作者：傅建宁蒋世仰 e.michel J.A.BeLMONTe M.ALVAReZ M.CHeVReTON M.AUVeRGNe M.J.GOUPIL A.BAGLIN A.MANGeNeY M.CHALOUPI T.ROCA CORTeS 江西大学物理系南昌330047 中国科学院北京天文台北京100080 Observatoire de Paris-Meudon MeudonFrance Instituto de Astrofisica Canarias TenerifeSpain Instituto de Astronomia Universidad National AutonomaMexico

本文利用三国联合观测获得的大量高精度光电测光数据,采用Fourier周期分析的方法,得到了δScuti型变星HD213534的多重脉动周期,认为该星存在五个以上的脉动频率.文中给出了该星的各项参量,并对其脉动模式进行了讨论,认为HD213534星是一... 详细信息

本文利用三国联合观测获得的大量高精度光电测光数据,采用Fourier周期分析的方法,得到了δScuti型变星HD213534的多重脉动周期,认为该星存在五个以上的脉动频率.文中给出了该星的各项参量,并对其脉动模式进行了讨论,认为HD213534星是一颗以非径向脉动为主的多重周期脉动变星.

关键词：周期分析变星 δ型测光频率

Using Optical Tweezers to Study the Friction of the Red Blood Cells

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Advances in Bioscience and Biotechnology 2024年第2期15卷 100-111页

作者： edoukoua Jean michel Konin Pavel Yale Abadê Ange-Boris N’guessan Kouassi Benoit Kouakou Abaka michel Kouacou eugene Megnassan Département des Sciences et Techniques Université Alassane Ouattara Bouaké C&#244te d’Ivoire Laboratoire d’Instrumentation Image et Spectroscopie (L2IS) Institut National Polytechnique Félix Houphou&#235t-Boigny (INPHB) Yamoussoukro C&#244te d’Ivoire Classes préparatoires aux grandes ecoles Université de San Pedro San Pedro C&#244te d’Ivoire Laboratoire de Physique Fondamentale et Appliquée Université Nangui Abrogoua (UNA) Abidjan C&#244te d’Ivoire

In the last two decades the study of red blood cell elasticity using optical tweezers has known a rise appearing in the scientific research with regard to the various works carried out. Despite the various work done, no study has been done so far to study the influence of friction on the red blood cell indentation response using optical tweezers. In this study, we have developed a new approach to determine the coefficient of friction as well as the frictional forces of the red blood cell. This approach therefore allowed us to simultaneously carry out the indentation and traction test, which allowed us to extract the interfacial properties of the microbead red blood cell couple, among other things, the friction coefficient. This property would be extremely important to investigate the survival and mechanical features of cells, which will be of great physiological and pathological significance. But taking into account the hypothesis of friction as defined by the isotropic Coulomb law. The experiment performed for this purpose is the Brinell Hardness Test (DB).

关键词： Friction Indentation Optical Tweezers Tribology Red Blood Cells

Modeling the Drying Kinetics of Pigeon Pea [Cajanus cajan (L.) Millspaugh]

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Open Journal of Applied Sciences 2024年第6期14卷 1425-1436页

作者： Nadia Pamela Gladys Pambou-Tobi Arnaud Wenceslas Geoffroy Tamba Sompila michel elenga Reyes Herdenn Gampoula Gloire Horiane Louya Banzouzi Sylvia Petronille Ntsossani National Institute for Research in engineering Sciences Innovation and Technology Brazzaville Congo National Polytechnic School Marien Ngouabi University Brazzaville Congo Pole of excellence in Food and Nutrition Faculty of Science and Technology Marien Ngouabi University Brazzaville Congo

We set out to model the oven-drying kinetics of a legume known as pigeon pea, harvested in the Bouenza department in the south-west of the Republic of Congo. The drying kinetics of pigeon peas was carried out in an oven under experimental conditions using temperatures of: 50°C, 60°C and 70°C. Seven mathematical models were used to describe pigeon pea drying. During drying, water loss was faster and shorter at 70°C [10.446 g/25 g wet weight (wwb) for 320 min (5.3 h)] compared to 50°C [10.996 g/25 g wet weight (wwb) for 520 min (8.6 h)] and 60°C [10.616 g/25 g wet weight (wwb) for 420 min (7.0 h)] where it was slower and longer. With regard to modeling, and based on the principle of choosing the right model focusing on the high value of R2 and low values of χ2 and RMSe, two models were selected, the Midili model for temperatures of 50°C and 60°C and the Henderson and Pabis model modified for temperature of 70°C showed better results. The R2, χ2 and RMSe values calculated for pigeon pea are 0.99985, 3.93404e-5 and 0.00627;0.9997, 9.245e-5 and 0.00962;0.99996, 1.56332e-5 and 0.00395 respectively at 50°C, 60°C and 70°C.

关键词： Cajanus cajan Legume Kinetic Models Drying

National Soil Organic Carbon Stocks Inventories under Different Mangrove Forest Types in Gabon

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Open Journal of Forestry 2024年第2期14卷 127-140页

作者： Rolf Gaël Mabicka Obame Neil-Yohan Musadji Jean Hervé Mve Beh Lydie-Stella Koutika Jean Aubin Ondo Farrel Nzigou Boucka michel Mbina Mounguengui Claude Geffroy Dé partement de Phytotechnologie Institut National d&#8217Agronomie et de Biotechnologies Universit&#233 des Sciences et Techniques de Masuku Franceville Gabon Dé partement des Sciences Fondamentales de l&#8217Ing&#233nieur Institut National d&#8217Agronomie et de Biotechnologies Universit&#233 des Sciences et Techniques de Masuku Franceville Gabon Institut Agronomiques et Forestiè res Centre National des Recherches Scientifiques et Technologiques Libreville Gabon Research Centre on the Durability and the Productivity of Industrial Plantations (CRDPI) Pointe Noire Republic of Congo Laboratoire Pluridisciplinaire des Sciences &#201cole Normale Sup&#233rieure Libreville Gabon Agence Gabonaise d’ &#201tude et d&#8217Observation Spatiale Immeuble les Arcades Libreville Gabon Dé partement de G&#233ologie Faculte des Sciences Universit&#233 des Sciences et Techniques de Masuku Franceville Gabon Institut de Chimie des Milieux et Maté riaux de Poitiers (IC2MP) Universit&#233 de Poitiers Poitiers France

Gabonese’s estuary is an important coastal mangrove setting and soil plays a key role in mangrove carbon storage in mangrove forests. However, the spatial variation in soil organic carbon (SOC) storage remain unclear. To address this gap, determining the SOC spatial variation in Gabonese’s estuarine is essential for better understanding the global carbon cycle. The present study compared soil organic carbon between northern and southern sites in different mangrove forest, Rhizophora racemosa and Avicennia germinans. The results showed that the mean SOC stocks at 1 m depth were 256.28 ± 127.29 MgC ha−1. Among the different regions, SOC in northern zone was significantly (p p e deeper layers contained higher SOC stocks (254.62 ± 128.09 MgC ha−1) than upper layers (55.42 ± 25.37 MgC ha−1). The study highlights that low deforestation rate have led to less CO2 (705.3 Mg CO2e ha−1 - 922.62 Mg CO2e ha−1) emissions than most sediment carbon-rich mangroves in the world. These results highlight the influence of soil texture and mangrove forest types on the mangrove SOC stocks. The first national comparison of soil organic carbon stocks between mangroves and upland tropical forests indicated SOC stocks were two times more in mangroves soils (51.21 ± 45.00 MgC ha−1) than primary (20.33 ± 12.7 MgC ha−1), savanna and cropland (21.71 ± 15.10 MgC ha−1). We find that mangroves in this study emit lower dioxide-carbon equivalent emissions. This study highlights the importance of national inventories of soil organic carbon and can be used as a baseline on the role of mangroves in carbon sequestration and climate change mitigation but the variation in SOC stocks indicates the need for further national data.

关键词： Mangroves Forest Soil Organic Carbon Stocks Rizophora Racemose Avicenia germinans Gabon

Phenotypic Characterization of extended Spectrum Beta-Lactamase, Class C Cephalosporinase and Carbapenemase-Producing Klebsiella Species Isolated from Patients Consulted at Four Yaounde-Based Hospitals

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Open Journal of Medical Microbiology 2024年第2期14卷 105-119页

作者： emilia enjema Lyonga Mbamyah Mangum Patience Kumcho michel Toukam Dieudonné Sedena Florence Anjabie enyeji Aime-Caesar Teukam Modestine Djuissi Martha Tongo Mesembe George Mondinde Ikomey Agnes Bedie eyoh Hortense Kamga Gonsu Faculty of Medicine and Biomedical Sciences The University of Yaounde 1 Yaounde Cameroon Center for the Study and Control of Communicable Diseases Faculty of Medicine and Biomedical Sciences The University of Yaounde 1 Yaounde Cameroon Department of Microbiology School of Health Sciences Catholic University of Central Africa Yaounde Cameroon Faculty of Science University of Buea Buea Cameroon Bacteriology Unit Yaounde University Teaching Hospital Yaounde Cameroon

Background: Klebsiella spp. are bacteria of medical importance for their role in opportunistic infections which are often difficult to treat because of resistance to one or several antimicrobials. The aim of this study was to determine antimicrobial resistance due to extended Spectrum Beta-lactamase (eSBL), Class C cephalosporinase (AmpC) and carbapenemase enzymes in Klebsiella spp. isolated from patients consulted at four hospitals. Methodology: The study was cross-sectional and descriptive. A total of 4190 non-repetitive patients specimens from 13 types of clinical specimens were analysed from February to November 2020. Two hundred and twenty-five (225) Klebsiella spp isolates were identified using API 20e and antimicrobial susceptibility testing done according to the Kirby Bauer disc diffusion method. eSBL and AmpC phenotypes were determined by the combination disc method and carbapenemases by double disc synergy method, referenced by eUCAST guidelines for the resistance testing. Results: The frequency of the species was Klebsiella pneumoniae (69%, 155/255), K. oxytoca (14%, 31/255), K. ozaenae (12%, 27/225) and K. rhinoscleromatis (5%, 11/225). Isolates were most resistant to sulphomethoxazole trimethoprim (84%, 189/225), cepaholosporins (80%, 180/225), and least resistant to carbapenems (10.7%, 24/225). Two K. oxytoca and one K. pneumoniae were resistant to all antibiotics tested. Klebsiella pneumoniae had the most multidrug resistant isolates (59.4%, 134/225). Most isolates (83.6%, 188/225) expressed at least one enzyme, while 63.6% (143/225) of the isolates expressed at least two enzymes. Some isolates were eSBL (71.6%, 161/225), carbapenemase (10.7%, 24/225) and AmpC (6.6%, 15/225) producers. Three carbapenemases (Klebsiella pneumoniae carbapenemase-KPC, Metallo-Beta Lactamase-MBL and OXA-48) were detected. Conclusion: These results revealed that resistance of Klebsiella spp. to cephalosporins is high and this may be exacerbated by co-expression of AmpC and

关键词： Klebsiella Spp. Multidrug Resistance eSBL AmpC Carbapenemase

On the viability of wearing evaluation by Thin Layer Activation in the presence of non-occupationally exposed individuals

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Nuclear Science and Techniques 2022年第3期33卷 103-112页

作者： michel de Almeida Franca Julio Cezar Suita Paulo Fernando Ferreira Frutuoso e Melo Celso Marcelo Franklin Lapa Graduate Program of Nuclear engineering COPPEFederal University of Rio de JaneiroRio de JaneiroRJ 21941914Brazil Instituto de engenharia Nuclear(IeN-CNeN) Rio de Janeiro 21941614Brazil Comissao Nacional de energia Nuclear(SeASe/DRS/CNeN) Rio de Janeiro 22290040Brazil

Thin Layer Activation is a nuclear technique that has key advantages over other wear measuring techniques for mechanical systems,especially for in site experiments on equipment important to safety in nuclear ***,it incurs radioactive dose and,thus,must be proved radiologically safe before use,otherwise,the utilization of this technique may be hindered *** said technique is safe previous to any operational/monetary cost is key,providing a methodology for this early assertion is the main contribution of this work—here,only non-occupationally exposed individuals are *** work offers a methodology,through a case study,to ascertain the Thin Layer Activation parameters to obtain safe levels of radioactive dose while maintaining statistically reliable *** methodology consists of using simulations,through the Monte Carlo Method,to obtain the floors and ceilings for the previously mentioned activation parameters based on operation and work conditions on site.

关键词： Thin Layer Activation Safety evaluation Simulation equipment wearing

Modelling and applications of dissolution of rocks in geoengineering

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2023年第1期24卷 20-36页

作者： Farid LAOUAFA Jianwei GUO michel QUINTARD National Institute for Industrial environment and Risks(INeRIS) Verneuil en Halatte60550France School of Mechanics and Aerospace engineering Southwest Jiaotong UniversityChengdu 610031China Universitéde Toulouse INPTUPSIMFT(Institut de Mécanique des Fluides de Toulouse)Allée Camille SoulaToulouseF-31400France CNRS IMFTToulouseF-31400France

The subsoil contains many evaporites such as limestone,gypsum,and *** rocks are very sensitive to *** deposit of evaporites raises questions because of their dissolution with time and the mechanical-geotechnical impact on the neighboring *** on the configuration of the site and the location of the rocks,the dissolution can lead to surface subsidence and,for instance,the formation of sinkholes and *** this study,we present an approach that describes the dissolution process and its coupling with geotechnical *** the first part we set the physico-mathematical framework,the hypothesis,and the limitations in which the dissolution process is *** physical interface between the fluid and the rock(porous)is represented by a diffuse interface of finite *** briefly describe,in the framework of porous media,the steps needed to upscale the microscopic-scale(pore-scale)model to the macroscopic scale(Darcy scale).Although the constructed method has a large range of application,we will restrict it to saline and gypsum *** second part is mainly devoted to the geotechnical consequences of the dissolution of gypsum *** then analyze the effect of dissolution in the vicinity of a soil dam or slope and the partial dissolution of a gypsum pillar by a thin layer of *** theoretical examples show the relevance and the potential of the approach in the general framework of geoengineering problems.

关键词： Dissolution Modelling Scaling evaporite Deformation Plasticity

Charge carrier mobilities of organic semiconductors:ab initio simulations with mode-specific treatment of molecular vibrations

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npj Computational Materials 2022年第1期8卷 2199-2209页

作者： Sebastian Hutsch michel Panhans Frank Ortmann School of Natural Sciences Department of ChemistryTechnische Universität MünchenGarching b.MünchenGermany

The modeling of charge transport in organic semiconductors usually relies on the treatment of molecular vibrations by assuming a certain limiting case for all vibration modes,such as the dynamic limit in polaron theory or the quasi-static limit in transient localization *** opposite limits are each suitable for only a subset of ***,we present a model that combines these different *** is based on a separation of the vibrational spectrum and a quantum-mechanical treatment in which the slow modes generate a disorder landscape,while the fast modes generate polaron band *** apply the combined method to 20 organic crystals,including prototypical acenes,thiophenes,benzothiophenes,and their *** mobilities span several orders of magnitude and we find a close agreement to the experimental *** analysis reveals clear correlations to simple mobility predictors and a combination of them can be used to identify high-mobility materials.

关键词： theory semiconductors limit

On 2D approximations for dissolution problems in Hele-Shaw cells

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Science China(Physics,Mechanics & Astronomy) 2023年第3期66卷 104-120页

作者： Jianwei Guo Farid Laouafa michel Quintard School of Mechanics and Aerospace engineering Southwest Jiaotong UniversityChengdu 610031China National Institute for Industrial environment and Risks(INeRIS) Verneuil en Halatte 60550France Institut de Mecanique des Fluides de Toulouse(IMFT) Universite de ToulouseCNRSToulouse 31400France

In this paper, we study the dissolution problems occurring in laterally large 3D systems with very small dimensions along the third coordinate, such as fractures or Hele-Shaw cells. On the basis of the scale separation assumption, we apply upscaling to the 3D pore-scale model using the volume averaging method to develop 2D averaged equations. The influence of the choice of momentum equations on the accuracy of the 2D Hele-Shaw model is discussed, and we show that the results obtained using Darcy-Brinkman equations are better than those obtained using Darcy’s law, because of the consideration of the viscous boundary layer. The validity and accuracy of the resulting 2D model are assessed based on comparisons with full 3D solutions for problems corresponding to the existence of geometrical 3D features to which a simple averaging procedure along a line(i.e., the height of the gap) perpendicular to the 2D plane cannot be applied, such as the dissolution of pillars. The results show that when Péclet and Reynolds numbers exceed certain limits, 3D effects must be considered. Moreover, natural convection effects are important when the Rayleigh number is large.

关键词： dissolution Hele-Shaw cell upscaling natural convection