buna - Automated Administration tool for Hosts and Virtual Machines under Libvirt Environment

Virtualization is very common and widely used in many data-centers nowadays. Easy management and administration of virtual machines and hosts is a crucial part of Virtualization. Currently there are automated virtual machine management systems that are in use. But the tools lack consideration of the needs of organizations with dynamically changing virtual machine environment, like Universities and Collages. They are also limited to specific virtualization platforms and don’t have host management capability. In this thesis an entirely new approach of virtual machine management based on mathematics Set-theory, Logic and Statistics is suggested. This approach provides a new virtual machine naming method that creates relationships between virtual machines. This makes the virtual machine and Host management automation simple, flexible and powerful. The suggested approach is implemented as a tool named buna using Perl programming language and libvirt management tools: virsh, virt-clone and virt-top. Buna has two major parts: automationt and plugin part. The automation part enables actions like create, start/stop and delete virtual machines; upgrade CPU and Memory and attach/detach devices on mass number of virtual machines. The plugin part controls host resources and status of virtual machines based on rules, where rules have conditions and actions those are set by system administrators. This avoids the need to perform routine tasks for administrators and it makes the virtual machine and host management easy and effective. In addition, critical system level tasks like load-balancing and power-saving can be done by giving organized rules. buna is tested on an environment with three hosts running KVM/QEMU virtualization system. It successfully performed the automatic virtual machine management actions between the hosts. It’s also given some rules to test its ability to perform actions based on resource usages of virtual machines

Water Balance Model: Implications for Groundwater Recharge Estimation in Data Scarce Arid Catchment, Northern Ethiopia

The paper presents results related to water balance model of the Gumselassa catchment (28.1 km2), Tigray, Northern Ethiopia. The catchment includes a small dam called Gumselassa dam having an effective watershed area of 22.14 km2 with reservoir capacity of 1.92 x 106 m3 and command area of about 1sq. km. The hydrology of the area was characterized on the basis of land use, soil, slope and climatic parameters. Different methods were employed in this study: rainfall coefficient method was used to determine monthly distribution of rainfall; Penman method to calculate evaporation from the reservoir; Thornthwaite method and Thornthwaite water balance model to determine potential and actual evapotranspiration; runoff coefficient method to estimate runoff; and, the water balance model was used to quantify the recharge. The catchment is characterized by one rainy season (three months) and two dry seasons (nine months) during the year. The mean annual rainfall of the catchment is 485.89 mm. The total annual water loss by evaporation from the reservoir is 1263.27 mm. The mean annual actual evapotranspiration of the effective watershed area one and two is 318.57 mm and 310.27 mm, respectively. The mean annual actual evapotranspiration of the water contributing area 1 and 2 to the command area is 337.06 mm and 355.29 mm, respectively. The mean annual actual evapotranspiration of the command area is 319.3 mm. The mean annual runoff generated from the effective watershed area one and two is 1.167 and 0.44 million cubic meters, respectively. The mean annual runoff generated from the water contributing area 1 and 2 to the command area is 0.048 and 0.349 million cubic meters, respectively. The mean annual runoff generated from the command area is 0.0875 million cubic meters. The total amount of water which is actually available to recharge the groundwater within the catchment is 4.065 million cubic meters, and any application of water for irrigation from the reservoir should take into account this readily available water

Assessment of plasma D-dimer level and its correlation with disease severity among hypertensive patients

It has been reported that inappropriate acute thrombus formation is the pathophysiological substrate underlying increased risk and severity of target organ damage in hypertension. However, the relationship between severity of hypertension and D-dimer has not been well characterized. This study was aimed to assess plasma D-dimer level and its correlation with disease severity among hypertensive at Yikatit 12 Hospital Medical College (Y12HMC), Ethiopia. A comparative cross-sectional study was conducted at Y12HMC among 100 participants (60 hypertensive and 40 controls). The correlations between variables were determined using correlation coefficients, regression analysis, and different parametric and nonparametric tests. We observed higher D-dimer levels among hypertensive compared to the healthy controls (P<0.001). The D-dimer levels were found to be increased significantly with the severity of hypertension (P<0.001). D-dimer was found to have a diagnostic power of 86.9% in differentiating complicated from uncomplicated hypertension at 0.83mg/l cut-off value. This study suggests that D-dimer level was higher among hypertensive than control groups and it was also increasing significantly with the severity of hypertension. This suggests that hypercoagulability of fibrin plays a role in the pathogenesis of cardiovascular disorders and thromboembolic complications of hypertensive patients. Further studies need be done on larger scale and using more robust study designs such as cohort to establish the causality of the association between severity of hypertension and D-dimer level

Developing community energy systems to facilitate Ethiopia's transition to sustainable energy

In Ethiopia, renewable energy offers people an affordable, dependable, and eco-friendly power supply while decreasing the carbon footprint. However, delivering a renewable future for the country requires a massive change in social practices and systems of provision. The slow progress of renewable development is hindering the transition to a cleaner energy future. Over 80 % of people live in rural areas where it is expensive to reach them via grid networks in Ethiopia, requiring off-grid alternatives. Community energy systems, which are off-grid energy systems in which communities play a key role, offer alternative strategies to close the country's energy access gap. However, community energy systems remain underdeveloped in Ethiopia. There is a need to understand the opportunities for community energy and the barriers that hinder its development in Ethiopia, and their role in energy transitions. This paper adopts an experimental lens to understand the diverse dimensions of community energy projects through how they are made, maintained, and lived. Using a comparative analysis of three multi-method, qualitative case studies, this paper argues that the political context poses the biggest obstacle to the development of community energy in Ethiopia despite these projects' tangible benefits. The analysis indicates that community energy projects allow communities to be involved in all stages of project development. In every project, communities assume project management responsibilities after commissioning. However, these projects encounter challenges in resourcing capital, managing supply chains, and building necessary skills among community members to understand business models to ensure sustained operation of the systems

Impacts of climate change on crop growing season characteristics in Northern Ethiopia

Understanding the likely impact of climate change on crop growth is very important to identify possible areas of intervention and consider climate-related impacts. This study aimed to investigate the future impact of climate change on the crop growing season in the Tigray region. Five global climate models under two representative concentration paths were projected for future periods using a delta downscaling approach. Results indicate that projections of rainfall showed an increase in annual and summer (Kiremt) rainfall at most stations. However, the Belg rainfall season had a declining trend except under RCP4.5 in a mid-term period that showed positive changes at most stations. On the contrary, projections of maximum and minimum temperatures indicated a continuous increase. In line with the increase in temperatures, the reference evapotranspiration consistently increased at all stations. Cumulatively, late onset and early cessation of rainfall are observed, accompanied by a 5.5–19% reduction in the length of the growing period (LGP), exacerbating the current short LGP in the study area and affecting the proper growth and maturity of major crops. The findings of this study have global implications in that similar areas may be alarmed to get prepared ahead and develop adaptive and sustainable crop production strategies. HIGHLIGHTS Future climate variables are expected to include more warming and larger changes in rainfall patterns.; Projections of the growing season in the main rainy season indicated a tendency for late onset and early cessation. These changes will present a challenge to crop production in the study area as well as in other similar areas.

Experimental evaluation on the effect of biochar addition with anaerobic digestion of the tannery wastewater to improve biogas production

The use of biochar as an additive material in various compositions to the anaerobic digestion of the tannery wastewater was investigated. Pyrolytic biochar made from Khat waste with different compositions was added to anaerobic batch digesters in laboratory-scale experiments. Biogas digesters of 500 ml volume were used to explore the effects of biochar on anaerobic digestion in the ratios of 5, 10, 15, and 20% (w/w) at constant mesophilic temperature (38 °C). The results show that for five experimental tests in digesters (D0, D1, D2, D3, and D4), which contains 0, 5, 10, 15, and 20% of biochar, the cumulative methane and biogas yields were, respectively, 17.04, 41.2, 43.8, 51.6, 48.6% and 150, 520, 680, 760, 690ml. Compared to the cumulative methane production efficiency of the digester without biochar (D0), the addition of 5, 10, 15, and 20% biochar had more favorable effects and increased the efficiency by 58.6, 61.1, 66.98, and 64.94%, respectively. From these results, adding 15% of biochar to anaerobic digestion causes a three-fold increase in methane compared to the control and more positive effects than all other biochar compositions. According to this result, the right dose of biochar must be added to maximize biogas production. HIGHLIGHTS Biochar addition in the right dose can increase methane yield from anaerobic digestion.; Tannery waste water treatment requires an inexpensive route to remove contaminants.; Biogas quality and quantity are enhanced by adding biochar to tannery waste water.

Ecosystem Service Values as Related to Land Use and Land Cover Changes in Ethiopia: A Review

Humans worldwide depend on ecosystems and the services they provide. Land use and land cover change increasingly, influencing ecosystem values to the extent that the rate and direction of change occurred. The objective of this study was to review the link between changes in Land Use and Land Cover (LULC) and Ecosystem Service Value (ESV), with emphasis on mountainous landscapes in Ethiopia. The reviewers used the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guideline in the reviewing process. Area-specific and country-level studies showed that the ESV changed as the result of the LULC changes in the country. The change in land use in Ethiopia resulted not only in the loss of ESVs but also in the gain of ESVs depending on the type of man’s activity. Negative change in LULC—especially the deterioration of land cover types such as forest land, shrub land and grass land—resulted in the loss of ESVs, whereas positive LULC change increased the value of ESVs. In Ethiopia, there is a loss of about USD 85 billion per year from the loss of ecosystem services. To save, improve and promote ESVs, land restoration and rehabilitation activities are important. The review provides insights into the need for and focus of future studies on LULC changes and the valuing of ESVs to understand the impact of changes in LULC on ESVs, considering existing and forecasted population increase in rapidly urbanizing areas

Test of AquaCrop model in simulating biomass and yield of water deficient and irrigated barley (Hordeum vulgare)

With the current water shortage in East Africa improving crop water use is vital especially in the arid and semi-arid regions of Ethiopia. To understand the response of barley to water and to simulate the biomass and grain yield of barley under various water inputs and planting dates, we tested the FAO AquaCrop model versions 3.0 using independent data sets during the cropping seasons of 2006, 2008 and 2009 at Mekelle site in northern Ethiopia. We found that the model is valid to simulate the barley biomass and grain yield under various planting dates in the study site. AquaCrop model can be used in the evaluation of optimal planting time. Out of the tested planting dates, planting on July 4 (early sowing) was found to maximize barley biomass, grain and water use efficiency. The model can also be used in the evaluation of irrigation strategies. Barley showed slightly lower performance under mild water stress condition compared to full irrigation condition. However, the model has indicated the possibility of obtaining more biomass and grain yield from a relatively larger barley field under (deficit irrigation) mild stress condition.AquaCrop model Barley Biomass Modeling Water use