Showing papers by "SRM University published in 2011"
TL;DR: The purpose of this review is to take a closer look on the wound dressing applications of biomaterials based on chitin, chitosan and their derivatives in various forms in detail.
1,559 citations
TL;DR: This is the first report where M. edule leaf broth was found to be a suitable plant source for the green synthesis of silver and gold nanoparticles, and the characterized nanoparticles of M.Edule have potential for various medical and industrial applications.
Abstract: We used an aqueous leaf extract of Memecylon edule (Melastomataceae) to synthesize silver and gold nanoparticles. To our knowledge, this is the first report where M. edule leaf broth was found to be a suitable plant source for the green synthesis of silver and gold nanoparticles. On treatment of aqueous solutions of silver nitrate and chloroauric acid with M. edule leaf extract, stable silver and gold nanoparticles were rapidly formed. The gold nanoparticles were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX) and Fourier transform infra-red spectroscopy (FTIR). The kinetics of reduction of aqueous silver and gold ions during reaction with the M. edule leaf broth were easily analyzed by UV-visible spectroscopy. SEM analysis showed that aqueous gold ions, when exposed to M. edule leaf broth, were reduced and resulted in the biosynthesis of gold nanoparticles in the size range 20-50 nm. TEM analysis of gold nanoparticles showed formation of triangular, circular, and hexagonal shapes in the size range 10-45 nm. The resulting silver nanoparticles were predominantly square with uniform size range 50-90 nm. EDAX results confirmed the presence of triangular nanoparticles in the adsorption peak of 2.30 keV. Further FTIR analysis was also done to identify the functional groups in silver and gold nanoparticles. The characterized nanoparticles of M. edule have potential for various medical and industrial applications. Saponin presence in aqueous extract of M. edule is responsible for the mass production of silver and gold nanoparticles.
313 citations
TL;DR: Results suggested that CS/nHAp/nAg bio-composite scaffolds have the potential in controlling implant associated bacterial infection during reconstructive surgery of bone.
261 citations
TL;DR: This review paper provides the recent development on chitosan derivatives available for gene delivery and its applications including the interaction and intracellular delivery of genetic materials.
240 citations
TL;DR: In this paper, the effect of antioxidant additives on NOx emissions in a jatropha methyl ester fuelled direct injection diesel engine have been investigated experimentally and compared with conventional diesel fuel.
223 citations
TL;DR: It is concluded that guar gum and its derivatives in the various forms such as coatings, matrix tablets, hydrogels and nano/microparticles can be exploited as potential carriers for targeted drug delivery.
187 citations
TL;DR: In this paper, the properties of concrete using coconut shell as coarse aggregate were investigated in an experimental study and the results showed that the experimental bond strength of coconut shell concrete is much higher than the bond strength as estimated by BS 8110 and IS 456:2000 for the mix selected.
187 citations
TL;DR: In this paper, the authors have proposed three different carrier pulse width modulation techniques, which can reduce the total harmonic distortion and enhance the output voltages from a five level inverter, adopting the constant switching frequency, variable switching frequency (VSF), and phase shifted pulsewidth modulation (PSPWM) concepts.
Abstract: Multilevel inverter is used in applications that need high voltage and high current. The topologies of multilevel inverter have several advantages such as lower total harmonic distortion (THD), lower electro magnetic interference (EMI) generation, high output voltage. The main feature of multilevel inverter is the ability to reduce the voltage stress on each power device due to the utilisation of multilevel on the DC bus. The advent of multilevel inverter topologies has caused variety of pulse width modulation strategies. In this paper, various carrier pulse width modulation techniques are proposed, which can minimise the total harmonic distortion and enhances the output voltages from five level inverter. Three methodologies adopting the constant switching frequency (CSF), variable switching frequency (VSF), and phase shifted pulse width modulation (PSPWM) concepts are proposed in this paper. The above methodologies divided into two techniques like subharmonic pulse width modulation which minimises total harmonic distortion and switching frequency optimal pulse width modulation which enhances the output voltages. Field programmable gate array (FPGA) has been chosen to implement the pulse width modulation due its fast proto typing, simple hardware and software design. The simulation and experimental results are presented.
181 citations
TL;DR: The use of c-SVC and nu-S VC models of support vector machine (SVM) with four kernel functions for classification of faults using statistical features extracted from vibration signals under good and faulty conditions of rotational mechanical system is presented.
Abstract: The shaft and bearing are the most critical components in rotating machinery. Majority of problems arise from faulty bearings in turn affect the shaft. The vibration signals are widely used to determine the condition of machine elements. The vibration signals are used to extract the features to identify the status of a machine. This paper presents the use of c-SVC and nu-SVC models of support vector machine (SVM) with four kernel functions for classification of faults using statistical features extracted from vibration signals under good and faulty conditions of rotational mechanical system. Decision tree algorithm was used to select the prominent features. These features were given as inputs for training and testing the c-SVC and nu-SVC model of SVM and their fault classification accuracies were compared.
168 citations
TL;DR: Using nickel and ferric nitrates and citric acid, NiFe 2 O 4 nanoparticles are prepared by a simple and cost-effective polyvinylpyrrolidone (PVP) assisted sol-gel auto-combustion method.
164 citations
TL;DR: This study focuses on the extracellular biosynthesis of highly stable Ag-BNPs from bacterial strain Bacillus megaterium by bio-reduction of silver ion using the culture supernatant, and to determine the antibacterial efficacy on multi drug resistant clinical pathogens such as Streptococcus pneumoniae and Salmonella typhi.
TL;DR: In this article, the direct and indirect band gaps are estimated from UV-vis-NIR absorption spectrum as 1.78 and 1.2 eV, respectively, due to phonon confinement effect.
TL;DR: A peptide having high antioxidant properties was isolated from horse mackerel viscera protein, Magalaspis cordyla and exhibited high activity against polyunsaturated fatty acid (PUFA) peroxidation than that of natural antioxidant, α-tocopherol.
TL;DR: The results of such a study using SVM and PSVM classifiers for statistical and histogram features of time domain signal are presented, very interesting and challenging; some useful conclusions were drawn and presented.
Abstract: Bearings in the machines are the major components of interest for condition monitoring. Their failure causes increase in down time and maintenance cost. A possible solution to the problem is developing an on-line condition monitoring system. The vibration characteristics can be a determining factor that will reveal the condition of the bearing parts. Visual inspection of frequency-domain features of the vibration signals may be sufficient to identify the faults, but it requires large domain knowledge and it is a function of speed. Automatic diagnostic techniques allow relatively unskilled operators to make important decisions. In this context, machine learning algorithms have been successfully used to solve the problem with the help of vibration signals. The machine learning procedure has three important phases: feature extraction, feature selection and feature classification. Feature selection involves identifying the good features that contributes greatly for classification and determining the number of such features. Often researchers overlook the later issue and arbitrarily choose the number of features. As there is no science that will tell the right number of features, for a given problem, an extensive study is needed to find the optimum number of features and this paper presents the results of such a study using SVM and PSVM classifiers for statistical and histogram features of time domain signal. The findings are very interesting and challenging; some useful conclusions were drawn and presented.
TL;DR: In this article, a polyvinyl alcohol (PVA) assisted sol-gel auto-combustion method was used to extract single-phase nickel ferrite (NiFe 2 O 4 ) nanoparticles.
TL;DR: In this paper, a polymer assisted co-precipitation method was used to synthesize a NiFe2O4 nanosheet, which was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscope (HRTEM), HRSEM, thermal analysis and vibrating sample magnetometry (VSM).
TL;DR: In this study, images with different known conditions were acquired, preprocessed, and histogram features were extracted, and the classification accuracies of C4.5 classifier algorithm and Naive Bayes algorithm were compared, and results are reported.
Abstract: Visual inspection on the surface of components is a main application of machine vision. Visual inspection finds its application in identifying defects such as scratches, cracks bubbles and measurement of cutting tool wear and welding quality. Machine learning approach to machine vision helps in automating the design process of machine vision systems. This approach involves image acquisition, preprocessing, feature extraction and classification. Study shows a library of features, and classifiers are available to classify the data. However, only the best combination of them can yield the highest classification accuracy. In this study, images with different known conditions were acquired, preprocessed, and histogram features were extracted. The classification accuracies of C4.5 classifier algorithm and Naive Bayes algorithm were compared, and results are reported. The study shows that C4.5 algorithm performs better.
TL;DR: Chitosan, nano-scaled silicon dioxide and zirconia were combined by freeze drying technique to fabricate a bio-composite scaffold that possessed a porous nature with pore dimensions suitable for cell infiltration and colonization.
TL;DR: The large number of transcripts reported in the current study together with existing ESTs and transcript sequences will serve as an invaluable genetic resource for crop improvement in jatropha.
Abstract: Jatropha curcas L. is an important non-edible oilseed crop with promising future in biodiesel production. However, factors like oil yield, oil composition, toxic compounds in oil cake, pests and diseases limit its commercial potential. Well established genetic engineering methods using cloned genes could be used to address these limitations. Earlier, 10,983 unigenes from Sanger sequencing of ESTs, and 3,484 unique assembled transcripts from 454 pyrosequencing of uncloned cDNAs were reported. In order to expedite the process of gene discovery, we have undertaken 454 pyrosequencing of normalized cDNAs prepared from roots, mature leaves, flowers, developing seeds, and embryos of J. curcas. From 383,918 raw reads, we obtained 381,957 quality-filtered and trimmed reads that are suitable for the assembly of transcript sequences. De novo contig assembly of these reads generated 17,457 assembled transcripts (contigs) and 54,002 singletons. Average length of the assembled transcripts was 916 bp. About 30% of the transcripts were longer than 1000 bases, and the size of the longest transcript was 7,173 bases. BLASTX analysis revealed that 2,589 of these transcripts are full-length. The assembled transcripts were validated by RT-PCR analysis of 28 transcripts. The results showed that the transcripts were correctly assembled and represent actively expressed genes. KEGG pathway mapping showed that 2,320 transcripts are related to major biochemical pathways including the oil biosynthesis pathway. Overall, the current study reports 14,327 new assembled transcripts which included 2589 full-length transcripts and 27 transcripts that are directly involved in oil biosynthesis. The large number of transcripts reported in the current study together with existing ESTs and transcript sequences will serve as an invaluable genetic resource for crop improvement in jatropha. Sequence information of those genes that are involved in oil biosynthesis could be used for metabolic engineering of jatropha to increase oil content, and to modify oil composition.
TL;DR: The results indicate that the fuzzy logic modeling technique can be effectively used for the prediction of surface roughness in machining of CFRP composites.
Abstract: In recent days, carbon fiber reinforced polymer (CFRP) composites play a vital role in various engineering and technological applications. They are replacing conventional materials due to their excellent properties. Tubes made of these materials are made up of either hand layup process or filament winding processes and are widely used in aircraft, automobile, sports industries, etc., The objective of this study is to examine the influence of machining parameters combination so as to obtain a good surface finish in turning of CFRP composite by cubic boron nitride (CBN) cutting tool and to predict the surface roughness values using fuzzy modeling. The results indicate that the fuzzy logic modeling technique can be effectively used for the prediction of surface roughness in machining of CFRP composites.
TL;DR: In this paper, an artificial neural network (ANN)-based approach for on-line voltage security assessment is presented. And the proposed approach uses radial basis function (RBF) networks to estimate the voltage stability level of the system under contingency state.
TL;DR: In this article, the authors compared the costs of a decentralised renewable energy system and providing electricity from a grid source and determined the critical or break-even distance that makes electricity from such a system cost effective over that from a conventional grid source.
TL;DR: In this paper, the authors focused on factors such as pore size, surface topography and roughness, protein adsorption and wettability of nano-structures and their interaction with cell surface integrins molecules.
Abstract: Bone tissue engineering is an interdisciplinary field which is emerged for the development of viable substitutes that restore and maintain the function of human bone tissues. The success of bone tissue engineering depends on designing of the scaffolds. The polymer-based composite scaffolds containing micro- and nano-structures could provide a platform influencing osteoblastic cell adhesion, spreading, proliferation, and differentiation. Osteoblasts may adhere strongly to the nano-structures than micro-structures in the scaffolds due to the large surface area, better osteo-integrative property and mechanical reliability etc. In this review we are focusing the factors such as pore size, surface topography and roughness, protein adsorption and wettability of nano-structures and their interaction with cell surface integrins molecules. A better understanding of the interactions of nano-structures with osteoblastic cells will have potential applications in the regeneration of bone.
TL;DR: In this paper, a sheet-like nickel ferrite (NiFe2O4) was synthesized with PVA matrices using co-precipitation technique, which is formed from the oriented aggregation of single crystalline NiFe 2O4 nanoparticles.
TL;DR: In this paper, a tool condition monitoring using Support Vector Machine (SVM) and N-SVM classifiers was discussed. And the results with other classifiers like Decision Tree and Naive Bayes and Bayes Net were analyzed.
Abstract: The studies on tool condition monitoring along with digital signal processing can be used to prevent damages on cutting tools and workpieces when the tool conditions become faulty. These studies have become more relevant in today's context where the order realization dates are crunched and deadlines are to be met in order to catch up with the competition. Based on a continuous acquisition of signals with sensor systems it is possible to classify certain wear parameters by the extraction of features. Data mining approach is extensively used to probe into structural health of the tool and the process. This paper discusses condition monitoring of carbide tipped tool using Support Vector Machine and compares the classification efficiency between C-SVC and @n-SVC. It further analyses the results with other classifiers like Decision Tree and Naive Bayes and Bayes Net. The vibration signals are acquired for various tool conditions like tool-good condition, tip-breakage, etc. The effort is to bring out the better features-classifier combination.
TL;DR: Positive regulation of C. quadrangularis on the proliferation, differentiation, and matrix mineralization of human osteoblast like SaOS‐2 cells is indicated.
Abstract: Osteoporosis is a public health problem which is associated with significant morbidity and mortality. The repair of bone defect is still a big challenge for orthopedic surgeons. Traditional use of Cissus quadrangularis (C. quadrangularis) in the treatment of bone disorders has been documented. The present study was employed to delineate the effects of ethanolic extract of C. quadrangularis on the proliferation, differentiation and matrix mineralization of human osteoblast like SaOS-2 cells. Lactate dehydrogenase assayed in the conditioned medium of control and C. quadrangularis treated cells did not differ significantly indicating that ethanolic extract of C. quadrangularis is nontoxic to osteoblastic cells. [(3)H] Thymidine incorporation assay revealed that C. quadrangularis treatment has increased the DNA synthesis of human osteoblastic SaOS-2 cells indicating increased proliferation of these cells. The data on alizarin red and ALP staining revealed increased matrix mineralization of human osteoblast like SaOS-2 cells. The study also revealed that the anabolic actions of ethanolic extract of C. quadrangularis in human osteoblast like cells are mediated through increased mRNA and protein expression of Runx2, a key transcription factor involved in the regulation of bone matrix proteins. Chromatin immunoprecipitation analysis revealed increased transcriptional activity of Runx2 on the promoter of osteocalcin after C. quadrangularis treatment. These results indicate positive regulation of C. quadrangularis on the proliferation, differentiation, and matrix mineralization of human osteoblast like SaOS-2 cells.
TL;DR: In this paper, the analysis of surface characteristics like surface roughness, micro cracks of Inconel-825 is carried out and an excellent machined nano finish can be obtained by setting the machining parameters at optimum level.
TL;DR: The use of electrospun scaffolds as drug carriers is promising for future biomedical applications, particularly in the prevention of post-surgical adhesions and infections, for postoperative local chemotherapy, and for bone and skin tissue engineering.
Abstract: Controlled delivery systems are used to improve therapeutic efficacy and safety of drugs by delivering them over a period of treatment to the site of action at a rate dictated by the need of the physiological environment. A wide variety of polymeric materials, either biodegradable or non-biodegradable but biocompatible, can be used as delivery matrices. Recently, nanofibrous scaffolds, such as the systems fabricated by electrospinning or electrospraying, have been used in the field of biomedical engineering as wound dressings, scaffolds for tissue engineering, and drug delivery systems. The electrospun nanofibrous scaffolds can be used as carriers for various types of drugs, genes, and growth factors, whereby the release profile can be finely controlled by modulation of the scaffold’s morphology, porosity, and composition. The main advantage of this system is that it offers site-specific delivery of any number of therapeutics from the scaffold into the body. The aim of this chapter is to review the recent advances on electrospun nanofibrous scaffolds based on biodegradable and biocompatible polymers for controlled drug and biomolecule delivery applications. The use of electrospun scaffolds as drug carriers is promising for future biomedical applications, particularly in the prevention of post-surgical adhesions and infections, for postoperative local chemotherapy, and for bone and skin tissue engineering.
TL;DR: Fraction IIIb did not show any cytotoxic effect for Vero cell lines and exerted a significant antiproliferative effect on Hep G2 cell lines, and the potent purified fraction was tested for cell cytotoxicity on Vero and Hep G1 cell lines.
Abstract: Summary
The aim of this study was to evaluate antioxidant, antiproliferative and antimicrobial properties of flying fish (Exocoetus volitans) backbone hydrolysed by three different enzymes namely papain, pepsin and trypsin. The in vitro antioxidant potencies of hydrolysates and purified peptides against 1, 1-diphenyl-2-picrylhydrazyl, superoxide and hydroxyl radicals were evaluated by electron spin resonance spectroscopy. The peptic protein hydrolysate showed maximum free radical scavenging potential and lipid peroxidation inhibition and was further purified by DEAE XK 26/20 anion exchange chromatography followed by G-25 gel permeation chromatography. The amino acid composition of potent purified fraction was determined by HPLC, contains essential and nonessential amino acids with glutamic acid (24.10%), lysine (23.62%), glycine (12.05%) and threonine (10.41%) as the dominant amino acids. The potent purified fraction was tested for cell cytotoxicity on Vero and Hep G2 cell lines. It was found that fraction IIIb did not show any cytotoxic effect for Vero cell lines and exerted a significant antiproliferative effect on Hep G2 cell lines.
TL;DR: Significant antidiabetic effect with the stem extract of G. montanum is clearly indicated and lends support for its traditional usage.