Journal of Engineering and Technological Sciences
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Study of Micro-hardness of High-Speed W9Mo4Co8 Steel Plates in Pendulum Grinding by Abrasive Wheel Periphery
Get PDFIn cutting tool assembly, grinding is the most important technological step of the finishing treatment, largely determining the workmanship. An increase of micro-hardness after grinding relative to the original one indicates the dominant role of abrasive tool force impact on the ground surface. A decrease, in contrast, evidences a significant softening under the influence of heat source. This research based on nonparametric statistics to predict the effect of wheel characteristics with abrasives 25A, 92A/25A, 34A, 5A, EKE, 5NQ, TGX, 5SG and with graininess 46 (F46), 60 (F60), 80 with different porosities (structure numbers 6-12), and the expected measures of position and dispersion on the micro-hardness of the surface of a high-speed cutting plate (HSCP) made of W9Mo4Co8 steel. It was found that grinding this HSCP by wheels 5NQ46I6VS3, 5SG46K12VXP, 5SG60K12VXP, 5SG46I12VXP, 25AF46M12V5"“PO, 25AF46M12V5"“PO3, 25ÐF46M10V5"“PO, 25AF46M10V5"“PO3, 25AF46K10V5"“PO3, 25AF60M10V5"“PO3, 25AF46L10V5"“KF35, EKE46K3V, 92A/25AF46L6V20 occurred without surface softening for 50% of the details from the operating batch
Switching Control Strategy for Greenhouse Temperature-Humidity System Based on Prediction Modeling: A Simulation Study
Get PDFIt is difficult to achieve coordination control of multiple facilities that are driven by on-off actuators in a greenhouse, especially when there is more than one indoor environmental factor to consider at the same time. With the consideration of indoor air temperature and relative humidity, we propose a switching control strategy based on prediction modeling. The operation of the greenhouse system was divided into several modes according to the on-off control characteristics of the available facilities. Then, a switching diagram was designed according to the relationship between the indoor air temperature and humidity and their setting ranges. When the two indoor environmental factors reach their upper or lower limits, IARX models are used to predict them over a specified horizon for each optional mode respectively. Mode switching is carried out based on prediction results. The switching control strategy was simulated based on a mechanistic model of the greenhouse microclimate. The results show that the facilities can be coordinated very well by the proposed control strategy and it is easy to implement. The control strategy is still applicative when more facilities or more indoor environmental factors need to be taken into account
Catalytic and Thermal Decarboxylation of Mg-Zn Basic Soap to Produce Drop-in Fuel in Diesel Boiling Ranges
Get PDFFatty acid deoxygenation is a method for producing renewable hydrocarbon fuels such as green diesel, jet biofuel and biogasoline. In the present commercial method, deoxygenation is directly applied to vegetable oils through liquid phase hydrotreatment. This method is expensive because it consumes a large amount of hydrogen and requires severe operating conditions. The objective of this study was the production of a diesel-like hydrocarbon fuel that can be considered as drop-in replacement for petroleum-based diesel fuels, by catalytic thermal decarboxylation of Mg-Zn basic soap. In particular, this study investigated the decarboxylation of Mg-Zn basic soap at low temperature and pressure, without external supply of hydrogen. The Mg-Zn basic soap (9/1 mole ratio of Mg/Zn) was derived from palm stearin and decarboxylated at 350 °C and atmospheric pressure for 5 hours. The basic soap effectively decarboxylated, yielding a diesel-like hydrocarbon fuel with a liquid product yield of 62%-weight. The resulting hydrocarbon product is a complex mixture consisting of normal paraffins in the range of carbon chain length C8"“C19, iso-paraffins and various olefin products
Finite Element Analysis of Bus Rollover Test in Accordance with UN ECE R66 Standard
Get PDFBus transportation plays a significant role in short and long distance mass transportation in Indonesia. The number of buses in Indonesia shows significant growth every year. However, there is a lack of regulations regarding bus construction safety and the increasing number of bus accidents is also becoming a major concern. In this paper, a computer simulation of bus rollover is presented. The bus structure was modeled to represent the mass distribution in a real bus. Two conditions were tested: the bus when empty and when fully loaded. Both the empty bus and fully loaded bus simulation results show that the bus did not comply with the UN ECE R66 safety standard. The results were validated by making a comparison with other tests that have been conducted by other researchers
Determination of Gas Pressure Distribution in a Pipeline Network using the Broyden Method
Get PDFA potential problem in natural gas pipeline networks is bottlenecks occurring in the flow system due to unexpected high pressure at the pipeline network junctions resulting in inaccurate quantity and quality (pressure) at the end user outlets. The gas operator should be able to measure the pressure distribution in its network so the consumers can expect adequate gas quality and quantity obtained at their outlets. In this paper, a new approach to determine the gas pressure distribution in a pipeline network is proposed. A practical and user-friendly software application was developed. The network was modeled as a collection of node pressures and edge flows. The steady state gas flow equations Panhandle A, Panhandle B and Weymouth to represent flow in pipes of different sizes and a valve and regulator equation were considered. The obtained system consists of a set of nonlinear equations of node pressures and edge flowrates. Application in a network in the field involving a large number of outlets will result in a large system of nonlinear equations to be solved. In this study, the Broyden method was used for solving the system of equations. It showed satisfactory performance when implemented with field data
The Effect of TiO2 Coating on Pile Penetration Depth in Clay
Get PDFPile driving tests were conducted using models of concrete piles with titanium dioxide (TiO2) coating and piles without coating. Pile surfaces coated with TiO2 become superhydrophilic, which enables water molecules in clay pores to be attracted to the pile during the pile driving process. The attraction suppresses the compression of the pore water in the clay soil, hence the result of the pile driving tests showed that piles with TiO2 coating could penetrate deeper than piles without coating with the same count of hammer strokes. An examination using FTIR confirmed the formation of bonds between water molecules for piles with coating and the absence of such bonding for piles without coating. Furthermore, it was successfully established that pile surface coating gives different results for pile driving in different clay soils