Cold Crack Susceptibility studies on High Strength Low Alloy Steel 950A using Tekken Test

In This research article deals with the study of cold cracking susceptibility of High Strength Low Alloy Steel (HSLA) 950A using Gas Metal Arc Welding process (GMAW). The cold cracking is a general problem while welding HSLA steels. It thus becomes mandatory to have a novel method of welding to minimize the effects of cold cracking. The cold cracking tendency of the material is determined using the Y groove Tekken test and the test is carried out with DIN EN ISO 17642–2 standard. The welding of the base metal has been carried out using the low hydrogen electrode ER 70SD2. The test procedure is followed under self-restraint condition for determining cold cracking susceptibility of weld metal. Micro structural constituent of the weld metal plays an important role in determining the cold crack susceptibility of the weld metal. Hence an attempt has been made to impart the microstructure having high resistance to cold cracking.  It has been observed that Acicular ferrite microstructure in the weld metal increases the cold cracking resistance of the welded joint.  In the present study, the effect of preheating temperature on cold crack susceptibility analyzed by varying the preheating temperature 100ºC, 150ºC and acicular ferrite microstructure observed in the microstructure analysis of the welded specimen. The effect of microstructure on cold cracking has also been established. But due to very limited range of temperature, the effect of preheating temperature on cold crack susceptibility was inconclusive. But the formation of acicular ferrite microstructure will have greater influence on cold crack susceptibility. In future, effects of Nickel, Manganese and other alloying elements of the filler material in increasing cold cracking resistance can also be studied for far reaching prospects of the research

Optimization of Cutting Parameters for Cutting Force in Shoulder Milling of Al7075-T6 Using Response Surface Methodology and Genetic Algorithm

AbstractThis paper aims at developing a statistical model to predict cutting force in terms of machining parameters such as cutting speed, cutting feed rate and axial depth of cut. Response surface methodology experimental design was used for conducting experiments. The work piece material was Aluminum (Al 7075-T6) and the tool was a shoulder mill with two carbide insert. The cutting forces were measured using three axis milling tool dynamometer. The second order mathematical model in terms of machining parameters was developed for predicting cutting force. The adequacy of the predictive models was tested by analysis of variance and found to be adequate. The direct and interaction effect was graphically plotted which helps to study the significance of these parameters with cutting force. The optimization of shoulder mill machining parameters to acquire minimum cutting force was done by genetic algorithms (GA). A Matlab genetic algorithm solver was used to do the optimization

Detection and Analysis of Lysozyme Activity in some Tuberous Plants and Calotropis Procera’s Latex

Tuber extract of all the plant species used in the study exhibited lysozyme activity confirming the ubiquitous presence of lysozyme in plants. Among the different plants screened for protein content the tuber extract of Solanum tuberosum showed highest buffer soluble protein while tuber extract of Raphanus sativus showed the lowest protein content in sodium acetate buffer (50 Mm; pH 5.0). Tuber extract of Raphanus sativus showed highest lysozyme activity among all the plant species tested in this study and the activity was increased when the tuber was extracted with sodium phosphate buffer (50mM; pH 7.0). The lowest lysozyme was observed with tuber extract of Daucus carota in phosphate buffer (50mM; pH 7.0). The latex of the tropical species Calotropis procera is well known for being a rich source of the lysozyme. Lysozyme of Calotropis procera latex is not thermo labile. It did not lose much of its activity when the latex was incubated at different temperatures for 24 hours. A positive pointer for purification of this enzyme in future. Calotropis procera lysozyme can be was specifically isolated and purified from the whole latex with ammonium sulphate precipitation with 95% saturation. Calotropis procera lysozyme retained its activity even after precipitation with ammonium sulphate and dialysis and could hydrolyse the cell wall of Micrococcus lysodeikticus.Key words: Micrococcus lysodeikticus, Tuberous Plants, Latex, Ammonium sulphate precipitation, Polyacrylamide gel electrophoresis M. Sakthivel et al. Detection and Analysis of Lysozyme Activity in some Tuberous Plants and Calotropis Procera’s Latex. J Phytol 2/11 (2010) 65-72

IDENTIFICATION AND ANTIMICROBIAL SUSCEPTIBILITY TESTING OF PATHOGENIC MICRO-ORGANISM FROM DENTAL PATIENTS

ABSTRACTObjective: To isolate and identify aerobic microbes present in the periodontal infected patients and to evaluate the choice of antibiotics in themanagement of periodontal diseases.Methods: In this study, these patients have not been treated previously for their conditions. An informed consent was obtained from these patientsbefore collection of an oral swab. This study was approved by the Institutional Ethical Committee. The details of the patient's age, sex, and clinicaldetails were recorded on a per forma meant for this study. The following methodologies were adopted for the isolation and identification of the microorganismsfromthese cases.Results: In this study out of 50 oral samples, culture positivity was recorded in 43 (86%) cases and no growth in 7 (14%) cases. Antibiotic susceptibilitytest using to identified as resistant, sensitive, intermediate of pathogenicity of oral microbes. Such antibiotics were methicillin, ceftazidime,clindamycin, amikacin, cloxacillin, and cefotaxime. This study should be kept in mind when a local application of antibacterial compounds is used inthe therapy of periodontal disease.Conclusion: This study highlights the different organisms involved in the different types of dental infections. The antibiotic pattern shown in this workwill be a guide to the clinician in the selection of proper antibiotics for the treatment of these infections. Hence in this study, the limitations were timeand the number of patients. For better outcomes, a larger study population for a longer period of time should be undertaken to know the bacteriologyand to the select the effective drugs of choice for dental infections. A comparative study of bacteriology and mycology and its antimicrobial propertywould be very fruitful in the future.Keywords: Dental, Periodontal, Bacteria, Antibiotics

Screening, Identifying of Penicillium K-P Strain and Its Cellulase Producing Conditions

Cellulase production by Penicillium species are of greater interest in microbial enzyme technology. Penicillium sp. was cultivated in liquid culture medium at different carbon sources, nitrogen sources in different pH and temperature conditions. The strain of K-P with high cellulase activity was screened. The cellulase activity was 198 U/mL in the presence of fructose on day fifth. Maximum activity was recorded 154 U/mL in with the presence of ammonium nitrate on the fourth day. And maximum cellulase activity was obtained when the pH was 3.0 (129 U/mL) on day fourth. But the highest cellulase activity recorded (274 U/mL) in the presence of fructose, ammonium nitrate, pH 3.0 on the fifth day. The results showed the profiles of cellulase were produced maximum level according to which enzyme is most active in that particular environment

Genetic Selection in Mariculture

The applications of molecular techniques in aquaculture are promising, but still some what uncertain. While high costs seem to be the only hindrance for widespread application of DNA markers for identification purposes and marker assisted selection, the situation regarding commercial use of genetically modified fish is more complex. Although the potential importance of gene transfer technology is large, a major concern relates to the possible impact, which release or accidental escapes of gene-modified individuals may have on natural ecosystems. Other technologies are also rapidly emerging which are either being used or are likely to be used in the future in the aquaculture species. For example micro-array technology has the potential to contribute very large amounts of information on the genes and pathways of genes, which affect the economic traits in aquaculture species

Gap junctions and connexin hemichannels in the regulation of haemostasis and thrombosis

Platelets are involved in the maintenance of haemostasis but their inappropriate activation leads to thrombosis, a principal trigger for heart attack and ischemic stroke. Although platelets circulate in isolation, upon activation they accumulate or aggregate together to form a thrombus, where they function in a coordinated manner to prevent loss of blood and control wound repair. Recent reports indicate that the stability and functions of a thrombus are maintained through sustained, contact dependent signalling between platelets. Given the role of gap junctions in the coordination of tissue responses, it was hypothesized that gap junctions may be present within a thrombus and mediate intercellular communication between platelets. Therefore studies were performed to explore the presence and functions of connexins in platelets. In this brief review, the roles of hemichannels and gap junctions in the control of thrombosis and haemostasis and the future directions for this research will be discussed

Przestrzenna zmienność morfologii plaży pod kątem grzbietów i strumieni spowodowana powstaniem kopalni złóż okruchowych wzdłuż Vembar – Wybrzeże Kallar w Indiach

This article does not contain abstracts in English.Celem tej pracy jest omówienie przestrzennych i krótkotrwałych zmian w morfologii plaży pod kątem grzbietów i strumieni na podstawie profili plaży w Vembar, na wybrzeżu Kallar, Tamil Nadu, Indie. Plaże składają się głównie z średniego do grubego piasku i ciężkich minerałów. Dla plaż charakterystyczne są grzbiety, strumienie i zagłębienia. Grzbiety i strumienie są niewielkie ze względu na prace kopalniane prowadzone w okolicy. Ustalono, że przestrzenne i tymczasowe zmiany w systemie grzbietów i strumieni są kontrolowane przez pianę morską/łamiące się fale. Zmiany objętości sedymentu wynikają z nieregulowanej aktywności kopalni. Erozja ma wpływ na profil wszystkich plaż, zwłaszcza strumieni. Strefy przyrostu znajdują się wyżej, to znaczy na najwyższych grzbietach i wałach plażowych. Krótkotrwałe zmiany wielkości plaży wyjaśniają zniekształcenie grzbietów i strumieni. Ma to związek z pobliską kopalnią. Zaobserwowano wzorzec wiatru wyżej plaży, gdzie warunki pozwalają na transport sedymentu piasku i jego ruch na grzbietach i strumieniach