bluuebunny/crossref_metadata_2025 huggingface dataset:
Determining the cross profile of manmade pawl and furrow before creating longitudinal pawl between cotton rows
Authors: Olimov K , Juraev A
Published: July 2020

This article outlines the results of the theoretical research based on the parameters of the working organs of the parameters of the construction of longitudinal pawl-creating device between cotton rows.
Device for forming longitudinal thresholds among rows of improved porosity
Authors: Murodov N , Abdualiev N , Murtazoev A
Published: July 2020

The article presents an improved technical tool and technology for the formation of longitudinal thresholds in the separation of the area between the processes that take place after the third cultivation in cotton-growing farms and between the processes that take place before the extraction of irrigation furrows into the Forties. To do this, the constructions of existing threshold forming devices are analyzed and a longitudinal threshold forming device is recommended among the rows of porous equipped with a condenser cathode, which has the most convenient constructive solution. When using this threshold generating device, there is an experimental study that allows to increase the productivity of work by 10-15 times without reducing labor costs by up to 7-8 times. As a result of the experimental research, the density of the floors formed after the application of the recommended device is 1195…The fact that it weighs 1298 κг/M3 is based on the existing parameters, saving water consumption on the account of reducing the leakage of water from one contour to another, as well as the yield from cotton fields to 50 c/ha. This innovation is reflected in the experiments that yield 25-30% higher after the formation of longitudinal upholstery among the rows of porous with the help of techniques and technology devices.
Experimental studies of deformation anisotropy of gravel soils
Authors: Bestuzheva A , Abduloev A
Published: July 2020

When gravel-pebble soil is laying and compacting into the dam body, particles are reoriented to form a layered body (transversely isotropic soil), in which not only the filtration but also the deformation properties are different in directions along and across the layering. To analyze the differences in the gravel-pebble soil deformations in correspondence with the particles’ orientation we have performed experimental researches on the river pebble gravel using odometer, vacuum triaxial compression machine, and a large scale triaxial apparatus. To obtain the deformation characteristics of the soil in different directions we’ve carried out experiments according to two schemes with gravel particles (fr. 10-60 mm) laid horizontally and vertically. More deformations occur in the cross-layerage axis of the soil rather than in the parallel direction (εy > εx), so for the soil in the dam body Ex > Ey. The experiments showed that for gravel-pebble soil the strain-induced anisotropy coefficient η is dependent on its loading conditions and changes in the range from 1 to 1.8. The change of anisotropy degree is bound with the main tension value σ1 with the increase in which the anisotropy decreases.
Chemical and mineralogical properties research of clay from the Republic of Karakalpakstan - as raw materials for Portland cement production
Authors: Orazimbetova G
Published: July 2020

In the Republic of Karakalpakstan, there are large reserves of unprocessed mineral building materials, which necessitate the development and targeted support of building materials manufacturing industries, which may become one of the engines of economic growth, further modernization, and diversification of the region’s industry. This article examined the chemical and mineralogical composition of technological samples of the clay component of the North Jamansay deposit. The results of determining the mineralogical composition of the averaged technological sample of clay from the Dzhamansay deposit are in good agreement with the data of chemical analysis. The heating curve of the averaged clay sample of the Dzhamansaysky deposit is marked by fourteen endothermic effects. The total weight reduction in the temperature range (60–900) °C according to the thermogravimetric curve is 9.53%. On the DTA curves of the clay of the Dzhamansayskoye deposit, endo effects associated with absorbed and ciolet water were identified, as well as endo effects corresponding to the gradual removal of constitutional water from the clay component, accompanied by destruction of the crystal lattice. Electron microscopic analysis of clay showed that the presence of particles of various sizes having a surface with rhombohedral protrusions. This can be seen both on the chips and on the surface of the particles, where rhombohedral protrusions characteristic of quartz are reflected. The chemical composition of the technological sample of the clay component of the North Jamansay field in terms of the content of regulated oxides (SiO2 = 62.64; Al2O3 = 17.54; MgO = 2.00; SO3 = 1.21; TiO2 = 0.46; P2O5 = 0, 25; R2O = 3.68)% meets the requirements of O’z DSt 2950: 2015 for the chemical composition of aluminosilicate (clay) raw materials used in the production of Portland cement clinker.
Physical modification of concrete mix and concrete
Authors: Khasanov B , Vatin N , Ismailova Z , Mirzaev T
Published: July 2020

Numerous studies have established that the physicomechanical properties of concrete, in addition to cement activity, type of aggregates, etc., are determined by the V/C value of the concrete mixture [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]. The dependence of the strength and water tightness of concrete on H/C follows from the physical nature of the formation of the concrete structure. Studying the process of cement hydration showed that cement, depending on the quality and duration of hardening, binds only 15 … 25% of the water of its mass [11, 12, 13]. During the first month, at least 20% of the water by weight of the cement is bound. At the same time, to give the concrete mixture plasticity, improve the conditions of binder hydration, a significantly larger amount of water is introduced, since at W/C = 0.20 the concrete mixture remains practically dry and it cannot be qualitatively laid, molded and compacted. Excess water, without entering into chemical reactions with cement, remains in concrete in the form of water pores and capillaries or evaporates, leaving air pores. Undoubtedly this is the main reason for the decrease in the strength and waterproofness of concrete.
Behavior of single pile and pile groups in consolidating clay
Authors: Znamenskiy V , Hegazy O , Sayed D
Published: July 2020

As the pile group is commonly in use but the effect of consolidation times on the distribution of negative skin friction and drag force along the shaft of each pile in pile groups is still not well defined and studied. This paper presents the three-dimensional (3D) numerical analysis to study the behavior of a single pile and piles group consist of 3x3 piles embedded in a consolidated clay. Three-dimensional numerical simulation is carried out using Abaqus, a finite element software. Single circular piles and 3×3 circular piles in rectangular piles group with a spacing of 2.5D has chosen, where D is the diameter of circular pile. Based on the analyses, it is found that the location of the neutral plane is significantly influenced by the consolidation times. Results of this study showed that the maximum negative skin friction at 90 % degree of consolidations developed along the shaft of corner, side, and central pile compared with a single pile are 69%, 61%, and 45%, respectively.
Joint work of a flat frame and pile foundations under dynamic impacts
Authors: Buzrukov Z , Khamrakulov A
Published: July 2020

In this paper, the basic data of theoretical and experimental studies of a flat frame on pile foundations are presented. Based on theoretical and experimental studies, methods for conducting experimental studies have been developed, the dynamic parameters of the system have been determined, the dynamic calculation scheme has been refined, and a method for calculating a flat frame with a pile foundation under dynamic loads has been developed. Calculation and comparative analysis of the results on the application of pile foundations following building standards are made and the advantage of the work of pile foundations under the condition of dynamic effects is established. Research results allow us to obtain the dynamic characteristics of a flat frame on pile foundations, necessary for subsequent calculations. An analysis of the modes of natural vibrations shows that for a system the 1st form of vibrations is apparently qualitatively different from the vibration form of a conventional single-mass system. To determine the degree of reliability of the developed methodology, the results of theoretical calculations carried out on the basis of the obtained formulas were compared with field tests for structures. The parameters used were adopted on the basis of theoretical calculations. Quantitatively, the discrepancy near the resonant frequency was about 15% in moving micron vs frequencies curves. The maximum amplitude of oscillations on this grillage very closely coincides with each other. With an increase in frequency in both cases, it leads to a decrease in the amplitude of oscillations of the grillage. The discrepancy between the theoretical and experimental values was about 16%.
The comparison of velaroidal shell structures of square plane load bearing properties
Authors: Tupikova E , Berdiev M
Published: July 2020

Velaroid surfaces is a class of analytical surfaces, formed by translating generatrix curves of variable curvature along the directrix curve of the same type, limited by plane contour lines. A new type of velaroidal shell –on the base of the catenary curve is introduced in this job, it’s surface equation obtained. The static structural analysis of the shells under equally distributed dead weight loading is conducted. Four types of structures of equal overall size and rising height were investigated: velaroidal shells on the base of catenary, parabola, ellipse, and sinusoid lines. The analysis is provided using the finite element method. The material has characteristics of reinforced concrete. The comparison revealed the peculiarities of each type of behavior under loading. The velaroidal shell with catenary generatrices demonstrates the most advantageous behavior under loading in the aspect of bending and membrane stresses ratio. This comparison is of interest for the potential introduction of such structures for roof elements.
Investigation of Multiparameter Trends and Anthropometric Measurements for Cardiorespiratory Fitness Assessment Among UTM Staff
Authors: Muralitharan Latha Nair , Zahari Wan Nor Syuhada Wan , Rosli Nor Aziyatul Izni Mohd , Ismail Norjihada Izzah , Malarvili MB , Kadir Mohammed Rafiq Abdul
Published: July 2020

Cardiorespiratory fitness (CRF) is known to reduce metabolic-related diseases like cardiovascular diseases (CVD), obesity, hypertension, and type II diabetes. On the other hand, the gold standard to measure CRF is by measuring maximal oxygen consumption, VO2 max over the years. This study is performed to identify parameters that influence CRF without solely relying on invasive features such as VO2 max. A number of 31 UTM staff aged between 30 and 40 years old have participated in this study with 17 female subjects and 14 male subjects. Anthropometric measurements are obtained by direct measurement and body composition analysis using a body composition monitor. Multiparameter trend measurements were obtained from vital sign monitors at rest. Single feature analysis was performed in terms of accuracy, specificity and sensitivity to identify which feature influences CRF the most. The features collected are body mass index (BMI), body fat (BF), muscle mass (MM), bone density (BD), waist circumference (WC), resting heart rate (RHR), resting systolic blood pressure (RSBP), forced expiratory volume in one second (FEV1), and recovery trend heart rate (RecHR). Next, all these features were validated using Naïve Bayes (NB) and Decision Tree (DT) classifiers. Finally, six features which are BF, BM, BD, RHR, RSBP and FEV1, with accuracy more than 70% were selected and identified as the features which influence CRF of UTM staff.
Design of Device to Monitor Asthma Severity Using Mainstream Technology while Administering Medication
Authors: Rosli Mohamad Haikal Bin Mohamad , Kumarasamy Rokini , Malarvili MB
Published: July 2020

A CO2 measuring device is proposed based on a mainstream technique which would be able to classify the asthmatic condition while administering the medication to the patients. A SprintIR CO2 sensor is used for extracting CO2 concentration from the patient. In order to provide medication to the patient, a nebulizer is used that was combined together with the CO2 measuring device which is designed by the 3D computer-aided design (CAD) software where the design is printed using 3D printing machine. The device uses a facemask to channel the gases where it measures the types of conditions which are ‘No Asthma’, ‘Mild Asthma’ and ‘Severe Asthma’. The preliminary test results for 9 asthmatic patients and 10 non-asthmatic individuals shows that the device can measure their conditions successfully. Meanwhile, it can also deliver medication to the patients if the condition is ‘Severe Asthma’.
Control and energy analyses of a driving force-based aromatic mixture distillation columns sequence
Authors: Zahran M F I , Zubir M A , Rahimi A N , Shahruddin M Z , Ibrahim K A , Hamid M K A
Published: July 2020

To minimize the energy usage of distillation systems, past researchers have developed algorithms that exploit the driving force of distillation, which is the difference in vapour and liquid fractions due to relative volatilities. So far, little is known about the degree of controllability of the energy efficient solutions. This paper aims to ascertain that idea by applying a simple methodology on a common mixture as the case study. The methodology is made up of four stages: (1) feed information gathering, (2) sequence determination, (3) energy analysis and (4) controllability analysis. The controllability was analysed in terms of input-output interaction and resiliency using RGAno and MRI, respectively. From the application, it has been found that the sequence determined using driving force algorithm is the most optimal sequence overall, measured by the use of a multi-objective function.
Ionic liquid-based ultrasonic-assistedextraction model for solvent design
Authors: Rahman Nur Rahilah Haji Abd , Yunus Nor Alafiza , Idris Ani , Mustaffa Azizul Azri
Published: July 2020

Ionic liquid is a favourable solvent in separation process due to the vast possibilities of ionic liquid structures. Many researches showed that ionic liquid extract higheramount of phytochemicals compared to conventional solvents. Even better, ionic liquid extraction coupled with ultrasonic-assisted extraction produced higher yield and less hassle. Therefore, ionic liquid can be considered as a suitable solvent for herbal extraction. This study is a part of a solvent design framework to obtain an extraction process model. It focuses on the process of ionic liquid-based ultrasonic-assisted extraction of flavonoid and phenolic acid from Labisiapumila. A two level, four factor of central composite design (CCD) was employed to determine the effect of the process factors towards yield of flavonoid and phenolic acid extracted from the herb. The process factors are the temperature (Celsius), extraction time (min), power (W) and type of ionic liquid (based on their dielectric point). The extracted samples were analysed to determine the yield of flavonoid and phenolic acid. Two models were developed for flavonoid and phenolic acid extraction based on the optimization results. The models are important as yield prediction in solvent process performance stage of the development of ionic liquid design framework.
Analysis of Cementing Carbonation During Co2 Sequestration
Authors: Zakariya S , Yao Tee T , Sidek A
Published: July 2020

Effects of global warming are well-known to be caused by emissions of greenhouse gases. As an effort to alleviate the gases production, Capture and Sequestration (CCS) is implied in oil and gas practices where carbon dioxide gas (CO2) is captured from different emission sites and injected into geological formations. However, problems arised in sequestration projects as exposure of CO2 degraded the Portland-based cement in the wellbore. Consecutively, the cement cracked and leakage of CO2 contaminated the underground drinking water. Hence, this paper aims to understand the physical and chemical reaction between CO2 and Class G cement further. Class G cement was obtained from Schlumberger Kemaman Supply Base and tested with water according to American Petroleum Institute (API) standard which water to cement ratio was set to 0:44:1. All of the samples were exposed to CO2 for six, eight and ten days accordingly and analyzed with unconfined compression, Field Emission-Scanning Electron Microscope (FESEM) and X-Ray Diffraction (XRD) testings. Ten days of CO2 exposure towards Class G cement showed the lowest compressive strength as to be compared to other samples. Carbonation reaction between water and CO2 was diagnosed to take place causing the cement to loose its strength. FESEM analysis on the other hand showed that the surface of the sample were uneven with long-shaped crystals with supporting XRD data presented large number of calcium carbonate ((Ca(CO)3). Nevertheless, the unexposed sample showed the opposite result with highest value of compressive strain and large number of calcium hydroxide ((Ca(OH)2).
Combustion and Emission Characteristics of Palm Oil-Based Biodiesel in a Liquid Fuel Burner
Authors: Ahmad Amirul A , Jaafar Mohammad N M , Othman Norazila B , Azli Anis A M , Said Mazlan , Rahim Muhammad R , Malik Muhammad S A , Omar Wan Z W
Published: July 2020

This paper presents an experimental investigation of the combustion characteristics of palm oil methyl ester (POME) or called as biodiesel (B), in an open-ended combustion chamber or called as open-ended liquid fuel burner. The performance of conventional diesel fuel (CDF) and various percentages of POME and CDF, which are B10 (10% biodiesel) and B30 (30% biodiesel) were studied to evaluate their performance. Combustion temperature profile in the combustion chamber and exhaust emission concentrations such as NOx, CO and SO2 have been carried out using five different equivalent ratios such as Φ = 0.6, 0.8, 1.0, 1.2 and 1.4. The results show that as the biodiesel content increased, the emission significantly increased except for the NOx emission. It was also found that higher biodiesel content resulting faster combustion rate at near burner region, especially for Φ = 1.0 due to higher Cetane Number (CN) although the lower overall temperature profile produced compared to CDF alone. This proved the suitability of biodiesel for an enhanced transportation engine performance in the near future.
A Review of Facilities Information Requirements towards Enhancing Building Information Modelling (BIM) for Facilities Management (FM)
Authors: Muhammad M Z , Mustapa M
Published: July 2020

Building Information Modelling (BIM) for facilities management (FM) benefits the owner the most by increasing the value of information in their possession and the amount of Return on Investment (ROI). Research and application of BIM in FM are lagging behind similar efforts in design and construction. Information management is a major threat facing FM practice where the multidisciplinary activities demand extensive information requirements. Lack of accurate transmission of building information from the earlier stages of a building project to FM professionals leads to a significant loss in the quality of building information for operational needs, significant costs and rework, impedes the promotion of an automated FM practice integrated and a life-cycle oriented construction. This paper reviews current literature to gain an overview of the significant challenges to the demand and supply of critical data for FM in a BIM model. It also sought to understand efforts addressing these challenges to provide direction for facility information management at the project and organisational level.
Potential of Water Pipeline Bursting Using Stochastic Approach in Geographical Information System
Authors: Sukor A H , Amerudin S , Yusof Z M
Published: July 2020

A pipe bursting is one of the major problems in water distribution systems. This problem resulted in losses, particularly in water wastage or shortage and infrastructure damages. Furthermore, several organisation and authorities do not have systems or database for water management monitoring, leading to a difficulty in monitoring and update the condition of the pipeline. Geographical Information System (GIS) can help to develop a geospatial database for the water distribution network; to determine the high potential of pipe to be burst and identify the areas affected by the pipe failure. In this study, the potential of pipe to be burst is determined using a stochastic approach to get the probability of the potential failure, which based on four factors; age, pressure, material and diameter of the pipe. A valve isolation trace function from ArcGIS tool is then used to determine the area affected by the pipeline failure. Results from the analysis are to produce maps of high potential pipeline bursting and the affected areas. The findings could help the management to monitor the conditions of the water pipeline regularly, detecting early warning, preparation for the pipe’s replacement and notify the residents to make initial preparations if the pipe has a potential to burst.
Oil Well Detection System for Seismic Surveying Based on Internet of Things (IOT)
Authors: Puad Norsyazwani Mohd , Siraj Maheyzah Md. , Sulaiman Nur Rafeeqkha
Published: July 2020

Seismic Surveying is a geophysical survey that was conducted to measure the physicals principle in earth’s geography like magnetic, gravitational and thermal. There are several simulations that have been produced to be used in oil and gas field, such as Petrel by Schlumberger and ECLIPSE. however, this simulation is confidential and cannot be used by individuals outside the company. Therefore, some of petroleum geologists are not able to use the simulations in their geology analysis. This issue is also experienced by students studying in this field as they are not able to access any simulations. Hence, making them not able to experience the real environment of the process for their future used. The existing software also do not analyse real time data, which will be covered in this project. Oil Well Detection System for Seismic Surveying is a web-based system that aims to analyse data for seismic surveying to give user better understanding on the process before conducting it in real life. This system also uses real time data in order to generate the result for the simulation. Users are able to generate the data in numeric data sets, 2D or 3D images. Notifications will be sent to users whenever there are data generating the best limestone result. This is to make sure that users have the best field for new oil reservoir and comparing the data of seismic surveying to make sure the best region to drill. The sensors technology will be used to detect the elements in limestone and send the data to user’s smartphones. Prototype Model Methodology is used throughout the development process alongside Firebase Cloud Database for storing information. This project will help petroleum geologists and students to experience the real time simulation in order to have better understanding about seismic surveying before conducting it in real life. They also can use it as study purposes as it is beneficial to students.
Named Entity Recognition of South China Sea Conflicts
Authors: Sulaiman Nur Rafeeqkha , Siraj Maheyzah Md , Din Mazura Mat
Published: July 2020

Online news articles not only provide us with useful and reliable information and reports, it also eases information extraction and gathering for research purposes especially in Natural Language Processing (NLP) and machine learning (ML). The topics regarding the South China Sea have been popular lately due to the rise of conflicts between several countries claim on the islands in the sea. Gathering data through Internet and online sources proves to be easy, but to process a huge amount of data and to identify only useful information is no longer possible. Because of that, relevant information and the classification of news articles in relation to the conflicts need to be done. In this paper, a model is proposed to use NER that search for and classifies important information regarding to the conflicts. In order to do that, a combination of POS and NER are needed to extract meaningful information from the news. This study also aims to classify conflict related news by using Conditional Random Field (CRF) algorithm as classification method by training and testing the data.
Exploring Social Media User Emotions And Emoticons Use Among Malaysia Universities
Authors: Mukhktar Mohamad Alif Fikri , Ismail Nor Azman , Majid Hairudin Abdul , Razak Mohd Sharul Hafiz
Published: July 2020

Expressing emotions through Twitter has been the norm to social media users especially university students. Emoticons has been used in their Tweet to represents their emotions to current issue. Emolyzer has been used to extract the Tweet of five active Malaysia universities community Twitter account which are USM, UTM, UKM, UiTM and UUM. With a variety of emoticons, people find it interesting as there are so many emoticons to symbolize different emotions. Different social media may differ in emoticons used, so the observation of frequently used emoticons in Twitter is a must. These emoticons are then categorized into happy, sad, annoying, angry and surprise. As a result, each different sentiment between these five universities can be compared. The study shows that USM has the highest percentage of happy while UiTM has the highest percentage of sad. This finding can be used to guide universities social media administrator to strategize in content strategy in social media.
Consideration of Educational Tools and Methods of Software Engineering Education for non-CSE Students
Authors: Hayashi Hidehiko
Published: July 2020

In the 4th Industrial Revolution (4IR), one of the important issues is to educate software engineering not only to computer sience and engineering (CSE) students who specialize in information but also to non-CSE students who major in humanities and society and so on. It is not only for gaining a job in developing and operating digital technology and systems, but also for solving many social problems such as sustainable development goals (SDGs) and also leading to ethics such as human happiness. It is necessary to combine all kinds of knowledge such as science, engineering, humanities, social science, etc. in order to solve complex social problems. Students majoring in humanities and society do not have enough knowledge and skills in engineering like first year student, so they need educational tools and methods to learn software engineering smoothly. In this case study, we conducted to combine the Learning Management System (LMS) of communication function which is a share tool by digital approach and Idea-sketching for idea generation by analog approach such as pen and paper. The classes for humanities and social sience students who are not good at computer operation have found that they learn smoothly. As contribution of this study, it suggested a possibility effective as an educational tools and methods for first year students majoring in computer science as well as students majoring humanities and social science.
Comparison of Lecturers’ Epistemological Beliefs in Teaching Electromagnetic Theory
Authors: Bakar M S , Mohd Yusof K , Rahman N F A , Mohd Kassim N , Ibrahim M H
Published: July 2020

This research was conducted to compare the epistemological beliefs of two lecturers in teaching Electromagnetic Theory course. The two lecturers were selected based on their experiences in teaching the course at a University in Malaysia. A series of interviews were conducted, audio recorded and transcribed. The data were analysed using thematic analysis approach. The research found that based on the Yu and Strobel framework of the epistemological beliefs, only a few items within the constructs were undefined and most of the items meet the learning environments.
IoT Based Noise Monitoring System (NOMOS)
Authors: Badruddin M B , Hamid S Z A , Rashid R A , Hamsani S N M
Published: July 2020

Presently, noise pollution has become a very big issue around the world. The adverse effects of this pollution include hearing impairment, negative social behavior, annoyance, sleep disturbance and intelligibility to understand people’s speech. In learning context, noise can affect understanding and behavior of people and places with high noise level are not suitable for learning and teaching process. Internet of Things (IoT) technology is one of the best choices to monitor the noise or sound intensity in the environment for the safety of human being. The aim of this paper is to deliver a development of an IoT based noise monitoring system comprises of a sound sensor, an IoT platform called NodeMCU, LCD and LEDs. The system will provide a real-time alert if the noise exceeds the threshold noise limit set by Environmental Department of Health standard. Equipped with an Android application, the data from the sound sensor will be transferred into the cloud server and subsequently transferred into the app for display and to enable remote monitoring. A case study is carried out using the developed prototype to ascertain the noise comfort for Universiti Teknologi Malaysia (UTM) students for studying or learning purpose. The sound level is measured for two different days during weekend and weekday. Based on Charted Institution of Building Service Engineers (CIBSE), 60dBA is the permissible ambient level and any readings that above 60dBA can interrupt speech intelligibility. From the research, the suitable time for students to study for weekend is all day starting from morning until midnight. As for weekday, the most suitable time to study is during midnight. These justifications are made based on the readings of the sound level.
Current usage by a DC motor to vary ratio in an electro-mechanical continuously variable transmission
Authors: Delhaise L J , Mazali I I , Daud Z H C , Kob M S C , Asus Z
Published: July 2020

In a typical continuously variable transmission (CVT) for automotive, engine torque is transmitted from the primary pulley (connected to the vehicle’s engine) to the secondary pulley (connected to the wheels) through a metal pushing V-belt. The CVT ratio (rCVT
) is defined as the pitch radius of the belt on the secondary pulley divided by the pitch radius on the primary pulley. Conventionally, rCVT
is varied using hydraulic pressure generated by an oil pump which is powered by the engine. A continuous hydraulic pressure is required to maintain high clamping force applied on the belt so that sufficient traction between the belt and the pulleys can always be provided. This requirement, unfortunately, causes significant power losses in the CVT and to address this, the idea of electro-mechanical CVT (EM CVT) is proposed. In an EM CVT, rCVT
is varied using a power screw mechanism and a DC motor while the desired ratio and the belt’s clamping force is maintained using the thread of the power screw mechanism, consequently eliminating the aforementioned issue. This paper describes the process of measuring the current used by a DC motor to vary rCVT
in an EM CVT. The results show that the current usage is higher during upshifting from rCVT
of 1.95 to 1.43 (about 45 A) as compared to downshifting from 1.43 to 1.95 (about 23 A). This is due to the application of disc springs in the secondary pulley that reduces the required motor torque for downshifting. The results also prove that no current is consumed by the motor during a constant rCVT
. In conclusion, the motor’s current usage has been successfully measured and the results can be used for a future development of the EM CVT’s battery system.
Study of multi-cell thin-walled tube with various configuration under lateral loading
Authors: Sofi M I M , Chow Z P , Wong K J , Ahmad Z
Published: July 2020

Thin-walled structure is one of the common structures that is widely used as an energy absorber due to inexpensive, high availability and lightweight. Moreover, the multi-cell structure is known as a useful method to elevate the effectiveness of thin-walled structures in crashworthiness. Energy absorber performance of multi-cell thin-walled tube structure is known to be greater than the single thin-walled tube. This is due to the limitation of plastic hinge zones of single tube during lateral loading condition. This paper presents the effect of multi-cell configuration on energy absorption responses under lateral loading condition. Experiment and numerical approach were used in this research. The validation of finite element model (FEM) was conducted by comparing the load-displacement responses and deformation mode of a quasi-static compression test. Multi-cell configuration study was performed to identify the energy absorption performance of multi-cell thin-walled tube with different arrangements. The results reveal that an increasing number of cells will increase the energy absorption capacity of multi-cell structure. The additional number of tube cells contribute to the increases of the contact joint between each tube consequently this generate additional permanent plastic-hinges.
Design and control of a motor wheel system controlled by smartphone
Authors: Asus Z , Mat Razi M F I , Mahmudin M F , Che Daud Z H , Mazali I I , Ardani M I
Published: July 2020

The purpose of this project is to design a wheel system controlled by smartphone for multiple utilisations and determine its efficient control. The motor wheel system is equipped with four mecanum wheels with ten movements: forward, reverse, left, right, clockwise, counter-clockwise, and four on diagonal. PID control which is a closed-loop control was implemented to regulate the speed of the wheel system. The system is equipped with Bluetooth and a mobile application was developed as its user interface. Two control mode was developed in this project which is the precision mode where the user controls the wheel system manually using the smartphone as a control panel and another mode is the following mode where smartphone internal gyroscope and accelerometer are combined together to move the wheel system automatically with respect to the user body movements. CAD model of the design is developed in Solidworks and finite element analysis is done using CAE. FEA analysis is studied and discussed with focus on the critical location of the design. The full-size prototype of the design is developed and tested in normal running conditions. The system is proven to be reliable to carry loads and can be controlled efficiently by smartphone.
Predictive simulation of single cylinder n-butanol HCCI engine
Authors: Roslan Muhammad Faizullizam , Veza Ibham , Said Mohd Farid Muhamad
Published: July 2020

Homogeneous Charge Compression Ignition (HCCI) is a commonly research new combustion mode due to its advantages over conventional combustion in internal combustion engine such as higher thermal efficiency as well as lower particulate matter (PM) and nitrogen oxides (NOx) emission. However, combustion phasing control difficulty is the main challenge in order to achieve this HCCI combustion due to the absence of direct auto-ignition control. The aim of this study is to investigate the effects of engine load conditions, intake charge temperature and exhaust gas recirculation (EGR) rate numerically on the combustion characteristics of HCCI engine in a single-cylinder and four-stroke engine fuelled with n-butanol. Predictive one-dimensional engine cycle simulation with single-zone model is employed in this study. A chemical kinetic mechanism of n-butanol is used to in this model to capture the chemical reaction process during the combustion. It was found that these parameters play important roles towards the combustion phasing of the HCCI engine as well as the in-cylinder pressure. This HCCI model is able to predict the trend of the combustion characteristics comprehensively with the variation of these critical parameters resulting in a good agreement with previous HCCI studies.
A novel double chamber rotary sleeve air compressor part I: design and thermodynamic model
Authors: Alduqri Y A , Kamar H M , Musa M N , Kamsah N B , Idris N R N , Alqaifi Gamal
Published: July 2020

This paper introduces a novel double chamber rotary sleeve compressor (DCRSC) concept. The compression mechanism is basically that of a rotary motion whereby the novelty lies in the usage of a rotating sleeves and a non-sliding vane that has one end fixed to a rotor and the other fixed end to an outer rotating sleeve. The main goal of this paper is to describe the compression processes of air as the working fluid and reveals the variations of pressure, temperature, mass and compression power inside the compressor working chambers at different rotational speed. Friction and leakage model of the proposed compressor are evaluated in Part II and Part III of this paper series. The compressor was theoretically analysed based on three thermodynamic compression approaches namely: adiabatic, polytropic and isothermal approaches. According to the thermodynamic simulation, a 171 cm3.rev−1 DCRSC can deliver a 15.4 m3.h−1 of compressed air at 9.3 bar, 6.8 bar and 4.9 bar when air undergoes adiabatic, polytropic and isothermal compression processes, respectively. The DCRSC compression mechanism shows a potential capabilities of a new compressor concept and to be well suited for the air conditioning and compressed air systems articles must contain an abstract.
Wettability Control of Nano-Columnar Dlc Thin Films Via Eb-Irradiation
Authors: Foo J. , Aizawa T
Published: July 2020

Amorphous carbon (a-C:H/a-C) or Diamond-like carbon, have a very high potential diverse engineering application especially in protective coating which made it an ideal method to be manipulated in process parameters so to achieve the desired mechanical and functional properties; this correlates to the smoothness, atomic density, and the sp3 content. The nano-structure of this amorphous carbon is characterized by its disordered state of sp2 and sp3. The mechanical property would response to the sp2/sp3 matrix with the small hydrogen content which leads to the significant increases in hardness, tribological and also the wettability properties. This vague columnar structure of DLC is strictly modified to fine and self-organized structure, where high-density, graphitic inter-columnar structure is embedded into the low-density amorphous carbon phase as being confirmed through characterization, mechanical properties and response. This unique hybrid system in the a-C:H films would control the functionality of the final coating in customized way to suit multi-disciplinary engineering applications. This Nano-columnar a-C:H system. However, this hybrid system is still bound to the triangular diagram of sp2-sp3-H in the formation of a-C or a-C:H. This formed nano-columanar a-C:H films shows a unique nano-structure and its graphatized inter-columnar network with amorphous columns responsible the desired properties manipulation. In this paper, correlation between the degree of graphitization and wettability is established.
Optimization procedure for parameter determination of caboche kinematic hardening model
Authors: Moslemi Navid , Golzardian Mohsen , Redzuan Norizah , Mozafari Farzin , Ayob Amran
Published: July 2020

The ratcheting behavior and prediction of 316L stainless steel pipe was developed using numerical finite elementapproach. The Chaboche model parameters to be used in the numerical method were adopted from symmetric post monotonic teston the pipe. The significant property, the elastic limitof the material,was extracted using incremental cyclic uniaxial test. Comparison between two well-known optimization methods, Particle Swarm Optimization and Genetic Algorithm gave the former a slightly better correlation with experimental tests.The Chaboche model in ANSYS was utilized to predict the uniaxial ratcheting behavior of the pipe specimen. Theclose comparison of rate of ratcheting between finite element simulation and experimental test indicates that accurate elastic limit extraction from post monotonic test alone results in improved ratcheting prediction, with PSO method adopted to optimize ratcheting parameters.
High-sensitivity detection of chlorothalonil via terahertz metasensor
Authors: Zhang Yixing , Ye Yunxia , Song Xiaoxian , Yang Maosheng , Ren Yunpeng , Ren Xudong , Liang Lanju , Yao Jianquan
Published: July 2020

Given the complex pretreatment and low sensitivity of pesticide residue detection with the conventional testing method, a Terahertz metasensor consisting of the four-division ring resonator (FSRRs) was proposed and fabricated for the identification and detection of chlorothalonil. Through simulations, the theoretical sensitivity of this metasensor was found to reach 156.3 GHz /RIU (RIU, refractive index unit) under an analyte layer 1 μm thick. Through experiments, firstly, the characteristic fingerprint spectrum of chlorothalonil in the THz band was obtained by detecting solid chlorothalonil with THz time-domain spectrum system. Then, Terahertz metasensor was used to detect the chlorothalonil solutions of different concentrations. The experimental results showed that the resonant peak of the metasensor was redshifted with the increase of chlorothalonil concentration. Compared with the detection strategy only using the characteristic fingerprint spectrum, the sensitivity of the metasensor improved 106 times, which was up to a minimum of 1 mg l−1. This study indicates that the metasensor is a promising optical device for detecting the pesticide residues with a very high sensitivity.
Optical and structural analysis of ultra-long GaAs nanowires after nitrogen-plasma passivation
Authors: André Yamina , Isik Goktas Nebile , Monier Guillaume , Hijazi Hadi , Mehdi Hussein , Bougerol Catherine , Bideux Luc , Trassoudaine Agnès , Paget Daniel , Leymarie Joël , Gil Evelyne , Robert-Goumet Christine , LaPierre Ray R
Published: July 2020

The structural and optical properties of individual ultra-long GaAs nanowires (NWs) were studied after different nitrogen passivation process conditions. The surface morphology of the NWs after passivation was characterized by high resolution transmission electron microscopy (HRTEM) and high angle annular dark field (HAADF) imaging. Electron energy loss spectroscopy (EELS) confirmed the presence of nitrogen on the NW surface. Micro-photoluminescence (μ-PL) on single NWs indicated an increase of the luminescence intensity upon passivation. This work reveals the efficacy of a plasma passivation process on complex nanometer-scale morphologies.
Internuclear potentials from the Sky3D code
Authors: Stevenson P D
Published: July 2020

This note presents a minor alteration to, and subsequent use of, the Sky3D nuclear time-dependent Hartree–Fock code to calculate ion-ion potentials in the Frozen Hartree–Fock approximation. An example of 16O + 16O is presented.
Low-cost descriptors of electrostatic and electronic contributions to anion redox activity in batteries
Authors: Davies Daniel W , Morgan Benjamin J , Scanlon David O , Walsh Aron
Published: July 2020

Conventional battery cathodes are limited by the redox capacity of the transition metal components. For example, the delithiation of LiCoO2 involves the formal oxidation from Co(III) to Co(IV). Enhanced capacities can be achieved if the anion also contributes to reversible oxidation. The origins of redox activity in crystals are difficult to quantify from experimental measurements or first-principles materials modelling. We present practical procedures to describe the electrostatic (Madelung potential) and electronic (integrated density of states) contributions, which are applied to the LiMO2 and Li2
MO3 (M = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, Ir, Pt, Au) model systems. We discuss how such descriptors could be integrated in a materials design workflow.
Integrated gasification and non-thermal plasma-catalysis system for cleaner syngas production from cellulose
Authors: Craven Michael , Wang Yaolin , Yang Haiping , Wu Chunfei , Tu Xin
Published: July 2020

An innovative integrated gasification and plasma-catalytic system has been developed to produce cleaner syngas from a model biofeedstock (α-cellulose). The influence of Co/γ-Al2O3 catalyst on the plasma reforming of tar-contaminated syngas has been investigated using a cylindrical dielectric barrier discharge reactor. The results show that plasma-catalytic processing of the syngas from biomass gasification significantly reduces the concentration of tars by 88% and enhances the total gas product yield and the syngas ratio (H2/CO) by up to 90%.
Temporal migration rates affect the genetic structure of populations in the biennialErysimum mediohispanicumwith reproductive asynchrony
Authors: Muñoz-Pajares A Jesús , Abdelaziz Mohamed , Picó F Xavier
Published: July 2020

Migration is a process with important implications for the genetic structure of populations. However, there is an aspect of migration seldom investigated in plants: migration between temporally isolated groups of individuals within the same geographic population. The genetic implications of temporal migration can be particularly relevant for semelparous organisms, which are those that reproduce only once in a lifetime after a certain period of growth. In this case, reproductive asynchrony in individuals of the same population generates demes of individuals differing in their developmental stage (non-reproductive and reproductive). These demes are connected by temporal migrants, that is, individuals that become annually asynchronous with respect to the rest of individuals of their same deme. Here, we investigated the extent of temporal migration and its effects on temporal genetic structure in the biennial plant Erysimum mediohispanicum. To this end, we conducted two independent complementary approaches. First, we empirically estimated temporal migration rates and temporal genetic structure in four populations of E. mediohispanicum during three consecutive years using nuclear microsatellites markers. Second, we developed a demographic genetic simulation model to assess genetic structure for different migration scenarios differing in temporal migration rates and their occurrence probabilities. We hypothesized that genetic structure decreased with increasing temporal migration rates due to the homogenizing effect of migration. Empirical and modelling results were consistent and indicated a U-shape relationship between genetic structure and temporal migration rates. Overall, they indicated the existence of temporal genetic structure and that such genetic structure indeed decreased with increasing temporal migration rates. However, genetic structure increased again at high temporal migration rates. The results shed light into the effects of reproductive asynchrony on important population genetic parameters. Our study contributes to unravel the complexity of some processes that may account for genetic diversity and genetic structure of natural populations.