Star Clusters in the Magellanic Clouds-1: Parameterisation and Classification of 1072 Clusters in the LMC

We have introduced a semi-automated quantitative method to estimate the age and reddening of 1072 star clusters in the Large Magellanic Cloud (LMC) using the Optical Gravitational Lensing Experiment (OGLE) III survey data. This study brings out 308 newly parameterised clusters. In a first of its kind, the LMC clusters are classified into groups based on richness/mass as very poor, poor, moderate and rich clusters, similar to the classification scheme of open clusters in the Galaxy. A major cluster formation episode is found to happen at 125 +- 25 Myr in the inner LMC. The bar region of the LMC appears prominently in the age range 60 - 250 Myr and is found to have a relatively higher concentration of poor and moderate clusters. The eastern and the western ends of the bar are found to form clusters initially, which later propagates to the central part. We demonstrate that there is a significant difference in the distribution of clusters as a function of mass, using a movie based on the propagation (in space and time) of cluster formation in various groups. The importance of including the low mass clusters in the cluster formation history is demonstrated. The catalog with parameters, classification, and cleaned and isochrone fitted CMDs of 1072 clusters, which are available as online material, can be further used to understand the hierarchical formation of clusters in selected regions of the LMC.Comment: 19 pages, 19figures, published in MNRAS on August 16, 2016 Supplementary material is available in the MNRAS websit

Comparison of CFD and DSMC Using Calibrated Transport Parameters

Hypersonic re-entry flows span a wide range of length scales where regions of both rarefied and continuum flow exist. Traditional computational fluid dynamics (CFD) techniques do not provide an accurate solution for the rarefied regions of such mixed flow fields. Although direct simulation Monte Carlo (DSMC) can be used to accurately capture both the continuum and rarefied features of mixed flow fields, they are computationally expensive when employed to simulate the low Knudsen number continuum regimes. Thus, a hybrid framework for seamlessly combining the two methodologies, CFD and DSMC, continues to be a topic of significant research effort. Ensuring consistency in the reaction kinetics and transport models employed within CFD and DSMC is a crucial requirement for obtaining a reliable solution from a hybrid framework for combined continuum/rarefied high speed flows. This paper represents one of the first studies to utilize the calibrated transport parameters developed to ensure consistency between CFD and DSMC solvers. The new variable soft sphere (VSS) parameters are compared to both previous standard variable hard sphere (VHS) parameters and also to solutions from the CFD transport properties that the new parameters were developed to reproduce

Calculation and experimental verification of m drop in tsia electrodes of chlor-alkali cells

A computer program to analyss the current distribution in a chlor-alkali cell using Titanium Substrate Insoluble Anode (TSIA) has baen developed. The program takes into account the polarisation resistance characteristics of anode and camode and the electrolyte resistance, in a d d i i to anode nodal resistance. The results are compared with the experimental data

Conceptual design study of a coal gasification combined-cycle powerplant for industrial cogeneration

A conceptual design study was conducted to assess technical feasibility, environmental characteristics, and economics of coal gasification. The feasibility of a coal gasification combined cycle cogeneration powerplant was examined in response to energy needs and to national policy aimed at decreasing dependence on oil and natural gas. The powerplant provides the steam heating and baseload electrical requirements while serving as a prototype for industrial cogeneration and a modular building block for utility applications. The following topics are discussed: (1) screening of candidate gasification, sulfur removal and power conversion components; (2) definition of a reference system; (3) quantification of plant emissions and waste streams; (4) estimates of capital and operating costs; and (5) a procurement and construction schedule. It is concluded that the proposed powerplant is technically feasible and environmentally superior

A case of telescoping of bowel during sailing

Intussusceptions as an entity is more common in children than adults in whom it is almost always secondary to some associated pathology. Moreover, the presentation is subacute or chronic in nature and all classical features of intussusceptions are rarely present together that makes the diagnosis more challenging. Here we presented a case of ileo-ileal intussusception in an adult male. Obligation of early diagnosis, initial management is unique in such cases. It also focuses on importance of availability of the imaging facilities in management of acute abdomen so as to assist in timely diagnosis as well as the definitive management of intussusceptions.

Motion Vector Estimation Search using Hexagon-Diamond Pattern for Video Sequences, Grid Point and Block-Based

Grid and block-based motion vector estimation techniques are proposed for motion tracking in video sequences. The grid technique is referred to the hexagon-diamond pattern. While, block-based technique is referred to 16 × 16 pixels of blocks in a single frame in video sequences. The hexagon and diamond pattern is applied onto the 16 × 16 pixels blocks in a single frame for motion tracking purposes in video sequences. The hexagon grid pattern will conduct a search to capture the motion in a particular block of the hexagon region before the diamond grid pattern takes place for the fine search. The diamond grid pattern provides accuracy to obtain the best grid vector coordinate for motion tracking purposes. The hexagon-diamond grid vector coordinate can be used to determine whether the object is moving toward the horizontal or vertical plane. The information determined at grid vector coordinate can be used as a reference when referring to the previous frame in video sequence processing. The grid vector coordinate will help to determine the area of interest to be examined based on the coordinate obtained. Besides the grid vector estimation, the Point Signal Noise-to-Ratio (PSNR) is also applied to measure the quality of the video

Characterization of airway inflammation in stable bronchial asthma

Fifty stable mild bronchial asthma patients were studied to characterize the airway inflammation using the technique of bronchoalveolar lavage (BAL). 18 normal non-smoking subjects were studied as control subjects. Total inflammatory cells (29.6±18.4 x 106 /dl vs 16.0±6.6 x 106/dl, p(<0.001), absolute macrophages (24.5±15.9 x 106/dl vs 13.3 ± 5.5 x 106/dl. p<0.001), eosinophils (1.0±1.5 x 106 dl vs 0.1±0.1 x 106/dl, p<0.001) and lymphocytes (3.8±4.2 x 106/dl vs 2.4±1.5 x 106/dl, p<0.05) were significantly higher in BAL fluid from patients with bronchial asthma compared to normal control subjects. Abnormally elevated eosinophils (>4%) and lymphocytes (>28%) in BAL fluid were seen in 15 (30%) and five (10%) patients respectively. This study demonstrates that chronic lung inflammation characterised by abnormally elevated macrophages, eosinophils and lymphocytes persists even in patients with stable mild bronchial asthma, despite medication with oral beta stimulants or theophylline

Modelling an electrically turbocharged engine and predicting the performance under steady-state engine

This paper discusses the evaluation of the energy recovery potential of turboshaft separated (decoupled) electric turbocharger and its boosting capability in a spark-ignition engine through simulation-based work and comparing it to a conventional turbocharged engine in terms of fuel consumption. The main objective of this study is to evaluate the amount of energy that can be recovered over a steady state full-load operating conditions and boosting capabilities from a decoupled electric turbocharger of an SI engine using a 1-D engine simulation software. The electric turbocharged system includes two motors and a battery pack to store the recovered electrical energy. Gt-Power engine simulation software was used to model both engines and utilizes each of the components described earlier. The conventional turbocharged engine is first simulated to obtain its performance characteristics. An electric turbocharger is then modelled by separating the turbine from the compressor. The turbine is connected to the generator and battery, whereas the compressor is connected to the motor. This electrically turbocharged engine was modelled at full load and controlled to produce the same brake power (kW) and brake torque (Nm) properties as the similarly sized conventional turbocharged engine. This step was necessary to investigate the effect an electrical turbocharger without a wastegate has on the engine’s BSFC and determine the energy that can be recovered by the electrical boosting components, and cycle�averaged fuel consumption was evaluated. The evaluation of energy recovered from the electrically turbocharged engine from the analysis can assessed in full-load steady state conditions that can be useful for research in part-load and transient studies involving the decoupled electrical turbocharger. The study revealed that a maximum of 21.6 kW of electrical power can be recovered from the decoupled electrical turbocharger system, whereas 2.6% increase in fuel consumption can be observed at 5000 rpm engine speed

Star Clusters in the Magellanic Clouds - II. Age-Dating, Classification and Spatio-Temporal Distribution of the SMC Clusters

Aim: We aim to estimate the age and reddening parameters of already identified star clusters within the Small Magellanic Cloud (SMC) in a consistent way using available photometric data, classify them based on their mass and strength, and study their spatio- temporal distribution. Methods: We have used a semi-automated quantitative method, developed in the first paper of this series (Paper I), to estimate the cluster parameters using the V and I band photometric data from the Optical Gravitational Lensing Experiment (OGLE) III survey. Results: We estimated parameters of 179 star clusters (17 newly parameterised) and classified them into 4 groups. We present an online catalog of parameters, and cleaned and isochrone-fitted Color Magnitude Diagrams of 179 clusters. We compiled age information of 468 clusters by combining previous studies with our catalog, to study their spatio-temporal distribution. Most of the clusters located in the southern part of the SMC are in the age range 600 Myr-1.25 Gyr, whereas, the clusters younger than 100 Myr are mostly found in the northern SMC, with the central SMC showing continuous cluster formation. The peak of the cluster age distribution is identified at 130 Myr, very similar to the Large Magellanic Cloud (LMC) in Paper I. Conclusion: We suggest that the burst of cluster formation at 130 Myr is due to the most recent LMC-SMC interaction. 90% of the studied sample is found to have mass <1700 M_sun, suggesting that the SMC is dominated by low mass clusters. There is a tentative evidence for compact clusters in the LMC when compared to those in the Galaxy and the SMC. A progressive shifting of cluster location from the South to North of the SMC is identified in last 600 Myr. The details of spatio-temporal distribution of clusters presented in two videos in this study can be used as a tool to constrain details of the recent LMC-SMC interactions.Comment: The paper is accepted for publication in A&A journa