scholarly journals The Effect of Artificial Weathering on Surface Properties of Thermally Modified Oriental Beech Wood

2021 ◽  
Vol 72 (3) ◽  
pp. 273-278
Author(s):  
Turkay Turkoglu ◽  
Huseyin Peker ◽  
Mustafa Kucuktuvek ◽  
Caglar Altay ◽  
Ahmet Gunduz ◽  
...  

The study aimed to determine some surface parameters such as surface roughness and color changes of thermally modified Oriental beech (Fagus orientalis L.) wood samples after 750 hours of artificial weathering. The results of the study showed that artificial weathering led to an increase in surface roughness of Oriental beech wood. Thermal modification interval of 210 °C - 230 °C gave a smoother surface than unmodified samples after artificial weathering. Artificial weathering caused darker, reddish, and yellowish tone of unmodified and thermally modified Oriental beech wood. According to the study fi ndings, surface properties of thermally modified Oriental beech wood were better than those of unmodified Oriental beech.

2020 ◽  
Vol 71 (6) ◽  
pp. 312-320
Author(s):  
Corina Voina ◽  
Adriana Muresan ◽  
Ada Delean ◽  
Amalia Ionela Moldovan ◽  
Violeta Popescu ◽  
...  

Esthetics of the enamel surface is an important factor for a good oral health care. The mastication process could damage the enamel surface by hydroxyapatite layer alteration via local demineralization and micro scratches. We developed an experimental green tea extract gel for enamel restoring treatment. Microstructure features were investigated by SEM microscopy and the surface details were revealed by AFM. The surface roughness and hydroxyapatite grains size and shape were the parameters followed into the investigation. The results show that the best restoring is obtained by the experimental gel leading to surface parameters similar to the healthy enamel better than the values obtained with opalescence carbamide gel.


Wood Research ◽  
2021 ◽  
Vol 66 (3) ◽  
pp. 379-390
Author(s):  
Ahmet C. Yalinkilic ◽  
Eyup Aksoy ◽  
Musa Atar ◽  
Hamza Cinar ◽  
Hakan Keskin

This study was carried out to determine the effects of bleaching chemicals and varnishes on the amount of carbon dioxide (CO2) in the combustion of oriental beech (Fagus orientalis Lipsky). For this purpose, samples of Oriental beech prepared according to ASTM D 358 contain 18% R1 = (NaOH + H2O2), R2 = (NaOH + Ca(OH)2 + H2O2), R3 = (Na2S2O5 + H2C2O4), R4 = (NaSiO3 + H2O2), R5 = (KMnO4 + Na2S2O5 + H2O2) solution groups, after bleaching with solution groups, water based, synthetic, polyurethane and acrylic varnish were applied according to ASTM D 3023 and combustion tests were carried out in accordance with ASTM E 160-50. Gas measurements were made with the SIGMA 74172 NSU flue gas device during the combustion process. As a result, in respect to the burning types; the highest amount of CO2 (ppm) was found in the self-combustion (8.468 ppm) while the lowest was obtained from the flame combustion source (4.599 ppm). In respect to the types of bleaching; the highest in R5 (7.458 ppm) and the lowest in R3 (4.059 ppm) were found. According to the varnish types; the highest value was found in the synthetic varnish (8.261), and the lowest value was found in the acrylic varnish (4.772 ppm). According to combustion type + bleaching solution + varnish type interaction, the highest values were found for without flame combustion (II) + R3 + Sn (18.40 ppm) and lowest for flame source combustion (I) + R5 + Pu (0.600 ppm). Consequently, the highest values for combustion gases were found in samples of oriental beech wood samples treated with water-based varnish with R1 solution. According to this, in terms of human health and life safety, possibility of fire in places, R3 solution and acrylic varnish may be used in the related industries.


1970 ◽  
Vol 17 (1) ◽  
pp. 52-55
Author(s):  
Jurgita KOŽENIAUSKIENĖ ◽  
Virginija DAUKANTIENĖ

In the present study the effect of technological treatment involving the processes of washing or washing and softening with chemical cationic softener "Surcase" produced in Great Britain on the surface properties of cellulosic textile materials manufactured from cotton, bamboo and viscose spun yarns was investigated. The changes in textile materials surface properties were evaluated using KTU-Griff-Tester device and FEI Quanta 200 FEG scanning electron microscope (SEM). It was observed that the worst hand properties and the higher surface roughness are observed of cotton materials if compared with those of bamboo and viscose materials. Also, it was shown that depending on the material structure the handle parameters of knitted materials are the better than the ones of woven fabrics.http://dx.doi.org/10.5755/j01.ms.17.1.249


2020 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Filipa Freitas ◽  
Teresa Pinheiro de Melo ◽  
António HS Delgado ◽  
Paulo Monteiro ◽  
João Rua ◽  
...  

Surface properties of composites such as roughness and color impact periodontal health and aesthetic outcomes. Novel bulk-fill composites with improved functionality are being introduced and, in light of the existing variety of finishing/polishing procedures, research of their surface properties is warranted. Sixty discs were prepared from bulk-fill composites (Filtek™ Bulk Fill Posterior Restorative and Fill-Up™) and incremental-fill Filtek™ Z250. They were further divided according to different polishing procedures (n = 5): three multi-step polishing procedures or finishing with a bur (control). Surface roughness (Ra) was measured using an atomic force microscope (The AFM Workshop TT-AFM). A spectrophotometer (Spectroshade Micro Optic) was used to determine color stability, after exposure to a coffee solution. Data were analyzed using two-way MANOVA (significance level of 5%). Resin composite type, polishing procedure, and their interaction had a statistically significant effect on surface roughness (p < 0.001) and color change (p < 0.001). Fill-Up™ exhibited the highest surface roughness and greatest color change. Differences in color change were statistically significant (p < 0.001). Filtek™ Bulk Fill registered the lowest surface roughness and color change, after the three-step polishing procedure. Both parameters were significantly correlated (ρ = 0.754, p < 0.001) and found to be material dependent and polishing-procedure dependent. Higher surface roughness relates to greater color changes.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Woo Jin Jeong ◽  
Jong Ik Lee ◽  
Hee Jung Kwak ◽  
Jae Min Jeon ◽  
Dong Yeol Shin ◽  
...  

We investigated the performance of single-structured light-emitting electrochemical cell (LEC) devices with Ru(bpy)3(PF6)2 polymer composite as an emission layer by controlling thickness and heat treatment. When the thickness was smaller than 120–150 nm, the device performance decreased because of the low optical properties and non-dense surface properties. On the other hand, when the thickness was over than 150 nm, the device had too high surface roughness, resulting in high-efficiency roll-off and poor device stability. With 150 nm thickness, the absorbance increased, and the surface roughness was low and dense, resulting in increased device characteristics and better stability. The heat treatment effect further improved the surface properties, thus improving the device characteristics. In particular, the external quantum efficiency (EQE) reduction rate was shallow at 100 °C, which indicates that the LEC device has stable operating characteristics. The LEC device exhibited a maximum luminance of 3532 cd/m2 and an EQE of 1.14% under 150 nm thickness and 100 °C heat treatment.


2013 ◽  
Vol 404 ◽  
pp. 3-9 ◽  
Author(s):  
Nihat Tosun ◽  
Ihsan Dagtekin ◽  
Latif Ozler ◽  
Ahmet Deniz

Abrasive waterjet machining is one of the non-traditional methods of the recent years which found itself a wide area of application in the industry for machining of different materials. In this paper, the surface roughness of 6061-T6 and 7075-T6 aluminum alloys are being cut with abrasive waterjet is examined experimentally. The experiments were conducted with different waterjet pressures and traverse speeds. It has been found that the surface roughness obtained by cutting material with high mechanical properties is better than that of obtained by cutting material with inferior mechanical properties.


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