ENHANCEMENT OF SUPERCONDUCTIVITY IN LEAD (Pb) BY INTENSIFIED GRAVITATIONAL INTERACTION BETWEEN ELECTRON PAIRS

This work focuses on the theoretical investigation of the possible enhancement of superconductivity for the superconducting lead (Pb) by intensified gravitational interaction (IGI) between electron pairs. By applying the quantization theory of gravity (QTG), we obtained expressions for the enhanced superconducting transition temperature (), and superconducting energy gap (). By using the experimental, theoretical values and some plausible approximations of the parameters in the obtained expressions, the phase diagrams of superconducting energy gap versus temperature for lead at  and the enhanced superconducting energy gap versus temperature for lead at are plotted. By combining the two phase diagrams, we had shown the possible enhancement of the superconducting transition temperature from to and its superconducting energy gap fromto  for the superconducting lead

Coexistence of Superconductivity and Ferromagnetism in Superconducting ErRh4B4

This research work focuses on the theoretical investigation of the possible coexistence of superconductivity and ferromagnetism in ErRh4B4. By developing a model Hamiltonian for the given system and by using the double time temperature-dependent Green’s function formalism, we obtained expressions for superconducting transition temperature (TC,), magnetic ordering temperature (Tm), superconducting and magnetic ordering parameters (Δ) and (η) respectively. By using the experimental and theoretical values and by considering plausible approximations of the parameters in the obtained expressions, the phase diagrams of superconducting transition temperature versus magnetic ordering parameter and magnetic ordering temperature versus magnetic ordering parameter are plotted. Finally, by combining the two phase diagrams, we showed the possible coexistence of superconductivity and ferromagnetism in ErRh4B4.Keywords: Superconductivity, ferromagnetism, order parameter, conduction electrons, localized electrons, Green’s function

Trader-supplier Coordination in the Agrifood Supply Chains in Northern Ethiopia

There exists a huge agrifood potential in Ethiopia. However, the country's agrifood supply chains are underdeveloped to deliver quality supply to traders and supplement household livelihoods from the sector. The key factors that determine the proper functioning of supplier-trader chains were not rigorously investigated, at least in the case study area. This paper aims at examining the key determinants in choosing vertical coordination for agrifood products in Tigray, Northern Ethiopia. Structured questionnaires were administered to 247 traders in 10 towns in Tigray. Probit model was employed to identify the key determinants of vertical coordination. Model results show that market information, product characteristics, firm characteristics, and product quality were found significant factors in determining the adoption of vertical coordination. An interesting finding is that traders tend to vertically coordinate so as to get credit from suppliers. Based on our findings we suggest that strengthening quality assurance and contract enforcement institutions appears to be an important intervention area to improve the agrifood chain in the study area. Moreover, providing financial support to encourage the private sector to operate in agro-processing is among the efforts that need to be focused so that it facilitates the rural development process in the region.vertical coordination, trader, supplier, agrifood, supply chain, Probit Model, Agribusiness,

Contingent valuation analysis of rural households’ willingness to pay for frankincense forest conservation

Frankincense from Boswellia papyrifera forest (BPF) is a traded non timber forest product (NTFP) used in pharmaceutical, food, cosmetic and chemical industries. However, the resource in northeastern Africa is under continuous degradation and requires conservation measures. Data from a discrete choice contingent valuation study are used to assess the factors influencing rural households’ willingness to pay (WTP) and willingness to contribute labor (WTCL) for BPF conservation in Ethiopia. The standard probit, bivariate probit and interval data models were used for modeling respondents’ WTP and WTCL. We found household income as the most important factor affecting WTP whereas number of household labor is the most important factor affecting WTCL. Mean lower bound annual WTP of US$ 4.68 and WTCL of 7.03 days per household were estimated. This study indicated that despite Ethiopia is a low income country, people are willing to contribute for conservation of the resource.Willingness to pay, Boswellia papyrifera, Conservation, Contingent valuation, Resource /Energy Economics and Policy,

A leadership model for the optimal institutionalisation of a results-based performance measurement and management culture in an emerging economy

Global reform has taken place in the public sector management as different internal and external driving forces and initiatives have come together, propelling governments, organisations, programmes, and projects to be more accountable to their stakeholders. Specifically, in Ethiopia, the institutionalisation of a results-based performance measurement and management (RBPMM) culture in the public sector needs reform. Currently, the RBPMM system is accepted and adopted as a management and leadership methodology for improved public sector efficiency, effectiveness and accountability. However, much remains to be done about the optimal institutionalisation of an RBPMM culture in public sector delivery. Moreover, scholarly research has not emphasised the systematic and holistic linkages of leadership roles and tasks and an RBPMM culture in the natural resource management sector and related sectors in the emerging economies. This study aimed to develop a leadership model that drives the optimal institutionalisation of an RBPMM culture for the natural resources management sector Ethiopia and related emerging economies. Therefore, the unit of analysis for the study is managing environmental resources to enable transition (MERET) programme of the natural resource management sector of Ethiopia. A concurrent mixed method design was adopted, and data were collected simultaneously, after which the two approaches were explored and triangulated to determine to what extent the two datasets converged or diverged. The target population for this study comprises middle-level leaders, senior-level professionals, community-level leaders, community-level development agents and community-level planning and development team members. The population consisted of a total of 484 and 40 respondents for the quantitative and qualitative studies, respectively. Simple random and census sampling techniques were used to select respondents for the quantitative survey, and a purposive sampling technique was used to select key informants for the qualitative data. The realised sample comprised 228 respondents for the quantitative study and 20 key informants for the qualitative study. A Likert-type questionnaire and an interview guide were used to collect the quantitative and qualitative data. The specific unit of analysis comprised different programme implementation hierarchies (federal, regional, and district and community level). The independent variable was Effective leadership roles and tasks, and the Optimal institutionalisation of an RBPMM culture was the dependent variable. Leading and Managing for a results-based culture was the mediator variable. SPSS version/AMOS version 23 was used as the statistical package to analyse the data. Descriptive statistics, ANOVA, structural equation modelling and confirmatory factor analysis were the main statistical techniques for the quantitative data, while thematic content analysis was used for analysing the qualitative data. The results reveal that the direct influence of leadership roles and tasks on the optimal institutionalisation of an RBPMM culture is not significant (r = 0.022, p = 0.848). Leadership roles and tasks significantly influence the Optimal institutionalisation of an RBPMM culture indirectly through the mediating variable (r = 0.874, p = 0.00). This finding was confirmed by both the quantitative and qualitative studies. The overall results of the study indicate that performance measurement information was adopted for control purposes and internal accountability. However, the actual use of performance measurement and management (PMM) information system to manage decision-making and wide-reaching accountability and transparency were not realised. The findings of this study may narrow the existing literature gap relating to the optimal institutionalising of an RBPMM culture in the natural resources management sector and in similar development programmes in Ethiopia and in the developing economies in general. The model could be used by policymakers and practitioners for the design and optimal institutionalisation of an RBPMM culture in their organisations.Business ManagementD.B.L

Theoretical Study of Upper Critical Magnetic Field ( H

This research work focuses on the theoretical investigation of the upper critical magnetic field, HC2; Ginzburg-Landau coherence length, ξGL(T); and Ginzburg-Landau penetration depth, λGL(T), for the two-band iron based superconductors BaFe2(As1-xPx)2, NdO1-xFxFeAs, and LiFeAs. By employing the phenomenological Ginzburg-Landau (GL) equation for the two-band superconductors BaFe2(As1-xPx)2, NdO1-xFxFeAs, and LiFeAs, we obtained expressions for the upper critical magnetic field, HC2; GL coherence length, ξGL; and GL penetration depth, λGL, as a function of temperature and the angular dependency of upper critical magnetic field. By using the experimental values in the obtained expressions, phase diagrams of the upper critical magnetic field parallel, HC2∥c, and perpendicular, HC2⊥c, to the symmetry axis (c-direction) versus temperature are plotted. We also plotted the phase diagrams of the upper critical magnetic field, HC2 versus the angle θ. Similarly, the phase diagrams of the GL coherence length, ξGL, and GL penetration depth, λGL, parallel and perpendicular to the symmetry axis versus temperature are drawn for the superconductors mentioned above. Our findings are in agreement with experimental observations

A Leadership Model for the Optimal Institutionalisation of a Results-Based Performance Measurement and Management Culture in the Agricultural and Natural Resource Sector of Ethiopia

The aim of the study was to construct a leadership model that drives the optimal institutionalisation of a results-based performance measurement and management (RBPMM) culture in the agricultural and natural resource sector of Ethiopia. A concurrent mixed-methods design was adopted for the research. The quantitative study comprised a total sample of 228 respondents, and face-to-face interviews were conducted with 20 key informants. The primary researcher administered a self-developed instrument with 167 items to the respondents, and made a discussion guide available to them in both English and Amharic. The methods of data analysis included various multivariate analysis methods and a structural equation analysis. A thematic content analysis was done to identify the themes emerging from the qualitative data. The direct influence of the independent variable of leadership roles and tasks on the optimal institutionalisation of an RBPMM culture was positive but not significant. Indirectly, this variable significantly influenced the indicator variables of the optimal institutionalisation of an RBPMM culture through the mediating variables of leading and managing for an institutionalised RBPMM culture. The adoption of performance measurement information for control and compliance purposes was evident in the Managing Environmental Resources to Enable Transition (MERET) programme, but its implementation to optimise decision-making, accountability and transparency was not evident. These results were confirmed by triangulating the qualitative findings with the quantitative results. The limitation of the study was that it focused on a specific region and a public service project in Ethiopia within a specific time frame and context. Therefore the study may not be representative of similar programmes in the private sector. Also, it was not a longitudinal study that tracked changes over time. The study contributes to scholarly discourse and the existing body of knowledge by presenting a leadership model that drives and optimally institutionalises an RBPMM culture in agricultural development programmes in Ethiopia. This model could be implemented in other developing economies as well. The mediating variables can be adopted by policy-makers and organisational practitioners for the optimisation of the institutionalisation of an RBPMM culture