Extractives relating to heartwood color changes in sugi (Cryptomeria japonica) by a combination of smoke-heating and UV radiation exposure

2003 ◽  
Vol 49 (2) ◽  
pp. 135-139 ◽  
Author(s):  
F. Ishiguri ◽  
S. Maruyama ◽  
K. Takahashi ◽  
Z. Abe ◽  
S. Yokota ◽  
...  
2020 ◽  
Vol 14 (2) ◽  
pp. 88
Author(s):  
Emad Yousif

This article focus on the calculation of photodecomposition rate constant of PVC films that containing sulfadiazine tin(IV) complexes 1-3 as photostabilzers during UV radiation exposure. This constant calculated as a method for evaluating the efficiency of sulfadiazine tin(IV) complexes 1-3 when used as a PVC photostabilizers after 300 hours of irradiation. The experimental results showed that sulfadiazine tin(IV) complexes 1-3 have reduced the rate of photodecomposition constant value of PVC films significantly with comparison to PVC (blank).


2009 ◽  
Vol 145 (9) ◽  
Author(s):  
Latrice C. Pichon ◽  
Joni A. Mayer ◽  
Katherine D. Hoerster ◽  
Susan I. Woodruff ◽  
Donald J. Slymen ◽  
...  

2001 ◽  
Vol 2 (3) ◽  
pp. 250-260 ◽  
Author(s):  
Horacio E Zagarese ◽  
Craig E Williamson

2016 ◽  
Vol 30 (1-2) ◽  
pp. 15-33
Author(s):  
Corina E. Rogge ◽  
Anya Shullman

Abstract In order to determine the light sensitivities of commonly encountered furs, 17 furs from 12 species were exposed to 1.97 Mlx hours of light from a xenon arc lamp, filtered either to simulate window-filtered daylight or to remove all ultraviolet (UV) radiation. Comparison with coexposed Blue Wools showed that most samples were relatively lightfast (Blue Wool 5 or better), with darker specimens being more lightfast. Examination of the Commission internationale de l'éclairage (CIE) L*a*b* values revealed fading but also other changes: some furs darkened, and other experienced changes in b* values. Removal of UV radiation prevented darkening and usually decreased the magnitude of ΔE76 but did not prevent color changes, and one species exhibited greater change under visible light. Changes in color were accompanied by photooxidation of the keratin of all species as assessed by attenuated total reflectance infrared spectroscopy; the extent of photooxidation was decreased by filtering out UV radiation. Pre-exposure treatment with a spray application of a 1% solution of Tinuvin 292, a hindered amine light stabilizer, offered some protection against both UV and visible light-induced changes. Tinuvin 292 pre-exposure also helped prevent keratin photooxidation and light-induced mechanical damage and thus may be an appropriate preventative treatment when light exposure is unavoidable.


2020 ◽  
Vol 4 (1) ◽  
Author(s):  
SITI HANIFAH MAHDIYANTI ◽  
Satoru Tsuchikawa ◽  
Katsuya Mitsui ◽  
Laszlo Tolvaj

Abstract. Mahdiyanti SH, Tsuchikawa S, Mitsui K, Tolvaj L. 2020. Steaming-caused chemical changes of sugi (Cryptomeria japonica) wood monitored by NIR spectroscopy. Asian J For 4: 7-10. Sugi (Cryptomeria japonica D. Don) wood samples were steamed, applying a broad range of steaming time (0-20 days) at 90 and 110°C steaming temperatures. NIR spectroscopy was used to monitor the chemical changes caused by steaming. The difference spectrum method was applied to find the absorption increases and decreases. Before the subtraction, the spectra were normalized to one unit at 1739 nm to eliminate the parallel shift of the spectra. Steam-induced chemical changes in the wavelength range of 1300-2100 nm are related to the absorption of water and the absorption of extractives, especially phenolic contents. These chemical changes are suspected to be strongly related to color changes in steamed wood. Longer duration of steaming caused phenolic compounds to change into similar contents in all wood tissues, which cause their color to change more uniformly. Steaming caused a water bounding capacity loss of the cell wall. This change was much faster at 110°C than at 90°C.


2019 ◽  
Vol 10 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Wan Insaniah Saleha Ahmad Shah ◽  
Ahmad Fairuz Omar

Abstract Gafchromic external beam therapy 3 (EBT3) film has widely been used in medical field applications. Principally, the EBT3 film’s color gradually changes from light green to darker color under incremental exposures by ionizing or even non-ionizing ultraviolet (UV) radiation. Peak absorbance of the EBT3 film can be used to predict absorbed doses by the film. However, until today, related researches still rely on spectrometers for color analysis of EBT3 films. Hence, this paper presents a comparative analysis between results produced by the spectrometer and a much simpler light-emitting diode-photodiode based system in profiling the color changes of EBT3 films after exposure by solar UV radiation. This work has been conducted on a set of 50 EBT3 samples with incremental solar UV exposure (doses). The wavelength in the red region has the best sensitivity in profiling the color changes of EBT3 films for low solar UV exposure measurement. This study foresees the ability of blue wavelength to profile films with a large range of solar UV exposure. The LED (light emitting diode)-based optical system has produced comparable measurement accuracies to the spectrometer and thus, with a potential for replacing the need for a multipurpose spectroscopy system for simple measurement of light attenuation.


2019 ◽  
Vol 26 (10) ◽  
pp. 9945-9954 ◽  
Author(s):  
Emad Yousif ◽  
Dina S. Ahmed ◽  
Ahmed A. Ahmed ◽  
Ayad S. Hameed ◽  
Safaa H. Muhamed ◽  
...  

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