A5069817012- Electrocatalysts for Energy Conversion
- Electrochemical Analysis and Applications
- Fuel Cells and Related Materials
- Heavy Metals in Plants
- Analytical chemistry methods development
- Phytase and its Applications
- Proteins in Food Systems
- Analytical Chemistry and Chromatography
- Pesticide Residue Analysis and Safety
- Electrochemical sensors and biosensors
- Conducting polymers and applications
- Banana Cultivation and Research
- Plant Micronutrient Interactions and Effects
- Protein Hydrolysis and Bioactive Peptides
- Bioactive Compounds and Antitumor Agents
- Ethnobotanical and Medicinal Plants Studies
- Agricultural Science and Fertilization
- Advanced battery technologies research
- Pharmacological Effects of Medicinal Plants
- Bee Products Chemical Analysis
- Catalysis and Hydrodesulfurization Studies
- Catalytic Processes in Materials Science
- Food composition and properties
- Catalysis and Oxidation Reactions
- Phytochemistry and biological activity of medicinal plants
Addis Ababa University
2018-2024
Southern Federal University
2014-2015
The purpose of this study was to assess how different processing techniques affected mineral compositions, antinutritional factors, and their interactions in red, white, black kidney beans consumed Ethiopia. Mineral contents were found be 41-44, 58-78, 112-126 mg Ca/100 g the raw, soaked, cooked samples, respectively. Iron content soaked samples 2.77-2.97, 1.94-2.20 2.87-3.28 Fe/100 g, respectively, showing 26-30% loss on soaking followed by 33-48% increase cooking. While Zn 2.47-3.26,...
Pt-non-precious transition metals (Pt-NPTMs) alloy electrocatalysts have gained considerable attention to develop cheaper and efficient for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). In this report, density functional theory (DFT) has been applied study the catalytic activity of Pt-skin Pt3V(111) electrocatalyst ORR PEMFCs. The results revealed that intermediates (O, OH OOH) lower binding energies on compared pure Pt(111) surface. surface proceed via OOH...
In this study, we use density functional theory to investigate the catalytic activity of graphene (G), single vacancy defective (GSV), quaternary N-doped (NGQ), and pyridinic (NGpy, 3NGpy, 4NGpy) on Co(0001) substrate for an oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). The results show a Co support exhibited better performance than NGQ free-standing systems. According results, ORR intermediates (*OOH, *O, *OH) become more stable due presence substrate....
ABSTRACT. The aim of this study was to determine the levels major (Na, Mg, K, Ca) and heavy (Cr, Mn, Fe, Ni, Cu, Zn, Cd) metals health risk assessment peel, flesh seed pumpkins cultivated in Ethiopia, using microwave plasma-atomic emission spectrometry. Dried powdered samples (0.5 g) were wet digested with 69% HNO3 30% H2O2 digester. percent recovery for three parts pumpkin 90-110%. mean concentration flesh, samples, respectively, K (27806±9767, 29531±2452, 10667±1133), Ca (5267±2092,...
Single-atom catalysts have been considered as potential candidates for fuel cell applications due to their good oxygen reduction reaction (ORR) activity. In this study, Co-N 3 S/C revealed a lower overpotential pathway ORR activity in acidic solution cell.
High-temperature oxidation processes of carbon microparticles Vulcan XC72 coated with platinum nanoparticles (Pt/C) were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The presence different specific temperature ranges in the support was shown to be due both peculiarities granulometric composition black microparticles, size, uneven spatial distribution pores on surface support. correlation between length a section thermograms fraction poorly can used...
High-density dispersive liquid-liquid microextraction method coupled with high-performance liquid chromatography a diode array detector (HD-DLLME-HPLC-DAD) was developed for extraction and determination of six commonly used sulfonylurea herbicides in matrices environmental waters. For simultaneous the target herbicides, optimum experimental parameters that 024influence efficiency were investigated. Under optimized conditions, limit detection (LOD) quantification (LOQ) 0.8-1.5 1.9-5.1 ng...
The objective of this study was to determine the level selected metals in leaves Ruta chalepensis L. (Rue) cultivated Ethiopia. Rue samples were randomly collected from four different parts Ethiopia (Kality and Alem Bank Addis Ababa Administration, Holeta (Oromia Region) Worabe (South Nations Nationalities Peoples Region)). A 0.5 g sample digested with 3.0 mL 69.5% HNO3 1.0 70% HClO4 levels determined by flame atomic absorption spectrometry. validity optimized procedure evaluated analyzing...
Transition-metal-doped carbon catalysts are promising Pt-free alternatives for low-temperature fuel cells. They frequently obtained from sacrificial N-rich zeolitic imidazolate frameworks (ZIFs) doped with Co and Fe. The optimal low loading of metals has to be achieved guarantee the competitive efficiency facilitate an inquiry into mechanism their catalytic activity. We report on microwave-assisted solvothermal synthesis Zn,Co-ZIFs a relatively (1-15 mol %) loading, which were further...
Ficus sur Forssk is one of the wild edible plants in Ethiopia. Its fruits are commonly used different parts and soil plant were collected from three region Levels selected metals (K, Ca, Mg, Fe, Mn, Zn, Cu, Cd, Pb) fruit determined by microwave plasma-atomic emission spectroscopy. The validity optimized procedure was evaluated analysis spiked samples whose recoveries range 90.5-108%. concentration (mg/kg) K (12372-13687), Ca (3261-5389), Mg (744-785), Fe (418-479), Zn (23.9-25.4), Mn...
In this study, a simple, inexpensive, selective, and fast salting-out assisted liquid-liquid extraction (SALLE) technique coupled with high-pressure liquid chromatography-diode array detection (HPLC-DAD) was developed for the extraction, preconcentration, analysis of trace level seven multiclass pesticide residues in pasteurized raw cow milk samples. The significant factors that affect extent to which target analytes are extracted, such as type solvent its volume, concentration salts, pH...
ABSTRACT. This study was focused on investigation of amount macro and trace metals present in the fruit samples Rubus steudneri Schweinf plant its underlying soil collected from Chencha, Dega Damot Fiche areas Ethiopia. The levels selected (K, Ca, Mg, Fe, Mn, Zn, Cu, Cd, Pb) were determined by microwave plasma-atomic emission spectroscopy using wet-digestion technique. validity method checked analysis spiked whose recovery found range 90.5-108%. mean concentration K, Pb Cd 9463-9836,...
In this work, the qualities of honey samples were evaluated by assessment some physicochemical parameters and levels heavy metals (Cd, Pb, Cr, Ni, Zn Cu). The collected from major producing regions Ethiopia; Gojjam, Gondar, Jimma Tigray. pH electrical conductivity (EC) determined using digital pH-meter meter, respectively. metal contents flame atomic absorption spectrometry (FAAS). validity method employed was spiking experiments with recoveries ranging 90.0 to 95.8%. FAAS results show...
Cymbopogon citratus is very important and of great interest due to its commercially valuable essential oils, common use in food beverage industries as well traditional folk medicine. The objective the present study was determine levels selected major (K, Mg, Ca) trace (Mn, Fe, Cu, Zn, Pb) metals lemongrass (Cymbopogon citratus) samples collected from Addis Ababa, Ankober, Finote Selam (Gojjam), Wondogenet by microwave plasma-atomic emission spectrometry. optimized wet acid digestion method...