Antioxidant, anti-inflammatory activity, and phytochemical constituents of ficus (Ficus amplissima Smith) bark

In the present investigation, phenolics (36.6 g gallic acid equivalents (GAE)/100 g extract), tannin (21.6 g GAE/100 g extract), and flavonoid content (67.5 g rutin equivalents/100 g extract) were found to be highest in acetone extract. Ficus (Ficus amplissima) acetone extract showed maximum antioxidant activity in phosphomolybdenum (958.8 mg ascorbic acid equivalents/g extract), DPPH (1.6 μg/mL), ferric reducing antioxidant power (2,993 mmol Fe (II)/g extract), and metal chelating (39.7 mg EDTA equivalents/g extract) assays. In anti-inflammatory study, 400 mg/kg acetone extract showed maximum reduction in the paw volume compare to indomethacin. GC-MS analysis indicated that bark contain rich source of non-polar compounds like Lup-20(29)-en-3-yl acetate (33.04%). Hence, Ficus can be valuable source for antioxidant and anti-inflammatory and seemed to be applicable in medicine.     

Study of slip velocity and application of drift-flux model to slip velocity in a liquid–solid circulating fluidized bed

The increasing applications of liquid–solid circulating fluidized bed in chemical/biochemical industries require a better understanding of hydrodynamics of such system. This work aims to experimentally investigate the slip between the phases in a LSCFB. The variation of slip velocity with superficial liquid velocity, solids velocity, bed voidage and particle size and density is discussed. The apparent slip velocity of the phases is higher than the particle terminal velocity of a single particle. The R–Z equation developed based on the homogenous flow characteristics underpredicts the slip velocity in a LSCFB. The drift-flux model which considers the radial non-uniformity and slip between the phases was applied to the data of the present study. The predicted value by the model agreed with the apparent slip velocity well. The study also proposed an empirical correlation to predict the slip velocity. The empirical correlations aggress well with the experimental data.     

An optimization study for preventing silica gelation and improving filtration effectiveness during pH reduction of high concentration silica solutions

The steam generation processes at the steam-assisted gravity drainage facilities result in huge quantities of wastewater streams, which are characterized by high pH and high silica levels. These concentrated streams need to be neutralized before their disposal via down-hole injection. The neutralization of these high-pH brines results in the formation of a gel-like substance, which makes it difficult to filter the amorphous silica gel. The wastewater used in this study was synthetically prepared using sodium metasilicate to mimic high-concentration silica solutions. Our experiments did not show any advantage of a two-step pH-neutralization process over the single-step process for suppressing silica gelation. A systematic experimental campaign was undertaken to investigate the effects of SiO₂ concentration, NaCl:SiO₂ ratio, and pH on the residual silica concentration, percent silica removal, filtration rate, and filtration effectiveness. For NaCl:SiO₂ ratios higher than 4.5, silica precipitation during pH reduction did not lead to the formation of gel or sol. The response surface methodology (RSM), based on the Doehlert design of experiments, was implemented to optimize the responses and provide high efficacy with fewer experiments. The results from the analysis of variance (ANOVA) analyses of the experimental data were used to evaluate the significance of each term in the quadratic model. 3D response surfaces and 2D contour plots were generated for determining the optimal ranges of independent factors for achieving the maximum silica removal, the highest filtration rate, the best filtration effectiveness, and the minimum residual silica concentration. An optimum operating region was established from the RSM analysis and overlay plot.     

RMCARTAM For DDoS Attack Mitigation in SDN Using Machine Learning

The impact of a Distributed Denial of Service (DDoS) attack on Software Defined Networks (SDN) is briefly analyzed. Many approaches to detecting DDoS attacks exist, varying on the feature being considered and the method used. Still, the methods have a deficiency in the performance of detecting DDoS attacks and mitigating them. To improve the performance of SDN, an efficient Real-time Multi-Constrained Adaptive Replication and Traffic Approximation Model (RMCARTAM) is sketched in this article. The RMCARTAM considers different parameters or constraints in running different controllers responsible for handling incoming packets. The model is designed with multiple controllers to handle network traffic but can turn the controllers according to requirements. The multi-constraint adaptive replication model monitors different features of network traffic like rate of packet reception, class-based packet reception and target-specific reception. According to these features, the method estimates the Replication Turning Weight (RTW) based on which triggering controllers are performed. Similarly, the method applies Traffic Approximation (TA) in the detection of DDoS attacks. The detection of a DDoS attack is performed by approximating the incoming traffic to any service and using various features like hop count, payload, service frequency, and malformed frequency to compute various support measures on bandwidth access, data support, frequency support, malformed support, route support, and so on. Using all these support measures, the method computes the value of legitimate weight to conclude the behavior of any source in identifying the malicious node. Identified node details are used in the mitigation of DDoS attacks. The method stimulates the network performance by reducing the power factor by switching the controller according to different factors, which also reduces the cost. In the same way, the proposed model improves the accuracy of detecting DDoS attacks by estimating the features of incoming traffic in different corners.     

Analysis of Mechanical and Tribological Properties of Silicon Incorporated Diamond like Carbon Nanocomposite Coating

Silicon - The Silicon (Si) contained diamond like carbon (DLC) nanocomposite were prepared by using thermal chemical vapour deposition (CVD) technique by varying the acetylene (C2H2) flowrates. The...