scholarly journals Effect of Water Leaching on Photodegraded Scots Pine and Spruce Timbers Monitored by FTIR Spectroscopy

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 833
Author(s):  
Edina Preklet ◽  
László Tolvaj ◽  
Eszter Visi-Rajczi ◽  
Tamás Hofmann
Keyword(s):  
Ftir Spectroscopy ◽  
Scots Pine ◽  
Uv Irradiation ◽  
Chemical Elements ◽  
Uv Light ◽  
Carbonyl Groups ◽  
Water Leaching ◽  
Absorption Bands ◽  
Chemical Changes ◽  
Absorption Increase

The goal of this research was the systematic study and comparison of the divided individual effects of UV light irradiation and water leaching during artificial weathering. Spruce (Picea abies Karst.) and Scots pine (Pinus sylvestris L.) samples were irradiated by ultraviolet (UV) light. Another sequence of samples was treated with the combination of UV irradiation and water leaching. The total extent of UV treatment was 20 days for both series of samples. Time relation of UV irradiation and water leaching was 2:1. The chemical changes were observed by FTIR spectroscopy. The difference spectrum was used for determination of the chemical changes. Degradation of lignin was greater for the leached samples than for the pure UV treated samples. Scots pine suffered greater lignin degradation than spruce, and produced higher absorption increase on the absorption region of unconjugated carbonyls. The unconjugated carbonyl groups were the most responsive chemical elements to leaching. Spruce was more susceptible to leaching of unconjugated carbonyl groups than Scots pine. Two absorption bands of unconjugated carbonyl groups at 1706 and 1764 cm−1 wavenumbers were produced by photodegradation. The absorption band at 1764 cm−1 was more sensitive to water leaching than the band at 1706 cm−1.

scholarly journals Discolouration of thermally modified wood during simulated indoor sunlight exposure

BioResources ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 434-446 ◽  
Author(s):  
Josip Miklečić ◽  
Vlatka Jirouš-Rajković ◽  
Alan Antonović ◽  
Nikola Španić
Keyword(s):  
Ftir Spectroscopy ◽  
Uv Light ◽  
Window Glass ◽  
Colour Change ◽  
Chemical Changes ◽  
Wood Discoloration ◽  
Two Component ◽  
Transparent Coatings ◽  
Thermally Modified Wood ◽  
Modified Wood

This paper deals with the effect of UV light through window glass on the changes in colour of surfaces of uncoated and clear-coated thermally modified wood, and on chemical changes of surfaces of uncoated thermally modified and unmodified wood. Discoloration of the uncoated wood samples and those treated with three commercial transparent coatings (two-component polyurethane varnish, water-borne varnish, and nano-impregnation) was measured spectrophotometrically using CIELAB parameters (L*, a*, b* and DE*). FTIR spectroscopy was used to study chemical changes caused by UV irradiation. Colour change (DE*) was recorded in all tested wood samples after exposure to UV light, and the smallest discoloration was recorded in wood samples coated with two-component polyurethane varnish. FTIR spectroscopy results show that thermal treatment and exposure to UV light modified the chemical structure of wood surface and that the thermally modified samples exposed to UV light showed similar changes as unmodified samples exposed to UV light, but less pronounced.

scholarly journals Leaching effect of water on photodegraded hardwood species monitored by IR spectroscopy

2020 ◽  
Vol 54 (6) ◽  
pp. 1407-1421
Author(s):  
Denes Varga ◽  
Laszlo Tolvaj ◽  
Zsolt Molnar ◽  
Zoltan Pasztory
Keyword(s):  
Uv Radiation ◽  
Black Locust ◽  
Robinia Pseudoacacia ◽  
Combined Treatment ◽  
Total Duration ◽  
Chemical Components ◽  
Carbonyl Groups ◽  
Water Leaching ◽  
Absorption Bands ◽  
Sessile Oak

Abstract Black locust (Robinia pseudoacacia L.), beech (Fagus sylvatica L.), aspen (Populus tremula L.) and sessile oak (Quercus petraea Liebl.) hardwood samples were irradiated by a strong ultraviolet (UV) emitter mercury lamp at 50 °C. Other series of specimens were exposed to a combined treatment of UV irradiation and water leaching. Ratio of UV radiation and water leaching time was 2:1. While the total duration of UV radiation was 20 days for both test series that of water leaching was 10 days. IR measurement was taken after both UV radiation and water leaching to monitor both effects separately. Lignin degradation proved to be more intensive in leached samples than in purely UV-irradiated samples. Guaiacyl and syringyl lignin showed similar degradation properties. Unconjugated carbonyl groups generated by the photodegradation were the most sensitive chemical components to leaching. Photodegradation generated two absorption bands of unconjugated carbonyl groups at around 1710 and 1760 cm−1 wavenumbers. The band at 1760 cm−1 was much more sensitive to water leaching than the band at 1710 cm−1. Three to ten days of water leaching was enough to remove all unconjugated carbonyls generated by the photodegradation, depending on the species. Sessile oak was the most sensitive species to water leaching, whereas black locust proved to be the most stable against both photodegradation and water leaching. Water was able to leach out unconjugated carbonyl groups (absorbing at 1745 cm−1) originally present in all investigated wood species.

scholarly journals Monitoring the Photodegradation of PVC Thin Films Containing Schiff Base Using FTIR Spectroscopy

2019 ◽  
Vol 4 (1) ◽  
pp. 12-17
Author(s):  
Ali Hassan ◽  
Dina S. Ahmed ◽  
Riyadh Noaman ◽  
Emad Yousif
Keyword(s):  
Thin Films ◽  
Schiff Base ◽  
Light Intensity ◽  
Metal Complexes ◽  
Ftir Spectroscopy ◽  
Uv Irradiation ◽  
Infrared Spectra ◽  
Uv Light ◽  
Base Derivative

Metal complexes of Cu(II), Cd(II), Zn(II), Ni(II) and Sn(II) containing Schiff base derivative (L) as a ligand (ML2) utilized as additives to avoid PVC films photodegradation during UV irradiation (λmax= 313 at a light intensity = 7.75 × 10-7 einstein dm-3 sec-1). Irradiation of PVC films with UV light due to changes in infrared spectra.

scholarly journals Effects of UV light irradiation on color changes in thermally modified rubber wood based on FTIR

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 5179-5197
Author(s):  
Xiaowen Li ◽  
Tongtong Li ◽  
Guanjun Li ◽  
Min Li ◽  
Quanji Lu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Color Change ◽  
Uv Light ◽  
Untreated Wood ◽  
Transformation Process ◽  
Carbonyl Groups ◽  
Chemical Changes ◽  
Color Changes ◽  
Rubber Wood ◽  
Treatment Conditions

To evaluate the effects of chemical changes during thermal modification on the resistance of wood against photodegradation, heat-treated specimens of rubber wood (Hevea brasiliensis) were exposed to ultraviolet light for 384 h. The color changes in the exposed wood surfaces were analyzed using a colorimeter; the chemical changes were monitored using Fourier-transform infrared spectroscopy (FTIR). The photoweathering performances of rubber wood treated at 155 °C for 2 h, 155 °C for 6 h, and 185 °C for 2 h were similar to that of untreated wood, as the lignin did not undergo profound chemical transformation under mild modification conditions. However, compared to untreated rubber wood, the photoaging performances of rubber wood treated at 185 °C for 6 h and 215 °C for 2 h were notably changed. The transformation process was confirmed by FTIR. A good linear relationship between color change and lignin degradation was observed after mild, but not severe, heat treatment. The concentration of carbonyl groups in the wood specimens generally increased during photoaging, although not all samples showed a good correlation between color change and the concentration of carbonyl groups. Only the photochromic performance of wood changed notably when lignin was extensively modified under severe heat-treatment conditions.

Synthesis of HTCMgFe for the degradation of indigo carmine through heterogeneous photo-Fenton treatment

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3273-3282
Author(s):  
I. Cosme-Torres ◽  
M.G. Macedo-Miranda ◽  
S.M. Martinez-Gallegos ◽  
J.C. González-Juárez ◽  
G. Roa-Morales ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Treatment Time ◽  
Uv Light ◽  
Indigo Carmine ◽  
Oh Radicals ◽  
Absorption Bands ◽  
Chromophore Group ◽  
X Ray ◽  
Catalytic Sites ◽  
Scanning Electron

AbstractThe heterogeneous catalyst HTCMgFe was used in the degradation of the IC, through the heterogeneous photo-fenton treatment, this material in combination with H2O2 and UV light degraded the dye in 30 min at pH 3. As the amount of HTCMgFe increases the degradation it was accelerated because there are more active catalytic sites of Fe2+ on the surface of the material, which generates a greater amount of •OH radicals. The HTCMgFe was characterized by infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray energy dispersive elemental analysis (EDS). The UV-vis spectrum shows that the absorption bands belonging to the chromophore group of the IC disappear as the treatment time passes, indicating the degradation of the dye.

scholarly journals Deposition of Zinc Oxide Coatings on Wood Surfaces Using the Solution Precursor Plasma Spraying Process

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 183
Author(s):  
Ghiath Jnido ◽  
Gisela Ohms ◽  
Wolfgang Viöl
Keyword(s):  
Zinc Oxide ◽  
Ftir Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Color Change ◽  
Uv Light ◽  
Beech Wood ◽  
Nitrate Solution ◽  
Ftir Spectra ◽  
Solution Precursor ◽  
Wood Surfaces

In the present work, the solution precursor plasma spray (SPPS) process was used to deposit zinc oxide (ZnO) coatings on wood surfaces using zinc nitrate solution as precursor to improve the hydrophobicity and the color stability of European beech wood under exposure to ultraviolet (UV) light. The surface morphology and topography of the wood samples and the coatings were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The formation of ZnO was detected with the help of X-ray photoelectron spectroscopy (XPS) and by Fourier transform infrared (FTIR) spectroscopy. The FTIR spectra of the coated samples showed the typical Zn–O band at 445 cm−1. According to the XPS analysis, the coatings consist of two different Zn-containing species: ZnO and Zn(OH)2. Variation of the deposition parameters showed that the most significant parameters affecting the microstructure of the coating were the solution concentration, the deposition scan speed, and carrier gas flow rate. The wettability behaviors of the coated wood were evaluated by measuring the water contact angle (WCA). The coatings that completely covered the wood substrates showed hydrophobic behaviors. UV-protection of wood surfaces after an artificial UV light irradiation was evaluated by color measurements and FTIR spectroscopy. The ZnO-coated wood surfaces were more resistant to color change during UV radiation exposure. The total color change decreased up to 60%. Additionally, the FTIR spectra showed that the wood surfaces coated with ZnO had more stability. The carbonyl groups formation and C=C-bonds consumption were significantly lower.

scholarly journals UV-induced neuronal degeneration in the rat cerebral cortex

2021 ◽  
Author(s):  
Mariko Nakata ◽  
Masayuki Shimoda ◽  
Shinya Yamamoto
Keyword(s):  
Uv Irradiation ◽  
Neuronal Degeneration ◽  
Uv Light ◽  
Brain Lesion ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Heme Oxygenase 1 ◽  
Dependent Manner ◽  
Focal Brain Injury ◽  
The Brain ◽  
And Oxidative Stress

Abstract Irradiation with ultraviolet (UV) light on the cortical surface can induce a focal brain lesion (UV lesion) in rodents. In the present study, we investigated the process of establishing a UV lesion. Rats underwent UV irradiation (365 nm wavelength, 2.0 mWh) over the dura, and time-dependent changes in the cortical tissue were analyzed histologically. We found that the majority of neurons in the lesion started to degenerate within 24 hours and the rest disappeared within 5 days after irradiation. UV-induced neuronal degeneration progressed in a layer-dependent manner. Moreover, UV-induced terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity and heme oxygenase-1 (HO-1) immunoreactivity were also detected. These findings suggest that UV irradiation in the brain can induce gradual neural degeneration and oxidative stress. Importantly, UV vulnerability may vary among cortical layers. UV-induced cell death may be due to apoptosis; however, there remains a possibility that UV-irradiated cells were degenerated via processes other than apoptosis. The UV lesion technique will not only assist in investigating brain function at a targeted site but may also serve as a pathophysiological model of focal brain injury and/or neurodegenerative disorders.

Optimization of ultraviolet irradiation of Clarias gariepinus (Burchell, 1822) eggs for androgen production

Zygote ◽  
2021 ◽  
pp. 1-6
Author(s):  
Victor Tosin Okomoda ◽  
Haziqah Jumahat Nursyaza ◽  
Ijabo Oga Samuel ◽  
Anuar Hassan ◽  
Abraham Sunday Oladimeji ◽  
...  
Keyword(s):  
Survival Rate ◽  
Uv Irradiation ◽  
Uv Light ◽  
Clarias Gariepinus ◽  
African Catfish ◽  
Chromosome Counting ◽  
Complete Inactivation ◽  
Cell Cleavage ◽  
Optimal Protocol ◽  
Prolonged Duration

Summary The optimum distance and duration of ultraviolet (UV) irradiation for the complete inactivation of African catfish Clarias gariepinus egg nucleus was investigated in this study. The UV light was suspended above the unfertilized eggs at four distances (5, 10, 20 and 30 cm) and for five durations (1, 2, 3, 4 and 5 min). Then, the irradiated eggs were activated with sperm from diploid C. gariepinus and cold shocked at 5°C for 5 min just moments before cell cleavage. Ploidy analysis was performed using karyotype chromosome counting. The results obtained suggested that the further the distance, the better the hatchability rate, however prolonged duration seemed to significantly reduced hatchability. All treatments with surviving progenies at the end of the study showed evidence of successfully diploid gynogen (2n = 56) induction at different percentages. However, the optimal protocol that gave a moderately high hatchability/survival rate and completely induced gynogens was exposure of the eggs to UV irradiation at 20 cm for 1 min. It was concluded that the distance and duration of UV irradiation affects gynogenetic induction in African catfish C. gariepinus.

scholarly journals Comparative Solid Phase Photocatalytic Degradation of Polythene Films with Doped and Undoped TiO2Nanoparticles

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Wasim Asghar ◽  
Ishtiaq A. Qazi ◽  
Hassan Ilyas ◽  
Aftab Ahmad Khan ◽  
M. Ali Awan ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Ftir Spectroscopy ◽  
Uv Radiation ◽  
Uv Irradiation ◽  
Weight Reduction ◽  
Solid Phase ◽  
Sem Analysis ◽  
Artificial Light ◽  
Metal Doping

Comparative photocatalytic degradation of polythene films was investigated with undoped and metal (Fe, Ag, and Fe/Ag mix) doped TiO2nanoparticles under three different conditions such as UV radiation, artificial light, and darkness. Prepared photocatalysts were characterized by XRD, SEM, and EDS techniques. Photocatalytic degradation of the polythene films was determined by monitoring their weight reduction, SEM analysis, and FTIR spectroscopy. Weight of PE films steadily decreased and led to maximum of 14.34% reduction under UV irradiation with Fe/Ag mix doped TiO2nanoparticles and maximum of 14.28% reduction under artificial light with Ag doped TiO2nanoparticles in 300 hrs. No weight reduction was observed under darkness. Results reveal that polythene-TiO2compositing with metal doping has the potential to degrade the polythene waste under irradiation without any pollution.

Synthesis of Galactomannan Sulfate-Citrate

2022 ◽  
Vol 1049 ◽  
pp. 218-223
Author(s):  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Anna S. Kazachenko
Keyword(s):  
Biological Activity ◽  
Ftir Spectroscopy ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Mixed Ester ◽  
First Time ◽  
Derivatives Of

Sulfated derivatives of polysaccharides have anticoagulant, hypolipedimic and other biological activity. In this work, a complex mixed ester of galactomannan, its sulfate-citrate, was obtained for the first time. The introduction of citrate and sulfate groups was proved by FTIR spectroscopy by the appearance of corresponding absorption bands. It was shown by X-ray diffraction that the introduction of the citrate group leads to the amorphization of the galactomannan structure.

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