Dr. Goitom Gebreyohannes (Ph.D) Berhe (original) (raw)
Papers by Dr. Goitom Gebreyohannes (Ph.D) Berhe
International journal of chemical engineering, Mar 8, 2024
Research Square (Research Square), 2024
Journal of the Indian Academy of Wood Science, 2020
ECS Meeting Abstracts, 2016
A Review Approaches for Extractive hydrometallurgy of niobium and tantalum from Ethiopian Kentich... more A Review Approaches for Extractive hydrometallurgy of niobium and tantalum from Ethiopian Kenticha Ores Abstract The Kenticha rare-element pegmatite, a globally important tantalite source in the Neoproterozoic of southern Ethiopia, is a highly fractionated, huge, subhorizontal, sheet-like body, discordantly emplaced in ultramafic host rock. It corresponds to the spodumene subtype of the rare element pegmatite class and belongs to the lithium–cesium–tantalum petrogenetic family. The Kenticha pegmatite is asymmetrically zoned from bottom to top into granitic lower zone, spodumene-free intermediate zone, and spodumene-bearing upper zone. The Kenticha pegmatite is rich in Ta-mineralized rare-element pegmatites. Thus, need to conduct research in enrichment of Ta2O5 and Nb2O5 and extraction of Nb and Ta into metallic form. This paper reviews the successful extraction of Nb and Ta from tanatlite ores. Its success normally depends on the physiochemical properties of the ore, choice of leaching extraction solvent. Currently, HF and methyl-isobutyl Ketone has been used for decomposition and separation of Nb and Ta from tantalite ore. Therefore Kenticha atantalite ore containe vaiaty compositions of elements and higher concentration of Li and U. Thus needs further investigation in extraction process in the sence of removing the use of HF for leaching and replacement of traditional organic solvents by "Green Solvents". This review gives directions for future development of extraction of Kenticha tantalite ore. Keywords: Kenticha; leaching; magnetic separation; pegmatite, rare-element; solvent extraction, sopdumene; tantalite.
Momona Ethiopian Journal of Science
This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff ... more This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff base, through the condensation process of salicylaldehyde and p-toludine, and its Cu and Zn complexes were successfully synthesized. The Schiff base and its complexes were characterized using molar conductivity, Ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and Fourier transform infrared (FTIR) techniques. Accordingly, these characterizations not only confirmed that the synthesized Schiff base acted as N,O bidentate ligand (through azomethine nitrogen and phenoxide oxygen) and chelated with Cu(II) and Zn(II) in the metal-to-ligand ratio of 1:2 but also revealed the characteristic electronic-transition of π→π*/n→π* of the ligand, and ligand-metal charge transfer and d-d of the metal complexes. Moreover, both Cu and Zn complexes recorded weak molar conductance of 54.12 and 51.41 S cm2 mol-1, respectively. Further, their antibacterial activities were evaluated by disc ...
Journal of Experimental Pharmacology
Momona Ethiopian Journal of Science
This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff ... more This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff base, through the condensation process of salicylaldehyde and p-toludine, and its Cu and Zn complexes were successfully synthesized. The Schiff base and its complexes were characterized using molar conductivity, Ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and Fourier transform infrared (FTIR) techniques. Accordingly, these characterizations not only confirmed that the synthesized Schiff base acted as N,O bidentate ligand (through azomethine nitrogen and phenoxide oxygen) and chelated with Cu(II) and Zn(II) in the metal-to-ligand ratio of 1:2 but also revealed the characteristic electronic-transition of π→π*/n→π* of the ligand, and ligand-metal charge transfer and d-d of the metal complexes. Moreover, both Cu and Zn complexes recorded weak molar conductance of 54.12 and 51.41 S cm2 mol-1, respectively. Further, their antibacterial activities were evaluated by disc ...
Journal of Food Quality
Adansonia digitata L (Baobab) is a large plant species which thrives in many semiarid regions of ... more Adansonia digitata L (Baobab) is a large plant species which thrives in many semiarid regions of the world with remarkable economic and nutritional importance. In Ethiopia, it grows in deserts and hot lowlands. Industrially, baobab fruit pulp (powder) is used for producing good quality jams. This study was carried out to (a) develop a formulation protocol for producing high-quality baobab jam, (b) characterize the jam using standard physicochemical, microbiological, and sensory evaluation methods, and (c) examine the effects of time and temperature of storage on the quality as well as shelf life of the jam. Out of the seven formulations tested, a formulation enriched with 55 g table sugar, 45 g baobab fruit powder, 0.50 g ascorbic acid, and 0.40 to 0.60 g citrus pectin jelling (formulation no. 6) and another one enriched with 60 g table sugar, 40 g baobab fruit powder, 0.50 g ascorbic acid, and 0.40 to 0.60 g citrus pectin jelling (formulation no. 7) resulted in the best jam product...
International Journal of Analytical Chemistry
Baobab (Adansonia digitata L) is a large tree species growing in semiarid and arid lowlands of Et... more Baobab (Adansonia digitata L) is a large tree species growing in semiarid and arid lowlands of Ethiopia and other places. The plant is valued by natives for its contributions as a cash crop and livelihood tree. Previous studies using samples from different countries have documented their phytochemical profiles and nutritional and health benefits. This study explored the phytochemical constituents and biological activities of fruit pulp extracts of baobab collected from Tekeze Valley, Tigrai, Ethiopia. To this end, qualitative phytochemical screening tests, quantitative phytochemical analyses, and gas chromatography-mass spectrometry (GC-MS) analysis were carried out using aqueous extract. Analyses of antioxidant activities were also conducted with aqueous- and methanol-extracts using of 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), and hydroxyl (OH) radical scavenging activity assays. The qualitative screening tests showed the presence of flavonoids, phenols, saponins, ta...
International Journal of Analytical Chemistry, Apr 4, 2020
International Journal of Analytical Chemistry, Feb 15, 2021
Transition Metal Chemistry, Jul 8, 2023
Physicochemical Problems of Mineral Processing, 2018
This study focused on the leaching of uranium and thorium from a high grade Ethiopian tantalite o... more This study focused on the leaching of uranium and thorium from a high grade Ethiopian tantalite ore using sulfuric acid. The effects of variables such as acid concentration, temperature and leaching time were studied. In general, the leaching efficiency of uranium increases with increasing temperature from 100 to 300 °C whereas the opposite trend was observed for thorium. The amount of uranium leached increased from 69.1% at contact time of 1 hr to 88.6% when the tantalite ore was leached for 3 hrs. On the other hand, for the experiments conditions considered in this study, the leaching behavior of uranium and thorium did not change significantly with varying sulphuric acid concentration from 70 to 90 wt%. Overall, the highest dissolution of uranium and thorium were achieved at 100 °C, 70 wt% H2SO4 concentration and 1 hr contact time.
H2Open journal, Jul 7, 2023
Journal of Experimental Pharmacology
Transition Metal Chemistry
H2Open Journal
In Ethiopia, holy water is used to treat various ailments. This study examined the safety of holy... more In Ethiopia, holy water is used to treat various ailments. This study examined the safety of holy water in May-Hibey, NW Tigray, Ethiopia consumed to treat gastrointestinal ailments. Sensory observation, compositional and elemental analyses of rock samples, and analyses of physicochemical properties and inorganic constituents of holy water samples were conducted. Sensory observation revealed that the water had a musty taste and rotten egg-like odor. Its consumption in drinking rituals caused instant vomiting and loose bowels. Geological studies of rock samples via X-ray diffraction revealed Si (62.456%), Fe (15.441%), and S (7.912%) as major elements. Physicochemical analyses of the holy water samples showed that temperature, electrical conductivity, total dissolved solids, pH, total alkalinity, total hardness, and concentrations of calcium, magnesium, iron, and sulfate were above the permissible limits of the World Health Organization and the Ethiopian Standards Agency. These imply...
International journal of chemical engineering, Mar 8, 2024
Research Square (Research Square), 2024
Journal of the Indian Academy of Wood Science, 2020
ECS Meeting Abstracts, 2016
A Review Approaches for Extractive hydrometallurgy of niobium and tantalum from Ethiopian Kentich... more A Review Approaches for Extractive hydrometallurgy of niobium and tantalum from Ethiopian Kenticha Ores Abstract The Kenticha rare-element pegmatite, a globally important tantalite source in the Neoproterozoic of southern Ethiopia, is a highly fractionated, huge, subhorizontal, sheet-like body, discordantly emplaced in ultramafic host rock. It corresponds to the spodumene subtype of the rare element pegmatite class and belongs to the lithium–cesium–tantalum petrogenetic family. The Kenticha pegmatite is asymmetrically zoned from bottom to top into granitic lower zone, spodumene-free intermediate zone, and spodumene-bearing upper zone. The Kenticha pegmatite is rich in Ta-mineralized rare-element pegmatites. Thus, need to conduct research in enrichment of Ta2O5 and Nb2O5 and extraction of Nb and Ta into metallic form. This paper reviews the successful extraction of Nb and Ta from tanatlite ores. Its success normally depends on the physiochemical properties of the ore, choice of leaching extraction solvent. Currently, HF and methyl-isobutyl Ketone has been used for decomposition and separation of Nb and Ta from tantalite ore. Therefore Kenticha atantalite ore containe vaiaty compositions of elements and higher concentration of Li and U. Thus needs further investigation in extraction process in the sence of removing the use of HF for leaching and replacement of traditional organic solvents by "Green Solvents". This review gives directions for future development of extraction of Kenticha tantalite ore. Keywords: Kenticha; leaching; magnetic separation; pegmatite, rare-element; solvent extraction, sopdumene; tantalite.
Momona Ethiopian Journal of Science
This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff ... more This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff base, through the condensation process of salicylaldehyde and p-toludine, and its Cu and Zn complexes were successfully synthesized. The Schiff base and its complexes were characterized using molar conductivity, Ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and Fourier transform infrared (FTIR) techniques. Accordingly, these characterizations not only confirmed that the synthesized Schiff base acted as N,O bidentate ligand (through azomethine nitrogen and phenoxide oxygen) and chelated with Cu(II) and Zn(II) in the metal-to-ligand ratio of 1:2 but also revealed the characteristic electronic-transition of π→π*/n→π* of the ligand, and ligand-metal charge transfer and d-d of the metal complexes. Moreover, both Cu and Zn complexes recorded weak molar conductance of 54.12 and 51.41 S cm2 mol-1, respectively. Further, their antibacterial activities were evaluated by disc ...
Journal of Experimental Pharmacology
Momona Ethiopian Journal of Science
This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff ... more This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff base, through the condensation process of salicylaldehyde and p-toludine, and its Cu and Zn complexes were successfully synthesized. The Schiff base and its complexes were characterized using molar conductivity, Ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and Fourier transform infrared (FTIR) techniques. Accordingly, these characterizations not only confirmed that the synthesized Schiff base acted as N,O bidentate ligand (through azomethine nitrogen and phenoxide oxygen) and chelated with Cu(II) and Zn(II) in the metal-to-ligand ratio of 1:2 but also revealed the characteristic electronic-transition of π→π*/n→π* of the ligand, and ligand-metal charge transfer and d-d of the metal complexes. Moreover, both Cu and Zn complexes recorded weak molar conductance of 54.12 and 51.41 S cm2 mol-1, respectively. Further, their antibacterial activities were evaluated by disc ...
Journal of Food Quality
Adansonia digitata L (Baobab) is a large plant species which thrives in many semiarid regions of ... more Adansonia digitata L (Baobab) is a large plant species which thrives in many semiarid regions of the world with remarkable economic and nutritional importance. In Ethiopia, it grows in deserts and hot lowlands. Industrially, baobab fruit pulp (powder) is used for producing good quality jams. This study was carried out to (a) develop a formulation protocol for producing high-quality baobab jam, (b) characterize the jam using standard physicochemical, microbiological, and sensory evaluation methods, and (c) examine the effects of time and temperature of storage on the quality as well as shelf life of the jam. Out of the seven formulations tested, a formulation enriched with 55 g table sugar, 45 g baobab fruit powder, 0.50 g ascorbic acid, and 0.40 to 0.60 g citrus pectin jelling (formulation no. 6) and another one enriched with 60 g table sugar, 40 g baobab fruit powder, 0.50 g ascorbic acid, and 0.40 to 0.60 g citrus pectin jelling (formulation no. 7) resulted in the best jam product...
International Journal of Analytical Chemistry
Baobab (Adansonia digitata L) is a large tree species growing in semiarid and arid lowlands of Et... more Baobab (Adansonia digitata L) is a large tree species growing in semiarid and arid lowlands of Ethiopia and other places. The plant is valued by natives for its contributions as a cash crop and livelihood tree. Previous studies using samples from different countries have documented their phytochemical profiles and nutritional and health benefits. This study explored the phytochemical constituents and biological activities of fruit pulp extracts of baobab collected from Tekeze Valley, Tigrai, Ethiopia. To this end, qualitative phytochemical screening tests, quantitative phytochemical analyses, and gas chromatography-mass spectrometry (GC-MS) analysis were carried out using aqueous extract. Analyses of antioxidant activities were also conducted with aqueous- and methanol-extracts using of 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), and hydroxyl (OH) radical scavenging activity assays. The qualitative screening tests showed the presence of flavonoids, phenols, saponins, ta...
International Journal of Analytical Chemistry, Apr 4, 2020
International Journal of Analytical Chemistry, Feb 15, 2021
Transition Metal Chemistry, Jul 8, 2023
Physicochemical Problems of Mineral Processing, 2018
This study focused on the leaching of uranium and thorium from a high grade Ethiopian tantalite o... more This study focused on the leaching of uranium and thorium from a high grade Ethiopian tantalite ore using sulfuric acid. The effects of variables such as acid concentration, temperature and leaching time were studied. In general, the leaching efficiency of uranium increases with increasing temperature from 100 to 300 °C whereas the opposite trend was observed for thorium. The amount of uranium leached increased from 69.1% at contact time of 1 hr to 88.6% when the tantalite ore was leached for 3 hrs. On the other hand, for the experiments conditions considered in this study, the leaching behavior of uranium and thorium did not change significantly with varying sulphuric acid concentration from 70 to 90 wt%. Overall, the highest dissolution of uranium and thorium were achieved at 100 °C, 70 wt% H2SO4 concentration and 1 hr contact time.
H2Open journal, Jul 7, 2023
Journal of Experimental Pharmacology
Transition Metal Chemistry
H2Open Journal
In Ethiopia, holy water is used to treat various ailments. This study examined the safety of holy... more In Ethiopia, holy water is used to treat various ailments. This study examined the safety of holy water in May-Hibey, NW Tigray, Ethiopia consumed to treat gastrointestinal ailments. Sensory observation, compositional and elemental analyses of rock samples, and analyses of physicochemical properties and inorganic constituents of holy water samples were conducted. Sensory observation revealed that the water had a musty taste and rotten egg-like odor. Its consumption in drinking rituals caused instant vomiting and loose bowels. Geological studies of rock samples via X-ray diffraction revealed Si (62.456%), Fe (15.441%), and S (7.912%) as major elements. Physicochemical analyses of the holy water samples showed that temperature, electrical conductivity, total dissolved solids, pH, total alkalinity, total hardness, and concentrations of calcium, magnesium, iron, and sulfate were above the permissible limits of the World Health Organization and the Ethiopian Standards Agency. These imply...