bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of Ozonation and ultrasonic cavitation on batik wastewater treatment with coagulation-flocculation as pre-treatment
Authors: Siahaan I N J , Saputra A E , Karamah E F 
Published: September 2021

AbstractThe batik industry produces large volumes of wastewater with high organic content. Dyes in batik wastewater are difficult to degrade by biological processes. Therefore, further processing is needed to reduce pollutants before being released into the environment. This study aims to observe the performance of the ultrasonic cavitation, ozonation, and combination of ozonation/ultrasonic cavitation to treat batik wastewater, which was first given a coagulation-flocculation pre-treatment with Polyaluminium Chloride (PAC) coagulants. The variations applied were ultrasonic intensity (20%, 30%, and 60%) and pH of wastewater (4, 7, and 10). In this study, it was found that the combination of the ozonation/ultrasonic cavitation method with a pH of 4 and ultrasonic intensity of 20% produced the best performance, namely COD, TSS, and color (Pt-Co) removal of 77.02%, 95.15%, and 94.88%. The ultrasonic intensity and initial pH of wastewater played an important role in the performance of the treatment process. In the ultrasonic cavitation method with an ultrasonic intensity of 20%, the highest percentage of COD, TSS, and color (Pt-Co) removal was 65.59%, 91.51%, and 93.41%. The ozonation method in acidic conditions (pH 4) produced a better performance with COD, TSS, and color (Pt-Co) removal of 70.51%, 94.35%, and 96.10% for 60 minutes.
The effect of Ozonation on the chemical structure of microplastics
Authors: Fitri A N , Amelia D , Karamah E F 
Published: September 2021

Abstract
Microplastics are not susceptible to microbial degradation, thus often end up in aquatic ecosystem. Moreover, microplastics cause danger to aquatic biota and human. Effective technological solutions to degrade microplastics in wastewater treatment plants are desirable. Biodegradation is one of the most applied techniques, but takes a long time. This study evaluates the ozonation as pre-treatment to transform the chemical structure of polyethylene microplastics into more susceptible to biodegradation. The process was done by using a corona-discharge ozonator and batch reactor, varied pH value (6, 7, 8, 10, 12), ozone flowrate (1, 3, 5 L/min), and contact duration (1, 2, 3 hours). The study was begun by quantification of OH radicals and dissolved ozone, ozonation of microplastics, evaluation of ozonation by gravimetric weight loss including the change of microplastics chemical structure through FT-IR (Fourier Transform Infrared). The results revealed chemical structure changes of polyethylene after ozonation confirmed by the appearance of carbonyl bonds and the loss of weight. The optimum operating condition appeared at pH 12 with 5 L/min ozone flowrate, resulted in 0.0482% weight loss and carbonyl bond intensity reached 104.556% after 3 hours ozonation.
Production of palm shell based activated carbon by two stage phosphoric acid impregnation and physical activation
Authors: Yuliusman  , Afifah T M 
Published: September 2021

Abstract
Activated carbon (AC) as a promising gas adsorbent has been widely used in various applications. One of the raw materials that can be utilized is palm shell waste. Palm shell has great potential in terms of quantity and composition as raw material for AC. Palm shell waste production in Indonesia is classified as high and increasing every year. The high amount of carbon and low ash in the palm shell can produce good porous carbon. In this study, The Palm shell was processed through preparation, carbonization, and activation. After being dried and reduced in size, the palm shell was immersed in phosphoric acid (H3PO4) for 24 hours and continued with carbonization at 350ºC for 30 minutes. Then, it was second chemically activated by H3PO4 with activator mass variations and physically activated by N2 gas at 600ºC for 1 hour. AC with the best characteristics was produced by a mass ratio of 2:1 in the second chemical activation. The iodine number and surface area obtained are 1164 mg/g and 1158 m2/g. Furthermore, Pores have formed perfectly on the surface of carbon and the carbon content of AC has reached 76.9%.
Partial discharge type detection and identification based on its sources
Authors: Putra R W , Sinaga H H , Purwasih N , Permata D , Yuniati Y , Sitorus H B H 
Published: September 2021

Abstract
Partial discharge (PD) is a symptom of initial damage to high voltage equipment insulators which if left for a long period will cause total damage to high voltage equipment. This study aims to detect and identify the type of PD based on the source of its discharge so that it can be useful in terms of monitoring and maintenance of high voltage equipment. In this research, the Hilbert fractal antenna sensor is used in the detection process of surface, cavity, and corona PD with different input voltage variables that successfully produce a total of 600 PD signal data on the oscilloscope. To reduce noise on the PD signal, the denoising process is done by utilizing the sym4 wavelet feature found in the MATLAB software. The denoising process generates new data so that the research data becomes 600 original PD signal data and 600 denoising PD signal data. With a statistical approach, all PD signal data is extracted successfully into the mean, skewness, kurtosis, and standard deviation parameters which are useful as input for the PD type identification process. From each of the PD signal statistical data, 450 data are used in the training data process and 150 data are used in the data testing process. The PD type identification process is performed using a back propagation neural network with a mean square error (MSE) level of 0.01. The identification results show that back propagation neural networks are able to identify PD types based on statistical input accurately. In addition, the denoising process also affects the accuracy of the identification results of the PD type that is 95.33% for the original discharge signal to 97.33% for the denoising signal.
Study of the potential utilization of local Lampung Province resources in development of dental implant bioceramics
Authors: Hendronursito Y , Sukmana I , Risano A Y E 
Published: September 2021

Abstract
The increasing of dental implants needs to be supported by local materials’ development as a form of independence for a nation. With its rich natural resources, Indonesia has the potential to be used as a dental implant material. Dental implant materials can be in bioceramic materials consisting of bioactive, bioresorbable, and bioinert. One of the bioactive materials of concern today is glass-ceramics from basalt rock. Meanwhile, the hydroxyapatite material sourced from limestone is the most widely used bioresorbable type. These materials, basalt, and limestone are very much found in Indonesia, including Lampung Province. However, the use of these two materials as bioceramic materials is still very little. Several methods of treating basalt as glass-ceramics and limestone as Hydroxyapatite are described in this article review. The utilization of local potential as a source of dental implant material will provide support for the independence of a nation in the welfare of its people.
Degradation on mechanical properties of virgin and recycled polylactic acid ageing in aqueous environment
Authors: Budin S , Koay M H , Maideen N C 
Published: September 2021

Abstract
A growing demand in polylactic acid (PLA) has increased in recent years due to the increasing of non-degradable plastic wastes. The recycling of PLA waste is seen to be another permissible solution to conserve the resources. This work aims to study the degradation rate of virgin PLA (VPLA) and recycled PLA (RPLA) in terms of the mechanical properties after ageing in different aqueous environment. The samples were immersed in river water (RW) and seawater (SW) for the duration of 150 days. Tensile strength, transverse rupture strength (TRS), impact energy and hardness properties were investigated as a function of immersed time. The results revealed that the loss in the tensile strength accelerated in river water when compared to seawater. There was at least 50% of tensile strength sacrificed in recycled PLA. The TRS had dropped approximately half from its initial value after ageing in river water and about 30% after ageing in seawater. Besides, a huge decrease ranging around 70-80% from its initial impact energy was identified. However, the reduction in hardness was relatively low. The findings will help to elucidate the degradation process of PLA and the desired effect on the mechanical performance for further application.
Densification and mechanical behaviour of zirconia containing flyash as dopant
Authors: Singh R , Ya’akub S R , Hamid A D A , Ibrahim Z , Ali M Y 
Published: September 2021

AbstractThe densification and mechanical behaviour of tetragonal zirconia doped with up to 2 wt% flyash as dopant were studied. In this work, the dopant was blended with commercial 3 mol% yttria-stabilised zirconia powders by attrition milling. Sintering was accomplished by firing the green bodies at various temperatures ranging from 1250 ºC to 1500 ºC under atmospheric conditions. Sintered bodies were evaluated for bulk density, phase retention, elastic modulus, Vickers hardness and fracture toughness. An improvement in the zirconia properties in terms of bulk density, Vickers hardness and matrix stiffness were evident at low sintering temperatures for samples containing up to 0.5 wt% flyash. In contrast, the fracture toughness and tetragonal phase stability of the zirconia was not influenced by the dopant and sintering temperature. The addition of 1 wt% and 2 wt% flyash, however were not effective in enhancing the properties of the sintered zirconia. This study also found that the addition of flyash as dopant was beneficial in suppressing the low-temperature degradation kinetics of tetragonal zirconia in steam environment.
Grafting the carboxyl groups onto DPNR by seeded emulsion polymerization to enhance the compatibility with silica filler
Authors: Woowong J , Phinyocheep P , Sakdapipanich J 
Published: September 2021

Abstract
The modification of deproteinized natural rubber (DPNR) with maleic anhydride (MAH) was synthesized to enhance the better compatibility between silica filler and natural rubber (NR). The presence of carboxylic acid groups (-COOH) of MAH after hydrolysis in the grafted DPNR with MAH (DP-g-MAH) would directly interact with the hydroxyl groups (-OH) of silica filler, resulting from the formation of the ester bonds due to the esterification reaction. It is leading to form the chemical bonding, which is the significantly strong interaction between DPNR and silica filler. The structural characterization of DP-g-MAH was analyzed by Fourier transform infrared spectrometer (FTIR) and proton nuclear magnetic resonance (1H-NMR), respectively. The % grafting level of MAH approximately highs to 99.37 % with the low gel content approximate 14.45 (wt%). In addition, the DP-g-MAH latex was compounded with silica nanofiller 10 phr by latex compounding method. The morphology of silica filled DP-g-MAH (DP-g-MAH/Si 10) was characterized by field-emission scanning electron microscope (FE-SEM) in order to observe the silica dispersion into the DP-g-MAH rubber. The FE-SEM shows that silica filler could disperse in grafted rubber more than the DPNR. In addition, the crosslink density was investigated to confirm the chemical networks, which could occur from esterification between DP-g-MAH and silica filler.
iAMR: intelligent auto-dispenser mosquito repellent system
Authors: Bakar W A W A , Man M , Hwa L C , Wang L Y 
Published: September 2021

Abstract
Dengue fever has become an increasingly significant health threat worldwide. Currently, due to lack of specific treatment or vaccine against dengue, vector control, which is available in many forms, remains a key strategy for dengue fever prevention. Hence, we introduce an iAMR: Intelligent Auto-Dispenser Mosquito Repellent, an innovative system in line with “Industry 4.0” concept where it includes current trend of automation and data exchange. It also includes cyber-physical systems, the Internet of things, cloud computing and cognitive computing. The iAMR solves the issues of when to spray (by auto-spray using sensor) and long live batteries (with LORAWAN technology). When combined with the mini aerosol (X’MOS), it provides an even more effective mosquito control. This all-in-one system ensures a mosquito-free environment in your home. The iAMR device relies on the microcontroller and sensor in order to operate the intended spraying task. The microcontroller used is an IoT based device called ESP8266 which is a WiFi-embedded microcontroller that utilized standard everyday WiFi band frequency which is at 2.4 GHz. A DC geared motor sensor for dispenser device is used. The main contribution of iAMR is to monitor and track for the mosquito repellant (X’MOS) to be refilled. The implementation shows the iAMR system able to update the level of each X’MOS in iAMR devices which reducing the cost of manual human checking for X’Mos refill.
Effect of 3D-printing parameters on the tensile strength of acrylonitrile butadiene styrene (ABS) polymer
Authors: Ya’akub S R , Ibrahim N , Singh R 
Published: September 2021

Abstract
In this research, the tensile strength behaviour of 3D-printed ABS polymer was studied. In particular, the following printing parameters were investigated i.e. angle orientation of 0°, 30° and 45°, layer thickness of 0.2 mm, 0.3 mm and 0.4 mm, and printing speeds of 60 mm/s, 40 mm/s and 20 mm/s. The samples were subjected to tensile loading in order to determine the stress-strain curve, UTS and the elastic modulus. The results indicated that the speed has no major impact on the strength of the 3D-printed samples. On the other hand, the 0.4 mm layer thickness gave the highest stiffness, whereas the angle orientation of 45° gave the highest tensile strength. However, the combination of 3D parameters that resulted in the overall best results was determined as 0.4 mm layer thickness with an angle orientation of 30°.
Microbial chitosan for the fabrication of piezoelectric thin film
Authors: Hazmi A T , Ahmad F B , Maziati Akmal M H , Ralib A A M 
Published: September 2021

AbstractChitin has proven to have a good mechanical and electrical properties to be used in making piezoelectric thin films. However, due to the restriction in solubilizing chitosan in many solvents, there is increasing interest in exploring the used of chitosan in producing thin films. Chitosan, compared to chitin, can be easily solubilized in certain dilute acids. Chitosan that has been extracted from fungal biomass can be used for the fabrication of biomaterial thin films. There are different ways that can be used to fabricate a thin film such as electrospinning, spin-coating, solvent casting and also the hot press technique.
Solar Photovoltaic Power Generation for Distillation Process
Authors: Mowaviq M I , Junaidi A , Putri T W O , Rosanda D 
Published: September 2021

Abstract
Indonesia is an archipelago which is one of the countries with the longest beaches in the world. One of the great potentials of the sea can be used to produce freshwater in coastal areas. One of the processes of converting seawater into freshwater vapor is the distillation process. The freshwater vapor condenses and turns into water. Distillation is carried out by evaporating seawater so that the freshwater is separated from the salt. In this research, the distillation process is assisted by a solar power plant with photovoltaic panels. The hardware design consists of a solar panel, solar charge controller, battery, inverter, pump, electric heater, temperature sensor, and level sensor. The solar panel uses a total of 1200Wp with a voltage of 12 V. The battery uses a 12V 100Ah battery and a 1000W electric heater. Meanwhile, the pump power is 48W. From the test results, it was found that in one hour, 1.3 liters of freshwater were obtained with a total capacity of 10 liters of water. The use of solar photovoltaic in a distillation system would be better if combined with direct solar energy heating methods.
Flow drags across three minibus car models arranged in tandem in four configurations
Authors: Salam N , Tarakka R , Jalaluddin  , Ihsan M , Jimran M A 
Published: September 2021

Abstract
The purpose of this study was to investigate the drag coefficient of flow on three tandem minibuses in four configurations and to determine the optimum drag coefficient across the three cars. Flow drags measurements have been conducted on a wind tunnel by force balance measurement. The minibus car models with a 1:40 ratio to the originals were constructed from iron material with a thickness of 1 mm. The three minibus cars are arranged in four configuration models where car 1 and car 2 are arranged in series while car 3 position changeable according to the configuration. Each configuration model was treated with 6 changes in the distance of the car to 3, while the distance between car 1 and 2 was constant, with similar 7 levels of treatment of velocities ranging from 8 m/s to 20 m/s. Results show a similar drag coefficient (Cd) pattern in all configuration models, where smaller Cd related to greater velocities and smaller distances of the three cars. Furthermore, at a similar Re = 49,608, the smallest Cd was obtained in model III (Cd = 0.78), and followed by model II (Cd = 0.80), model IV (Cd = 0.81) and model I (Cd = 0.84).
Maneuverability analysis on flying vehicle with thrust vectoring system
Authors: Al Aviev V H , Sasongko R A 
Published: September 2021

Abstract
Fighter aircraft often require unconventional maneuverability that civil aircraft cannot perform. The conventional flight control devices are not sufficient for this maneuver. Thus, to be able to perform unconventional maneuvers, additional control devices may be required, such as the thrust vectoring system (TVS). This paper will discuss the effect of TVS implementation in improving maneuverability. In this work, a dynamic model of F-4 Phantom is used as the basis for the study. The dynamic model of the aircraft with TVS is constructed analytically and numerically. The nonlinear model obtained from the modeling process then linearized at a particular flight condition and some TVS deflection values. Further, the linear system and control approach is employed for evaluating and designing the linear controllers for stabilization and maneuvering tasks. The closed-loop system, which is implemented in the MATLAB/Simulink environment, then numerically simulated and observed for analyzing the effect of implementing different TVS deflection on the required control effort in high angle of attack maneuvers. The simulation results show that the TVS can affect the performance of the closed-loop system in stabilization tasks. While at some deflection values, TVS can also help to reduce the required control effort to tracking attitude reference command when executing the high angle of attack maneuvers.
Missile threat assessment system using Naive Bayes classifier approach
Authors: Dewangga W , Sasongko R A 
Published: September 2021

Abstract
In the modern era, missiles have been used to serve both defence and offense purposes. Numerous research projects have been conducted to improve various aspects of missile systems. One area of main interest regarding the development of missiles in general is automation, particularly surrounding a feature known as guidance system. This feature had been proven to relieve a missile user of several workloads, particularly during aim and launch phase. One key component of a guidance system is known as threat assessment system. Such system is assigned to assess the threat situation that a missile’s engaged in. In this research paper, the developed guidance system uses an approach that is based on the naive Bayes classifier concept. The idea is to establish a system that first describes relationship between a missile and its’ target during mission in the form of a set of combat parameters. These combat parameters are then treated as evidence that is used by the Bayesian algorithm to update an assigned prior belief, yielding an updated posterior belief. The belief comes in a form of probability distribution with each probability representing a predefined threat situation class.
Essential characterization of metal powder for additive manufacturing
Authors: Ramli S M Q M , Fadzil N A , Ghazali H , Viklund P , Ali W F F W 
Published: September 2021

Abstract
The aerospace industry is mostly focused on complex, low production volume as the components are often known with complicated internal geometries and dimensions. Heavy market competitions and restrictions in high manufacturing cost could be overcome with additive manufacturing (AM). AM has received notable attention in its ability to produce customized metal parts and exhibiting top-notch capabilities that would lead the AM industry in the future. Nonetheless, in producing trusted, high-quality products, characteristics of metal powders should be accounted so it would meet proper quality such as powder morphology, particle size distribution, porosity, and powder’s ability to flow. SEM, OM, laser diffraction and rheometer are suggested in studying the powder’s characteristics. All characterization methods found are used practically. These characteristics are important to assess AM quality. Comparison in different aerospace materials is studied to get the actual material combination in getting an optimum metallurgical bond between the substrate and molten pool of the powders. Therefore, characterization methods of 3D metal additive and characteristics of aerospace materials are evaluated and presented systematically.
Comparison analysis of abaca fiber/polyester and abaca-e-glass/polyester hybrid composites to impact strength and its application to ballistic
Authors: Banowati L , Sari P , Hadi B K 
Published: September 2021

Abstract
The aim of this study consentrates of mechanical properties of abaca fiber and compares with the hybrid fiber composite on using abaca-e-glass fiber as reinforcement for composites. The fibers were arranged to make a bidirectional ±45º fiber arrangements by using polyester as a matrix with hand lay-up method is used to manufacture the composite. Based on the impact test results showed that the abaca-E-glass/polyester has a higher strength than the abaca/polyester specimen. Therefore, the abaca-E-glass/polyester hybrid composite has a better ability to ballistic test.
Short review on heteropoly acid based catalyst for valorization of biomass waste into valueable chemicals
Authors: Adil N L Z Z , Saharuddin T S T , Ozair L N , Harun F W 
Published: September 2021

Abstract
Depletion of fossil fuels resources has triggered more research on finding potential alternative sources that are more sustainable such as biomass waste. However, deconstruction of the complex biomass waste into desired products is too challenging and usually require a strong catalyst with a great hydrolysing property. Common acids such as sulphuric acid, hydrochloric acid and nitric acid were the most studies for biomass conversion. These liquid acids catalysts suffer low recovery and recyclability that can be overcome by a solid acid catalyst. Heteropoly acid (HPA) catalyst is the preferred choice to replace these common acid catalysts as it is known to have a strong Bronsted acid site with an oxidizing property that allows this catalyst to hydrolyse and oxidize in one-step reaction. Furthermore, heteropoly acid (HPA) catalyst can be modified into heterogenous type of catalyst by solidifying HPA to increase the surface area and recyclability. Future work of this research is necessary to improvise the previous method of the catalyst preparation and to suppress the by-products after the catalytic process. In this review, we summarize the use of HPA catalyst in the complex reaction process of biomass conversion to valuable chemical products.