Hydrodynamic Performance and Acoustic Response of Ship Propeller

The aim of the paper is to predict the hydrodynamic performance and noise generated by the propeller at different advance ratio and the speed of the propeller. Three bladed, DTMB 4119 propeller model was created using the NACA66 modified line, a = 0.8 hydrofoil profile. ANSYS Workbench software is used for mesh generation and computational analysis. A large-eddy simulation turbulence model and Ffowcs Williams-Hawkings (FWH) acoustic model is used for all simulations. A moving reference frame is used to simulate the rotational effects of the propeller. The speed of the propeller is 792 rpm, the propeller being 0.2 m, and inlet velocity is varied to study the effect of the advance ratio. A transient analysis is carried out using a time step value of 0.0005 seconds and the total simulation time is 0.6 seconds. The hydrodynamic performance parameters are validated by comparing with the experimental data available in the literature. The sound pressure level (SPL) is plotted over the frequency range of 0 to 1000 Hz at different locations, speed, and an advance ratio of 0.5, 0.7, 0.833, and 0.9,1. The structural, acoustic and hydrodynamic behaviour of the propeller was predicted using a two-way fluid structure interaction at an advance ratio of 0.833. The major conclusions drawn from the analysis are that the sound pressure level values are increased at the propeller off-design conditions and varying with the receiver locations. The data generated from this study is useful for the designers to carry out further research in order to reduce the noise generated from the propeller

Iodine nutrition and its assessment during pregnancy: a need for concern

Micro nutrient iodine was essential in biosynthesis of thyroid hormones (TH). These hormones play a vital role in the growth and development of human beings at various stages of life. TH are required for normal brain development at embryonic, fetal and at past natal stages. If deficiency of iodine occurs then thyroid hormone production was impaired, if deficiency of TH occurs it can cause irreversible damage of brain which leads to various disorders like metal retarded ness, cretinism and goiter known as iodine deficiency disorders (IDD). When compared to normal adults, pregnant women and school children 5-12 years age are more vulnerable IDD. Due to the physiological variations during pregnancy iodine requirements rose significantly from 150 µg/day in non-pregnant adult women to 250 μg/day. However recent iodine nutrition studies showed adequate iodine status but few countries like Sweden and South Africa showed iodine deficiency. This review gives an over view on iodine nutrition on global front

Heat and Mass Transfer Effects of Peristaltic Transport of a Nano Fluid in Peripheral layer

This paper deals with a theoretical investigation of heat and mass transfer effects of peristaltic transport of a nanofluid in peripheral layer. By using appropriate methods, the velocity in the core region as well as in the peripheral region, pressure drop, time averaged flux, frictional force, temperature profile, nanoparticle phenomenon, heat transfer coefficient and mass transfer coefficient of the fluid are investigated, using lubrication theory. Effects of different physical parameters like viscosity ratio, mean radius of the central layer, Brownian motion parameter, thermophoresis parameter, local temperature Grashof number as well as local nanoparticle Grashof number on pressure rise characteristics, frictional force, heat transfer coefficient, mass transfer coefficient, velocity profiles and streamline patterns of the fluid are studied. The computational results are presented in graphical form

Uninterrupted Detection of Segment Nodes in Wireless Sensor Networks

Abstract Neighbor discovery is an important task in wireless networks, and especially in sensor networks. Neighbor information can be used to improve routing, clustering and scheduling algorithms. A sensor network may contain a huge number of simple sensor nodes that are deployed at some inspected t site. In large areas, such a network usually has a mesh structure. In this case, some of the sensor nodes act as routers, forwarding messages from one of their neighbors to another. The nodes are configured to turn their communication hardware on and off to minimize energy consumption. Therefore, in order for two neighboring sensors to communicate, both must be in active mode. In the sensor network model considered in this paper, the nodes are placed randomly over the area of interest and their first step is to detect their immediate neighbors -the nodes with which they have a direct wireless communication -and to establish routes to the gateway. In networks with incessantly heavy traffic, the sensors need not invoke any special neighbor detection protocol during normal operation. This is because any new node, or a node that has lost connectivity to its neighbors, can hear its neighbors simply by listening to the channel for a short time. However, for sensor networks with low and irregular traffic, a special neighbor detection scheme should be used

An appraisal of pollution level in the sediments of forthcoming Vizhinjam port zone, Southwest coast of India

137-142A pilot study on the granulometry and geochemical distribution of major and trace elements were carried out in the surface sediments of the port zone. Granulometric studies inferred the dominance of sand fractions in this high energy regime. Heavy metal concentrations in the area are below the threshold levels associated with the toxicological effects and the regulatory limits and this confirms the lithogenic origin of metals. Metal enrichments observed at Kovalam, an international tourist destination specifies the anthropogenic influence. Present study reveals that as of now there is no distinctiveness either in the distribution of sediments or the heavy metals signifying an immaculate coastal environment

Kurosh-Amitsur Right Jacobson Radical of Type 0 for Right Near-Rings

By a near-ring we mean a right near-ring. J0r, the right Jacobson radical of type 0, was introduced for near-rings by the first and second authors. In this paper properties of the radical J0r are studied. It is shown that J0r is a Kurosh-Amitsur radical (KA-radical) in the variety of all near-rings R, in which the constant part Rc of R is an ideal of R. So unlike the left Jacobson radicals of types 0 and 1 of near-rings, J0r is a KA-radical in the class of all zero-symmetric near-rings. J0r is not s-hereditary and hence not an ideal-hereditary radical in the class of all zero-symmetric near-rings

N-Square Approach For Lossless Image Compression And Decompression

There are several lossy and lossless coding techniques developed all through the last two decades. Although very high compression can be achieved with lossy compression techniques, they are deficient in obtaining the original image. While lossless compression technique recovers the image exactly. In applications related to medical imaging lossless techniques are required, as the loss of information is deplorable. The objective of image compression is to symbolize an image with a handful number of bits as possible while preserving the quality required for the given application. In this paper we are introducing a new lossless encoding and decoding technique which even better reduces the entropy there by reducing the average number of bits with the utility of Non Binary Huffman coding through the use of N-Square approach and fasten the process of searching for a codeword in a N-Square tree, we exploit the property of the encoded image pixels, and propose a memory efficient data structure to represent a decoding N-Square tree. Our extensive experimental results demonstrate that the proposed scheme is very competitive and this addresses the limitations of D value in the existing system by proposing a pattern called N-Square approach for it. The newly proposed algorithm provides a good means for lossless image compression and decompression

Glioblastoma invasion and NMDA receptors: A novel prospect

Purpose Glioblastoma cells create glutamate-rich tumor microenvironment, which initiates activation of ion channels and modulates downstream intracellular signaling. N-methyl-D-aspartate receptors (NMDARs; a type of glutamate receptors) have a high affinity for glutamate. The role of NMDAR activation on invasion of glioblastoma cells and the crosstalk with α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) is yet to be explored. Main methods LN18, U251MG, and patient-derived glioblastoma cells were stimulated with NMDA to activate NMDAR glutamate receptors. The role of NMDAR activation on invasion and migration and its crosstalk with AMPAR were evaluated. Invasion and migration of glioblastoma cells were investigated by in vitro trans-well Matrigel invasion and trans-well migration assays, respectively. Expression of NMDARs and AMPARs at transcript level was evaluated by quantitative real-time polymerase chain reaction. Results We determined that NMDA stimulation leads to enhanced invasion in LN18, U251MG, and patient-derived glioblastoma cells, whereas inhibition of NMDAR using MK-801, a non-competitive antagonist of the NMDAR, significantly decreased the invasive capacity. Concordant with these findings, migration was significantly augmented by NMDAR in both cell lines. Furthermore, NMDA stimulation upregulated the expression of GluN2 and GluA1 subunits at the transcript level. Conclusions This study demonstrated the previously unexplored role of NMDAR in invasion of glioblastoma cells. Furthermore, the expression of the GluN2 subunit of NMDAR and the differential overexpression of the GluA1 subunit of AMPAR in both cell lines provide a plausible rationale of crosstalk between these calcium-permeable subunits in the glutamate-rich microenvironment of glioblastoma

Characterization and Tensile Fractography of Nano ZrO2 Reinforced Copper-Zinc Alloy Composites

Nano particulates fortified metal lattice composites are finding extensive variety of utilizations in car and sports hardware fabricating businesses. In the present investigation, an endeavor has been made to create copper-zinc-nano ZrO2 particulates strengthened composites by utilizing fluid liquefy technique. 4, 8 and 12 wt. % of nano ZrO2 particulates were added to the Cu-Zn base grid. Microstructural studies were finished by utilizing SEM and EDS examination. Mechanical behavior of Cu-Zn-4, 8, 12 wt. % of nano ZrO2 composites were assessed according to ASTM benchmarks. Checking electron micrographs uncovered the uniform dispersion of nano ZrO2 particulates in the copper zinc composite network. EDS examination affirmed the nearness of Zr and O components in nano ZrO2 strengthened composites. Further, it was noticed that hardness, UTS, yield quality of Cu-Zn composite expanded with the expansion of 4, 8 and 12 wt. % of nano ZrO2 particulates. Ductility of nano composites was decreased by adding zirconium oxide particulates. Fractography of tensile specimens were carried out by using SEM micrographs to understand the failure mechanisms.           &nbsp

A PARTIAL RATIO AND RATIO BASED FUZZY-WUZZY PROCEDURE FOR CHARACTERISTIC MINING OF MATHEMATICAL FORMULAS FROM DOCUMENTS

Retrieval of mathematical text from data is a key predicament in present circumstances. To achieve this, we have considered three different algorithms viz., Sequence matcher, Levenshtein Distance and Fuzzy-Wuzzy. Two different variants of Fuzzy-Wuzzy are found applicable to this study out of four variants. Performance of these variants in retrieving mathematical texts, is calculated using efficiency measure, sensitivity analysis and time series exploration. Fuzzy-Wuzzy partial ratio algorithm scored better over the other variants on efficiency measure and sensitivity analysis