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Search Results: 1 - 10 of 21276 matches for " Sarat Kumar Dash "
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Dynamic Mechanical Behavior of Luffa cylindrica Fiber-Resorcinol Composites  [PDF]
Chhatrapati Parida, Chinmay Pradhan, Sarat Kumar Dash, Sarat Chandra Das
Open Journal of Composite Materials (OJCM) , 2015, DOI: 10.4236/ojcm.2015.51005
Abstract: Dynamic mechanical behaviour of resorcinol-formaldehyde matrix and its composites reinforced with natural fibers of Luffa cylindrica (LC) has been studied. The effects of fiber loading, alkali treatment on fiber, temperature and frequency on storage modulus and mechanical-loss factor of the composites were studied. The dynamic mechanical behaviour of the composites and pure matrix has been investigated in the frequency range from 0.1 Hz to 10 Hz and temperature range from 26 to 100. The experimental results show that the values of storage modulus of the composites increase with increase in fiber loading. The storage modulus of treated LC fiber composites were found to be enhanced when compared with the untreated fiber composites. It was also found that mechanical-loss factor was more when untreated LC fibers were incorporated in the composites and decreased with the incorporation of treated LC fiber. The storage modulus of all the composites increased with frequency but decreased with rise of temperature. The glass transition temperature of the composites was evaluated from the peaks of tan delta variations.
FTIR and Raman Studies of Cellulose Fibers of Luffa cylindrica  [PDF]
Chhatrapati Parida, Sarat Kumar Dash, Chinmay Pradhan
Open Journal of Composite Materials (OJCM) , 2015, DOI: 10.4236/ojcm.2015.51002
Abstract: In view of biomedical applications of cellulose fibers in orthopedics, dentistry and reconstructive surgery, Luffa cylindrica (LC), a local forest product of Orissa, India, has been used for preparation of alkali treated LC fiber modified with calcium carbonate and calcium phosphate separately by following standard procedures. FTIR and Raman spectra were obtained for these samples at wavelength range 500 - 4000 cm1 and 300 - 3000 cm1 respectively. Lattice structures of cellulose i.e., crystalline cellulose and amorphous cellulose were detected using Raman spectroscopy and discussed. The property of cellulose such as its degree of crystallinity was determined from intensity of FT IR peaks and was found to be 74.12%. The presence of calcite and hydroxy apatite, polymorphs of calcium carbonate and calcium phosphate respectively were confirmed in the treated modified LC fibers which can be used as bioactive materials.
Mechanical Properties of Injection Molded Poly(lactic) Acid—Luffa Fiber Composites  [PDF]
Chhatrapati Parida, Sarat Kumar Dash, Pinaki Chaterjee
Soft Nanoscience Letters (SNL) , 2015, DOI: 10.4236/snl.2015.54008
Abstract: The influence of cellulose nano fibers extracted from the fruit of luffa cylindrica (LC) on the tensile, flexural and impact properties of composite materials using poly lactic acid (PLA) processed by micro compounding and injection molding was studied. Preliminary results suggested promising mechanical properties. The impact strength, tensile strength and flexural strength of the composites increased with incorporation of very low content of LC fiber up to 2 wt%. But when the wt of LC fiber in the composite increased (5 wt% and 10 wt%), mechanical strength of the composites reduced probably due to agglomeration of cellulose fibers. However, modulus of composites was enhanced with increase in wt of fiber content in the composites. Before reinforcement, the LC fibers were modified with calcium phosphate in order to explore the possibilities of using these composites in biomedical industries. The novelty of this work is that there is no use of compatiblizer and coupling agent during the processing so that the cost of processing is reduced.
The Thermal and Crystallization Studies of Luffa Fiber Reinforced Poly Lactic Acid Composites  [PDF]
Chhatrapati Parida, Sarat Kumar Dash, Pinaki Chaterjee
Open Journal of Composite Materials (OJCM) , 2016, DOI: 10.4236/ojcm.2016.61001
Abstract: Poly lactic acid (PLA)—chemically treated fiber of Luffa cylindrica (LC) composites were fabricated by micro-compounding followed by injection molding method. Before reinforcement, LC fibers were exposed to chemical treatment like alkali treatment, bleaching and acid hydrolysis. The chemically treated LC fibers were then modified with Ca salts to explore their uses in bio medical industries. Thermal stability of chemically extracted cellulose fibers of LC and PLA composites reinforced with 2 wt%, 5 wt% and 10 wt% LC fibers were studied by thermo gravimetric analysis (TGA) in the temperature range from 30℃ to 700. Better interfacial bonding between fiber and matrix was evidenced by increased thermal stability of composites due to incorporation of fiber. Crystallization and melting behavior of PLA composites were studied in the temperature range from 30 to 170 at heating rate of 10°/minute. The crystallization temperature and crystallization enthalpy increased up to 2 wt% of LC fiber content and gradually decreased with further increase of fiber content in the composites. Double melting peaks were observed for all composite samples and possible explanations were suggested on the basis of different crystalline structure of PLA and melt crystallization phenomena.
Prediction of hydrophobic regions effectively in transmembrane proteins using digital filter  [PDF]
Jayakishan Meher, Mukesh Kumar Raval, Gananath Dash, Pramod Kumar Meher
Journal of Biomedical Science and Engineering (JBiSE) , 2011, DOI: 10.4236/jbise.2011.48072
Abstract: The hydrophobic effect is the major factor that drives a protein molecule towards folding and to a great degree the stability of protein structures. Therefore the knowledge of hydrophobic regions and its prediction is of great help in understanding the structure and function of the protein. Hence determination of membrane buried region is a computationally intensive task in bioinformatics. Several prediction methods have been reported but there are some deficiencies in prediction accuracy and adaptability of these methods. Of these proteins that are found embedded in cellular membranes, called as membrane proteins, are of particular importance because they form targets for over 60% of drugs on the market. 20-30% of all the proteins in any organism are membrane proteins. Thus transmembrane protein plays important role in the life activity of the cells. Hence prediction of membrane buried segments in transmembrane proteins is of particular importance. In this paper we have proposed signal processing algorithms based on digital filter for prediction of hydrophobic regions in the transmembrane proteins and found improved prediction efficiency than the existing methods. Hydrophobic regions are extracted by assigning physico-chemical parameter such as hydrophobicity and hydration energy index to each amino acid residue and the resulting numerical representation of the protein is subjected to digital low pass filter. The proposed method is validated on transmembrane proteins using Orientation of Proteins in Membranes (OPM) dataset with various prediction measures and found better prediction accuracy than the existing methods.
The Role of Combined OSR and SDF Method for Pre-Processing of Microarray Data that Accounts for Effective Denoising and Quantification  [PDF]
Jayakishan Meher, Mukesh Kumar Raval, Pramod Kumar Meher, Gananath Dash
Journal of Signal and Information Processing (JSIP) , 2011, DOI: 10.4236/jsip.2011.23026
Abstract: Microarray data is inherently noisy due to the noise contaminated from various sources during the preparation of microarray slide and thus it greatly affects the accuracy of the gene expression. How to eliminate the effect of the noise constitutes a challenging problem in microarray analysis. Efficient denoising is often a necessary and the first step to be taken before the image data is analyzed to compensate for data corruption and for effective utilization for these data. Hence preprocessing of microarray image is an essential to eliminate the background noise in order to enhance the image quality and effective quantification. Existing denoising techniques based on transformed domain have been utilized for microarray noise reduction with their own limitations. The objective of this paper is to introduce novel preprocessing techniques such as optimized spatial resolution (OSR) and spatial domain filtering (SDF) for reduction of noise from microarray data and reduction of error during quantification process for estimating the microarray spots accurately to determine expression level of genes. Besides combined optimized spatial resolution and spatial filtering is proposed and found improved denoising of microarray data with effective quantification of spots. The proposed method has been validated in microarray images of gene expression profiles of Myeloid Leukemia using Stanford Microarray Database with various quality measures such as signal to noise ratio, peak signal to noise ratio, image fidelity, structural content, absolute average difference and correlation quality. It was observed by quantitative analysis that the proposed technique is more efficient for denoising the microarray image which enables to make it suitable for effective quantification.
Design of a Concentration Sensor Based on Photonic Crystal Fiber Placed between Two Single Mode Fibers  [PDF]
Jitesh Kumar Verma, Sonali Prava Dash, Sukanta Kumar Tripathy
Soft Nanoscience Letters (SNL) , 2013, DOI: 10.4236/snl.2013.34A010
Abstract: We demonstrate the use of photonic crystal fiber (PCF) joined in between two single mode fibers (SMF) as a concentration sensor. To realize this, one micrometer length PCF of hexagonal lattice is sandwiched between two SMF having one micrometer length each. To maximize the coupling between SMF and PCF, the core diameters are made equal. Then the output from a given input through this structure is analyzed with respect to different concentrations in the air holes of PCF using Finite Difference Time Domain (FDTD) method. It is found that the variation of electric field intensity at the output is linear with respect to concentration of alcohol.
Do the Indian Agricultural Commodities’ Prices Exhibit Non-Linear Mean Reversion? An Empirical Evidence  [PDF]
Aviral Kumar Tiwari, Mothkuri Aruna, Aruna Kumar Dash
Theoretical Economics Letters (TEL) , 2015, DOI: 10.4236/tel.2015.52039
Abstract: Indian economy’s inflation index often reflects double digit tendencies due to supply side shortages caused by droughts, rise in the prices of crude oil in the international markets etc. These factors may be responsible for non-linear behaviour of inflation index. Against this backdrop, an attempt is made in this study to capture non-linear mean reversion of prices of 47 agricultural commodities of India. The study employs powerful non-linear unit root test so as to generate robust findings to infer valid policy implications. The results of the study indicate the presence of unit root with drift process for Food Grains, Cereals, Pulses, Fruits, Vegetables, Primary Articles, Ragi and Rice. And for rest of the commodities, it is observed that there is evidence of mean reversion and therefore, the impact would be only temporary in nature. Thus, the empirical inferences enable the policy makers to design appropriate short term and long term polices related to the prices of agricultural commodities.
Analysis of Adaptive Fuzzy Technique for Multiple Crack Diagnosis of Faulty Beam Using Vibration Signatures
Amiya Kumar Dash
Advances in Fuzzy Systems , 2013, DOI: 10.1155/2013/164853
Abstract:
Analysis of Adaptive Fuzzy Technique for Multiple Crack Diagnosis of Faulty Beam Using Vibration Signatures
Amiya Kumar Dash
Advances in Fuzzy Systems , 2013, DOI: 10.1155/2013/164853
Abstract: This paper discusses the multicrack detection of structure using fuzzy Gaussian technique. The vibration parameters derived from the numerical methods of the cracked cantilever beam are used to set several fuzzy rules for designing the fuzzy controller used to predict the crack location and depth. Relative crack locations and relative crack depths are the output parameters from the fuzzy inference system. The method proposed in the current analysis is used to evaluate the dynamic response of cracked cantilever beam. The results of the proposed method are in good agreement with the results obtained from the developed experimental setup. 1. Introduction Beams are one of the most commonly used structural elements in numerous engineering applications and experience a wide variety of static and dynamic loads. Cracks may develop in beam-like structures due to such loads. Considering the crack as a significant form of such damage, its modeling is an important step in studying the behavior of damaged structures. As stated, beam type structures are being commonly used in steel construction and machinery industries. Studies based on structural health monitoring for crack detection deal with change in natural frequencies and mode shapes of the beam. An analytical study has been performed by Yang et al. [1] on the free and forced vibration of inhomogeneous Euler-Bernoulli beams containing open edge cracks. Analytical solutions are obtained for cantilever, with different end conditions to evaluate the dynamic response of the beam due to the edge crack. Orhan [2] has performed a free and forced vibration analysis of a cracked beam in order to identify the cracks in a cantilever beam. Their study reveals that free vibration analysis provides more suitable information for the detection of cracks than the forced vibration analysis. Damage in a cracked structure has been analyzed using genetic algorithm technique by Vakil-Baghmisheh et al. [3]. For modeling the cracked-beam structure, an analytical model of a cracked cantilever beam has been utilized, and natural frequencies are obtained through numerical methods. A genetic algorithm is utilized to monitor the possible changes in the natural frequencies of the structure. Theoretical and experimental dynamic behaviors of different multibeams systems containing a transverse crack have been performed by Saavedra and Cuitio [4]. A new cracked stiffness matrix is deduced based on flexibility, and this can be used subsequently in the FEM analysis of crack systems. Bakhary et al. [5] used Artificial Neural Network (ANN) for
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