Showing papers in "Malaysian Journal of Fundamental and Applied Sciences in 2019"
TL;DR: In this paper, the authors report the recent information from synthesis to the characterization of Fe 3 O 4 nanoparticles as well as the discussion of future perspective in this research area and discuss three conventional wet chemical methods, including chemical co-precipitation, sol-gel synthesis and thermal decomposition, for the preparation of superparamagnetic Fe 3 o 4, with controlled size and magnetic properties.
Abstract: Magnetic magnetite (Fe 3 O 4 ) nanoparticles have attracted a great deal of attention in both fundamental research and practical applications over the past decades. Down to the nanoscale, superparamagnetic Fe 3 O 4 nanoparticles with only a single magnetic domain exhibit high magnetic susceptibility, which provides a stronger and faster magnetic response. Their superparamagnetic properties together with other intrinsic properties such as low toxicity, high surface area-to-volume ratio and simple separation methodology, making them ideal for environmental remediation, biomedical, and agricultural applications. This review discusses three conventional wet chemical methods, including chemical co-precipitation, sol-gel synthesis and thermal decomposition for the preparation of superparamagnetic Fe 3 O 4 nanoparticles with controlled size and magnetic properties. Nowadays, with the growing research interest in Fe 3 O 4 nanoparticles, there is a great amount of researches reported on efficient routes to prepare size-controlled magnetic nanoparticles. Thus, this review is designed to report the recent information from synthesis to the characterization of Fe 3 O 4 nanoparticles as well as the discussion of future perspective in this research area.
57 citations
TL;DR: In this paper, an investigation was conducted to characterize the antioxidant and antimicrobial properties of kombucha by variation of carbon sources: white sugar (S), jaggery (J), and Kelulut honey (H) in black tea (BT) and green tea (GT) media over a period of 7, 14, 28 and 60 days.
Abstract: Kombucha is a traditional fermented drink and has recently gained popularity due to its numerous claims on therapeutic effects. It is prepared by sweetening black tea and fermented using a symbiotic culture of acetic acid bacteria and yeasts known as SCOBY. The drink can also be brewed using different type of tea and carbon sources. An investigation was conducted to characterize the antioxidant and antimicrobial properties of kombucha by variation of carbon sources: white sugar (S), jaggery (J) and Kelulut honey (H) in black tea (BT) and green tea (GT) media over a period of 7, 14, 28 and 60 days. The antioxidant and antimicrobial efficacy were tested post fermentation. All samples shown the highest value of DPPH inhibition for antioxidant activity at 7 days of fermentation but subsequently decreased with longer fermentation time except for the combination of green tea with jaggery (GT+J). Fermentation of green tea with white sugar (GT+S) showed the highest value with 84%. On the other hand, black tea with jaggery (BT+J) showed least DPPH activity, 9%. Fermentation with green tea demonstrated a higher antioxidant activity compared to black tea, whereas fermentation of any tea with jaggery showed the least antioxidant activity in comparison to white sugar and honey. Thus, it can be said that extended periods of fermentation reduce the DPPH inhibition of kombucha and jaggery itself as carbon source shows an interesting property. Antimicrobial activity was tested using disk diffusion method against E. coli, S. aureus, P. aeruginosa, B. subtilis and S. marcescens. The efficacy increases with time of fermentation for all combinations. Combination of black tea with all carbon sources was found to have most antimicrobial activity.
25 citations
TL;DR: Graphene was successfully synthesized by activating rice husk ash (RHA) using potassium hydroxide (KOH) at 800 o C with 1:2 impregnation ratio as discussed by the authors.
Abstract: Graphene was successfully synthesized by activating rice husk ash (RHA) using potassium hydroxide (KOH) at 800 o C with 1:2 impregnation ratio. Raman spectroscopy analysis confirmed the presence of graphitic structure. The demonstrated methodology utilizes RHA as carbon source and used as sacrifice to prevent oxidation during synthesis process on the mixture of KOH and RHA against air at high temperature. The novelty of this synthesis methodology use environmentally-friendly biomass resource as a starting material, does not utilize catalysts, and prove that graphene can be synthesized at a relatively low synthesis temperature.
23 citations
TL;DR: In this paper, the performance of the gelatin extracted from red tilapia fish skin treated with HPP was evaluated using the Texture Profile Analysis (TPA) method, in comparison with the commercial fish gelatin.
Abstract: High Pressure Processing (HPP) is a novel extraction method. This technique increases the yield of gelatin and enhances its properties. In this study, the performance of the gelatin extracted from red tilapia fish skin treated with HPP was evaluated using the Texture Profile Analysis (TPA) method, in comparison with the commercial fish gelatin. Based on the Total Soluble Solid (TSS) results, the jelly prepared with HPP-treated gelatin has a longer shelf life. The sensory textures of the lychee jelly were described based on the force-time plot. The results showed that the hardness, adhesiveness, gumminess and chewiness of the jelly prepared using HPP-treated gelatin are higher compared with the commercial gelatin while the cohesiveness and the springiness are similar for both jellies. In conclusion, the jelly prepared using gelatin treated with HPP is preferable compared to the commercial gelatin because it is more rigid, firm and adhesive.
21 citations
TL;DR: In this paper, a modification of the PES membrane was carried out by incorporating carbon-based nanomaterials (graphene oxide (GO)) and a well-known organic polymer (polyvinylpyrrolidone (PVP)).
Abstract: Membrane based separation system is considered as a promising technology to purify water, owing to its simplicity and efficiency in operation. However, the application is limited by membrane fouling, which can lead to the declination of water flux and premature failure of membrane. The fouling can be controlled through membrane surface modification by blending hydrophilic materials during the casting solution preparation. Polyethersulfone (PES) membrane is naturally hydrophobic due to lack of oxygen functional group, which limits its application in the filtration of water. Therefore, modification of PES-based membranes is required. In this work, modification of the PES membrane was carried out by incorporating carbon-based nanomaterials (graphene oxide (GO)) and a well-known organic polymer (polyvinylpyrrolidone (PVP)). The effect of each additive toward the hydrophilicity of composite PES membrane was then investigated. GO was synthesized using modified Hummers method due to its simpler and shorter process. Each additive was added during the casting solution preparation and the amount added was varied from 0.5 to 1.0 wt%. The resultant composite PES membranes were characterized using XRD, FTIR and TGA prior to hydrophilicity and pure water flux (PWF) measurement. It was observed that the additives (PVP and GO) have significantly affected the membranes hydrophilicity, resulting in lower contact angle and higher pure water flux. The highest value of PWF (230 L/m 2 .h) with lowest contact angle (42 °) were observed for PES-1.0GOPVP membrane due to high amount of GO and PVP. Improved PWF performance of composite PES-1.0GOPVP membrane was attributed to the better dispersibility of the PVP and GO and increased surface hydrophilicity of the modified composite membranes. This study indicated that PVP and GO are effective modifiers to enhance the performance of PES membrane
20 citations
TL;DR: In this paper, the effect of pyrolysis temperature on the biochar yield and properties via slow pyrolynsis of coconut flesh waste was investigated, and the results indicated that higher pyroleysis temperature could reduce the percentage of biochar yields.
Abstract: The aim of this study was to investigate the effect of pyrolysis temperature on the biochar yield and properties via slow pyrolysis of coconut flesh waste. The temperature used in the slow pyrolysis experiment was varied between 350°C to 600°C at a constant heating rate of 5°C/min. The results indicated that higher pyrolysis temperature could reduce the percentage of biochar yield. The increment of pyrolysis temperature from 350°C to 600°C would reduce the biochar yield from 23.54 wt.% to 13.97 wt.%. The effect of pyrolysis temperature was also significant on the composition and physical properties of biochar yield. The physicochemical properties of biochar were identified by proximate, elemental, heating value, SEM images and BET surface area analyses. The increment of pyrolysis temperature from 350°C to 600°C increased the ash content of biochar from 4.63 wt.% to 8.19 wt.%, the fixed carbon content from 45.20 wt.% to 79.09 wt.% and carbon content from 72.70 wt.% to 83.25 wt.%. Meanwhile the volatile matter and oxygen content of biochar were decreased from 50.17 wt.% to 12.71 wt.% and 13.86 wt.% to 10.99 wt.%, respectively as the pyrolysis temperature was increased from 350°C to 600°C. The increment of pyrolysis temperature from 350°C to 600°C increased the surface area of biochar by 8 fold from 0.3971 m2/g to 3.4486 m2/g. Meanwhile, the higher heating value of biochar was decreased from 33.95 MJ/kg to 27.49 MJ/kg as the pyrolysis temperature was increased from 350°C to 600°C.
18 citations
TL;DR: Sugarcane bagasse is a cheap agro-based waste material and it has a lot of potential to be converted into useful products such as carbon as discussed by the authors, however, it is not suitable to be applied in the industry compared to acidic solution.
Abstract: Sugarcane Bagasse is a cheap agro-based waste material. These biomass materials have a lot of potential to be converted into useful products such as carbon. Sugarcane Bagasse was extracted by Sodium Hydroxide. Several characterizations has been done to analyse the chemical properties of Sugarcane Bagasse after extraction by Sodium Hydroxide including FTIR, XRF, HPLC and SEM-EDS. SEM shows an increases in internal surface area of the lignocellulose particles, as well as weakening the structural while EDS shows 60.59 % content of carbon. HPLC results show some peak at different retention time. The organic compound can be observed by at retention time 9.611 minute with 66.428 % height and it was identified as schaftoside. FTIR shows that when peak at 1096 cm -1 to 1638 cm -1 there was presence of H-O-H (water adsorption). The element with the highest concentration that are found by using XRF in untreated sugarcane bagasse is water, H 2 O (98.5 %), followed by Sodium, Na (0.669 %), and Sulfur, S (0.638 %). The concentration of each element were decreasing (except H 2 O) after being treated with NaOH. Sugarcane bagasse which is treated with alkaline solution is more suitable to be applied in the industry compared to acidic solution. This is due to the high reactivity of acidic solution that may damage the entire structural compounds of sugarcane bagasse
17 citations
TL;DR: In this article, the reduction agent from fruit extracts of Ananas Comosus is used to synthesize zinc oxide nanoparticles, and the average size of the nanoparticles was found to be in the range of 30-57nm.
Abstract: Biosynthesis of metallic nanoparticles using plants, enzymes, and microorganism have been known as eco-friendly alternatives to conventional physical and chemical methods. Recently, the biological synthesis of nanoparticles has been a keen interest amongst researchers and scientist due to its simple technique, eco-friendliness, non-toxic, inexpensive and potential to perform in antibacterial activity. Thus, in this current work, the synthesis of zinc oxide (ZnO) nanoparticles using reduction agent from fruit extracts of Ananas Comosus is reported. The biosynthesized zinc oxide was characterized using Field Emission Scanning Electron Microscope (FESEM) with Energy Dispersive X-ray analysis (EDX), UV-Vis absorption spectroscopy and X-ray diffraction (XRD). The average size of the nanoparticles was found to be in the range of 30-57nm. The antibacterial activity of ZnO nanoparticles was carried out via agar diffusion method against pathogenic organisms. It is observed that the biosynthesized ZnO in the process has the efficient antibacterial activity. In conclusion , the green synthesis of zinc oxide nanoparticles using the fruit extract of Ananas Comosus is considered as a potential additive to substitute other metal oxides such as silver (Ag) and titanium dioxide (TiO 2 )but also provide antibacterial effect that able to enhance the nanoparticle performance.
17 citations
TL;DR: In this paper, a simple and green method was developed for the synthesis of copper(II) oxide nanoparticles (CuO NPs) using an aqueous extract of Murayya koenigii leaves.
Abstract: Copper(II) oxide nanoparticles (CuO NPs) has a wide range of applications as catalysts. The natural abundance of copper and its relatively low cost make it a viable alternative to catalysts made from expensive precious metals such as platinum and palladium. In this study, a rapid, simple and green method was developed for the synthesis of CuO NPs using an aqueous extract of Murayya koenigii leaves. Several parameters were optimized, namely, the volume of leaf extract, pH, reaction temperature and reaction time. The optimum condition for the biosynthesis was obtained by using 3 mL of leaf extract; 10 mL of 5 mM CuSO, at pH 11, at room temperature. The biosynthesis was completed within 50 minutes. The synthesized CuO NPs were characterized using Ultraviolet-visible Spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Transmission Electron Microscope (TEM) analyses. The UV-Vis absorption spectra confirmed the formation of CuO NPs with characteristic peak at 634 nm. The FTIR spectroscopic analysis of the biosynthesized CuO NPs confirmed the surface adsorption of the bioactive components in the leaf extract that acted as the reducing agent and stabilizing agent for the metal nanoparticles. XRD analysis showed a series of diffraction peaks at 2θ of 32.5°, 35.5°, 38.6°, 48.8°, 53.4°, 58.1°, 61.5°, 66.3°, 68.0°, 72.4° and 75.0°, corresponding to (110), (002), (111), (202), (020), (202), (113), (311), (220), (311) and (222) respectively . From TEM images, CuO NPs were of spherical shape with a mean diameter of 8.4 nm. The biosynthesized CuO NPs demonstrated good catalytic activities on the reduction 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride, NaBH 4 and can be reused three times without significant decrease in the catalytic activities
16 citations
TL;DR: In this paper, Artificial Neural Networks (ANN) and Multiple Linear Regressions (MLR) coupled with sensitivity analysis (SA) were used to recognize the pollutant relationship status over particulate matter (PM10) in eastern region.
Abstract: The comprehensives of particulate matter studies are needed in predicting future haze occurrences in Malaysia. This paper presents the application of Artificial Neural Networks (ANN) and Multiple Linear Regressions (MLR) coupled with sensitivity analysis (SA) in order to recognize the pollutant relationship status over particulate matter (PM10) in eastern region. Eight monitoring studies were used, involving 14 input parameters as independent variables including meteorological factors. In order to investigate the efficiency of ANN and MLR performance, two different weather circumstances were selected; haze and non-haze. The performance evaluation was characterized into two steps. Firstly, two models were developed based on ANN and MLR which denoted as full model, with all parameters (14 variables) were used as the input. SA was used as additional feature to rank the most contributed parameter to PM10 variations in both situations. Next, the model development was evaluated based on selected model, where only significant variables were selected as input. Three mathematical indices were introduced (R2, RMSE and SSE) to compare on both techniques. From the findings, ANN performed better in full and selected model, with both models were completely showed a significant result during hazy and non-hazy. On top of that, UVb and carbon monoxide were both variables that mutually predicted by ANN and MLR during hazy and non-hazy days, respectively. The precise predictions were required in helping any related agency to emphasize on pollutant that essentially contributed to PM10 variations, especially during haze period.
14 citations
TL;DR: In this article, the authors presented a novel yet simple filter design for S-band radar in the frequency range of 2.9 to 3.1 GHz, where the center frequency of the filter was designed at 3 GHz with a bandwidth of 200 MHz, insertion loss larger than 3 dB and return loss less than -20 dB.
Abstract: Radar has been widely used in many fields, such as telecommunication, military applications, and navigation. The filter is one of the most important parts of a radar system, in which it selects the necessary frequency and blocks others. This paper presents a novel yet simple filter design for S-band radar in the frequency range of 2.9 to 3.1 GHz. The center frequency of the filter was designed at 3 GHz with a bandwidth of 200 MHz, insertion loss larger than -3 dB and return loss less than -20 dB. Fifth order microstrip hairpin bandpass filter (BPF) was designed and implemented on Rogers 4350B substrate which has a dielectric relative constant value of (e r )= 3.48 and substrate thickness of (h) =1.524 mm. One element of the square groove was added as Defected Ground Structure (DGS) which can decrease the filter size, reduce harmonization, and increase return loss. Two scenarios were used in the measurement, i.e. with and without enclosed aluminum casing. Results showed that BPF without casing obtained the insertion loss of -1.748 dB at 2.785 GHz and return loss of -21.257 dB in the frequency range between 2.785 to 2.932 GHz. On the other hand, BPF with casing shows a better performance, in which it obtained the insertion loss of -1.643 dB at 2.921 GHz and return loss of -19.529 in the frequency range between 2.820 to 3.021 GHz. Although there is small displacement of frequency and response value between the simulation and implementation, our BPF has the ability to work on S-band radar with a frequency range of 2 to 4 GHz.
TL;DR: In this paper, Fourier transform infrared spectroscopy (FTIR) was used to calculate the deacetylation degree of chitosan, which was then used for demineralization.
Abstract: Water-soluble chitosan (WSC) has been derived from different marine sources such as squid pen, shrimp, mussel, and crab shells. Chitosan was obtained by deacetylation of chitin. Degradation of chitosan by hydrogen peroxide would produce WSC. Demineralization process was optimized by varying incubation time and temperature to minimize the mineral content in chitin. WSC that obtained was characterized by Fourier-transform infrared spectroscopy (FTIR) to calculate the deacetylation degree. Deacetylation degree of WSC was also studied by titrimetric method. The ash content of chitin from marine sources was measured to obtain the optimum demineralization incubation time. The optimum incubation time for demineralization process was 12 hours and stirred at 50 rpm. Recovery and deacetylation degree of WSC were found to be varied and depended on the source of WSC. Each sample of WSC from shrimp shell, mussel shell, squid pen and crab shell has the degree of deacetylation of 64.18%, 35.03%, 58.04% and 53.91% respectively. The presence of amine group was confirmed from FTIR spectra ofsynthesized WSC.
TL;DR: In this paper, the authors investigated the adsorption of phenol from its solution using biochar produced from EFB through carbonization, and the results indicated that the optimized carbonization conditions were; 500 °C for temperature, 10 °C/min of heating rate and 80 min for reaction time, which led to 7.57% phenol removal.
Abstract: Malaysia, as one of the leading palm oil producers in the world faces problems in disposal of oil palm empty fruit bunch (EFB), which can be converted into various value-added products, including adsorbents. This study investigated the adsorption of phenol from its solution using biochar produced from EFB through carbonization. Response Surface Methodology (RSM) with Box-Behnken design was used to investigate the effects of three parameters (temperature, time and heating rate) during carbonization on phenol removal by the biochar produced. This was followed by process optimization based on statistical analysis. The results indicated that the optimized carbonization conditions were; 500 °C for temperature, 10 °C/min of heating rate and 80 min for reaction time, which led to 7.57% of phenol removal. SEM revealed coarse and uneven surface of the biochar surface, with small degree of pore development. Comparison between FTIR spectrum of EFB and biochar revealed the loss of water and hydroxyl compounds from EFB during carbonization. The lack of oxygenated groups (especially carbonyl groups) on the adsorbent surface as well as limited number of pores were the possible reasons leading to low phenol adsorption by biochar, therefore conversion of the biochar to activated carbon was necessary for higher adsorption performance.
TL;DR: It was found that H. itama produced the most active extract compared to other species, and would be the basis for further investigation on therapeutic application especially for cytotoxic activity, antioxidant and phytochemical screenings for four Malaysian stingless bees of propolis.
Abstract: Propolis is a plant-derived substance collected by stingless bee’s product from various sources, including plant resins with combination of bee’s saliva and wax. Propolis has been used to treat several diseases since ancient times and it is an important source of bioactive natural compound and drug derivatives. The aim of this study was to evaluate biological and chemical profiles of ethanolic extracts from propolis produced by Heterotrigona itama (HI), Geniotrigona thoracica (GT), Lepidotrigona terminate (LT), and Tretrigona apicalis (TA). Cytotoxicity activity was evaluated by using 3-(4,5-Dimethylthiazol-2-YI)-2,5-Diphenyltetrazolium Bromide (MTT) assay against three cancer cell lines. H. itama extracts showed the highest cytotoxicity effect with of 5 µg/mL, 4 µg/mL and 8 µg/mL for MDA-MB-231, SK-UT-1 and HeLa, respectively. Other species only possessed moderate to weak cytotoxicity effect against tested cells. Phytochemical screening was carried out by thin layer chromatography (TLC) analysis and visualized by derivatives agents in order to detect the presence of terpenoids, steroids, saponins, essential oils and phenol. It was found that H. itama (HI) possessed the highest antioxidant activity with the lowest of 30 µg/mL with percetange of inhibition at 85.69 % evaluated by (2,2-diphenyl-1-picryl-hydrazyl-hydrate) DPPH scaveging assay. In conclusion, bee species was considered as important factor in selecting the quality of propolis. It was found that H. itama produced the most active extract compared to other species. The data obtained from this study would be the basis for further investigation on therapeutic application especially for cytotoxic activity, antioxidant and phytochemical screenings for four Malaysian stingless bees of propolis.
TL;DR: The main objective for unit commitment, in general, minimizes the total cost of operating a unit, and at the same time maintain the constraints met, and according to the plan of mixing unit and operating constraints is met.
Abstract: The daily load is the main issue for many power plant industries that are affected by the varying maximum and minimum peak hours. Due to electricity being used less during the weekends, compared to weekdays, where the spending is higher. The same logic applies to day and night spending, which requires balancing among the units so that it can operate during high demand hours. The main problem is to determine the units that will be affected according to the operation schedule which means which unit, and for how long, will it stay on or off. In this context, the main objective for unit commitment, in general, minimizes the total cost of operating a unit, and at the same time maintain the constraints met. Several approaches and techniques used in existing studied, each have a solution for the optimal unit commitment problem. Some of the approaches presented, use complex methods in order to address the issues, while others use simple forms to do the same task. The problem of operation scheduling for unit commitment will be different depending on the type of industry, and according to the plan of mixing unit and operating constraints.
TL;DR: In this paper, the optimum dosage, pH, shaking speed and contact time for ammonia nitrogen removal were determined based on the adsorption of ammonia nitrogen by zeolite in rubber wastewater.
Abstract: Rubber industry wastewater contains high concentration of nitrogen, organic compound and another contaminant. If an elevated level of ammonia and nitrogen is discharged to water bodies, it could contribute to undesirable eutrophication and lead to death of some aquatic organisms. This experiment was designed to investigate the efficiency of zeolite as adsorbent in removing ammonia nitrogen from rubber wastewater. In this study, wastewater samples were collected directly from the wastewater discharge point of a manufacturer in Kluang, Malaysia. The optimum of dosage, pH, shaking speed and contact time for ammonia nitrogen removal were determined. Result indicated the optimum dosage, pH, shaking speed and contact time respectively was 4g, pH 7, 150 rpm and 90 minutes based to the adsorption of ammonia nitrogen by zeolite. The zeolite resulted in 87.2% of ammonia removal efficiency.
TL;DR: In this article, N'-benzoylisonicotinohydrazide derivative compounds (a-l ) were prepared using acylation reactions between isonic-drugs and benzoyl chloride derivatives, employing the reflux method.
Abstract: Tuberculosis (TB) is a chronic disease as a result of Mycobacterium tuberculosis . It can affect all age groups, and hence, is a global health problem that causes the death of millions of people every year. One of the drugs used in tuberculosis treatment is isonicotinohydrazide (Isoniazid). In this study, N'-benzoylisonicotinohydrazide derivative compounds ( a-l ) were prepared using acylation reactions between isonicotinohydrazide and benzoyl chloride derivatives, employing the reflux method. Molecular docking studies suggested that all of the compounds had better interaction with Mycobactarium tuberculosis enoyl-acyl carrier protein reductase (InhA) than isonicotinohydrazide. It can be concluded that N'-benzoylisonicotinohydrazide derivatives ( a-l ) can be used as anti-tuberculosis candidates. The docking results obtained revealed that all of the compounds were interacted well with InhA, with compound g exhibiting the best interaction.
TL;DR: In this paper, the ability of Ralstonia pickettii on biodegradation of crude oil under high salinity medium was investigated, and the results showed that R. picketti had successfully degraded the crude oil in the high-salinity artificial seawater.
Abstract: Bacterium Ralstonia pickettii has ability to survive and thrive in low nutrient condition as well as a capability to remediate some pollutants and using them as carbon and energy source. In this study, the ability of R. pickettii on biodegradation of crude oil under high salinity medium was investigated. R. pickettii was pre-incubated in nutrient broth (NB) medium and then, washed and transferred to artificial seawater medium. Crude oil was added to each culture and incubated for 7 and 14 days. The biodegradation of crude oil was analysed using Gas chromatography mass spectrometry (GC-MS). The result showed that R. pickettii had successfully degraded the crude oil in the high salinity artificial seawater. The incubation on 7 and 14 days did not show a significant effect on the number of the degraded compounds. The optimum recovery percent was obtained from the derivation of 2,6,10,14-tetramethyl hexadecane with the recovery percentage of 12.7% and 16.0% for 7 and 14 days respectively. This study indicates that R. picketti can be potentially used for bioremediation of crude oil under high salinity environments.
TL;DR: The modification to SR1 update was proposed by simply approximating the inverse Hessian matrix with an identity matrix without computing the Jacobian, which yielded a method that is suitable for solving symmetric systems of nonlinear equations.
Abstract: The systems of nonlinear equations emerge s from many areas of computing, scientific and engineering research applications. A variety of an iterative methods for solving such systems have been developed, this include the famous Newton method. Unfortunately, the Newton method suffers setback, which includes storing matrix at each iteration and computing Jacobian matrix, which may be difficult or even impossible to compute. To overcome the drawbacks that bedeviling Newton method, a modification to SR1 update was proposed in this study. With the aid of inexact line search procedure by Li and Fukushima, the modification was achieved by simply approximating the inverse Hessian matrix with an identity matrix without computing the Jacobian. Unlike the classical SR1 method, the modification neither require storing matrix at each iteration nor needed to compute the Jacobian matrix. In finding the solution to non-linear problems of the form 40 benchmark test problems were solved. A comparison was made with other two methods based on CPU time and number of iterations. In this study, the proposed method solved 37 problems effectively in terms of number of iterations. In terms of CPU time, the proposed method also outperformed the existing methods. The contribution from the methodology yielded a method that is suitable for solving symmetric systems of nonlinear equations. The derivative-free feature of the proposed method gave its advantage to solve relatively large-scale problems (10,000 variables) compared to the existing methods. From the preliminary numerical results, the proposed method turned out to be significantly faster, effective and suitable for solving large scale symmetric nonlinear equations.
TL;DR: In this article, the polymer electrolyte materials based on poly caprolactone (PCL) have been synthesized and characterized by impedance spectroscopy X-ray diffraction (XRD) and Infrared Spectrometer (FTIR, Scanning Electron Microscope (SEM).
Abstract: In this research the polymer electrolyte materials based on poly caprolactone (PCL) has been synthesized and characterized. Polycaprolactone is a non-toxic and biodegradable polymer that is environmentally friendly. The preparation of the polymer electrolyte film is carried out by a casting method whereby the PCL polymer is dissolved in a tetrahydrofuran (THF) solvent. Lithium perchlorate salt (LiClO 4 ) as a source of lithium ions then was added to solution with a composition (5-40)% by weight. The solution was evaporated slowly in vacuum oven until the film was formed. The ionic conductivity, crystal structure, morphology and thermal properties of the polymer electrolyte were characterized by impedance spectroscopy X-ray diffraction (XRD) and Infrared Spectrometer (FTIR, Scanning Electron Microscope (SEM). and Differential Scanning Calorimeter (DSC) respectively. The results of the conductivity measurements showed that the PCL conductivity increased from 3.45 x 10 -11 Scm -1 to 5.52 x 10 -6 Scm -1 with a 30% weight salt content of LiClO 4 . Observations with XRD show a more amorphous polymer with more salt addition and FTIR results show that there is interaction between active groups on polymers with salt. The thermal properties show that the melting points of polymer become lower with more salt addition.
TL;DR: Water-Soluble Chitosan (WSC) was synthesized form shrimp and mussel shells wastes and used as corrosion inhibitor on tinplate in 2% NaCl as mentioned in this paper.
Abstract: Water-Soluble Chitosan (WSC) was synthesized form shrimp and mussel shells wastes and used as corrosion inhibitor on tinplate in 2% NaCl. Chitin was extracted from shrimp and mussel shells wastes by demineralization and deproteinization reactions.Chitin was deacetylated to crude chitosan. WSC was obtained by shortening the crude chitosan polymer chain using H 2 O 2 . WSC was characterized by FTIR. WSC performance as corrosion inhibitor on tinplate in 2% NaCl was studied by weightloss and potentiodynamic polarization methods. WSC inhibition efficiency was studied in various concentrations from 10-1500 mg/L. Maximum inhibition efficiencies of WSC from shrimp shells waste were 72,73% (weightloss method) and 91,41% (potentiodynamic polarization method), while maximum inhibition efficiency of WSC from mussel shells waste was 54,55% (weightloss method) with the addition of 1300 mg/L WSC concentration. Weightloss studies revealed that WSC acted as mixed type of inhibitor and obeyed Freundlich adsorption isoterm.
TL;DR: Two tetradentate phenolic Schiff base ligands, namely 2,2'-((1 E, 1' E )-(1,2-phenylenebis(azanyl-ylidene))bis(methanylylidene)diphenol, L1H, L1F and their new nickel(II) complexes were successfully synthesized, characterized and evaluated for their in vitro anticancer activities against human colon cancer cell lines, HCT116.
Abstract: Two tetradentate phenolic Schiff base ligands namely 2,2'-((1 E ,1' E )-(1,2-phenylenebis(azanyl-ylidene))bis(methanylylidene))diphenol, L1H , 2,2'-((1 E ,1' E )-(1,2-phenylenebis(azanylylidene))bis-(methanylylidene))bis(4-fluorophenol), L1F and their new nickel(II) complexes were successfully synthesized, characterized and evaluated for their in vitro anticancer activities against human colon cancer cell lines, HCT116. The compounds were characterized using FT-IR, 1 H and 13 C NMR, UV-Visible, elemental analysis and melting point. The anticancer results revealed that the parent ligands were more active than their corresponding complexes with L1F being the most potent anticancer compound with IC 50 of 2.8 mg/ml.
TL;DR: In this article, the structural and characterization of insoluble Thai Bombyx Mori SF with different types of post-treatement was conducted to compare their structural conformation, characterization and thermal stability.
Abstract: Bombyx Mori fiber consists of two major proteins which are fibroin and sericin. The silk fibroin (SF) is the core structural protein of silk fiber. SF protein structures comprise of primary and secondary structures; where the primary structure contains series of amino acid and secondary structure with Silk I refers to the water-soluble and Silk II, high β sheet extent which is insoluble. This study was conducted to compare the structural and characterization of insoluble Thai Bombyx Mori SF with different types of post-treatement. Thai silk cocoons, which were degummed and dissolved in 9.3 M LiBr solution at 60 °C. The obtained SF solutions were dialyzed and purified. SF films were prepared by solution casting and immersing in methanol and ethanol, followed by water annealing in water saturated vacuum. Post-treatment was purposely done to regenerate and induce of the β sheet structure to enhance the insolubilities and the stabilities properties of the SF films. The SF films structural conformation, characterization and thermal stability were characterized. Attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR) showed that SF films were presented in a more stable form after ethanol post treatment, which also supporting by X-ray diffraction (XRD) analysis which indicated the tendency to higher structural organization. Thermal analysis resutls showed that SF was thermally stable and improved after post treatment. The contact angle of post treated SF increased the hydrophobicity of the films. The thai SF films could be the promising candidate for applications in tissue regeneration, optical devices, and flexible electronic displays with the possibility to control the SF structure and properties.
TL;DR: In this paper, a hard template for ZTC, called Zeolite-Y, was synthesized via hydrothermal method, and the template was removed through acid treatment to obtain ZTC which was used as filler for membrane preparation.
Abstract: Zeolite templated carbon (ZTC), a structurally unique carbon material was used as new filler s for the preparation of composite polymeric membrane derived from BTDA-TDI/MDI (P84) co-polyimide. The thermal stability of membrane, the structure evolution, morphology and topology, as well as gas separation performance of modified membranes were investigated. Zeolite-Y, a hard template for ZTC, was synthesized via hydrothermal method. The ZTC was synthesized via impregnation of sucrose as carbon precursor into zeolite pore and followed by carbonization at 800°C. The zeolite template was removed through acid treatment to obtain ZTC, which was used as filler s for membrane preparation. The membrane was prepared using P84 co-polyimide as membrane precursor via phase inversion process. Synthesized materials were characterized using SEM, XRD, N 2 adsorption-desorption isotherm and TEM. The thermal stability of membrane was improved by the addition of ZTC. As the result of ZTC loading into P84 co-polyimide membrane, the gas permeability of CO 2 increased thirty-four times, as well as the CO 2 /CH 4 selectivity boosted from 0.76 to 5.23. The ordered pore structure in ZTC plays important role in increasing the permeability and selectivity performances of the P84 co-polyimide membrane.
TL;DR: In this review article, 16 research journals showed that deep learning algorithm has high diagnostics accuracy in assisting the professional diagnosticians to determine diagnosis outcome accordingly.
Abstract: Diagnosis is a crucial step to identify the disease that experienced by the patient. Diagnosis includes information gathering, integration, and interpretation. However, diagnosis process is not an easy task. Diagnostic accuracy is depending on the experience and cognitive ability of diagnosticians. The new algorithm called deep learning that is developed by simulating the human visual mechanism has been implemented in medical diagnostics. One of the diseases that can be diagnosed by using deep learning algorithm is the breast cancer. Several studies showed that deep learning algorithm can be used for detecting and classifying lesions, detecting mitosis, and predicting specific gene status. In this review article, 16 research journals were reviewed and discussed. The limitations of each algorithm are provided. All of the journals showed that deep learning algorithm has high diagnostics accuracy in assisting the professional diagnosticians to determine diagnosis outcome accordingly.
TL;DR: In this article, two crude kaolin were obtained at various locations in Peninsular Malaysia to serve as precursor for synthesis of zeolite, and the synthesized product was then analyzed using X-ray diffraction and scanning electron microscopy to evaluate the potentials of the process and the product.
Abstract: The use of kaolin as a source of silica and alumina for synthesis of zeolite has been widely reported with various compositions and processing routes. However, since kaolin is highly influenced by geological origin and geographical formation, coupled with the processing method, two different crude kaolin were obtained at various locations in Peninsular Malaysia to serve as precursor for synthesis of zeolite. Hydrothermal treatments were made at reasonable low temperature of 90 ° C in an oven. The synthesized product was then analyzed using X-ray diffraction and scanning electron microscopy, to evaluate the potentials of the process and the product. The outcome of the analysis suggested that the breaking down of the clay structure and the armophization process can improve raw material reactivity. However, the crystallinity and composition of the crude kaolin together with appropriate incubation time can greatly influence the synthesis process and the product.
TL;DR: In this article, a self-doped titanium dioxide (C/TiO 2 ) photocatalyst was synthesized by a simple sol-gel method using titanium isopropoxide as both the titanium precursor and carbon source.
Abstract: Carbon self-doped titanium dioxide (C/TiO 2 ) photocatalyst was synthesized by a simple sol-gel method using titanium isopropoxide as both the titanium precursor and carbon source. The effects of calcination temperatures in the range of 300 to 700 °C to the structure and physicochemical properties of the C/TiO 2 were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray (EDX), Fourier transform infrared (FTIR) spectroscopy, UV-visible diffuse reflectance (UV-Vis DR) spectroscopy, photoluminescence spectroscopy, N 2 adsorption-desorption and X-ray photoelectron spectroscopy (XPS). XPS results proved the presence of self-doped carbon at the interstitial and substitutional lattice of TiO 2 . The C/TiO 2 calcined at 300 and 400 °C (C/TiO 2 -300 and C/TiO 2 -400, respectively) showed mesoporous characteristic and large surface area of about 100 m 2 g -1 . The C/TiO 2 photocatalysts were then tested in the photo-oxidation of styrene under visible light irradiation with aqueous hydrogen peroxide as the oxidizing agent. The C/TiO 2 photocatalysts were successfully activated under the irradiation of visible light, where C/TiO 2 -300 and C/TiO 2 -400 showed the highest total concentration of products (benzaldehyde and styrene oxide) at 1.1 mmol and 1.0 mmol, respectively. For video presentation, kindly please visit this link:
TL;DR: From the findings, the pin placement at the second cortex of bone provided optimum stability in terms of stress distribution and displacement, which should be considered for better treatment for transverse tibia fracture.
Abstract: Biomechanical perspective of external fixator is one of the greatest factor to consider in successfully treating bone fracture. This is due to the fact that mechanical behavior of the structure can be analyzed and optimized in order to avoid mechanical failure, increase bone fracture healing rate and prevent pre-term screw loosening. There are three significant factors that affect the stability of external fixator which are the placement of pin at the bone, configuration and components of external fixator. These factors lead to one question: what is the optimum pin placement in which exerts optimum stability? To date, literature on above mentioned factors is limited. Therefore, we conducted a study to evaluate the uniplanar-unilateral external fixator for two different pin placement techniques in treating transverse tibia fracture via finite element method. The study was started off with the development of transverse tibia fracture using Mimics software. Computed tomography (CT) data image was utilized to develop three dimensional tibia bone followed by crafting fracture on the bone. Meanwhile, the external fixator was developed using SolidWork software. Both tibia bone and external fixator were meshed in 3-matic software with triangular mesh element. Simulation of this configuration was took place in a finite element software, Marc.Mentat software. A load of 400 N was applied to the proximal tibia bone in order to simulate stance phase of a gait cycle. From the findings, the pin placement at the second cortex of bone provided optimum stability in terms of stress distribution and displacement, which should be considered for better treatment for transverse tibia fracture. On the other hand, the pin placement at first cortex should be avoided to prevent many complications.
TL;DR: It is suggested that agarwood hydrosols of Aquilaria malaccensis possess both anti-attachment and cytotoxic effects on Calu-3 lung cancer cells, and holds a potential to be further investigated as a source of anti-cancer compounds.
Abstract: This is the first report discussing the chemical profile of agarwood hydrosol and its potential anticancer effects. Agarwood hydrosols, from two batches, obtained from Negeri Sembilan, Malaysia, were used in this study. Calu-3 cancer cells were used as a model cell line for lung cancer. The cells were cultured in Eagle’s minimum essential medium (EMEM) supplemented with 10% (v/v) fetal bovine serum (FBS). The study was carried out in two phases, namely the anticancer study via an attachment (AT) assay and cell viability (CV) assay, and then profiling the hydrosol from the two batches via GCMS and hSPME-GCMS. Design Expert software’s two-factor face-centered central composite design (FCCCD) was used to study the effects of agarwood hydrosol amount and time of exposure on cell attachment (AT) and viability (CV). The findings suggest that agarwood hydrosols of Aquilaria malaccensis possess both anti-attachment and cytotoxic effects on Calu-3 lung cancer cells. A linear model was developed for anti-attachment effects and a quadratic model for the cytotoxic effects with exposure duration being significant in both cases. From the profiling data, 1-tricosene and 16-hentriacontanone were identified as potential contributors to the anti-attachment and/or cytotoxic activity observed. In conclusion, agarwood hydrosol holds a potential to be further investigated as a source of anti-cancer compounds.
TL;DR: In this article, a study on the development of water quality index of ex-mining ponds was carried out for proper assessment and utilization of the abundant exmining ponds in Malaysia, where heavy metals were analyzed using inductively coupled plasma mass spectrophotometer (ICPMS), and physico chemical parameters were analyzed in-situ.
Abstract: In this paper, a study on the development of water quality index of ex-mining ponds was carried out for proper assessment and utilization of the abundant ex-mining ponds in Malaysia. Heavy metals were analyzed using inductively coupled plasma mass spectrophotometer (ICPMS), and physico chemical parameters were analyzed in-situ. Chemometric analysis was successfully applied for the parameter selection process. The water quality index of existing Malaysian river did not accommodate the toxic metal pollutants that dominanted in ex-mining water. The acceptable index should therefore incorporate the metal pollutants in order to evaluate the quality status of ex-mining water for human consumption which is the major point of consideration. Two water quality indices were developed to assess the water quality status of ex-mining ponds with reference to Malaysia’s water quality standard (INWQS). The heavy metal index was comprised of contribution from Pb, As, and Cd as the selected metals, while the physico-chemical parameter index has BOD, pH, DO, and AN. Chemometric analysis revealed the dominance of the selected heavy metals in ex-mining water, and physico-chemical parameters were important in water quality monitoring. Heavy metal water quality index revealed that most ex-mining ponds in Klang Valley were classified to be very poor hence could not be used for human consumption. Due to domestic input in some of the lakes in Klang Valley, the physico-chemical water quality index was in very poor status as well. In Melaka and Negeri Sembilan, ex-mining ponds and lakes were classified as excellent in both indices.