Experimental design for copper cementation process in fixed bed reactor using two-level factorial design

AbstractThis work deals with cementation of copper onto iron grid in a fixed bed reactor. The influence of several parameters is studied, namely: initial concentration of copper [Cu2+]0, temperature and flow rate. Moreover, their influence on the copper cementation reaction is investigated statistically by the experimental design in view of industrial application. The estimation and the comparison of the parameter’s effects are realized by using two-level factorial design. The analysis of these effects permits to state that the most influential factor is initial concentration of copper [Cu2+]0 with an effect of (+2.4566), the second in the order is the temperature with an effect of (+0.18959), the third is the flow rate of the electrolytic solution with an effect of (−0.4226). The significance interactions found by the design of experiments are between initial concentrations of copper ions–flow rate (x1x3) with an effect (b13=+0.6965)

Influence of gallic and tannic acids on enzymatic activity and growth of Pectobacterium chrysanthemi (Dickeya chrysanthemi bv. chrysanthemi)

The effect of phenolic acids (gallic and tannic acids) on growth of Pectobacterium chrysanhemi, and its protease and pectate lyase activities was tested. The results obtained showed a significant inhibitingeffect of the tannic and gallic acids on the growth of this strain. The growth rate decreases in the presence of 400 g/ml for gallic acid and 100 ìg/ml fortannic acid. The enzymatic activity retardationwas observed with the two phenolic compounds as well but the rate of inhibition varied from one compound to another. The highest antimicrobial potentials and the highest effect on enzymatic activities were observed with the tannic acid at 200 g/ml, which inhibited 91% of the tested microorganisms, and 88% of pectate lyase activity

A generalized quantum nonlinear oscillator

We examine various generalizations, e.g. exactly solvable, quasi-exactly solvable and non-Hermitian variants, of a quantum nonlinear oscillator. For all these cases, the same mass function has been used and it has also been shown that the new exactly solvable potentials possess shape invariance symmetry. The solutions are obtained in terms of classical orthogonal polynomials

Sondage sérologique de la fièvre Q chez les ovins par la méthode ELISA et prévalence des avortements dans la région de Ksar El Boukhari (Algérie)

Serological Survey of Q Fever Using an ELISA Assay and Prevalence of Abortion in a Sheep Flock of Ksar El Boukhari (Algeria). The objective of this study is to investigate about the prevalence of abortions in sheep flock in the region of Ksar El Boukhari, and verify a possible correlation between herd-level Coxiella burnetii seroprevalence and herd-level abortion. A sample was taken from 20 mixed flock in the region of ksar El Boukhari during the lambing season of 2011. The serum taken from 184 sheep was used to identify the infection using ELISA kit. Following this investigation, we obtained a prevalence of abortions in the order of 40%±4.38 but 75%±2.44 (6/8) of aborted flock are seropositive, however the obtained results showed that there is no significant correlation between herd-level Coxiella burnetii seroprevalence and the herd-level abortion

Different areas of chronic stress and their associations with depression

Background: Research shows a connection between stress and depression, but there is little differentiation between areas of stress, making it difficult to identify and address specific areas in the context of public health measures. We utilized a multi-dimensional approach to chronic stress to better understand the relationship between different areas of stress and depression. Methods: We conducted linear regression analyses and used data from a sub-sample of the LIFE-Adult-Study (N = 1008) to analyze the connection between nine different areas of chronic stress (TICS) and depression (CES-D). In the second analysis, we controlled for sociodemographic variables, personality, physical activity, and social support. Results: There was a significant positive association between the stress domains Excessive Demands from Work, Lack of Social Recognition, Social Isolation, and Chronic Worrying and depression and a significant negative association between Pressure to Perform and depression. After adding control variables, only Pressure to Perform, Social Isolation, and Chronic Worrying remained significant predictors. Conclusions: By focusing on the connections between chronic stress and depression, researchers can help identify the areas that matter most and contribute to the creation of meaningful and efficient interventions. On the basis of our results, measures for the prevention of depression that focus on the reduction of worrying and social isolation are recommended