16 research outputs found
Annealing effect on structural and electrochemical performance of Ti-doped LiNi1/3Mn1/3Co1/3O2 cathode materials
NMC 111 cathode materials exhibit engaging properties in high energy density and low cost, making it great potential for the next generation of high-energy lithium-ion batteries. However, it still faces challenges such as fast capacity fade, especially at high C rates. Herein, we implement the novel Ti-doped cathode material, LiNi0.3Mn0.3Co0.3Ti0.1O2 (NMCT) synthesized via the combustion method. It was discovered that NMCT can effectively improve capacity delivery at high C rates. The T80 material demonstrated superior electrochemical annealed at 800 ˚C for 72 h, with an exceptional specific discharge capacity of 148.6 mAh g-1 and excellent cycle stability (capacity retention 96.8 %) after 30th cycles at 3 C. The results demonstrated that Ti-doped NMC had superior advantages for LiNi1/3Mn1/3Co1/3O2 (NMC 111) material at the optimum temperature of 800 °C for 72 h. It is one of the potential cathode materials for Li-ion batteries
Steel wire cleaning using cold plasma
Current galvanizing process used hydrochloric acid to remove oxide layer and mild acidic bath to remove oil on metal wire surface. These cleaning processes are compulsory before steel wire coated with zinc. These chemicals cleaning technique cause ecological harm and produce toxic waste. To consider of minimizing these problems, cold plasma was introduced for metal wire cleaning. Previous research already proves that cold plasma capable to remove oil by using dielectric barrier discharge (DBD) and remove oxide layer on copper by using RF plasma discharge. Therefore, in this research, the same plasma discharge system that is DBD was used to remove oil and oxide layer on steel wire. 8kV of voltage and air was used to generate plasma. By using copper and steel wire as electrode, it can remove oil around 82% and oxide layer around 54%
Study of Heavy Metal Levels among Farmers of Muda Agricultural Development Authority, Malaysia
Heavy metals, particularly cadmium, lead, and arsenic, constitute a significant potential threat to human health. This study was conducted to determine the levels of cadmium, lead, and arsenic in nail samples from farmers at Muda Agricultural Development Authority (MADA), Kedah, Malaysia, and evaluate factors that can contribute to their accumulations. A total of 116 farmers participated in this study. Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze concentration of heavy metals in the nail samples and questionnaires were given to participants to get demographic, health status, and their agricultural activities data. In this paper, the level of heavy metals was within the normal range and varies according to demographic factors. We found that there were significant correlations between working period with level of lead and arsenic (r = 0.315 and r = 0.242, resp., P < 0.01) and age with lead level (r = 0.175, P < 0.05). Our findings suggested that agricultural activities could contribute to the accumulation of heavy metals in farmers. Hence, the control of environmental levels of and human exposure to these metals to prevent adverse health effects is still an important public health issue
Catalytic gasification of oil palm frond biomass in supercritical water using MgO supported Ni, Cu and Zn oxides as catalysts for hydrogen production
Non-noble metal supported catalysts such as 20NiO/MgO, 20CuO/MgO and 20ZnO/MgO were catalyzed the gasification of oil palm frond biomass in supercritical water for hydrogen production. All the catalysts are found to be pure with no impurities present. The specific surface area of these catalysts can be arranged in the order of 20NiO/MgO (30.1 m2 g–1) > 20CuO/MgO (16.8 m2 g–1) > 20ZnO/MgO (13.1 m2 g–1). Although catalysts with larger specific surface area are beneficial for catalytic reactions, in this study, the largest specific surface area did not lead to the highest catalytic performance. It is found that the 20ZnO/MgO catalyst (118.1 mmol ml−1) shown the highest H2 yield than the 20CuO/MgO (81.1 mmol ml−1) and 20NiO/MgO (72.7 mmol ml−1) catalysts. In addition, these supported catalysts also shown higher H2 selectivity with reached 83.8%, 84.9% and 87.6% for 20CuO/MgO, 20NiO/MgO and 20ZnO/MgO catalysts. Other factors such as dispersion, basicity and bond strength play more important roles in supercritical water gasification of biomass to produce hydrogen
Catalytic supercritical water gasification of oil palm frond biomass using nanosized MgO doped Zn catalysts
In this work, nanosized MgO doped Zn catalysts (Mg1-x Znx O; x = 0.05, 0.10, 0.15, 0.20) were catalyzed the supercritical water gasification (SCWG) of oil palm frond (OPF) biomass for hydrogen production. Increased the amount of Zn in the catalyst enlarged the crystallite size, thus, reduced the surface area. Interestingly, all the synthesized catalysts have crystallite sizes of less than 50 nm. In-depth Rietveld refinement analysis revealed that the enlargement of the crystallite size is due to the phenomenon of cell expansion when the smaller Mg2+ ions being replaced by the larger Zn2+ ions during the doping process. Increased the Zn content also improved the basicity properties. Among the synthesized catalysts, the Mg0.80 Zn0.20 O exhibited the highest total gas volume of 213.5 ml g-1 of the biomass with 438.1% of increment in terms of H2 yield. The metal oxide doped materials serve as a new catalyst structure system for the SCWG technology
Spawn treatment by cold plasma for increase mushroom germination and production
Cold plasma technology has found favour in the agricultural industry for growth stimulating by environmental friendly approach. However, there are still leaking studying of cold plasma technology on the mushroom needs. Current convectional mushrooms germination process requires long duration (∼6 weeks) for fruiting to growth. Therefore, this study aims to investigate the cold plasma efficacy towards the oyster mushroom germination speed and fruiting body production. By using novel atmospheric cold plasma pen system, the mushroom spawn grains were generates towards the spawn. Atmospheric pressure with flow rate of 4, 5 and 6 SLM by considering different duration plasma exposure (0, 5, 15, 30, 45 and 60 seconds) with ∼7 kV of supply voltage was supplied. The efficiency of the treatment was characterised by mushroom cultivation performance particularly on (i) mycelium growth rate and (ii) mushroom fruiting body productions. The results show cold plasma processing parameter, flow rate and treatment time absolutely influence the mushroom germination and production. CP pen system optimized at 5 SLM and 15 s presents triple production of mushroom weight and speed the mycelium growth rate (only 4 weeks) compared to control spawn grains (6 weeks). As conclusion, cold plasma pen system capability applies in mushroom industry
Evaluation of antiinflammatory, antioxidant and antiproliferative activities of Quassia borneensis Noot. (Simaroubaceae) extracts
Quassia borneensis has been traditionally used as antihypertensive agent without any scientific literature on its mechanism of action. The objective of this study was to evaluate the antiinflammatory, antioxidant and antiproliferation properties of Q. borneensis extracts. The hexane, chloroform and aqueous extracts of root and bark of Q. borneensis were subjected to nitric oxide (NO) inhibition assay in LPS-stimulated RAW 264.7 cells. Expression of inducible NO synthase (iNOS) protein level was analyzed by Western blot. The antioxidant and antiproliferative activities of the extracts on HL-60 cells were determined using Ferric Reducing Antioxidant Power (FRAP) and MTT assays, respectively. The chloroform extract of Q. borneensis root obtained by soxhlet method (CSR) significantly inhibited 97.64 ± 0.96% of NO production (p < 0.001) and suppressed iNOS expression (p < 0.05) at the highest concentration of 1.0 μg/ml. The chloroform extract of bark obtained by maceration (CMB) exhibited the highest antioxidant capacity in the absence and presence of HL-60 cells, where the FRAP value were 125.45 ± 9.10 μM FeSO4.7H2O and 181.55 ± 3.45 μM FeSO4.7H2O, respectively. The greatest inhibition of HL-60 cell proliferation was exhibited by the chloroform extract of bark obtained by soxhlet method (CSB) with the IC50 of 5.0 μg/ml. The findings suggested that the chloroform extracts of Q. borneensis possess antiinflammatory, antioxidant and antiproliferative activities
Gene mutation effect of aqueous and methanol extracts of salted fish from Pulau Pinang, Malaysia towards V79 lung fibroblast cells
Salted fish is a locally processed raw food which is used in everyday cooking among Malaysians. Previous studies suggested that salted fish intake was a risk of nasopharyngeal cancer. Hence, this study was carried out to evaluate gene mutation effects through the induction of mutagenic effect of aqueous and methanol extracts of salted fish from Balik Pulau, Pulau Pinang, Malaysia. Balik Pulau was chosen for sampling purpose due to its popularity as a commercial centre for local raw fisheries in Malaysia. Evaluation of mutagenic effect was carried out by hprt Gene Mutation Assay towards V79 lung fibroblast cells. It was found that the aqueous and methanol extracts of salted fish were not cytotoxic towards V79 lung fibroblast cells. It was also found that the extracts of salted fish from Balik Pulau were not mutagenic towards hprt gene of V79 lung fibroblast cells as the mutation frequency of the extracts did not exceed 3 times of the value for negative control mutation frequency. In conclusion, both aqueous and methanol extracts of salted fish from Balik Pulau did not have gene mutation effect towards hprt gene in vitro. However, other toxicological profile could be assessed to determine the mechanism of toxicity of salted fish
Gas phase analysis of SIC film deposition in PECVD using FTIR spectroscopy
Fourier Transform Infrared Spectroscopy was used to investigate the gas phase reactions during the deposition process of Silicon Carbide (SiC) film using VelY High Frequency - Plasma Enhanced Chemical Vapor Deposition (VHF-PECVD). The VHFPECVD operated at plasma excitation frequency of J50MHz and 25 W of RF power was applied to generate plasma. Argon (Ar) was used to initiate plasma while methane and silane gas was used as precursor to deposit SiC. Hydrogen gas was added to the system and the flow rates were varied from 0 to 500 sccm. FTIR absorption spectra were recorded during the deposition process and the dissociation of silane and methane gas was investigated. Silane found to be fully decomposed during the deposition and methane shows a dependency of hydrogen flow rates
Mechanism of the formation of novel Al2-xHfxO3 materials via a combustion synthesis method
In this paper, the synthesis mechanism of novel hafnium-doped alumina, Al2-xHfxO3 (x ?= ?0.001, 0.002 and 0.003) materials have been successfully formed via a self-propagating combustion (SPC) method. In-depth study of the materials through characterization by simultaneous thermogravimetric analysis (STA), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and energy dispersive X-ray (EDX) were systematically done. STA technique were used to characterize the thermal profile of the precursors. From the analysis, the synthesis mechanism of the materials was proposed. XRD results reveal that hafnium doped materials correspond to the hexagonal crystal structure of Al2O3 that shows a success of the substitutional doping. The FESEM micrographs shown that the morphology of the materials was not significantly affected by the dopant concentrations. However, the presence of Hf4+ ions in Al2O3 were confirmed where the synthesized stoichiometry of all materials were perfectly identical to the obtained stoichiometry from EDX