bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on Electric Harvesting of Combine Harvester
Authors: Yang Zhengtao , Wang Haili , Sun Han , Wang Pengfei , Cao Qixin
Published: March 2022

The electrification and intelligent transformation of harvester to make it have independent operation ability is an important embodiment of the development trend of agricultural automation and intelligence. Based on a full feed combine provided by relative company, this paper makes an electric transformation for its reaping and threshing part, including mechanical design, electric circuit construction, brushless DC(Direct Current) motor installation and test. Based on the finite automatic state mechanism, the control system of the electric operation part is built. Its sequential start and stop functions, reel speed following function and blockage detection and discharge function are tested in no-load experiment and farmland harvesting experiment. Through the continuous wheat harvesting test for 30 minutes, the power characteristics when harvesting wheat are measured, and the stability of its work is verified.
Research on the Friction Pairs in Water Hydraulic Piston Pumps
Authors: Yang Yousheng , Yankey Richmond Polley , Li Hao
Published: March 2022

Power control hydraulics (PCH) has one of the most versatile research fields and technologies that has many applications especially in the mechatronic industries. It also comes with drawbacks especially with issues concerning the use of mineral oil as a pressurized fluid in most of it applications. Furthermore, in the mechatronic field, researches in the ocean environment has become more difficult due to mineral oil incompatibility with the ocean water. One of the most accepted solution is to find alternatives to mineral oil as a PCH pressurized fluid which has led to water being the safest candidate. As a result, more researches have been carried out on water as a pressurized fluid in PCH systems. Axial hydraulic piston pump has been one of the best pumps for PCH systems. It was realized in this paper that, more options for material selection for the friction pairs were available and therefore water hydraulics can realize its main goals of providing a safe environment as well as being cost-effective. This paper seeks to review the various material friction pair selection that has been suggested by various researchers in this field and analyze their various methodologies and experimentations.
Dynamic Analysis of Rudder Transmission Mechanism Considering Clearance Joint and Friction
Authors: Zhang Tao , Liu Geng , Ma Shangjun
Published: March 2022

Based on the theory of multi-body dynamics, this paper proposes typical impact model and friction model to research the dynamic characteristics of the transmission mechanism with clearance joints in ADAMS softwear environment; On this basis, considering the hinge gap and friction factors under the rigid condition of the mechanism, a multi-body model is developed. Dynamic simulation analysis has studied the influence of five hinge gaps and three friction coefficients on the speed and output displacement of the rudder transmission mechanism. The research results lay an important foundation for the further development of the rigid-flexible coupling and thermal-mechanical coupling dynamic characteristics of the rudder transmission mechanism base.
Design and Experiment Study on Three-dimensional Rotating Ultrasonic Composite Generating Electrolysis Machining
Authors: Cheng Wanwan , Li Jing , Ge Zhenghui , Zhu Yongwei
Published: March 2022

Proposed a multi-dimensional rotating ultrasonic composite electrochemical generating machining method. Designed and built the shaft and radial three-dimensional rotary ultrasonic composite electrolytic generating machining system, analyzed and studied the machining mechanism according to the interaction relationship between rotary ultrasonic, mechanical and electrolysis.Selecting and optimizing the machining parameters for to machine plane by grinding, ultrasonic and rotary ultrasonic composite electrolytic machining. By the tests, the machining system is stable and reliable, and the rotary ultrasonic composite electrolytic generative machining technology could effectively improve the machining efficiency and accuracy. Adding 3µm-5µm radial ultrasonic vibration, carried on the rotating ultrasonic generating machining the plane and cutting the grooves, the technical advantages of two-dimensional rotary ultrasonic composite electrochemical machining are verified.
Angle Steel Tower Bolt Installation Detection Based on Simplified Attention Mechanism
Authors: Zhang Jinfeng , Zhang Tianzhong , Lou Yihua
Published: March 2022

Incorporating position and channel attention into the image semantic segmentation network is an important strategy to improve the segmentation effect. However, there is a huge computational overhead in counting the correlation between any two positions or channels. To address the issue, this paper proposes a simplified attention mechanism network integrating position attention and channel attention. In addition, to further optimize the segmentation results, this paper adopts a new data-dependent upsampling method to expand the high-level feature map to the input size. Compared with the traditional attention network, our method reduces 32.6% of parameter and calculation amount, and obtains an average cross-comparison result of 95.42% on the dataset of angle steel tower bolt.
Realization of Parameterized Serialization Design of Flanges in Chemical Equipment
Authors: Liu Dongchen , Wang Junli , Zhang Yan
Published: March 2022

Flanges are important parts in the fields of machinery, chemicals, wind power, and sewage treatment. They are used in large quantities and have formed a series of products at present. In the paper, the secondary development of AutoCAD was adopted to parameterized series design, and 960 parts from 4 series flange (plate flat welding flange, neck flat welding flange, neck butt welding flange, socket welding flange) were drawn. The efficiency of part design has been significantly improved.
Research and Development of Electric Power Lifting Truck
Authors: Yao Zhao , Li Hejia , Zhou Liang
Published: March 2022

Equipment and materials are completely dependent on large machinery and human forklift, which is difficult to ensure the high efficiency of transportation. As a supplement to large transportation machinery and vehicles, it can make up for the lack of low transportation capacity of human-based transportation equipment, and solve the prominent problems such as backward material transportation equipment, poor road adaptability, time-consuming and laborious. The electric power assisted lifting truck to be developed can realize “one kilometer” of materials the transportation reserve with high travel efficiency has become the “range extender” of large vehicles. With the help of high and new technology, the R & D of electric power assisted lifting truck adopts the contractor guarantee mode to realize complementary advantages, resource sharing, joint development and win-win cooperation, so as to provide technical support for material support. The electric power assisted lifting truck is mainly composed of walking system, lifting system, control system and auxiliary system, which meets the needs of strong road trafficability, time-saving and labor-saving, simple operation, convenient maintenance, safety and reliability and low cost, and improves the rapid, accurate and convenient guarantee ability of materials.
Research on Design of the D-knotter Split Spindle
Authors: Guo Jiayu , Cen Haitang , Tang Hao , Shuang Zihan , Na Risu
Published: March 2022

The knotter is the core component of the square baler. The structure of the knotter is complex, the working load is large and the working environment is bad, which makes the knotter easily damaged. The imported D-knotter is widely used at present, once the parts are damaged, they often need to be disassembled and assembled as a whole, which takes a long time and seriously affects the efficiency of field operation. Aiming at the problem that the D-knotter assembly and its parts are inconvenient to replace after damage, this paper designs the split spindle of the knotter, and ensures the strength requirements of the spindle when working through an integral key connection. When replacing the knotter parts, the spindle is separated from the middle, and the knotter assembly is directly removed without removing other parts on the spindle, which obviously saves the replacement time of the damaged parts of the knotter. The statics and modal analysis show that the split spindle of the knotter can meet the strength requirements, and the spindle does not produce resonance.
Structural Design and Analysis of Part of Manipulator
Authors: Ma Yan , Jiang Xingqiao , Xu Jingxi , Liu Huang , Yuan Yue
Published: March 2022

In this paper, the manipulator can carry and grasp objects as the research object, manipulator is mainly composed of hands and motion mechanism. The adsorption type hand is mainly composed of suction cups and so on. The design object has three degrees of freedom, through the stepper motor and ball screw to complete the telescopic arm, through the cylinder to complete the lifting of the adsorption part, the workpiece from one coordinate adsorption and transport to another coordinate. Air suction hand structure design, hand calculation, cylinder control loop, cylinder working pressure, cylinder gas consumption analysisis presented.
Research on Fuzzy Control Algorithm of Self-walking Platform for Maintenance of Circular Tunnel
Authors: Liu Hao , Zhang Wen , Wu Zhenglong , Guo Tieying , Luo Dan , Peng Weiping , Zhang Tao
Published: March 2022

Self-walking platform is used to support subway tunnel maintenance and construction. However, the kinematics model and motion control of the subway tunnel self-propelled platform are different from that of the plane, it is a non-holonomic constrained system with serious sliding, strong coupling and highly nonlinear, and the pipeline environment is complex, so it is difficult to accurately model. In order to solve these differences, the kinematic characteristics of wheels in cylindrical workspace are discussed first. The geometric constraints of self-walking platform in circular tunnels are also analyzed. Secondly, considering the complexities of self-walking platform motion model, a control algorithm based on fuzzy logic is proposed. Finally, through MATLAB and ADAMS joint simulation, the scenarios for virtual platform moving in circular tunnels are simulated, which shows the effectiveness of the algorithm.
An Adaptive Threshold Selected Method from Remote Sensing Image based on Water Index
Authors: Qi Yanan , Dou Hongtao , Wang Zhaoming
Published: March 2022

Water is one of the most common and important objects on the earth, and its extraction is of great significance to many related researches in remote sensing domain. Water index method is most commonly used, and the accuracy of image interpretation is an unavoidable problem. However, traditional interpretation methods are subjective, and the efficiency of interpretation is relatively low. An adaptive threshold selected method based on modified normalized difference water index (MNDWI) is proposed here to extract water completely and accurately from remote sensing image. First, the study compares the effect of three commonly used water index methods (NDWI, MNDWI and MBWI) to extract water in Baiyangdian watershed, the result shows that MNDWI is better in separating water from background; then, a probability index method integrated water Z-score (IWZ) is used to segment MNDWI results. It shows that the optimized result with IWZ is more accurate than the traditional result with 0 as the dividing point, the former is 5% higher accuracy than the latter.
Research on Identification and Calculation Method of Moment of Inertia of Virtual Synchronous Generator
Authors: Guo Fusheng , Lv Zhiyuan , Bai Hao , Liu Dapeng , Wang Yongqing , Li Weichao
Published: March 2022

Because wind power itself does not have the ability to automatically adjust the frequency, the current continuous increase in the proportion of wind power in the grid makes it difficult for the frequency stability of the system to meet operating requirements. VSG control is to introduce the mathematical model of the synchronous generator into the control strategy of the inverter to make the inverter show the characteristics of the synchronous generator. As a control strategy of the inverter, Virtual Synchronous Generator (VSG) has flexible and adjustable control parameters. Features. This paper first analyze the current equivalent inertia calculation method. Based on the above-mentioned equivalent moment of inertia research method, a new improved equivalent inertia calculation method is proposed. The improved method further reduces the error on the base of the original method. At the same time, the amount of calculation is greatly reduced, which is of great significance to the stable calculation of the power system.
Numerical study of the effect of Inlet paired Swirl on Performance and Stability of Axial compressor
Authors: Cai Beijing , Liu Kaili , Yang Liu , Yang Xinyu , Guan Jian
Published: March 2022

In order to study the effect of inlet paired swirl distortion on the performance and stability of compressor, a full-annulus unsteady numerical simulation of the effects of swirl distortion on performance and stability of transonic rotor Rotor 37 is carried out in this paper. The result shows that: the rotor performance deteriorates and the stable working range decreases under the effect of vortex flow distortion; the circumferential side flow caused by vortex swirl distortion leads to the uneven circumferential distribution of flow parameters at the inlet and the outlet of the compressor; the rotor blade has a very significant attenuation effect on the swirl distortion, and the swirl distortion intensity decreases along the axial direction; the circumferentially inhomogeneous distribution of rotor angle causes excessive local aerodynamic load on the rotor, and high intensity leakage vortices and excitation vortices are generated at the blade tip. The circumferentially unevenly distributed swirl angle causes excessive local aerodynamic load of the rotor, resulting in high-intensity leakage vortex and shock wave interference in the blade tip area, which severely blocks the flow path and eventually leads to unstable flow in the Rotor37.
Optimization Study of Nacelle mounting position for Blended-Wing-Body Aircraft
Authors: Yang Liu , Liu Kaili , Zhong Yuan , Zhou Shirui , Cai Beijing , Yang Xinyu
Published: March 2022

Blended-wing-body aircraft is a new type of aircraft form that has been used in military aircraft. The potential for application in civil aircraft is being explored. Due to its special shape, the blended-wing-body aircraft is difficult to adopt the conventional under-wing engine mounting form, and usually applies the back braced mounting. The engine mounted on the back could cause surge and separation problems, which affects the flow field quality of the whole aircraft. In this paper, the effect of height and axial mounting position on the overall flow field of the aircraft is determined by modelling and calculation of the blended-wing-body aircraft. The effect of airflow separation is analysed. The engine axial mounting position is discovered to have a significant effect on the elimination of flow separation.
Modeling and simulation of equipment support scheme based on Agent
Authors: Guo Lu , Liu Xiaodong , Wei Dongtao , Zhu Pu
Published: March 2022

The core of missile equipment support task is to improve the availability of equipment. Support scheme simulation is an economical, feasible and efficient method to evaluate the effect of equipment support. According to the characteristics of air defense missile equipment, the modeling framework of missile equipment support scheme based on Agent is proposed, and the state change warning modeling and equipment support scheme modeling are carried out. The simulation process and concrete implementation method are explained. Finally, a certain type of missile equipment is taken as an example to verify the simulation results. The simulation results show that the established model can reflect the actual health status of the equipment, and the availability of the equipment can be improved according to the maintenance support strategy given by the simulation.
Effects of Forebody on Supersonic Parachute Aerodynamic Performance
Authors: Kou Zp , Zhan HR
Published: March 2022

As a typical aerodynamic deceleration device, supersonic parachute is widely used in aerospace return and recovery. The influence of the precursor on the aerodynamic performance of parachute is very important due to operating conditions under the wake of the precursor.In order to study the effects of supersonic forebody wake on parachute performance, numerical simulation of supersonic parachute is carried out, and the calculation results are in good agreement with the results of the wind tunnel test. The flow characteristics and flow field distribution of supersonic parachutes under free flow are analyzed. On this basis, the flow field characteristics and distribution laws of forebody and parachutes under different inflow Mach numbers and the aerodynamic characteristics of parachutes are studied. The results show that the compression wave and expansion wave generated by the forebody are reflected through the wall, and the reflected wave alternately appears in the downstream flow field. Affected by the forebody wake and reflected waves, the inflow velocity of the parachute has been asymmetrically distributed, and the velocity in the upper area has been seriously attenuated.
Functions and effective generation conditions of typical switched reluctance power generation systems
Authors: Tian Yuan , Zhan Ye , Hu Chunhong , Zhang Lijing
Published: March 2022

Switched Reluctance Motor (SRM) is a new type of high technology motor used in the most advanced warplanes. This paper combines the principle of SRM and takes the typical SRM power generation system of modern warplanes as an example to analyze the functions and power generation process of each part of the system, as well as its effective power generation conditions.
Numerical Research on the Simulation Nacelle of Ejector Engine
Authors: Du Xubo , Chen Pengfei , Yang Qingzhen , Chen Yuxi
Published: March 2022

The numerical simulation research of single-nozzle center ejector and double-ducted multi-nozzle ejection nacelle was carried out to study the dynamic simulation nacelle under variable working conditions required by advanced aero-engine test technology. The shock wave structure and blocking effect in the supersonic central ejector are analyzed in detail, and the internal flow field characteristics of the ejector under the condition of non-central axisymmetric supersonic ejection were examined. The aerodynamic characteristics of the single-ducted and double-ducted ejector nacelles are studied; and the flow field simulation with analyzation of the inner and outer ducts under the condition of variable duct ratio was carried out. The relevant conclusions obtained from the research can provide theoretical guidance and reference for the analysis of the multi-condition test run of the aero-engine test cell.
Analysis of Flow Pattern of Turbulent Boundary Layer Jet in Rectangular Nozzle
Authors: Mu Guozhen , Lyu Qiongying
Published: March 2022

The design of the rectangular nozzle affects the thrust and stealth performance of the propeller. The relationship between the outlet area and the jet flow pattern is studied through the simulation analysis of three different outlet area rectangular nozzles with an aspect ratio of 8. From the simulation results, it can be seen that the exit area under a single variable determines the value and range of the jet Mach number, which produces a huge change in the mixing zone of the turbulent boundary layer, but it has nothing to do with the development trend of the near and far field.
Analysis of Turbulent Boundary Layer Jet Flow Pattern of Laval Nozzle
Authors: Mu Guozhen , Lyu Qiongying
Published: March 2022

The rationality of the structure design of the Laval nozzle directly affects its work efficiency. The simulation software is used to simulate and analyze the structure and operating conditions of the Laval nozzle, and to find the relationship between the change of the turbulent boundary layer jet flow pattern. From the simulation results, it can be seen that the outlet diameter under a single variable cannot directly determine the value and range of the jet Mach number, but it produces a huge change in the mixing zone of the turbulent boundary layer, which directly affects the turbulent kinetic energy.
Research on Cascading Effect Analysis of Civil Aircraft WOW Signals Failures
Authors: Wang Yuqing , Shi Zhijian , Zheng Youshi
Published: March 2022

The WOW signals of landing gear system are important signals for most aircraft systems to judge the state of the aircraft in the air or on the ground. As common signals adopted by multiple systems, it has a wide range of failure effects and it is difficult to determine the failure effects consequences. In this paper, cascading effect analysis is used to evaluate the safety effects of WOW signals failures. The method of identifying the initiating condition of WOW signals is given, and an initiating condition is taken as an example to analyze its direct effects and indirect effects. On this basis, the aircraft-level comprehensive safety assessment is carried out to obtain the comprehensive classification of the initiating condition. Compare the comprehensive failure effect analysis results with the source analysis to evaluate whether they meet the safety requirements.
Coupled analysis of a high rate of fire artillery considering temperature rise
Authors: Jian Runji , Zhang Xin , Li Hao , Liu Xianfu
Published: March 2022

In order to study the influence of the temperature rise of the inner chamber on the dynamic characteristics of the projectile during the continuous firing process of the artillery, the thermal-mechanical coupling finite element model of the projectile and the barrel is established based on the damage effect of the projectile and the ductile damage fracture. The dynamic characteristics of the projectile in the process of squeezing into the projectile after continuous shooting are obtained by calculation, and the influence of different numbers of continuous fire on the movement characteristics and force of the projectile is discussed. The research results show that the temperature response of the wall of the barrel inside the barrel rises in a regular and periodic pulse-like shape during burst shooting; the temperature rise after 7 bursts and 20 bursts has an effect on the movement, force and structural strength of the projectile in the bore. The impact is not obvious.
An Analysis of Vision Based Soft Landing
Authors: Hou Beiran
Published: March 2022

The soft landing based on visual analysis is of great significance to planetary exploration, and there is also a good development prospect in the future. This paper introduces the process of soft landing technology and the working process of the landing camera. Taking Chang’e-3 as the main example, using methods such as descent image processing and SIFT feature matching, it explains the algorithm of Chang’e-3 to complete high-precision positioning and the process of autonomous hazard avoidance during landing. Also the accuracy of the positioning point is analyzed, which shows the effectiveness of the positioning method.
Research on calibration of accelerometer combined Norm-observation method based on global optimization
Authors: Zhang Xiaolong , Wang Shiming , Li Yibin
Published: March 2022

This paper provides a method for the overall calibration of the accelerometer combined error model coefficients. The calibration of the accelerometer error coefficients is achieved by using the Norm-observation method. It is important to achieve the calibration of the quadratic coefficient of the accelerometer. First, the Tylor series is used to expand the solution of the acceleration model, the nonlinear equations to be solved are obtained by using the least square method and Norm-observation method. Finally using 1stOpt platform of global optimization algorithm for the solution of equations for quadratic order coefficient, scale factor and zero bias. A 12-position method is designed to calibrate the accelerometer combination, the effectiveness of the method is verified by simulation.
Study on the influence of typical faults in AC area on DC voltage
Authors: Ren Hongtao , Lv Huiqing
Published: March 2022

By summarizing the architecture and operation control of the existing models, this paper establishes a typical DC power distribution structure model, and studies the wiring mode and working principle of the converter. For the DC distribution network under VSC pseudo bipolar operation mode, when considering the grounding mode, we focus on the neutral point of the connection transformer on the AC side, the filter neutral point on the AC side and the capacitor neutral point on the DC side. The causes and recovery process of DC positive and negative unbalanced voltage are analyzed. Begin in the asymmetric fault in the AC area, the paper proposes the cause and recovery process theory of unbalanced voltage of capacitors on DC side, the paper also analyzed the fault characteristics in AC area, and proposes the suitable grounding mode.
Electric vehicle charging station planning method based on charging service capacity quantification and distribution grid acceptance capacity constraints
Authors: Yang Yang , Wei Mengju , Liu Zhao , Wang Yongli , Qin Yumeng , Liu Zhen , Zhou Xiangyi
Published: March 2022

The planning of EV charging stations that integrates the quantification of charging service capacity and distribution grid acceptance capacity constraints is of great significance for the synergistic development of EVs and distribution grids. The charging service capacity quantification of the charging network is analyzed to derive the basis for judging whether the electric vehicle traffic on the path can be captured; with the objective of minimizing the total cost of construction and operation, a charging facility planning model is established, and the distribution grid acceptance capacity constraint is set, and the genetic algorithm is used to solve the problem, and the best planning scheme for electric vehicle charging stations is finally derived.
Research on Operation Management Technology of Cable Joints of Ring Network Cabinet Based on Temperature Sensors
Authors: Shang Shuning , Liang Guangsheng , Liu Changhua , Chen Jin , Shang Qiongling , Yu Jie , Chen Zhongbin
Published: March 2022

In this paper, aiming at the operation and maintenance of the internal cable joints of the ring main unit, the research on the operation and management technology of the ring main unit cable joints based on temperature sensors is carried out. Starting from the principle of temperature sensing technology for cable joints, an online temperature monitoring system for the cable joints of the ring network cabinet is developed during the operating cycle. Comprehensive consideration of factors such as seasons, ambient temperature and humidity, line load current, etc., to evaluate the operating status of the cable joint temperature data as the main basis. A simple and adjustable bracket suitable for the fixed installation of the non-contact temperature sensor of the ring main unit has been developed. A method of managing the cable joints of the ring main unit during the operating cycle is proposed to realize the effective evaluation of the cable joint status. It can greatly improve the accuracy of condition monitoring, and improve the efficiency and level of operation and maintenance.
Analysis of ultrasonic partial discharge characteristics of GIS’s reducing unit based on Finite Element Method
Authors: Gong Duohu , Chen Wentao , Zhan Zhongqiang , Dilyar·Dolkun
Published: March 2022

GIS’s reducing unit is a new and environment-friendly structural unit, which can greatly reduce the consumption of aluminum alloy material and insulating gas. The structural size of this unit is much smaller than the conventional one. In this paper, an acoustic-structure coupling interaction model of partial discharge in reducing unit of gas insulated switchgear (GIS) is presented. The interaction between the internal acoustic source of partial discharge and structure of GIS is simulated with the finite element analysis, and the acoustic pressure levels distribution of GIS is obtained. The results show that the sound pressure distribution of the reducing unit is basically the same as that of the conventional one, but the amplitude is larger. At the same time, the high-frequency part of the acoustic signal attenuates more quickly in the reducing unit. This paper provides a theoretical guidance basis for the ultrasonic partial discharge detection of the GIS reducing unit.
A novel distributed secondary voltage control method for AC microgrids based on voltage observer
Authors: Liu Jiayu , Tang Min , Zhou Jian , Zhang Qiqi , Zhang Luyuan
Published: March 2022

Since the islanded AC Microgrid is affected by the impedance of line, it is difficult to coordinate the voltage regulation and reactive load distribution. A distributed secondary voltage controller based on observer is proposed for isolated AC Microgrids, and it does not need more voltage communications. This method can guarantee the estimated average voltage equals to average of actual output voltages that can converge to the nominal values, and realize accurate proportional load sharing in a microgrid. Then, the convergence of the voltage observer is proved. Finally, the proposed control method is verified by time-domain simulation.
Research on the Characterization of Electric Vehicle Energy Storage Capacity and Coordination Mechanism with Distribution Network Based on Two-stage Method
Authors: Ma Dong , Song Yujiao , Zhou Zhaohui
Published: March 2022

This paper firstly analysed the characteristics of electric vehicle movement behaviour in multiple dimensions, extracts the correlation among electric vehicle energy storage characteristics and driving behaviour, state of charge (SOC), and charging behaviour, establishes a regional vehicle state transfer machine model, and dynamically adjusts the parking status of electric vehicles. Based on the measured data of electric vehicle charging, the probability distribution of charging behaviour parameters and their correlations were modelled in detail, the electric vehicle load was predicted, and the electric vehicle charging load model was established, and the available capacity assessment method was proposed.
Research of Thermal Behaviour of Li-ion Battery Module Based on Liquid Cooling
Authors: Guo Zhenqi , Zeng Fancong , Jiang Zhebin
Published: March 2022

An effective battery thermal management system (BTMS) is crucial to ensure the battery temperature in an appropriate range and prolong the battery life. In this paper, a liquid cooling thermal management method for a li-ion battery module which is consisting of 12 prismatic batteries is set up, three circuitous channels embedded with a cooling plate are studied. Meanwhile, the performance evaluations of the battery module by considering different cooling conditions and battery arrangement are investigated numerically. The effects of the flow area of cooling plate and mass flow rate of coolant on the peak temperature and temperature difference of the battery module during charge/discharge process are examined. The larger flow area is experienced with a lower maximum temperature. Increases of maximum temperature and temperature difference are shown at lower mass flow rate. This paper provides guidance for the design and optimization of the module and thermal management.
Operation optimization study of integrated energy system based on multi-energy complementary
Authors: Jia Shaokun , Xu Jian , Pan Yaqi , Tian Liyue , Gu Rui
Published: March 2022

Integrated energy systems integrate power and heat supply systems, and explore the energy saving potential of the systems by means of multi-energy coordination. For two typical multi-energy complementary integrated energy systems, the key factors affecting the system energy consumption are searched for, based on which a comprehensive evaluation model is established, and then a coordinated control method is proposed, which can be used to guide the operation optimization of the multi-energy complementary energy system.
Clinical study of injectable collagen scaffold with autologous fat cells for repair of severe vocal fold injury
Authors: Jin Xiaofeng , Liu Weiyuan , Wang Jian , Xiao Zhifeng , Niu Yanyan , Chen Bing , Zhao Yannan , Dai Jianwu
Published: March 2022

Cell retention and survival after transplantation remains a major problem for long-term efficiency in therapy of severe vocal fold injury with autologous cells. In this study, injectable collagen scaffold was used to deliver autologous fat cells (AFCs) for repairing of severe vocal fold injury. We found injectable collagen scaffold could enhance the retention and survival of green fluorescent protein (GFP) labeled fat cells in the transplantation sites in rats. Based on these data, a randomized controlled clinical trial was conducted to evaluate the safety and efficiency of transplantation of collagen scaffold with AFCs for severe vocal fold injury. Ten patients with vocal fold paralysis were randomly assigned to control (AFCs only) and intervention (AFCs + collagen) groups. AFCs with or without collagen scaffold were injected into vocal folds of patients under general anesthesia, respectively. The safety and efficacy were regularly assessed during 24 months post-surgery. No obvious complications occurred in all patients during the follow-up. The collagen scaffold maintained the stability of implants after injection and reconstructed the vocal fold structure. The improvement of voice quality of patients was observed through voice quality evaluation with the voice handicap index (VHI) questionnaire, as well as acoustic analysis of maximum phonation time, jitter, and shimmer. The VHI score of patients in AFCs + collagen group improved significantly than those in AFCs group at 6, 12 and 24 months post-surgery. It demonstrates the injectable collagen scaffold is safe and efficient for delivering AFCs for vocal fold injury.
Assessment of causes and control of fire disaster in Arepo neighbourhood, Ogun State, Nigeria
Authors: Oloke O.C. , Oluwatobi A.O. , Oni A. , Oke D.
Published: March 2022

This study examined the occurrence of fire disaster in Arepo community of Obafemi-Owode Local Government Area of Ogun State with emphasis on residential buildings. Questionnaires were administered to 210 adult residents of the neighbourhood while only 150 valid questionnaires are subsequently used for the analysis. Responses were measured on 5-Point Likert scale while the mean score, relative important index as well as frequency and percentages were also used for the analysis. Results were presented with Tables and charts. The study found that residential fire disaster ranked 2ndamong the six segments/object of fire disaster that had occurred in the community. It was further observed that faulty electrical appliances, carelessness and faulty cooking gadget ranked 1st, 2ndand 3rdamong the causes of residential fire outbreak in the neighbourhood and that majority of residential housing units are ill-equipped against fire outbreak within the residential neighbourhood in the community. The study therefore concluded by suggesting that government provide firefighting station in the community of Arepo and that the general public has to be enlightened on the importance of providing active firefighting equipment such as fire alarm system, smoke detector, flame detector, heat detector fire extinguisher etc. in their homes.
Production and purification of biogas from cassava peel using cow dung as inoculum
Authors: Fagbenle E.O. , Olukanni D.O.
Published: March 2022

The study examined biogas production from cassava peel and cow dung due to the large quantity of cassava peel disposed at dumpsites in local cassava processing sites. A 200L biodigester was used for the experiment. It contained 25 kg of cassava peel, 25 kg of cow dung and 100 kg of water in the ratio of 1:1:4, respectively. A cumulative volume of 937.3L of biogas was generated after the 30 days digestion period. The biogas generated was pass through a combined absorption and adsorption pre-treatment process to reduce the concentration of impurities in the biogas. The procedure had a 91.5% CO2removal efficiency and 88% H2S removal efficiency. The biogas, after purification can be used for cooking. Also, the digestate from the anaerobic digestion process is rich in NPK, which can be used as fertilizer.
Experimental investigation of contaminated clay slabs for X-ray shielding
Authors: Egbeyale Godwin Babatunde
Published: March 2022

The advent of radiation is a challenge to the human race therefore; a suitable material is a solution to effective radiation shielding. This research aims to investigate the effectiveness of clay slabs mixed with some heavy metals in radiation shielding. Thereafter, absorption coefficients (mass and linear) were calculated from both incident and transmitted intensity measured with a detector at different energies: 40 keV, 60 keV, 80 keV, 100 keV,120 keV, 150 KeV and 200 Kev. The following procedures were taken: the clay was mixed with heavy metals (Lead, Nickel Cadmium, Zinc and Copper) using the ion exchange capacity technique and then slabs were moulded using a wooden frame of dimensions 4 cm x 4 cm x 1 cm. A narrow collimated beam transmission geometry condition was used for the measurements. The measured values of these parameters were in good agreement with the literature. At selected energies, the values of linear and mass attenuation for lead were 2.29 cm-1 and 0.466 gcm-2, 1.58 cm-1 and 0.392 gcm-2, 1.23 cm- 1 and 0.281 gcm-2, 1.09 cm-1 and 0.216 gcm-2, 0.88 cm-1 and 0.180 gcm-2, 0.74 cm-1 and 0.168 gcm-2 and 0.57 cm-1 and 0.161 gcm-2, respectively. The results obtained were compared with concrete. The clay slabs mixed with heavy metal showed good shielding properties for moderate radiation energy. Hence, these slabs are feasible and cost effective compared with traditional concrete used for construction.
Assessment of chromium and nickel in agricultural soil: implications for sustainable agriculture
Authors: Kayode O.T. , Ogunyemi E.F. , Odukoya A.M. , Aizebeokhai A.P.
Published: March 2022

Fertilizers in soil management can alter soil physical, chemical and biological compositions, and introduce trace elements such as chromium (Cr) and nickel (Ni) into the agricultural soils. The carcinogenic tendencies of these trace elements at elevated concentrations in plants, animals and humans make it a serious concern. Soil samples from a farm in Ota, Southwest Nigeria wereanalysed using inductively coupled plasma mass spectrometry (ICP-MS). The results indicate that the farm's nickel (Ni) is within the permissible limits, while chromium (Cr) concentrationsexceeded the WHO/FAO allowable limits. Nickel has a mean value of 47.12 mg/kg in the soil, while chromium has a mean value of 152.20 mg/kg. These toxic elements' contamination assessment result has shown the descending order of Ni>Cd in the studied farm. The toxicity of nickel and chromiumin soils causes chlorosis, stunted rootsand inhibits plants growth.
Aeromagnetic data processing using MATLAB
Authors: Oni Olubukola A. , Aizebeokhai Ahzegbobor P.
Published: March 2022

This study focuses on the evaluation of magnetic field variation in a two-dimensional plot in form of a contour map by carrying out interpolation on the magnetic field data and mapping regional structures to infer the direction of dykes. To pinpoint areas of magnetic highs and lows, MATLAB program was used to delineate magnetic field trends on the data. The program was also used to produce graphical, colourized and contoured plots of data from XYZ files (data with random locations) using interpolation functions. The program was used for both gridding and smoothening of the magnetic field data and also allow the setting of contour values and utilization of vivid colour scales. The aeromagnetic data vector may contain outliers which are due to instrumental error and data extraction during field data collection. These outliers were removed and replaced using three interpolation methods including linear, nearest-neighbour and cubic spline to have a non-distorted representation plot and they were also used to fit surfaces to the gridded data. The result shows that the piecewise cubic spline interpolant contour plot has finer precision with higher details at the output edges. From the piecewise linear surface B(X,Y), where X is normalized by mean 2.235e+05 and standard deviation of 3.202e+04 and Y is normalized by mean 7.809e+05 and standard deviation of 551. The residual magnetic intensity plot shows the magnetic field range between -200 nT for magnetic low and 200 nT for magnetic high. However, the use of MATLAB is not to displace Oasis Montaj geosoftware but to give more scientific meaning to the automation of the filtering techniques used in Oasis.
Application of 2-D resistivity and seismic tomography in the control of environmental degradation
Authors: Adewoyin O. O. , Omeje M. , Adagunodo T. A.
Published: March 2022

One of the most serious dangers facing the world today is environmental degradation. The disruption of the earth is one of the factors that compose deterioration of the environment. The adverse effect of this cannot be downgraded. As important as site characterization is, if not properly managed can adversely affect our environment. As a result, alternative approaches may be considered to the traditional method of investigation, which is characterized by digging and invasion of the subsurface. Two methods of investigation were deployed in this study, they are electrical resistivity and seismic refraction tomography. The results obtained from these methods showed that the subsurface is non-homogeneous and vary in condition from place to place. The depth to competent layer for engineering construction purposes is between 7.5 and 16 meters, according to this survey, hence pile foundation is advised for building construction. This survey also discovered that the depth to competent layer for engineering construction purposes is between 7.5 m and 16 m, thus pile foundation is recommended for building construction. This research effort clearly revealed that engineering site characterization can be conducted without altering the original state of our environment.
The effects of microplastics in oceans and marine environment on public health – a mini-review
Authors: Emenike P.C. , Araoye O.V. , Academe S.O. , Unokiwedi P. , Omole D.O.
Published: March 2022

Plastic’s versatility is one reason why production or use has not decreased over the years. The production of plastic globally was 359 million metric tons as of 2018, and this number increased by 3.5% in 2019. Microplastics, which are tiny particles of various types and forms of plastic, can be found in cosmetics, fabrics, car parts, machinery, footwear,products packaging, polythene bags and so on. Over time, these particles, through the process of wear and tear of these various plastic products, indiscriminate disposal, runoffs, and erosion, find their way into water bodies from rivers and streams into larger water bodies like seas and oceans. These tiny non-biodegradable particles find their way into living organisms carrying along with them other harmful chemical contaminants. This study reviews the effects that microplastics found in marine environments have on public health in general. It covers the types and sources of microplastics and the various ways in which microplastics have affected human health and different aquatic species in the marine environment. The review showed all pointers of microplastics present in the environment to have negative impacts on the ecosystem. Certain research gaps are pointed out, like the integration of researchinto policies to help improve the environment and the standardization of dedicated procedures and methods of reporting microplastic pollution. Suggestions were made for possible solutions like the reduction of plastic use for product packaging, provision of biodegradable and eco-friendly materials as substitutes, and general public awareness on the harm of microplastic pollution in the immediate environement.
Association of Tai Chi exercise with physical and neurocognitive functions, frailty, quality of life and mortality in older adults: Singapore Longitudinal Ageing Study
Authors: Lee Shuen Yee , Nyunt Ma Shwe Zin , Gao Qi , Gwee Xinyi , Chua Denise Qian Ling , Yap Keng Bee , Wee Shiou Liang , Ng Tze Pin
Published: March 2022

Background

real-world observations on the long-term benefits of Tai Chi (TC) exercise, in terms of physical and cognitive functioning, frailty, quality of life (QOL) and mortality are lacking.

Methods

prospective cohort study participants were community-dwelling adults aged 55+, including 5,407 non-frequent TC participants (<1x/week) and 572 frequent TC participants (≥1x/week). Outcome measures at baseline and 3–5 years follow-up included physical performance (Knee Extension Strength, POMA Balance and Gait, Timed-up-and-go, Gait Speed) and neurocognitive performance (attention and working memory, visual-motor tracking and mental flexibility, verbal learning and memory, visual memory, spatial and constructional ability), Frailty Index ≥0.10, impaired QOL (SF12 physical and mental component) and all-cause mortality from mean 13 years follow-up. Effect estimates were adjusted for socio-demographics, other physical activities, nutritional risk and presence of cardiometabolic diseases.

Results

frequent TC participation was associated with 0.7-fold lower prevalence of impaired physical QOL [95% confidence interval (CI) = 0.57–0.91], decreased 0.4-fold odds of incident prefrailty/frailty among robust participants at baseline and 0.7-fold odds of impaired mental QOL at follow-up among participants with normal mental QOL at baseline. Lower odds of mortality risk (HR = 0.89, 95%CI = 0.72–1.09) were not significant after controlling for socioeconomic, behavioural and health factors. Composite indexes of physical functional and neurocognitive performance were maintained at high level or increased at follow-up among frequent TC participants.

Conclusion

TC exercise practised among community-dwelling older adults is associated with better physical, cognitive and functional wellbeing.
A Forced Choice Performance Validity Test for the Repeatable Battery for the Assessment of Neuropsychological Status
Authors: Crowell Timothy A , Terpstra Alex R
Published: March 2022

Objective

We aimed to assess the utility of a novel and easy-to-administer performance validity test (PVT), the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Forced Choice recognition trial (RFC), compared with previously developed RBANS PVTs.

Method

We compared the RFC with the RBANS Effort Index (EI) and Effort Scale (ES) in a sample of 62 non-litigating older adults (mean age = 74 years, 52% female) with varying levels of cognitive impairment.

Results

A significantly greater proportion of the sample met EI criteria for non-credible performance (EI > 2; 31%) compared with RFC criteria (RFC < 9; 15%). Among participants with Major Neurocognitive Disorder, 60% met EI criteria for non-credible performance, 32% met ES criteria (ES > 12), and 24% met RFC criteria.

Conclusions

The RFC may have greater specificity than other RBANS PVTs among individuals with more severe cognitive impairment. Further research is needed to establish the classification accuracy of the RFC for assessing performance validity.