Prediction of Melting Profile of Mild Steel Weld Metals Using Regression Analysis

The microstructure of a weldment can be maintained by ensuring a steady state homogenous melting profile of the welding operation, which includes the deposition of optimum volumes of melted filler wire and substantial part of the heat affected zones of the parent metal to form the weld pool. The melting pattern of the entire welding process should be protected from atmospheric air, so as to enhance weldment quality. In this study, the melting profile of mild steel is investigated by looking at the parent metal angular distortion bead width and penetration volumes of deposited filler and the melting efficiency was determined. Predictive models were also developed to determine the above listed melting properties by applying the regression analysis. The result obtained showed that, there is almost a perfect fit between the calculated and predicted angular distortion, as well as between the calculated and predicted volume of filler wire melted. There is also a close correlation between the calculated and predicted melting efficiency. However, for the bead width, bead penetration and volume of weld metal deposited, there were variations of values and a heterogeneous correlation between the calculated, measured and predicted values. The effects of the process parameters on the obtained properties of the melting profile were investigated and optimum process parameters were determined.

Synthesis of Glycosidic (β-1′′→6, 3′ and 4′) Site Isomers of Neomycin B and their Effect on RNA and DNA Triplex Stability

Glycosidic (β-1′′→6, 3′ and 4′) site isomers of neomycin B (i.e., neobiosamine (β-1′′→6, 3′ and 4′) neamines) have been synthesized in a straightforward manner. Peracetylated neomycin azide was used as a common starting material to obtain neobiosamine glycosyl donor and 6, 3′,4′-tri-O-acetyl neamine azide that after simple protecting group manipulation was converted to three different glycosyl acceptors (i.e., 5,6,4′-, 5,3′,4′- and 5,6,3′-tri-O-acetyl neamine azide). Glycosylation between the neobiosamine glycosyl donor and the neamine-derived acceptors gave the protected pseudo-tetrasaccharides, which were converted, via global deprotection (deacetylation and reduction of the azide groups), to the desired site isomers of neomycin. The effect of these aminoglycosides on the RNA and DNA triplex stability was studied by UV-melting profile analysis.

Effect of Inulin DP on Various Properties of Sugar-Free Dark Chocolates Containing Lactobacillus paracasei and Lactobacillus acidophilus

In the present study, the effect of different polymerization degree of inulin on the quality parameters of conventional and sugar-free dark chocolate products as well as on the vitality of probiotics used in the chocolates were investigated. To produce sugar-free dark chocolates prepared with the addition of maltitol,Lactobacillus paracasei/L. acidophilusand inulin with DP higher than 23 and lower than 10 were used as probiotic and prebiotic agents, respectively. After 90 day of storage, more than 6 log cfu/25 g probiotics were observed in the chocolates produced by supplementing of 9 log cfu/25 g probiotics. Considering the probiotic level for both conventional and sugar-free dark chocolate, the highest probiotic level was observed in the samples prepared fromL. acidophilusand inulin with DP<10. In addition, inulin with DP<10 was found as more suitable in terms of rheological characteristics of the samples. Other quality parameters (texture, colour, melting profile and water activity) changed in narrow range which was allowable when compared with the control samples. Consequently, sugar-free chocolate containingL. paracaseiandL. acidophiluscould be produced which might satisfy the expectations of the consumers and appropriate to industrial production similar to conventional chocolate. The findings of the present study highlighted the importance of the selection of the most suitable prebiotic/probiotic combination for maximizing probiotic level in the chocolate products.

Detection of DNA mutations by PCR-TTGE method

In our study PCR-temporal temperature gelelectrophoresis (TTGE) and MeltINGENY bioinformatic program were used to analyse the mutations in the genes of melanocortin-1 receptor (MC1R) and pituitary adenylate-cyclase activating polypeptide (PACAP) in cattle. Amplification of target DNA by PCR was performed with GC-clamp primers and non-GC-clamp primers in simplex PCR reactions. The fragments were separated by denaturing polyacrylamide gelelectrophoresis (denaturing agents: high temperature, urea) after PCR reactions.MC1R homozygous individuals were used for the reaction. We concluded that MeltINGENY program makes the decision and detection system easier, and more simple as the melting profile of target sequence is determined by the software. In case of MC1R gene, PCR-TTGE method is appropriate for SNP detection, however PACAP gene polymorphism can not be identified by the method, because PACAP mutations are not included in melting domains, therefore PCR-TTGE cannot detect them.