bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of insurance agents performance using data mining in OV agency
Authors: Habyba A N , Fitriana R
Published: December 2020

One problem that occurs in the insurance industry is the high turnover rate of insurance agents. It makes many companies must pay a large fee for the recruitment and training of new agents. OV Agency had high insurance agent turnover rate. This company wants to improve the agents performance to avoid the turnover. This research aims to identify prospective insurance agents who have better performance at recruitment process by using classification task of data mining. There are three classification methods were used . They were decision tree (J48), Neural Network (MLP) and Naive Bayes. Based on the result, MLP has the best average accuracy value 84.2% and ROC area value 0.87 (good classification). MLP was chosen to predict the 25 insurance agent candidates and 3 agents were selected because they entered class A (better performance) in all performance criteria. The prediction results show that three agents are men, aged 25-32 years old, divorced, senior high school education and master degree, work status in other companies, and have work experience of 0-3 years. The OV Agency can consider these result in new agent recruitment process.
Optimization of bi-objective permutation flow shop scheduling with electricity cost consideration
Authors: Kurniawan B , Fujimura S
Published: December 2020

Increasing energy demand can create undesired problems for many governments worldwide. Several policies, such as time-of-use (TOU) tariffs, have been put in place to overcome such demand. The TOU policy’s objective is to reduce electrical load during peak periods by shifting the use to off-peak periods. To that end, this paper addresses the bi-objective permutation flow-shop scheduling, minimizing total weighted tardiness and electricity costs. We propose a meta-heuristic algorithm based on SPEA2 to solve the problem. We conducted numerical experiments to evaluate the efficacy of the proposed algorithm by comparing it with NSGA-II. The results show that the proposed approach was more efficient compare with NSGA-II.
Knowledge base integration management system quality, safety and environmental to improve organizational performance in construction company
Authors: Apriyati Retno , Latief Yusuf
Published: December 2020

Development in Indonesia showed high progress in the economics but had low progress for social; institutional; and in environmental sectors. Furthermore, Indonesian Construction Company still inhibited by low competitiveness; along Safety system management application; safety record and bad occupational health. Based on Indication in above, it’s necessary to apply an integrated management system between Quality, Safety and Environmental for manage the projects construction. The Implementation of an integrated management system, it’s necessary to improve with knowledge base Integration Management System; due to accelerated targets achievement of integration and to learned cause of the failure of integration aspect. Therefore, this research aims to validated Knowledge Base Integration Management System of Quality, Safety and Environmental to improve organization’s performance on Construction Service Company. This research was conducted with case studies and expert validation for the integration model, objectives and risk relationships.
Design and analysis of cell phone case from recycling plastic bottle
Authors: Benhardy M T A , Solihin A , Primaseta E F , Sahroni T R
Published: December 2020

Recognizing the large amount of plastic waste produced by humans today, recycling is one solution to reduce the accumulation of plastic waste. This study aims to analyze the recycling of HDPE (High Density Polyethylene) plastic waste into cell phone cases. This study compares the strength of recycled plastic cell case with other materials that are often used for cell phone cases in general. The methodology of this paper begins with the development of new 2D and 3D cellphone cases, and for processing with injection molding. The parameters are focused on the strength of the material. The simulation is presented using Autodesk Inventor with free fall analysis, and presented stress, displacement, main stress and strain. The results show that the results of stress analysis and material comparison between HDPE and other materials do not show significant differences in other words HDPE can be used as an alternative material for cell phone case materials.
Minimize the potential failures in the wire rod production process using six sigma and multi attribute failure mode analysis method
Authors: Ulfah Maria , Ekawati Ratna , Amalia Nafila
Published: December 2020

Wire rod mill (WRM) plant is one of the factories in Company X that produces wire rod. In 2018 and 2019, WRM was recorded producing high quantity of rejected product exceeding the set standard. This study deploys systematic problem identification and improvement to the process. The methods used was Six Sigma method to evaluate current condition and process capability, followed by Multi Attribute Failure Mode Analysis (MAFMA) with Grey AHP approach to identify root cause and weighted failure process that will be put into priority of improvement. Based on the research results, the sigma value obtained is 4.297503 o with DPMO value is 2,928.626. Improvements to the five highest of the causes of process failure is to improve the state of bearing roll, roll entry, hydraulic valve, an improvement on roll adjustment and improvement of inter-roll partings. It was concluded that the potential causes that the hot button bearing roll has the highest weight is 0.94569, so making it a top priority improvement.
Analysis of benzene exposure considering workers characteristic in the oil and gas industry
Authors: Attaqwa Yusita , Mahachandra Manik , Prastawa Heru
Published: December 2020

Operations and processes in the oil and gas industry have hazardous chemicals. Hence the possibility of having a work accident is high. Chemicals that exist are produced by activities related to the oil and gas industry processes, one of which is benzene. Because it has a severe impact on occupational health and safety, benzene exposure must be measured. Measurements were run through risk analysis to assess Hazard Index (HI) and make predictions of benzene exposure by focusing on the characteristics of workers, which can worsen the effect of the exposure. This study elaborated on several workers’ characteristics from a literature study’s human factors point of view. These characteristics were smoking, age, type of task, personal protective equipment use, exposure duration, regulations, hand washing habits, length of exposure, and nutritional status. Literature study results showed that regulatory characteristics, handwashing habits, and length of exposure were worsening the benzene exposure to workers. The other factors were in between agreed and disagreed in worsening the benzene exposure. These results perform as a base study in the further benzene analysis of oil and gas end distributor.
Evaluation criteria and ranking supplier raw materials waste paper with the methods ahp and topsis (case study paper company in west java)
Authors: Sayuti Muhamad , Akda Zahrotul W , Perdana Robin
Published: December 2020

The study is done at a paper company in west java by doing evaluation of waste paper supplier of raw materials with the aim of gaining evaluation criteria supplier and ranking supplier. The process of making evaluation criteria supplier is done by using the method hierarchy (AHP) analytical process and ranking with the approach of the supplier technique for order preference by similarity to (TOPSIS) solution of a problem. according data processing by using both the main criterion used this method produced 6, the quality criteria, delivery, the price of, resources, service, and company management and putting quality criteria as the criteria with the weighting for 30,7 % of as much as. While the supplier of ranking. the best supplier PT. CMN and PT. AMN supplier as the worst alternative supplier of 5. Made with a model evaluation criteria and ranking supplier is expected to supplier evaluation process useful for other types of businesses the same paper companies.
Optimization of supply chain operation cost and gas usage quantity using non-dominated sorting genetic algorithm II (NSGA-II) Method
Authors: Ridwan A , Bahauddin A , M Naufal R P
Published: December 2020

ABC plant is one of seven plants in XYZ industry which produce Cold Rolling Coil (CRC) and Cold Rolling Sheet (CRS). The problems faced by ABC plant in its supply chain network are the high overall costs of supply chain operations and the quantity of gas usage. The characteristics of this problem consist of more than one objective, the best method for solving this problem called multi-objective optimization. This research is aim to identify the decision variables that will be optimized and determine the optimal quantity of each decision variable using NSGA-II method. The parameters used in this research are the population size of 50, crossover probability with range 0.1-0.9, mutation probability 0.1 and 0.2 also the number of generation 50 and 100. The result shows that the selected parameters for this research are the crossover probability of 0.7, mutation probability of 0.1, number of generation 100. Four decision variables that are optimized, namely CRC produced (Lite, Medium, and Heavy) and CRC stored with the quantities simultaneously are 40,918, 112,479, 173,758, and 43,209 tons. This result will assist the ABC plant in minimizing the overall cost of supply chain (124,532,272 USD) and the quantity of gas usage (39,634,749,440 Kcal).
Implementation of lean manufacturing using waste assessment model model (WAM) in food industry (case study in usaha mikro kecil menengah (umkm) xyz)
Authors: Febianti E , Irman A , Juliana M
Published: December 2020

The waste occurring on the production line leads to inefficient production and loss to the company. Based on the results of brainstorming with UMKM XYZ owners, it is known that there is a reduction in the production time of up to 20% of the production time is 4 hours per cycle. The waste that occurs will be identified and minimized using methods of Waste Assessment Model (WAM) and Fault Tree Analysis (FTA) for proposed repairs. The purpose of the research is to calculate the percentage of waste and know the dominant waste, knowing the repair to minimize the largest waste, and calculating the amount of production time. The results showed that the dominant waste was the transportation of 17,09% with improvements was to change the layout of the production, change the design of tools, expand the production floor, implement a more integrated fixed contract system and minimize the production process. The average time that can be minimized for donut products, bread, and molen is 490 seconds per cycle or 8.167 minutes per cycle.
Identify factors that caused false and violation by motorcycle rider
Authors: Lady Lovely , Try Mulyo Teguh , Kumino Kulsum
Published: December 2020

A motorcycle is a vehicle that is widely used by Indonesia community. However, increasing of motorcycle users were not followed by a good driving behaviour, the increasing was directly proportional to increase in the number of traffic accidents. The motorcycle is one of the dominant causes of the traffic accident in Indonesia. This research aims to identify the causes of the deviation and violation in driving that conducted by motorcyclists. The characteristics of driving and the type of deviation committed by motorcyclists collected using Driver Behavior Questionnaire (DBQ). The respondents were motor drivers who have a motorcycle driving license (SIM) in 8 districts in Cilegon. The data processing used the factor analysis method to identify the factors that caused traffic deviation by the motorcyclists. This research find seven factors that caused the deviation and violation by drivers, the dominant factor that explained 16.857 % deviation in riding is lack knowledge of traffic rules. Next factors were vehicle speed exceeds the threshold, the emotions, hasty, careless, not paying attention to the health, and not focus in driving.
Selection of IoT-based technology for electric smart meter on PLN Disjaya
Authors: Mulyono Adi , Farizal F.
Published: December 2020

With so many platforms or protocols developed by several organizations or institutions, such as LoRa, NB-IoT and SigFox that have their own advantages and limitations. While it takes a large and long-term investment to deliver IoT technology. Apart from that, losses caused by the use of conventional meters on electricity customers cause a decrease in income by electricity supply companies. In this study aims to choose the internet-based technology of things for electricity smart meters in the PLN Disjaya region between three LoRa, NB-IoT and Sigfox technologies. This research is doing network design, coverage analysis, capacity analysis and network utilization, cost benefit calculation and analysis, data rate speed and proprietary. From the analysis results obtained SigFox superior in terms of coverage, capacity and network utilization, cost benefits (NPV, IRR, Payback Period, BCR, ROI), LoRa superior in terms of proprietary and NB-IoT superior in terms of data rate speed.
Productivity measurement using Objective Matrix: case study in plate mill
Authors: Wahyuni N , Alya R
Published: December 2020

A decline of production level in December 2018 requires an evaluation. Productivity measurement is required to calculate performance. The purpose of this study is to measure the level of productivity using the objective matrix (omax). There were four steps to perform Omax. First step is select performance criteria, second is establish performance scales, third is rate the relative importance of the performance criteria, and the last is calculate the team productivity indicator. There were five ratios that become performance criteria, namely actual production compared to the target, material consumption, available time, makeup water consumption, and electricity consumption. The weight of each ratio is known in sequence from ratio 1 to ratio 5 were: 30%, 20%, 30%, 5%, and 15%. The performance index obtained the 3rd week has the highest productivity value, while the 4th week has the lowest productivity value, but the value is higher than standard value. From the value per ratio, we learned the ratio 1 has a fairly good performance, while the ratio 3 performance is considered less, because it is in the red zone.
Designing a computerization management production system in PT Akrilik Kurnia Kencana using barcode
Authors: Silalahi Rudy Vernando , Ishak  , Marciello
Published: December 2020

As technology develops, the production process of each industry also develops to become more sophisticated and modern. Barcode is a form of technological development in the production process and is useful for manufacturing companies to be able to store data so that it can be well integrated in a system. PT Akrilik Kurnia Kencana (AKK) is one of the companies engaged in manufacturing EPS (Expanded Polystyrene) and has a problem in finished goods warehouse where the company does not have a good system due to warehouse capacity inadequate. This study aims to identify current system implemented at PT AKK and develop a new system to solve the problems experienced by PT AKK. Data collection is done by the method of observation and interviews with the company to get the necessary data. After being collected, the data will be processed in such a way that it can be interpreted properly. Then, the data will be used as an input in designing a production management system-based application using the System Development Life Cycle (SDLC) waterfall model. By using this system, users can monitor the presence of each finished goods that has been produced and enter the warehouse through the information contained in the barcode.
The ergonomic factor application for improvement of performance office staff
Authors: Hernadewita  , Hendra  , Kristianti R. , Asih I. , Dhimas S. , Yuliani E.N.S.
Published: December 2020

Comfortable workplace, healthy and safely is the goal of implementing occupational safety and health requirements. Ergonomics is one of the factors that can affect employee productivity. Achieving harmony between labor, equipment, environment, work methods and work processes is the most important application of ergonomics. The purpose of this study is to investigate the improvement of working conditions through the application of ergonomics in the workplace. Ergonomic testing is carried out using the Rapid Upper Limb Assessment (RULA) analysis method to evaluate worker posture on work machines or operating systems and to investigate reduction in upper extremities and Ergonomic Factor Policy Identification (SHORT), which is an ergonomic evaluation method that focuses on frequency, duration, weight and posture to identify ergonomic hazards faced by everyday workers using an assessment system. The results of ergonomic application analysis are on average at a low risk level. Improvements can be made to reduce the level of risk experienced by employees in accordance with ergonomic standards, including improving the design of tables and chairs, adjusting work positions, avoiding odd work positions, stretching muscles while doing work at the computer.
Design of warehouse model with dedicated policy to minimize total travel costs: a case study in a construction workshop
Authors: Irman Ade , Muharni Y , Yusuf Andri
Published: December 2020

Warehousing is one of the many important activities in a company. One of the important things in managing the warehouse is how to store finished or semi-finished goods, raw materials, spare parts, equipment, or other goods in the right location to minimize total travel costs inside the workshop. In a workshop construction company usually uses a raw material in a big size and the cost of moving a big size usually need a high cost also. Dedicated storage policy becomes an option to make a model where the material should be store inside the warehouse. A mathematical model as an Integer Linear Programming problem used to model the case problem. LINGO 17 used to solve the mathematical model in this research. The model can find the optimal solution in a fast time. The minimum total travel cost in this research resulted from LINGO is IDR 17.326.320.000. Minimizing warehouse operation cost will also minimize the total company operation cost, mean higher profit will be got by the company.
Analysis of covariance for completely randomized design (case study: the life times of cutting tools used with lathes
Authors: Arina Faula , Ulfah Maria , Lintang Trenggonowati Dyah
Published: December 2020

Analysis of covariance (ancova) is a blend of regression and analysis of variance (anova) used for upgrade precision of an experiment. Ancova can be used for all experimental design including completely randomized design. The completely randomized design is the response are randomly intrusted to treatments. Application ancova on completely randomized design in the manufacture is given to observe the effect of types of cutting tools of lifetimes of cutting tools . In this experiment covariate variable is lathe speed. Lathe speed affects tool life meaning that the involvement of the covariate variables in the covariance analysis model is appropriate. From the covariance analysis, it is also found that tool type influences tool life. The coefficient of variance in ancova is lower than anova. This proves that the ancova has a better level of precision than anova, so that ancova is more appropriate to use than anova.
Fabrication of fluorine-doped tin oxide by using Indonesian local stannic chloride precursors with spin coating method
Authors: Yustanti E , Fahmi G , Lalasari L H , Arini T , Andriyah L , Subhan A , Firdiyono F , Trenggono A
Published: December 2020

Fluorine-doped tin oxide is a thin layer of transparent conductive oxide, which has a function as a semiconductor. Fabrication of fluorine tin oxide from this research was expected to replace indium-doped tin oxide. Indium-doped tin oxide function as a commercial transparent conductive oxide. The raw material of indium was limited, so the price of indium is higher than fluorine. The material used are Indonesia local tin (IV) Chloride, ammonium fluoride, and methanol. Conductive liquids has made by the sol - gel method. Sol gel liquids doped with ammonium fluoride to make a high conductivity. The transmittance value at the 1, 2, 3, 4, and 5 minutes deposition time were respectively 69.7; 43.6; 14.4; 14.1 and 34.7%. In this research, spin coating method under 3000 RPM on fix substrate temperature of 300°C. The results of the experiment shows, increased deposition time, make the thickness of the layer increased while resistivity and transmittance decreased. The optimum parameter for glass conductivity fabrication were obtained at 4 minutes time deposition, substrate temperature at 300°C has a resistivity of 125 k Ω, transmittance 14.1% and band gap energy 2.48 eV.
The potential of attached growth of microalgae on solid surface for biomass and lipid production
Authors: Chuah Sze Yu , Dasan Yaleeni Kanna , Cheng Yoke Wang , Lim Jun Wei , Ho Yeek Chia , Tan Inn Shi , Yew Foo Henry Chee , Kiew Peck Loo , Leong Sim Siong , Lam Man Kee
Published: December 2020

Microalgae cultivation is usually performed via suspended growth system; however, the subsequent harvesting technologies are either costly or energy intensive. Herein, attached growth of Chlorella vulgaris was investigated using low-cost supporting materials (polystyrene foam and cotton duct) to ease the microalgae harvesting process. Cotton duct served as a better supporting material than polystyrene foam as it promoted microalgae attachment. Evidently, the attached cultivation performed on cotton duct granted higher biomass yield (16.40 g/m2) than the attached cultivation with polystyrene foam (11.70 g/m2) after 14 days of cultivation. From the studied range of 0.1 – 0.3 v/v%, the optimal inoculum concentration for the attached cultivation of C. vulgaris on cotton duct was 0.3 v/v%. After 14 days of cultivation, the optimized attached cultivation of C. vulgaris was capable to produce a biomass yield of 18.2 g/m2. The lipid content of dried microalgae from optimized attached cultivation (43 wt%) was higher than that of suspended cultivation (32.7 wt%).
Hydrothermal Treatment of Palm Oil Mill Effluent (POME) under Oxidative and Non-oxidative Conditions
Authors: Lee Zhan Sheng , Cheng Chin Kui , Chin Sim Yee
Published: December 2020

The performances of oxidative (OHT) and non-oxidative (NOHT) subcritical hydrothermal treatments of palm oil mill effluent (POME) were investigated. The experiments were performed in a pressurised 500 mL-autoclave at different temperature (493 K – 533 K) and reaction time (2 h – 8 h). At 533 K and 8 h, the OHT reaction showed the highest removals of 5-day biochemical oxygen demand (BOD5) and chemical oxygen demand (COD), recording 87.30% and 71.23% respectively, with the pH of liquid product attained 6.5 from an initial value of 3.5. The reduction of COD and BOD5 in NOHT was lower than that in OHT, which were 61.43% and 68.02%, respectively. The mechanism of OHT reaction was via the free radical’s pathway. In contrast, the organic compounds originally present in POME degraded into water-soluble products, accompanied by deoxygenation that consisted of decarboxylation and dehydration during the NOHT.
Hydrogen sulfide reduction by conductive concrete with MFCs strain
Authors: Fukushima M , Promunuan K , O-Thong S , Suzuki T , Imai T
Published: December 2020

The objective of this study is to reduce the production of Hydrogen sulfide (H2S) in sewer pipe by using conductive concrete and electricity-producing bacteria (EPB). This work was mainly focused on evaluating the effect of inoculation of EPB isolated from sewage sludge from municipal wastewater treatment plant for decreasing production of H2S. The experimental results showed that inoculation of EPB could decrease the concentration of H2S, indicating that produced H2S in an anaerobic sludge sediment layer (bottom of sewer pipe) was biologically oxidized by EPB. These results demonstrated that conductive concrete can provide an electron pathway from anaerobic sludge sediment in the bottom of sewer pipe to oxygen dissolved in surface water, and as a result the electron generated from hydrogen H2S oxidation in anaerobic environment was accepted by oxygen via conductive concrete.
The influence of calcination temperature on (photo)electrochemical property of TiO2 prepared by the sol-gel method
Authors: Poo-arporn Yingyot , Luengprasert Kanokrat , Tonlublao Surangrat , Loiha Sirinuch , Ruangvittayanon Anuchit , Poo-arporn Rungtiva P.
Published: December 2020

In this work, titanium dioxide (TiO2) was successfully synthesized via the sol-gel method using Titanium (IV) isopropoxide as a precursor. The mixture was heated to 115°C to obtain the solid powder of TiO2. Ti K-edge XANES measurement was performed to determine its structure. Three pre-edge peaks at energy levels between 5460-5480 eV were clearly observed. These features correlated to 1s→d electronic transition in the distorted-octahedral structure of anatase TiO2. The in situ XANES experiment at 700°C revealed no phase transformation from anatase to rutile. There was no characteristic of the rutile phase on the XRD pattern of TiO2 calcined at 700°C. This result confirmed the stability of anatase. SEM images revealed the circular shape of TiO2 particles with a diameter of around 50 nm. The highest (photo)electrochemical activity of TiO2 was obtained at the calcination temperature of 300°C as investigated by a cyclic voltammetry.
Monitoring system for 5-kW Solar pumping system
Authors: Phetsong Sivapong , Somasri Patiwat , Hudakorn Teerasak , Weerayuth Nantawatana
Published: December 2020

Solar pumping system has been used extensively in agriculture and irrigation system. It is an old pumping system replacement because the old pumping system requires more maintenance and replacement. This article is reported on the study and development of the solar pumping system and the remote monitoring system. The system consists of the 5-kW solar panel and the 2.2kW submersible pump with a solar pump controller. It has been installed in the rural area which cannot easily accessible from the city. The monitoring system has been developed by integrating the electrical power modules, water measurement modules, weather measuring modules, and main controller modules. All of them communicate over the RS485 bus. The main controller unit integrates with software, gather all data from every modules and display on touch screen. It also makes data post-processing and records it on a USB drive and prepare data protocol for sending via communication modules. The system can work properly but it still need some further development in the future.
Extraction of lutein from marigold flower using solvent extraction
Authors: Kasemwattanarot P , Chuachang S , Ramakul P
Published: December 2020

The solvent extraction of lutein from marigold flowers was studied. The influence of three variables namely, the extraction temperature, ratio of the marigold flowers in the solvent, and ratio of ethanol in the solvent were investigated by a central composite design (CCD). The relationship between the yield and these variables was obtained by a regression model. The optimum condition was also determined. The highest yield for lutein (91.4%) was predicted by the regression model, which showed good agreement with the experimental results.
Zinc electrodeposition of mild steel in the presence of ginger, pomegranate and celery extracts
Authors: Loto Roland T. , Loto Cleophas , Akinyele Marvellous
Published: December 2020

Zn electrodeposition on low carbon steel (LCS) within an acid bath composed of ZnCl2, H3BO3and KCl solution at predetermined quantities of ginger, celery and pomegranate extracts with respect to plating time was evaluated. Results obtained showed the plant extracts significantly influenced Zn electrodeposition on LCS with respect to concentration. Ginger extracts induced the highest Zn electrodeposited with values between 0.0867 g and 0.1219 g. Comparison of corrosion resistance between the non-plated and Zn electrodeposited LCS (with and without extract additives) were determined with potentiodynamic polarization method. Results showed ginger, pomegranate and celery extracts enhanced the corrosion resistance of Zn electrodeposited LCS with highest corrosion rate values of 2.48 mm/y, 2.78 mm/y and 1.95 mm/y compared to 7.96 mm/y for non-plated LCS and 6.58 mm/y for Zn electrodeposited LCS without plant extracts.
Foamability of Natural rubber (NR)/Poly(butylenes adipate-co-terephthalate) (PBAT) Thermoplastic Vulcanizate with OBSH as a blowing agent
Authors: Srikham J , Thongpin C
Published: December 2020

Natural rubber, NR, is bio-based material that is generally used for foam preparation as it results in good softness and high resilience. Among many applications, NR foam/sponge is often used for shoe sole either insole or outsole. Likewise, rubber sponge is very important for healing Plantar Fasciitis as rubber sponge is soft, elastic and capable in impact absorption. NR is in fact non-biodegradable resulting in increasing of waste which is a hot issue at present. Huge interest has paid attention in using biodegradable polymer in various products and applications. Polybutylene adipate-co-terephthalate, PBAT, is one of many bioplastics that possesses biodegradability characteristic. It also shows excellent flexibility similar to elastomer. Many attempts have been focus on blending this polymer to improve toughness in brittle plastic. Our research is aimed to incorporate PBAT into NR and producing thermoplastic vulcanizate. NR/PBAT TPV foam is then produced using 4,4-’Oxybis-benzenesulfonyl hydrazide (OBSH) as a blowing agent. The ratios of NR/PBAT are varied as follow: 70/30 65/35 60/40 55/45 50/50 45/55. The polymer blends were mixed on a two-roll mill with the formulation of ZnO 3 phr, luperox 101 1 phr and OBSH 10 phr. Compression molding was used in order to prepare rubber sponge at 160 °C, 1500 psi. Cell size, cell size distribution, density and compression set of NR/PBAT foam were investigated.
Corrosion inhibition effect of 1-thia-3-azaindene on type 304 austenitic stainless steel in 3M H2SO4 solution
Authors: Loto R T , Loto C A , Awodein F
Published: December 2020

Corrosion inhibition of 1-thia-3-azaindene (T3A) on type 304 austenitic stainless steel was studied in 3 M H2SO4 solution at specific concentrations by potentiodynamic polarization. Results showed T3A performed effectively with optimal inhibition efficiency of 92.58% at 1.5% volumetric concentration with the corresponding corrosion rate of the steel at 0.53 mm/y compared to 6.72 mm/y in the acid solution without T3A compound. Inhibition performance increased with inhibitor concentration. T3A exhibited anodic type chemisorption inhibition according Langmuir, Temkin, Frumkin and Freundlich adsorption isotherms with correlation coefficient generally above 0.9. Polarization plots showed significant passivation behaviour after metastable pitting activity before breakdown at pitting potential signifying extensive surface coverage of the steel. The cathodic portion of the polarization plot showed H2 evolution and O2 reaction mechanisms are under activation control.
Corrosion inhibition study and statistical data of thymus mastichina and alicium verum oil on low carbon steel in dilute H2SO4 and HCl solution
Authors: Loto R T , Ororo S
Published: December 2020

Data on the corrosion inhibition of thymus mastichina and alicium verum (TA) on mild steel in H2SO4 and HCl solution was evaluated by coupon measurement and statistically through analysis of variance. The inhibition performance of TA was observed to decrease significantly with exposure time at 1% TA, beyond which the extent of decrease reduced. In HCl solution TA inhibition efficiency varied significantly with exposure time from 1%-4% TA concentration. Data showed TA effectively inhibited the mild steel after 1% concentration with optimal value of 81.24% and 5% TA concentration. TA performed poorly in HCl with optimal value of 68.33% at 5% TA concentration. Standard deviation showed variation of TA inhibition efficiency from mean inhibition value was significant at 1-5% TA concentration in HCl and at 1% TA concentration in H2SO4. 88% of TA inhibition data were above 70% inhibition with respect to exposure time and TA concentration at margin of error of +0.09% compared to 53% in HCl at margin of error of +0.1%. Analysis of variance showed TA concentration is the dominant source of variation responsible for the inhibition performance of TA with statistical relevance value of 88.83% while TA concentration and exposure time were both influential in HCl solution with values of 67.96% and 26.97%.
Influence of Annealing Temperature on Structural Properties and Stability of CsPbBr3/TiO2 Core/Shell
Authors: Nuket Parina , Kida Tetsuya , Vas-Umnuay Paravee
Published: December 2020

Although all-inorganic CsPbBr3 perovskites quantum dots exhibit an excellent photophysical properties, which could be applied in various applications, they still suffer from poor structural stability owing to environment factors. Therefore, TiO2 was coated on the CsPbBr3 QDs as a protecting shell to enhance their stability. Moreover, anatase phase of TiO2 shell was obtained by annealing at more than 300°C due to its most effective electron extraction properties among other crystalline forms of TiO2. However, the CsPbBr3 QDs can be degraded under high temperature. Herein, the annealing temperatures ranging from 300-500°C were optimized to obtain the anatase TiO2 shell and good crystallinity of CsPbBr3 QDs core. The morphology and optical properties of CsPbBr3 QDs, CsPbBr3/TiOx and CsPbBr3/TiO2 were studied by using transmission electron microscope (TEM), photoluminescence (PL) measurement and UV-Visible spectroscopy, respectively. Finally, the CsPbBr3/TiO2 annealed at the optimum temperature was compared with the bare CsPbBr3 QDs to prove the enhancement of their structural stability under ambient air by using X-ray diffraction (XRD).
Effect of Sintering Temperature and Cooling Rate on the Microstructure and Hardness of Fe-Cr-Mo-V-W-C Sintered Steel added with MoS2
Authors: Songsujaritkul V. , Mahathanabodee S. , Tongsri R.
Published: December 2020

In this work, the Fe-Cr-Mo-V-W-C sintered steels added with MoS2 (1, 3 and 5 wt.%) were produced by powder metallurgy process. The specimens were prepared by mixing, compacting and sintering at temperatures of 1150, 1200 and 1250°C for 45 min in vacuum furnace. After sintering, the specimens were cooled down with N2 at the different cooling rate (0.1 and 5.2°C/s). The density, hardness and microstructure of the sintered Fe-Cr-Mo-V-W-C steels were investigated. The experimental results indicated that the density and hardness of sintered steel could be improved by increase MoS2 addition, cooling rate and sintering temperature. The sintering mechanism was varied from solid state sintering to liquid phase sintering depend on sintering temperatures and MoS2 content. The presence of liquid phases and the increasing of cooling rate resulted in the amount of carbide precipitated decreased in the steel grain but increased precipitation at grain boundaries. The solidified of liquid and eutectic phases were found rising by increased cooling rate. Carbide precipitation in steel grain could be improved by added MoS2 and sintered at low temperature. From the results, it was indicated that the addition of MoS2, increase sintering temperature and cooling rate resulted in the precipitation of carbide, solidified liquid and eutectic phases, and grain growth in the sintered Fe-Cr-Mo-V-W-C steel.
Deterioration of Open-cell Aluminum Foam in Strong Sulfuric Acid
Authors: Sooksaen Pat , Thongyoug Penpisuth
Published: December 2020

Open-cell aluminium foam was fabricated by pressure infiltration and salt leaching method. The processing conditions to obtain uniform interconnected pore structure aluminium foam were melting at 650°C for 1.5 h with the applied pressure of 1.5 bar. Aluminum foams were sectioned into thin pieces to investigate for deterioration behaviour in strong sulfuric acid for 30 days. Significant weight reduction of about 50% was observed when the specimen piece was submersed in 1.0 M H2SO4 in the first three days after which the weight reduction slightly increased to 60%. Al and Cu were the two main elements that had been leached out from the surface of aluminum foam in contact with the acid resulting in the formation of sulfates.
The temperature-dependent structural and optical properties of SrAl2O4-based phosphor
Authors: Loryuenyong V , Kornsawat J , Nakhowong W , Klinjan W , Buasri A
Published: December 2020

This research studied the thermal stability of SrAl2O4 : Eu2+, Dy3+ phosphor for the fabrication of luminescent glasses. The temperature-dependent structural and optical properties of the phosphor were investigated. The results showed that SrAl2O4 : Eu+, Dy3+ phosphor could emit the green light when excited by ultraviolet (UV) light. It was also found that annealing could induce further growth of SrA2O4 crystals, which gave rise to more intense green-light emission. However, at high annealing temperature, the luminescence attained a maximum and started decreasing. An intense luminescence was observed for the SrAl2O4 : Eu2+, Dy3+ phosphor annealed at 750°C. The phosphor degradation at temperatures above 750°C could be because of the formation of secondary phases and the oxidation of the rare-earth atoms that were doped in phosphor. The results showed that, with proper fabrication processes, phosphors could be considered as promising materials for various applications.
Kinetic study for the co-pyrolysis of water hyacinth biomass with waste polystyrene
Authors: Phiwchaaum C , Ksapabutr B , Chaiyut N , Panapoy M
Published: December 2020

Co-pyrolysis behavior of water hyacinth (WHC) and waste PS using thermogravimetric analysis to determine kinetic parameters was investigated. TG and DTG results indicated that the pyrolysis of WHC and mixture of WHC and waste PS could be divided into three stages. It was found that co-pyrolysis of WHC and waste PS delayed the pyrolysis process with a wider decomposition temperature range, when compared with the pyrolysis of PS. The results compared with the pyrolysis of individual components revealed a positive synergistic interaction between WHC and waste PS according to the difference in weight loss. Coats-Redfern method was applied in the second stage to evaluate the activation energy (Ea) and pre-exponential factor (A) from the data of weight loss using three major reaction mechanisms. Two conversion temperature zones, zone I of 240-400 °C and zone II of 400-530 °C, were identified and a best-fit model describing the co-pyrolysis behavior of mixture was achieved. The addition of waste PS to WHC led to a slight decrease in the activation energy in the first zone and then the activation energy significantly reduced in the second zone. Chemical reaction and diffusion-controlled reaction mechanisms could be kinetically examined and enabled good explanation of the co-pyrolysis behavior of the mixture of WHC and waste PS as well as individual pyrolysis.
Mechanical properties and foaming behavior of Poly(lactic acid) blend Polybutylene Succinate
Authors: Bualuang W. , Threepopnatkul P. , Sittattrakul A.
Published: December 2020

The extensive use of non-biodegradable plastics has been causing serious environmental pollutions because of the degradability issue from especially consumable food packaging. In this research, biodegradable materials i.e., Poly(lactic acid) (PLA) and Polybutylene succinate (PBS) are chosen for the study. PLA/PBS foam was prepared using Azodicarbonamide (ADC) and Poly(ethylene glycol) (PEG) 20 wt% as a blowing agent and plasticizer, respectively. Foamability of different content PLA/PBS blend were investigated. PLA/PBS foam were characterized by Water absorption, Flexural testing, Scanning Electron Microscope (SEM). Flexural properties of PLA/PBS foam (70/30) showed the highest flexural modulus of 384 MPa due to the smallest cell size while PLA/PBS foam (20:80) showed the highest flexural stress of 11 MPa. PLA/PBS foam showed uniform cell size distribution. PLA/PBS foam had water absorption ability due to its porous structure.
Effect of Glycerol on Gluten filled in Natural Rubber/WG Blend
Authors: Thongpin C , Wongprat C , Srithavorn P , Muenchee P
Published: December 2020

In recently, a large number of utilization of NR has been found in several applications such as foam, insole but they do not provide good properties. In order to improve mechanical properties, in this work, wheat gluten (WG) which is a complex protein derived from wheat was used as a reinforcement. Furthermore, NR with WG (plasticized WG) can reduce costs of materials and easily degrade. NR-WG blend was prepared by mixed NR and WG, plasticized by glycerol, then mixed each other by using two rolls mill and compressed to get specimens. SEM, MDR, tensile testing and tear testing were used to characterize compounds. The effect of glycerol contents added and acting as plasticizer were also studied. The results show that the presence of glycerol also affected vulcanization behavior of rubber matrix. The increasing of glycerol content can also improve dispersion of WG in rubber matrix and indeed improve mechanical properties of NR.
Physicochemical, physical characteristics and antioxidant activities of three edible red seaweeds (Kappaphycus alvarezii, Eucheuma spinosum and Eucheuma striatum) from Sabah, Malaysia
Authors: Farah Nurshahida M S , Nazikussabah Z , Subramaniam S , Wan Faizal W I , Nurul Aini M A
Published: December 2020

Kappaphycus alvarezii (KA), Eucheuma spinosum (ESp) and Eucheuma striatum (Est are tropical red seaweeds taken from Kunak, Sabah, contain essentials source of bioactive compounds to produce variety of functional foods. This study was intended to investigate the physicochemical, physical properties and antioxidant activities related to these edible seaweeds. Physicochemical properties value of swelling capacity (SWC) and oil retention capacity (ORC) in KA species showed the highest value (p<0.05) compared to ESp and ESt, and water retention capacity (WRC) in ESp species was significantly different than KA and ESt (p<0.05). As in physical properties, ESp exhibited higher in moisture content and opacity than KA and ESt. KA showed the highest water solubility (p<0.05) which associated to its carrageenan compound. The antioxidant activities; DPPH and TEAC assay with total phenolic content (TPC) of three seaweed species indicated that KA displayed the highest TPC (19.17±0.04 mg GAE/g DW) and the lowest radical scavenging activity in both TEAC and DPPH assays. Hence, the findings disclose the physical and physiochemical properties and antioxidant values of these seaweeds application as new information and potential antioxidant sources in foods manufacturing commodities.
Beneficial effects of spontaneous fermentation in enhancing the phenolic contents, antioxidant activity and cultivation of lactic acid bacteria of Carica papaya leaf
Authors: So’aib M S , Hamid K H K , Salihon J , Tan H L , Hamid A.
Published: December 2020

Spontaneous fermentation using endogenous microorganisms is a reliable method for enhancing the bioactivity of medicinal plant. Here, the method was applied on Carica papaya leaf (CPL) for the first time to enhance the phenolic contents, antioxidant activity, and cultivation lactic acid bacteria. The antioxidant activity was estimated in terms of 2,2-diphenyl-1-picryl-hydrazyl-hydrate DPPH scavenging activity. Meanwhile, the microorganism fingerprinting was carried out by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method. Total phenolic content and antioxidant activity of fermented CPL (day 90) were 45.64±0.69 mg GAE/g dm and 467.38±4.09 mM TE/g dm, respectively, higher than 12.13±0.69 mg GAE/g dm and 275.46±3.09 mM TE/g dm, respectively of control, unfermented CPL. The cultivation of lactic acid bacteria (LAB) was marked by its viable cell counts between 103 to 107 colony forming unit (CFU)/mL on De Man, Rogosa and Sharpe (MRS) agar medium and the fingerprints of Weisella, Lactobacillus and Lactococcus species on PCR-DGGE throughout the fermentation period.
Extraction of Kaffir Lime (Citrus hystrix
DC.) essential oil by steam distillation and evaluation of chemical constituents
Authors: Quyen N T C , Ngan T T K , Phong H X , Hien T T , Dung L T
Published: December 2020

Citrus hystrix which is commonly known as Kaffir Lime, is a plant with great potential for research and commercialization. C. hystrix essential oil is used as a fragrance to increase appetite in food, or sweet-smelling in cosmetics and antibacterial properties in the health field. Most research have focused on the peels, yet the EO content in C. hystrix leaves is also noteworthy. There are many essential oils extraction methods from conventional to advanced techniques. However, it is necessary to consider the influence of heat during heat transfer to constituents in materials, which easily decompose the volatile compounds contained in the essential oil. Steam distillation method can limit this disadvantage by separating the solvents and materials into two places that are only connected by a steam pipe. In this study, the steam distillation method was employed to extract the EOs from C. hystrix leaves. The chemical components in this EOs was evaluated by gas chromatography–mass spectrometry (GC-MS) method. C. hystrix leaves achieved an essential oil yield of 1.24%. Moreover, different compounds in Kaffir Lime EOs obtained from steam distillation method were identified, including β-citronellol, citronellyl acetate, linalool, caryophyllene, pinene, sabinene, and naphthalene. Findings from the present study provide helpful insights to effective essential oil extraction from C. hystrix leaves with high content of valuable phytochemical compounds.
Phytochemical screening and antioxidant potential of crude drug “Cao Khai” in Ninh Thuan Province, Vietnam
Authors: Nguyen N Q , Pham T N , Nguyen V T , Nguyen M T , Dung L T , Bach L G
Published: December 2020

For a long time, the ethnic minorities in Ninh Thuan province, Vietnam have mixed Coptosapelta tomentosa Rubiaceae with other types of medicinal herbs to create an esoteric remedy called “Cao Khai”. This study had provided scientific evidence on phytochemical screening and antioxidant potentials of diethyl ether, ethanol and aqueous extracts of “Cao Khai”. Phytochemical screening of crude “Cao Khai” extracts showed the presence of mutiple components such as saponins, flavonoids, volatile oils, triterpenoids, organic acids, anthraquinon, coumarin, reducing compounds and polyuronid. The polyphenols and flavonoids content were determined using gallic acid and quercetin as a standard, respectively. 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2′–azino–bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods were used to measure free radical scavenging capacity. Results have shown that the total polyphenol and flavonoids content achieved 49.67 ± 0.35 µgGAE/mg and 5.49 ± 0.84 μgQE/mg, respectively. “Cao Khai” had low IC50 values of 126.06 ± 1.33 µg/mL (DPPH) and 35.4 ± 0.74 µg/mL (ABTS), which indicated that the crude drug “Cao Khai” illustrated significant free radical scavenging activity in a dose-dependent manner, as compared to ascorbic acid.