824 research outputs found
Phytotoxic, Antibacterial and Haemagglutination activities of the aerial parts of Myrsine africana L.
The crude methanolic extract and various fractions derived from the aerial parts of Myrsine africana were screened in vitro for possible phytotoxic, antibacterial and haemagglutination activities. Moderate phytotoxic activity (31.25 %) was observed against Lemna minor L at 1000 μg/ml by chloroform fraction (CHCl3). The crude methanolic extract and CHCl3 fraction showed good antibacterial activity against Klebsiella pneumoniae (MIC50 = 2.45 and 2.1 mg/ml respectively). The crude methanolic extract and other fractions showed moderate activity against tested bacterial strains. The CHCl3 and aqueous fractions showed no activity against Escherichia coli. Similarly, the ethyl acetate (EtOAc) and butanol (BuOH) fractions were found to be non active against Bacillus pumilus and Enterobacter aerogenes, respectively. Moderate haemagglutination activity was observed against human red blood cells (RBCs) of blood group AB- by crude methanolic extract and CHCl3 fraction and against AB+ by aqueous fraction, respectively. The plant specie can be a source of antibacterial agent(s) and phytolectins.Keywords: Myrsine africana, phytotoxicity, haemagglutination, antibacterial and MIC5
Performance Enhancement of Wearable Antenna Using High Impedance Surfaces
This paper presents a novel textile wearable antenna that has been designed to operate at Wi-Fi bands of 2.4GHz & 5.8GHz. Antenna performance in free space environment showed Gain of 1.8dBi at 2.4GHz and 4.5dBi at 5.8GHz. However, performance deteriorated when antenna was operated near human body which is lossy and complex in nature. For mitigating the human body effect on antenna performance, high impedance surface (HIS) was designed and integrated with this textile antenna. Due to shielding effect of HIS, antenna Gain increased to 8dBi at 2.4GHz and 9dBi at 5.8GHz. The SAR values were also reduced to 0.682W/Kg at 2.4GHz and 0.0692W/Kg at 5.8GHz for 10g tissue. The proposed antenna was also tested under bending and crumpling conditions. It was observed that antenna performance was not significantly deteriorated. The proposed textile antenna can have exciting applications in emerging wearable technologies
Identification and predictive control of spray tower system using artificial neural network and differential evolution algorithm
Increasing demands for high precision environmental protection measures regarding
particulate matter (PM) emission from industrial productions and non-linear
characteristics of spray tower system lead to the application of an intelligent control
technique to adequately deal with these complexities. This includes the use of an artificial
neural network (ANN) based predictive control strategy and differential evolution (DE)
optimization algorithm to determines the optimal control signal, uk (liquid droplet size,
d D ) by minimizing the cost function such that the output is set below the allowable PM
concentration. A recurrent neural network (RNN) based on non-linear autoregressive with
exogenous inputs (NARX) model has been used to develop the dynamic model of the
system. The data for the training was obtained from empirical model of a spray tower
system which involved 500 data sets representing the process input and the output PM
concentration. The control process was implemented using MATLAB code by considering
two DE optimization strategies; DE/best/1/bin and DE/rand/1/bin. The effectiveness of the
controllers was demonstrated for different iterations by tuning the control parameters such
as the prediction horizon, weight factor and control horizon. From the control response, it
can be seen that the controller for the DE/rand/1/bin does a very good job of controlling
the PM below the WHO allowable emission rate of 20g/μ
Concurrent Lateral Condyle Mass Fracture With Olecranon Fracture: A Case Report and Brief Review of Literature
Introduction: There is very limited literature describing the association of lateral condyle mass (LCM) fracture of the distal humerus associated concurrently with olecranon fracture. Herein, a case is reported of a displaced LCM fracture with displaced olecranon fracture, due to complex trauma while getting out of a vehicle, which was managed by open reduction and internal fixation.
Case Presentation: A 4.5- year- old boy suffered severe pain and swelling around his right elbow due to trauma which he suffered while trying to get out of a vehicle which was in motion. Plain radiographs of the anteroposterior, lateral, and oblique views showed a displaced lateral mass fracture associated with a displaced olecranon fracture. Open reduction and internal fixation was carried out and near normal function was achieved.
Conclusions: In view of the paucity of literature and rare incidence of this injury, this case report highlights the need to be aware of other injuries which can occur in association with LCM fractures in children
CFD based parametric analysis of gas flow in a counter-flow wet scrubber system
Environmental protection measures regarding industrial emissions and tightened regulations for air pollution led to the selection of a counter-flow wet scrubber system based on applicability and economic considerations. The flow dynamics of gas transporting particulate matter and gaseous contaminants is a key factor which should be considered in the scrubber design. In this study, gas flow field were simulated using ANSYS Fluent computational fluids dynamic (CFD) software based on the continuity, momentum and k-ε turbulence model so as to obtain optimum design of the system, improve efficiency, shorten experimental, period and avoid dead zone. The result shows that the residuals have done a very good job of converging at minimum number of iterations and error of 1E-6. The velocity flow contours and vectors at the inlet, across the scrubbing chamber and the outlet shows a distributed flow and the velocity profiles have fully conformed to the recommended profile for turbulent flows in pipes. The total pressure within the scrubber cross-section is constant while the minimum and maximum pressure drops was obtained to be 0.30 pa and 3.03 pa which has conformed to the recommended pressure drop for wet scrubbers. From the results obtained, it can be deduced that the numerical simulation using CFD is an effective method to study the flow characteristics of a counter-flow wet scrubber system
Genetic Variation of Flowering Trait in Maize (Zea mays L.) under Drought Stress at Vegetative and Reproductive Stages
A study was conducted under water stress in vegetative and reproductive growth stages at two locations (Shambat and Medani) in Sudan during the season (2003/2004). Genotypic and phenotypic variability, genetic advance and heritability in a broad sense were estimated in a split-plot layout within randomized complete block design with three replications. Fifteen genotypes of maize were used for the study. Phenotypic correlation coefficient between grain yield and 25%, 50% and 95% of flowering trait anthesis and silking were evaluated. All flowering stages were found significant differences among the genotypes, except days to 95% anthesis. Significant differences among water treatments were observed for days to 25% silking at Medani. High heritability, genotypic coefficient of variation and genetic advance were exhibited by days to 25% silking. Grain yield was significantly and negatively associated with days to (50% and 95%) silking. Based on the results drought stress at vegetative and reproductive stages of maize results in a drastic reduction in grain yield, and flowering character would be the important selection, creation for maize improvement under drought stress. Keywords: Maize (Zea mays L.), Genetic variability, heritability, correlation, flowering, drought
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