bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Microwave Absorbing Material on the Straight-Through Performance of Millimetre Wave Coaxial Attenuator
Authors: Zhang Yanchu , Kong Zhigang
Published: September 2020

This paper takes the attenuation unit of the millimetre wave coaxial attenuator working in the through state as the research object. The 3D model of the attenuation unit was created. The insertion loss and the VSWR of the attenuation unit were simulated with the help of the HFSS software. The consequences of signal integrity issues were analysed with transmission line theory. The insert loss and VSWR of attenuation unit were simulated by adding a ferrite microwave absorbing material to the model and the thickness of the absorbing material is taken as a variable at different thickness. The relationship between the insertion loss and the VSWR and the thickness of the absorbing material are fitted by numerical fitting and the thicknesses of the absorbing material which optimizes the insertion loss and the VSWR are obtained respectively.
Vibration Characteristics of PMSM Grinding Motorized Spindle
Authors: Li Xiaoquan , He Jiangjiang , Zhao Yuwei
Published: September 2020

This paper presents electromechanical vibration characteristics in parallel misalignment of a shaft by analyzing the vibration of PMSM grinding motorized spindle. The unbalanced magnetic pull (UMP) of the PMSM grinding motorized spindle is established as electromechanical model based on the Maxwell stress tensor, which is used to the spindle to cause the electromechanical vibration and calculated under different eccentricities through FEA (Finite Element Analysis). It increases with increasing eccentricity under no load and on load and is maximum value when mixing eccentricity. Applying a Jeffcott rotor model to analyse the dynamic characteristics of the spindle with UMP excitation and mass imbalance. The number of pole-pair is 6 and the number of slots is 36 for the PMSM grinding motorized spindle, the vibrations of 1fr, 2fr and 3fr are generated and the limit cycle is more complicated at 4500rpm. Simulated results agree well with the experimental results, and it indicates the electromechanical vibration with the shaft eccentricity and the UMP is obviously on the shaft.
Research on Key Technologies of Small House Type Ultra-Low Energy Consumption Residential Buildings
Authors: Lu Guozhong
Published: September 2020

For ultra-low energy consumption buildings, passive mode is emphasized to realize ultra-low energy consumption and provide comfortable indoor environment. It mainly relies on the high-performance building enclosure, new air heat recovery, air tightness, adjustable sunshade and other building technologies, but the difficulty of realizing passive ultra-low energy consumption mainly lies in the technical suitability. How to meet the energy demand of heating and cooling under the condition of non mechanical, non energy consumption or less energy consumption through the reasonable design of key technologies. Based on the climate characteristics of Beijing, this paper studies the key technologies of ultra-low energy consumption buildings, and tries to make a positive exploration on the technology promotion of ultra-low energy consumption buildings.
General Stress Field for Cracked Orthotropic Plate
Authors: Jia Purong , Suo Yongyong , Jia Cheng
Published: September 2020

The solution of singular stresses is discussed for the crack problem of the orthotropic plate. Essential equations are introduced on the basis of linear elastic mechanics and complex variable method. The complex variable functions including the material parameters are fully analyzed for solving the partial derivation equation and to meet the needs of the crack boundary conditions. By constructing new stress functions, the mechanic analysis of the cracked orthotropic plate is carried out, and also the stress boundary problem is resolved. The expressions of the singular stress fields at the crack-tip are determined.
Experiment of Engine Lubricating Oil Bubble Fraction in the Driving Cycles
Authors: Lin Jian , Liu Yongqing
Published: September 2020

Cavitation phenomenon always occurs in gerotor pumps. Bubble fraction of oil has remarkable influence in bearing lubricating characteristic. Oil mass flow rate and density is measured in a gerotor oil pump performance test, bubble fraction is analyzed based on measured oil density. Experimental results show that bubble volume fraction linearly decrease with the increasing of outlet pressure at constant pump speed. With the increasing of pump speed, influence of outlet pressure on bubble mass fraction decreases gradually. In the driving cycles, bubble mass fraction also increases with the increase of pump outlet pressure, and has a closely positive correlation with oil flow and pump speed. When the temperature of lubricating oil rises from 25°C to 100°C, the average volume fraction decreases about 72.6%, and the average mass fraction decreases about 84.3%. The changing rate of oil bubble fraction apparently lags behind the pump speed, it means that oil bubble fraction in acceleration stage is much higher than deceleration stage.
Comparative Analysis of Economic Effects of Soft Microgel Flooding and Polymer Flooding
Authors: Ye Yinzhu , Wu Xingcai , Liu Yang , Bo Xiaosong , Xu Hanbing , Peng Huanhuan , Li Shichao
Published: September 2020

Soft microgel is discontinuous phase. Profile control and flooding technique of soft microgel, deferent from polymer flooding, is a technical method of secondary development of old oil fields. In this paper, we further enrich the flooding mechanism of soft microgel and propose the mechanism of targeting of oil displacement on the basis of synchronous flooding. Profile control and flooding technique of soft microgel has been applied in many oil fields at home and abroad and achieved significant effect of reducing water production and increasing oil. For evaluating the technical and economic effects, firstly, we summarize and analyse the field test results of SMG flooding technology in five oilfield blocks including Huabei oilfield, Changqing oilfield and son on. What’s more, the field data of polymer flooding is investigated by consulting scientific papers. At last we compare and analyse the economic effects of soft microgel and polymer flooding by using EOR value and barrel oil cost as evaluation indexes, According to the incomplete statistical data, the economic effect of soft microgel deep flooding technology is better than that of polymer flooding technology.
Degradation Mechanism of Polyimide Film Irradiated by Gamma Rays
Authors: Shen Zicai , Xia Yan , Zhao Chunqing , Ding Yigang , Fan Peng , Li Jian
Published: September 2020

The Co-60 radiation ground simulation test was conducted on the Mechanical property of polyimide film, thermo gravimetric and XPS was used to analyze the evolution mechanism of polyimide film in different dosages. It was found that the mechanical properties such as tensile force, tensile strength and rupture elongation of polyimide film in gamma ray radiation increase firstly and then exponent decrease. The corresponding initial decomposition temperature of the gamma ray-radiated polyimide film changed from 570°C to 590°C for weight-loss ratio of 2%. From XPS analysis, it can be found that there were rupture and crosslink of chemical bond in polyimide film. In early stage of gamma ray radiation, the rupture of C-N bond and following crosslink is for the increase of mechanical properties of polyimide film, and as the increase of radiation, the rupture of C=O and –N(CO) bond, formation of C-N bond, release of N was for the decrease of mechanical properties of polyimide films.
Effect of Various Carbon Nanotubes Contents on Surface Resistance and Thermal Degradation of Polypropylene/ Polyamide 6/Glass Fiber Composite
Authors: Liu Xin , Liu Fangyi , Ai Wei , Yang Hongjun , Pan Shiling , Li Jun , Liu Hongtao
Published: September 2020

The composite samples containing commercially available carbon nanotubes (CNTs), polypropylene (PP), polyamide 6/glass fiber composite (PA6/GF, 50%/50%) were prepared. They were (x%CNTs)/PP/(PA6/GF) (x/80/20, x% is the percentage of CNTs in the obtained composites, where x=0, 1, 2, 3, 4, 5, 6, respectively.). PA6/GF (50%/50%) and PP samples were also made as control. Surface resistance and thermal degradation for all the samples were measured. According to the resulting data, it is found that, with the increasing of carbon nanotubes contents, the surface resistance for the composite samples decreased, while the initial decomposition temperature increased. The result may be helpful to choose proper carbon nanotubes contents for antistatic and anti-degradation polymeric materials.
Novel Insulator Isolated Si NW Sensors Fabricated using Bulk Substrate with Low-cost and High-quality
Authors: Zhang Qingzhu , Liu Ruonan , Tu Hailing , Tang Siqi , Yan Jiang , Li Bo , Zhang Jing , Zhang Zhaohao , Wei Qianhui , Yin Huaxiang
Published: September 2020

In this paper, insulator isolated Si NW array were fabricated using self-allied spacer image transfer (SIT), multi-step time division multiplexing (TDM) etching and linear oxidation processes. The insulator isolated Si NWs owe a pentagonal shape, well single crystal morphology and high nanowire quality. The fabricated Si NW array were used to fabricate insulator isolated Si NW sensors. The low-cost insulator isolated Si NW sensor fabricated from bulk silicon substrates exhibits a linearly variation of current response to the laser at this wavelength, exhibiting good repeatability and the prospect of replacing SOI materials. The proposed approach of Si NW materials and sensors fabrication realizes the high efficiency, low cost and small fluctuation of Si NW pattern and device preparation, overcoming the problems of low efficiency for e-beam lithography and the difficulty of large-scale array formation.
Optimal Layer Thickness during the Design of Carbon Fiber Composite under Bending Loading
Authors: Zhang Shijie
Published: September 2020

Carbon fiber resin composite materials are widely used in manufacturing and industrial production due to their many performances better than that of traditional materials. However, how to use the limited carbon fiber resin composite material to design the product with the excellent bearing capacity and relatively low processing cost still needs to be explored. The layer thickness is an important parameter during the design of carbon fiber composite. Large layer thickness between carbon fiber layer and resin layer could lead to poor mechanical properties. Small layer thickness could improve the bearing capacity but accompany with the high cost of production. Optimal layer thickness can balance the mechanical properties and production costs. Here, Abaqus software was employed to establish the finite element models with the same size but different number of layers, by dividing the mesh and finding the ultimate bearing capacity of each model, the relationship between the model layer and the ultimate loading force was obtained. Based on the calculated results, the optimal design scheme of carbon fiber resin composite materials was proposed.
Characterization of Hibiscus Flower as a Potential Source of Electric Supply
Authors: M.E. Emetere , E.T. Akinlabi
Published: September 2020

Deriving energy from plant has generated new technologies that are impressive. The success of harnessing energy in plants means that a global challenge has been truly solved. In this paper, the focus was to improve upon the plasmon technology in converting light to electricity such as photovoltaic. A metallic coated plant extract (MCPE) was synthesized and characterized in an unusual characterization set-up to determine the basic properties required for the plasmon technology. The MCPE was found to have band gap of 3.15 eV and possesses the basic properties of electron clouds oscillating about a mean position. This result means that the MCPE is a bio-particulate option that can replace the inorganic nanoparticles in the plasmon experiment. Further work on testing the MCPE in plasmon set-up is recommended.
Facile One-step Fabrication of Functional Cellulose Nanocrystals with High Efficiency under Microwave-ultrasound Synergy
Authors: Lu Qilin , Ran Linlin , Chen Shichao , Lu Linna , Li Lu , Li Yonggui
Published: September 2020

The use of cellulosic biomass for the manufacture of functional cellulose nanocrystals (FCNs) in a mild and green process is limited due to the multiple hydrogen bonds between cellulose. Based on the mechanochemical mechanism, an efficient and green approach to cleave hydrogen bonds and fabricate FCNs was realized via microwave-ultrasound synergy. In the one-step process, impact force, crash force, friction, chemical action, and thermodynamic interaction combined to create synergistic effects, accelerating the cleavage of hydrogen bonds and formation of FCNs synchronously. One-step purification of FCNs was implemented after reaction for the recovery of byproducts, which was critical to cost reduction and waste liquor treatment. FCNs with high crystallinity of 80%, high charge density, and good dispersion stability were obtained. Thus, a facile versatile green avenue for the large-scale production of FCNs was achieved in the study, and is expected to carry significant benefits in terms of economy and sustainability.
Hovenia Acerba Structure of Nano-Silver Materials in the Process of Synthesis of Silver Nanoparticles under Alkaline Condition
Authors: Tang Junqi , Ge Linlin , Sun Leiqing
Published: September 2020

Silver nanoparticles (AgNPs) are attracting tremendous attention in materials, nanotechnology, biomedicine and chemical sensor fields. This paper describes the hovenia acerba structure of nano-silver materials in the process of synthesis of silver nanoparticles under alkaline condition. The analysis shows that the appearance of this structure is due to the adding of ammonium hydroxide and this structure is the intermediate state of the AgNPs.
Study on the Treatment of Domestic Sewage by Lactococcus
Authors: Li Hongcui , Zhang Ming
Published: September 2020

As a commonly probiotics, lactococcus produces a large amount of lactic acid during the growth and metabolism process, which can regulate the pH value of the environment. At the same time, lactic acid can also transform the refractory organic matter in sewage into degradable or easily degradable substances, thus accelerating the degradation rate of pollutants. The removal rate COD, TP and TN were selected as the test indexes in the experiment. The single-factor experiment was carried out first. Orthogonal experiments were carried out according to the result of single-factor experiment. Experiments showed that the optimal reaction time of COD, TP and TN removal was 54h/42h/24h, the optimal dosage was 9.00mL/4.00mL/9.00mL, the optimal pH value was 6.00/6.00/8.00, and the removal rate was 68.41%/80.04%/32.54% respectively. It can be concluded that the degradation efficiency of lactococcus on TP and COD is better, while the degradation efficiency on TN is worse.
Research on Inhibitory Effect of Green Algae of C30 Coral Aggregate Concrete Surface with Different Mortar Coatings
Authors: Song Putao , Wang Jing , Guan Qingfeng , Zhou Yongxiang , Hang Jing , Leng Faguang
Published: September 2020

In this paper, maximum fluorescence value was first applied to indicate the anti-green algae properties of concrete, the lower the maximum fluorescence value, the better the anti-green algae properties of concrete. This study investigates the effect of strength grade of mortar coating and types of hydrophobic materials and admixture on the fluorescence value of C30 coral aggregate concrete. The results show that adding a certain proportion of hydrophobic material directly can reduce the maximum fluorescence value of coral aggregate concrete. Using mortar of different strength grades as concrete coating can also reduce the fluorescence value of concrete surface. The higher the strength grade of mortar is, the greater the decrease of the maximum fluorescence value will be. Using mortar mixed with hydrophobic material as coating can minimize the maximum fluorescence value of the concrete surface of coral aggregate concrete. In general, the maximum fluorescence value of M100 mortar coating with 5% of the total mass of cementitious material can be reduced to the minimum. Compared with the C30 coral aggregate concrete without hydrophobic agent, the maximum fluorescence value can be reduced by 75.4%.
Architecture Design of Intelligent Assembly System Based on Complex System
Authors: Zhang Dashun , Meng Fanjun , Wang Jing , Miao Liqin , Hu Huizhong , Li Penghui , Li Xueguang
Published: September 2020

For complex system and product, the virtual and intelligent assembly system can short the designing and manufacturing time effectively, especially for administration of life cycle of product, it can provide the digital models for different period using. In this paper, the intelligent assembly system architecture was designed which includes three-layers, application layer, data layer, and output layer. By using this intelligent assembly system the virtual assembly of complex system products is realized. Then, the framework of intelligent assembly information modelling was designed further which includes geometric information, assembly constraint information, and assembly relationship information. This assembly information model can not only express the connection between assembly parts and assembly relationships, but also provide information sources and acquisition mechanisms for assembly process planning. At last, an example of product assembly is presented which includes 3D models analysis and attribute set for simulation, the intelligent assembly function is accomplished in the end.
Research on Vehicle Routes Optimization for Emergency Materials Distribution
Authors: Zhang Jiashan , Lin Xiaoqun
Published: September 2020

Disasters such as earthquake, flood and diseases are sudden and urgent. In order to improve the efficiency of emergency materials distribution, scientific decision on vehicle routes plays an important role. This article assumes that the emergency materials required by each disaster site are allowed to be delivered in advance but not delayed. Considering vehicle maintenance and driver’s continuous working ability, taking the distribution cost as the objective function, a mathematical optimization model for the problem is established. Based on ant colony algorithm, optimization algorithm is designed to solve the model. Then, effects of different optimization algorithms were compared. The application shows that the method operates quickly and the results are rational, which can provide scientific basis for decision-making.
Comparison of Material Composition and Road Performance of Different Natural Asphalts
Authors: Hui Wei , Fan Liang , Li Yongzhen , Liang Hao
Published: September 2020

Because of the differences in material composition and structure, different natural asphalt will lead to different road performances and technical approaches. Based on years of research data, the composition and characteristics of different natural asphalt are reviewed. It is considered that the difference of performance of different natural asphalt is closely related to asphalt content and ash content. Aging property is related to oil content and microstructure of asphaltene. Because the mineral composition of lake asphalt is mostly volcanic ash, it shows different modification effect from natural rock asphalt, and has more advantages in the comprehensive performance of asphalt mixture, especially in low temperature performance and fatigue resistance.
Study on Problems and Countermeasures of Clean Heating in Rural Areas of North China—a Case of Shandong Province
Authors: Qiao Liang , Liu Doudou , Xu Xiang , Yuan Xueliang
Published: September 2020

Clean heating is an important part of the transformation of new and old driving forces and the revitalization of rural areas. Speeding up the promotion of clean heating is an important measure to improve rural public service facilities, guarantee and improve people’s livelihood. This paper introduces the development status of clean heating in rural areas of Shandong Province, and the target tasks to be completed in 2020 and 2022. Through household survey, a questionnaire survey was conducted among 910 clean heating users in rural areas of Shandong Province. Problems of clean heating in rural areas of Shandong Province are pointed out, and countermeasures and suggestions are put forward accordingly.
The Exploration of the Path of the Guangdong-Hong Kong-Macao Greater Bay Area Sports Town Facilitating Rural Rejuvenation
Authors: Wan Fada , Wang Xiange , Li Jinji
Published: September 2020

The development of sports towns in Guangdong-Hong Kong-Macao Bay area should keep pace with the strategy of rural revitalization, and contribute to the revitalization of rural industry, Talents, culture and ecology. It is concluded that the sports towns have five missions of rural economic, social, political, cultural and ecological civilization development. The Guangdong-Hong Kong-Macao Bay area has a Superior Sports Industry Foundation, a good sports competition atmosphere, and a diversified sports culture, the revitalization of rural industry can be promoted by building sports brand events in Guangdong-Hong Kong-Macao Bay area, developing sports characteristic industry chain with sustainable development, one main and many auxiliary sports items, and establishing sports industry cooperation and exchange mechanism with the participation of government, enterprises and people in the bay area We should attach importance to the development of human resources, the training of local talents, the work of sending talents to the countryside, the gathering of talents from small towns, the promotion of the integration and development of traditional culture and sports culture, the promotion of the spread of sports culture and the revitalization of rural culture Improve the utilization rate of natural resources, improve the level of ecological construction, promote the town ecological system construction, ecological facilities construction and ecological protection behavior guide to help the rural ecological revitalization.
Simulation of Land Use Changes in Jiaodong Peninsular based on the Logistic-CA-Markov Model
Authors: Wu Li , Zhu Mingming , Zhang Guorui , Yang Rui
Published: September 2020

Based on Landsat TM/ETM+ images acquired in 2000, 2005, 2010 and 2015 respectively, land use maps of Jiaodong Peninsular were created to analyze the characteristics of land use change. Then the Logistic-CA-Markov model was selected to simulate the spatial-temporal patterns of land use changes in 2010, 2015 and 2020 at 100 m spatial scale and five-year time interval. The results showed that: (1)During the period 2000-2015, areas of farmland decreased continuously, while urban area, rural settlement and independent industrial-mining increased continuously and rapidly; (2) Ten impact factors were chosen as the independent variables of Logistic regression analysis to establish eight logistic regression equations for eight land use types; (3) As the Logistic-CA-Markov model has a good performance in the simulation of land use maps in 2010 and 2015, it was further used to simulate land use change in 2020. (4)The simulation results showed that farmland, forest would decline during 2015 and 2020; Urban area would still increase.
Design of a Kind of Low-Cost and High-Precision Power Measuring Device
Authors: Pan Dawei
Published: September 2020

A kind of low-cost and high-precision power measuring device is designed, which is realized by hardware circuit and embedded software. The signal acquisition circuit, switching value input and output circuit, communication circuit of the device are analyzed. The power calculation program, storage program, timer interrupt program and communication program are described. The device has been applied in the field, and the application shows that the device meets the requirements of industrial level and has the merits of low cost, high precision and high stability.
Development and Application of a New Type of X-ray Fluorescence Online Grade Analyzer Based on STM32
Authors: Cheng Xiaozhou , Liu Zhiyuan
Published: September 2020

In order to achieve more accurate measurement of the pulp element grade in the beneficiation process, a new generation of nuclear-free X-ray fluorescence online grade analyzer was developed based on the previous generation of nuclear online grade analyzer. This new X-ray fluorescence grade analyzer is developed based on the STM32F407 control chip. It adopts a measurement structure that combines X high voltage light tube and semiconductor detector. Its technical structure and analysis principle are: X-ray tube and semiconductor detector constitute a measurement unit. The X-rays excited by the X-ray tube are irradiated to the surface of the slurry to be measured, and the semiconductor detector receives X-characteristic fluorescence excited by the element to be measured in the slurry. The main control unit receives and processes the data signals uploaded by the semiconductor detector. Send the measured element count rate to the upper computer of the industrial computer through serial communication. Finally, the higher-level software calls Matlab mathematical analysis tool while using BP neural network to perform data modeling analysis and obtain the grade value. According to a field industrial test conducted at a ore dressing plant in Shaoxing, compared with the previous generation nuclear grade analyzer, the measurement accuracy and operating stability of the new X-ray online grade analyzer have been significantly improved, and various parameters All met the design requirements for development.
Mathematical Modeling and Experimental Verification of Oil-Gas Spring
Authors: Chen Yijie , Zheng Guanhui , Han Xiaoling , Zhang Xu , Xu Mengyan
Published: September 2020

A method for studying the flexural deformation of the damping valve when subjected to a local uniform load was proposed, according to the physical model of valve platevalve platevalve platevalve platevalve platevalve platevalve plate and the related theory of thin plate mechanics, the differential equation of the deformation potential energy of the valve plate was solved, and the analytical formula of the flexural deformation under the local uniform load was derived. Further, combining the analytic formula of flexural deformation of the valve plate, the analytic formula of the annular gap throttling and the actual gas state equation, the mathematical model of the indicator characteristic of the hydro-pneumatic spring was derived. Through programming simulation, the relationship between the elastic force of the system and the total output force with displacement were analysed, compared with the test data, the correctness of the mathematical model of the hydro-pneumatic spring was verified, and the theoretical basis was provided by analytical formula of valve plate deformation.
Design and Implementation of Elevator WeChat Public Supervision System based on SOA
Authors: Chen Jie
Published: September 2020

A WeChat public supervision system for elevator maintenance was designed aimed at the problems of elevator maintenance status monitoring and elevator safety supervision. Combined with “Internet +” and big data supervision, aiming at the loose coupling characteristics of the system, using the unified development technology system (J2EE), introducing the concept of SOA layered and distributed system architecture, and finally the unified application service management platform was established. On this basis, the unified management of the elevator application management system was realized. The elevator information supervision system has the characteristics of public participation supervision, traceability of maintenance records, and benigh interaction between supervision and the public, which will contribute to the further development of intelligent elevator supervision.
Control of a New Cycling Rehabilitation Robot Based on Fuzzy PID
Authors: Jiang Dawei , Shi Guoquan , Pang Zaixiang , Li Shuang , Tian Yuan
Published: September 2020

For completing the standardized rehabilitation training of the affected limb based on the lower limb rehabilitation training robot system, it is designed that a lower limb rehabilitation robot control system based on fuzzy PID control method to realize stable and accurate control of the rehabilitation training process. First of all, this paper analyzes the ranges of motion of human hip and knees, and a single degree of freedom lower limb rehabilitation training robot system based on the belt transmission principle is designed. Then the fuzzy PID control is analyzed. And the Matlab is used to simulate the passive rehabilitation mode of the lower limb rehabilitation training robot system under different control strategies. The designed rehabilitation training test shows that the control system of the lower limb rehabilitation robot based on the fuzzy PID control method has a small speed overshoot, high control accuracy and smoother operation.
Stress Analysis of the Solar Cells in PV Modules
Authors: Li Zhiqi
Published: September 2020

In this paper, an analytical solution for evaluation of the stress in the solar cells was developed. The stresses of the solar cells in PV module of 1580mm×808mm were calculated by the present solution and the wind pressures and the effects of the storage shear modulus of the EVA were considered. The results by the present solution were in good agreement with those from FE.
Quantitative Characterization of Graphite Morphology in Cast Iron from 3D Perspective
Authors: Ma Zhijun , Yang Zhong , Guo Yongchun , Li Jianping , Liang Minxian , Wang Shaogang
Published: September 2020

Compared with 2D microstructure characterization, quantitative characterization of graphite morphology from 3D perspective can make it more possible to predict and improve properties of cast iron with relatively high accuracy. In the present study, based on 2D metallographic photos, X-ray tomography was utilized to investigate 3D morphology of graphite clusters in different cast iron and 3D quantitative characterization of graphite morphology was carried out by Avizo software. The results show that basically all nodular graphite in ductile iron are isolated and almost all graphite phase is interconnected in gray iron. The interconnectivity of compacted graphite iron is closely related with vermicularity. The flake-shaped graphite in gray iron is different with coral-shaped graphite in compacted graphite iron from 3D perspective. The quantity proportion of graphite clusters smaller than 10000μm3 is as high as 99.7% and 97.1% respectively in gray iron and compacted graphite iron with 91.3% vermicularity. The volume of graphite clusters larger than 100000μm3 basically accounts for most of graphite volume and the proportion is over 95% in gray iron and compacted graphite iron with high vermicularity. The difference of graphite volume distribution among different cast iron is mainly concentrated in the volume range from 10000 to 100000μm3.
Numerical Simulation on Characteristics of Heat Transfer with Different Elliptic Tube Cross Sections
Authors: Gao Quanfu , Ma Sen
Published: September 2020

With the developing of manufacturing technique and the lack of material in recent years, the elliptic tube-fin bank heat exchangers have been paid more and more attentions. The numerical simulation has become an important mean and effective way for studying the flow and heat transfer. The heat transfer capacity of the heat exchanger is affected by multiple factors, among which the cross sections of the elliptic tube is a major factor. In this article, we take numerical analysis methods and SIMPLE algorithm in body-fitted coordinate system to analyze the effect of the different elliptic cross sections on heat transfer characteristics, the results will provide basis for designing and manufacturing compact heat exchangers.
Applying Baydur Composite Material in Designing Automotive Door Beams
Authors: Ma Lingyue , Liu Mingji , Chen Zhiyuan
Published: September 2020

This work studied the application of Baydur pultrusion composite material to the side door anti-collision beams of cars. The beams are currently made of high-strength steel materials and arranged inside the door to meet the requirements of road safety laws and regulations. The Baydur pultrusion composite material has many advantages that metal steel does not have. Based on the characteristics of the composite materials and safety standards for vehicle side collisions, we proposed a design to use Daybur composite material instead of steel as the anti-collision beam material in automobile side doors. The structural design of the beam with the composite material is optimized so that it can effectively improve the safety performance during side collisions and reduce the body weight to save fuel consumption. The feasibility of the design has been investigated from three aspects of technical manufacturing, safety performance and market application. The application of the composite material in the anti-collision beams will provide new options for the safety and energy efficiency of civil vehicles.
Comparison of Various PID Control Algorithms on Coupled-Tank Liquid Level Control System
Authors: Yang Yang
Published: September 2020

On account of the unsatisfactory control effects of traditional PID control theory on dealing with complicated or nonlinear control system, the paper focused on multiple intelligent control theories, including fuzzy self-adaptation modulation PID control, BP neural network modulation PID control and RBF neural network modulation PID control. By setting double-Tank model as an example, and adopting MATLAB software programming, the research is aimed to realize tank level control via four PID control algorithms. By comparing the simulation curves of the four control algorithms, the superiority of the REF neural network in arbitrarily accurate approximating any continuous function is proved.
The Scientometric Approach of Mapping Sustainable Green Infrastructure Research Developments
Authors: Retno D P , Wibowo M A , Hatmoko J U D
Published: September 2020

While sustainable green infrastructure research has progressed substantially in the last decade, there has been a lack of study mapping on the developments of existing research publications in this area. This research aims to systematically review and map the development of existing publications during the period of 2009 – 2019 using the Scientometric review approach of Scopus metadata and VOSviewer software. The results show there were 1784 publications and 4894 authors from 109 countries, with the top 3 countries, i.e. the United States (472 publications), the UK (162 publications) and China (151 publications). The top 3 rankings of the main research area trends were green infrastructure (260), sustainability (211), and sustainability development (134). The publications were dominated by articles (50.2%), conference papers (32.2%), book chapters (7%), reviews (7%), and books (6.4%), which consist of 338 open-access documents, and 1396 closed-access documents. The top 3 authors with the most citations were Wang J. (261 citations), Jensen M.B. (82 citations) and Haase D. (76 citations). The outcomes of this study are expected to fill the existing research gap as well as to provide an overview of the development of sustainable green infrastructure research publications and to see future research development opportunities.
A Review of the Discrete Element Method Application on Concrete Materials
Authors: Ma’arif F , Gao Z , Li F
Published: September 2020

This paper describes an attempt to analyze each methodology and bring it all together in one place for crossreferencing expert analysis. The advantage of using DEM compared to continuum-based techniques is in cracking and fragmentation starting and spreading because the DEM system is naturally disconnected. Concrete is a non-homogeneous composite material with significant heterogeneity of quasi-brittle characters. Structural failure behavior in concrete usually preceded by initial cracking and influenced by the mesoscale structure, interface between aggregate and mortar matrix, especially under complex pressure conditions. The ability of the DEM to produce 3-phase material representation in concrete will significantly depend on the application of the contact model between particles that have bound during the simulation. The main development area in this paper is related to stages (particle contact, contact model), parameters, and implementation that are entirely established in the simulation phase of materials. It will assist future researchers in improving analysts when modeling concrete to select appropriate methods and procedures, and to identify critical parameters for specific applications.
The Study on Modulus of Elasticity (MoE) and Modulus of Rupture (MoR) of Lamina Beams on The Lime Wood (dryobalanops spp.)
Authors: Suryono J , Bhakti S O W
Published: September 2020

The aims of this study are to determine the stiffness, flexural strength of lamina beam of lime wood by using both of adhesive Dovebond 30 and Synteko 1909. The testing was conducted based on standard ASTM D 143-05. Data was processed and analyzed by factorial design. The board made by using a log wood with a diameter of more than 40 cm and display 1 m which then split into several pieces of sheet board with 2; 1; 2 cm, thickness 5 cm. The board sheet was cut to a width of 5 cm, 2; 1; 2 cm thick and 71 cm long to make multiple walking joints and types. The entire adhesive resurfacing system was carried out using a cape/brush. Both lamina (double spread) surfaces was sprinkled with 200-220 g/m2 melting weight. The adhesion sliding strength of lime beam used 1.03 kN/cm2 of adhesive Synteko 1909 and 0.84 kN/cm2 of adhesive Dovebond 30. The measured three-layer lamina beam was the measurement results of lime wood that provides the stiffness efficiency (MoE) of 38.91% of solid beam stiffness (MoE) and the flexure strength (MoR) of 10.26% of the flexure strength of the solid beam. Three-layer lamina beam with five finger joints was the measurement result for the highest MoE stiffness of 1,321 kN/cm2 using the adhesive Dovebond 30, and the highest flexure strength of 80.6 kN/cm2 using the adhesive Synteko 1909.
Value Engineering in The Implemetation of Kumkang Formwork (Case Study: The Alton Apartment Project in Semarang Indonesia)
Authors: Suwandi P A P , Husodo I T , Suryadi M W
Published: September 2020

Value engineering is usually done by substitution of materials or change in construction method. One of them is in The Alton Apartment Project in Tembalang, Semarang, which is apply Korean technology on aluminum formwork system called Kumkang. The objectives of this study are to calculate the coefficient of worker productivity, to find out the time required to install the aluminum form (Kumkang) compared to conventional one, and to compare the workers’ costs for conventional formwork and Kumkang aluminum formwork. The analytical method of the study uses the Value Engineering Method. The calculation of the workers unit price coefficient analysis of aluminum formwork work (kumkang) equal to 0.025 MD, while of the unit price of workers on the formwork according to the Indonesian National Standard Work Unit (AHSP-SNI) equals to 0.330 MD. The time required of the aluminum formwork (kumkang) installation are 2,47 days for 1582.10 m2 formwork while the conventional formwork needs 32,6 days for the same volume. The cost calculation shows that the worker cost to install Kumkang Formwork is Rp. 7,200,000 while for the conventional formwork is Rp. 79,200,000. Based on the results, it can be concluded that Kumkang formwork technology is more efficient than conventional system.
Member Sizing Optimization of Large Scale Steel Space Trusses Using a Symbiotic Organisms Search Algorithm
Authors: Wong F T , Prayogo D , Putra R E , Joseph J
Published: September 2020

A systematic approach of optimization is needed to achieve an optimal design of large and complex truss structures. In the last three decades, several researchers have developed and applied various metaheuristic optimization methods to the design of truss structures. This paper investigates a new metaheuristic algorithm called symbiotic organisms search (SOS) for member sizing optimization of relatively large steel trusses. The case studies include a 120-bar dome truss and a 942-bar tower truss. The structural analyses are carried out using the standard finite element method. The profiles of the truss members are circular hollow structural sections selected from a set of the American Institute of Steel Construction standard profiles. The design results using the SOS are then compared to those obtained using other metaheuristic methods, namely the particle swarm optimization, differential evolution, and teaching-learning-based optimization. The comparison shows the superior performance of the SOS in terms of the optimal solution, consistency, and convergence. Thus, the SOS is a good alternative for optimizing the design of steel truss structures in real engineering practice.
Mechanical Properties of Lightweight Concrete Using Class F Fly Ash as a Partial Replacement for Ordinary Portland Cement
Authors: Salain I M A K
Published: September 2020

This study shows the mechanical properties of lightweight concrete (LWC) made by partially replacing ordinary Portland cement (OPC) with class F fly ash (FFA). Natural sand and pumice were used as the fine aggregate and coarse aggregate, respectively. Five LWC mixtures, M1, M2, M3, M4, and M5, were made by replacing, by weight, of 0%, 10%, 20%, 30 %, and 40% OPC with FFA, respectively. The mix proportion of LWC, by weight, was 1.00 binder: 3.24 fine aggregate: 1.19 coarse aggregate, and the water-binder ratio was 0.32. Tests of the LWC mechanical properties were conducted at the hydration time of 28 and 56 days using 150 by 300 mm cylindrical specimens. The results indicate that the use of FFA as a partial replacement for OPC improved the development of the mechanical properties of LWC. The compressive strength and the modulus of elasticity of the LWC increased in all the mixtures during the hydration time. The optimal proportion of FFA for replacing OPC in LWC is about 20%. With this optimal proportion and after 56 days of hydration, the compressive strength and the modulus of elasticity are, respectively, about 113% and 105% of those produced by LWC made with 100% OPC.
Optimizing Prediction Accuracy of Concrete Mixture Behavior Using Hybrid K-means Clustering and Ensemble Machine Learning
Authors: Wijaya D , Prayogo D , Santoso D I , Gunawan T , Widjaja J A
Published: September 2020

Concrete is the most used material in infrastructure development, especially in a developing country. The concrete used in project must not only satisfy the desired concrete strength, but also the workability. Additionally, due to different conditions in construction projects, the requirement for workability varies. Workability can be measured using several methods. Previously, traditional trial-and-error of concrete mix design were used to achieve desired slump and flow test value. However, the experiment is often inexpensive, and the obtained results may not be sufficiently accurate. Recently, the potential of the AI method has been gaining increased attention as the new and promising alternative method to predict slump and flow tests, based on historical data. Thus, this study develops an effective hybrid AI-based method to predict slump and flow tests from the given concrete mixture dataset. A total of 103 historical data are used. At the beginning, the samples are separated into two groups using k-means clustering. Each cluster is modelled using the ensemble of six prediction methods, which are REG, CART, GENLIN, CHAID, ANN and SVM. The obtained results show that our proposed method can build the prediction method with a high accuracy, measured by several performance indicators.
Effectiveness of Glass Powder as a Partial Replacement of Sand in Concrete Mixtures
Authors: Safarizki H A , Gunawan L I , Marwahyudi
Published: September 2020

Concrete is commonly used as the main component in a building. Concrete is obtained by mixing Portland cement, water, aggregates, and sometimes added ingredients at certain comparisons in the form of chemicals, fibrous materials, and non-chemical materials. Utilization of glass powder waste for concrete mixtures is now being developed. This research was conducted to determine the optimum composition of glass powder as a partial replacement of sand against the compressive strength of concrete. The content of the glass powder mixture used is 10%, 15%, 20%, and 30% of the weight of sand in the concrete mixture. Slump test results showed that in the variation of coarse glass powder concrete slump decreased due to lack of bonding capacity between the aggregates. In concrete with a variation of fine glass powder the slump slightly decreases because the fine glass powder absorbs too much water. Concrete compressive strength testing is carried out at 28 days. The results of concrete compressive strength test showed the optimum value can be achieved by 22.8 MPa with 15% variation in glass powder content. The use of glass powder is effective as a substitute for partial sand at 15% of coarse glass powder.
The Effect of Traffic Movement Design Study at The Manahan Flyover to the Road Network Performance Using Traffic Micro-Simulation VISSIM
Authors: Yulianto B , Setiono  , Putri S N
Published: September 2020

Level crossings between railway and highway causes transportation problems in the form of traffic jams and accidents. The Manahan Flyover development in the Surakarta city is an effort to minimize transportation problems in the Manahan and Kota Barat areas. Field condition shows that traffic congestion in the Manahan Flyover can be minimized, but traffic accident rate is increasing. Within nine months an accident occurred with two dead victims. The potential of traffic accident is inseparable with the design of the Manahan Flyover with the design of three-way intersection. The aim of study is to redesign traffic movement in the Manahan Flyover and surrounding Manahan area. Traffic micro-simulation VISSIM model is used to evaluate the performance of road networks at peak traffic conditions with different simulation models. The scenario simulation model is developed based on the calibrated base simulation model. In order to avoid potential accidents, therefore, the direction of traffic movement at the Manahan Flyover is made with a one-way system. The modelling scenario results indicate that the diversion of traffic movement at the Manahan Flyover must be followed by various traffic management and engineering efforts in the Manahan area including road widening, parking management, application of a one-way system.
Methods for Handling Rob Floods in the Banger River Basin in Semarang City
Authors: Ikhwanudin  , Wahyudi S I , Soedarsono
Published: September 2020

In the area of North Semarang often occurs tidal floods. The current government has dealt with the flooding of Rob by making dykes on the north coast of semarang. There is a method of handling tidal flooding by making a retention pool, Longstorage equipped with a pump if there is a flood the water is stored in a retention pond then the water is pumped into the river. The purpose of this study is to formulate a correlation between pumps and retention ponds. Alternative flood control using the count of 50 years. The method used is using HEC-HMS. There are three alternatives used in the simulation: 1st alternative pond with an area of 3.8 m3 and a storage volume of 114,000 m3, with inflow of 31.4 m3/s in this alternative the capacity of pump is 30 m3/s, second alternative pool with an area of 4.7 m2 and reservoir volume of 142,000 m3, with inflow of 31.4 m3/s, with pump capacity of 27 m3/s. third alternative ponds with an area of 5.0 m2 and a reservoir volume of 150,000 m3, with inflow of 31.4 m3/s. In this alternative a pump with a capacity of 25 m3/s used.