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Typical grout material is made from ordinary Portland cement. This work focuses on feasibility of producing fly ash based geopolymer grouting material. Geopolymer based materials actually have several advantages but the improvement of their rheological performances remains a challenging task, as the raw materials, especially sodium silicate and metakaolin, do not have favorable properties and the main chemical admixtures used to optimize cement-based materials have not been found compatible. Considering the performances in both fresh and hardened states, a comprehensive study is necessary to develop a promising geopolymer based grout material. Fly ash allowed reducing the viscosity and increasing the setting time and the stabilizer provided the fresh mixes with better homogeneity and stability. Detailed morphological study of raw fly ash was performed in this work. Scanning electron microscopy shared the macrospehre and inner microsphere structure within fly ash micrographs. Curing condition and solids to liquid ratio is kept constant in this study. The different concentration of NaOH solution (10 M and 12 M) and sodium silicate-to-sodium hydroxide (Na2SiO3/NaOH) ratios (1.5, 2.0, 2.5 and 3.0) were used in the production of geopolymer. [ABSTRACT FROM AUTHOR]

Smoking is an addictive behavior and can result major health complications. Nowadays, many young adults tend to pick up this unhealthy habits which could potentially harm their health and affects the future workforce of the nation. Most of the habitual smokers have difficulties in ceasing this habit and require external assistance in the form of group therapy, medical interventions to quit smoking. Therefore, the main aim of this study is to investigate the speech signals of the subjects in an effort to identify the habitual smokers non-invasively. Through this detection, young smokers could be identified. Voice samples from VOice ICar fEDerico II from PhysioNet database were used for this study. Wavelet Packet Transform was used to extract non-linear features from the signals. Due to uneven data, ADASYN algorithm was used to produce a balanced dataset through synthetic data sampling. Subspace KNN and SVM classifiers were used for the investigations and classification accuracies up to 83.7% and 94% of AUC curve were observed from the analysis. The results suggests that the proposed method is effective in detecting habitual smokers, and can be considered as an early screening for smoking habits in young adults for targeted rehabilitation strategies. [ABSTRACT FROM AUTHOR]

The production of propylene from propane dehydrogenation process in the petrochemical sector regularly produce high concentration of sulphur in the form of sodium sulphide (Na2S). High concentration of sulphide can lead to corrosion in sewage pipes, massive fish kill and obnoxious odors into the atmosphere. Adsorption technique using low-cost and environmentally friendly adsorbents derived from natural resources such as rice husk ash (RHA) may offer a suitable alternative for in situ removal of contaminants such as sodium sulphide in industrial wastewater. In this work, the use of silica synthesized from RHA was investigated for its potential in removing high concentration of sulphide (S2-) in the form of sodium sulphide from wastewater. Results showed that pure silica with the size around 0.9 to 2.0 µm was successfully synthesized from RHA. Significant reduction of sulphide level was observed after being treated with RHA-based silica calcined with clay compared to other adsorbents such as chemically treated nanoporous zeolite and natural clay itself with more than 90 % removal after 120 minutes of treatment with the value of the pseudo-first-order rate constant, k of 0.1404, 0.14 and 0.1519 for silica compared to zeolite. This suggests that the use of silica derived from RHA has a potential to be used as sulphide remover in industrial wastewater without extensive chemical treatment to improve its removal capacity. [ABSTRACT FROM AUTHOR]

Pyrolysis of coconut shell was investigated in a fixed-bed reactor to determine the effects of pyrolysis parameters (temperature and heating rate). The effect of zeolite and dolomite catalyst on the product yields and the qualities of the liquid product was investigated. The result showed that the optimal conditions for liquid (bio-oil) yield (48.03%) were at pyrolysis temperature of 4500C, heating rate of 50 °C/min, gas flow rate of 50 L/min and particle size of 300 µm. The yield of bio-oil without catalyst is higher than with catalyst. However, the characterisation of bio-oil, indicated that the catalytic pyrolysis upgraded the bio-oil quality. The coconut shell showed that the bio-oil was highly oxygenated containing high fraction of phenol-based compounds. [ABSTRACT FROM AUTHOR]

In this study, pyrolysis of sawdust was investigated using a fixed bed reactor. The objectives of this project were to study the effect of pyrolysis parameters on production of bio-oil and bio-char and to analyze the characteristics of pyrolysis product. The variations of pyrolysis temperature are 450, 500, 550, 600 and 650 °C. The particle size was varied in the range of >1.18mm and <1.18 mm. The heating rate was at 40, 50 and 60 °C/min. The maximum product yield of bio-char was 49.28% obtained at 550 °C, with heating rate of 50 °C/min and particle size of <1.18mm. The maximum bio- oil yield was 28.86% and the maximum gas yield was 68.83%. The optimum gas was at the pyrolysis temperature of 450°C, heating rates of 60°C/min and particle size of <1.18mm. Sawdust can be utilized as biomass feedstock to increase bio-char product. It has high lignin content which can increase yield of bio-char. The bio-char is potential source of renewable fuel and chemical feedstock. [ABSTRACT FROM AUTHOR]

The catalytic pyrolysis of agricultural waste by waste eggs shell had been studied in the fixed bed reactor. The objectives of this study were to investigate the potential use of waste eggs shell as catalyst in pyrolysis process and to determine the effect of pyrolysis product with various pyrolysis parameters which are temperature, heating rate and biomass size and to determine the effect of catalyst on bio oil production. The optimum parameter for maximum bio oil yield from this study were at temperature of 450°C, heating rate of 50°C/min and biomass size of 425 µm. In this study, the used of eggs shell as a catalyst produced the highest bio oil yields of 65.67%. [ABSTRACT FROM AUTHOR]

Geopolymer, an inorganic compound exhibit a wide variety of desirable properties especially in the field of construction. The use of new geopolymer sources materials such as fly ash and rice hush ash have potential as geopolymer bricks to reduce the emission of carbon dioxide caused by ordinary Portland bricks that also indirectly contributes to global environmental impact. The parameter for fly ash and rice hush ash geopolymer brick is by fixing the solid/liquid ratio at 2.0 while the ratio of Na2SiO3/NaOH is 2:5 and NaOH molarity of 12 During mixing process, sample is allowed to pre-cure at room temperature to allow completion of gelling phase and then at 70°C for 24 hours to get the reliable early strength. Samples are then subjected to mechanical testing, which is compressive strength to support findings of the best formulation. The best mix design for fly ash geopolymer brick was at 2.5 with highest compressive strength at 44.2 MPa. The best mix design also correlates with highest result obtained in water absorption study. [ABSTRACT FROM AUTHOR]

The catalytic pyrolysis of biomass in fixed bed reactor using calcium-based catalysts had been studied in fixed bed reactor. The objective of this study was to determine the influence of parameters on pyrolysis product and to determine the potential of calcium-based catalysts in pyrolysis of palm shell. The results were obtained with various temperature, biomass size and catalyst ratio. The maximum bio oil from this study were at the temperature of 500 °C, biomass size of 425 µm and percentages catalyst ratio of 20%. In this study the use of Cryptomya Elliptica as a calcium-based catalyst produced the highest amount of bio oil yield of 32.71%. [ABSTRACT FROM AUTHOR]

Rice husk and polystyrene waste were combined to obtain bio-oil through pyrolysis process. The bio-oil produced from mixtures of rice husk and polystyrene waste also potential to be used as fuel. The parameters were used for this study are ratios of mixture, temperature, particle sizes and holding time. High yield of bio-oil was obtained on a rice husk/polystyrene waste of 70:30, temperature of 450°C, particle size of 300 µm and holding time of 2 minutes. Results of bio-oil characterization from combination between rice husk and polystyrene proved that the hydrocarbons become increased and the content of acid was decreased. The bio-oil majority consisted of aliphatic and aromatic amines. [ABSTRACT FROM AUTHOR]

The focus of current research work is to investigate the water to solids interaction and characteristic of geopolymer grout material. Previous researchers proposed fly ash as an environmentally friendly binder material known as geopolymer. This new binder needs to be mixed between alkaline liquids and materials rich in silica and alumina. Fly ash class C, used as source material with alkaline activators such as sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). This paper concluded that the concentration of NaOH solution and sodium silicate-to-sodium hydroxide (Na2SiO3/NaOH) ratios have a significant effect on water absorption behavior of geopolymer end product. The different concentration of NaOH solution (10 M and 12 M) and sodium silicate-to-sodium hydroxide (Na2SiO3/NaOH) ratios (1.5, 2.0, 2.5 and 3.0) were used in the production of geopolymer. The parameters such as curing and solid-to-liquid (S/L) ratio were controlled in this paper. The main evaluation techniques in this study were water absorption and optical microscopy (OM). The optimum water absorption percentages were observed on samples with 10 M of NaOH concentration as compared to 12 M NaOH concentration. Based on the OM image, geopolymer grout showed fewer poresand denser structure on samples with 10 M NaOH concentration after 28 days. [ABSTRACT FROM AUTHOR]

Undeniable need of an alternative material for Ordinary Portland Cement has led to major focus of geopolymer source materials. Production of one ton of cement emits 0.87 ton of carbon dioxide (CO2), The use of new sources materials such as fly ash a have potential as geopolymer bricks plus can reduce the emission of carbon dioxide by ordinary Portland bricks which cause the environmental impact to the global. First part of this work is to determine the feasibility of using rice husk as a reinforcing material for fly ash geopolymer brick. Mix design of 2:5 Na2SiO3/NaOH ratio, 12 M NaOH concentration and solid-to-liquid ratio of 2.0 with varying rice husk loading was tested and cured at room temperature then at 70°C for 24 hours to get stable early strength. The microstructure of fly ash geopolymer brick with rice husk ash were analysed for raw material (fly ash and rice husk ash) and geopolymer brick product. From morphology analysis, almost all particles has took part in geopolymerization process and compacted area has represent the form of geopolymer gel through microstructure analysis that has carried out both fly ash and rice husk ash in geopolymer brick. The best mix design also correlate with highest result obtained density analysis. [ABSTRACT FROM AUTHOR]

The ordinary Portland cement (OPC) is the function as a binder for grout material. However, a massive used of OPC had caused pollution to the environment. Thus, the earlier research proposed the environmental friendly binder known as geopolymer. This new binder needs to be mixed between alkaline liquids and materials rich in silica and alumina. In this paper, fly ash class C was used as source material with alkaline activators such as sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). This paper concluded that the concentration of NaOH solution and sodium silicate-to-sodium hydroxide (Na2SiO3/NaOH) ratios have a significant effect on compressive strength. The different concentration of NaOH solution (10 M and 12 M) and sodium silicate-to-sodium hydroxide (Na2SiO3/NaOH) ratios (1.5, 2.0, 2.5 and 3.0) were used in the production of geopolymer. The parameters such as curing and solid-to-liquid (S/L) ratio were controlled in this paper. The main evaluation techniques in this study were compressive strength and optical microscopy (OM). The optimum compressive strength obtained was 15.5 MPa for 28 days resulted from 12 M of NaOH concentration and Na2SiO3/NaOH with ratio 2.5. [ABSTRACT FROM AUTHOR]

Co-gasification of pretreated palm kernel shell (PKS) and Mukah Balingian (MB) coal and gasification of individual feedstock were carried out in a fixed bed reactor system. The synergistic effect of pretreated feedstock in cogasification was probed. The results showed that the co-gasification of pretreated biomass and coal samples had a synergistic effect at all blending ratios. The experimental value of co-gasification on 50 % biomass blending ratio generated the highest gas yield of 69.43 % and lowest tar yield of 10.11 %. This was supported with the different of experimental value and calculated mean value (Exp-Cal) that showed the highest synergistic effect on product yield using 50 % biomass blending ratio of the pretreated samples. Thus, the pretreated PKS and MB coal, by which their physical and chemical properties have been enhanced through pretreatment process are suitable to be used in co-gasification. [ABSTRACT FROM AUTHOR]

This study describes the properties of upgraded palm kernel shell (PKS) and mukah balingian (MB) coal by microwave irradiation pretreatment. The microwave power level and processing time were varied in this research. The pretreated samples were analysed for mass and energy yield, calorific value and proximate and elemental composition. The characteristics of pretreated samples were improved with increasing microwave power level and reaction time. The oxygen content, O/C ratio of upgraded sample were reduced with increasing microwave power level. The carbon content of pretreated PKS was closed to the untreated MB coal properties with comparable calorific value was obtained. The microwave power level of 450 W and processing time of 8 min were appropriate to upgrade the PKS and MB coal for cogasification. Thus, it can be concluded that the change in physical and chemical properties of upgraded PKS and MB coal revealed the potential of applying these feedstocks in co-gasification for hydrogen production. [ABSTRACT FROM AUTHOR]

Co-gasification of pretreated palm kernel shell (PKS) and pretreated Malaysian low rank coal has been conducted using a fix bed reactor system. Response surface methodology (RSM) based on central composite design (CCD) was used to determine the optimum condition on gas yield in co-gasification products. The effect of the three factors, i.e. gasification temperature, biomass blending ratio and steam flow rate on response variables (gas, tar and char yield) were examined. The p-value <0.05 for all factors indicated that the factors were significant. The predicted optimum conditions for gasification temperature, biomass blending ratio and steam flow rate were at 767 °C, 52 % and 54 ml/min, correspondingly. These optimum conditions produced maximum gas yield, minimum char and tar yield of 67.28 %, 20.83 % and 11.90 %, respectively. Thus, this study showed that the assessed RSM model has effectively determined the optimum process condition, which designates to the optimum gas yield in co-gasification. [ABSTRACT FROM AUTHOR]