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Effect of silica forms in rice husk ash on the properties of concrete

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International Journal of Minerals,Metallurgy and Materials 2012年第3期19卷 252-258页

作者： Le Anh-tuan bui Chun-tsun Chen Chao-lung Hwang Department of Construction Engineering Taiwan University of Science and Technology

The strength and durability properties of concrete with or without three types of rice husk ash （RHA）, namely, amorphous, partial crystalline, and crystalline RHA, were investigates. The three types of RHA were added into concrete at a 20% replacement level. Consequently, the pozzolanic reactivity of amorphous RHA was higher than that of partial crystalline and crystalline RHA. Concrete added with amorphous RHA showed excellent characteristics in its mechanical and durability properties. The results showed that the higher the amount of crystalline silica in RHA, the lower the concrete resistivity value became. When compared with each other, concretes with 20% of the ce- ment replaced with these types of RHA achieved similar ultrasonic pulse velocity values, but all were lower than that of the control concrete. The incorporation of these kinds of RHA significantly reduced chloride penetration. The results not only encourage the use of amorphous materials, they also support the application of crystalline or partial crystalline RHA as mineral and pozzolanic admixtures for cement.

关键词： rice husk ash silica concrete compressive strength durability waste management

Hybrid model to optimize object-based land cover classification by meta-heuristic algorithm:an example for supporting urban management in Ha Noi,Viet Nam

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International Journal of Digital Earth 2019年第10期12卷 1118-1132页

作者： Quang-Thanh bui manh Pham Van Nguyen Thi Thuy Hang Quoc-Huy Nguyen Nguyen Xuan Linh Pham Minh Hai Tran Anh tuan Pham Van Cu Center for Applied Research in Remote sensing and GIS(CARGIS) VNU University of ScienceHa NoiViet Nam VNU University of Science Ha NoiViet Nam Vietnam Institute of Geodesy and Cartography Ha NoiViet Nam Ministry of Education and Training Ha NoiViet Nam

This study proposed a novel object-based hybrid classification model named GMNN that combines Grasshopper Optimization Algorithm(GOA)and the multiple-class Neural network(MNN)for urban pattern detection in Hanoi,*** bands of SPOT 7 image and derivable NDVI,NDWI were used to generate image segments with associated attributes by PCI Geomatics *** segments were classified into four urban surface types(namely water,impervious surface,vegetation and bare soil)by the proposed ***,three training and validation datasets of different sizes were used to verify the robustness of this *** all tests,the overall accuracies of the classification were approximately 87%,and the Area under Receiver Operating Characteristic curves for each land cover type was ***,the performance of this model was examined by comparing several statistical indicators with common benchmark *** results showed that GMNN out-performed established methods in all comparable *** results suggested that our hybrid model was successfully deployed in the study area and could be used as an alternative classification method for urban land cover *** a broader sense,classification methods will be enriched with the active and fast-growing contribution of metaheuristic algorithms.

关键词： Urban remote sensing object-based classification neural network grasshopper optimization algorithm

Examining unobserved factors associated with red light running in Vietnam:A latent class model analysis

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Transportation Safety and Environment 2022年第1期4卷 110-122页

作者： Tien Dung Chu Tomio Miwa tuan Anh bui Quang Phuc Nguyen Quang Huy Vu Department of Highway and Traffic Engineering University of Transport and CommunicationsNo.3 Cau Giay StreetLang Thuong WardDong Da DistrictHanoi 10001Vietnam Institute of Materials and Systems for Sustainability Nagoya UniversityFuro-choChikusa-kuNagoya cityAichi Prefecture464-8603Japan

Red-light running(RLR)is a crucial violation that causes traffic accidents and *** factors that affect RLR is very significant to reduce the potential of this *** studies have paid considerable attention to the observable factors,but not to unobservable *** study aims to examine the effects of observable and unobservable factors on *** study uses a latent class model(LCM)to assign individuals into two classes—red-light-respectful and red-light-disrespectful road users—by surveying 751 respondents who use private transportation *** study incorporates psychological determinants into the LCM to account for unobservable *** contribution of this study is the in-depth investigation into law-respectful and law-disrespectful behaviours and intentional and unintentional *** a study has not yet been conducted in the existing *** addition,a comprehensive comparison of the LCM and a traditional ordered probit model was ***,the results suggest that the LCM is superior to the model that does not consider latent *** estimation results are in alignment with previous studies on RLR:males,younger drivers/riders,less educated road users and motorcyclists are more likely to run red *** analysis of the latent variables shows that surrounding conditions—the behaviour of other violators,the absence of traffic police,and long waiting times—increase the possibility of *** on these results,we provide suggestions to policymakers and traffic engineers:the implementation of enforcement cameras and penalties for violators are critical countermeasures to minimize the potential of RLR.

关键词： red light running(RLR) developing country latent class model(LCM) multiple indicator multiple cause(MIMIC)model latent variables(LVs) motorcycles(MCs) traffic violation

Monte Carlo simulation of a cone-beam CT system for lightweight casts

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Radiation Detection Technology and Methods 2021年第4期5卷 504-512页

作者： Thuy Duong Tran Ngoc Ha bui Kim tuan Tran Ngoc Toan Tran Department of Nuclear Engineering and Environmental Physics School of Engineering PhysicsHanoi University of Science and Technology01 Dai Co VietHai Ba TrungHanoiVietnam Vietnam Atomic Energy Institute 59 Ly Thuong KietHoan KiemHanoiVietnam

Cone-beam computed tomography(CBCT),a modern technique with many applications,is becoming increasingly important and essential in many areas of economics and *** equipment has been commercialized in both hardware and ***,having a device system suitable for a specific group of objects will be the *** work used Monte Carlo simulation to optimize the design of a Cone-beam Computed Tomography(CBCT)for lightweight and small-size *** affecting image quality such as radiation-source,flat-panel detector,and geometrical distance were *** results indicate that an X-ray generator with a focal spot size of 4×4µm^(2),high voltage of 240 kV,and a radiation intensity of 10^(13) photon/s with a flat panel CsI(Tl)detector of 0.3 mm thickness and a pixel size of 0.1–0.2 mm,is suitable for a CBCT to inspect small objects in *** Monte Carlo model was validated against experiments and to evaluate some characteristics of the existing system.

关键词： Cone-beam computed technology Monte Carlo simulation Lightweight casts in industry Applied radiation

Calibration of a neutron dose rate meter in various neutron standard fields

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Nuclear Science and Techniques 2020年第6期31卷 75-82页

作者： tuan Khai Nguyen Hoai-Nam Tran Quynh Ngoc Nguyen Thi My Linh Dang Van Loat bui Thiansin Liamsuwan Ngoc-Thiem Le Vietnam Agency for Radiation and Nuclear Safety 113 Tran Duy HungHanoi 100000Vietnam Institute of Fundamental and Applied Sciences Duy Tan UniversityHo Chi Minh 700000Vietnam Faculty of Natural Sciences Duy Tan University3 Quang TrungDa Nang 550000Vietnam Institute for Nuclear Science and Technology VINATOM179 Hoang Quoc VietHanoi 100000Vietnam Faculty of Physics VNU University of Science334 Nguyen TraiHanoi 100000Vietnam Nuclear Research and Development Division Thailand Institute of Nuclear TechnologyOngkharakNakorn NayokThailand 7 Faculty of Medicine and Public HealthHRH Princess Chulabhorn College of Medical ScienceChulabhorn Royal AcademyBangkokThailand

This paper presents the calibration of a neutron dose rate meter and the evaluation of its calibration factors(CFs)in several neutron standard fields(i.e.,two standard fields with bare sources of252Cf and241Am-Be,and five simulated workplace fields with241Am-Be moderated sources).The calibration in standard fields with bare sources was conducted by following the recommendations of the ISO 8529 *** measured total neutron ambient dose equivalent rates,denoted as H*(10)tot,were analyzed to obtain direct components,denoted as H*(10)dir,using a reduced fitting *** CF was then calculated as the ratio between the conventional true value of the neutron ambient dose equivalent rate in a free field,denoted as H*(10)FF,and the value of H*(10)*** contrast,in the simulated workplace neutron fields,the calibration of the neutron dose rate meter was conducted by following the ISO 12789 *** CF was calculated as the ratio between the values of H*(10)totmeasured by a standard instrument(i.e.,Bonner sphere spectrometer)and the neutron dose rate *** CF values were obtained in the range of 0.88–*** standard uncertainties(k=1)of the CFs were determined to be in the range of approximately 6.6–13.1%.

关键词： Neutron standard fields Neutron dose rate meter Calibration factor 252Cf source 241AmBe source

Ethanol extracts of Scutellaria baicalensis protect against lipopolysaccharide-induced acute liver injury in mice

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Asian Pacific Journal of Tropical Biomedicine 2015年第9期5卷 733-738页

作者： Hai Nguyen Thanh Hue Pham Thi Minh tuan Anh Le Huong Duong Thi Ly Tung Nguyen Huu Loi Vu Duc Thu Dang Kim Tung bui Thanh School of Medicine and Pharmacy Vietnam National University Hanoi University of Pharmacy

Objective: To investigated the protective potential of ethanol extracts of Scutellaria baicalensis(S. baicalensis) against lipopolysaccharide(LPS)-induced liver injury. Methods: Dried roots of S. baicalensis were extracted with ethanol and concentrated to yield a dry residue. Mice were administered 200 mg/kg of the ethanol extracts orally once daily for one week. Animals were subsequently administered a single dose of LPS(5 mg/kg of body weight, intraperitoneal injection). Both protein and m RNA levels of cytokines, such as tumor necrosis factor alpha, interleukin-1β, and interleukin-6 in liver tissues were evaluated by ELISA assay and quantitative PCR. C yclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB protein levels in liver tissues were analyzed by western blotting. Results: Liver injury induced by LPS signifi cantly increased necrosis factor alpha, interleukin-1β, interleukin-6, cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor-κB in liver tissues. Treatment with ethanol extracts of S. baicalensis prevented all of these observed changes associated with LPS-induced injury in liver ***: Our study showed that S. baicalensis is potentially protective against LPS-induced liver injury in mice.

关键词： Scutellaria baicalensis Lipopolysaccharide Liver injury Cytokine Nuclear factor-κB

Assessing Satellite-Based Precipitation Products to Create Flood Forecasting in the Da River Basin, Vietnam

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Journal of Geoscience and Environment Protection 2019年第11期7卷 113-123页

作者： Le Viet Son Luong Ngoc Chung bui tuan Hai Sai Hong Anh Nguyen Duy Quang Division for Water Resources Planning for the North Region Institute of Water Resources Planning Hanoi Vietnam Board of directors Institute of Water Resources Planning Hanoi Vietnam Department of Agro-Environmental Sciences Graduate School of Bioresource and Bioenvironmental Sciences Kyushu University Fukuoka Japan

The Da River Basin is an international basin where available access to hydrological data is limited;it has a total basin area of 52,900 km2, about 50% of the area in which it is located, Vietnam. The Da River is the primary source of water for agriculture in 25 provinces and cities, and the primary source of drinking water for more than 30 million people in both urban and rural areas. It has huge economic and historical value. However, flood forecasting for the Da River basin has not been adequately addressed yet because of the challenge of the inconsistency, scarcity, poor spatial representation, as well as difficult access and incompleteness of the availability of ground observed rainfall data. In this research, the IFAS model has been utilized to assess the benefits of using satellite-based precipitation products to create flood forecasting for the whole research area. The results showed that the Integrated Flood Analysis System (IFAS) model was able to integrate the satellite-based precipitation products for simulating the flood event in the Da River basin. Also, the 3B42RT algorithm showed a definite improvement in reproducing the flood peak and low flow very well in the research area. These results could be used to enhance the effectiveness of flood management strategy in the basin.

关键词： IFAS Flood Flow 3B42RT and GSMaP Algorithm

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马河流域气候和土地利用变化的水文响应研究

马河流域气候和土地利用变化的水文响应研究

作者：裴英俊（bui ANH tuan）昆明理工大学

学位级别：硕士

本论文基于SWAT分布式流域水文模型,对构建的不同气候和土地利用变化情景下的马河流域径流响应进行模拟研究。通过收集和野外调查等方式获取流域的地形(DEM)、土地利用、土壤等数据,并通过裁剪、投影转换等数据处理建立模型模拟所需的... 详细信息

本论文基于SWAT分布式流域水文模型,对构建的不同气候和土地利用变化情景下的马河流域径流响应进行模拟研究。通过收集和野外调查等方式获取流域的地形(DEM)、土地利用、土壤等数据,并通过裁剪、投影转换等数据处理建立模型模拟所需的输入数据库。以流域下游控制水文站Cua Dat站1999年实测日流量数据对模型参数进行率定,用2005年实测日流量数据对模型参数进行了验证。径流模拟精度确定性系数达到0.8以上、效率系数达到0.7以上,表明SWAT模型在马河流域具有较强的适用性。根据IPCC (Intergovernmental Panel on Climate Change)的预测及马河流域近30年的实测资料反映出的气候变化趋势,设置2种气候变化情景(A2和B2情景),利用率定好的SWAT模型对两种气候变化情景下的马河流域的径流过程进行了模拟。A2和B2的气候演变趋向对二十一世纪的极端现象带来较大影响。这样的气候变化会导致丰水期最大月平均流量上涨约20%(A2情景,8月份),而在枯水期最干旱月份的平均流量下降约27%(A2情景,4月份) 根据流域内地形、坡度,土壤等的空间分布特征及人口增长、经济的发展需求设置了3种不同土地利用情景,定量分析了土地利用变化对流域水循环的影响。结果表明,流域径流量、腾发量、产水量等指标对于土地利用的变化是比较敏感的。土地利用极端的变化对年径流量影响不大,但对径流的年内分配影响较大。合适的土地利用方式,能减少雨季洪水的威胁,也能减轻旱季的干旱程度,并在一定程度上改善流域的经济发展状况。对气候和土地利用变化相结合的情景研究表明,每一年的径流减少约1.3%-1.4%,同时也能减少丰水季节的径流约2%-26%,并增加旱季的径流约11%-48%。这表示恰当的结合方式能克服因气候和土地利用的独立变化所引起的径流极端变化。借助不同的情景模拟,从水资源利用与管理角度,探讨研究区土地利用以及气候变化的水文响应,可为马河流域水资源管理及可持续利用提供参考依据。

关键词：气候变化土地利用 SWAT模型马河流域

越南农作物病虫害预警防控体系发展现状及思考

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中国植保导刊 2020年第6期40卷 92-94页

作者：陆明红姜玉英刘万才翟保平谢茂昌施伟韬吕荣华 Hoang Anh tuan bui Xuan Phong 全国农业技术推广服务中心北京100125 南京农业大学植物保护学院江苏南京210095 广西壮族自治区植保总站广西南宁530022 江西省植保植检局江西南昌330096 广西壮族自治区农业科学院广西南宁530007 越南农业和农村发展部植物保护局越南河内115302

简述了越南区域植物保护中心的地位和职能、水稻病虫测报调查技术、近年来水稻病虫防控技术的发展以及越南农业合作社发展现状。结合中越水稻迁飞性害虫监测与防治合作项目研究进展,明确了越南水稻迁飞性害虫发生对我国具有重要的指示意... 详细信息

简述了越南区域植物保护中心的地位和职能、水稻病虫测报调查技术、近年来水稻病虫防控技术的发展以及越南农业合作社发展现状。结合中越水稻迁飞性害虫监测与防治合作项目研究进展,明确了越南水稻迁飞性害虫发生对我国具有重要的指示意义,提出了进一步扩大合作范围、深化合作内容的建议,以期为两国预测迁飞性害虫发生动态提供更为充分的依据,全面提升两国植保能力,为保障两国农业发展和粮食安全发挥重要作用。

关键词：越南水稻病虫预警防控体系