227 research outputs found

    Studies on the antioxidant properties of Tualang honey of Malaysia

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    Honey has been used since ancient times for its nutritional as well as curative properties. Tualang honey is collected from wild honey bees’ hives on Tualang trees found in the Malaysian rain forest. It has been used traditionally for the treatment of various diseases, where its therapeutic value has partly been related to its antioxidant properties. This study therefore assessed the colour intensity, total phenolic content, antioxidant activity and antiradical activity of gamma irradiated Tualang Honey. The colour intensity at ABS45O was 489.5 ± 1.7 mAU, total phenolic content was 251.7±7.9 mg gallic acid /Kg honey, total antioxidant activity by FRAP assay was 322.1±9.7 (μM Fe(II)) and the antiradical activity by DPPH assay was 41.30 ± 0.78 (% inhibition). The data confirms that the antioxidant properties of gamma irradiated Tualang honey are similar to other types of honeys reported in the literature.Key words: Tualang honey, Malaysia, Total antioxidant activity, Gamma radiation, Phenolic content, DPPH assa

    Analysis of tubewell performance as an evaluation of the physical aquifer model being developed

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    Physical aquifer model is used as a tool for further understanding of groundwater concept. Demonstration and observation activities on water level drawdown in the observation well, performance of pumping well, groundwater flow and solute transport of groundwater contamination can be carried out on this aquifer model. The objective of this study is to evaluate the physical aquifer model developed in the laboratory, used as a teaching tool and research material through the analysis of well performance. Well efficiency is an indicator in determination of the performance of pumping well developed in the aquifer model. Using stepdrawdown pumping test technique, the optimum pumping discharge rate for the pumping well is determined at 0.0612m3/hr and its efficiency is calculated to be 99%. This technical evaluation helps to study further of the aquifer hydraulic properties which accomplished on this artificial aquifer model

    Application of organic fertilisers on natural stand bamboos for sustainable management in Peninsular Malaysia

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    This paper highlights research on the influence of three organic fertilisers (chicken dung, palm oil mill effluent and peat materials specially made for fertilisers) on the number of new shoots, the diameter at breast height, the height of the culms and the number of culms. Especially the number of new shoots and the diameter at breast height are positively influenced, which is promising for commercial purposes

    A novel secret key generation based on image link

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    One of the main problems with symmetric encryption is key distribution especially when involving large number of users i.e to generate identical keys at different locations. To address this challenge, we proposed a novel algorithm of secret key infusion protocol (SKIP) to generate an identical secret key. While, the key is generated based on a provided image link, starting pattern and string length which must be kept in secret as the algorithm is publicly known. The image from website must be a static image and used as the input of random bits to produce string of hexadecimal values. In a case where image link is compromised, the adversary has to guess other layers of parameters in starting pattern and string length. The generated secret keys were identical at two different locations. In other observation, different secret keys were generated even with the same image link and pattern length but different starting pattern

    Adaptation of counters redundant bits with the provision of dual supply and modified clock gating to favour of low power in VLSI

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    750-757The utilization of usual supply voltage and clock for repetitive state transistors in digital circuits is a fundamental driver for high power utilization. Most significant bit states of the counter stay longer than the least significant bit states and it has some repetitive states. To limit the supply voltage and stop the clock for MSB Flip Flop (FF) transistor, our method uses Control Combinational Logic, Voltage selector and Modified Integrated Clock Gating blocks. The LSB transistor always have a supply voltage of 1.2V and succession of the clock, while MSB transistor gets just 480mV and the clock will be stopped by the this technique. Bring down the supply voltage and quit the clock for redundant states either 0 or 1 in MSB. Meantime supply 1.2V and clock for state changes over from one state to next state. The experimental simulation was done in 45nm CMOS technology using Cadence virtuoso indicates that this asynchronous counter achieves a power savings of 23.57% and the same modified technique when applied to the counters with transmission-gate FF, hybrid-latch FF and sense amplifier FF will have more than 40% power savings and the technique applied in some benchmark circuits will have more than 22% power savings than existing techniques

    Adaptation of counters redundant bits with the provision of dual supply and modified clock gating to favour of low power in VLS

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    The utilization of usual supply voltage and clock for repetitive state transistors in digital circuits is a fundamental driver for high power utilization. Most significant bit states of the counter stay longer than the least significant bit states and it has some repetitive states. To limit the supply voltage and stop the clock for MSB Flip Flop (FF) transistor, our method uses Control Combinational Logic, Voltage selector and Modified Integrated Clock Gating blocks. The LSB transistor always have a supply voltage of 1.2V and succession of the clock, while MSB transistor gets just 480mV and the clock will be stopped by the this technique. Bring down the supply voltage and quit the clock for redundant states either 0 or 1 in MSB. Meantime supply 1.2V and clock for state changes over from one state to next state. The experimental simulation was done in 45nm CMOS technology using Cadence virtuoso indicates that this asynchronous counter achieves a power savings of 23.57% and the same modified technique when applied to the counters with transmission-gate FF, hybrid-latch FF and sense amplifier FF will have more than 40% power savings and the technique applied in some benchmark circuits will have more than 22% power savings than existing techniques

    In vitro antiproliferative and antioxidant activities of the extracts of Muntingia calabura leaves.

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    The in vitro antiproliferative and antioxidant activities of the aqueous, chloroform and methanol extracts of Muntingia calabura leaves were determined in the present study. Assessed using the 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay, the aqueous and methanol extracts of M. calabura inhibited the proliferation of MCF-7, HeLa, HT-29, HL-60 and K-562 cancer cells while the chloroform extract only inhibited the proliferation of MCF-7, HeLa, HL-60 and K-562 cancer cells. Interestingly, all extracts of M. calabura, which failed to inhibit the MDA-MB-231 cells proliferation, did not inhibit the proliferation of 3T3 (normal) cells, indicating its safety. All extracts (20, 100 and 500 μg/ml) were found to possess antioxidant activity when tested using the DPPH radical scavenging and superoxide scavenging assays with the methanol, followed by the aqueous and chloroform, extract exhibiting the highest antioxidant activity in both assays. The total phenolic content for the aqueous, methanol and chloroform extracts were 2970.4 ± 6.6, 1279.9 ± 6.1 and 2978.1 ± 4.3 mg/100 g gallic acid, respectively. In conclusion, the M. calabura leaves possess potential antiproliferative and antioxidant activities that could be attributed to its high content of phenolic compounds, and thus, needs to be further explored

    A review of the effect of UAE optimization parameters on antioxidant activity

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    Optimization of Ultrasound-assisted extraction parameters is necessary to determine the optimum level of the parameters, including solvent-to-material ratio, power, extraction time, solvent concentration, temperature, and pH. This review focuses on the UAE parameters' effects on the antioxidant activity, their interactions, and the best method of examining antioxidant activity to respond to the UAE's optimization. It was determined that the optimal extraction time is 15 minutes, and any duration longer than that could result in reduction of antioxidant activity. The temperature effect is important, wherein antioxidant activity decreases significantly when the extraction temperature is higher than 45 °C. Increasing the solvent concentration beyond 50% decreased the antioxidant activity. No increase in antioxidant activity was observed with a solvent/sample ratio greater than 40 ml/g. Increased ultrasound power leads to increased antioxidant compounds, especially in the range of ultrasound power, such as 50 to 150 W. However, higher ultrasound power creates free hydroxyl radicals that destroy the antioxidant compound. With an increase in pH, the radical scavenging activity increases significantly. It should, however, be at a near-neutral level, such as pH 6. Comparative literature has shown that optimizing UAE contributes to enhanced antioxidant activity and enhances resource conservation, such as energy and chemical

    Effect of heat treatment on the corrosion behaviour of LM6 in sulphuric acid and sodium hydroxide

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    Sulphuric acid (H2SO4) and sodium hydroxide (NaOH) are the main solutions used in water treatment stations to adjust the potential of hydrogen (PH). Pumps used in such stations must bear acidic and alkaline mediums. Pump parts such as impellers and casings could be made by aluminium silicon alloy (LM6) due to their cast-ability and corrosion resistance. In this paper, the corrosion behaviour of LM6 in acidic and alkaline solutions was investigated. The corrosion test samples of LM6 were prepared using a carbon dioxide sand casting mould. Test samples subjected to solution heat treatment. A corrosion test was conducted using the weight-loss method by immersing the samples in H2SO4 and NaOH. Resulted showed that the LM6 was more corroded in the alkali than in acid. Cumulative weight loss of non-heat-treated LM6 in H2SO4 was 11.23 mg/cm2 while in NaOH was 177 mg/cm2. Cumulative weight loss of heat-treated LM6 in H2SO4 was 8.44 mg/cm2 while in NaOH was 192 mg/cm2. The corrosion rate of non-heat-treated LM6 in H2SO4 was 78 MPY while heat-treated LM6 was 56 MPY. Concluded that LM6 is more corroded in NaOHthan in H2SO4 and the heat-treated LM6 was more corrosion resistance than the non-heat-treated one
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