Diffusion Coefficient Estimations by Thin-Channel Column Inverse Gas Chromatography : Preliminary Experiments

A thin-channel gas chromatography column was designed and used to measure diffusion coefficients of water and iso propanol in polymer phase via inverse gas chromatography (ICC) technique. The thin-channel column inverse gas chromatography technique proved to be a simple, fast and efficient alternative to sorption and desorption methods for measuring diffusion coefficients of permeants in thin polymer membranes films; the technique is especially useful when the problems associated with the irregularity of polymer distribution severely limit the accuracy of ICC measurement. Thin homogeneous chitosan membranes prepared by the solution casting technique were used as the stationary phase to provide a relatively uniform layer of polymer phase in the gas chromatography column. The diffusion coefficient of water was higher than that of isopropanol and diffusion coefficients of the permeants increased with column temperature. The effects of permeants size on diffusion coefficients were investigated on a series of alcohols: methanol, ethanol and isopropanol. The diffusion coefficients were inversely related to the permeants size

Natural Gas Dehydration Optimization

Natural Gas is a vital component of the world's supply of energy. It is one of the deilfiest, safest, and most useful of all energy soutees. Undet normal production conditions, it saturated with water vapor. Water vapor increases natural gas corrosivity especially when acid gases are present. This report discusses the research done and basic understanding of the chosen topic, which is natural gas dehydration optimization. The objectives of this project are to do the comparison between different types of Natural Gas dehydration technology on the basis of efficiency and capacity and to do the simulation to optimize operating condition of gas dehydration technology. The current technologies used to dehydrating gas have some weaknesses in term of efficiency, capacity, cost effectiveness and are harmful to environment M for this study, gas dehydration using solid desiccant is being considered. It is a common technology used widely in the world especially in oil and gas industries. In order to optimize this technology, a simulation model base on the actual dehydration unit in the liquefied natural gas (LNG) plant is used. The optimization is base on manipulating temperature and pressure to see the effect to the adsorption capacity and later, from the manipUlated pressure, the hydrate fOrmation temperature can be predicted. From this, the optimum temperature and pressure of operating the dehydration unit can be known. Furthermore, a study of increasing the moisture removal by adding pre-dehydration unit is also discussed in this study

Preparation and Characterization of Magnetic Biosorbent Based On Ceiba Pentandra

Cationic dye methylene blue (MB) and anionic dye Congo Red (CR) are among pollutant dyes that must be removed from the waste water stream especially from textile industries. The use of biosorbent for the removal of pollutants from waste water is inceasingly becoming attractive due to low cost and ease of preparation and application. In this study, magnetic biosorbent was developed based on Ceiba pentandra or kapok fiber to remove MB and CR dyes from aqueous solution. The raw kapok fiber (RKF) was first treated with sodium hydroxide (NaOH). Then, Fe3O4 magnetic nanoparticles (MNPs) were introduced onto the surface of the RKF and treated-kapok fiber (NaOH-treated (SKF)). The magnetic nanocomposites (MNCs) based on kapok fiber could be separated out easily from the aqueous solution by an external magnet for its magnetic property. It can also provide more surface area and increase the adsorption capacity. The RKF-MNCs and SKF-MNCs were characterized morphologically and chemically by Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscope (TEM), and Field Emission Scanning Electron Microscope (FESEM). Comparison of performance between RKF, RKF-MNCs and SKF-MNCs was studied for dye removal in batch mode for three different parameters; initial concentration, contact time and pH value. From the results obtained using Ultraviolet-Visible (UV-VIS) test, the optimum conditions for the adsorption process will be determined. Then corresponding SKF-MNCs adsorbent was used in adsorption experiment that conducted in these optimum conditions and it is expected that it will give the highest adsorbability compared to other adsorben

A comparative study between the effects of adding dolomite as additive against thermal treatment on solidification of municipal solid waste bottom ash concrete / Mohd Syazwan Mohd Ghazali

Incineration bottom ash (lBA) may pollute soil, surface water or underground water if it contains toxic substances such as heavy metals. If this pollution is not appropriately managed, it can cause serious health risks and problem to the surrounding environment. In this study, incineration bottom ash from municipal solid waste (MSW) was used as a substitute to sand to form concrete-like material in a process known as solidification. Two methods of solidification were tested and examined. Four different composition of ash: sand ratio were used, i.e, (30:70), (50:0), (70:30) and (100:0). The solidification processes were evaluated by carrying out compressive strength and leaching tests . Results show that; of four different concrete produce, the (30:70) concrete was found to be best in term of strength and produced a lighter density material compare to normal concrete . Of the two solidification processes; thermally treatment performed better than addition dolomite as additive

Studies To Determine The Prevalence Of Candidate Gene Polymorphism For Hypertension Among Malays

Hipertensi atau peningkatan tekanan darah arteri adalah merupakan masalah kesihatan umum yang penting dan adalah merupakan faktor risiko yang utama bagi kebanyakkan kecacatan dan kematian kardiovaskular. Hypertension or elevated arterial blood pressure is a substantial public health problem and is a major risk factor for many common causes of cardiovascular morbidity and mortality

Small Farmers' Decisions: Utility Versus Profit Maximization

Farmer's risk attitudes are modelled using the Cobb-Douglas, transcendental, negative exponential, and conjoint measurement utility functions. The farmers' perception of the riskiness ofaltemative crops are also measured and a quadratic programming algorithm is used to derive the most efficient expected meanvariance (E- V) frontier of each farmer. The E- V frontiers are then used in conjunction with the utility junctions to determine the optimal farm plans. Farm plans that maximise expected profit are also determined. The results reveal that the conjoint measurement utility model predicts actual behaviour better than the other models. The expected profit model, on the other hand, is the worst predictor. This indicates that risk does playa role in decision-making and that the farmers are utility maximizers rather than profit maximizers only. Therefore, more effective programs would be those that tend to reduce risks and uncertainties faced by the farmers

Rectangular Electrode Characteristic in Electrodynamic Solid Particle Measurement

Electrodynamic sensor was used in process industry because of lower price and robust designed. It is also used to increase the efficiency of energy and raw materials usage and to improve product quality and process efficiency. Three types of electrode are available in particular application such as pin shape, quarter ring shape and ring shape. This paper focused on the investigation of the pin shape structure and the characteristic of the rectangular shape by using different structure sizes of various lengths and with fixed width. Non-instrusive method was applied to the design of rectangular electrode. The characteristic based on sensitivity of electrode and the spatial filtering effect of sensor will be investigated by using different size of electrodes.Then, the model will be proposed and compared with experimental result

Effectiveness of Arbuscular Mycorrhiza and Slow Release Fertilizer to the Growth of Merawan Siput Jantan (Hopea Odorata Roxb.)

Merawan siput jantan (Hopea odorata Roxb.) is a forest tree species that can be used for plantation establishment in marginal lands. Arbuscular Mycorrhiza (AM) and fertilizer are believed to have the ability to increase tree growth in the nursery and in the field. This study was conducted to determine the effectiveness of mycorrhiza and fertilizer application on the growth of merawan siput jantan in both conditions. The nursery study was conducted in FRIM’s nursery, Kepong. It was conducted to determine the optimum level of AM inoculation and fertilizer application required for maximum tree growth. The merawan siput jantan seedlings were inoculated with three levels of AM (Draz-M) inoculation viz; 0, 100 and 200 g per seedling. The levels of nutrient (Vitality/ slow release fertilizer) were applied in four different amount viz; 0, 5, 10 and 20 g per seedling. Results of the study showed that inoculation using 100 g per seedling had given the highest increment of height and diameter, 6 months after the treatment. It was found that, application of AM alone did not contribute on the tree growth because the AM acts as biological booster rather than supplying nutrients. However, based on the analysis, it was found that height increment had been significantly increased by application of both AM and fertilizer compared to fertilization alone due to their synergistic interaction. A field study to evaluate application of AM and fertilizer had been conducted at plantation areas in LKPP Sg. Charu, Kuantan, Pahang. It was conducted by applying inoculated AM and fertilizer to merawan siput jantan trees in Block A: 8 months after planting and Block B: 14 months after planting. The trees were treated with two different levels of AM viz; 0 and 500 g tree-1, and three different levels of fertilizer viz; 0, 250 and 500 g tree-1. Results of the field study had further supported results of nursery study that AM had contributed on the tree growth. It was found that, application of slow release fertilizer (NPK 10:7:7) at 500 g tree-1 had significantly increased (P<0.001) the height of merawan siput jantan in both blocks. The growth of tree canopy also showed similar result.Application of slow release fertilizer indicated increased nutrients in the soil especially P and Mg at the end of the experiment. The effects of AM and fertilizer application can be observed after one year of treatments viz; i. The AM inoculated plot especially incorporated with fertilizer had increased Ca content in leaves while N is found increased in stem. ii. Contents of K and Mg in roots were also increased due to the fertilizer application. It shows that AM is able to increase nutrient absorption by the roots of the trees through symbiosis. iii. Results from nursery and field studies showed that application of AM and fertilizer have positively contributed to the tree growth. Therefore, it is recommended that the AM and fertilizer should be applied to trees both in nursery an in the field as they have been proven to improve growth

Gallium nitride nanowire by nitridation of electrochemically grown gallium oxide on silicon

GaN is a wide bandgap semiconductor with superb thermal, chemical, mechanical and electrical properties which makes it suitable for high power electronic and optoelectronic devices. Si substrate is preferable for the heterostructure growth of GaN due to its availability in large wafer size, low price and maturity. The co-integration of GaN-based devices on Si is very attractive towards the realization of advanced heterogeneous integration . A transformation of the grown Ga2O3 structures on Si to GaN by a so-called nitridation process is considered as a simple method to create a GaN/Si heterostructure. In the first stage, a synthesis of ß-Ga2O3 nanostructures on Si substrate by electrochemical deposition using a mixture of Ga2O3, HCl, NH4OH, and H2O was performed. The morphologies strongly depended on the molarity of Ga2O3 and pH level of electrolyte. ß-Ga2O3 nanodot-like structures were grown at low molarity of Ga2O3. However, Ga2O3 nanodot structures covered with nanorods on top of their surfaces were obtained at higher molarity, and the densities of nanorods seem to increase with the decrease of pH level. In the next stage, the nitridation of the electrodeposited Ga2O3 was performed. The complete nitridation was achieved at temperature of 900°C. Here, several prominent diffraction peaks correspond to hexagonal GaN (h-GaN) planes were detected with no diffraction peak of Ga2O3 structure. Temperature is a key parameter in a nitridation process where the deoxidization rate of Ga2O3 to generate gaseous Ga2O increase with temperature. It was found that a complete transformation cannot be realized without a complete deoxidization of Ga2O3. A significant change of morphological structures takes place after a complete transformation of Ga2O3 to GaN where the original nanorod structures of Ga2O3 diminish, and a new nanowire-like GaN structures appear. The studied method seems to be promising in producing high-quality h-GaN nanostructures on Si