• Textile Coloration and Finishing
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• v.26 no.1
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• pp.53-62
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• 2014

This study examined the dyeability, color fastness and functionality of cotton fabrics dyed with residual parts of cultivated Pteridium aquilinum. UV-Vis absorption spectrum, TLC and FT-IR spectra analysis showed that colorants of Pteridium aquilinum are a mixture of pyrogallol tannin and catechol tannin. Optimum dyeing conditions was confirmed colorant concentration of 500% at $100^{\circ}C$ for 60 minutes. Color fastness followed to washing, rubbing, perspiration and light as 4-5, 5, 4-5(acidic), 3-4(alkaline) and 2, respectively. Deodorization rates of ammonia($NH_3$) and acetic acid ($CH_3COOH$) were analyzed 88.8% and 78.0%. UV protection rate was 94.2% of UV-A and 96.8% of UV-B. UV protection factor(UPF) was 27. Therefore residual parts of cultivated Pteridium aquilinum could be used for a new functional colorant.

• Transactions on Electrical and Electronic Materials
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• v.17 no.4
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• pp.204-207
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• 2016

Experimental study of UV-irradiated O₂/H₂ gas phase cleaning for PMMA (Polymethylmethacrylate) removal is carried out in a load-locked reactor equipped with a UV lamp and PBN heater. UV enhanced O₂/H₂ gas phase cleaning removes polymethylmethacrylate (PMMA) better at lower process pressure with higher content of H₂. O₂ gas compete for UV (184.9 nm) absorption with PMMA producing O₃, O(¹D) and lower dissociation of PMMA. In our experimental conditions, etching reaction of PMMA at the substrate temperature between 75℃ and 125℃ had activation energy of about 5.86 kcal/mol indicating etching was controlled by surface reaction. Above the 180℃, PMMA removal was governed by a supply of reaction gas rather than by substrate temperature.

• Journal of Food Hygiene and Safety
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• v.8 no.3
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• pp.151-155
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• 1993

Since there have been no method which can applicable to the screening of commercial sesame oil adulterated with other vegetable oils, the present investigation was carried out particularily focusing on the the pattern of IN absorption of sesame oil and other vegetable oils. For this, a variety of oil samples prepared by the conventional method from sesame seeds, perilla seeds, com, soybean, and rice bran were analyzed by IN spectrophotometer. IN spectra of sesame oil and oil of unheated sesame seeds showed absorption peaks at 215, 230 and 290 nm. While UV spectra of com oil, perilla oil and soybean oil all showed absorption peaks at 215, 230 and 280 nm, that of rice bran oill showed peaks at 215, 290 320 nm. When sesame oil was mixed with com oil, perilla oil or soybean oil, respectively, from which the absorbance of peaks at 290 nm were lower than pure sesame oil. The peak at 320 nm which was typical absorption peak of rice bran oil was still observed in the spectnun of mixture of sesame oil with rice bran oil.

• Journal of Powder Materials
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• v.27 no.3
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• pp.233-240
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• 2020

Nano-sized ZnSe particles are successfully synthesized in an aqueous solution at room temperature using sodium borohydride (NaBH₄) and thioglycolic acid (TGA) as the reducing agent and stabilizer, respectively. The effects of the mass ratio of the reducing agent to Se, stabilizer concentration, and stirring time on the synthesis of the ZnSe nanoparticles are evaluated. The light absorption/emission properties of the synthesized nanoparticles are characterized using ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and particle size analyzer (PSA) techniques. At least one mass ratio (NaBH4/Se) of the reducing agent should be added to produce ZnSe nanoparticles finer than 10 nm and to absorb UV-vis light shorter than the ZnSe bulk absorption wavelength of 460 nm. As the ratio of the reducing agent increases, the absorption wavelengths in the UV-vis curves are blue-shifted. Stirring in the atmosphere acts as a deterrent to the reduction reaction and formation of nanoparticles, but if not stirred in the atmosphere, the result is on par with synthesis in a nitrogen atmosphere. The stabilizer, TGA, has an impact on the Zn precursor synthesis. The fabricated nanoparticles exhibit excellent photo-absorption/discharge characteristics, suggesting that ZnSe nanoparticles can be alloyed without the need for organic solutions or high-temperature environments.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.21 no.1
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• pp.31-46
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• 1993

A radiative transfer model with two-stream/delta-Eddington approximation has been developed to calculate the vertical distributions of atmospheric heating rates and radiative fluxes. The performance of the model has been evaluated by comparison with the results of ICRCCM (Intercomparison of radiative codes in climate models). It has been demonstrated that the presented model has a capability to calculate the solar radiation not only accurately but also economically. The characteristics of ultraviolet-B radiation (UV-B; 280-320nm) are examined by comparison of relation between the flux at the top of atmosphere and that at the surface. The relation of UV-B is quadratic due to the strong ozone absorption in this band. Also, the dependence of the UV-B radiation on the stratospheric ozone depletion and stratospheric aerosol haze due to volcanic eruption on the stratospheric ozone depletion and stratospheric aerosol haze due to volcanic eruption has been tested with various solar zenith angles. The surface UV-B increases as the solar zenith angle increases. The existence of stratospheric aerosols causes an increase in the planetary albedo due to the aerosols' backscattering. The planetary albedo with aerosol's effect has been increases as the solar zenith angle is not sensitive. It may be caused by the fact that the aerosols' scattering effect becomes saturated with the relatively long path length in a large solar zenith angle. Finally, the regional impact of stratospheric aerosols due to volcanic eruption on the intensity of UV-B radiation at the surface has been estimated. A direct effect is that the flux is diminished at the low latitudes, while it is enhanced in the high latitudes by the aerosols' photon trap or twilight effect. In the high latitudes, both aerosols' scattering and ozone absorption have strong and opposite impacts to the surface UV-B radiation is located at the mid-latitudes during spring season in both hemispheres.

• Journal of the Korea Furniture Society
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• v.26 no.4
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• pp.428-434
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• 2015

In this study, we received each wood plastic composites (WPC) from three manufacturers. These WPCs were evaluated regarding their physical and mechanical properties of both before and after accelerated weathering by ultraviolet (UV) irradiation. The total time of exposure of the WPCs to UV irradiation was 1800 h. The water absorption, volumetric swelling and shrinkage of WPCs did not affected by UV irradiation. Among the mechanical properties, there was no significant differences in bending strength and screw withdrawal resistance of UV treated WPCs compared with those of reference WPCs. However, surface hardness of WPCs showed decrease under UV irradiation. Stereoscopic microscopy observation revealed deterioration of the surface layer polymer in all weathered WPCs by UV. Exposure of the WPCs to UV irradiation caused decomposition and disappearance of the polymer layer. From this result, we can estimate that damage of polymer by UV led to a decrease in the surface hardness of the WPCs. The wood flours retained original shape after accelerated weathering by UV irradiation.

• Corrosion Science and Technology
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• v.19 no.1
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• pp.16-22
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• 2020

It is important to realize that benzoate was intercalated into hydrotalcite (HTC-Bz) by the co-precipitation method. In this case, acrylic coating with 0.5 wt% HTC-Bz was deposited on carbon steel using the spin coating method. Next, the HTC-Bz structure was characterized by Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). In fact, an ultraviolet vision spectroscopy (UV-Vis) was used to determine the benzoate content in HTC-Bz, and the UV absorption ability of HTC-Bz. Using electrochemical techniques, water contact angle measurement, and thermal-gravimetric analysis, we compared the protective properties before and after QUV test, hydrophobicity and the thermal stability of acrylic coating containing HTC-Bz. The obtained results showed that HTC-Bz with a plate-like structure was successfully synthesized; benzoate was intercalated into the interlayer of hydrotalcite with a concentration of 28 wt%. Additionally, it was noted that HTC-Bz has an UV absorption peak at 225 nm. In conclusion, the addition of HTC-Bz enhanced the UV stability, hydrophobicity and the thermal stability of acrylic coating.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.361-367
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• 2004

In this study, a different UV (ultra-violet) ray absorption system is presented in which butyl methoxydiben-zoylmethane (BMDM, a model UV-A absorbent, 320$\~$400 nm) is stabilized in phase-controlled poly(methyl methacrylate) (PMMA) microspheres. The photochemistry of BMDM in the microspheres was investigated considering its phase characteristics therein. The analysis of a differential scanning calorimeter and X-ray diffractometer showed that the BMDM in the microspheres was present with a non-crystalline state. The phase control of BMDM in the polymer microsphere has an excellent ability to protect UV-A with maintaining its photo- and thermal stability. The results obtained in this study illustrate well that the phase control of the UV absorbents in the polymer microspheres is another key factor that de-termines its photochemistry and photostability in the final formulations.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.2
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• pp.27-30
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• 2009

Purpose: Transmittance at UV-visible spectra range was measured to confirm the effect of wet/dry state of commercially available SCL on human eyes. Method: Commercially available five SCLs fabricated by different materials were selected to measure optical properties according to humidity. Results: A relatively high transmittance above about 80% in the visible spectra range of the SCLs were observed. In the UV spectra range, the wet samples showed higher transmittance than those dried except an unusual case. Conclusions: All the samples having a high optical properties in the visible spectra range exhibit a high transmittance in the UV region. Further research will be needed to develop new materials having a sharp absorption edge in the UV spectra range.

• Textile Coloration and Finishing
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• v.21 no.6
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• pp.39-45
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• 2009

The importance of nano gold particles has been increased in the field of bio physics and medicine, recently. In this regard, the study aims to analyze how the harmless nano gold particles can be transformed by respective variables. In this study, electrospun PU nano-webs were impregnated with aqueous $HAuCl_4$ solution and UV light was irradiated on the webs. Au-ions were reduced to nano particles by photocatalytic reduction and these nano gold particles were characterized by SEM, UV-vis, Zetasizer, Spectrophotometer, EDS. $HAuCl_4$ solution concentration and UV irradiation time have heen examined to change the amount of absorption. Nano gold particles size and UV-Vis absorbances were increased with $HAuCl_4$ solution concentration and UV irradiation time.