The Possible Mechanism on the Formation and Intensification of the Maximum Wind Core in Tropical Cyclone

Zhong Zhong,Xiao-ting Wang,Jin-shan Zhang 한국기상학회 2007 Asia-Pacific Journal of Atmospheric Sciences Vol.43 No.2

Heavy concrete shielding properties for carbon therapy

Jin-Long Wang,Jiade J Lu,Da-Jun Ding,Wen-Hua Jiang,Ya-Dong Li,Rui Qiu,Hui Zhang,Xiao-Zhong Wang,Huo-Sheng Ruan,Yan-Bing Teng,Xiao-Guang Wu,Yun Zheng,Zi-Hao Zhao,Kai-Zhong Liao,Huan-Cheng Mai,Xiao-Dong Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

As medical facilities are usually built at urban areas, special concrete aggregates and evaluation methods are needed to optimize the design of concrete walls by balancing density, thickness, material composition, cost, and other factors. Carbon treatment rooms require a high radiation shielding requirement, as the neutron yield from carbon therapy is much higher than the neutron yield of protons. In this case study, the maximum carbon energy is 430 MeV/u and the maximum current is 0.27 nA from a hybrid particle therapy system. Hospital or facility construction should consider this requirement to design a special heavy concrete. In this work, magnetite is adopted as the major aggregate. Density is determined mainly by the major aggregate content of magnetite, and a heavy concrete test block was constructed for structural tests. The compressive strength is 35.7 MPa. The density ranges from 3.65 g/cm³ to 4.14 g/cm³, and the iron mass content ranges from 53.78% to 60.38% from the 12 cored sample measurements. It was found that there is a linear relationship between density and iron content, and mixing impurities should be the major reason leading to the nonuniform element and density distribution. The effect of this nonuniformity on radiation shielding properties for a carbon treatment room is investigated by three groups of Monte Carlo simulations. Higher density dominates to reduce shielding thickness. However, a higher content of high-Z elements will weaken the shielding strength, especially at a lower dose rate threshold and vice versa. The weakened side effect of a high iron content on the shielding property is obvious at 2.5 µSv=h. Therefore, we should not blindly pursue high Z content in engineering. If the thickness is constrained to 2 m, then the density can be reduced to 3.3 g/cm³, which will save cost by reducing the magnetite composition with 50.44% iron content. If a higher density of 3.9 g/cm³ with 57.65% iron content is selected for construction, then the thickness of the wall can be reduced to 174.2 cm, which will save space for equipment installation.

Design of Abnormal Data Analysis and Processing System Based on RFID Supply Chain

Chunfeng Wang,Shuiming Zhong,Jin Wang 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.11

With the deep application of RFID, the deployment of the RFID system is gradually to have the large-scale, networked, distributed development trend. The previous abnormal data analysis and processing way can not meet with the need of data processing. According to the survey of international famous consulting company (Gartner) for the "information overload", results show that more than 90% of the enterprises think the enterprise competitiveness is closely related to its information capacity. In order to obtain the useful information, we must analyze, process the data, and exclude "exception" data. So, it is very important to realize the detection of abnormal data. This paper presents the RFID supply an abnormal data analysis and processing system of RFID supply chain based on distance, rules and middleware technology .This system is divided into three levels: data processing layer, anomaly analysis lay and graphical display layer. Finally, through the performance analysis of the system, the effectiveness of the system has been verified.

Copper Can Still Be Epitaxially Deposited on Palladium Nanocrystals To Generate Core–Shell Nanocubes Despite Their Large Lattice Mismatch

Jin, Mingshang,Zhang, Hui,Wang, Jinguo,Zhong, Xiaolan,Lu, Ning,Li, Zhiyuan,Xie, Zhaoxiong,Kim, Moon J.,Xia, Younan American Chemical Society 2012 ACS NANO Vol.6 No.3

<P>Here we report the synthesis of Pd@Cu core–shell nanocubes <I>via</I> epitaxial growth, where the lattice mismatch is 7.1%. The synthesis involved the use of Pd seeds with different shapes (including cubes, cuboctahedra, and octahedra) for the epitaxial growth of Cu shells. Different from the conventional growth mode, Cu atoms initially nucleated only on a few of the many faces of a Pd seed, onto which more Cu atoms were continuously added to generate Cu blocks. Later, the Cu atoms also started to nucleate and grow on other faces of the Pd seed until the entire surface of the seed was covered by a Cu shell. As a result, the Pd seed was rarely located in the center of each core–shell structure. The final product took a cubic shape enclosed by {100} facets regardless of the type of Pd seeds used because of the selective capping of Cu(100) surface by hexadecylamine. The edge lengths of the Pd@Cu nanocubes could be tuned from 50 to 100 nm by varying the amount of Pd seeds while keeping the amount of CuCl<SUB>2</SUB> precursor.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2012/ancac3.2012.6.issue-3/nn2050278/production/images/medium/nn-2011-050278_0001.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn2050278'>ACS Electronic Supporting Info</A></P>

A 3-D Steady-State Analysis of Thermal Behavior in EHV GIS Busbar

Jin Lei,Jian-ying Zhong,Shi-jin Wu,Zhen Wang,Yu-jing Guo,Xin-yan Qin 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Busbar has been used as electric conductor within extra high voltage (EHV) gas insulated switchgear (GIS), which makes EHV GIS higher security, smaller size and lower cost. However, the main fault of GIS is overheating of busbar connection parts, circuit breaker and isolating switch contact parts, which has been already restricting development of GIS to a large extent. In this study, a coupled magneto-flow-thermal analysis is used to investigate the thermal properties of GIS busbar in steady-state. A three-dimensional (3-D) finite element model (FEM) is built to calculate multiphysics fields including electromagnetic field, flow field and thermal field in steady-state. The influences of current on the magnetic flux density, flow velocity and heat distribution has been investigated. Temperature differences of inner wall and outer wall are investigated for busbar tank and conducting rod. Considering the end effect in the busbar, temperature rise difference is compared between end sections and the middle section. In order to obtain better heat dissipation effect, diameters of conductor and tank are optimized based on temperature rise simulation results. Temperature rise tests have been done to validate the 3-D simulation model, which is observed a good correlation with the simulation results. This study provides technical support for optimized structure of the EHV GIS busbar.

Performances of the Effervescent Atomizer for Water Mist Fire Extinguishing

( Jin Xiang Wu ),( Qiang Liang ),( Lian Sheng Liu ),( Yun Zhong Yan ),( En Yu Wang ),( Qing Miao ) 한국액체미립화학회 2005 한국액체미립화학회 학술강연회 논문집 Vol.2005 No.-

Based on the mechanism of effervescent atomization, a new effervescent atomization system of water mist was designed. In this system, the gas medium is carbon dioxide, which is soluble and can be used in fire suppression. High pressure saturated carbon dioxide-water solution flowed through the throttle orifice, carbon dioxide was bubbled, and the two-phase flow was formed in the mixing chamber of nozzle. At last, the water mist was formed downstream of the exit orifice of nozzle. In order to examine the feasibility of this system, data were collected, processed and analyzed with DUAL PDA. The velocity profile and drop-size distribution (D10, D32, Dv0.9) downstream of the effervescent atomizer were gained. The efficiency of fire suppression of this system were experimentally investigated by putting out the fire of industry alcohol and diesel oil. The experimental results showed that this water mist system is feasible for fire suppression.

Optimization of biodiesel production from trap grease via acid catalysis

Jin-Suk Lee,Zhong-Ming Wang,Ji-Yeon Park,Chuang-Zhi Wu,Zhen-Hong Yuan 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.4

As a kind of waste collected from restaurants, trap grease is a chemically challenging feedstock for biodiesel production for its high free fatty acid (FFA) content. A central composite design was used to evaluate the effect of methanol quantity, acid concentration and reaction time on the synthesis of biodiesel from the trap grease with 50% free fatty acid, while the reaction temperature was selected at 95 oC. Using response surface methodology, a quadratic polynomial equation was obtained for ester content by multiple regression analysis. Verification experiments confirmed the validity of the predicted model. To achieve the highest ester content of crude biodiesel (89.67%), the critical values of the three variables were 35.00 (methanol-to-oil molar ratio), 11.27 wt% (catalyst concentration based on trap grease) and 4.59 h (reaction time). The crude biodiesel could be purified by a second distillation to meet the requirement of biodiesel specification of Korea.

Novel biodiesel production technology from soybean soapstock

Jin-Suk Lee,Ji-Yeon Park,Chuang-Zhi Wu,Zhen-Hong Yuan,Zhong-Ming Wang 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.6

Production of biodiesel from soapstock using an ion-exchange resin catalyst

Jin-Suk Lee,Ji-Yeon Park,Deog-Keun Kim,Zhong-Ming Wang,Joon-Pyo Lee,Soon-Chul Park 한국화학공학회 2008 Korean Journal of Chemical Engineering Vol.25 No.6

The feasibility of biodiesel production from soapstock containing high water content and fatty matters by a solid acid catalyst was investigated. Soapstock was converted to high-acid acid oil (HAAO) by the hydrolysis by KOH and the acidulation by sulfuric acid. The acid value of soapstock-HAAO increased to 199.1 mg KOH/g but a large amount of potassium sulfate was produced. To resolve the formation of potassium sulfate, acid oil was extracted from soapstock and was converted to HAAO by using sodium dodecyl benzene sulfonate (SDBS). The maximum acid value of acid oil-HAAO was 194.2 mg KOH/g when the mass ratio of acid oil, sulfuric acid, and water was 10 : 4 : 10 at 2% of SDBS. In the esterification of HAAO using Amberylst-15, fatty acid methyl ester (FAME) concentration was 91.7 and 81.3% for soapstock and acid oil, respectively. After the distillation, FAME concentration became 98.1% and 96.7% for soapstock and acid oil. The distillation process decreased the total glycerin and the acid value of FAME produced a little.

Production and characterization of biodiesel from trap grease

Jin-Suk Lee,Ji-Yeon Park,Zhong-Ming Wang,Deog-Keun Kim 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.6

The feasibility of the production of biodiesel from trap grease containing 51.5% free fatty acids (FFAs)was investigated. The esterification of FFAs by an acid catalyst followed by the transesterification of triglycerides by an alkali catalyst was examined. The esterification of trap grease by sulfuric acid as a homogeneous catalyst or by Amberlyst-15 as a heterogeneous catalyst was optimized through a response surface methodology. After the two-step esterification of trap grease by sulfuric acid, the acid value decreased from 102.9mg KOH/g to 2.75mg KOH/g. Through the transesterification by potassium hydroxide, fatty acid methyl ester (FAME) content reached 92.4%. Following the esterification of trap grease by Amberlyst-15, the acid value decreased to 3.23 mg KOH/g. With the transesterification by potassium hydroxide, FAME content increased to 94.1%. After the distillation of the produced biodiesel, FAME content increased again, to 97.6%. The oxidation stability of the trap grease biodiesel was 0.17 h, and its cold filter plugging point was 4 oC. As the FAME content of the trap grease biodiesel satisfies the Korean Biodiesel Standard, the trap grease biodiesel seems to be applicable for use as an engine fuel after properties improvement.