Oil-palm-boiler clinker (OPBC) is an agricultural solid waste sourced from the palm oil industry in tropical regions. This study investigates the use of OPBC as coarse aggregate instead of conventional coarse aggregates to produce a greener concrete, which will help in implementing sustainable construction practices by reducing the usage of raw materials. For this purpose, normal weight coarse aggregates was substituted with dry OPBC aggregates up to 75% (by volume) in a high strength normal weight concrete. The effectiveness of this substitution on the properties of the concrete such as workability, density, compressive strength, splitting tensile strength and modulus of elasticity was studied. The slump test results showed that using OPBC in dry condition reduced the workability of the concrete and therefore can be used up to 50% of the total volume of coarse aggregate. Concrete containing 50% OPBC can be considered as semi-lightweight concrete with high strength. Using OPBC in concrete reduced the splitting tensile strength and modulus of elasticity, however, the reduction was not significant.
A simple and green method was presented to embed TiO2 on regenerated cellulose membranes via cellulose dissolution-regeneration process. The physical, chemical and mechanical properties of the composite membranes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier- Transform Infrared (FTIR), ultraviolet (UV) - visible spectroscopy and tensile test. The results indicated that cotton linter has been converted from cellulose I to cellulose II after the regeneration process, while the TiO2 nanoparticles embedded inside the membrane maintaining its original crystal structures. The TiO2 composite membranes possessed high ability of water absorption with total pore volume ranged from 0.45±0.01 to 0.53±0.02 cm3/g. The elongation at break of the prepared membranes increased 29% averagely from dry state to wet state. The tensile strength of the membranes remained at a minimum value of 0.50±0.03 MPa in wet state thus enabled the films to withstand in wet for long period of time under weak UV irradiation. The regenerated cellulose membranes with TiO2 performed well in photocatalytic activity while exhibiting distinct absorption abilities. This study provides a potential application in energy-saving decomposition system in which the dye compound can be easily removed via two simultaneous pathways: Absorption and photocatalytic decomposition.
Reduced graphene oxide nanosheet (RGO)/Pt nanocomposite have been successfully prepared through a facile chemical reduction method. The reduction of Pt precursor was carried out using sodium borohydride as the efficient chemical reductant. The morphology of RGO/Pt nanocomposite was investigated using high resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). HRTEM analysis showed that platinum nanoparticles were homogenously distributed onto the surface of RGO. The electrochemical study proved that Pt nanoparticles were successfully incorporated onto RGO. Therefore, it can be concluded that the proposed method could provide well-dispersed of Pt nanoparticles onto RGO to form RGO/ Pt nanocomposite.
In this study, magnetic cellulose membranes (MCM) have been prepared by using cotton linter as cellulose source and NaOH/urea as cellulose solvent at different magnetite content. Cellulose was dissolved in pre-cooled NaOH/urea solvent at -13°C to form cellulose solution. The cellulose solution then was mix with magnetite (Fe3O4) nanoparticles synthesized via co-precipitation method of Fe2+ and Fe3+ in the presence of sodium hydroxide (NaOH) to form MCM. The MCMs formed at different percentage of Fe3O4 i.e., 10, 20 and 30%. Analysis from vibrating sample magnetometer (VSM) shows that the saturation magnetization of the MCM increase as the percentages of Fe3O4 nanoparticles increased. However, the addition of Fe3O4 nanoparticles in the regenerated cellulose membrane has decreased the crystallinity index of MCM. The surface morphology of the MCM showed that the Fe3O4 nanoparticles were dispersed in the pore of the membrane. Tensile test showed decreasing in the tensile strength of the cellulose membrane with the addition of Fe3O4 nanoparticle.
Bisphenol A is an endocrine disruptor with widespread applications, especially in the production of polycarbonate and epoxy resins. Dispersive liquid-liquid microextraction based on solidification of floating organic technique has been developed for the extraction of bisphenol A from water and soft drink. The 1-undecanol has been applied as the extraction solvent because of its low density and melting point and high affinity to the analyte. The technique offered rapid and simple analysis as the 1-undecanol was homogeneously dispersed in the sample solution to speed the extraction and the collection of extraction solvent was simplified by centrifugation, cooling and melting steps.
We report herewith the study of fingernail clippings obtained from the residents of Tokyo, Japan. A total of 18 participants with no health problems and occupational exposure to metals were recruited to provide fingernails samples for this study. Through the use of instrumental neutron activation analysis (INAA), 18 elements (Ag, Al, As, Ca, Cl, Co, Cu, Fe, Hg, K, Mg, Mn, Na, S, Sb, Se, V, and Zn) were determined. The results showed that the toxic elements in the fingernails are in the lower range when compared to literature values. There were no chronic exposures to toxic elements such as As and Hg found. The level of Hg found is lower than that reported 20 years ago, possibly due to the strict regulation control in Japan on the release of Hg to the environment. The elements Se and Zn are found to be rather uniformly distributed among participants and are in agreement with results from other countries. There were no significant differences in elemental concentrations due to genders and smoking habits. The overall data from this study showed similar concentrations to those of healthy participants from other countries. Thus, the current data could represent the background level of elemental concentrations in fingernails of residents in Tokyo, which could serve as reference values for future study.
Baram Delta Operation had been producing oil and gas since 1960's and serious pipelines failure was reported in the year of 2005. The final investigation has concluded that one of the species of bacteria that has been identified to cause microbiologically influenced corrosion, specifically known as sulfate reducing bacteria (SRB) was found to be one of the potential contributing factors to the incidents. This work investigates the potential use of ultraviolet (UV) radiation to inhibit the SRB consortium that was cultivated from the crude oil in one of the main trunk lines at Baram Delta Operation, Sarawak, Malaysia. The impact of UV exposure to bio-corrosion conditions on carbon steel coupon in certain samples for 28 days was discussed in this study. The samples were exposed to UV radiation based on variations of parameters, namely: time of UV exposure; and power of UV lamp. The significant changes on the amount of turbidity reading and metal loss of the steel coupon were recorded before and after experiment. The results showed that SRB growth has reduced rapidly for almost 90% after the UV exposure for both parameters as compared to the abiotic samples. Metal loss values were also decreased in certain exposure condition. Additionally, field emission scanning electron microscopy (FESEM) coupled with energy dispersive spectroscopy (EDS) was performed to observe the biofilm layer formed on the metal surface after its exposure to SRB. The evidence suggested that the efficiency of UV treatment against SRB growth could be influenced by the particular factors studied
The Geant4 simulation code was developed to study the Hp
(10) energy response of the LiF:Mg,Cu,P (TLD-100H). Initial
study chose the simulation conditions similar to the work reported by Obryk et al. in year 2011, in which a TLD-100H chip
without filter was used. The work went further to simulate the Hp
(10) results obtained experimentally at SSDL Malaysia.
The experiment used a TLD-100H chip embedded in a TLD card and the card was enclosed in a badge complete with PTFE
filter. Irradiation with eleven photon energies in the range of 24-1250 keV was applied. The simulation code therefore
took into accounts the details of the badge (the materials type and the dimensions of the chip, the card, the badge and
the filters) and the set-up of the experiment (the source distance and the energies). In comparison with Obryk’s work, the
simulation code yielded the mean deviation of 0.59%. For the experimental work, the simulated Hp
(10) curves obtained
were quite similar and comparable and a mean deviation of 13.96% was obtained. As both 0.59% and 13.96% deviations
are within the acceptable limit of ±25%, it was concluded that a satisfactory level of accuracy has been achieved by the
developed simulation code and the selection materials and physics processes that have been adapted in the code were
correct. Sources of uncertainty that has contributed to this deviation are discussed.
The fabrication of high quality graphene has become the main interest in current chemical vapour deposition (CVD) method due to the scalability for mass production of graphene-based electronic devices. The quality of graphene is determined by defect density, number of layers and properties changed such as electron mobility, transparency and conductivity as compared to the pristine graphene. Here, we did a study on the effects of reaction conditions such as methane, CH4 concentration and deposition time towards the quality of graphene produced. We found that by lowering both CH4 concentration down to 20% and deposition time to 5 min, a better quality graphene was produced with higher I2D/IG ratio of 0.82 compared to other reaction condition. Through the analysis, we concluded that there are two important parameters to be controlled to obtain high quality graphene.
The effect of graphene content on the structure and conductivity of an eco-friendly cellulose/ graphene (CG) composite was investigated. Different compositions of graphene content from 0 to 70 wt. % were prepared using the sol-gel method. Ionic liquids 1-butyl-3-methyl-imidazolium chloride was used to disperse graphene between the cellulose. The investigation showed that CG composite with higher graphene composition exhibits higher conductivity. The highest conductivity (2.85×10-4 S cm-1) was observed at 60 wt. % graphene composition. Sample without graphene showed the lowest conductivity of 1.77×10-7 S cm-1, which acts as an insulator. The high conductivity of CG composite can be associated with the X-ray diffraction (XRD) patterns. The XRD patterns of α-cellulose exhibits a decrease in crystallinity at peak 15° and 22° due to the depolymerization in CG composite. At 60 wt. % composition, XRD pattern showed the decrease in intensity at peak 26° indicates that graphene is more dispersed in the cellulose mixture. This is supported by Fourier transform infrared spectrum of CG composite where the absorption peaks of C-O stretching are weakened at wavelength of 1163 and 1032 cm-1, suggested dehydration and rupture of cellulose. The dehydration and rupture of cellulose result in the high conductivity of CG composite. This research is believed to provide an eco-friendly method to produce cellulose/graphene composite which is useful in future applications of energy.
A nanofluid is a suspension of nano-sized particles dispersed in a base fluid. It is very much obligatory to know more about stability and thermal characteristics of such a nanofluid for their further use in practical applications. In this research, multiwalled carbon nanotubes (CNT) is dispersed in water. CNT dispersed in water is highly unstable and it sediments rapidly due to the Vander Waals force of attraction. Therefore, to overcome this limitation, xanthan gum (XG) was added which behave as a promising dispersant followed by 4 h water bath sonication. Experimental work includes stability studies using UV Vis spectroscopy with respect to CNT concentration (0.01 and 0.1 wt. %) and XG concentration (0.04 and 0.2 wt. %). The thermal conductivity of the most stable suspensions was measured using KD 2 Pro as a function of temperature (25-70°C) and CNT concentration. The optimum XG concentration was found for each CNT concentration studied. Thermal conductivity was observed to be strongly dependent on temperature and CNT concentration. The dispersion state of the CNT-water nanofluid is further examined using scanning electron microscope (SEM). In short, CNT nanofluids are found to be more suitable for heat transfer applications in many industries due to their enhanced thermal conductivity property. This work provides useful insight on the behavior of CNT nanofluids.
Various production methods have been developed for graphene production, but each of them falls short in either the economic or quality aspect. In this paper, we present the flame deposition method, a modified chemical vapor deposition (CVD) that uses an open-flame. In this method, resulting carbon deposits were found to be graphitic in nature, thereby suggesting multilayer graphene growth in a very short reaction time of 5 min. Furthermore, the deposits were transferred onto a cyanoacrylate plastic substrate and its sheet resistance was measured to be 81 ohm/square. The results showed that open-flame deposition exhibits high potential for low-cost, low-energy and high-quality production of graphene.
Nitrogen doped titanium dioxide (N-doped TiO2
) was synthesized by microwave using urea as nitrogen sources with
commercially available TiO2
-P25. The N-doped TiO2
was compared with unmodified TiO2
by carrying out the investigation
on its properties using x-ray diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET), Fourier transformed infrared
spectroscopy (FTIR) and diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic activities of N-doped TiO2
and unmodified TiO2 were studied for photodegradation of reactive red 4 (RR4) under light emitting diode (LED) light
irradiation. An active photoresponse under LED light irradiation was observed from N-doped TiO2
with 60 min of time
irradiation to complete RR4 color removal while no photocatalytic degradation was observed from unmodified.
Herbal medicine is usually made using dry powdered herbs in the form of capsule. Capsule form herbal supplement suffers lower shelf life as compared to compact herbal powder in tablet form. In this study, Diabecine™, a blend of herbal medicine traditionally used as herbal supplement for diabetic patients was selected and transformed into a compressed tablet. Direct compression method and minimal usage of excipients were the aims of this study. By using direct compression, the blend of 40% fine powder herbs and 60% of excipients performed the best and fulfill the pharmaceutical standard. The safety data of microbial and heavy metal testing obtained met the safety requirements for herbal supplement category under the National Pharmaceutical Control Bureau of Malaysia. In conclusion, the tablet formulation of Diabecine™ is suitable to be manufactured by using direct compression method. This research implicates the possibility of producing tablets with high dose of herbal powder by direct compression method.
There is growing interest in the use of plant bioresources for managing type 2 diabetes. In this study, Rhodamnia cinerea, which is used traditionally to manage diseases in Malaysia, was explored for its antidiabetic effects. Type 2 diabetic rats were managed for 4 weeks using aqueous extract of R. cinerea or quercetin. Weights and fasting glucose were measured weekly, while serum lipid profiles, insulin, antioxidant status, urea, creatinine and liver enzymes were assayed at the end. Sorbitol contents, antioxidant capacities and aldose reductase activities of the kidney, lens and sciatic nerve were also assessed. The results showed that the aqueous extract of R. Cinerea mainly contained Myricitrin and it reduced glycemia (p>0.05), lipid profiles (p<0.05), F2-isoprostanes (p<0.05) and overall metabolic condition of type 2 diabetic rats. R. cinerea also attenuated sorbitol contents of the nerve (p<0.05) and kidney (p<0.05), partly through regulating the activity of aldose reductase (p<0.05 for nerve) and sorbitol dehydrogenase (p<0.05 for kidney) in comparison with diabetic untreated group. Quercetin is a known aldose reductase inhibitor and can improve several metabolic indices related to Type 2 diabetes. In this study, the results of R. cinerea were comparable to or better than those of quercetin, suggesting that R. cinerea extract can be a good candidate for managing Type 2 diabetes and its complications related to sorbitol accumulation.
According to the World Cancer Research Fund International (WCRFI), breast cancer is the most common type of cancer in women worldwide with recorded 1.7 million new cases in 2012. The main line of treatments is still limited to chemotherapy, surgery and radiotherapy which could lead to a wide range of dangerous side effects. This study was conducted to evaluate the effect of low intensity ultrasound (LIUS) on cell proliferation, percentage of living and dead cells and the induction of apoptosis on the MCF-7 cell line with CHO cells as the control for non-cancerous group. In order to achieve the objective of this study, several methods of cell-bioguided assays were used including the MTT assay for cell proliferation, Live/Dead assay for the determination of both live and dead cells and gene expression study for the detection of apoptosis in the cells. The cytotoxicity and Live/Dead assays data provided preliminary data that the LIUS has potential to induce apoptosis in a wide population of breast cancer cells. Furthermore, the LIUS treatment induced the expression of p53-mRNA at a detectable level via qPCR analysis, indicating the activation of apoptosis. In short, our study suggested LIUS dosage used in this study could potentially show positive effects in the induction of apoptosis selectively on the MCF-7 with less harm to the control CHO cells.
MeSH terms: Animals; Breast Neoplasms; Cricetulus; Female; Financial Management; Cricetinae; Humans; RNA, Messenger; Ultrasonography; Tumor Suppressor Protein p53; CHO Cells; Apoptosis; Cell Proliferation; MCF-7 Cells
Abdominal obesity is an important contributor for health risk factors such as hypertension, diabetes mellitus and hypercholesterolemia. Therefore, the application of a proper method is important prerequisite in performing abdominal obesity assessment. In this study, we applied 3D body scanning technology to measure waist circumference (WC), hip circumference (HC) and waist to hip ratio (WHR) precisely in an effort to improve the current health assessment for abdominal obesity. A total of 200 Malaysian women with sedentary lifestyle, aged between 18 and 60 years participated in this study. Paired t-test was used to determine the differences between the automated (3D body scanner) and manual measurements of WC, HC and WHR. 3D body scanner measurements show that 27% of subjects had mild abdominal obesity (80 - 90 cm) and 34.5% of subjects had severe abdominal obesity (≥90 cm) based on WC cutoff points. Based on WHR cutoff points, 57% of subjects had abdominal obesity (≥0.85) while the remaining were without abdominal obesity (<0.85). Lower percentages of abdominal obesity prevalence were reported for both WC and WHR categories using manual measurements. We also found that in normal BMI category, 8.5% of subjects have mild abdominal obesity based on automated measurements while only 5.5% of subjects were identified on manual measurements. The result of this study indicated that 3D body scanner provided better assessment method as it enables detection of abdominal obesity in more subjects based on WC and WHR categories. Public agencies are encouraged to consider the application of 3D body scanning in health assessment of abdominal obesity.
Rat bioassay was used to evaluate the nutritional quality of beef burger as influenced by the addition of selected herbs and vegetables. The selected herbs and vegetables used were pucuk ubi (Mannihot esculenta), pucuk gajus (Anacardium occidentale), pegaga (Centella asiatica) and jantung pisang (Musa paradisiaca) as treatment group with casein and skimmed milk as reference. The rats were fed with herbs and vegetables at the rate of 0.5 (low dose) and 25 (high dose) g/kg body weight. The samples were analyzed for proximate analysis, protein quality and protein digestibility. The rats fed with pucuk ubi (high dose) (364.30 ± 25.34 g) indicated the highest mean of increased body weight (121.05 ± 14.65 g) while rats fed with skimmed milk (310.98 ± 18.92 g) showed the lowest mean increase in body weight (88.33 ± 14.25 g). As for the Protein Efficiency Ratio (PER) value, all the rats fed with herbs diet showed PER values that were significantly lower (p<0.05) compared to the casein. As for the in vivo apparent protein digestibility test, casein showed the highest digestibility value (86.33 ± 4.20) while pucuk gajus (high dose) (59.59 ± 5.41) showed the lowest. As for the in vitro digestibility analyses, casein indicated the highest value for in vitro digestibility (93.84 ± 0.33). Administration of herbs and vegetables at low and high doses show significant effects (p<0.05) on nutritional quality of beef burger. In conclusion, it was found that antinutritional factors in selected herbs and vegetables might affect the nutritional quality of beef burger.
Condition Index (CI) was used to estimate the reproductive biology cycle of the hard clam Meretrix lyrata based on dry
body weight and shell weight. High CI value was observed due to the increase in the body weight of the hard clam that
corresponding to the maturity stage and early spawning. The CI value of M. lyrata from Buntal Village, Kuching, Sarawak
showed three highest peaks during the 12-month study on May and October 2013 and March 2014. The lowest CI values
were obtained in September and November 2013 and April 2014. Ammonia nitrogen was the only water parameter that
significantly correlated to the CI values. The CI application is important to estimate the maturity of hard clam gonad
to facilitate conservation activity through the hard clam harvesting out of the gonad maturation and spawning period.
Over many years, forested land transformation into urban, agriculture and mining areas within Tasik Chini Catchment become more intense. These activities have negatively affected the catchment through soil erosion and increased the amount of sediments that deposited into the lake. Hence, the present study aimed to estimate soil erosion risk within Tasik Chini Catchment integrating the Revised Universal Soil Loss Equation (RUSLE) model and remotely sensed geospatial data. The multispectral imagery from LANDSAT 8 was used to provide up to date information on land cover within the catchment. The result shows the majority of Tasik Chini Catchment is classified at very low class (< 10 ton ha−1 yr−1) about 4835.34 ha (92.38%), followed by the low class (10-50 ton ha−1 yr−1) with total area of 175.47 ha (3.35%), moderate high class (50-100 ton ha−1 yr−1) with total area of 65.11 ha (1.24%), high class (100-150 ton ha−1 yr−1) with total area of 38.37 ha (0.73%) and very high class (> 150 ton ha−1 yr−1) with total area of 120.04 ha (2.30%). Tasik Chini Catchment is very susceptible to soil erosion especially on northwest and southeast regions, where the main sources of soil loss come from the agricultural, new settlements and mining activities. To conclude, the estimation of soil erosion model using remotely sensed data can be used to build sustainable development strategy within Tasik Chini Catchment in the future.