Improvement of the homogeneous nucleation rate measurements in a static diffusion chamber with use of a CCD camera

Ždímal, Vladimír; Smolík, Jiří; Hopke, Philip K.; Matas, Jiří
August 2000
AIP Conference Proceedings;2000, Vol. 534 Issue 1, p311
Academic Journal
A photographic approach introduced recently to study nucleation kinetics in a static diffusion chamber, has been further improved by using a sensitive CCD camera instead of a photographic one. The method is based on illuminating the chamber from side by a flattened vertical laser beam. Trajectories of droplets, formed by nucleation and growing inside this beam, are recorded by a camera positioned perpendicular to this beam. Evaluation of starting points of droplet trajectories leads to vertical distribution of nucleation rate, which can then be related to calculated local values of temperature and supersaturation. This approach is independent on any nucleation theory. The main drawback of the photographic method, tedious production and evaluation of photographs, is replaced here by an automated procedure. Digitized pictures are downloaded to a PC and evaluated by standard methods of image analysis. The starting points of individual droplets are sought using a normalized correlation with a template. The position of liquid films is found using a method of maximizing sum of intensities on a line. The approach seems to keep the advantages of the photographic one, but is much more effective.


Related Articles

  • Homogeneous nucleation rate measurements of 1-propanol in helium: The effect of carrier gas pressure. Brus, David; Zˇdímal, Vladimír; Stratmann, Frank // Journal of Chemical Physics;4/28/2006, Vol. 124 Issue 16, p164306 

    Kinetics of homogeneous nucleation in supersaturated vapor of 1-propanol was studied using an upward thermal diffusion cloud chamber. Helium was used as a noncondensable carrier gas and the influence of its pressure on observed nucleation rates was investigated. The isothermal nucleation rates...

  • Homogeneous nucleation rates from the piston-expansion tube using a digital camera. Peters, Franz; Graßmann, Arne // AIP Conference Proceedings;2000, Vol. 534 Issue 1, p79 

    Homogeneous nucleation rates of n-pentanol in nitrogen are obtained from a piston-expansion tube (pex-tube) involving the nucleation pulse method which generates a limited number of nuclei that grow into droplets. The detection of the droplets is achieved by a new counting method developed on...

  • Optical method for determining the hardness of metals and alloys. Khilo, N.; Ropot, P.; Kazak, N.; Belyi, V.; Mashchenko, A. // Journal of Applied Spectroscopy;May2009, Vol. 76 Issue 3, p434 

    We present an optical method for determining the hardness of metals, based on the correlation between the thermal diffusion coefficient and the hardness of the material. Spatial and temporal modulation localized in the nonstationary thermal wave profiles is transferred to the surface of the...

  • Initial investigation of the homogeneous nucleation of cesium vapor. Cha, Gyu-Suk; Uchtmann, Hermann; Fisk, Jeffery A.; Katz, Joseph L. // Journal of Chemical Physics;7/1/1994, Vol. 101 Issue 1, p459 

    Initial measurements of the homogeneous nucleation of supersaturated cesium vapors using an upward thermal diffusion cloud chamber specially designed for use with highly reactive materials are presented. Comparison of the supersaturations measured at higher temperatures (greater than 455 K) with...

  • The flow diffusion nucleation chamber: A quantitative tool for nucleation research. Vohra, Vivek; Heist, Richard H. // Journal of Chemical Physics;1/1/1996, Vol. 104 Issue 1, p382 

    We have developed a flow diffusion nucleation chamber designed to quantitatively investigate the nucleation of vapors. The design and operational characteristics of the nucleation chamber are presented and discussed. Critical supersaturation data obtained with this nucleation chamber are...

  • CCD sensor for color/black-and-white video measures 1/5 in. sq. Schweber, Bill // EDN;12/21/95 Supplement, Vol. 40 Issue 26, pLL7 

    Features a variety of CCD cameras from Sony Semiconductor Co. Specifications and capabilities; Price; Contact information.

  • Upgraded CCD camera.  // Astronomy;Aug95, Vol. 23 Issue 8, p88 

    Features CWIP-S, a second-generation CWIP CCD camera by Sirius Instruments. CCD chip; Built-in image-processing software to make the use of computer optional; Storage and retrieval of images as digital from videotape.

  • Image-archiving software saves the big picture for posterity. Masi, C.G. // R&D Magazine;Feb96, Vol. 38 Issue 2, p59 

    Reports that the CCD camera, is the solution to storing primary data in the form of images. What's in a syustem; Comments made by product specialist, Frank Toye; Cost of CCD camera.

  • New products.  // Astronomy;May94, Vol. 22 Issue 5, p118 

    Evaluates CCD800 and CCD1600 Cameras from CompuScope. Features of the cameras; Price; Contact point.


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics