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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
Spectroscopy is an analytical method used to determine the structure of atoms. Spectroscopy is also the study of the interaction of electromagnetic radiation with matter, resulting in the absorption or emission of wavelength or frequency of radiation. This interaction will help us to investigate the structure of matter on an atomic scale by using spectra. The absorption and emission of electromagnetic radiation will form a spectrum that gives the detailed study of the atomic configuration of matter. Absorption spectroscopy measures the absorption of wavelength or frequency of radiation when it interacts with the sample. When the electromagnetic radiation is absorbed, electrons will excite from a lower energy level to a higher energy level and form an “absorption spectrum.” In emission spectroscopy, the electrons will be excited from a higher energy level to lower energy level when the matter interacts with electromagnetic radiations. This excitation will emit radiation of different frequencies or wavelengths that produce a line spectrum called an “emission spectrum.” There are different types of spectroscopies used for the characterization of nanoparticles, including UV-Vis spectroscopy and FTIR spectroscopy.
Experimental and Characterization Techniques
Published in Amit Sachdeva, Pramod Kumar Singh, Hee Woo Rhee, Composite Materials, 2021
Rahul, Rakesh K. Sonker, P. K. Shukla, Pramod K. Singh, Zishan H. Khan
The UV-visible absorption spectroscopy is the measurement of the attenuation of a beam of light with wavelength after it passes through a sample or after reflection from a sample surface. The short-wavelength limit for simple UV-visible spectrometers is 180 nm, due to absorption of ultraviolet wavelength below 180 nm by atmospheric gases. The absorbance A is related to the input and output intensities according to the Beer-Lambert Law [37], given by the equation llo=e−A
Experimental Measurements on Magnetic Quantization
Published in Chiun-Yan Lin, Ching-Hong Ho, Jhao-Ying Wu, Thi-Nga Do, Po-Hsin Shih, Shih-Yang Lin, Ming-Fa Lin, Diverse Quantization Phenomena in Layered Materials, 2019
Shih-Yang Lin, Thi-Nga Do, Chiun-Yan Lin, Jhao-Ying Wu, Po-Hsin Shih, Ching-Hong Ho, Ming-Fa Lin
Optical spectroscopies are very powerful in characterizing the absorption [31], transmission [51], and reflectance [33] of any condensed-matter systems, especially for the diverse optical properties of emergent layered materials. They can provide the rather sufficient information on the single-particle and many-body vertical optical excitations, directly reflecting the main features of energy bands and strongly coupled excitons [electron-hole pairs attracted by the longitudinal Coulomb interactions; [31, 51]], e.g., the experimental examinations on the predicted energy gap, the threshold excitation frequency, the band-edge state energies, the special absorption structures, the electric-field effects, and the magneto-optical selection rules. Absorption spectroscopy, which is based on the analytical method of measuring the fraction of incident radiation absorbed by a sample, is one of the most versatile and widely used techniques in the sciences of physics, chemistry, and materials. This well-developed tool is available within a wide frequency range. The measured spectral functions are frequency-dependent functions for characterizing the fundamental electronic properties of materials. The experimental setup related to the light source, sample arrangement, and detection technique is sensitive to the frequency range and the experimental purpose.
Looking at ancient objects under a different light: cultural heritage science at Elettra
Published in Radiation Effects and Defects in Solids, 2022
Matteo Amati, Alessandra Gianoncelli, Emanuel Karantzoulis, Barbara Rossi, Lisa Vaccari, Franco Zanini
Among the characterisation techniques considered in this contribution, infrared spectroscopy deals with radiation of longer wavelengths and lower energetic content: the infrared light. Infrared radiation (IR) extends from the nominal red edge of the visible spectrum to microwaves, a spectral range conventionally described by three regions, near-infrared (between 14,000 and 4000 cm−1), mid-infrared (between 4000 and 400 cm−1) and far-infrared (between 400 and 10 cm−1) depending on their relation to visible light. Infrared spectroscopy encompasses a broad range of techniques, mostly based on absorption spectroscopy: infrared light absorbed by a molecule induces molecular transitions to excited vibro-rotational states, at frequencies that are characteristic of the molecule, primarily through the mass of covalently bonded atoms and the strength of their linkage. Fundamental vibrations are excited by mid-IR light, while vibrational overtones and combination bands are in the near-IR, and rotational details are searchable in the far-IR. All over, infrared spectroscopy provides qualitative and, in controlled conditions, quantitative information on the chemical moieties constituting a molecule, in a safer manner, being IR nonionising and without suffering from the fluorescence effects that often limit both visible and UV Raman spectroscopy.
A rapid, spatially dispersive frequency comb spectrograph aimed at gas phase chemical reaction kinetics
Published in Molecular Physics, 2020
Frances C. Roberts, H. J. Lewandowski, Billy F. Hobson, Julia H. Lehman
Frequency comb lasers are a simultaneously broadband and high-resolution light source generated by the phase stabilisation of a mode-locked femtosecond laser. Although these lasers have been most often designed for near-infrared wavelengths, partially because of convenient wavelength fibres operating near 1560 nm or 1040 nm, frequency comb lasers have begun to be extended into the mid-infrared wavelength range where there are many vibrational transitions of chemically important functional groups extending to the ‘fingerprint region’ of the spectrum. Operating in these regions of the spectrum is beneficial in chemistry since fundamental vibrational frequencies have at least an order of magnitude larger oscillator strength compared to vibrational overtones accessible in the near infrared. This increases the potential detection sensitivity in direct absorption spectroscopy measurements, allowing the technology to progress further into trace gas detection and monitoring of transient chemical phenomena.
Characterization of the Buoyant Jet above a Catalytic Combustor Using Wavelength Modulation Spectroscopy
Published in Combustion Science and Technology, 2019
Torrey R. S. Hayden, Nicholas T. Wimer, Caelan Lapointe, Jason D. Christopher, Siddharth P. Nigam, Aniruddha Upadhye, Mark Strobel, Peter E. Hamlington, Gregory B. Rieker
Laser absorption spectroscopy is an excellent option to achieve these objectives in a heated, buoyant jet because it is quantitative, species-selective, robust and portable, and can provide millisecond time resolution (Lackner, 2011). Other laser-based techniques, such as laser-induced fluorescence (LIF) and Raman or Rayleigh scattering, can provide the desired quantitative spatial and temporal information (Daily, 1997; Mcenally et al., 2000); however, they can require large optical experimental systems that are impractical for industrial applications. Absorption spectroscopy measures the fraction of light absorbed by a gas sample as a function of wavelength. Light will be absorbed if the wavelength is resonant with a quantum transition of a target molecular species. One form of absorption spectroscopy is tunable diode-laser absorption spectroscopy (TDLAS), in which the wavelength of a diode laser is tuned across one or two transitions of the target species. TDLAS provides quantitative, non-intrusive, line-of-sight-averaged measurements of the thermodynamic properties of the gas, and thus has been used extensively in combustion research.