bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical investigation on the performance of a honeycomb-shaped channel
Authors: Yang Xi , Guo Qiang , Zhang Liyu , Liu Xing , Lu Zhao , Meng Xiangzhao , Jin Liwen 
Published: July 2019

Abstract
A certain number of researches have been implemented on the fluid flow and heat transfer in fractal-like channels for their excellent heat transfer performance, which can be attributed to the effects of the bifurcations causing diffluence flow and confluence flow on thinning thermal boundary layer and inducing secondary flow. In this paper, the three-dimensional numerical models of the honeycomb-shaped minichannels were established to research the effects of branching angles on the hydrodynamic and thermal characteristics in the case of laminar flow. A comparative study was carried out to evaluate the performance of the current structures with the straight minichannel based on approximately the same hydraulic diameter, heat flux density and convective heat transfer area. In the simulation results the superiority of overall performance of the honeycomb-shaped minichannels over the straight minichannel was discovered. In addition, the studies showed that the honeycomb-shaped minichannel with smaller branching angle attained the higher overall performance within the relatively high Reynolds number range. It was found that the honeycomb-shaped minichannel with branching angle of 60° yields the best overall performance at the Reynolds number of 400.
Analysis of the human health damage and ecosystem quality impact of the palm oil plantation using the life cycle assessment approach
Authors: Obaideen Khaled , Chai Tan Yong , Seng Yap Pow , Awang Muhamad , Abd Ghani Abdul Azim , Subramaniam Vijaya , Cent Tai Vin 
Published: July 2019

Abstract
In recent years the palm oil has been criticized because of its impacts on the environment and human health. Therefore, this study focused on the investigation of human health and ecosystem quality impacts that arose from the plantation of fresh fruit bunch of palm oil by employing an open-source software, namely OpenLCA version 1.5. The life cycle assessment approach was used for the analysis of the investigated impacts. The effects of land use changes on the human health and ecosystem quality were assessed. By employing ReCiPe Endpoint methodology in life cycle impact assessment phase the total ecosystems impact 0.00017 species per year while total human health damage was 0.00146 DALY The results showed that the land use change has an impact on all the impacts categories except the freshwater eutrophication, freshwater ecotoxicity, ozone depletion, terrestrial ecotoxicity, and terrestrial acidification. In addition, the analysis showed that the application of the fertilizers and pesticides were the main contributor in all the impact categories. The results show that transportation is not the major contributor in any one of the impact categories
Effect of Different Carbon Additives on Hydrogen Storage Properties of AZ31 Magnesium Alloy by High Energy Ball Milling and Equal Channel Angular Pressing
Authors: Huang SJ , Rajagopal V , Chen YL 
Published: July 2019

Abstract
This study investigated the effect of carbon additives on the hydrogen storage performance of AZ31 Magnesium alloy. Different weight percentages (0 wt.%, 3 wt.%,) of activated carbon (AC), carbon black (CB)and graphene (G) were used as catalyst to explore the effect of different carbon material additives on the hydrogen storage performance. In addition, the effect of employing different processes like High energy ball milling and Equal channel angular pressing on hydrogen storage performance was also examined. AZ31 magnesium-based composites with different carbon materials were prepared through stir casting method. Micrographs were recorded through OM (optical microscope) and SEM (scanning electron microscope with EDS). The average particle size of the prepared powder samples was measured using particle analyzer. The hydrogenation kinetics was measured using Sievert’s type apparatus. It was found that the addition of carbon materials and refined microstructures effectively enhanced the hydrogen storage performance of AZ31 Mg-alloy. In High energy ball millingprocess AZ31-3G (graphene) reaches the maximum storing capacity of 6.83±0.04 wt.% within 792±144.34 seconds and desorbed the entire hydrogen in 143 seconds. And in the case of ECAP process, the alloy AZ31-3CB (carbon black) reaches the hydrogen storage capacity of 6.72±0.05 wt.%.
An Urban Based Smart IOT Farming System
Authors: Mungai Bryan Njoroge , Fei Thang Ka , Vinesh Thiruchelvam 
Published: July 2019

Abstract
Recent technological developments have led to the emergence of new trends in agriculture to ensure increased production through sustainable utilization of resources. One of the new trends is Precision Agriculture (PA). However, like many new emerging trends, PA is faced with a number of uncertainties and hurdles. One of the major issues and hurdles in precision agriculture is the uncertainty of optimum application of resources necessary for optimum yield production while minimizing resource wastage for sustainable agricultural production. Therefore, this paper presents a fuzzy based Decision Support System (DSS) to intelligently allocate water and fertilizer used in crop production based on the age of the plant and data collected from the soil and surrounding environment with the aid of a network of sensors. An embedded hardware system consisting of a Cartesian robot has also been implemented to ensure effective application of the fuzzy derived decisions. Two Fuzzy Inference Systems (FIS) consisting of linear, non-linear Membership Functions and a 149-rule base for the PA system have been developed in MATLAB, implemented using Arduino microcontrollers and tested on spinach plants whereby results show that the linear FIS is able to achieve more accurate results in terms of the quality of yield realized and resource utilllisation. Resource utilllisation comparison with other systems in literature reviewed is also done whereby the DSS is able to save up to 2031 ml and 524 ml of water and fertilizer respectively.
Digital Light Processing 3-Dimensional Printer to Manufacture Electrolyzer Bipolar Plate
Authors: Husaini Teuku , Kishida Ryuhe , Affiqah Arzaee Nurul 
Published: July 2019

Abstract
Bipolar plate is one of the largest and most important components in Polymer Electrolyte Membrane Electrolyzer and Fuel Cell that functions as a cell separator, electrical and heat conductor, reactant feed distributor, for the flow of gas-liquid mixture and supporting components for the Membrane Electrode Assembly. In general, injection, compression moulding or Computer Numerical Control-machines are commonly used to produce bipolar plate. These methods, however, cannot be used to produce complex 3-dimensional shapes, such as vertically inverted cone shape or creating a channel inside the plate. By using a 3-dimensional printing machine with laser-based stereolithography or digital light processing, complex design problems and problems in making channels in the plate can be solved easily. In this study, polymer-based bipolar plate was developed using 3-dimensional printing technology which was made conductive by introducing nickel and gold layers through spray coating and electrocoating processes. The nickel layer was optimized by controlling the applied voltage during electrocoating. Since low voltage formed very thin layer whereas high voltage caused “burning” of the sample, applied voltage of 5V was found to be the optimum condition. Employment of gold layer increases the conductivity from 300 S cm−1 to 400 S cm−1 which enabled the corrosion current density to drop to 0.470 uA cm−2, meeting the standard set by US Department of Energy. The porosity test also proved that the bipolar plate was impermeable to hydrogen gas. Therefore, this manufacturing method has great potential to be used for the production of sophisticated electrolyzer cell or fuel cell in the future.
Human Interaction Theory for Sustainable City
Authors: Illia Ibrahim Filzani , Diyana Nizarudin Norhanis 
Published: July 2019

Abstract
In relation to open spaces, Malaysia has received very little attention from researchers, unlike other countries where many studies have explored how human needs are fulfilled by urban open spaces. It is strongly believed that aspects such as the amount of urban open spaces per inhabitant, public parks and recreational areas are often mentioned as vital factors to make the city livable, pleasant and attractive for its citizens. This paper is undertaken to fill the knowledge gap of how human interacts in the urban open spaces that will then be developed as among the indicators for city sustainability. The objectives of this paper are to identify the human-nature and human-human interactions, at the same time identify the perceived benefits from physical, social and natural interactions towards open spaces. The expected outcome of this study is, it will help to emphasize the importance of citizen participation towards the open spaces and how it affects the level of sustainability. Furthermore, it will help in improving urban planning strategies and policy decision for the sustainability of the city.
Space optimization of concentrator photovoltaic systems based on levelized cost of electricity in solar power plant
Authors: Oon Li-Voon , Tan Ming-Hui , Wong Chee-Woon , Yew Tiong-Keat , Chong Kok-Keong , Tan Woei-Chong , Lim Boon-Han 
Published: July 2019

Abstract
Inappropriate layout design of concentrator photovoltaic (CPV) systems in the solar field will incur optical losses due to mutual shadowing among adjacent CPV systems. This will deteriorate the energy generation of a solar power plant (SPP). The trivial solution is to increase the separating distance between adjacent CPV systems. Unfortunately, it causes ineffectiveness in land usage and will be reflected to an increase in land-related costs. Therefore, optimization of layout design is an important procedure to determine the best trade-off between land usage and energy generation. The levelized cost of electricity (LCOE) of the SPP must be competitive to attract the interest of investors venturing into the solar energy business. A new computational algorithm has been proposed to optimized the field layout system of the CPV system by using the local weather data with the consideration of the shadowing effect. In this paper, a case study has been conducted in Kota Kinabalu, Malaysia to evaluate the performance of CPV systems in the SPP with different D/L ratios. The simulated results show that the optimized field layout for the CPV systems is at D/L ratio of 2.25, which accommodate the lowest value of LCOE.
A computational analysis of construction – operation – environment cost of real estate development projects
Authors: H A Tran Tuan 
Published: July 2019

Abstract
Similar to many highly populated cities in South East Asia, Ho Chi Minh City (HCMC) is the largest city of Vietnam acting as the economic driver for the whole country. Its urban life attractions and economic opportunities have drawn people across the country and the region, resulting in a high demand of housing. HCMC becomes a hot spot for many local and foreign real estate investors and developers. Many property development projects in HCMC have been rapidly increasing in recent years. However, many real estate developers usually pay more attention on profit-related criteria while neglecting sustainable aspects, partly due to lack of knowledge and an appropriate tool. A construction - operation – environment cost analysis workflow based on an urban simulation tool coupled with other scripting and modelling tools is proposed to quantify environmental cost and operational cost besides construction cost for a real estate development project in HCMC. Three alternative design scenarios are derived from a baseline at the early stage of design process originally provided by a developer. Computational analysis from these scenarios on construction cost in comparison to operational and environmental cost provides more information to the investment decision making process allowing the developer not only to meet their investment return expectation but also to take environmental impact and residents’ expense during the project’s life cycle.
An Innovative Autoclaved Aerated Concrete (AAC) with Recycled AAC Powder for Low Carbon Construction
Authors: Rafiza AR , Chan HY , Thongtha A , Jettipattaranat W , Lim KL 
Published: July 2019

Abstract
Recycling of materials, in particularly concrete was not frequently practiced in construction and moreover no study has been carried out yet. Furthermore, the environmental impact of recycling in construction was not known and no study has been carried out, thus now it leads to give an abundance of wasted concrete at site. Autoclaved aerated concrete (AAC) is one of the lightweight concretes that commonly used in construction. AAC is relatively light in weight, having lower thermal conductivity, higher heat resistance, lower shrinkage, and faster in construction process when compared to the conventional concretes. AAC consist of silica sand, cement, lime, water and expansion agent. To reduce the construction waste, an innovative AAC block has been developed by using recycled AAC in powder form to replace sands in the manufacturing process. The new developed AAC was conducted by replacing sand with recycled AAC in ratio of 0%, 15%, 20%, 25%, 30%, 45%, 40% and 45%. Microstructure analysis were conducted using optical microscopic and scanning electron microscopic (SEM) while the chemical analyses were conducted using X-ray diffraction (XRD). Mechanical tests such as density, compressive strength, flexural strength and water absorption also have been carried out. It could be observed that by replacing the sand content with recycled AAC, AAC with fine recycling powder content of 30% by weight has a compressive strength that is approximately 16.1% greater than conventional AAC and is between 30-110% higher than any value obtained by utilizing industrial waste product.
Optimization of Alkaline Pulp Extraction from Napier Grass Using Response Surface Methodology
Authors: Yong Kang Low , Ayu Haslija A.B 
Published: July 2019

Abstract
Napier grass which has several types of them has been studied by researchers for few applications such as biofuel, sugar and pulp production. This research focused on specific type of Napier grass which is the Dwarf Napier due to high cellulose content to produce pulp. Delignification of Dwarf Napier grass was carried out by soda anthraquinone pulping under varying conditions selected according to experimental design software with three factors. The influence of these three factors including concentration of sodium hydroxide (15%, 17.5% and 20%), concentration of anthraquinone (0.05% and 0.1%) and duration of cooking time (30, 60 and 90 min) on pulp yield was studied. 18 runs of experiment were conducted and the result obtained was used to analyse the optimized condition for pulp extraction by using RSM. Results indicated that the optimized response obtained while Napier grass stem is treated with 17.5% sodium hydroxide and 0.05% AQ with 66 mins of cooking time meanwhile the predicted yield is 34.87 %. However, the actual pulp yield obtained (36.38%) is higher than the predicted yield. The pulp which extracted with optimized condition is then bleached with hydroxide peroxide. Fourier transform infrared spectroscopy (FTIR) was used to characterize the raw grass fiber and pulp obtained. Napier grass is successfully demonstrated to be an effective alternative source for producing paper pulp. In the this study Dwarf Napier grass fibres were successfully pulped applying soda AQ process although the obtained pulp is not as high as the studied done before due to the limitations. FTIR analysis also confirmed the removal of lignin as well as most of the hemicellulose during the pulping process. Therefore, the abundance and fast growth of Napier grass are an added advantage as an alternative non-wood source for papermaking
Performance Evaluation of a Building Integrated PV (BIPV) at Heriot-Watt University Malaysia
Authors: Arnaout M. A. , Yun Ii Go 
Published: July 2019

Abstract
Building Integrated Photovoltaics (BIPV) is a promising technology that combines the generation of energy into the building structure where the modules act as building material or blend completely with architectural design. This study analyses the performance characteristics of a proposed BIPV system for Heriot-Watt University Malaysia building, the system is designed with aim to utilize the curved roof area of the building. The available roof area of 7725 m2 is curved with varying tilt angles from 1.5° to 26°. The environmental plugin Ladybug integrated within Grasshopper was used to visualize and estimate the energy potential from the roof surface in Rhinoceros 3D modeling software. Additionally, detailed system simulations are conducted with PVSyst software. Eight proposed system variants of different PV technologies and modules types are studied with capacities of 411.8 kW to 1085.6 kW. The recommended system has a size of 1085.5 kW and utilizes Thin-film CdTe PV modules. The system generates 1415 MWh annually with a performance ratio of 84.9%, which saves 62.8% of the electricity bill and has an estimated cost of 901 thousand USD. Installation of the proposed system should preserve the aesthetical value of the building’s roof and satisfy BIPV rules.
Screening the factors affecting torrefaction of palm kernel shell by using Plackett-Burman Design
Authors: Indum Panadda , Mueanmas Chokchai 
Published: July 2019

Abstract
Torrefaction is a thermochemical treatment for the production of solid fuel from biomass which promotes the increasing of fuel quality. This process involves the heating of lignocellulose at temperature range 200°C – 320 °C in the absence of oxygen. The decomposition of cellulose, hemicellulose and lignin depends on several parameters. This research aims to investigate the screening of factors affecting torrefaction of palm kernel shell (PKS) which is a waste from oil palm tree. A Plackett–Burman experimental design is applied for screening the influence of operation parameters such as temperature, time, oxygen feed ratio, heating rate and biomass size. Mass yield (MY), moisture content (MC), volatile matter (VM), fixed carbon content (FC), ash content (AC) and calorific value (CV) are analyzed as the response to evaluate the performance of torrefaction conditions. The significant parameters are selected based on the analysis of variance (ANOVA) results. The results show that the temperature, time, oxygen feed ratio and biomass size are significant parameters. The fuel properties of torrefied product were compared with the standard for solid fuel. These results show that the quality of torrefied PKS satistifies the standards. Therefore, the torrefaction process can be used as the potential technique for improve the quality of PKS fuel properties.
Assessment of the fuelwood value chain in Yobe, Nigeria
Authors: Ali B , Saadun N , Alias M A , Norizah K 
Published: July 2019

Abstract
This study aims to assess the characteristics of the fuelwood value chain in Yobe, Nigeria. Data were collected through state government records, direct observations, focus group discussions, and interviews with key informants using open-ended questionnaires. Results showed that the fuelwood value chain comprises five functions: harvesting, transporting, trading, retailing, and consumption. The analysis further revealed five sub-chains characterized by actors in which two sub-chains were classified as formal (registered with associations and functioning with licenses) and three were classified as informal (not registered with an association and functioning without license). The presence of informal actors in the value chain observed in this study is widespread due to weak governance, high fuelwood demand, and corruption. Consequently, their poor practices have added extra pressure on the forest and is threatening the environment, fuelwood availability, accessibility, and market. The intrusion of informal actors needs to be properly addressed by the government through measures that include an efficient and flexible licensing system, strict implementation of fuelwood regulations, active monitoring, increase of awareness on the benefits of licensing and operating as registered actors in an organized group on job security, profits, and the environment and improved supervision of the forest laws’ enforcement agents to curtail corruption.
Investigation on surface morphological and optical properties of black silicon fabricated by metal-assisted chemical etching with different etchant concentrations
Authors: Noor N A M , Pakhuruddin M Z 
Published: July 2019

Abstract
In this study, the surface morphological and optical properties of black silicon (b-Si) fabricated by two-step metal-assisted chemical etching (MACE) process are investigated. The two-step MACE combines low-temperature annealing of silver (Ag) thin film to produce Ag nanoparticles (NPs) and short etching duration of crystalline silicon (c-Si) wafer. The etching is carried out in HF:H2O2:DI H2O solution for 70 s with different etchant concentrations (represented in the form of volume ratio). The MACE process produces b-Si nanopores on the wafer. Compared with planar c-Si reference, broadband reflection (in 300-1100 nm wavelength region) of the b-Si is significantly lower. B-Si wafer with volume ratio of 1:5:10 exhibits the lowest broadband reflection of 3% at wavelength of 600 nm, which is believed to be due to refractive index grading which leads to enhanced light coupling into the b-Si wafer. The best b-Si wafer (with lowest reflection) shows 50 nm average pillar width and 300 nm height. The increased broadband light absorption results in the highest maximum potential short-circuit current density (Jsc(max)) of 40.9 mA/cm2. This represents 55.4% enhancement, if compared with the planar c-Si reference wafer, assuming unity carrier collection.
Generating Efficient Production Plans for Heater Manufacturing Industry
Authors: Kai Sin Chong , Tan Ching Ng , Lip Huat Saw 
Published: July 2019

Abstract
Nowadays, manufacturers in Malaysia as well as global have been facing challenges in order to overcome the uncertainty of demand fluctuations, supplier capability and achieved customer expectations and satisfaction. To increase competitiveness in global market, manufacturers from various aspects keep one’s eyes open on lean implementation and factory automation. This journal aims to develop an efficient production plans for heater manufacturing industry in order to achieve higher productivity and reduce wastes. With the traditional production line which had been implemented for years, several difficulties have been faced by company. For instance, abundance numbers of worker in production line which is not fully utilize and product quality is highly depends on skilled operators due to manual process. Smoothness index is used to determine the improvement of proposed production plan. Although minimization of smoothness index is essential in solving line balancing problem, this research has highlighted that researcher or company shall not rely on smoothness index alone while other aspect such as acceptable productivity and minimization of human resource should be considered.