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Tyrosinase Biosensor Used for the Determination of Catechin Derivatives in Tea: Correlation with HPLC/DAD Method

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Food and Nutrition Sciences 2013年第1期4卷 108-118页

作者： Saloua Nadifiyine Carole Calas-Blanchard Aziz Amine Jean-Louis Marty Institut de Modélisation et d’Analyse en Géo-Environnement et Santé Univ. Perpignan Via Domitia Perpignan France Institut de Modélisation et d’Analyse en Géo-Environnement et Santé Univ. Perpignan Via Domitia Perpignan France&Laboratoire d’Analyses Chimiques et Biocapteurs Faculté des Sciences et Techniques Université Hassan II Mohammedia Morocco. Laboratoire d’Analyses Chimiques et Biocapteurs Faculté des Sciences et Techniques Université Hassan II Mohammedia Morocco.

Tea, one of the most popular consumed worldwide beverages, is known to be rich in polyphenols, more particularly in catechins. An amperometric biosensor based on tyrosinase was developed in order to monitor the phenolic content in black and green teas. The enzyme was immobilised by coreticulation with glutaraldehyde on carbon screen-printed electrodes (CSPE). Initially, the performances of the biosensor were evaluated referring to catechol as a model substrate. This analytical tool exhibits a high sensitivity (217 nA/μM), low limit of detection (LOD) = 0.03 μM, good intra-electrode and inter-electrode reproducibilities with RSD lower than 3% (n = 5 injections) and RSD = 8.14% (n = 12 sensors) respectively. The storage stability was also studied;the biosensor retained successively 85% and 70% of its initial response after 34 and 53 days. Subsequently, several catechin derivatives frequently found in teas were tested and classified relatively to their sensitivities. For tea samples, the results obtained with the biosensors were compared to high performance liquid chromatography (HPLC) analysis. A good correlation between the two methods was obtained. The calculated recovery was between 90% and 96%, proving that the proposed tyrosinase biosensor can be an alternative analytical tool for global determination of catechin derivatives in tea.

关键词： Tea Polyphenol Catechin Tyrosinase Amperometric Biosensor HPLC

冲绳海槽200ka的孢粉记录及冰期-间冰期旋回古环境重建

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中国科学：地球科学 2013年第10期43卷 1231-1248页

作者：郑卓黄康有邓韫曹玲珑余少华 Jean-Pierre SUC Serge BERNE Francois GUICHARD 中山大学地球科学系广州510275 Paleoenvironnements et Paleobiosphere Universite Claude Bernard-Lyonl Villeurbanne 69622 France 国家海洋局南海海洋工程勘察与环境研究院广州510300 Institut des Sciences de la Terre Paris Université P. et M. Curie Pads 75005 France Université de perpignan via domitia Perpignan 66860 France Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette 91191 France

本文对冲绳海槽中部MD982194钻孔29.78m近200kaBP的岩芯进行了孢粉研究.结果表明,孢粉组合主要表现为裸子植物与草本植物花粉之间的交替.带气囊类的松属、铁杉在间冰期的1,3,5和7氧同位素期显著增高,而草本则在冰期阶段占优,两者的含量... 详细信息

本文对冲绳海槽中部MD982194钻孔29.78m近200kaBP的岩芯进行了孢粉研究.结果表明,孢粉组合主要表现为裸子植物与草本植物花粉之间的交替.带气囊类的松属、铁杉在间冰期的1,3,5和7氧同位素期显著增高,而草本则在冰期阶段占优,两者的含量变化显示出对冰期-间冰期环境变化的敏感响应.本钻孔发现莎草科花粉在冰期阶段含量大幅度增加,伴随蒿属、禾本科、菊科、藜科和淡水藻类的显著升高.它们与轨道尺度的海平面变化呈现十分吻合的负相关关系.草本花粉总量的周期性变化可以作为该区域海平面变化的替代性指标.末次盛冰期的海平面下降导致陆地与冲绳海槽的距离大幅缩小,源于长江的物质随河流进入大陆架后因流速急剧降低发生沉降,导致上游物质难以被远距离搬运到海槽.因此,冰期阶段冲绳海槽的孢粉物质可能主体来自于大陆架前缘的地表植被,而间冰期带气囊类花粉的比例增大与海岸距离较远和风力搬运物质的比例增加有关.钻孔的孢粉组分更替与气候变化也有显著的对应关系,反映出氧同位素7,5和1期木本含量高,并与东亚夏季风增强和降雨量增大有关.其中MIS5.3,MIS5.1和MIS3.3段的松属花粉峰值可能与轨道和亚轨道周期的地表太阳辐射和季风增强有密切联系.研究认为,盛冰期的东海陆架平原的气温和降雨量都有较明显的下降,但低海面时期裸露的大陆架平原可能并非由半干旱的地带性草原所覆盖,而是以疏林草地及密布的隐域性植被(河流补给淡水湖沼和湿地)组成.海平面变化引起的海岸距离伸缩和源区气候变化对陆源物质通量和孢粉组分更替起到联合制约的作用,而冲绳海槽冰期-间冰期尺度的海岸线距离变化在孢粉信号中的表现要明显强于陆源区域的气候变化.

关键词：冲绳海槽孢粉分析东海陆架海平面陆源植被气候变化

Effect of Adsorbent/Adsorbate Couple on the Performance of Adsorption Solar Refrigerator

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Engineering（科研） 2022年第3期14卷 95-112页

作者： Guy Christian Tubreoumya Eloi Salmwendé Tiendrebeogo Oumar Bailou Téré Dabilgou Belkacem Zeghmati Alfa Oumar Dissa Jean Koulidiati Antoine Bere Laboratoire de Physique et de Chimie de l’Environnement (LPCE) Université Joseph Ki Zerbo Ouagadougou Burkina Faso LAboratoire de Mathématiques et Physique (LA.M.P.S) Université de Perpignan Via Domitia (UPVD) Perpignan France

This work presents a contribution to the study of the process of cold production by adsorption from solar energy. In this paper, we discuss a comparative study of the operation of a solar adsorption refrigerator using the silica gel-water couple and the zeolite-water couple through dynamic modeling and simulation. The mathematical model representing the evolution of heat and mass transfer at each component of the adsorption solar refrigerator has been developed. It appears from this study that the evolution of the temperature of the two adsorbents (zeolite and silica gel) is quasi-similar throughout the operating cycle. However, the maximum mass of water vapor adsorbed by the silicagel (0.24 kg/kg) is higher than that adsorbed by the zeolite (0.201 kg/kg). In the same way, the mass of water vapor cycled, obtained with the silicagel-water couple which is 0.14 kg/kg, is higher than that obtained with the zeolite-water couple which is 0.081 kg/kg. Therefore, the amount of cold produced 9.178 MJ and the solar coefficient of performance 0.378 obtained with the solar refrigerator using the silica gel-water couple, are better.

关键词： Solar Cooling Adsorption Zeolite Silica Gel Water Heat and Mass Transfer

Contribution to the Modeling of a Solar Adsorption Refrigerator under the Climatic Conditions of Burkina Faso

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Energy and Power Engineering 2017年第2期9卷 119-135页

作者： Guy Christian Tubreoumya Alfa Oumar Dissa Eloi Salmwendé Tiendrebeogo Xavier Chesneau Aboubacar Compaoré Kayaba Haro Charles Didace Konseibo Belkacem Zeghmati Jean Koulidiati Laboratoire de Physique et de Chimie de l’Environnement (L.P.C.E) Universit&eacute Ouaga I Ouagadougou Burkina Faso LAboratoire de Mathé matiqueset PhySique (LA.M.P.S) Universit&eacute de perpignan via domitia (UPVD) Perpignan France Centre Ecologique Albert Schweitzer (CEAS) Ouagadougou Burkina Faso

This work concerns a dynamic modeling and a numerical simulation of the operation of an adsorption solar refrigeration system using the zeolite-water couple. For this, a mathematical model representing the evolution of heat and mass transfer at each component of the solar adsorption refrigerator has been developed. We have adopted the Dubinin-Astakhov model for the adsorption kinetics of the zeolite/water pair. This model allows to describe the phenomenon of adsorption and to calculate the rate of adsorbate (water) in the zeolite (adsorbent) as a function of the temperature and the pressure. The equations governing the operation of the solar adsorption refrigerator, deduced from the thermal and mass balances established at the collector adsorber, condenser and evaporator components, were solved by an implicit finite difference scheme and Gauss Seidel’s iterative method. We have validated the model established by applying it to the model of Allouhi et al. 2014. We analyzed the influence of the adsorbate/adsorbent couples, the solar flux, the ambient temperature on the adsorption and desorption process. The temperature profiles obtained representing the temperature evolution of the glass, the absorbent plate, the zeolite-water mixture, the condenser, the evaporator, as well as the pressure and the adsorbed mass allowed us to evaluate the performance of the solar adsorption refrigerator. SCOP is higher the higher the solar flux captured by the collector-adsorber.

关键词： Solar Refrigeration Simulation Adsorption Zeolite/Water Burkina Faso

Performance Assessment of a Box Type Solar Cooker Using Jatropha Oil as a Heat Storage Material

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Energy and Power Engineering 2022年第2期14卷 124-132页

作者： Jacques Nébié Sidiki Zongo Guy C. Tubreoumya Augustin S. Zongo Ilyassé Konkobo Boubou Bagré Ali Diané Tizane Daho Serges W. Igo Belkacem Zeghmati Antoine Béré Laboratoire de Physique et de Chimie de l’Environnement (LPCE) Université Joseph Ki-Zerbo Ouagadougou Burkina Faso Département Energie Institut de Recherche en Sciences Appliquées et Technologies (IRSAT/CNRST) Ouagadougou Burkina Faso Laboratoire de Mathématiques et Physique (LAMPS) Université de Perpignan Via Domitia Perpignan France

Solar cookers are a good option in developing countries with high solar potential for environmentally friendly cooking and reduced pressure on forests. However, they are still affected by the intermittency of the sun. In order to overcome this problem, in this work, a box type solar cooker integrated Jatropha oil as a heat storage material is fabricated and experimented with. The design was examined with a maximum stagnation temperature of 157.7°C. The recorded cooking power vanished between 78.4 and 103.6 W, while thermal efficiency varied from 41.26% to 58.78%. The energy transfer cycle test, including charge and discharge revealed that 91.18% of the heat lost through the cooker could be recovered by the heat storage unit and a large amount is restored to the system during cloudiness or a temperature perturbation.

关键词： Solar Cooker Kapok Wool Performance Heat Storage Jatropha Oil

Ultrasound aspects and risk factors associated with urogenital schistosomiasis among primary school children in Mali

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Infectious Diseases of Poverty 2023年第2期12卷 133-133页

作者： Privat Agniwo Bakary Sidibé Assitan Diakité Safiatou Doumbo Niaré Hassim Guindo Ahristode Akplogan Moudachirou Ibikounlé Jérôme Boissier Abdoulaye Dabo Department of Epidemiology of Infectious Diseases Faculty of PharmacyIRl 3189(USTTB/UCAD/UGB/CNRST/CNRS)University of SciencesTechniques and Technologies of BamakoBamakoMali Interactions Hôtes-Pathogènes-Environnements(IHPE) Univ.MontpellierCNRSIfremerUniv.Perpignan Via DomitiaPerpignanFrance Centre de Recherche pour la lutte contre les Maladies Infectieuses Tropicales(CReMIT/TIDRC) University of Abomey-CalaviAbomey CalaviBenin

Background Urogenital schistosomiasis is endemic in Mali and is a major cause of serious morbidity in large parts of the *** disease is responsible for many socio-economic and public health *** aim of this study was to investigate the impact of the disease on morbidity and to describe demographic and socioeconomic factors in relation to the status of children with urogenital schistosomiasis in *** We conducted a cross-sectional study in November 2021 of 971 children aged 6 to 14 years selected at random from six schools in three districts in the Kayes Region of *** and socioeconomic data were collected on survey *** data were collected following a medical *** was systematically searched for through the use of *** search for Schistosoma haematobium eggs in urine was done via the filtration *** urinary tract was examined by *** between each of these variables and disease infection were tested using multivariate logistic *** The overall prevalence of urinary schistosomiasis detected was 50.2%.The average intensity of infection was 36 eggs/10 ml of *** associated risk factors for urogenital schistosomiasis showed that children who bathed,used the river/pond as a domestic water source,and who habitually urinated in the river/pond were more affected(P<0.05).Children with farming parents were most affected(P=0.032).The collection of clinical signs revealed that boys had more pollakiuria(58.6%)and dysuria(46.4%)than *** data showed that focal lesion rates were recorded in all villages with the lowest rate in Diakalel(56.1%).Ultrasound and parasitological findings showed that irregularity and thickening were strongly associated with urinary schistosomiasis(P<0.0001).Conclusions Schistosoma haematobium infection was still endemic in the study site despite more than a decade of mass treatment with ***,the high percentage of symp

关键词： Schistosoma haematobium Morbidity Prevalence Risk factor Mali

Evaporation and Combustion of a Drop of Liquid Fuel—A Review

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Smart Grid and Renewable Energy 2022年第2期13卷 28-54页

作者： Dabilgou Téré Tubreoumya Guy Christian Haro Kayaba Bagre Boubou Sandwidi Sayouba Daho Tizane Koulidiati Jean Sanogo Oumar Zeghmati Belkacem Bere Antoine Laboratoire de Physique et de Chimie de l’Environnement (LPCE) Université Joseph Ki-Zerbo Ouagadougou Burkina Faso Laboratoire de Mathématiques et Physiques (LAMPS) Université de Perpignan via Domitia Perpignan France Centre National de la Recherche Scientifique et Technologique (CNRST) Institut de Recherche en Sciences Appliquées et Technologies (IRSAT) Ouagadougou Burkina Faso

The accelerated depletion of oil reserves and the often exorbitant cost of fossil fuels contribute to the development of fuels from renewable sources. The objective of this work is to analyze the influence of the properties of renewable fuels on their evaporation in natural convection, their combustion and their use in internal combustion engines. A summary of the various numerical and experimental works from the literature has been presented in this work. This work focuses on the numerical modelling of the natural convection evaporation of an isolated drop of a liquid fuel in natural convection. The transfers in the liquid and vapour phases are described by the conservation equations of mass and species, momentum and energy. The main feature of this work is the consideration of advection, azimuthal angle and thickness of the vapour phase of the drop during evaporation of the drop.

关键词： Drop Evaporation Combustion Convection Modelling Temperature

Temperature Dependence of Density,Viscosity,Thermal Conductivity and Heat Capacity of Vegetable Oils for Their Use as Biofuel in Internal Combustion Engines

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Advances in Chemical Engineering and Science 2019年第1期9卷 44-64页

作者： Augustin SampawindéZongo Gilles Vaitilingom Tizane Daho Christian Caillol Jean-Francois Hoffmann Bruno Piriou Jeremy Valette Bila Gérard Segda Pascal Higelin LPCE Département de physiqueUniversitéOuaga 1 Pr JKZBurkina Faso Unitéde recherche BioWooEB CIRAD MontpellierBat 1673 rue JF BretonMontpellierFrance Laboratoire PRISME Universitéd’Orléans8 rue Léonard de Vinci45072 Orléans Cedex 2France Laboratoire PROMES-CNRS UPR-8521 Universitéde perpignan via domitia Rambla de laThermodynamiqueTecnosudPerpignanFrance

This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Knowing vegetable oils’ physical properties to these ranges of temperature is of fundamental importance when modeling their combustion in diesel engine. However, vegetable oils’ experimental physical properties data are rare in the literature for temperature above 523 K. This paper describes experimental measurements and estimation methods for density, dynamic viscosity, thermal conductivity and heat capacity of vegetable oils for this particular range of temperature. The methodology uses several correlative methods using group contribution approach for each property and compares experimental data with predicted one to select the more accurate model. This work has shown the rapeseed and jatropha oils’ physical properties can be satisfactorily predicted as a function of temperature using group contribution approach.

关键词： Rapeseed Oil Jatropha Oil Physical Properties Group Contribution Method Energy Diesel Engine

Modelling of a Two-Phase Thermosyphon Loop for Passive Air-Conditioning of a House in Hot and Dry Climate Countries

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Energy and Power Engineering 2021年第6期13卷 243-260页

作者： Abdoulaye 1 Diallo Xavier Chesneau Idrissa Diaby Djanfar El-Maktoume Laboratoire de Modélisation Pluridisciplinaire et Simulations (LAMPS) Université de Perpignan Via Domitia Perpignan France Laboratoire d’Enseignement et de Recherche en Energétique Appliquée (LEREA) Université Gamal Abdel Nasser de Conakry Conakry Guinée Laboratoire énergétique de l’équipe d’Accueil Doctoral physique du Globe de l’Energie et de l’Environnement (PGEE) Université d’Antananarivo Antananarivo Madagascar

The two-phase thermosyphon loop is an efficient solution for space cooling. This paper presents the simulation results of numerical studies on the heat transfer and thermal performance of a two-phase thermosiphon loop for passive air-conditioning of a house. The fluid considered in this study is methanol, which is compatible with copper and is environmentally friendly. These numerical results show that the temperature at the evaporator wall drops from 23°C to 13°C and increases at the condenser. The solar flux density has a strong influence on the condenser temperature. The mass flow rates and masses at the evaporator and condenser increase with temperature. The variation of evaporating and condensing temperature affects the performance of the system. For a constant evaporating and condensing temperature of 2°C and 29°C, the COP is 0.77 and 0.84 respectively. With these results, the use of the two-phase thermosyphon loop in air conditioning is possible to obtain a thermal comfort of the occupants acceptable by the standards but with a large exchange surface of the evaporator.

关键词： Two-Phase Thermosiphon Loop Modelling Passive Air Conditioning Thermal Performance