bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of three gaps in the teaching system of environmental impact assessment (EIA) and the improvement based on application-oriented talent training
Authors: Tian Dayong , Wang Tao , Su Wenhui , Yang Shuang , Zheng Yong , Zhao Menglei , Cheng Sisi , Niu Yongshen , Liu Xiaotao
Published: November 2020

With the rapid industrialization of China in the past decade, China’s environmental management system, especially the environmental impact assessment (EIA) system, has changed greatly. The relevant regulations and guidelines have been revised significantly. This set higher requirements for the teaching system of environmental impact assessment in universities. Some problems occurred between the continuously updated EIA system and the outdated teaching system. How to develop an appropriate teaching system for application-oriented talent training is becoming a hot issue in the current research on the teaching reform of EIA. The objective of this study is to investigate the problems existing in the teaching system of EIA, analyse the changes of the guidelines, and develop a new method of teaching reform based on case-teaching and the defense-based assessment method. The study provides an insight for the training of application-oriented talents in the field of environmental engineering.
A Study of China’s Regulations and Standards Concerning Safety Risk Control of Dangerous Goods in Ports and Waterborne Transport
Authors: Ma Minglu , Fengyun Chen
Published: November 2020

To find out the weaknesses of China in safety risk control of dangerous goods in ports and waterborne transport and give some suggestions on improvement, this paper explored relevant Chinese regulations and standards and compared some of them with foreign ones. Building on this, it made a comprehensive analysis of the regulations and standards in four aspects – control over major hazard installations, risk management, potential hazard inspection and elimination, and emergency management. After analyzing the requirements and operability of the regulations, this paper pointed out the disconnections and loopholes in the existing regulations and standards; besides, it gave some suggestions on strengthening safety risk control of dangerous goods in ports and waterborne transport and formulating and revising the regulations and standards concerning the four aspects. All these will be significant for defining China’s risk control and improving its management in ports and waterborne transport.
Risk Assessment on Ship’s Oil Spill of Yangtze River Main Line Wharf
Authors: Shangyu Li , Jian Deng
Published: November 2020

With the rapid development of the inland shipping in recent years, the risk of wharf pollution from ship is increasing. Thus, it is necessary to make a scientific assessment on ship pollution risk. This paper proposes a risk assessment according to the ship pollution at regional port by using a typical petrochemical wharf in Wuhan section of Yangtze River main line as an example, carries out a comprehensive evaluation from the aspects of risk identification, risk probability and risk level calculation, and pollution consequence prediction. The results of the wharf risk assessment are important for the development of the ship pollution risk counterplans.
Photocatalytic degradation of oily wastewater by ZrO2(Er3+)/TiO2 composite photocatalyst
Authors: Liu Yunqing , Feng Dan , Wang Xinglei
Published: November 2020

Photocatalyst/polypropylene ball which can float on the water is prepared through coupling agent method, and the photocatalyst is the ZrO2(Er3+)/TiO2 which is fabricated by co-precipitation. The diesel and crude oil degrading experiments are made with the floating photocatalyst and powder photocatalyst. After 8 hours illuminating in visible light, the removal rate of diesel in float experiment can reach 98%, however the rate in ZrO2(Er3+)/TiO2 powder experiment is 68%. The removal rate of crude oil in float experiment is more than 96%, which is much higher than the removal rate of 39% of crude oil in ZrO2(Er3+)/TiO2 powder experiment.
Experimental study on interference source of smoke fire detector in religious building environment
Authors: Zhong Chen , Li Xiaobai , Liu Xiaopeng , Ding Hongjun
Published: November 2020

In this paper, the interference sources of smoke fire detectors in religious buildings and sacrificial places are analyzed, and focuses on the study of smoke interference generated by incense and butter lamps that may affect smoke detectors. Based on the standard combustion laboratory and testing methods stipulated by the International Organization for Standardization (ISO), different types of sandalwood and butter were used to carry out the incense burner and butter lamp simulation tests. Through data analysis of the smoke interference of incense and butter lamps, and the comparison of the response performance from the same detector under 4 standard test fires and interference, the possibility of false alarm of smoke detector caused by typical interference sources in religious buildings is analysed.
Numerical simulation of the effects of Yangtze River runoff on pollutant transport and diffusion in the Yangtze River estuary
Authors: Ren Zhuoyu , Li Kai , Han Songlin , Han Jibin
Published: November 2020

The coastal-estuary area is one of the areas most seriously affected by human activities, and the quality of the water environment has received extensive attention from society and scholars. In order to analyze the characteristics of pollutant transport in the Yangtze River Estuary, a two-dimensional hydrodynamic model of the Yangtze River Estuary waters was established, and the model was verified using measured hydrological data. On this basis, the effects of the dilution and diffusion of pollutants (COD) under different runoff rates are studied and the transport characteristics of the pollutants of the Yangtze River estuary are studied. The results show that after the calculation reaches a relatively stable level, the concentration at the measuring point of the pollutant input from the Yangtze River in the high and low water period is about 6mg/L and 1.2mg/L, which is diluted by 42.9% and 88.6% respectively compared with the pollutant concentration at the discharge outlet. When the sewage is discharged from the sewage outlet, the highest COD concentration does not exceed 3mg/l during the high and low water periods, indicating that the sewage discharged from the planned sewage project will not have a serious impact on water quality.
Sedimentation study on separation tailings and backwater of a water-quenched copper slag
Authors: Shi Guiming , Zeng Li , Wang Jie , He Chunyan , Wang Chengdong , Zhu Lang , Zhou Yichao
Published: November 2020

The sedimentation test of separation tailings and backwater of a water-quenched copper slag were carried out. The experimental contents included: chemical analysis of multi-elements of tailings, particle size analysis of tailings, tailings sedimentation test, natural sedimentation of backwater, sedimentation test of backwater with reagents, etc. The results shown that the tailing granularity was very thin, almost all passed the 0.037 mm sieve. Under different concentration, when the settling time of 180 min, tailings could be settled completely and concentration without influence, thus settling time determined to 180 min. With the same dosage, KAl(SO4)2 had a better sedimentation effect than CaCl2. In this test, KAl(SO4)2 200 g/m3 was recommended in consideration of reagents dosage and backwater sedimentation rate and CaCl2 200 g/m3 was recommended in consideration of drug price and treatment cost.
Study on Environmental Risk Assessment and Control Countermeasures of Tailings pond in a Mountainous Area of North China
Authors: Song Shuang , Chu Jinglong , Zhang Hua
Published: November 2020

The safety and environmental accidents of the tailings pond are likely to cause pollution of surrounding soil and water bodies, and endanger the safety of life and production of surrounding residents. In this study, the analytic hierarchy process (ahp) was used to score environmental sensitivity and control mechanism reliability of tailings ponds. The environmental risk rating model was used to characterize the environmental risk rating of tailings pond. The risk level characterization and evaluation results show that the four tailings ponds were general risks to downstream residents and the environment. Suggestions on environmental risk control of the upstream tailings pond were put forward.
Analysis of groundwater pollution caused by mine leachate leakage considering natural impermeable layer
Authors: Chu Jinglong , Song Shuang , Tan Haiwei , Liu Nannan , Liu Fang
Published: November 2020

Aiming at the problem of groundwater pollution caused by mine leachate leakage, a numerical model of saturated-unsaturated groundwater is established by using FEFLOW software, and the spatial and temporal distribution of pollutants in vadose zone and aquifer is predicted, in this paper. The results show that the impervious layer of natural clay can slow down the entry of pollutants into the aquifer and reduce the impact of pollutants diffusion on the aquifer. This paper can provide some references for mine groundwater pollution prevention and control.
Study on the Distribution of Sand Body and Fluid in Shallow Stratum of a Development Area
Authors: Qingshan Li
Published: November 2020

This paper explores the distribution of sand body, fluid and formation pressure in the shallow stratum of a development area through MDT formation tests and logging data, which provides a basis for finding new petroleum geological reserves and preventing casing damages of oil-water wells.
Deformation behavior and damage analysis of underground high-voltage cable duct bank encased by concrete
Authors: Guo Jingen , Wang Yanfeng , Cai Liangyi , Liu Tingjin , Yang Yubing
Published: November 2020

Due to the shallow burial depth, the concrete duct bank for underground cables frequently encountered differential settlement, tilt and other damage like cracking when construction activity was carried out in the vicinity. This paper briefly presents an experimental study of concrete duct bank with a 1/4 part of real structure under a monotonic static loading, which was put into a soil box in the laboratory. And then numerical simulations were performed for the 1/4 part of real structure and a real-scale concrete duct bank respectively, to investigate the deformation and damage pattern of concrete structure and the wrapped inside conduits. Both the test and numerical results indicated that the failure of concrete duct bank presented a distinct brittle pattern. The mechanical properties of underlying soil play a more dominant role in the bearing capacity, mid-span vertical displacement and mid-span deflection of concrete duct bank. It is proposed that the vertical displacement of concrete duct bank can be set as the monitoring item to reveal its safety state, and the minimum curvature radius of longitudinal deformation profile obtained from vertical settlement at different locations can be computed and be taken as the control index.
Construction of Spatial local C-vine model and application of air temperature interpolation
Authors: Dai Lin , Liu Jianxiu
Published: November 2020

Based on the daily average temperature of 73 meteorological stations and the geographical location information of each station from 1980 to 2010 in Yunnan Province, spatial interpolation method of temperature data suitable for Yunnan province was explored. Based on the definition of spatial local C-Vine, the full model, horizontal distance model and vertical distance model were constructed. Using maximum likelihood, Akaike information criterion (AIC)and Bayesian information criterion (BIC) select the three models to obtain full model as the optimal model. 6 stations in the region were randomly selected and temperature interpolation was made using full model, Ordinary Kriging and Inverse Distance Weighting method. The results showed that full model based on Spatial local C-vine had better prediction accuracy.
Test research on flow patterns at intake area of a pumping station
Authors: Zhou Minzhe , Ding Yuan , Li Tongchun , Qi Huijun , Gao Lingang
Published: November 2020

This paper focuses on the problem of the flow pattern in the inlet area of a drainage pumping station for its safety. Limited to the restrictions on terrain conditions and surrounding constructions, this pumping station was designed with a compact layout which could not followed by regular standards. The small size may affect the hydraulic conditions at the intake of this pumping station, which in turn will affect the safe operation of the project. Therefore, in order to ensure whether the pumping station works stably, it is necessary to conduct an intensive study on the flow pattern at the intake area of this pumping station via a model test. Research shows that the original design may bring hydraulic problems. In the test, we found intermittent suction vortexes in the inlet area. This hydraulic phenomenon should be avoided in the inlet area of pump stations. In this case, it is proposed to reduce the elevation of the water intake system to increase the depth of submergence. According to the test results, harmful vortexes disappeared and the water flow became smoother in all operating conditions after adopting improvement measures. This shows that the proposal is effective and makes the project safer.
Application of Structural Mechanics Solver in Internal Force Calculation of Frame Structure
Authors: Liu Xiaoling , Du Peng , Wu Shengchao , Zheng Jie
Published: November 2020

The internal force calculation of frame structure is a difficult problem in civil engineering graduation design. This article introduces the basic principles of bending moment distribution method and structural mechanics solver method. Taking a two-story, two-span frame structure as an example, a comparative study is carried out and the results show that there is Certain error, and analyze the cause of the error. The research has certain guiding significance for the teaching of structural mechanics and civil engineering graduation design.
The research on the influence of boiler operating parameters on thermal efficiency
Authors: Cai Qin , Wu Xiaoyang , Huang Yong , Wang Xi
Published: November 2020

The influence of operating parameters on thermal efficiency was analyzed by thermal balance experiment of the boiler. The mathematical model of thermal efficiency was obtained by thermal balance equation. The results showed that the thermal efficiency decreased with the increase of exhaust gas temperature. The excess air coefficient had an important effect on thermal efficiency of the boiler. The thermal efficiency decreased with the increase of excess air coefficient. The increase of inlet air temperature leaded to the increase of thermal efficiency when other operating parameters remained unchanged. The thermal efficiency increased with the increase of fuel calorific value. As a result, in order to improve thermal efficiency, the optimum excess air coefficient should be adjusted as much as possible to ensure combustion condition of the boiler. For running boiler, the economizer should be installed on heated surface at the end of boiler.
Research on thermal aging life of cable based on second-order dynamics modification equation
Authors: Lin Jindong , Yang Yue , Liao Xiaoyong
Published: November 2020

With the increasing application of cable in various fields, more and more attention has been paid to the aging of cable. In order to ensure the operation safety of instruments and all kinds of equipment, it is urgent to find a fast and accurate method to evaluate the residual life of cable. In this paper, a second-order kinetic model is adopted and the Arrhenius thermal aging equation is improved. In view of the working environment with relatively high temperature, the thermal aging life prediction model for cable is obtained to calculate the residual life rapidly. It provides theoretical support for timely detection of risks and elimination of potential accidents.
Research on vibration elimination of a 350 MW heat supply unit during cold start
Authors: Ma Lyuzhou
Published: November 2020

A 350MW heat supply unit in a power plant encountered abnormal vibration of IP rotor bearing during cold start after overhaul. By analyzing the vibration data in the start-up process, the reason for abnormal vibration was found out to be excessive vibration of IP rotor passing through critical speed and rubbing between IP rotor and casing. Through the field high dynamic balancing test and adopting the most suitable operation control mode of this type of heat supply unit, the abnormal vibration of the unit was eliminated.
A Microgrid Operation Control Strategy Based on Wide Area Information
Authors: Wang Mingjin
Published: November 2020

Distributed Generator (DG) has many environmental benefits and potential values, but it is not controllable power for the large power grid, and brings many bad influences to the power grid, so that the power grid takes the way of isolation and restrictions that greatly limits the development of DG. In order to effectively solve the contradictions between DG and the power grid, the microgrid concept is putted forward. Microgrid is a small power system containing micro powers and local loads, which can operate with connecting to the power grid, or run in isolated island way with breaking away from the power grid. On the basis of analyzing the principle of DG, two control methods are established: PQ Control and V/f Control. And then, a microgrid operation control strategy based on wide area information is proposed. Using wide area information to get the following data: the switching power and the breaker state of the Point of Common Coupling (PCC); the output of DG; the local loads and so on. In the operation of isolated island, the control strategy controls and adjusts the DGs and loads quickly, makes the power balance, ensures that the voltage and frequency in the microgrid conforms to the standard, and ensures the important loads working steadily and reliably. Finally, the feasibility and effectiveness of the proposed control strategy are verified by matlab/simulink simulation.
A Weight Calculation Method for Reducing Mutual Interference of Transformer State Evaluation Indicators
Authors: Yigang He , Wei Wu , Jin Tong
Published: November 2020

Aiming at the problem that the traditional indicator weight calculation method ignores the mutual influence between indicators and causes the deviation of the calculation results, this paper proposes a transformer state evaluation calculation methods combining of FAHP(Fuzzy Analytical Hierarchy Process) — DEMATEL (Decision-making Trial and Evaluation Laboratory) method and CRITIC (Criteria Importance Though Intercriteria Correlation) method; after selecting the index parameters and dividing the state level, the state evaluation index system is established; based on the combination weighting method to calculate the two methods The optimal weight is combined with the transformer status score to obtain the status evaluation of the transformer. After the case analysis, it can be seen that the method is practical compared with the actual situation obtained from the maintenance; based on the traditional FAHP method and the experimental method in this paper, the Gaussian white noise is added to experimental data increase the interference between enhancement indicators. After simulation analysis, it is found the final state score of the transformer obtained by this method is smoother and more stable. Compared with traditional methods, this paper reduces the errors caused by the mutual influence of indicators and makes the evaluation results more accurate.
Research on wide-range micro force generator based on interdigital capacitor array modules
Authors: Xu Li , Li Qian , Wang Shuxiang , Zheng Peiliang , Huang Zhenyu , Luo Xudong
Published: November 2020

The micro Newton level standard force generator was important in the micro/nano force measurement and traceability device. How to obtain a stable and wide-range standard micro force at a lower voltage (≤220V) was a important technical problems for improving the measurement accuracy and range. The interdigital capacitor array modules were used to generator the standard micro force at a lower voltage. The research results showed that the device could achieve stable, high-accuracy, wide-range micro force output under a relatively low constant voltage. The device output range would be expanded and the output resolution would be improved without increasing the complexity of the device. The symmetrical arrangement of the micro force generator array modules and the interdigital capacitor structure greatly reduced the influence of the unbalanced load of the device and the deformation of the elastic support structure on the output micro force value. These structures were ensuring the accuracy of the micro force generator. It provided a useful basis for the design and manufacture of low-voltage and wide-range force generator in micro force measurement and value traceability devices.
Influence of growth rate on minority carrier lifetime of multicrystalline silicon ingot
Authors: Yang Xiufan , Zhang Dianxi , Guo Zhongzheng , Yan Wanjun , Zhang Houyong
Published: November 2020

Multicrystalline silicon was grown by directional solidification method, and different growth rates was obtained by optimizing the growth process. The influence of the growth rate on the minority carrier lifetime of the multicrystalline silicon ingot was studied. The results show that the infrared image of the middle and lower part of the silicon block with an average growth rate of 1.0cm/h has a lighter shade. The area with minority carrier lifetime of the silicon block is less than 4 us accounts for about 50%, and the average minority carrier lifetime is 5.28 us. Reduce the growth rate to 0.94cm/h, the infrared image of the crystal is pure and the crystal grains are coarse, the average minority carrier lifetime of the silicon block is increase to 5.65 us. When the growth rate is further reduced to 0.87cm/h, the crystal growth deviates from the vertical direction. The area of silicon block less than 4 us accounts for about 40%, and the average minority carrier lifetime is reduced to 5.39 us. The phase field method is used to calculate the growth of multicrystalline silicon. The results show that the greater the flow rate, the faster the growth of crystal nucleus and the easier the formation of competitive growth, which is in good agreement with the experiment.
Research on Optimization of cold chain logistics distribution path of fresh products based on Hybrid Genetic Algorithm
Authors: Fu Mian , Wang Dandan
Published: November 2020

In view of the actual situation of cold chain logistics distribution path of fresh products, taking the minimum total cost of fixed cost, variable cost, refrigeration cost, damage cost and penalty cost as the optimization objective, this paper constructs the optimization model of cold chain logistics distribution path of fresh products, and makes an empirical study on the distribution path of an enterprise by using hybrid genetic algorithm, and solves it by coding on MATLAB. It is found that the optimized scheme improves the vehicle loading rate and reduces the distribution cost, which proves the feasibility and effectiveness of the model and algorithm.
Fluid simulation model and analysis of partial discharge characteristics of tip defects
Authors: Zhen-hua Xing , Zhi-guo Zhao , Xing Xu , Zhao-fei Li , Jun Ye , Yu-yan Guo
Published: November 2020

The tip discharge is modeled and the micro discharge characteristics are studied. The hydrodynamic model of tip discharge in transformer oil is established. The development process of streamer discharge under pulse voltage is analyzed. The distribution of space charge density and space electric field under different pulse voltage amplitude and rising edge is obtained. The numerical results show that: with the increase of applied voltage amplitude, the average velocity of streamer development changes more significantly with the same discharge spacing; the steeper the rising edge pulse is, the faster the average discharge development speed is and the larger the discharge radius is. At the same time, according to the change law of streamer morphology development under AC voltage, the discharge frequency is less, the amplitude is higher, and the phase distribution is narrow when the applied voltage is positive half cycle. When the applied voltage is negative half cycle, the discharge times are more and the phase distribution is wide, and the tip discharge has obvious polarity effect.
Sex-specific impacts on the accumulation of polycyclic aromatic hydrocarbons and the development of offspring of sea urchins exposed to heavy fuel oil
Authors: Wang Xuanbo , Li Xishan , Ren Hang , Chen Huishu , Ju Zhonglei , Xiong Deqi
Published: November 2020

The sensitivity of female and male individuals of the same species to environmental stress is often different. The present study investigated sea urchins (Strongylocentrotus intermedius) of both sexes that were exposed to water-accommodated fractions of heavy fuel oil (HFO-WAF) for 7 d. Polycyclic aromatic hydrocarbons (PAHs) bioaccumulation in sea urchin gonad tissue was significantly increased following the exposure to HFO-WAF. However, PAHs bioaccumulation significantly differed between females and males, which may be related to the lipid content of gonad tissue. We found a significant increase in the percentage of anomalies in their larvae 24 h post fertilization. This indicates that parental exposure to HFO-WAF can have an adverse effect on the offspring, which may consequently affect population recovery and maintenance.
Preparation and Evaluation of PPGs for High-Temperature Conformance Control
Authors: Wu Hao , Song Longfei , Ge Jijiang
Published: November 2020

In this paper, the synthesis and thermal behavior of nanocomposite performed particle gels (PPGs) was investigated. The nanocomposite PPGs were synthesized via free radical polymerization at room temperature, using acrylamide (AM), N-vinylpyrrolidone (NVP) as monomers and N, N-methylenebis (acrylamide) (MBA) as crosslinker. Thermal stability evolutions were conducted by aging PPGs at 130°C and salinity of 2.2×105 mg/L for 90 days. Swelling ratio (Sw) and modulus were measured as a function of aging time. A three-stage swollen history was discovered by means of rheological experiments and swelling measurements. Eexperimental results show that increasing the concentration of monomer, crosslinker and clay leaded to higher swelling ratio and lower modulus during the aging term. PPGs prepared with 30 wt % monomers, NVP: AM ratio of 6:4, 0.25 wt % crosslinker and 3.0 wt % clay exhibited optimum properties for conformance control at high temperature reservoir condition.
Research on Indoor Comprehensive Sensor Layout Method Based on Grid Method
Authors: Han Ninghui , Li Fei , Chen Songsong , Zhang Kai , Feng Jian
Published: November 2020

With the development of key technologies for environment change perception, accurate perception of user load status becomes possible. Sensing the user’s load status can reduce the transformation of the medium-voltage power grid, save the investment cost of the equipment for supporting the construction of the power grid, and improve the investment efficiency of the power grid. In this paper, based on the consideration of the user’s indoor scene, space area, flexible device distribution and building structure, etc., with the goal of maximizing the credibility of the indoor perception network, an optimal networked indoor sensor layout model is established. The weight of each sensing grid is calculated based on the sawing mapping, and the layout method with the highest trust is selected as the optimal indoor comprehensive sensor layout scheme. Finally, based on the case of an actual house, the effectiveness and correctness of the proposed model and method in indoor sensor layout are verified.
The influence of pressure and thinner on the bonding properties of adhesives to metal and composite materials
Authors: Li Qinghua , Tian Ranran , Zhang Yan , Zeng Yu , Zhao Ming
Published: November 2020

In order to judge the influence of pressure and thinner on the bonding shear strength of composite material and metal, the experiment uses different proportions of thinner epoxy resin to impregnate 3K 240G carbon fiber cloth; Kevlar fiber is subjected to different curing pressures the 45 steel specimens bonded with cloth composite materials were cured at high temperature. Through the international standard ISO1747-1976 determination of the adhesive shear strength of vulcanized rubber and rigid metal plate-four-plate shear method, the shear strength of specimens under different proportions of thinner and different curing pressures is measured. The results show that the fiber cloth composite material with the same immersion time will not increase the shear strength of the specimen when a certain pressure is applied during the bonding and curing process with the metal. At the same time, the thinner in the adhesive of the immersion fiber cloth is 10% When, better shear strength can be obtained.
Single-photon Counting System Based on a 4H-SiC Avalanche Photodiode
Authors: Liu Fei , Zhang Leng , Li Fangzheng
Published: November 2020

Weak ultraviolet (UV) signal detection systems have broad application prospects in fields such as space science, aerospace, and military communications. 4H-SiC avalanche photodiode (APD) devices have a high internal gain and can be used in single-photon-based UV radiation counting systems when in Geiger-mode operation. The system comprises an APD drive circuit, a passive quenching circuit, a signal conditioning circuit, a counting and control circuit based on a microprogrammed control unit, and a display module, which can perform real-time monitoring of changes in weak UV radiation.
Research on Microstructure and Performance of Welded Joint of High Strength Match
Authors: Wang Yan
Published: November 2020

This paper studied the microstructure, hardness and impact property of the high match welded joint of Q235A steel. The experiment results showed the grain of the same feature region gradually tended to be coarsening under the approximately same welding speed when the welding current increased. Under the same welding current, the weld zone hardness was the highest, the normalized zone hardness was medium and the overheated zone hardness was lowest but the hardness of each zone was still higher than the hardness of the base metal. The sample impact toughness under 120A welding current was the highest. Under the experimental conditions, the best welding current for high matching welded joints was 120A. The comprehensive mechanical properties of low carbon steel welded joint were the best when the welding current was 120A.
Study on Surface Structure of Filter Material of Cabin Air Filter Impacted by Droplets
Authors: Wei Yin , Tianqiang Du , Chao Chen , Yongao He , Shuhong Wei
Published: November 2020

As the filter material of cabin air filter is closely related to the filtration effect, this paper establishes a physical model of the droplet impact on different surface structures of filter material and numerically simulates dynamic characteristics of the droplet impact on different surface structures. The results show that the ability of filter material to capture droplets is directly proportional to the hydrophilic strength of filter material and the surface roughness (⩽ droplet diameter).
Numerical investigation on the sealing performance of pipeline inspection gauge (PIG) Crossing Elbows
Authors: Jiang Jinxu , Kang Yang , Jiao Chunxiao , Shi Haoyu , Wang Kai , Zhang Hong , Liu Xiaoben
Published: November 2020

The pipeline inspection gauge (PIG) is one of the most popular pigging equipment. In recent years, blocking and stagnation accidents during PIG’s operation process seriously affect the safe operation of energy pipelines. In order to investigate the sealing performance of the PIG’s rubber cup, a four cup drain PIG’s movement in elbow was considered as a prototype in this study. Based on a validated finite element model, the contact stress between sealing cups and the pipe wall and pressure relief area of cup are obtained. The results indicate that when the PIG is operated in a small curvature elbow, the sealing performance of the cup is obviously weakened. Increasing the sealing cup interference and the differential pressure of the sealing cup surface can enhance the sealing performance of the PIG cup. When the PIG’s sealing cup is detached from the inner wall of the pipe, reducing the elastic modulus of the pig’s cup material can be a reasonable measure to enhance the sealing performance of PIG cups.
Direct shear test on the interface between concrete and bedrock of dam foundation of a reservoir
Authors: Wang Yong , Li Haifeng , Wang Wenxuan , Zhang Jianwei
Published: November 2020

The weak failure surface of the dam body and the bedrock cementation surface is one of the key points of dam safety research at home and abroad. The direct shear strength of the contact surface between the dam foundation concrete and the bedrock is used as the current research on whether the dam will “slip” along the contact surface. Based on this, many different methods are used at home and abroad to determine the direct shear strength. In this paper, through the excavation of the dam foundation rock and on-site rock structure samples, 5 sets of 25-point in-situ direct shear tests on the interface between concrete and bedrock were carried out on the medium-thick-thick feldspar quartz sandstone of the main rock mass of the dam foundation to determine the dam foundation. Mechanical parameters of rock mass. Based on the results of field experiments, some reference opinions for field direct shear tests and direct shear strength selection in engineering design are put forward, which also provide a basis for subsequent numerical simulation calculations.
Artificial Seawall By Blasting Squeezing Silt And amelioration treatments in Saline-alkali Soil With Toilet Revolution without sewers
Authors: Xu Cheng , Rui-ze Han , Li-ying Zhang , Jerry Tien , Wen-ping Cai , Ganqin Wang , Xiaoling Wu , Liqun Wang
Published: November 2020

Artificial seawall by silt squeezing with blasting dike, a small price for a good seawall than with mechanical dredging, and is effective in preventing this kind of accident from tsunami and typhoon disaster. This paper briefly discusses the pollution situation of poultry and mankind waste in China. For the first time gives the techniques for harmless (China patent ZL 201220109642.1, no flush heathy toilet.) and utilization of waste in China are presented and analysed for benefit utilization. Sanitary toilet without sewers -2019 world break-through technologies (no flush heathy toilet) driven reinvent the toilet challenge, RTTC. Authors also show the technique for harass and utilization of wastes in China. The authors suggest that all the mankind and animal waste, after harmless processing, should be used in a way of useful things as feed, fertilizer, etc. to benefit human society, prevent disease (covid-19, sars) propagation and reduce greenhouse gases. It is also can be used on ship, aircraft, coach and out space etc. (China patent ZL 201220109642.1 is one of several ways of human and livestock faeces harmless treatment, ultraviolet disinfection, ozone fumigation), its weight less than 15kg, volume less than 0.12m3.
Three-dimensional Simulation and Analysis of Spray Structure inVertical MOCVD Reaction Chamber
Authors: Changjiang Liu , Zhiming Li , Runqiu Guo , Lansheng Feng , Tao YangShun
Published: November 2020

In the vertical spray MOCVD reactor, a spray structure composed of fan bodies was proposed. CFD was used to simulate the gas deposition process in GaN-MOCVD reactor. The characteristics of changing the concentration of reaction gas above the substrate surface with the height of the fan, the distance between the spray nozzle and the substrate surface, and the substrate rotation speed were given. Compared with the traditional spray structure, the cylindrical spray structure composed of fan body can effectively reduce the premixing problem of reaction gas sprayed from the spray nozzle before entering the reaction chamber and reaching the substrate surface. At the same time, the simulation structure shows that when other conditions are fixed, with the increase of the fan height, the increase of the distance between the spray nozzle and the substrate surface and the acceleration of the substrate rotation speed, the uniformity of GaN deposition on the substrate surface can be better under the same isolation effect, so that the utilization rate of TMG can be as high as possible under the condition that the uniformity is satisfied.
Study on Relationship between Material Vickers Hardness and Yield Stress of A508 Nuclear Material
Authors: Zhuang Zecheng , Lan Minhua , Yao Yinjing , Xu Shichao , Xu Jie
Published: November 2020

It is difficult to directly obtain the mechanical properties of local materials of actual engineering structure (such as welded joints) by traditional mechanical test. Indentation test and ABAQUS finite element test were used in this paper, the relativity between Vickers hardness and yield stress of nuclear material A508 were studied, and a new method of using material surface Vickers hardness to acquire material properties was established. It can be used in the welded lines of nuclear dissimilar metal welded joints to obtain material parameters of mechanical property uneven zone of welded joints, and this new method was supported for complex engineering structure material mechanical parameters.
First-principles calculation of the interface stability of 3C-SiC(111)/Mg(0001)
Authors: lv Zhao , Yao Junping
Published: November 2020

The first-principles plane wave pseudopotential method based on density functional theory was used to study four SiC(111)/Mg(0001) interface models, and the ideal work of adhesion, charge density distribution, charge density difference and Mulliken population of the four interface models were calculated. The calculation results show that the structure of four interface models has not changed significantly, except for the more or less decrease in the interface spacing after geometry optimization. The Center-site interface of the C-terminated has the largest work of adhesion and the smallest interface spacing, which is the most stable structure among the four models. The calculation of the electronic structure shows that interfacial bonding of these two terminated interfaces of Center-site is a mixture of covalent and ionic bonds.
3D face modeling and rapid casting based on reverse design
Authors: Liu Huihui , Ye Shengping , kong Ming , Zhu Yueting , Jin Ya , Yang Weihong
Published: November 2020

This paper first obtains human body data based on a 3D scanner, combines with Geomagic Studio to obtain a 3D model; and explores three 3D printing technologies for rapid prototyping of the model. The 3D prototype is turned out of the wax mold using the silicone rubber reworking process, and finally the melting is used. Mold casting process to complete portrait casting. Practice has proved that this method realizes the entire workflow of 3D face data acquisition, rapid prototyping, and rapid casting, and has high application value and market prospects in the production of 3D portrait artwork.
Optimization of the Vehicles Production by Using Lightweight Carbon Fibre Composite Materials
Authors: Lin Minfeng , Mei Qiang
Published: November 2020

Through a brief introduction of the current application of lightweight materials in the automotive market, it is proposed that carbon fibre composites are a promising application. Therefore, it is constructive to study the advantages and disadvantages of the application and then put forward suggestions for improvement.
Effect of Magnetized Water on Working Performance of Cement Mortar
Authors: Zhang Zhifeng , Li Borong , Song Nan , Yao Pengcheng
Published: November 2020

Compared with common drinking water, magnetized water seems to have the potential to save water for concrete production. The main purpose of this paper is to combine theoretical analysis and experimental verification of multiple sets of comparative tests to study the effect of magnetized water on the performance of cement mortar. This paper starts with the structure of water and the mechanism of hydrogen bond formation, clarifies the activation mechanism of magnetized water, and combines the properties of magnetic field to activate water to explain the mechanism of magnetized water enhances the performance of cement mortar. Through a cross-contrast test that combines four magnetic field strengths and three mortar strength grades, it is found that when cement mortar is mixed with magnetized water, the compressive strength increases by about 20% compared with ordinary water mixing, and the maximum increase can be as high as 25.3 %. Also, the additional strength obtained through the use of magnetized water meets the need to reduce the amount of cement in mortar, and at least 10% of cement can be saved when the design strength of the reference mix proportion is met.
A concept to evaluate procurement principles implementation of public construction project in Surabaya
Authors: Sandi P V , Rohman M A , Utomo C
Published: November 2020

Public construction procurement is a Government program to meet infrastructure needs. As a government program that uses the public budget as a source of funding, public procurement tends to be vulnerable to various problems and criticisms, especially related to public trust as users. Therefore, the government must prove that the implementation of procurement including the procurement of construction can be relied upon, so it must be carried out professionally and ethically. To guarantee that, construction procurement must adhere to the principles set out in the regulation. Presidential Regulation of the Republic of Indonesia Number 16/2018 regulates Public Procurement of Goods and/or Services and establishes 7 principles of procurement implementation, including: efficient, effective, transparent, open, competitive, fair, and accountable. This paper is an initial stage of research to evaluate the implementation of the principles of construction public procurement. The purpose of this study is to identify the indicators that must be met by the government in the implementation of these principles. These principles will become the research variables, while the indicators are obtained from related literature studies. The data in this study were obtained by distributing questionnaires and interviews with several parties concerned with the public procurement in Surabaya. According to the experts’ opinion, there are found that 48 indicators of the principles which could be used to evaluate the principles of the implementation of public construction project procurement in Surabaya.
A Literature Review of Methods in Research on Green Building Cost Analysis
Authors: Yasinta R B , Utomo C , Rahmawati Y
Published: November 2020

Development greatly influences environmental sustainability and quality. The concept of green building is one solution to minimize environmental damage due to construction. The concept of green building requires greater investment than conventional building. Life Cycle Cost (LCC) impacts the cost of planning, building’s operational and maintenance cost and residual cost. Recently, research of green building on cost analysis is developing rapidly. There are so many studies of green building on cost analysis with different methods. This research addressed several relevant methods and is expected to set clear which methods to use for the future research under green building topics. This journal is meant to find out research method used in determining green building on cost analysis. The method to be carried out is a literature review of 14 relevant reputable journals from 2013-2020. The most widely used method is the Life Cycle Cost Analysis (LCCA).
Weighting variables for building performance evaluation
Authors: Simbolon L N S , Wiguna I P A , Adi T J W
Published: November 2020

Building performance appraisal needs to be done as a form of evaluation, so that the level of usability of a building can be seen at the operation and maintenance stages. The purpose of this study is to give weight to the variables used in evaluating the performance of a building. In this study, the identification of building performance variables is based on literature studies and semi-structured interviews from the experts of the field. The determined variables are then filtered using the Relative Important Index (RII) method, and weighted using the Pairwise Comparison method. All this process is conducted based on the opinion of experts who are competent in the field of building, and all stages are conducted by questionnaire. The results of the filtering and weighting of variables produce 5 (five) variables and 24 (twenty four) sub-variables used in building performance evaluation, with the results of weighting for safety variable with a weight of 59.2%, health variable with a weight of 24.6%, comfort variable with a weight of 10.2%, ease variable with a weight of 4.3%, and utility variable with a weight of 1.8%.
Inspection and evaluation of bridge structures for earthquakes risk
Authors: Setiati R
Published: November 2020

The 2017 Earthquake Source and Hazard Map Update in 2017 showed a significant change to the previous earthquake map. An increase in the number of active faults and high magnitude earthquake events indicates an increased potential for earthquake risk. The availability of qualified seismic manual is a must to support the direction of government policy in the provision of infrastructure, especially roads and bridges in a sustainable manner. This study aims to determine the value of the vulnerability of existing bridges against earthquakes and alternative reinforcement that can be done. The reinforcement philosophy is based on performance, similar to the philosophy used in the design of new bridges. Performance criteria are examined using earthquakes with a probability of exceeding 7% in 75 years. Performance criteria are determined based on the level of importance and remaining life of the bridge service. An example of a case study was made by examining and evaluating a prestressed girder bridge located in the earthquake zone 4 of the Jakarta area. Analysis and evaluation of bridge capacity is made using the SAP 2000 program. The 3 (three) dimension model is used to calculate the effect of 3 (three) structural dimensions on the dynamic behavior of the bridge. Earthquake input is made in the form of spectra response according to SNI 2833-2016. For earthquake loading in the X and Y direction the g/R scale factor is used (9.81/5), which is 1.96. The basic shear capacity of the column is calculated according to SNI 2833-2016 which consists of the shear capacity of the contribution of the concrete section and reinforcement. Based on the analysis, it was obtained that the column sliding capacity was 1333.3 kN. The value of the capacity is greater than the ultimate shear load of 519.07 kN so it can be concluded that the sliding capacity of the column still meets the earthquake load so that no structural reinforcement is needed.
Vs and CPT based evaluation of location with high liquefaction damage during 2018 Palu earthquake
Authors: Rahmawati H A , Prakoso W A , Rahayu A
Published: November 2020

Palu earthquake occurred on 28 September 2018 caused severe liquefaction damages for the city. Based on field surface damage survey by Indonesia Geology Agency, a location was classified within the high liquefaction damage area. The pre-event soil characteristics of this location was provided by resutls of MASW (Multichannel Analysis of Surface Wave) and CPT (Cone Penetration Test) surveys. The soil deposit could characteristized by relatively low shear wave velocity (Vs) and low of cone resistance (qc) values. The potential liquefaction presented by safety factor (0.6 to 0.9) obtained based on both methods was consistent to depths from 2.0 m to 5.0 m. This safety factor appears to be consistent with the high liquefaction damage reported by the Agency.