About Addis Ababa University Institutional Repository (AAU-ETD)
AAU-ETD is an electronic open access institutional repository of Addis Ababa University that makes available and digitally preserves the scholarly outputs produced at AAU. The repository contains both published and unpublished work including: theses and dissertations,preprint,staff and student publications.
Services provided by AAU Library repository specialist:
- Create Colleges/Institutes and collections
- Provide depositing services
- Train and facilitate community members to add materials
- Review and add additional descriptive information (metadata) to each record.
- Maintain open access and ensure preservation of materials
- Maintain the software and hardware required for continuous service
- Research copyright and seek permissions
All faculty are invited to submit their research to the AAU-ETD which is operated and maintained by Addis Ababa University Library. For further information please contact us at ________
Colleges/Institutes in AAU-ETD
Select a College/Institute to browse its collections.
Recent Submissions
Design and Development of Steam Sterilizer
(Addis Ababa University, 2023-06) Yemane Tesfay; Dawit Assefa (PhD)
According to the 2010 WHO infectious disease report, hundreds of millions of patients around the world are affected by healthcare-associated infections which cause extended clinic stays, long-term disability, massive additional costs, and unnecessary deaths. This folds higher in low-income countries but it is a global burden. To minimize the burden of these infections, cleaning, disinfection, and sterilization techniques have been applied. For a sterilization technique, different steam sterilizers are available in the market ranging from the simplest electro-mechanical portable systems to the complex microcontroller-based double-door floor fixed types. However, those steam sterilizers can’t adjust environmental pressure for altitudinal changes that often fail to function properly under significant pressure variation. Countries like Ethiopia have great geographical diversity, known altitude ranges from the highest peak at Ras Dashen (4,620m) down to the Dallol Depression (-148m), which highly affect the performance of steam sterilizers. The main intent of this thesis study is to design a microcontroller-based smart steam sterilizer that adjusts itself to variable altitudes since steam sterilizers that work in all altitudes are vital for the healthcare system. The sterilizer also comes with a water electrical conductivity sensor to completely avoid the use of hard water integrated with a water level regulator to protect the heater when water runs out inside the chamber. Interfacing between the proposed smart pressure compensator, conductivity sensor with water level regulator of steam sterilizers is worked out in this study. The developed control system senses the environmental condition using BMP280 sensor to adjust itself based on the altitudinal changes as well as water electrical conductivity, water level, pressure, and temperature sensors. A formula is developed based on the altitude pressure compensation to solve the problem of altitudinal effect and for water quality and quantity measurement guided by a programmable microcontroller. The control system can adjust the pressure based on the altitudinal variations. The system offers better efficiency, precision and comes with great ease of use. The designed smart steam sterilizer is as effective as existing modern sterilizers with an added feature of blocking use of hard water. Meanwhile, further research might be needed to make the device more efficient, lower cost, durable, and safer.
A Trilingual Android Application with Automatic Malaria Detection from Microscopic Images of Red Blood Cells
(Addis Ababa University, 2023-12) Berihun Nigussa; Dawit Assefa (PhD)
Malaria, which is a mosquito-borne blood disease caused by Plasmodium parasites, is one of the virulent
infectious diseases affecting human beings and other animals since antiquity. Even though there
were promising progresses in the reduction of malaria morbidity and mortality in the past two decades
before the outbreak of COVID-19, the latest two reports of theWorld Health Organization (WHO) statistics
indicate that malaria has been overlooked due to the COVID pandemics. Malaria is still prevalent
specifically in low resource setting areas such as the sub-Saharan African countries, including Ethiopia.
WHO reported that there were 229 million new cases of malaria and 409,000 deaths globally in 2019,
alone. Whereas in the year 2021, the morbidity and mortality was reported to rise up to 247 million
and 619,000, respectively. Timely diagnosis and treatment as well as good awareness about the disease
play a major role to combat malaria. In the current project work, it was intended to design and develop
a multi-lingual Android App that offers useful information about the malaria disease and is capable of
automatically detecting malaria infected red blood cells (RBCs) from color microscopic images based
on a deep learning approach. The Convolutional Neural Network (CNN) based deep learning model
was trained, validated and tested on a publicly available dataset composed of microscopic images of
RBCs taken from individuals with confirmed malaria infection as well as normal control groups. Experimental
results generated from the deep learning model showed that the detection capability of the
model achieved 100% training accuracy, 96% validation accuracy and 96% testing accuracy. The developed
App avails useful information about malaria disease in general and tips users with fundamental
information regarding its prevention and transmission mechanisms acting as an m-health system.
Development and Characterization of Papaya Based Fruit Leather Supplemented with Orange-Fleshed Sweet Potato and Haricoat Bean Flour
(Addis Ababa University, 2023-02) Eftu Tesfaye; Solomon Kiros (PhD)
The goal of this study was to investigate the production of nutritional fruit leather using haricot bean and orange fleshed sweet potato flours to partially substitute papaya pulp. The study examined β-Carotene content, functional property, anti-nutrient composition, and physicochemical properties, proximate composition of the raw materials and composite pulps, additional to this mineral and microbiological analysis, texture and color analysis, and finally sensory characteristics of the fruit leather were analyzed using standard methods. The formulation for composite flour was developed using a D-optimal mixture design ratio applying Design-Expert®, version 13. Accordingly, 11 composite pulp samples were developed (R1, R2……. R16) and the data analyzed using mini-tab software, the result was evaluated by used one-way analysis of variance (ANOVA) and test of significant (p<0.05).The composite puree samples are significantly different each other at (p<0.05) with increasing haricot bean and orange fleshed sweet potato flour ratios on papaya puree. the optimum fruit leather at run(sample) 11 was made with 60.02% papaya pulp, 19.98% haricot bean, and 20.00% orange-fleshed sweet potato flour showed significantly higher values of β-carotene (746 μg/g), protein (12.05%), fiber (5.32%), and fat (4.09%), and a moisture content (15%) than the control fruit leather(100%papaya pulp),Moreover the texture analysis result of the fruit leather indicated that the hardness, chewiness, and fracturability decreased with the increased amount of haricot bean and orange-fleshed sweet potato flours. The mineral contents of the fruit leathers ranged from Ca 5.37 to 21.49, Mg 11.49 to 22.49, Na 7.88 to 24.20, K 29 to 24.50 mg, Fe 0.13 to 1.72 (mg/100 kg), and Cu, Mn, and Zn were also detected in the zero range In terms of all the sensory parameters except taste and mouth-feel, the optimum fruit leather showed significantly higher scores than the control fruit leather. Generally the results showed that the supplementing of haricot bean and orange fleshed sweet potato flour to papaya puree improved the nutritional quality of the fruit leather.
Comprehensive Study on Oil Extraction from Papaya (Carica) Seed and Analysis of its Characteristics, Bioactive Components and Antimicrobial Properties
(Addis Ababa University, 2024-03) Mekdes Amare; Shimelis Admassu (Prof.)
The utilization of whole fruits and vegetables, including the typically discarded parts during food processing, presents an opportunity to reduce agro-industrial waste. This study focused on evaluating the proximate and nutritional potential of Carica papaya seeds and its oil. The oil from papaya seeds was characterized, and the effects of operating parameters (moisture content, temperature and heating time) on oil yield were investigated using a screw expeller. The Box-Behnken design was utilized for the experimental design, and response surface methodology was used to assess the effects and significance of the models on the response variable (oil yield). The maximum extraction efficiency 24.248%. achieved with a moisture content of 6.32 %, heating time of 9.82 minutes, and temperature of 69.54℃. Furthermore, the byproducts obtained from the screw press meal and cake underwent oil recovery through Soxhlet extraction, and the effects of moisture content, particle size, and extraction time were evaluated. Moreover, Physical and chemical properties of the oil also evaluated. Despite the growing interest in papaya seed oil, there is a lack of comprehensive research on its bioactive components and antimicrobial properties. Gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) analysis were employed to identify these components and functional groups for different extraction methods and also Total Phenolic content and Flavonoid content, were determined using standard methods. The results showed an average total Phenolic content of 19.41 ± 1.33 mg GAE/ml of sample and 2.25 ± 0.787 mg QE/g Total Flavonoid content. Antimicrobial properties were assessed using the agar diffusion method, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined through broth dilution methods. The oils exhibited effectiveness against Staphylococcus aureus, Bacillus subtilis, and Escherichia coli. MIC values ranged from 3.125 to 12.5 μl/ml, while MBCs varied from 6.25 to 50 μl/ml.
Development and Quality Assessment of Nutritionally Enriched Texturized Soya Protein with Ground Flaxseed Flour
(Addis Ababa University, 2024-03) Memiru Michael; Kumsa Delessa (PhD)
Texturized soya protein is one of the most important meat alternative product among plant proteins. Texturized Soya protein is currently limited to soyabean and cereal in many countries. Whole soyabean and flaxseed were cleaned, milled and defated. The soybean and flaxseed flour were blended using Response(Box-Bhnken) design to formulate composite flour with the ratio of 90%,85%,80% and 10%, 15%,20% respectively where as 120 oc,135oc,140oc, 145oc, 150oc and 60oc, 70oc, 80oc were used for baking and drying respectively. The data generated were statistically analyzed by general linear model analysis of variance using the Minitab software program version 18. Functional properties and proximate analysis were carried out on the flour and texturized Soya protein sample, the result indicated that , fiber,ash ,carbohydrate,moisture value of composite flour increased with the increase in blend proportion (p<0.05) the bulk density,water absorbition capacity,oil absorbition capacity were observed with an increase in flaxseed flour proportion in the composite flour. The mineral content (Fe,Zn,K,Mn,) of texturized Soya protein were improved by the presence of flaxseed flour. Significant difference(p<0.05) in sensory quality of Texturized Soyaprotein with an increase in flaxseed flour was observed. the result of optimization confirmed that texturized soya protein which was dried with drying temperature 60 oc, drying time 24.087 min and blending ratio 20% flaxseed flour with response of moisture content of 8.69,flavor 7.59, overall acceptability 7.64 was selected. it was concluded as the increseang of ground flaxseed flour had increased sensory, proximate,functional properties and mineral content of texturized soya protein.