Philippine Engineering Journal

Includes bibliographical references.

Thermodynamic analysis and performance evaluation of a proposed novel combined cooling and power system -- Analysis of crack propagation under different die until tilt configuration on a small outline transistor -- Investigation of silicon die crack for varying silicon die parameters and die attach material -- Proof of Concept Implementation of an Enterprise Service Bus for Health Information Exchanges -- Potentiostatic electrodeposition as an option to the traditional recovery of silver in artisanal gold smelting wastewater in bulacan, Philippines.

[Article Title: Thermodynamic Analysis and Performance Evaluation of a Proposed Novel Combined Cooling and Power System / John Carlo S. Garcia and Menandro S. Berana, p.1-18] Abstract: A novel combined cooling and power (CCP) system, wherein an organic Rankine cycle is coupled with a compressor-driven ejector refrigeration cycle, is proposed. The ejector primary flow of this refrigeration system comes from one of the streams that is pumped from the condenser, which is unconventional from the existing studies wherein the turbine exhaust is its primary flow source. Parametric analysis was conducted to study the effects of the heat source and evaporator temperature, and entrainment ratio on the coefficient of performance (COP) and exergy efficiency of the proposed system using three working fluids, namely R123, R141b, and R245fa. In the novel setup, the COP improvement can be theoretically associated to the produced turbine power that reduces the power input to the system. Among the parameters observed, the entrainment ratio and evaporator temperature had the greatest effect on the performance of the system. The system exergy efficiency varies inversely with entrainment ratio and evaporator temperature; on the other hand, the COP improves with the increase in the evaporator temperature and decrease in the entrainment ratio. The performance of three working fluids was also investigated. Among the three refrigerants, the system that used R141b had the highest COP and exergy efficiency at 3.26 and 46.92%, respectively.A novel combined cooling and power (CCP) system, wherein an organic Rankine cycle is coupled with a compressor-driven ejector refrigeration cycle, is proposed. The ejector primary flow of this refrigeration system comes from one of the streams that is pumped from the condenser, which is unconventional from the existing studies wherein the turbine exhaust is its primary flow source. Parametric analysis was conducted to study the effects of the heat source and evaporator temperature, and entrainment ratio on the coefficient of performance (COP) and exergy efficiency of the proposed system using three working fluids, namely R123, R141b, and R245fa. In the novel setup, the COP improvement can be theoretically associated to the produced turbine power that reduces the power input to the system. Among the parameters observed, the entrainment ratio and evaporator temperature had the greatest effect on the performance of the system. The system exergy efficiency varies inversely with entrainment ratio and evaporator temperature; on the other hand, the COP improves with the increase in the evaporator temperature and decrease in the entrainment ratio. The performance of three working fluids was also investigated. Among the three refrigerants, the system that used R141b had the highest COP and exergy efficiency at 3.26 and 46.92%, respectively.;[Article Title: Analysis of Crack Propagation Under Different Die Tilt Configuration on a Small Outline Transistor / Jennifer Callanga, Hannah Erika Macaspac, Louis Angelo Danao, and Manolo Mena, p. 19-32] Abstract: In today's microelectronic industry, the increasing demand for miniaturization and high function integration poses a big challenge in maintaining the reliability of the package. It was found out that majority of the reliability problems can be attributed to thermal and mechanical loadings during manufacturing and assembling process. Die cracking and die tilting are two of the most common defects originating from this process that affect the reliability of the electronic packages. This study aims to investigate the influence of die tilting to the propensity of crack propagation on the silicon die. In this research, the cooling phase of the die and clip attach reflow of small outline transistor was simulated using a finite element-based software. An initial crack was incorporated in the silicon die model to show the imperfections acquired during manufacturing stage.;[Article Title: Investigation of Silicon Die Crack for Varying Silicon Die Parameters and Die Attach Material / Hannah Erika Macaspac, Jennifer Callanga, Richard Raymond Dimagiba, and Manolo Mena, p. 33-48] Abstract: Demand for small sized, portable electronic devices continually increases until today. Compact electronics would mean a reduction in size of semiconductors that would translate to further shrinking of components inside of it such as the small outline diode (SOD) and the small outline transistor (SOT). This work utilized the finite element method with a fracture mechanics approach to analyze the effect of varying geometric parameters on the J-integral of an induced crack on the silicon die.;[Article Title: Proof of Concept Implementation of an Enterprise Service Bus for Health Information Exchanges / Philip Christian Zu├▒iga, Joseph Benjamin Del Mundo, Edgardo Felizmeno, Marie Jo-anne Mendoza, and Rose Ann Zu├▒iga, p. 49-66] Abstract: Integration of health systems is one of the biggest problem in eHealth today. There are a lot of systems, yet they were developed using different platforms and technologies, making them virtually impossible to connect. In this paper, we discussed how to implement an ESB as the integration platform for health data. We identified use cases and functional requirements. Logical and deployment architecture were developed, and an actual proof of concept of an ESB is developed. Experiments were also done to determine the overhead caused by the ESB. Some of the functionalities of the ESB were examined to determine their individual overheads.;[Article Title: Potentiostatic electrodeposition as an option to the traditional recovery of silver in artisanal gold smelting wastewater in bulacan, Philippines / Michael Vincent Laurio, Jomuel Velandres, Catalino Alfafara, Veronica Migo, Monet Concepcion Detras, Jennifer Marie Sunga-Amparo, and Marlo Mendoza, p. 67-86] Abstract: Potentiostatic electrodeposition for silver recovery in the artisanal gold smelting of Bulacan, Philippines was investigated as an alternative cost-effective method to prevent the generation of copper nitrate-rich effluent. The electrodeposition of dominant metal ions (silver, copper, iron, and lead) were observed from time-course profiles of metal ion removal efficiencies and measured currents at varying constant operating voltages. Initial silver ion removal rates increased with operating voltage supplied, however, redissolution also occurred during high-potential operation (1.5V to 2.0V). The occurrence of co-deposition and redissolution was managed by determining critical electrodeposition conditions.