Nanofiltration Treatment For Pesticides Removal: A Case Study For Atrazine And Dimethoate

Tesis ini memfokuskan kepada penyingkiran racun serangga dari larutan akues menggunakan membran penurasan nano. This thesis focuses on the removal of pesticide from aqueous solution using nanofiltration membrane

Nanofiltration Treatment For Pesticides Removal : A Case Study For Atrazine And Dimethoate [SB951. T161 2007 f rb].

Tesis ini memfokuskan kepada penyingkiran racun serangga dari larutan akues menggunakan membran penurasan nano. Dua jenis racun serangga, atrazin dan dimetoat, telah dipilih untuk diuji. This thesis focuses on the removal of pesticide from aqueous solution using nanofiltration membrane. Two pesticides, atrazine and dimethoate, were selected for study in this research

Investigation on the potential of bioethanol synthesis from honeydew melon rind

Honeydew melon rind is an abundant and low-cost fruit waste, which holds potential for glucose and eventual bioethanol synthesis. In this study, alkaline pre-treatment was introduced to break down the lignin structure before conducting acid hydrolysis to further breakdown the cellulosic components into glucose. The functional group of the pre-treated and raw samples were analysed using Fourier-Transform Infrared (FTIR) spectroscopy to evaluate the effectiveness of alkaline pre-treatment in lignin removal. Alkaline pre-treatment was found to effective in lignin removal from the rind, thus, improving the accessibility of cellulose and hemicellulose for acid hydrolysis. Using response surface methodology (RSM) based on the central composite design, a maximum glucose concentration of 9.847% w/v was obtained using an acid concentration of 6% w/v, a reaction temperature of 75°C for 60 minutes. The hydrolysate which was fermented using the Saccharomyces cerevisiae (baker’s yeast) revealed the presence of ethanol as the major product with some traces of impurities. This shows that honeydew melon rind has the potential as lignocellulosic biomass source for bioethanol synthesis

Application of Analytical Hierarchy Process (AHP) in Prioritizing HAZOP Analysis for Pilot Plant

Injuries, accidents or even fatalities while working in pilot plant are reported worldwide. The implementation of process hazards analysis (PHA) in pilot plant is expected to further reduce the risks of accidents. Hazard and operability (HAZOP) analysis is one of the most widely used methods for PHA. Generally, the outcome of HAZOP analysis could results in identifying large number of hazards thus poses a challenge for assessors to take actions in dealing with all the hazards. The common practice in prioritizing the critical hazards is based on assessors’ experience through deductive judgment using rating scale, taking into consideration safety and the associated costs. However the novel operations and process used, unproven or changing technology, and lack of safety information due to developmental stages have led to poor hazards prioritization and difficulty in selecting actions. This paper presents an application of analytical hierarchy process (AHP) in prioritizing HAZOP analysis for pilot plant. Through this approach, the significant hazards identified using HAZOP will be quantitatively weighted and ranked based on their priority along with the appropriate counter measures to be taken. Application of this approach at the high pressure CO2-hydrocarbon absorption system pilot plants as case study showed that the proposed methodology is capable of identifying and ranking the significant hazards in the process following HAZOP analysis. This is particularly useful as a leading indicator to process designers/engineers/researcher in prioritizing their efforts and resources on more significant hazards, hence prevent accidents of the pilot plant

Selection of renewable energy in rural area via life cycle assessment-analytical hierarchy process (LCA-AHP): a case study of Tatau, Sarawak

With a growing global population and energy demand, there is increasing concern about the world’s reliance on fossil fuels, which have a negative impact on the climate, necessitating the immediate transition to a cleaner energy resource. This effort can be initiated in the rural areas of developing countries for a sustainable, efficient and affordable energy source. This study evaluated four types of renewable energy (solar, wind, biomass, and mini-hydro energy) using the integrated Life Cycle Assessment (LCA) and Analytical Hierarchy Process (AHP) approaches to select the best renewable energy source in Tatau, Sarawak. The criteria under consideration in this study included the environment, engineering and economics. The AHP results showed that solar energy received the highest score of 0.299 in terms of the evaluated criteria, followed by mini-hydro, biomass and wind energy, which received scores of 0.271, 0.230 and 0.200, respectively. These findings can be used to develop a systematic procedure for determining the best form of renewable energy for rural areas. This approach could be vital for the authorities that are responsible for breaking down multi-perspective criteria for future decision making in the transition into renewable energy

Cryopreservation of Neurospheres Derived from Human Glioblastoma Multiforme

Cancer stem cells have been shown to initiate and sustain tumor growth. In many instances, clinical material is limited, compounded by a lack of methods to preserve such cells at convenient time points. Although brain tumor-initiating cells grown in a spheroid manner have been shown to maintain their integrity through serial transplantation in immune-compromised animals, practically, it is not always possible to have access to animals of suitable ages to continuously maintain these cells. We therefore explored vitrification as a cryopreservation technique for brain tumor-initiating cells. Tumor neurospheres were derived from five patients with glioblastoma multiforme (GBM). Cryopreservation in 90% serum and 10% dimethyl sulfoxide yielded greatest viability and could be explored in future studies. Vitrification yielded cells that maintained self-renewal and multipotentiality properties. Karyotypic analyses confirmed the presence of GBM hallmarks. Upon implantation into NOD/SCID mice, our vitrified cells reformed glioma masses that could be serially transplanted. Transcriptome analysis showed that the vitrified and nonvitrified samples in either the stem-like or differentiated states clustered together, providing evidence that vitrification does not change the genotype of frozen cells. Upon induction of differentiation, the transcriptomes of vitrified cells associated with the original primary tumors, indicating that tumor stem-like cells are a genetically distinct population from the differentiated mass, underscoring the importance of working with the relevant tumor-initiating population. Our results demonstrate that vitrification of brain tumor-initiating cells preserves the biological phenotype and genetic profiles of the cells. This should facilitate the establishment of a repository of tumor-initiating cells for subsequent experimental designs

Characterization and kinetic studies of poly(Vinylidene fluoride-co-hexafluoropropylene) polymer inclusion membrane for the malachite green extraction

Textile industry effluent contains a high amount of toxic colorants. These dyes are car-cinogenic and threats to the environment and living beings. In this study, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) was used as the based polymer for PIMs with bis-(2-ethylhexyl) phosphate (B2EHP) and dioctyl phthalate (DOP) as the carrier and plasticizer. The fabricated PIMs were employed to extract the cation dye (Malachite Green; MG) from the feeding phase. PIMs were also characterized by scanning electron microscopy (SEM), atomic force micro-scope (AFM), contact angle, water uptake, Fourier-transform infrared spectroscopy (FTIR) and ions exchange capacity. The performance of the PIMs was investigated under various conditions such as percentage of carrier and initial dye concentration. With permeability and flux values of 0.1188 cm/min and 1.1913 mg cm/min, PIM produced with 18% w/w PVDF-co-HFP, 21% w/w B2EHP, 1% w/w DOP and 40% w/w THF and was able to achieve more than 97% of MG extraction. The experimental data were then fitted with a pseudo-second-order (PSO) model, and the calculated R2 value was ~0.99. This shows that the data has a good fit with the PSO model. PIM is a potential alternative technology in textile industry effluent treatment; however, the right formulation is crucial for developing a highly efficient membrane

Peng-Robinson cubic equation of state based on key group contribution and calculation of nitrogen gas solubility in MMA dimer

Previously authors have reported facts that nitrogen (N2) and oxygen solubilities in styrene is the same as those in benzene and divinylbenzene at 303 K. Though the three compounds have an atomic composition, (CH)n (n=6, 8 and 10), the gas solubilities are thought to depend on the number of aromatic carbons in the solution. Then, authors named it ‘a key group in solubility'. In this research, the key group was investigated for N2 solubility in methyl methacrylate (MMA) and its dimer, ethylene glycol dimethacrylate (EGDMA). Therefore, the calculations were carried out by Peng-Robinson (PR) equation of state based on group contribution methods. The experimental data employed were those of Lai et al., where N2 solubility are reported in MMA at 303 K. The N2 solubility in EGDMA was assumed to be double of that in MMA at 303 K, because EGDMA has two MMA units in the molecule. Two types of group contribution methods were proposed to calculate N2 solubility in EGDMA. One was for the critical temperature and pressure proposed by Joback and Reid. Using these properties, the attractive and excluded volume parameters in PR equation were evaluated for EGDMA. Other was similar to a method proposed by Orbey and Sandler. The excluded volume parameter in PR equation can be evaluated from those of MMA by multiplying the number of repeating units, and the attractive by multiplying the squared number

Mutation signatures implicate aristolochic acid in bladder cancer development

10.1186/s13073-015-0161-3Genome Medicine71Article number 3

Association of maternal Vitamin D status with glucose tolerance and caesarean section in a multi-ethnic Asian cohort: the growing up in Singapore towards healthy outcomes study

10.1371/journal.pone.0142239PLoS ONE10111-16GUSTO (Growing up towards Healthy Outcomes