Papers by Daniel Gebeyehu
The objective of this study was to investigate the fiber properties of Acacia decurrence as a alt... more The objective of this study was to investigate the fiber properties of Acacia decurrence as a alternative raw material quality evaluation for pulp and paper production. Trees from an even-aged stand with a similar stem diameter class were selected randomly. Wood discs were cross cut systematically from a log at the bottom (10%), middle (50%), and top (90%) position along the merchantable height, as well as a block of wood (2cmx2cmx2cm), was taken from pith to periphery: at near pith (10%), middle(50%), and near bark (90%) of disk radius. Fiber properties were determined, and their change with tree height and distance from the pith to the bark were evaluated. The fiber length, fiber width, lumen diameter, and cell wall thickness were measured while the derived fiber values were computed from the measured fiber dimensions. All the data were analyzed using a two-way analysis of variance. The results showed that the overall means were 1.37mm, 39.60µm, 9.68µm, 1.93µm, 0.39, 35.38, 24.82,...
The aim of this study was to investigate the fiber properties and pulp and paper-making potential... more The aim of this study was to investigate the fiber properties and pulp and paper-making potential of Eucalyptus globulus grown in Farta Woreda, Amhara National Regional State, Ethiopia. Six trees with an age of eight years were sampled, and sample discs were taken at the bottom (10%), middle (50%) and top (90%) along the tree height, as well as 2x2x2 cm blocks of wood at 10%, 50% and 90% of the disc radius (distance from the pith to the bark of the tree). Fiber properties were determined, and their variation along tree height and transversally from pith to bark was evaluated. The results showed that the overall mean values along tree height and distance from the pith to the bark were 0.77mm for fiber length, 12.38µm for fiber diameter, 2.94µm for cell wall thickness, 8.23µm for lumen diameter, 19.61µm for fiber width, 0.74 for runkel ratio, 39.22% for slenderness ratio, 67.83% for flexibility coefficient, and 0.47 for wall coverage ratio. Fiber length, lumen and fiber diameter, fibe...
Top row 1st-Hogenia abyssinica trees (Precious and endangered indigenous tree species); middle-lo... more Top row 1st-Hogenia abyssinica trees (Precious and endangered indigenous tree species); middle-logo of forest products characteristics and utilization research, and top right-one of the Symbolic E. globulus trees left at Entoto Mariam (Addis Ababa) planted during the era of Menelik; 2nd row-author names of this publication, highland bamboo and suit case made from laminated lumber of, different tree species; 3rd row left-model lumber stacking at FPURCT seasoning yard and right-Coffee table (double set) made of decorative 1 face veneer.
European Journal of Engineering Research and Science, 2019
This paper studied the chemical composition of cultivated 3, 4 and 5 year-old highland bamboo (Y.... more This paper studied the chemical composition of cultivated 3, 4 and 5 year-old highland bamboo (Y. alpina) which were classified into three position (top, medium and bottom) to determined the main compositions especially cellulose, lignin, extractive and ash content. From all culms representative samples were converted to the required size of wood chips to prepared sample for chemical testing. Then the specimens prepared from bottom, middle and top portions for the three ages were used to determine the chemical properties in accordance to American Society for Testing and Materials (ASTM) standards except for cellulose test determined according to Kurschner and Hoffer method. All parameters in the experiment were expressed by percent based on dry basis. From this research, we have found small but significant increases in mean cellulose content from the base to the top of the culm at all three ages. The lignin content in Y. alpina species of bamboo is in the ranged of 23.04 to 30.03%. ...
The aim of this study was to make comparison of chemical compositions of the indigenous species o... more The aim of this study was to make comparison of chemical compositions of the indigenous species of bamboo, Yushania alpina, which is grown at Tikur-Enchini in the north part of Ethiopia. The experiment has been conducted to determine extractive yield, cellulose content, lignin content and ash content based on the culm position of the bamboo species. Chemical characterization was carried out according to the standard outlined in American Society for Testing Materials (ASTM) except, determination of cellulose content, which was conducted using Kurschner and Hoffer method. The results were analyzed by using Statistical Analysis System (SAS) Software. From the study, it has been shown that the main effect of culm positions on cellulose content and the interaction effect between age and culm positions on cellulose and lignin content is not significantly (p<0.05) different. The main effects of extractive yield and ash content with respect to bamboo age and culm position is highly signi...
The aim of this review was to know and highlight the effects of silivicultural practices such as,... more The aim of this review was to know and highlight the effects of silivicultural practices such as, thinning, pruning, stand density, fertilizer application, growth period and rate on some selected wood properties. The review work will help to highlight the positive and negative effects of applying growth accelerating treatments on the different wood properties. Wood properties like fiber length, cell wall thickness, growth ring, earlywood and latewood ratio, density and modulus of elasticity are affected by the different silivicultural practices. Accelerated growth rate of trees due to various silivicultural practices resulted in lower quality wood products. Tree grown with wider spacing produced wider growth rings, which indirectly decrease the density of wood because wider rings contain more earlywood. On the other hand, as the stand density increases, competition for light occurs causing crown recession and delayed crown development, which could cause a growth rate reduction and l...
Quantitative wood anatomy investigates quantitatively the variability of anatomical features in t... more Quantitative wood anatomy investigates quantitatively the variability of anatomical features in the xylem of trees, shrubs and herbaceous species. This is related to plant functioning, growth and environment and often explores how these relationships change over time. Xylem performs a wide range of functions that are essential for plants to grow and survive. Fiber length, cell diameter, cell wall thickness and lumen diameter are some of the anatomical futures which are investigated in wood anatomy. Fiber length is the distance from one end to another end whereas cell diameter is the diameter of fiber measured from side to side end and it is usually measured across the fiber length. The cell lumen diameter is the diameter of the internal cavity. It is determined by averaging the radial diameter and tangential diameter. Cell wall thickness of wood fiber is defined as half values of double wall thickness including compound middle lamella. Investigation of wood anatomy is very important...
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Papers by Daniel Gebeyehu