Advanced Journal of Graduate Research
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Mechanical Properties and Microstructure of Dissimilar Friction Stir Welding of Pure Aluminum to Low Carbon Steel
Get PDFThe purpose of this research is to use friction stir welding (FSW) to join dissimilar metals, annealed low carbon steel and A1050 pure aluminum. A butt joint with a similar sheet thickness of 1.9 mm was applied. The novelties of the research are relatively using high generated heat produced by a combination of low traverse speed and high rotational speed to perform the dissimilar joints and using a tool material (K107cold work tool steel) which has not been used in FSW with tool cooling. The present work studied the effect of FSW variables such as tilt angle, tool cooling, base metal location on mechanical properties. Tensile tests were used to evaluate the mechanical properties of the dissimilar joints. The microstructure specimens were examined using a scanning electron microscope (SEM). Sound dissimilar joints were successfully produced. The maximum joint efficiency obtained in this study is 51.7% of the aluminum tensile strength. The microstructure images showed that many steel fragments were sheared off from the steel surface by the tool action and scattered in the weld nugget, a continuous intermetallic compound (IMC) layer formed at the interface, the thickness of the IMC layer at the interface decreased in the thickness direction of the weld. FeAl3 IMC phase was only observed at the interface
Evaluating the Nasal Cytology in Acute Rhinosinusitis
Get PDFRhinitis has been found to have profound direct and indirect negative effects on business including costs attributed to loss of productivity and the amount of over the counter medications consumed. Several other studies have examined the immune system’s response in immunocompromised patients by using nasal cytology. This study focused on nasal cytology for a common illness such as acute rhinosinusitis (ARS), in otherwise healthy individuals. Most studies have used nasal cytology to analyze immunocompromised patients, however, this study considers otherwise healthy patients in order to better understand the basic immune response. This study aimed to examine the relationship between neutrophil frequencies found over the course of ARS and symptom severity experienced by subjects. Nasal smears were obtained from subjects at days five, nine, and fourteen of their ARS symptoms. A published symptom survey for ARS was given to participants to provide a qualifying score, signifying a high enough level of symptoms for this study. This survey monitored both emotional and physical symptoms throughout the fourteen-day illness period. Nasal smears were obtained on each visit and stained to observe the different cells present. Wilcoxon Sum Rank Tests were found to be significant between all symptom score visits 1,2, and 3 (p<0.05). The average neutrophil counts between all the visits were not significant (p>0.05). Less than ten percent of eosinophils were present in 88.89 percent of subjects. 55.5 percent of subjects did follow an increased amount of neutrophils over the course of their illness. This study reinforces the use of nasal cytology by obtaining nasal smears to demonstrate how neutrophil frequencies change with symptom severity
Parameter Estimation of Spring-Damping System using Unconstrained Optimization by the Quasi-Newton Methods using Line Search Techniques
Get PDFOptimization is the basic tools to study the behaviour of many complicated mechanical systems by having the knowledge of differential equations which determine the system. The basis of this paper was to present a method to estimate the parameters such as spring constant and damping coefficient of the spring damped system by unconstrained optimization using derivative methods Such as quasi-newton method by Broyden-Fletcher-Goldfarb-Shanno and davidon-Fletcher-Powell hessian updating method by using backtracking line search methods along with Armijo’s condition.it uses the output error approximation procedure. It shows the convergence of different methods which are used to estimate the parameters and how accurately they are measured
Study of the Effect of Crude Oils on the Metallic Corrosion
Get PDFCorrosion is a severe matter regarding the most of metal using industries such as the crude oil refining. The formation of the oxides, sulfides or hydroxides on the surface of metal due to the chemical reaction between metals and surrounding is the corrosion that highly depended on the corrosive properties of crude oil as well as the chemical composition of ferrous metals since it was expected to investigate the effect of Murban and Das blend crude oils on the rate of corrosion of seven different ferrous metals which are used in the crude oil refining industry and investigate the change in hardness of metals. The sulfur content, acidity and salt content of each crude oil were determined. A series of similar pieces of seven different types of ferrous metals were immersed in each crude oil separately and their rates of corrosion were determined by using their relative weight loss after 15, 30 and 45 days. The corroded metal surfaces were observed under the microscope. The hardness of each metal piece was tested before the immersion in crude oil and after the corrosion with the aid of Vicker’s hardness tester. The metallic concentrations of each crude oil sample were tested using atomic absorption spectroscopy (AAS). The Das blend crude oil contained higher sulfur content and acidity than Murban crude oil. Carbon steel metal pieces showed the highest corrosion rates whereas the stainless-steel metal pieces showed the least corrosion rates in both crude oils since that found significant Fe and Cu concentrations from some of crude oil samples. The mild steel and the Monel showed relatively intermediate corrosion rates compared to the other types of ferrous metal pieces in both crude oils. There was a slight decrease in the initial hardness of all the ferrous metal pieces due to corrosion
Genetic Algorithm Parameter Effect on 3D Truss Optimization with Discrete Variable
Get PDFThe Genetic Algorithm is one of the advanced optimization techniques frequently used for solving complex problems in the research field, and there are plenty of parameters which affect the outcome of the GA. In this study, a 25-bar truss with the nonlinear constraint is chosen with the objective to minimize the mass and variables being the discrete area. For the same, GA parameter like Selection Function, Population Size, Crossover Function, and Creation Function are varied to find the best combination with minimum function evaluation. It is found that the Uniform selection gives the best result irrespective of the creation function, population size or crossover functions. But this is at the cost of a large number of function evaluations, and the other selection function fails to reach the global optimum and has a smaller number of function evaluation count. If the analysis of selection function is done one at a time, it is seen that all Cases performs better in Roulette but, Case A which is non-integer type with 200 population size being computationally cheaper than Case B and C of population size 300. In the Tournament selection, Case A, B with smaller population size and Case C with higher population size performs better. Case C performs better at Remainder selection with smaller population size, and Case A and B for Stochastic Uniform with higher population size. And, it is clear that the function evaluation count increases with the population size in every Case from this study
SiC Particulate Reinforced Aluminium Metal Matrix Composite
Get PDFAl or Al alloy Metal Matrix Composites have wide range of applications i.e. aerospace, automobile etc. due to its lightweight, high tensile strength, high wear resistance. This review paper characterized the SiC particulate reinforced Al Metal Matrix Composites. The SiC particulates are dispersed in Al or Al alloy by liquid state processing route and solid-state processing route. Stir casting liquid processing route has been followed by no. of researchers due to its simplicity and low processing cost and at the time of reinforcement small amount of Mg is added to increase the wettability of SiC in molten Al or Al alloy. When Al or Al alloy reinforced with SiC, then its mechanical and tribological properties are enhanced. The effect of particle size, weight or volume fraction of the SiC on density, porosity, hardness, impact toughness, tensile strength, ductility, sliding wear resistance, slurry erosion resistance, erosion-corrosion resistance, corrosion resistance and fatigue strength of Al or Al alloy MMCs are reported. The effect of extrusion and machinability of the SiC particulate reinforced Al MMCs are also discussed in this review article
The Launch of “Advanced Journal of Graduate Research”
Get PDFAdvanced Journal of Graduate Research (AJGR) is Published by “AIJR (India): an online open access journal publisher”. This journal has been established to enable a wide academic community to access important and exciting research carried out by university students. AJGR aims to disseminate research activity undertaken by Bachelor and Master program students as a part of their dissertation/project report. This initiative will help university students to embed globally in the research cultures of their disciplines with the potential to benefit both students and the wider academic community
Investigation of Mechanical Properties of Sisal Fiber Reinforced Polymer Composites
Get PDFThe aim of this work is to study the influence of sisal fiber content on mechanical (i.e. tensile, flexural, impact, hardness and abrasion resistance) and thermal (i.e. TGA) properties of composites by varying the fiber and epoxy percentage. The composite was prepared by melt-mixing method, followed by compression molding process. The percentage of sisal fiber is varied from 4% to 10% in steps of 2%. Similarly epoxy content is varied from 96% to 90% in steps of 2%. Detailed mechanical Properties of Sisal Fiber Reinforced Polymer Composites have been studied. The major mechanical properties viz Tensile, Hardness, Impact, Flexural, Moisture absorption, and Moisture content are studied
Amyotrophic Lateral Sclerosis and Oral Health
Get PDFAmyotrophic lateral sclerosis (ALS), commonly referred to as Lou Gehrig’s disease is a progressive degenerative disorder that affects the nervous system, particularly the motor neurons. It may affect either spinal or bulbar neurons, which classify how symptoms present in the individual. Currently, the cause of ALS is unknown, although research indicates the possibility of genetic and environmental factors affecting its incidence. It is important for health care practitioners to understand amyotrophic lateral sclerosis to enable them to make modifications to patient care as needed
Novel Prototype of Mining Helmet to Facilitate Cooling
Get PDFThe thermal comfort of mining helmet during mining process is important as it can affect the physiological and psychological condition of the worker. Project deals with the development of cooling system for mining helmet using powerful fan technology. The system consists of mainly two fans and batteries. Electrical power is used to run the fan, which creates a temperature difference inside the helmet and facilitates cooling. Fans are used to suck the air from the surrounding and air is circulated inside the helmet and provides a soothing cool breeze inside the helmet. The numerical and experimental results indicate that the temperature inside the helmet can be reduced by 4-5 0C in approximately 3-4 minutes in the mining helmet