Modeling of Properties and SI Engine Pollution of Associated Petroleum Gas in Iraq

Modeling and simulation of process performance has been conducted around the use of theIraqi associated petroleum gas as fuel for the spark-ignition engine. The study included astatistical evaluation of the effect of each component on the total properties of the gas.Finally, the gas was tested as a possible fuel for the spark-ignition engine from theemission point of view. This was done numerically using commercial software wellestablished and verified for modeling the operation and performance of spark-ignitionengines.The study was conducted on Ricardo E6/T variable compression ratio engine. The range ofthe speed studied was 1000-3000 rpm and was limited to a lean range 0.8-0.95. It was alsofound that the presence of Methane in higher quantity helped in improving the calorificvalue (on a mass basis) but at the cost of gas density. The presence of higher carbon valuegasses did not help improve the fuel heating value.The highest negative impact on the heating value is CO, H2S, and C2H6 respectively. Thestudy also showed that the associated gas can be used as a fuel after removing sulfur fromit.

Multiscale Lithium-Battery Modeling from Materials to Cells

New experimental technology and theoretical approaches have advanced battery research across length scales ranging from the molecular to the macroscopic. Direct observations of nanoscale phenomena and atomistic simulations have enhanced the understanding of the fundamental electrochemical processes that occur in battery materials. This vast and ever-growing pool of microscopic data brings with it the challenge of isolating crucial performance-decisive physical parameters, an effort that often requires the consideration of intricate interactions across very different length scales and timescales. Effective physics-based battery modeling emphasizes the cross-scale perspective, with the aim of showing how nanoscale physicochemical phenomena affect device performance. This review surveys the methods researchers have used to bridge the gap between the nanoscale and the macroscale. We highlight the modeling of properties or phenomena that have direct and considerable impact on battery performance metrics, such as open-circuit voltage and charge/discharge overpotentials. Particular emphasis is given to thermodynamically rigorous multiphysics models that incorporate coupling between materials’ mechanical and electrochemical states.

Electrodeposited Copper-Graphite Composites for Low-CTE-Integrated Thermal Structures

Emerging high-power and high-temperature electronic modules require thick copper structures for power supply, thermal vias, heat spreaders, and also as carriers or lead frames for high-power packages. Such structures should coexist with glass and other substrates with low coefficient of thermal expansion (CTE) to meet high-temperature performance, dimensional stability, and superior device interconnection reliability with low stresses and warpage. The primary challenge with these packages arises from the CTE mismatch between the conductors and the substrates. Cu-graphite composites with glass-matched CTE are explored to address this challenge through analytical modeling of properties such as CTE, Young's modulus and thermal conductivity, finite-element-modeling predictions of glass warpage and stresses, process development to deposit copper-graphite composite films with high graphite loading of 64 vol. %, and warpage measurements using shadow moiré. Results indicate that Cu-graphite composites can mitigate the warpage and stress issues in high-temperature and high-power packages.

Electrodeposited copper-graphite composites for low-CTE integrated thermal structures

Emerging high-power and high-temperature electronic modules require thick copper structures for power-supply, thermal vias, heat-spreaders, and also as carriers or lead-frames for high-power packages. Such structures should coexist with glass and other low-CTE substrates to meet high-temperature performance, dimensional stability and superior device interconnection reliability with low stresses and warpage. The primary challenge with these packages arises from the coefficient of thermal expansion (CTE) mismatch between the conductors and the substrates. Cu-graphite composites with glass-matched CTE are explored to address this challenge through analytical modeling of properties such as CTE, Young's modulus and thermal conductivity, FEM predictions of glass warpage and stresses, process development to deposit copper-graphite composite films with high graphite loading of 64 vol. %, and warpage measurements using shadow-moiré. Results indicate that Cu-graphite composites can mitigate the warpage and stress issues in high-temperature and high-power packages.