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Radiation—ionising and non-ionising
Published in Sue Reed, Dino Pisaniello, Geza Benke, Kerrie Burton, Principles of Occupational Health & Hygiene, 2020
The eye is the most vulnerable organ to visible and near infrared radiation because the wavelengths from these sources are focused by the lens on to the retina, where thermal or photochemical damage may result. Photochemical injury to the retina is most likely due to long exposures to visible light, peaking at 440 nm. Thermal injury to the retina is more common with short exposures to near infrared radiation. The lens is most vulnerable to middle infrared, and the formation of cataracts is common in glass-blowers (‘glass-blower’s cataract’) and furnace workers unless eye protection is worn. Far infrared is absorbed at the surface of the eye and may cause superficial burns to the cornea or skin. However, skin is not usually at risk unless the source is very intense and pulsed, because the pain reflex limits the duration of exposure.
Radiation—ionising and non-ionising
Published in Sue Reed, Dino Pisaniello, Geza Benke, Principles of Occupational Health & Hygiene, 2020
The eye is the most vulnerable organ to visible and near infrared radiation because the wavelengths from these sources are focused by the lens onto the retina, where thermal or photochemical damage may result. Photochemical injury to the retina is most likely due to long exposures to visible light, peaking at 440 nm. Thermal injury to the retina is more common with short exposures to near infrared radiation. The lens is most vulnerable to middle infrared, and the formation of cataracts is common in glass-blowers (‘glass-blower’s cataract’) and furnace workers unless eye protection is worn. Far infrared is absorbed at the surface of the eye, and may cause superficial burns to the cornea or skin; however, skin is not usually at risk unless the source is very intense and pulsed, because the pain reflex limits the duration of exposure.
Radiation and Spectral Signatures
Published in Julio Sanchez, Maria P. Canton, William Perrizo, Space Image Processing, 2018
Julio Sanchez, Maria P. Canton
Wavelengths beyond the visible color red are referred to as infrared. The infrared region is usually considered to extend between 0.72 and 1000 μm. It is subdivided into three regions: the near infrared extends between 0.72 and 1.3 μm, the mid infrared between 1.3 and 3.0 jam, and the far infrared between 7.0 and 1000 μm. In optical systems, radiation in the near and mid infrared behaves very much like radiation in the visible portion of the spectrum. Therefore, in the near and mid-infrared region, it is possible to use film, cameras, and sensors similar to those designed for visible light. Far-infrared radiation is mostly emitted by earth in the form of heat or thermal radiation. The far-infrared region can also be sensed by instruments and often provides valuable information, as can be seen in Color plate number 7.
Novel drying techniques for controlling microbial contamination in fresh food: A review
Published in Drying Technology, 2023
Dayuan Wang, Min Zhang, Ronghua Ju, Arun S. Mujumdar, Dongxing Yu
Infrared (IR) is a part of the electromagnetic spectrum with a wavelength range of 0.78–1000 μm, which can be classified as near-infrared (NIR, 0.78–1.4 μm), mid-infrared (MIR, 1.4–3 μm) and far-infrared (FIR, 3–1000 μm) according to the length of the wavelength.[101] Food components can absorb IR radiation in all three wavelength bands, but mainly in the FIR wavelength range: proteins (3–4 and 6–9 μm), lipids (3–4, 6 and 9–10 μm), sugars (3, 7–10), and water (3, 4.7, 6 and 15.3 μm).[102] IR radiation, also known as thermal radiation, can be absorbed by objects and converted into thermal energy, and its ability to propagate depends on the moisture content.[103] The IR rays that can pass through the moisture are mainly short waves, and the long waves are absorbed by the surface, so the heating efficiency of FIR is higher for thin-layer food. At present, FIR is most widely used in the food industry.[104] IR drying with high drying efficiency has become an alternative to traditional drying technologies in the food industry. In addition, IR does not produce ionizing radiation to pollute the environment, and the main effect on living organisms is the thermal effect. Therefore, IR drying is a relatively friendly and safe method of drying.[105]
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 novel dryer design with carbonic heating film technology and drying of high moisture lignite coal
Published in International Journal of Coal Preparation and Utilization, 2022
Hasan Hacifazlioglu, Buse Bolat
The heat generation mechanism in the carbonic heater is provided by electromagnetic wave, that is, radiation. Carbon heater film is a state-of-the-art flat far infrared (FIR) heater created by processing the carbon layer and the anti-pollution layer to the non-conductive and noncombustible film, after the preparation of the electrode with the copper strip and the lamination with the laminex film (PET-Polyethylene Terephthalate). There is no heating wire, heating cable, or resistance inside the film. As can be seen from Fig. 1, its main raw materials are nano carbon particles, silver, and copper bars. The heat source is the ultra-fine carbon paste (29–90 nanometer), standing in the middle of the laminex film. With the electrical energy given to the carbon layer, far-infrared rays are emitted and the film becomes hot. Far infrared radiation (FIR) produced by the carbon heating film are rays containing wavelengths between 5.6 and 1000 microns. These rays can be scattered by the sun’s rays, human body, metals, and some minerals (Yuce 2017). The total thickness of the film is 0.5 mm. Heating films give the same temperature from each point at the same time. The length of the films can be produced up to 100 m and the width up to 1 m. With the current technology, the surface temperatures of carbon films can go up to 55°C. However, the surface temperatures of special fabrication carbonic films can go up to 120°C (Anon 2020).