Cluster formation process in metal vapor plume

2019 ◽  
Author(s):  
N. Y. Bykov ◽  
Yu. E. Gorbachev
Keyword(s):  
Formation Process ◽  
Cluster Formation ◽  
Metal Vapor ◽  
Vapor Plume

scholarly journals Shock-induced star cluster formation in colliding galaxies

2010 ◽  
Vol 6 (S270) ◽  
pp. 483-486 ◽  
Author(s):  
Takayuki R. Saitoh ◽  
Hiroshi Daisaka ◽  
Eiichiro Kokubo ◽  
Junichiro Makino ◽  
Takashi Okamoto ◽  
...  
Keyword(s):  
High Resolution ◽  
Shock Compression ◽  
Smoothed Particle Hydrodynamics ◽  
Formation Process ◽  
Cluster Formation ◽  
Star Clusters ◽  
Star Cluster ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Number Of Particles

AbstractWe studied the formation process of star clusters using high-resolutionN-body/smoothed particle hydrodynamics simulations of colliding galaxies. The total number of particles is 1.2×108for our high resolution run. The gravitational softening is 5 pc and we allow gas to cool down to ~10 K. During the first encounter of the collision, a giant filament consists of cold and dense gas found between the progenitors by shock compression. A vigorous starburst took place in the filament, resulting in the formation of star clusters. The mass of these star clusters ranges from 105−8M⊙. These star clusters formed hierarchically: at first small star clusters formed, and then they merged via gravity, resulting in larger star clusters.

Analysis of Image Characteristics of Plume and Spatter of High Power Disk Laser Welding Based on K-L Transform

2012 ◽  
Vol 532-533 ◽  
pp. 330-334
Author(s):  
Qian Wen ◽  
Xiang Dong Gao
Keyword(s):  
Laser Welding ◽  
High Power ◽  
High Speed ◽  
Metal Vapor ◽  
Mean Value ◽  
Gray Level ◽  
Characteristic Parameters ◽  
Transform Method ◽  
Disk Laser ◽  
Vapor Plume

Metal vapor plume and spatters are the important phenomena in the process of high power disk laser welding, and there exists a close relationship with the welding stability. The images of metal vapor plume and spatters which captured by a high speed camera during high power disk laser welding were analyzed in this experiment. Image processing techniques such as median filtering, Wiener filtering, gray level threshold and lightness transform were used to process the images so that the image characteristic parameters such as the area and number of spatters in an image, the average gray, mean value, variance and entropy of a spatter gray level image and the coordinate ratio of the centriod of plume and the welding point can be extracted. To reflect the actual welding results obviously by those characteristic parameters, K-L transform method was used to get a new set of characteristic parameters. Experimental results showed that this new set of characteristic parameters could reflect the actual welding effectively.

scholarly journals CS Lines and Dust Continuum Observations of the OMC2 Infrared Cluster

1994 ◽  
Vol 140 ◽  
pp. 245-246
Author(s):  
T. Umemoto ◽  
N. Ohashi ◽  
Y. Murata ◽  
K. Tatematsu ◽  
M. Suzuki
Keyword(s):  
Formation Process ◽  
Molecular Clouds ◽  
Large Scale ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Cluster Formation ◽  
Young Stars ◽  
Ir Sources ◽  
Near Ir ◽  
Molecular Core

It is known that stars in GMCs are often born as clusters. Recently, near infrared imaging has enabled us to study the young stars within molecular clouds (e.g., Lada & Lada 1991). Orion Molecular Cloud 2 (OMC2) is located 12' north of the Trapezium cluster in the Orion A cloud, and contains a cluster of about 20 near-IR sources and several FIR sources distributed within a diameter of 0.2 pc (Rayner et al... 1989; Johnson et al. 1990; Mezger, Wink, & Zylka 1990). By large scale mapping observations using the NRO 45 m telescope, this infrared cluster is found to be associated with a dense molecular core (Tatematsu et al. 1993, Umemoto et al. 1993). The region was observed using the Nobeyama Millimeter Array (NMA) to elucidate the structure and cluster formation process within a core.

Enhanced imaging of a pulsed Nd:YAG metal vapor plume

1998 ◽  
Vol 10 (2) ◽  
pp. 85-89 ◽  
Author(s):  
M. Essien ◽  
D. M. Keicher
Keyword(s):  
Metal Vapor ◽  
Vapor Plume ◽  
Enhanced Imaging

Analysis of Characteristic of Metal Vapor Plume during High-Power Disc Laser Welding

2012 ◽  
Vol 201-202 ◽  
pp. 1126-1129
Author(s):  
Qian Wen ◽  
Xiang Dong Gao
Keyword(s):  
Laser Welding ◽  
High Power ◽  
High Speed ◽  
Welding Process ◽  
Metal Vapor ◽  
Welding Quality ◽  
Absolute Value ◽  
Coordinate Difference ◽  
Vapor Plume ◽  
The Absolute

Metal vapor plume which induced during high power disc laser welding contains lots of information that related to the welding quality. Stainless steel 304 was taken as the experiment object for the high power disc laser welding experiment. A high-speed camera was used to capture the ultraviolet band and visible light band metal vapor plume images in the laser welding process. Image processing techniques such as median filtering, Wiener filtering, gray level threshold and image binarization were applied to get the images that only metal vapor plume was included. The ratio of the absolute value of coordinate difference between the centroid of plume and welding point was taken as the characteristic parameter. Welding experimental results and analysis of the changing of the ratio of the absolute value of coordinate difference between the centroid of plume and welding point confirmed that the welding quality could be monitored by the metal vapor plume during high power disc laser welding.

scholarly journals Cluster formation patterns: the general indicators, criteria, stages and gestation phases overview

2014 ◽  
Vol 36 (3) ◽  
pp. 688-700
Author(s):  
Rasa Viederytė
Keyword(s):  
Process Improvement ◽  
Dynamic Process ◽  
Formation Process ◽  
Cluster Formation ◽  
Study Objective ◽  
Cluster Development ◽  
The Competitiveness Of Enterprises ◽  
Corporate Trust ◽  
Comprehensive Study ◽  
Dynamic Criteria

In order to enhance the competitiveness of enterprises and strengthen the competitive positions in the market, the cluster formation is increasingly becoming one of the essential conditions for the increasing of business cooperation and development, especially in initiating general joint projects and corporate trust. Cluster formation is a dynamic process that is recognized by the general Indicators and Criteria, consisting of consequential Stages and having different maturity Gestation Phases. Therefore, the Objective of the Study - to assess the General Indicators, Criteria, Stages and Phases of Gestation significance of Cluster Formation process. The Study Objective conducted a comprehensive study of the Cluster Formation process, involving both the Cluster Formation process Phases, Gestation Stages and Cluster Development through the Analysis of dynamic Criteria and General Indicators analysis. According to the Study, the main features of Cluster general Indicators, the parameters of Gestation Phases, Stages and Criteria were determined, the main barriers to the formation of clusters were identified and the reasonable conclusions of the Cluster Formation process improvement were prepared.

scholarly journals A Fair and Secure Cluster Formation Process for Ad Hoc Networks

2010 ◽  
Vol 56 (3) ◽  
pp. 625-636 ◽  
Author(s):  
Helena Rifà-Pous ◽  
Jordi Herrera-Joancomartí
Keyword(s):  
Ad Hoc Networks ◽  
Formation Process ◽  
Ad Hoc ◽  
Cluster Formation ◽  
Hoc Networks

scholarly journals The Roles of Protostellar Outflow Feedback in Clustered Star Formation

2012 ◽  
Vol 8 (S292) ◽  
pp. 54-54
Author(s):  
Fumitaka Nakamura ◽  
Zhi-Yun Li
Keyword(s):  
Star Formation ◽  
Observational Data ◽  
Formation Process ◽  
Cluster Formation ◽  
Parent Cluster

AbstractWe discuss the roles of protostellar outflow feedback in cluster formation using observational data of nearby cluster-forming regions like rho Oph, NGC1333, and Serpens. The observations suggest that observed protostellar outflow feedback appears to be sufficient both to maintain supersonic turbulence and to dynamically support the parent cluster-forming clumps. However, it is not enough to destroy the parent clumps by the current outflow activity. This implies that star formation process may not be too short and probably last at least for several local dynamical times.

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