202 research outputs found

    Automatic classification of MR brain tumor images using KNN, ANN, SVM and CNN

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    A brain tumor classification system has been designed and developed. This work presents a new approach to the automated classification of astrocytoma, medulloblastoma, glioma, glioblastoma multiforme and craniopharyngioma type of brain tumors based on first order statistics and gray level co-occurrence matrix, in magnetic resonance images. The magnetic resonance feature image used for the tumor detection consists of T2-weighted magnetic resonance images for each axial slice through the head. To remove the unwanted noises in the magnetic resonance image, median filtering is used. First order statistics and gray level co-occurrence matrix-based features are extracted. Finally, k-nearest neighbor, artificial neural network, support vector machine and convolutional neural networks are used to classify the brain tumor images. The application of the proposed method for tracking tumor is demon­strated to help pathologists distinguish its type of tumor. A classification with an accuracy of 89%, 90%, 91% and 95% has been obtained by, k-nearest neighbor, artificial neural network, support vector machine and convolutional neural networks

    COPRAS Decision Model to Optimize Blind Spot in Heavy Vehicles: A Comparative Perspective

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    AbstractThe visibility of a driver is the key phenomenon in the road accidents. Reduction of blind spot improves the area of visibility which leads to reduce the possibility of the accidents. In this paper an effort is taken to reduce the blind spot area through the optimization of design parameters used in the design of rear view mirror in heavy vehicles. This is achieved by using a multi criteria decision making (MCDM) approach called COPRAS (Complex Proportional Assessment of alternatives) technique. The effectiveness of the developed model is proved by a case study conducted in a public transport corporation located in the southern part of India. The weights of the design parameters are calculated using three different approaches such as AHP (Analytical Hierarchy Process), FARE (Factor Relationship) method and Entropy Measurement and the results are compared

    MATHEMATICAL MODELLING AND SIMULATION OF GRID CONNECTED SOLAR PHOTOVOLTAIC SYSTEM

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    This paper presents the mathematical modeling of three-phase grid connected inverter fed by Solar Photovoltaic (SPV) system with Maximum Power Point Tracking (MPPT). Analysis has been carried out to choose the proper modulation index for maximum output for three-phase inverter. With this modulation index, the variation of the active and reactive power for different loads has been presented along with major parameters like Transfer ratio and Efficiency. Also the Real and Reactive power output of the SPV has been measured with various solar Radiation levels

    Synthesis, characterization, antimicrobial and cytotoxic studies of a novel vanadium dodecylamino phosphate

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    AbstractA novel vanadium dodecylamino phosphate was synthesized by mixing phosphoric acid and vanadyl acetylacetonate with dodecylamine at ambient temperature. The material was characterized by various spectroscopic and analytical techniques to know its morphological and structural characteristics. The biological activity of the material toward antimicrobial, nematicidal, DNA cleavage and cytotoxicity has been screened. The material exhibits moderate to good antimicrobial activity against Gram-positive bacteria. The percentage mortality on Meloidogyne incognita nematode was found to increase with increase in concentration of VDDAP at 48h. Further, the material was investigated for cytotoxicity on human cancer cell lines such as cervix (HeLa), leukemia (HL60) and breast (MCF7). The cells were dosed with varying concentrations of the VDDAP and cell viability was measured by sulforhodamine B (SRB) assay to determine their GI50 values. Interestingly, the compound shows GI50 values of 25.4μgmL−1 (HeLa), 29.1μgmL−1 (MCF7) and a superior value of 11.6μgmL−1 (HL60) respectively. The DNA cleavage activity of the material was investigated using agarose gel electrophoresis

    Mechanical properties evaluation of sisal fibre reinforced polymer composites: a review

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    Recently, growing environmental impact associated with production, disposal and recycling of synthetic fibre based polymer composites triggers the development of ecofriendly composite for various applications such as automotive, marine, chemical, Infrastructure, sporting goods etc. Among many natural fibres like kenaf, jute, oil palm, cotton, flax, banana and hemp, sisal are gaining attention as they are abundantly available, cheaper, eco-friendly and possess remarkable and satisfactory mechanical properties to hemp, banana and jute. Sisal fibre will play a key role to fabricate a varied range of structural and non-structural industrial products with different polymer matrix. This review article deals the mechanical properties of sisal fibre and the several factors influencing the mechanical properties of its polymer composites, such as fibre loadings, fibre length, fibre architecture, chemical treatments and hybridization by incorporating different natural/synthetic fibre/fillers or additive, according to the application and strength requirements. Attempt also been made to investigate the effect of water absorption, chemical concentration, exposure time, filler weight% and individual fibre loading % in the hybrid configuration on the mechanical properties. Overall present review article was designed to explore, highlights and gathered the previous reported studies directing the mechanical properties of sisal fibre and its polymer composites to provide a perfect source of data and literature for doing future research to reveal it as construction and building materials like synthetic fibres

    Functional interaction of the retinoblastoma and Ini1/Snf5 tumor suppressors in cell growth and pituitary tumorigenesis

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    The Ini1 subunit of the SWI/SNF chromatin remodeling complex suppresses formation of malignant rhabdoid tumors in humans and mice. Transduction of Ini1 into Ini1-deficient tumor-derived cell lines has indicated that Ini1 arrests cell growth, controls chromosomal ploidy, and suppresses tumorigenesis by regulating components of the retinoblastoma (Rb) signaling pathway. Furthermore, conditional inactivation of Ini1 in mouse fibroblasts alters the expression of various Rb-E2F-regulated genes, indicating that endogenous Ini1 levels may control Rb signaling in cells. We have reported previously that loss of one allele of Ini1 in mouse fibroblasts results only in a 15% to 20% reduction in total Ini1 mRNA levels due to transcriptional compensation by the remaining Ini1 allele. Here, we examine the effects of Ini1 haploinsufficiency on cell growth and immortalization in mouse embryonic fibroblasts. In addition, we examine pituitary tumorigenesis in Rb-Ini1 compound heterozygous mice. Our results reveal that heterozygosity for Ini1 up-regulates cell growth and immortalization and that exogenous Ini1 down-regulates the growth of primary cells in a Rb-dependent manner. Furthermore, loss of Ini1 is redundant with loss of Rb function in the formation of pituitary tumors in Rb heterozygous mice and leads to the formation of large, atypical Rb(+/-) tumor cells lacking adrenocorticotropic hormone expression. These results confirm in vivo the relationship between Rb and Ini1 in tumor suppression and indicate that Ini1 plays a role in maintaining the morphologic and functional differentiation of corticotrophic cells

    Preparation and properties of cellulose / tamarind nut powder green composites

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    Using biopolymer cellulose as the matrix and tamarind nut powder (TNP) obtained from agricultural waste of tamarind nuts as the filler, the green composites were made. Cellulose was dissolved in environmental friendly solvent of aq. 8 wt. % Lithium hydroxide and 15 wt. % urea which was precooled to −12 ° C. To the cellulose solutions, TNP was added in 5 wt. % to 25 wt. % of cellulose separately. Each solution was evenly spread on glass plates and the wet composites were prepared by regeneration method using ethyl alcohol coagulation bath. The wet films were dried in air at room temperature. The dried composite films were characterized by FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis and also tested for their tensile properties. The tensile strength and the % elongation at break of the composites were higher than those of the matrix and increased with TNP content. While the matrix had a tensile strength of 111.8 MPa, the cellulose/TNP composite loaded with 25 wt.% TNP possessed a tensile strength of 125.4 MPa (12% increase). Though the thermal stability of the composites was lower than cellulose matrix, all the composites were stable up to a temperature of 350 °C

    Influence of Ply Stacking Sequences on the Impact Response of Carbon Fibre Reinforced Polymer Composite Laminates

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    © 2019 The Author(s). This an open access work distributed under the terms of the Creative Commons Attribution Licence: https://creativecommons.org/licenses/by/4.0/.In recent years, there has been a growing demand for high strength-to-weight ratio and lightweight structures in several applications, such as wind energy, automotive, aerospace, telecommunication and construction industries. Carbon fibre reinforced polymeric (CFRP) composite is one of the promising materials with aforementioned inherent properties and applications. These properties vary with different techniques of their manufacturing, such as stacking sequence. Hence, it is germane and important to conduct an extensive study to investigate the effect of stacking sequences on the properties of CFRP composites. Consequently, this paper experimentally investigated the influence of different ply stacking sequences on quasi-static low-velocity impact behaviour of approximately 150 x 130 x 2 mm CFR epoxy composite laminates, manufactured by hand lay-up technique. Five different stacking sequences, denoted as samples A, B, C, E and F were tested under impact loads of 2.00, 2.25 and 2.50 kN. The results showed that the Sample A with stacking sequence of [90/±45/0]s exhibited the highest impact resistance under a maximum load of 2.50 kN before it finally fractured at a maximum displacement of nearly 10.20 mm, prior to an inter-ply delamination occurrence at displacement of approximately 5.50 mm. Similarly stacked sample B recorded the lowest inter-ply delamination damage, while sample C exhibited highest delamination damage. Both samples E and F exhibited similar impact properties. Moreover, samples A, B and C absorbed impact energies of 17.50, 6.25 and 14.13 J, respectively. Conclusively, sample A with highest impact resistance and absorbed energy is hereby recommended, been a promising material for engineering application within the test conditions and parameters, especially under a low-velocity impact load.Peer reviewe

    Mechanical properties of phormium tenax reinforced natural rubber composites

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    The introduction of natural fibers as a filler in a natural rubber (NR) matrix can be of relevance for their eco-friendly and sustainable nature as the substitute for carbon-based fillers. In this work, short Phormium tenax fibers were introduced in random orientation into a NR matrix in different lengths (6, 10, and 14 mm) and various amounts (10, 20, and 30%, taking 100 as the NR weight). The composite was fabricated using a two-roll mill according to American Society for Testing and Materials (ASTM) D3184-11 standard. Several properties were determined, namely tensile and tear characteristics, hardness, and abrasion resistance. The results suggest that the shortest fiber length used, 6 mm, offered the best combination between loss of mechanical (tensile and tear) properties and hardness and the most acceptable resistance to abrasion, with the properties increasing with the amount of fibers present in NR. As a consequence, it is indicated that a higher amount of fibers could be possibly introduced, especially to achieve harder composites, though this would require a more controlled mixing process not excessively reducing tensile elongation at break
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