A DSC/TGA STUDY OF THE HETEROGENEOUS NUCLEATION OF CRYSTALLIZATION IN POLYPROPYLENE COPOLYMER

The study is aimed at the evaluation of the influence of nucleating agent (t-butyl)benzoic aluminum (NA) in changing clarity, crystallization temperature (Tp) and radiation resistant properties of polypropylene copolymer, PP (co) with 6% of ethylene. It has been shown that crystallization temperature of PP (co)+NA did not change when the content of the NA less than 2%, but the super cooling temperature is a little bit increased when the content of the NA was 2 or higher than 2%. Clarity of the blend comprising of PP (co)+NA decreases with the addition of 2% or more NA (t-butyl)benzoic aluminum. However, the increase of the supercooling temperature makes possible to improve radiation resistance of the material

CÁC YẾU TỐ ẢNH HƯỞNG ĐẾN SỰ PHÂN BỐ ĐỘ MẶN CỦA NƯỚC LỖ RỖNG TRONG LỚP TRẦM TÍCH BIỂN TUỔI ĐỆ TỨ VÙNG NAM ĐỊNH

This paper presents the results of studies and analysis, assessment the controlling factors to the distribution of salinity (mainly NaCl) in the Quaternary marine sedimentary in Nam Dinh area by using a combination of different methods such as boreholes logging, undisturbed sediment sampling, pore water squeezing, analysis of chemical and stable isotope compositions of pore water.Based on the correlation between concentration of Cl-, Na+ ions and NaCl versus electrical conductivity of marine sediment at different depth according to geophysical borehole results determine the distribution of concentration of salinity (NaCl) of pore water at different depths. In addition, results from the analysis of stable isotopes δ18O and δ2H of porewater in the marine sedimentary layer show the mixing of marine water and meteoritic water in the sediments. Distribution of NaCl of marine sediments is due to difference in density and molecular diffusion.ReferencesCharles D. Shackelford, David E. Daniel, 1990. Diffusion in Saturated soil. Journal of Geotechnical Engineering 117, 467 - 484.Crooks, V. E. and Quigley, R. M., 1984. Saline leachate migration through clay: A comparative laboratory and field investigation. Can. Geotech. J., 21(2), 349 - 362.Đoàn Văn Cánh, Lê Thị Lài, Hoàng Văn Hưng, Nguyễn Đức Rỡi, Nguyễn Văn Nghĩa, 2005. Groundwater Resource Of Nam Định Province, J. of Geology, B/25, Hà Nội.Frank Wagner, Dang Tran Trung, Hoang Dai Phuc, Falk Lindenmaier, 2011. Assessment of Groundwater Resources in Nam Dinh Province. Final Technical Report of improvement of Groundwater Protection in Vietnam, Ha Noi.Hoàng Văn Hoan, Flemming Larsen, 2007. Phương pháp xác định độ lỗ hổng hiệu dụng, hệ số thấm của tầng chứa nước và TDS của nước bằng phương pháp địa vật lý lỗ khoan, lấy ví dụ vùng đồng bằng sông Hồng. TC KHKT Mỏ - Địa chất, 20/10-2007. Hà Nội, 101-107.Hoan V. Hoang, Nhan Q. Pham, Flemming Larsen, Long V. Tran, Frank Wagner And Anders V. Christiansen, 2011. Processes Controlling High Saline Groundwater in the Nam Dinh Province, Vietnam. 2nd Asia-Pacific Coastal Aquifer Management Meeting October 18-21, 2011, Jeju Island, Korea.Hoàng Văn Hoan, Phạm Quý Nhân, Flemming Larsen, Trần Vũ Long, Nguyễn Thế Chuyên, Trần Thị Lựu, 2012. Ảnh hưởng của quá trình khuếch tán tới sự phân bố độ mặn của nước lỗ rỗng trong lớp trầm tích biển tuổi Đệ tứ khu vực Nam Định. Báo cáo hội nghị khoa học lần thứ 20, ĐH Mỏ - Địa chất. Hà Nội.Nguyễn Kim Ngọc, Kiều Vân Anh, Nguyễn Thị Hạ, Hoàng Văn Hoan, Đỗ Tiến Hùng, Hoàng Văn Hưng, Nguyễn Văn Lâm, Phạm Quý Nhân, Nguyễn Thị Thanh Thủy, 2005. Thủy Địa Hóa học. Nhà xuất bản Giao thông vận tải, Hà Nội, 315tr.Kooi H., Groen J., Leijnse A., 2000. Modes of seawater intrusion during trangressions, Water resources research, Vol. 36, No. 12, phương pháp 3581-3589.Rowe, R. K., Caers, C. J., and Barone, F., 1988. Laboratory determination of diffusion and distribution coefficients of contanminants using undisturbed clayey soil. Can. Geotech. J., 25, 108-118.Schincariol RA, Schwartz FW, Mendoza CA., 1997. Instabilities in variable density flows: stability and sensitivity analyses for homogeneous and heterogeneous media. Water Resour Res; 33(1), 31-41.Simmons CT, Fenstemaker TR, Sharp JM., 2001. Variable-density groundwater flow and solute transport in heterogeneous media approaches resolutions and future challenges. J Contam Hydrol; 52(1-4), 245-75. 148.Tanabe, S., Hori, K., Saito, Y., Haruyama, S., Vu, V.P., Kitamura, A., 2003a. Song Hong (Red River) delta evolution related to millen-nium-scale Holocene sea-level changes. Quaternary Science Reviews 22, 2345-2361.Tanabe, S., Hori, K., Saito, Y., Haruyama, S., Doanh, L.Q., Sato, Y., Hiraide, S., 2003b. Sedimentary facies and radiocarbon dates of the Nam Dinh-1 core from the Song Hong (Red River) delta. Viet-nam. Journal of Asian Earth Science 21, 503-513.Tanabe, S., Hori, K., Saito, Quang Lan Vu, Till J. J. Hanebuth, Quang Lan Ngo, Akihisa Kitamura, 2006. Holocene evolution of Song Hong (Red River) delta system, north Vietnam. Sedimentary Geology 187, 29-61.Weixing Guo and Christian D. Langevin, 2002. User’s Guide to SEAWAT: A computer program for simulation of three-dimensional variable-density groundwater flow, USGS, Florida, USA.This paper presents the results of studies and analysis, assessment the controlling factors to the distribution ofsalinity (mainly NaCl) in the Quaternary marine sedimentary in Nam Dinh area by using a combination of differentmethods such as boreholes logging, undisturbed sediment sampling, pore water squeezing, analysis of chemical andstable isotope compositions of pore water.Based on the correlation between concentration of Cl-, Na+ ions and NaCl versus electrical conductivity of marinesediment at different depth according to geophysical borehole results determine the distribution of concentration ofsalinity (NaCl) of pore water at different depths. In addition, results from the analysis of stable isotopes δ18O and δ2H ofporewater in the marine sedimentary layer show the mixing of marine water and meteoritic water in the sediments.distribution of NaCl of marine sediments is due to difference in density and molecular diffusion

Characterization of cassava production systems in Vietnam.

Using a nationally representative survey of cassava-growing households in Vietnam and a robust method of varietal identification based on DNA fingerprinting, this paper provides a broad picture of cassava production and socio-economic characteristics of cassava producers in the country. It presents a descriptive analysis of cassava production practices, varietal use, varietal preferences, as well as cassava utilization, and marketing. Results indicate that more than 85% of the cassava area in Vietnam is planted to improved varieties. The average yield at national level is 19 tons per hectare. About 69% of total cassava produced per household is sold as either fresh roots and/or dried chips. The remaining 31% is either for own consumption or for livestock feed. Of all the six regions surveyed, the Southeast is characterized by the most intensive cassava production practices. It also has the largest average cassava area per household, the highest percentage of tractor use, and a higher percentage of fertilizer application on cassava fields. The findings suggest that there are huge challenges for sustainable cassava intensification, specifically in identifying the needs for market diversification, dealing with emerging pests and diseases, and implementing adequate soil management practices. This is particularly challenging in a system that is driven by the need to maximize output with minimum investment. Future research and development should focus on integrated value chain development with multiple actors focusing attention on integrated pest and disease management, seed systems development, breeding for resistance and earliness, and climate change adaptation, among others

Optimisation de l’ordonnancement de recharges des véhicules électriques

Our research deals with the problem of the charging scheduling of electric vehicles (EV). The variation in the total power available to load vehicles, user the behaviour constraints and the uncertainties of daily energy demands require an efficient and secure scheduling. We defined five industrial configurations: ACPF (1,2) and ACPV (1a, 1b and 2), each of which corresponds to a set of technical constraints. Studies on formulations, including a conjunctive and a disjunctive, are based on the analysis of the strength of their LP-relaxation. The matrix form of the mathematical formula is composed of a partitioned matrix, which is decomposable by the Dantzig-Wolfe principles. The latter allows us to develop a Branch-and-Price Algorithm for the exact solution of the problem. A deterministic constructive heuristic was then designed for the allocation of the resource, which is very efficient: a quick resolution (less than a second) for a car park with about thirty EVs. Finally, to implement all algorithms in the microprocessor, and to establish a forecasting model and an online scheduling, we have created a stand-alone scheduler, based on the predictive-reactive rescheduling. The research carried out is part of the problems of energy reasoning. They, therefore, can combine with other works, including the smart grid problemsNotre travail de recherche traite de la problématique de l’ordonnancement de recharge des véhicules électriques (VE). La variation de la puissance totale disponible pour charger des véhicules, les contraintes de comportement des utilisateurs et l'incertitude des demandes énergétiques journalières demandent un ordonnancement efficace et sécurisé. Nous avons défini cinq configurations industrielles : ACPF (1,2) et ACPV (1a, 1b et 2) qui correspondent chacune à un ensemble de contraintes techniques. Les études sur les formulations, dont une conjonctive et une disjonctive, reposent sur l’analyse de la force de leurs relaxation-LP. La forme matricielle de la formule mathématique est composée d’une matrice partitionnée, qui est décomposable par le principe de Dantzig-Wolfe. Cette dernière nous permets de développer un algorithme de type Branch-and-Price pour la résolution exacte du problème. Une heuristique constructive déterministe a ensuite été conçue pour l’allocation de la ressource, qui se trouve très efficace : une résolution rapide (moins d’une seconde) pour un parking d’une trentaine VEs. Finalement, pour implémenter tous les algorithmes dans le microprocesseur, et pour établir un modèle prévisionnel et un ordonnancement en temps réel, nous avons créé un planificateur autonome, qui se base sur le réordonnancement prédictif-réactif. Les recherches effectuées font partie des problèmes de raisonnement énergétique. Elles possèdent donc la capacité de se combiner avec d’autres travaux, notamment le problème de smart gri

Identical Machine Scheduling Problem with Sequence-Dependent Setup Times: MILP Formulations Computational Study

International audienceThis work aims to give a systematic construction of the two families of mixed-integer-linear-programming (MILP) formulations, which are graph-based and sequence-based, of the well-known scheduling problem Pm|rj,sij|∑Cj. Two upper bounds of job completion times are introduced. A numerical test result analysis is conducted with a two-fold objective 1) testing the performance of each solving methods, and 2) identifying and analyzing the tractability of an instance according to the instance structure in terms of the number of machines, of the jobs setup time lengths and of the jobs release date distribution over the scheduling horizon

Détermination automatisée de la composition de calculs urinaires - étude de 413 calculs urinaires vietnamiens et comparaison avec des données cliniques

CHATENAY MALABRY-Ecole centrale (920192301) / SudocSudocFranceF

Workload Balancing on Identical Parallel Machines: Theoretical and Computational Analysis

International audienceThis paper considers the problem of assigning nonpreemptive jobs on identical parallel machines to optimize workload balancing criteria. Since workload balancing is an important practical issue for services and production systems to ensure an efficient use of resources, different measures of performance have been considered in the scheduling literature to characterize this problem: maximum completion time, difference between maximum and minimum completion times and the Normalized Sum of Square for Workload Deviations. In this study, we propose a theoretical and computational analysis of these criteria. First, we prove that these criteria are equivalent in the case of identical jobs and in some particular cases. Then, we study the general version of the problem using jobs requiring different processing times and establish the theoretical relationship between the aforementioned criteria. Based on these theoretical developments, we propose new mathematical formulations to provide optimal solutions to some unsolved instances in order to enhance the latest benchmark presented in the literature