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Introduction to Optical, Infrared, and Terahertz Frequency Bands
Published in Song Sun, Wei Tan, Su-Huai Wei, Emergent Micro- and Nanomaterials for Optical, Infrared, and Terahertz Applications, 2023
Song Sun, Wei Tan, Su-Huai Wei
Besides hot planets, various artificial UV sources are developed including lamps, light-emitting diodes (LED) and lasers [5]. There are several kinds of lamps that could emit UV radiations. The first type is called black light or Wood’s lamp, which produces long wave UV radiation based on either fluorescent or incandescent mechanism. Black light is commonly used in the situation where no visible light is needed, for instance, to trace fluorescence-tagged biochemical substance or to detect counterfeit money. The second type is the short-wave UV lamp, which typically emits short-wave UV-C light with peaks at 253.7 nm and 185 nm due to the mercury vapor filled within the lamp. These short-wave UV lamps are extensively utilized for disinfection purpose (also named germicidal lamps) in biomedical, food and water industries. The third type is the gas-discharge lamp, which could empower flexible UV radiation at various spectral lines depending on the gas types containing in the tube. The most commonly used gas-discharge lamps are neon lamp, deuterium arc lamp, xenon arc lamp, and mercury-xenon arc lamp, which cover the whole UV-A/UV-B/UV-C bands. The fourth type is the metal-halide lamp offering a high intensity white radiation via a mixture of gaseous mercury and metal halide (e.g., sodium iodide), since the metal ion could disassociate from the halide compound during the operation and produce additional emission power. Lastly, excimer lamp is a quasi-monochromatic UV source originated from the spontaneous emission of excimer molecules, which spans over a wide range of UV spectra depending on the molecule types [6].
Selecting Laser-Protective Eyewear
Published in D. C. Winburn, Practical Laser Safety, 2017
According to the Encyclopaedia Britannica:ultraviolet light [is] that portion of the electromagnetic spectrum adjacent to the short wavelength, or violet end of the light range. Often called black light, ultraviolet light is invisible to the human eye; but, when it falls on certain surfaces, it causes them to fluoresce, or emit visible light.… The ultraviolet spectrum is usually divided into two regions: near ultraviolet (nearer the visible spectrum), with wavelengths 2000 to 3800 angstrom units (200 to 380 nm); and far ultraviolet, with wavelengths 100 to 2000 angstrom units (10 to 20 nm).
Principles of Penetrants
Published in Don E. Bray, Roderic K. Stanley, Nondestructive Evaluation, 2018
Don E. Bray, Roderic K. Stanley
The partial electromagnetic spectrum given in Fig. 34-9 shows the location of the ultraviolet spectrum as well as that of the visible region previously discussed. Because the ultraviolet light spectrum is not normally seen by the human eye, ultraviolet lights have been labeled black-lights.’ The advantage of this in penetrant inspection is that regions holding greater amounts of the fluorescent penetrant appear very bright. When the inspection is performed in very subdued light, the regions clear of penetrant material will appear black. With this scenario, the visibility of very small indications is greatly enhanced.
Reduction deposition of Pd nanoparticles on ZnO flowers used for photodegradation of methylene blue and methyl orange under UV light
Published in Inorganic and Nano-Metal Chemistry, 2021
Anukorn Phuruangrat, Phattareeya Boonnoi, Thawatchai Sakhon, Somchai Thongtem, Titipun Thongtem
Methylene blue (MB, cationic dye) and methylene orange (MO, anionic dye) were used as molecular probes for photocatalytic evaluation. The photocatalytic reaction was conducted at room temperature under UV light of three 18 W black light with λmax of 370 nm. The reaction was carried out using 200 mg catalyst dispersed in 200 ml of 1 × 10−5 M dye aqueous solution. Prior to irradiation, the suspension solutions were magnetically stirred in the dark for 30 min to establish an adsorption/desorption equilibrium of the dye and photocatalyst. During photocatalytic testing, approximately 5 ml solution was withdrawn every 20 min and centrifuged to remove any suspended catalytic nanoparticles. The residual concentration of the MB/MO dye containing in a liquid cuvette was measured at 664 nm for MB and 464 nm for MO with de-ionized water as a reference by a UV-visible spectrophotometer (PerkinElmer Lambda 25). The decolorization efficiency was calculated by the below equation. Co is the initial dye concentration and Ct is the dye concentration after photocatalytic treatment for a period of time (t).
Facile coating of carbon nanotubes by different resins for enhancing mechanical, electrical properties and adhesion strength of NR/Nylon 66 systems
Published in The Journal of Adhesion, 2021
H. Moustafa, N. A. Darwish, A. M. Youssef
H Pull-out tests (H-test) were used to evaluate the adhesion force between the rubber and nylon cords. Dipped cords were bonded to rubber compounds according to ASTM D 2138–83 and tested in accordance with ASTM D 4776–18. The sample preparation and test conditions were described elsewhere.[34] H Pull-out tests for investigated specimens were performed before and after exposure to UV radiations. For UV aging, the specimens were exposed under continuous UV irradiations for 2 weeks using CL1000 Ultraviolet Cross-linkers, VUP, UK, with black light lamps (λ = 365 nm) in accordance with ASTM D1148-13. The pull-out force was expressed in Newton and the average value taken from at least five trials for each sample.
Microwave-assisted deposition synthesis, characterization and photocatalytic activities of UV-light-driven Ag/BiOCl nanocomposites
Published in Inorganic and Nano-Metal Chemistry, 2021
Anukorn Phuruangrat, Titipun Thongtem, Somchai Thongtem
Photocatalytic activity was evaluated through the degradation of MB and MO as model dye solutions. Each 0.2 g photocatalyst was added to 0.64 mg of 200 mL MB solution and 0.65 mg of 200 mL MO solution which were magnetically stirred to form homogeneous solutions. During photocatalysis, the suspension solutions were irradiated by UV black light and xenon visible light sources. For every 60 min specific time interval, 5 mL solution was sampled and centrifuged. The concentration of dye was measured by a UV–visible spectrophotometer at λmax of 664 nm for MB and 464 nm for MO. The degradation efficiency was calculated using the below equation.