Synthesis and characterization of graphene filled PC-ABS filament for FDM applications
Present investigation focuses on development of graphene filled PC-ABS filament for Fused Deposition Modeling applications. Compounding and twin screw extrusion was employed to synthesis graphene filled FDM filament of 1.75mm diameter. Percentage of graphene was varied from 0.1 vol% to 0.25 vol% in steps of 0.05. Developed filaments were subjected to SEM studies, dimensional accuracy and density measurements. In order to achieve filament of 1.75mm diameter, filament extrusion temperature was optimized using Taguchi's L25 orthogonal array, microstructure shows homogeneous dispersion of graphene particles in PC-ABS matrix, density decreases with increased content of graphene particles. 2018 Author(s).
Tambrallimath V.; Keshavamurthy R.; Saravanbavan D.; Kumar G.S.P.; Kumar M.H.
https://doi.org/10.1063/1.5085610 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85060469117&doi=10.1063%2f1.5085610&partnerID=40&md5=ab2f46a0b3fb5cb9b7f6d5824f75ac98
Tambrallimath V., Department of Automobile Engineering, Dayananda Sagar College of Engineering, Bangalore, 560078, India; Keshavamurthy R., Department of Mechanical Engineering, Dayananda Sagar College of Engineering, Bangalore, 560078, India; Saravanbavan D., Department of Mechanical Engineering, Dayananda Sagar University, Bangalore, 560078, India; Kumar G.S.P., Department of Mechanical and Automobile Engineering, Christ University, Bangalore, 560074, India; Kumar M.H., Department of Mechanical and Automobile Engineering, Christ University, Bangalore, 560074, India
Experimental investigation on the effect of varying percentage of E-waste particulate filler in GFRP composite laminates
E-waste particulate fillers; Flexural strength; GFRP composite laminates; Mechanical characterization; Shore D tests
The advent of newer technology increases the electrical and electronic devices into the market in a rapid phase, thereby causing the previous generation gadgets to become obsolete, in spite of the gadgets being in good working condition. This is one of the main causes for the increase of E-waste. In the past two years itself the e-waste has gone up by 8% with respect to weight globally. An attempt is made to utilize the e-waste in a productive manner as a filler material and study its characteristics when subjected to different mechanical tests. This paper describes the fabrication and mechanical characteristics of new polymer composites consisting of E-glass fiber reinforcement along with filler material. Study of composites play a very important role in material science, metallurgy, chemistry, solid mechanics and engineering applications. The specimens were fabricated with the help of hand layup technique followed by vacuum bagging process. Mechanical tests viz., tensile test, Flexural test, and Shore D test has been performed. Samples were made of three different compositions of E-waste filler particulate, 5%, 10% and 15%. These tests have been conducted to find out the impact of varying percentage of filler material on the composite laminates. With the increase in the percentage of e-waste filler, there is a reduction in the tensile strength of the laminate, while the flexural strength of the laminates increased with increase in the filler material. The laminate with 5% filler material exhibited higher hardness than the other two samples. 2019 Elsevier Ltd.
Mathivanan N.R.; Aiyappa A.C.; Kumar M.H.
Materials Today: Proceedings, Vol-28, pp. 1130-1134.
https://doi.org/10.1016/j.matpr.2020.01.094 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85087816143&doi=10.1016%2fj.matpr.2020.01.094&partnerID=40&md5=33e5415c4aef99c98216d2a255606fe1
Mathivanan N.R., Department of Mechanical Engineering, Pes University, Bangalore, 560085, India; Aiyappa A.C., Department of Mechanical Engineering, Pes University, Bangalore, 560085, India; Kumar M.H., Department of Mechanical and Automobile Engineering, Christ University, Bangalore, 560074, India
Effect of MWCNT concentration on microstructures, mechanical properties and sintering behaviour of spark plasma sintered AA2219-MWCNT composites
aluminium composites; ball milling; MWCNT; Spark plasma sintering (SPS)
Uniform dispersion of nano tubes without any structural damage is still a challenge in processing of metal matrix nano composites. Effective dispersion of MWCNT (0, 0.5, 0.75, 1, 2 wt. %) in AA 2219 alloy powder has achieved with a combined effect of premixing process and ball milling. An effort is done using spark plasma sintering (SPS) to consolidate the composites and to investigate the effect of MWCNT concentrations on enhancement of the properties of the composites. Particle boundary clustering was observed on consolidated composites even after a uniform distribution is achieved in alloy powder. Significant improvement in mechanical property is observed by reinforcing with MWCNT. Preferable level of MWCNT for bulk sampling was selected as 0.75 wt. % and 1 wt.%. Addition beyond the limit will cause agglomeration and will act like a lubricant during ball milling. 2019 Elsevier Ltd.
Materials Today: Proceedings, Vol-22, pp. 1424-1432.
https://doi.org/10.1016/j.matpr.2020.01.486 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085571505&doi=10.1016%2fj.matpr.2020.01.486&partnerID=40&md5=74c9105e3579b0c4fcfb3bb51a7ab34d
Thomas S., Department of Mechanical Engineering, CHRIST (Deemed to Be University), Bangalore, India; Tom P., Department of Mechanical Engineering, CHRIST (Deemed to Be University), Bangalore, India; Umasankar V., School of Mechanical and Building Sciences, Vellore Institute of Technology (Deemed to Be University), Chennai, India
Thermal Barrier Coating Development on Automobile Piston Material (Al-Si alloy), Numerical Analysis and Validation
Atmospheric Plasma Spray; Material characterization; Numerical analysis; Thermal barrier coatings; Yttria Stabilized Zirconia
This work is focused on the thermal barrier coating (TBC) development on aluminium-silicon (Al-Si) alloy casting materials, widely used as automobile components (cylinder blocks, pistons etc.). TBCs enable enhanced combustion within the chambers of diesel engines resulting in improved performance and components life. Uniform coating thickness development on complex contours of automobile pistons is a challenging task worldwide which results in varying thermal barrier characteristics across the non-uniform thickness. In consistent (in thickness) coatings are most likely to lead to uneven thermal barrier effects across the TBC thicknesses which directly affect the performance and the lubrication system of the engine. This warrants the development of stable and consistently thick coatings for ideal performance of the Low Heat rejection (LHR) engine. The present research work involved building different thicknesses (100, 125 and 150?m) of commercial 6-8%Yttria stabilized zirconia (YSZ) TBCs on 50? to 75? thick nickel aluminide (NiAl) bond coat. The influence of thickness on thermal barrier characteristics via experimentation and numerical analysis has been studied. Flat plates machined from automobile pistons were used as substrates. The coatings were characterized for thermal barrier effects for hot ceramic surface face temperatures up to 550C (by using oxy-acetylene flame to heat up the TBC surface), structural phase analysis by X-ray Diffraction (XRD) and microstructure analysis in metallographic cross section by employing Scanning Electron Microscope (SEM). An analytical investigation also was carried out to determine the approximate temperature at each interface. A code was developed to calculate the temperature drops across the coated plate and the net heat available at the coated surface using MATLAB. This is important considering the effects, small changes in temperatures will bring on the creep life on the metal. 2019 Elsevier Ltd.
Reghu V.R.; Mathew N.; Tilleti P.; Shankar V.; Ramaswamy P.
Materials Today: Proceedings, Vol-22, pp. 1274-1284.
https://doi.org/10.1016/j.matpr.2020.01.420 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085585753&doi=10.1016%2fj.matpr.2020.01.420&partnerID=40&md5=8dad543b023ae4da25c18fd0ab7d50ce
Reghu V.R., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 566074, India; Mathew N., Research Scholar, IIT Mandi, 175005, Himachal Pradesh, India; Tilleti P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 566074, India; Shankar V., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 566074, India; Ramaswamy P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 566074, India
A Novel Approach to Automatic Ear Detection Using Banana Wavelets and Circular Hough Transform
adaptive histogram equalization; banana wavelets; biometric; ear detection; hough transform; skin segmentation
Ear is an attractive biometric trait that maintain their structure with increasing age. Because of the complex geometry of ear, its detection is very difficult. This paper proposes a modified algorithm for automatic detection of 2D ear images using Banana wavelets and Hough transform. Banana wavelets derived from bank of stretched and curved Gabor wavelets are used to identify curvilinear ear structure. Addition of a preprocessing stage, prior to application of banana wavelets is found to improve the detection results further. The proposed algorithm is brought in to comparison with three existing algorithms and evaluated on standard databases. In addition to manual detection accuracy, this paper also calculates the efficiency of the proposed method using automatic classification techniques. The features like LBP and Gabor extracted from segmented ear image is used by different classifiers to determine whether the segmented portion of the image is class Ear or Non ear. 2019 IEEE.
2019 International Conference on Data Science and Communication, IconDSC 2019
Institute of Electrical and Electronics Engineers Inc.
https://doi.org/10.1109/IconDSC.2019.8816919 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85072759298&doi=10.1109%2fIconDSC.2019.8816919&partnerID=40&md5=3ff7270e489904690196de77df006743
Resmi K.R., School of Computer Science, Mahatma Gandhi University, Kottayam, India; Raju G., Department of Computer Science and Engineering, Christ Deemed To be University, Bengaluru, India
Synthesis and Studies on Partially Stabilized Zirconia and Rare-Earth Zirconate Pyrochlore Structured Multilayered Coatings
Thermal barrier coatings; Thermal shock cycles; Zirconia based pyrochlore
This work is focused on the thermal fatigue behaviour studies of ceramic coatings, as TBC (Thermal Barrier Coating) system, its importance in determining the thermo-mechanical properties and service-life estimation of the coatings when exposed to elevated operating temperatures. Commercial 6-8%Yttria stabilized zirconia (YSZ) top coat (TC) and NiCrAlY bond coat (BC) in (a) conventional YSZ (BC and TC), (b) multi-layered functionally graded materials (FGM) i.e., BC-blend (50BC+50TC)-(TC) configuration and (c) lab synthesized Zirconia based pyrochlore (Lanthanum Zirconate-LZ) were the coating materials involved. Nickel based super alloy Inconel 718 substrates were coated by using Atmosphere Plasma Spray (APS) system with three different (varying power) plasma spray parameters. All the sides of the 25mm x 10mm x 5mm thick substrates were completely covered with the bond coat and ceramic coating. FGM configuration was spray coated only on one side of the Inconel flat plates. Thermal shock cycle tests were performed on the coated specimen by following the ASTM B214-07 guidelines which comprised of introducing the coated specimen in a muffle furnace at 1150C, held in it for 2 minutes before removing from furnace followed by forced fan air cooling (one shock cycle). The specimen were periodically subjected to visual inspection for faults, before continuing the shock cycles, until the coating flaked off or cracked or detached from substrate. Cross section metallographic samples were prepared and analysed under SEM (Scanning Electron Microscope) and Energy Dispersive spectroscope (EDS) to study the as-sprayed coating morphology and interface quality, measure coating thickness, study defects characteristics and the chemical composition. Crystal structural phases were analysed using X-Ray Diffraction (XRD). 2019 Elsevier Ltd.
Teja Pasupuleti K.; Manikanta Dunna U.; Ghosh S.; Ramaswamy P.; Murty Svs N.
Materials Today: Proceedings, Vol-22, pp. 1244-1252.
https://doi.org/10.1016/j.matpr.2020.01.417 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085585001&doi=10.1016%2fj.matpr.2020.01.417&partnerID=40&md5=2818db347f9e12e7d96ee22f1f4e9a2a
Teja Pasupuleti K., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India; Manikanta Dunna U., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India; Ghosh S., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India; Ramaswamy P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India; Murty Svs N., Materials Characterization Division, Vikram Sarabhai Space Center, Trivandrum, 695022, India
Framework for Controlling Interference and Power Consumption on Femto-Cells In-Wireless System
Cellular network; Coverage; Energy efficiency; Femto-cells; Power consumption
Utilization of femto-cells is one of the cost effective solution to increase the internal network connectivity and coverage. However, there are various impediment in achieving so which has caused a consistent research work evolving out with solution. Review of existing literature shows that maximum focus was given for energy problems in cellular network and not much on problems that roots out from interference. Therefore, the proposed system has presented a very simple and novel approach where the problems associated with interference and energy in using large groups of femto-cells are addressed. Adopting analytical research methodology, the proposed model offers on-demand utilization of the selective femto-cells on the basis of the traffic demands. The study outcome shows that proposed system offers better performance in contrast to existing approach. Springer Nature Switzerland AG 2019.
Advances in Intelligent Systems and Computing, Vol-1046, pp. 199-208.
Sowmya Naik P.T., Department of Computer Science and Engineering, City Engineering College, Bengaluru, India; Narasimha Murthy K.N., Faculty of Engineering, Christ (Deemed to be University), Bengaluru, India
Synthesis of Magnetorheological fluid Compositions for Valve Mode Operation
agglomeration; Carbonyl Iron; Magnetorheological fluid; sedimentation; Smart material; valve mode, MR damper
Smart materials such as Magnetorheological Fluids (MRF) have become sought-after material in wide ranging applications due to the ability to change properties in a controlled manner under application of stimulation such as a variable current, magnetization, heat, force, stress and deformation. Magnetorheological fluids in the rheological fluid domain has found use due to its ability to change its shear strength based on the applied magnetic field. Magnetorheological fluids are composed of magnetizable micron sized iron particles and a non-magnetizable base/carrier fluid. The shear strength of commercially available MRF varies from 0 to 100kPa under the effect of the magnetic field. In a valve mode, the Magnetorheological damper (MR Damper or MRD), the MR fluid flows between two-fixed poles, which are parallel to each other. When the fluid flows between them, due to the applied magnetic field the magnetic particles align themselves in a chain form (on state) which is easily reversible when the field is removed (off state). Physical change of the fluid from liquid to semi-solid is controlled by the magnetic field, which makes the fluid a reliable member in active vibration control applications. In this study, two types of magnetizable particles (Carbonyl iron (CI) and Electrolytic iron (EI)) are taken and characterized using an Anton Paar MCR 702 rheometer set-up, in on and off states. To overcome issues like sedimentation, agglomeration and corrosion of the MR fluid, the iron particles are coated with natural gum like guar and xanthan, to the carrier fluid grease and other thixotropic additives are added. The addition of grease and thixotropic additives will inhibit the microbiological degradation of natural gum over an extended period. These engineered MR fluids are then used to analyze the performance of designed and developed stand-alone MR damper, which is tested using an electro-dynamic shaker. The response and damping performance of the MR Damper is analyzed with controlled changes in variables including percentage of additives in MR fluid & magnetization values 2019 Elsevier Ltd.
Materials Today: Proceedings, Vol-22, pp. 1870-1877.
https://doi.org/10.1016/j.matpr.2020.03.086 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085561433&doi=10.1016%2fj.matpr.2020.03.086&partnerID=40&md5=ba6eb10d2ac5021b2594875d729a56b8
Kumar J.S., CHRIST (Deemed to Be University), Faculty of Engineering, Dept. of Mechanical and Automobile Engineering, Kengeri Campus Mysore Road, Kumbalgodu, Kanmanike, Bengaluru, Karnataka, 560074, India; Alex D.G., CHRIST (Deemed to Be University), Faculty of Engineering, Dept. of Mechanical and Automobile Engineering, Kengeri Campus Mysore Road, Kumbalgodu, Kanmanike, Bengaluru, Karnataka, 560074, India
Self lubricating property of MWCNT in AA2219 composites during high energy ball milling
Aluminium composites; Ball milling; MWCNT; Nano composites; Self lubrication
Revolutions in nanotechnology enabled the development of advanced nanocomposites with superior properties for engineering applications especially in automotive and aerospace industries. Among this carbonaceous nano materials like MWCNT have got more attention. Addition of MWCNT in metal matrix results in retardation of friction coefficient and improvement on other mechanical properties based on its dispersion. MWCNT won't have sufficient space to occupy over the powder surface, when the addition is beyond a limit and acts as a solid lubricant during milling. Investigations on self lubricating property during milling were done by using scanning electron microscope, X-ray diffraction and powder density. Uniform dispersion was the bottleneck to utilize their attractive properties of the reinforcement. An attempt had been done for a uniform dispersion during premixing process using a combination of ultra-sonication, magnetic and mechanical stirring followed by high energy ball milling. 2019 Elsevier Ltd.
Thomas S.; Umasankar V.; Joseph C.; Mathew J.
Materials Today: Proceedings, Vol-18, pp. 3387-3393.
https://doi.org/10.1016/j.matpr.2019.07.265 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077554724&doi=10.1016%2fj.matpr.2019.07.265&partnerID=40&md5=6f3df6a798b48e2b069a48548c1c8a67
Thomas S., Department of Mechanical Engineering, Faculty of Engineering, CHRIST (Deemed to be University), Bangalore, 560 074, India; Umasankar V., School of mechanical and Building Sciences, Vellore Institute of Technology, Deemed to be University, Chennai, 600 127, India; Joseph C., Department of Mechanical Engineering, Faculty of Engineering, CHRIST (Deemed to be University), Bangalore, 560 074, India; Mathew J., Department of Mechanical Engineering, Faculty of Engineering, CHRIST (Deemed to be University), Bangalore, 560 074, India
Effect of Temperature on Electrical Properties of Reduced Graphene Oxide (rGO)/Li-ion Embedded Flexible Solid Polymer Electrolyte Films
Impedance spectroscopy; Ionic conductivity; Polymer electrolyte; reduced Graphene Oxide (rGO)
Reduced graphene oxide (rGO) was synthesized from graphite powder by modified Hummers method. The rGO is emerged with Polystyrene sulfonic acid/Lithium phosphate to prepare PL-rGO solid polymer electrolyte films. The electrical properties of Polystyrene sulfonic acid/Lithium phosphate/reduced graphene oxide composites were analyzed, which is an essential property to obtain the performance, reliability and lifetime of battery with respect to temperature. The mass and charge transfer process that takes place at the interface of electrode and electrolyte was obtained by Impedance analyzer. The Nyquist plots were plotted in the frequency range 1 Hz-35 MHz at different temperatures (30-100OC). The ionic conductivity of PL-rGO polymer electrolyte is 1.4x10-3 S/c.m has been observed for the composition PSSA/Li3PO4/rGO::50:45:05 wt%. The conductivity of PL-rGO composites is directly related to temperature. The hopping of the ions in the PL-rGO is observed by using dc conductivity which follows the Arrhenius relationship. 2019 Elsevier Ltd.
Materials Today: Proceedings, Vol-24, pp. 2250-2254.
https://doi.org/10.1016/j.matpr.2020.03.752 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088016717&doi=10.1016%2fj.matpr.2020.03.752&partnerID=40&md5=3a06fd74abd17893fe52055b3700f167
Pandey M., Department of Physics, Christ (Deemed to Be University), Bengaluru Karnataka, 560029, India; Manoj B., Department of Physics, Christ (Deemed to Be University), Bengaluru Karnataka, 560029, India
An insight into the superior performance of ZnO@PEG nanocatalyst for the synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles under ultrasound
3-c]pyrazol-6-amine Four-component synthesis Multicomponent reaction; 4-dihydropyrano[2; ZnO@PEG nanoparticle Ultrasonic irradiation 1
The investigation presents a straightforward synthesis of fifteen 1,4-dihydropyrano[2,3-c]pyrazoles using ZnO@PEG nanocatalyst in ethanol via Multicomponent approach under the influence of ultrasound. The present methodology successively tolerates a variety of functional groups and offers several advantages such as excellent yields without chromatographic purification, milder reaction conditions, shorter reaction times, and the use of an environmentally benign reusable catalyst. Ecstatically, the reaction was successfully scaled to gram level ascertaining the wider applicability of ZnO@PEG nanoparticles in multicomponent reactions. 2019 Elsevier Ltd. All rights reserved.
Tabassum S.; Sunaja Devi K.R.; Govindaraju S.
Materials Today: Proceedings, Vol-45, pp. 3898-3903.
https://doi.org/10.1016/j.matpr.2020.06.283 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107381679&doi=10.1016%2fj.matpr.2020.06.283&partnerID=40&md5=4c1db366d70a8877f4b75cb5cc1979cd
Tabassum S., Department of Chemistry, Surana College, South End Road, Basavanagudi, Bengaluru, 560004, India; Sunaja Devi K.R., Department of Chemistry, CHRIST (Deemed to be University), Bengaluru, 560029, India; Govindaraju S., Department of Sciences and Humanities, School of Engineering and Technology, CHRIST (Deemed to be University), Kumbalagodu, Mysore Road, Bengaluru, 560074, India
Narrowband and Wideband Directional Beamformer with Reduced Side Lobe Level
Antenna pattern synthesis; Narrowband beamformer; Spatial filter; Wideband beamformer
In this paper, the synthesis of narrow and wideband beamformers with reduced side lobe level and wide beam steering capability is presented. A closed form expression with slope equalization technique is derived for array factor of the beamformer to meet the desired beam-pattern specifications of Half Power Beam-Width (HPBW)and Side Lobe Level (SLL). The proposed beamformer design is adaptable to any bandwidth and null placement in the desired direction. The slope equalization method improves the SLL of the beamformer. Compared to Kaiser, Chebyshev, DPSS and Taylor beamformers, the proposed narrowband and wideband beamformers exhibit lower and tapered side lobes, hence improved First Null to Last Null (FNLN)ratio. The proposed wideband beamformer exhibits superior performance in the wideband frequency range of 1-3GHz. 2019 IEEE.
Rodrigues J.; Lonappan L.; Menon D.; Gudino L.J.
https://doi.org/10.1109/IconDSC.2019.8816958 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85072760691&doi=10.1109%2fIconDSC.2019.8816958&partnerID=40&md5=4d6a7c9d7c92bcbeb36f54ff4b1f51f9
Rodrigues J., Dept. of Electrical and Electronics Engg., CHRIST, Deemed to be University, Bengaluru, India; Lonappan L., Dept. of Electrical and Electronics Engg., CHRIST, Deemed to be University, Bengaluru, India; Menon D., Dept. of Electrical and Electronics Engg., CHRIST, Deemed to be University, Bengaluru, India; Gudino L.J., Dept. of Computer Science and Information Systems, Birla Institute of Technology and Science, Pilani, India
Detection and Classification of Potholes in Indian Roads Using Wavelet Based Energy Modules
Canny operator; Markov random; Median filter Neural Network. Wavelet Energy Field
Maintenance of roads is one the major challenge in the developed countries. The well maintained roads always indicates the economy of the whole country. The heavy use of roads, environmental conditions and maintenance is not performed regularly that leads the formation of potholes which causes the accidents and unwanted traffics. The paper discuss about the detection of potholes based on wavelet energy field. The proposed method mainly includes three phases (A)Wavelet energy filed is constructed in order to detect the image by using geometric criteria and morphological processing (B)Extracting Region of intersect by edge based segmentation technique (C)Classifying the potholes using Neural Network. 2019 IEEE.
https://doi.org/10.1109/IconDSC.2019.8816878 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85072762234&doi=10.1109%2fIconDSC.2019.8816878&partnerID=40&md5=eb76696d1087c3cac5a03dee75846f90
Manjunatha H.T., Department of Computer Applications, Jawaharlal Nehru National College of Engineering, Shimoga, Karnataka, India; Danti A., Department of Computer Science and Engineering, Christ (Deemed to be University), Bangalore, India
Synthesis and Characterization of Carbon Nanomaterial Derived from Anthracite
Anthracite; Carbon nanotubes; Cyclic Voltammetry; FTIR; XRD
Among various storage devices, carbon based supercapacitors grabs the recent trends in the electronic devices. The present research work describes the synthesis of carbon nanomaterials derived from anthracite by using staudenmaier method. Anthracite was used as a precursor because of its high carbon content. The structural and chemical complex formation carried out by using XRD and FTIR confirms the formation of CNT's. The calculated value obtained from the XRD peaks confirms the formation of multilayer carbon nano-materials. The electrode was prepared by coating synthesized CNT on copper rod. The electrochemical performance of prepared working electrode was carried out by using cyclic voltammetric performance. Electrode characterization was performed for different scan rates 10, 20, 30 and 50 mV/sec in a potential window from-0.08 to 0.2V. The CV curves represents symmetric nature which imply that electrode material have stable capacitive process. 2019 Elsevier Ltd.
Materials Today: Proceedings, Vol-24, pp. 2352-2357.
https://doi.org/10.1016/j.matpr.2020.03.764 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088018096&doi=10.1016%2fj.matpr.2020.03.764&partnerID=40&md5=f69f8109b260cb8b61c28bf75e9dcc3f
Maria S., Department of Physics, Christ Deemed to Be University, Bengaluru Karnataka, 560029, India; Singh S., Department of Physics, Christ Deemed to Be University, Bengaluru Karnataka, 560029, India; Pandey M., Department of Physics, Christ Deemed to Be University, Bengaluru Karnataka, 560029, India; Manoj B., Department of Physics, Christ Deemed to Be University, Bengaluru Karnataka, 560029, India
Performance Evaluation of Area-Based Segmentation Technique on Ambient Sensor Data for Smart Home Assisted Living
Activity Recognition; Elder Care; Machine Learning; Segmentation; Smart Home
Activity recognition(AR) is a popular subject of research in the recent past. Recognition of activities performed by human beings, enables the addressing of challenges posed by many real-world applications such as health monitoring, providing security etc. Segmentation plays a vital role in AR. This paper evaluates the efficiency of Area-Based Segmentation using different performance measures. Area-Based segmentation was proposed in our earlier research work. The evaluation of the Area-Based segmentation technique is conducted on four real world datasets viz. Aruba17, Shib010, HH102, and HH113 comprising of data pertaining to an individual, living in the test bed home. Machine learning classifiers, SVM-R, SVM-P, NB and KNN are adopted to validate the performance of Area-Based segmentation. Amongst the four chosen classification algorithms SVM-R exhibits better in all the four datasets. Area-Based segmentation recognise the four test bed activities with accuracies of 0.74, 0.98, 0.66, and 0.99 respectively. The results reveal that Area based segmentation can efficiently segment sensor data stream which aids in accurate recognition of smart home activities. 2019 Procedia Computer Science. All rights reserved.
Procedia Computer Science, Vol-165, pp. 314-321.
https://doi.org/10.1016/j.procs.2020.01.044 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081993451&doi=10.1016%2fj.procs.2020.01.044&partnerID=40&md5=cf42aceffd821d7f1c13d5da65a8b56f
Kavitha R., CHRIST (Deemed to Be University), Bangalore, Karnataka, India; Binu S., Bangalore, Karnataka, India
Synthesis of high temperature (1150 C) resistant materials after extraction of oxides of Al and Mg from Aluminum dross
Alumina; Aluminium dross; Industrial waste; Magnesium aluminate; Refractories Aluminium nitride leaching
Aluminum Dross (Al-dross) is a well-known Industrial waste generated in an Aluminium industry from the melting of the metal itself. It gets made yearly in hundreds of thousands of tons worldwide, due to the wide use and demand of Aluminum in almost every industry. However, Al-dross is not completely a waste as it contains two compounds of interest, namely Aluminum Oxide (Al2O3) and Magnesium Aluminate (MgAl2O4). They are the basic compounds present in any refractory which are products featuring low thermal conductivity and high temperature shock characteristics in the order of 1000 C+. Thus, Aluminum Dross becomes a vital candidate to be considered for the extraction of the two of the aforementioned compounds. Recent studies have shown that Al-dross indeed can be used to extract Al2O3 and MgAl2O4. However, Al-dross also contains Aluminum Nitride (AlN) a compound that exhibits the exact opposite properties demonstrated by refractories. In addition to being technically unsuitable for use as refractory material, AlN also possesses another huge issue. When Al-dross is dumped into landfills, the AlN present in the dross combines with the moisture in the soil and is energized by geothermal heat which leads into an exothermic reaction, thereby releases highly toxic and health hazardous gases. Keeping the above techno-environment challenges in mind, prior to utilizing the beneficiated Al-dross in any industrial application, it is important to leach out the AlN from the dross in an environment friendly manner. This paper deals with the successive leaching of AlN from the Al-dross using two laboratory procedures. Sintered (to be added) pellets made out of the processed powder in the lab were subjected to analysis of structural phases and chemical constituents by employing XRD and EDS. Cyclic thermal shock test cycles were also carried out by subjecting the pellets to 1150 C and quenching in air alternately, to study the refractory characteristics. 2019 Elsevier Ltd. All rights reserved.
Ramaswamy P.; Ranjit S.; Bhattacharjee S.; Gomes S.A.
Materials Today: Proceedings, Vol-19, pp. 670-675.
https://doi.org/10.1016/j.matpr.2019.07.751 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076467879&doi=10.1016%2fj.matpr.2019.07.751&partnerID=40&md5=cf3b2eb3cd9892e5395e26b29f27bb9c
Ramaswamy P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to be University), Bengaluru, 560 074, India; Ranjit S., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to be University), Bengaluru, 560 074, India; Bhattacharjee S., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to be University), Bengaluru, 560 074, India; Gomes S.A., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to be University), Bengaluru, 560 074, India
Adhesion strength studies on zirconia based pyrochlore and functionally gradient thermal barrier coatings
Adhesion strength; Air plasma spray; Functionally gradient; Thermal barrier coating; Zirconia based pyrochlore
Thermal Barrier Coating (TBC) plays a major role in the improvement of gas turbine and engine components in terms of their service life and performance. Generally, all coatings must possess certain primary properties to perform in the intended applications. However, regardless of applications, suitable adhesion strength is one major characteristic they must have to adequately protect the basic components on which they are applied upon. In TBCs, adhesion (or Bond) strength is a parameter that helps to illustrate the resistance of the ceramic top coat against spallation either from the bond coat (and component) or within the TBC layers itself. The performance of TBCs are reliant upon the adhesion between the coating and the metal substrate and also adhesion (or cohesion) between the bond coat and the overlying ceramic top coat layer. The de-bonding of the top coat layer or the inter-metallic bond coat layers are the main reasons of the failure of the overall TBC system. Some of the prominent problems associated with coatings applications are residual stresses, micro-cracks and pores etc. These and many other factors influence the adhesion of the coatings in addition to service environment conditions and pre coating substrate preparations such as substrate cleaning, grit blasting and very importantly plasma spray parameters. In the present work, results obtained from adhesion strength measurements carried out by following the ASTM C 633 standard test method, on various types of TBCs are being shared. Thermal barrier coatings (TBCs) were synthesized with NiCrAlY bond coat deposited on SS 304L substrate by using air plasma spray and different ceramic top coats (a) commercial 8%Yttria Stabilized Zirconia (8YSZ) (b) lab synthesized plasma spray powders of (i) Lanthanum Zirconate (La2Zr2O7) (ii) Lanthanum Ceria Zirconate (La2 (Zr0.7Ce0.3)2O7) and (iii) Lanthanum cerate (La2Ce2O7). The coating depositions were carried out in different configurations i.e. two layers, three layers and gradient layers (Functionally gradient materials). The evaluation of properties includes the studies of morphology of the strength (adhesive/cohesive failure mode) tested specimen as well. General conclusions drawn from the studies on several specimen in various configurations are that cohesive failures (between the ceramic top coat layers) is the predominant mechanisms followed by few adhesive failures in bond coat coat/ceramic interface. 2019 Elsevier Ltd. All rights reserved.
Pasupuleti K.T.; Prasad G.V.; Prabhu Akhil M.; Ramaswamy P.; Narayana Murty S.V.S.
Materials Today: Proceedings, Vol-19, pp. 568-574.
https://doi.org/10.1016/j.matpr.2019.07.735 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85077302271&doi=10.1016%2fj.matpr.2019.07.735&partnerID=40&md5=59e84abfc3a97b2f1d3bfc147b9b10ec
Pasupuleti K.T., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to be University), Bangalore, 560074, India; Prasad G.V., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to be University), Bangalore, 560074, India; Prabhu Akhil M., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to be University), Bangalore, 560074, India; Ramaswamy P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to be University), Bangalore, 560074, India; Narayana Murty S.V.S., Materials Characterization Division, Vikram Sarabhai Space Center, Trivandrum, 695022, India
Plasma Sprayed Refractory Coatings from Aluminium Dross
Aluminium dross; industrial waste; plasma spray coatings; refractory
Refractory coatings on metals offer a unique blend of chemical inertness, stability and mechanical properties at temperatures higher than what the metal can normally withstand. However, a balance must be struck with many factors: Thickness, adhesion, performance, durability, economy and suitability for specific end use requirements. The present-day technology requires the coating to give effective service under extreme temperatures while being environmentally friendly and be easily available. One application of refractory coating is in steel industry-pipe linings. This research works highlights the potential to use aluminum dross, an industrial waste material to generate refractory coatings, comprised of Al2O3 and MgAl2O4 after suitable processing. Al dross is a byproduct of the Aluminium smelting process which can be recycled mechanically to separate the residual Aluminium metal from the Aluminium oxide. These are usually produced in tones every year and are found to be dumped in landfills and other empty spaces which generate toxic fumes like methane and other gases when reacted with moisture. The Aluminium dross used in this work was analyzed and found to comprise of its usual constituents such as metallic Al, MgAl2O4, Al2O3, AlN and other oxides and nitrides in minute quantities. Manual procedures were conducted to synthesize plasma spray-able dross which was further introduced to standard laboratory tests for the removal of undesirable constituents like AlN and other nitrides which led to the optimization of quality of powders. Atmospheric plasma spray (APS) coating methodology was used to deposit 250?m thick coatings of re-processed Al dross, involving the spraying of the processed powder onto a bond coated (NiCrAlY) steel substrate. The raw, reprocessed and the plasma sprayed coated Al dross were evaluated for their material characteristics by employing X-ray Diffractometry (XRD) for crystal structural phases, microstructure and chemical composition by employing sophisticated microscopy (SEM) technique and EDS associated with the SEM. The paper is presented keeping in in view the aptness of reprocessed Al dross, an industrial waste material to be utilized as refractories for use in engineering industries. 2019 Elsevier Ltd.
Ramaswamy P.; Tilleti P.; Pinto R.; Ranjith S.; Benjamin J.
Materials Today: Proceedings, Vol-22, pp. 1285-1294.
https://doi.org/10.1016/j.matpr.2020.01.421 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085550697&doi=10.1016%2fj.matpr.2020.01.421&partnerID=40&md5=e8ecbab051b146e8a82e13586996edae
Ramaswamy P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, India; Tilleti P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, India; Pinto R., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, India; Ranjith S., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, India; Benjamin J., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, India
REMAP: Determination of the inner edge of the dust torus in AGN by measuring time delays
Active; Galaxies; Quasars; Reverberation; Seyfert
Active galactic nuclei (AGN) are high luminosity sources powered by accretion of matter onto super-massive black holes (SMBHs) located at the centres of galaxies. According to the Unification model of AGN, the SMBH is surrounded by a broad emission line region (BLR) and a dusty torus. It is difficult to study the extent of the dusty torus as the central region of AGN is not resolvable using any conventional imaging techniques available today. Though, current IR interferometric techniques could in principle resolve the torus in nearby AGN, it is very expensive and limited to few bright and nearby AGN. A more feasible alternative to the interferometric technique to find the extent of the dusty torus in AGN is the technique of reverberation mapping (RM). REMAP (REverberation Mapping of AGN Program) is a long term photometric monitoring program being carried out using the 2 m Himalayan Chandra Telescope (HCT) operated by the Indian Institute of Astrophysics, Bangalore, aimed at measuring the torus size in many AGN using the technique of RM. It involves accumulation of suitably long and well sampled light curves in the optical and near-infrared bands to measure the time delays between the light curves in different wavebands. These delays are used to determine the radius of the inner edge of the dust torus. REMAP was initiated in the year 2016 and since then about one hour of observing time once every five days (weather permitting) has been allocated at the HCT. Our initial sample carefully selected for this program consists of a total of 8 sources observable using the HCT. REMAP has resulted in the determination of the extent of the inner edge of the dusty torus in one AGN namely H0507+164. Data accumulation for the second source is completed and observations on the third source are going on. We will outline the motivation of this observational program, the observational strategy that is followed, the analysis procedures adopted for this work and the results obtained from this program till now. 2019 Societe Royale des Sciences de Liege. All rights reserved.
Mandal A.K.; Rakshit S.; Pal I.; Stalin C.S.; Sagar R.; Mathew B.
Bulletin de la Societe Royale des Sciences de Liege, Vol-88, pp. 158-165.
All Open Access; Bronze Open Access; Green Open Access
Mandal A.K., Department of Physics and Electronics, CHRIST (Deemed to be University), Hosur Road, Bangalore, 560 029, India, Indian Institute of Astrophysics, Block II, Koramangala, Bangalore, 560 034, India; Rakshit S., Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Vesilinnantie 5 Quantum, 20014, Finland; Pal I., Indian Institute of Astrophysics, Block II, Koramangala, Bangalore, 560 034, India; Stalin C.S., Indian Institute of Astrophysics, Block II, Koramangala, Bangalore, 560 034, India; Sagar R., Indian Institute of Astrophysics, Block II, Koramangala, Bangalore, 560 034, India; Mathew B., Department of Physics and Electronics, CHRIST (Deemed to be University), Hosur Road, Bangalore, 560 029, India
Synthesis of Value Added Refractories from Aluminium Dross and Zirconia Composites
Aluminium dross; Composite; Industrial waste; Refractories; Thermal shock; Zirconia
Results of a developmental study on the potential to synthesize industrial grade refractories from aluminum dross with un-stabilized zirconia are reported. The merit of the developed product to perform as refractories suitable for use at or above 1000C was assessed by studying the thermo-physical behavior as per guidelines of ASTM and IS. Aluminum dross, an industrial waste (slag) is generated in several millions of tons in the production of Aluminum and is dumped into landfills, which releases poisonous gases like methane and ammonia upon contact with moisture present in the land and the heat generated by the earth, warranting stringent mitigation efforts. Rich in aluminum metal (?15%), ?-Al2O3 (7-15%), MgAl2O4 (10-15%) and AlN (20-30%), the general prime dross composition draws interest due to its abundance and presence of ?-Al2O3 and MgAl2O4, for the production of refractories with insulating, shock resistance and stability at high temperature (?1000C and above) characteristics. Nevertheless, presence of AlN, a good thermal conductor acts as a deterrent in the production of refractories. Aluminium dross (after leaching out AlN) was processed with un-stabilized zirconia (monoclinic ZrO2) to synthesize the refractory composites. Conventional process (calcination, ball milling, compaction and sintering (1550C/6 hrs)) was employed. Characterization involved thermal shock cycling (air quench at furnace ambient of 1000C and room temperature) to determine the number of shock cycles endured before failure. Structural phase analyses at various stages of processing were carried out by via XRD. Magnesia present in dross did not appear to stabilize either the tetragonal or cubic ZrO2. Microstructural and chemical composition studies were carried out via SEM and EDS. The favourable results confirm the viability of the process methodology. 2019 Elsevier Ltd.
Ramaswamy P.; Tilleti P.; Bhattacharjee S.; Pinto R.; Avijit Gomes S.
Materials Today: Proceedings, Vol-22, pp. 1264-1273.
https://doi.org/10.1016/j.matpr.2020.01.419 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085544727&doi=10.1016%2fj.matpr.2020.01.419&partnerID=40&md5=e6c50b4204385bbf0261eb9a348036b0
Ramaswamy P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India; Tilleti P., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India; Bhattacharjee S., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India; Pinto R., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India; Avijit Gomes S., Department of Mechanical and Automobile Engineering, CHRIST (Deemed to Be University), Bangalore, 560074, India