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Effect of the HNTs nanotubes together with MWCNTs nanotubes on the IS of PMMA composites compared to PMMA matrix FIGURE 4. Therefore, this research was done to study the effects of incorporating HNTs and MWCNTs into the PMMA denture base, in terms of PMMA properties concerning Vicker's hardness, and impact strength. Effect of the HNTs nanotubes together with MWCNTs nanotubes on VH of PMMA composites compared to PMMA matrix. Figure 7 shows the impact fracture surface of 4.5 wt% HNTs+ 0.5wt% MWCNTs nanotubes filling the PMMA matrix, where the surface was full of sharp ridges and rough cracks propagation, which proves the interaction between the nanotube fillers and PMMA matrix. [Extracted from the article]

The current work reports on the development of Au nanoparticles (NPs) supported on titania membrane towards enhancing catalytic reduction of p-nitrophenol. Titania membrane was successfully fabricated via chemical anodization method at 50 V in ethylene glycol: water as the electrolyte. A well-ordered nanotubular array of 138±18 nm pore diameter was observed by electron microscope. The Au NPs were deposited on titania in form of membrane (Au/TiO2 MF) by immersing in Au precursor (HAuCl4) solution at pH 7 for 2 hours. Meanwhile, the preparation of Au/TiO2 powder form (PF) follows similar procedures but using commercial TiO2 (Degussa P25). The FTIR result shows the shifting of peak at 1067 cm-1 to 1107 cm−1 for TiO2 membrane and Au/TiO2 MF, respectively which corresponds to Ti-O bond. Meanwhile the Ti-O bond was shifted from 1066 cm-1 (titania powder) to 1097 cm-1 for Au/TiO2 PF. The shifting of IR peak indicates successful attachment of Au on titania. Surface morphology by FESEM shows the Au of 27.95±5.8 nm and 30.59±2.11 nm size was obtained for Au/TiO2 in MF and PF, respectively. The Au/TiO2 MF exhibits superior catalytic activity in the reduction of p-nitrophenol, with a rate constant (k) value of 5.9 x 10-3 s−1. A slight decreased in the k value was observed after this catalyst been reused. This study offers an effective development of catalytic membrane with high activity and good stability. [ABSTRACT FROM AUTHOR]

Rare earth (RE)–doped glass ceramics are promising materials for various photonics applications as the ions have photoluminescence properties from ultraviolet to near infra-red regions. In this paper, we present a report on SiO2− ZrO2:Er3+/Yb3+ planar waveguides, prepared using the sol-gel/dip coating technique. Thin films of 70SiO2 −30ZrO2 doped with three different ratios of Er3+/Yb3+ doping were fabricated on fused SiO2 glass and silicon (Si) wafer substrates. Optical and structural properties were obtained by prism coupler, atomic force microscopy (AFM), UV-VIS-NIR spectrophotometer, photoluminescence spectrophotometer and Raman spectrophotometer. Thin films coated on Si wafer showed positive effect on the film properties compared to the fused SiO2 substrate. The study showed that all samples emit red and green emission with the Si wafer coated film shows higher emission intensity and smoother surface morphology. The addition of high Er3+/Yb3+ doping increases the refractive index of the film which is beneficial for waveguiding properties. The Raman study showed that the substrates influenced the crystallinity of the films. Interaction between the RE ion doping and host material is critical in optimizing the performance of the devices. [ABSTRACT FROM AUTHOR]

This paper reviews the piezoelectricity in the ZnO which having enough feasibility for flexible piezoelectric energy harvesting. ZnO is chosen as a new lead-free replacement material of PZT due to its great advantages for piezoelectric material. The low cost and small-time require for the synthesis of ZnO thin films for industrial requirements are always a need. The ZnO nanostructures can be used in applications such as foldable or re-formable power sources, artificial skins, touch sensors, and flexible displays. It is also possible for ZnO nanostructures to generate the current and potential under an external mechanical strain. The mechanism of the power generator relies on the piezoelectric and semiconducting properties of ZnO as well as the formation of a Schottky barrier between the metal and ZnO contacts. ZnO is piezoelectric material which is popularly used as one of the pollution-free piezoelectric material and has the additional advantage of flexibility in processing. This paper reviews the reported piezoelectric energy harvesting of ZnO material and piezoelectric device configurations. [ABSTRACT FROM AUTHOR]

A polycrystalline manganite sample of La0.90Bi0.10MnO3 has been synthesized using the solid-state reaction method and its dielectric properties and ac conductivity has been investigated in detail. X-ray diffraction result shows that the sample possesses orthorhombic Pnma structure and from scanning electron microscope, the sample was compact with some voids. Both, the dielectric permittivity and dielectric loss of the sample are frequency and temperature dependent. Fitting analysis using universal capacitor response indicates that the electron motion is highly correlation between inter and intra-clusters. From the ac conductivity measured at 298 K to 453 K, the conduction process follows the correlated barrier hopping (CBH) model which allows for hopping of both single and pair of electrons from between Mn3+ and Mn4+. The magnetic characteristic of the sample yields coercivity, Hc of 36.109 G and retentivity, Mr of 2.7504 x 103 emu/g. [ABSTRACT FROM AUTHOR]

Polyvinylidene Fluoride (PVDF) thin films were prepared using solvent casting technique at constant formulation and stretched with various mechanical stretching time (1, 2, 3, 4 and 5 minutes). PVDF were stirred for 24 hours by magnetic stirrer at 600 rpm and were casted on glass petri dish before dried in an oven at 115 °C until fine thin film formed. The thin film successfully stretched with tensile machine with constant speed at 10 mm/min at different stretching time. The different of polymorphism on PVDF thin films were studied using Differential Scanning Calorimetry (DSC) and Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR). Three minutes stretching time showed to experience a yielding and necking area. Degree of crystallinity calculated also revealed that three minutes stretching time have the highest number which is 51.57% crystallinity. In addition, three minutes stretching time has been identified to have high β phase observed by ATR-FTIR due to shifting and decreasing intensity at 1178 cm−1 while increasing of transmittance at 834 cm−1 wavenumbers. Thus, it is concluded that three minutes stretched PVDF thin film have high β phase in polymorphism among those other stretching time. This β phase is desirable in PVDF because the development is required in sensor application. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the effects of cooling rates on contact angle, joint strength and intermetallic of Sn-9Zn solder alloy. Solder alloy was cooled at different cooling rates after reflow process on the Cu substrate at temperature of 250 °C for 1 minute. Samples were cooled at cooling rates of 0.17 °C/s, 1.08 °C/s, 1.23 °C/s and 1.31 °C/s. Scanning Electron Microscope (SEM) was used to observe the intermetallic compound of the solder alloy. Meanwhile, tensile strength machine was used to measure joint strength of solder alloy. Optical microscope was used to measure wetting angle. Under slower cooling rate, which is cooling on hot plate, intermetallic thickness was 9.66 µm, contact angle was 57.00° and it has lowest tensile strength of 26.25 MPa among the cooling rates. While, for faster cooling rate of 1.31 °C/s has intermetallic thickness of 2.77 µm, contact angle of 39.58° and has highest tensile strength among all the cooling rates which was 35.08 MPa. [ABSTRACT FROM AUTHOR]

Aluminium zinc oxide (AZO) thin film has been fabricated using a spray pyrolysis method. The thin film deposition has been carried out by spray pyrolysis on Teflon substrates. The structural properties of AZO thin films were characterized using X-Ray Diffraction (XRD) for the crystallinity of AZO thin films. The structural analysis of AZO thin films deposited with different nozzle-substrate distance have a preferred orientation along the direction (100). The optical properties of AZO thin films were examined by using UV-Vis-NIR spectrophotometer for reflectance and optical band gap energy. The optical analysis shows that the AZO thin films have reflectance value in between 55 – 80%. The optical band gap values were deduced from the optical spectra vary between 3.18 and 3.24 eV. [ABSTRACT FROM AUTHOR]

Maleated soybean oil (MSO), was used as production of eco-friendly thermoset resins. Sample of Epoxidized soybean oil (ESBO) was initially reacted with maleic anhydride, hydroquinone and ethanol in a reaction vessel at 70°C for 150 minutes by using mechanical stirrer at 300 rpm. The esterification process of maleated soybean oil (MSO) was observed by Oxirane Oxygen Content (OOC) and Acid Value (AV) determination via wet titration. The mixture of MSO, propylene glycol (PG) as a curing agent and 3-triethoxysylilpropilamine (TP) as a catalyst were stirred in a beaker at 60°C for 15 minutes to produce thermoset films. Three formulation ratios of PG to TP were used (30PG:70TP, 50PG:50TP, 70PG:30TP). The viscosity test, Fourier Transform Infra-Red (FTIR), Volatile Organic Compound (VOC) test, pencil hardness and gel content test was used to evaluate the performance of the films. FTIR results for MSO were confirmed by the existence of 3321.6 cm−1 represents the OH functional group, while the peak at 1757 cm−1 is an ester C=O functional group indicates the successful of esterification process. The wavenumber at 3458.11 cm-1, 3452.60 cm-1 and 3457.98 cm-1 corresponded to the hydroxyl group that exist in the structure of MSO films. MSO produced 3% VOC content indicates that it is safe to use as bio-based coating as it emits low emission of VOC. The sample with the best films properties is 70PG:30TP which lead to get H hardness and has 90% gel content. This could be representative for the maximum crosslinking degree. [ABSTRACT FROM AUTHOR]

Ab initio calculations within the density-functional theory (DFT) are carried out to investigate the electronics and magnetic properties of the p-block elements doped two-dimensional GaN (2D GaN). We have selected Al, Si, P and S dopants as the representative for Group III, IV, V and VI elements, respectively. Depending on the type of dopant and substitution site, the semiconducting characteristic of the 2D GaN can be changed into metallic. Similarly, magnetism can be induced on the 2D GaN with the total magnetization varied from 0.5 µB to 1.46 µB. [ABSTRACT FROM AUTHOR]

The study investigated the performance of the solar/TiO2 photocatalysis process for the photocatalytic degradation of organic compounds: fluoranthene (FLT) and pyrene (PYR) from synthetic rainwater samples. Central composite design (CCD) based on the response surface method (RSM) was employed to study the interaction between operating parameters that can influence the removal of FLT and PYR, including the initial concentration, TiO2 dosage, and pH to identify the optimum operating conditions required for the maximum removal efficiency of FLT and PYR. Findings from the analysis of variance (ANOVA) revealed that quadratic models for FLT and PYR removals were significant with low probabilities (< 0.0001). Experimental removal responses for both FLT and PYR well correlated with the predicted models, thus confirming the validity of the model. The highest removal rate for FLT and PYR was 88% and 90%, respectively, under optimum operating conditions of initial concentration (125 µg/L), TiO2 dosage (1.5 g/L), and pH 7. [ABSTRACT FROM AUTHOR]

Ethylene Propylene Diene Monomer Rubber (EPDM) waste is a vulcanize rubber waste that content a highly crosslinking molecular structure which makes recycling and waste management of the EPDM waste to be a challenge. Hence, the microwave devulcanization method is one of the most promising method to recycle rubber waste as it gives a uniform heating throughout the rubber waste. The microwave radiation may effectively break the rubber waste crosslink molecular structure. In this study, grind EPDM (G-EPDM) was devulcanize at a different exposure microwave radiation time (3, 5, 7 and 9 minutes) and blended with natural rubber (NR). Then, the blends were characterized for Fourier Transform Infrared (FTIR), cure characteristics, swelling, and crosslink density. The Fourier Transform Infrared (FTIR) spectrum of the microwave devulcanized EPDM shows changes after the radiation. The FTIR spectrum of G-EPDM and microwave devulcanized EPDM was focused at wavenumber of 1659 cm−1 (C=C link), 1532 cm−1 (methyl-assisted conjugated double bond), 1392 cm−1 (CH3) and 856 cm-1 (RC=CH2 group). Observed of spectrum changes after the G- EPDM was exposed to the microwave radiation. Meanwhile, the infrared spectrum of NR/G-EPDM and NR/M (5)–EPDM, were studied at wavenumber of 1272 cm-1, 962.3 cm−1, and 874 cm−1 and 667 cm−1 indicate the C-N aromatic group, S-O bond and C-S bond, respectively. From G-EPDM until 5 minutes exposure times, crosslink density shows an increment pattern of 21.13% conversely swelling of rubber which shows a decrement pattern of 5.14 %. [ABSTRACT FROM AUTHOR]

A gel polymer electrolytes (GPEs) comprising of 62.3 mol% of epoxidized-30% poly(methyl methacrylate) grafted natural rubber (62.3 mol% of EMG30) as a polymer host, LiCF3SO3 as a dopant salt and ethylene carbonate (EC) as plasticizer were prepared by solution-casting technique. The temperature dependence of the conductivity of the polymer plasticizer were prepared by solution-casting technique. The temperature dependence of the conductivity of the polymer films obey the Vogel-Tamman-Fulcher (VTF) relationship. The complexation between polymer, salt and plasticizer is observed in FTIR results. In the EMG30-LiCF3SO3-EC samples, the shifting of the v(C=O) mode of EC can be due to the interaction between EC and polymer or the coordination of Li+ on EC. The Li/Li+ interface stability of GPE with the oxidation occurs at the potentials 5.7 V making it suitable for possible use in the fabrication of lithium polymer cells. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) dispersion in different solvents has been investigated by Fourier-transform infrared spectrometer (FTIR), UV-Vis spectrometer, densimeter and Semiconductor Parameter Analyzer (SPA). GO was prepared by modified Hummers method and dispersed in different solvents, namely acetone (A-GO), ethanol (E-GO) and deionized water (DIW-GO) Full exfoliation of each dispersion was achieved by sonication. The prepared GO dispersions has been compared with raw graphite during characterization and conductivity analysis. From FTIR analysis, peak characteristics of GO can be observed at 3595 cm−1 (E-GO), 3740 cm-1 (A-GO) and 3733 cm−1 (DIW-GO) which correspond to hydroxyl group. In UV-Vis spectra analysis, two major absorbance peaks around 230 nm which correspond to л-л* transitions can be observed in all GO dispersions except for graphite. It is found that E-GO had the highest density value (2.26 g/cm3). Result obtained by SPA analysis shows that the highest resistance value (Ω) is denoted by DIW-GO (5.81x107 Ω) followed by graphite (4.86x106Ω), A-GO (4.59x106 Ω) and E-GO (3.69 x106 Ω) respectively. The results reported in this study could serve as a basis to facilitate the fabrication of GO material in various applications. [ABSTRACT FROM AUTHOR]

Herbicides are well known in agriculture to kill unwanted plants such as weeds that invading the crops and affecting its quality. However, the application of herbicides at a large scale can be alarming to the environment especially to the human health. The synthesized nanohybrid can minimize the negative impacts to the environment caused by the higher concentration of common herbicides as the system controls the delivery rate of the agrochemicals. In this study, Layered Hydroxide Salt (LHS) was used whereby has successfully interleaved with the herbicide, namely 4-chlorophenoxyacetic acid (4CPA) to form zinc layered hydroxide-4CPA (Z4CPA) nanohybrid. Z4CPA was synthesized by ion exchange method followed by hydrothermal treatment at anions concentration of 0.1 M. Characterization using PXRD validated the claim due to in the Z4CPA diffractogram, zinc oxide fingerprint peaks disappear while the basal spacing of 21.6 Å that complement the previous study signifying an interleaved metal hydroxide existed has indeed appeared. FTIR spectrum further shows that 4CPA prominent bands exist in the Z4CPA spectrum with slight changes in wavenumber hinting the possibility of interleaved happened due to the formation of new bands. The result from BET proves that the product was mesoporous material with increased surface area as compared to the zinc oxide precursor. The FESEM-EDX shows the surface morphologies from irregular to flaky shapes for ZnO and Z4CPA nanoybrid. Control release study was performed using UV-Vis spectroscopy in 0.01 M media solution of NaCl, Na2CO3 and Na3PO4 respectively after positive results were obtained from PXRD, FTIR, FESEM-EDX and BET analysis. The saturated release of the anions is in the order of phosphate>carbonate>chloride with percentages of 90%, 75% and 50%, respectively. This study indicates the potential application of LHS as a host for herbicide, 4CPA, with controlled release capability apart of providing an alternative for a low-cost and green herbicide. [ABSTRACT FROM AUTHOR]

Dye water pollution is the common problem in industries, especially textile industry. The conventional biological waste water treatment is not efficient enough to fully degrade coloured dye waste water stream. However, dye pollutants are able to be more efficiently broken down by light sources. Photocatalytic degradation of rhodamine B (RhB), methylene blue (MB) and methyl orange (MO) under sunlight by self-made photoreactor were studied. Graphitic carbon nitride (g-C3N4) with band gap energy of 2.75 eV is used as the photocatalyst. It is a visible light activated photocatalyst synthesized at temperature of 500 °C for 3 hours in muffle furnace. The degradation rate of different dye was investigated and the effects of flow rate were studied. RhB dye showed the highest potential to be degraded under sunlight illumination. With the use of self-made photoreactor model at highest flow rate, the degradation efficiency was found to be 100% under 2 hours of sunlight illumination. The modifications on reactor successfully increase the sunlight concentration and improved the rate of degradation. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) capture by using calcium (Ca)-based adsorbents derived from natural wastes has attracted the attentions of many researchers nowadays. Utilization of these natural materials in CO2 capture is able to reduce the cost of the adsorbents and favor to the production cost. In this research, CaO-based adsorbents that derived from natural clam (Meretrix meretrix) shells and cockle (Anadara granosa) shells were modified for their properties through ethanol-water hydration treatment and studied for their performance in CO2 capture. The effect of ethanol concentrations in ethanol-water hydration treatment was investigated in order to identify the optimum ethanol concentration to achieve desired adsorbent properties and best performance in CO2 capture. Ethanol was found to have a role in expanding the pore structure of CaO sorbents in this study. Treated CaO-based adsorbents derived from shells were found to have a higher surface area and pore volume as compared to untreated samples. CaO-based adsorbent derived from clam shells and cockle shells treated with ethanol were found to achieve higher CO2 adsorption capacity at 13.72 mmol CO2 / g adsorbent and 16.57 mmol CO2 / g adsorbent, respectively, as compared to untreated clam shells and cockle shells, which recorded CO2 adsorption capacity of 7.95 mmol CO2 / g adsorbent and 9.61 mmol CO2 / g adsorbent, respectively. This was corresponded to the higher surface area of the treated adsorbent samples, which promoted the CO2 adsorption activity. [ABSTRACT FROM AUTHOR]

Palladium(II) chloride is used as a catalyst in various carbon-carbon (C-C) coupling reactions such as the Heck, Sonogashira, Stille, Negishi and Suzuki reactions. This study involved two palladium(II)-hydrazine complexes with different functions namely dichloro-4-methoxy-N'-(3-nitrobenzylidene)benzohydrazide palladium(II) (Pd-L1) and di-4-methoxy-N'-(4-chlorobenzylidene) benzohydrazide palladium(II) (Pd-L2) as catalysts in the Heck reaction. The catalytic activity study of both catalysts in the Heck reaction between 1-bromo-4-nitrobenzene and styrene were investigated. Previously only 50% conversion rate of Heck reaction product can be observed using a similar catalyst. To enhance the catalytic performance as well as to reduce cost and time, an optimised reaction condition is needed. Several parameters have been selected, i.e., the effect of base, solvent and temperature. The excellent catalytic activity of Pd-L1 as a catalyst with 99.87% conversion rate can be achieved using 0.5 mmol % catalyst loading, Na2CO3 as the base, and DMA as the solvent at 50 °C within a 60 min reaction time. [ABSTRACT FROM AUTHOR]

Graphene treated with silane based unsaturated polyester resin was successfully prepared for primer coatings application sonication process. Corrosion has been a major issue worldwide due to its failure building structure and high maintenance. The usage of Unsaturated Polyester (UPE) alone is insufficient to inhibit the corrosion. Hence, primer coatings using UPE filled graphene (GR) been developed as a significant step to preserve the steel structures. The objectives of this study was to investigate the mechanical, adhesion and corrosive properties of various graphene loading (0, 2, 4, 6 wt%) filled unsaturated polyester reinforced on metal substrate and determine the effect of silane treatment on graphene reinforcement in unsaturated polyester-graphene coating for primer application with different silane loading (1, 3, 5 wt%) and GR loading at 4%. Mechanical properties testing has been conducted by hardness test, while as for adhesion properties testing through pull out test and contact angle measurement. Immersion test and Tafel Polarization method was conducted to determine the corrosive properties of coating. For hardness testing, UPE- GR/GPS regardless of its loading have the higher value of scratch resistance at 5H. While as for pull out test, UPE/GR and UPE/GR- GPS show the same scale which is scale 5. Hence, it shows that properties of graphene itself are higher in strength since it does not affect when the pull-out test was carried out. 3 % of UPE/GR-GPS gives high value for advancing which is 153.544° and receding is at 127.254° compared to others samples. Other than that, immersion test in two medium which is NaCl and seawater solution show an improvement of corrosion when addition of silane was implemented on graphene due to the presence of corrode can be seen at day 6 compare to other samples that started to corrode at day 3. As for Tafel polarization, 3 % UPE/GR-GPS has the highest polarization resistance which is 185.56 n and has the lowest for corrosion rate which is 0.148 mmpy. Overall, the incorporation of graphene/silane into composite improve the mechanical, adhesion and corrosive properties and the optimum coating was found at 3 % UPE/GR-GPS. [ABSTRACT FROM AUTHOR]

Progressive development of natural materials for automotive interior parts has attracted the industry attention and given rise to a need for effective simulation of designs and concepts to help achieve an efficient manufacturing product. For this purpose, numerical simulation of the preliminary forming process was conducted using the geometry model. The numerical simulation is performed using PAM-FORM software in order to stimulate the thermoforming behavior towards shear angle, thickness distribution and strain value. Upon completion of the research, three main parameters are count to consideration including puncher velocity, puncher radius and heating temperature. Results indicated that, the optimum forming process of 10 m/s of puncher velocity, 2 mm of puncher radius and 160 °C of heating temperature was recorded to acquire an excellent end-product formation especially using hot-pressing technique. Findings indicated that the optimum parameters to produce a robust design, while improving the preliminary forming process, were a thickness and shear angles of 14.1 mm and 2.2°, respectively. [ABSTRACT FROM AUTHOR]

A simple parallel plate capacitor was applied to determine the dry rubber content (DRC %) of the field latex. Based on an electrostatic theory used to describe capacitors, a parallel plate capacitor was specially designed and fabricated. Both experiments and statistical analysis have shown a good correlation between capacitance values and corresponding DRC% values in the inverse relationship. Ranges of capacitance and DRC% have presented 910 nF to 935 nF and 45 to 25, respectively. The study suggests that the DRC% can be measured with sufficient sensitivity and accuracy by parallel plate capacitor. [ABSTRACT FROM AUTHOR]

To fabricate low cost fired clay brick (FCB), rice husk ash (RHA) as agriculture waste has been successfully substituted into clay soil employing solid-state sintering process without pre-drying under natural heat process. Rice husk (RH) was first inverted into RHA as amorphous silica-based materials by burning at 800 °C for 5 hours. Then it was admixture with clay soil (CS) with the composition of RHA were varied accordingly, molded and sintered at 900 °C and 1000 °C for 2 hours. The sintered FCB was then studied through physical and mechanical through bulk density, linear shrinkage, water absorption, and mechanical force. Higher RHA content FCB is prone to shrinkage by having pronounced increment in bulk density and linear shrinkage, meanwhile ideal mechanical force (0.2 kN) was achieved by sintered at the highest temperature. Higher silica-based (40 wt%) appeared to absorbed less water in 24 hours at about 17.25%. Hence, this novel study has been promoted less time and energy consumption by reducing long drying process of molded bricks whilst utilizing an agriculture waste for an effective solution in handling the natural clay soil shortage sources by producing 3rd class classified FCB that is applied as a basic building block in a less heavy rainfall tabulation area. [ABSTRACT FROM AUTHOR]

In this paper, the sample La1-xSrxMn0.4Ti0.6O3 (x = 0.32, 0.34 and 0.38) has been fabricated using solid-state reaction method and its structural and electrical properties have been studied. The X-ray diffraction patterns reveal that the sample's structure was attributed to the cubic structure ("a" = 3.8968 Å) with space group Pm-3m and a volume of 59.17 Å3. The surface morphology shows the sample's grain and grain boundaries are well formed. As the strontium doping increase, merging between grains occurred. The electrical properties of the samples analyzed using the Cole-Cole Impedance possesses one semi-circle due to grain effect. A model using an electrical circuit has been purposed. The values of capacitance obtained are approximately 2 x10-10 F to 6 x10−10 F. [ABSTRACT FROM AUTHOR]

Oryza sativa (Rice straw) is a natural resource that has the potential as a raw material in the ceramic field. Rice straw ash (RSA) contains high silica (SiO2) after it goes through the calcination process. This paper presents the investigation on the effects of crystalline glaze using RSA as an alternative substance for silica in the glaze formulation. Silica is significant material was used in the crystalline glaze to react with zinc oxide to seeding crystals as willemite (Zn2SiO4) in the form of spherulites during the firing process. This study is performed to identify SiO2 content from RSA because this residue is still not fully utilized in Malaysia. The aims of the present study are to identify the effects of adding RSA to ceramic crystalline glaze and the potential of conventional silica replaced with RSA, as well as identifying the optimum calcination temperature of rice straw. Rice straws were fired at different firing calcination temperatures of 700 °C, 800 °C, 900 °C, and 1000 °C. Crystalline glaze samples were then fired at 1200 °C for four hours of gloss temperature and hold for five hours at crystallization temperature. After firing, the morphology of the crystalline structure on the ceramic substrate body identified using visual observation. In summary, amorphous silica derived from RSA brings high silica content. It provides a potential alternative material for silica used in crystalline glaze, SiO2 content in rice straw ash combined with zinc oxide to encourage the nucleus crystal seed. From XRF test, 89.7% silica content was determined in RSA and the results also show apparent growth of crystals on the ceramic substrate samples with different effects. [ABSTRACT FROM AUTHOR]

The aim of this study is to enhance the physical properties of the fired industrial waste-clay bricks (FIWCB) by reducing the use of clay soil (CL) as the main source of material as well as to shorten the process of making FIWCB. Industrial waste materials were used such as cockle shells (CS) due to their high thermal insulation and physical strength properties as well as soda lime silica (SLS) glass to reduce firing temperature and shorten drying process. The process only requires low energy consumption as the mixtures of SLS glass, clay soil and CS were made, the molded mixtures were then subjected to firing process to shorten the drying period of the FIWCB as oppose to the conventional method of making Fired Clay Brick (FCB) which could take up to one whole day of conventional FCB making which is rather time and energy consuming. Once completed, the FIWCB were then characterized using dimensional measurement by digital analytical and digital vernier caliper for linear shrinkage and bulk density respectively. Water absorption test was also done to investigate the durability of the FIWCB. Results showed that with optimized firing temperature of 900 oC and SLS addition of 50% by weight as well as CS addition of 0.05 wt. % into CL soil had shown the best decrement in bulk density and linear shrinkage together with lowest water absorption rate of the FIWCB. [ABSTRACT FROM AUTHOR]

In this study, the removal of lead in soil samples was carried out by eggshells activated carbon (ESAC). Magnesium chloride (MgCl2) was used as the activation agent at 500 °C for an hour. The prepared ESAC was characterized by Fourier Transform Infrared (FTIR), field emission scanning electron microscopy coupled with energy dispersive X-ray (FESEM-EDX), and Brunauer-Emmett-Teller (BET) technique was used to determine the surface area of the prepared activated carbon. The FTIR spectrum confirmed the formation of ESAC material. Besides, the EDX spectrum showed that the elements of ESAC such as carbon (C), nitrogen (N), oxygen (0), magnesium (Mg), and calcium (Ca) present in the matrix. The BET analysis showed that the surface area of ESAC was 0.5566 m2/g, and the type of pores present on the surface was macropores with an average diameter between 0.05 to 2 µm. Atomic absorption spectroscopy (AAS) was used to determine the percentage removal of lead in soil using the Aqua Regia method. [ABSTRACT FROM AUTHOR]

In this research, an attempt to synthesize a highly mesoporous carbon (MC) was done from Ceiba pentandra. Ceiba pentandra was prepared under carbonization and oxidation process at 500 °C at a heating rate of 5 °C min-1 for 30 min and 300 °C for 3 h respectively. The iodine number and percentage yield of the prepared MC was 1463.926 mgg−1 and 99.85% respectively. The raw material and the prepared MC were preliminary characterized by several characterization methods such as Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM) and CHNS/O Analyzer. FTIR analysis showed difference in IR functional groups of raw and prepared MC. Many functional groups that present in the raw material were disappeared for prepared MC due to the carbonization and oxidation process. In raw material, a strong absorption peak present at 1736.58 cm−1 indicates the presence of carbonyl group (C=O) due to existence of hemicellulose and lignin. However, the peak disappeared for the prepared MC. SEM showed no pores formation for the raw material but, enhanced porosity with an opening hole was observed for the MC. While, CHNS/O analyzer confirmed the increased in the carbon content in the prepared MC (63.84%) compared to the raw Ceiba pentandra (43.54%). This research showed a great venture in the utilization of waste biomass into quality mesoporous carbon. [ABSTRACT FROM AUTHOR]

In this work, an attempt to synthesize highly porous activated carbon (ZnCl2−AC) was carried out from dried rind Garcinia xanthochymus with 1:1.5 impregnation ratio of Raw material: ZnCl2, impregnation time of 30 min and activation temperature of 400 °C. The raw material and ZnCl2−AC were characterized by CHNS/O analyzer, Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) analyses. ZnCl2−AC was subjected for iodine number evaluation by sodium thiosulphate titration which resulted in 1033.41 mgg−1 and it registered a percentage yield of 36.43. CHNS/O analysis confirmed the increase in Carbon% in ZnCl2−AC (61.78%) compared to the raw dried rind Garcinia xanthochymus (42%). FTIR analysis proved that some functional groups observed in the IR spectra of raw disappeared for the prepared AC due to the carbonization and activation processes. SEM analysis showed changes in porosity of raw and prepared AC where the opening hole and cave occurred in surface of prepared ZnCl2−AC. To conclude, a highly porous and high surface area AC was successfully derived from low cost dried rind Garcinia xanthochymus. [ABSTRACT FROM AUTHOR]

In this research, the cellulose has been successfully extracted from different type of wastes such as paper waste (empty tissue roll (ETR) & egg tray (ET) and fruit waste (jack fruit rind (JR)). From the extracted cellulose, the cellulose had been modified to Cellulose Acetate (CA). Modification of cellulose to CA involved acetylation process that used sulphuric acid (H2SO4) as catalyst. FTIR results showed that some of the peak disappeared after extraction process at certain wavelength (1700 – 1600 cm−1, ∼1500 cm−1). The intensity of few peaks at 3500 – 3000 cm-1 and 3000 – 2800 cm-1 also decreased after extraction process. All samples (ETR, ET and JR) for CA24 exhibit lowest intensity compared to other contact time. This might be due to the increasing of acetyl group in cellulose backbone and hydrophobicity of the film. This is due to the removal of certain compounds such as lignin and hemicellulose in all raw sample. The effect of contact time (1 to 24 hours) to the acetyl content and degree of substitution (DS) had been studied. It found that, for all wastes exhibited high acetyl content and high of degree of substitution when the contact was 24 hours. In mechanical properties, all CA24 film exhibit slightly higher tensile strain compare to cellulose film for both samples (ET, ETR and JR). Young's Modulus and tensile stress for CA24 film is also higher compare to cellulose film. This is due to the elimination of OH- groups which reduce the water sensitivity of cellulose and due to the internal plasticization of CH3CO- groups. Moreover, acetylation process increase the mechanical properties of the film produced. It can also be seen that Young's modulus increase with increase in CA contact time. This is expected, as addition of CA give a dense structure to film resulting in higher modulus values than porous structure. CA-24 film has the lowest moisture uptake. This is because CA-24 has lower OH- group presence in it. Therefore, ca-24 film shows better hydrophobicity. CA-24 film has lowest solubility most likely due to the replacement of OH- groups to CH3CO- groups. The replacement of OH- groups in cellulose with CH3CO- groups reduced its solubility in water but enhance its solubility in organic solvents. DSC results revealed that the CA24 for all samples (ETRP, ETR and JR) exhibit low Tg. This is due to the fact that, the increasing of contact of time, will increase the number of acetyl group. Hence, when the number of acetyl group increased, the hydrophobicity of the film also increased. Therefore, the ability of CA to form hydrogen bonding with water molecules also decrease. Hence, the segmental molecular ability increase due to the decreasing of hydrogen bonding in CA film. [ABSTRACT FROM AUTHOR]

Bioplastic is created to overcome plastic contamination while maintaining the characteristics of plastics which are flexible, cost effective and durable. In this study, bioplastic was formulated by using agriculture waste from cassava peel. Three different concentration of glycerol were set up at 20%, 30% and 40% with constant amount of CaCO3 (filler) were used for the optimization. The characterization of the bioplastic was carried out using FTIR analysis. Each sample shows similarities in spectra, indicating similar chemical composition of functional group present - which are hydroxyl group in alcohol and phenol (O-H), aliphatic saturated hydrocarbon chain (C-H) and ester, ether, carboxylic acid as well as anhydride group (C-O). In mechanical tests, the bioplastics are divided into tensile test, water absorption test and soil burial degradation test. Through tensile test, the bioplastic with 20% of glycerol shows the highest strength up to 5.82 ± 1.00 MPa, with Young's modulus at 99.79±42.03 MPa and tensile strain at 10.34±2.43%. Through water absorption test, the highest level of water absorbance was found to be at 40% glycerol addition at 28.64±0.16% meanwhile the lowest level of absorption was at 20% which is 24.49±0.21%. Even though the 40% glycerol shows the highest degradation rate, it was found that the 20% glycerol yielded higher mechanical properties and could maintain the characteristics of plastics better than the 40% glycerol. [ABSTRACT FROM AUTHOR]

Global energy consumption has increased tremendously throughout these recent years. Fossil fuels remain as our main source of energy despite being non-renewable and finite resource. This situation will eventually lead to shortage of energy if not addressed properly. In light of this issue, renewable energy has been one of the most promising alternatives to fossil fuels as energy source. Energy are not necessarily required at large scales. For instance, conventional batteries are widely used to power up small electrical appliances. However, these batteries are not without their drawbacks hence various researches have been conducted to develop fuel cells that can be used to power up small electrical appliances. This study aims to develop reference data by using glucose as substrate in the microbial fuel cell (MFC) as well as to screen fruit waste of orange, banana and mango to be used as substrate in the MFC. The reference data was successfully developed at different amount of glucose and different temperature. High glucose concentration gives higher peak voltage output compared to low glucose concentration. However, the voltage output at low glucose level shows more stable reading. When operated at room temperature of 28 °C, the MFC produced highest peak voltage output at 360 mV. Meanwhile, the MFC of temperatures 40 °C, 50 °C and 60 °C produced highest voltage output of 259 mV, 255 mV and 320 mV respectively. Based on the collected data and other references, the MFCs were able to be effectively operated between 28 °C and 60 °C. The results from screening of fruit wastes as substrate for MFC showed that fruit waste from orange produced highest voltage output 357 mV, followed by banana and mango fruit waste. [ABSTRACT FROM AUTHOR]

Loss circulation is the total or fractional loss of drilling fluid known as mud, that happens when the fluid flows into fractures of formations, hence hindering its recirculation in oil and gas well during drilling process. This phenomenon poses a serious threat during drilling activities, especially in ensuring the consistency of formations' structure and pressure of the well. To minimize this problem, fluid loss additive known as lost circulation material (LCM) is mixed into drilling mud to seal the formation in order to prevent further loss of drilling mud. The objectives of this paper are to conduct parametric study of banana peels and sugarcane bagasse as environmentally friendly LCM additive for drilling mud application and to investigate thermal stability of the formulated banana peels and sugarcane bagasse-based LCM. The performance of banana peel and sugarcane bagasse with different particle size were tested using Fann Viscometer and Low Pressure, Low Temperature (LPLT) filter press. The performance of the banana peels in rheological properties and filtration properties studies exhibited higher efficiency compared to the sugarcane bagasse and mud without LCM. The thermal stability test conducted on water-based mud with banana peels as LCM indicates that temperature significantly affects the stability and resistant rheology of the water-based mud. [ABSTRACT FROM AUTHOR]

Biopolymer films have attracted interest in food preservation and packaging. Moisture content is a necessity to determine product stability at different storage conditions. In order to understand the behavior of film at different environmental conditions, moisture sorption isotherm at various water activity should be performed. The moisture sorption of cassava starch film with the incorporation of kaffir lime oil was measured by the gravimetric method at 30±1 °C using several salt solutions that provide ranges of relative humidity conditions. The equilibrium moisture content increased with increasing water activity. The addition of kaffir lime oil did not give much influence on the equilibrium moisture content of the film at targeted water activity. The fitting of the sorption data to GAB, Smith, Oswin and Halsey model shows that all models were accepted to describe the moisture sorption of cassava starch film with kaffir lime oil. According to the coefficient of determination (R2), the Smith model showed a perfect fit with R2 ≥ 0.98, followed by the Halsey model (R2 ≥ 0.97), Oswin model (R2 ≥ 0.94) and GAB model (R2 ≥ 0.89). The root mean square error (RMSE) values for the Smith model were the very least as compared to other models. The percentage of mean relative error (% MRE) of Halsey and GAB model show the best fit with a value less than 5 %. The Halsey model was well correlated to the moisture sorption data with a high value R2, less value of RMSE and a low % MRE. The moisture sorption of the film can be further correlated to other physical and mechanical properties of the film. [ABSTRACT FROM AUTHOR]

The six invited speakers were Dr. Mohd Syamsul Nasyriq Samsol Baharin (Universiti Sains Malaysia), Assoc. Prof. Dr. Ng Eng Poh (Universiti Sains Malaysia), Dr. Siti Zafirah Zainal Abidin (Universiti Teknologi MARA) and Dr. Mohd Hafiz Mohd Zaid (Universiti Putra Malaysia). Preface: 4 th International Sciences, Technology & Engineering Conference (ISTEC) 2020- Exploring Materials for the Future We are pleased to introduce the Proceedings of the 4 th International Sciences, Technology & Engineering Conference (ISTEC) 2020- Exploring Materials for the Future. [Extracted from the article]

Polymethyl methacrylate (PMMA) resin is commonly used for the fabrication of a denture base for heat curing polymerization. The objective of this work to investigate the effects of using two types of nanotube technology: Halloysite nanotubes (HNTs) and Multi-walled carbon nanotubes (MWCNTs), on the impact strength (IS), and Vickers hardness (VH) of PMMA denture base. The denture base composites were fabricated by incorporating PMMA powder, 0.5wt% of benzoyl peroxide (BPO), fixed nanotubes at 5wt% of HNTs / MWCNTs(5/0, 4.5/0.5, 4/1, 3.5/1.5, and 0/5) nanotubes as powder components. PMMA powder was mixed with a liquid (made from 90% methyl methacrylate (MMA) and10% ethylene glycol dimethyl-acrylate (EGDMA), as a crosslinking agent). The results show that the mean of impact strength significantly increased by the incorporation of 5wt% of HNTs/MWCNTs nanotubes with the ratio of (4:1 wt%) by 10.51 KJ/m2compared to unenhanced PMMA. However, the Vicker's hardness of the PMMA decreased by incorporation of 5wt% of HNTs/MWCNTs nanotubes, to17.42kg/mm2. The addition of HNTs and MWCNTs nanotubes to the PMMA matrix improved the impact strength but not the Vicker's hardness. Therefore, hybrid reinforced PMMA denture base composite with HNT and MWCNT nanotubes fillers is appropriate to be used for high performance prosthodontics applications. [ABSTRACT FROM AUTHOR]