bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental study of the influence of laser radiation power on the reflection coefficient of germanium and silicon at a wavelength of 355 nm
Authors: Malinskiy T V , Zheleznov V Yu , Rogalin V E , Kaplunov I A
Published: December 2021

The dependences of the reflection coefficients at a wavelength of λ = 355 nm for germanium and silicon single crystals on the energy density of impacting laser radiation in the range 0.01 - 0.1 J/cm2 have been measured. Analytical expressions were obtained. It is assumed, that they are also valid in the range 0.1 - 1.0 J/cm2. With a further increase in the energy density, the dependence should acquire a more complex character due to the resulting optical breakdown.
The Rayleigh wave scattering on a rectangular lattice of the solid roughness discontinuities
Authors: Chukov Vitalii N.
Published: December 2021

The problem of the surface acoustic Rayleigh wave scattering on a deterministic three-dimensional roughness, occupying a finite size rectangular region of an isotropic solid free surface, is solved in the Rayleigh-Born approximation of the perturbation theory in a roughness amplitude. Formula for the displacement field in the scattered Rayleigh wave at a big distance from the roughness, as compared to rough region sizes L1,2
along the x1,2- axes respectively, and asymptotic formulas for this displacement field in the Bragg, i.e. short-wavelength λ≪ L1,2
limit, where λ is the wavelength, are derived. The new laws of scattering are obtained. They are caused by a strong modulation of scattering by the roughness form. They exceed the fundamental physical conception, that a wave scattering in the short-wavelength limit takes place on a medium discontinuities, by the statement, that a wave strongly senses the structure of a medium in the near vicinity of discontinuities as well as the form-factor of the discontinuities lattice. This form-factor is a dependence of the discontinuity amplitude, i.e. of a difference of the left and right limit values of a roughness non-zero derivative, including one of zero order, in coordinate at a point of discontinuity, on a number of this discontinuity in a lattice. This exceeded physical conception violates the classical Laue-Bragg-Wulff laws of scattering.
Tight focusing of circularly polarized light limited by semicircular aperture
Authors: Zaitsev V D , Stafeev S S , Kotlyar V V
Published: December 2021

In this work, the focusing of a circularly polarized plane wave (wavelength 532 nm) was simulated by a lens with a numerical aperture NA = 0.95. The wave front was considered flat. When integrating according to the Richards-Wolf formulas, the semicircular aperture was set by limiting the azimuthal angle from 0 to π. It was shown that when focusing light with right and left circular polarization, the focal spot turns out to be elliptical - elongated along the y axis, and, depending on the direction of polarization, its center shifts by about 0.05 μm in different directions along the x axis. It was also shown that the reverse flow region is located near the focal spot (at a distance of 0.25 μm from the center). Depending on the direction of polarization, it is located either to the right or to the left of the focal spot. Thus, the polarization state of the incident radiation can be determined from the displacement of the spot in focus.
Multijunction solar cell spectral response determination at radiation damage study
Authors: Levina S , Emelyanov V , Mintairov M , Nakhimovich M , Shvarts M
Published: December 2021

This paper discusses multijunction solar cells with optically coupled p-n junctions under radiation exposure photosensitivity spectral response study. It is shown that if the measurement technique does not consider the luminescent coupling and does not track the optical coupling degradation, then instead of a decrease (which is a natural response of a photoconverter to radiation damage), an abnormal increase in the narrow-bandgap photoresponse (receiving luminescent radiation) subcell due to radiation damage can be observed. Accordingly, with an increase in the irradiation dose, an increase in the subcell photocurrent forming a “negative” degradation dependence of MJ SC being used in space applications is recorded.
Zn diffusion technology for InP-InGaAs avalanche photodiodes
Authors: Andryushkin V V , Gladyshev A G , Babichev A V , Kolodeznyi E S , Novikov I I , Ya Karachinsky L , Maleev N A , Khvostikov V P , Ya Ber B , Kuzmenkov A G , Kizhaev S S , Bougrov V E
Published: December 2021

This paper presents a study of Zn diffusion process into InP and InGaAs/InP epitaxial heterostructures grown by molecular beam epitaxy. It was found that both diffusion systems: a resistively heated quartz reactor with a solid-state Zn vapor source placed inside and hydrogen or nitrogen as the carrier gas and MOCVD reactor with hydrogen as the carrier gas allow achieving similar dopant concentration above 2*10e18 cm-3. The depth of the diffusion front in the InP layer is located from 2 to 3.5 μm depending on the temperature and time of the diffusion process. The diffusion of Zn into InP through the intermediate InGaAs layer provides better surface quality comparing with direct zinc diffusion into InP surface.
Specific features of the formation of optical waveguides, contact pads and electrical interconnections on lithium tantalate substrates
Authors: Konyaev I V , Borodkin I I , Bormontov E N
Published: December 2021

The article considers the formation of titanium channel optical waveguides in LiTaO3 substrates. These structures were obtained by dry etching of grooves in SF6 plasma and magnetron sputtering of titanium film. After that, waveguides were formed by plasma etching using photoresist as mask. Technological features and modes of microstructure production are described. Al contact pads were produced by magnetron sputtering thin metal films on LiTaO3. Aluminum wires were ultrasonically bonded to Al contact pads using Delvotec 5630. The developed technology of formation of contact pads and bonding modes made it possible to obtain a bonded joint with a bond strength of 23-25 Gs.
Study of power limitation of AlGaInN LEDs in pulse regime at high current
Authors: Aladov A V , Chernyakov A E , Ivanov A E , Zakgeim A L
Published: December 2021

LEDs operating under high pulsed current are of a great interest for different applications, in particular, for VLC (LiFi) systems and laser pumping. Current dependences of the efficiency and emission spectra as well as the rise and fall times of high-power blue LEDs were investigated under extremely high pulse current density up to 7 kA/cm2 and pulse duration from 100 ns to 3 μs. Analysis of the pulse behaviour of the LEDs reveals that the main droop in the efficiency and change in spectra occur up to the current densities ~ 1 kA/cm2 and seems to be non-thermal.
Investigation of the characteristics of a radioisotope source based on a (Y)PO4/(238Pu) self-glowing crystal and an AlxGai_ xAs/GaAs photovoltaic converter
Authors: Prudchenko K K , Tolkachev I A , Silantieva E A , Kontrosh E V
Published: December 2021

The possibility of creating of a radioisotope source of energy based on a radio-luminescent crystal of YPO
4:Eu/(238
Pu) and AlxGa1-xAs/GaAs photovoltaic converter is demonstrated and its characteristics are analyzed. A prototype of an ecologically safe radioisotope source with low content (< 0.1%) of the
238Pu isotope, efficiency of ~1.4%, and long service life has been developed.
New parametrization for the 3He(d, p) 4He fusion reaction rate and refinement of the Lawson criterion for d-3He thermonuclear reactors
Authors: Alper I B , Godes A I , Shablov V L
Published: December 2021

We present a new parametrization of the d + 3He → p + 4He fusion reaction astrophysical factor based on the effective range approximation, which is an effective theoretical method for describing near-threshold, including resonance, nuclear reactions. In the framework of this approximation we describe experimental data on the energy dependence of the cross section and the astrophysical factor within the experimental uncertainties in the energy range of 0-800 keV. On this basis we calculate the temperature dependence of the Maxwellian-averaged reaction rate in the range of 0-400 keV. In conclusion, we discuss the effect of the calculated reaction rates on the Lawson criterion for thermonuclear reactors based on d-3He fuel.
Instability of local supersonic regions over a flat-sided airfoil with a blunt trailing edge
Authors: Kuzmin A.
Published: December 2021

The two-dimensional turbulent transonic flow over a symmetric flat-sided airfoil with a blunt trailing edge is studied numerically. Solutions of the Reynolds-averaged Navier-Stokes equations are obtained with a finite-volume solver on a fine computational mesh. The non-uniqueness of flow field in certain bands of the given free-stream Mach number and angle of attack is demonstrated. Intricate dependence of the lift coefficient on the free-stream parameters is discussed. Adverse free-stream parameters, which admit abrupt changes of the flow structure and lift, are identified.
Influence of the femoral artery-graft junction patient-specific geometry on blood flow structure and wall shear stress
Authors: Ivanova Y F , Tikhomolova L G , Yukhnev A D , Smirnov E M , Kalmikova R V , Morozov A N , Suprunovich A A , Vrabiy A A , Khubulava G G , Vavilov V N
Published: December 2021

The paper presents a comparative numerical study of pulsatory blood flow in five patient-specific models of femoral-popliteal artery anastomosis. Three-dimensional geometric models of a proximal junction of the common femoral artery/graft were constructed on the bases of CT angiography. The influence of junction geometry on the blood flow and wall shear stress is analyzed. The ratio of the measured CFA and graft diameters and the junction angle are considered as the major geometrical parameters. Numerically calculated velocity fields are analyzed, and stagnant zones in the anastomoses flow are identified. Time-averaged distributions of wall shear stress and oscillatory shear index obtained for five patient-specific model are compared.
Analysis the dynamics formation of a vapor supersonic jet under outflow from thin nozzle
Authors: Bolotnova R Kh , Korobchinskaya V A , Faizullina E A
Published: December 2021

The dynamics formation of a vapor jet with near-critical state parameters outflowing from a high-pressure vessel through a thin nozzle is studied. The numerical modeling of this process, by using a system of model equations for gas-vapor-liquid mixture, which include conservation laws of mass, momentum, and energy of phases in accordance with one-pressure, one-velocity and two-temperature approximations, was conducted, taking into account heat and mass transfer processes of evaporation and condensation under conditions of equilibrium state with modified reactingTwoPhaseEulerFoam solver of open package OpenFOAM. The process of barrel shock formation in supersonic boiling jet with shaping Mach disk is shown. It was found that the process of boiling fluid outflow is accompanied by formation of vortex zones near axis of symmetry and leads to generation of acoustic wave pulses series preceding the main jet flow, which are the source of pulsations, observed in experiments. The justification of applied numerical method reliability is shown by comparing the computational and analytical solutions for Sedov’s problem of a point explosion in gas-water mixture at the plane case.
Experimental study of the flow in the elastic model of the abdominal aortic bifurcation
Authors: Sinitsina D E , Zaitsev D K
Published: December 2021

This paper reflected preliminary results of physical modeling of pulsating flow in a model of abdominal aortic bifurcation with taking into account the physiological elasticity of the vessel walls. Elastic vessel models were made via molding from a silicone mixture based on Lasil-T4 silicone rubber. The auxiliary study was performed to assess the elastic properties of the silicone mixture and select a necessary composition. The experiment on the pulsating flow in the rigid and elastic models of the abdominal aortic bifurcation was carried out using a blood flow simulator with circulation of blood-emulating fluid. It was revealed that interaction between the elastic model and closed rigid circuit of the blood flow simulator resulted in generation of intense parasite flow oscillations and prevented from getting similar flow conditions for rigid and elastic models. A way to solve the problem is to include dampers with liquid in the hydraulic circuit of the blood flow simulator at the inlet and the outlets of the elastic model.
Nonlinear optical dynamics of 2D super-crystals of quantum Λ-emitters
Authors: Ryzhov Igor V. , Malikov Ramil F. , Malyshev Andrey V. , Malyshev Victor A.
Published: December 2021

We study theoretically the optical response of a 2D super-crystal of quantum Λ-emitters which are coupled by their secondary dipole field. The latter introduces a feedback into the system, the interplay of which with the intrinsic nonlinearity of emitters results in an exotic behavior of the system’s optical response, such as periodic or quasi-periodic self-oscillations and chaotic dynamics. We argue therefore that these predicted features can be promising for various nanophotonic applications.
Pulsating fields of a thin film in a static magnetic field under vertical vibrations
Authors: Volodin I V , Alabuzhev A A
Published: December 2021

In the present paper a dynamics of a thin ferrofluid film under the vertical vibration in a static magnetic field is examined. The vibrational amplitude is assumed to be greater than film thickness so that vibrational force is greater than magnetic and gravitational forces. The pulsating part and the averaged part of the hydrodynamics fields are obtained. The solution of pulsating part for the traveling surface wave is found. The equation for the averaged surface profile is found.
Poly(Lactic) Acid Reinforced with Alkaline Lignin Biocomposites Prepared by Thermal Extrusion for Sustainable 3D Printing Process
Authors: Rahman Nurul Amirah Abd , Anuar Hazleen , Ali Fathilah , Suhr Jonghwan
Published: December 2021

The focus of this work is the mechanical characterization of biomaterials produced by 3D printing based on fused filament fabrication (FFF) process that has been mainly used for prototype rather than functional components due to the limited mechanical properties of pure thermoplastics parts. Addition of reinforcements from natural fiber has been adopted to improve the mechanical properties of the 3D printed parts. In this study, alkaline lignin powder that has been extracted from oil palm empty fruit bunches (OPEFB) via alkaline extraction process were used as filler in the production of biocomposites with poly(lactic) acid (PLA). Poly(lactic) acid filaments filled with 1% of alkaline lignin powder and has been compared with the presence of 5% of epoxidized palm oil (EPO) by means of thermal extrusion and further proceed with 3D printing. The samples were mechanically characterized using tensile tests and the fractography were observed. Tensile test that has been done on the filaments reveal that the filament with addition of lignin and EPO shows improved mechanical properties with higher tensile strength as well as lower stiffness. The 3D printed samples of the filament compositions also exhibit similar trend where the said filament has the best mechanical properties when the EPO is incorporated in the filament.
Image Watermarking Approach Using LSB and Laplacian Filter
Authors: Imran N , Hameed S , Hafeez Z , Faheem Z , Waseem M , Latif U , Amin M S
Published: December 2021

With the growth of information technologies, E-industry safety has recently become the mutual attention of education and business firms. Digital image watermarking is a technique that refers to the security of multimedia data. It is a process referred to the security and authentication of a digital image, video, and audio by embedding a watermark. Watermarking technique applies a number of variable editions to the host content, where the addition is related to embed information. In the past, researchers develop multiple simple watermarking techniques, today race is to find a region where the watermark is imperceptible and have a high payload. In this paper, an invisible image watermarking technique based on the least significant bit (LSB) and laplacian filter is proposed. The original image is divided into blocks and the laplacian filter is applied on each block. Laplacian is a derivative filter that uses the second derivate to find out the area of rapid changes in the image and the least significant bit is a technique to embed a watermark into the bit positions. Watermark is embedded on these regions which is favourable in achieving high desirable properties. This technique shows strong robustness against image processing and geometrical attacks. In evaluation with state of art methods, the proposed technique shows satisfactory progress.
Eliciting User Requirement for Flood Monitoring Application
Authors: Mohamed S E , Ismail N A , Mukthar A , Hafiz M S
Published: December 2021

Flood disaster is the most disastrous hydrological event that can lead to property destruction and loss of lives. One of the efforts to mitigate the impact is by providing an advance technology in monitoring and event alert. The flood monitoring application is developed to provide real-time weather forecast and disaster warnings. To increase disaster management efficiency, we conducted this research to identify the needs and requirements for a flood monitoring application. The study is mainly focusing on user perspective and preferences. The participant of this survey includes the authorities, non-government agency (NGO) and public. The participant is given a set of questionnaires containing thirteen questions, including the combination of open-ended and close-ended questions covering three sub-topics: user background, user experience, and user knowledge. List of important flood monitoring application features based on user requirements analysis and empathy map has been used to visualize user attitudes and behaviours.
A Modified Cuckoo Search Algorithm and Its Applications in Function Optimization
Authors: Ye Shao Qiang , Wang Fang Ling , Zhou Kai Qing
Published: December 2021

A modified Cuckoo search algorithm (MCS) is proposed in this paper to improve the accuracy of the algorithm’s convergence by implementing random operators and adapt the adjustment mechanism of the Levy Flight search step length. Comparative experiments reveal that MCS can effectively adjust the search mechanism in the high-dimensional function optimization and converge to the optimal global value.
TSP Solving Utilizing Improved Ant Colony Algorithm
Authors: Yao Xuan-Shi , Ou Yun , Zhou Kai-Qing
Published: December 2021

To solve the premature issue of TSP solving using the ant colony optimization algorithm (ACO), this paper proposes an improved ACO using particle swarm optimization (PSO) to solve the classic traveling salesman problem (TSP). The algorithm’s strategy includes three stages: firstly, establishing a mathematical model according to the optimization objective, and then solving the optimal path obtained by the particle swarm optimization algorithm. Finally, the pheromone concentration of this path in the ant colony mathematical model is enhanced according to the particle swarm optimization algorithm’s optimal path. A classic TSP case is used to compare the PSO and ACO. The results show that the proposed improved algorithm has a faster convergence speed and can converge to the optimal global solution, and its performance is better than that of ACO and PSO.
Defining-Measuring-Analysing-Improving-Controlling (DMAIC): Process and Improve Stability in Carbon Steel Industry
Authors: Ishak M S , Jusoh M S , Rosli A G M , Yusuf D H M , Ismail M S
Published: December 2021

Phosphating is most common method for surface treatment and finishing of ferrous and nonferrous metal. It has excellent corrosion resistance, wear resistance, adhesion and lubricating properties besides its economic values and speed of application. Steel is one of the cheapest materials used in various industries and it requires corrosion resistance therapy. This study aims to provide possible solution to the rusty issue on carbon steel product by improving coating stability using Defining–Measuring–Analysing–Improving–Controlling (DMAIC) method. The result proposed that zinc phosphate coating material has to replace current iron phosphate coating due to the former is more corrosion time resistant than that of the latter.
The Sound Absorption Coefficient of Railway Concrete Sleepers Containing Palm Oil Fuel Ash (POFA) As a Cement Replacement Material
Authors: Sulaiman Nurfarhanna Ahmad , Adnan Suraya Hani , Izaan Abdul Hadi , Osman Mohamad Hairi , Ahmad Jeni Mohamad Luthfi , Wan Jusoh Wan Amizah , Jamellodin Zalipah , Abdul Hamid Noor Azlina , Salleh Norhafizah
Published: December 2021

Major noise and vibration during train operation can cause disturbance to the surrounding. One of the methods to reduce this disturbance are by installing concrete sleepers. The use of railway concrete sleepers may be a high potential to reduce the noise and vibration. To produce concrete sleepers cement usage will be used with greater volume. Approximately 100 million tons of Palm Oil Fuel Ash (POFA) was disposed to the landfill currently. POFA contains high silica content and porous particles which indicated its pozzolanic properties and sound absorption characteristics. Therefore, this study was to determine the sound absorption coefficient of railway concrete sleepers containing POFA as a cement replacement material. Concrete sleepers with a strength grade of 55 and a w/c ratio of 0.35 were prepared in this study. Three design mixes with 0% (control), 20%, and 40% of POFA tested by using an impedance tube test at 28 days of curing age. The results show, the sound absorption coefficient and noise reduction coefficient increases as the percentage of POFA increases. The best performance was obtained by concrete sleepers containing 40% of POFA, with a recorded sound absorption coefficient of 0.10 for low frequency and 0.44 for high frequency. Meanwhile, the noise reduction coefficient recorded was 0.33, which reduce 32% of noise compared to OPC.
Abaqus Simulation on Basalt Fibre Reinforced Polymer Epoxy Tube Subjected to Axial Compression for Energy Absorption
Authors: Sivakumar Vinu , Mattioni Martin , Chouw Nawawi
Published: December 2021

In practical application, fibre reinforced polymer (FRP) technology is implemented as the outer jackets in structural elements such as column, beam and in automobile engineering as light weight components in the head liners of car, brake pads and energy. In civil engineering FRP is mainly used in the retrofitting technique against corrosion, in columns, piles and poles. The research aims to provide a recyclable, natural, low-cost energy absorption material capable of increasing the load bearing capacity of the structure by increasing the fabric layer. The study focuses on the finite element analysis (FEM) of the energy absorption characteristics of basalt fibre reinforced polymer epoxy tube (BFRPE) subjected to axial compression with varying BFRPE layers. The results also discuss the failure modes of the specimens using abaqus. Parameters such as the energy absorption, crush force efficiency (CFE) are discussed. Energy absorption is defined as the area under the load displacement and CFE is defined as the ratio of the mean load to that of the initial peak force. The test results indicate that as the number of layers increases the ultimate load and CFE of the tube also increases. Compared to flax fibre reinforced polymer the thickness of the basalt fibre is very less with better energy absorption.
Crystal Structure and Thermal Behaviour of Calcium Monosilicate Derived from Calcined Chicken Eggshell and Rice Husk Ash
Authors: Jakfar Nur Hazlinda , Fhan Khor Shing , Johar Banjuraizah , Shima Adzali Nur Maizatul , Mohd. Yunus Siti Nur Hazwani , Meng Cheng Ee
Published: December 2021

This study focuses on the synthesis of synthetic calcium monosilicate ceramic from chicken eggshells and rice husks waste through the mechanochemical route that relatively straightforward without adding any binders. Synthetic calcium monosilicate was mixed using a 1:1 ratio of calcined eggshell and rice husk ash, which both materials known as rich in calcium oxide and silica sources, respectively. The mixed powder was pressed using uniaxial pressing before fired at 1100°C, 1150°C, 1200°C, 1250°C, and 1300°C for 120 minutes with a heating rate of 5°C/min. The XRD spectrum from 1100°C to 1200°C mainly consists of pseudowollastonite (ICSD: 98-005-2576), wollastonite and silicon dioxide phases. However, as the sintering temperature increases, the wollastonite phases was completely transformed into pseudowollastonite, leaving some unreacted silica.
Design and Development of Smartphone Application Control
Authors: Mohd Yusof Siti Malihah , Yusof Munirah Mohd , Hafit Hanayanti
Published: December 2021

Smartphone Application Control is a project designed to block other phone applications that have excessive use by users. Excessive phone use is often experienced by children aged 7-18 years old. At the same time, many parents nowadays do not have time all day long to monitor and limit the use of their children’s phone due to work. The efforts of the mass media to advise on the use of phone do not give much positive impact on these children. Therefore, a robust alternative such as Smartphone Application Control is essential to curb these issues. To develop this application, a methodological approach has been used namely the Evolutionary Prototyping model. Android Studio version 3.6.2 is used to develop this application while SQLite Database acts as a database for storing all application usage statistics and Google-Cloud Firebase is used to store user-related information for user authentication purposes. To create an attractive user interface, Adobe Photoshop CS6 is used to design background and interface buttons. This app is able to track usage hours of other apps and block them if they exceed their daily usage limits. The time limit for such use can only be set by parents. Additionally, notification of excess usage will be sent to parents via email as a notification. A pop-up alert notification will be issued when user has reached his or her application limit. Smartphone Application Control is very important in helping user to control their phone usage behaviour.
Smart Irrigation System for Urban Gardening using Logistic Regression algorithm and Raspberry Pi
Authors: Aminuddin R , Sahrom A S , Halim M H A
Published: December 2021

People have shown an increasing interest in urban gardening. Irrigation is one of the common methods used to take care of the plant growth. However, the proper irrigation timing of plant is much unclear for most people. Moreover, the manual irrigation is impossible when people do not have physical access to the plant in a long period of time. Hence, a smart irrigation system using Raspberry Pi has been proposed to ease the irrigation. In this system, three different sensors, including moisture, humidity and temperature sensors are installed in the soil of the plant. The collected data from the sensors will be used to predict whether the plant need to be watered or not. This system implements a machine-learning algorithm called Binary Logistic Regression using Python library to test the accuracy of the system. The accuracy of the algorithm to predict the irrigation is 82%. The finding from this study is believed to be helpful as it may contribute to the development of better irrigation system.
A Review of Simulation and Application of Agent-Based Model Approaches
Authors: Sie Chiew L , Shahabuddin A , Zainab M Y
Published: December 2021

In the past, various traditional methods used experiments and statistical data to examine and solve the occurred problem and social-environmental issue. However, the traditional method is not suitable for expressing or solving the complex dynamics of human environmental crisis (such as the spread of diseases, natural disaster management, social problems, etc.). Therefore, the implementation of computational modelling methods such as Agent-Based Models (ABM) has become an effective technology for solving complex problems arising from the interpretation of human behaviour such as human society, environment, and biological systems. Overall, this article will outline the ABM model properties and its applications in the criminology, flood management, and the COVID-19 pandemic fields. In addition, this article will review the limitations that occurred to be overcome in the further development of the ABM model.
Phase Analysis of Bio-Based Derived Tricalcium Disilicate From 2CaO:1SiO2 By X-ray Diffraction
Authors: Yunus Siti Nur Hazwani , Fhan Khor Shing , Johar Banjuraizah , Adzali Nur Maizatul Shima , Jakfar Nur Hazlinda , Meng Cheng Ee
Published: December 2021

In this paper, tricalcium disilicate was formed from dicalcium silicate compound powder, synthesised via a mechanochemical technique using a stoichiometric 2CaO:1SiO2. Compound CaO and SiO2 were derived from the bio-waste of eggshell and rice husk at the calcination temperature of 900°C and 800°C, respectively. The dicalcium disilicate powder was sintered for 2 hours at different temperatures ranging from 1150°C to 1350°C. Using X-ray diffraction with Rietveld analysis, it was found that the amount of tricalcium disilicate with monoclinic (beta) crystal structure increases on sintering temperature at the expense of dicalcium silicate. The complete formation of single-phase tricalcium disilicate began at a sintering temperature of 1300°C. The effect of sintering temperatures on the crystallisation and phase transition of dicalcium silicate is reported. The size of crystallites depends on the sintering temperature. The finding of this study rebound to the benefit of society by reducing the risk-off pollution cause by accessive redundant bio-waste eggshell and rice husk and also reduced the amount of CaO and SiO2 used in the fabrication of Ca3Si2O7.
Determination of Silicon Electrical Properties Using First Principles Approach
Authors: Hashim Uda , Adam Tijjani , Afnan Uda M N , Uda M N A
Published: December 2021

Silicon nanowires have attracted attention as basis for reconfigurable electronics. However, as the size decreases, the electronic properties of the nanowires vary as a result of confinement, strain and crystal topology effects. Thus, at the thin diameter regime the band gap of Silicon nanowires can no longer be derived from a simple extrapolation of the isotropic bulk behaviour. This study compares band gap parameters in sub 10nm nanowires obtained from first-principles density-functional band structure calculations with extrapolations using continuum theory in order to rationalize the changes of the overall conductance, resistance and band gap. The device consists of silicon nanowire of size between 1 nm to 6nm. The results indicate an increase of, both the energy gap and the resistance along with reduced conductivity for the thinnest wires and a dependence on the crystal orientation with gaps reaching up to 4.3 eV along <111>, 4.0 eV along <110>, and 3.7 along <100>.
Capillary Driven Muilti Channels Microfluidic
Authors: Hashim Uda , Adam Tijjani , Ehfaed Nuri A.KH. , Afnan Uda M N , Uda M N A
Published: December 2021

The paper present design and fabrication of capillary driven muilti channels microfluidic. AutoCAD assisted layout design was conducted and fabricated based on cold photolithography process with precise geometry for capillary flow. The design was bonded with glass to test the flow and bonding integrity. The device was tested for flow and it was found the uniform capillary flow was established with strong bonding energy.
Analysis on the barrier properties of thin film PLA/PBAT reinforced with microcrystalline cellulose
Authors: Mhd Ramle Sitti Fatimah , Rahim Aqilah Abdul , Jusoh Nur Hafizzah , Rawi Nurul Fazita Mohammad , Alam Che Ku Abdullah Che Ku
Published: December 2021

In recent times, awareness on plastic pollution had increase which brings innovation on new productions to be environmental friendly. Various polymers has been used to analyse the suitability to produce thin films. In this study, Poly lactic acid (PLA) and Polybutylene adipate terephthalate (PBAT) reinforced with microcrystalline cellulose (MCC) were investigated. MCC were produced from selected bamboo for obtaining cellulose, then followed by an acidic hydrolysis process for the processing of microcrystalline cellulose (MCC). In this study, the thin film are focusing on the barrier properties such as water absorption, solvent resistance and absorption test. From the results shows that, the lowest rate of water absorption rate is 1.9% by 1% B-MCC/PLA/PBAT, meanwhile, the highest rate of water absorption is 60.1% by 5% C-MCC/PLA/PBAT. The water absorption rate decrease gradually with the decreasing of amount of MCC in the samples. Lastly, the thin film samples can resist with oleic acid solvents as the condition of thin film samples is still remain but they were not resistance with xylene as the thin film samples were shrinked and degraded. This thin film have a potential to replace the non-biodegradable petrochemical polymer based on their properties such as food contact, availability and cost.
Explorations of A Real-Time VR Emotion Prediction System Using Wearable Brain-Computer Interfacing
Authors: Suhaimi Nazmi Sofian , Mountstephens James , Teo Jason
Published: December 2021

The following research describes the potential of using a four-class emotion classification using a four-channel wearable EEG headset combined with VR for evoking emotions from each individual. Multiple researchers have conducted and established emotion recognition by using a 2-D monitor screen for stimulus responses but this introduces artifacts such as the lack of concentration on-screen or external noise disturbance and the bulky and cumbersome wires on an EEG device were difficult and time-consuming to set up thus restricting to only the trained professionals to operate this complex and sensitive medical equipment. Therefore, using a small and portable EEG headset where it was accessible for consumers was used for the brainwave signal collection. The wearable EEG headset collects the brainwave samples at 256Hz at specific locations of the brain (Tp9, Tp10, AF7, AF8) and samples were transformed via FFT to obtain the five bands (Delta, Theta, Alpha, Beta, Gamma) and were classified using random forest classifier. An emotion prediction system was then developed and the trained model was used to benchmark the 4-class emotion prediction accuracy from each individual using a 4-channel low-cost EEG headset. Subsequently, a real-time prediction system was implemented and tested. Early findings showed that it could achieve predictions as high as 76.50% for intra-subject classification results.
Preliminary Study on Different Materials of Geogrid by using Finite Element Model
Authors: Atil Aida Atiqah , Mat Hassan Nik Normunira , Yusop Fatimah Mohamed , M. Rus Anika Zafiah , Leman Abdul Mutalib , Marsi Noraini , Samiran Nor Afzanizam
Published: December 2021

In recent years, environmental concerns related to the overexploitation of natural resources and the need to manage large amounts of wastes arising from construction activities have intensified. This paper presents a preliminary study carried out to characterize the interaction impact with different material geogrids (a polyester (PET), high-density polyethylene (HDPE), and polyurethane (PU) geogrid through Finite Element Model (FEM) simulation. The effects of the geogrid specimen size, displacement rate by the pressure through the geogrids are evaluated. The results show that the measured peak pullout resistance of the geogrid increases with the specimen size imposed displacement rate The pressure ranged from 10 000 N/m2 and 50 000 N/m2. The FEM analysis result is important due to quantify the benefit-cost ratio of geosynthetics application in pavements needed for a detailed Life-Cycle Cost Analysis (LCCA).
Performance of Castor Oil and Neem Oil as Metal Cutting Fluids in Drilling Inconel 718 Using MQL Technique on Tool Wear and Surface Roughness
Authors: Safie Syahilia Syahira , Murad Muhamad Nasir , Lih Tan Chye
Published: December 2021

Inconel 718 is hard to cut material due to its high hardness, high strength at elevated temperatures, low thermal diffusivity and affinity to react with tool materials. The high temperature during machining results in aggressive tool wear and poor hole quality. Therefore, the application of metal cutting fluids (MCF) as a lubricating and cooling agent is very significant in the drilling of nickel-based superalloys such as Inconel 718. The present study embraces these issues by evaluating the performance of non-edible vegetable oils such as castor and neem oil under minimal quantity lubrication (MQL) conditions towards the tool wear and surface roughness. The drilling experiments were carried out using coated (TiAlN) carbide drill with diameter of 6 mm at different cutting speeds of 10 and 20 m/min and a constant feed of 0.015 mm/rev. The results of this study showed that castor oil significantly outperformed the neem oil in drilling performance regarding tool wear and surface roughness.
Analysis on Inlet Nozzle Design Geometry of Tesla Turbine
Authors: Halim Sufi , Rahman Md Tasyrif Abdul , Rahman Anas Abdul , Mohd Amin Nasrul Amri , Roslan Nur Shuhaila , Ghazli Mohd Fathullah
Published: December 2021

Tesla turbine is a bladeless turbine that uses a set of discs arranged at a certain distance to rotate and one of the parameters controlling turbine performance is the inlet parameter. The purpose of this study is to optimize the design of the inlet nozzle and analyse its effects on the flow of the fluid. A total of four nozzle designs have been proposed using CATIA while the Solidworks Flow Simulator is used to analyse the fluid flow at various inlet velocities. Then, the most efficient design is then fabricated via 3D printing and put to test by connecting it with the actual Tesla turbine model. Through the results obtained from the analysis, it is observed that Design 4 is the most efficient of all tested nozzles and the highest RPM and output voltage achieved from the nozzle is 7940 RPM and 13.56 V. The difference in velocity and pressure increases as the area of the nozzle outlet reduces, whereas nozzle efficiency decreases as the inlet velocity increases. The result of this study is a source material for increasing the effectiveness of an alternative power turbine in generating electricity by manipulating the inlet design geometry.
Autonomous Underwater Vehicle in Internet of Underwater Things: A Survey
Authors: Okereke Chinonso , Abdul Wahab Nur Haliza , Mohamad Mohd Murtadha , Zaleha S H
Published: December 2021

Water, mostly oceans, covers over two-third of the earth. About 95% of these oceans are yet to be explored which includes 99% of the sea-beds. The introduction of the Internet of Underwater Things (IoUT) underwater has become a powerful technology necessary to the quest to develop a SMART Ocean. Autonomous Underwater Vehicles (AUVs) play a crucial role in this technology because of their mobility and longer energy storage. In order for AUV technologies to be effective, the challenges of AUVs must be adequately solved. This paper provides an overview of the challenges of IoUT, the contributions of AUVs in IoUT as well as the current challenges and opening in AUV. A summary and suggestion for future work was discussed.
Effect of Current Density and Bath Temperature to The Corrosion and Wear Behaviour of Tungsten Carbide - Nickel Electrodeposition Coating
Authors: Hamidi Natasha Alina , Kamdi Z , Ainuddin A R , Hussin R , Ibrahim S A
Published: December 2021

The composite (ceramic-metal) coating has become a desired coating due to its higher wear and corrosion behaviour compares to metal coating only. This study focuses on the effect of the deposition parameter which is the current density and bath temperature on the corrosion and wear behaviour of the coating. As the current density and temperature will affect the movement of the electron during deposition, it is important to evaluate its effect on the coating thickness and its wear and corrosion performance. The mild steel was used as the substrate and nickel-tungsten carbide (Ni-WC) as the coating. Watts’s bath was used as an electrolyte with the addition of 25 g/l WC. 0.2 A/cm2 and 0.5 A/cm2 has been chosen as the current density while 30 °C and 50 °C as their temperature. The coating was characterised using a scanning electron microscope (SEM) and x-ray diffractometer (XRD). Immersion test and weight loss test was used to evaluate the corrosion and wear behaviour respectively. The 3 g/l silicon carbide was used as abrasive materials in the wear testing. Vickers micro-hardness tester was used for hardness property evaluation. It is found that higher current density and higher bath temperature results in lower corrosion and wear rate which shows higher resistance.
Development of a Novel Aeration Measurement System to Evaluate Water Treatment Process in a River
Authors: Rani M F H , Kamarrudin N S , Shahriman A B , Razlan Z M , Wan K , Hashim M S M , Ibrahim I , Rahman A , Ibrahim Z , Faizi M K , Hassan M A S M , Abd Manap A A , Zainuddin I F
Published: December 2021

A novel aeration measurement system was developed to evaluate the water treatment process in a river to acquire a more comparable dissolved oxygen value even if various types of aerations are tested. The system comprises of DO sensor, water flowmeter, anemometer, PVC pipes, water pump, air compressor pump, and truck tyre tubes. The PVC pipes consisting of a main drainage hole, 5 holes for dissolve oxygen data collection, 1 hole as the location of aerator system, and connectors were designed as the major part of the system by using Computer Aided Design software. The main drainage hole (horizontal pipe) was designed to be 288.5 cm in length, while the measured holes (vertical pipes) were designed to be 45.7 cm in height. By considering a systematic approach, the designed system is hopefully able to solve measuring issue of dissolved oxygen in moving water and to provide a better evaluation of water treatment process.
The expert system for assessing fire risks of electrical installations in the agrarian industrial complex based on neural networks
Authors: Gabova M A , Nikolsky O K , Guner M V
Published: December 2021

The article is devoted to the analysis of fire risks of the operation of electrical installations in the agro-industrial complex of the region. According to statistics, the number of fires occurring for electrical reasons is steadily increasing, which makes the issue of fire risk management relevant. In order to identify and prevent these risks, a technogenic safety system has been developed, presented as a set of methods and tools, which are based on the generation of new data on the causes of threats to the operation of electrical installations based on the analysis of data on the current state of the system. Highlighted characteristics such as Human Parameters, Electrical Installation Parameters and Environmental Parameters. Mathematical models of the given components are considered, a fire risk assessment tree is compiled, in which the input parameters and intermediate vertices with the solution methods in them were determined. The developed model can be used to carry out experiments in order to study the behavior of an electrical installation under various conditions. The application of this method is especially important in cases where the removal of indicators and testing of the operation of an electrical installation is impossible due to the risk of injury or material damage.
Optimization of a heterogeneous computing system architecture based on its coordination with a sensors group of a mobile unmanned platform
Authors: Stepanyuk V S , Emelyanov A M , Mirzoyan D I
Published: December 2021

This article analyses the existing variety of sensors used in robotics and related fields and also proposes the architecture of a heterogeneous computing system designed to analyze data obtained from sensors of a mobile unmanned platform (MUP). A feature of unmanned platforms is the presence of tasks that require a significantly different level of performance of the on-board computing system for processing data from sensors of the corresponding type. Therefore, the adaptation of existing universal computing systems seems to be impractical, compared to the development of a specialized computing system with a heterogeneous architecture. The computing system is designed to solve problems of local navigation, stabilize the position of the MUP and control its movement, as well as control special equipment installed on the MUP. Often, if the goal is to ensure maximum efficiency, expressed in speed, accuracy and reliability, it is necessary to develop specialized devices. The article provides information on sensors of the main types used in robotics and indicates the requirements for the performance of a computing system necessary for processing data from sensors of this type. This, in turn, made it possible to propose a heterogeneous architecture containing processor subsystems focused on processing data from sensors requiring low, medium and high performance according to the considered classification.
Perspectives on tipping points in integrated models of the natural and human Earth system: cascading effects and telecoupling
Authors: Franzke Christian L E , Ciullo Alessio , Gilmore Elisabeth A , Matias Denise Margaret , Nagabhatla Nidhi , Orlov Anton , Paterson Shona K , Scheffran Jürgen , Sillmann Jana
Published: December 2021

The Earth system and the human system are intrinsically linked. Anthropogenic greenhouse gas emissions have led to the climate crisis, which is causing unprecedented extreme events and could trigger Earth system tipping elements. Physical and social forces can lead to tipping points and cascading effects via feedbacks and telecoupling, but the current generation of climate-economy models do not generally take account of these interactions and feedbacks. Here, we show the importance of the interplay between human societies and Earth systems in creating tipping points and cascading effects and the way they in turn affect sustainability and security. The lack of modeling of these links can lead to an underestimation of climate and societal risks as well as how societal tipping points can be harnessed to moderate physical impacts. This calls for the systematic development of models for a better integration and understanding of Earth and human systems at different spatial and temporal scales, specifically those that enable decision-making to reduce the likelihood of crossing local or global tipping points.
A Proposed Improvement of Belanti II Tidal Irrigation Scheme, Kalimantan, to Support Leaching of Acid Sulphate Soil Reclamation
Authors: Setiawan A , Wignyosukarto B S , Rahardjo A P , Yakubson
Published: December 2021

The reclamation process of acid sulphate soil of the Belanti II tidal irrigation scheme remains unfinished. During ebb tide, the upstream acidic drainage water retains and settles in the irrigation canals. During high tide, the acidic water flows back into some parts of the agricultural land and reduces rice productivity. The measured pH is about 2.5 ~ 3.5 and the measured electric conductivity is about 0,25 ~ 0,35 mS/cm. Sedimentation in the middle to the end of the primary, secondary, and collector canals and tidal pond at the upstream end of the primary canal, preventing the leaching process of sulfuric acid soil. Primary canal normalization as an alternative solution to increase the capability of acidity leaching is proposed. Leaching the acidic soil of Belanti II irrigated area of 3.976 ha requires 500 m3/ha/day of freshwater, equivalent to 1.998.000 m3/day. The one-dimensional HEC RAS mathematical model is used to evaluate the hydraulics performance to support the leaching process. The hydraulic analysis was carried out using two tidal cycles on the existing channel and the normalized channel. Channel normalization has succeeded in reducing the water supply deficit to support the leaching process from 39% to 9%.