Published Papers by Hussam Jawad
A numerical simulation has been conducted to investigate the thermodiffusion phenomenon in a poro... more A numerical simulation has been conducted to investigate the thermodiffusion phenomenon in a porous layer sandwiched between two liquid layers that are wetted with water alcohol mixtures at different water concentrations. Two different binary mixtures with different Soret coefficients have been used in the entire system, one with a negative Soret coefficient and the other one with a positive sign. The results show that the direction of the component migration in a porous layer depends on the sign of the Soret coefficient. For a binary mixture with a negative Soret coefficient, such as 10% isopropanol and 90% water, the heavier species move in the direction of the hot surface, while for a mixture with a positive Soret effect, such as 50% isopropanol and 50% water, the heavier species migrate toward the colder surface. To reduce the gravity effect, the cavity was heated from the top with different temperatures ranging from 5 to 20 K.
Just-In-Time (JIT) suggests that inventory is a waste and should be reduced. However, under some ... more Just-In-Time (JIT) suggests that inventory is a waste and should be reduced. However, under some conditions , smaller and more frequent shipments can generate more waste, consume more resources and increase congestion in a supply chain rendering the JIT policy less effective. This paper first modifies the standard economic manufacture quantity (EMQ) models by including within them the costs of transportation , worker stress, process quality, energy, and greenhouse gas emissions. Then, it uses the second law of thermodynamics to calculate the entropy generated in the modified EMQ and JIT models, using entropy as a measure of system sustainability. To make the comparison meaningful, the EMQ model is modified to capture some of the costs that will work for and against EMQ and JIT. The modification then adds an entropic component to the cost functions of EMQ and JIT to capture the costs of disorder (entro-pic) that classical inventory analyses seldom include. The results show that when worker stress and entropy costs are considered, a JIT policy can be more expensive to operate than an EMQ policy.
The Economic Order Quantity, EOQ, model has been popular among academicians and practitioners for... more The Economic Order Quantity, EOQ, model has been popular among academicians and practitioners for decades. Despite the many variants of the EOQ that have appeared in the literature to fine-tune it to reality, it still has limitations. A major one is that it does not take into account the hidden costs inherent in inventory systems. Some of these costs relate to sustainability issues including environmental, social labor, and economic effects. This paper considers some of these costs, referred to as the exergetic costs, and estimates them using the Extended Exergy Accounting, EEA, approach. Extended Exergy Accounting assigns equivalent exer-getic values to capital, labor and environmental remediation costs of a system. The analysis combines the classical exergy analysis with the sustainability factors, which are the labor, capital and environment. The paper uses an exergetic model to determine the EOQ inventory policies for three firms operating in the USA, Germany and China. The results show that the EOQ is different for the three firms because the equivalent exergy of capital, labor and environment remediation costs is different in each country.
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Published Papers by Hussam Jawad