Traditional butter making in Ethiopia and possible improvements

Summarises the results of a study on the traditional methods of butter making-conducted to determine the efficiency of the process and the quality of butter produced. Reports on initial experiments carried out to devise improved methods of butter making

Importance of irrigated agriculture to the Ethiopian economy: capturing the direct net benefits of irrigation

Irrigated farming / National income / Economic growth / Crops / Prices / Sensitivity analysis / Crop management / Irrigation schemes / Ethiopia

Genetic diversity and population structure of Ethiopian lentil (Lens culinaris Medikus) landraces as revealed by ISSR marker

Characterization of genetic resources maintained at genebanks has important implication for future utilization and collection activities. The objective of this study was to assess the level of geneticdiversity, genetic structure and genetic distance, and to indirectly estimate the level of gene flow among populations of Ethiopian lentil landraces using intersimple sequence repeat (ISSR) marker. Forthis purpose, seeds of seventy landrace accessions collected from seven different administrative regions of Ethiopia were obtained from Inistitute of Biodiversity Conservation and grown at SinanaAgricultural Research Center (Bale-Robe, Ethiopia) on-station field plot. DNA was extracted from a bulk leaf sample of fifteen randomly selected seed-raised plants using a triple CTAB extraction technique.ISSR data were generated using four primers. The total genetic diversity ( T H ), the intrapopulation genetic diversity ( S H ) and the interpopulation genetic diversity ( ST D ) were 0.175, 0.095 and 0.079,respectively. High intrapopulation genetic diversity was observed for Gonder, Shewa and Wello populations, while Arsi, Bale, Tigray and Gojam populations showed low intrapopulation diversity.There was high genetic differentiation (GST = 0.455) but intermediate gene flow level (Nm = 0.60) among populations. The genetic distance ( D ) between populations ranged from 0.012 – 0.228. Cluster analysisrevealed two groups of Ethiopian lentil landrace populations. The results provide important baseline for future germplasm conservation and improvement programs

Practices in the Teaching of Listening in Grade 9 EFL Classrooms of Mote Secondary School

This study was designed to examine the practices in the teaching of listening in Grade 9 EFL classrooms of Mote Secondary School. The study employed a descriptive survey design to attain the objective. The research used 108 Grade 9 students and 6 English language teachers who were teaching English as subjects of the study. To gather proper data for the study, questionnaire (both for students and teachers) and classroom observations were used. The data collected through questionnaire and classroom observations were analyzed both quantitatively and qualitatively. The findings of the study indicated that the teaching of listening in EFL classrooms (and that of English language teaching in general) is at a critical risk since teachers do not use the pre-listening, the while-listening and the post-listening activities to promote and facilitate the development of listening comprehension and because they never adapt or adopt activities which help students learn the skill effectively. Hence, the study recommended that an intensive training on classroom teaching and on the teaching materials which are currently in use are required for EFL teachers

Inter Simple Sequence Repeat (ISSR) analysis of wild and cultivated rice species from Ethiopia

The genetic diversity of three wild rice populations of Ethiopia along with three cultivated rice populations were studied using Inter simple sequence repeats (ISSRs) as a molecular marker. A total of 93 clear and reproducible bands were generated using four dinucleotides and two tetra nucleotides primers. Both UPGMA and neighbor joining trees were constructed for each individual and population using Jaccard’s similarity coefficient. The trees and PCO clearly indicated six distinct groups which are based on populations of origin. Oryza glaberrima, Oryza sativa and NERICA-3 clustered as a major group while Oryza barthii and Oryza longistaminata were clustered as the second major group. Such clustering of O. glaberrima with O. sativa and NERICA-3 is considered to be due to genetic admixture of O. glaberrima with O. sativa. The over all gene diversity and percent polymorphisms were found to be higher in wild rice (0.14; 38.3 respectively) than in cultivars (0.11; 28.3 respectively). The Shannon’s diversity index also confirmed the existence of higher diversity in wild rice populations than cultivated species. Furthermore, partitioning of the Shannon’s diversity showed that the majority of the variations were observed among population (63%). Similarly, AMOVA demonstrate highly significant (P = 0.00) genetic differences among populations (72.9) than within populations (27.1).Key words: Genetic diversity, wild rice populations, cultivated rice, Oryza sativa, Oryza glaberrima, NERICA, ISSR

Seasonal changes in nematode faecal egg counts of sheep in Ethiopia

Describes the seasonal pattern of nematode faecal egg counts of sheep slaughtered at the Addis Ababa abattoir from July 1985 to June 1986. Presents data on strongyle and trichostrongyle faecal egg counts. Suggests possible strategic measures for th econtrol of gastrointestinal nematodes of sheep in central Ethiopia

Exploration of Mechanical Properties of Enset–Sisal Hybrid Polymer Composite

Enset and sisal fibers are among the most widely used reinforcement to fabricate natural fiber-based composite materials. Hand lay-up techniques were employed in this study to fabricate enset–sisal (E/S) hybrid fiber composite with volume ratios of 100/0, 75/25, 50/50, 25/75, and 0/100 and constant polyester resin. The tensile, flexural, impact strength, water absorption and morphological properties of the fabricated composite were investigated experimentally. The effects of hybridization to volume ratio were determined and the results show that hybrid composites excel in mechanical properties, compared with single composites. For better mechanical properties, the enset fiber has been hybridized with sisal fiber. Tensile and flexural strengths were enhanced by 47.3% and 41.03%, respectively, at 50/50 E/S volume ratio compared with 100/0 E/S composite. The impact strength of sisal fiber composite was improved by adding enset fiber in the composites. The inherent benefits and limitations of these two fibers were balanced out by each other in a positive way. While sisal fiber helped the composite intermesh of tensile, flexural, and reduction of water absorption, enset ensured impact strength. Morphological analysis was carried out in order to observe the fracture behavior and fiber pull-out of the samples by means of scanning electron microscopy.publishedVersio

Study of Machinability in Drilling Operation of Enset–Sisal Hybrid Polyester Composite

Due to their light weight, low density, high-specificity strength, and ease of fiber surface treatment, natural-fiber-reinforced composites are recognized as the most suitable materials for interior part applications. Moreover, natural fibers are widely accessible and environmentally friendly. The fabricated parts are assembled predominantly by fastening using drilled holes, which makes drilling operations common machining processes for the composite parts. Damage occurs at the entry and exit surfaces of drilled holes. In this study, hand layup procedures are used to create unidirectional and woven forms of 1:1 ratio enset (false banana)/sisal hybrid polyester composites that have been treated with 5% NaOH. The drill operation was performed using a computer numerical control (CNC) drill machine with high-speed steel twist drill. A Taguchi design tool was used to complete the analysis. The experiments were conducted at different levels of drilling speeds: 600, 1200, and 1800 rpm. Feed rates of 0.1, 0.2, and 0.3 mm/rev and drill bit diameters of 6, 9, and 12 mm were used. These were determined to be the study parameters that influenced the delamination factors (Fd) and surface roughness (SR) of the hybrid composite drilled parts. Delamination occurred at the entry and exit surfaces of the drilled holes, and surface roughness occurred at the inner surface of the sectioned drilled hole. The quality of the drilled holes was compared based on the delamination factor and the surface roughness, as analyzed by the 3D optical surface profiles.publishedVersio

Experimental study of physical, chemical and mechanical properties of enset and sisal fibers

The properties of composites depend on type and properties of the fiber, fiber structure and treatment. In this study, effects of NaOH treatment on the physical, chemical and mechanical properties of fibers collected from South-West Ethiopia were investigated using untreated, 5% and 10% alkali treated enset and sisal fibers. The effects of NaOH on diameter, moisture absorption, density, lignin and hemicellulose was experimentally studied. In addition, tenacity of both fibers was investigated by using optical microscopy, Fourier transform infrared spectroscopy and single fibers tensile strength tester. The 5% and 10% NaOH treatment significantly improved the moisture absorption and diameters. The moisture absorption of 5% and 10% NaOH treated enset fibers improved by 33% and 34%, while the same treatment on sisal fibers improved the moisture absorption by 30% and 40% respectively. The 5% NaOH treated enset and sisal fiber showed better tenacity, which is an indication of the tensile strength of single fiber, than untreated and 10% NaOH treated fibers. Improving moisture content, diameter, lignin and hemicellulose contents of the fibers contributes to better bonding as interlock with the matrix materials enhancing the mechanical properties of composites.publishedVersio