The study focuses on using simulating tool to study direct laser lithography. GenISys - lithography simulation software was used as it is thoroughly observed in the literature. The LAB Module of this software was adopted for modelling and simulating effect of Depth of Focus in the direct laser lithography process. A negative photoresist material was used for simulation and results were obtained by keeping constant exposure dosage by varying Depth of Focus. The 3D resist profile was obtained for evaluating the effect of Depth of Focus. The results showed that, good quality resist profile is obtained at 45 mJ/cm2 and -15?m Depth of Focus.
This study focuses on the effect of nanoparticles on the surface tension of liquids. Nanofluid is characterized by liquid that contains nanometer-sized particles. The surface tension of two nanofluids SiO2 and TiO2 are measured using drop volume method. Measured surface tension is compared with that of DI-water. It is observed that nanoparticles affect significantly the surface tensions. Measurements shows that SiO2 nanoparticles have a tendency to increase the surface tension and TiO2 nanoparticles lead to a decrease of surface tension.
This paper reviews the synthesis and applications of different nanofillers which are carbon black, carbon nanotube, clay and graphene. Next, it discusses various combinations of the nanofillers/polymer nanocomposites and the thermal crystallization kinetics of these nanocomposites. To analyze the data for the isothermal crystallization kinetics, the Avrami method is used. To analyze the data for non isothermal crystallization kinetics, the Avrami equation was insufficient. Therefore, a modified Avrami model was used. The ozawi and Mo models were also used. The type of crystal growth were determined. Recently, polymer based nanocomposites have gained increased attention by the academic and industrial community due to their unique properties and applications. These fillers, due to their exceptional properties have attracted a great deal of interest. The fillers were found to have a nucleating effect on the matrix. However, in some cases, increasing the filler content resulted in a decrease in the nucleating effect.
Stress corrosion cracking (SCC) is a type of corrosion which causes failure of metals due to the combined effect of tensile stress and a corrosive environment. Generally, sudden and unpredictable failure of materials takes place due to SCC. This is an examination on the combined effect of shot peening and application of corrosion inhibitors on the stress corrosion cracking (SCC) behavior of Austenitic stainless steels (316L) in high pH chloride solutions using a U-bend. Electrochemical techniques such as linear polarization resistance (LPR), Tafel analysis and open circuit potential (OCP) are used to determine the electrochemical behavior of 316L stainless steel in different cases. The 316L fracture and surface morphology in different cases are studied using SEM analysis and different characterization techniques including XRF, hardness measurement, tensile tests, optical microscopy, EDS and XRD are performed to study the changes in material properties before and after corrosion.
In this study, experimental testings were conducted on mild steel in brine solution containing 3.5 % NaCl in the presence of imidazole as corrosion inhibitor to determine the critical velocity and Reynolds number limit below which erosion-corrosion is tolerated and beyond which the inhibitor loses its effectiveness and adherence using an empirical relation which will be developed from experimental results. Moreover, this study investigates the temperature's effect on erosioncorrosion of mild steel in the presence of corrosion inhibitor. Finally, the study explores the optimal inhibitor concentration to be used for best performance. The critical velocity was found to be 20 m/s. It was also observed that temperature has a significant effect on the results with the corrosion rates increasing proportionally as the temperature increased. Finally, the optimal inhibitor concentration was found to be 50 ppm.
It is vital to understand the influence of loading conditions on the behavior of the rock formation in order to predict their utility in various industries like construction and drilling. In this paper two Bandera Brown sandstone samples were tested under monotonic and cyclic loading conditions in order to get a preliminary understanding of their behavior and to serve as a basis for planning future tests.
Sandwich structures are special types of composite materials, constructed by attaching a thick and porous core material between two thin and stiff sheets, and became commonly used in applications where stiffness to weight ratio is to be maximized. The overall structural rigidity depends on the amount of material used in constructing the cores, which basically governed by the core cell size(d) and thickness(t). Different loading conditions and different loading orientations play a big role in the selection criteria of the best fit cell size and thickness, so this work aims to characterize the out-of-plane attributes of Aluminum sandwich structures considering a wide range of cell sizes and thicknesses as well as different cell configurations, and relating the field output to the relative density. The study stated that the out-of-plane properties depends on the amount of material used, (i.e. known as the projected area), regardless of the cell size and thickness.
In this study, we conducted experiments and numerical simulations on water flooding, which is one of the techniques used in enhance oil recovery operation. The experiments were conducted in a 3D printed model of a cross section rock matrix, obtained from high-resolution microcomputed tomography. The experimental results were compared with those obtained from the numerical simulations, conducted in COMSOL. The study shows a good agreement between the experiments and the simulations. The study shows also that foam improves the recovery of the displacement of oil with water.
Carbon anode baking is one of the most important and costly step in Aluminum production. The unbaked (green) anode are formed by compaction of base ingredients; i.e. coal tar pitch, calcined coke and recycled anode butts. The green anode does not possess the necessary thermo-electromechanical properties necessary to withstand the harsh thermo-electrical conditions in the electrolysis pot. Hence, baking them in a furnace modifies their microstructure making them utilizable in the electrolysis cell. This research work aims at applying thermodynamics and phasefield theory to evaluate the baking level at any stage of the baking process. The evolution of baking level would in turn governs the evolution of materials properties of the anode. The developed evolution equations of material properties are calibrated using available published experimental data.
This article investigates the thermal - hydraulic characteristics behaviors of Pressurized Water Reactor (PWR) via computational fluid dynamics (CFD). The results obtained from this analysis including flow, turbulence and the heat transfer can assist in the improvement and to achieve the optimum design of the fuel rod bundle for the PWR's core to achieve better performance. In this study, a three-dimension (3D) CFD model with standard k-? turbulence model proposed to simulate a single sub-channel of the coolant within the rod bundle and subsequently evaluate the effect of different flow rates on flow mixing and heat transfer. The turbulent heat convective for heat removal is numerically investigated by applying standard k-? turbulence model using ANSYS FLUENT. It is shown in the simulation results that increasing the inlet velocity will influence on the fluid turbulence by increasing the flow mixing which has significant effect on enhancing the heat transfer capability.
