Applied Mechanics and Materials Vols. 465-466

Abstract: Almost identical properties with petroleum-derived diesel make biodiesel one of the best options of renewable and sustainable fuel supply to the transportation sector. Thanks to plentiful sources of palm oil and reasonable cost, it can be a proper feedstock for biodiesel production in Malaysia. Still, there is a paucity of studies concerning the effects of palm biodiesel on the environment. This paper, therefore, deals with life cycle assessment (LCA) of palm biodiesel to find out and validate the common belief regarding suitability of palm biodiesel as a green and sustainable fuel. The LCA study was conducted through three main stages including agricultural activities, oil milling, and transesterification process of biodiesel production. Palm oil biodiesel production results in the production of 1627.748kgCO2-eq of GHG and energy consumption of 12449.48MJ per ton PME. The results indicate that the most relevant environmental impact of this biofuel system is depletion of fossil resources.

Abstract: The influence of ceramic shell mould thickness and permeability on investment casting of AZ91D alloy using in-situ melting technique was investigated. AZ91D granules together with melting flux were charged into two different moulds having different thicknesses and four various permeabilities; then were heated at 650°C in order to be melted. Visual inspection and scanning electron microscopes were used to characterise the surface quality of cast samples. Thermal analysis was employed to further analyse the effect of mould thickness on cooling and solidification behaviour of molten metal. The findings of this research showed that thinner mould provided higher solidification rate, which is believed to favour in-situ melting enhancement. It enabled melting of the granules at the investigated temperature resulted in suppressing mould-metal reaction and producing cast samples with good surface quality. The results also showed that the permeability of shell mould was ineffective in suppressing mould-metal reaction.

Abstract: Tin tailing sand is one of the residues from tin extraction. Tailing sand for sampling was taken from Batu Gajah, which was one of the active locations in tin mining in Malaysia. The silica content of tailing sand from Batu Gajah is between 95.9 to 98.9%. This research is to determine the effect of grain size by the increasing of water content on the permeability number. Grain size is a major determinant of mould and core permeability and surface finish of the casting. In this research involved the process of conducting the mechanical sieve grading to identify the grain size for this research. Sample was graded into 425 μm, 297 μm and 149 μm. Experiments were conducted according to American Foundrymen Society (AFS) standard of procedures. Cylindrical test pieces dimensioning of Ø50 mm×50 mm in height from various grain sand sizewater ratios bonded with 5wt% clay, were compacted by applying three ramming blows of 6666 g each using Ridsdale-Dietert metric standard rammer. The test pieces were tested for permeability number with Ridsdale-Dietert permeability meter. Grain sand size of 297 μm was discovered has appropriate permeability number with the water content of 4% which is within the requirement as moulding sand.

Abstract: This paper discussed the behavior of cutting tool in terms of tool wear, tool life and surface roughness when machining an AISI D2 hardened steel. An experimental test was conducted at different cutting speeds (V_c) and radial depth of cut (a_e) using PVD TiAlN coated carbide tool under dry condition. Tool failure modes and tool wear mechanism for all cutting tools were examined at various cutting parameters. Flank wear was found to be the predominant tool failure for cutting tools. The highest volume material removal (VMR) attained was 3750 mm³ meanwhile the highest tool life (T_L) was 9.69 min. The surface roughness (R_a) values from 0.09 to 0.24 μm can be attained in the workpiece with a high material removal. The relationship of tool wear performance and surface integrity was established to lead an optimum parameter in order to have high material removal, maximum tool life as well as acceptable surface finish.

Abstract: Great deal of concerns have been aroused after the global surge of prices of petroleum along with shrinking resources of non-renewable fossil fuel and regarding the necessity of renewable energy sources as alternative fuel. Despite the many positive characteristics of biofuels, they cause a variety of environmental, economical, and social challenges that were not known to decision-makers by usual evaluation tools such as life cycle assessment (LCA) and Environmental Impact Assessment (EIA). This paper aims to design a Decision Support System (DSS) which covers weakness of existing assessment tools, using Strategic Environmental Assessment (SEA) and life cycle assessment (LCA) models. Furthermore, a sustainable framework for decision making through assessing and considering wider environmental, economic, and social issues pertinent to different steps of development of biofuel is developed.

Abstract: As many researches focused on application of non-destructive testing, very less concerned on the critically to reduce the inspection time rely on decrease cost operation. Liquid penetration testing has been broadly used for over 30 years in creation industrial operation. The need for reducing time in liquid penetration testing process is crucial to ensure the inspection systems vigour towards achieving master production schedule and customers satisfaction. This paper investigates and experimentally, the influence of penetration dwell time on development time in liquid penetration testing. Also considering value of hardness and surface roughness as the factor, the obtained results confirm that high penetration dwell time show strongly change the development time of liquid penetration time in directly decrease the inspection time.

Abstract: Some machining process requires coolant to reduce the cutting temperature and helps to flush away the chips from the cutting zone. However, conventional flood coolant possesses some issues towards workers and the environment, regarding health and waste management. The implementation of Minimal Quantity Lubrication (MQL) as an alternative technique seems to be promising although the effectiveness of this technique were influenced by several factor. In turning process for instance, the distance of nozzle to the cutting zone contributes to the variation of machining performance. This study is to compare the effect on cutting performance between two internal MQL nozzle designs. The cutting tool holder were modified to have two internal MQL oil channel. The oil channel design were tested and the performance was evaluated in terms of cutting speed and cutting temperature for different cutting speed, feed rate and depth of cut. The result shows that the single channel performs better in terms of cutting force while dual channel significantly improve the cutting temperature.

Abstract: Grinding is one of the most difficult processes in machining operations. Normally, the flood coolant method was used as a cooling agent in the grinding process. The most common defects using flood coolant are higher grinding friction, higher heat generation, and thermal damage. Therefore, the minimum quality lubricant (MQL) was introduced to minimize the defects. The main objective of this project is to compare the performance of MQL and flood coolant techniques in terms of grinding temperature, grinding force and specific energy. Three levels of cutting speeds, three levels of feed rate and depth of cut are adopted in the evaluation. The experiments were conducted on a thin plate of mild steel AISI 1020. The result shows that the MQL technique was effectively supplied to the grinding contact zone. This research revealed that the MQL technique exhibited an advantages on the surface temperature compared to the flood coolant.

Abstract: The quantity of palm oil fruits supplied from palm oil estates often affects the number of workers required and the area to be harvested. Thus, the ultimate objective of this research is to develop a system to forecast monthly delivery quantities such that the companys profit will increase through proper balance between supply and demand. This research is limited to 10 years of monthly deliveries from a palm oil estates deliver to only one palm oil mill as the case study. Two forecast techniques were chosen; the linear regression and additive forecast methods. Based on theories and formulations of the selected forecast techniques, forecast software was developed. For this software, user only needs to specify the year to be forecasted and choose one forecast technique to be used. Then, the forecasted values and errors were calculated and the results were displayed on the GUI. The performance of each technique was compared based on the mean absolute percentage error (MAPE). The generated results showed that the additive method produced lower MAPE compared to the linear regression method. This proved that the additive method is a better technique to predict the monthly delivery quantities of the palm fruits by the estate.

Abstract: In the institution of vocational education, students skill competencies should be gained by practical program in its workshop, therefore a product media is needed. In manufacturing field, job shop is the interesting type of work for the students due to its variety challenges, machine layout advantages for variety requirements and its appropriateness with practical competency aim. In usual way these product media are initiated from structured exercise goods and research result as internal project, but with an industrial collaboration concept it could be combined with the needs from external customer with good order handling arrangement by management. Since job shop had the fluctuation consequence due to variety process required, developing practical program with Batch Product could widening students practical product spectrum. Regarding the characteristic differences between Job Shop, Batch and Research Project related with competency that students should get, creating batch and project assembly area separately from job shop caused better time schedule and order handling properness. This combination is buffering media work that keep the education operation is running, encourages the student practical product to gain comprehensive activities in each area and more focus handling of all involved parties to each kind of jobs. Moreover, the QCD requirement of such products are reached easier.