bluuebunny/crossref_metadata_2025 huggingface dataset:
Cooling times’ dependence on the glassy NiTi at extremely low temperatures: a result from rapid solidification using molecular dynamics simulations
Authors: Alif Mahendra Bagus Nurcahyo , Arifin Rizal , Malyadi Muhammad , Munaji  , Ghulam Asrofi Buntoro , Ridwan  , Alfiyan Sukron Huda , Frengky Vion Dwi Ariadhi
Published: January 2020

In this paper, we evaluate the structure of glassy NiTi at 10 K obtained from molecular dynamics simulations using various cooling times. The final configurations of glassy NiTi were produced by decreasing the temperature of liquid NiTi rapidly from 2500 K to10 K during 0.1 nanoseconds (ns) to 1.0 ns of cooling times. The results show that the count of BCC-like and Icosahedral-like local structure increases at the longer cooling times, while the count of HCP-like local structure decreases when the cooling times become longer. We also observe that the count of FCC-like local structure almost remains constant for all cooling time variations.
Thermoelectric Properties of BiTe
Authors: Faisal Fikri Oktaviantoni , Singsoog Kunchit , Melania Suweni Muntini , Seetawan Tosawat
Published: January 2020

Research on crystal structures and thermoelectric properties has been carried out using BiTe material. The sintering method used is hot press. Hot press pressure comes from the bottom up. Temperature variations used in hot press are 400, 450, and 500°C. Analysis of crystal structure used XRD. Based on the XRD results, the result is that the crystal structure of BiTe bulk is hexagonal. Thermoelectric properties measurements used ZEM-3. The sample is measured in a temperature range of 50–200°C. Based on the measurements, the sample with hot press 500°C has the highest Seeback coefficient and power factor values which are –71µV/K and 3.6 x 10–4 W/mK2, respectively. The sample has the best performance at room temperature and has decreased performance with increasing temperature. While, the best electrical resistivity value is owned by the sample with hot press 450°C with a value of 1.28 mΩ cm at room temperature. Overall, the higher the temperature used when sintering, the better the performance produced. Thus, the BiTe material can be considered as a thermoelectric material.
Effect of Temperature and Residence Time Torrefaction Palm Kernel Shell On The Calorific Value and Energy Yield
Authors: Dirgantara M , Karelius  , Cahyana B T , Suastika K G , Akbar A RM
Published: January 2020

Torrefaction was thermochemical processes to make biomass a fuel that had better properties, such as increased carbon content and calorific value. It was a temperature-sensitive process that was effective between 200 °C and 300 °C in an inert environment with a residence time of 20-60 minutes. Palm kernel shell was one of the biomass that has the potential to be used as fuel, where its availability was abundant and has good physical properties. In this study of palm kernel shell torrefaction was carried out from 0.5 cm sieve with three variations in temperature and residence time follows 250 °C - 300 °C and 20-40 minutes. The results obtained were the increase in temperature and holding time causes an increase in the calorific value but relatively on energy yield because of a large mass loss at a temperature of 300 °C. The optimum process for torrefaction of palm kernel shell according to calorific value and energy yield was 275 °C with residence time 20 minutes.
Environmental assessment of pre-feasibility of smart offshore npp (onpp) technology for indonesia: a-review
Authors: Santosa Sigit , Khotimah Khusnul , Yasmine Hanna , Kurniawan Rusbani
Published: January 2020

Land needs for energy infrastructure needs, such as the construction of the planned NPP in Jepara, Central Java, often lead to conflicts with the communities because they consider the existence of this infrastructure will Cause environmental damage. One of the solutions studied to improve the development and move the nuclear power plant is to move the location of the nuclear power plant from land to offshore. Besides, Indonesia has a potentially special offshore site on the eastern Sumatra coastline, northern Java coastline, and the Kalimantan coastline. The purpose of this paper is to review the environmental aspects of the implementation of GBS Nuclear power plant in Indonesia. The method used is the review of the literature and subsequently conducted a descriptive analysis. The results showed that SMART offshore NUCLEAR power plants should be considered because it offers clean energy sources, improved safety aspects, availability of offshore sites, and better community of acceptance.
The Role of pH in Synthesis Silver Nanoparticles Using Pometia pinnata (Matoa) Leaves Extract as Bioreductor
Authors: Handayani W , Ningrum A S , Imawan C
Published: January 2020

Green synthesis of silver nanoparticles (AgNPs) using plant extract have been developed due to ecological friendly and their simple procedure. Plant contains bioreductor to reduce silver precursor into nanoparticles. Plant compound beside of their medicinal properties also can be functional for this biosynthesis process. The synthesis process can be affected by pH, which can determine the shape and size from AgNPs. Therefore, in this research biosynthesis of AgNPs has been done to study the effect of aqueous extract pH on the AgNPs synthesize on acidic and alkaline condition. The synthesis was done by mixing 2% Matoa aqueous extract and 1 mM AgNO3 each solution adjusted to 4 and 11, and 5 as the nature pH for comparison. The AgNPs were characterized based on color changes, UV-Vis spectrophotometers, TEM (Transmission Electron Microscopy), and PSA (Particle Size Analyzer). The UV-Vis spectrum had absorption between 400-500 nm. The TEM results showed that the shape of the nanoparticles produced varies considerably from triangles, spherical, and hexagons. The PSA results show that increasing pH tend to produce the small size of nanoparticles, which had moderately stable nanoparticle and moderate stability. This result showed that the AgNPs synthesized can be optimized by adjusting the pH to obtain particular shape and size from the AgNPs.
Investigation on Physical and Optical of Praseodymium Doped Sodium Aluminium Barium Phosphate Glasses
Authors: Sangwaranatee N. W. , Kiwsakunkran N , Kaewkhao J
Published: January 2020

Sodium aluminium barium phosphate glasses doped with different concentration of Pr2O3 were synthesized by melt quench technique. These glasses were varied concentrations of Pr2O3 at 0, 0.05, 0.10, 0.50, 1.00 and 2.00 mol%. Their physical properties like density (ρ) and refractive index (n) were measured at room temperature. Also, optical absorption and photoluminescence spectra of these glasses have been acquired at room temperature. It was found that the intensity were increase with increasing concentration of Pr2O3. UV-Vis and NIR (250-2500 nm) spectra have been measured for all studied glass samples and discussed. The photoluminescence spectra recorded under 445 nm excitation exhibited the emission bands at 528, 598 and 639 nm corresponding to the emission transitions 3P1 → 3H5, 1D2 → 3H4, and 3P0 → 3F2 respectively. The Judd-Ofelt (JO) parameters Ωλ (λ = 2, 4 and 6) have been calculated to explore the bonding environment around the Pr3+ ions. The CIE chromacity color coordinates (x,y) are calculated from the emission spectra which indicates the located in the yellow-orange region. The prepared glasses are potential candidates for laser applications.
Computational Modelling Based on Modellus to Improve Students’ Critical Thinking on Mechanical Energy
Authors: Jonny Haratua Panggabean , Rajagukguk Donna , Rajagukguk Juniastel
Published: January 2020

Mechanical energy is one of the topics of learning physics in high school that is related to concepts and mathematical equations. Modellus is a computer application designed to explore mathematical models based on functions that are represented in the form of animations, graphics, and tables that are useful for focusing learning activities on understanding student physics concepts. In this study describes computational modelling activities using Modellus software and carried out the Modellus quality testing phase as a medium of physics learning to improve understanding of students’ concepts on the topic of mechanical energy. Based on the data obtained, Modellus is included in the “very good” category used in physics learning especially on the topic of mechanical energy and critical thinking skills students obtain an average score of 65,45 in the “good” category using Modellus.
Automatic and Realtime Control of pH Level in Water Catfish Cultivation
Authors: Fathurrahman  , Nasution T I , Ningsih H W , Tarigan K , Pulungan I H
Published: January 2020

A water pH control device in catfish cultivation has been successfully made and tested. The working principle of this device has been designed to maintain the pH of catfish pond water in the range of 6,5-8,5. It was found that if the pH value was outside this range, the sensor ordered the water pump to automatically and in the realtime drain the pond water through a filter to return the pH to the specified value. Thus, the application of this sensor has succeeded in reducing catfish deaths due to stress.
Ergonomics Analysis Of Public Seat In The Kudus Town Square
Authors: Sokhibi Akh , Alfarisi Salman , Ajeng Alifiana Mia
Published: January 2020

The public seat is one of the public facilities provided by the government as a form of public service to improve better human development. Public seats are in public buildings, public parks, city squares. In the Kudus town square, there are two types of public seats that are widely used by the public. However, the public seats provided do not have a backrest and elbow rest. Therefore ergonomics analysis is needed to determine the comfort level of public seats. Qualitative methods have been used by taking data about the height of users of public seats using random sampling. Then the data is used to calculate anthropometric measurements of chairs based on the comparison of body size to the height from the ASEAN Regional Institute for School Boarding Research. Based on research that has been done, the results obtained in the form of public seats in the Kudus town square designed by not considering aspects of ergonomics.
The Dynamics of Ureter Changes After Medial and Distal Unilateral Ureteral Obstruction in Rat
Authors: Rickyawan Nofan
Published: January 2020

Unilateral ureteral obstruction is an abnormality that often occurs in the urinary tract. Obstruction can be placed proximal, medial or distal ureter. The physiological response that occurs depends on the severity, duration, location and type of obstruction. The aim of this study was to look at the macroscopic and histopathological changes of the ureter also Hydronephrosi Hydroureter Index after medial and distal unilateral ureteral obstruction. Thirty-six white rats were divided into 3 groups and each group consist of 12 individuals. Group I as a control got a laparotomy without ureter ligation. Group II laparotomy with medial right ureteral ligation and group III laparotomy with distal right ureter ligation. Three rats in each group were randomly collected at weeks 1, 2, 3 and 4 after treatment. The kidneys and ureters were removed from the abdominal cavity to measure the diameter of the ureter and weigh. After the accumulated liquid was taken, the weighing was done again. An ureter sample was taken for histopathological preparations. The results of the macroscopic and histopathological examination of the ureter were discussed qualitatively. Measurement of the diameter and thickness of the ureteric wall was analyzed using statistical analysis of factorial pattern variations 3x4. The accumulation of fluid in the ureter causing changes in the shape, color, size and structure of the ipsilateral ureter in both ligation groups. Histopathological observations showed depletion, alteration and damage to the structure of the ipsilateral ureteric wall structure. Unilateral ureteral obstruction affected ureter diameter increase, thinning of the ureteral wall and ipsilateral IHH (P <0.05). The presence of unilateral ureteral obstruction had no impact on the contralateral ureter (P> 0.05).
The Effect of Quercetin towards Adipocytes Count in Toxoplasma gondii Profilin - exposed Adipocytes In Vitro
Authors: Setia Y D , Poeranto S , Hernowati T E , Iskandar I , Sudjari
Published: January 2020

Toxoplasma gondii is one of the protozoan causes of chronic infection that allegedly causes obese (infectobesity). Some previous studies have showed that profilin Toxoplasma gondii has a role in inflammation by promoting interleukin-12 (IL - 12) which induce adipocyte dysfunction through the hyperplasia and hyperproliferation of adipocyte cells. Those processes lead to metabolic syndrome which increase adipocytes count through reducing insulin receptor’s sensitivity. On the other hand, Toxoplasma gondii, as an obligate intracellular parasite, can also damage the pancreatic beta cells. In response to inflammation, adipocytes produce Reactive Oxygen Species (ROS). To scavenge ROS antioxidants are required. Quercetin, an exogenous antioxidant, can be widely found in natural products that might be a promising candidate for development of antioxidant treatment interventions to prevent adipocytopathy. This research aims to explore the effects of quercetin towards Adipocytes Count stimulated from T. gondii profilin-exposed adipocytes. This research using visceral adipocyte rat that was cultured in Dulbecco’s Modified Eagle Medium (DMEM). After 70% confluency, adipocytes were exposed to 20 μΜ T. gondii profilin and treated with four doses of quercetin; 31.25, 62.5, 125, and 250 μΜ that incubated 48 hours. After incubation period, adipocytes were observed using inverted microscope and were captured in high power field magnification using camera. Adipocytes were counted from each captured photo and all groups were analyzed using Analysis of variance (ANOVA) test. The results showed that quercetin significantly reduced adipocyte cell count T. gondii profilin-exposed adipocytes compared to untreated cells (ANOVA p = 0,00). The effective dose to lower adipocyte cell count was 31,25 μΜ. This study implies that quercetin has a potent antioxidant that can prevent toxoplasmosis-mediated adipocytopathy.
Supporting Factors to Improve the Lack during Lean Manufacturing Implementation
Authors: Mardiana Dewi Putri , Alfarisi Salman
Published: January 2020

Product quality and customer satisfaction were challenges faced by many manufacturing or services companies which considered the global challenges, thus encouraged many companies to improved quality and satisfied costumer needs. Most of companies implemented lean with their unique way it caused by internal problems such as the lack of knowledge and understanding of lean, and etc. This can result the lack in implementation lean manufacturing. To avoid the lack in implementation of lean manufacturing required support factors such as support factors continuous improvement (kaizen). For this reason, previous literature research needed to resolved this problem. Implementation of lean manufacturing required good leadership that impacts in implementation process and employee contributions.
Android-Based Lecturer Workload Simulation Application
Authors: Triyanto Wiwit Agus
Published: January 2020

In carrying out their duties, lecturers must conduct Tri dharma education activities which include teaching, research and service according to their respective fields of science. Every tri dharma activity carried out must be reported once every semester in the form of a lecturer workload report.The number of activities contained in the rubric makes many lecturers experience confusion to calculate how the credit performance in the Tridharma activities carried out. Therefore, it is necessary to have a simulation application that helps the calculation of credit performance of Tridharma activities in accordance with the BKD rubric. The lecturer workload simulation application can help lecturers to calculate credits for the Tridharma activities that have been carried out. The lecturer workload simulation application can also provide information on what physical evidence needs to be prepared by the lecturer.
Optimization Model for Subsidized Housing using Linier Programming Associated with Land Suitability
Authors: Murti Alif Catur , Ghozali Muhammad Imam , Sugiharto Wibowo Harry
Published: January 2020

The increasing population from year to year raises the problem of population density. The population density of the Kudus Distric from 2010 to 2014 increases in quality every year. Recorded in the Central Bureau of Statistics in 2010 the population density (Soul Per Km2) around 1833 and in 2014 reached 1931. Population growth rate is proportional to the growth rate of existing houses as shelter. The Government of Kudus District as a program implementing “million houses” from the President of the Republic of Indonesia provides solutions in terms of security in the administration of land administration. Developers of subsidized housing need to take several aspects in development, such as Spatial Planning in each region, especially Kudus District, the long-term program and government functions. There needs to be a system capable of determining the optimal level of the type of housing to be built with the suitability of existing land. There needs to be a system capable of determining the optimal level of the type of housing to be built with the suitability of existing land. condition that need to reach the optimal level can be done by using linear programming method. All these things can be integrated and execute with the existence of eco-friendly Development System
Destruction features of the cylindrical samples with the annular notching at cyclic loading
Authors: Ganzulenko O Y , Emelyanov A V
Published: January 2020

This article is devoted to the issues of metals fatigue destruction under the cyclic loading. There is the experimental procedure description given, as well as an analysis of the parameters characterizing the reliability of the obtained results held.
The effect of plastic deformation on the temperature dependences of ultrasonic velocities in Al-Mg alloy
Authors: Kurashkin K V , Gonchar A V
Published: January 2020

This work deals with an experimental investigation of the effect of damage resulting from plastic deformation on the temperature dependences of ultrasonic velocities in 93% Al -6% Mg alloy. For samples with different degrees of plastic deformation, the velocities of shear and longitudinal waves linearly decrease with increasing temperature from 230 K to 320 K. For both shear and longitudinal waves, results showed the average value of the temperature-velocity factor varies linearly with plastic deformation. The discovered structural sensitivity of the temperature-velocity factor opens up new possibilities for nondestructive evaluation of metal alloys with accumulated damage, but requires further research.
Theoretical investigation of the deformation stability and thermostability of carbon diamond-like phases
Authors: Greshnyakov V A , Belenkov E A
Published: January 2020

In this work, first-principle calculations of the mechanical and thermal stability of diamond-like LA3 and LA5 phases with equivalent atomic positions were carried out. It was established that these phases can be stable under uniaxial deformations in the pressure range from -62 to 85 GPa. The calculations also showed that LA3 and LA5 phases should be stable at a temperature of 500 K and normal pressure.
The use of generalized models in the variational formulation of the prediction tasks defining characteristics of composite materials
Authors: Gusev E L , Bakulin V N
Published: January 2020

Within the framework of variational refined statements of inverse problems of forecasting, thequestions of development of effective, refined methods of forecasting resource, strength, reliability, durability of structures made of polymeric, composite materials are investigated. Formulated the principle of a plurality of prediction models, whose inclusion in the refined formulation of the inverse task of forecasting opens new and promising possibilities to improve the efficiency of solving problems of forecasting the defining characteristics of structure composites.
Hardening of coatings with Ni-Co-Cr alloy dye to nanostructure
Authors: Schmidt V V , Denisenko D V , Zhikhareva I G
Published: January 2020

The purpose – receiving a nanostructural electrochemical covering Ni-Co-Cr (Cr-NiCo) alloy with a high microhardness. The composition of electrolyte (a ratio of ions of metals in solution – Cr58.6Ni22.5Co18.9 (α-Cr + β-Ni + NiO); Ni58.7Cr25.0Co16.3(β-Ni + α-Cr)), optimum phase structure by means of 4 criteria of a phase formation. The nanostructure of d=50 of nanometer is received by means of special multifunctional additives. In the presence of H-acid a covering of Cr-Ni-Co HV = 690 MPa, and for (NH2)2CO additive – HV = 985 MPa possesses. Alloys are recommended for use in radioelectronics and microelectronics for resistor and the strain-resisting elements.
Molecular dynamics simulation of a nonequilibrium grain boundary in titanium under the ultrasonic action
Authors: Mukhametgalina A.A. , Nazarov A.A.
Published: January 2020

Effect of oscillating tension-compression stresses on a nonequilibrium grain boundary containing a disclination dipole in titanium is studied by means of molecular dynamics simulations. The system with nonequilibrium boundary was constructed by joining two bicrystals with tilt boundaries Ɵ = 36.87 ° and Ɵ = 28.07 °, thus the disclination dipole had a strength ω = 8.8 °. The system was relaxed and equilibrated at temperature T=300 K for 200 ps. Then a sinusoidal stress σ = σ0×sin (2πt / τ) with a period τ = 160 ps was applied along x axis at the same temperature and its effect on the structure of the bicrystal was studied. It is shown that under the action of oscillating stresses the nonequilibrium boundary emits lattice dislocations that sink at appropriate surfaces. This process is irreversible and leads to relaxation of the nonequilibrium structure of the boundary. There is an optimal amplitude at which the nonequilibrium boundary emits a sufficient number of dislocations to relieve internal stresses.
Study of the high-velocity impact of tungsten particles with a steel target
Authors: Petrov E V , Trofimov V S , Kopytskiy V O
Published: January 2020

The high-velocity impact of a tungsten particle flux with the surface layer of steel (U8) samples is studied. High-speed photography which was used to record the motion of tungsten particles and detonation products shows that tungsten particles move with an average velocity of 2.4 km/s. Microstructure studies have revealed that upon the impact of tungsten particles with the surface of the target, the temperature in the active zone exceeds the temperature of the peritectoid reaction in the Fe-W system, and the polymorphic transformation of iron takes place with the formation of austenite and the dissolution of tungsten carbide in austenite under these temperature conditions.
Investigation of the stress state of the connecting rod of the oppositional compressor and evaluation of the probability of its trouble-free operation
Authors: Petrova I M , Filimonov M A
Published: January 2020

Calculating and experimental methods were used to study the stress-strain state of the connecting rod of the oppositional compressor operating in the chemical industry. Computational and experimental methods for assessing the stress-strain state of the compressor connecting rod head were previously tested on models, since the connecting rods are large and conducting research on a running compressor is extremely difficult. Similarity criteria are defined that allow the methods and results of studies obtained on models to be applied to the assessment of the stress-strain state of connecting rods. The dependence of the contact angle between the connecting rod and the connecting rod finger on the load, the gap in the coupling and the geometric characteristics of the head was obtained. For the connecting rod head, a numerical experiment was used to calculate the stress state under loads and gaps in the connecting rod – pin, corresponding to the operational ones. Analysis of the stress distribution obtained by the calculation allowed us to estimate the dependence of stresses on the magnitude of the applied load, the magnitude of gaps in the interface and the change in the angular coordinates of the sections with the maximum stress values. Taking into account the obtained results, a method has been developed and a study of the stress distribution of the compressor head in operation has been carried out. For the maximum loaded sections of the connecting rod head, the fatigue resistance characteristics and the characteristics of regular variable loading in operation at rated load are determined. Based on the results obtained, the probability of failure depending on the magnitude of the loads and the size of the gaps was evaluated.
Evaluation of the method of measuring crack resistance by the introduction of the vickers indentor for aluminum oxynitride ceramics
Authors: Prosvirnin D V , Prutskov M E , Larionov M D , Kolmakov A G
Published: January 2020

Results are given after studies of materials on the aluminum oxynitride (AlON) for their surface crack resistance using. The comparison of fracture toughness data obtained by the two methods and two types of ceramics. Assessment of fracture toughness data in comparison with the results from the literature in the field of ceramic materials research..
New polymorphic varieties of boron nitride with structure similar to graphyne
Authors: Ryashentsev D S , Belenkov E A
Published: January 2020

Seven new layer polymorphic varieties of boron nitride, with a structure similar to the structure of the α, β and γ types of graphyne layers, were theoretically studied. The calculation of the structure and electronic properties was carried out by the ab initio method of the density functional theory. The sublimation energy varies from 16.29 eV (BN)−1 (minimum for the BN-α-L6 layer) to 17.00 eV (BN)−1 (maximum for the BN-γ1-L6 layer). The structure of BN polymorphs differs in the values of the Def parameters characterizing the relative degree of deformation of their structure. The band gap of the boron nitride layers varies from 2.14 to 4.02 eV.
Lecture and non-lecture week baseline energy model development and energy prediction in Malaysia educational building
Authors: Mustapa R F , Dahlan N Y , Yassin A I M , Nordin A H M
Published: January 2020

The development of baseline energy models and prediction of energy consumption in educational buildings especially universities are heavily depending on its operation period. The main operation period can be divided into two period i.e. lecture week and non-lecture week. Possible independent variable candidates that may have an effect towards energy consumption during this two period differ with each other. In addition, spaces that occupies the educational building such as classrooms, laboratories and office rooms within the same building operates differently depending on its operation period. In order to achieve accurate baseline energy models in educational buildings, the operation period have to be considered based on the independent variables that will have an effect towards the energy consumption. Thus, the twofold objectives of this paper are to develop a baseline energy model for two operation period in educational buildings and predicting the energy consumption using multiple linear regression model. One building in a university compound was selected as a case study for modelling and prediction purposes. Independent variables were selected based on the two-period mentioned and from the modelling and prediction results, the independent variables that were selected gives a high coefficient of correlation (R2) value which suggest that the independent variables effect the educational building’s energy consumption.
A review: Partial discharge detection using acoustic sensor on high voltage transformer
Authors: Akashah N A , Rohani M N K H , Rosmi A S , Isa M , Rosle N , Ismail B , Wooi C L
Published: January 2020

Partial discharge (PD) is an electrical discharge which is one of the most critical breakdown factor that is affecting the electrical equipment. The loss of the power will affect consumers and system operation. High voltage (HV) transformer is one of the equipment’s subjected to phenomena PD. In this paper reviews an application of acoustic methods in transformer and piezoelectric sensors application on PD detection in HV transformer. Based on this review, the new design in acoustic sensor is required in order to improve the sensitivity and bandwidth for PD detection at HV transformer. The valuable parameter such as materials, size, and PD frequency range were discussed in this paper and can be used for early stage on designing new acoustic sensor. This detection method given some benefits on preventing the power electrical system from breakdown.
Influence of PD source and AE sensor distance towards arrival time of propagation wave in power transformer
Authors: Khalid K N , Rohani M N K H , Ismail B , Isa M , Rosmi A S , Wooi C L , Yii C C
Published: January 2020

Partial discharge (PD) often begins with cracks or gas-filled voids in solid insulation or with gaseous bubbles in liquid insulation. These presences can degrade the quality of insulator. PD detection can identify these cracks at high voltage equipment such as power cables and power transformer at the early stage. One of PD detection methods is acoustic emission (AE) detection. PD produces an ultrasonic signal that can be captured by an AE sensor. The signal captured is then analysed by capturing the time of the receiving signal onto the sensor. The information related to time can be used for allocating the PD for maintenance purpose. This paper shows the influence of the distance between PD source and the AE sensor towards the arrival time of propagation wave in power transformer. In this study, the four placements of sensors were analysed by having three possible PD sources to represent the variety of distances between the PD source and the sensor. The simulated signal is generated by MATLAB and the arrival time is captured using time of arrival (TOA) method. The time captured and the distance between the PD source and arrival time showed that the relationship is proportional to one another.
Load shedding analysis on microgrid during island mode
Authors: Najihah Abu Bakar Nur , Muhamad Azmi A’lia Najwa , Rosle N. , Sufiah Abd Wahid Siti , Sufian Ramli Mohd
Published: January 2020

This paper evaluates implementation load shedding strategy in island mode of microgrid(MG). Microgrid normally operates in interconnected mode either with the medium voltage(MV) and low voltage(LV) network. Microgrid can function both in grid and island mode connected. As electricity demand increases, microgrid deployment becomes an attractive option to meet energy demands. Microgrid during utility grid failure, however, suffers from crucial stability problems come from many aspects. Load Shedding Strategy (LSS) is one of the method used to sustain operation of power system in stable state. The main objective in this paper is to analyze the implementation of Load Shedding Strategy (LSS) on two different cases. The simulation model developed from a mix of generator, photovoltaic cell of source and the lumped load. ETAP software was used in analysing the result.
Simulation of multiple pulse width modulation (MPWM) transformerless photovoltaic inverter (TPVI) system
Authors: Masri M , Irwanto M , Alam H , Mashor Y M
Published: January 2020

Pulse width modulation technique is always applied in the design of inverter. The output voltage waveform of inverter is not relative pure sinusoidal, especially if it is applied linear pulse width modulation. A non-pure sinusoidal voltage waveform can affect the life time of inverter and also the alternating current (AC) loads. The inverter always also uses a transformer that can increase the losses and reduce the efficiency. A technique of multiple pulse width modulation (MPWM) is suitable to be applied in the transformerless photovoltaic inverter (TPVI) system. It can generate pure sinusoidal voltage waveform and increase the performance of inverter. This paper presents a simulation of MPWM TPVI system using SIMULINK MATLAB. It consists of pulse driver circuit to drive four MOSFETs in the full bridge inverter circuit with the output voltage waveform still multiple pulse wave and it is converted to be pure sinusoidal voltage waveform by applying a LC filter circuit.
Microgrid synchronization using power offset through a central controller
Authors: Syahril M , Roslan M A , Ismail Baharuddin
Published: January 2020

A high penetration of renewable energy in power systems gives rise to the inverter based distributed generators (DG) in the current microgrid system. With the ability of microgrid to operate in both islanded and grid connected mode, a robust and reliable coordination and synchronization between the DGs and the utility grid is crucial to provide a seamless transition between operation modes. Droop based technique is the most popular method in microgrid system, however, voltage or current transient are present during mode transition. A power offset synchronization technique is proposed to provide a seamless transition between modes of operation. The results show that the mode transition is smooth and seamless without any voltage or current transients.
Design and simulation of single phase inverter using SPWM unipolar technique
Authors: Farhana Abdul Hamid Nurul , Alleef Abd Jalil Muhammad , Syafiqah Syahirah Mohamed Nor
Published: January 2020

This paper presents the design and simulation of single-phase inverter using sinusoidal pulse width modulation (SPWM) unipolar technique. The circuit has been designed and simulated using the Matlab/Simulink program. Metal Oxide Semiconductor Field Effect Transistor (MOSFET) has been used as a switch. The project aims to use the Matlab/Simulink program to design, analyze and control switching for inverter circuits. Single-phase inverter circuits are divided into three main divisions which are the inverter part that consists of the MOSFET switch, the control circuit which generates switching pulses generated through the microcontroller and filter parts that contain inductors, capacitors and resistors to reduce harmonic. The results of the experiment show the output of the sine wave with the output voltage of 230 V and 50 Hz.
Electric vehicle with sliding mode control super-twisting control strategy
Authors: Ghazali A K , Hassan M K , Radzi M A M , As’arry A
Published: January 2020

The braking system is the crucial part in vehicle system. The main purpose of braking system is to slow down or stop the moving vehicle. The regenerative braking system (RBS) designed to recapture more energy during braking. The electric vehicle dynamic model was design using Matlab/Simulink. Sliding mode controller with super-twisting (SMCST) was designed to avoid overcharging and improved the batteries’ SOC. Conventional sliding mode control (SMC) shows convergence within the desire level of accuracy, in which chattering is the main issue related to destructive phenomenon. SMCST intentionally to eliminate chattering with high accuracy. The results from the simulation show that the super-twisting control strategy offers higher regeneration efficiency.
Design of a single phase series-parallel current injection resonant converter with wireless power transmission
Authors: Firdaus Mohd Zin Mazratul , Nawawi Seroji Mohammad , Abdul Kadir Ermeey
Published: January 2020

This paper proposes a new circuit topology of single phase AC to DC Series-Parallel Current Injection Resonant Converter (SPCIRC) with wireless power transmission function. Thus, characteristics are accomplished such as shaping the current waveforms of the sinusoidal line with improved power factor resulting in small total harmonic distortion (THD). This is implemented by employing the resonant conversion technique, involving two active soft switches that generate high frequency currents. The circuit operation is explained and the analysis of the converter is presented. The full detailed circuit simulation is then carried out to ascertain the workability of the converter and its ability to operate with wireless power transmission. As a result, a low input current THD of 3.52% was obtained with 130V output DC voltage when supplied by 240V AC input voltage. The efficiency of the proposed SPCIRC is calculated as 87.5%. The current injection topology’s main operation is described in detail.
Forecasting Electric Load Demand through Advanced Statistical Techniques
Authors: Silva Jesús , Senior Naveda Alexa , García Guliany Jesús , Niebles Núñez William , Hernández Palma Hugo
Published: January 2020

Traditional forecasting models have been widely used for decision-making in production, finance and energy. Such is the case of the ARIMA models, developed in the 1970s by George Box and Gwilym Jenkins [1], which incorporate characteristics of the past models of the same series, according to their autocorrelation. This work compares advanced statistical methods for determining the demand for electricity in Colombia, including the SARIMA, econometric and Bayesian methods.
Intelligent Model for Electric Power Management: Patterns
Authors: Viloria Amelec , Hernández Palma Hugo , Gamboa Suarez Ramiro , Niebles Núñez William , Solórzano Movilla José
Published: January 2020

When talking about electric power, the first thing to think about is whether enough electrical energy is generated to use without paying attention to it, similar to thinking that water will never runs out, but when faced with extreme droughts, people think that water can be depleted and they must save. In this sense, electrical energy must be saved and used completely and that is why the term energy efficiency is born. This new trend seeks to save electric power to avoid electricity supply shortages, as when countries face phenomena such as El Niño that generate droughts in some areas and rains in others. So, saving energy is a trend because it is important to be prepared for these phenomena, and guaranteeing a sustainable country. This document shows the importance of energy savings, as well as the need to design intelligent models that help to support the reduction of the problem of excessive consumption of electricity.
NaOH treated Kenaf/Glass hybrid composite: The effects of nanosilica on longitudinal and transverse tensile properties
Authors: Manap Norhashidah , Jumahat Aidah , Abd Rahman Norhanifah , Ain Abd Rahman Nur
Published: January 2020

Nanocomposite has been one of recent study interest among researcher, scientists, and students. With public consciousness about environment, there is a change in using environmental friendly’s materials. With the incorporation of nanotechnology, the strength of the composite shouldn’t be sacrificed because of the use of natural fibre. Kenaf has been studied extensively and has been one of the candidates to be used in composite and with hybridizing with glass fibre, The strength of the composite could be retained to be used widely. In this study, nanosilica was impregnated in hybrid kenaf and glass epoxy composite to and was tested for its longitudinal and transverse tensile properties. From this study, incorporation of nanosilica in hybrid kenaf and glass epoxy composite help to increase its tensile modulus up to 34.52%, and longitudinal tensile strength up to 13.64%.
The study of photovoltaic systems performance using various azimuth angles and solar array tilt positions
Authors: Poobalan Banu , Abdul Hamid Haziah , Hasnizam Hanafi Noor , Chin Leong Wooi
Published: January 2020

The study of photovoltaic energy and load predictions have become essential with the increase of energy demand. The objective of this paper is to present an analytical study on the performance of photovoltaic system with various azimuth angles and solar array tilt positions. The output power of a solar module is mainly dependent on its tilt position, solar irradiation, type of solar cell, and the technical properties of the module. The data used in this work consist of two different locations. The outcome of this work shows that the energy production influenced heavily on the weather conditions, location, azimuth angles and tilt positions. Within this work, parameters such as planes-of-array irradiance, net to inverter output power, net to grid output power and performance ratio have been studied. The developed analytical study is anticipated to provide a better understanding on the energy production and load usage in accordance with suitable tilt angle of solar array in a specific location.
Design of an autonomous standing frame prototype for older adults with motorized disability
Authors: Terán Héctor C. , Arteaga Oscar , Chiluisa Kléber , Morales Klever D. , Kevin Pérez O , Andrés G , Pérez  , Llano Edison J.
Published: January 2020

This paper shows the mechanical design of a mechatronic system focused on providing assistance to older adults with motor disabilities. The main objective is to keep these people standing on their lower extremities, facilitating their mobility and at the same time providing greater support to their body structure. The mechanical design of the permanent station was developed using CAD (Computer Aided Drawing) software, including concept design, structural analysis and selection of mechanical actuators; elements designed for this mechatronic system. In addition, it shows the study to ensure ergonomics and safety for users using standards UNE-EN ISO 10535-2006, UNE-EN IEC 60601-1-2010 and EN 13480-2-2002 with the compliance of a structural safety factor through the software CAE (computer-assisted engineering), as well as the adaptability of the design of the system to the various anthropometric measures of the world demographic environment.
Prototyping a RF signal-based lightning warning device using with Internet of Things (IOT) integration
Authors: Hwang Y J , Wooi C L , Rohani M N K , Mehranzamir K , Arshad S N M , Ahmad N A
Published: January 2020

Lightning had caused at least 25, 000 deaths worldwide each year. The study aims to investigate the induced voltage generated by lightning strikes using a lightning detector. Proteus software was employed to simulate the main board of the lightning detector before fabrication. The lightning detector was designed as a radio frequencies receiver and it was tuned to the level (300 kHz to 500 kHz) which enabled it to receive signals from lightning strikes. A lightning simulator was designed using various resistance (100 Ω to 200 Ω) to test the functionality of a lightning detector in order to validate the accuracy of the proposed model. This lightning detector could be activated whenever a small induced voltage (0.2 V and above) were generated by lightning events occurred within 10 km from the detector. This detector captures both the induced voltage and the time difference detected lightning discharge and its sound for further analysis. The time to thunder method was employed to find the estimated lightning discharges distances in parallel to this system in order to validate the current lightning detector. The accuracy of the lightning detector was found to be 88.03%.The analysed data were delivered to the user’s smartphone using cloud system
L / C / X Triple band compact dipole array antenna for RADAR application
Authors: Koushick V , Divya C , Lakshmi G
Published: January 2020

This article describes about L / C / X triple band compact dipole array antenna for RADAR communication using FR-4 Substrate. The proposed antenna is designed over a range of 1.0–10.0 GHz. The objective of the paper is to achieve appreciable basic antenna parameters for ease adaptation in Monolithic Microwave Integrated Circuits (MMIC) Technology. It is able to preserve its high recital over RADAR Communication system operating at Triple band (L, C, X – band) microwave frequency range. The proposed structure resonates at L / C / X Microwave bands and thus the antenna becomes inevitability for numerous wireless applications. The antenna is fictitious on a substrate with height of 1.6 mm, length 48mm, width 60mm and a relative permittivity of 4.2. The proposed antenna yields a VSWR of about 1.74 (1.70 GHz), 1.66 (6.70 GHz), 1.26 (8.30 GHz) and gain of 2.56 dBi (1.70 GHZ), 1.78 dBi (6.70 GHz) and 3.94 dBi (8.30 GHz) under simulation. The antenna is designed and simulated using HFSS, which helps to obtain the antenna parameters such as VSWR, gain and Return loss.
A real time face emotion classification and recognition using deep learning model
Authors: Hussain Shaik Asif , Salim Abdallah Al Balushi Ahlam
Published: January 2020

Facial Detection and recognition research has been widely studied in recent years. The facial recognition applications plays an important role in many areas such as security, camera surveillance, identity verification in modern electronic devices, criminal investigations, database management systems and smart card applications etc. This work presents deep learning algorithms used in facial recognition for accurate identification and detection. The main objective of facial recognition is to authenticate and identify the facial features. However, the facial features are captured in real time and processed using haar cascade detection. The sequential process of the work is defined in three different phases where in the first phase human face is detected from the camera and in the second phase, the captured input is analyzed based on the features and database used with support of keras convolutional neural network model. In the last phase human face is authenticated to classify the emotions of human as happy, neutral, angry, sad, disgust and surprise. The proposed work presented is simplified in three objectives as face detection, recognition and emotion classification. In support of this work Open CV library, dataset and python programming is used for computer vision techniques involved. In order to prove real time efficacy, an experiment was conducted for multiple students to identify their inner emotions and find physiological changes for each face. The results of the experiments demonstrates the perfections in face analysis system. Finally, the performance of automatic face detection and recognition is measured with Accuracy.
Time Series Decomposition using Automatic Learning Techniques for Predictive Models
Authors: Silva Jesús , Hernández Palma Hugo , Niebles Núñez William , Ovallos-Gazabon David , Varela Noel
Published: January 2020

This paper proposes an innovative way to address real cases of production prediction. This approach consists in the decomposition of original time series into time sub-series according to a group of factors in order to generate a predictive model from the partial predictive models of the sub-series. The adjustment of the models is carried out by means of a set of statistic techniques and Automatic Learning. This method was compared to an intuitive method consisting of a direct prediction of time series. The results show that this approach achieves better predictive performance than the direct way, so applying a decomposition method is more appropriate for this problem than non-decomposition. The agricultural sector will be used as the study subject.
Mining Spatial Co-location Patterns from Vague Set
Authors: Shijian Gao , Jiankun Yu
Published: January 2020

The target of mining spatial co-location patterns is discovering spatial association rule from spatial database, which plays an important role in many fields, investigate the distribution of plants for instance. Vague set extend the concept of fuzzy set, more flexible in terms of express and process fuzzy information. Some concepts such as vague spatial neighborhood relationship, vague participation ratio and vague participation index are defined in this paper first, after that, vague data filter rule and the algorithm of mining co-location patterns form vague set are proposed, the efficient prune strategy is presented in order to improve the efficiency of algorithm finally. The significance and efficiency of the techniques we propose are verified by experiments.