89 research outputs found

    Water Security in the Mekong River Basin Challenges, Causes and Solutions

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    Water, an essential element in sustaining life is of special importance to society and economic development. Although renewable, water resources are not infinite. It can be said that equitable and sustainable water resource management in the context of climate change is a challenge that all Mekong countries have been facing. The challenge becomes bigger in the context of water scarcity when the total amount of water is sharply decreasing and the water quality is declining, failing to meet domestic and industrial needs. Based on a study into the current situation of water security in the Mekong River, the author points out the basic challenges that threaten water security in the river basin. At the same time, the author discusses the reasons leading to this situation. Based on the research on the current situation of challenges and underlying causes, the author proposes a number of necessary solutions to cope with current and upcoming challenges. These solutions, including legal, diplomatic, economic and political solutions, should be implemented in a synchronized and long-term manner in the future

    Prediction of penetration rate and optimization of weight on a bit using artificial neural networks

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    Relevance. Achieving the greatest rate of penetration is the aim of every drilling engineer because it is one of the most significant factors influencing drilling costs. However, a variety of drilling conditions could have an impact on rate of penetration, complicating its forecast.   Aim. To suggest a novel strategy to accurately predict rate of penetration and optimize drilling parameters. Objects. Real-time drilling data of a few wells in the Ca Tam oil field, Vietnam, with more than 900 datasets including significant parameters like rotary speed, weight on bit, standpipe pressure, flow rate, weight of mud, torque. Methods. Various methods using Artificial Neural Network was proposed to estimate rate of penetration. Results. The number of neurons in a hidden layer was varied then the results of different Artificial Neural Network models were compared in order to obtain the optimal model. The final Artificial Neural Network model shows high exactness when contrasted with actual rate of penetration, in this manner, it tends to be suggested as a successful and reasonable approach to predict the rate of penetration of different wells in the Ca Tam oil field. Based on the proposed Artificial Neural Network model, the optimal weight on bit was determined for the drilling interval from 1800 to 2300 m of oil wells in the research region.  

    Synthesis and Optical Characterization of Dye Doped in Ormosil Nanospheres for Bioapplications

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    Dye-doped ORMOSIL (organically modified silicate) nanoparticles (NPs) have significant advantages over single-dye labeling in signal amplification, photostability and surface modification for various biological applications. The dyes: Rhodamine 6G (R6G) and Rhodamine B (RB) were successfully incorporated into ORMOSIL nanoparticles fabricated by micellar nanochemistry from Trimethoxysilane CH3_3Si(OCH3_3)3_3 precursor. The optical characterization of dye-doped ORMOSIL NPs was studied in comparison with it’s of free dye in solution. The results shown that the photostability of ORMOSIL dye doped nanospheres is much improved in comparison with it’s of dye in solution. Other studies of the photophysical properties such as anisotropy, fluorescence lifetime and energy transfer were also done

    g-INFO portal: a solution to monitor Influenza A on the Grid for non-grid users

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    International audienceIn this paper, we introduce a portal for monitoring Influenza A on a grid-based system. Influenza A keeps on being a major threat to public health worldwide; especially if one virus can mutate itself so that it acquires the capacity for human to human transmission of H1N1 as well as the high death rate of H5N1. The existing g-INFO (Grid-based Information Network for Flu Observation) project provides a complete system for monitoring flu virus on the Grid. We present here a portal that operates on top of the g-INFO system as a solution for non-grid users to utilize grid services for analyzing molecular biology data of Influenza A

    Accounting for Vietnam’s Wealth: The Role of Natural Resources

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    This study estimates the capital or stock value of Vietnam’s natural resources. Natural resources are special economic goods because they are not produced. As a consequence, natural resources yield economic profits—rents—if properly managed. These rents can be an important source of development finance for poor countries (World Bank, 2006). The value of natural resources is estimated based on the net present value of income flows that can be generated from these resources (resource rents). Thus the capital value of natural resources is the based on the value an investor would pay for the resource based on its income flow potential. Together with measures of the value from Vietnam’s other important resources, human and produced capital, one could then assess whether Vietnam is on a sustainable development path by monitoring the value of its wealth overtime

    CÁ MÚ GIỐNG VÀ BẢO VỆ BÃI GIỐNG Ở ĐẦM THỊ NẠI, VỊNH QUY NHƠN VÀ ĐẦM CÙ MÔNG

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    The wild grouper fingerling have provided the important seed source for the development of commercial fish farming. Among the wild grouper fingerling collected in the Thi Nai lagoon, Quy Nhon bay (Binh Dinh) and Cu Mong lagoon (Phu Yen), 7 species of grouper have been identified as Banded grouper (Epinephelus amblycephalus), Yellow grouper (E. awoara), Longtooth grouper (E. bruneus), Malabar grouper (E. malabaricus), Sixbar grouper (E. sexfasciatus), Orange-spotted grouper (E. coioides) and grouper (Epinephelus sp.); in which three species of Longtooth grouper, Malabar grouper and Orange-spotted grouper were endangered in Red List Categories Criteria of IUCN as VU and NT. The Malabar grouper seed makes up a high proportion of over 30%. The total length of the juveniles is different between species, ranging from an average of 25.0 mm to 116.82 mm; Orange-spotted grouper is 112.48 mm in total length; four grouper species Banded grouper, Yellow grouper, Longtooth grouper and Malabar grouper are longer than 30 mm in total length with 31.96, 32.23, 33.78 and 33.86 mm respectively. The Sixbar grouper and grouper (Epinephelus sp.) are smaller than 30 mm. The catching of grouper fingerling is distributed in wide area, along the bank, mangroves in the lagoon, along the western shore of the Quy Nhon bay, from Ghenh Rang to the southern part of the coast and along the Cu Mong lagoon (from south to southwest). The production of grouper seed fluctuates irregularly, 3 - 4 million seeds per year for highest yields, alternating with very low yields. The protection of nursing grounds is necessary with the solution of selective catching and limiting artisanal fishing.Cá mú giống khai thác tự nhiên đã cung cấp nguồn giống quan trọng cho việc phát triển nuôi cá thương phẩm. Nguồn cá mú giống khai thác tự nhiên ở vùng đầm Thị Nại, vịnh Quy Nhơn (Bình Định) và đầm Cù Mông (Phú Yên) đã xác định được 7 loài là cá mú chấm vạch (Epinephelus amblycephalus), cá song gio (E. awoara), cá song nâu (E. bruneus), cá mú điểm gai (E. malabaricus), cá mú sau sọc (E. sexfasciatus), cá mú mè (E. coioides) và cá song (Epinephelus sp); trong đó có ba loài là cá song nâu (E. bruneus), cá mú điểm gai (E. malabaricus) và cá mú mè (E. coioides) là những loài được IUCN xếp ở mức nguy cấp bậc VU và NT. Con giống cá mú điểm gai chiếm tỉ lệ khá cao trên 30%. Chiều dài toàn thân trung bình cá giống của các loài khác nhau, từ 25,0 - 116,82 mm; cá mú mè  có chiều dài toàn thân lớn nhất đếm 112,48 mm, ba loài cá mú chấm vạch, cá song gio và cá mú điểm gai có chiều dài lớn hơn 30 mm tưong ứng là 31,96; 32,23; 33,78 và 33,86 mm. Hai loài còn lại là cá mú sáu sọc và cá song đều có kích thước nhỏ hơn 30 mm. Vùng khai thác cá mú giống khá rộng; dọc theo các cồn, dãi cây ngập mặn trong đầm Thị Nại, ven bờ phía bắc lên phía tây của vịnh Quy Nhơn; nơi tập trung khai thác ở ven gần bờ phía tây vịnh, từ Ghềnh Ráng kéo dài vào đến khu vực phía nam và vùng dọc bờ của đầm Cù Mông (từ phía nam đến tây nam). Sản lượng khai thác các mú giống biến động khá thất thường, năm có sản lượng cao lên đến 3 - 4 triệu con/năm, xen kẽ có năm sản lượng rất thấp. Việc bảo vệ bãi giống là cần thiết với các giải pháp khai thác có chọn lọc và hạn chế khai thác tận thu

    Outcome and impact assessment of the Climate-Smart Village Program in Northern Vietnam

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    Yen Bai province inherits representative biophysical, socio-economic, smaller-holder farming characteristics to economic marginalization and climatic risks and impacts to agricultural production and local livelihoods of Vietnam’s northern mountain region (NMR). The CCAFS project deployed to Ma Climate-Smart Village (CSV) in Yen Bai in 2015 with bilateral funding support from two other research projects aimed at setting up a demonstration-for-scaling example of a rural community equipped with capacities for enhanced climate adaptation and resilience. This study applied a three tier interview data collection methodology (key informant interviews – focus group discussions – indepth farmer interviews) to thoroughly investigate 120 households about six main outcomes accomplished by the project up until 2021. The project has achieved great outcomes from the village to the provincial levels. However, the project work still has a potential to be scaled to the National Target Program on New Rural Development (NTM) given its interest in developing resilient communities in climate-vulnerable regions across the country applying the CSV approach in its 2021-2025 strategy. Despite the closing of the CCAFS program by December 2021, this most important scaling pathway will be continued by the VIBE 2018.05 (funded by the Irish Aid) and COALESCE/2020/34 (funded by the Irish Research Council) under the management of Vietnam National University of Agriculture – a long-term strategic partner of the CCAFS program in the NRM

    Streptococcus suis, an Important Cause of Adult Bacterial Meningitis in Northern Vietnam

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    Streptococcus suis can cause severe systemic infection in adults exposed to infected pigs or after consumption of undercooked pig products. S. suis is often misdiagnosed, due to lack of awareness and improper testing. Here we report the first fifty cases diagnosed with S. suis infection in northern Viet Nam.In 2007, diagnostics for S. suis were set up at a national hospital in Hanoi. That year there were 43 S. suis positive cerebrospinal fluid samples, of which S. suis could be cultured in 32 cases and 11 cases were only positive by PCR. Seven patients were blood culture positive for S. suis but CSF culture and PCR negative; making a total of 50 patients with laboratory confirmed S. suis infection in 2007. The number of S. suis cases peaked during the warmer months.S. suis was commonly diagnosed as a cause of bacterial meningitis in adults in northern Viet Nam. In countries where there is intense and widespread exposure of humans to pigs, S. suis can be an important human pathogen
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