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Journal of Rock Mechanics and Geotechnical Engineering 2020年第6期12卷 1272-1289页

作者： Wei Zhang leo Rothenburg Department of Civil and Environmental Engineering University of WaterlooWaterlooN2L 3G1Canada

The fluid-coupled discrete element method(DEM)and the constant volume method as two types of discrete modeling methods for fundamental study of undrained responses of granular materials,have been discussed by many *** fluid-coupled DEM,which couples the motions of discrete particles with pore fluid movements,is theoretically robust although it requires a large amount of computation *** a substitution for the complex fluid-coupled DEM,the constant volume method simulates an undrained condition for a saturated granular material by simply preserving the total volume of a granular assembly without considering interactions between fluids and particles;hence,the validity of its results is *** this paper,the undrained behaviors of granular assemblies simulated using the aforementioned two methods are *** on a comparison of both macroscopic and microscopic responses given by the two methods,it is demonstrated that the constant volume method may reasonably simulate the responses of a loose saturated granular material with very coarse grains,which has a high permeability,and thus a rapid pore pressure ***,it is ineffective in simulating the responses of a loose material with fine components due to its failure to capture the process of a slow dissipation of the excess pore pressure among the individual *** regard to the dense material adopted,similar behaviors at the early and intermediate shearing stages given by the two methods are displayed.

关键词： Micromechanics Constant volume method Fluid-coupled discrete element method (DEM) Undrained behavior

PAHs Sorption and Desorption on Soil Influenced by Pine Needle litter-Derived Dissolved Organic Matter

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Pedosphere 2014年第5期24卷 575-584页

作者： YANG Xiu-Hong P.GARNIER WANG Shi-Zhong V.BERGHEAUD HUANG Xiong-Fei QIU Rong-liang School of Environmental Science and Engineering Sun Yat-sen University Guangdong Provincial Key laboratory of Environmental Pollution Control and Remediation Technology INRA UMR1091 EGCBP 01 F-78850 Thiverval-Grignon (France)

Study of the relationship between plant litter-derived dissolved organic matter(DOM) and organic pollutant transport in soil is important for understanding the role of forest litter carbon cycling in influencing pollutant behaviour and fate in forest *** the aim of providing insight into the capacity of plant litter-derived DOM to influence sorption and desorption of selected polycyclic aromatic hydrocarbons(PAHs) on soil, batch experiments were carried out with application of a sorption-desorption model incorporating DOM effects. Freshly fallen pine(Pinus elliottii) needles were used as the source of organic matter. Input of the pine needle litter-derived DOM was found to significantly decrease desorption hysteresis as well as soil adsorption capacity of phenanthrene(PHE) and fluoranthene(FlA). Addition of 1 728 mg l-1dissolved organic carbon(DOC) lowered the organic carbon-normalized sorption distribution coefficient of PHE from 7 776 to 2 541 l kg-1C and of FlA from 11 503 to 4 368 l kg-1C. Decreases of the apparent sorption-desorption distribution coefficients of PHE and FlA with increased DOC concentration indicated that DOM favored desorption of PAHs from soil. Increases in the fraction of apparently dissolved PAHs were attributable to the dissolved PAH-DOM complexes, accounting for the dissolved proportions of 39% to 69% for PHE and 26% to 72% for FlA in the sorption and desorption processes as the concentration of the added DOM solution rose from 0 to 1 728 mg l-1. Our results suggest that pine needle litterderived DOM can have a substantial effect of inhibiting PAHs sorption and promoting PAHs desorption, thus leading to enhanced leaching in soil, which should be taken into account in risk assessment of PAHs accumulated in forest soil.

关键词： dissolved organic carbon distribution coefficient fluoranthene hysteresis phenanthrene

level of Exposure of Populations to Atmospheric Pollution in Southern Benin

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Open Journal of Air Pollution 2023年第4期12卷 160-181页

作者： Sèdami Codjo Joël Dossou-Gbete Dominique Kpadonou Gbaguidi Magloire Acakpo Nonvignon Vitalique Elegbede Alassane Youssao Abdou Karim Kpessou Virtus Mickael Saizonou Firmin léonce Dovonon Doctoral School of Exact and Applied Sciences University of Abomey-Calavi (UAC) Abomey-Calavi Benin Applied Chemistry Study and Research laboratory Department of Chemical Engineering-Processes (GC-P) Ecotoxicology and Quality Study Research Unit Polytechnic School of Abomey-Calavi University of Abomey-Calavi Abomey-Calavi Benin

This study focuses on monitoring the exposure of populations in South Benin to atmospheric pollution. Thirteen (13) monitoring points were identified where the Air quality measurements were taken using autonomous electronic devices called “Air Quality Monitor”. Calibrated and turned on, the measuring device automatically determines the concentrations of carbon dioxide CO2, Total Organic Compounds, methanal (HCHO), particulate matter PM2.5 and PM10, temperature in degrees Fahrenheit and relative humidity (RH). Per site, air pollution levels are recorded for 5 minutes every 30 minutes from 7 a.m. to 6 p.m. After the analyses, it appears that the carbon dioxide CO2 contents vary from 400 to 1444 ppm with an average of 486.80 ± 184.3 ppm, the daily contents of Total Volatile Organic Compounds from 0.01 to 6 .91 mg/m3 with a daily average of 0.36 ± 0.65 mg/m3, aldehydes from 0.005 to 3 mg/m3 with an average of 0.05 ± 0.17 mg/m3, for particulate matter of diameters less than or equal to 2.5 μm (PM2.5) pollution levels vary between 5 and 173.8 μg/m3 with an average of 21.5 ± 17.62 μg/m3. On the other hand, for PM10, the contents vary from 5 to 449.6 μg/m3 with an average of 28.17 ± 31.74 μg/m3, the Air Quality Index (AQI) varies from 0, 3 to 243 with an average of 39 ± 33.16. From the results observed, it appears that the south-western part of South Benin is heavily polluted by CO2, Total Volatile Organic Compounds, PM10 and especially PM2.5 with the city of Cotonou at its head, in particular the Red Star crossroads, the Toyota crossroads and the crossroads after the friendship stadium. The impacts of this pollution could be significant on sensitive people such as the elderly, newborns and patients with acute and chronic respiratory illnesses.

关键词： Ambient Air Quality Southern Benin Cotonou Atmospheric Pollution

Exploring the effects of dietary inulin in rainbow trout fed a high‑starch,100%plant‑based diet

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Journal of Animal Science and Biotechnology 2024年第2期15卷 713-732页

作者： Raphaël Defaix Jep lokesh laura Frohn Mickael le Bechec Thierry Pigot Vincent Veron Anne Surget Sandra Biasutti Frederic Terrier Sandrine Skiba-Cassy Jerome Roy Stephane Panserat Karine Ricaud Universite de Pau Et Des Pays de l’Adour E2S UPPAINRAENUMEASaint‑Pee‑Sur‑NivelleFrance Universite de Pau Et Des Pays de l’Adour E2S UPPACNRSIMT Mines AlesIPREMPauFrance Universite de Pau Et Des Pays de l’Adour E2S UPPAIUT des Pays de l’AdourDepartement Genie BiologiqueMont de MarsanFrance.

Background High dietary carbohydrates can spare protein in rainbow trout(Oncorhynchus mykiss)but may affect growth and ***,a prebiotic,could have nutritional and metabolic effects,along with anti-inflammatory properties in teleosts,improving growth and *** tested this hypothesis in rainbow trout by feeding them a 100%plant-based diet,which is a viable alternative to fishmeal and fish oil in aquaculture *** a two-factor design,we examined the impact of inulin(2%)as well as the variation in the carbohydrates(CHO)/plant protein ratio on rainbow *** assessed the influence of these factors on zootechnical parameters,plasma metabolites,gut microbiota,production of short-chain fatty acids and lactic acid,as well as the expression of free-fatty acid receptor genes in the mid-intestine,intermediary liver metabolism,and immune markers in a 12-week feeding *** The use of 2%inulin did not significantly change the fish intestinal microbiota,but interestingly,the high CHO/protein ratio group showed a change in intestinal microbiota and in particular the beta diversity,with 21 bacterial genera affected,including Ralstonia,Bacillus,and 11 lactic-acid producing *** were higher levels of butyric,and valeric acid in groups fed with high CHO/protein diet but not with *** high CHO/protein group showed a decrease in the expression of pro-inflammatory cytokines(il1b,il8,and tnfa)in liver and a lower expression of the genes coding for tight-junction proteins in mid-intestine(tjp1a and tjp3).However,the 2%inulin did not modify the expression of plasma immune ***,inulin induced a negative effect on rainbow trout growth performance irrespective of the dietary *** With a 100%plant-based diet,inclusion of high levels of carbohydrates could be a promising way for fish nutrition in aquaculture through a protein sparing effect whereas the supplementation of 2%inulin does not appear to improve the use of CHO wh

关键词： Aquaculture Fish nutrition Gut microbiota Immune markers Intermediary metabolism Inulin Prebiotic Rainbow trout Short-chain fatty acids

Frequency of Modifiable Cardiovascular Risk Factors Such as Obesity, Diabetes Mellitus and Hypertension in a Benin Rural Area

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Open Journal of Internal Medicine 2015年第3期5卷 50-57页

作者： Djimon Marcel Zannou Anthelme Kouessi Agbodande Angèle Azon-Kouanou Finagnon Armand Wanvoegbe léopold Codjo Albert Dovonou Dédé Priscillia Tatiana Baglo Fabien Houngbe National Teaching Hospital-HKM of Cotonou University of Abomey-Calavi Abomey-Calavi Benin Departmental Hospital of Oueme-Plateau (Oueme Plateau) University of Abomey-Calavi Abomey-Calavi Benin Departmental Hospital of Borgou-Alibori University of Parakou Parakou Benin

The fight against cardiovascular diseases requires the knowledge of their modifiable risk factors. This study aimed to assess the level of modifiable cardiovascular risk factors in a rural area in order to develop a prevention program. Methods: This is an analytical and cross-sectional study on data collected during a fairground medical consultation of adults from 20 to 25 May 2013, in both border districts of the municipality of Djidja (Agouna and Houto). The studied parameters were the capillary blood glucose profile, blood pressure profile, waist circumference (WC) and Body Mass Index (BMI). Diabetes is defined by a fasting blood glucose ≥ 1.26 g/l two times. Hypertension is defined according to the criteria of JNC VII and obesity by BMI ≥ 30 kg/m2;abdominal obesity is defined by a WC above 102 cm in men and 88 cm in women. Data were analyzed using SPSS software version 18.0. Results: A total of 926 people were included among whom 57.8% were women. The average age was 38.43 ± 15.84 years. The prevalence of diabetes mellitus was 2.9%. The prevalence of obesity (BMI ≥ 30 kg/m2) was 8.4%;10.8% of studied population had abdominal obesity and 19.2% had hypertension. Age above 35 years and obesity were significantly associated with hypertension. Risk factors of obesity (IMC ≥ 30 kg/m2) were the place of residence (Agouna), the female gender, age between 35 and 64 and abdominal obesity. Conclusion: The frequency of cardiovascular risk factors, although small compared to the national level, remains a concern in the investigated rural communities. This must lead to undertake a survey on the lifestyle and dietary habits of the inhabitants of these areas.

关键词： Rural Area Cardiovascular Risk Factors Diabetes Mellitus Hypertension Obesity

Mechanisms of electrochemical magnesium(de)alloying of Mg-Sn and Mg-Pb polymorphs

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Journal of Magnesium and Alloys 2022年第6期10卷 1609-1616页

作者： Clément Pechberty Antoine Klein Bernard Fraisse lorenzo Stievano Romain Berthelot ICGM CNRSUniv.MontpellierENSCMMontpellierFrance RS2E CNRSHub de l’EnergieAmiensFrance

Different polymorphs of Mg-Sn and Mg-Pb intermetallic compounds were prepared by high-energy mechanical alloying and then investigated as active material in magnesium batteries. Beside thermodynamically stable Mg_(2)Sn and Mg_(2)Pb crystallizing in the anti-fluorite structure, other polymorphs Mg_(~2)Sn and Mg_(~2)Pb were prepared by increasing the ball-milling time. The first dealloying process is almost complete only for the cubic polymorphs, then similar capacities are observed during the subsequent alloying and dealloying *** to operando X-ray diffraction, the electrochemical mechanism is revealed and shows that the cubic polymorphs Mg_(2)Sn and Mg_(2)Pb tend to preferentially form during the alloying whatever the pristine intermetallic. Weak traces of Mg_(~2)Sn and Mg_(~2)Pb are observed during the alloying, suggesting that these polymorphs act as a by-product and/or an intermediate phases of the electrochemical process. Finally, the compatibility of cubic Mg_(2)Sn and Mg_(2)Pb with Mg(TFSI)_(2)-based electrolyte is confirmed in full cell vs. a positive electrode based on the Chevrel phase Mo6S8, although limited performance is achieved. This fundamental work provides new insights in the behavior of alloy-type negative electrodes for magnesium-ion batteries.

关键词： Magnesium batteries Alloy electrode Mechanochemistry Operando X-ray diffraction

In-situ stress inversion in liard Basin, Canada, from caliper logs

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Petroleum 2020年第4期6卷 392-403页

作者： Hongxue Han Shunde Yin Civil and Environmental Engineering University of WaterlooONN2L 3G1Canada

This paper proposes an integrated method of analytical calculation,artificial intelligence,and probabilistic analysis to cost-effectively determine geomechanical properties and in-situ stresses from borehole deformation via caliper ***'s also demonstrated in this paper that the actual borehole size can not be simply taken as the bit size by default,and adjusted borehole size has to be used to find the reasonable borehole *** the proposed method,an artificial neural network(ANN)is applied to map the relationship among in-situ stress,adjusted borehole size,geomechanical properties,and borehole *** genetic algorithm(GA)searches for the set of unknown stresses and geomechanical properties that match the objective borehole deformation *** analysis is conducted after ANN-GA modeling to estimate the most possible ranges of the *** hybrid method has been demonstrated by a field case study to estimate the adjusted borehole size,Young's modulus,and the two horizontal in-situ stresses using borehole deformation information reported from four-arm caliper logs of a vertical borehole in liard Basin in Canada.

关键词： Adjusted borehole size In-situ stress Caliper log Borehole deformation Artificial neural network Genetic algorithm Probabilistic analysis

Secure and Privacy-Preserving Decision Tree Classification with lower Complexity

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Journal of Communications and Information Networks 2020年第1期5卷 16-25页

作者： liang Xue Dongxiao liu Cheng Huang Xiaodong lin Xuemin(Sherman)Shen Department of Electrical and Computer Engineering University of WaterlooWaterloo N2L 3G1Canada School of Computer Science University of GuelphGuelph N1G 2W1Canada Department of Electrical and Computer EngineeringUniversity of WaterlooWaterloo N2L 3G1Canada

As a widely-used machine-learning classifier,a decision tree model can be trained and deployed at a service provider to provide classification services for clients,e.g.,remote *** address privacy concerns regarding the sensitive information in these services(i.e.,the clients’inputs,model parameters,and classification results),we propose a privacy-preserving decision tree classification scheme(PDTC)in this ***,we first tailor an additively homomorphic encryption primitive and a secret sharing technique to design a new secure two-party comparison protocol,where the numeric inputs of each party can be privately compared as a whole instead of doing that in a bit-by-bit ***,based on the comparison protocol,we exploit the structure of the decision tree to construct PDTC,where the input of a client and the model parameters of a service provider are concealed from the counterparty and the classification result is only revealed to the client.A formal simulation-based security model and the security proof demonstrate that PDTC achieves desirable security *** addition,performance evaluation shows that PDTC achieves a lower communication and computation overhead compared with existing schemes.

关键词： decision trees data privacy model privacy secure comparison machine-learning classification

Effect of Maruca vitrata （lepidoptera： Crambidae） host plants on life-history parameters of the parasitoid Apanteles taragamae （Hymenoptera： Braconidae）

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Insect Science 2012年第4期19卷 518-528页

作者： Elie A. Dannon Manuele Tamo Cvriaaue A qboton Arnold van Huis Marcel Dicke Facult des Sciences Agronomiques Universit d'Abomey-Calavi Cotonou International Institute of Tropical Agriculture (IITA) BeninStation Cotonou Benin laboratory of Entomology Wageningen University Wageningen the Netherlands

The effect of four host plant species of the herbivore Maruca vitrata Fabri- cius （lepidoptera： Crambidae） on development time, longevity, fecundity and sex ratio of the parasitoid Apanteles taragamae Viereck （Hymenoptera： Braconidae） was investi- gated under laboratory conditions. The larvae were parasitized when in the second instar. Maruca vitrata larvae were fed with flowers of four legumes, that is, Vigna unguiculata （cowpea）, Sesbania rostrata, lonchocarpus sericeus and Pterocarpus santalinoides, or an artificial diet both before and after parasitization. The parasitoid did not develop in hosts feeding on l. sericeus or E unguiculata at 25℃, or on P. santalinoides at 25℃ or 29℃. Apanteles taragamae had the shortest development time on artificial diet at both 25℃ and 29℃ while the longest development time was recorded on l. sericeus at 29℃. Female wasps took longer to develop compared to males at the two temperatures, regardless of the feeding substrate of their host. The longevity of the wasps at 25℃ varied among feeding substrates, but not at 29℃. Survival rate of parasitized larvae depends on the feeding sub- strate. Moreover, infection of host larvae with Maruca vitrata multi-nucleopolyhedrovirus （MaviMNPV） killed larger proportions of parasitized larvae at 25℃ than at 29℃, which was likely caused by the difference in parasitoid developmental rate. The proportion of female parasitoids was lowest on l. sericeus. The daily fecundity showed a nonlinear trend regardless of the feeding substrate, indicating that A. taragamae is a pro-ovigenic species. The data support the slow growth-high mortality hypothesis.

关键词： Apanteles taragamae artificial diet development feeding substrates hostplants Maruca vitrata nutritional quality

Effect of Fish Meal Replacement by Unconventional Meal in the Post-larval Diet of Clarias Gariepinus in Benin (West Africa)

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Agricultural Sciences 2022年第10期13卷 1091-1102页

作者： Edmond Sossoukpe Isidore N. Odjo Théophile Godome Emile D. Fiogbe laboratory of Wetland Research Department of Zoology Faculty of Sciences and Techniques University of Abomey-Calavi Abomey-Calavi Benin

To reduce the pressure on aquatic resources due to the use of fishmeal in fish feed, the mastery and use of alternative sources of fishmeal in all stages of fish development are essential. Five diets including 4 experimental and one control diet were considered. Experimental diets of post-larvae were developed from unconventional ingredients in which fishmeal was completely replaced by a mixture of brewer’s yeast, chicken viscera and maggots. These foods were tested on Clarias gariepinus post-larvae with an initial average weight of 80 ± 1 mg. 1500 fish individuals were equally distributed in 15 concrete basins with a volume of 500 l forming five treatments in triplicate. Fish individuals were fed, manually at a ration rate of 20%, four times per day. The specific growth rates were 8.38%/day in imported food and 6.35%/day in the experimental food receiving 45.5% of protein from unconventional meal. Similar results were obtained with the feed consumption index. These encouraging results show that it is possible to partially or completely replace fishmeal in catfish feed and obtain an economically profitable production. The recovery of waste such as chicken viscera, brewer’s yeast and soybean meal in fish food formulation as tested in this study is a good contribution to environmental sanitation.

关键词： Maggot Meal Brewer’s Yeast Diet Post-larvae Fish Meal Replacement Benin