King Fahd University of Petroleum and Minerals

About: King Fahd University of Petroleum and Minerals is a education organization based out in Dhahran, Saudi Arabia. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 7603 authors who have published 24030 publications receiving 443803 citations. The organization is also known as: College of Petroleum and Minerals.

Inventory Models Involving Lead Time as a Decision Variable

Abstract: Most of the literature dealing with inventory problems assumes lead time as prescribed, whether deterministic or probabilistic. In certain cases, lead time can be reduced but at an added cost. In t...

Chromium removal from water by activated carbon developed from waste rubber tires

Abstract: Because of the continuous production of large amount of waste tires, the disposal of waste tires represents a major environmental issue throughout the world. This paper reports the utilization of waste tires (hard-to-dispose waste) as a precursor in the production of activated carbons (pollution-cleaning adsorbent). In the preparation of activated carbon (AC), waste rubber tire (WRT) was thermally treated and activated. The tire-derived activated carbon was characterized by means of scanning electron microscope, energy-dispersive X-ray spectroscopy, FTIR spectrophotometer, and X-ray diffraction. In the IR spectrum, a number of bands centred at about 3409, 2350, 1710, 1650, and 1300–1000 cm−1 prove the present of hydroxyl and carboxyl groups on the surface of AC in addition to C═C double bonds. The developed AC was tested and evaluated as potential adsorbent removal of chromium (III). Experimental parameters, such as contact time, initial concentration, adsorbent dosage and pH were optimized. A rapid uptake of chromium ions was observed and the equilibrium is achieved in 1 h. It was also found that the adsorption process is pH dependent. This work adds to the global discussion of the cost-effective utilization of waste rubber tires for waste water treatment.

A review on supercooling of Phase Change Materials in thermal energy storage systems

Abstract: Thermal energy storage is at the height of its popularity to harvest, store, and save energy for short-term or long-term use in new energy generation systems. It is forecasted that the global thermal energy storage market for 2015–2019 will cross US$1,300 million in revenue, where the highest growth is expected to be in Europe, Middle East, and Africa followed by Asia-Pacific region. Thermal energy storage has become an inevitable component of fluctuant renewable energy systems due to their significant role in increasing efficiency and Quality of Service (QoS). Currently, one major research stream in such systems is improving the efficiency of heat exchangers and heat carriers. Hence, studying thermal behavior and thermophysical properties of heat storages is of great importance. In this study, we review a common but not very well-known problem of supercooling of Phase Change Materials (PCM). Supercooling is a thermophysical property of PCMs that is problematic in thermal storage applications. This review looks at supercooling from another point of view and investigates applications (such as specialized thermal storage applications) that can put supercooling into operation. To achieve this, development of techniques to increase state stability and designing reliable and stable supercooled heat storage systems will be investigated. The study will look at the thermal energy storage of supercooled liquids, degree and measurement of supercooling. Furthermore, factors that influence degree of supercooling and their effect on output capacity will be discussed. It looks at the supercooled material in four major categories and looks into the mechanisms for triggering crystallization in supercooled liquids. Applications including solar thermal storage will be the discussed in details. From the results discussed in this review researchers will identify and gain insight into supercooling control techniques, which are necessary for developing efficient heat exchangers, and also essential for promoting adoption of sustainable renewable energies.