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.

Dual fuel engines fueled with three gaseous and biodiesel fuel combinations

Abstract: Alternative fuels have numerous advantages over fossil fuels as they are renewable, biodegradable, provide energy security and foreign exchange savings, and help in addressing environmental concern...

Load balancing techniques: Major challenge in Cloud Computing - a systematic review

Abstract: Cloud Computing is an emerging area in the field of information technology (IT). Load balancing is one of the main challenges in cloud computing. It is a technique which is required to distribute the dynamic workload across multiple nodes to ensure that no single node is overloaded. Load balancing techniques help in optimal utilization of resources and hence in enhancing the performance of the system. The goal of load balancing is to minimize the resource consumption which will further reduce energy consumption and carbon emission rate that is the dire need of cloud computing. This determines the need of new metrics, energy consumption and carbon emission for energy-efficient load balancing in cloud computing. This paper mainly focused on the concept of load balancing technique in cloud computing, the existing load balancing techniques and also discusses the different qualitative metrics or parameters like performance, scalability, associated overhead etc.

Antibacterial Activity of Coumarins and Carbazole Alkaloid from Roots of Clausena anisata.

Abstract: Clausena anisata is one of the medicinal plants used traditionally for treatment of parasitic infections, irritation (boils, ringworm, and eczema), flatworm infestations, influenza, abdominal cramps, and constipation. Phytochemical screening test of dichloromethane/methanol (1 : 1) roots extract revealed the presence of flavonoids, phytosterols, coumarins, phenols, alkaloids, tannins, terpenoids, and free reducing sugars and the absence of saponins. Silica gel column chromatographic separation of the dichloromethane/methanol (1 : 1) extract afforded a carbazole alkaloid derivative of heptazoline (1) and three coumarins (2–4), including the known coumarins imperatorin (3) and chalepin (4). Structures of the compounds were elucidated by spectroscopic techniques (IR, 1H NMR, 13C NMR, and DEPT-135). Antibacterial activity of the crude extracts and isolated compounds was screened using agar diffusion method against strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Bacillus substilis. The results of antibacterial test revealed derivative of heptaphylline (1) and imperatorin (3) exhibited comparable antibacterial activity against S. aureus and B. substilis (14 and 13 mm zone of inhibition, respectively) to that of ciprofloxacin (15 mm zone of inhibition) at a concentration of 20 µg/mL. Chalepin (4) revealed more antibacterial activity against B. substilis (16 mm zone of inhibition) compared to ciprofloxacin (15 mm).

Facile green synthesis of fluorescent carbon quantum dots from citrus lemon juice for live cell imaging

Abstract: Facile and green one pot hydrothermal method was used for synthesis of fluorescent carbon quantum dots (CQDs) using citrus lemon juice as precursor. The synthesized CQDs were characterized using UV–Vis spectrophotometer, fluorescence spectrometer, transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), field emission scanning electron microscope equiped with energy dispersive X-ray spectroscopy (FESEM-EDS) and fluorescence microscopy. The obtained CQDs have high photoluminescence of 10.20% quantum yield. The photoluminescence intensity of CQDs depends on pH of the solution and maximum intensity obtained at pH of 6. The particle size of the carbon dots were distributed in narrow range of 2–10 nm with an average of 5.8 nm. The highly water soluble CQDs have high cell viability even at high concentration which rich up to 85%. MTT assay was used to investigate the potential application of CQDs and the results indicated that the material can be used as florescent probe in the cell imaging.

A Novel and Simplest Green Synthesis Method of Reduced Graphene Oxide Using Methanol Extracted Vernonia Amygdalina: Large-Scale Production

Abstract: The large-scale production of high-quality graphene is the major focus of scientists and engineers recently. However, its massive manufacturing routes from its precursor graphene oxide (GO) are involved in the production of toxic gasses and consist of hazardous explosive steps that severely hurt and threaten ecological balance and human health. Therefore, in this study, we investigated the green, effective, and economical approach for the synthesis of graphene by using Vernonia amygdalina (VA) plant leaf extracts for the effective and efficient reduction of GO. The nonexplosive two-step synthesis of GO in a short period of time in the absence of an ice bath was used in this study. The appropriate solvent for the extraction of VA for the green synthesis of graphene was methanol, and the reducing and capping agent in the plant extract was identified to be terpenoids and polyphenols. The graphene/rGO obtained this way was characterized by UV-VIS, XRD, FTIR, SEM, HR-TEM, and EDAX that confirmed the successful reduction of GO to graphene under the hydrothermal process. The HR-TEM images showed the development of few layers of graphene. The FTIR result also shows the complete reduction of GO. Hence, methanol extracted VA leaves consisted of the most appropriate compounds for reducing and capping agent in the green synthesis and could be the preferred method for the large-scale production of graphene-based materials.