The derivation of an adsorption isotherm is, largely, by empirical deductions on which basis isotherms like the Langmuir, Freundlich, Temkin, Frumkin, Flory-Huggins, El-Awady, Dubinin-Radushkevich, etc. were developed. We hereby propose yet another two-parameter empirical adsorption isotherm known as Adejo-Ekwenchi isotherm, derived from the data obtained from our corrosion inhibition of mild steel in 2 M H 2 SO 4 using three plant extracts using weight loss method studied at the temperature between 303 and 315 K. The isotherm is centred on the fact that, for any adsorption process, the amount of adsorbate uptake from bulk concentration is, always, inversely proportional to the difference between the total available surface on the adsorbent and the fraction that is covered by the adsorbate at a given temperature, prior to the attainment of maximum value of surface coverage. Therefore, at any time during the adsorption process, (1 -θ) is the available surface and this decreases with increase in concentration, and thus;(1) "Equation 1" in a linear form is,"Equation 2" is known as Adejo-Ekwenchi isotherm. Results obtained therefrom the isotherm correlate very well with those obtained through other well-known isotherms.
Hydrogen atoms, generated by the mercury (3P1) sensitization of Hz, were allowed to react with dimethyldisulfide in the temperature range of 25-155'C. The only retrievable product is methanethiol, formed in the primary metathetical reaction H + CH3SSCH3 k,' CH3SH t
CH3S. The intermediacy of thiyl radicals was clearly demonstrated in experiments carriedout in the presence of ethylene where one of the major products detected was ethyl methyl sulfide, formed via CH3S + CzHs -C H~S C Z H~. The major fate of the CH3S radical is recombination and disproportionation, and the yield of methanethiol formed via disproportionation contributes less than 5% to the total thiol yield. The rate coefficient of step 1, from competition with the reaction H + CzH4 k' CzHs, is k l = (5.7 f 1.2) X exp[-(100 f 100)/RT] cm3/mol sec.
The adsorption isotherm model best fit of the methanol leaf extract of Securinega virosa as corrosion inhibitor for the corrosion of mild steel in 2 M HCl medium was determined with the assistance of the Adejo-Ekwenchi adsorption isotherm. The corrosion inhibition study was carried out using the weight loss method at the temperature range of 301 K to 313 K. The inhibition efficiency, %IE, of the extract was found to increase with increase in both concentration and temperature. On the account of, R 2 this adsorption process well fitted into Langmuir, Freundlich, Temkin isotherm, FloryHuggins and Adejo-Ekwenchi models. However, through the parameter b of the Adejo-Ekwenchi isotherm, which clearly shows the adsorption process to be chemisorption, the best isotherm fit for the extract has been resolved to be the Langmuir isotherm and Temkin isotherm models.
Various solvent extracts of the leaves of Monechma ciliaturn (family Acanthecaea) were tested for oxytocic properties on uterine preparations in uiuo and in uitro. The methanol extract (HME) contracted the nonpregnant uterus of the rat, guinea-pig and mouse as well as preparations obtained from guinea-pigs on days 6-7 and 11-12 of pregnancy. The rat pregnant uterus was not affected by the extract. Oral administration of HME to rats on days 15, 16 and 17 of pregnancy had no abortifacient effect compared with oxytocin. However, laparotomy on day 23 revealed fetal death in utero. The extract was also found to have oestrogenic activity based on parameters such as uterine weight ratio, premature vaginal opening and degree of vaginal cornification.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.