Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Optical characteristics

Thin films are used to modify the optical characteristics of a system and a brief review of these characteristics is in order. [Pg.404]

The Electromagnetic Spectrum. The optical properties of a material are related to the electromagnetic spectrum (see Ch. 15, Fig. 15.1). The portions of the spectrum of interest are the following  [Pg.404]

Reflectance. The optical property of reflectance is the ratio of reflected flux of light to the incident flux. Unless otherwise specified, the total reflectance is meant, which includes specular and diffuse reflectance. [Pg.404]

Transmittance.Transmittance is the ratio of the radiant flux transmitted by a material to the incident flux. [Pg.404]

Absorption. Absorption, the attenuation of a beam through a transparent medium, can be characterized by an absorption coefficient. For thin films, such as those of optical oxides, absorption is very small and can usually be ignored. In metallic or semiconductor coatings however, absorption is a major factor. [Pg.404]


Fischer U Ch 1985 Optical characteristics of 0.1 pm circular apertures in a metal film as light sources for scanning ultramicroscopy J. Vac. Sc/. Technol. B 3 386... [Pg.1730]

Optical characteristics include transmitting portions of the infrared. Boron is a poor conductor of electricity at room temperature but a good conductor at high temperature. [Pg.13]

The following sources provide further information on the optical characteristics of gratings and their method of production. [Pg.458]

Grossman, W. E. L. The Optical Characteristics and Production of Diffraction Gratings, /. Chem. Educ. 1993, 70, 741-748. Palmer, C. Diffraction Gratings, Spectroscopy 1995, 10(2),... [Pg.458]

Fig. 38. Diagram comparing the optical characteristics of a standard binary chrome mask with a phase-shift mask. The changes in the electric fields introduced by the phase-shift elements result in a sharper light intensity profile at the wafer surface. Fig. 38. Diagram comparing the optical characteristics of a standard binary chrome mask with a phase-shift mask. The changes in the electric fields introduced by the phase-shift elements result in a sharper light intensity profile at the wafer surface.
Particle Morphology, Size, and Distribution. Many fillers have morphological and optical characteristics that allow these materials to be identified microscopically with great accuracy, even in a single particle. Photomicrographs, descriptions, and other aids to particle identification can be found (1). [Pg.366]

Tables 4—6 Ust ASTM methods used for the characterization of PB and PMP. A number of specialized methods were developed for testing particular articles manufactured from polyolefins several of these determine the performance of PB and PMP film, including the measurement of the film s dart impact strength and tear strength. Dart impact strength is measured by dropping a heavy dart with a round tip on a stretched film. Tear resistance, which reflects the film s resistance to tear propagation, is measured with the Ehnendorf tear tester. Two values for the tear strength are usually reported, one in the machine dkection of the film and the other in the transverse dkection. Pipes manufactured from PB are tested by pressurizing them internally with water the time-to-burst failure is determined at various temperatures (46). The standard test method for haze and luminous transmittance (ASTM D1003) is used for the measurement of PMP optical characteristics. Tables 4—6 Ust ASTM methods used for the characterization of PB and PMP. A number of specialized methods were developed for testing particular articles manufactured from polyolefins several of these determine the performance of PB and PMP film, including the measurement of the film s dart impact strength and tear strength. Dart impact strength is measured by dropping a heavy dart with a round tip on a stretched film. Tear resistance, which reflects the film s resistance to tear propagation, is measured with the Ehnendorf tear tester. Two values for the tear strength are usually reported, one in the machine dkection of the film and the other in the transverse dkection. Pipes manufactured from PB are tested by pressurizing them internally with water the time-to-burst failure is determined at various temperatures (46). The standard test method for haze and luminous transmittance (ASTM D1003) is used for the measurement of PMP optical characteristics.
Careflil examination of a piece of coal shows that it is usually made up of layers or bands of different materials which upon microscopic examination are distinct entities distinguishable by optical characteristics (10—12). The study of the origin, composition, and technological appHcation of these materials is called coal petrology, whereas coal petrography involves the systematic quantification of the amounts and characteristics by microscopic study. The petrology of coal may involve either a macroscopic or microscopic scale. [Pg.213]

Impairment of visibility involves degradation of the ability to perceive the environment. Several factors are involved in determining visibility in the atmosphere (Fig. 10-1) the optical characteristics of the illumination source, the viewed targets, the intervening atmosphere, and the characteristics of the observer s eyesight (1). [Pg.136]

The lens is an avascular transparent tissue surrounded by an elastic, collagenous capsule. Disturbances in the normal metabolism of the lens and rupture of the lens alter its optical characteristics, and may cause cataract, i.e., reduced transparency of the lens. For example exposure to a herbicide, 2,4-dichlorophenol, may cause cataract. [Pg.293]

Both thermal and optical characteristics of each type of window must be specified, including the dependence on the incidence angle. These characteristics normally are precalculated using a specific code (see Section 11.3.,3, Heat... [Pg.1074]

The chalcogenides are binary compounds of a chalcogen (i.e., the elements of Group Ilb zinc, cadmium, mercury) with a less electropositive element, such as those of Group VIb (oxygen, sulfur, selenium, and tellurium). This section covers the sulfides, selenides, andtellurides. Oxides are reviewed above in Ch. 11. Most of the chalcogenides have useful optical characteristics and their applications are usually found in optics. [Pg.336]

Handbook of Chemical Vapor Deposition 2.0 OPTICAL CHARACTERISTICS... [Pg.404]

Other analyzers such as the Gilford Automated Enzyme Analyzer and the LKB-8600 Reaction Rate Analyzer analyze discrete samples one at a time. These instruments provide kinetic analyses, digital data reduction at the time each sample is analyzed, and excellent electronic and optical characteristics. Recently, Atwood has developed kinetic enzyme analyzers which require only 9 seconds for measuring an enzyme activity, using highly stable and sensitive electronic circuits (12). This short read out time allows a large number of samples to be processed by one instrument in an automated mode. [Pg.182]

The theoretical framework for near-field imaging, on the other hand, is not as straightforward as that for the far-field optical measurements. This is primarily because the effects of perturbation from the near-field probe on the optical characteristics of the samples are not well known. Further developments in theoretical treatments and practical and precise simulation methods for realistic near-field measurement systems are desired. [Pg.52]

Figure 18. Electro-optic characteristics of an FM/AM-TN LCD with AgPd nanoparticles (5CB-AgPd 0.1%) where the frequency of operating voltages is used as a parameter. (Reprinted from Ref [236], 2006, with permission from IEEE.)... Figure 18. Electro-optic characteristics of an FM/AM-TN LCD with AgPd nanoparticles (5CB-AgPd 0.1%) where the frequency of operating voltages is used as a parameter. (Reprinted from Ref [236], 2006, with permission from IEEE.)...
Material Firing temperature (°C) Porosity (%) Optical characteristics... [Pg.271]

Instrumental measurement of whiteness has been the subject of much research. The parameters needed for unambiguous characterisation in the assessment of whiteness and tint of fluorescent substrates have been reviewed [21]. The importance of seeking good correlation between different instruments is stressed [20]. Various trials have demonstrated that it is possible to adjust modern instruments used to measure the optical characteristics of FBA-treated samples of paper so that the results agree with a standard deviation of the order of one CIE whiteness unit [22]. [Pg.302]

Phosphors for CRTs are predominantly based on zinc and cadmium sulfides. Selected CRT phosphors are listed in Table 1 which also includes their precursors, their P-numbers , and their uses. (The system used to classify CRT phosphors came from JEDEC, the former Joint Electronic Device Engineering Council, now JT- Committee on Phosphor and Optical Characteristics within the Electronic Industries Association. JEDEC established the original code for these phosphors in terms of P-numbers .8 Many manufacturers of CRTs use these when specifying phosphor screen characteristics.) Although the precursors are tabulated, the mole ratios used in the syntheses are not. [Pg.692]

Probably the most extensive use of particle morphology and microscopy has been in the area of chemical microscopy. With this approach, derivatives of the analyte species are prepared, crystallized, and identified through the morphological characteristics of these derivatives [21]. Most of these applications have been superseded by modem methods of analysis, but the microscopic method can still be used by skilled practitioners for the study of trace quantities of analyte. The literature developed during the heyday of chemical microscopy is too large to be reviewed here, but advances in the field are still chronicled in the Annual Reviews issue of Analytical Chemistry [22]. A substantial review of the optical characteristics of organic compounds is available [23]. [Pg.139]

Optical characteristics of nanocrystals and nanocrystal assemblies have been extensively studied in the past,66,67 whereas their electronic properties have attracted considerable attention only recently.68"70 Charge transport in... [Pg.324]

Correlation Between Global Conformation and Optical Characteristics of Polysilanes... [Pg.209]

The conformational mobility of a chromophoric main-chain polymer is often connected to its electronic structure. Therefore, changes in the UV-visible absorption spectra and/or chiroptical properties are spectroscopically observable as thermo-, solvato-, piezo-, or electrochromisms. It is widely reported that o-conjugating polysilanes exhibit these phenomena remarkably clearly.34 However, their structural origins were controversial until recently, since limited information was available on the correlation between the conformational properties of the main chain, electronic state, and (chir)optical characteristics. In 1996, we reported that in various polysilanes in tetrahydrofuran (THF) at 30°C, the main-chain peak intensity per silicon repeat unit, e (Si repeat unit)-1 dm3 cm-1, increases exponentially as the viscosity index, a, increases.41 Although conventional viscometric measurements often requires a wide range of low-dispersity molecular-weight polymer samples, a size exclusion chromatography (SEC) machine equipped with a viscometric detector can afford... [Pg.216]


See other pages where Optical characteristics is mentioned: [Pg.822]    [Pg.127]    [Pg.402]    [Pg.294]    [Pg.341]    [Pg.137]    [Pg.137]    [Pg.434]    [Pg.58]    [Pg.164]    [Pg.532]    [Pg.324]    [Pg.147]    [Pg.292]    [Pg.39]    [Pg.49]    [Pg.55]    [Pg.157]    [Pg.34]    [Pg.330]    [Pg.313]    [Pg.717]    [Pg.122]   
See also in sourсe #XX -- [ Pg.61 ]




SEARCH



Cellulose derivatives optical characteristics

Characteristics optical properties

Electro-optic characteristics

Evanescent wave characteristics, optical

Fluids optical characteristics

Light optical characteristics

Nanocomposites optical/electronic characteristics

Optical Characteristics of the Silicon-Centered PCs

Optical Transmission Characteristics of Pseudo-SIPNs

Optical absorption characteristics

Optical fibers characteristics

Optical fibres characteristics

Optical microscopy characteristics

Optical switching devices materials characteristics

Optical transmission characteristics

Physical properties - optical and spectral characteristics

Scanning optics characteristics

Stress-optical characteristics

Textile optical fibre characteristics

© 2024 chempedia.info