Characterization and Testing of Palm Fiber/Polypropylene
Nature of Work: Experimental.
There is a considerable potential for use of agro-based wastes and fibers, which are renewable and abundantly available, as fillers and reinforcements in plastics. Environmental aspects of using renewable materials is an important consideration. Moreover, since large amounts of the agro-based natural fibers (40% (vol) and maybe more) can be incorporated in high speed molding of plastics, these renewable materials reduce the use of the plastics used in the composite material. Therefore, material cost savings and reduced energy utilization by replacing glass fibers with these natural materials is possible.
It is therefore the overall objective of this study to investigate the feasibility of utilizing wood fibers obtained from waste palm tree cellulose fiber resulting from the annual proning and cutting of date palm trees which are abundantly available in Saudi Arabia (in excess of 15,000,000 trees) in reinforcing polypropylene, a thermoplastic produced by Saudi Basic Industries Corporation (SABIC) at a rate of 200,000 metric tons per year (mty) with planned additional capacity of 180,000 mty. If demonstrated to be feasible, it will not only result in cost and energy savings, but in addition will be environmentally beneficial.
|Note:||This is a funded KACST (King Abdulaziz City for Science and Technology) Project, compensation for graduate students (in addition to their monthly salaries) will be provided. Available equipments are a Thermokinetic Mixer, an Injection Molder and a Mechanical Testing Unit.|
"A Study of Water Sorption
Characteristics of Aluminum Powder Filled Epoxy Adhesive"
Nature of Work: Experimental.
Introduction and Objective:
The most common of the high-performance structural adhesives are epoxies, especially in automotive and aircraft industry. They are usually formulated with metal fillers to increase their thermal conductivity. The properties of epoxy adhesives are adversely affected by water absorption and exposure to other deleterious environments. Because epoxy adhesives are permeable to water, water diffuses through them and eventually invades the metal substrate underneath in adhesively bonded metal joints. It is the objective of this study to investigate the effect of filler content on moisture sorption characteristics of aluminum powder filled epoxy adhesive in aqueous solutions.
The choice of which adhesive to use in an industrial application requires assessment of its behavior in the real service environment. This assessment involves exposure of the adhesive to the simulated environment for a certain period, and evaluation of the exposed adhesive for changes in properties. Water- and fluid-immersion tests have been widely utilized to evaluate changes in the properties of adhesives. Water-immersion tests are performed by immersing specimens in distilled water and fluid-immersion tests are performed by immersing specimens in a fluid to which the adhesive may be exposed to during industrial use. A sodium chloride solution is the most commonly utilized test solution for testing adhesively bonded automotive joints. Both the water- and fluid-immersion tests are effective techniques in evaluating the properties of adhesives such as the absorption rates of solutions in adhesives, the stability of adhesives, swelling of adhesives, color changes in adhesives, and delamination of adhesives from metal adherents.
The emphasis will be placed upon determining the moisture absorption behavior of aluminum powder filled epoxy adhesive under complete immersion in distilled water and in NaCl solutions. The water absorption rate of the adhesives will be measured as a function of the filler content, concentration of the sodium chloride solution and exposure time. Formation of possible micro-debonds due to water uptake will be examined by scanning electron microscopy.
"Influence of Metal Fillers within an
Adhesive on the Performance and Degradation of Adhesively Bonded
Metal Joints in Aggressive Environment"
Adhesives are fast becoming the fastening of choice because adhesion is faster, neater, lighter, and cheaper than bolts, rivets, and the like. Adhesives result in more uniform distribution of stress and increased fatigue life. They also help prevent or reduce corrosion between dissimilar metals, or galvanized and ungalvanized steel. The most common of the high-performance structural adhesives are epoxies, especially in automotive and aircraft industry. Epoxies are attractive because they cure without producing volatile by-products, their shrinkage upon curing is low, and they are able to bond well to a variety of treated or untreated metal surfaces. They are usually formulated with metal fillers to increase their thermal conductivity. However, mechanical properties of the adhesive joints and their degradation and corrosion behavior when exposed to detrimental environments might be influenced strongly by the presence of metal fillers in the adhesive. An experimental program is described to develop information on the influence of metal filler additives within an epoxy adhesive on the performance of adhesive joints in non-corrosive as well as corrosive local (Saudi Arabian) environments.
Reinforcing Steel Corrosion under Atmospheric Condition"
Atmospheric corrosion is an electrochemical process which primarily results from conjoint action of oxygen and moisture. Atmospheric parameters that affect corrosion are humidity, pollutants and temperature. Generally the atmospheric corrosion rate of metals increase rapidly when the relative humidity rises above a certain threshold value known as the "critical relative humidity", below which corrosion is negligible. The most prominent corrosive pollutants which prevail in marine-industrial atmosphere are sulfur dioxide and sea-salt. Two together exert a synergistic corrosive effect which aggravates corrosion of metals to the extend several times beyond the corrosion that would be caused by each of these pollutants alone.
The atmospheric conditions in the Arabian Gulf region is corrosive to metallic structures due to high relative humidity, high ambient temperature, especially during summer, and high levels of contamination of the atmosphere with sea-salt and sulfur dioxide originating from the Gulf and industrial complexes in the region.
The Saudi Iron and Steel Company (HADEED), in Jubail, produces about 2 million metric tons of formed and smooth, hot and cold rolled steel rods of various diameters. The mechanical properties of HADEED steel products meet international standards. However, one serious problem they face is the discoloration of their steel products in the stockyard in Jubail due to atmospheric corrosion.
The objective of this study is to search for an inexpensive inhibitor to be used in the HADEED production line to prevent atmospheric corrosion/discoloration of the steel surface. For this purpose three inexpensive inhibitors will be selected and evaluated by accelerated and free corrosion tests using weight loss and electrochemical techniques, and scanning electron microscopic identification. The underlying inhibition mechanisms will also be studied by utilizing surface analytical techniques.
|Note:||This is a KACST (King Abdulaziz City for Science and Technology) Project. Compensation for graduate students (in addition to their regular monthly salaries) will be provided.|
"Numerical and Experimental
Investigation of Phase Change (Melting/Solidification) with
Nature of Work: Numerical and experimental.
Introduction and Description of the Problem:
Phase change problems play important roles in many industrial and natural processes. These include metallurgical operations, edible margarine production, plastics processing, chemical processes involving molten solids, freezing and thawing of ice and soil, transport via waterways, pipeline operations, heavy oil and sulfur processing. Also (de)sublimation processes fall into the same category.
During a phase change operation the phase front, in general, moves and its position and shape are not known a priori. Although the physical description of these processes is routine, the mathematical description and simulation aspects are very complicated.
Thus far, in literature, solutions for only simplified problems are available. . The effect of natural convection is usually ignored. In addition, the theoretical studies lack the experimental verification.
"Numerical Analysis of
Entropy Generation in Laminar Viscous Fluid Flow in Rectangular
To determine the thermodynamic perfection of a system, not only the processes occurring within the system but also the interaction between energy and material flows outside the systems boundaries must be taken into consideration. Only then the actual performance of the system and its impact on the environment can be evaluated. The entropy generation during the complete life of processes allows evaluating the degree of thermodynamic perfection.
Determination of the entropy generation for laminar fluid flow in noncircular ducts has importance in a large variety of traditional engineering disciplines, such as heating and cooling devices used in electronics, biomechanics, aerospace, instrumentation, and, in particular, for compact heat exchanger and solar collector designs. Generally, one way to reduce heat exchanger costs is to use more compact surfaces, as both the cost per unit area and heat transfer flux per unit temperature difference are simultaneously improved.
Consider a laminar fully developed steady flow of a viscous incompressible fluid through a duct of rectangular cross-section. The pressure gradient along the axial direction (dP/dx) is considered to be constant and uniform throughout the cross-sectional area of the duct. The boundary condition for the temperature on the wall of the duct is either constant specified temperature Tw or uniform specified heat flux qw. Using the Navier-Stokes equations, the two dimensional velocity, temperature and entropy generation profiles are to be obtained.
The tasks in this numerical investigation are as follows:
"Second Law Analysis of Viscous Flow in
Nature of Work: Analytical and Numerical (the software Matlab can be used for the numerical solution).
The main objective of this study is to investigate analytically the entropy generation for a fully developed turbulent viscous fluid flow such as crude oil in a circular pipe during a heating process. The pipe wall boundary conditions are considered to be either constant temperature or uniform heat flux. The temperature dependence on the viscosity will be taken into consideration in the analysis. Thus, the availability losses (exergy destruction) as a result of entropy generation in the viscous fluid flowing through the pipe will be determined.
Description of the Problem:
The irreversibilities (entropy generation) associated with fluid flow through a duct are usually related to heat transfer and viscous friction. The irreversibility associated with viscous friction is directly related to the viscosity of the fluid in both laminar and turbulent flows. Therefore, its is necessary to investigate the effect of a change of viscosity during a heating process for an accurate determination of entropy generation. This is important for efficient thermal operation in industrial sector handling and processing viscous fluids such as petrochemical and process industries.
Second law analysis work on viscous fluids found in the literature mostly deal with constant viscosity assumption. However this is not true for highly viscous fluids and for situations where considerable temperature variation exist. Almost no study can be found in the literature dealing with second law (exergy) analysis using variable thermal properties. Since the significant variation of viscosity affect the viscous friction related irreversibilities considerably, it is necessary to analyze the entropy generation considering the variable viscosity model. This gives an accurate determination of exergy losses due to the entropy generation. This is the aim of this study.