bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational fluid dynamics study of a single stage solar still for water treatment
Authors: Hussain M , Shoukat B , Wahid A A , Shukrullah S , Anwar M , Ashraf M Z , Naz M Y
Published: June 2020

The freshwater is only 2.5% of the total water on this earth and rest is the brackish. At present, the human being is facing a serious problem of availability of potable water. The amount of potable water can be enhanced by translating brackish water into drinkable through solar distillation in solar stills. Different geometries of solar stills are being designed to serve the distillation purpose. The performance of a solar still is mainly influenced by its design parameters and wall material. In the presented work, a 3-dimentional geometric modeling of a solar still was carried out by using k-epsilon model in ANSYS-FLUENT. The objective was to study the effect of the design parameters on performance of a solar still through CFD modelling followed by the experimental validation. ANSYS-FLUENT 14.0 package was used to simulate the solar still system. The simulated work was compared with the experimental data and a good agreement was seen among the experimental and simulated data.
Effect of calcination temperature on the structural and morphological properties of zinc sulphide nanomaterials
Authors: Ahmad G , Batool A , Iqbal Q , Iqbal A , Ali F , Nawaz S , Shad N A , Sajid M M , Javed Y
Published: June 2020

Metal sulfide nanomaterials have emerged an important material in recent times due to its potential applications in optical devices, nanoelectronics and nano-optoelectronics. In current research work, zinc sulfide (ZnS) nanoparticles were synthesis by simple chemical co-precipitation method and effect of calcination temperature on the structural and morphological properties of the nanomaterials have been investigated. It was observed that when temperature rises to 500 °C, cubic structure of ZnS transformed into hexagonal phase. Further increase in temperature oxidize the sulfide and ZnS changes into zinc oxide at 750 °C. This temperature rise was also evident in the SEM images where nanoparticles transformed into rod like morphology at 750 °C. Oxidation of the ZnS to ZnO also confirmed by FTIR spectrum which shows Zn-O bonds presence. These studies show that temperature variation can affect the structure and ultimately their relevant technological applications.
Application of central composite design for optimization of microbial growth inhibition using pineapple leaves juice
Authors: Ya’acob A , Zainol N
Published: June 2020

Microbial growth inhibitor is very important to prevent transmission of disease and infection. In this research paper, pineapple (Ananas comosus) leaves juice (PLJ) was used as microbial growth inhibitor agent. Microbe from infected pineapple leaves was used as microbe model. The selected factors in this study were temperature and microbial inhibition time with the range between 35 to 39 °C and 10 to 50 minutes respectively. In order to determine the optimum condition for microbial growth inhibition process, an experiment were designed according to a central composite design (CCD) in two variables following the response surface methodology (RSM). Microbial growth inhibition was measured from cell dry weight of microbe using dry weight measurement method. Result from RSM showed that microbial inhibition time have significant effect on the microbial growth inhibition. Model validation from experiments showed good correspondence between experimental and predicted values. The highest error was achieved at 8.03%. The optimal condition obtained for microbial growth inhibition was at 37 °C and 34.25 minutes. Minimum cell dry weight was found at 0.0508 gram which indicated the microbial growth inhibition at 94.73%. Optimal condition from this study would be useful for the application of PLJ in pineapple plantation.
Air co-gasification of palm kernel shell and polystyrene: Effect of different polystyrene content
Authors: Basha M H , Sulaiman S A
Published: June 2020

Plastic waste management has been a problem as most of the plastics are not biodegradable. Although plastics are recyclable, only 21% of total plastic wastes are recycled. Using plastics as gasification feedstock/co-feedstock and converting it to usable energy is one of the solutions of removing plastics waste. Co-gasifying polystyrene (PS) with palm kernel shell (PKS) is promising as both of the feedstocks are abundant and have high energy content. However, the performance of air gasification of PKS and PS has not been studied previously. In this work, co-gasification of PKS and PS was carried out, focusing on the effect of PS content in the feedstock. The PS content was varied from 0 to 30 wt%. By increasing the PS content, the CH4 volume percentage increases, while CO and H2 volume percentage decreases. The high heating value of the producer gas increases with PS content, from 11.95 MJ/Nm3 at 10 wt% PS, to 12.36 MJ/Nm3 at 30 wt% PS. Higher PS content also increases the gas yield percentage.
Influence of non-covalently functionalized graphene nanoplatelets on viscosity and wettability for improved oil mobility at reservoir conditions
Authors: Hamdi S S , Muhsan A S , Al-Kayiem H H
Published: June 2020

Noncovalent functionalized graphene nanoplatelets (GNPs) were successfully prepared with Gum Arabic as exfoliation solvent via an ultrasonication-assisted process to produce a highly dispersed material under high salinity and high temperature conditions. The implementation of the functionalization groups was validated with Fourier transform infrared spectroscopy and Transmission Electron Microscopy. The functionalized graphene nanoplatelets with Gum Arabic were dispersed in 3 wt.% high salinity brine with various concentrations to prepare Gum Arabic-GNP/brine nanofluids. The dynamic viscosity of the produced nanofluid at different concentrations was higher than that of crude oil at a high temperature (90 °C) and a high shear rate (1000 L/s). The functionalized graphene with Gum Arabic altered the wettability of sandstone from oil to water and changed the contact angle from 108° to 21° at 0.1 wt.%. Moreover, the value of contact angle reduced to 87% with presence 0.1 wt.% of GA-GNPs. These results are demonstrating that the GA-GNPs nanofluids could improve the mobility of the residual oil from the porous media to the production well with high efficiency of oil displacement.
Correlation between microstructure and micro-hardness of 316L nitrided austenitic stainless steel
Authors: Hussain P , Mahmoud H , Basha S N , Mohamad A I
Published: June 2020

This paper presents the effect of duration of solution nitriding towards microstructure and microhardness of AISI 316L stainless steel. The AISI 316L stainless steel was exposed to high temperature gas nitriding process at 1200 °C by using 50% ammonia gas and 50% nitrogen gas for different durations of 8, 15 and 20 hours. The nitrided austenitic stainless steel then underwent several analyses and tests to find the effect of different durations of nitriding towards its microstructures and microhardness. From the experiments conducted to the nitrided samples, it was found that the higher duration of nitriding resulted in the increase of microhardness of the samples due to the increase of nitrogen content in the stainless steel. However, there was no effect found on the microstructure of the nitrided samples. It was noted that the highest hardness was obtained from the nitrided sample of 20 hours that has 245.1 HV which is about 70% higher than the as-received sample.
An investigation of thermal stability and heat capacity of imidazolium based ionic liquids at elevated temperature
Authors: Bakthavatchalam B , Habib K , Saidur R , Irshad K , Hussein O A
Published: June 2020

In this paper, the thermal stability and specific heat capacities of four imidazolium based ionic liquids namely 1-ethyl-3-methyl imidazolium octylsulfate, 1-ethyl-3-methylimidazolium diethyl phosphate, 1,3-dimethyl-imidazolium dimethyl phosphate and 1-butyl-3-methylimidazolium chloride have been experimentally analysed using Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The thermal stability was assessed by conventional and high resolution modulated TGA with the temperature range of 0 to 700 °C. The specific heat capacity was measured by using DSC within the temperature interval of 0 to 200 °C. The factors influencing the thermal stability and heat capacity of ionic liquids were studied. The thermal analysis results indicate that 1-ethyl-3-methylimidazolium octylsulfate exhibited excellent thermal stability even at 440 °C while 1-ethyl-3-methylimidazolium diethyl phosphate obtained a maximum specific heat capacity of 4.52 J/g.K.
Multi-objective model optimisation using genetic algorithms for pleurotus sp. cultivation
Authors: Zainol N , Fakharudin A S , Dzulkefli N A , Bakar M F A
Published: June 2020

Malaysia is the largest exporter of Elaeis Guineensis (Palm oil) in the international market. Oil palm cultivation generates a significant amount of lignocellulosic biomass derived from empty fruit bunches (EFB) as waste product. This research focused on optimizing the mycelium growth in Pleurotus sp. cultivation by using EFB as a culture medium. The EFB was cut into the range of size of substrate (S) from 1.5 cm to 3.0 cm, soaked in water for overnight, applied steam treatment and incubated at the selected range of temperature (T) from 29 °C to 32 °C. The responses were mycelium extension rate (M) and nitrogen concentration in mycelium (N). The multi-objective optimisation of M and N requires the objective functions which represent both processes. For this type of problem, multi-objective genetic algorithm was chosen as the methodology, specifically using NSGA-II algorithm. Through the implementation of selected multi-objective genetic algorithm, it was able to produce the pareto front for optimising both nitrogen concentration and the extension rate of the mycelium. The highest nitrogen concentration and mycelium extension rate was from the result with crossover and mutation probability of 0.5 and 0.2. It produced 388.45 mg/L of nitrogen concentration and 0.370 cm/day of mycelium growth.
Review on effects of gasifying agents, temperature and equivalence ratio in biomass gasification process
Authors: Sidek F N , Abdul Samad N A F , Saleh S
Published: June 2020

Biomass gasification is one of the promising technologies for converting biomass into gaseous fuels. It is crucial to fully understand the influence of operation parameters and types of gasifier on the performance of biomass gasification. It also can provide useful information for a better design and operation of gasification process. The general overview on each types of gasifier are discussed where it can be classified into fixed bed and fluidized bed gasifiers. Most of the review from literature focuses more on the effects of temperature and equivalence ratio rather than gasifying agent. However, the review on the effect of gasifying agent is still limited whereas the effect of gasifying agent is also important as it influences the yield and composition of product gas. In the present work, the effects of gasifying agent, temperature and equivalence ratio on the gasification process were reviewed. Firstly, this article highlights the advantages and disadvantages of each gasifiers which consists of fixed bed and fluidized bed. Based on review, a detailed comparison was made in terms of syngas composition obtained by using steam, air, oxygen and carbon dioxide as gasifying agents in order to provide basic knowledge regarding the selection of gasifying agents. The effects of temperature and equivalence ratio (ER) on the gas composition, tar content and reaction rate were discussed and analyzed. Finally, guidelines on the operation parameters in terms of gasifying agent, temperature and equivalence ratio are suggested in the summary review.
Effects of pure and mixed stabilizers on opto-electrical properties and morphology of TiO2nanoparticles synthesized by sol-gel method
Authors: Ayyaz M , Huda N U , Rasool F , Sami-ur-Rehman H , Mehmood A , Naz M Y , Shukrullah S , Ghaffar A
Published: June 2020

Titanium dioxide (TiO2) is acknowledged as the most advanced nanomaterial. It has been used in certain application, such as semiconductor, photocatalyst, dye solar cells, paints, dyes, cosmetics, antifogging coatings, self-cleaning windows, etc. Although TiO2nanoparticles occur naturally in mineral form, but the particles are also being synthesized through different well-known techniques. The past literature reveals that sol-gel methodology is considered as the most attractive and suitable technique for the preparation of such kind of nanoparticles. This article reports the effects of three different stabilizers (HCl, HNO3and mixture of HCl+HNO3) on the morphological and opto-electrical properties of TiO2nanoparticles. The nanoparticles of TiO2were synthesized through sol-gel process by using titanium tetra isopropoxide (TTIP) as precursor in a solution of deionized water and isopropanol at 80 °C under constant stirring. The synthesized TiO2nanoparticles were characterized through X-ray Diffractometry (XRD), Scanning electron microscopy (SEM) and UV-Visible spectrophotometry. The grain size with perfect crystallinity obtained through XRD were in good agreement with SEM results. The grain size of the prepared TiO2nanoparticles using HCl, HNO3and (HCl+HNO3) were 3 nm, 2.8 nm and 3.3 nm, respectively. The optical characterization of TiO2revealed band gap energy values of 4.10 eV, 6.16 eV and 6.14 eV corresponding to absorption edges at 302 nm, 201.2 nm and 201.73 nm, respectively. The smaller grain sizes were having larger band gaps.
Synthesis and characterization of silver nanorods using water coupled atmospheric pressure dc plasma
Authors: Saleem S , Asghar I , Manzoor S , Abbas A , Shukrullah S , Naz M Y , Hussain Z
Published: June 2020

Non-thermal microplasmas are gaining attention of research community due to their unique physical, chemical, optical and catalytic properties. Due to theses remarkable properties, microplasmas are being used in medicine, electronics, material processing and biotechnology. In this study, silver nanorods (AgNRs) were synthesized by coupling dc plasma with aqueous solution of silver nitrate (AgNO3). Sucrose was added in the solution as a stabilizing agent. AgNRs were produced in aqueous solution by reducing AgNO3 with dc plasma jet of argon at atmospheric pressure. No additional reducing agent was added used during production of AgNRs. Different molar ratios of AgNO3 were used to control the size and dispersion of nanorods. Chemical composition and surface morphology of AgNRs were examined by using different techniques, such as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The EDX spectrum confirmed that nanorods are AgNRs metallic silver with atomic weight of 16.86%. SEM micrographs revealed the formation of AgNRs. The rod length varied from 5 nm to 100 nm, depending on the molarity of solute.
Effect of DC micro-plasma treatment on bacteria in its vegetative bacteria
Authors: Naeem M , Bashir W , Altaf N U H , Naz M Y , Shukrullah S , Rehman S U , Shahid M
Published: June 2020

Argon gas plasma consists of discharge pattern of micro hollow cathode. The pattern is used to inactivate the two main kinds of bacteria. The Culture of Escherichia Coli (gram positive) and Staphylococcus aureus (gram negative) are subjected to the plasma exposure. The micro-plasma jet (MPJ) discharge was generated in the voltage range of 2-10 kV with an operating current of 20-35 mA. Under such conditions, a MPJ of approximately 1 cm visible length was produced. The power efficiency of this device was approximately 80%. The efficacy of MPJ to inactivate the bacteria is determined by observing colony forming unit (CFU) counts before and after plasma exposure. The Colony counter is used here to find the CFU/plate. The effect of plasma exposure is observed by varying the time at 15, 30, 60, 90, 120, 150 and 180 seconds. An efficient reduction in CFU is observed after plasma exposure, particularly for 120 seconds. Approximate 50% decay of both cultures is observed after treatment time of 120 seconds.
Performance assessment of stratified chilled water thermal energy storage tank at district cooling plant
Authors: Majid M A A , Hui P S , Soomro A A
Published: June 2020

Thermal energy storage (TES) is the key component of the district cooling (DC) plants. Its performance is important to be analysed. Various works have been carried out to analyse the TES tank performance. Among the methods, the most common are thermocline thickness and figure of merit. In this study nonlinear regression is used to analyse the temperature profiles of a stratified TES tank at DC plant at Universiti Teknologi PETRONAS. The TES performance was also evaluated using thermocline thickness and 1/2FOM. Results indicate curve fitting approach is enabled to plot temperature profiles during charging. The plots assist in understanding the development of thermocline within the TES tank during charging process. Results on the thermocline thickness and 1/2FOM during the understudy charging period indicate increased of thermocline thickness and decreased of 1/2FOM values respectively during the study period. Hence it can be concluded that deterioration occurred to the TES tank during the study period.
Investigation of the effect of annealing temperature on photophysical properties of manganese dioxide nanostructure prepared via co-precipitation route
Authors: Iqbal M S , Iqbal M , Haseeb M , Aftab M , Amin A , Anwar H
Published: June 2020

Co-precipitation method was used to synthesize Manganese dioxide (MnO2) nanostructures. The synthetization of Manganese dioxide (MnO2) requires Manganese dichloride tetrahydrate (MnCl2.4H2O), Sodium hydroxide (NaOH) and distilled water. Manganese dioxide nanostructures were synthesized by taking suitable amount of manganese dichloride tetrahydrate and mixing it with 100 mL of distilled water. Sodium hydroxide (NaOH) was added into the precursor solution to adjust pH 12 and stirred for 18 hours. The prepared MnO2 nanoparticles were characterized through various techniques such as X-ray diffraction (XRD), UV-visible spectroscopy and scanning electron microscopy (SEM). XRD results revealed that MnO2 had tetragonal single phase. Average crystallite size for prepared samples is found in the range 39 to 45 nm. It is increased with increasing of annealing temperature. Volume and density of unit cell are found to be 258.83 Å3 and 4.522 g/cm3 respectively. SEM results showed that the annealing temperature has affected the shape of MnO2. The morphology of MnO2 changed from spherical to rod-like shape as annealing temperature increase. Absorption peaks are obtained between 362 nm to 366 nm of wavelength. These Manganese dioxide (MnO2) nanoparticles can be applied as catalysts, permeable of toxic metals, ion/molecular-sieves, component of dry cell, inorganic pigment, electrodes for electrochemical batteries, electrodes for supercapacitors and cleaning of water.
Microwave plasma assisted sol-gel technique for synthesis of TiO2nanoparticles
Authors: Ayyaz M , Naz M Y , shoukat A , Marriam M , Akram M U , Hussain Z , Shukrullah S , Toqeer I
Published: June 2020

Titanium dioxide (TiO2) nanoparticles have attracted the attention of research community due to their novel functionalities as compared to the bulk material. TiO2is an excellent photocatalyst due to its high photosensitivity, nontoxicity, high refractive index, strong oxidizing ability, high stability, wide band gap and high resistance to photochemical. The main objective of this study was to investigate the influence of microwave (MW) plasma treatment on TiO2nanoparticles synthesized using sol-gel method. TiO2nanoparticles were obtained through sol-gel method at ambient temperature. The suspension was heated at 300 °C for 2 hours to evaporate the organic content. The obtained nanoparticles were placed in partially vacuumized chamber for MW plasma treatment. The plasma treatment is a promising technique for oxidation of nanomaterials. Both plasma treated and untreated samples were evaluated with X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Visible spectroscopy for crystallite size, crystal phases, band gap energy and surface morphology. The obtained results confirmed the existence of anatase and rutile phases of TiO2with smaller particle size within the range of 0.2 to 14 nm. The particles were of aggregated and trigonal shapes. The MW Plasma treatment improved the photocatalytic activity of TiO2nanoparticles by raising their band gap energy and reducing the grain size.
Plasma-fabric interaction for surface activation and functionalization: A review
Authors: Saleem M , Kousar N , Shoukat B , Shoaib-ur-Rehman M , Batool F , Naz M Y , Ghaffar A
Published: June 2020

The applications and effects of plasma on textile fabrics are the main focus in this paper. We surveyed available literature on the plasma-fabric interaction and found that there are variation of parameters affected the plasma application. The parameters can be classified as weight loss, tensile strength, contact angle, aging effect and addition of contents of different chemical functional groups. The increase or decrease in weight of fabrics after oxygen, nitrogen, and atmospheric plasma treatment was obtained in this study. The weight loss increased with the exposure time of plasma but decreased with the pressure. The tensile strength decreases with plasma duration and increases with plasma power. The type of plasma also affects the wettability of fabric. Wettability of a fabric increases with plasma treatment time. The plasma treatment of fabric adds different elements such as oxygen, carbon and nitrogen on the surface. The amount of oxygen increases but carbon and sulphur decreases. The increase or decrease in contact angle depends on the conditions of plasma treatment. The aging time of plasma depends on different parameters of plasma treatment. The hydrophilicity character also affected by plasma treatment. The hydrophilicity decreased with treatment time.
Compressive behaviour of aluminium rectangular hollow tube using Digital Image Correlation (DIC) method
Authors: Quanjin M , Merzuki M N M , Rejab M R M , Noh M Z C
Published: June 2020

The lightweight structural application is commonly used aluminium material, which generally applied in automotive, military, aerospace and naval applications. The rectangular cross-section hollow tube of aluminium material performs the better compressive properties compared to other cross-section shapes. In order to investigate the compressive behaviour of aluminium tube, Digital Image Correlation (DIC) method is used to study the evolution of deformation and strain value. The quasi-static compressive test was performed, and the experimental result was compared with the DIC measurement results. It was obtained that the failure behaviour of the aluminium rectangular hollow tube was buckling mode with several inwards and outwards deformation. In addition, it was concluded that the DIC method results were lower than the experimental values on the maximum compressive stress and compressive modulus, which was considered as a good agreement between this two methods with 1.7 % percentage of error. It is suggested that DIC method is a sufficient method to measure the deformation and strain values with non-contact and non-destructive features.
A preliminary study on new cooling techniques for stingless bees hive
Authors: Halim L A , Basrawi M F , Yusof T M , Yusof M H , Mustafa Z , Ibrahim T K
Published: June 2020

Stingless bees are a type of insect which are very sensitive to the changes of their surroundings, especially to severe heat wave. A report stated that at temperature as high as 38 ºC can cause death of the bees especially to the pupae. Therefore, the objective of this research is to evaluate new methods in regulating the temperature in the hive. To achieve this goal, two cooling methods were studied. One method is using greenroof, a type of roof which contains green vegetation and soil. It is used to cool down the space under the roof. Another method is using a photovoltaic (PV) powered thermoelectric cooler (TEC). Three units of MUSTAFA-hives were exposed under sunlight, one is without any temperature regulation and the other two hives used cooling techniques stated above. The temperatures inside each hive was measured at two points, and was compared with the hive without temperature regulation. It was found that, for the hive integrated with greenroof, the average hive temperature was about 3 ºC and 6 ºC lower in the honey cassette and brood-cells compartment, respectively. On the other hand, the hive with PV powered TEC recorded average temperatures of about 0.5 °C and 3 °C lower in honey cassette and brood-cells compartment, respectively. Therefore, it can be concluded that the implementation of greenroof or TEC could solve the problem of stingless bees’ hive overheating. However, the greenroof has a better thermal performance, besides being economic and simpler solution.
Experimental analysis on the effect of cooling surface area and flow rate for water cooled photovoltaic module
Authors: Basrawi M F , Anuar M N A F , Ibrahim T K , Razak A A
Published: June 2020

Application of water spray or water flow on the surface of photovoltaic (PV) modules is one of the techniques used to increase efficiency. Main parameter that affect the performance by this technique is water flow rate and cooling surface are. However, there is less study focus on those parameters. Thus, the objective of this paper is to investigate the effect of water-cooled surface area and water flow rate on the temperature and power output of the PV. Orifices were used to create half-cooled and fully-cooled surface area for water to flow as cooling techniques while the hand valve was used to control the flow rate of water at 120 L/h, 180 L/h and 240 L/h flowing onto the panel. A solar simulator was constructed and used to provide 600 W/m2, 1,000 W/m2, and 1,200 W/m2 irradiance for the panel. The testing methodology consists of three different experiments for each irradiance level. It was found that more cooling surface area covered could significantly reduce temperature in any irradiance level, and fully-cooled module could keep the temperature at below 40 °C eventhough the irradiance was at 1,200 W/m2. In addition, the optimum flow rate also depends on the cooling surface area. Thus, there is a unique relation between cooling surface area and optimum flow rate. Thus, further investigation is needed on this relation.
Stabilizing solar farm power output by micro gas turbine integration: Emission performance
Authors: Al-Anati A , Basrawi M F , Yusof M H , Ibrahim T K , Razak A A , Chand M R R
Published: June 2020

Worldwide growth of Photovoltaics (PV) technology has been close to exponential rate in the past decades. However, the increase of power generation by PV imposes new challenges on the existing electrical grid due to the unpredictability of PV power output that depends mainly on solar irradiance. One of the solutions to stabilize solar farm power output fluctuation by hybridizing Micro Gas Turbines (MGTs) that is controlled to meet the total power production target. Thus, the objective of this paper is to investigate the effect of different operation strategies on the environmental performance on MGT integrated solar farm. Different operation strategies for MGT integrated solar farm have been implemented to constantly produce a total power output of 800 kW throughout the year. The three strategies then compared by analysing emission produced by MGTs. A simulation was conducted in Simulink environment using real ambient temperature and global sun irradiance data. It was found that Operation Strategy 3 reduced carbon dioxide (CO2) by 13.8%, nitrogen oxides (NOx) emission by 3.2%, and carbon monoxide (CO) by 97.9%. This shows that the proposed strategy could stabilize the total power output of the solar farm at minimum emission level.
Investigation of the role of pH on structural and morphological properties of titanium dioxide nanoparticles
Authors: Sadiq S A , Waseem Z , Hanif S , Riaz S , Hayat K , Batool A I F , Jamil Y , Naz M Y , Anwar H
Published: June 2020

In the present research work, titanium dioxide (TiO2) nanoparticles were synthesized by sol-gel method in which titanium tetraisopropoxide (TTIP) used as a precursor and the effect of pH on their structural and morphological properties was investigated systematically. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the prepared samples. The acidity-alkalinity of the gel was adjusted to different pH values (1, 4, 7 and 10) by using respective media, i.e. HCl and NH4OH. The results showed that from strong acidic media to strong basic media, the average particle size was found to increase from 14 nm at pH 1 to 20 nm at pH 10, whereas the average particle size was 19 nm at pH 7. All peaks in XRD patterns perfectly indexed to the stable anatase tetragonal phase except sample at pH 1, where some traces of rutile phase was also present. XRD results showed the formation of single phase high purity nanoparticles. TiO2 nanoparticles showed homogeneous morphology with low agglomeration at pH 7 and pH 10.
R1234yf vs R134a in automotive air conditioning system: A comparison of the performance
Authors: Sharif M Z , Azmi W H , Zawawi N N M , Mamat R , Hamisa A H
Published: June 2020

The main objective of this study is to evaluate the performance of a compact automotive air conditioning (AAC) system operating with R1234yf and R134a refrigerant. The different ranges of initial refrigerant charge and compressor speed have been tested on the AAC to evaluate the effect of different refrigerant on the thermodynamic performance. The results of this study have shown that the cooling capacity of R1234yf AAC system is significantly lower (between 5 to 25 %) than R134a system. In the experiment, the power of the compressor is slightly lower (up to 11 %) for refrigerant R1234yf compared to R134a inside the AAC system. Finally, the experimental results reveal that, under the same operating conditions, the COP of R1234yf AAC system is always lower than with R134a (14.5 % on average). In order to maximize the efficiency and performance of AAC system, further optimization needs to be done in order to reduce the gap in term of performance of the AAC system operating with R1234yf refrigerant.
Forced convection heat transfer and friction factor of water/bio-glycol mixture based TiO2-SiO2 nanofluids
Authors: Zainon S N M , Azmi W H
Published: June 2020

The research on nanofluids as heat transfer fluid has been done for many years and the manipulation of nanoparticles kept evolving as time passes by. After an exceptional heat transfer performance enhancement was found in single nanofluids, combining two types of nanoparticles in a base fluid has garnered researcher’s attention all over the globe. The study on performance of heat transfer for a combination of two types of nanoparticle in a mixture of water and Bio-glycol has yet to be established; hence, the present study was conducted to investigate the heat transfer performance of TiO2-SiO2 nanofluids in 60:40 mixture of water and Bio-Glycol. The TiO2-SiO2 nanofluids was prepared by using the two-step method at three different particle concentration, namely 0.5%, 1.0% and 1.5%. Forced convection heat transfer experiment was carried out at bulk temperature 30°C and Reynolds number in the range of 1000 to 8000. A constant heat flux was supplied to the test section throughout the experiment. The Nusselt number of TiO2-SiO2 nanofluids was found at particle concentration 1.5%, 70.11% enhanced from the base fluid. The average enhancement of heat transfer coefficient for each particle concentration 0.5%, 1.0% and 1.5% are 40.3%, 63.4% and 70.3%, respectively. Heat transfer coefficient enhancement for 1.0% and 1.5% particle concentration almost similar at low concentration, however, as Reynolds number increase, the augmentation gap increases. The results of friction factor displayed a decrease trend with the increase of Reynolds number. While the friction factor of TiO2-SiO2 nanofluids insignificantly increased from the base fluid, the increment between particles concentration almost negligible.
The effect of Al2O3/PAG nanolubricant towards automotive air conditioning (AAC) power consumption
Authors: Redhwan A A M , Azmi W H , Sharif M Z , Zawawi N N M , Zulkarnain O W , Aminullah A R M
Published: June 2020

The usages of Automotive Air Conditioning (AAC) today is vital because of the hot and humid climate. The AAC is used to provide comfort in the automotive cabin temperature, consequently, increases fuel consumption, and release significant amount of CO2, and greenhouse gas into the air. Nanotechnologies could be employed into AAC system via lubricant compressor which can decrease power consumption, eventually increase power saving. The main objective of this paper is to experimentally investigate the effect of Al2O3/PAG nanolubricant onto the power consumption. The study on the stability and characteristic of the Al2O3/PAG nanolubricant has been done prior the experiment. The result shows that the Al2O3/PAG nanolubricant is stable event after 28 days with concentration ratio above 70%. The highest power saving percentage of 23.89% is achieved when the AAC system is operated with 0.010% Al2O3/PAG nanolubricant. Further, it has been shown that the condenser pressure and evaporator pressure are correlated with the increment of the power consumption with average deviation of 3.129% and 2.919%, respectively. Finally, the power consumption of AAC system reduce with the usage of the Al2O3/PAG nanolubricant at low concentration.
Influence of detergents types and clean method on PV cells performance: An experimental study
Authors: Hussein N F , Ismaeel A A , Ibrahim A K
Published: June 2020

Accumulation the dust and dirt soiling on photovoltaic (PV) panels’ surfaces represents a major problem which inevitably undermines their operational performance. Thereby, removing the soiling and cleaning the panel surfaces is necessary to upgrade the PV cells performance. In this study the influence of detergent types as a cleaning material on PV panels’ outcomes has been investigated experimentally. Three detergents types that widely materials using in the home cleaning include: Tap water, mixture of dishwashing liquid with water and glass cleaner were tested. Furthermore, manual cleaning by using a piece of cloth or wiper were utilized as a cleaning tools were also evaluated. The experimental results appeared that enhancement the PV panel performance after using home detergents materials, where the performance increased by 25.35% and 19% when used a glasses cleaner and mixture of water and dishwashing liquid respectively, compared with 7.34% when used tap water only. In addition, using the manual wiper as a cleaning technique was achieved a better PV panel performance than piece of cloth for all detergents materials.
Synthesis and properties evaluation of sodium grease formulated from used transformer oil as base oil
Authors: Japar N S A , Aziz M A A , Hamid N
Published: June 2020

This study aimed to prepare sodium grease using used transformer oil as a base oil and investigate the prepared grease properties. Oil, whether it is new or used, is a significant contributor to water pollution due to its toxicity towards the environment. In this study, used transformer oil (UTO) is utilized as grease’s base oil. The properties of the grease were evaluated in terms of their consistency, drop point, oil separation, and bled oil in accordance with ASTM D217, D2265, D1742, and IP 121, respectively. The grease also characterized by using the FTIR-ATR. The results show that the grease can be formulated using UTO with significant grease properties of >180 °C dropping point, −15% to +15% of oil bleeding at both 25 °C and 70 °C, no separated oil during storage, and slightly tarnish on copper strip. The best UTO-based sodium grease formulation was 67.5:32.5 of oil-to-thickener ratio and it was classified as NLGI 2 grease. Moreover, the FTIR spectrum shows no contaminants or unknown chemical changes or additive in UTO and the prepared grease. The addition of MoS2in grease shows no significant improvement in sodium grease properties. Thus, UTO was able to work as grease base oil and exhibited overall good properties but, UTO-based grease analysis on its tribology is necessary to study the prepared grease performances during operation.
Comparative CFD power extraction analysis of novel nature inspired vertical axis wind turbines
Authors: Ashwindran S N , Azizuddin A A , Oumer A N
Published: June 2020

The aim of this paper is to investigate the power extraction performance of three biologically inspired vertical axis wind turbine. In this study, the proposed turbines are simulated in 2D in Ansys using URANS approach based on two equation turbulent transport model-SST. The turbines are simulated under the similar solver and numerical configuration. FVM is adapted to analyse the turbines assisted by sliding mesh method (SSM) under non-conformal mesh configuration. The proposed turbine is analysed in terms of moment and power coefficient. Design 1 and Design 2 indicated promising result for a feasible and practical wind turbine. However, Design 3 indicated poor performance in power coefficient at high RPM value.
Experimental studies of single cylinder engine run on diesel-biodiesel-butanol blends
Authors: Izzudin I , Yusop A F , Sapee S , Hamidi M A , Yusri I M , Mamat R , Erdiwansyah
Published: June 2020

Biodiesel and butanol are excellent additive fuels, especially for diesel fuel. Many studies in literature reported that the biodiesel-butanol with various ratios is applied to diesel engines. In this experiment, diesel engines operated using biodiesel-butanol blend in low proportions 5-5%, 5-10% 10-5%, 10-10%, 15-5% and 15-10% mixed with pure diesel, and the blend is characterized. This blend of fuels can be represented as B5Bu5, B5Bu10, B10B5, B10Bu10, B15Bu5 and B15B10 with a numeric number in the fuel blends. This fuel blend is used as test fuel which is operated on a single cylinder diesel engine, four steps, direct injection (DI) at a constant speed of 1200 rpm and engine load of 25% and 50%. The combustion characteristics, performance and engine emissions are analyzed and evaluated by comparing each load and the speed of the engine being operated. Furthermore, fuel additives with pure diesel are needed to check emissions from the engine when the engine is run with a blend of diesel-biodiesel-butanol fuel. Among the six fuel blends samples examined in this experiment, better performance was shown in the B5B10 blend and produced fewer emissions. The results of the whole experiment are presented in full in this paper.
Stability and density analysis of mango bark and mango leaf nanofluids
Authors: Chen J L T , Oumer A N , Azizuddin A A
Published: June 2020

Thermal conductivity is one of the primary properties for nanofluids application investigated by many researchers. However, there are other factors such as stability and density that need to be considered to reduce sedimentation, pressure drop as well as sustain the enhanced thermal physical properties of nanofluid. The purpose of this study is to investigate and analyse the stability and density of mango bark (MB) and mango leaf (ML) nanofluids as well as hybrid nanofluids between mango bark and leaf with SiO2 and TiO2. The stability of nanofluids was measured using sedimentation method. The nanofluids arranged in order of pure ML nanofluid with increasing volume concentration of 0.25%, 0.50% and 1.00% followed by MB nanofluid, ML/SiO2 nanofluid, MB/SiO2 nanofluid, ML/TiO2 nanofluid and MB/TiO2 nanofluid. The density of nanofluids was measured using KEM DA-640 density meter and calculated using mixture rule equation. The results show that the stability of the nanofluids started to show sedimentation after 1 day of storing. Mango bark nanofluids were more stable than mango leaf nanofluids. At 1% concentration, MB nanofluid has the highest density (0.9981) followed by MB/TiO2 (0.9970), ML/TiO2 (0.9964), ML (0.9963), MB/SiO2 (0.9962) and ML/SiO2 (0.9962). Density of nanofluids have small increment with volume concentration. Meanwhile, the density of nanofluids have small decrement with volume concentration using analytical calculation. The results also shows small average error of 0.17% between experiment and analytical calculation.
Effect of bath temperature on sodium diethyldithiocarbamate trihydrate loading of halloysite nanotube
Authors: Kumar S S , Kakooei S , Ismail M C , Haris M
Published: June 2020

Smart coatings have become one of the most sought after solutions for corrosion control in industries. A need to encapsulate the corrosion inhibitor by means of a nano/micro container has come into the picture as the conventional methods are not favourable and has demerits. Halloysite nanotube based smart coatings are effective given that it is environment-friendly unlike most of its competitors. The current work focuses on the effect of bath temperature in a vaporizer on the loading ability of Halloysite nanotube is studied with Sodium diethyldithiocarbamate trihydrate as a corrosion inhibitor. The loading was carried out at three different bath temperatures which are 40, 60 and 80 °C and the resultant samples were investigated by characterization using Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and UV-Vis Spectroscopy. It was found that an increase in bath temperature to 80 °C, it will increase the loading capacity of halloysite nanotubes.
Rudimentary analysis for solar chimney enhancement
Authors: Jamil I E , Sing C Y , Al-Kayiem H H
Published: June 2020

This paper presents fundamental results for solar chimney enhancement. Solar radiation proves to be an important factor in influencing the efficiency of the solar chimney power plant, but its effects on the ambient conditions outside the system has not been considered. Using the Discrete Ordinates radiation model on the semi-transparent collector component of the two-dimensional system, the work presented in this paper simulates the velocity and temperature inside the solar chimney as the ambient temperature of air outside is varied from 307 K to 314 K. At the highest ambient temperature, results show an increase in air velocity of 0.55 m/s at ground level and 1.85 m/s at a height of 1 m along the chimney. To further investigate of this study, a simulation model to include the ambient domain is proposed as a conclusion.
A study on the performance analysis of bioethanol produced from sugarcane molasses in SI engine
Authors: Maárof M I N , Chala G T , Gunness D , Saad I
Published: June 2020

Recently with ethanol being a renewable, bio-based and ecofriendly, it is projected to be the best replacement for petrol as a fuel in SI engines. Ethanol is derived mainly from sugarcane, cassava, corn and other waste biomass materials. These materials are rich in calories and could be utilized either as complements or as alternatives for conventional fuel sources. This paper aims to experimentally determine the properties of ethanol/gasoline blends and tests its performances in an SI engine. The E10, E20 and E30 ethanol-gasoline blends were studied and compared to gasoline fuel. It was found that the performance of the engine using bioethanol blends was almost comparable to that of pure gasoline, especially at lower ethanol content blends. Yet, increasing the ethanol content only gives adverse effects to the overall engine performance, resulting in 8.86% power loss at 2000 rpm for E20 and 8.18% for E30 compared to E0. Suggestively, with more research and experiments, bioethanol-fuel blends can replace pure gasoline fuels easily and with many added benefits on the same or slightly modified engines.
A Diverse and Inclusive Academic Membership for All
Authors: Puac-Polanco Victor , Morabia Alfredo
Published: June 2020

With the growing recognition that diversity and inclusion are essential for the improvement of science and innovation, we provide some perspectives on 3 findings of DeVilbiss et al. (Am J Epidemiol. 2020;189(10):998–1010). We provide points of discussion on factors and strategies to consider when drafting diversity and inclusion programs for the Society for Epidemiologic Research.
Orb-weaving spiders show a correlated syndrome of morphology and web structure in the wild
Authors: Fisher David N , Pruitt Jonathan N , Yeager Justin
Published: June 2020

Extended phenotypes are traits that exist outside the physical body of organisms. Despite their role in the lives of the organisms that express them and other organisms influenced by extended phenotypes, the consistency and covariance with morphological and behavioural traits of extended phenotypes has rarely been evaluated. We repeatedly measured an extended phenotype involved in prey acquisition (web structure) of wild orb-weaving spiders (Micrathena vigorsii), which re-build their webs daily. We related web structure to behaviours and spider body length. Web diameter and web density were repeatable among individuals, reaction to a predation threat was very marginally so, and response to a prey stimulus and web evenness were not repeatable. Larger spiders spun wider webs, had webs with increased thread spacing, and the spider possibly tended to react more slowly to a predation threat. When a spider built a relatively larger web it was also a relatively less dense and less even web. The repeatability of web construction and relationship with spider body size we found may be common features of intra-population variation in web structure in spiders. By estimating the consistency and covariances of extended phenotypes we can begin to evaluate what maintains their variation and how they might evolve.
Social Workers in Israel: Daily Stressors, Work Benefits, Burnout and Well-Being
Authors: Savaya Riki , Levin Lia , Roziner Ilan
Published: June 2020

In this article, we report findings pertaining to connections between social workers’ exposure to daily stressors, the work benefits they receive, their levels of burnout and their well-being. We examined (i) the associations between social workers’ perceived exposure to daily stressors and their well-being; (ii) the mediating effect of burnout on these associations; and (iii) the moderating effect of extrinsic and intrinsic work benefits on the relationships between perceived exposure to daily stressors and burnout. Participants were 486 social workers, working in various organisations and with diverse populations in Israel. Of the various findings, two are of particular interest. One is that workers’ depersonalisation of their clients mediated the relationship between the workers’ exposure to daily stressors and their psychological distress. The other is that neither intrinsic nor extrinsic work benefits weakened the association between workers’ exposure to daily stressors and their burnout, in terms of personal accomplishment. On the contrary, high benefits of either kind strengthened this association. These unexpected findings are discussed within the frameworks of relationships between service users and service providers and of Wilensky’s compensatory theory. While this study was based in Israel, its conclusions bear relevance to social workers in other countries as well.