8,787 research outputs found
Hydrogen Bonding Interaction between 1-Propanol and Acrylic Esters in Non-polar Solvents: An FTIR Study
The association between 1-propanol and acrylic esters (methyl methacrylate, ethyl methacrylate and butyl methacrylate) in non-polar solvents, viz. n-heptane, CCl4, and benzene has been investigated by means of FTIR spectroscopy. The formation constants of the 1:1 complexes have been calculated using Nash’s method. The values of the formation constant and the Gibbs energy vary with ester chain length, which suggests that the strengths of the intermolecularOH…O=Cbonds are dependent on the alkyl group of the acrylic ester and the results show that the proton accepting ability of acrylic esters is in the order methyl methacrylate < ethyl methacrylate < butyl methacrylate. The results also show a significant dependence of the association constant upon the solvent used. The solvent effect on the hydrogen bond equilibria is discussed in terms of specific interactions between the solute and the solvent.KEYWORDS: FTIR spectroscopy, acrylic esters, hydrogen bonding, solvent effects
Non-identity of reaction centres for pyrophosphatase and toxic actions of cardiotoxin II: the status of cardiotoxin II as a metalloprotein
Cardiotoxin II of the Indian cobra (Naja naja) contains approximately four Mg2+ per mol. Complete demetallation of the toxin is achieved by three cycles of treatment with ethylenediamine tetraacetate and gel filtration. Reconstitution of toxin by treatment of the apo-protein with Mg2+ restores metal content and inorganic pyrophosphatase activity only to the extent of two atoms/mol and 65%, respectively. Use of Mg (II)-EDTA in the reconstitution experiment yields restoration of half the original enzyme activity. Mg2+ is required for the inorganic pyrophosphatase action of the toxin. A definitive statement on the non-essentiality of Mg2+ for the lethal toxicity of the toxin is not possible at present, although experimental observations indicate that demetallated toxin is as toxic as the native toxin. Based on this and the differing sensitivities of the enzyme and toxic activities of the toxin to heat, it is suggested that the reaction centres in the toxin for the two activities are different and that the pyrophosphatase activity is not causally connected with the lethal toxicity of the toxin
Online Shopping In The UK
This paper will contribute to current academic literature in the area of online retailing and consumer behaviour. Our research outlines a survey conducted with respondents from the UK to ascertain their attitudes to grocery shopping both off and online. The findings indicate that, whilst the vast majority of our sample has experience of online shopping, few actively engage in online grocery shopping. Some of the reasons for this are highlighted and the key issues relate to consumer trust and confidence in both online and offline aspects of the service. If these issues are addressed, it is proposed that more people would be encouraged to shop for groceries online
Marital Adjustment and Interpersonal Needs of Married Individuals
The present study was conducted to explore the dyadic adjustment and interpersonal needs of married individuals. For this purpose the responses were obtained on Revised- Dyadic Adjustment Scale and Fundamental Interpersonal Relations Orientation-Behavior Scale by 351 married individuals who were selected using snowball sampling technique. The obtained responses were scored and analyzed using ANOVA, Pearson Correlation and Multiple Regression Analysis (hierarchical stepwise). The findings of the study were that situational factors like qualifications, number of children and structure of family had statistical significant effect on dyadic adjustment. For interpersonal needs along with all these factors number of dependent family members also had significant effect. Apart from situational factors, the results also indicate that there was significant negative relationship between interpersonal needs and dyadic adjustment of married individuals. Moreover, significant impact of interpersonal need on their dyadic adjustment was also found
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