Study of factors influencing construction delays at rural area in Malaysia

Construction is one of an important industry which contributes to the economic growth in Malaysia. However, it has been revealed that 79.5 percent and 66.7 percent of the public and private projects were not completed within the time specified in the contracts out of 359 projects in Malaysia. Therefore, the purpose of this study is to investigate the delay factor caused project delay at rural area. A 5-points Likert scale questionnaire survey were answered by 111 respondents which having experience with rural construction project. The questionnaire data were analysed by using Relative Importance Index (RII). Five top factors were determined from this study based on their RII values which are improper construction method implemented by contractor, weather condition, difficulties in providing delivery to site, breakdown of site equipment, and poor qualification of contractor’s technical staffs

Impact resistance study on rigid polyurethane foam

Polyurethane foam was synthesizes generally using isocyanate and polyol that already mix with the surfactant or catalyst as to aid polymer processing and modify properties of the polymer. Polyurethane can be divided to two types which are flexible foam and rigid foam. Usually, the flexible foam will be used in furniture industry to produce soft furniture cushioning and bedding. Rigid foam generally used for composite structured component and insulation. Main focus of this research is to produce a prediction assessment against penetration resistance of rigid polyurethane foam under specific dynamic load. Evaluation is by using analytical prediction method to evaluate the depth of penetration and energy absorption. The fabricated rigid polyurethane foam was undergoing compression test to obtain its mechanical properties and impact test to verify the prediction model with two significant measurements concerned, impact energy and the penetration depth leave by impactor. The impact speed was set up at 1.5 m/s, 1.7 m/s and 2 m/s. Results of experiment shows variations for depth of penetration and energy absorption to the predicted value from the analytical model. This variation is caused by the specimen’s rigidity disordered during the specimen producing process

Pretreatment and enzymatic hydrolysis of lignocellulosic biomass for reducing sugar production

Conversion of lignocellulosic biomass into reducing sugar has contributed to an alternative use of lignocellulose source, especially in the production of value-added products such as amino acids, biofuels, and vitamins. In the bioconversion process, pretreatment of lignocellulosic biomass is important to enhance the accessibility of enzyme hydrolysis, thus increasing the yield of reducing sugar. Lignocellulosic biomass has a very complex arrangement of structure that needs a proper study in pretreatment and enzymatic hydrolysis process to obtain an optimum yield of reducing sugar. This chapter discusses chemical and enzymatic pretreatment methods that are commonly applied to effectively modify the chemical structures of lignocellulosic biomass. Acid pretreatment using dilute sulfuric acid (H2SO4) is the most commonly employed for chemical pretreatment while sodium hydroxide (NaOH) is the most commonly applied for alkaline pretreatment because of its ability to delignify biomass. Then, enzymatic hydrolysis of lignocellulosic biomass for the production of reducing sugar is discussed in detail. The kinetics and optimization of hydrolysis which are the key parameters that determine the yields of reducing sugar are also presented. The right pretreatment method combined with an efficient hydrolysis process will ensure successful conversion of lignocellulosic biomass into reducing sugar, thus providing a sustainable production of reducing sugar from biomass for various applications