Biodegradation of Chrysene by Consortium of Bacillus Cereus and Pseudomonas Putida in Petroleum Contaminated-soil on Slurry-phase Bioreactor

Pollution by chrysene compounds in the polluted soil of petroleum, due to exploration activities, production and disposal of petroleum waste into the environment causing serious damage to the ecosystem environment, became the target of processing with bacteria as a model of remediation of pollution sites. Thus, the study focused on the use of a bacterial consortium to degrade chrysene in petroleum-contaminated soil. The study was conducted by mixing 20:80 (% wt) of contaminated soil with water. The consortium of Bacillus cereus and Pseudomonas putida 10%(v/v) and 15%(v/v) bacteria with ratios; 2:3; 1:1; 3:2 is inserted into the slurry bioreactor. Biodegradation process is run with agitation of 100 rpm and temperature 26<sup>o</sup>C – 30<sup>o</sup>C and in aeration. Identification of chrysene using gas chromatography–mass spectrometry (GCMS) and bacterial populations with haemycitometer. The initial concentration of chrysene is 24.48 ng/μL. After 49 days remediation period for a 10% (v/v) reduced chrysene bacteria consortium and bacterial populations were 8.68 ng/μL; 7.56 ng/μL; and 8.07 ng/μL; with biodegradation rate is 67.01%; 69.10%; And 64.54%. As for the 15% (v/v) bacteria consortium with the same ratio, chrysene was degraded to 2.60 ng/μL; 1.57 ng/μL; and 2.02 ng/μL and the measured chrysene biodegradation rate was 89.39%; 93.58%; And 91.73%. These findings suggest that the percentage of low crude oil is degraded because of the increasing concentration of crude oil

Optimum Design of Doherty RFPA for Mobile WiMAX Base Stations

YesRF power amplifiers in mobile WiMAX transceivers operate in an inherently nonlinear manner. It is possible to amplify the signal in the linear region, and avoid distortion, using output power back-off; however, this approach may suffer significant reduction in efficiency and power output. This paper investigates the use of Doherty techniques instead of back-off, to simultaneously achieve good efficiency and acceptable linearity. A 3.5 GHz Doherty RFPA has been designed and optimized using a large signal model simulation of the active device, and performance analysis under different drive levels. However, the Doherty EVM is generally poor for mobile WiMAX. Linearity may be improved by further digital pre-distortion, and a simple pre-distortion method using forward and reverse AM-AM and AM-PM modeling. Measurements on the realized amplifier show that this approach satisfies the EVM requirements for WiMAX base stations. It exhibits a PAE over 60%, and increases the maximum linear output power to 43 dBm, whilst improving the EVM

Gum exudates of Acacia senegal linn is an alternative binding agent in Drosophila melanogaster culture for laboratory maintenance of stocks

The gum exudates of Acacia senegal Linn was utilized as a single agent or in combination with agar-agar in the formulation of Drosophila diet. Eight (8) corn-meal diets were formulated in two sets consisting of 15 – 40 % (w/w) A. senegal as a single binding agent or a mixture of A. senegal in the ratios of 1:5, 1:2, 1:1 and 2:1 to agar-agar per 100 g corn-meal diet. Biochemical markers of toxicity were analyzed spectrophotometrically. Standard methods of AOAC were employed to determine the physicochemical and proximate compositions of the formulated corn-meal diets. The results from this study showed high level of safety of the gum on adult Drosophila melanogaster (Harwich strain) of both sexes and of the same lineage. LC50 > 100 mg/g with insignificant mortality in all groups at varying concentration (1 – 100 mg/g) of the gum exudate was observed after 7 days of treatment. Significant increases in eclosion in the A. senegal – exposed flies at concentrations of 2, 4 and 5 mg/g diet was also observed after the treatment. A normal trend in locomotor activity was observed in all groups when flies were subjected to negative geotaxic assay, however, at concentrations of 50 mg/g there was an impairment in locomotion. The formulated A. Senegal containing diets have shown varying differences in physicochemical properties, even though no significant changes in the biochemical parameters including SOD1, Catalase and GST in all groups were seen. The collective findings of the present study revealed that the gum exudates of A. senegal L. may be a cost-effective alternative of agar-agar in corn-meal diet for laboratory maintenance of Drosophila melanogaster stocks

Explanation of DC/RF Loci for Active Patch Antennas

YesA characteristic loop locus of dc power versus RF output power was observed as the frequency was varied around the optimum point of an operational active antenna. A new technique was introduced into the simulation, plotting the dependence of parameters such as supply current, efficiency or output power on internal impedance as seen by the naked transistor. It is now clear that the loop was formed as a consequence of the interaction of the transistor packaging elements with the patch impedances

A Survey on Energy Optimization Techniques in UAV-Based Cellular Networks: From Conventional to Machine Learning Approaches

Wireless communication networks have been witnessing an unprecedented demand due to the increasing number of connected devices and emerging bandwidth-hungry applications. Albeit many competent technologies for capacity enhancement purposes, such as millimeter wave communications and network densification, there is still room and need for further capacity enhancement in wireless communication networks, especially for the cases of unusual people gatherings, such as sport competitions, musical concerts, etc. Unmanned aerial vehicles (UAVs) have been identified as one of the promising options to enhance the capacity due to their easy implementation, pop up fashion operation, and cost-effective nature. The main idea is to deploy base stations on UAVs and operate them as flying base stations, thereby bringing additional capacity to where it is needed. However, because the UAVs mostly have limited energy storage, their energy consumption must be optimized to increase flight time. In this survey, we investigate different energy optimization techniques with a top-level classification in terms of the optimization algorithm employed; conventional and machine learning (ML). Such classification helps understand the state of the art and the current trend in terms of methodology. In this regard, various optimization techniques are identified from the related literature, and they are presented under the above mentioned classes of employed optimization methods. In addition, for the purpose of completeness, we include a brief tutorial on the optimization methods and power supply and charging mechanisms of UAVs. Moreover, novel concepts, such as reflective intelligent surfaces and landing spot optimization, are also covered to capture the latest trend in the literature.Comment: 41 pages, 5 Figures, 6 Tables. Submitted to Open Journal of Communications Society (OJ-COMS

A simple and rapid method for blood collection from walking catfish, Clarias batrachus (Linneaus, 1758)

Blood is collected from experimental animals for a wide range of scientific purposes including; hematology, clinical biochemistry parameters, immunology, studies in bacteriology, parasitology and investigations in reproductive performance and health. The number of methods employed to collect blood from fish include; the puncture of caudal vein, dorsal aorta or cardiac vessels and the severance of the caudal vein. Unfortunately, all these procedures are practically found to be slow and stressful to Clarias batrachus, including the popular caudal vein approach, likely due to the small size of caudal veins relative to the size of the species. In line with the universal ethical recommendations for taking blood from small research animals, we propose an alternative one-operator approach for C. batrachus that is simple, rapid and without the need to sacrifice the fish as with other methods. This procedure targets the dorsal aorta (a relatively larger blood vessel) in a sedated fish, punctured by inserting a needle directly from the anterior part of the anal fin about 2-5 mm behind the genital papilla, to draw the desired amount of blood. The technique is a one-operator procedure not requiring the help of an assistant or any special equipment to restrain the fish. The operation of the protocol is unique since it permits the continuous collection of blood from the same experimental fish over a varied time course and reduces the need for a large number of replicate animals. The advantages of the proposed protocol are also highlighted and discussed in detail

A survey of machine learning applications to handover management in 5G and beyond

Handover (HO) is one of the key aspects of next-generation (NG) cellular communication networks that need to be properly managed since it poses multiple threats to quality-of-service (QoS) such as the reduction in the average throughput as well as service interruptions. With the introduction of new enablers for fifth-generation (5G) networks, such as millimetre wave (mm-wave) communications, network densification, Internet of things (IoT), etc., HO management is provisioned to be more challenging as the number of base stations (BSs) per unit area, and the number of connections has been dramatically rising. Considering the stringent requirements that have been newly released in the standards of 5G networks, the level of the challenge is multiplied. To this end, intelligent HO management schemes have been proposed and tested in the literature, paving the way for tackling these challenges more efficiently and effectively. In this survey, we aim at revealing the current status of cellular networks and discussing mobility and HO management in 5G alongside the general characteristics of 5G networks. We provide an extensive tutorial on HO management in 5G networks accompanied by a discussion on machine learning (ML) applications to HO management. A novel taxonomy in terms of the source of data to be utilized in training ML algorithms is produced, where two broad categories are considered; namely, visual data and network data. The state-of-the-art on ML-aided HO management in cellular networks under each category is extensively reviewed with the most recent studies, and the challenges, as well as future research directions, are detailed