China
Africa
Explore chapters and articles related to this topic
Confocal Raman microscopy
Published in Raquel Seruca, Jasjit S. Suri, João M. Sanches, Fluorescence Imaging and Biological Quantification, 2017
M. Gomez-Lazaro, A. Freitas, C.C. Ribeiro
Relevant for the acquisition of chemical information in biological samples is the combination of the spectral and the spatial information within the sample. In order to combine these two types of information, a Raman spectrometer can be coupled to a microscope, allowing high-magnification visualization of a sample area. Then it is possible to obtain a Raman spectrum from a micrometer laser spot area using the objective of the microscope as the light-collecting device. By working with high numerical aperture (NA) objectives, we can enhance the efficiency of the acquisition of the Raman signal through the increase of the photon density per area, but also the collection efficiency (Table 5.1). However, depending on the laser wavelength, intensity, and acquisition time, the utilization of an objective may lead to sample heating due to focusing of the laser beam. Therefore, care must be taken not to destroy the sample. By using a confocal Raman microscope, additional advantages arise such as improvement in the lateral resolution and increased sensitivity. Lateral resolution can be narrowed down to the light diffraction limit. For a confocal setup, the lateral spatial resolution can be calculated as follows, relying on the laser wavelength (λ) and the numerical aperture (NA) of the objective: δlat=0.62λNA
Raman Microscopy
Published in John Girkin, A Practical Guide to Optical Microscopy, 2019
At the core of a Raman microscopy system is the requirement to deliver a laser to a specific spot on the sample and to then collect the Raman signal for subsequent detection. However, as can be appreciated from the description of the physical processes that take place to generate the Raman signal, the details, and practical implementation, of these core requirements vary depending on the exact Raman process being used to generate the contrast in the image. In general though, practical Raman microscopes use a beam scanning technique to generate images and the core configuration is similar to that used in a confocal microscope.
Evaluation of tire derived rubber (TDR) fixed biofilm reactor (FBR) for remediation of Methylene blue dye from wastewater
Published in Environmental Technology, 2021
D. Naresh Yadav, Iffat Naz, K. Anand Kishore, Devendra Saroj
Raman microscopic technique is applied in the present research for chemical investigation of the TDR SSM before (raw TDR) and after (1st and 9th week TDR SSM samples) the treatment. Further, MB simulated wastewater sample was also examined by Raman. All Raman spectra were recorded using a Raman Microscope (RENISHAW in via confocal Raman microscope, STFC Rutherford Appleton Laboratory [RAL], UK). The Raman signals were collected in the spectral interval 600–2000 cm−1; at 830 nm wavelength laser source with integration time of 10 s. The experiments were performed at 5X objective extended scan using 50 pc power and 5 accumulations.
Uranium dissolution and uranyl peroxide formation by immersion of simulated fuel debris in aqueous H2O2 solution
Published in Journal of Nuclear Science and Technology, 2022
Yuta Kumagai, Ryoji Kusaka, Masami Nakada, Masayuki Watanabe, Daisuke Akiyama, Akira Kirishima, Nobuaki Sato, Takayuki Sasaki
The simulated debris samples were analyzed by Raman spectroscopy before and after the leaching to detect changes in the surface chemistry. The measurement was performed with a Raman microscope (NRS-4500, JASCO) equipped with a 532 nm excitation laser (0.5 mW) and a confocal optical system. The Raman microscope had a three-axis micromotored stage and provides c.a. 1 μm spatial resolution through a 100× objective lens. The Raman spectra were measured by point analysis, and an averaged spectrum was obtained typically from 100 to 1000 measurements of different points in a sample.