Assam Don Bosco University Journals
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Investigation on Mechanical properties of dissimilar joints of TIG welded AISI 304 and AISI 310 steels using Response Surface Method
No full textJoining of dissimilar metals has found its use extensively in power generation, electronic, nuclear reactors, petrochemical and chemical industries. A variety of problems come up in dissimilar welding like cracking, large weld residual stresses, migration of atoms during welding causing stress concentration on one side of the weld, compressive and tensile stresses, stress corrosion cracking, etc. In the present work dissimilar joints of AISI 304 and AISI 310 steels are produced using Tungsten Arc Welding (TIG) welding. Welding current, flow rate of gas, welding speed and edge included angle are considered as input parameters and tensile strength, Impact strength and Maximum bending load are considered as output responses. Response Surface Method (RSM) is adopted using Central Composite Design (CCD) and 31 experiments were performed for 4 factors and 5 levels. Tensile strength, impact strength and maximum bending load are measured. Effect of welding parameters on output responses are studied and optimal combination of welding parameters are identified for desired weld quality
A Perturbed Self-organizing Multiobjective Evolutionary Algorithm to solve Multiobjective TSP
Get PDFTravelling Salesman Problem (TSP) is a very important NP-Hard problem getting focused more on these days. Having improvement on TSP, right now consider the multi-objective TSP (MOTSP), broadened occurrence of travelling salesman problem. Since TSP is NP-hard issue MOTSP is additionally a NP-hard issue. There are a lot of algorithms and methods to solve the MOTSP among which Multiobjective evolutionary algorithm based on decomposition is appropriate to solve it nowadays. This work presents a new algorithm which combines the Data Perturbation, Self-Organizing Map (SOM) and MOEA/D to solve the problem of MOTSP, named Perturbed Self-Organizing multiobjective Evolutionary Algorithm (P-SMEA). In P-SMEA Self-Organizing Map (SOM) is used extract neighborhood relationship information and with MOEA/D subproblems are generated and solved simultaneously to obtain the optimal solution. Data Perturbation is applied to avoid the local optima. So by using the P-SMEA, MOTSP can be handled efficiently. The experimental results show that P-SMEA outperforms MOEA/D and SMEA on a set of test instances
A GEOMETRICAL AND EXPLORATORY TESTAMENT OF THE DOSE AT THE CENTRAL RAY OF THE DIVERGING GAMMA RADIATION BEAM USED IN RADIOTHERAPY
Get PDFThe foremost intention of the study is to reaffirm the relevance of the phenomenon that the dose at the central ray of a diverging Gamma radiation beam used in Radiotherapy is maximum. This study has been conducted in an all together different dimension - mathematical dimension using Pythagoras Theorem and Inverse Square law. After experimentation and thorough analysis, it has been found that the assumption is valid from a mathematical perspective
CRITIQUE OF THE TREATMENT OF EINSTEIN'S SPECIAL THEORY OF RELATIVITY IN ISAACSON'S BIOGRAPHY
Get PDFConsideration is given to the properties expected for inertial systems, that is, objects which are not subject to unbalanced external forces. Isaacson points out correctly that Einstein based his version of relativity theory on the motion of such inertial systems. It is overlooked, however, in both his discussion and also the original work of Einstein himself that, consistent with Newton's First Law of Motion (Law of Inertia), the rates of inertial clocks must remain constant so long as no unbalanced force is applied to them. As a consequence, it can be safely concluded that the ratio of any two such rates must also be constant. This in turn leads to a prediction about the relationship between elapsed times measured by two inertial clocks (Newtonian Simultaneity), namely they must always occur in strict proportion to one another (Δt=QΔt'). The latter result is shown to stand in direct contradiction to the predictions of the Lorentz transformation derived by Einstein in his famous 1905 paper, namely the occurrence of space-time mixing and remote non-simultaneity (RNS). It is furthermore pointed out that the frequency of sound waves is independent of the state of motion of the source because, as Einstein argued in a 1907 paper in which he derived the gravitational red shift, the number of wave crests emitted by the source per unit time is not changed thereby. This fact has a definite bearing on Einstein's postulate of relativity according to which he assumed that the speed of light in free space is independent of the state of motion of both the observer and the source. It indicates instead that the postulate must be reformulated to state that the speed of light relative to its source is always the same in free space, a version that Einstein also carefully considered, as clearly mentioned in Isaacson's narrative. Accordingly, it becomes clear that Einstein was incorrect in his claim that the classical (Galilean velocity transformation) is not applicable to light. His relativistic velocity transformation only has validity for specific cases in which the speed of light is measured under different circumstances by a single observer, such as in the famous Fresnel/Fizeau light-drag experiment in which the motion of light waves in refractive media is investigated. The failure of the Lorentz transformation necessitates a rethinking of some of its well-known predictions such as time dilation and Lorentz-FitzGerald length contraction. Experimental evidence is presented which indicates instead that the slowing down of clocks upon acceleration is accompanied by isotropic length expansion. The applicability of these theoretical developments for the Global Positioning System of navigation is discussed. Opportunities for carrying out new experiments on this basis are also outlined in the present critique.
Ocean Surface Trash Collector
Get PDFThis paper describes the design of a robot for collecting waste floating on the water surface. Three important issues for designing the aquatic robots are a cost-effective solution along with robustness and durability. Due to the nature of the cleaning work, we designed the robot structure with car like mechanism that can provide high stability, good ability in maneuver and can easily collect all the waste flowing on the water. The plastic pipe container works best for this case and fulfils all structural stability criteria. For collection of waste, a motor-driven conveyor belt has been designed for collecting the wastes and deploy it into a plastic box connected to the platform. This design provides simple and effective waste removal and accommodates large amounts of waste within a little space. This light-weight and tough structure support the total weight of the collected waste, conveyor as well as the hardware components used. The rotating arms system based a differential drive mechanism has been designed, which allows the robots to require a 360 turn on the spot and provides high thrust. Electronic circuit and motors have been placed on the platform, in order to protect them from water. The robot is automatically controlled by Arduino, sensors, motor driver, GPS and GSM modules. The testing of the robot prototype proved to be effective in waste collecting and getting back to the way-point. The maximum trash loads that robot can bear is up 5 kg. The main aim of the project is to optimize time, energy and overall process speed
Evaluation of Lightning Impulse Voltages Superimposed with Oscillations and Overshoot using the Test Voltage Function
Get PDFThe frequency and amplitude of the superimposed oscillations or overshoot near the peak in Lighting Impulse (LI) voltage have an influence on the 50% Break-Down Voltage (BDV). The evaluation of test voltage incorporating frequency dependent test voltage function known as -factor takes the physical breakdown behaviour of the different dielectric materials. The paper presents two methods for implementation of -factor and the complete procedure to evaluate the test voltage magnitude and time parameters of lightning impulse voltage waveform. The first method is based on mean curve approach using Double Exponential (DE) function whereas second method uses Single Exponential (SE) function fitting on the tail of the measured impulse. The standard IEC 61083-2 Test Data Generator (TDG) waveforms are used for evaluation and comparison of these methods
A Review on ANFIS based Linearization of Non Linear Sensors
Get PDFLow cost sensors having high sensitivity, better resolution and linear characteristics are required for industrial applications based on instrumentation and control. Unfortunately, the natural non linear characteristic of sensor itself and also the dynamic nature of the environment, aging effect, inherent sensor’s noise and data loss due to transients or intermittent faults affects the sensor characteristics non linearly. As the transfer characteristic of most sensors is nonlinear in nature, obtaining data from such a nonlinear sensor, by using an optimized device, has always been a design challenge. Linearization of nonlinear sensor characteristic in digital environment, is a vital step in the instrument signal conditioning process. This paper gives a brief review about how to overcome this nonlinear characteristic of the sensor using artificial intelligence such as Hybrid Neuro Fuzzy Logic (HNFL) based on digital linearization technique using VLSI technology such as Field Programmable Gate Array (FPGA)
A Novel Fault Tolerant Full Bridge DC/DC Converter for Photovoltaic application
Get PDFAbstract: Power switches in converters are prone to open and short circuit faults. Faulty power switch in converters worsens the converter performance and it may result in failure of other devices also. Further when main power switch fails, it results in breakdown of entire system. Therefore for reliability improvement of full bridge DC/DC converter in PV system, this research paper presents a novel fault tolerant converter topology for exact faulty power switch localization and isolation from main path so that redundant faulty power switch can be brought in action and still system will provide desired output power. The converter presented here need two redundant power switches and relays to provide fault tolerant competence. It has four operating states which are normal state, faulty state, fault diagnostic state and fault recovery state. In the technique presented here RMS current at given test points is computed and compared with threshold RMS current for determination of faulty power switch. Graph theory is used to show the topological equivalence of converter in normal and fault recovery states. Simulation and experimental results have shown that converter efficiency remains same in both normal and fault recovery state
