Search

Your search keyword '"R.M. Hassan"' showing total 3 results
Start Over Author "R.M. Hassan" Search Limiters Full Text
3 results on '"R.M. Hassan"'

1. Kinetics and mechanistic approach to the chromic acid oxidation of l-tryptophan with a spectral detection of chromium(III) product

Author

A. Fawzy, S.S. Ashour, M.A. Musleh, R.M. Hassan, and B.H. Asghar

Subjects
Kinetics, Mechanism, Oxidation, l-tryptophan, Chromic acid, Chemistry, QD1-999
Abstract

The kinetics of chromic acid oxidation of l-tryptophan in H2SO4 medium at a constant ionic strength of 0.6 mol dm−3and at 25 °C have been investigated spectrophotometrically. The reaction exhibits a 3:2 stoichiometry (tryptophan:chromic acid). The reaction shows a first order dependence on [chromic acid], a fractional-first order dependence on [tryptophan] and fractional-second order dependence on [acid]. Increasing ionic strength and dielectric constant had no significant effect on the oxidation rate. The final oxidation products of tryptophan were identified as the corresponding aldehyde (indole-3-acetaldehyde), ammonium ion and carbon dioxide. A spectral evidence for the formation of chromium(III) product was obtained. The experimental results suggest formation of an intermediate complex between the protonated tryptophan and chromic acid which decomposes in the rate-determining step to yield the products. The mechanism of such reaction has been proposed. The thermodynamic parameters with respect to the first step of the suggested mechanism were evaluated and discussed.

Published
2016
Full Text
View/download PDF

2. STOCHASTIC MAIZE PRODUCTION TECHNOLOGY AND PRODUCTION RISK ANALYSIS IN DADAR DISTRICT, EAST ETHIOPIA

Author

B. Fufa and R.M. Hassan

Subjects
Economics and Econometrics, Returns to scale, Yield (finance), Geography, Planning and Development, Risk effect, Frost, Economics, food and beverages, Production risk, Sowing, Production (economics), Agronomy and Crop Science, Agricultural economics
Abstract

A stochastic production technology that allows risk effects of factor inputs was estimated for maize farmers in Ethiopia. The results suggested that the promoted improved maize technology exhibits constant returns to scale whereas non-adopters use decreasing returns to scale technology. The study showed that timely planting is critical for maize yield stability among both adopters and non-adopters and suggests the importance of using oxen and higher efforts to achieve that. Nevertheless, the results showed that most of the factors under the control of the farmers do not offer powerful explanation to maize yield variability compared to natural factors such as rainfall, frost, pests and diseases.

Published
2003

3. A stochastic based voltage collapse indicator

Author

R.M. Hassan and Chika O. Nwankpa

Subjects
Operating point, Engineering, business.industry, Stochastic process, Energy Engineering and Power Technology, Perturbation (astronomy), Hardware_PERFORMANCEANDRELIABILITY, Voltage collapse, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, law.invention, Electric power system, Control theory, law, Electrical network, Hardware_INTEGRATEDCIRCUITS, Electric potential, Electrical and Electronic Engineering, business, Voltage
Abstract

The voltage collapse of a power system is analyzed as the result of the eventual push of the system operating point beyond the boundary of voltage security due to random fluctuations in the system load characteristics. The effect of different fluctuation intensity levels at load buses on the eventual voltage collapse of a power system is studied with the help of a stochastic based voltage collapse indicator. It is shown that this indicator, will provide further insights into the power system's vulnerability due to the high degree of uncertainty that exists in present day voltage collapse load models. >

Published
1993

Catalog

Books, media, physical & digital resources
See catalog results