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Journal of Energy Chemistry 2017年第4期26卷 815-819页

作者： Saiful Islam Muhammad Hilmy Alfaruqi Jinju Song Sungjin Kim duong tung pham Jeonggeun Jo Seokhun Kim Vinod Mathew Joseph Paul Baboo Zhiliang Xiu Jaekook Kim Department of Materials Science and Engineering Chonnam National University300 Yongbong-dongBukguGwangju 61186Republic of Korea

In this study, we report the cost-effective and simple synthesis of carbon-coated α-MnOnanoparticles(α-MnO@C) for use as cathodes of aqueous zinc-ion batteries(ZIBs) for the first time. α-MnO@C was prepared via a gel formation, using maleic acid(CHO) as the carbon source, followed by annealing at low temperature of 270 °C. A uniform carbon network among the α-MnOnanoparticles was observed by transmission electron microscopy. When tested in a zinc cell, the α-MnO@C exhibited a high initial discharge capacity of 272 m Ah/g under 66 m A/g current density compared to 213 m Ah/g, at the same current density, displayed by the pristine sample. Further, α-MnO@C demonstrated superior cycleability compared to the pristine samples. This study may pave the way for the utilizing carbon-coated MnOelectrodes for aqueous ZIB applications and thereby contribute to realizing high performance eco-friendly batteries.

关键词： Carbon coating Manganese dioxide Zinc-ion battery Electrochemical properties

Metal organic framework-combustion: A one-pot strategy to NiO nanoparticles with excellent anode properties for lithium ion batteries

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Journal of Energy Chemistry 2018年第1期27卷 300-305页

作者： Vaiyapuri Soundharrajan Balaji Sambandam Jinju Song Sungjin Kim Jeonggeun Jo pham tung duong Seokhun Kim Vinod Mathew Jaekook Kim Department of Materials Science and Engineering Chonnam National University

NiO nanoparticles with average particles size of 30 nm are synthesized using a one-pot metal–organic framework-combustion（MOF-C） technique, for use as an anode material in rechargeable lithium ion batteries（LIBs）. The structural and electronic properties of these nanoparticles are studied using various techniques, including powder X-ray diffraction（PXRD）, transmission electron microscopy（TEM）, scanning electron microscopy（SEM）, X-ray photoelectron spectroscopy（XPS）, and N_2 adsorption/desorption studies. The as-synthesized NiO nanoparticles sustained reversible stable capacities of 748 and 410 mAh/g at applied current densities of 500 and 1000 m A/g, respectively, after 100 cycles. Furthermore, the anode displays a notable rate capability, achieving a stable capacity of ~200 mAh/g at a high current density of10 A/g. These results indicate that the size of the NiO nanoparticles and their high surface area influence their electrochemical properties. Specifically, this combustion strategy is clearly favorable for improving the cyclability and rate capability of various metal oxides in rechargeable battery electrodes.

关键词： Metal-organic frameworks Combustion NiO nanoparticles Lithium ion batteries High rate capability

Development of a Peristaltic Micropump for Bio-Medical Applications Based on Mini LIPCA

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Journal of Bionic Engineering 2008年第2期5卷 135-141页

作者： Thanh tung Nguyen My pham Nam Seo Goo Department of Aerospace Engineering Konkuk University Department of Advanced Technology Fusion Konkuk University

This paper presents the design, fabrication, and experimental characterization of a peristaltic micropump. The micropump is composed of two layers fabricated from Polydimethylsiloxane （PDMS） material. The first layer has a rectangular channel and two valve seals. Three rectangular mini lightweight piezo-composite actuators are integrated in the second layer, and used as actuation parts. Two layers are bonded, and covered by two Polymethyl Methacrylate （PMMA） plates, which help increase the stiffness of the micropump. A maximum flow rate of 900μ*** 1 and a maximum backpressure of 1.8 kPa are recorded when water is used as pump liquid. We measured the power consumption of the micropump. The micropump is found to be a promising candidate for bio-medical application due to its bio-compatibility, portability, bidirectionality, and simple effective design.

关键词： peristaltic micropump LIPCA PDMS bio-medical applications

Drought and conflicts at the local level: Establishing a water sharing mechanism for the summer-autumn rice production in Central Vietnam

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International Soil and Water Conservation Research 2019年第4期7卷 362-375页

作者： Chuong Van Huynh Catharien Terwisscha van Scheltinga Ty Huu pham Non Quoc duong Phuong Thi Tran Linh Hoang Khanh Nguyen tung Gia pham Ngoc Bich Nguyen Jos Timmerman Hue University Viet Nam Climate Change and Adaptive Land and Water Management Group Wageningen Environmental ResearchNetherlands University of Agriculture and Forestry Hue UniversityViet Nam

In recent years,water for agricultural production gradually became a significant challenge in the context of climate change in *** solutions are required,which consider the use of resources for both human needs and ecology,and that account for the equitable distribution and the livelihood of the farmers now and in the *** particular,the farmers in the province of Quang Nam faring water shortage in the cultivation of paddy in the summer-autumn *** arise regarding the sharing of the water between the farmers,the drinking water company and the hydropower *** the context of climate change,the water shortage is expected to increase in the *** article presents the results of participatory action research (PAR) approach to develop a local level mechanism for water sharing,in which stakeholders actively *** sharing mechanism was developed,envisioning a sustainable solution for inclusive water *** mechanism was successfully implemented in two cases,one at commune level (Tho stream) and one at the district level (Mo stream).The participatory approach proved to be successful in setting up a broadly acceptable mechanism that will need to be further incorporated in the institutional set-up.

关键词： Adaptation Agriculture Climate change Governance Rice production Water sharing

Performance evaluation of a two-way relay network with energy harvesting^and hardware noises

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Digital Communications and Networks 2021年第1期7卷 45-54页

作者： Nguyen Tien tung pham Minh Nam Phu Tran Tin Faculty of Electronics Technology Industrial University of Ho Chi Minh CityHo Chi Minh CityVietnam Wireless Communcations Research Group Faculy of Electrical and Electronics EngineeringTon Duc Thang UniversityHo Chi Minh CityVietnam

In this paper,we propose a Two-Way Cognitive Relay Network(TWCRN)where the secondary users operate on an underlay mode to access the licensed *** the proposed protocols,two secondary sources transmit their data to a relay in the first time slot,and then the relay would forward the received information to both sources in the remaining ***,the relay is self-powered by harvesting energy from ambient Radio Frequency(RF)signals,using the Time Switching(TS)and the Power Switching(PS)*** paper concentrates on eval-uating the performance of the secondary networks under the impact of hardware impairments and co-channel interference from the primary *** particular,based on the secondary transmitters'constraint power,we derive the closed-form expressions of the outage probability and the throughput over Rayleigh fading channels in two cases:TS and *** also investigate the energy efficiency issue and the locally optimal position of the relay to maximize the system throughput,which provides much information to install the relay ***,our derivations are verified by Monte Carlo simulation.

关键词： Energy harvesting Two-way relay Energy efficiency Hardware impairments Cognitive network

Integrated universal soil loss equation (USLE) and Geographical Information System (GIS) for soil erosion estimation in A Sap basin:Central Vietnam

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International Soil and Water Conservation Research 2018年第2期6卷 99-110页

作者： tung Gia pham Jan Degener Martin Kappas Cartography GIS and Remote Sensing DepartmentGottingen UniversityGermany University of Agriculture and Forestry Hue UniversityVietnam

Central Vietnam is very susceptible to soil erosion due to its complicated terrain and heavy rainfall. The objective of this study was to quantify soil erosion in the A Sap river basin, A Luoi district, Thua Thien Hue Province, Vietnam, using the Universal Soil Loss Equation (USLE) and Geographical Informa-tion System (GIS). The results showed that 34% of land area lost accumulated to 10 t ha-1 year-1 while 47% of the total area lost less than 1 t ha-1 year-1. Natural forest land lost the most with an average of about 19 t ha-1 year-1, followed by plantation forest with approximately 7 t ha-1 year-1 and other agricultural lands at 3.70 and 1.45 t ha-1 year-1 for yearly crops and paddy rice, respectively. Soil erosion was most sensitive to the topographic factor (LS), followed by the practice support factor (P), soil erodibility factor (K), cropping management (C), and the rainfall erosivity factor (R). Implications are that changes to the cultivated calendar and implementing intercropping are effective ways to prevent soil erosion in cultivated lands. Furthermore, introducing broad leaves trees for mountainous areas in A Sap basin was the most effective practice in reducing soil erosion. The study also pointed out that the combination of available data sources used with the USLE and GIS technology is a viable option to cal-culate soil erosion in Central Vietnam, which would allow targeted attention toward a solution is to reduce future soil erosion.

关键词： Central Vietnam GIS Soil erosion USLE

Assessment of soil quality indicators under different agricultural land uses and topographic aspects in Central Vietnam

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International Soil and Water Conservation Research 2018年第4期6卷 280-288页

作者： tung Gia pham Hung Trong Nguyen Martin Kappas Cartography GIS and Remote Sensing DepartmentGottingen UniversityGeorge August University of GoettingenGoldschmidstr.537077 GoettingenGermany University of Agriculture and Forestry Hue UniversityVietnam Ministry of Natural Resources and Environment Vietnam

Soil quality assessment is valuable for agricultural production. In this research, 155 soil samples at two soil depths were collected from four land use types in an agricultural area of the A Luoi district in the Central Vietnam. Differences of soil organic carbon, total nitrogen in soil and soil pH under different land use types and topographic aspects were compared. Soil organic carbon contents in arable land and plantation forest are higher than those in natural forest and grassland (p < 0.05). Conversely, the total nitrogen in natural forest was significantly lesser in comparison to other land use types. Meanwhile there were no significant differences of the total nitrogen content (p < 0.05) among arable land, plantation forest, and grassland. The soil of grassland, natural and plantation forests land use types were more significantly acidic than those of the soils of the arable land use type. Soil organic carbon and total nitrogen showed a decreasing trend while soil depth increased in all land use types. The soil pH in plantation forest and arable land use types showed no significant change in relation to soil depth. Significant differences were not found in topographic aspects and soil organic carbon content;however, the different changing trends of soil organic carbon content between land use types and aspects were found. The impact of slope, elevation, farming system or soil texture accounted for the differences in these soil indicators under different land use types in the A Luoi district.

关键词： Central Vietnam Land use type Hilly area Soil quality Topographic aspects

STRONG CONVERGENCE OF AN INERTIAL EXTRAGRADIENT METHOD WITH AN ADAPTIVE NONDECREASING STEP SIZE FOR SOLVING VARIATIONAL INEQUALITIES

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Acta Mathematica Scientia 2022年第2期42卷 795-812页

作者： Nguyen Xuan LINH duong Viet THONG Prasit CHOLAMJIAK pham Anh TUAN Luong Van LONG Department of Mathematics Mathematics Falcuty of Information TechnologyNational University of Civil Engineering Division of Applied Mathematics Thu Dau Mot UniversityBinh Duong ProvinceVietnam School of Science University of PhayaoPhayao 56000Thailand Paculty of Mathematical Economics National Economics UniversityHanoi CityVietnam

In this work,we investigate a classical pseudomonotone and Lipschitz continuous variational inequality in the setting of Hilbert space,and present a projection-type approximation method for solving this *** method requires only to compute one projection onto the feasible set per iteration and without any linesearch procedure or additional projections as well as does not need to the prior knowledge of the Lipschitz constant and the sequentially weakly continuity of the variational inequality mapping.A strong convergence is established for the proposed method to a solution of a variational inequality problem under certain mild ***,we give some numerical experiments illustrating the performance of the proposed method for variational inequality problems.

关键词： Inertial method Tseng’s extragradient viscosity method variational inequality problem pseudomonotone mapping strong convergence

Tunable colors and conductivity by electroless growth of Cu/Cu2O particles on sol-gel modified cellulose

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Nano Research 2020年第10期13卷 2658-2664页

作者： Justus Landsiedel Waleri Root Christian Schramm Alexander Menzel Steffen Witzleben Thomas Bechtold tung pham Research Institute for Textile Chemistry and Textile Physics University of Innsbruck6850 DornbirnAustria Department of Physical Chemistry University of Innsbruck6020 InmsbruckAustria Department of Natural Sciences Bonn Rhein sSieg University of Applied Sciences5359 RheinbachGermany

Development of colored surfaces by formation of nano-structured aggregates is a widely used strategy in nature to color lightweight structures (e.g. butterflies) without the use of dye pigments. The deposition of nanoscale particles mimics nature in it’s approach coloring surfaces. This work presents sol-gel modification of cellulose surfaces used to form a template for growth of Cu/Cu2O core–shell particles with defined size-distributions. Besides improving the adhesion of the deposited particulate material, the sol-gel matrix serves as a template for the control of particle sizes of the Cu/Cu2O structures, and as a consequence of particle size variation the surface color is tunable. As an example, red color was achieved with an average particle size of 35 nm, and shifts gradually to blue appearance when particles have grown to 80 nm on the sol-gel modified fabric. The copper concentration on representative fabrics is kept low to avoid modifying the textile characteristics and were all in the range of 150–170 mg per g of cellulose material. As a result of copper deposition on the surface of the material, the cellulose fabric also became electrically conductive. Remarkably, the electrical conductivity was found to be dependent on the average particle sizes of the deposits and thus related to the change in observed color. The generation of color by growth of nano-sized particles on sol-gel templates provides a highly promising approach to stain surfaces by physical effects without use of synthetic colorants, which opens a new strategy to improve environmental profile of coloration.

关键词： electroless copper deposition sol-gel support thin film structural coloration tunable sheet resistance LSPR

Deep learning long short-term memory combined with discrete element method for porosity prediction in gravel-bed rivers

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International Journal of Sediment Research 2023年第1期38卷 128-140页

作者： duong Tran Anh Ahad Hasan Tanim Daniel Prakash Kushwaha Quoc Bao pham Van Hieu Bui HUTECH University Center for River Harbor and Landslide Research Chittagong University of Engineering & Technology Govind Ballabh Pant University of Agriculture and Technology Institute of Applied Technology Thu Dau Mot University Faculty of Mechanical Engineering Thuyloi University

The porosity of gravel riverbed material often is an essential parameter to estimate the sediment transport rate, groundwater-river flow interaction, river ecosystem, and fluvial geomorphology. Current methods of porosity estimation are time-consuming in simulation. To evaluate the relation between porosity and grain size distribution(GSD), this study proposed a hybrid model of deep learning Long Short-Term Memory(LSTM) combined with the Discrete Element Method(DEM). The DEM is applied to model the packing pattern of gravel-bed structure and fine sediment infiltration processes in threedimensional(3D) space. The combined approaches for porosity calculation enable the porosity to be determined through real time images, fast labeling to be applied, and validation to be done. DEM outputs based on the porosity dataset were utilized to develop the deep learning LSTM model for predicting bed porosity based on the GSD. The simulation results validated with the experimental data then segregated into 800 cross sections along the vertical direction of gravel pack. Two DEM packing cases, i.e., clogging and penetration are tested to predict the porosity. The LSTM model performance measures for porosity estimation along the z-direction are the coefficient of determination(R~2), root mean squared error(RMSE), and mean absolute error(MAE) with values of 0.99, 0.01, and 0.01 respectively, which is better than the values obtained for the Clogging case which are 0.71, 0.14, and 0.03, respectively. The use of the LSTM in combination with the DEM model yields satisfactory results in a less complex gravel pack DEM setup, suggesting that it could be a viable alternative to minimize the simulation time and provide a robust tool for gravel riverbed porosity prediction. The simulated results showed that the hybrid model of the LSTM combined with the DEM is reliable and accurate in porosity prediction in gravel-bed river test samples.

关键词： Numerical modeling Discrete element method LSTM Bed porosity Gravel-bed river