Growth and suitability of some tree species selected for planting in adverse environments in Eritrea and Ethiopia

The thesis addresses some important silvicultural issues raised in Eritrea and Ethiopia and the objective was to evaluate various tree species in terms of growth in adverse environments. Three field and two greenhouse studies were performed using the main species Eucalyptus globulus, Cordia africana, Casuarina cunninghamiana, and Acacia tortilis, A. nilotica and Leucaena leucocephala. Growth of E. globulus tree was influenced by altitude and stand density when assessed in a planted stand in Ethiopia. Decreasing altitude increased growth only up to the middle of the valley hillside. Increasing density increased growth. Soil depth had no impact on growth of E. globulus and this shows that the species is suitable for planting on shallow soils. Data from a C. africana spacing trial in Eritrea were analysed to improve the management of C. africana plantations established on degraded dry lands by evaluating the response of the species to various initial spacings. Planting C. africana trees at wider spacing can be advantageous in terms of growth, but not stem quality. Different provenances of C. cunninghamiana were tested in two field trials in Eritrea to identify the provenance matching marginal lands of the Eritrean highlands. For firewood and small pole production, the use of the fast growing provenances ‘Coonabarabran’ (CN), ‘Flag stone’ (FS), and ‘Rollingstone’ (RS) is recommended. However, the use and wide spread of the three provenances must be taken with caution due to the risks involved in the use of exotic tree species. Two greenhouse experiments investigated the suitability of A. tortilis for manure production and rehabilitating salt affected marginal lands. The species has a greater potential to produce mulch rich in nitrogen and phosphorus compared to L. leucocephala. Nevertheless, further research under field conditions would be needed to confirm the results and the sustainability of such a practice. A. tortilis and A. nilotica seem to be sensitive to salinity. However, because the two acacias have a wide distribution covering a large salinity gradient, there could be other provenances or ecotypes of both species that are more tolerant to salinity. Therefore, screening tests involving various genotypes of both species could be promising to find suitable trees for afforestation on salt affected soils in arid and semiarid Africa

Evaluation of Durum Wheat Genotypes for Grain Yield in Southern Tigray, Ethiopia

An experiment was conducted with the objective of assessing the seasonal adaptation and grain yield stability of durum wheat genotype in ofla district. In this trial, twelve durum wheat genotypes were evaluated in three consecutive cropping seasons during 2011-2013.The trial was laid out in randomized complete block design (RCBD) with two replication . The analysis of variance (ANOVA) revealed that there was significant difference (P< 0.05) for genotype and genotype by season interaction. The genotypes captured (34.5%) sum of square implying the presence large differentia in the durum wheat genotypes. Using the additive main effect and multiplicative interaction biplot analysis and additive main effect and multiplicative interaction stability value, the genotypes Yerer and Kokate were with higher grain yield and stable in performance across seasons. The genotypes Tate and Local were unstable genotypes contributing more to the increased magnitude genotype by season interaction. Keywords: AMMI, ASV, Durum Wheat, Seaso

Discrete Element Modelling (DEM) For Earthmoving Equipment Design and Analysis: Opportunities and Challenges

Simulation of granular materials (soil, rocks) interaction with earthmoving machines provides opportunities to accelerate new equipment design and improve efficiency of earthmoving machine performances. Discrete Element Modelling (DEM) has a strong potential to model soil and rocks bulk behavior in response to forces applied through interaction with machinery. Numerical representation of granular materials and methodology to validate and verify constitutive micro-mechanical models in DEM will be presented. In addition, how DEM codes can be integrated to CAE tools such as multibody dynamics will also be discussed. A case study of tillage bar-soil interaction was modeled in EDEM to predict tillage draft force and soil failure zone in front of tool moving at 2.68-m/sec and depth of 102-mm. The draft force and soil failure zone was predicted at 10% and 20% error from laboratory measured data

Impact of government road sector spending on economic growth in Ethiopia

This study analyzes the impact of government road spending on economic growth in Ethiopia using annual time series data for the period 1974-2010. To do so, both descriptive and econometric analyses are employed in the study. From the descriptive analysis the findings indicate that the trend of government road sector spending has increasing for the past few years. Regarding the performance of road sector, the road network is by now growing at an encouraging rate. The issue of rural accessibility still remains far from the desired level that the country needs to have. Thus, the country needs to do a lot to graduate to middle income country status in terms of road network expansion and improved accessibility. The Econometric analysis, With the help of co integration and vector error correction analysis, the impact of government road spending on economic growth was assessed in the long-run as well as in the short-run. The findings reveal that government spending on road has a significant and positive effect on the economic growth (GDP) in the short-run as well as in the long-run. By way of recommendation, the government need to strengthen its support on road infrastructure through allocate more road financing to expand the road network with the aim of increasing the current rural accessibility, thus, improving agricultural productivity and market access of the poor rural .population with the aim of boost the current economic growth.Jimma University

Discrete Element Modeling (DEM) of Cone Penetration Testing on Soil With Varying Relative Soil Density

Modeling soil-tool interaction is essential for equipment design and performance evaluation on soil behavior responses under loading. Computational tools based on particle-based mechanics such as Discrete Element Modeling (DEM) and Smoothed Particle Hydrodynamics (SPH) have potential in modeling large strain soil dynamic behaviors from soil-tool interaction. The objective of this study is to validate the accuracy and robustness of DEM calibration methodology as it relates to soil deformation during cone penetration on varying initial soil relative density. The influence of factors such as DEM material properties and cone to particle size ratio on DEM cone penetration simulation will be investigated. The paper presents a comparison of DEM predicted cone penetration resistance and laboratory measured penetration data on Norfolk sandy loam. Soil mechanical behavior was modeled with Hertz-Mindlin (HM) contact stiffness model and a new coupled frictional law for static and rolling resistance coefficients. The DEM material properties were calibrated using residual strength from direct shear test. DEM simulations were performed using LIGGGHTS, open source DEM code. Cone penetrometer experiments using anÂASABE standard cone with 12.53 mm cone base diameter and 30-degree cone tip were used to validate the calibrated DEM model. DEM prediction of cone penetration resistance trend and steady state values were in close agreement with the laboratory measured data for relative density range from 5 to 30%. At higher dense states (relative density of 90%), DEM calibration requires further improvement

Evaluation of Low Inflation Tire Technologies on Soil Compaction

Evaluation of recent advances in tire technologies such as advanced deflection agricultural tires (Firestone IF and VF) and precision tire inflation technologies on soil compaction, traction, fuel economy and crop yield responses are important. The purpose of the study was to investigate the effects of field and transport (road) tire inflation pressure settings of row-crop agricultural tractor and planter tires on soil compaction. A randomized complete block design experiment was conducted at the Iowa State University farm at Boone, Iowa for two tire inflation pressure levels on Dual Front (Firestone IF 420/85R34) and Dual Rear (Firestone IF 480/80R50) tires on a John Deere 8310R MFWD tractor, and transport tires (Super single 445/50R22.5) on a John Deere DB60 planter. Soil compaction was measured using Stress State Transducers (SSTs) buried at 15-cm and 30-cm depths beneath the untrafficked soil surface. The soil cone index depth profile was measured at tire-centerline, tire-edge and 20 cm laterally outboard of the tire edge before and after tractor-planter tire passes. Peak Octahedral Normal Stress (ONS) and the corresponding Octahedral Shear Stress (OSS) values in soil were calculated from the SST data. The peak ONS and corresponding OSS values from the road tire inflation pressure settings were statistically higher (p-value \u3c 0.05) than the field tire inflation pressure settings. The maximum ONS was observed at 15 cm soil depth from the road tire inflation pressure setting of the rear tractor tires (179 kPa tire inflation pressure and 33 kN load per tire). The ONS from the front tractor tires (138 kPa tire inflation pressure and 17 kN load per tire) and planter transportation tires (620 kPa tire inflation pressure and 16.5 kN load per tire) were similar. Cone index data also showed significant differences, comparing before and after tires passes, at the tire-centerline. The peak cone index values for the 0 to 100 mm soil depth range were 1.3 MPa and 1.2 MPa from the road and field tire inflation pressure settings, respectively

Back to Reality: A Critical Review of Performance of the Export Oriented Manufacturing in Ethiopia

This article critically reviews the performance of the export oriented manufacturing industry in Ethiopia and its role in deriving the industrial development and structural transformation of the economy. Detail analysis of available panel of data indicates that overall performance of the manufacturing sector, as measured from plan targets and the move towards structural transformation, is not promising. The more export promotion deepens, the weaker is the overall industry performance and fate of moving to economic structural transformation is meagre. More importantly, it is a contradiction to find weakening performance of sectors dedicated to exports production while the country deepens the efforts to export manufacturing. Thus, the article argues that export lead industrialization is counterproductive in Ethiopia. Despite this fact, production for local market has not been adequately surfaced in to the intention of the government. The experiences of Latin America and South East Asian countries prove that production for local market is critical for a successful industrialization and ensuring economic structural transformation. Therefore, Ethiopia’s industrialization needs to back in to reality of the economic life. The export lead industrial development should be replaced by a comprehensive industrialization where export oriented production and producing for national consumption are implemented simultaneously and one is complementing the other. Keywords: Export lead industry, import substitution, industrialization, structural transformatio

A Study on Accounting Practice and Financial Reporting in SMEs (In Case of Arba Minch Town, Snnpr, Ethiopia)

The research was conducted on ‘Accounting practices and Financial reporting in Small and Medium Sized Enterprises (SMEs)’ in Arba Minch Town, SNNPR, with the motive of to sort out areas of accounting practice and financial reporting information that are likely to be of significance to managers/owners of SMEs in their provision of information to users. To fulfill the objective of the study, descriptive research approach was used. Stratified sampling technique applied for the research study; in this regard out of 178 SMEs operating in Arba Minch Town 64 firms was selected. The required data were collected from primary source of data by using self-administered questionnaire and secondary source document which are available for the study including financial statement of the small enterprise. The collected data was analyzed by using different methods like tabulation and percentage code used for numerical and organizing large volume of data into homogenous group. The major finding of the study disclosed that the bookkeeping practices in SMEs are not organized to produce required information to both external and internal users for decision making purposes. Further the result shows that SMEs operating in construction sector maintained all receipts and invoices of their transaction in a systematic manner than the other sectors, while none of urban agricultural SMEs kept these activities well. However, the study show that the majority of SMEs encounters challenges in complying with accounting requirements and that most SMEs outsource the preparation of their financial statements to specialist service. One of the areas of financial reporting information that have been sorted out in this study as likely to be of significance to managers of SMEs in their provision of information to users is cash flow. Keywords: Accounting Practice, Financial Reporting, SMEs, Managers

Examining the Need for Comprehensive Refugee Protection and Asylum Seekers Policy in Ireland today

Asylum seekers and refugees are one of the most demonised and marginalised social groups in Europe. Ireland's current agenda for dealing with refugees and asylum seekers is inadequate. The government of Ireland is aware of the inadequacy of response and has proposed to make a number of changes that will improve the standard of living for those who chose to apply for inclusion in Ireland. However, many of the issues that are discussed in the Core Policy Objective: Intercultural & Migration Issues have already been addressed in the set of directives, regulations, and guidance provided by the EU on the topic of immigration and refugee policy. Ireland has opted out of participating in several of these programs, choosing instead to establish its own policies of caring for the disenfranchised who seek refugee status. While change in legislation in Ireland is taking place, it is evolving slowly, and many of today‟s greatest issues are being addressed very cautiously. As a result, many of the humanitarian provisions adopted by the EU are just now being considered by Ireland. This project examines the need for Comprehensive Refugee Protection and Asylum Seekers Policy in Ireland today