Adama University

About: Adama University is a education organization based out in Nazrēt, Ethiopia. It is known for research contribution in the topics: Population & Adsorption. The organization has 840 authors who have published 1010 publications receiving 5547 citations. The organization is also known as: Adama Science and Technology University & ቴክኖሎጂ ዩኒቨርሲቲ, አዳማ ሳይንስና ቴክኖሎጂ ዩኒቨርሲቲ.

Magmatic evolution and post-crystallization hydrothermal activity in the early Cretaceous Pingtan intrusive complex, SE China: records from apatite geochemistry

Abstract: We conducted in situ geochemical (major-, trace-element and Nd isotope compositions) analyses on apatite, together with whole-rock geochemistry from gabbro, granodiorite and granite in the Cretaceous Pingtan intrusive complex (SE China), aiming to investigate the roles of magmatic evolution and post-crystallization hydrothermal activity during its formation. Regardless of limited range in initial Nd isotopes ranges in both bulk rock [ɛNd(t) = − 2.0 to − 0.4] and associated apatite [ɛNd(t) = − 3.8 to − 0.4] from the Pingtan igneous complex, the apatite shows wide compositional and textural variations from gabbro to granite. Apatite from the gabbro (Group 1) displays a zoning structure characterized by increasing F and Sr but decreasing Cl and LREE from the core to rim. The increase of Sr from the core to rim is attributed to plagioclase accumulation, and the decreases of LREE and Cl from the core to rim is caused by post-crystallization hydrothermal activity. The high Cl content in the primitive Group 1 apatite further suggests derivation of the mafic magma from a mantle wedge metasomatized by Cl-rich sediment. In contrast, apatite from the granite (Group 2) has the lowest Cl and Sr but the highest F and Yb contents, which can be further divided into two subgroups of Group 2A and 2B based on texture and composition. Group 2A apatite shows homogenous composition with trace elements similar to apatite from I-type granite. The positive correlation between Sr and Eu/Eu* indicates that crystallization of Group 2A apatite is co-precipitated with a feldspar-dominated fractionation. However, Group 2B apatite contains mineral inclusion of monazite and has the highest U content and F/Cl ratio, resembling apatite from S-type or highly fractionated I-type granite. These features are consistent with the influence of post-crystallization hydrothermal activity. Apatite from the granodiorite (Group 3) has an intermediate composition between Group 1 and 2A apatite and shows a homogenous texture with trace element features similar to that from I-type granite. Group 3 apatite defined a negative correlation of Sr with La/Yb, which is attributed to fractional crystallization of hornblende and plagioclase. The geochemistry of apatite indicates that the gabbro and granitic rocks of the Pingtan intrusive complex were, respectively, derived from the mantle and crustal sources with similar ɛNd(t) values. Our study, therefore, demonstrates that apatite geochemistry has a potential to monitor the magma source, magmatic evolution and post-crystallization fluid activity of an igneous complex.

Magnetite nanoparticle decorated reduced graphene oxide for adsorptive removal of crystal violet and antifungal activities

Abstract: This work reports the synthesis and application of magnetic rGO/Fe3O4 NCs using a pod extract of Dolichos lablab L. as areducing agent. GO was synthesized by a modified Hummers method, however GO was reduced using the plant extract to produce rGO. The as-synthesized rGO/Fe3O4 NCs were characterized by UV-vis spectrophotometer, Fourier transform infrared (FT-IR) spectroscopy, FT-Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy supported with energy dispersed X-ray spectroscopy (FESEM-EDX), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The synthesis of magnetic rGO/Fe3O4 NCs was confirmed from characterization results of FT-Raman, TEM and VSM. The FT-Raman results showed the D and G bands at 1306.92 cm−1 and 1591 cm−1 due to rGO and a peak at around 589 cm−1 due to Fe3O4 NPs that were anchored on rGO sheets; TEM results showed the synthesis of Fe3O4 with an average particle size of 8.86 nm anchored on the surface of rGO sheets. The VSM result confirmed the superparamagnetic properties of the rGO/Fe3O4 NCs with a saturation magnetization of 42 emu g−1. The adsorption capacity of rGO/Fe3O4 NCs towards crystal violet (CV) dye was calculated to be 62 mg g−1. The dye removal behavior fitted well with the Freundlich isotherm and the pseudo-second-order kinetic model implies possible chemisorption. Besides, rGO/Fe3O4 NCs showed antifungal activities against Trichophyton mentagrophytes and Candida albicans by agar-well diffusion method with a zone inhibition of 24 mm and 21 mm, respectively. Therefore, rGO/Fe3O4 NCs can be used as an excellent adsorbent to remove organic dye pollutants and kill pathogens.

The current status, challenges and prospects of using biomass energy in Ethiopia.

Abstract: Despite enormous challenges in accessing sustainable energy supplies and advanced energy technologies, Ethiopia has one of the world's fastest growing economies. The development of renewable energy technology and the building of a green legacy in the country are being prioritized. The total installed capacity for electricity generation in Ethiopia is 4324.3 MW as on October, 2018. Renewable energy accounts for 96.5% of total generation; however, despite the county's enormous biomass energy potential, only 0.58% of power is generated using biomass. Ethiopia has surplus woody biomass, crop residue and animal dung resources which comprise about 141.8 million metric tons of biomass availability per year. At present the exploited potential is about 71.9 million metric tons per year. This review paper provides an in-depth assessment of Ethiopia's biomass energy availability, potential, challenges, and prospects. The findings show that, despite Ethiopia's vast biomass resource potential, the current use of modern energy from biomass is still limited. As a result, this study supports the use of biomass-based alternative energy sources without having a negative impact on the socioeconomic system or jeopardizing food security or the environment. This finding also shows the challenges, opportunities and possible solutions to tackle the problem to expand alternative energy sources. The most effective techniques for producing and utilizing alternate energy sources were also explored. Moreover, some perspectives are given based on the challenges of using efficient energy production and sustainable uses of biomass energy in Ethiopia as it could be also implemented in other developing countries. We believe that the information in this review will shed light on the current and future prospects of biomass energy deployment in Ethiopia.

GTIKF- Gabor-Transform Incorporated K-Means and Fuzzy C Means Clustering for Edge Detection in CT and MRI

Abstract: The detection of edges is the one of the important stage in the application, associated with the machine vision, computer vision and the image processing. It is most commonly and highly preferred in the area were the extraction or the detection of the attribute are necessary. As the manual methods of diagnosis in the medical images acquired from the CT (computed tomography) and the MRI (magnetic resonance images) are very tedious and as well as time consuming, the paper puts forth the methodology to detect the edges in the CT and the MRI by employing Gabor Transform as well as the soft and the hard clustering. This proposed method is highly preferred among the image with dynamic variations. The technique used in the paper is evaluated using 4500 instance of the MRI and 3000 instance of CT. The results on the basis of the figure of merit (FOM) and Misclassification rate (MCR) are compared with other standard approaches and the performance was evinced.