Microscopy polarizing microscope

The compensation birefringence measurement is very easily coupled to optical microscopy in the transmission and reflection modes, thus allowing characterizing orientation with a spatial resolution of a few hundreds of nanometers [14]. Polarizing microscopes are widely available and are often used for birefringence studies even if spatial resolution is not required. Objectives specifically designed for cross-polarized microscopy are necessary to avoid artifacts. 

Liquid crystal textures were observed by optical microscopy between crossed polars. The instrument used was an Olympus BH-2 polarizing microscope equipped with a Linkam TH-600RH hot stage. 

Structures. The three types of mesomorphic phases are usually identified by using the polarizing microscope (11). The different types of lyotropic smectic mesophases can also be distinguished through their microscopic textures (26) by careful and detailed study. Using the microscope for such identifications is sometimes made more difficult by the tendency of the mesophases to orient when placed in contact with a surface. This orientation, of course, changes the microscopic textures. A mesophase in the presence of a crystalline phase may also be difficult to identify by microscopy. NMR can provide distinguishing characteristics which are unique for several mesophases. The use of the NMR characteristics for phase... 

If a polarizing microscope is available, the experimental technique involved is relatively straightforward. Many of the difficulties arise from a lack of understanding of the physical principles behind the method, and initial study of the theoretical principles of polarizing microscopy is well worth while. F or studying stress distributions a component can be placed in a light box with polarizing plates at each end. 

Optical microscopy is particularly useful for investigating various anisotropic features of polymeric systems. Polymers are intrinsically anisotropic objects and, when arranged in anisotropic structures such as crystalline and liquid crystalline phases, they display macroscopic optical anisotropy. These are investigated using a polarizing microscope, i.e., under crossed polarizers. 

Besic et al. (1962) have examined undecalcified tooth sections in an infrared microscope in the range 0.76-1.20 n. Hypocalcification spots can be distinguished by infrared microscopy from sections of early caries when they are imbibed in media (water, glycerol, or eugenol) that show them to be similar in appearance when viewed only with visible-light and polarizing microscopes. 

The pleated sheet can also be observed with optical polarization microscopy [119, 133]. Fig. 15 demonstrates the origin of the various banded patterns in the polarizing microscope, which are seen on a longitudinal section of a fiber. In the dark areas the chains are aligned parallel to the analyzer or polarizer direction. Such a banded texture is often observed in films and fibers of lyotropic and thermotropic polymers. 

Light microscopy has been used for well over 100 years for the determination of mineral species. This analysis is carried out using specialized polarizing microscopes... 

Recent advances in microscopy have provided instruments that can identify new polymorphs more precisely. Using a PC interfaced to a hot-stage polarizing microscope, thermal events can be visualized and archived and even be used to create a video file. Hot-stage microscopy (HSM) facilitates the identification of phase transformations, monotropic and enantiotropic relationships, crystalline to amorphous phase transitions, the appearance... 

The fiber diameter distribution was studied by microscopy (optical microscope, Hitachi TM-1000 scanning electron microscope). Fiber orientation was studied by using birefringence and polarization IR-spectroscopy (SPECORD M 80 IR-spectrometer). Crystalline phase of polymer was studied by differential scaiming calorimetry (DSC) (differential scanning calorimeter). The packing density of fibrous materials was calculated as a function of airflow resistance variation with a special manometric pressure unit [7]. 

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