bluuebunny/crossref_metadata_2025 huggingface dataset:
Space Setting Process in Floating Houses (Rumah Lanting)
Authors: Putro Jawas Dwijo , Zain Zairin
Published: May 2021

Rumah Lanting is a floating construction house that can be found in several areas of West Kalimantan. The dwellers in Rumah Lanting have a favorable ability to adapt to their environment. They have general roles in controlling and adjusting to the changes that occur in their environment. The relationship between behavior and environment determines the adaptation process of the occupants of the floating houses. This research was conducted in the Kapuas Riverside area in the Kapuas Hulu Regency by a descriptive qualitative method. The sample was taken through a Purposive Sampling with the Behavior Mapping technique by schematics and diagrams about an area where humans carry out various activities. This study’s objective is to describe the behavior and the relationship pattern between human behavior to a specific design form. The study found a formulation of behavior and space form of the occupants in the floating houses of Kapuas Hulu Regency. First, the types of occupations affect the intensity of the duration of stay in Rumah Lanting. The duration of hours to do some activities inside the house will obliquely affect the behavior patterns, and those patterns are formulized in the formation as a space setting to the house. Second, the behavior patterns of the occupants create a centralized model of activities by making a space as a flexible and communalize.
Quantifying the Air Temperature Reduction with Greenery in UiTM Shah Alam: A Microscale Study
Authors: Hazeman Muhammad Hamizan , Hashim Nurhanisah , Salim Pauziyah Mohammad , Ibrahim Illyani , Salleh Siti Aekbal
Published: May 2021

Growth in cities population has caused urban sprawl which is the key factor in the issues of high temperatures as well as UHI in many countries. This issue has affected the urban microclimate as well as the indoor and outdoor conditions of human thermal comfort. This issue is also aggravated by the replacement of natural greenery area with building and other man-made features. For that reason, greening the cities, as part of bioclimatic concept of build environment, could be the way to decrease the outdoor temperature and making the surrounding more comfortable. To understand this issue further, ENVI-met software was used to simulate all activities either natural or man-made to attain accurate prediction and evaluation for microclimate changes in certain area. For this study, the simulations were run in three scenarios of pavement, asphalt pavement without plants (scenario 1), concrete pavement without plants (scenario 2), and asphalt pavement with plants (scenario 3). Plants were design in area surrounding the building and in courtyard consisting of pine trees and hedges of 2 metre height. The result shows that greenery plants can influence air temperature and airflow in the surrounding thus improving thermal comfort in the area. Existing plants can decrease temperature from 0.5°C to 2.3°C and air velocity become slower at 0.05 m/s to 0.15 m/s. Overall, although the changes are at small scale, it is shown that plants are able to improve microclimate surrounding better towards thermal comfort standards.
Derivation of MSL Riverbank Line from UAV DSM Data based on Tidal Slope Analysis
Authors: Mohamad N , Ahmad A , Din A H M
Published: May 2021

Deriving a riverbank line at a tidal river is complicated, since dynamic factors such as tide and slope topography influence its location. Hence, this study utilises the Unmanned Aerial Vehicle (UAV), geodetic, and tidal data to identify the exact riverbank line based on Mean Sea Level (MSL) value from UAV products. We carried out two epochs of UAV data collection during low and high tide conditions. Orthometric height (H) has been applied in UAV data processing to produce a high accuracy of orthophoto and Digital Surface Model (DSM). UAV-MSL derived riverbank lines have been identified from the UAV orthophoto image using supervised classification and feature extraction techniques. DSM model provides the topographical height in three-dimensional (3D) view and enables identifying low and high tide, MSL, and lowest astronomical tides (LAT) at the riverbank. The study found that UAV-MSL derived riverbank line was identified in between the MSL value (at 2.302 m) and chart datum (at 1.043 m). This study also identified the correlation model, R2 value at 0.9288 between UAV-MSL derived riverbank line with MSL-tide gauge data. This study provides an alternative for researchers to determine riverbank lines based on UAV derived MSL instead of using only tide gauge data.
Towards the Development of Malaysia’s Subsurface Asset Management Framework
Authors: Ariffin Ezam , Amin Zulkarnaini Mat
Published: May 2021

Underground utility detection survey has been practiced in Malaysia for a long time but it was never regulated. While there are guidelines to govern the practice of utility detection survey, an enabling clause is required to regulate the practice. The aim of this paper is to study the available subsurface asset management framework and to propose a framework for subsurface asset management in Malaysia. The methodology to carry out this research shall involve data collections from stakeholders in the form of interviews, questionnaires and discussions. A case study of an underground utility detection survey shall provide data on the process flow a project which involves stakeholders and the authorities. The final input shall be in the form of intellectual discourses with expert committees related to subsurface utility survey and policy makers. From the findings, it was observed that there were significant discrepancies between the engineering and cadastral survey records. While the engineering survey information related to subsurface utility was up to date, the cadastral survey record was never updated. Furthermore, it was observed that the is no enabling clause in existence to govern the management of subsurface assets. The result of this research is a proposed framework for subsurface asset management based on the data collected. In conclusion, it was recommended for the subsurface asset management framework to be tested in the real working environment and to continue with the efforts to realise the framework.
Landslide Hazard Analysis using Landsat-8 OLI and AHP Technique in Tanjung Bungah, Penang
Authors: Saad N , Bahari N A , Talib N , Zaki N A Mohd , Rasam A R Abdul
Published: May 2021

Various technique and application have been used in determining the hazard analysis. AHP technique was chosen for this study in effort to find the most factors cause the landslide in the study area. The aim of this study is to determine the factors of landslide hazard using satellite imagery Landsat-8 OLI and Analytic Hierarchy Technique (AHP) in Tanjung Bungah, Penang. This study embarks on three objectives which are to identify the parameter involved in landslide hazard based on surface characteristics, to derive topographical surface from satellite image Landsat 8 OLI in relation of landslide hazard and to determine the correlation of identified parameter and derived topographical information for landslide hazard using AHP technique in Tanjung Bungah, Penang. There are 6 parameters used which are slope, aspect, lithology, rainfall, land surface temperature (LST), and soil-adjusted vegetation index (SAVI). Landsat 8 has been processed to provide the secondary data used in GIS platform. All the processed data are then overlaid using weighted overlay analysis. The output of the analysis shown is spatially visualized to examine the location of the landslide hazards risk. The map produced help in better understanding of nature impact of past, current and future development decision making.
Research on Key Technologies of Eco-city Construction Planning
Authors: Hong Xiaoling , Cheng Xiao
Published: May 2021

As one of the main forms of urbanization in my country, urban construction is the process of building original natural or semi-natural ecosystems into urban artificial ecosystems from the perspective of ecology. It is the construction and replacement of ecosystem types and the process of encroachment. Urban planning must pay particular attention to the forward-looking nature of its ecological planning. While truly enhancing the city’s overall ecosystem service capabilities, it also prevents new ecological and environmental problems from being induced. Through theoretical analysis of the characteristics of ecosystem changes in the process of urban construction, combined with typical cases, several key issues in urban ecological planning have been summarized and condensed, and corresponding planning strategies and techniques have been proposed, with a view to providing ecological solutions for large-scale urban development in my country. Provide theoretical support for environmental protection work.
Discussion on Coordinated Development of Energy Economy and Environment in China
Authors: Shi Lin
Published: May 2021

in recent years, China’s economy has made great progress, its development is based on energy consumption as the energy power, the problem of energy consumption is that the pressure on the environment is increasing day by day. The pollution caused by the combustion of fossil energy is especially serious. China’s future economic development, energy development is both the foundation and guarantee, and clean, pollution-free environment is the necessary basic conditions for our human survival. Therefore, how to achieve the coordinated and sustainable development of economy, energy and environment is an unavoidable subject in the future economic development of our country.
Development trend analysis of variable oxygen concentration combustion research based on bibliometrics
Authors: Wang Yiqi , Chen Lei , Zhang Dingran
Published: May 2021

Based on CiteSpace, 955 journal literature related to variable oxygen concentration combustion research collected in the web of Science (WOS) core database were analyzed visually. The results show that: 1 Literature publication trends. According to the total number of published literature, it can be divided into three stages: initial development, steady development, and rapid development. 2. Analysis of the author’s co-occurrence map. The author’s cooperation network in this field is obvious, but the overall cooperation network presents a “core-edge” structure, and the cooperation of academic teams is scattered. 3. Research hotspots, the related research mainly focused on the combustion characteristics of polymer synthetic materials, and chemical cycle combustion related to the field of energy and power engineering. 4. Research on the frontier trend. At present, “mechanical property” and “Nanoparticles” are the keywords representing the latest frontier trend in this field.
The Evaluation of Coal Mine Safety Based on Entropy Method and Mutation Theory
Authors: Mi Xin , Cao Qinggui , Li Dan , Wang Junqing
Published: May 2021

In order to accurately evaluate the safety status of coal mines and improve the safety level of coal mines, the method of evaluating the state of coal mine safety combined with entropy method and mutation theory is proposed. By analyzing the influence factors of coal mine safety status, 17 evaluation indicators were established from the four aspects of employee quality, equipment facilities, natural conditions and safety management, and the evaluation index system of coal mine safety status was established. Based on this evaluation model and process, the safety status evaluation and analysis of the example coal mine are carried out, and the evaluation results are consistent with the actual safety status of the coal mine, which confirms the reasonable feasibility of the evaluation method. This method can be used to evaluate the safety status of coal mine and provide the basis for the formulation of safety countermeasures.
Intercropping Effects of Sophora davidii and Silage Maize on Soil Physicochemical Properties, Enzyme Activities and Yield
Authors: Zou Chao , Ding Leilei , Zhang Yujun , Wang Puchang , Chen Chao , Long Zhongfu
Published: May 2021

Crops-beans intercropping has the advantages of efficient utilization of light energy, space environmental resources and increasing land productivity. People have done a lot of research on the yield and soil nutrient utilization of grain crops intercropping system, which proves that crops-beans intercropping is of great significance in production practice. However, there is little research on the soil properties and yield affected by intercropping forage grass with shrub legume. In order to explore the ecological value and yield effect in the intercropping mode of shrub legume and forage grass, and to provide the high-quality forage resources in the region, we selected Sophora davidii and silage corn for field intercropping experiment. To study the benefit of intercropping and the feedback regulation between crop yield and soil fertility. The results showed that the land equivalent ratio was 1.501 under intercropping mode, and intercropping silage corn between S. davidii rows could improve the land use efficiency, and compared with S. davidii monoculture system, the land yield increased by 1286.4% in fresh matter and 738.5% in dry matter. At the same time, intercropping increased the content of available N in soil and promoted the sustainable utilization ability of soil. This has important enlightenment for the restoration area of S. davidii planting in karst area, taking into account the restoration effect, improving soil, increasing grass and increasing efficiency.
Research on High Cycle Fatigue Performance of Q345B
Authors: Zhu Pengxiao , Wen Jun , Li Yi , Zhang Dongya , Ma Xuejiao
Published: May 2021

The high cycle fatigue properties of Q345B were studied by optical microscope, conventional mechanical properties and fatigue tests. The results showed that the microstructure of hot-rolled Q345B was ferrite + pearlite, and the inclusions were MnS. In the case of high fatigue strength, the dispersion of fatigue life was low. With the decrease of fatigue strength, the dispersion of fatigue life gradually increased. The fatigue crack initiated at the MnS inclusion on the subsurface.
Analysis of deformation and failure characteristics of soft and broken surrounding rocks of super-large section tunnel constructed using benching tunneling method
Authors: Wan Fei , Fu Chongtao , Zhou Changwu , Li Lei , Zhang Xuan
Published: May 2021

The benching tunneling method can overcome the problems of insufficient working space and low construction efficiency in the soft and broken surrounding rock tunnel with super large section, but the design and construction theory and method are under developing. In order to solve the problem of insufficient basis for the design of the large-section bench method in the weak and broken surrounding rock, a three-dimensional elastoplastic model was established. The deformation and fracturing of the surrounding rock outside the tunnel excavation profile and in front of the tunnel face were used as indicators to analyze the deformation and failure characteristics of the weak and broken surrounding rock under benching tunneling method. The calculation results show that the grade of surrounding rock worsens (grade IV-V). Depending on the initial support design conditions, instability of the supporting structure or the tunnel face may occur. In the condition that grade of surrounding rock does not lose stability, the leading deformation accounts for a larger proportion of the whole deformation, indicating that the leading deformation is the key to the stability control in the benching tunneling method. When the tunnel face is unstable, the surrounding rock within 4.5m in front of the tunnel and 1.5m above the arch collapses, and the deformation and damage develop from the vault down to the foot of the wall.
Evaluation and Repair of Construction Damage to an Old Factory Building
Authors: Wang Hongnan , Liu Huabo
Published: May 2021

This paper describes the performance based seismic rehabilitation of an old four-story RC frame building which is being remodeled to be reused as an office building in the creative industrial park. The building is part of the city’s adaptive reuse and redevelopment program. It was designed and constructed in the 1980’s and, therefore, does not meet current design and detailing standards. To make matters worse, two of the first floor columns were badly damaged during renovation and were in danger of collapsing at any time. This paper presents the effects of the accident, failure mechanism, as well as the actions taken to repair the building. The damaged columns are strengthened by a reinforced concrete jacket. The beams closer to damaged columns are retrofitted by externally bonded CFRP. Structural redesign made it feasible to rehabilitate and strengthen the structure sufficient to meet seismic criteria that were judged to be compatible with the site conditions.
Research on Application of Wall Construction Technology in Building Construction - Case study on the Modern Art Design Teaching and Training Center Building of Shanghai Art & Design Academy
Authors: Liu Zhen
Published: May 2021

Wall cracks is the most commonly seen wall quality issue in the construction of industrial and civil architectures. The areas where cracks occur are also extensive, including the connection parts of masonry infill walls, concrete beams and columns. This article is based on the case study of lightweight wall panels utilization in the interior wall project of the Modern Art Design Teaching and Training Center Building of Shanghai Art & Design Academy. In view of cracks commonly experienced in the new wall materials, projects should fully consider various elements including joint stress, construction operation, putty treatment, construction environment, design and other factors, analyze the root cause, and get repair in place (strengthen the mortar joint, strictly follow the construction operation procedures, and strengthen the lightweight wall panel Installation). It is also pointed out that flexible treatment is an effective method for wall repair and damage prevention, which can effectively control the cracks at the joints of the lightweight wallboard and the cracks on the board surface.
Transient Analysis Based on Finite Element Method for Ball Grid Array Package
Authors: Luo Wenhao , Su Wei , Dong Xianshan , Nie Zhenhua , Tomar Agam
Published: May 2021

In this paper, finite element simulation is carried out for BGA sample. The authors establishes the model of fixture, ceramic panel and metal sheet. Based on this model, several layers papers are laid on the metal sheet for simulation test. Then, ANASYS Workbench is used to conduct transient analysis of the samples to study the influence of different thickness papers on acceleration and time. The results provide useful reference for the adjustment of dynamic response parameters.
Research on 3D Contrast Image Segmentation Based on an Improved Otsu Algorithm
Authors: Wu Xiaoling
Published: May 2021

This article mainly introduces typical segmentation methods of medical images, especially when using the advantages of threshold segmentation when segmenting blood vessels, and it is effective when selecting the principle of maximum between-class variance and global threshold. Sex is explained. Based on this, the key role played by the local threshold in the segmentation of angiographic images is explained. In addition, the block method used in this article is a fixed size. Considering when the block size can show the best segmentation effect, the article proposes an index that can determine the block size, namely block the rate of change of the internal standard deviation of the image, and the proposed method is also demonstrated.
Dynamic Optimal Configuration Method for Distribution Network Based on Multidimensional Reliability Improvement
Authors: Guo Haoming , Chen Yinghua , Jiang Yinghan , Liao Mengke , Liu Wenxia , Huang Yuchen
Published: May 2021

The power supply company has invested a lot of money to enhance the reliability of the distribution network by improving the grid structure, increasing the level of distribution automation, and increasing the coverage of live operations. However, blind investment will cause a lot of waste of assets. In view of the current situation, this article firstly constructs a reliability calculation model based on the minimum path method, which considers the mutual influence of multiple methods. Then, from the perspective of the life cycle, a corresponding life cycle cost (LCC) model is established. Next, based on grid search, a multi-dimensional dynamic optimal configuration method of distribution network considering the full life cycle is presented. Finally, this paper takes a regional distribution network as an example, and verifies the validity of the model through simulation calculations. The research results can provide a theoretical basis for the investment of distribution network assets.
Economic Stimulation Signal on Power Supply Optimization From Distribution Cost Allocation Based on Shapley Value in Integrated Energy Park
Authors: Gao Xiao
Published: May 2021

This paper discussed the economic incentives of the distribution cost distribution based on the Shapley value of cooperative game in the integrated energy service park for the optimization of the park’s power supply mode. The application of cooperative game in the distribution of power distribution costs gives an economic signal reflecting the difference in power supply to users in the park. In the concept of multiple solutions in cooperative game theory, the Shapley value determines the power flow contribution of each user to the power grid with its uniqueness, determines the user’s power distribution cost based on the power flow, and its economic background also clarifies the user’s responsibilities, and the user chooses differently. The power distribution costs borne by the power supply are also different, thereby promoting power supply optimization. The 5-node calculation example verifies the effectiveness of the distribution cost allocation based on the Shapley value for the economic incentive of power supply optimization.
Machine Learning in Smart Home Energy Monitoring System
Authors: Xiao Gengyi
Published: May 2021

In order to solve the insufficiency of the existing smart home energy monitor ing system in autonomous adaptability, a smart home energy monitoring system based on machine learning and embedded technology is proposed. The system uses a gatewa y to collect sensor data, and then uses a cloud computing platform running Hadoop and machine learning algorithms to learn and identify user behaviours to achieve autonom ous decision-making capabilities. Through the analysis of examples, it can be seen that the solution greatly improves the humanization of the smart home system.
Numerical studies on fluid-structure interaction of a liquid-filled tank with baffles
Authors: Duan Linlin , Yang Zhirong , Liu Cenfan , zhang Chongchong , Deng Guide
Published: May 2021

CFD is used to simulate liquid sloshing which affects the safety of baffles in this study, a three-dimensional model of a tank is established. The fluid-structure interaction method is applied to analyze the liquid sloshing phenomenon, deformation and stress of baffles during the acceleration. The distribution of liquid phase in a tank with 0.5 and 0.8 liquid filling ratios are studied. Force distribution of the baffles at different times under 0.8 liquid filling ratio is researched to obtain deformation and stress of baffles under this condition. The simulation results show that the liquid distribution in a tank with 0.8 liquid filling ratio is more stable than that with 0.5. During the acceleration process of the tank with 0.8 liquid filling ratio, the deformation and stress of the baffles are inversely proportional. The roots of baffles suffer from large stress, which is easy to crack under certain conditions. It should take protective measures at the root of the baffles to avoid cracking.
Research on optimization control of vehicle road noise performance
Authors: Su Jintao , Lou Jianping , Jiang Xiaolu
Published: May 2021

By analyzing the road noise problem of a car model, it is confirmed that the car exists in the car when driving at uniform speed on rough road surface. The front and rear row road noise problem. Based on the existing vehicle CAE model, the TPA analysis of the vehicle model was carried out by using MSC NASTRAN software to obtain the contribution of each transfer path to road noise, and the main path influencing the road noise was locked. The key factors on the main path are further identified through acceleration response analysis of key positions in the transfer path. Through vehicle test and ODS simulation analysis, the main vibration modes of the components that affect the road noise are determined. Combined with CAE and test methods, a reasonable chassis optimization scheme was developed to improve the road noise performance of the vehicle.
Research on Campus Attendance System Based on Face Recognition and Trajectory Tracking
Authors: Cao Fengping , Zhu Lin
Published: May 2021

The traditional Morning jog attendance in colleges and universities is limited to manual supervision by swiping card attendance, which is prone to queuing and sign-in on behalf of others. In addition, the lack of quantitative records of exercise data makes supervision difficult. Location-based attendance systems represented by Dingding time attendance, or simple face recognition attendance systems cannot achieve accurate attendance. The campus happy running system based on face recognition and trajectory tracking innovatively combines face recognition and trajectory tracking, and students achieve accurate attendance certification within the designated “geo-fence”. Practice shows that the system can meet the special needs of colleges and universities for Morning jog attendance and data recording, and it effectively improves the accuracy of identity verification.
Project Research Based on Electronic Engineering Innovation Practice
Authors: Chen Ze , Zhong Xiaolei
Published: May 2021

In this paper, combined with the practical conditions of our university training center, puts forward the project, for traction, on the basis of the module, dominated by technology training, to cultivate students’ engineering consciousness and innovation ability as the core of electronic engineering training teaching system, to adapt to the “double top” and innovation personnel training in our university. The teaching system and content, through one year’s teaching practice, integrates the design of the project, the design and production of PCB, the testing of electronic components, the assembly and debugging, the writing and defense of the science and technology report, and the teaching effect is very significant and is well received by the students.
Analysis and Research on Factors Affecting the Reliability of Medium Voltage Power Supply
Authors: Duan Weidi , Jia Junqing , Si Qin , Dong Wenjuan , Deng Fengting
Published: May 2021

With the continuous development of social economy, the demand for electricity is increasing day by day. Power users have higher and higher requirements on the reliability of power supply. In case of grid failure, The impact on businesses and individuals is also growing. The reliability of medium voltage power supply system has been paid more and more attention. The reliability of medium voltage power supply has a direct impact on users’ satisfaction with electricity consumption. Power supply reliability has become an important index to reflect the continuous power supply capacity of enterprises. Power supply enterprises pay more attention to power supply reliability year by year. Improving the reliability of power supply for medium voltage users has become an important part of reliability management. The author summarizes the work experience, the main factors affecting the reliability of medium voltage supply are analyzed. The measures and methods to improve the reliability of medium voltage power supply are put forward.
An Image Enhancement Method Based on Partial Differential Equations to Improve Dark Channel Theory
Authors: Li Pengcheng , Gu Xiaohui
Published: May 2021

Image applications appears in all aspects of life, such as medical imaging, electronic monitoring, face recognition, aerial photography remote sensing, fingerprint analysis, robot vision, automatic driving, intelligent car and so on in the civil field, as well as tanks, armored vehicles, artillery, missiles, bat submunitions in the military field. However, in the process of image acquisition or storage and transportation, the image quality will decline due to environmental conditions, equipment conditions or transmission compression, and so on. In order to accurately analyze the image, we need to carry out enhancement processing. In this paper, the current research status of image enhancement methods is analyzed. The traditional dark channel prior algorithm has some problems, such as edge or texture blur and so on. The processing effect is not ideal. Considering the limitations of the traditional dark channel prior algorithm, this paper proposes a improved algorithms based on the dark channel prior by combining partial differential equation. The main work includes the following aspects. First, the partial differential equation algorithm is combined with the dark channel prior method, and the improved algorithm is applied to enhance the image with fog. The contrast experiment of enhancement effect and running time is designed to verify the image enhancement effect of the improved algorithm. Second, the improved algorithms proposed in this paper are compared with traditional algorithms. After making the subjective and objective evaluation, it is found that the improved method in this paper has better image processing effect, stronger fog and noise removal effect, better edge retention effect, more information acquisition, and higher computational efficiency.
Study of deformation manifestations in the excavation working floor when it is supported by roof bolting
Authors: Demin VF , Isabek TK , Nemova NA
Published: May 2021

The diagrams for supporting workings by floor and roof bolts are considered, which allow to reduce the swelling of floor rocks and manifestations of rock pressure. The degree of influence of mining and engineering factors on the bolting effectiveness of workings is established.
Stress concentration analysis in rock pillars in the framework of non-local elastic model with structural parameter
Authors: Altukhov VI , Lavrikov SV , Revuzhenko AF
Published: May 2021

The regularities of changes in the stress-strain state of coal in rock mass depending on the main mining geological and engineering factors are identified. Using these factors, it is possible to find the optimal support parameters in specific conditions to increase the stability of preparatory mine workings. The degree of influence of mining and engineering conditions of exploitation on displacements in marginal rocks with various types of support in excavation workings is investigated.
Measuring system to investigate geo- and gas-dynamic processes in hydraulic fracturing of coal seams
Authors: Drobchik AN
Published: May 2021

A measuring system has been developed for a test bench allowing the study of gas-dynamic processes in large-sized rock samples when performing hydraulic fracturing of a coal seam in a borehole model. This system provides collection of the data on pressure in a hydraulic fracturing device and loading of pneumatic jacks which create compressive stresses in the borehole zone, it also records acoustic emission during crack formation. An additional capability is implemented to measure the flow rate of gas supplied to sample through the holes on its side wall and pumped from the borehole.
Adsorption properties of Kemerovo manganese ore toward zinc
Authors: Kovalenko KA
Published: May 2021

Zinc is a toxic and a prevailing pollutant contained in wastewater in nonferrous metallurgy. With a view to ensuring the environmental safety, it is required to develop an integrated wastewater treatment technology to remove heavy metals from effluents. A promising approach to natural and waste water treatment is adsorption using various natural materials. The author analyzes the adsorption capacity of manganese ore from Durnovskoe and Usa deposits toward zinc in static conditions. The adsorption isotherms are described by the Langmuir equation at a high correlation factor. The maximal adsorption capacity, the sorption equilibrium constant and the change in the Gibbs energy are evaluated. Usa manganese ore reveals higher adsorption capacity toward zinc.
Investigation on continuous FAME production using rotor reactor with bumpy number variation under theoretical methanol to oil molar ratio condition
Authors: Thaiyasuit Prachasanti , Khiowthong Wuttisan , Seehanam Wirapan
Published: May 2021

Continuous methyl ester production process from waste cooking oil (WCO) was studied by using a transesterification process at room temperature. The aim of this research was to investigate the optimized production conditions and specific energy consumption (SEW*h/kg of neat biodiesel) of the bumpy surface rotor reactor. There are 6.9%, 13.8%, and 27.6% of area fractions (AF) respectively. The reaction was under the condition being theoretical methanol to oil molar ratio and the reactor volume was 0.5L. At 2,000-4,000rpm of rotor speed, 1.0-1.5%w/w of KOH and 1.132-5.110L/min of precursor flow rate are used. It was found that the highest FAME content (fatty acid methyl ester in neat biodiesel, %) being 98.6%. It was achieved by using AF 27.6% rotor reactor under experimental conditions including 3,000rpm, 1.50%w/w of KOH and 2.027L/min of precursor flow rate. In addition, this condition gave SEC of 12.5W*h/kg. It was lower than that of orifice hydrodynamic cavitation reactor, power ultrasonic reactor, and mechanical stirring reactor around 93.2%, 95.0%, and 97.5% respectively. The properties of produced FAME met both EN 14214 and ASTM D 6751 standards.
Design for crash safety of electric heavy quadricycle structure
Authors: Kongwat Suphanut , Jaroenjittakam Suchanet , Chaianan Siravit , Atchariyauthen Intuch , Jongpradist Pattaramon
Published: May 2021

An electric small four-wheeler, categorized by the European Union as L7e so-called heavy quadricycle or microcar, is one of the solutions to eco-friendly and sustainable mobility for personal transport. Nonetheless, quadricycles typically do not offer the equivalent passive safety as larger passenger car models, in case of accidents, owing to the lack of energy absorption in the vehicle’s structure. This paper presents a proposed heavy quadricycle structure using plain weave carbon fibre-reinforced polymer in the passenger cell and aluminium alloy 6061-T6 in the crumple zone. The behaviors of electric heavy quadricycles under impact are simulated in accordance with the test guidelines of European New Car Assessment Programme using a non-linear finite element analysis via LS-DYNA to examine structural crashworthiness and characteristics. A full-frontal crash with a rigid wall at 30 km/h to 50 km/h shows that the front crush box, longerons and subframes in the crumple zone can efficiently absorb energy from a frontal crash up to 54.8%. The maximum damage in the structure occurs at the joints of the A-pillars and side beams to the front panel. Whilst the occupant safety space is safe under side collision by a 1350-kg moving deformable barrier at 50 km/h speed. However, the quadricycle tends to experience overturns from a side crash due to the vehicle’s lightweight and high center of gravity. Finally, suggestions for crashworthiness improvements to the composite passenger cell are provided based on the attained damage mechanism under a crash.
Analysis of aluminum front bumper beam for heavy quadricycles under impact loading
Authors: Phanmueang Kiadtikun , Jongpradist Pattaramon , Ruangjirakit Kitchanon
Published: May 2021

A heavy quadricycle is a small four-wheeled vehicle suitable for urban mobility owing to its compact, lightweight and energy-efficient advantages. However, such small vehicles have a comparatively short crumple zone leading to a higher risk of occupant injury in case of frontal collision. In this paper, the structural performance and energy absorption of aluminum alloy AA6063-T6 thin-walled front bumper beams for heavy quadricycles are studied. Mechanical characteristics of the beams with simple cross-sectional profiles, i.e., square, rectangle and double-cell rectangle as well as a commercially available bumper beam of a heavy quadricycle under cylindrical-rod impact loading are investigated through finite element analysis using LS-DYNA. A parametric study is also performed to examine the effects of open and closed sections, different cross-sectional shapes and various fillet radii on impact responses of the bumper beam including energy absorption, specific energy absorption, peak force, and crush force efficiency. The results show that although section profiles with sharp corners possess higher energy absorption, a larger fillet radius could mitigate the unfavourable peak force from impact up to 40%. The partition plate of the double-cell rectangle section induces a much higher peak force compared to others. In addition, when comparing an open-section beam with closed-section beams, it is found that an open-cell hat-shape model with fillet radius of 8 mm is the most efficient design. The crush force efficiency and peak force of the section are 32% higher and 17% lower, respectively, when compared to the closed-cell section with fillet radius of 8 mm.
Investigation of power transfer efficiency: utilizing different coil designs in wireless charging of electric vehicles
Authors: Thein M. E. , Charoensuk J. , Masomtob M. , Onreabroy W. , Kaewpradap A.
Published: May 2021

EV battery can be wirelessly charged by inductive coupling method between two electromagnetic couplers. In this study, the transmitter and receiver coils are designed. The effect of the number of turns for transmitter and receiver coils are studied. The results show that efficiency is decreased with the reduction of turns for both coils. Next, the spacing between each turn of coils is analyzed by 1mm of increasing for each simulation and the increased efficiency is only 2.6% for every 1mm spacing. Then, the power transfer efficiency is investigated for different coil designs. The efficiency can be improved with the proper consideration of air gap length, operation frequency, suitable coil designs and coil properties. Five coil designs such as circular, rectangular, double-D, double-D quadrature (DDQ) and bipolar designs are selected. The best design for maximum power transfer efficiency is DDQ design but the structure is complex since more wires are used in this design. The air-gap length between two coils is selected as 120mm and frequency is 85 kHz in this study.
Influence of axial force and characteristics of axial force affecting on total knee replacement constraint test
Authors: Musikul Tanapat , Kitkamthorn Usanee , Mitsomwang Pusit , Sindhupakorn Bura , Borrisutthekul Rattana
Published: May 2021

The result of testing for determination of Total Knee Replacement (TKR) Constraint (ASTM F1223) is necessary for surgeons for matching the knee prosthesis with the different degrees of severities of knee osteoarthritis patients. In the knee replacement constraint test, the axial compressive load and translation displacement are the control and the adjusting variables. The magnitude of axial compressive load during testing is affected by the slope of knee bearing surface. According to ASTM 1223 standard, the axial compressive load is not clarifyingly mentioned. Namely, it should be equal 710 N during testing or only in state of initiation. It may lead to testers to perform the test into different two modes which consequently in possibly different constraint result. Therefore, the objective of this research is to clarify the differences in test results when applying two axial compressive load characteristics during testing. The six-axis testing machine (Prosim Universal Joint Simulator) was used to determine the anterior posterior constraint (AP) of fix bearing posterior sacrifice (FB PS) system. Bovine serum was directly applied to the bearing surfaces as a lubricant. An initial axial compressive load 710 N was used. Two axial compressive load characteristics during testing, 1) keeping the axial force at given value as mentioned during testing (load-controlled testing) and 2) with allowing the change in axial compressive load during testing (displacement-controlled test), were used. From the results, the AP load resistance hysteresis loop patterns obtained by both testing modes were similar. The magnitude in forward direction load resistance is higher, while the backward AP load resistance showed the lower, in case of displacement control mode. It resulted in span between AP load resistance was larger. Moreover, the higher constraint in case of displacement control was indicated. Thus, if the test modes are not mentioned in test result, the surgeons will be possibly choosing the wrong TKR for their patient.
Stress analysis in upper fillet and rail-end bolt hole at rail joint
Authors: Le SaiKham , Wongsa-Ngam Jittraporn
Published: May 2021

Rail joint between two adjacent rail ends in the transportation of railway track structure is one of the weakest components leading to defects and failures. In this study, the rail joint components such as rail, joint bars, bolts, and sleeper are modelled by 3D Abaqus/CAE software and Finite-element method are used to investigate stress distribution in rail under static wheel load condition. The wheel load positions and bolt-hole locations vary as a parametric study. The results show that the critical stress occurs at the upper fillet rail end and at the edge of the rail-end bolt hole (1st hole from the rail end). The wheel load position affects stress only in case of the rail-end bolt hole located at 80 mm from the end. In addition, overall trends for the effect of rail-end bolt hole positions are similar in which the stress decreases when the distance from rail end to the rail-end bolt hole increases. Taken together, these findings suggest stress distribution is the basic information that helps understand the failure mechanism.
Line tracking control of royal Thai air force nursing mobile robot using visual feedback
Authors: Moudpoklang Jeerasak , Pedchote Chamnan
Published: May 2021

The specific objective of this study was to design a Royal Thai Air Force (RTAF) nursing robot, so-called Thadloom, to assist medical personnel in delivering food, medical supplies and communicating remotely with patients during the COVID-19 pandemic. This study also seeks to develop many identical mobile robots to be used in concerned places, such as hospitals or clinics, to reduce the risk of infection to medical personnel when entering the controlled area COVID-19-patients. This paper presents the design and implementation of real-time vision systems for the RTAF nursing robots when used in the controlled area of COVID-19-patients, with a capacity of delivering food and medical supplies automatically. The robots were able to follow lines on the floor using visual feedback. A contour tracing algorithm was implemented for line identification and position estimation. Linear segments with parabolic blends were used for the robot’s trajectory planning. The robot can track a line on the floor effectively by employing a PID controller. This experimental result showed that the developed vision-based state estimation and the designed PID controller. It was also found that it received a good satisfaction towards the accuracy of the position within 3.5 centimeters, i.e., The distance from the center of the robot to the center of the line.
Numerical investigation of air flow in a vertically paddy bed dryer using computational fluid dynamics
Authors: Chaiworapuek Weerachai , Chuenboonma Nuttakorn , Thungthong Teerapat , Munprom Ratiporn , Sae-tan Sudathip , Onwimol Damrongvudhi
Published: May 2021

This research focuses on the numerical investigation of air flow in a vertically paddy bed dryer using computational fluid dynamics - CFD. In this study, the Tubtim Chumphae paddy and perforated plates were assumed to be porous media and their properties were characterized experimentally in a 0.05 m × 0.05 m × 1 m duct. In this paper, the obtained porosity and permeability were applied to a numerical model, the air flow through a 100 kg paddy, stored in a vertical bed dryer. The results from the simulation and experiment agreed well with each other via the calibration process. The pressure drop across the dryer was found to increase when the inlet velocity gained from 0.025 to 0.1 m/s with an increment of 0.025 m/s. In this study, the results showed that air flow was controlled past the paddy with the deviation of less than 2.82% to achieve a high rice quality after the drying process. Because this drying technique used low temperature air and had low energy consumption, therefore, it is found to be one of the promising techniques and truly benefits the farmer in the future.
Energy management of precooling process for green cabbages
Authors: Naemsai Thanwit , Niyomvas Banyat , Jareanjit Jaruwat
Published: May 2021

Cold storage is one of the most widely used and effective processes to preserve shelf-life harvested agricultural products during long periods. Research to date has not yet determined the energy management of pre-cooling methods of green cabbage. This study seeks to investigate the cooling performance of the cold storage, keeping green cabbages with good quality and to report different pre-cooling strategies. The cold storage specifications included 15 HP compressor with a voltage of 380 V, a temperature range of -50 to 50°C, and R22 refrigerant. The mass of green cabbage was examined with three values of 30, 40, and 50 kg. Moreover, the pre-cooling strategies of the green cabbages were divided into four scenarios including the parallel pattern in the front zone, staggered pattern in the front zone, parallel pattern in the back zone, and staggered pattern in the back zone. The experimental results revealed that the coefficient of performance (henceforth COP) was significantly affected by the mass of the cabbage and cooling zone of the cold storage. While the pattern in case of 30 kg cabbage precooling had a slight effect on cooling performance due to the lower density arrangement and heat extraction. The highest COP appeared at the 30 kg cabbage precooling with the strategy of staggered pattern in the front zone. The COP value was 2.61.
Numerical study of performance augmentation of a vertical coil and shell heat exchanger using high frequency ultrasonic waves
Authors: Chaiworapuek Weerachai , Chungprempree Jirameth , Pukrushpan Jaytawee , Khaothong Kunthakorn
Published: May 2021

This research focuses on the performance augmentation of a coil and shell heat exchanger using high frequency ultrasonic waves by the commercial computational fluid dynamics program FLUENT. The model was validated both heat transfer and ultrasound propagation with the results from other researchers. Then, the simulation of the flow and heat transfer enhancement in the heat exchanger under 1.7 MHz ultrasound. Four ultrasonic transducers were installed at the corners of the shell at the middle height of the coil. The ultrasound from transducers was emitted to induce the vortex flow in the shell with the angle of 0, 15, and 30 degrees with the horizontal line. The results show that the high frequency ultrasound is applicable for heat transfer enhancement of a shell and coil heat exchanger. Therefore, the obtained results can be used to innovate an ultrasonic coil and shell heat exchanger in the future.