275 results on '"Losses"'
Search Results
2. Losses after Harvesting and Management
- Author
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Mohamed Aezeden, Liet Zachariah, Goru Donovan, and David Japhet
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fresh fruits ,losses ,postharvest ,process ,storage ,vegetables ,Environmental sciences ,GE1-350 - Abstract
It is widely recognized that postharvest losses in agriculture have a significant impact on the sustainability and security of the world’s food supply. This essay aims to investigate the reasons behind these losses, their effects, and possible solutions. Several factors, such as insufficient infrastructure, inadequate storage facilities, improper handling procedures, and limited market access, are analyzed as potential causes of postharvest losses. The discussion primarily focuses on the negative consequences of these losses on farmers’ livelihoods, food supply, and resource utilization, as well as the economic, environmental, and social implications. The paper suggests several strategies to minimize postharvest losses, including strengthening value chains, promoting appropriate technology for processing and storage, enhancing farmer education and training, and upgrading transportation and storage infrastructure. Additionally, the significance of market processes and policy interventions in reducing losses is highlighted. By reducing postharvest agricultural losses, it is expected that food security, resource efficiency, and sustainable development will be improved.
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- 2024
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3. Losses along the tuberculosis sputum sample referral cascade for Mpongwe District, Zambia
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Lyson Nkhoma, Josphat Bwembya, Edwin Chansa, Ramya Kumar, Ibou Thior, Victoria Musonda, Gershom Chongwe, and Alwyn Mwinga
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tuberculosis ,sputum ,sample ,referral ,cascade ,losses ,examination ,diagnosis. ,Medicine ,Public aspects of medicine ,RA1-1270 - Abstract
Background: In resource limited-settings, timely tuberculosis (TB) diagnosis depends upon referral of sputum samples from non-diagnostic to diagnostic facilities for examination. The TB programme data for 2018 suggested losses in Mpongwe District’s sputum referral cascade. Aim: This study aimed to identify the referral cascade stage where loss of sputum specimen occurred. Setting: Primary health care facilities in Mpongwe District, Copperbelt Province, Zambia. Methods: Data were retrospectively collected from one central laboratory and six referring health facilities between January and June 2019, using a paper-based tracking sheet. Descriptive statistics were generated in SPSS version 22. Results: Of the 328 presumptive pulmonary TB patients found in presumptive TB registers at referring facilities, 311 (94.8%) submitted sputum samples and were referred to the diagnostic facilities. Of these, 290 (93.2%) were received at the laboratory, and 275 (94.8%) were examined. The remaining 15 (5.2%) were rejected for reasons such as ‘insufficient sample’. Results for all examined samples were sent back and received at referring facilities. Referral cascade completion rate was 88.4%. Median turnaround time was six days (IQR = 1.8). Conclusion: Losses in the sputum referral cascade for Mpongwe District mainly occurred between dispatch of sputum samples and receipt at diagnostic facility. Mpongwe District Health Office needs to establish a system to monitor and evaluate the movement of sputum samples along the referral cascade to minimize losses and ensure timely TB diagnosis. Contribution: This study has highlighted, at primary health care level for resource limited settings, the stage in the sputum sample referral cascade where losses mainly occur.
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- 2023
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4. Geostatistička analiza ljudskih gubitaka u koncentracionom logoru Jasenovac
- Author
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Dragan Cvetković
- Subjects
Independent State of Croatia (NDH) ,civilians ,concentration camp ,Jasenovac ,Serbs ,Jews ,Roma ,Croats ,Muslims ,population ,regions ,losses ,victims ,History of Eastern Europe ,DJK1-77 - Abstract
The paper is an attempt to show the role of the Jasenovac concentration camp in the destruction of peoples from different parts of the Independent State of Croatia (NDH) based on partially revised list „Victims of War 1941–1945” from 1964. On the basis of achieved results in the process of revision of the census list, a calculation of the total losses of the civilians of Yugoslavia, of those in the NDH and its regions, with particular focus on losses in the Jasenovac camp was made. The losses in Jasenovac were analyzed through the prism of the general losses of the civilian population of NDH during the war, in all its parts. They were all compared with the demographic structure of the population of the NDH and its regions. Jasenovac camp system, was the largest concentration camp in the NDH, where a quarter of all killed civilians in this territory lost their lives (24.53%). The scope of the crimes committed in the Jasenovac camp clearly identify it as a destruction camp. The victims in Jasenovac were brought to the camp from all parts of the NDH. Most of the dead were originally from the two regions with which the camp was bordering, 30.60% from Slavonia and 25.13% from Bosanska Krajina, with 12.62% of losses originating from Eastern Bosnia. The victims from 4 regions had a greater share in losses in Jasenovac than their representation in the population of NDH, Banija 2.25 times, Bosnian Krajina 2.14 times, Slavonia 2.13 times and Srem 1.19 times, while Kordun had equal share. The victims of the other 7 NDH regions had much less participation in the losses in Jasenovac than their representation in the population, from 19.12 and 11.21 times lower in the part of Dalmatia and Lika, up to 2.27 and 1.23 times lower in Northwestern Croatia and Eastern Bosnia. Jasenovac was the site of the death of half of all killed Slavonia civilians (54.11%), two fifths from Srem (38.30%), one third of killed civilians from Banija (32.73%), a quarter from Northwestern Croatia (26.70% ) and Bosanska Krajina (23.27%), but also minimal parts of the killed civilians from Lika (1.28%), Dalmatia (3.49%) and Herzegovina (5.57%). Jasenovac was the central place of death in the NDH, where 78.08% of all victims of the Roma lost their lives, 61.68% of the victims of the Jews, 23.24% of Serbian civilian victims, 11.81% of Croats, 3.50% of Muslims and 4.39% of members of other and unknown nationalities. In nine of the twelve NDH regions, Serbs accounted for the bulk of the loss of prisoners in the camp, everywhere with a predominant majority of 92.43% in the Bosnian Krajina and 91.85% in Banija, up to 54.87% in Srem, the Jews were majority in two regions (Eastern Bosnia 55,35% i Northwest Croatia 36,21%), and the Romas in one. Three-quarters of Serbs killed the Jasenovac (74.61%) come from three regions (36.88% from Bosanska Krajina, 27.20% from Slavonia, 10.53% from Banija). Of all Serb civilians victims from Slavonia, 55.54% lost their lives in Jasenovac, as well as 33.99% of Serb civilian victims from Northwestern Croatia, 33.70% from Banija, 28.34% from Srem, 23.50% from Bosanska Krajina, while the share of victims of Jasenovac in the other seven regions was far smaller or minimal (Lika 0.89%). Half of all Jews victims in Jasenovac were from Eastern Bosnia (47.65%), with 21.27% from Northwestern Croatia and 18.63% of Slavonia, while 12.45% were from the other nine regions. While in Eastern Bosnia almost all Jews lost their lives in Jasenovac (90.74%), from Jews from Slavonia and Northwestern Croatia, 54.69% and 35.89% of them were killed in that camp. Of the dead Roma in Jasenovac, 59.95% originated from Slavonia, where life was lost by four fifths of all the Romas victims from Slavonia, Srem and Northwestern Croatia. Of the Croats killed in Jasenovac, 45.92% were from northwestern Croatia, while 43.22% of the Muslims killed in the camp were from the Bosnian Krajina.
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- 2019
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5. Perception des paysans sur la contrainte de la mineuse de l’épi Heliocheilus albipunctella De Joannis, ravageur important du mil en zone sahélienne
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N. Oumarou, I. Baoua, A.A. Saidou, L. Amadou, and D. Stern
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control methods ,heliocheilus albipunctella ,losses ,niger. ,pennisetum glaucum ,Agriculture - Abstract
Farmers’ Perception of the Pearl Millet Head Miner Heliocheilus albipunctella De Joannis, a Major Millet Pest in the Sahelian Area Heliocheilus albipunctella De Joannis is an important millet pest in the Sahelian zone. To assess the farmers’ perception related to this pest, a survey was carried out in 5 agricultural areas of Niger. The survey was carried out in April 2016 including 732 pearl millet growers. The obtained results showed that: 1) 17% of the respondents were able to describe the life cycle of H. albipunctella; 2) since 28 years the pest causes an average production loss of 43 to 82% depending on the region; 3) 37-78% of the farmers are aware that early sowing, droughts and sandy soil favor the infestations of the Millet Worm; 4) most pest damages were observed at the millet maturity stage as indicated by half of the respondents; 5) more than 80% of farmers do not know any pest control method. The results showed a negative incidence of H. albipunctella on millet yield in these precarious zones. The development of an Integrated Method Program is recommended.
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- 2019
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6. Analysis of losses in the mixing section of the central air conditioner using the entropy-statistical method
- Author
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Zdobnov M.I., Lavrov N.A., and Shishov V.V.
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central air conditioning ,mixing section ,air flow ,outdoor air ,recirculation air ,losses ,entropy-statistical analysis ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
The article presents an entropy-statistical analysis of losses in the mixing section of a central air conditioner. The temperature and humidity of the outdoor and recirculating air were measured. The methodology for determining losses using the entropy-statistical method is presented in the work. The calculation of losses in the mixing section of the central air conditioner due to the mixing of air flows depending on the flow rate of the supply and recirculation air as well as due to hydraulic losses. A comparative analysis of the results is carried out and the distribution diagrams of the component losses are presented. Proposed conclusions regarding the way to reduce losses.
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- 2020
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7. Incidence de la bactérie Xhantomonas oryzae pv oryzae sur la production du riz (Oriza sativa L.) au Niger
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Basso, A., Haougui, A., Abdoul Habou, Z., Adam, T., and Séré, Y.
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Xhantomonas oryzae ,Rice ,Incidence ,Losses ,Relay hosts ,Niger ,Agriculture - Abstract
Incidence of Xhantomonas oryzae pv oryzae on the Production of Rice (Oriza sativa L.) in Niger. Rice bacterial blight due to Xhantomonas oryzae pv. oryzae is one of the diseases causing economic damage on rice in Niger. Investigations were led in the two most important irrigated rice producing areas (along the river Niger and the river Komadougou yobé) in order to evaluate its importance. It comes out from the study that bacterial blight is present in both rice producing areas, with a prevalence of 10 to 75% and production losses ranging from 19 to 63%, which amounts from 200.000 to more than 500.000 FCFA/ha. It was noted that some cultural practices such as phased transplanting favor the development of bacterial outbreaks. The search for alternative hosts to the bacterium made it possible to identify 13 species. These hosts belong to Poaceae (more than 80%) and Cyperaceae (nearly 20%) families.
- Published
- 2013
8. Diversité floristique, ethnobotanique et taxonomie locale des mauvaises herbes de l'oignon au Nord-est du Bénin
- Author
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Bello, S., Ahanchédé, A., Gbèhounou, G., Amadji, G., and Aho, N.
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Maize ,Granaries ,Insecticidal plants ,Storage modes ,Damage ,Losses ,Senegal ,Agriculture - Abstract
Floristic Diversity, Ethno-botanic and Local Taxonomy of Onion's Weeds in the North East of Benin. A study has been conducted in order to document scientific names, local names and their significations, and also to apprehend onion's weed species nomenclature adopted by farmers in the North East of Benin. Thirty onion's households have been surveyed through semi-structured interviews and a floristic inventory was carried out in each of them. Weeds'species and their botanic families and also the criteria of their local names have been identified and have served to elaborate a local taxonomy typology. 71 species which belong to 26 botanic families and 17 species belonging to six families constitute respectively the general flora and the flora associated to onion in vegetation.Poaceae,Cyperaceae, Commelinaceae, Malvaceae, Fabaceae and Portulacaceae are the most important families according to their number of species. Ecology, morphology, resistance to hoe weeding and socio-cultural usages are the criteria that were used to develop the local denomination of 39 among 71 identified species, and have served to elaborate the typology of local taxonomy. The other 32 species without local names do not have any major agroecological, nor socio-cultural interest for farmers. The evaluation of the agronomic importance of the flora associated to onion's vegetation can contribute to a better control of the weeds of this crop.
- Published
- 2013
9. Efficiency of Traditional Maize Storage and Control Methods in Rural Grain Granaries: a Case Study from Senegal
- Author
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Gueye, MT., Goergen, G., Ndiaye, S., Asiedu, EA., Wathelet, JP., Lognay, G., and Seck, D.
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Maize ,Granaries ,Insecticidal plants ,Storage modes ,Damage ,Losses ,Senegal ,Agriculture - Abstract
Maize storage and pest control method as practiced in traditional clay granaries in the Kédougou region in eastern Senegal were evaluated under rural conditions during two successive years. Three storage modes, i.e. maize cobs, winnowed and non-winnowed maize grains, were tested in seven granaries where the insecticidal plants Hyptis spicigera or H. suaveolens were either incorporated in the store structure or deposited as layers intermittently with maize. At the beginning of the storage period, all granaries were artificially infested with 7 pairs Tribolium castaneum and Sitophilus zeamais. No damage, losses or live insects were observed during 7 months of storage when maize cobs were placed between layers of H. spicigera. Compared with the control, incorporation of insecticidal plants within the granary bottom had no significant effect on the damage and loss level irrespective of the storage mode. Non-winnowed maize always suffered less damage and losses than the winnowed variant. In all granaries depredation, insect abundance and moisture content were highest toward the end of storage period between June and July.
- Published
- 2013
10. Déterminants socio-économiques et institutionnels de l'adoption d'innovations techniques concernant la production de maïs à l'ouest du Cameroun
- Author
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Tene, GLM., Havard, M., and Temple, L.
- Subjects
Maize ,Granaries ,Insecticidal plants ,Storage modes ,Damage ,Losses ,Senegal ,Agriculture - Abstract
Socio-economic and Institutional Variables that Affect Adoption of Technical Innovations Concerning Maize Production in Western Cameroon. The low productivity of farms in sub-Saharan Africa including Cameroon is due among others to the low adoption rates of innovations developed by agricultural research. This paper is a case study of the adoption of the technical package (improved varieties, fertilizers, pesticides, mono-culture) for maize cultivation in Western Cameroon. Data from a sample of 52 farmers were analyzed using a logit model and it was found that the maize cultivated area, the market orientation of production, contact with extension services, land tenure are factors that determine the likelihood of a farmer to adopt the technical package. However, it was adopted by less than 20% of the farmers surveyed, the others adopted only one, two or three components of the package according to their specific needs and strategies. These results challenge the agricultural research and extension to adapt their proposals to the diverse needs of farmers and to explain the reasons for the non-adoption of the whole package.
- Published
- 2013
11. Modelling SuperOx Power Cables to Predict the AC-Losses of a Double Layered Triaxial Cable
- Author
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Clegg, Matthew, Ruiz, Harold, and Sciencesconf.org, CCSD
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COMSOL ,Formulation ,Losses ,Triaxial Cables ,AC ,[SPI.NRJ] Engineering Sciences [physics]/Electric power - Published
- 2022
12. Earthquake Capacity Assessment Based on Geospatial Model At North Lombok, West Nusa Tenggara
- Author
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Kusdiah Gemeliarini I Gusti Ayu and Helmi Muhammad
- Subjects
Earthquake ,Losses ,Community Capacity ,Overlay ,Arcgis ,Environmental sciences ,GE1-350 - Abstract
Environmental management related to seismic activities should be given attention, especially in Indonesia. One of the areas in Indonesia that has an active volcano is the Lombok island, namely Rinjani Mount. According to the center of Volcanology and Disaster Mitigation Bandung, Rinjani Mount still wary status. Losses incurred from a disaster caused by the low human capacity in the region is.Thus it is necessary to know which areas have high, medium and low capacity. So that the community capacity can be optimized, especially in areas with low capacity of the community. The method of this research is to determine the capacity indicator that is used in determining the capacity level of society to earthquake. Create a thematic map for each indicator, then overlay for each indicator that has been given weight according to the level of influence.
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- 2018
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13. Problems of mineral raw material losses of quality and quantity management in developing of large-scale complex-structure deposits.
- Author
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Tkach Sergei
- Subjects
mining and geological conditions ,Mining unit ,Losses ,Impoverishment ,Mining flow ,Setting ,Efficiency ,Environmental sciences ,GE1-350 - Abstract
The article deals with the problems of mineral raw material losses of quality and quantity management in developing of large-scale complex-structure and composition deposits of solid minerals. It is shown that a very high degree of mining and geological conditions variability in time and space for the development of mining units is typical for such deposits. This significantly complicates the qualitative and quantitative operating losses setting and accounting of mineral raw materials during its extraction in the framework of existing general and industry regulatory documents. Conceptual principles for face-by-face operational setting of losses and impoverishment of minerals for the conditions of bulk mining of complex-structure deposits with the formation of gross mining flow with economically feasible and specified level of quality (the content of commercial and harmful components) are stated. These principles generally do not contradict effective instructions main provisions and are made to minimize the total operating losses during the processing of several mine sections (faces).
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- 2018
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14. Amplified fragments length polymorphism (AFLP) analysis of markers associated with H5 and H22 Hessian fly resistance genes in bread wheat
- Author
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Boukhatem N., El-Jaafari S., Najimi B., Jlibene M., Paul R., and Jacquemin J.M.
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triticum ,mayetiola destructor ,crop losses ,yields ,pest resistance ,genetic resistance ,genetic markers ,identification ,morocco ,africa ,biological properties ,cecidomyiidae ,diptera ,insecta ,losses ,mayetiola ,north africa ,poaceae ,resistance to injurious factors ,Biotechnology ,TP248.13-248.65 ,Environmental sciences ,GE1-350 - Abstract
Hessian fly, Mayetiola destructor (Say), is one of the most destructive pest of wheat (Triticum species) worldwide. In Morocco, damage caused by Hessian fly can result in total crop loss if high infestations occur during early stages of crop development. Genes that confer resistance to Hessian fly provide the most efficient and economical means of crop protection against this damaging insect. To date, 27 resistance genes (HJ-H27) have been reported in wheat; among these, 11 are very effective in Morocco. In this study, we have utilized amplified fragment length polymorphism (AFLP) analysis in conjunction with near-isogenic lines (NILs) and bulked segregant analysis (BSA) to identify molecular markers linked to Hessian fly resistance genes in bread wheat. Two pairs of NILs were used as source of DNA, one differing for H5 resistance gene and the other for H22 resistance gene. Using 42 primers combinations, 4200 selectively DNA fragments were analyzed throughout the wheat genome, with an average of 100 bands per combination and per pair of NILs. This technique appeared to be promising, since 28 polymorphic bands were detected, among which 13 associated to H5 locus and 15 to H22 locus.
- Published
- 2002
15. Effect of diet supplementation on growth and reproduction in camels under arid range conditions
- Author
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Abdouli H., Slimane N., Majdoub A., Khaldi G., Khorchani T., Hammadi M., Portetelle D., and Renaville R.
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dromedaries ,females ,pregnancy ,puerperium ,supplementary feeding ,weight gain ,weight losses ,reproductive performance ,birth weight ,arid zones ,tunisia ,africa ,animal developmental stages ,body weight ,camelidae ,camels ,climatic zones ,developmental stages ,domestic animals ,feeding ,livestock ,losses ,mammals ,north africa ,physiological functions ,reproduction ,sex ,sexual reproduction ,useful animals ,Biotechnology ,TP248.13-248.65 ,Environmental sciences ,GE1-350 - Abstract
Eighteen pregnant dromedary females (Camelus dromedarius) were used to determine the effect of concentrate supplement on growth and reproductive performances in peri-partum period. The females were divided into supplemented (n = 9; S) and unsupplemented (n = 9; C) experimental groups. All animals grazed, with one mature male, 7 to 8 hours per day on salty pasture rangelands. During night, they were kept in pen, where each female of group S received 4 kg per day of concentrate supplement during the last 3 months of gestation and 5 kg per day during the first 3 months post-partum. During the last 90 days of gestation daily body weight gain (DBG) was at least tenfold more important in group S than in group C (775 g vs. 72 g respectively). Supplementation affected birth weight of offspring (30.3 kg vs. 23.4 kg) and its DBG (806 g vs. 430 g) in group S and group C respectively. During the post-partum period, females in group S gained in weight (116 g per day) whereas females in group C lost more than 200 g per day. The mean post-partum interval to the first heat and the percentage of females in heat were 29.5 day and 44.4/ vs. 41.2 day and 71.4/ for the C and S groups, respectively. We conclude that under range conditions, dietary supplementation of dromedary during late pregnancy stage and post-partum period improves productive and reproductive parameters.
- Published
- 2001
16. Les cent fins de 'Rectify'
- Author
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Taïeb, Emmanuel, Triangle : action, discours, pensée politique et économique (TRIANGLE), Centre National de la Recherche Scientifique (CNRS)-Sciences Po Lyon - Institut d'études politiques de Lyon (IEP Lyon), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Université Lumière - Lyon 2 (UL2)-École normale supérieure - Lyon (ENS Lyon), Sciences Po Lyon - Institut d'études politiques de Lyon (IEP Lyon), Université de Lyon, École normale supérieure de Lyon (ENS de Lyon)-Université Lumière - Lyon 2 (UL2)-Sciences Po Lyon - Institut d'études politiques de Lyon (IEP Lyon), and Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Freedom ,Fins ,Losses ,Endings ,R��v��lation ,[SHS.ART]Humanities and Social Sciences/Art and art history ,16. Peace & justice ,Revelation ,[SHS.SCIPO]Humanities and Social Sciences/Political science ,Pertes ,Libert�� ,Framing ,séries ,Cadrage ,Rectify ,ComputingMilieux_MISCELLANEOUS - Abstract
�� l���image de son h��ros, Daniel, qui essaie de renouer avec la vie, le dernier ��pisode de Rectify sugg��re qu���il est possible de se r��concilier avec le monde apr��s la fin d���une s��rie, en acceptant ses limites. En proposant plusieurs �� fins �� au cours de son r��cit, avant ce dernier ��pisode, la s��rie peut ne pas se conformer aux passages oblig��s et s���offrir un d��nouement tr��s libre. L�����pilogue ne l��ve pas tous les myst��res et acte au contraire que la fiction ne peut pas tout., In Rectify, as the hero, Daniel, tries to take up with his life, the last episode suggests that it���s possible de connect again with the world after a TV shows has ended. By giving multiple �� endings �� during its narration, before the final episode, the program can avoid the mandatory stages and offer an open denouement. The outcome doesn���t unveil the mysteries and tells that fiction is not almighty.
- Published
- 2021
17. Outil de développement et d'optimisation dédié aux onduleurs SiC de forte puissance
- Author
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Voldoire, Adrien, Laboratoire de Génie Electrique de Grenoble (G2ELab ), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Université Grenoble Alpes [2020-....], Jean-Luc Schanen, and Jean-Paul Ferrieux
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Optimization ,Pertes ,Losses ,Voltage Source Inverter (VSI) ,Electronique de puissance ,Filtrage ,[SPI.NRJ]Engineering Sciences [physics]/Electric power ,Onduleur de tension ,Composants passifs ,Filters ,Optimisation ,Passive components ,Power Electronics - Abstract
The exponential development of aircraft transportation is a threat in the context of global warming. One of the solutions investigated consists in increasing the amount of embedded electrical power systems and actuators. Using a deterministic optimization tool appear as a promising solution to take into account the multiple compromises in a power converter design during the pre-design step, with the goal to minimize the weight. An optimization tool is proposed to bring comparative elements between different inverter topologies and technological solutions.The development of the tool requires elaborating analytical models to be compliant with the gradient-based algorithm. Harmonic analyses with Fourier transform enable calculating the signal ripples, to respect aircraft standards. Components are also designed precisely with appropriate loss models to estimate the converter efficiency. All the developed models are experimentally validated with a 10 kW prototype.As the use a gradient-based algorithm is not common in power electronics, studies are carried out to validate this proposed methodology. These studies show the effectiveness of the algorithm choice in the pre-design step, and indicates some limits and forecasts. Finally, the algorithm is used to compare different architectural and technological solutions on aircraft cases. The results are discussed regarding classical sizing methodologies.; La volonté de diminuer la consommation en carburant en aéronautique amène à repenser les architectures de distribution et de conversion de puissance embarquées. L’utilisation d’un outil d’optimisation déterministe apparait comme une solution prometteuse pour prendre en compte les compromis intrinsèques aux convertisseurs statiques en pré-dimensionnement, avec pour objectif de minimiser leur masse. Un outil d’optimisation est donc proposé pour apporter des éléments de comparaison entre différentes topologies d’onduleur et entre différentes solutions technologiques.Le développement de l’outil passe par l’élaboration de modèles analytiques pour être compatible avec l’utilisation d’un algorithme à base de gradients. Une analyse harmonique reposant sur des transformées de Fourier permet de reconstituer les ondulations de chaque signal, en regard des normes aéronautiques. La modélisation s’intéresse également à la construction de modèles pour les composants passifs et actifs, permettant en particulier d’évaluer les pertes et donc le rendement du convertisseur. L’intégralité des modèles développés fait l’objet d’une validation expérimentale sur un prototype à 10 kW.L’utilisation d’un algorithme à base de gradient n’étant pas classique en électronique de puissance, des études sont menées pour valider la méthodologie proposée. Ces études montrent l’adéquation du choix d’un tel algorithme avec le besoin de pré-dimensionnement, tout en indiquant ses limites et les perspectives. Enfin, l’outil d’optimisation est utilisé pour comparer différentes solutions architecturales et technologiques sur des cas d’application aéronautiques. Les résultats obtenus sont discutés en regard des méthodes de dimensionnement classiques.
- Published
- 2020
18. Modélisation d'un jet au sein d'un canal inter-aube de machine thermique
- Author
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Descombes, Georges, Maroteaux, Fadila, Jullien, Jacques, and Pluviose, Michel
- Subjects
- *
TURBOCHARGERS , *COMPRESSORS , *TURBOMACHINES , *ROTORS - Abstract
Abstract: The results of study concerning energy transformation within the variable geometry nozzle of a turbocharger are presented in this paper. A detailed analysis is carried out in order to study the effect of losses on the permeability characteristics of the vaned channel, and to observe the flow-turbine structure interaction resulting at the rotor. Particular attention is paid to the local jet structure at outlet from the variable geometry channel when sonic conditions are likely to be reached at the diffuser throat. A supersonic flow layer can be observed in the mixing zone at the rotor inlet, this phenomenon generates high losses in this region. [Copyright &y& Elsevier]
- Published
- 2005
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19. Perception des paysans sur la contrainte de la mineuse de l’épi Heliocheilus albipunctella De Joannis, ravageur important du mil en zone sahélienne
- Author
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Oumarou, N., Baoua, I., Saidou, Abdoul-Aziz, Amadou, L., and Stern, D.
- Subjects
Lutte antiravageur ,Agriculteur ,Enquête sur exploitations agricoles ,lcsh:S ,H10 - Ravageurs des plantes ,control methods ,losses ,heliocheilus albipunctella ,lcsh:Agriculture ,Attitude ,pennisetum glaucum ,niger ,Perte de récolte - Abstract
Heliocheilus albipunctella De Joannis est un important ravageur des épis du mil en zone sahélienne. Pour documenter la perception des paysans par rapport à ce ravageur, une enquête a été réalisée en avril 2016 avec un échantillon de 732 producteurs dans cinq principales régions agricoles du Niger. Les résultats obtenus ont montré que: 1) 17 % des répondants ont pu décrire le cycle biologique de H. albipunctella; 2) le ravageur cause en moyenne 43 à 82 % de perte de production, une moyenne obtenue depuis 28 ans selon les régions; 3) 37 à 78 % des producteurs savent que les infestations des épis du mil sont favorisées par les semis précoces, les sécheresses et la nature sableuse du sol; 4) d’après la moitié des répondants le plus de dégâts sont observés au stade grenaison du mil; 5) plus de 80 % des producteurs ne connaissent aucune méthode de lutte contre ce ravageur. Ces informations interpellent sur l’incidence négative de H. albipunctella sur le rendement du mil dans ces zones précaires. La nécessité de développer un programme participatif de gestion intégrée de ce ravageur est recommandée., Farmers’ Perception of the Pearl Millet Head Miner Heliocheilus albipunctella De Joannis, a Major Millet Pest in the Sahelian Area Heliocheilus albipunctella De Joannis is an important millet pest in the Sahelian zone. To assess the farmers’ perception related to this pest, a survey was carried out in 5 agricultural areas of Niger. The survey was carried out in April 2016 including 732 pearl millet growers. The obtained results showed that: 1) 17% of the respondents were able to describe the life cycle of H. albipunctella; 2) since 28 years the pest causes an average production loss of 43 to 82% depending on the region; 3) 37-78% of the farmers are aware that early sowing, droughts and sandy soil favor the infestations of the Millet Worm; 4) most pest damages were observed at the millet maturity stage as indicated by half of the respondents; 5) more than 80% of farmers do not know any pest control method. The results showed a negative incidence of H. albipunctella on millet yield in these precarious zones. The development of an Integrated Method Program is recommended.
- Published
- 2019
- Full Text
- View/download PDF
20. Les semences
- Author
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Turner, M. and Feyt, H.
- Subjects
Maize ,Granaries ,Insecticidal plants ,Storage modes ,Damage ,Losses ,Senegal ,Agriculture - Abstract
Les semences. Une étude a été conduite pour documenter les noms scientifiques, les noms locaux et leurs significations et appréhender la nomenclature des mauvaises herbes de l'oignon adoptée par les producteurs au Nord-est du Bénin. 30 exploitations produisant de l'oignon ont été enquêtées par des entretiens semi-structurés et un inventaire floristique a été réalisé dans chacune d'elles. Les espèces et leurs familles botaniques ainsi que les critères de leurs dénominations locales ont été identifiés et ont servi à l'élaboration d'une typologie de taxonomie locale. 71 espèces appartenant à 26 familles botaniques et 17 espèces réparties dans six familles constituent respectivement les flores générale et associée à l'oignon en végétation. Les familles qui regroupent le plus d'espèces sont les Poaceae, les Cyperaceae, les Commelinaceae, les Malvaceae, les Fabaceae et les Portulacaceae. L'écologie, la morphologie, la résistance au désherbage manuel et les usages socio-culturels sont les critères qui fondent la dénomination de 39 des 71 espèces recensées et qui ont servi à l'élaboration d'une typologie de taxonomie locale. Les 32 autres espèces qui n'ont pas de nom local ne présentent pas un intérêt agro-écologique et ni socioculturel majeur pour les producteurs. L'évaluation de l'importance agronomique de la flore associée à l'oignon en végétation pourra contribuer à une meilleure maîtrise de l'enherbement de cette culture.
- Published
- 2013
21. RELATION BETWEEN THE SWELLING OF METAL FUELS AND THE RELEASE OF FISSION GAS. Relation entre le Gonflement de combustibles metalliques et le replacement des gaz de fission
- Author
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Mikailoff, H.
- Published
- 1970
22. Annular electromagnetic pumps-construction and testing-theory, and comparison with experimental results; Pompes electromagnetiques annulaires - construction et essais - theorie et confrontation avec l'experience
- Author
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Schwab, Bernard
- Published
- 1964
23. Study on the thermal behaviour of a gear unit
- Author
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Laruelle, Sandrine, Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon, Christophe Changenet, Fabrice Ville, and STAR, ABES
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Electric motor ,Thermal transfer ,Impact environnemental ,Tribology ,Losses ,Transfert thermique ,Moteurs électriques ,Transfert de chaleur ,Tribologie ,Engrenages spiro-Coniques ,Environmental impact ,Contact mechanics ,Pertes ,Mécanique des contacts ,Heat transfer ,[SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph] ,Transmission ,Spiral bevel gears ,[SPI.MECA.THER] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph] - Abstract
Environmental concern leads to improvements in both efficiency and power density of electrical motors. For compact transmissions, thermal issues can become critical: the surface available for thermal exchange with the environment is reduced, minimizing the possibility to cool down the elements. To ensure the system reliability, the operating temperature for each operating condition must not exceed the required maximum oil temperature. In order to evaluate its thermal behavior, the whole system should be therefore evaluated in terms of power losses and heat transfer. This PhD proposes a thermal model of an existing oil bath lubricated gear unit with spiral bevel gears. The thermal model uses the thermal network method, which needs an accurate prediction of power losses of the different elements and heat transfer between them. A review of the existing methods is presented. Since the churning losses of spiral bevel gears has never been fully characterized, specific tests have been done on a dedicated test bench. The last part of this work suggests possible improvements on the gearbox design., La diminution de l’impact environnemental des moteurs électriques conduit à des améliorations du rendement et de la compacité. Puisque la taille de la transmission est réduite, des problèmes d’échauffements peuvent apparaître car la surface d’échange avec l’environnement est fortement réduite, diminuant les possibilités de refroidissement. L’ensemble du système doit être caractérisé en termes de pertes de puissance et de capacité de transfert thermique pour déterminer si la température maximale en fonctionnement correspond aux exigences de fiabilité tout au long de la durée de vie du système. Cette thèse propose un modèle thermique d’une transmission avec des engrenages spiraux coniques, lubrifiée par bain d’huile. Le modèle thermique utilise la méthode des réseaux thermiques. Par conséquent, une estimation précise des pertes et des transferts thermiques entre les différents éléments est nécessaire. Une revue des méthodes existantes est présentée, indiquant que les pertes par barbotage des engrenages spiraux coniques ne sont pas totalement maîtrisées, entraînant la conduite d’une série d’essais sur un banc d’essai dédié. Cette étude se conclue sur l’application du modèle à la transmission ainsi que la proposition de points d’améliorations.
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- 2017
24. Enjeux socio-économiques et impacts des pertes agricoles et alimentaires
- Author
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Esnouf, Catherine, Huyghe, Christian, Collège de Direction (CODIR), Institut National de la Recherche Agronomique (INRA), and Unité de gestion de la direction scientifique agriculture, activites, territoires
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aliments ,economy ,pertes ,food ,eau ,[SDV]Life Sciences [q-bio] ,water ,GES ,GHG ,impacts ,economie ,losses ,agriculture - Abstract
Ce numéro présente les travaux conduits dans le cadre de l’analyse des Pertes agricoles et alimentaires dont une synthèse a été présentée lors du colloque du 28 novembre 2015 à Paris.; National audience; Food losses and wastes are a cutting edge question for national, European and international politics, as they represent a major lever for global food security. They represent around 30% of global production and consume useless resources with linked environmental and economic impacts. These losses are agriculture dependent in less developed countries and at the retail and consumption stage in developed countries. On global level they emit 3.3GT carbon equivalent greenhouse gases, use 250 km3 of water, first rank of every country’s agriculture water consumption, and consume 28% of agricultural land surface. Economically, they represent 750 billion $ at agricultural level, and 2 to 3 times more at the consumer level. All these are rough estimates, as figures differ depending on references, countries and typology of products.; La question des pertes alimentaires est présente dans les agendas politiques au niveau national, européen et international, car elle représente un levier majeur pour la sécurité alimentaire mondiale. Estimées au nouveau mondial à 30% de la production, elles conduisent à une consommation de ressources inutile et aux impacts environnementaux, et économiques correspondants. Situées au niveau de la production dans les pays les moins développés et au niveau de la distribution et de la consommation dans les pays développés, elles représentent ainsi des émissions de gaz à effet de serre de 3,3GT équivalent Carbone, une consommation d’eau de 250 km3 par an, soit le premier rang de la consommation agricole des différents pays, et la consommation de 28% des terres agricoles mondiales.. En termes économiques, l’impact représente 750 Milliards de $ au niveau agricole, 2 à 3 fois plus au niveau du consommateur. Toutes ces estimations sont des ordres de grandeur, les chiffres étant variables selon les sources, les pays et les types de produits.
- Published
- 2015
25. Costs of flood events : spatio-temporal analysis of insured damages
- Author
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Bourguignon, David, Gouvernance, Risque, Environnement, Développement (GRED), Université Paul-Valéry - Montpellier 3 (UPVM)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Université Paul Valéry - Montpellier III, Freddy Vinet, Roland Nussbaum, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and STAR, ABES
- Subjects
Insurance ,Losses ,Partenariats public-Privé ,[SHS.HIST] Humanities and Social Sciences/History ,Assurance ,Inondation ,Public-Private partnership ,Dommages ,Observation des territoires ,[SHS.HIST]Humanities and Social Sciences/History ,Flood ,Territorial observatories - Abstract
Cost analysis of past flood events is essential for public and private stakeholders to improve the management and risk prevention. For instance, past events lessons learnt allow floodplain managers to justify their preventive measures or insurers to comfort by experience the assessments made on their portfolio's exposure. Yet only the most deadly, costly or dramatic (in the media at least) floods are being studied. Few in number, information and data are available on less damaging events which are more local and frequent, but they are difficult to use because they are produced by a variety of actors who do not communicate with each other and have different scopes of actions.The aim of this PhD work is to promote the sharing of knowledge between public and private stakeholders to better understand the origin of the claims and propose new ways to improve the flood prevention. The research is therefore based on the concept of natural event spatio-temporal scopes, the flood damage assessment and territorial observation., L'étude du coût des inondations passées est essentielle pour permettre aux parties prenantes, publiques et privées, d'améliorer la gestion et la prévention des risques. Les retours d'expérience sur les dommages économiques sont notamment utiles aux gestionnaires de bassin pour justifier leurs mesures de protection ou aux assureurs pour évaluer l'exposition réelle de leurs portefeuilles. Pourtant seuls les événements les plus meurtriers, coûteux ou médiatiques sont étudiés de manière approfondie. Même si elles sont rares, il existe des informations et des données sur des événements moins dommageables, plus locaux et fréquents ; mais elles sont difficiles à exploiter car produites par des acteurs très variés qui communiquent peu entre eux et agissent sur des périmètres différents.L'objectif de cette thèse est de favoriser le partage d'informations entre assureurs et acteurs locaux pour améliorer les connaissances sur les facteurs explicatifs de sinistralité et proposer des pistes d'amélioration dans la prévention des inondations, en exploitant les concepts de périmètres spatio-temporels des événements naturels, l'évaluation des dommages causés par les inondations et les notions d'observation territoriale.
- Published
- 2014
26. Déterminants socio-économiques et institutionnels de l'adoption d'innovations techniques concernant la production de maïs à l'ouest du Cameroun
- Author
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Mabah Tene, Gwladys Laure, Havard, Michel, and Ludovic Temple
- Subjects
lcsh:Agriculture ,Damage ,Storage modes ,Losses ,E14 - Économie et politique du développement ,F01 - Culture des plantes ,Granaries ,lcsh:S ,Insecticidal plants ,Senegal ,Maize - Abstract
La faible productivité des exploitations agricoles en Afrique subsaharienne notamment au Cameroun est due en partie aux faibles taux d'adoption des innovations proposées par la recherche agricole. Cet article est une étude de cas de l'adoption du paquet technique (semences de variétés améliorées, engrais chimiques, pesticides, mono- culture) pour la culture du maïs à l'ouest du Cameroun. L'analyse économétrique, à l'aide d'un modèle logit, des données d'un échantillon de 52 exploitants agricoles a permis d'identifier les facteurs qui déterminent la probabilité d'avoir recours au paquet technique: la superficie cultivée en maïs, l'orientation marchande de la production, le contact avec les serv ices de vulgarisation agricole et le mode d'accès à la terre. Le paquet technique vulgarisé est adopté par moins de 20% des exploitants de l'échantillon, les autres exploitants ne l'adoptent qu'en partie (1, 2 ou 3 éléments) selon leurs besoins et stratégies spécifiques. Ces résultats interpellent la recherche et la vulgarisation agricoles à adapter leurs pro- positions aux besoins diversifiés des exploitants agricoles et à expliquer les raisons de la non adoption du paquet technique dans son ensemble.
- Published
- 2013
27. Regulations concerning the monitoring of radioactive effluents and their application in Belgium
- Author
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Stallaert, P
- Published
- 1974
28. Conception d'un entraînement électrique à aimants permanents pour une chaîne de traction de véhicule hybride électrique
- Author
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Christophe Espanet, Zhenwei Wu, Daniel Depernet, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), ANR-07-PDIT-0005,ARCHYBALD,ARChitectures HYBrides Adaptées aux véhicules Lourds à forte Disponibilité(2007), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Optimal design ,Engineering ,Powertrain ,Véhicule Hybride Electrique Série-Parallèle ,Mechanical engineering ,Efficiency ,7. Clean energy ,Energy storage ,Automotive engineering ,[SPI.AUTO]Engineering Sciences [physics]/Automatic ,Pertes ,Hybrid Electric Heavy Vehicle ,Inverter ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,Electrical and Electronic Engineering ,Modélisation analytique (MA) ,Losses ,business.industry ,MSAPS ,SMPMSM ,[SPI.NRJ]Engineering Sciences [physics]/Electric power ,Analytical modelling ,Onduleur de Tension ,Finite element method ,Geometric design ,Internal combustion engine ,Magnet ,[PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph] ,Rendement ,business - Abstract
International audience; In this paper, the authors describe a modeling and design method for a permanent magnet drive used in a power train for Hybrid Electric Heavy Vehicle, based on a Series-Parallel architecture. The hybrid powertrain structure enables high requirements for boost mode of acceleration and full electric mode. A 'Ravigneaux' train was integrated in this hybrid powertrain structure in order to split energy among the vehicle wheels, the thermal engine, the electrical motor and the alternator. To compare the classical simple epicyclic train used in series-parallel Toyota hybrid structure, this 'Ravigneaux' train developed by Nexter group presents a better adaptation to high mechanical constraints (high power and torque) because of its double stages compound structure. Several operation modes of vehicle were analyzed by assuming that the two electrical machines were identical and reversible (they can both operate as a motor or an alternator). In this paper, a simple drive is considered: it deals with a Surface-Mounted Permanent Magnet Synchronous Machine (SMPMSM) and a two level Voltage Source Inverter (VSI). An analytical modeling based on three working points: boost working point, nominal working point and maximal rotation speed working point has been elaborated. The analytical modeling makes it possible to model the physical behavior of different components. It enables to analyze quickly the relationship between the different parameters. A numerical modeling using 2D finite elements is also presented in this paper. The aim of 2D finite elements analysis (2DFEA) is to validate the machine performances obtained by analytical modeling. It enables to model some physical phenomena with a better accuracy, such as magnetic saturation. Generally, the results given by 2DFEA will be closer to experimental results. The control law of the electrical machine was investigated by the way of a single-phased electromechanical modeling. With this model, the flux weakening analysis has been taken into account in order to adapt the motor winding according to the rotation speeds defined in the specifications. The flux weakening was realized by considering mechanical and electrical characteristics linked with power, torque, rotation speed, DC-link voltage, feeding voltage of electrical machine, Id and Iq currents, cyclic inductance, winding resistance, back-electromotive force, phase difference between back electromotive force and phase current... The electrical machine losses have been calculated by neglecting the mechanical losses and PM losses. The machine losses calculation includes the copper losses and the iron losses (eddy currents losses and hysteresis losses). The flux density in the stator yoke and the teeth was evaluated by taking into account the magnetic flux created by permanent magnet and the one created by armature reaction (stator current). The inverter losses were calculated too, by considering the commutation and conduction losses of both diodes and IGBT transistors. Thus, the total losses and the global efficiencies of motor and inverter were evaluated and the best working points can be deduced from those calculations. The previous models enable to evaluate global energy performances of electrical machines and inverters by respecting the constraints defined in the specifications. This methodology is general and can be a first step of a complete power train optimal design, including the electrical drive, the gear, the energy storage units and possibly the internal combustion engine.
- Published
- 2011
29. Un algorithme de parcimonie efficace pour la réconciliation d'arbres de gènes/espèces avec pertes, duplications et transferts
- Author
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Doyon, Jean-Philippe, Scornavacca, Celine, Szöllősi, Gergely J., Ranwez, Vincent, Berry, Vincent, Méthodes et Algorithmes pour la Bioinformatique (MAB), Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier (LIRMM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Center for Bioinformatics (ZBIT), Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, Bioinformatique, phylogénie et génomique évolutive (BPGE), Département PEGASE [LBBE] (PEGASE), Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Institut National d'Etudes Supérieures Agronomiques de Montpellier (Montpellier SupAgro). Montpellier, FRA., Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Eberhard Karls Universität Tübingen, and Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)
- Subjects
reconciliation ,gene and species trees ,duplications ,[INFO.INFO-DS]Computer Science [cs]/Data Structures and Algorithms [cs.DS] ,[INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM] ,[SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM] ,transfers ,losses ,parsimony - Abstract
National audience; Tree reconciliation is anapproach that explains the discrepancies between two evolutionary trees by a number of events such as speciations, duplications, transfers and losses. It has important applications in ecology, biogeography and genomics, for instance to decipher relationships between homologous sequences. (Results) We provide a fast and exact reconciliation algorithm according to a parsimony criterion that considers duplication, transfer and loss events. We also present experimental results that give first insights on the conditions under which parsimony is able to accurately infer evolutionary scenarios involving such events. Over all, parsimony performs well under realistic cases, as well as for relatively high duplication and transfer rates. As expected, transfers are in general less accurately recovered than duplications. Availability: www.lirmm.fr/phylariane/
- Published
- 2010
30. Caractérisation des supraconducteurs à haute température critique en vue d'application en électrotechnique
- Author
-
Hoàng, Thê Cuong and UL, Thèses
- Subjects
Measurement ,Électrodynamique ,Mesures électriques ,Losses ,Courants alternatifs ,[SPI.OTHER] Engineering Sciences [physics]/Other ,Critical current density ,Supraconducteurs à hautes températures ,Pertes ,Champ propre ,[PHYS.COND.CM-GEN] Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other] ,Mesure ,HTS ,Self-field ,Supraconducteur HTc ,Densité de courant critique - Abstract
The main of this thesis is the characterization of high critical temperature superconductors (HTS). First, we have presented the generality of the HTS. The possible use in the future, of the HTS for the transport current, involves to study more particularly the losses in self-field, or fed by a sinusoidal current. Then we have recalled the losses calculations based on the Bean model critical state for various forms of the sample, as a plate, a cylinder, a tube cylindrical hollow and an HTS cable. For the second time, we have characterized the HTS which allows make the characteristics E(J), U(I), Jc(B), and n(B) of an HTS tube cylindrical hollow. The characterization has been made by the electrical method. Then we have tried a self-field compensation of an HTS tube by two different methods. After we have measured the magnetic field diffusion in an HTS plate and we have determined its Jc by the magnetic field measurement in complete penetration. In the last time, we have calculated analytically the losses in self-field of the HTS tube, using the Bean model critical state. We have also showed that in self-field, the magnetic field penetration inside the HTS material happens in order. First of all, there is magnetic field incomplete penetration from outside to inside the material, then when the penetration is complete, the magnetic field increase uniformly throughout the material. These losses calculation results have been compared to measurement results, this comparison shows a clear coincidence. For the last experiment, we have measured and analysed the losses in an HTS coils fed by a sinusoidal current 50Hz frequency. These results have showed that the losses of this HTS coils are mainly losses in the superconducting material and not in the superconducting matrix., Le thème principal de cette thèse est la caractérisation des supraconducteurs à haute température critique (SHTc). Dans un premier temps, nous avons présenté des généralités des SHTc. L'utilisation possible dans l'avenir, des SHTc pour le transport de courant, nous a mené à étudier plus particulièrement les pertes en champ propre, donc parcouru par un courant sinusoïdal. Puis nous avons rappelé les calculs de pertes basés sur le modèle de l'état critique Bean pour différentes formes d'échantillon, comme une plaque, un cylindre, un tube cylindrique et un câble SHTc. Dans un deuxième temps, nous avons caractérisé des SHTc qui permet d'obtenir les caractéristiques E(J), U(I), Jc(B), et n(B) d'un tube cylindrique SHTc. La caractérisation a été effectuée à l'aide de la méthode électrique. Puis nous avons tenté la compensation du champ magnétique propre du tube par deux méthodes différentes. Ensuite nous avons mesuré la diffusion du champ magnétique dans une plaque SHTc et de la détermination du Jc de la plaque par la mesure de champ de pénétration complète. Dans un dernier temps, nous avons calculé analytiquement des pertes dans un tube SHTc en champ propre, à l'aide du modèle de l'état critique de Bean. Nous avons également montré qu'en champ propre, la pénétration du champ magnétique à l'intérieur du matériau SHTc, se passe en deux temps. Tout d'abord il y a pénétration incomplète du champ magnétique de l'extérieur vers l'intérieur du matériau, puis quand la pénétration est complète, le champ magnétique augmente uniformément dans tout le matériau. Ces résultats de calcul de pertes ont été comparés aux celles mesurées, cette comparaison montre une concordance manifeste. Pour la dernière expérience, nous avons mesuré et analysé des pertes dans une bobine SHTc alimentée en courant sinusoïdal de fréquence 50 Hz. Ces résultats nous ont montré que les pertes dans cette bobine sont principalement les pertes dans le matériau supraconducteur et non les pertes dans la matrice des supraconducteurs
- Published
- 2010
31. Modélisation des machines asynchones et synchrones à aimants avec prise en compte des harmoniques d'espace et de temps : application à la propulsion marine par POD
- Author
-
Lateb, Rambane, Groupe de Recherche en Electrotechnique et Electronique de Nancy (GREEN), Université de Lorraine (UL), Institut National Polytechnique de Lorraine, and Farid Meibody-Tabar
- Subjects
Navires Propulsion ,Pulsating torque ,Harmoniques (ondes électriques) ,POD propulsion ,Couples de détente ,Permanent magnets motor ,Space harmonics ,Pertes ,Finite element ,Moteur à aimants permanents ,Moteur asynchrone ,Moteurs asynchrones -Modèles mathématiques ,Segmentation des aimants ,Magnet segmentation ,Harmoniques d?espace ,Induction motor ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,Couples pulsatoires ,Moteurs à aimants permanents -Modèles mathématiques ,Losses ,Éléments finis ,Time harmonics ,Cogging torque ,Propulsion par POD ,Méthode des ,Harmoniques de temps - Abstract
This work concerns the modeling and the design of the permanent magnets and asynchronous motors intended for POD ship propulsion. A state of the art is presented, where various topologies of motors designed for this application are approached there. The permanent magnet motor and the induction motor have been chosen for the application. For the permanent magnets motor, a finite element analysis is adopted to design and minimize the main harmonics leading to a quasi sinusoidal back EMF. A finite element model coupled to an electrical circuit allows to predict both current and torque waveforms including time harmonics knowing the voltage waveform of the inverter. The induction motor is designed in such a way to have minimum losses and pulsating torque. For this purpose, a 2D complex finite element method coupled to an electrical circuit is developed. In addition, another 2D finite element-electrical circuit model is proposed to evaluate time harmonics losses and to reconstitute the current and torque waveforms. This model allows to predict the pulsating torques. The validation and verification step is done by using a time stepping finite element software Flux2D and some available measurements (for the permanent magnets motor). The comparison of the calculations obtained by the different methods and software, as well as the available measurements is satisfactory; Ce travail porte sur la modélisation et le dimensionnement des moteurs à aimants permanents et asynchrones destinés à la propulsion marine par POD. Un état de l'art est présenté, où les différentes topologies de moteurs pour ce type d'application y sont abordées. La Machine à aimants permanents et la machine asynchrone on été retenue pour notre application. Dans le cas de la machine à aimants permanents, une analyse par éléments finis est effectuée pour dimensionner la machine à aimants permanents et minimiser les principaux harmoniques de la FÉM. Un modèle éléments finis 2D en magnétostatique couplé à un modèle circuit est développé pour la prédiction des couples pulsatoires dues aux harmoniques du convertisseur. En ce qui concerne la machine asynchrone, Pour tenir compte des harmoniques d'espace et évaluer leurs pertes, un modèle électromagnétique utilisant la résolution par éléments finis 2D en magnétodynamique couplé à un modèle circuit est développé. Par ailleurs, un autre modèle basé sur le principe de couplage éléments finis- circuit électrique est développé pour tenir compte des harmoniques de temps du variateur, ce modèle permet d'évaluer à la fois les pertes dues aux harmoniques de temps, mais aussi des couples pulsatoires. Dans la phase de validation et vérification des différents calculs, nous avons utilisé l'outil Flux2D de calcul par éléments finis qui tient compte de la rotation du rotor (pas à pas dans le temps) et effectué certaines mesures (cas de la machine à aimants permanents). Les résultats des calculs obtenus par les modèles développés concordent avec ceux obtenus par la méthode temporelle (pas à pas dans le temps) et les quelques mesures dont nous disposons
- Published
- 2006
32. Modélisation des machines asynchrones et synchrones a aimants avec prise en compte des harmoniques d'espace et de temps : application à la propulsion marine par POD
- Author
-
Lateb, Ramdane and Pierson, Christine
- Subjects
segmentation des aimants ,[SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,[SPI.ELEC] Engineering Sciences [physics]/Electromagnetism ,pulsating torque ,éléments finis ,moteur asynchrone ,couples pulsatoires ,[PHYS.COND.CM-S] Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con] ,magnet segmentation ,couples de détente ,time harmonics ,induction motor ,losses ,POD propulsion ,harmoniques d'espace ,Permanent magnets motor ,cogging torque ,finite element ,pertes ,Moteur à aimants permanents ,propulsion par POD ,harmoniques de temps ,space harmonics ,[SPI.NRJ] Engineering Sciences [physics]/Electric power - Abstract
This work concerns the modeling and the design of the permanent magnets andasynchronous motors intended for POD ship propulsion. A state of the art is presented, wherevarious topologies of motors designed for this application are approached there. The permanentmagnet motor and the induction motor have been chosen for the application.For the permanent magnets motor, a finite element analysis is adopted to design andminimize the main harmonics leading to a quasi sinusoidal back EMF. A finite element modelcoupled to an electrical circuit allows to predict both current and torque waveforms includingtime harmonics knowing the voltage waveform of the inverter.The induction motor is designed in such a way to have minimum losses and pulsatingtorque. For this purpose, a 2D complex finite element method coupled to an electrical circuit isdeveloped. In addition, another 2D finite element-electrical circuit model is proposed to evaluatetime harmonics losses and to reconstitute the current and torque waveforms. This model allowsto predict the pulsating torques.The validation and verification step is done by using a time stepping finite elementsoftware Flux2D and some available measurements (for the permanent magnets motor). Thecomparison of the calculations obtained by the different methods and software, as well as theavailable measurements is satisfactory., Ce travail porte sur la modélisation et le dimensionnement des moteurs à aimantspermanents et asynchrones destinés à la propulsion marine par POD. Un état de l'art estprésenté, où les différentes topologies de moteurs pour ce type d'application y sont abordées. LaMachine à aimants permanents et la machine asynchrone on été retenue pour notre application.Dans le cas de la machine à aimants permanents, une analyse par éléments finis esteffectuée pour dimensionner la machine à aimants permanents et minimiser les principauxharmoniques de la FÉM. Un modèle éléments finis 2D en magnétostatique couplé à un modèlecircuit est développé pour la prédiction des couples pulsatoires dues aux harmoniques duconvertisseur.En ce qui concerne la machine asynchrone, Pour tenir compte des harmoniques d'espaceet évaluer leurs pertes, un modèle électromagnétique utilisant la résolution par éléments finis 2Den magnétodynamique couplé à un modèle circuit est développé. Par ailleurs, un autre modèlebasé sur le principe de couplage éléments finis- circuit électrique est développé pour tenir comptedes harmoniques de temps du variateur, ce modèle permet d'évaluer à la fois les pertes dues auxharmoniques de temps, mais aussi des couples pulsatoires.Dans la phase de validation et vérification des différents calculs, nous avons utilisé l'outilFlux2D de calcul par éléments finis qui tient compte de la rotation du rotor (pas à pas dans letemps) et effectué certaines mesures (cas de la machine à aimants permanents). Les résultats descalculs obtenus par les modèles développés concordent avec ceux obtenus par la méthodetemporelle (pas à pas dans le temps) et les quelques mesures dont nous disposons.
- Published
- 2006
33. Contribution à l'étude de l'alternateur à griffes Application au domaine automobile
- Author
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Bouarroudj, Lilya, Laboratoire de Génie Electrique de Grenoble (G2ELab), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Grenoble - INPG, Albert FOGGIA(albert.foggia@g2elab.inpg.fr), and Garcia, Sylvie
- Subjects
[SPI.NRJ]Engineering Sciences [physics]/Electric power ,iron losses ,mono objectiveoptimization ,axial flux ,losses ,harmoniques ,Alternateur à griffes ,pertes fer ,flux axial ,pertes ,optimisation mono objectif ,harmonics ,Claw-pole alternator ,[SPI.NRJ] Engineering Sciences [physics]/Electric power - Abstract
Claw pole alternator widely used as generator in passenger cars. It has to generatesufficient energy for all electric consumers and to keep the battery charge in balance. Ourwork aims at improving the output performance, increasing the efficiency and reducingthe magnetic audible noise. Measurements of the total losses in combination with asubtraction of all analytically defined loss mechanisms lead to build losses distributionsmodel behaviour at several speeds, according to the output current. Using the finiteelement method, we have defined the aim stator copper losses sources and iron lossessources in both of the rotor and the stator while highlighting the stator losses create by theaxial flux component. Thereafter, several solutions have been studied in order to increasethe output current, to reduce the audible noise and to reduce both of the stator copperlosses and the total iron losses, all these solutions have been tested on prototypes. Finally,a mono objective optimization method is used in order to increase the output current anddecrease the torque wave form with an aim of reducing the magnetic noise., L'alternateur à griffes est utilisé comme générateur d'électricité dans les véhicules. Ila pour rôle d'alimenter en courant continu tous les récepteurs reliés au réseau de bord, etplus particulièrement de charger la batterie. Les travaux de cette thèse ont pour butd'augmenter le courant fourni par l'alternateur, d'augmenter son rendement et de réduireson bruit acoustique d'origine magnétique. L'application de la méthode des pertesséparées a permis d'étudier la répartition des pertes en fonction de la vitesse de rotation etdu courant débité. En s'appuyant sur des simulations éléments finis, les principalescauses des pertes Joule statoriques et des pertes fer totales sont déterminées, aussi bienles pertes fer statoriques dues à la composante axiale du flux. Des solutions sontproposées dans le but d'augmenter le courant fourni ainsi que le rendement et de réduirele bruit acoustique d'origine magnétique, toutes ces solutions ont fait l'objet d'unevalidation expérimentale sur prototypes. Pour finir, une méthode fondée sur desoptimisations mono objectif est proposée dans le but d'augmenter le débit et de réduireles ondulations de couple sources du bruit acoustique d'origine magnétique.
- Published
- 2005
34. Expériences de laboratoire en économie et incitations monétaires
- Author
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Nathalie Etchart-Vincent, Centre international de recherche sur l'environnement et le développement (CIRED), and Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École des hautes études en sciences sociales (EHESS)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Ecole Nationale du Génie Rural, des Eaux et des Forêts (ENGREF)
- Subjects
incitations monétaires ,05 social sciences ,contextes de pertes ,050109 social psychology ,économie expérimentale ,experimental economics,monetary incentives,intrinsic motivation,loss domain,économie expérimentale,incitations monétaires,motivation intrinsèque,contextes de pertes ,[SHS.ECO]Humanities and Social Sciences/Economics and Finance ,losses ,loss domain ,JEL: C - Mathematical and Quantitative Methods/C.C9 - Design of Experiments/C.C9.C90 - General ,experimental economics,monetary incentives,intrinsic motivation,losses,économie expérimentale,incitations monétaires,motivation intrinsèque,contextes de pertes ,JEL: B - History of Economic Thought, Methodology, and Heterodox Approaches/B.B4 - Economic Methodology/B.B4.B41 - Economic Methodology ,0502 economics and business ,Political Science and International Relations ,motivation intrinsèque ,0501 psychology and cognitive sciences ,experimental economics, monetary incentives, intrinsic motivation, loss domain ,050207 economics ,experimental economics ,intrinsic motivation ,monetary incentives - Abstract
A strong positive relation is generally assumed between monetary incentives and effort on the one hand, and between effort and performance on the other hand, which legitimates the introduction of monetary incentives in economic laboratory experiments. Still, the empirical impact of incentives on effort and/or performance appears to be rather mixed or even negative. We examine the ins and outs of the debate since they all are, in a more or less radical manner, an invitation to a more pragmatic attitude towards incentives. We first show that embarrassing empirical results cannot be ascribed to an alleged inappropriateness of the incentive procedure (as regards the level of incentives or the procedure itself). We then examine the robustness of the relation between incentives, effort, and performance and elaborate upon the reasons why incentives sometimes do not enhance (or even damage) effort and/or why effort sometimes does not induce better performance (whether it be ineffective or harmful upon it). Next, we discuss the peculiar case of experimentation in the loss domain, which raises the more fundamental question of whether monetary incentives can be introduced. We finally conclude on the need of a pragmatic use of monetary incentives, depending on the very features of the experimental design (including subjects' cognitive and psycho-logical characteristics)., La mise en place d'une procédure monétaire incitative dans le cadre d'une expérience de laboratoire en économie suppose l'existence d'une relation positive étroite entre incitation et effort d'une part et entre effort et performance d'autre part. Pourtant, sur le plan empirique, l'impact des incitations monétaires sur l'effort et/ou la performance apparaît plus mitigé, voire négatif. Nous revenons ici sur un certain nombre d'arguments théoriques et empiriques avancés dans la littérature pour expliquer cet écart. Sont ainsi mis en cause le montant insuffisant des incitations, l'inadéquation des procédures incitatives utilisées, la fragilité du lien entre incitation et effort et/ou entre effort et performance, le rôle ambigu de la motivation intrinsèque. Nous nous intéressons ensuite au cas particulier de l'expérimentation dans des contextes de pertes, qui pose de manière plus fondamentale la question de l'opportunité des incitations monétaires. Nous concluons sur la nécessité d'une utilisation pragmatique de ces dernières selon la nature de l'étude envisagée.
- Published
- 2005
35. Reverberation Chamber Modeling Using Finite-Difference Time-Domain Method
- Author
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Petit, Frédéric and Electronic Engineering
- Subjects
eigen mode ,stirrer ,numerical error ,FDTD ,quality factor ,reverberation chamber ,PDF ,FFT ,non-uniform mesh ,mode-stirred chamber ,statistical test ,Chi2 law ,finite difference time domain ,QC ,T1 ,Modeling ,numerical method ,statistical criterion ,Rayleigh low ,losses ,modal study ,statistical study ,Gauss law ,eigen frequency ,mode density ,modes overlapping ,CDF ,frequency shift ,correlation angle - Abstract
Since the last few years, the unprecedented growth of communication systems involving the propagation of electromagnetic waves is particularly due to developments in mobile phone technology. The reverberation chamber is a reliable bench-test, enabling the study of the effects of electromagnetic waves on a specific electronic appliance. However, the operating of a reverberation chamber being rather complicated, development of numerical models are of utmost importance to determine the crucial parameters to be considered.This thesis consists in the modelling and the simulation of the operating principles of a reverberation chamber by means of the Finite-Difference Time-Domain method. After a brief study based on field and power measurements performed in a reverberation chamber, the second chapter deals with the different problems encountered during the modelling. The consideration of losses being a very important factor in the operating of the chamber, two methods of implementation of these losses are set out in this chapter. Chapter~3 consists in the analysis of the influence of the stirrer on the first eigenmodes of the chamber; the latter modes can undergo a frequency shift of several MHz. Chapter~4 shows a comparison of results issued from high frequency simulations and theoretical statistical results. The problem of an object placed in the chamber, resulting in a field disturbance is also tackled. Finally, in the fifth chapter, a comparison of statistical results for stirrers having different shapes is set out.
- Published
- 2002
36. Limitation de courant à partir de matériaux supraconducteurs HTC
- Author
-
Buzon, Didier, Centre de Recherches sur les Très Basses Températures (CRTBT), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Grenoble - INPG, TIXADOR Pascal, and Le Moulec, Nathalie
- Subjects
[PHYS.COND.CM-S]Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con] ,pertes ,échanges thermiques ,thermal exchanges ,supraconducteur HTc ,transition ,[PHYS.COND.CM-S] Physics [physics]/Condensed Matter [cond-mat]/Superconductivity [cond-mat.supr-con] ,thermal diffusion ,diffusion thermique ,HTc superconductors ,Limiteur de courant ,losses ,Fault current limiter - Abstract
This report deals with the possibility to use HTc superconductors for current limitation. The transition from a superconductive to a high dissipative state could be used to limit inrush currents. This application of superconductivity is very attractive because it's an innovative device for electrical networks without any conventional equivalence at high voltage. This device would allow to improve the density of connections and the continuity of the electrical distribution. This study can be divided into two fields. The aim of the first one is to analyse the behaviour of different HTc superconductors for current limitation. We carried out experimental measurements to characterise those conductors during a nominal AC rating (measurements of losses) and during a fault setting. Particularly, a description of the transition in bulk textured YBCO samples near Tc was made of inhomogeneous transition of the device and to estimate its losses. Finally, a 1 kV / 100 A demonstrator made of 43 meanders of textured YBCO was tested at 90,5 K. Thermal gradients seem to be responsible of the altering of some of the samples. The other part of this study concerns the dynamic of the transition. Near Tc, our experiments showed that the transition is more homogeneous. Experimental measurements also showed the influence of thermal exchanges with the cryogenic surrounding on the transition. This point can be justified if the dissipated energy is locally concentrated., Ce mémoire traite de la limitation de courant à partir de supraconducteurs HTc. L'utilisation de la transition naturelle d'un état supraconducteur vers un état dissipatif est envisagée pour limiter les courants de défaut sur les réseaux de distribution électrique. Cette application de la supraconductivité est très prometteuse puisque aucune solution conventionnelle ne réalise cette fonctionnalité pour la haute tension. Le gain réalisé par l'installaton de limiteurs de courant serait une densification des réseaux électriques et une amélioration de la qualité de l'énergie distribuée. Cette étude se scinde en deux points. Le premier concerne l'étude expérimentale du comportement de différents matériaux supraconducteurs HTc pour la limitation de courant. Cette caractérisation a été menée en régime nominal alternatif (mesures des pertes) et en régime de défaut. Dans le cadre de cette étude, le matériau YBCO mono domaine a fait l'objet d'une analyse approfondie à haute température. Un travail de modélisation numérique visant à prédire les conséquences d'une transition inhomogène et à estimer les pertes en régime assigné a également été mené. Afin de valider la faisabilité d'un appareillage haute tension, un démonstrateur 1 kV / 100 A constitué de 43 méandres d'YBCO texturé a été testé à une température de 90,5 K. Cette étude s'est également focalisée sur la dynamique de la transition des matériaux supraconducteurs. Nos expériences semblent montrer que la transition est plus homogène au voisinage de Tc. Cette observation est principalement justifiée par la faible valeur de Jc au voisinage de Tc, par des considérations thermiques (meilleure propagation du front de transition) et magnétiques (ancrage magnétique et mécanisme avalancheux de la transition différents près de Tc). Des résultats expérimentaux mettent également le doigt sur l'importance des échanges thermiques latéraux sur la transition des supraconducteurs. L'analyse menée montre que l'énergie dissipée au sein du matériau étudié semble l'être de façon localisée.
- Published
- 2002
37. Calculation of losses in a type-II superconducting wire in alternating current and magnetic field
- Author
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Mailfert, A
- Published
- 1967
- Full Text
- View/download PDF
38. RADIOLYSIS OF AQUEOUS SOLUTIONS BY HEAVY PARTICLE RADIATIONS. I. RADIOREDUCTION INDUCED BY THE NUCLEAR REACTION $sup 10$B(n,$alpha$)$sup 7$Li IN SULFURIC ACID SOLUTIONS OF Ce(IV) IN THE PRESENCE OF Tl(I) AND OF Ce(III).
- Author
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Pucheault, J
- Published
- 1968
39. PROPERTIES OF SOLID INSULATORS AT CRYOGENIC TEMPERATURES.
- Author
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Perrier, M
- Published
- 1968
40. CHARACTERISTIC ENERGY LOSSES OF ELECTRONS IN COPPER, SILVER, AND GOLD
- Author
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Simon, R
- Published
- 1962
41. DETERMINATION OF THE STANDARD REACTIVITY AND MEASUREMENT OF THE EFFECTIVENESS OF DELAYED NEUTRONS IN "PROSERPINE"
- Author
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Tachon, J
- Published
- 1962
- Full Text
- View/download PDF
42. VARIATIONS OF THE CHARACTERISTIC 2.5-eV ENERGY LOSS OF ELECTRONS IN GOLD ACCORDING TO THE THICKNESS OF THE SAMPLES.
- Author
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Carillon, A
- Published
- 1968
43. THE ELASTIC SCATTERING OF ELECTRONS
- Author
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Zouckermann, R
- Published
- 1957
44. CONTRIBUTION TO THE STUDY OF THE RANGE-ENERGY CURVE FOR ELECTRONS FROM 23 TO 90 kev IN NUCLEAR EMULSION
- Author
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Sacton, J
- Published
- 1957
45. EQUATION OF THE FORCES IN THE REDUCTION BY HF FIELDS OF LOSSES BY PERPENDICULAR DIFFUSION
- Author
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Le Gardeur, R
- Published
- 1962
46. Radiochemical Analysis by Thermal Neutron Activation: Determination of Cobalt by Measurement of the Activity of Cobalt-60m (Half Life of 10.5 Minutes)
- Author
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Vogel, J.
- Published
- 1961
- Full Text
- View/download PDF
47. EFFECT OF AN ELECTRIC FIELD ON WEAKLY IONIZED GAS. III. INFLUENCE OF INELASTIC COLLISIONS ON THE ELECTRON DISTRIBUTION FUNCTION AT LOW ENERGIES.
- Author
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Peyraud, N
- Published
- 1968
48. FADING OF ALPHA PARTICLE TRACKS IN ILFORD C2 PLATES
- Author
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Picciotto, E
- Published
- 1957
49. STORED ENERGY IN IRRADIATED GRAPHITE. EFFECTS OF IRRADIATION TEMPERATURE
- Author
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Rappeneau, J
- Published
- 1962
- Full Text
- View/download PDF
50. CONSTRUCTION OF RADIATIVE SOLUTIONS APPROXIMATING EINSTEIN EQUATIONS.
- Author
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Choquet-Bruhat, Y
- Published
- 1968
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