The Influence of geometrical and operational parameters on internal flow characteristics of Internally Mixing Twin-Fluid Y-Jet Atomizers

Internally mixing twin-fluid Y-jet atomizers are widely used in coal fired thermal power plants for start-up, oil-fired thermal power plants and industrial boilers. The flow through internally mixing Y-jet atomizers is numerically modeled using the compressible Navier-Stokes equations; Wall Modeled Large Eddy Simulations (WMLES) is used to resolve the turbulence with Large Eddy Simulations whereas the Prandtl Mixing Length Model is used for modeling the subgrid scale structures, which are affected by geometric and operational parameters. Moreover, the Volume-of-Fluid (VOF) method is used to capture the development and fragmentation of the liquid-gas interface within the Y-jet atomizer. The numerical results are compared with correlations available in open literature for the pressure drop; further results are presented for the multiphase flow regime maps available for vertical pipes. The results show that the mixing point pressure is strongly dependent on the mixing port diameter to airport diameter ratio, specifically for gas to liquid mass flowrate ratio (GLR) in the range 0.1 < GLR < 0.4; the mixing port length moderately affects the mixing point pressure while the angle between mixing and liquid ports is found not to have an appreciable effect. Moreover, it is found that the vertical pipe multiphase flow regime maps in the literature could be applied to the flow through the mixing port of the twin-fluid Y-jet atomizer. The main flow regimes found under the studied operational conditions are annular and wispy annular flow

Monocrotophos: Toxicity Evaluation and Respiratory Responses of Cyprinus carpio (Linnaeus)

Static rencval bioassay method was used to determine the 96 hr LC50 of monocrotophos on Cyprinus carpio. Oxygen consumption and behavioral responses were recorded at lethal and at two sublethal (1/10th and 1/15th) concentrations.  Oxygen consumption responses were concentration dependent. The data indicated maximum decrease in oxygen consumption at lethal exposure (86.4 µg/L) over control on 4th day followed by 2nd, 3rd, 1st days.  At 1/10th of lethal concentration (8.64 µg/ L) continuous decrease on 1st, 10th and 20th day but decrease was reduced on 30th day. Similar variations were observed at 1/15th of lethal exposure (5.76 µg/ L) from day 1 to day 10. The decrease continued on 30th day which was witnessed to be very less amongst all. Behavioral responses were significant in lethal exposures due to intoxication.  Fish showed hyper excitation, erratic swimming, jumping, and lethargy due to low breathing frequency followed by muscular rigidity and abundant mucous secretion over the gills

Atomization Mechanism of Internally Mixing Twin-Fluid Y-Jet Atomizer

The atomization mechanism of the gas-liquid multiphase flow through an internally mixing twin-fluid Y-jet atomizer has been studied by examining both the internal and external flow patterns. Superheated steam and light fuel oil (LFO) are used as working fluids. The flow is numerically modeled using the compressible Navier-Stokes equations; the hybrid large eddy simulation approach through wall-modeled large eddy simulations (WMLES) is used to resolve the turbulence with the large eddy simulations, whereas the Prandtl mixing length model is used for modeling the subgrid-scale structures, which are affected by operational parameters. A volume-of-fluid to discrete phase model (VOF-to-DPM) transition mechanism is utilized along with dynamic solution-adaptive mesh refinement to predict the initial development and fragmentation of the gas-liquid interface through VOF formulations on a sufficiently fine mesh, while DPM is used to predict the dispersed part of the spray on the coarser grid. Two operational parameters, namely, gas-to-liquid mass flow rate ratio (GLR) and liquid-to-gas momentum ratio, are compared; the latter is found to be an appropriate operational parameter to describe both the internal flow and atomization characteristics. It is confirmed that the variation in the flow patterns within the mixing port of the atomizer coincides with the variation of the spatial distribution of the spray drops

Desirable Ontologies for the Construction of Semantic Applications

The intended goal of semantic web is to provide the search results to the user with at most accuracy and good precision. To make possible, the object of semantic web is to add semantics to the existing information on the Web using semantic web languages. These web languages have been to express detail information of the content present on the web with help of Ontologies. Ontology is expressed in a knowledge representation language, which provides a formal frame of semantics. Therefore we provide a brief explanation of semantic web languages in which some of them uses description logic and frames as basis. These semantic languages used in construction and understanding of ontologies clearly. The goal of this paper is to provide a brief survey of state-of-the-art ontology languages which are used to express ontology over the Web, a basic understanding of ontologies and how the ontologies are constructed

CMFRI to strengthen research networks in Marine Biodiversity, allied areas

In the News section, you may find news about – In a move to strengthen research networks in marine biodiversity and allied areas, the Central Marine Fisheries Research Institute (CMFRI) has inked a pact with Maharaja’s College to carry out collaborative research programmes and to popularise scientific technologies among the public. A Memorandum of Understanding (MoU) was signed by CMFRI Director Dr A Gopalakrishnan and Maharaja’s College Principal Dr K N Krishnakumar. The linkage is aimed at boosting research works related to marine fisheries, marine biotechnology, marine biodiversity and mariculture along with various awareness programmes

Evaluation of Anti-Urolithiatic Activity of Ethanolic Seed Extract of Cassia Auriculata in Wistar Rats

The glomerular filtration rate decreases in urolithiasis due to the obstruction to the outflow of urine by stones in the urinary system and the waste products such as urea and uric acid get accumulated in blood. This indicates marked damage of kidney. The uric acid crystals adsorb glutamic acid and other organic compounds and promote calcium oxalate crystals growth. The results showed a significant increase in uric acid level in serum as well as in urine in the ethylene glycol control group compared to normal control. The uric acid levels decreased after treatment with ESCA –I & II and cystone, thereby hastening the process of dissolving the preformed stones and prevention of new stone formation in the urinary system. It has been postulated from several in vitro and in vivo studies that high levels of oxalate may have a detrimental effect on renal architecture mediated through intracellular oxidative stress, followed by changes in membrane structure, membrane lipid peroxidation, and cell death.[94] It was observed in the present study that administration of ethylene glycol increased MDA content of kidneys and decreased activity of the antioxidant enzymes in the kidneys. The ESCA – I & II treatment protected against the changes associated with oxidative stress. Several studies have shown that crystal formation results in cell damage and cell detachment from the basement membrane and the released degradation products further promote nucleation of crystals.[95] Renal epithelial injury promotes crystal retention, as epithelial injury exposes a variety of crystal adhesion molecules on epithelial surfaces. In conclusion, the results indicate that administration of ethanolic seed extract of Cassia auriculata Linn. (ESCA – II) significantly reduced the growth of urinary stones. It also seems that the treatment effect is more effective than its preventive effect. The underlying mechanism could be due to its diuretic effect, antioxidant, nephroprotective property, and lowering the concentration of urinary stone-forming constituents. Further experimental and clinical studies are required to elucidate the chemical constituents of the extract and the mechanism(s) that are responsible for the pharmacological activities

Neurodevelopmental outcome of babies with hypoxic ischemic encephalopathy

Background: The aim of the study was to find out the neurodevelopmental outcome of babies with hypoxic ischemic encephalopathy at 6 months of age and to predict early markers of abnormal neurological outcome in those babies.Methods: 50 babies admitted with hypoxic ischemic encephalopathy were enrolled in this prospective study and followed up at 3 and 6 months of age at Mahatma Gandhi Memorial Government Hospital, Trichy. The neurological outcome of the babies was assessed by CDC grading of motor milestones, Trivandrum development screening chart, Amiel Tison angles head circumference and weight measured. USG cranium was done for all the babies and MRI brain was done in babies with abnormal neuro sonogram and abnormal outcome. Vision and hearing were tested clinically.Results: The incidence of abnormal neurological outcome was 14%. The early markers predicting abnormal neurological sequele are identified.Conclusions: Early identification of abnormal neuro behaviour helps in starting early intervention to improve the long term outcome

Personality Mediated Career Development under Islamic Work Ethics in Pakistani Religious Schools

Religious schools known as Madrassas in Pakistan contribute significant human resource development (HRD) to the society enabling career development (CD) of protégés under Islamic work ethics (IWE). Yet the impact of IWE on CD and protégés’ personalities in recognized and well reputed Madrassas need elaboration. This study hypothesized that personality mediates the relationship between IWE and CD. It collected data employing stratified random sampling for 280 final year protégés in the Madrassas from Lahore, Pakistan. Data was analyzed using Pearson’s correlation, linear regression and Baron and Kenny test. Results confirmed full mediation of personality among IWE and CD and also the direct correlation of IWE as a significant determinant of CD in the selected context. While results of this study remained akin to various studies describing CD for business organizations it contributed value adding role of IWE in CD of religious human resource