bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of electric disturbance at frequencies 2-150 kHz on analogue kilowatt-hour meter
Authors: Purnamaputra R P , Sudiarto B
Published: November 2020

Along with the times and technology, more often we find housing or offices that use a smart home system or smart building that integrates electrical appliances at home and offices into a single system, for example, lighting, air conditioning, security systems, etc. The use of electrical equipment that uses a system with an inverter technology can trigger disturbances related to the frequency switching used. The disturbance may affect the energy measured by energy meter. The study observes the impact of electric disturbances at frequencies range of 9-150 kHz on kWh meter. The disturbances are generated manually using Personal Computer and injected to the system through coupling network device. The disturbance generated has single and multifrequency disturbance in the range of 9-150 kHz. The result shows that there are inaccurate measurements on the analogue kWh meter when exposed to disturbances with an average percentage error of 2.91%. What can be done in the future is to install filters to reduce disturbances at these frequencies so as not to interfere with the performance of these devices.
The techno-economic analysis of vertical axis wind turbine implementation for scattered electricity loads
Authors: Rouf A , Sudiarto B , Setiabudy R
Published: November 2020

The Vertical Axis Wind Turbine (VAWT) can generate electricity by low wind speed and it can be simply implemented for scattered electricity loads. The objective of this study was to determine the specification, quantity, power capacity, capacity factor, and optimum production cost of the VAWT. Based on historical data of the wind speed, the future wind speed distribution can be simulated by using the Weibull and Rayleigh distribution approach. The parameters varied in this simulation included turbine specification, power capacity, and wind speed. The result showed that the optimal design of VAWT to implement in Raja Ampat was 10 kW turbine Type-H darrieus, with 3.5 m/s cut-in speed, 12 m/s rated speed and 9.49% capacity factor. This individual turbine can generate 8313 kWh Annual Energy Production or can supply the demand amount 432,983 kWh by 39 units with LCOE 20.5 Cent USD/kWh/unit or lower than Production Cost Regulated (21.34 cent USD/kWh). This indicated that the vertical axis wind turbine was the techno-economically appropriate alternative for archipelago countries that had scattered electricity loads such as Indonesia.
Rice husk-based biochar for carbon dioxide adsorption in biogas
Authors: Pertiwiningrum A , Besari R N , Wuri M A , Harto A W , Fitriyanto N A , Yanuari A A S
Published: November 2020

Rice husk-based biochar has been prepared by pyrolysis process for carbon dioxide adsorption in biogas. Biochar is considered as porous material for carbon dioxide adsorption. In this study, the adsorption of carbon dioxide, the largest impurity in biogas, was evaluated. The adsorptions were conducted in five treatments (mass variation): 80 grams of biochar (RB1), 60 grams of biochar and 20 grams of zeolite (RB2), 40 grams of biochar and 40 grams of zeolite (RB3), 20 grams of biochar and 60 grams of zeolite (RB4), 80 grams of zeolite (RB5). The best performance of carbon dioxide adsorption showed by RB1 with the decrease in carbon dioxide up to 31.59%. Characterization of adsorbents were also investigated by surface area analyzer to know relation between surface area and adsorption capability. It was found that the larger surface areas are favorable to adsorb carbon dioxide.
Dynamic simulation of a hybrid PV/Wind/Diesel system using power factory
Authors: Renaldhy Z R , Hutajulu A R , Husnayain F , Aryani D R , utomo A R
Published: November 2020

Economic growth is one factors driving the need for expansion of the electricity system. However, power systems in some isolated areas are found to be unreliable because of some issues such as the transportation of components of the power system and fuel. The potential of local renewable energies can be the alternative for the development of power plants in these areas. However, most renewable energy sources produce relatively unstable voltage and power due to fluctuating primary energy sources conditions. This study proposes a hybrid generation system that utilizes the potential of local RES such as a PV system and a wind turbine generator, combined with existing diesel generators and equipped with a battery energy storage system. Simulations are carried out to observe and study the dynamic response of each component in response to the system frequency using PowerFactory software. The result shows the proposed hybrid system still operate well and stably due to the dynamic performance and coordination control between diesel generators and the battery energy storage system.
Sensitivity analysis of using unreliable rain gauge stations for evaluating the accuracy of radar rainfall estimates
Authors: Hambali R , Legono D , Jayadi R
Published: November 2020

Providing reliable rainfall information through the integration of all possible data sources such as rain gauge and radar can make a valuable contribution to the development of the lahar flow warning system. However, the reliability of radar rainfall (R) data still needs to be evaluated based on ground rainfall (G) given the estimated value of radar rainfall depth is not so precise compared to ground rainfall. The selection of which ground rainfall data can be used as an evaluation reference is based on the assessment of the variance analysis. Through the Scheffe test, the unreliable rain gauge stations can be known. The use of unreliable rain gauge stations for evaluating the accuracy of radar rainfall estimates affecting the parameter values of radar rainfall and ground rainfall conformity. This paper discusses sensitivity analysis of using unreliable rain gauge stations for evaluating the accuracy of radar rainfall estimates. Based on the Scheffe test, several scenarios are set to assess the change of conformity parameter values. The conformity between radar rainfall and ground rainfall are evaluated by using Log (G/R), FSE, and RMSE index. A number of 10-minute rainfall intensity data during 2016-2018 from 21 automatic rain gauge and X-band MP radar stations in the Merapi volcano region are used in the analysis. The result show that the less unreliable rain gauge stations used to assess the radar rainfall accuracy, the better the conformity parameter values.
Application of artificial neural network with backpropagation algorithm for estimating leaf area
Authors: Asriani E , Robika
Published: November 2020

Leaf area plays an important rules in plant growth and production. There are some methods used to measure leaf area with different approach namely regression equation, grid count, gravimetric, planimeter, image processing, adaptive neural based fuzzy inference system, and other. In this research, the excellencies of Artificial Neural Network (ANN) with backpropagation algorithm will be inspected to estimate leaf area of seven plants species. Two parameter, leaf length and leaf width, used as an input variables and leaf area as output variable. The result indicated that ANN with 2-50-1 architecture has a good performance in predicting leaf area of seven plants species at 99.99% degree of accuracy.
Design of system for setting the temperature and monitoring bees in and out the hive
Authors: Supandi  , Arkan F , Gusa R F , Jumnahdi M , Kurniawan R
Published: November 2020

Trigona bee is one genus of bee without the sting producing honey and propolis. Activities in and out of the nest are activities to protect the nest from enemy attacks, remove dirt from the nest and most importantly forage. Foraging activities will affect the weight of the bee colony and its products, namely honey, bee pollen, and propolis. Temperature and humidity around the hive are important factors for trigona bees to move. This study aims to monitor temperature, humidity, light intensity, the volume of propolis, and the activity of bees in and out of the hive via a smartphone, to determine the effect of temperature, humidity, and light intensity on the activity of bees in and out of the hive. The average yield of bee activity in and out of the hive by controlling the temperature of the activity of bees in and out of the hive was 155 bees, a temperature of 29.64°C, and humidity of 89.15%. Nest temperature regulation has a significant effect on the activity of bees in and out of the hive. The activity of bees in and out of the hive is high in the morning around 07:00-10:00 at lower temperatures and higher humidity than the time of day or evening. The light intensity around the hive did not significantly affect the activity of bees in and out of the hive.
Economic feasibility analysis of Gintung Dam
Authors: Kalsum A U , Sutjiningsih D , Anggraheni E , Murniningsih S
Published: November 2020

Gintung Dam is a dam resulting from the post-disaster reconstruction and rehabilitation in 2009. In this study, economic feasibility analysis post reconstruction and rehabilitation is carried out. The feasibility analysis is reviewed based on economic value of the benefits of Gintung Dam and investment cost as well as Operational and Maintenance (O&M) costs. Economic valuation, which is an attempt to provide quantitative value to the goods and services produced by natural resources and the environment, is carried out for the benefits of dam. The method used is the investment criteria method which uses NPV, BCR, PBP, and IRR as parameters in determining the feasibility of project. Based on the results, for Gintung Dam with its function as a flood control was obtained NPV = Rp.14,023,230,130.29, BCR = 1.88, PBP = 27 years, and IRR = 12% and as groundwater conservation was obtained, NPV = Rp. 87,704,518,835.06, BCR = 6.51, PBP = 2.7 years, and IRR = 46.25%. The results of the analysis shows that the Gintung Dam reconstruction and rehabilitation project is economically feasible with the value results NPV > 0, BCR > 1, PBP < project life span (100 years), and IRR > interest rate used (10%).
Analysis of parking needs for sustainable parking lots in commercial area of Pangkalpinang City
Authors: Safitri R , Amelia R , Sujarwanto D
Published: November 2020

Pangkalpinang Plaza-Bangka Trade Center (BTC) Area is the largest commercial area in Pangkalpinang City. As the largest commercial area, this area causes a large pull of vehicle trips that needs a large number of parking spaces. Therefore, parking needs must be analyzed to provide sustainable parking lots in this area. This study aims to analyze parking needs for sustainable parking in Pangkalpinang Plaza-Bangka Trade Center (BTC) Area. In this research, the parking survey methods used are an inventory survey and a vehicle license plate survey. Parking needs analysis is reviewed based on parking volume and parking accumulation. Then, parking needs are determined based on the biggest interval between vehicle arrivals and departures from parking accumulation. The research finds that the amount of parking needs of on-street parking is 540 SRP for motorcycles and 120 SRP for passenger cars. Meanwhile, the amount of parking needs of off-street parking is 208 SRP for motorcycles in front of Ramayana and 238 SRP for motorcycles in basement Ramayana. Furthermore, these results will be useful for providing sustainable parking lots in Pangkalpinang Plaza – Bangka Trade Center (BTC) Area.
Kelubi Fruit (Eleiodoxa conferta) extract as a Green Catalyst Synthesis of 3,4-dihydropyrimidin-2 (1H)-ones
Authors: Mahardika R G , Sari R P , Nazrun  , Roanisca O , Abdussalam M
Published: November 2020

The use of synthetic strong acid catalysts or lewis acid catalysts from metals often causes environmental problems at the end of a chemical reaction. In this research offers an alternative solution using kelubi fruit extract (Eleiodoxa conferta) as a green catalyst, especially in the synthesis of 3,4-dihydropyrimidin-2 (1H)-ones derivatives which are reported to be active as therapeutic and bioorganic chemistry. So the purpose of this research was to develop a green catalyst from natural fruit for the synthesis of 3,4-dihydropyrimidin-2 (1H)-ones using kelubi fruit. The Green catalysts are obtained from water extracts of kelubi fruit that are ripe. Then the catalyst is added to the reagent for the synthesis of pyrimidine derivatives that consist of urea, benzaldehyde, and ethyl acetoacetate (equivalent). As a comparison, HCl is used as an acid catalyst. The result is the highest yield (67,7%) at the use of 0,2 ml green catalyst and reaction time 180 minutes. Spectrum UV-Vis of characteristics compound has a maximum wavelength of 306 nm.
Dynamic interaction between tidal current and upstream discharge at the Kapuas River mouth
Authors: Danial M M , Herawati H , Budiman F , Ramdani
Published: November 2020

This paper explores the dynamic interaction between tidal current and upstream discharge at the Kapuas River mouth. Long term time series data of tidal current and river discharge obtained from software Windwave 05 and hydrograph data, respectively. Three prominent parameters, i.e., river discharge, tides, and tidal current were analyzed using the wavelet method, Hilbert function, and low pass filter to evaluate the tidal characteristics and phase difference of M2, M4, K1, O1. The relationship between the tidal current and water level shows a mimic standing wave with the phase difference around ∼ -180 – 900, indicating the tidal current leads the water level. The low-pass filter results indicate that the increasing river discharge hampers the tides and reduces the tidal current at the mouth. The Hilbert function result reveals the asymmetric tide and flood dominant flow which has the opposite direction with the seaward direction of the current. Moreover, the subtidal water level flows in a seaward direction. This happened because the net seaward current modulated by the river discharge. The currents at the mouth are affected significantly by the swell wave.
The role of mangrove ecotourism towards the environmental sustainability in Bangka Regency
Authors: Hayati L , Bahtera N I
Published: November 2020

The exploitation of natural resources becomes an undeniable reality to fulfil the need and to improve economic growth. Excessive exploitation has threatened environmental sustainability. Creating ecotourism related to sustainability, education, economy and participative movement of society becomes solution to tackle the issue. The study aims to analyse the role of mangrove ecotourism towards environmental sustainability. Qualitative descriptive with interactive analyses was used as the method of the study. Observation and in-depth interviews were employed as the data collection technique. The study discovered that ecotourism mangrove played a vital role in ensuring environmental sustainability. It showed that tourism awareness groups built the tourist attraction by utilizing the 40 ha of mangrove forest. It implied that the livelihoods of society had altered from tin mining into the brackish water aquaculture. This had decreased the number of natural resource exploitation of tin mining
Local Wisdom of Jerieng Tribe in Utilizing Biological Resources
Authors: Afriyansyah B , Novalia  , Camelia A , Nukraheni Y N , Juairiah L , Ihsan M
Published: November 2020

Jerieng Tribe is one of the ethnic groups found in Bangka, precisely in Simpang Teritip District, West Bangka Regency. The Jerieng ethnic group is included in the Malay tribe of Bangka, in addition to the Lom ethnic group and the Sawang ethnic group on Belitung Island. Biodiversity of plants and animals has been widely utilized by the Jerieng Ethnics in fulfilling the needs of life, such as food, medicine, customs and cultural rituals. This study aims to examine the use and local knowledge of Jerieng Ethnics in utilizing and protecting biodiversity. The method used is Ethnodirect Sampling and Open-ended Interview. The Jerieng people have local wisdom in utilizing plant biological resources, such as traditional home and clothing, folk weapons, musical instruments, herbal medicine, and alternative food. For animal biological resources, such as the implementation of existing rituals, clothing. Traditional medicine and musical instruments. The utilization of biological resources must have a conservation strategy involving indigenous institutions, indigenous peoples, local Governments (Regents and village heads), and the central government (Ministry of Environment and Forestry). In conclusion, the Jerieng people kept their customary values and traditions and implemented a conservation strategy in the utilization of biological resources.
Managing social media in development program of sustainable region
Authors: Budiarto R , Novitasari D , Arif Z , Aliyah F , Salis F R
Published: November 2020

The Centre for Development of Sustainable Region (CDSR) is a collaborative centre of research and development led by Universitas Gadjah Mada. In its first phase of development, this centre comprises seven Indonesian universities and one US university. Two of three targeted outcomes of the CDSR are 1) strengthening institutional environment for research and management in involved higher education institutions and 2) development of sustainable archipelago region. During July 2017 – June 2020 CDSR has conducted more than a hundred activities. As a part of strategic tools in achieving the targets, CDSR systematically manages five social medias to share the news, research and activities using Facebook, Instagram, Twitter, YouTube and Website. This paper explains strategy to manage the social media platforms. Besides to share information and activities, social media is also managed as a tool to engage with people and institutions outside CDSR. During period started from February 2018 to June 2020 CDSR conducted intensive monitoring and evaluation on performance of CDSR information in the social media. The impression gained from Facebook, Twitter, Instagram, YouTube and Website are 90,387, 210,013, 45,454, 15,264 and 7,581 respectively. These impressions provide important information to evaluate continuous improvement in the program to develop sustainable archipelago region.
Nature-based solutions and similar concepts on water management
Authors: Woo H
Published: November 2020

Nature-based solutions (NbS’s) refer to the sustainable management and use of nature for tackling socio-environmental challenges such as, focusing on water issues, water security, flood protection, and water pollutions. This newly emerging concept is conceptually compared, in the aspect of water management, to existing similar solutions with different naming, all of which are based on ecosystem functions. NbS seems significant and meaningful both educationally and understandably, since that it can comprehensively cover and include the existing methodologies and solutions using the services of the natural ecosystem to socio-environmental challenges. However, it seems not entirely different from the broad-meaning of green infra, including Eco-DRR, in the aspect of approaching methodologies in water management. The conceptual and spatial hierarchy of each practice can be expressed in the narrowing order of NbS - (Ecological engineering) - BGI (Blue-green infra) - (CRT, Close-to-river techniques) - GI (Green infra) - LID (Low-impact development).
Correlation complexation constants of Ce4+ and F−
Authors: Jiang Ying , Wang Xuemei , Chen Yunzhu , Nengzi Lichao
Published: November 2020

Measured CeFn (n=1, 2, 3) complexation constant and solubility product constant of CeF4 and Na2CeF6 by ICP-AES and UV spectrophotometer, when Ce4+ and F− complexation reaction in water medium and nitric acid medium respectively, and the effects of Re3+and nitric acid concentration on Ce4+ and F− complexation reaction were studied. The experimental results show that the first-order complexation constant of Ce4+ and F− is CeF3
+=6.94*106, the second-order complexation constant is CeF2
2+=4.541*1011, and the third-order complexation constant is CeF3
+=6.232*1014. Compared with the complexation reaction of Ce4+ and F− in water medium and nitric acid medium, the complexation reaction of Ce4+ and F− in nitric acid medium is better. Re3+ appears, which affects the complexation reaction between Ce4+ and F−. When in nitric acid medium, the higher the concentration of nitric acid, the more unfavorable the complexation of Ce4+ and F−. The study of the relevant physical constants of Ce4+ and F− in this paper can be helpful for the separation of Ce4+ and F−, enrich the physical and chemical information of rare earth elements, and provide the basic theoretical basis for the rare earth fluoride that is difficult to be separated and recovered from the tailings, so as to reduce the harm to the soil environment.
Drought and flood characteristics evolution in peninsular region of Shandong Province based on standardized precipitation index
Authors: Zhao Weijun , Yan Tingting , Peng Shuzhen , Ding Min , Lai Xiaodan
Published: November 2020

Data research in recent decades shows that drought and flood disasters occur frequently in China due to the uneven spatial and temporal distribution of rainfall. Taking Shandong Peninsula as an example, this work selected the standard precipitation index (SPI) as the precipitation characteristic analysis index, calculated the SPI values at 4 different time scales in multiple meteorological stations from 1961 to 2013, and analysed the inter annual and seasonal variation characteristics of drought and flood. The results show that: (1) the standardized precipitation index can better reflect the characteristics of inter annual and seasonal drought and flood changes in the study area on a long time series scale. (2) The most flood period occurred in 1964 and 2007, and the most drought period occurred in 1981, 1991 and 1998, and all reached the severity of extreme drought. (3) The intensity of drought and flood varied in different time scales. In spring, autumn and winter, the drought intensity and affected area showed a decreasing trend. However, the flood intensity and its affected area were on the rise in summer, and the rainfall intensity was on the rise in time scale.
Measures, methods and cases of river ecological restoration
Authors: Zhang Xinmin , Zhang Xingliang , Zhang Zihao , Zhang Jingshen , Fan Pengyu
Published: November 2020

This work analyzed the main causes of river ecosystem degradation by summarizing the problems of river ecological environment. Second, it formulated measures and methods of river ecological restoration aiming at all kinds of ecological environment problems. In order to strengthen the pollution control and ecological environment protection, it then put forward management measures of administrative functional departments from the aspects of carrying out pipe network pollution interception, strengthening water law enforcement, pollution control of non-point sources of living and farmland, and river system control. In order to restore the degraded river ecosystem, the technical measures of ecological restoration in terms of water quantity, water quality, habitat and biodiversity were summarized. Finally, it clarified principles, steps and objectives of river ecosystem restoration, which has certain reference significance for the comprehensive and systematic restoration of river ecosystem.
Research on spatial resilience characteristics and response mechanism of Chengdu-Chongqing urban agglomeration based on power-law
Authors: Cao Qi , Shi Manjiang
Published: November 2020

Urban agglomeration is the spatial organization form of urban development and the main carrier of population, economy and information gathering to promote regional coordinated development. Therefore, it is important to research the sustainable development of urban agglomeration. Focus on the scientific issue of the relationship between power-law distribution structure of spatial elements and spatial resilience of urban agglomeration; using the number of urban permanent population and urban built-up area size as the key spatial elements of Chengdu-Chongqing urban agglomeration, firstly, we discussed the spatial-temporal evolution law of power-law characteristics of key spatial elements of Chengdu-Chongqing urban agglomeration. Secondly, we revealed the response mechanism of spatial resilience to power-law distribution of key spatial elements of Chengdu-Chongqing urban agglomeration. The conclusions as following: (1) The spatial resilience of Chengdu-Chongqing urban agglomeration characterized as “concentration” dominated by large cities. (2) The spatial resilience and Pareto distribution of Chengdu-Chongqing urban agglomeration have a remarkable and stable response relationship. (3) In order to maximize the spatial resilience of Chengdu-Chongqing urban agglomeration, it is urgent to control the number of urban permanent population and built-up area scale of large cities.
Difficulty and complexity in dealing with visual pollution in historical cities: The historical city of Ibb, Yemen as a case study
Authors: Alwah A A Q , Li W , Alwah M A Q , Drmoush A A K , Shahrah S , Tran D T , Xi L B
Published: November 2020

The historical cities in the third world suffer from many environmental problems; one of them is the spread of visual pollution manifestations. These phenomena increase with low levels of public awareness and low per capita income. Despite the historical and cultural importance of the Old City of Ibb, the manifestations of visual pollution are increasing day after day. This study aimed at identifying the difficulty and complexity of dealing with visual pollutions manifestations in the historical city of Ibb and to provide appropriate solutions that are suitable for the complex and contradictory circumstances. The study relies on an inductive approach to achieve its aims through two methods; the first is a visual survey of the visual pollution phenomenon, based on images and observations. The second method is the analyses of the opinions and impressions of three parties related and interested in the phenomenon, namely residents and visitors of the city, competent authorities’ officials, and some specialists in the field of the urban environment. The study presents an analysis of the phenomenon of visual distortion of the historical city of Ibb in terms of its appearances and causes. Furthermore, this study provides appropriate solutions, which are suitable for complex and contradictory circumstances. These solutions focused on the methods to stop the spread of visual distortions, and the ways of addressing the current visual pollutions.
Empirical study on carbon emission measurement and influencing factors of urban traffic based on “Population-Economy-Environment”
Authors: Liu Chunmei , Wang Xiaohua , Lai Fengbo , Huang Yujuan
Published: November 2020

Economic growth, urban expansion, traffic dependence, and urban lifestyle have caused a large amount of energy consumption and greenhouse gas emissions in cities. The issue of urban greenhouse gas emissions has become a global focus and a research hotspot. This paper analysed the causality of driving factors and identified the key elements such as urban population, economy, energy and motor vehicles through system dynamics (SD) and econometric model. Then, it conducted empirical analysis and explored the impact of factors on urban transportation carbon emissions taking Beijing as an example. The research results showed that in addition to energy consumption, other factors were positively correlated with traffic carbon emissions. It believed that in order to control urban traffic carbon emissions, we must control the urban population, economy and the number of vehicles rationally. With the optimization of energy structure, the structural adjustment of traffic energy consumption is conducive to energy conservation and emission reduction in the transportation industry, and the decoupling of the total energy consumption of traffic and the carbon emissions from transportation.
Oxide Growth Behaviour of Fe-Ni-Cr Alloy at High Temperature Oxidation
Authors: Parimin Noraziana , Hamzah Esah
Published: November 2020

The isothermal oxidation test has been investigated on two types of Fe-Ni-Cr alloy, namely Fe-33Ni-19Cr and Fe-40Ni-24Cr alloys. Both alloys were undergoing an isothermal oxidation test at temperature of 500? for 500 hours exposure time. The weight change per surface area of the oxidized samples has been recorded to calculate the oxidation kinetics of both alloys. The oxide growth behaviour of oxidized samples has been examined using scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) spectrometer. The oxide phase formed on the sample surface has been analyzed using x-ray diffraction (XRD) technique. The results show that both alloys were followed a parabolic rate law, indicating a diffusion-controlled oxide growth mechanism. In addition, the oxidation kinetics indicating an increasing weight gain trend as the exposure time increase. Several oxide phases had formed on the oxidized surface of both alloys, consists of Cr-rich, Ti-rich, Fe-rich and spinel oxide structure. The surface morphology of both alloys demonstrated a continuous oxide scale formed on the alloy surface. Additionally, Fe-33Ni-19Cr alloy recorded a formation of Ti-rich oxide, whereas, Fe-40Ni-24Cr alloy displayed a formation of overgrown Nb-rich oxide particle which. Roles of the precipitates in oxidation mechanism give new insights into the alloy optimization.
Influence of Solution Treatment Temperature on the Microstructure of Ni-based HR-120 Superalloy
Authors: Parimin Noraziana , Hamzah Esah
Published: November 2020

The solution treatment process has been carried out on Ni-based HR-120 superalloy (Fe-40Ni-24Cr) at six different temperatures, namely 950ºC, 1000ºC, 1050ºC, 1100ºC, 1150ºC and 1200ºC. All samples were soaking for 3 hours at desired temperature, followed by water quench. The main objective of the solution treatment process is to vary the grain size of the alloy. The effect of solution treatment process on the alloy has been investigated in term of microstructure, grain size, phase present and hardness test, by using optical microscope, scanning electron microscope (SEM) equipped with energy dispersive x-ray (EDX) spectrometer, x-ray diffraction (XRD) technique and Vickers hardness test. As a results, the grain size of the solution-treated alloy were increase as the solution treatment temperature increase from 27.27 μm to 40.86 μm for solution-treated alloy at 950ºC to 1200ºC, respectively. Three precipitate phases were detected during phase analysis which are NbC, TiC and (Nb,Ti)C on the solution-treated alloy. In addition, as the grain size increase when the solution treatment temperature increase, the hardness value was decrease.
Effect of Chemical Treatment on Tensile Properties of Oil Palm Empty Fruit Bunch (OPEFB)-based All Cellulose Composite (ACC) Films
Authors: Zailuddin Nur Liyana Izyan , Osman Azlin Fazlina , Rahman Rozyanty
Published: November 2020

This study explored the potential of using oil palm empty fruit bunch (OPEFB) in the production all-cellulose composite (ACC) films. The isolation process of the raw OPEFB fiber was carried out using chemical process to extract the OPEFB nanocellulose. The ACC films from the OPEFB and microcrystalline cellulose (MCC) were prepared using dimethylacetamide (DMAC) and lithium chloride solvent system whereby the partially dissolved cellulose was transformed into the matrix phase surrounding the remaining non-dissolved fiber. The ACC films containing 1, 2, 3 and 4 % (wt/vol) OPEFB cellulose and 3 % (wt/vol) microcrystalline cellulose (MCC) were prepared and the effects of 2-ethylhexyl acrylate chemical treatment of the OPEFB cellulose on tensile properties of the ACC film were investigated. Results indicate that the chemical treatment using 2-ethylhexyl acrylate has reduced the hydroxyl group composition in the cellulose and allowing greater dissolution of the cellulose during the formation of the ACC film. As a result, the tensile strength and modulus of elasticity of the ACC film were significantly enhanced. However, both untreated and treated ACC films experienced the reduction in both properties when the cellulose concentration was increased from 1 % to 4% (wt/vol), due to the saturation of the cellulose particles and non-homogeneity of the ACC system.
Study of thermoelectric properties of Sr0.92A0.08TiO3 (A=Yb / Tm) perovskite oxide using density functional theory method
Authors: Adewale Akeem Adekunle , Chik Abdullah , Zaki Ruhiyuddin Mohd
Published: November 2020

The first principle methods have been employed to investigate electronic and thermoelectric properties of Sr0.92Yb0.08TiO3 and Sr0.92Tm0.08TiO3 perovskite-oxide based molded samples. Generalized gradient approximation (GGA) with Hubbard U parameter is used by WIEN2k code for the calculations. The straight band line was observed in the band structure of both studied samples. This was generated from 4f-orbitals as shown in partial density of state diagrams. It is also noticed that Yb and Tm doped in SrTiO3 changed the perovskite-based oxide from a wideband insulator to metallic nature. A thermoelectric power factor of Sr0.92Tm0.08TiO3 sample is higher than that of Sr0.92Yb0.08TiO3, this is as a result of its huge electrical conductivity. The dependent of chemical potential to temperature was revealed in the study where high value of power factor was recorded for high temperature.
Effect of Surface Treatment on Mechanical Properties of Rice Husk Reinforced Recycled High Density Polyethylene (rHDPE) Composites
Authors: Salleh Mohd Nazry , Aziz Roslaili Abdul , Razak Mohd Fairul Sharin Abdul , Musa Luqman , Ying Hong Li
Published: November 2020

The aim of this work was to investigate the effect of surface treatment on rice husk reinforced recycled high density polyethylene (rHDPE) composites. Three types of surface treatment on rice husk were carried out which were maleated treatment, alkaline treatment and acrylic acid treatment. The characteristics and mechanical properties of the composites were analysed. The results for all treatments showed that tensile strength and break elongation of composites decreased significantly when the rice husk filler loading increased. Further findings showed that maleated treatment on rice husk can further enhance the mechanical properties due to the present of ester bond formed in FTIR analysis.
Preparation and characterization of LDPE/TPS blend filled with calcium carbonate
Authors: Halim Anis Adila Ab , Wahab Mohamad Kahar Ab
Published: November 2020

The measurement of low-density polyethylene / thermoplastic starch (LDPE/TPS) composite with different loading of calcium carbonate (CaCO3) as filler was conducted under several testing such as the tensile test and scanning electron microscopy. The preparation of LDPE/TPS/CaCO3 composite was divided into three stages. The first stage involved the preparation of TPS with and without modification with carboxylic acid. The second stage, LDPE was blended with TPS to produce LDPE/TPS blend. LDPE/TPS blends with blend ratio of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 was prepared. Each composition will undergo tensile testing to analyze their mechanical properties. The optimum LDPE/TPS blend ratio was chosen for subsequent study. Third stage involved the compounding of the chosen LDPE/TPS blend ratio with CaCO3. The result indicate that LDPE/TPS with incorporation of CaCO3 gave higher value of tensile properties as compared to LDPE/TPS blend. Based on the SEM micrograph, treated TPS with citric acid and ascorbic acid performed better interfacial phase as compared to untreated TPS, with no agglomeration and voids formation.
The effect of twin screw compounding parameters on the tensile properties of pineapple leaf/sea shell hybrid polymer composite using DOE approach
Authors: Ching Ng Tian , Halim Khairul Anwar Abdul , Omar Mohd Firdaus , Osman Azlin Fazlina , Zakaria Muhammad Salihin
Published: November 2020

Pineapple leaf and sea shell were used as natural fillers in this research due to its biodegradable nature, wide availability, continuous resources and low cost. This research work was carried out to investigate the effect of compounding process using twin screw extruder on the tensile performance of pineapple leaf / sea shell polymer composite using Design of Experiment (DOE) approach. A total of nine runs of were formulated and the resulitng hybrid composites were compounded using twin screw extruder. The short term tensile test was carried out to determine the tensile properties and the data were sunsequently analyse using DOE software. Pareto chart of the standardized effect and the main effect plot were employed to investigate the relationship between processing parameters and the tensile performance of the hybrid composite systems. Based on the initial DOE analysis, it is shown that compounding parameters had influenced the final mechanical behavior of the hybrid composites.
Sugarcane Bagasse Reinforced Polyester Composites: Effects of Fiber Surface Treatment And Fiber Loading on The Tensile And Flexural Properties
Authors: Zakaria Muhammad Salihin , Musa Luqman , Nordin Razif Muhammed , Halim Khairul Anwar Abdul
Published: November 2020

The effect of fiber surface treatment and fiber loading on the tensile and flexural properties of untreated and treated fiber-based sugarcane bagasse reinforced polyester (SBRP) composites have been investigated. Sugarcane bagasse fibers were alkalized with 1, 3 and 5% concentration of sodium hydroxide (NaOH) solution combined with different fiber loading formulation 0, 20, 30 and 40 php, and hot-pressed to form natural fibers composite were prepared. The results indicated that the incorporation of bagasse fiber composites alkalized with 3% NaOH solution improved the tensile strength and modulus of reinforced composites meanwhile the untreated bagasse gave the lowest value. However, the elongation at break (Eb) indicated that treated bagasse fiber composites show a lower value compared to untreated composites. A similar trend also obtained for flexural strength and modulus.
The effect of choline chloride: acetamide deep eutectic solvent to physicochemical and mechanical properties of pectin-based bioplastic
Authors: Azman Mohamad Azhar , Rizana Yusof , Dalina Samsudin , Hanaphi Roziana Mohamed
Published: November 2020

The rapid increment of synthetic plastic wastes in our environment has triggered in production and development of new biomaterial for resolving problems such as pollution as well as weak mechanical properties. Pectin polysaccharides are recognized as a new potential biomaterial in developing bioplastic. The main purpose of this study is to develop and characterize citrus pectin bioplastic using deep eutectic solvents (DES) of choline chloride: acetamide (1:2), CC:Ac as a plasticizer. The potential of produced bioplastic (BP-CC:Ac) was studied through investigation of their physicochemical and mechanical properties which include pH, thickness, opacity, solubility, tensile strain, tensile stress and Young Modulus. A citrus pectin-based bioplastic without the plasticizer (CI) and with the conventional plasticizer of pure acetamide (C2) were prepared as controls. The produced BP-CCAc showed a higher value of thickness (0.2658 ± 0.0015mm), opacity (0.492 ± 0.02A), and solubility (23.26 ± 0.03%) than the control, CI (0.1963 ± 0.0032mm, 0.407 ± 0.01A, and 16.42 ± 0.01% respectively) and C2 (0.1833 ± 0.001mm, 0.447 ± 0.01A, and 17.88 ± 0.05% respectively). The high acidity of BP-CC:Ac (pH 3.21) provide a strong inhibition toward bacteria which is highly demanding for medical purposes. The tensile strain, tensile stress and Young Modulus of BP-CC:Ac were measured at 5.080 ± 0.04 %, 2.221 ± 0.08 MPa and 113.946 ± 0.08 MPa, respectively. It was found the BP-CCAc was more flexible and have smooth surface texture than both controls, CI and C2 which suitable for plastic wrapping. Other than being natural and biodegradable, the addition of CCAc DES had improved the physicochemical and mechanical properties of pectin based-bioplastic. In conclusion, the addition of CCAc DES has enhanced the properties of BP-CCAc and increased the potential of plastic as an ecofriendly and sustainable future material.
A Short Review on Selection of Electrodes Materials for Symmetrical Solid Oxide Fuel Cell
Authors: Yusoff Wan Nor Anasuhah Wan , Baharuddin Nurul Akidah , Somalu Mahendra Rao , Muchtar anastuti , Samat Abdullah Abdul
Published: November 2020

Symmetrical solid oxide fuel cells (SOFCs) operate at high temperatures and consist of a dense electrolyte which is sandwiched between two electrodes. An anode acts as a fuel electrode where fuel is oxidised, while a cathode serves as an air electrode in which oxygen is reduced. However, the use of two different materials as electrodes poses several significant issues concerning durability, reliability and fabrication costs of SOFCs. Furthermore, at least two thermal steps are required for the sintering of both electrodes, thereby increasing energy usage. In overcoming these challenges posed by conventional SOFCs, the concept of symmetrical solid oxide fuel cells (S-SOFCs) has been introduced. S-SOFCs comprise of two identical materials for the anode and cathode. The use of two similar materials decreases the interfacial regions among the electrolyte and electrodes and consequently improves the compatibility among the components. Sulphur poisoning and carbon deposition at the fuel electrode can be solved by merely reversing the flow of oxidant and fuel to oxidise all the species that degrade the performance of SOFCs. Although, the electrode material for S-SOFCs requires some unique properties, such as high electrocatalytic activity for fuel oxidation and oxygen reduction, high electrical conductivity in oxygen and hydrogen/hydrocarbon environments, promising the capability to resist sulphur poisoning and carbon deposition in hydrocarbon fuels and good structural and chemical stability under actual fuel cell conditions. As the works related to S-SOFCs are limited in this respect, this paper reviews the available reports in this field to allow a better understanding of the operational mechanism and the potential of S-SOFCs.
The Effect of Germanium Addition on the Lead-free Solder Alloys: A Short Review
Authors: Tan Chi Ying , Salleh Mohd Arif Anuar Mohd , Saud Norainiza
Published: November 2020

The Restriction of Hazardous Substances (RoHS) has been enforced a law to restrict the use of hazardous materials in electronic and electrical industries. Hence, it leads to the development of lead-free solder among the electronic industry. SnAg, SnCu, SnAgCu, and SnZnBi solders are found to be alternatives to replace SnPb solder alloys. However, they still have many problems, such as large undercooling and large intermetallic compounds are still present in the solder alloys. Later, researchers come up with the idea of adding alloying elements to lead-free solders to further enhance the properties of lead-free solders. This review paper is aimed to analyze and summaries the effects of germanium (Ge) addition to lead-free solders focusing on its microstructure and thermal properties. The Ge has an almost similar crystal structure as pure tin (Sn), so it is expected that the properties of the lead-free solder could be enhanced by adding an appropriate amount of Ge. Nevertheless, Ge has a unique characteristic as it could act as an antioxidant agent in the lead-free solders.
Impact of Thermal Ageing and Multiple Reflow on Lead Free Composite Solder : A Short Review
Authors: Zaimi Nur Syahirah Mohamad , Salleh Mohd Arif Anuar Mohd , Abdullah Mohd Mustafa Al Bakri , Mostapha Marliza , Ahmad Romisuhani
Published: November 2020

This paper reviews the impact of the thermal ageing and multiple reflow to the intermetallic compound (IMC) layer and mechanical performance of lead free solder reinforced with various reinforcements. Based on available literatures it had been proved that, the IMC layer and mechanical properties can be affected with the exposure of different temperatures and time. Besides that, the incorporation of the reinforcement in the matrix of solder alloys could improve the thickness of IMC layer and strength of the solder joints although it had been subjected to thermal ageing and multiple reflow cycles as compared to unreinforced solder. Therefore, the composite solder system could be possibly applied and adapted in current electronic devices even with the exposure of high temperatures.
Influence of squeegee impact on stencil printing process: CFD approach
Authors: Ishak M.H.H. , Abdul Aziz M.S. , Abdul Samad M.H.S. , Ismail Farzad , Mohd Salleh M.A.A
Published: November 2020

This work has been conducted to predict the real time observation of solder paste Sn96.5Ag3.0Cu0.5 (SAC305) filling process into stencil apertures as well as print quality in stencil printing by using Computational Fluid Dynamics (CFD) approach. A 3-Dimensional stencil printing model was developed and simulated in FLUENT by using different squeegee parameters which are the angle and printing speed. An experimental work was performed to be compared with part of the simulation results in term of print quality for validation purpose. It is found that squeegee angle 60° to 80° has potential to obtain good print quality of solder paste. In addition, print speed range between 35 mm/s to 95 mm/s also can be the good print speed option to achieve good print quality in stencil printing process. Finally, the maximum pressure distribution of solder paste also changes substantially as the squeegee travel further with respect to different values of tested parameters.
Development of Integrated Solar Water Heater Using Phase Change Material
Authors: Munusamy Yamuna , Seng Ong Kok
Published: November 2020

Main barriers for installation of conventional solar water heating system (SWHS) are requirement of large installation area and heavy weight of the heat storage tank consisting water. A storage tank with minimum capacity of 230 liters are needed for household usage and this tank when empty can weigh up to 100 kg while a filled tank could weigh up to 400 kg. In reality, installation of this conventional system require more space and heavy structural support on the roof, which is not available in most houses. As a solution, a form stable light harvesting phase change material (FSLHPCM) integrated compact system is proposed. This new SWHS consists of glass – topped collector cum storage tank filled with FSLHPCM. This new FSLHPCM is form stable, does not leak and exhibit stable latent heat when tested to 1000 thermal cycles. It is capable to not only store heat but can improve the collector efficiency by harvesting the visible light and converting it to heat. The additional light to heat conversion efficiency was 22%. In the new system a maximum 75 liters’ glass-topped collector tank is sufficient to substitute a 230-liter tank. This will reduce installation, renovation and maintenance costs for the SWHS.
Mechanical performance and thermal behaviour of Carrageenan Gel with Lavender Essential Oil
Authors: Mat Amin Khairul Anuar , Abdul Hadi Taqiah
Published: November 2020

This study determines the mechanical performance and thermal behaviour of carrageenan (CR) gel with lavender essential oils (LEO). The CR gel was produced via crosslink with calcium ion followed by inclusion of LEO at different concentrations. The compressive strain of CR gel was increased upon addition of LEO could be due to formation of micelles in the gel matrix and therefore restrain the strain and improved the flexibility of the gels. In contrast, the compressive stress of the CR-LEO gels was decreased than CR gels. The water vapour transmission rates (WVTRs) of the CR-LEO2 gel were improved and assumed due to micelles formation and allowed water diffused through the gel’s matrix. The thermal behaviour of CR-LEO gels was improved with reducing weight loss (%) of the gel with higher concentration of LEO. CR gel shows weight loss at 91%, and CR-LEO3 gel shows the weight loss at 76%. In conclusion, the inclusion of LEO has shown promising results in tailoring the mechanical performances and thermal activity and can be applied as biomaterials for pharmaceutical applications.