bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rice husk ash (RHA) based geopolymer mortar incorporating sewage sludge ash (SSA)
Authors: Zaidahtulakmal M Z , Kartini K , Hamidah M S 
Published: December 2019

Abstract
Geopolymer based cementitious materials were produced to reduce or completely eliminate the use of cement in concrete in which could be incorporated with waste materials. In this study, rice husk ash (RHA) which is a waste having rich in silica content after burnt was intended to be used as based geopolymer. Besides, sewage sludge ash (SSA) was incorporated with RHA producing geopolymer mortar in which also having pozzolanic element of Si and Al. Geopolymerisation requires Si and Al elements to react with highly alkaline solution to produce geopolymeric material. Therefore, combination of RHA and SSA will be possible solution as base geopolymer mortar in order to provide Si and Al. The effect of SSA inclusion was investigated under different sodium hydroxide (NaOH) molarity and curing conditions to the strength development. NaOH and sodium silicate were used as activator with ratio of 1:1 and the solution to ashes ratio of 1:1 was used. Compressive strength was tested at 7, 14 and 28 days. The results showed that the geopolymer mortar made of SSA replacement exhibited higher compressive strength with reference to those made of RHA (control sample). In addition, the results showed that geopolymer mortar specimen containing 15% of SSA replacement activated with 8M NaOH solution gave the highest strength recorded 15.0MPa in oven curing condition (60°C for 24 hours). As conclusion, SSA up to 20% replacement has potential to be used in producing geopolymer as replacement alternative to RHA.
Eco-efficiency index analysis of single story structure of reinforced concrete house using economical and environmental score approach
Authors: Hamid M S A , Jasni O O , Shafiq N 
Published: December 2019

Abstract
Reinforced concrete structure is widely used in Malaysia as a common structural system of a building. As a common understanding, reinforced concrete is also known as a composite structure that combined two type of materials which is concrete and steel. Due to rapid development of residential houses, this situation was creating to higher energy consumption by producing high content embodied carbon emission Therefore, three main criteria should be considered in sustainable development that is economic, environment and social in order to produce better environment. This study was developed to produce eco-efficiency design of single story residential house for different optimization of concrete characteristic strength by using economical score and environmental score analysis method. Finding was recorded blast furnace slag reinforced concrete produce an eco-efficiency design than fly ash reinforced concrete due to positive impact to the economical and environmental criteria. Therefore, it can be concluding that waste materials need to be analyzed as an alternative material in concrete because it may produce high content of embodied carbon that give negative impact to the environment.
A Simulation Study Of Tubercles Effect Of Aerodynamics Performance On Car Rear Spoiler
Authors: Ghaffar H. , Yusoff H. , Ibrahim D. , Budin S. , Razak M.R.A. 
Published: December 2019

Abstract
The tubercle effect is a recently discovered phenomenon where the sinusoidal pattem ‘bumps’ on the leading edge of an airfoil can improve the aerodynamic performance. This effect was inspired by looking at the humpback whale pectoral flippers that give an exceptional acrobatic manoeuvrability in the water such as somersaults, also allowing for easier capture of prey. The objective of this research is to study the effect of implementing the tubercles concept on the car spoiler in order to see whether it bring advantage or disadvantage in the aerodynamic performance of a car. The design and simulation process are done by using Solidworks. The design of airfoil spoiler based on Selig S2091 (low Reynolds number airfoil) with sinusoidal pattern leading edge were computationally used. The Airfoil spoiler with 270 mm of the chord length (C), 1200 mm wingspan (L) and angles of attack of -5°, 0°, 5°, 10°, 15°, 20°, 25°, 30° were improvised with tubercles at 40 mm amplitude of bumps (h) and the distance of the wavelength between peaks (λ) of 1200 mm, 240 mm and 133.33 mm. The simulation was tested at 40 m/s. The investigation shown that the tubercles can improve the aerodynamic performance of car rear spoiler where the tubercles are able to increase the lift coefficient but has a significant decrease in drag only at 20° and above angle of attack.
Correlation between california bearing ratio (CBR) with plasticity index of marine stabilizes soil with cockle shell powder
Authors: Nujid M M , Idrus J , Azam N A , Tholibon D A , Jamaluddin D 
Published: December 2019

Abstract
Subgrade soil is important for design purpose of both flexible and rigid pavement structures; flexible and rigid. The quality of flexible and rigid pavement structures is correlated on the strength and stabilization of subgrade layers. The main function of subgrade is to act as a foundation for pavement layers and supporting the load which is transmitted from the overlying layers. The marine soil is a problematic soil which low in strength and do not suitable for road embankment for highway construction. Therefore, the soil strength can be improved by adding stabilizer or admixture to increase its strength. Soil stabilization change its physical and mechanical properties from its original soil. Thus, the physical properties of marine stabilized with cockle shell powder were determined and the potential of Cockle Shell Powder (CSP) as soil stabilizer based on percentage added in CBR test was investigated. Based on previous research, the performance of soil mixed with CSP in the proportion of constant 2.5%, 5%, 7.5% and 10% was examined with CSP properties and California Bearing Ratio (CBR) tests. The results obtained indicates an increment in specific gravity and decreasing in the plastic index (PI) with the addition of 2.5% of CSP. The CBR and PI show a good correlation and thus inclusion of CSP in marine soil could be used as alternative material for subgrade layer in increasing soil strength.
The waste heat recovery for power generation from automotive exhaust using thermoelectric cell (TEC)
Authors: Yaakob Y , Fahmi A , Ghafar H , Ibrahim D , Moria H 
Published: December 2019

Abstract
The internal combustion process to move the vehicles had indirectly releasing waste heat into the environment which contributed to global warming. Thermal-electric Cell (TEC) is a device that able to convert thermal energy to electrical energy cleanly. The TECs system work when it is sandwiched between the hot and cold side. The objective of this study is to investigate the possibility of tapping a waste heat using thermoelectric cell (TEC) from car exhaust. The experiment had been carried out in stagnation condition in the laboratory using 1500 cc petrol engine DOHC (4G91). Four TECs (SP1848-27145) were connected in series on the top of exhaust muffler. The experiments were run in two type of cooling methods using air flow from standing fan and the flowing cold water. The maximum voltage of 2.42V was produced when temperature difference, DT reached 83°C. The LED bulbs were connected to TEC and light up when the voltage of 1.60V is obtained. The results have proved that the temperature difference between two sides is the dominant effect to determine the TEC performance. The generated power could be utilized to power an auxiliary application in the vehicle itself.
An experimental study on the influence of tubercles on aerodynamics performance of car rear spoiler
Authors: Halidi S N A M , Yusoff H , Rosmidi M R Z , Farhan A , Suhaimi S 
Published: December 2019

Abstract
In this study, the aerodynamic performance of a car spoiler with tubercles configurations that was inspired by Humpback whale flipper morphology was investigated. This was done by producing three (T0, T3, and T9) spoiler designs where, tubercles sinusoidal protrusions pattern was applied at the leading edge of the spoiler. T0, is a base line spoiler that has no tubercles, T3, that contains three tubercles protrusions, and T9, contains nine tubercle protrusions. The baseline spoiler design was based on the Selig s2091 spoiler and the spoiler has a chord length (C) 100mm and 290mm wingspan. The spoiler was tested angle of attack from - 20 to 30° and at Reynolds number 60000 in an open circuit subsonic wind tunnel. The aerodynamic performance of the spoiler was measured by the recorded time averaged lift and drag. From the recorded it was observed that at certain angles of attack, the presence of a tubercle pattern can bring a significant aerodynamic improvement.
An experimental study on thermal conductivity of T2 copper with different surface roughness
Authors: Abdullah N S , Yusoff H , Zaba H S , Ghafar H , Farhan A , Budin S , Suhaimi S 
Published: December 2019

Abstract
Recent previous studies have shown that there is a correlation between heat conductivity and surface materials. In this project, the heat conductivity 3 different samples of T2 copper with different surface roughness was studied. This was done by measuring the temperature of the samples at 9 different point using SOLTEQ Heat Conduction Study Bench (Model HE106). The surface roughness of the different samples was achieved using sandpaper and measured using the (SURFTEST SJ-410) where the different surface roughness was A: Ra=0.379μm, B: Ra=0.71μm, C: Ra=0.053μm. The sample was heated using a heater with 10W of power. From the collected data, it was observed that the specimen with the smoothest surface roughness has the best performing heat transfer with the specimen C that have the highest decreasing percentage temperature followed by specimen B and specimen A.
Feasibility study on the application of alum sludge (AS) as alternative landfill liner material in sustainable landfill infrastructure model: XRD and SEM analysis
Authors: Muhamad Bashar N A , Syarhida Isa N H , Sofiyah Rahman N R , Alias S , Chay T C , Abdul Aziz N H , Jamalludin D 
Published: December 2019

Abstract
The increasing number of Alum Sludge (AS) in water treatment plant (WTP) from water treatment process has been directed to the reduction of storage capacity for keeping of AS waste itself in the landfill. Other than disposed in the landfill site, this accumulated AS can be commercialized into a useful product such as landfill barrier. Conventionally, clay is used as the protection layer in the engineered sanitary landfill to reduce the leachate intrusion into groundwater. However, due to higher usage and demand on the clay (C) material caused its depletion and higher in cost. Therefore, accumulated AS can be recycled and reused to reduce the disposal problem in landfill and financial burden facing by the landfill operator. In this study, AS was investigated and compared with the kaolin clay (KC) in terms of XRD and SEM characteristics. The index properties and hydraulic conductivity, k test were also conducted to classify the AS and KC composition. Based on the testing, AS can be classified as High Plasticity Clay and the value of k for AS is higher than KC. Based on the results from XRD, both of KC and AS samples was having a similar crystalline phase which is Quartz. Based on the summary of compounds elements, the chemical elements of Oxygen, Aluminium, Silicon and Iron presence in AS have a quite similar percentage of weight (%) with KC. From all of these results, it can be concluded that the AS is mostly having similar materials to KC and amorphous in nature.
Ultraviolet photodetectors based on doped ZnO films
Authors: Ng Z N , Chan K Y 
Published: December 2019

Abstract
In this paper, we report the realization of ultraviolet (UV) photodetector based on doped ZnO films. The ZnO p-n junction was fabricated on indium tin oxide (ITO) coated glass, which consists of n-type and p-type layers based on Ga-doped (2 at.%) and N-doped (20 at.%) ZnO films, respectively. The current-voltage (IV) characteristics, photosensitivity, photoresponsitivity, and photocurrent gain were derived to determine the performance of the device. At 5 V reverse bias, the ZnO-based UV photodetector exhibits photosensitivity of 10.9, photoresponsivity of 2.1 × 10−2 AW−1, and photoconductive gain of 7.2 × 10−2.
Outstanding performance of waste chicken eggshell derived CaO as a green catalyst in biodiesel production: Optimization of calcination conditions
Authors: Lani N S , Ngadi N , Jusoh M , Mohamad Z , Zakaria Z Y 
Published: December 2019

Abstract
The utilization of conventional catalyst such as sodium hydroxide in biodiesel production possesses several disadvantages as they are difficult to separate from biodiesel products, particularly prone to soap formation and require a multiple neutralization step. For this reason, CaO derived from waste chicken eggshell was explored as an alternative catalyst. Normally, CaO from natural source was synthesized through the calcination process. Thus, this paper aims to identify the optimum condition of calcination process for high biodiesel yield. On the basis of statistical analysis, a central composite design (CCD) was used to optimize the calcination conditions which are calcination temperature and time to achieve high yield of biodiesel. The calcination temperature and time were varied in the range of 600 to 1000 °C and 60 to 300 minutes, respectively. The optimum calcination conditions are 900 °C and 3.5 hours, whereby the most significant factor affecting biodiesel yield was identified as calcination temperature. The result also indicated that the second order model was adequate for both independent variables on the response with R2 of 0.9383. The maximum biodiesel yield of 92.81 and 94.72% were obtained by experimental and predicted values, respectively.
Optimization of supercritical fluid extraction of Mariposa Christia Vespertilionis leaves towards antioxidant using response surface methodology
Authors: Ariff MAM , Tukiman S , Razak NAA , Osman M S , Jaapar J 
Published: December 2019

Abstract

Mariposa Christia Vespertilionis (MCV) or also known as butterfly wing leaves, is popular in the traditional medicine practice. The objective of this study is to optimize the antioxidant components (based on antioxidant activity analysis) from the MCV leaves extract using Supercritical Fluid Extraction (SFE) based on different temperature, pressure, and particle size via Response Surface Methodology (RSM). Besides that, it is also to evaluate the optimal condition of different extracting antioxidant activity from MCV leaves using Design Expert 10 software. The condition range for both pressure and temperature were between 150-350 bar and 30-70 °C with constant extraction time. The size of particle samples were between 63 μm-1000 μm. The antioxidant was analyzed using UV–vis Spectrophotometer (UV-vis). The lowest antioxidant activity was 8.20 % and higher antioxidant activity was obtained at 49.76 %. Lower absorbance indicated highest free radical scavenging activities. Maximum percentage (%) indicated high scavenging activities, thus higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) is a good indication for antioxidant. The predicted RSM optimal condition of antioxidant activity was at temperature 50 °C, pressure 282 bar, and particle size 500 μm, which the predicted antioxidant was 50.62 %. Upon verification through experiment, it was found out that the antioxidant activity value was close to the predicted value with an average error of less than 1%.
A hybrid electrocoagulation-adsorption process for fluoride removal from semiconductor wastewater
Authors: Jalil S N A , Amri N , Ajien A A , Ismail N F , Ballinger B 
Published: December 2019

AbstractSemiconductor processing facilities regularly emit wastewater with fluoride concentrations exceeding 100 mg/L which can cause major health issues in the local population. This research aims to address this issue by optimising an electrocoagulation-adsorption (EC-AD) process using two aluminium electrodes and activated carbon. The applied voltage (5, 15, and 20V) and adsorbent dosage (0.20, 0.50, and 1.00g) parameters were varied to treat a synthetic wastewater solution containing 100 mg/L of fluorine. It was found that fluoride removal efficiencies are significantly affected by the adsorbent dosages and applied voltages used. Increasing the applied voltage from 5V to 20V increased the removal efficiency from 37.55% to 64.25% for 0.2g adsorbent dosage and from 33.85% to 67.25% for 0.5g dosage. After all the parameter combinations were tested, an applied voltage of 20V and an adsorbent dosage of 0.50g produced the maximum fluoride removal efficiency. These parameter values thus define the optimal conditions for the EC-AD process to reduce fluoride from highly concentrated wastewater. The AD, EC, and hybrid EC-AD process achieved fluoride removal efficiencies of 2.86%, 41.13%, and 67.25% respectively from synthetic wastewater. Therefore, it was showed that the combination EC-AD process performs better than adsorption (AD) or electrocoagulation (EC) processes used in isolation.
Characterisation of polysaccharide composite incorporated with turmeric oil for application on fresh-cut apples
Authors: Sharif Z I M , Jai J , Subuki I , Zaki N A M , Mustapha F A , Mohd Yusof N 
Published: December 2019

Abstract
Composite edible coatings were made up from two types of polysaccharide which are cassava starch and carboxymethyl cellulose (CMC) incorporated with turmeric oil (TO) as an antioxidation agent. Weight loss, firmness loss and moisture content were studied to determine the effect of composite edible coating incorporated with different TO concentration and dipping times towards the quality of fresh-cut Fuji apples. Findings showed that the coating with 17.5 μL/mL concentration of TO and 180 s dipping time had the lowest weight loss and percentage of firmness loss. While for percentage of moisture content, 17.5 μL/mL concentration of TO with 60 s dipping time had the lowest moisture content loss. Surface morphology was analysed to observe the uniformity of coating on fresh-cut Fuji apples surface. The oxidase enzyme activities of fresh-cut Fuji apples reduce when there is TO present in edible coating. It showed that the coating with 180 s dipping time had the best surface coating compared to 60 s and 300 s dipping time. The composite edible coating emulsion can be huge potential as fresh-cut fruits coating to preserve the quality of the fruits.
Characterization of type III and IV solar radio bursts from e-CALLISTO
Authors: Ansor N M , Hamidi Z S , Shariff N N M 
Published: December 2019

Abstract
This paper presents the characterization of solar radio burst type III and IV obtained from e-CALLISTO website. Solar radio burst (SRB) is one of the tools in space weather studies as each type of SRB indicates the production of solar activity at that moment which can also bring it towards the prediction of solar events. Generally, SRB has five different type of emissions which are named as type I, II, III, IV and V, this paper will only focus on type III and IV. Data of type III and IV bursts were selected on 15th Sept. 2015 and 27th Feb. 2018 respectively and discussions on each type of bursts include two stations to make a comparison. At the end of this work, type III bursts show a rapidly drift structure from high to low frequency, strongly associated to solar flares and the burst is due to Langmuir waves. Meanwhile, type IV bursts are recognized by its broadband continuum with rapidly fine structure and they act as a hint of geomagnetic storm commencement. More details on the formation of these burst are discussed.
Optimization of biodiesel production from Chlorella Vulgaris using CuO, NiO and MgO on zeolite 4A catalysts
Authors: Ariffin M I , Abdullah N , Bahruji H , Mohd Kasim N A , Abdul Halim N , Yun Hin T Y 
Published: December 2019

Abstract
The activities of metal oxide on zeolite as catalysts for production of fatty acid methyl ester from microalgae lipid oil were investigated by impregnation of MgO, CuO and NiO on zeolite 4A. The physical properties of the catalysts were characterized using TGA, XRD, Fe-SEM and Nitrogen Physisorption analysis. Evaluation on activity for biodiesel production from Chlorella vulgaris microalgae shows the trend of catalysts performance as CuO/Zeo>NiO/ZeO>MgO/Zeo. The amount of catalysts, the methanol to oil ratios and the length of reaction times affects the production of biodiesel with 69% of biodiesel produced using CuO/Zeolite catalysts at optimized conditions.
Rock water interaction on the effect of drying and wetting to the mechanical and dynamic properties of tropical weathered granite
Authors: Hasan A S Md , Osman N M , Ismail M K A , Albar A , Razali M 
Published: December 2019

Abstract
This study deals with the effect of water on the tropical weathered granite and sandstone rock characteristics. Water act as an agent in the weathering process that lead to the weakness of the cementation and bonding condition. The process of wetting and drying are able to take place with the presence of water inside the rock microstructure, then further created the numbers of micro-pore which contributing to weakens the rock structure. Thus, this study is focusing to analyses the effect of the presence of water on the mechanical and dynamic properties of granitic rock depending on its weathering degree. The interaction between water and rock was observed through the water-rock interaction test by using saturation and caliper method, where all the rock samples, totalling 81 samples allowed to experience the wet and dry conditions for 21 days, 56 days and 90 days. Uniaxial compressive strength test, indirect (Brazilian) tensile strength and point load tests were conducted to determine the strength of the rock. Meanwhile, P-wave velocity test was conducted to measure the wave velocity that able to penetrate through the intact rock. In conclusion, the increasing of weathering degree, will allowed the rock to absorb the water as their particles has not more tightly bonding. Therefore, it found that the strength of tropical weathered granite was decrease as the interaction with water causes the interlocking of the rock particles is reduces from the process of weathering.
Cation-exchanged NaY Zeolite: Effect of temperature and ion concentration to membrane performance
Authors: Isa M A , Halim M H 
Published: December 2019

Abstract
Zeolite membranes possess well defined pore structures which able to separate gasses with high selectivity. The separation between adsorptive and non-adsortive gasses depends on the affinity of permeating gas molecules with the zeolites structures whereby different types of cations resides in the zeolitic framework will affect the permeselectivity of the membranes. Several efforts have been made to modify zeolite membranes in order to enhance their capability in gas separation by ion exchange process. Here, investigations were performed on the ion exchange process of zeolite NaY membrane with Ag+ cation at different concentrations (0.1M, 0.025M) and temperatures (ambient temperature and 80°C). The results revealed that temperature plays significant role in maintaining the morphologies of zeolite NaY membranes. Dealumination process was also observed to occur simultaneously with the ion exchange process. Overall, CO2/CH4 selectivity of the cation-exchanged NaY zeolite membranes increased by 100% with less CO2 flux reductions were recorded by samples which had been ion exchanged with less concentrated ion exchange solution i.e. 0.0125M at ambient temperature. Nevertheless, CO2/CH4 selectivity decreased for membrane samples which had been ion exchanged at higher temperature (80°C) due to dissolution of the zeolite membranes layer.