Experimental Characterization of Electrical Discharge Machining of Aluminum 6061 T6 Alloy using Different Dielectrics

Electrical discharge machining is a non-traditional machining method broadly employed in industries for machining of parts that have typical profiles and require great accuracy. This paper investigates the effects of electrical parameters: pulse-on-time and current on three performance measures (material removal rate, microstructures and electrode wear rate), using distilled water and kerosene as dielectrics. A comparison between dielectrics for the machining of aluminum 6061 T6 alloy material in terms of performance measures was performed. Aluminum 6061 T6 alloy material was selected, because of its growing use in the automotive and aerospace industrial sectors. The experimental sequence was designed using Taguchi technique of L9 orthogonal array by changing three levels of pulse-on-time and current, and test runs were performed separately for each dielectric. The results obtained show that greater electrode wear rate (EWR) and higher material removal rate (MRR) were achieved with distilled water when compared with kerosene. These greater EWR and MRR responses can be attributed to the early breakage of the weak oxide and carbide layers formed on the tool and alloy material surfaces, respectively. The innovative contributions of this study include, but are not limited to, the possibility of machining of aluminum 6061 T6 alloy with graphite electrode to enhance machinability and fast cutting rate employing two different dielectrics.Peer reviewe

Comprehensive Study on Tool Wear During Machining of Fibre-Reinforced Polymeric Composites

© 2021 Springer-Verlag. The final publication is available at Springer via https://dx.doi.org/10.1007/978-981-33-4153-1.The use of fibre reinforced polymeric (FRP) composites has increased rapidly, especially in many manufacturing (aerospace, automobile and construction) industries. The machining of composite materials is an important manufacturing process. It has attracted several studies over the last decades. Tool wear is a key factor that contributes to the cost of the machining process annually. It occurs due to sudden geometrical damage, frictional force and temperature rise at the tool-work interaction region. Moreover, tool wear is an inevitable, gradual and complex phenomenon. It often causes machined-induced damage on the workpiece/FRP composite materials. Considering the geometry of drill, tool wear may occur at the flank face, rake face and/or cutting edge. There are several factors affecting the tool wear. These include, but are not limited to, drilling parameters and environments/conditions, drill/tool materials and geometries, FRP composite compositions and machining techniques. Hence, this chapter focuses on drilling parameters, tool materials and geometries, drilling environments, types of tool wear, mechanisms of tool wear and methods of measurement of wear, effects of wear on machining of composite materials and preventive measures against rapid drill wear. Conclusively, some future perspectives or outlooks concerning the use of drill tools and their associated wears are elucidated, especially with the advancement in science and technology.Peer reviewedFinal Accepted Versio

Metrics for Assessing Overall Performance of Inland Waterway Ports: A Bayesian Network Based Approach

Because ports are considered to be the heart of the maritime transportation system, thereby assessing port performance is necessary for a nation’s development and economic success. This study proposes a novel metric, namely, “port performance index (PPI)”, to determine the overall performance and utilization of inland waterway ports based on six criteria, port facility, port availability, port economics, port service, port connectivity, and port environment. Unlike existing literature, which mainly ranks ports based on quantitative factors, this study utilizes a Bayesian Network (BN) model that focuses on both quantitative and qualitative factors to rank a port. The assessment of inland waterway port performance is further analyzed based on different advanced techniques such as sensitivity analysis and belief propagation. Insights drawn from the study show that all the six criteria are necessary to predict PPI. The study also showed that port service has the highest impact while port economics has the lowest impact among the six criteria on PPI for inland waterway ports

Purification and Characterization of Pomphorhynchus kashmirensis Somatic Antigens

Fish fauna is ecologically very important and plays a vital role in food chain. There is a great scope for the development of fishery resources in the valley of Kashmir so as to overcome the prevailing animal protein defiency in the diet of the local people. In country like India, intake of meat & milk is low, so fish has special importance as a supplement to ill- balanced cereal diet. Fish flesh is also a highly perishable commodity constituted by 60-80 %water & 13-20 % protein & being low in cholesterol & free from fats. Fish protein hydrosylates also have antioxidant properties. The flesh also contains phosphorus & vitamins. Freshwater fishes form one the important food sources in both the developed as well as underdeveloped countries. A lot of research work has been done on various aspects of these vertebrates but a meagre work is available on the molecular aspects particularly immunogenicity of parasites of the fish host. Therefore, study on the characteristics of the protein profile of the fish parasite Pomphorhynchus kashmirensis was undertaken. The fishes were collected from Dal Lake and River Jhelum and it forms the first study of its type in this part of the country. In order to have a glimpse of the related work done in the past, an attempt was made to review the available literature on the subject. Parkhouse, et al., (1987) characterized and studied the protective effect of nematode antigens. Bunyatova and Elchiev (1989) constructed electrophoretic spectrum of proteins of an acanthocephalan Leptorhynchoides plagicephalus. Coscia and Oreste (2000) investigated the presence of antibodies against protein antigens of the nematode parasite Pseudoterranova decipiens in the plasma and bile of the Antartic Teleost, Trematomus bernachii. Knopf, et al., (2000) studied the humoral response of the European eel Anguilla Anguilla elicited by an experimental infection with a swim bladder nematode Anguillicola crassus. Noga, et al., (2000) purified antimicrobial proteins from rainbow trouts and sunshine bass by RP-HPLC and SDS-PAGE. Saifullah, et al., (2000) worked on the excretory /secretory (ES) metabolic products released by Gastrothylax crumonifer (trematode:Digenea) during in vitro incubations and the somatic extract of the adult parasites were analyzed using PAGE. As obvious, it was not possible to review all the available literature on the said topic, the important ones were penned down in the dissertation. Studies on the fishes has showed that Pomphorhynchus kashmirensis is usually found in the intestine by boring its proboscis into it and thereby produces lesions and makes it prone to further secondary infections. Besides, it is also present in the body cavity, liver and spleen of its fish host. It causes tremendous damage to the intestinal walls at the site of its attachment. The lamina propia gets thickened and goblet cells in this region become more prominent and their number also gets increased (Yildiz, et al, 2004; Ahanger, et al., 2008).This parasite is considered to be one of the most dangerous parasite responsible for fish mortality and morbidity (Ahanger, et al., 2008). Hence the need was felt to study this parasite at molecular level so that our fish fauna are spared from them. A total of 363 fish specimens of Schizothorax species were collected and out of which, 203 fishes were collected and examined from Dal Lake and 160 fishes were collected and examined from River Jhelum during the present study. The host was collected with the help of local fishermen in live condition. Fishes were dissected & body cavity was thoroughly examined for any parasite. Intestines were placed in Petri dish containing normal saline (0.75%Nacl, Cable 1958) to allow adhering parasites to be released from the lumen. Pomphorhynchus was carefully removed from the intestines with the help of brush and needle. A regular record of this parasites was recorded and then subjected to various immunological and biochemical techniques in order to understand the nature of somatic antigens. Out of 203 specimens examined from the Dal Lake only 42 specimens were found infected with the Pomphorhynchus kashmirensis which constitutes the prevalence of 20.68%. Similarly out of 160 specimens examined from the River Jhelum only 52 specimens were infected with the Pomphorhynchus kashmirensis which constitutes 32.5% prevalence. Also, Pomphorhynchus kashmirensis showed a wide host range and was successfully establishing in various species of Schizothorax. The highest prevalence were found in S. niger (30 %) (26.19% in Dal and 34.85% in Jhelum) followed by S. curvifrons (27.11 %) (19.11% in Dal and 38% in Jhelum) and least prevalence were found in S. esocinus (17.89%) (13.72% in Dal and 22.73% in Jhelum). Pomphorhynchus infection also revealed definite seasonal prevalence of infection in all the three species of Schizothorax, with highest infection in summer and lowest in winter. There was a gradual increase in the prevalence rate from spring to summer and falls down with onset of autumn and least observed prevalence during winter season. In summer the prevalence was 34.54% (S. niger 46.34%, S. curvifrons 31.11% and S. esocinus 30%) and the least prevalence was found during the winter season 8.16% (S. niger 14.28 %, S. curvifrons 6.89 % and S. esocinus 9.52%). Gender wise observations were also made which revealed that the sex wise differences were not much prominent but in most cases males 30.30% (S. niger 32.50%, S. curvifrons 27.65% and S. esocinus 28.94%) were found to be more infected than females 27.27% (S. niger 27.14%, S. curvifrons 36.61% and S. esocinus 15.78%). To characterize the somatic antigens from Pomphorhynchus kashmirensis, the sera of the fish was used as a source of antibodies. For this purpose affinity chromatography is the most appropriate technique to be utilized. From this technique the eluted bound protein was dialyzed extensively against 20 mM Tris-saline buffer, pH 7.4, concentrated with PEG 20,000 and was designated as affinity purified P. kashmirensis somatic antigen (Aff-PSAg). The protein content of the antigen was determined spectrophotometrically. SDS-PAGE confirmation of purified antigen Aff-PSAg was done by SDS-PAGE followed by staining with Coomassie Brilliant blue. Electrophoretic separation of Aff-PSAg resolved into 5 prominent polypeptides of molecular weight ranging from 29 to 66 kDa which is inferred to the presence of 5 or more number of active somatic antigens of P. kashmirensis. To measure the antigenicity of the purified antigens the commonly used serotest viz., Ouchterlony double diffusion (ODD) was used. Crude somatic and partially purified pooled fractions of Pomphorhynchus kashmirensis were subjected to double immunodiffusion against rabbit hyper immune sera. Ouchterlony gel diffusion test of somatic antigens showed one precipitation arch against heterogeneous hyper immune sera and many precipitation arches against homogenous hyper immune sera. In nutshell, it is observed that the somatic antigens derived from the Pomphorhynchus kashmirensis can be used as good immunogens and hence can be exploited for mounting the protective immune response in fish. The results of the present study suggest that low molecular weight antigens of Pomphorhynchus kashmirensis deserve further investigation

Studies on Karyotypes of some economically important species of Grasshoppers of Kashmir Valley

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