Browsing by Author "Nigussie, Biniyam"

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    Complete and incomplete Fusion Studies in Some 14n + 59co Systems
    (Addis Ababa University, 2012-06) Nigussie, Biniyam
    The excitation functions for eight reactions produced in the interaction of 14N+59Co system measured in the energy range ≈32-56 Mev and reported in the literature are compared with theoretical values calculated using the computer programs COMPLET and, a statistical model based Monte-Carlo simulation code PACE4. The effect of the variation of various parameters on calculated excitations functions have been studied. From this excitation functions study, the complete and incomplete fusion reactions in the light (medium) target nucleus could be studied. The present analysis shows that excitation functions are in good agreement with the theoretical predictions. It has been observed that complete fusion, incomplete fusion and pre-equilibrium emission processes play important roles in heavy ion reactions at these energies
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    The Practices, Challenges & Performance Of Supply Chain Management Of Sheraton Addis Hotel By
    (Addis Ababa University, 2020-05) Nigussie, Biniyam; Mitiku, Shiferaw (Ph.D)
    The main objective of the study was to assess the practice, identify the challenges, and measure the supply chain management performance of Sheraton Addis hotel. The purpose of supply chain management is to reduce costs, introduce innovative products, make the operations run smoothly, meet uncertain demand with rapidly delivery and satisfy customers in order to increase revenue, allowing businesses to confront the competitive market. The study adopted qualitative research approach, and used descriptive & explanatory research design. The data was analyzed using both descriptive and inferential statistics. Primary data was collected from Sheraton Addis hotel associates using pre-tested and self-administered questionnaire. The researcher used census method, as the numbers of respondents were 41 and collected all the data accordingly. Statistical package for social science version 26 software was used to analyze the data. According to the findings of the study both the supply chain management practice and performance of Sheraton Addis hotel found to be influential or very good. The correlation between aggregated factors affecting the supply chain management and supply chain management Performance of Sheraton Addis Hotel also found to be positive and significant. The multiple regression analysis result also discovered that from the eight independent variables only environmental uncertainty found to be significant to affect the supply chain management performance of Sheraton Addis hotel. The researcher also recommended that Sheraton Addis should make every effort to advance its supply chain management, mitigate the main internal and external challenges and improve the supply chain management performance so as to be competitive enough in the hotel industry.
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    Systematic Study of the Properties of Rotational Excited Levels in the Deformed Even-Even Nuclei In the Framework of Asymmetric Rotor Model
    (Addis Ababa University, 2019-01-04) Nigussie, Biniyam
    The measurement of B(E2) values, meanlives and energies of excited states in nuclei are most active areas of nuclear structure physics. In this work, the asymmetric rotor model of Davydov- Filippov (DF) has been employed to study the reduced transition probabilities, meanlives and energies of excited states in the rotational excited state band even-even nuclei of lanthanide and actinide series, which comprises of 57 nuclides. The E2-transitions ranging up to 12+ spin states have been studied, in detail, in the spectra of nuclei whose mass number ranges as 150<=A<=190 and A>=228, and for those the first excited state 2+ and the second excited state 2+’ gamma band energies are available. In data calculations, experimental and theoretical methods have been employed. The best input parameters for these approaches have also been determined. These input parameters comprise of energy involved in transitions, internal conversion coefficient, half-life, intrinsic quadrupole moment Qo and nuclear asymmetric parameter γ. The reduced transition probability B(E2), meanlives and energies of excited states have been calculated by making use of the most recent available experimental data, for input parameters. Comparison of the calculated results of B(E2) values, meanlives and energies with the corresponding most recent experimental data shows a very good agreement, including high angular momentum states. Both the empirical and experimental B(E2) values usually increase with spin, for low-lying states, within a rotational ground state band. This work has determined, particularly, the B(E2) values for rotational nuclear excited states of which no work has been done so far. Moreover, this work has incorporated many nuclides and transitions for which neither experimental nor theoretical values are available.