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Áp dụng phương pháp ước lượng tốt nhất kết hợp phân tích độ bất định và phương pháp thận trọng
Nghiên cứu này thực hiện phân tích an toàn thủy nhiệt độc lập cho bài toán LB-LOCA trên lò phản ứng VVER-1200/V491 và đánh giá sự phụ hợp của các kết quả của phương pháp thận trọng với khuyến cáo của IAEA, cả hai phương pháp ước lượng tốt nhất và thận trọng sử dụng chương trình RELAP5/MOD 3.3 đều được áp dụng. Nhiệt độ đỉnh của vỏ thanh nhiên liệu (PCT) được xác định như là hình ảnh đặc trưng để phân tích (FOM).
4/4/2023 1:11:02 AM +00:00
Development of a neutron detector for radiation protection monitoring
The paper presents the results of the development of a neutron detector for radiation protection purposes. Monte Carlo simulations, using MCNP5 code, were performed to optimize the configuration of the neutron detector. The developed detector consists of a 3He proportional counter embedded in a multi-layer moderator made of high-density polyethylene (HDPE) and Cadmium.
4/4/2023 1:10:54 AM +00:00
Application of evolutionary simulated annealing method to design a small 200 MWt reactor core
This paper presents the application of an evolutionary simulated annealing (ESA) method to design a small 200 MWt reactor core. The core design is based on a reference ACPR50 reactor deployed in a floating nuclear power plant. The core consists of 37 typical 17x17 PWR fuel assemblies with three different U-235 enrichments of 4.45, 3.40 and 2.35 wt%.
4/4/2023 1:10:42 AM +00:00
Kết quả nghiên cứu công nghệ nhiên liệu hạt nhân tại Viện công nghệ xạ hiếm
Viện Công nghệ xạ hiếm đã thực hiện có hệ thống các nghiên cứu công nghệ chế tạo và đánh giá trạng thái viên gốm urani dioxit (UO2 ) mô phỏng là viên gốm nhiên liệu hạt nhân cho lò phản ứng. Các nghiên cứu được tiến hành từ giai đoạn điều chế bột gốm UO2 đến chế tạo viên gốm UO2 và đánh giá trạng thái của chúng vận hành trong lò phản ứng. Mời các bạn tham khảo!
4/4/2023 1:10:36 AM +00:00
A sensitivity study of physical models using in RELAP5 code based on FEBA experimental data
This study conducted a sensitivity analysis of physical models in RELAP5 code based on experimental data measured on the FEBA test facility. Sixteen physical models have been selected for sensitivity analysis to find the most important models that influence the calculation results. Based on two criteria, the maximum cladding temperature and the quench time, the sensitivity analysis results show that four physical models significantly impact the calculation result. Four chosen physical models are considered further in the next step of their uncertainty evaluation.
4/4/2023 1:10:26 AM +00:00
Developing a database for Cs-137 radioactivity concentration and assessing residual levels in surface soils of Quang Ninh, Hai Phong, and Lang Son provinces
The radioactivity concentration of Cs-137 was determined in 826 soil samples collected from Hai Phong, Quang Ninh, and Lang Son. The residual levels of Cs-137 have also been assessed and compared with previous publications to obtain a trend in Cs-137 in the surface soil.
4/4/2023 1:07:01 AM +00:00
Application of particle image velocimetry (PIV) to measure the displacement of sandy soil in laboratory
This paper aims to verify the applicability of this method in determining the displacement of sandy soil under different saturation conditions and soil grain sizes. The results showed that this method could effectively determine soil displacement with an accuracy of 0.13 mm. Furthermore, the degree of saturation of soil did not influence the PIV results whereas the homogeneity of soil, as indicated by grain size distribution, reduced the precision of the PIV method.
4/4/2023 1:06:39 AM +00:00
Phát triển phần mềm tính nồng độ trong hệ đệm hỗ trợ chuẩn bị dung dịch điện ly nền trong phân tích bằng phương pháp điện di mao quản
Nghiên cứu này phát triển một phần mềm cho phép xác định nồng độ của một hợp phần khi biết nồng độ của một hợp phần còn lại và pH của dung dịch, trong đó có tính tới ảnh hưởng của lực ion. Phần mềm được xây dựng bằng ngôn ngữ C# với giao diện Windows Form trên công cụ Microsoft Visual Studio. Với nồng độ tính từ phần mềm đã phát triển, sự sai khác (|ΔpH|) giữa giá trị pH của các BGE thu được trong thực tế so với giá trị pH mong muốn đều nhỏ hơn 0,07, tương ứng với sai số dưới 2%.
4/3/2023 9:00:04 PM +00:00
Khảo sát tính chất hoá lý và điện hoá của các hệ điện giải nồng độ cao với muối LiBF4 ứng dụng cho pin sạc Li-ion điện thế cao 5V
Nghiên cứu này khảo sát tính chất hoá lý và điện hoá của các dung dịch điện giải có nồng độ cao sử dụng muối lithium tetrafluoroborate (LiBF4 ) hoà tan trong các dung môi như tetramethylene sulfone (TMS) hoặc trimethyl phosphate (TMP) theo các tỷ lệ mol khác nhau. Kết quả cho thấy hệ điện giải LiBF4 /TMS tỷ lệ 1:3 (nồng độ ~3,4 M) có độ bền oxy cao nhất (6,2 V vs. Li+ /Li) và độ dẫn ion cao 1,0 mS/cm, phù hợp để sử dụng làm hệ điện giải cho pin sạc Li-ion có vùng thế hoạt động từ 3,5 đến 4,9 V.Nghiên cứu này khảo sát tính chất hoá lý và điện hoá của các dung dịch điện giải có nồng độ cao sử dụng muối lithium tetrafluoroborate (LiBF4 ) hoà tan trong các dung môi như tetramethylene sulfone (TMS) hoặc trimethyl phosphate (TMP) theo các tỷ lệ mol khác nhau. Kết quả cho thấy hệ điện giải LiBF4 /TMS tỷ lệ 1:3 (nồng độ ~3,4 M) có độ bền oxy cao nhất (6,2 V vs. Li+ /Li) và độ dẫn ion cao 1,0 mS/cm, phù hợp để sử dụng làm hệ điện giải cho pin sạc Li-ion có vùng thế hoạt động từ 3,5 đến 4,9 V.
4/3/2023 8:57:09 PM +00:00
Healthcare data analysis using water wave optimization-based diagnostic model
This paper presents a new diagnostic model for various diseases. In the proposed diagnostic model, a water wave optimization (WWO) algorithm was implemented for improving the diagnosis accuracy. It was observed that the WWO algorithm suffered from the absence of global best information and premature convergence problems.
4/3/2023 8:39:55 PM +00:00
Dispersion relations in bilayer graphene at finite temperature
This paper calculates the dispersion relations in a bilayer graphene structure at finite temperatures using the random-phase approximation. The numerical results show that as temperature increases from zero, the plasmon frequency decreases slightly near the Dirac points and then increases noticeably.
4/3/2023 8:39:48 PM +00:00
Optical bistability in a degenerate two level eit medium under the influence of an external magnetic field: An analytical approach
The effects of the intensity of the coupling laser field and the parameters of the system on the behavior of optical bistability are also considered. The proposed model is useful for applications in all-optical switches and magneto-optic storage devices.
4/3/2023 8:39:40 PM +00:00
The anomaly detection efficiency of kernel density estimation functions on UAV images
In this study, evaluate anomaly detection efficiency on UAV images through a number of common kernel functions typically cited in researches on KDE, and follow up with making recommendations for appropriate uses of kernel functions. Experiments and evaluations are carried out on the sample data set photographed on varied terrain types and objects of interest.
4/3/2023 8:39:24 PM +00:00
Protograph LDPC code design for LS-MIMO 1-bit ADC systems
Research works have proposed 1-bit ADC as a good candidate for LS-MIMO systems in order to save both transmission power and circuit energy dissipation. However, we observed that previously reported P-LDPC codes might not have good performance for LS-MIMO systems with 1-bit ADC. Hence, we perform a re-design of the P-LDPC codes for the above systems in this paper. The new codes demonstrate a good coding gain from 0.3 dB at rate 1/2 to 0.5 dB at rate 2/3 in different LS-MIMO configurations with 1-bit ADC.
4/3/2023 8:38:50 PM +00:00
Geometry and topology of external and symmetric products of varieties
The result brief overview of recent developments on the calculation of generating series for invariants of external products of suitable coefficients (e.g., constructible or coherent sheaves, or mixed Hodge modules) on complex quasi-projective varieties.
4/3/2023 8:37:44 PM +00:00
An algorithms for planning S-curve motion profile considering arbitrary short path length
The main target in motion control is fast, accurate, small oscillations, no overshoot in both position and velocity. However, the traditional velocity planning methods cannot satisfy the requirements. One of the most popular control methods is using S-curve motion profile. Many papers and researchers have reported on this method.
4/3/2023 8:37:24 PM +00:00
Effect of the chemical vapor deposition condition on the electrochemically catalytic efficiency for hydrogen evolution reaction in MoS2 nanoparticles
The optimum growth time was acquired to be 11 hours. Thereby such obtained electrode exhibited the maximum HER activity with onset over the potential of 220 mV versus reversible hydrogen electrode (RHE), and the Tafel slope of 66 mV per decade (mV/dec). Conclusion: Our results suggest a good technique for the research of high-efficient HER electrocatalyst based on atomicthickness layered materials.
4/3/2023 8:36:53 PM +00:00
Ag-grafted on ZnO nanorod arrays using UV-assisted irradiation for enhanced SERS behavior in CV detection
The results revealed that the SERS performance of ZnO NRs incorporating with AgNPs exhibited higher detection of crystal violet (CV) probe molecules at a low concentration of 10−8 M than that of the pristine ZnO NRs. This effect originates from the localized surface plasmonic resonance of AgNPs that could cause a strong electromagnetic field and synergistic effects of Ag, ZnO, and CV molecules in ZnONRs@Ag/CV SERS system.
4/3/2023 8:36:43 PM +00:00
The phytochemical investigation from n-hexane extract of the lichen Roccella montagnei
The crude extract was obtained from the dried lichen powder's extraction at room temperature. The n-hexane, n-hexane-ethyl acetate, and ethyl acetate extracts were obtained by the liquid-liquid partition method. The organic compounds were isolated from n-hexane extract by silica gel and Sephadex LH-20 column chromatography. Their chemical structures were identified by the NMR and HR-ESI-MS data analysis and the comparison of their NMR data with the published data.
4/3/2023 8:36:35 PM +00:00
The effect of excitation light source and humidity to photocatalytic activity of g-C3N4 nanosheets for NO removal
This study successfully synthesized two dimensions (2D)-structured g-C3N4 nanosheets by a simple thermal-exfoliation method with annealing route at 2 oC/min. Firstly, melamine was placed in a ceramic crucible with cover and then undergone the annealing route at 550 oC for 2 h to develop into the g-C3N4 bulk. Then the assynthesized g-C3N4 bulk was further annealed without the cover at 550 oC for 2 h to form the final product, g-C3N4 nanosheets.
4/3/2023 8:36:22 PM +00:00
Dynamics of a contracting fluid compound filament with a variable density ratio
This paper focuses on the numerical simulation of an incompressible, immiscible, and Newtonian fluid for the contraction process of a fluid compound filament by solving the Navier-Stokes equations. The front-tracking method is used to solve this problem, which uses connected segments (Lagrangian grid) that move on a fixed grid (Eulerian grid) to represent the interface between the liquids.
4/3/2023 8:35:53 PM +00:00
Effects of the hybrid plasmonic Ag/SrTiO3 nanocubes for efficient photo-catalytic of H2 generation and RhB decomposition
The result, the photo-catalytic performance of the obtained Ag/STO hybrid photocatalyst was higher than that of the pristine STO nanocubes due to i) the efficient charge separation and transfer of photogenerated electron-holes pairs; ii) the improvement of the light-harvesting efficacy in the visible light. The high photo-catalytic RhB decomposition of the achieved Ag/STO hybrid photo-catalytic was obtained compared to the pure SrTiO3 nanocubes under UV and visible light exposure.
4/3/2023 8:35:19 PM +00:00
Sxperimental characterization of drag coefficient of an UAV recovery parachute
The purpose of the research is to determine and compare the impact of some factors on aerodynamic drag force during the inflation of a parachute. The canopy’s shape (flat circular type and extended skirt 10% flat type), of the length of suspension lines (be in proportion to nominal diameter from 0.6 to 1.5) are considered. Measurement of the drag force of the parachute models is carried out in an open return wind tunnel.
4/3/2023 8:33:43 PM +00:00
Simulation: Early detection of brain vessels stroke by applying electromagnetic waves non invasively
The main reason behind the fatal consequences of stroke is the delay of detection. Therefore, this research paper aims to early detection of the type of stroke without delay until the appropriate diagnosis of each type is made, and then the appropriate treatment without delay.
4/3/2023 8:32:20 PM +00:00
A generalized space vector modulation for cascaded H-bridge inverters under faulty conditions
In this research, a new space vector modulation control algorithm is proposed to increase the reliability and the accuracy of the cascaded H-bridge multilevel inverters in case of faulty situations where one or several power cells do not function. When one or more switches of a cell are opened or shorted, that cell is considered faulty. By giving a detailed analysis on the impact of the faulty power cells on the voltage space vectors, the inapplicable voltage vectors are removed precisely.
4/3/2023 8:31:43 PM +00:00
An exact linearization method for DC-side controllers of Z- source inverters in grid tied PV system applications
This paper presents a new control strategy for grid-connected Z-source inverter which is a part of the residential photovoltaics (PV) system. The control system consists of a DC control loop, which is designed based on the exact linearization method to guarantee that the DC input voltage of the ZSI quickly tracks the reference value which is given by the maximum power point tracking (MPPT) algorithm.
4/3/2023 8:31:35 PM +00:00
Probabilistic locational marginal price by monte carlo simulation with latin hypercube sampling and scenario reduction techniques
his fast forward selection algorithm is needed to cut down the number of samples while keeping most of the stochastic information embedded in such samples. The LHS-FFS-based P-LMP is investigated using IEEE 6-bus and 24-bus systems. This method is compared with SRS and LHS only. The LHS-FFS approach is found to be efficient and flexible; therefore, it has the potential to be applied in many power system probabilistic problems.
4/3/2023 8:29:52 PM +00:00
Direct numerical simulation study of water droplets freezing on a horizontal plate
The distinct phases are separated by the interfaces represented by connected elements. So, there is a three-junction point among three phases: solid, liquid, and gas. The water droplets are assumed as a spherical cap and placed on the cold plate which is kept at a subfreezing temperature. At the end of solidification, we obtain a small protrusion shape at the top of the frozen water droplet and its height is also higher than that of the initial water droplet.
4/3/2023 3:46:23 PM +00:00
Anti - diabetic effects of glucomanno - oligosaccharides via AMPK activation in C2C12 myotubes
In this paper, antidiabetic activities of glucomanno-oligosaccharides (GMO) were in vitro and in vivo investigated. Treatment with 100 μg/ml and 50 μg/ml of GMO for 1 hour caused 1.47-fold and 1.81-fold phosphorylation of AMPK, respectively. Oral administration of GMO (6 g/kg-1 of body weight day-1 ) lowered blood glucose levels (p < 0.05) at 120 min as compared to control group. These results suggested that GMO exhibited anti-diabetic effects via activation of AMPK and could be useful for diabetes prevention.
4/3/2023 3:44:40 PM +00:00
Virtual screening stategies in drug discovery – A brief overview
In the second part, recent database of compounds provided worldwide and drug-like parameters which are helpful in supporting for the virtual screening process will be discussed. This information will provide a good platform to estimate the advance of applying these techniques in the new drug-lead identification and optimization.
4/3/2023 3:44:07 PM +00:00