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Examples of image blurring
Published in Mario Bertero, Patrizia Boccacci, Christine De Mol, Introduction to Inverse Problems in Imaging, 2021
Mario Bertero, Patrizia Boccacci, Christine De Mol
An optical microscope is a system that uses visible light and lenses to magnify images of small samples. Most microscopes used nowadays in biology are based on the physical phenomenon of fluorescence: the specimen (cells or living tissues) is stained by fluorophores, fluorescent chemical compounds that can re-emit light upon excitation by a light source, for instance a laser. The illuminating light has a specific wavelength and its absorption by the fluorophores causes the nearly simultaneous emission of light with a longer wavelength (Stokes shift). Therefore, in the case of fluorescence microscopy, the object f(0)(x) is the distribution of the fluorophores within the biological specimen (see, for instance, [33] for a very brief and synthetic account of fluorescence microscopy for users of image deconvolution).
Analytical Methods
Published in Colin R. Gagg, Forensic Engineering, 2020
‘Reflected light microscopy is used to study the microstructure of opaque materials. Contrast in the viewed image, is the result of differences in reflectivity of the microstructure. The maximum magnification achievable is limited to around 1000×’[3,6]. The primary purpose of a microscopic examination is to reveal detail that is too small to be seen by the naked eye or by macroscopic examination. Magnifications would usually range from 20 to 1000× for a standard optical microscope. Microscopic examination of etched sections can be used to reveal grain structure such as grain size, inclusions, phase distribution, cracks, porosity, internal defects, surface coatings, etc., as well as thermal and mechanical history and external features such as corrosion. In short, optical microscopic examination can reveal a great deal about the past history of a specimen and how it will (or did) react in service. However, it should be remembered that the technique will reveal detail about a particular (and often small) portion of the specimen and therefore may or may not be representative of the entire article. Further details of the techniques involved can be found in standard textbooks on microscopy.[7]
Introduction to Biological Light Microscopy
Published in Jay L. Nadeau, Introduction to Experimental Biophysics, 2017
Jay L. Nadeau, Michael W. Davidson
Illumination is a critical factor in determining the overall performance of the optical microscope. For nearly all imaging techniques, including brightfield, darkfield, polarization, and DIC, the best results are usually achieved by adjusting the illumination system following the principles introduced by August Köhler in 1893. The existence of two interrelated optical paths and two sets of image planes characterizes Köhler illumination and allows the various adjustable diaphragms and aperture stops in the microscope to be used to control both the cone angle of illumination, and the size, brightness, and uniformity of illumination of the field of view. Köhler illumination was developed in order to obtain a bright, evenly illuminated sample without creating artifacts caused by the bulb or filament used for illumination. Its principles are simple: a collector lens on the lamp housing is required to focus light emitted from the various points on the lamp filament at the front aperture of the condenser while completely filling the aperture. Simultaneously, the condenser must be focused to bring the two sets of conjugate focal planes (when the specimen is also focused) into specific locations along the optical axis of the microscope. With the specimen and condenser in focus, the focal conjugates will be in the correct position so that resolution and contrast can be optimized by adjusting the field and condenser aperture diaphragms.
Performance comparison of EDM oil and biodiesel flushing media while µED milling of Inconel 718
Published in Materials and Manufacturing Processes, 2023
ArunPillai K.V, Saravanakumar P, P. Hariharan
Microhardness is one of the surface characteristics that measures the hardness of the machined surface. Microhardness is measured using Wilson hardness at 1000 g of load. Hardness is measured at three points in machined surface, and average value is plotted using line graph. It is a semiautomatic machine in which load can be applied upto 1000 g. The machine can also be used as an optical microscope with magnifications of 200X, 550X, and 1000X. Applications of machined microchannels in Inconel 718 are heat exchanger, turbine blades, microcoolers, and microchannels heat pipes. The overcut and depth of microchannels are measured using VMS and three-dimensional profilometer.