Elliptic supersonic jet morphology manipulation using sharp-tipped lobes

Elliptic nozzle geometry is attractive for mixing enhancement of supersonic jets. However, jet dynamics, such as flapping, gives rise to high-intensity tonal sound. We experimentally manipulate the supersonic elliptic jet morphology by using two sharp-tipped lobes. The lobes are placed on either end of the minor axis in an elliptic nozzle. The design Mach number and the aspect ratio of the elliptic nozzle and the lobed nozzle are 2.0 and 1.65. The supersonic jet is exhausted into ambient at almost perfectly expanded conditions. Time-resolved schlieren imaging, longitudinal and cross-sectional planar laser Mie-scattering imaging, planar Particle Image Velocimetry, and near-field microphone measurements are performed to assess the fluidic behavior of the two nozzles. Dynamic Mode and Proper Orthogonal Decomposition (DMD and POD) analysis are carried out on the schlieren and the Mie-scattering images. Mixing characteristics are extracted from the Mie-scattering images through the image processing routines. The flapping elliptic jet consists of two dominant DMD modes, while the lobed nozzle has only one dominant mode, and the flapping is suppressed. Microphone measurements show the associated noise reduction. The jet column bifurcates in the lobed nozzle enabling a larger surface contact area with the ambient fluid and higher mixing rates in the near-field of the nozzle exit. The jet width growth rate of the two-lobed nozzle is about twice as that of the elliptic jet in the near-field, and there is a 40\% reduction in the potential core length. Particle Image Velocimetry (PIV) contours substantiate the results.Comment: 19 pages, 16 figures. Revised version submitted to Physics of Fluids for peer review. URL of the Video files (Fig. 6 & Fig. 14) are given in the text files (see in '/anc/*.txt'

Effects of Gas Metal Arc Welding Variants on the Mechanical and Microstructural Characteristics of AISI 304 Stainless Steel

The impact of variants of gas metal arc welding on the tensile properties of AISI-304 stainless steel is presented in this article. A single V-butt joint with a groove angle of 60° and thickness of 12 mm is fabricated by four gas metal arc welding variants, such as constant current, pulsed current, double pulsed current, and cold metal transfer, under optimized conditions. The tensile properties are analysed on the cross-sectional specimen of the welded joint. The highest tensile strength of 657 MPa is recorded on the specimen welded by the cold metal transfer. The highest elongation of 19% is observed on the specimen welded by cold metal transfer, while the elongation of base metal is 45%. The results show that the joints fabricated using the cold metal transfer have superior tensile properties to those fabricated by the other three variants of the gas metal arc welding process; this is due to the electromagnetic force exerted by this welding process. The joint fabricated using the cold metal transfer process has received a low heat input, resulting in high joint efficiency and notch strength ratio

History and Reconstruction of Thirugnanasambandar

Religious literature in Tamil is full of fiction with many unnatural events. Such stories were created for the development of religion. Beyond the tendency to approach them superficially as mere fiction, it is essential for the intelligent community to explore them on the basis that every fictional story has a background cause.Thus, the scriptures tell the story of Thirugnanasambandar, who is considered to be a Saiva (Devotee of Lord Siva) doing impossible deeds, differently from each other. This article reviews the obvious readings and reconstructions of the history of Thirugnanasambandar by Vannacharabam Dhandapani Swami in his Puluvar Puranam. They convey the oral stories and ideas about Thirugnanasambandar, that existed in the 19th century, as well as the logical study of history and the fictional background of antecedents

BRIEF REVIEW OF SPECTROPHOTOMETRIC METHODS FOR THE DETECTION OF TETRACYCLINE ANTIBIOTICS

Antibiotics are one of the most common pharmaceutical products, used for the treatment of bacterial ,fungal and parasitic infections. Among antibiotics, tetracyclines are extensively used in both human and animal welfare. Hence the monitoring and estimation of the levels of tetracycline in pharmaceutical products and effluents have become a necessity for researchers and industries. Current methods for estimation are based on high-level technologies ,and suffer from several disadvantages such as being time consuming, expensive and require  extensive training to operate.Much focus has been made on the development of simple ,quick and inexpensive methods that can be used in a routine manner. Most methods use either redox reaction of the tetracycline using an oxidizing agent or the use of polyvalent cations for chelation and complexometric reactions. Spectrophotometric methods for detection of antibiotics are simple  but rare. The objective of this review article is to present an insight into the various spectrophotometric methods available for the detection of tetracycline, with data regarding the reagents, wavelength used for the measurement and optimum concentration range applicable for each method

Online Shopping In The UK

This paper will contribute to current academic literature in the area of online retailing and consumer behaviour. Our research outlines a survey conducted with respondents from the UK to ascertain their attitudes to grocery shopping both off and online. The findings indicate that, whilst the vast majority of our sample has experience of online shopping, few actively engage in online grocery shopping. Some of the reasons for this are highlighted and the key issues relate to consumer trust and confidence in both online and offline aspects of the service. If these issues are addressed, it is proposed that more people would be encouraged to shop for groceries online

Phytomediated synthesis of silver nanoparticles against microbial pathogens and cytotoxicity on human breast cancer cells (MCF-7)

Silver nanoparticles (AgNPs) are synthesized from the root extract of the Abutilon indicum plant. Nitrate reductase enzyme and/or other extra cellular proteins released from the extract reduce the silver nitrate to silver ions. These proteins or enzymes serve as a template for the silver nucleation sites in the development of silver nanoparticles, and also act as capping agents, preventing silver ion agglomeration. XRD analysis predicts the phase of the nanoparticles. Transmission Electron Microscope (TEM) and Scanning Electron Microscope analyses have revealed that the synthesized AgNPs are spherical in shape, with an average size of 17 nm. From the data, it is noted that the protein molecules and fatty acids present in the root extract of Abutilon indicum, play a vital role in reducing silver salts and as capping AgNPs at various concentrations. Bactericidal activity acting against the clinical pathogens was performed, and it was observed that NP inhibition is highly dependent on their size and surface. Cytotoxic studies were carried out with these synthesized silver nanoparticles using MTT assay on MCF-7 cells

Fuzzy-based fault-tolerant and instant synchronization routing technique in wireless sensor network for rapid transit system

In the present era, rapid transits are one of the most affordable means of public transport with various useful integrated application systems. The majority of the integrated applications are deployed in concern over safety and precautionary measures against the worst side-effects of unfortunate emergencies. For such cases, high-end reliable and autonomous systems provide possible positive solutions. Wireless Sensor Network is one of the suitable choices for rapid transit applications to gain positive results with inexpensive implementation cost. However, managing few network consequences like fault tolerance, energy balancing and routing critical informative packets are considered to be the challenging task due to their limited resource usage restriction. In this paper, a novel fuzzy logic-based fault tolerance and instant synchronized routing technique have been proposed specifically for the rapid transit system. On utilizing the fuzzy logic concepts, most of the computational complexities and uncertainties of the system is reduced. The central thematic of the proposed design is concerned over the synchronized routing and permanent faults which abruptly depicts the non-functional nature of the sensor nodes during normal operations. Moreover, our proposed simulation outcomes proved to be improvised evidence on obtaining maximum packet delivery ratio which tends to handle an emergency situation in the compartments of rapid transits

Phytomediated synthesis of silver nanoparticles against microbial pathogens and cytotoxicity on human breast cancer cells (MCF-7)

Silver nanoparticles (AgNPs) are synthesized from the root extract of the Abutilon indicum plant. Nitrate reductase enzyme and/or other extra cellular proteins released from the extract reduce the silver nitrate to silver ions. These proteins or enzymes serve as a template for the silver nucleation sites in the development of silver nanoparticles, and also act as capping agents, preventing silver ion agglomeration. XRD analysis predicts the phase of the nanoparticles. Transmission Electron Microscope (TEM) and Scanning Electron Microscope analyses have revealed that the synthesized AgNPs are spherical in shape, with an average size of 17 nm. From the data, it is noted that the protein molecules and fatty acids present in the root extract of Abutilon indicum, play a vital role in reducing silver salts and as capping AgNPs at various concentrations. Bactericidal activity acting against the clinical pathogens was performed, and it was observed that NP inhibition is highly dependent on their size and surface. Cytotoxic studies were carried out with these synthesized silver nanoparticles using MTT assay on MCF-7 cells