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Search Results: 1 - 10 of 1097 matches for " Samikkannu Raja "
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Finite Element Analysis and Vibration Control of a Deep Composite Cylindrical Shell Using MFC Actuators
Gangolu Vijay Kumar,Samikkannu Raja,Karavadappa Basavarajappa Prasanna,Valliappan Sudha
Smart Materials Research , 2012, DOI: 10.1155/2012/513271
Abstract: A four-node composite facet-shell element is developed, accounting for electromechanical coupling of Macrofiber Composite (MFC) and conventional PZT patches. Further a warping correction is included in order to capture correctly the induced strain of conformable MFC, surface bonded on a cylindrical shell. The element performance to model the relations between in-plane electric field to normal strains is examined with the help of experiment and ANSYS analysis. In ANSYS, a simple modeling scheme is proposed for MFC using a parallel capacitors concept. The independent modal space control technique has been revisited to address the control of combination resonances through a selective modal space control scheme, where two or more modes can be combined to form the vibrating system or plant in modal domain. The developed control schemes are implemented in a digital processor using DS1104 and the closed-loop vibration control experiments are conducted on a CFRP shell structure. The influence of directionally induced actuation of MFC actuators on elastic couplings of composite shell is studied theoretically and is subsequently demonstrated in experiments. MFC actuators provide the much needed optimization domain for achieving the vibration control of combination resonances of elastically coupled deep-shell structure. 1. Introduction Active control techniques are becoming more popular in recent years due to the emergence of a field called “Smart Materials and Structure.” Smart materials such as piezoelectric, shape memory alloys, and magnetostrictive have got multi functional behaviors, namely, actuation, sensing, and load carrying. Among these, the electromechanically coupled piezoelectric materials possess immense potentials because of its dynamic characteristics (wider frequency band, large force) and their availability in different forms (bar, patch, composite, stack, etc.). Piezoelectric patches and composites such as Macrofibre Composite (MFC), Active Fibre Composite (AFC) are increasingly considered as actuators by research communities to address various vibration control-related problems in recent years [1–7]. Shell structures are commonly adopted in aerospace vehicles [8]. The wing panels, fuselage outer skins, tail panels, and so forth are constructed with shell structural elements using aluminum and composite materials. Light weight aerospace, naval and civil engineering structures usually employ shell configurations to attain structural efficiencies such as improved stiffness, desired shape, optimal weight, and aeroelastic characteristics. Although
Protecting Water Quality and Public Health Using a Smart Grid  [PDF]
Ken Thompson, Raja Kadiyala
Computational Water, Energy, and Environmental Engineering (CWEEE) , 2013, DOI: 10.4236/cweee.2013.22B013
Abstract: After the attacks on September 11, 2001 and the follow-up risk assessments by utilities across the United States, securing the water distribution system against malevolent attack became a strategic goal for the U.S. Environmental Protection Agency. Following 3 years of development work on a Contamination Warning System (CWS) at the Greater Cincinnati Water Works, four major cities across the United States were selected to enhance the CWS development conducted by the USEPA. One of the major efforts undertaken was to develop a process to seamlessly process “Big Data” sets in real time from different sources (online water quality monitoring, consumer complaints, enhanced security, public health surveillance, and sampling and analysis) and graphically display actionable information for operators to evaluate and respond to appropriately. The most significant finding that arose from the development and implementation of the “dashboard” were the dual benefits observed by all four utilities: the ability to enhance their operations and improve the regulatory compliance of their water distribution systems. Challenge: While most of the utilities had systems in place for SCADA, Work Order Management, Laboratory Management, 311 Call Center Management, Hydraulic Models, Public Health Monitoring, and GIS, these systems were not integrated, resulting in duplicate data entry, which made it difficult to trace back to a “single source of truth.” Each one of these data sources can produce a wealth of raw data. For most utilities, very little of this data is being translated into actionable information as utilities cannot overwhelm their staffs with manually processing the mountains of data generated. Instead, utilities prefer to provide their staffs with actionable information that is easily understood and provides the basis for rapid decision-making. Smart grid systems were developed so utilities can essentially find the actionable needle in the haystack of data. Utilities can then focus on rapidly evaluating the new information, compare it known activities occurring in the system, and identify the correct level of response required. Solution: CH2M HILL was engaged to design, implement, integrate, and deploy a unified spatial dashboard/smart grid system. This system included the processes, technology, automation, and governance necessary to link together the disparate systems in real time and fuse these data streams to the GIS. The overall solution mapped the business process involved with the data collection, the information flow requirements, and the system and
A New Clock Gated Flip Flop for Pipelining Architecture  [PDF]
Krishnamoorthy Raja, Siddhan Saravanan
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.78119
Abstract: The objective of the work is to design a new clock gated based flip flop for pipelining architecture. In computing and consumer products, the major dynamic power is consumed in the system’s clock signal, typically about 30% to 70% of the total dynamic (switching) power consumption. Several techniques to reduce the dynamic power have been developed, of which clock gating is predominant. In this work, a new methodology is applied for gating the Flip flop by which the power will be reduced. The clock gating is employed to the pipelining stage flip flop which is active only during valid data are arrived. The methodology used in project named Selective Look-Ahead Clock Gating computes the clock enabling signals of each FF one cycle ahead of time, based on the present cycle data of those FFs on which it depends. Similarly to data-driven gating, it is capable of stopping the majority of redundant clock pulses. In this work, the circuit implementation of the various blocks of data driven clock gating is done and the results are observed. The proposed work is used for pipelining stage in microprocessor and DSP architectures. The proposed method is simulated using the quartus for cyclone 3 kit.
A BP Artificial Neural Network Model for Earthquake Magnitude Prediction in Himalayas, India  [PDF]
S. Narayanakumar, K. Raja
Circuits and Systems (CS) , 2016, DOI: 10.4236/cs.2016.711294
Abstract: The aim of this study is to evaluate the performance of BP neural network techniques in predicting earthquakes occurring in the region of Himalayan belt (with the use of different types of input data). These parameters are extracted from Himalayan Earthquake catalogue comprised of all minor, major events and their aftershock sequences in the Himalayan basin for the past 128 years from 1887 to 2015. This data warehouse contains event data, event time with seconds, latitude, longitude, depth, standard deviation and magnitude. These field data are converted into eight mathematically computed parameters known as seismicity indicators. These seismicity indicators have been used to train the BP Neural Network for better decision making and predicting the magnitude of the pre-defined future time period. These mathematically computed indicators considered are the clustered based on every events above 2.5 magnitude, total number of events from past years to 2014, frequency-magnitude distribution b-values, Gutenberg-Richter inverse power law curve for the n events, the rate of square root of seismic energy released during the n events, energy released from the event, the mean square deviation about the regression line based on the Gutenberg-Richer inverse power law for the n events, coefficient of variation of mean time and average value of the magnitude for last n events. We propose a three-layer feed forward BP neural network model to identify factors, with the actual occurrence of the earthquake magnitude M and other seven mathematically computed parameters seismicity indicators as input and target vectors in Himalayan basin area. We infer through comparing curve as observed from seismometer in Himalayan Earthquake catalogue comprised of all events above magnitude 2.5 mg, their aftershock sequences in the Himalayan basin of year 2015 and BP neural network predicting earthquakes in 2015. The model yields good prediction result for the earthquakes of magnitude between 4.0 and 6.0.
Ashwagandha (Withania somnifera) Reverses β-Amyloid1-42 Induced Toxicity in Human Neuronal Cells: Implications in HIV-Associated Neurocognitive Disorders (HAND)
Kesava Rao Venkata Kurapati, Venkata Subba Rao Atluri, Thangavel Samikkannu, Madhavan P. N. Nair
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0077624
Abstract: Alzheimer’s disease (AD) is characterized by progressive dysfunction of memory and higher cognitive functions with abnormal accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles throughout cortical and limbic brain regions. At present no curative treatment is available, and research focuses on drugs for slowing disease progression or providing prophylaxis. Withania somnifera (WS) also known as ‘ashwagandha’ is used widely in Ayurvedic medicine as a nerve tonic and memory enhancer. However, there is a paucity of data on the potential neuroprotective effects of W.somnifera against β-Amyloid (1–42)-induced neuropathogenesis. In the present study, we have tested the neuroprotective effects of methanol:Chloroform (3:1) extract of ashwagandha against β-amyloid induced toxicity and HIV-1Ba-L (clade B) infection using a human neuronal SK-N-MC cell line. Our results showed that β-amyloid induced cytotoxic effects in SK-N-MC cells as shown by decreased cell growth when tested individually. Also, confocal microscopic analysis showed decreased spine density, loss of spines and decreased dendrite diameter, total dendrite and spine area in clade B infected SK-N-MC cells compared to uninfected cells. However, when ashwagandha was added to β-amyloid treated and HIV-1 infected samples, the toxic effects were neutralized. Further, the MTT cell viability assays and the peroxisome proliferator-activated receptor-γ (PPARγ) levels supported these observations indicating the neuroprotective effect of WS root extract against β-amyloid and HIV-1Ba-L (clade B) induced neuro-pathogenesis.
Crystallization and Characterization of a New NonLinear Optical Crystal: L Proline Succinate (LPS)  [PDF]
P. Paramasivam, C. Ramachandra Raja
Journal of Crystallization Process and Technology (JCPT) , 2012, DOI: 10.4236/jcpt.2012.21004
Abstract: In this analysis, the single crystal of L-Proline Succinate (LPS) has been successfully synthesized and the purity of ma- terial has been increased by repeated recrystallization process. Single crystal was grown by adopting the method of growing in a slow evaporation solution using water as solvent at room temperature. The LPS single crystal has been synthesized by taking equimolar quantity of L-Proline and succinic acid, by mixing them thoroughly using deionized water. The prepared concentrated solution was placed in an undisturbed condition, and the solution was inspected regu- larly. The single crystal has been harvested over a period of 1 month. The same crystal was characterized by different techniques for finding its suitability for device fabrications. The grown crystal was characterized by Single crystal XRD, Powder XRD, FTIR, UV-vis-NIR, DTA/TGA and SHG analyses, respectively. The observed results from various char- acterization show the suitability for NLO application. The second harmonic generation of this grown crystal was checked using Kurtz Perry technique which showed positive results. The UV cut-off wavelength and the decomposition temperature of this grown crystal were found to be good when compared with the existing organic crystals.
Simple Estimation of Bosentan in Tablet Formulation by RP-HPLC  [PDF]
Selvadurai Muralidharan, Jaya Raja Kumar
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.311095
Abstract: A simple, precise, and accurate method is developed and validated for the analysis of Bosentan tablet formulation. The method has shown adequate separation of the ingredients from Tablets. Separation was achieved on a C18 column using a mobile phase consisting of acetonitrile: 10 Mm ammonium acetate (pH 4.5) buffer (70:30, v/v) at a flow rate of 1.0 ml/min and UV detection at 265 nm. This new method is validated as per the ICH, which includes accuracy, precision, selectivity, linearity and range, robustness and ruggedness. The current method demonstrates good linearity over the range of 5 - 70 ng/ml of bosentan with r2 of 0.999. The average recovery of the method is 98.6%. The degree of reproducibility of the results obtained as an outcome of small deliberate variations in the method parameters and by changing analytical operator has proven that this method is robust and rugged.
Reproductive Performance and Fiber Quality Responses of Cotton to Potassium Nutrition  [PDF]
Suresh Lokhande, K. Raja Reddy
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.67099
Abstract: Potassium (K) deficiency affects cotton growth and development and fiber properties. An experiment was conducted in an outdoor pot culture facility by imposing four potassium stress treatments (100%, 40%, 20% and 0% of optimum K level) prior to flowering during 2010 and 2011 growing season. Upland cotton cultivar, TM-1, was seeded in the pots comprised of fine sand as rooting medium. Flowers and bolls were tagged daily to estimate boll maturation period (BMP). Leaf samples were collected every four days from flowering to maturity to estimate leaf K content. Plant height and node numbers were recorded from emergence to 21 days after treatment. Photosynthesis and stomatal conductance were measured weekly from day of treatment imposition to physiological maturity at an interval of seven days. Stem, leaf, and boll dry-component weights, and boll numbers were recorded at the end of the experiment in each year. From each boll, the lint samples were collected and grouped based on average leaf potassium concentration during BMP, and fiber quality parameters were recorded for each group in each treatment. At high K deficient (0 K) condition, total biomass declined by 27% and 28% in years 2010 and 2011, respectively. Significantly, lower numbers of bolls were retained per plant at 0 K stress treatment during both the years. Leaf photosynthesis (r2 = 0.92) and stomatal conductance (r2 = 0.80) declined with declining leaf K levels. Fiber length, strength, micronaire, and uniformity declined linearly with decrease in leaf K content. Weaker fibers with medium length were produced under K-deficient conditions with micronaire values in the discount range. Fiber uniformity, however, did not decline with decrease in leaf K. The identified leaf K status-specific relationships for fiber properties could be used to improve management practices under potassium deficiency and to develop new sub-routines of the existing cotton simulation models. New and improved models will be useful not only in management, but also in arena of policy decisions including future climate change impact assessment analysis.
Studies on the Growth and Characterization of L-Arginine Maleate Dihydrate Crystal Grown from Liquid Diffusion Technique  [PDF]
K. Ramya, C. Ramachandra Raja
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2016, DOI: 10.4236/jmmce.2016.42014
Abstract: Nonlinear optical crystals of L-Arginine maleate dihydrate were grown from liquid diffusion method. The lattice parameters of the crystal were identified using single crystal and powder crystal X-ray diffraction analyses. Fourier transform infrared spectroscopy and Fourier transform Raman spectroscopy were made to study the vibrational functional groups in the grown crystal. Optical absorption and transmission ranges were measured from UV-VIS-NIR spectrum. The molecular structure of the crystal is established through 1H-NMR and 13C-NMR studies. Thermal stabilities and decomposition of the grown crystal were studied from TG/DTA and DSC analyses. Nonlinear optical property of the crystal was determined by Kurtz and Perry powder technique.
Professional Development And Practices In Classroom
Raja Ambethkar
Golden Research Thoughts , 2012, DOI: 10.9780/22315063
Abstract: The new Oft said Framework is one sign that teachers professionalism is being revived, in a sense. The idea that teachers should just deliver curricula has made them sound more like workers than professionals and this de motivating terminology as, to some extent, been recognized as such by government and other bodies. This potential improvement can be coupled with the increasing evidence that many teachers are leaving after only a few years, literally because they find much of the current accountability framework to be oppressive. This is where the establishment of the GTC may lead to greater self-regulation and a return to a more trusted and autonomous teaching profession. Overall, then, teachers work over the last decade has been made increasingly accountable but also more controlled and restricted. More recently, the damaging effect of this oppressive framework has been recognized and a number of measures suggest a return to more teacher autonomy and professional integrity. This will be discussed further below in relation to the role of teaching assistants.
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