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Item Use of redox mediators for the enhanced degradation of selected nitrophenols(2019) Yaseen; Mohammed; Manu; Basavaraju; Kudri; Najaruddin; Govardhanaswamy; H. S.In the present study, sequential anaerobic-aerobic treatment was used for the enhanced degradation of selected nitrophenols. Five identical reactors were used to assess the degradation of 2-nitrophenol and 2,4-dinitrophenol. Reactor 1 was used as control, and another four reactors were operated in anaerobic phase followed by sequential aerobic treatment. The performance of reactors was studied for nitrophenol concentrations of 5, 10, 20 and 40 mg/l and in next phase effect of redox mediators [lawsone and anthraquinone sulphonic acid (AQSA)], along with kinetics of degradation studied for 40 mg/l of nitrophenols. More than 98% degradation of nitrophenols was achieved at lower concentrations but for 40 mg/l removal percentage was reduced, and also COD inhibition was observed. However, with the addition of redox mediators, both nitrophenols and COD removal percentage were greater than 95% and 85%, respectively. Kinetics of degradation revealed that the rate of degradation was found to increase with the increase in concentration of redox mediators from 10 to 20 mg/l, and it was found that degradation was faster with the use of AQSA in comparison with lawsone solution. It indicates that use of redox mediators is favourable for the enhanced degradation of nitrophenols. Sequential anaerobic-aerobic treatment is possible potential treatment method for treating nitrophenolic wastewaters.Item Studies on electrodeposited Zn-Fe alloy coating on mild steel and its characterization(2019) Bhat R.; Hegde A.C.Chloride bath containing ZnCl2.7H2O, FeCl2.H2O and a combination of sulphamic acid and citric acid (SA+CA) were optimized for electrodeposition of bright Zn-Fe alloy coating on the mild steel. Bath constituents and operating parameters were optimized by the Hull cell method for highest performance of the coating against corrosion. The effect of current density and temperature on deposit characteristics such as corrosion resistance, hardness, thickness, cathode current efficiency and glossiness, were studied. Potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) methods were used to assess corrosion behaviour. Surface morphology of coatings was examined using scanning electron microscopy (SEM). The Zn-Fe alloy with intense peaks corresponding to Zn (100) and Zn (101) phases, evidenced by X-ray diffraction (XRD) study, showed the highest corrosion resistance. A new and economical chloride bath for electrodeposition of bright Zn-Fe alloy coating on mild steel was proposed and discussed. © 2019 by the authors.Item Probiotic and biotherapeutic properties of tannase positive lactobacillus plantarum MTCC 2621 strain(2019) Oriabinska L.B.; Prasanna D.B.; Lazarenko L.M.The article presents the data on the probiotic properties of Lactobacillus plantarum MTCC 2621 strain obtained from the collection of microorganisms and the gene bank of the Institute of Microbial Technologies of India. The distinctive feature of the strain is its ability to produce tannase enzyme, which is connected with the antioxidant properties of the probiotic. It was shown that L.plantarum MTCC 2621 is antagonistic to Gram-positive and Gram-negative bacteria, as well as yeast. Its high potential for adhesion (IAM — 7.10±0.39) and selective resistance to a wide range of antibiotics (oxacillin, benzylpenicillin, gentamicin, kanamycin, enrofloxacin, polymyxin C and polymyxin M) were established. The immunological tolerance of the strain as well as its ability to stimulate nonspecific antiviral defense and innate immune system of the organism due to the activation of the synthesis of type I interferon were revealed in series of preclinical studies. The method of spectral-dynamic analysis shows the potential antitumor activity of L.plantarum MTCC 2621 against such oncological diseases as squamous and keratinized cervical cancer, uterine myoma, and cystic process. © 2019 Media Sphera Publishing Group. All rights reserved.Item Performance evaluation of horizontal and vertical flow constructed wetlands as tertiary treatment option for secondary effluents(2019) Thalla; Arun Kumar; Devatha; C. P.; Anagh; K.; Sony; ElsaConstructed wetlands (CWs) are simple low-cost wastewater treatment units that use natural process to improve the effluent water quality and make it possible for its reuse. In the present study, a comparison is made between horizontal subsurface flow (HSSF-CW) and vertical flow (VFCW) constructed wetland in effectively post-treating the effluents from the secondary biological treatment system. Locally available plants, viz. Pennisetum pedicellatum and Cyperus rotundus, which are abundantly available in the Western Ghats, were used in the wetland. A pilot-scale study was undertaken in National Institute of Technology, Karnataka Campus. The experiments were conducted at two hydraulic retention times, i.e., 12 h and 24 h. The experimental study was carried out in February 2018 to May 2018. Concentration-based average removal efficiencies for HSSF-CW and VFCW were BOD, 77% and 83%; COD, 60% and 65%; NH4+-N, 67% and 84.47%; NO3-N, 69% and 66.75%; and PO4-P, 85% and 90%, respectively. VFCW showed a better overall removal efficiency than HSSF-CW by 7.14%. Thus, constructed wetland can be considered as a sustainable alternative to the tertiary conventional treatment of domestic wastewater, thus making it possible for reuse.Item A Wideband Circularly Polarized Slot Antenna Backed by a Frequency Selective Surface(2019) Rajanna; Puneeth Kumar Tharehalli; Rudramuni; Karthik; Kandasamy; KrishnamoorthyThis paper presents the design of a coplanar waveguide (CPW)-fed single-layer wideband circularly polarized (CP) planar slot antenna backed by a frequency selective surface (FSS). The planar slot antenna is fed with a stub-loaded modified CPW feed line to tune and optimize the impedance bandwidth. The corners of the square slot antenna are perturbed to produce two orthogonal degenerate modes required for a wideband CP operation. The FSS layer is placed under the slot antenna to increase the gain and axial ratio bandwidth. The measured results of the proposed antenna provide an impedance bandwidth of 63.22% and an axial ratio bandwidth of 31.14% with a peak gain of 4.87 dB. The proposed antenna has a simple geometry, a wide CP bandwidth, and a good gain.Item Investigation of physical and chemical characteristics on soil due to crude oil contamination and its remediation(2019) Devatha; C. P.; Vishal; A. Vishnu; Rao; J. Purna ChandraOil contamination causes serious geoenvironmental concern and adversely affects the soil environment due to the release of toxic by-products. Hence, the aim of the study was to investigate the influence of oil contamination on soil physical and chemical properties and phytoremediation as a treatment option based on field studies conducted for analyzing significant parameters. The sites selected were near National Institute of Technology, Surathkal, Karnataka (site-1), and another is close to the oil refinery (Kuthethur, Karnataka, India, as site-2). Phytoremediation of oil-contaminated samples was carried out by Chromolaena odorata. The evaluation of soil physical and chemical properties includes field and laboratory tests. A pumping test was conducted to estimate aquifer parameters in the field. The hydraulic conductivity for field soil sample (unsaturated condition) is carried out by a filter paper test. Laboratory tests to evaluate physical and chemical parameters include total petroleum hydrocarbons of contaminated (crude oil varying from 0 to 10% at an interval of 2%) and uncontaminated samples and plant parameters. Characterization of contaminated and uncontaminated soil sample was performed by Fourier transform infrared (FTIR) spectroscopy. The results obtained reveal that physical properties of soil (moisture content, liquid and plastic limit) got affected due to oil contamination. Relative hydraulic conductivity was established as 0.46 (uncontaminated) and 0.57 (contaminated) for soil samples and led to the conclusion that hydraulic conductivity was drop down by 10% due to oil contamination. Total petroleum hydrocarbon analysis reveals that the uptake/presence of hydrocarbons by showing increased concentration in contaminated soils (5% and 10%) by the plant species. This is further confirmed by FTIR results. The TPH concentrations in the contaminated soils were reduced up to 50-60% and also showed better plant growth after 7weeks of transplantation. Hence, considered plant species possess high potential for degrading oil contaminated in the soil.Item Investigation of magnetorheological brake with rotor of combined magnetic and non-magnetic materials(2019) Acharya S.; Kumar H.Magnetorheological (MR) brakes are a type of electromagnetic brakes that make use of controllable viscoelastic properties of magnetorheological fluid for braking. The torque capacity of the MR brake depends on the magnitude of magnetic flux density generated in the MR fluid. In this study, the effect of combination of magnetic and non-magnetic materials for rotor disk of MR brake with the objective to maximizing the flux density in the MR fluid gap at the rotor periphery was investigated. Initially, the MR brake rotor disk radius and MR fluid gap thickness were determined by using Genetic Algorithm optimization technique for desired torque ratio and torque capacity. Magnetostatic analyses were performed at different current magnitudes to determine the magnetic field and flux density in the MR brake. Further, to enhance the magnetic field intensity in the MR fluid at the rotor periphery, the rotor was modeled with three different configurations of MR brake with combinations of magnetic and non-magnetic steel and magnetostatic analyses of the MR brake were performed. It was found that the leakage of flux away from rotor periphery was reduced and there is significant increase and concentration of the magnetic field and flux density in the MR fluid gap through the use of rotor disk with combined magnetic and non-magnetic materials which would subsequently increase the torque capacity of the MR brake. © 2019, Springer Nature Switzerland AG.Item Internet of Things: A primer(2019) Paul A.; Jeyaraj R.We admire the emerging technologies that fascinate us, as it has become part of our daily life. Internet of Things (IoT) plays a major role in simplifying human effort. It leaps forward taking the advantages of latest wireless devices and communication technologies. IoT is a combination of technologies such as ubiquitous and pervasive computing, wireless communication devices and sensors, Internet protocol, and others. IoT logically interconnects and interoperates physical objects (sensors, wired/wireless communication devices) and virtual objects (web applications, virtual machines) over existing Internet infrastructure. IoT collects and records heterogeneous data (such as documents, images, videos, audios, and others) from heterogeneous applications (such as CCTV, medical images, barcode reader, and others) with the help of Internet. People, physical objects, and virtual objects are logically connected to the network to observe and analyze for decision-making. Therefore, IoT has transformed to be an important evolving technology and inevitable in every sectors. © 2019 Wiley Periodicals, Inc.Item Hydroelastic analysis of a truss pontoon mobile offshore base(2019) Somansundar S.; Panneer Selvam R.; Karmakar D.Very Large Floating Structures (VLFS) are one among the solution to pursue an environmentally friendly and sustainable technology in birthing land from the sea. VLFS are extra-large in size and mostly extra-long in span. VLFS may be classified into two broad categories, namely the pontoon type and semi-submersible type. The pontoon-type VLFS is a flat box structure floating on the sea surface and suitable in regions with lower sea state. The semi-submersible VLFS has a deck raised above the sea level and supported by columns which are connected to submerged pontoons and are subjected to less wave forces. These structures are very flexible compared to other kinds of offshore structures, and its elastic deformations are more important than their rigid body motions. This paper presents hydroelastic analysis carried out on an innovative VLFS called truss pontoon Mobile Offshore Base (MOB) platform concept proposed by Srinivasan and Sundaravadivelu (2013). The truss pontoon MOB is modelled and hydroelastic analysis is carried out using HYDRAN-XR*for regular 0°waves heading angle. Results are presented for variation of added mass and damping coefficients, diffraction and wave excitation forces, RAOs for translational, rotation and deformational modes and vertical displacement at salient sections with respect to wave periods. © 2019 Techno-Press, Ltd.Item High-temperature wear and frictional behavior of partially oxidized Al with NiCr composite coating(2019) Medabalimi S.R.; Ramesh M.R.; Kadoli R.The influence of composite coating in improving wear and frictional behavior from room temperature to 600 °C was investigated. Partially oxidized Al powder was prepared with a flame spray process by spraying pure Al powder into distilled water. The composite powder is the mixture of 30 weight percent of partially oxidized Al and 70 weight percent of NiCr alloy powder. The composite powder was subsequently coated on MDN321 steel by air plasma spray process. The composite coatings are characterized with respect to adhesion strength, porosity, micro-hardness, and density. Wear and frictional behavior of coatings are evaluated under disc speed of 1 and 2 m s-1, loads of 10, 20 and 30 N and 3000 m sliding distance. The test results indicated that at room temperature, frictional heat generated due to applied load produce three-body abrasion at the interface caused to increase the wear and friction in the coating. The oxide film formed at high temperature due to plastic deformation avoids surface degradation at the interface and reduce the wear and friction. The worn surfaces at 600 °C consist phases of α-Al2O3, NiO, and Cr3O. These phases are contributing to improving the wear resistance of the coating more than 4-times compared to uncoated steels under varying load and sliding velocities. The coefficient of friction reduced with increase in temperature due to generated oxides act as lubricants at the interface. © 2019 IOP Publishing Ltd.