检索结果-南通市图书馆

Multi-Mesh-Scale Approximation of Thin Geophysical Mass Flows on Complex Topographies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2021年第1期29卷 148-185页

作者： Yih-Chin Tai Jeaniffer Vides boniface Nkonga Chih-Yu Kuo Department of Hydraulic and Ocean Engineering National Cheng Kung UniversityTainanTaiwan LEMMA R&D Services Sophia AntipolisBiotFrance&Maison de la SimulationGif-sur-YvetteFrance Universit́e Cˆote d’Azur(UCA) LJAD Nice&Inria Sophia Antipolis–ḾediterrańeeFrance Research Center for Applied Sciences Academia SinicaTaipeiTaiwan

This paper is devoted to a multi-mesh-scale approach for describing the dynamic behaviors of thin geophysical mass flows on complex topographies.Because the topographic surfaces are generally non-trivially curved,we introduce an appropriate local coordinate system for describing the flow behaviors in an efficient way.The complex surfaces are supposed to be composed of a finite number of triangle elements.Due to the unequal orientation of the triangular elements,the distinct flux directions add to the complexity of solving the Riemann problems at the boundaries of the triangular elements.Hence,a vertex-centered cell system is introduced for computing the evolution of the physical quantities,where the cell boundaries lie within the triangles and the conventional Riemann solvers can be applied.Consequently,there are two mesh scales:the element scale for the local topographic mapping and the vertex-centered cell scale for the evolution of the physical quantities.The final scheme is completed by employing the HLL-approach for computing the numerical flux at the interfaces.Three numerical examples and one application to a large-scale landslide are conducted to examine the performance of the proposed approach as well as to illustrate its capability in describing the shallow flows on complex topographies.

关键词： Multi-mesh-scale approach complex topography shallow flows unstructured mesh vertex-centered formulation

Evaluation of the Fetal-Maternal Radiation Doses in CT-Pelvimetry and Estimation of the Fetal Radiation Risks in 03 Radiology Departments in Douala-Cameroon

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Radiology 2022年第3期12卷 113-124页

作者： Celestin Mpeke Mokubangele Alexandre Ngwa Ebongue Daniel Bongue Maurice Moyo Ndontchueng boniface Moifo Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ) University of Douala Douala Cameroon Department of Physics Faculty of Science University of Douala Douala Cameroon National Radiation Protection Agency of Cameroon Yaounde Cameroon Department of Radiology and Radiation Oncology Faculty of Medicine and Biomedical Sciences University of Yaounde 1 Yaounde Cameroon Radiology Department Yaounde Gynaeco-Obstetric and Pediatric Hospital Yaounde Cameroon

Background: CT in pregnant patients requires careful consideration of the radiation dose and corresponding radiation risks from ionizing radiation to the unborn child. The determination of foetal dose in diagnostic radiology is of interest as a basis for risk estimates from medical exposure of the pregnant patient. Objective: To evaluate the foetal-maternal radiation doses delivered during the CT-Pelvimetry procedure and to estimate the risk to the unborn child to develop a cancer in childhood and hereditary disease. Materials and Methods: We investigate the foetal-maternal radiation doses during CT-scan Pelvimetry in Douala (Cameroon). Data of 194 helical acquisition CT-Pelvimetry were collected between May 2017 and May 2019. An average DLP for the examination was established and the average effective dose was evaluated. The fetal dose was calculated and the FetDose V5 program was used for risk estimations. Results: The average dose length product (DLP) was 56.17 mGy·cm (range: 51.69 - 59.21 mGy·cm). The average effective dose received by women pregnant was 0.78 mSv. The mean individual fetal dose was 1.5 mGy (range: 0.76 - 1.87 mGy). The risk of Childhood Cancer calculated was: range 1 in 16,000 to 1 in 10,000 and 1 in 260,000 to 1 in 106,000 to the risk of Hereditary Disease, respectively. Conclusion: This study shows that the foetal-maternal doses delivered during CT-Pelvimetry examinations are very low and the risks of childhood cancers and hereditary diseases are derisory, the technology should be further investigated to ensure its full potential for optimal diagnostic accuracy.

关键词： CT-Pelvimetry Fetal-Maternal Radiation Dose Fetal Radiation Risk

Evolution of Sedimentation in a Headrace Canal for Hydroelectric Production Case of the Shongo Basin of the Inga Complex from February 2020 to May 2021 (Kongo Central Province/DR Congo)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2023年第5期11卷 404-426页

作者： Omer Kawende Kalonda Ivon Ndala Tshiwis boniface Mumbimb Atalatala Clement N’Zau Umba-Di-Mbudi Geo-Hydro-Energy Research Group University of Kinshasa Kinshasa Democratic Republic of the Congo Department of Geosciences Faculty of Science and Technology University of Kinshasa Kinshasa Democratic Republic of the Congo Polytechnic Faculty President Joseph Kasa-Vubu State University Boma Democratic Republic of the Congo

The headrace of the Inga hydropower complex is experiencing siltation problems, reducing the exploitable draft and limiting the production capacity of the two main Inga hydropower plants during the low water period. During the 2019 low water period, several sediment slumps occurred in the Shongo basin, disrupting the production of hydroelectric power generated by the Inga 1 & 2 power plant, resulting in massive load shedding of power supply to downstream customers. The cardinal aim of this study is to determine the quantities of sediments deposited and those eroded, in order to know the evolution of sedimentation in the Shongo basin from February 2020 to May 2021. The results obtained show that the running index of the generating units is determinant and influences the sedimentation process in the Shongo basin. The cleaning of the Shongo basin in terms of the spatial distribution of sedimentation from February 2020 to May 2021 is plausible.

关键词： Quantities Erode Deposede Load Shedding and Index

Studies on a low Reynolds number airfoil for small wind turbine applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第7期54卷 1684-1688页

作者： Joji WATA Mohammed FAIZAL boniface TALU Lesia VANAWALU Puamau SOTIA M.Rafiuddin AHMED Division of Mechanical Engineering University of the South Pacific

In contrast to large horizontal axis wind turbines (HAWTs) that are located in areas dictated by optimum wind conditions, small wind turbines are required for producing power without necessarily the best wind conditions. A low Reynolds number airfoil was designed after testing a number of low Reynolds number airfoils and then making one of our own; it was tested for use in small HAWTs. Studies using XFOIL and wind tunnel experiments were performed on the new airfoil at various Reynolds numbers. The pressure distribution, C p , the lift and drag coefficients, C L and C D , were studied for varying angles of attack, α. It is found that the airfoil can achieve very good aerodynamic characteristics at different Reynolds numbers and can be used as an efficient airfoil in small HAWTs.

关键词：小型风力发电机组低雷诺数翼型应用空气动力特性风洞实验压力分布阻力系数

Influence of automobile industrial wastewater on soil quality

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2014年第6期7卷 123-128页

作者： Ugwu Samson Nnaemeka Anyadike Chinenye Chukwuemeka Echiegu Emmanuel Nwoke Oji Achuka Ugwuishiwu boniface Department of Agricultural and Bioresources Engineering University of NigeriaNsukkaNigeria

Reuse of industrial wastewater(effluent)for irrigation purpose is a common practice.However,lack of adequate treatment of the effluent can cause soil deterioration,vegetation destruction and contamination of the aquatic environment.These adverse effects necessitated the study of wastewater irrigation in Emene Industrial Layout,Enugu State,Nigeria.Wastewater and soil samples were collected,analyzed and subjected to Analysis of Variance(ANOVA)for Completely Randomized Design(CRD)at 5% probability level using GENSTAT software.The results obtained from the study were compared with FAO soil and water standards.The wastewater analysis suggested that contamination at the untreated stage was very high and results at the treatment level were within the FAO reuse range.The study also found wide variation in chemical status of industrial wastewater treated soil.Almost all the values for the wastewater treated soil were not within the FAO irrigated soil chemical properties standards.This suggests high re-contamination along the open channel(from non-point sources)before reuse.This calls for proper monitoring and treatment of the industrial effluent prior to irrigation application.

关键词： irrigation soil quality contamination wastewater automobile industry

Estimating the economic and social consequences for patients diagnosed with human African trypanosomiasis in Muchinga,Lusaka and Eastern Provinces of Zambia(2004-2014)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Infectious Diseases of Poverty 2017年第1期6卷 1330-1342页

作者： Allan Mayaba Mwiinde Martin Simuunza boniface Namangala Chitalu Miriam Chama-Chiliba Noreen Machila Neil Anderson Alexandra Shaw Susan C.Welburn School of Veterinary Medicine University of ZambiaLusakaZambia Department of Economics University of ZambiaLusakaZambia Division of Infection and Pathway Medicine and Centre for Infectious Diseases School of Biomedical SciencesCollege of Medicine and Veterinary MedicineThe University of EdinburghChancellor’s Building49 Little France CrescentEdinburghScotland EH164SBUK The Royal(Dick)School of Veterinary Studies and the Roslin Institute University of EdinburghRoslin EH259RGUK AP Consultants Walworth Enterprise CentreAndover SP105APUK School of Veterinary Medicine Department of Disease Control University of ZambiaP.O Box 32379LusakaZambia

Background:Acute human African trypanosomiasis(rHAT)caused by Trypanosoma brucei rhodesiense is associated with high mortality and is fatal if left untreated.Only a few studies have examined the psychological,social and economic impacts of rHAT.In this study,mixed qualitative and quantitative research methods were used to evaluate the socio-economic impacts of rHAT in Mambwe,Rufunsa,Mpika and Chama Districts of Zambia.Methods:Individuals diagnosed with rHAT from 2004 to 2014 were traced using hospital records and discussions with communities.Either they,or their families,were interviewed using a structured questionnaire and focus group discussions were conducted with affected communities.The burden of the disease was investigated using disability adjusted life years(DALYs),with and without discounting and age-weighting.The impact of long-term disabilities on the rHAT burden was also investigated.Results:Sixty four cases were identified in the study.The majority were identified in second stage,and the mortality rate was high(12.5%).The total number of DALYs was 285 without discounting or age-weighting.When long-term disabilities were included this estimate increased by 50%to 462.The proportion of years lived with disability(YLD)increased from 6.4%to 37%of the undiscounted and un-age-weighted DALY total.When a more active surveillance method was applied in 2013-2014 the cases identified increased dramatically,suggesting a high level of under-reporting.Similarly,the proportion of females increased substantially,indicating that passive surveillance may be especially failing this group.An average of 4.9 months of productive time was lost per patient as a consequence of infection.The health consequences included pain,amnesia and physical disability.The social consequences included stigma,dropping out of education,loss of friends and self-esteem.Results obtained from focus group discussions revealed misconceptions among community members which could be attributed to lack of knowledge about rHAT.Conclusions:The social an

关键词： Human African trypanosomiasis Hat Sleeping sickness T.B.Rhodesiense Social and economic burden DALYs Zambia

Diversity, Host Plant Range and Distribution of Thrips spp. (Thysanoptera: Thripidae) in Three Vegetable Production Basins in Burkina Faso

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advances in Entomology 2023年第3期11卷 143-155页

作者： Madi Nacanabo Issaka Zida Wendnéyidé Mathieu Sawadogo Maxime Ouattara Rémi Dabiré Babo boniface Bakouan Souleymane Nacro Centre Agricole Polyvalent de Matourkou Bobo-Dioulasso Burkina Faso Direction Régionale de Recherches Environnementales et Agricoles de l’Ouest Bobo-Dioulasso Burkina Faso Institut du Développement Rural Université Nazi Boni Bobo-Dioulasso Burkina Faso Centre Régional de Recherches Environnementales Agricoles et de Formation de Kamboinsé Ouagadougou Burkina Faso

Onion is the most important vegetable produced in Burkina Faso. It contributes to food and nutrition security and is a source of income for farmers. Thrips, which feed on the leaves of the plant, are the main insect pest of onion. The objective of this study was to access the diversity, the host range and the distribution of Thrips spp. in three main onion production areas in Burkina Faso. Three sites were chosen in each vegetable production basin, and plant species present were sampled and inspected to determine their thrips’ infestation status. Seventeen cultivated or wild plant species were attacked by thrips. The incidence of attacks was highest on zucchini plants followed by cucumber, eggplant, and onion, respectively. Six thrips species were recorded of which Thrips tabaci (Lindemman) represented more than 70% of the total. The average density of Thrips spp. per plant varied significantly between production basins and plant species. The highest average number of Thrips spp. per plant was recorded on zucchini (40.28 ± 10.28;17.43 ± 13.48 and 14.33 ± 7.11 respectively in the North, Hauts Bassins, and Central Plateau). This study provided basic information that can lead to further research and the development of control methods.

关键词： Onion Thrips Diversity Host Plants Burkina Faso

Cancer Occurrence and Associated Factors to Malignancy in BIRADS-3 Lesions in Yaoundé: The Need to Be More Proactive for Patients above 40, Non-Compliant with Imaging Follow-Up and Presenting with Nipple Discharge

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Medical Imaging 2023年第4期13卷 127-135页

作者： Joseph-Francis Nwatsock Ambroise Merci Seme-Engoumou Coralie Reine Bertine Mendouga-Menye Etienne Atenguena-Okobalemba Lionel Tabola boniface Moifo Department of Medical Imaging and Radiation Oncology Faculty of Medicine and Biomedical Sciences University of Yaoundé I Yaoundé Cameroon Department of Morphological Sciences and Pathology Faculty of Medicine and Biomedical Sciences University of Yaoundé I Yaoundé Cameroon Oncology Service Yaoundé General Hospital Yaoundé Cameroon

Background and objectives: Breast Imaging Reporting and Data System in Category 3 (BIRADS-3) includes probably benign lesions which need a short-term imaging follow-up. However, in our context, the lesions graded BIRADS-3 remain insufficiently evaluated. We therefore conducted this study to assess the cancer occurrence and associated factors in BIRADS-3 lesions during the follow-up in order to propose an adaptation of the management for lesions in this category in our setting. Patients and methods: A retrospective longitudinal study of patients with lesions initially classified as BIRADS-3 and who realised each at least one additional imaging check-up between January 2014 and December 2022 in five Yaoundé hospitals. All clinical and imaging data were analysed using SPSS® 21.0 software with a significant p-value Results: Patients were aged 13 to 73 (33.0 ± 13.4) years, with a history of breast mass (315 cases;79.7%), breast pain (25 patients;6.3%), nipple discharge (20 patients;5.1%) or past family history of breast cancer (25 cases;6.3%). The most common baseline abnormalities were mammogram opacities (64.8%) and microcalcifications (48.6%), whereas initial breast ultrasound showed solid masses (77.0%) and cystic lesions (11.1%). Compliance with imaging appointment periods was low with only 23.9% of all patients performing an imaging control at the scheduled moment. During the follow-up, 115 patients (29.1%) were upgraded to BIRADS-4 and histology performed revealed 43 cancers (10.9% of overall initial BIRADS-3 sample). The presence of malignancies was associated to age above 40 years (p = 0.0001) and to the presence of nipple discharge (p = 0.0375). Conclusion: The frequency of malignancies among initial BIRADS-3 lesions in our series is higher than that described in the guidelines. This study highlights the need to be more proactive in the management of BIRADS-3 lesions in our setting as the compliance with follow-up is low. So, biopsy should be considered as an alternative to long-term follow-up for

关键词： BIRADS-3 Cancer Occurrence Associated Factors to Malignancy Imaging Follow-Up Yaoundé

Access to Child Health Care, Medical Treatment of Sick Children and Childhood Mortality Relationships in Kenya

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Health 2014年第11期6卷 1152-1164页

作者： boniface Omuga K’Oyugi Population Studies and Research Institute University of Nairobi Nairobi Kenya

Child health care factors such as medical treatment of sick children have direct and indirect effect on childhood mortality. Through international cooperation, a number of countries including Kenya have gathered information on provision of child health services at facility level from periodic Service Provision Assessment (SPA) surveys. Kenya has also gathered information on medical treatment of sick children at household level from periodic Demographic and Health Surveys (DHS). However, establishing how health care information in the SPA surveys relates to childhood mortality and also how these factors relate to medical treatment of sick children in the DHS has been constrained by differences in sample designs of the surveys. This study deployed a fstrategy of constructing community level variables derived from the SPA survey data and incorporated them into DHS data which served as the main data source. The SPA and DHS sampling designs for Kenya allow computation of stable estimates of regional demographic and health service indicators at provincial level. This study analyzed information gathered from 690 health facilities in 2010 SPA and 6079 births born less than 60 months from 2008/09 DHS. The study found that access to child health services, waiting time before service in facility and time to the nearest referral facility were significant facilitating factors for medical treatment of sick children. The study also established that waiting time before service in facility was the only access to health care factor which had a significant effect on childhood mortality when HIV prevalence was excluded in the analysis. However, the significance of waiting time before service diminished with inclusion of HIV prevalence. Further research is required to refine definition and measurement for child health care variable on female autonomy.

关键词： Access to Child Health Care Medical Treatment Childhood Mortality Kenya