Parameter determination and experimental validation of a wire feed additive manufacturing model

“Laser metal deposition is an additive manufacturing method with great scope and robustness. The wire fed additive manufacturing method has great opportunities in space applications and other zero gravity manufacturing processes. Process parameters play an important role in controlling the complex phenomenon and obtaining an ideal manufactured part. These parameters can be efficiently determined using simulation tools which are highly essential in visualizing real world experiments, therefore saving time and experimental costs. The objective of this study is to develop a transient 3D model of laser aided wire feed metal deposition which realizes the heat transfer and fluid flow behavior of the melt pool and wire deposition with varying process parameters. The model was programmed in Python and a 1 KW Gaussian beam fiber laser was used to conduct experiments. Design of experiments was utilized to determine all possible levels of factors and experiments were conducted on Ti-6Al-4V alloy with and without wire deposition to establish the behavior of the critical outputs with varying parameters. The effect of laser exposure to the melt pool profile and deposit profile is obtained and the results are compared with the model. The comparison of simulation and experimental results shows that this model can successfully predict the temperature profile, fluid characteristics and solidified metal profile. The optimum input parameters based on material properties can be identified using this model”--Abstract, page iii

Selection of Machining Parameters of Face Milling operation for Aluminium with HSS cutter using Response Surface Methodology and Genetic Algorithm

Components used in chemical equipments are produced from forging, extrusion and casting processes with classic dimension tolerances due to its producing ability. So machining processes were introduced for close tolerance assembly and improve the product working efficiencies. At present,  lot of machining processes are available for producing chemical equipments such as turning, milling, drilling and grinding etc.,. Milling operation is playing critical role on making the chemical equipment’s components with high accuracy and higher productivity. Face milling operation is one of the milling processes which is used for achieving higher flatness and surface finish of chemical equipment’s parts. Thiswork concentrates the parameters influence on Material Removal Rate (MRR) and Surface Roughness (SR) by using aluminium as work piece material. Actually, aluminium alloy has the  most significant in chemical industries because of its inherent properties such as, corrosive resistance , low weight to strength ratio. The milling parameters such as feed rate, spindle speed  and depth of cut are selected as parameters for improving the quality and productivity. This work put together the link between input and response variables for developing the face milling performances. The Response Surface Methodology (RSM) is employ for making the link between dependent and independent variables. Building the empirical model by conducting regression analysis The performance of developed regression models are verified with experimental results. Verification results show the developed models have best agreement with experimental results. The developed models are used for achieving the best input parameters by using Genetic Algorithm (GA). Finally, the optimal parameters are evaluated by GA

भारत के दक्षिण पूर्व तट पर कवाकवा मछली (यूथिन्नस) एकिनिस का विदोहन और इसका जीवविज्ञान

कृपया पूरा लेखा पढ

Application of Genetic Algorithm Technique for Machining Parameters Optimization in Drilling of Stainless Steel

Abstract This work is aimed at developing relations between the pertinent variables that affect drilling process of stainless steel using artificial neural network. The experiments were conducted on vertical CNC machining centre. The parameters used were spindle speed and feed rate. The effect of machining parameters on entry burr height, exit burr height and surface roughness was experimentally evaluated for different spindle speeds and feed rates. A model was established between the drilling parameters and experimentally obtained data using ANN. The predicted values and measured values are fairly close, which indicates that the developed model can be effectively used to predict the burr height and surface roughness in drilling of stainless steel. Genetic algorithm (GA) technique was used in this work to identify the optimized drilling parameters. Confirmation test was conducted with the optimized parameters and it was found that confirmation test results were similar to that of GA-predicted output values

Sharptail mola landed at Thoothukudi

A large Sharptail mola (Masturus lanceolatus) measuring 180 cm in Total length (TL) landed on 28.07.2016 at Tharuvaikulam Landing Centre, Gulf of Mannar. Interaction with the local fishermen indicated that it was caught at a depth of 150 m in a drift gill net conducting multiday fishing for 4-5 days about 40 km from shore

Incidents of ingestion of plastic by marine fishes

Although impacts of plastic pollution on fishthrough entanglement in discarded fishing gear anddirect ingestion have been reported, the reportsfrom India especially on ingestion of plastic bymarine fishes are rare. Two instances of plasticsobserved in the stomachs of fishes caught from Gulfof Mannar off Thoothukudi, south-east coast of Indiaare reported

Large sized oilfish Ruvettus pretiosus (Cocco, 1833) ever recorded from Gulf of Mannar, south-east coast of India

Ruvettus pretiosus belonging to the Family Gempylidae of perciform fishes is closely related to Scombridae. Gempylidae fishes are commonly called as snake mackerels or escolars and this family has 16 genus and 24 valid species. R. pretiosus is one of the large sized fishes with the maximum record of 300 cm total length (Nakamura and Parin, 1993). It is bentho-pelagic, reported to be distributed along the tropical and temperate seas of the world

CYTOTOXICITY AND ANTIMICROBIAL ACTIVITY OF MONO-, DI- AND TRINUCLEAR RUTHENIUM(II) POLYPYRIDINE COMPLEXES

Objectives: To evaluate the in vitro cytotoxicity, antibacterial and antifungal activity of the synthesized mono-, di- and trinuclear ruthenium(II) polypyridine complexes.Methods: A series of synthesized ruthenium(II) complexes, R1, R2 and R3, are screened for in vitro antiproliferative activity against HepG2 cancer cell line using 96-well plate method. An assay of antimicrobial activity was performed by disc diffusion method. In addition an assay of an antifungal was performed by broth micro-dilution method.Results: The cytotoxicity of complexes revealed IC50 values of 14.52 (R3), 19.53 (R2) and 22.32 μM (R1) against HepG2 cell line in a dose dependent manner. All the complexes inhibited moderately the growth of Gram positive bacteria (G+) such as Staphylococcus aureus (MRSA), Eubacterium lentum, and Bacillus subtillis, quite meagerly the growth of the Gram negative bacterium (G─), Enterobacter aerogenes, but did not inhibit at all the growth of Erwinia amylovora (MTCC 2760) and showed a slight antifungal activity.Conclusion: From this study, we could suggest that the systematic increase in number of imidazole moiety along with expanding cloud of conjugated Ï€-electron system of ruthenium(II) polypyridine complexes is responsible for the antiproliferative activity which increases in the order, R1 < R2 < R3 against HepG2 cancer cells. Consecutively, the complexes show good antimicrobial activity against Gram positive bacteria, but show poor or no effect against Gram negative bacteria and exhibit a little antifungal activity.Â

Occurrence of deep sea prawns in the stomach of Yellowfin tuna

The earlier studies on yellowfin tunas (Thunnus albacares) from Indian waters have shown that the fish is an opportunistic feeder, consuming fishes, cephalopods and crustaceans. The main crustacean component is the deep sea pelagic crab, Charybdis smithii. The food and feeding studies of yellowfin tuna from Thoothukudi during the period 2011-2014 were also in conformity with the results of earlier studies

First record of the twostripe goby, Valenciennea helsdingenii (Gobiidae, Gobiiformes) from the southeast coast of India

Two specimens of Valenciennea helsdingenii (Bleeker, 1858) were collected off Punnakayal coast, from Gulf of Mannar, southeast coast of India in November 2012. The morphometric and meristic characters of the recorded specimens are described and discussed. This is the first record of the species from the Indian waters that is a range extension of its known range within the Indian Ocean