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.
In term of material used in redox flow batteries, electrodes nano-material carbon-based composites are the most common (including carbon nano-tubes and graphene). Such materials have high porosity, enlarging the active surface area of the electrode. In these Nano- porous materials the electrolyte flow through a 3D electrode. Unlike in planar materials the electrolyte flow past 2D electrode. To study the effect of porosity on electrical properties and electrochemical response of the electrode; porosity and morphology of the sample were varied in a systematic approach. Then the effect on electrochemical response and kinetics were captured by cyclic voltammetry. This allows correlating pore structure variation to electrochemical properties. This have shown that the increase in porosity results in an enhancement in the diffusivity and kinetics.
Development of optical epoxy coating with self-healing abilities to withstand the harsh desert environment. Two self-healing approaches, intrinsic and capsule based, are incorporated into the epoxy using Cellulose Acetate Butyrate as the self-healing agent. Fabrication methods of the mixture preparation and coating technique are briefly discussed along with the outdoor testing of samples and the results obtained.
The ability of hygroscopic materials to adsorb moisture (H2O) from the humid air has been extensively studied and their applications are countless. Hygroscopic materials used as cloud seeding are capable to modify weather conditions and augment precipitations. Conventional cloud seeding such as NaCl has a limited water uptake performance. This study demonstrates that novel hygroscopic materials of NaCl coated with thin layer of either TiO2 or SiO2 show better hygroscopic properties and water uptake capacity.
