Haramaya Institute of Technology

Utilization of Orange Flesh Sweet Potato and Chickpea Flour to Improve the Nutrient Content of Wheat Based Bread

Sat, 01 Jun 2024 00:00:00 GMT

Utilization of Orange Flesh Sweet Potato and Chickpea Flour to Improve the Nutrient Content of Wheat Based Bread Tewodros Sharew; Solomon Abera (D. Eng.) Bread is a worldwide staple food that is crucial for food security in Ethiopia. The country faces significant public health issues such as protein malnutrition and vitamin A deficiency. Nonetheless, there is a limitation of raw materials, wheat flour due to imported raw material. Therefore, it is essential to supplement wheat flour with locally available raw materials to improve the nutritional value of bread. Therefore, the study aims to investigate the possibility of blending chickpea and OFSP flour with wheat for preparation of bread. The experiment was conducted with two factors: flour blending ratio and bread baking temperature. A full factorial design was used to conduct the experiment and the analysis of the data was done using a statistical software package version 9.4. The flour blending ratio of wheat, chickpea and OFSP were 80:10:10, 70:15:15, 60:20:20, 50:20:30 respectively and control sample 100% wheat flour. The baking temperatures were 180, 200 and 220°C. The results of proximate composition of bread displayed that partial replacing wheat with chickpea and orange fleshed sweet potato increased the moisture content 28.84 to 35.79, protein 10.85 to 14.59, fat 0.85 to 2.05, fiber 1.49 to 1.84, ash 0.93 to 2.06% and β- carotene 0 to 8.04 μg/g of bread but reduced carbohydrate 57.66 to 51.81%, and energy 281.64 to 257.10 Kcal/100, due to wheat flour high source of carbohydrate and energy. On the contrary, loaf weight of bread was 123.28 to 131.29 g increased due to higher water absorption capacity of both chickpea and OFSP flour than wheat while loaf volume 359.17 to 205.83 cm3 and specific volume of bread 2.91to 1.58 cm3/g were reduced due to reduction of gluten content present in wheat flour. With the rise in the proportion of chickpea and OFSP flour, the sensory acceptability of composite bread recorded in a scale 7 point were decreased from 6.19 to 2.77 in color, from 5.78 to 2.62 in texture, from 5.70 to 2.44 in flavor and from 5.90 to 2.58 in overall acceptability of bread. In conclusion, blending wheat with both chickpea and OFSP flour in bread formulations is found to be promising to improve the nutritional quality, especially protein and beta carotene contents of bread. In addition, giving attention to those locally under-utilized raw materials 110

DESIGN, FABRICATION AND PERFORMANCE EVALUATION OF MOTORIZED HOLE DIGGER FOR PERENNIAL CROP TRANSPLANTATION

Sun, 01 Jun 2025 00:00:00 GMT

DESIGN, FABRICATION AND PERFORMANCE EVALUATION OF MOTORIZED HOLE DIGGER FOR PERENNIAL CROP TRANSPLANTATION Fikre Yigezu Abebe; Solomon Abera (Dr. Ing) Ethiopian smallholder farmers are confronting a shortage of farm machinery for growing perennial crops. They are still employing old conventional farm hand equipment and human force to make holes for planting perennial crop seedlings. However this kind of farming is exceedingly tedious, time-consuming and labor-intensive and resulted in extremely low production and productivity. Therefore, this study was conducted to improve production and productivity those farmer’s and make attractive perennial crop farming environment by developing a hole digger for perennial crop production. In this study a motorized hole digger was designed, fabricated and evaluated for its performance. To evaluate the digging performance of the digger, an experiment with full factorial design at three replications was conducted on sandy and clay soil at different soil moisture content and working speed. The digger was tested on clay and sandy soils separately at soil moisture content of (15.00, 22.00 and 29.00%) and working speed of (100.00, 150.00 and 180.00 rpm). The result of the test revealed that the maximum digging capacity and efficiency of the digger were 45.00, 43.33 hole/hr and 85.00%, 84.67% observed at working speed of 180.00 rpm and soil moisture content of 29.00 % for hole dug on sandy and clay soil respectively at depth of 40.00cm and 35.00 cm diameter. The highest fuel consumption of 0.68 L/hr was observed when the soil moisture content was 15.0% and at working speed of180.00 rpm on clay soil. Generally, the study was successful in designing, fabricating, and testing a motorized hole digger prototype. The performance evaluation result showed that the digger's digging capacity and efficiency were greatly increased by raising the working speed from 100.00 to 180.00 rpm and the soil moisture content from 15.00 to 29.00%. 82p.

INVESTIGATION OF CHANNEL ESTIMATION METHODS FOR MASSIVE MIMO SYSTEM WITH PILOT DECONTAMINATION IN RICIAN FADING

Sun, 01 Dec 2024 00:00:00 GMT

INVESTIGATION OF CHANNEL ESTIMATION METHODS FOR MASSIVE MIMO SYSTEM WITH PILOT DECONTAMINATION IN RICIAN FADING Moata Haile; Ritesh Pratap Singh (PhD); Mr. Eyob Mersha Massive multiple input multiple output (MIMO) systems are essential to meet the growing need for enhanced capacity and faster data rates in modern wireless communication networks, particularly in the fifth generation (5G). These systems serve many users at once on the same frequency band by using a lot of antennas at the base station (BS). The computational complexity of many antenna numbers and pilot contamination are the main obstacles to estimating the channel of the massive MIMO system. To overcome pilot contamination challenges, this thesis aims to investigate pilot-based channel estimate methods with pilot decontamination in Rician fading. In this thesis, soft pilot reuse is combined with the weighted graph coloring pilot decontamination mechanism to overcome the impact of pilot contamination in Rician fading scenarios, which is the main weakness in massive MIMO systems. In both Rayleigh and Rician fading, the accuracy of the channel estimate is increased by mitigating the effects of pilot contamination. MATLAB simulations are used to examine how well the minimum mean squared error (MMSE), element-wise minimum mean squared error (EW-MMSE), and least squares (LS) techniques work with the Rayleigh and Rician fading channels model. The simulation result shows that the better method for channel estimation in both uplink and downlink situations is MMSE with Rician fading. In the uplink system, spectral efficiency (SE) of the channel estimate is increased from 20.9 b/s/Hz/cell to 24.7 b/s/Hz/cell with pilot decontamination at BS antenna M = 90. For downlink, it increased from 21.8 b/s/Hz/cell to 27.5 b/s/Hz/cell. In Rayleigh fading, for the uplink system, SE increased from 14.0 b/s/Hz/cell to 16.5 b/s/Hz/cell at M = 90 with pilot decontamination,whereas in the downlink it improved from 14.2 b/s/Hz/cell to 17.5 b/s/Hz/cell. The results show that the addition of decontamination techniques increases the accuracy of channel estimates, hence improving system performance for massive MIMO networks. So, MMSE are useful for utilizing channel characteristics, while the proposed method (soft pilot reuse combined with weighted graph coloring) is a reliable way to reduce the impact of pilot contamination on Rayleigh and Rician fading. 103p.

Effects of Postharvest Treatments, Packaging Materials and Storage Period on Physicochemical and Sensory Quality of Avocado (Persea Americana Mill.): Hass Variety

Fri, 01 Jan 0202 00:00:00 GMT

Effects of Postharvest Treatments, Packaging Materials and Storage Period on Physicochemical and Sensory Quality of Avocado (Persea Americana Mill.): Hass Variety Adem Abdi, Abdi Avocados (Persea Americana Mill.) are classified as climacteric fruits, which are susceptible to rapid physiological deterioration so that requires well-integrated postharvest technologies to maintain its final quality. Thus, the aim of this study were to evaluate the effects of postharvest treatments, packaging materials and storage periods on the physicochemical and sensory quality of the ‘Hass’ variety avocado fruits. The experiment include of four postharvest treatments (control, hot water, garlic extract and wax), three packaging materials (room storage, carton box, and low-density polyethylene), and 12-days of storage period with four interval of data collection days (day0, day4, day8, and day12) with three replications, that was arranged with a full factorial design. The interaction effects of postharvest treatments, packaging materials and storage period on avocado physicochemical quality of avocado were found to be highly significant (P<0.05) over a 12-days of storage period. Compared to samples stored in carton boxes and room temperature, the interaction effect of postharvest treatments with low density polyethylene (LDPE) significantly (P<0.05) produced the highest physiochemical quality during storage periods. The combination of garlic extract and low density polyethylene bags also maintained better physicochemical qualities than control or hot water treated samples. Generally, after a 12-day of storage period, the avocado treated with a combination of wax and LDPE bags showed the best physiochemical qualities, including highest firmness (2.9N), moisture content (46.2%), pH (5.91), ascorbic acid (13.53mg/100g1), and lowest weight loss (1.8%), titratable acidity (28.8%), and total soluble solid (34.4obrix), no decay loss, and the best marketability (100%), after 12-days of storage period at 95% confidence of interval (P<0.05). As storage time increases, the final quality of avocado were determined by postharvest treatment and packaging materials used. Therefore, proper postharvest technologies and durations are essential for preserving the avocado quality. In order to further optimize postharvest handling practices and maintain the quality of avocado for extended period of time. The future researcher should examine the long-term effects of different postharvest treatments and packaging options on quality of different variety of avocado fruit. 91