bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance Evaluation of Absorber Rod Type Solar Air Collector
Authors: Saberi Zainab , Fudholi Ahmad , Ibarahim Zahari , Sopian Kamaruzzaman 
Published: July 2019

Abstract
Solar air collector is a device that collects heat energy from the sun where the solar energy is converted to heat energy. A good solar air collector is when it can absorb maximum heat and can reduce as minimum as heat loss possible. In this study, a solar air collector device has been designed and constructed by attaching aluminium rod of 210 pieces with height 2 cm on the absorber plate to increase the heat transfer surface area. Apart from that, fin also built in airway to increase transfer of heat from plate absorber to air flow. There are 4 parameter of intensities value and mass flow rate is changed in this experiment which are 101.5 W/m2, 302.4 W/m2, 530.6 W/m2 and 720.0 W/m2 while for the mass flow rate is 0.0236 kg/s, 0.0340 kg/s, 0.0452 kg/s and 0.0584 kg/s. The aim of this study was to investigate the effect of mass flow rate and the solar intensity in improving the efficiency of thermal solar collectors. The results showed that the efficiency is between 57.2% to 77.4%. Maximum thermal efficiency mass flow rate recorded at 0.0584 kg/s with radiation intensity of 530.6 W/m2. Changes in temperature, ΔT are decreased when mass flow rate is increased which 19.0°C to 1.2°C is depending on the solar radiation intensity.
Potential Evaluation of Wind Energy in Kuala Terengganu, Malaysia through Weibull Distribution Method
Authors: Saberi Zainab , Fudholi Ahmad , Sopian Kamaruzzaman 
Published: July 2019

Abstract
Malaysia faces many challenges in the development of wind energy as it is located in areas with slower wind speeds. Malaysia is located on the equator line where land and sea breezes can affect the wind regime. The wind does not blow uniformly and fluctuate by month and area. Therefore, the objective of this study is to determine the potential of the latest wind power in Kuala Terengganu. The scope of the study was not comprehensive because it focused only on Kuala Terengganu, Malaysia which is located at latitude 5° 23′ N and longitude 103° 06′ E. The wind data used in this study was obtained from the Malaysian Meteorological Department. The wind data that had been observed and collected was the wind direction and wind speed for year 2017 where the height of the sea level is 5.2 meters. This study uses the Weibull Distribution method as it shows a good consideration to estimate the density of wind power in Malaysia [1] The daily wind speed pattern for year 2017 can be seen that it has a corresponding pattern where it shows high wind speed at the beginning and end of the year. The wind speed frequency is also variable for the winds of the Northeast Monsoon and is almost constant during the south monsoon of the Southwest Monsoon and the Transition Monsoon. Overall, the potential of wind power in Kuala Terengganu is not too large. The annual average for 2017 is 2.01 m/s only. Wind power is high during the Northeast Wind Monsoon season.
Investigation of TiO2 and MWCNT Nanofluids-based Photovoltaic-Thermal (PV/T) System
Authors: Binti Rukman Nurul Shahirah , Fudholi Ahmad , Mohd Razali Nur Farhana , Hafidz Ruslan Mohd , Sopian Kamaruzzaman 
Published: July 2019

Abstract
Nanofluids as a new generation of cooling fluid has been found in recent years to improve the heat-transfer coefficient and enhance the system performance. This study presents investigation conducted on the performances of TiO2 and MWCNT nanofluids-based PVT systems. The preparation of nanofluids using two step method and dispersing of surfactant for a stable nanofluid. The experimental investigation with the effect of different concentration, mass flow rate (0.012 kg/s to 0.0255 kg/s) and solar radiation (500 W/m2 to 900 W/m2) on the performance of nanofluids-based PVT system is presented. The lowest temperature of the PV module and highest fluid’s change of temperature were recorded when the collector uses TiO2 fluid 1.0 wt% which is 2.01°C and 1.80°C.
Valorising fermentation effluent rich in short-chain fatty acids and sugars for biohydrogen via photofermentation by Rhodobacter sphaeroides KKU-PS1
Authors: Fitri Hanipa Muhammad Alif , Mohamed Abdul Peer , Md Jahim Jamaliah , Sobri Takriff Mohd , Reungsang Alissara 
Published: July 2019

Abstract
Growing fermentative chemical production will increase effluents from industrial fermentations containing short-chain fatty acids and residual sugars, which are exploitable for biohydrogen through photofermentation. Previous studies have concentrated on single substrates and photofermentation study using fermentation effluent from bio-succinate production containing residual sugars and short-chain organic acids has yet to be reported to the best of authors’ knowledge. Rhodobacter sphaeroides KKU-PS1 grown on succinate was used for hydrogen production from medium containing mixture of substrates mimicking final effluent from bio-based succinate production. Prior to that, hydrogen producibility test with succinate-only medium was carried out. Photofermentation from succinate by this strain yielded 1217 ml H2/l of maximum cumulative hydrogen with maximum hydrogen rate of 6.7 ml H2/l/h, comparable to malate which was previously reported as best single substrate for the strain. Hydrogen production profiles using mixed substrates was well-fitted by modified Gompertz model with maximum cumulative hydrogen and maximum hydrogen production rate of 1005 ml H2/l and 4.1 ml H2/l/h, respectively. Only glucose, xylose and succinate followed modified Gompertz model for substrate consumption. Instantaneous succinate consumption compared to extended lag time of 100h for consumption of both sugars indicated higher affinity towards short-chain fatty acid utilization during initial growth phase. Xylose showed highest overall substrate consumption signifying its importance for hydrogen generation, which continued after stationary growth phase started reaching a total of 91.9% consumption. Significant remaining substrate levels other than xylose suggested that the process was not inhibited by limited substrates. The study highlighted potential of fermentation effluents containing mixed substrates for biohydrogen, with further optimization needed.
Synthesis, Characterisation and Catalytic Activity of NiO supported Al2O3 for CO2 Hydrogenation to Carboxylic Acids: Influence of Catalyst Structure
Authors: Hasan S Z , Ahmad K N , Isahak W N R W , Pudukudy M , Masdar M S , Jahim J M 
Published: July 2019

Abstract
Utilisation and conversion of carbon dioxide into valuable chemicals and fuels are the promising ways to reduce carbon dioxide concentration in the atmosphere. In addition, the conversion of carbon dioxide into fuels, such as methane, methanol and formic acid has been proven a good method for hydrogen storage. In this work, the catalyst structure plays an important role in the production of formic acid and acetic acid at low temperature. Nickel oxide supported alumina catalysts were synthesised by using the solid-state fusion method at 550 °C and 700 °C. Calcined catalysts were characterised by X-ray diffraction, Brunauer-Emmett-Teller surface area, high-resolution field emission scanning electron microscopy, Auger electron spectroscopy with X-ray photoelectron spectrometer and transmission electron microscopy. Carbon dioxide hydrogenation was performed in the batch reactor. The products obtained were analysed by using high-performance liquid chromatography and gas chromatography with a thermal conductivity detector. The highest levels of formic acid and acetic acid production were 4.08 and 1.58 mmol/L, respectively.
Development of a Reduced Biodiesel Surrogate Fuel Model for Multi-Dimensional Computational Fluid Dynamic Simulations
Authors: Poon H M , Ng H K , Gan S , Chong W T 
Published: July 2019

Abstract
This work reports the development of a reduced biodiesel surrogate fuel model for multi-dimensional Computational Fluid Dynamic simulations. The model is derived using an integrated kinetic mechanism reduction scheme and the final chemistry comprises only 83 species. The model is well validated in zero-dimensional chemical kinetic calculations under a wide range of auto-ignition and jet-stirred reactor conditions. The fidelity of the model is also further assessed in two-dimensional simulations of a constant-volume combustion vessel with respect to the experimental results of soy-methyl ester combustion. The results obtained reveal that ignition delay, lift-off lengths and soot volume fractions are reasonably well replicated by the reduced model. Furthermore, the compositions of the reduced model are varied according to the saturation/unsaturation levels of various biodiesel feed-stocks, such as palm-methyl ester and sunflower-methyl ester. In this work, it is demonstrated that the reduced model can potentially be used as a universal surrogate fuel model to predict the reactivity of biodiesel feed-stocks with low degree of saturation (≤30%) in both kinetic and fuel spray simulations.
Synthesis of Solid Catalyst from Palm Empty Fruit Bunch for Production of Biodiesel through Esterification
Authors: Kam Huei Wong , Lim Steven , Yean Ling Pang , Chin Yi Yap 
Published: July 2019

Abstract
Application of solid acid catalyst in biodiesel production gains much attention from researchers as it is suitable for most of the non-edible and low value oils which will significantly cut down the total production cost and reduce corrosion issue. In this research, biomass from palm empty fruit bunch is used as the carbon precursor to synthesis activated carbon (AC) before sulfonated by 4-benzenediazonium sulfonate (4-BDS) to produce solid acid catalyst. The synthesized catalysts were characterized and the performances were tested in esterification of palm fatty acid distillate (PFAD) to produce biodiesel. Scanning Electron Microscope (SEM) showed that a clear porous and rough surface was developed after calcination at relative low temperature (200 ° C) which favors the attachment of the acid active site. It also found that that the total acid sites of the catalyst increased when sulfanilic acid loading increased during sulfonation. In catalytic activity test, the result showed that catalyst calcined at 200 ° C and catalyst sulfonated with 15:1 sulfanilic acid to AC ratio was the optimum catalyst as they gave the highest biodiesel yield at 73.14%.
Thermal Insulation Properties of Organic and Inorganic Material in Clay Brick - A Review
Authors: Nazira Ab. Karim Nur Fatin , Nabilah Sarbini Noor , Abdul Shukor Lim Nor Hasanah , Syahrizal Ibrahim Izni , Aminuddin Eeydzah , Rosseira Abu Talib Adrina 
Published: July 2019

Abstract
Pore forming agent is widely used in clay brick making process whether originally organics or inorganics materials which can improve thermal insulation facing global warming issue. Many researchers trigged to discover the thermal insulation materials since the past decade due to responsibility to develop a comfort living demand for heating or cooling. This paper review on different types of thermal inorganic and organic insulation materials added into a clay brick to improve the thermal insulation properties. The scope of these reviews lies to the materials of; paper residue, rice husk, rice husk ash, olive stone flour, wheat straw, perlite, cigarette butt, vermiculite, waste marble powder and waste glass sludge. The discussions are made based on the properties of organic and inorganic materials used in improving the thermal insulation in clay brick. Hence, a throughout review of the composition and properties of brick and various factor related to manufacturing process is highly required for better standardization of clay bricks. A better understanding of different wastes incorporating clay brick utilize of various mining and industrial as well as achieving the goal of sustainable development.
Multi-objective Design of a Biomass-based Polygeneration for Iron and Steel Manufacturing
Authors: Ubando A T , Chen W H 
Published: July 2019

Abstract
Iron and steel manufacturing is considered a major contributor to the global carbon emission and energy-intensive industry. To sustainably produce iron and steel, various approaches have been explored to generate the needed power to support the production while mitigating the carbon dioxide emission. One of the viable approaches is the integration of a biomass-polygeneration system to produce biochar and other energy streams needed by the iron and steel manufacturing plant. A polygeneration system is composed of a combination of various existing technologies which seeks to recover wasted energy and to reuse by-products through process integration, thus, improving the overall thermodynamic efficiency of the system. In designing such complex systems, multiple objectives should be considered to assimilate the real-life requirements of the system. However, recent studies on the design of polygeneration system for iron and steel industry used a single-objective approached which may not consider the trade-offs between multi-objectives. Hence, this study proposes to design a biomass-based polygeneration system using a multi-objective approach employing fuzzy linear programming (FLP) model. The FLP model allows partial satisfaction of multi-objectives through the use of linear membership functions. A case study is presented involving biochar production from torrefaction, pyrolysis, and gasification together with power and heat production. The results indicate the optimal polygeneration process network consisting of a gas turbine for the generation of power, a heat recovery steam generator attached to the gas turbine for the heat generation, a gasifier for syngas, and torrefaction for biochar production. The developed model aims to aid engineers and managers in cost-effectively integrating a biomass-based polygeneration system in iron manufacturing.
Study of transient conjugate heat transfer in helical closed-loop geothermal heat exchangers for application of thermal energy storage in backfilled mine stopes
Authors: Templeton JD , Ghoreishi-Madiseh SA , Hassani FP , Sasmito AP , Kurnia JC 
Published: July 2019

Abstract
The geothermal potential available from deep underground mines has yet to be utilized. However, stope coupled heat exchangers (SCHE) are aiming to take advantage of the unused low-grade geothermal energy. Backfilled stopes provide a unique opportunity to install non-linear heat exchangers, as the geometry is not limited to the shape of a borehole. Helical pipes deliver superior fluid mixing and heat exchange compared to straight pipes, due to the effect of the secondary flow within the helical pipe. The helical closed-loop geothermal heat exchanger enables the backfilled stopes of the mine to be repurposed as thermal energy storage units. This paper delves into the experimental results from a laboratory scale helical closed-loop heat exchanger with varying thermo-physical parameters. Additionally, a conjugate numerical model is developed and its results are validated against the base case of the experimental studies. The results of the numerical model suggest that the pumping rate through the SCHE has a significant effect on the heat exchange rate and the overall energy transfer between the SCHE and the backfill.
Energy and Exergy Analysis of Steam Power Plant in Paiton, Indonesia
Authors: Rudiyanto Bayu , Kusuma Wardani Tri Ajeng , Anwar Saiful , Al Jamali Lutfi , Prasetyo Totok , Mukti Wibowo Kukuh , Agung Pambudi Nugroho , Huat Saw Lip 
Published: July 2019

Abstract
The exergy analysis of steam power plant system in PT. Jawa Power-YTL, East Java unit 5 was performed based on the first and second law of thermodynamics. Exergy flow and exergy efficiency were calculated for each component of the plant i.e. the boiler, HTP, IPT, LPT, deaerator, condenser, HPH, LPH, CEP and FWP. The exergy steam-flow of 970288 kW produced 610.000 kW of electricity with an exergy efficiency of 26.36%. Sankey diagram showed the exergy loss on each component of the steam power plant. The irreversibility of the boiler, condenser, turbine, LPH, HPH, pump and daerator were 1677003 kW (17,28 %), 738122 kW (7,61 %), 152894 kW (1,58 %), 111881 kW (1,15 %), 470520 kW (4,85 %), 193494 kW (1,99 %) and 1081771 kW (11,15 %), respectively. The total exergy that could be converted into electrical energy in the system was 5276259 kW (54,39%). The highest irreversibility was in the boiler with 1677003 kW (17,28%). The optimization result showed that the highest efficiency was 94.04% at an output pressure of 41 bar.
Possibility of Using Stirling Engine as Waste Heat Recovery – Preliminary Concept
Authors: Saadon S. 
Published: July 2019

Abstract
Growing consumption of primary fossil fuels and massive discharge of pollutants are some of the results caused by the world’s growing population, and eventually the enlarging energy demand. It is therefore the main concerns that the developing world must face nowadays are the energy shortfall and the environmental destruction. And for these valid reasons the awareness of reusing the low-grade heat has captivated researchers in recent years. Due to its unique features, Stirling engines, is a powerful candidate to recover the waste heat by converting it into power. However, Stirling engine shows a drastic performance penalization if connected with lower temperature heat sources and therefore research has to be done to increase the performance of the heat transfer in the Stirling engine. Exhaustive research has been done by many investigators to enhance the heat transfer characteristics inside the tube heat exchangers. However, the areas related to outer tube geometries with different materials and different fins attachment have not yet been explored and this part is the important factor for an external combustion engine to enhance the heat transfer. Thus, the development of Stirling engine as waste heat recovery needs to focus on identification of heat transfer enhancement methods that can be applied at the outer part of tubular heater in order to achieve an optimum performance of the engine. Starting from a comprehensive review of Stirling engine, this paper presented a rigorous derivation of a novel waste heat recovery system using Stirling engine with large power that can benefit the environment and in line with national GTMP. Such result will be very useful in the preliminary design of a waste heat recovery system using Stirling engine and can be used in the estimation of power output for many applications.
Winterization of biodiesel through progressive freezing for cold flow properties improvement
Authors: Yee Min Hoo , Aini Amran Nurul , Samsuri Shafirah 
Published: July 2019

Abstract
In cold environment, pure biodiesel cannot be used directly as an alternative fuel as it crystalizes easily at low temperature due to its saturated fatty acid (SFA) content. Thus, the winterization method is used to reduce the SFA content that gives high melting point to biodiesel. However, the conventional winterization method was reported to be complicated and ineffective in separating the liquid and solid content formed. Progressive freezing (PF) is introduced to improve the separation efficiency in the winterization process by removing the solid SFA layer formed on the wall of the crystallizer without the use of complicated equipment. In this study, the initial value of cloud point (CP) and pour point (PP) of the biodiesel were measured and compared with the values obtained after the PF process. The effect of coolant temperature, freezing time and stirring rate towards the efficiency of the PF process were also determined. The obtained results showed that the best performance of winterization was observed at coolant temperature of 6 °C, freezing time of 20 minutes and stirring rate of 50 rpm. At this condition, the recovery of biodiesel is 65.46% while CP, PP and SFA content were reduced by 2.65 %, 14.29 % and 3.96%, respectively.
Power Output Prediction for LM Wind Turbine Blade using Blade Element Momentum Theory and GH Bladed Software
Authors: Augusto G , Culaba A , Chen W 
Published: July 2019

Abstract
The blade element momentum theory with Prandtl’s tip loss and Glauert’s correction factors was utilized to compute the power coefficient and to predict the power output of LM rotor blade as a function of hub wind speed ranging from 3 m/s to 25 m/s. The blade length is 43.8 m and consists of five (5) different airfoils. The design tip speed ratio is 8.65 suitable for Class IIA wind turbine which can generate a capacity of 2.5 MW at rated speed of 16 rpm using permanent magnet direct-drive wind turbine generator. The thrust force and driving force profiles in terms of dimensionless blade length as well as the power coefficient and predicted power output were examined and compared with the theoretical equations derived from GH Bladed. Numerical results indicate that there are some degrees of similarities with GH Bladed software output having a maximum power coefficient of 0.49.
Integration of Maceration and Freeze Concentration for Recovery of Vitamin C from Orange Peel Waste
Authors: Abdurrahman Isa Abdulmajeed , Samsuri Shafirah , Aini Amran Nurul 
Published: July 2019

Abstract
Vitamin C (L-ascorbic acid) is found in orange which provides health benefits to a human body. Orange peel is considered as a waste and dumping the peel can be avoided by extracting it to get valuable compound such as vitamin C. However, none of the vitamin C presents in orange peel has been utilized. Thus, integration of maceration and progressive freeze concentration (PFC) for recovery of vitamin C from orange peel was studied. Maceration is a conventional extraction technique that mostly used for obtaining compound extracts from plant and PFC is currently become attention for concentration process. For this purpose, different operating conditions for maceration and PFC were evaluated with regard to vitamin C recovery. The operating conditions that were analysed are drying temperature (30 to 45 °C), coolant temperature (-10 to -16 °C), cooling time (20 to 35 minutes) and stirring rate (200 to 800 rpm). Titration was done to analyse and correlate the increase of vitamin C in a concentrated solution for different operating conditions. Highest recovery was found at 35 °C of drying temperature, -12 °C of coolant temperature, 20 minutes of cooling time and 400 rpm of stirring rate. The highest value of recovery was found to be 72.06 %. Integrating both maceration and PFC methods add value to the orange peel waste and provide solution for environmental problems.
Numerical modelling of the power pack system for remote islands electrification
Authors: Saw LH , Cheow JS , King YJ , Yeo WH , Lim BH , Tey JY , Ng TC 
Published: July 2019

Abstract
Electricity is one of the indispensable elements in the daily life. From domestic to commercial sector, electricity has been used to provide a wide range of applications. However, access to electricity is only limited to the urban area while rural area electrification is always a challenge due to the geographical location and high cost of the electrification infrastructure. Therefore, electrification using solar energy is projected to be one of the feasible solutions in the rural area. A typical power pack system used for the rural area electrification consists of solar panels, voltage converters and battery pack. Although lead acid battery provides an economic solution for the energy storage system, they are also associated with other disadvantages such as low depth of discharge, bulky and low energy density. Li-ion battery is a new generation of battery technology with high energy density, light weight and high depth of discharge which offer a promising solution for an off grid power systems. In this study, an off grid power pack consists of Li-ion batteries, voltage converters and photovoltaic modules are modelled to evaluate the electrical performances of the system under Malaysia weather conditions. Then, the numerical modelling results are compared with experiments. It is found out that the numerical model correlated well with the experimental data with a relative error less than 5%.