Nagaraju G.,Jain University
Zeitschrift fur Anorganische und Allgemeine Chemie | Year: 2012
A simple low temperature hydrothermal method was found to yield Na 0.28V 2O 5 nanobelts after two days at 130 °C in acidic medium (H 2SO 4) without using any surfactant. The obtained products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy. Their morphology was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Additionally, their electrochemical behavior in a lithium battery was investigated. The XRD pattern shows that the product is composed of monoclinic Na 0.28V 2O 5 nanobelts. From the FTIR spectrum, the band centered at 961 cm -1 is assigned to V=O stretching vibration, which is sensitive to intercalation and suggests that Na + ions are inserted between the vanadium oxide layers. SEM/TEM analyses reveal that the products consist of a large quantity of nanobelts which have a thickness of 60-150 nm and a length of several tens of micrometers. The electrochemical results show that the nanobelts exhibit an initial discharge specific capacity of 390 mAh·g -1, and its stabilized capacity still remained around 200 mAh·g -1 after the 18th cycle. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Ashokkumar C.R.,Jain University
AIAA Guidance, Navigation, and Control Conference 2012 | Year: 2012
In autonomous control operations of unmanned micro air vehicles, the trajectories are generated first for a known mission profile and then they are reconstructed online. In some cases, a fixed-gain feedback controller is used to reconstruct the trajectories. However, for pitch plane autonomous operations of small fixed wing micro air vehicles, the human-made fixed gain feedback controller is sometimes inadequate. That is, the trajectory reconstruction process demands an online control system design with adaptive feedback gains. Although trajectory generation in pitch plane is a subject by itself, this paper focuses on the online control system design procedures so that the generated trajectories for autonomous control are reconstructed. It is shown that the extended Kalman filter in state and parameter estimation framework is an excellent tool to perform the control system design. The software that accepts an output from the trajectory generation module and performs trajectory reconstruction using a set of adaptive feedback gains is referred as 'autonomous control agent'. A single input nonlinear micro air vehicle model is considered to illustrate the underlying principles of autonomous control agent with gains computed and tuned by the extended Kalman filter. Thus the human participation in micro air vehicle operation at pitch plane is minimized. © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Reddy N.,Jain University
Journal of Reinforced Plastics and Composites | Year: 2015
Considerable efforts have been made to develop biocomposites that can replace the non-biodegradable synthetic polymer-based composites. Most often, composites are made using either the matrix or reinforcement derived from renewable resources, but are still referred to as biocomposites. However, the biodegradability of such composites, especially those containing synthetic polymers as matrices, is questionable. Attempts have also been made to develop completely biodegradable composites that contain both the matrix and reinforcement from renewable and biodegradable sources. Composites containing biopolymers as matrix have shown to have good tensile and flexural properties but typically fail to have adequate resistance to moisture leading to poor performance at high humidity or aqueous conditions. Among the various biopolymer matrices used, soy-based matrices are extensively studied due to the abundant and low cost availability of coproducts. Soy proteins, soy concentrate, soy flour and soy oil obtained as coproducts of soybean processing have been studied as possible matrices for composites in their native form and also after chemical and physical modifications. Although extensively studied, information on composites containing soy-based matrices is incoherent and the suitability of the composites developed for practical applications is not clear. This review provides an overview of the literature available on composites developed using thermoplastic soy-based resins, properties of such composites and their limitations and future potential. © The Author(s) 2015.
Yallappa S.,Kuvempu University |
Manjanna J.,Rani Channamma University |
Dhananjaya B.L.,Jain University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2015
A green chemistry approach for the synthesis of Au, Ag and Au-Ag alloy nanoparticles (NPs) using the corresponding metal precursors and Jasminum sambac leaves extract as both reducing and capping media, under microwave irradiation, is reported. During the formation, as expected, the reaction mixture shows marginal decrease in pH and an increase in solution potential. The formation of NPs is evident from their surface plasmon resonance (SPR) peak observed at ∼555 nm for Au, ∼435 nm for Ag and ∼510 nm for Au-Ag alloy. The XRD pattern shows fcc structure while the FTIR spectra indicate the presence of plant residues adsorbed on these NPs. Such a bio-capping of NPs is characterized by their weight loss, ∼35% due to thermal degradation of biomass, as observed in TG analysis. The colloidal dispersion of NPs is stable for about 6 weeks. The near spherical shape of NPs (20-50 nm) is observed by FE-SEM/TEM images and EDAX gives the expected elemental composition. Furthermore, these NPs showed enhanced antimicrobial activity (∼1-4-fold increase in zone of inhibition) in combination with antimicrobials against test strains. Thus, the phytosynthesized NPs could be used as effective growth inhibitors for various microorganisms. © 2014 Elsevier B.V. All rights reserved.
Ashokkumar C.R.,Jain University
JVC/Journal of Vibration and Control | Year: 2015
Substantial developments have taken place in the areas of structural health monitoring, wherein, the objective is not only to detect damage but also to determine its size and location across the structure. Often, the damaged structures do not become obsolete unless the damage is severe. Thus, it is important to mitigate the growth of damage and prevent the possibilities of a structural failure. Vibration is an important source of damage growth. Therefore, it is important to control vibrations such that the damage growth is mitigated. Supposing an effect of damage in the structure is said to be mitigated when the vibration response of the damaged structure with control is the same as the vibration response of the undamaged structure, then one of the requirements is that the closed loop eigenstructure of the damaged structure needs to match with the open loop eigenstructure of the undamaged structure. In this framework, this paper uses a linear algebraic technique to assign the undamaged eigenvalues and eigenvectors for the damaged structure with a stiffness loss using a state feedback controller. Through this technique, it is shown that the vibration control using an actuator load can help to mitigate damage growth by reducing the vibration response magnitudes at the damaged structural degrees of freedom, while these magnitudes at other nodes are allowed to increase due to the actuator loads. Vibration control in this sense for structural damage mitigation is illustrated using discrete and continuous structures. © SAGE Publications.