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Critical Factors Affecting the Synthesis of Bionanomaterials and Biocomposites
Published in Naveen Dwivedi, Shubha Dwivedi, Bionanotechnology Towards Sustainable Management of Environmental Pollution, 2023
Rachita Sharma, Priya Singh, Ved Kumar Mishra, Naveen Dwivedi, Nikita Singhal
Microscopy in an analytical technique which uses microscopes. Microscopes are the instruments used to visualize the objects or samples that cannot be seen through the naked eye by producing a high-resolution image. Microscopy is further classified into optical microscopy, electron microscopy, scanning probe microscopy, and x-ray microscopy based on the source used.Optical microscopy. In optical microscopy, the visible light travels through one or more lenses to form a magnified image.Electron microscopy. In electron microscopy, the beam of an electron with a small wavelength is used as the source of light. It is of two types: scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electron microscopy is the most preferred type of microscopy used to analyze nano-sized particles.Scanning probe microscopy. It includes atomic force microscopy (AFM) and scanning tunneling microscopy (STM). They both use a solid tip to physically scan the surface of the sample.
Introduction to Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
What is a microscope, and what is meant by microscopy? A microscope is an instrument that uses an optical lens or a combination of lenses, electronic or other processes, to produce magnified images of small objects, in particular those objects that are too small to be seen by the unaided eye. A microscope augments the power of the eye to see small objects. Microscopy is the technical field of using microscopes to view samples or objects. It deals with the examination of minute objects by means of a microscope, and is the science of interpretive use and application of microscopes for research.
Electrical characterization of electro-Ceramics
Published in Amit Sachdeva, Pramod Kumar Singh, Hee Woo Rhee, Composite Materials, 2021
An electron microscope uses electrons rather than light to form an image. The scanning electron microscope (SEM) images the sample surface by scanning it with a high-energy beam of electrons in a raster scan pattern. The electrons interact with the atoms that make up the sample, producing signals that contain information about the sample’s surface topography, composition, and other properties such as electrical conductivity. It has a large depth of field, which allows a large amount of the sample to be in focus at one time. The images produced have high resolution, which means that closely spaced features can be examined at a high magnification.
Analysis of Dispersibility Effect of Carbon Additives on Ignitability of Ammonium-Dinitramide-Based Ionic Liquid Propellants Using Continuous Wave Laser Heating
Published in Combustion Science and Technology, 2022
An effective approach regarding to validate the correlation is obtaining micro-scale observations; such light microscopy. When targets few to several tens of micro-meters in size are observed, the working distance of microscopes between such targets and the object lens is under 10 mm. Applying microscopic observations to CW laser ignition tests of mixtures of ADN-EILPs and carbons is difficult from the standpoint of safety and configuration of equipment. Therefore, fluorescence microscopy, as a micro-scale observation method, was selected. In principle, fluorescence microscopes can imitate CW laser ignition of the mixture of ADN-EILPs and carbon additives using their simulants. Fluorescence microscopes are equipped with metal halide lamps. The lamps are able to generate higher power light of visible wavelengths for the excitation of targets. The illuminations can be treated as low-power lasers. By using dye solutions as the ADN-EILP simulant, illuminations in fluorescence microscopes heat carbons without their excitation, and dye solutions are excited. Carbon materials do not exhibit fluorescence in the visible wavelength region. Carbons and dye solutions can be distinguished by the contrast between the microscope images. Hence, the phenomenon of carbon additives dispersion heated by a laser can be simulated using fluorescence microscopy.
The dépaysement art of the new media era incorporating the microscopic world
Published in Digital Creativity, 2021
Electron microscopes, which are generally used in various scientific experiments, are different from the lenses or light sources of optical microscopes. Electron microscopes use electron beams instead of visible light to create images. One can see the image through an optical microscope, but an electron microscope can see it through a fluorescent plate or a photographic plate. In addition, an optical microscope absorbs or reflects light from a sample to create an image. However, in an electron microscope, secondary electrons, reflected electrons, and X-rays generated when electron beams collide with the surface of the sample are measured, and the shape of the sample's surface is captured as a video.
Depletion of carbon dots in stimulated emission depletion microscopy developed with 405/532 nm continuous-wave lasers
Published in Journal of Modern Optics, 2022
Wenxuan Zhao, Shenghua Ma, Yueqiang Zhu, Chen Zhang, Xiaoqiang Feng, Wei Zhao, Guiren Wang, Kaige Wang
Optical microscopy is an essential detection technique in the imaging of microstructures, such as biological cells and tissues in life science. Owing to Abbe’s diffraction limit, conventional optical microscopy is not capable to distinguish the featured structures with sizes below , where is wavelength of light and is numerical aperture of the objective lens [1]. To break the diffraction barriers, several super-resolution techniques are proposed and developed [2] in the last two decades, e.g. photoactivated localization microscopy [3], stochastic optical reconstruction microscopy [4], stimulated emission depletion (STED) [5], saturated structured illumination microscopy [6] and others [7–9]. Among several techniques, STED has many unique advantages. By reducing the volume of effective fluorescence emission, STED microscopy shrinks the point spread function and breaks the diffraction barriers to achieve a spatial resolution below 30 nm [10] through a purely physical method without post-reconstruction and chemical reactions [9]. The lateral spatial resolution () of STED microscopy is determined by the following equation [11,12]: where denotes the maximum intensity of the STED beam and is the saturation intensity where the probability of fluorescence emission is reduced to a half of maximum. Therefore, increasing the ratio of the could effectively improve the spatial resolution. Developing highly efficient fluorescence probes with the low and excellent photobleaching resistance is essential for STED applications [13].