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Traditional and Advance Characterization Techniques for Natural Fibers
Published in Shishir Sinha, G. L. Devnani, Natural Fiber Composites, 2022
G. L. Devnani, Shishir Sinha, Dileep Kumar, Shailendra Kumar Pandey
Normally the thickness or diameter of the natural fiber is measured with the help of a digital micrometer or by using an optical/scanning electron microscope. The accuracy of measurement using a digital micrometer is 0.001 mm. It is well known that the diameter measurement of natural fibers is a difficult task because of the irregular shape of fibers and variation of thickness at different cross sections. For consistency, 5–10 samples are use to be tested at different locations across the length and average value of diameter is calculated. Image analysis software is used for this estimation of diameter (Sanjay et al., 2019).
Microbiological Considerations in the Selection and Validation of Filter Sterilization
Published in Maik W. Jornitz, Filtration and Purification in the Biopharmaceutical Industry, 2019
Because viruses are not possessed of metabolic apparatus, they have a remarkably simple and efficient structure. In their most basic configuration, they can consist of nothing more than a rather small single strand of genetic material and a handful of structural proteins. For example, the enteroviruses, a collection of several hundred distinct viral serotypes, contains among its numbers a significant array of human and animal pathogens. Two notable examples are the polioviruses and their close relatives the Coxsackie viruses as well as the foot and mouth disease virus. The reader may recall a significant outbreak of foot and mouth disease virus in Great Britain in 2001 and 2002, which resulted in tremendous public health concerns and billions of dollars of loses in the food animal industry in that country. These viruses consist of a single strand of RNA with a total size of ~1 × 106 D, but in comparison a typical bacteria would contain genetic material (double-stranded DNA) with a mass of >1012 D. These viruses have an icosahedral shell made up of four structural proteins and a small nucleic acid-associated protein. Not surprisingly, these viruses can be quite small in fact on average they are roughly 25–30 nm in diameter. A nanometer is 10−9 m or 1,000 times smaller than a micrometer. Thus, it seems unlikely that a filter with a mean pore size rating of 0.2-mm would fare well against a challenge by Enterovirus, at least in terms of separation by sieve retention.
Nanoengineered Material Applications in Electronics, Biology, and Energy Harnessing
Published in Anupama B. Kaul, Microelectronics to Nanoelectronics, 2017
Daniel S. Choi, Zhikan Zhang, Naresh Pachauri
The nano term is derived from nanometer (10–9 meters); 1 micron (μ) corresponds to 103 nanometers. People should know how big a millimeter is. A micrometer is a thousand times smaller than a millimeter. A human hair measures ~80 to 100 micrometers. A nanometer is a thousand times smaller than a micrometer. The nanometer scale is at the levels of atoms and molecules.
Conductivity measurement of metal films based on eddy current testing
Published in Nondestructive Testing and Evaluation, 2023
Binghua Cao, Shanshan Lv, Mengbao Fan, Chao Li
The average relative error of the conductivity is the smallest when the thickness is 0.10 mm, and it is the largest when the thickness is 0.20 mm. Therefore, the thickness of specimens should be close to that of calibrations in order to ensure the measurement accuracy of conductivity. Additionally, thickness measurement is another important factor for conductivity measurement. There are many digital display micrometres with an accuracy error of±0.002 mm. The variation in conductivity measurements caused by thickness measurement errors is shown in Figure 9. is the standard thickness of specimen, and is the standard conductivity of specimen. The conductivity measurements are greater than the standard conductivity when the thickness measurement value is less than the standard thickness.
The ruling engines and diffraction gratings of Henry Augustus Rowland
Published in Annals of Science, 2022
Although made primarily for calibrating the photographic map, Rowland felt that others would find his measurements useful, and published a summary of this work in 1887.77 The apparatus he used had concave gratings of 21½ feet radius, the same as used for the photographic map, and 5- or 6-inches diameter with 7200 or 14 400 lines per inch. The micrometer had a run of 5 inches (127 mm), and errors of less than 1/20000 of an inch (1.25 µm). The paper listed the tiny residual corrections to the wavelength scale on the map, the ‘coincidences’ between lines in different orders of spectra that Rowland had used, and the wavelengths of about 300 standard lines. The single wavelength on which all the others depended was Louis Bell’s measurement of Fraunhofer’s D1 line, described in a paper printed alongside Rowland’s.78 Bell used two of the very few Rowland gratings ruled on glass. They were small, 30 mm wide with lines 19 mm long, ruled on plane sextant mirrors, one with about 7200 lines per inch and the other, ruled with a tangent screw fitted to the ruling engine, with 400 lines per millimetre. The grating spacings were measured against two standard bars made by William Rogers. Bell used a Meyerstein spectroscope, no doubt the one described in the laboratory apparatus list. Bell compared his measurements very carefully with all the other available measurements, especially those of C. S. Peirce.