Browsing by Author "Ngah C.W.Z.C.W."
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- Some of the metrics are blocked by yourconsent settings
Publication Colorimetric Determination of Al(III) Based on the Aggregation of Gold Nanoparticles Functionalized with Novel 4-Benzoyl Pyrazolone Derivative(American Institute of Physics Inc., 2018) ;Abubaker M. ;Ngah C.W.Z.C.W. ;Ahmad M. ;Kuswandi B. ;Institute of Halal Research and Management (IHRAM) ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM)University of JemberA sensitive and selective colorimetric method has been developed for detection of Al3+ ion using 4-benzoyl pyrazolone-functionalized gold nanoparticles (BMPBP-AuNPs) as novel colorimetric probes. The BMPBP-AuNPs were characterized by UV-visible spectrometry and transmission electron microscopy (TEM). It was found that the addition of the Al3+ ions led to a rapid aggregation of the BMPBP-AuNPs, which changed the color of the mixture from red to blue. Furthermore, there was a shift in the characteristic surface plasmon resonance (SPR) peak from 524 to 650 nm of BMPBP-AuNPs, which confirmed that a good linear relation (R2 = 0.9935) was present between the absorption ratio of 524 and 650 nm. Also, the assay detected the Al3+ ion concentrations in the linear range 0-12 ppm with the detection limit is 0.05 ppm. Finally, the synthesized BMPBP-AuNPs were successfully used as a colorimetric sensor for the selective and sensitive detection of the Al3+ ions in water samples. - Some of the metrics are blocked by yourconsent settings
Publication Hybrid Solid Polymer Electrolyte From Diapers As Separator For Electrochemical Double Layer Capacitor (EDLC)(American Institute of Physics Inc., 2018) ;Hashim M.A. ;Nadhrah Md Yatim ;Mahmud N.A.C. ;Sazali N.E.S. ;Hamdan E. ;Yahya M.A. ;Ngah C.W.Z.C.W. ;Suhaimi S. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)EDLC was fabricated using hybrid solid polymer electrolyte from PVA-diapers and an activated carbon powder as electrode by using solution casting method. For comparison, four types of EDLC cells were constructed and tested. It was found that an EDLC with a PVA-diapers (60:40) polymer electrolyte exhibited much higher capacitance and longer cycle-life. The electrocapacitive properties of the supercapacitor (P50HD50, P60HD40, P70HD30 and P80HD20) were done using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge discharge (GCD). Results from these analysis showed that P60HD40 cell had recorded excellent rate capability and highest Csp value of 179 F g-1 (EIS), 50 F g-1 (CV), 328 F g-1 (GCD) respectively. Futher, results from ESR (GCD) analysis showed that P60HD40 composition of PVA/H3PO4 liquid electroyte gave a lower value of 88.05 ? in the supercapacitor cell compared with another cells. - Some of the metrics are blocked by yourconsent settings
Publication Novel 1-((benzoimidazole-2-yl)methyl)-3-phenyl- 1,4-dihydropyrazole-5-one and their derivatives: Synthesis and preliminary cytotoxicity test as anti-breast cancer(American Scientific Publishers, 2017) ;Abubaker M. ;Ngah C.W.Z.C.W. ;Ahmad M. ;Kuswandi B. ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM)University of JemberThis work presented synthesis of new pyrazolone derivatives and their cytotoxicity assay. The synthesis of pyrazolone derivatives have been achieved using condensation of 2-hydrazinyl methyl-1H-benzoimidazole (H1) with ethylbenzoylacetate in presence of ethanol, which in turn, yielded 1-(benzoimidazole-2-yl)methyl-3-phenyl-1, 4-dihydropyrazole-5-one (BPP). Then, it has reacted with diazonium solution in ethanol and benzoyl chloride in hot dioxin to give 4-azo pyrazolone (BMPAP) and 4-acyl pyrazolone (BMPBP) respectively. The newly synthesized compounds were characterized by FT-IR, 1H NMR and13C NMR. The cytotoxicity assay of the BPP, BMPAP and BMPBP on human breast cancer cells (MCF7) demonstrated their killing ability similar with naturally occurring toxins or immune-mediator cells. The cytotoxicity test was performed using MTT assay (3-[4, 5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). Cell culture with the concentration of 2�104 cells/ml was prepared and was plated (100 �l/well) onto 96-well plates. The diluted ranges of sample extracts were added to each well with identified concentrations: 100, 50, 25, 12.5, 6.25, 3.13 and 1.56 �g/ml and then incubated for 72 hr. MTT solution was added at the end of incubation samples to the cells and continued further for incubation in 3 hr. After solubilization of the purple formazan crystals using DMSO were completed, the Optical Density (OD) was measured using an ELISA reader at a wavelength of 570 nm. The cytotoxicity was recorded as the drug concentration causing 50% growth inhibition of the tumor cells (IC50 value). Overall cytotoxicity test was varied between pyrazolone derivatives with 50% or higher inhibition below 27 �g/ml, and it was considered active and potentially target for further screening. � 2017 American Scientific Publishers All rights reserved. - Some of the metrics are blocked by yourconsent settings
Publication Optimisation of digestion method for determination of arsenic in shrimp paste sample using atomic absorption spectrometry(2012) ;Ngah C.W.Z.C.W. ;Yahya M.A. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)The microwave digestion method was developed and verified for the determination of arsenic in shrimp paste samples. Experimental design for five factors (HNO3 and H2O2 volumes, sample weight, microwave power and digestion time) were used for the optimisation of sample digestion. For this purpose, two level half factorial design, which involves 16 experiments, was adopted. The concentration of arsenic was analysed by graphite furnace atomic absorption spectrometry. Design Expert� 7.0 software was used to interpret all data obtained. The combination of 2 mL HNO3 and 1 mL H2O2 volumes, 0.1 g sample weight, 1400 W power and 5 min digestion time was found to be the optimum parameters required to digest the shrimp paste samples. Tests with spiked samples presented good recoveries with relative standard deviations between 0.32% and 5.35%. � 2012 Elsevier Ltd. All rights reserved. - Some of the metrics are blocked by yourconsent settings
Publication Optimization of digestion method for determination of copper in shrimp paste sample using flame atomic absorption spectrometry(Chemical Publishing Co., 2016) ;Yahya M.A. ;Amin K.K.M. ;Al-Qodah Z. ;Ngah C.W.Z.C.W. ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM)Taibah UniversitySample preparation using microwave assisted digestion has been a well-known procedure worldwide. Nowadays, experimental designs have been used to facilitate this process. This study uses factorial design approach to study the concentration of copper in shrimp paste sample. The aim of the study was to optimize the digestion procedures for digesting the shrimp paste samples. Flame atomic absorption spectrometry was used to study the copper concentration. DOE software-Design Expert�7.0 was used to interpret all the data obtained. The combination of 4 mL HNO3, 2 mL of H2O2, 0.1 g of sample weight, 1400 W of power and duration of 5 min were found to be optimum in digesting shrimp paste sample for copper analysis. - Some of the metrics are blocked by yourconsent settings
Publication Optimization of polymer inclusion membranes (PIMs) preparation for immobilization of Chrome Azurol S for optical sensing of aluminum(III)(Elsevier, 2014) ;Ngarisan N.I. ;Ngah C.W.Z.C.W. ;Ahmad M. ;Kuswandi B. ;Faculty of Science and TechnologyUniversiti Sains Islam Malaysia (USIM)Determination of Al(III) from aqueous samples using Chrome Azurol S (CAS) as reagent immobilized in polymer inclusion membranes (PIMs) was discussed. The PIMs was prepared using poly (vinyl chloride) (PVC), 2-nitrophenyl octyl ether (2-NPOE) and Aliquat 336 as polymer matrix, solvent and ion carriers respectively. Experimental designs for four factors (weight of PVC, Aliquat 336, 2-NPOE, and the concentration of CAS) were used for the optimization of the membrane fabrication. For this purpose, a two level half factorial design, which involves eight experiments, was adopted. The combination of 200 mg of PVC, 50 mg of Aliquat 336, 50 mg of 2-NPOE and 1 � 10-3 mol/L CAS was found to be the optimum formulation for the preparation of PIMs. Wide dynamic range of Al(III) determination (0.2-50 ppm), better reproducibility within the same batch, good repeatability and photostability with RSD 1.21% and 0.93%, respectively. The calculated t values indicated that there is no significant difference between the two methods at the 95% confidence level and thus there is no bias in the method. � 2014 Elsevier B.V. - Some of the metrics are blocked by yourconsent settings
Publication Preparation and characterization of activated carbon from desiccated coconut residue by potassium hydroxide(Chemical Publishing Co., 2015) ;Yahya M.A. ;Al-Qodah Z. ;Ngah C.W.Z.C.W. ;Hashim M.A. ;Faculty of Science and Technology ;Universiti Sains Islam Malaysia (USIM)Taibah UniversityThis study investigates the effect of temperature and impregnation ratio on the physicochemical properties of activated carbon prepared from desiccated coconut residue by chemical activation using potassium hydroxide. Desiccated coconut residue sample was first carbonized at three different temperatures for 1 h at 400, 500 and 600 °C, respectively. The resulting chars were impregnated with KOH at three different impregnation ratio; 1:1, 1:2 and 1:3, respectively and activated under nitrogen atmosphere for 1 h at three different temperatures based on its carbonization temperature. The BET surface area and pore volume was strongly affected by temperature in which increased in temperature caused increased in BET surface are and pore volume. The BET surface area also increased with impregnation ratio but then decreased due to pore widening of activated carbons.