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| 1 | Vegetation structural characteristics and topographic factors in the remnant moist Afromontane forest of Wondo Genet, south central Ethiopia显示文摘For forest ecosystem management to be effective, knowledge of the horizontal and vertical structural diversity of a forest is essential. The moist Afromontane highlands of Wondo Genet in south-central Ethiopia present an opportunity to restore and rehabilitate and enhance the ecosystem services to be obtained from this forest sustainably. We focused on the forest structural characteristics to better understand the current forest conditions to assist in the sustainable management of this resource. A total of 75 (20 m × 20 m) quadrats were sampled and diameter at breast height (DBH)≥2 cm and stem height≥2 m were measured. Species identity and abundance, elevation, slope, and aspect were recorded for each plot. Structural characteristics were computed for each plot. Relationship of topographic factors with vegetation characteristics was conducted using R-Software. A total of 72 woody species was recorded. Whereas, the overall diameter distribution shows an inverted J-shaped curve, the basal area followed a bell-shaped pattern. Five types of population structures are revealed. The mean tree density and basal area was 397.3 stems ha-1 and 31.4 m2·ha-1 , respectively. Only 2.8% of the tree species have densities of≥25 stems ha-1 and the percentage distribution of trees show 56.2% in the DBH class 2-10 cm, indicating that the forest is dominated by medium-sized trees. Celtis africana (8.81 m2·ha-1 ) and Pouteria adolfi-friedericii (5.13 m2·ha-1 ) make the highest contribution to the basal area and species importance value index. The families/species with the highest importance value index are Ulmaceae, Fabacea and Sapotaceae. Species abundance (r2 = 0.32, p <0.001) and species richness (r2 =0.50, p <0.001) are positively related with tree density. Tree density is negatively related with elevation (r2 = -0.36, p <0.001), slope (r2 =-0.15, p <0.001) and aspect (r2 = -0.07, p <0.05). While basal area is negatively related with elevation (r2 =-0.14, p <0.001), it has a positive relationship with tree density (r2 =0.28, p <0.001 and species richness (r2 =0.098). Species with poor population structure should be assisted by restoration tasks and further anthropogenic disturbance such as illegal logging and fuel wood extraction should be restricted. | Mamo Kebede Markku Kanninen Eshetu Yirdaw Mulugeta Lemenih | 2013 | Journal of Forestry Research2013，24，3： | 6 |
| 2 | Comprehensive review and performance evaluation of maximum power point tracking algorithms for photovoltaic system显示文摘A photovoltaic array is environmentally friendly and a source of unlimited energy generation.However,it is presently a costlier energy generation system than other non-renewable energy sources.The main reasons are seasonal variations and continuously changing weather conditions,which affect the amount of solar energy received by the solar panels.In addition,the non-linear characteristics of the voltage and current outputs along with the operating environment temperature and variation in the solar radiation decrease the energy conversion capability of the photovoltaic arrays.To address this problem,the global maxima of the PV arrays can be tracked using a maximum power point tracking algorithm(MPPT)and the operating point of the photovoltaic system can be forced to its optimum value.This technique increases the efficiency of the photovoltaic array and minimizes the cost of the system by reducing the number of solar modules required to obtain the desired power.However,the tracking algorithms are not equally effective in all areas of application.Therefore,selecting the correct MPPT is very critical.This paper presents a detailed review and comparison of the MPPT techniques for photovoltaic systems,with consideration of the following key parameters:photovoltaic array dependence,type of system(analog or digital),need for periodic tuning,convergence speed,complexity of the system,global maxima,implemented capacity,and sensed parameter(s).In addition,based on real meteorological data(irradiance and temperature at a site located in Addis Ababa,Ethiopia),a simulation is performed to evaluate the performance of tracking algorithms suitable for the application being studied.Finally,the study clearly validates the considerable energy saving achieved by using these algorithms. | Asegid Belay Kebede Getachew Biru Worku | 2020 | Global Energy Interconnection2020，3，4： | 3 |
| 3 | Allometric equations for aboveground biomass estimation of Olea europaea L.subsp.cuspidata in Mana Angetu Forest显示文摘Introduction:African wild olive,Olea europaea L.subsp.cuspidata(Wall.ex G.Don)Cif.,L‘Olivicoltore is widely distributed in dry forest and forest margins,often with Juniperus procera,in east Africa and Ethiopia.It reaches southern Africa,also India and China,ranging from tall trees to stunted shrubs.Does best in good forest soil,but hardy and drought resistant once established,even in poor soils.It is used for firewood,charcoal,poles,posts,timber(furniture,carving,floors,and paneling),medicine(stem,bark,and leaves),bee forage,milk flavoring(smoking wood),toothbrushes(twigs),and walking sticks.Although the species has many economic and ecological functions,its environmental uses like carbon storage and climate change mitigation are less assessed.Therefore,the objective of the study was to develop species-specific allometric equations for O.europaea L.subsp.cuspidata using semi-destructive method and evaluate allometric models for estimating the aboveground biomass(AGB).Results and Discussions:After all the necessary biomass calculations were done,seven AGB equations were developed.These regression equations relate AGB with diameter at breast height(DBH),height(H),and density(ρ)individually and in combination.Out of seven,four allometric equations were chosen based on goodness-of-fit statistics and three were rejected.The selected models were tested for accuracy based on observed data.The best models selected have higher R2-adj and lower residual standard error and Akaike information criterion than rejected equations.The relations for all selectedmodels are significant(p<0.000),which showed strong correlation of AGB with selected dendrometric variables.Accordingly,the AGB was strongly correlated with DBH and was not significantly correlated with wood density and height individually in O.europaea L.subsp.cuspidata allometric equation development.In combination,AGB was strongly correlated with DBH and height;DBH and wood density;and the combination of DBH,height,and wood density.Species-specific equations are used for better carbon assessment than general equations. | Birhanu Kebede Teshome Soromessa | 2018 | Ecosystem Health and Sustainability2018，4，1： | 2 |
| 4 | Educationg leaders in hospital management:a new model in Sub-Saharan Africa显示文摘 | Sosena Kebede Yigeremu A bebe | | 0，，01： | 1 |
| 5 | A principal component regression approach to simulate the bedevolution of reservoirs显示文摘 | Kebede Gurmessa T Bardossy A | 2009 | Journal of Hydrology2009，368，14： | 1 |
| 6 | Hypertension in pregnancy : A comprehensive update显示文摘 | Jim B Sharma S Kebede T | 2010 | Cardiol Rev2010，18，4： | 1 |
| 7 | Structure, Composition, and Properties of Silk from the African Wild Silkmoth, Anaphe Panda ( Boisduval) ( Lepidoptera; Thaumetopoeidae ) 显示文摘 | Kebede A T Raina S K Kabaru J M | 2014 | International Journal of Insect Science2014，6，4038： | 1 |
| 8 | Initial presentation of acute transverse myelitis in systemic lupus erythematosus : demographics, diagnosis, man- agement and comparison to idiopathic cases显示文摘 | Schulz S W Shenin M Mehta A Kebede A Fluerant M Derk CT | 2012 | Rheumatolo- gy International2012，32，9： | 1 |
| 9 | Intestinal microsporidiosis in diarrheal patients infected with human immunodeficiency virus-1 in Addis Ababa, Ethiopia显示文摘 | Endeshaw T Kebede A Verweij JJ et ol | 2006 | Jpn J Infect Dis2006，59，5： | 1 |
| 10 | Does One Size Fit All? Drug Resistance and Standard Treatments: Results of Six Tuberculosis Programmes in Former Soviet Countries显示文摘 | Bonnet M Sizaire V Kebede Y Janin A Doshetov D Mirzoian B Arzumanian A Muminov T Iona E Rigouts L Rusch-Gerdes S Varaine F | 2005 | Int J Tuberc Lung Dis2005，9，10： | 1 |
| 11 | Hypertension in preg- nancy:a comprehensive update 显示文摘 | Jim B Sharma S Kebede T | 2010 | Cardiol Rev2010，18，4： | 1 |
| 12 | Effect of source germplasm and season on the in vivo haploid induction rate in tropi- cal maize显示文摘 | Kebede A Z Dhillon B S Schipprack W | 2011 | Euphytica2011，150，： | 1 |
| 13 | A safe inexpensive method to isolate high quality plant and fungal DNA in an open laboratory environment 显示文摘 | Niu C Kebede H Auld D L | 2008 | African Journal of Biotechnology2008，7，16： | 1 |
| 14 | A large left atrial myxoma causing multiple cerebral infarcts显示文摘 | Kebede S Edmunds E Raybould A | 2013 | BMJ Case Rep2013，，： | 1 |
| 15 | Hypertension in pregnancy :a comprehensive updatey显示文摘 | Jim B Sharma S Kebede T | 2010 | Cardiol Rev2010，18，4： | 1 |
| 16 | Primary hyperparathyroidism presenting with musculoskeletal manifestations in a young patient:a case report显示文摘 | Kebede T Hagos E | 2004 | Ethiop Med J2004，42，： | 1 |
| 17 | Coronary artery fistulae显示文摘 | Luo L Kebede S Wu S | | 0，，： | 1 |
| 18 | Schizophrenia: Illness impact on family members in a traditional society - rural Ethiopia显示文摘 | Shibre T Kebede D Alem A | 2003 | Soe-Psychiatry Epidemiol2003，38，1： | 1 |
| 19 | On the measurement of risk aversion from experimental data显示文摘 | Mette W Kebede T A Bergland O | 2004 | Applied Economics2004，，： | 1 |
| 20 | Coronary artery fistulae 显示文摘 | LUO L KEBEDE S WU S | 2006 | Am Med Sciences J2006，332，2： | 1 |
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