scholarly journals Effects of artificial weathering on the color, gloss, adhesion, and pendulum hardness of UV system parquet varnish applied to doussie (Afzelia africana) wood

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1616-1627
Author(s):  
Levent Gürleyen
Keyword(s):  
Wood Species ◽  
Accelerated Weathering ◽  
Fluorescent Lamp ◽  
Surface Adhesion ◽  
Aging Effects ◽  
Artificial Weathering ◽  
Pendulum Hardness ◽  
A Value ◽  
Before And After ◽  
Afzelia Africana

An important wood species in the furniture and parquet industry today is “doussie” wood. In this study, the effects of artificial weathering on ultraviolet-cured varnish (3 coats and 5 coats) applied to doussie (Afzelia africana) wood were investigated. The samples of the UV system cured varnishes were exposed to aging effects for 252 h and 504 h via an UV-A 340 nm lamp. The coated specimens were exposed to UV-A 340 nm fluorescent lamp in a QUV accelerated weathering tester for 252 h and 504 h. The surface adhesion strength, color (L*, a*, b*, ∆E*, ∆L*, ∆a*, and ∆b*) parameters, pendulum hardness, and glossiness (parallel (//) and perpendicular (⊥) at 20°, 60°, and 85°) of UV varnishes coated samples were quantified before and after weathering. According to the results, while the a* value increased, the adhesion, L*, b*, and glossiness values decreased with aging. As a result, it was concluded that doussie wood can be used in the production of flooring with UV-cured varnish.

scholarly journals Accelerated Aging Effects on Surface Hardness and Roughness of Lingual Retainer Adhesives

2008 ◽  
Vol 78 (1) ◽  
pp. 140-144 ◽  
Author(s):  
Sabri Ilhan Ramoglu ◽  
Serdar Usumez ◽  
Tamer Buyukyilmaz
Keyword(s):  
Surface Roughness ◽  
Vickers Hardness ◽  
Statistical Significance ◽  
Accelerated Aging ◽  
Aging Effects ◽  
Surface Microhardness ◽  
Halogen Light ◽  
Before And After ◽  
The Mean ◽  
Lingual Retainer

Abstract Objective: To test the null hypothesis that accelerated aging has no effect on the surface microhardness and roughness of two light-cured lingual retainer adhesives. Materials and Methods: Ten samples of light-cured materials, Transbond Lingual Retainer (3M Unitek) and Light Cure Retainer (Reliance) were cured with a halogen light for 40 seconds. Vickers hardness and surface roughness were measured before and after accelerated aging of 300 hours in a weathering tester. Differences between mean values were analyzed for statistical significance using a t-test. The level of statistical significance was set at P < .05. Results: The mean Vickers hardness of Transbond Lingual Retainer was 62.8 ± 3.5 and 79.6 ± 4.9 before and after aging, respectively. The mean Vickers hardness of Light Cure Retainer was 40.3 ± 2.6 and 58.3 ± 4.3 before and after aging, respectively. Differences in both groups were statistically significant (P < .001). Following aging, mean surface roughness was changed from 0.039 μm to 0.121 μm and from 0.021 μm to 0.031 μm for Transbond Lingual Retainer and Light Cure Retainer, respectively. The roughening of Transbond Lingual Retainer with aging was statistically significant (P < .05), while the change in the surface roughness of Light Cure Retainer was not (P > .05). Conclusions: Accelerated aging significantly increased the surface microhardness of both light-cured retainer adhesives tested. It also significantly increased the surface roughness of the Transbond Lingual Retainer.

scholarly journals Perbandingan Tindakan Massage Counterpressure dan Pemberian Dark Chocolate terhadap Penurunan Nyeri Haid (Dismenorea)

2019 ◽  
Vol 3 (1) ◽  
pp. 281-291
Author(s):  
Rindang Fitriana Ulfa ◽  
Agus Suwandono ◽  
Kamilah Budhi
Keyword(s):  
Pain Medication ◽  
Dark Chocolate ◽  
Control Group ◽  
Menstrual Pain ◽  
Control Group Design ◽  
Group Design ◽  
A Value ◽  
Before And After ◽  
Massage Group ◽  
Quasi Experimental

The purpose of this study was to see the comparison between the administration of Massage Counterpressure and the provision of dark chocolate to reduce menstrual pain (dysmenorrhoea). The design uses a quasi-experimental design with two groups of pretest and posttest with control group design. The results showed that in the dark chocolate and anti-pain medication group, massage counterressure and anti-pain medicine obtained ρ value of 0,000. there are significant differences before and after the administration of action. The results of the man whitney test found that there were differences between the 2 groups with a value of ρ value of 0,000. Conclusion, there is a difference of influence between the dark chocolate group and the counterpressure massage group on the intensity of menstrual pain. Giving 100 grams of dark chocolate for 2 days and anti-pain medication is more effective than a 20-minute counterpressure massage for 2 days and anti-pain medication for menstrual pain intensity.   Keywords: Dark Chocolate, Massage counterprssure, Menstrual pain

scholarly journals Terapi Musik terhadap Depresi pada Lansia

2019 ◽  
Vol 13 (2) ◽  
pp. 72-81
Author(s):  
Theresia Widyastuti
Keyword(s):  
Music Therapy ◽  
Geriatric Depression Scale ◽  
Depression Scale ◽  
Sampling Technique ◽  
The Elderly ◽  
Rank Test ◽  
A Value ◽  
Before And After ◽  
The Difference ◽  
Quasi Experiment

 Depression is a mood disorder that is generally characterized by hopelessness, excessive helplessness, and lack of enthusiasm for life. Starting from stress that is not overcome, then a person can fall into a phase of depression. This study aims to look at the effect of providing music therapy in reducing depression in the elderly before and after being given a commitment. To achieve this goal, this study uses a quasi-experimental method (Quasi Experiment). The type of research design used is Quasi Experiment with one group pretest and posttest design. The sampling technique was purposive sampling where participants based on population criteria obtained a sample of 16 people. Data collection methods using tests with a scale measuring instrument namely Geriatric Depression Scale (GDS) consisting of 30 item questions, observation methods and interview methods .. Based on data analysis it was concluded that the results obtained were Man Whitney Test U = 0.500 with a value of p = 0.001 ( p <0.01) where the mean ranks on the gain score is 12.44 and the sum of ranks is 99.50, this shows the difference in effectiveness of the effects of music therapy before and after treatment and to test the difference in levels of depression before and after being given music therapy using Wilcoxon Sign Rank test analysis . the results obtained z value = -2.539 with a value of p = 0.11 (p <0.01) so that it can be concluded that there are differences in changes in the level of depression in the elderly before and after given treatment.

scholarly journals NMR-Spectrometric Determination of the Fragmented Oil Composition from the Karazhanbas and Zhangurshi Oil Deposits

2018 ◽  
Vol 20 (3) ◽  
pp. 229
Author(s):  
D.U. Bodykov ◽  
T.M. Seilkhanov ◽  
M. Nazhipkyzy ◽  
A.S. Toylybayev ◽  
R. Salakhov
Keyword(s):  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
High Viscosity ◽  
Oil Composition ◽  
Alkyl Chains ◽  
H Nmr ◽  
A Value ◽  
Heavy Oil Residues ◽  
Before And After ◽  
Integrated Intensities

The methods of 1 H, 13C NMR-spectroscopy were used to study the fragmentary compositions of oil from the Karazhanbas, Zhangurshi deposits (Kazakhstan) and heavy oil residues obtained before and after the electrohydraulic effect of water hammer after topping a light fraction of oil products. Their fragmentary composition were determined by the value of integrated intensities of 1 H, 13C NMR signals of the oil under study. The obtained results have shown that the composition of oil samples understudy includes terminal CH3-groups of long alkyl chains having a value of 0.87 ppm. The presence of long alkyl chains of oil components imparts a high viscosity and bituminous consistency to the latter. The content of aromatic protons according to the integrated intensities of 1 H NMR in both oil samples does not exceed 2.08%; but there are no aromatic nuclei by the integral intensities of carbon atoms at all. The low content of protons of Hα-type in hydrocarbon crude (5.2–5.3%) indicates a low content of aromatic and carbonyl carbons as well as heteroatoms in the studied samples. The content of the greater proportion of protons of the Hγ-type in Karazhanbas oil (33.0%) compared to the Zhangurshi oil (23.8%) indicates a greater length of aliphatic hydrocarbons of the latter and its increased viscosity.

scholarly journals Application of Waterborne Acrylic and Solvent-Borne Polyester Coatings on Plasma-Treated Fir (Abies alba M.) Wood

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 370
Author(s):  
Hadi Gholamiyan ◽  
Behnam Gholampoor ◽  
Reza Hosseinpourpia
Keyword(s):  
Plasma Treatment ◽  
Treated Wood ◽  
Abies Alba ◽  
Untreated Wood ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Accelerated Weathering ◽  
Water Contact ◽  
Before And After ◽  
Carbon Dioxide Co2

This research investigates the effect of plasma treatment with air, nitrogen (N2), and carbon dioxide (CO2) gases on the performance of waterborne (acrylic) and solvent-borne (polyester) coated fir (Abies alba M.) wood samples. The properties of the plasma-coated samples were analyzed before and after exposure to accelerated weathering and compared with those of untreated and solely treated ones. According to pull-off testing, the coating adhesion of the wood samples was considerably improved by plasma treatment, and obvious differences were observed between different plasma gases. The effect was more pronounced after the weathering test. Similar results were obtained for the abrasion resistance of the samples. The water contact angle measurement illustrated more hydrophilic character in the solely plasma-treated wood in comparison with the untreated wood. The application of coatings, however, strongly improved its hydrophobic character. The performances of waterborne and solvent-borne coatings on plasma-treated wood were comparable, although slightly better values were obtained by the waterborne system. Our results exhibit the positive effect of plasma treatment on coating performances and the increased weather resistance of the waterborne and solvent-borne coating systems on plasma-treated wood.

scholarly journals Lidar observation and model simulation of a volcanic-ash-induced cirrus cloud during the Eyjafjallajökull eruption

2012 ◽  
Vol 12 (6) ◽  
pp. 15675-15707 ◽  
Author(s):  
C. Rolf ◽  
M. Krämer ◽  
C. Schiller ◽  
M. Hildebrandt ◽  
M. Riese
Keyword(s):  
Volcanic Ash ◽  
Model Simulation ◽  
Cirrus Cloud ◽  
Backward Trajectories ◽  
Microphysical Properties ◽  
Ice Nuclei ◽  
A Value ◽  
Lidar Measurements ◽  
Before And After ◽  
Western Germany

Abstract. Heterogeneous ice formation induced by volcanic ash from the Eyjafjallajökull volcano eruption in April 2010 is investigated based on the combination of a cirrus cloud observed with a backscatter lidar over Jülich (Western Germany) and model simulations along backward trajectories. The microphysical properties of the cirrus cloud could only be represented by the microphysical model under the assumption of an enhanced number of efficient ice nuclei originating from the volcanic eruption. The ice nuclei (IN) concentration determined by lidar measurements directly before and after cirrus cloud occurrence implies a value of around 0.1 cm−3 (in comparison clean IN conditions: 0.01 cm−3). This leads to a cirrus cloud with rather small ice crystals having a mean radius of 12 μm and a modification of the ice particle number (0.08 cm−3 instead of 3 × 10−4 cm−3 under clean IN conditions). The effectiveness of ice nuclei was estimated by the use of the microphysical model and the backward trajectories based on ECMWF data, establishing a freezing threshold of around 105% relative humidity with respect to ice in a temperature range from −45 to −55 °C. Only with these highly efficient ice nuclei was it possible for the cirrus cloud to be formed in a slightly supersaturated environment.

MO736ELECTROCHEMICAL SKIN CONDUCTANCE BY SUDOSCAN: A NEW TOOL TO PREDICT INTRA-DIALYTIC HYPOTENSION

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Pauline Reach ◽  
Maxime Touzot ◽  
Yannis Lombardi ◽  
Catherine Maheas ◽  
Emmanuelle Sacco ◽  
...  
Keyword(s):  
Skin Conductance ◽  
Cumulative Risk ◽  
Intradialytic Hypotension ◽  
Multiple Risk Factors ◽  
Non Invasive ◽  
Invasive Test ◽  
Arterial Blood ◽  
A Value ◽  
Increased Risk ◽  
Before And After

Abstract Background and Aims Intradialytic hypotension (IDH) is a common complication in hemodialysis (HD) patients. It is associated with multiple risk factors including cardiac dysfunction and alterations of the peripheral autonomic nervous system. To which extent, dysautonomia may contributed to the occurrence of IHD remains elusive. We sought to investigate the clinical utility of Sudocan®, a device that quantify dysautonomia, in the prediction of IDH. Method We conducted a prospective monocentric study in adult HD patients from July 2019 to February 2020. Dysautonomia was assessed by the measurements of hand and foot Electrochemical Skin Conductance (ESC) by Sudocan®, before and after the end of HD. A pathological hand ESC was defined by an ESC value &lt; 40 μs in Caucasian or &lt; 30 μs in afro-American and Caribbean patients, and a pathological foot ESC by a value &lt; 50 μs in Caucasian or &lt; 30 μs in afro-American and Caribbean patients. Arterial blood pressure (BP) was monitored before, every thirty minutes and after the end of the HD session. The primary end point was the incidence of IDH, according to the NKD/K-DOQI definition, during the 3 month-period study. Results A total of 176 HD patients (64 ±14 years old) were enrolled. Mean pre-dialysis hand and foot ESC were 45±20 μS and 54±22 μS, respectively. Thirty-five and 40% of patients had a pathological ESC at the hand and foot, respectively. Forty-Six IDH occurred during the study period. Logistic regression showed that a pathological hand ESC was associated with an increased risk of IDH [OR=0.39, IC95% (0.15-0.97), p= 0.04]. The cumulative risk incidence of IHD during the study was 2.17 [IC95% (1.21-3.89), p= 0.01] and 1.89 [IC95% (1.06-2.38), p= 0.03], with a pathological hand and foot ESC, respectively. Conclusion A pathological hand ESC, as assessed by a simple, non-invasive test, such as Sudoscan®, is associated with an increased risk of IDH.

EXPERIMENTAL INVESTIGATION OF THE DURABILITY OF LOAD BEARING TIMBER-GLASS COMPOSITES UNDER THE EFFECTS OF ACCELERATED AGING

2019 ◽  
Vol 14 (2) ◽  
pp. 45-59 ◽  
Author(s):  
Halet Almila Arda Buyuktaskin ◽  
Mehmet Serkan Yatagan ◽  
Gulseren Erol Soyoz ◽  
Leyla Tanacan ◽  
Morvarid Dilmaghani
Keyword(s):  
Raw Materials ◽  
Accelerated Aging ◽  
Structural Elements ◽  
Atmospheric Conditions ◽  
Aging Effects ◽  
Glass Composite ◽  
Load Bearing ◽  
Glass Composites ◽  
Before And After

Although timber was used extensively as a structural material for traditional buildings in Turkey in the past, usage of structural timber decreased significantly over time and timber has been largely replaced by other materials. As timber is a natural, durable and sustainable material, it would be desirable to re-introduce timber structural elements to contemporary construction in a form that is appealing to industry. Timber-glass composite structural elements are potentially a good candidate for this purpose. To that end, a series of tests were conducted on load-bearing timber-glass composites in order to understand the long–term structural performance of the composite material under atmospheric conditions; to decrease the recurring cost of repair and maintenance; and to minimize the exhaustion of raw materials and energy. In this paper, the first part of this experimental work is presented, which focuses on the durability of timber-glass composite under the effects of accelerated aging, carried out on small-sized timber-glass composite specimens. Accelerated aging effects were observed under wetting-drying, freezing-thawing, UV effects, resistance to acids and high temperature. The mechanical strength of the timber-glass composite specimens before and after the effect of accelerated aging was measured by adhesion and shear strength tests and a comparative analysis of the results was carried out. The results of the experiments indicate that timber-glass composite is suitable to be used under protection from environmental conditions.

Artificial weathering of tropical woods. Part 2: Color change

Holzforschung ◽  
2004 ◽  
Vol 58 (5) ◽  
pp. 558-565 ◽  
Author(s):  
Masanori Kishino ◽  
Takato Nakano
Keyword(s):  
Diffuse Reflectance ◽  
Color Change ◽  
Reflectance Spectra ◽  
Acacia Auriculiformis ◽  
Eucalyptus Marginata ◽  
Artificial Weathering ◽  
Diffuse Reflectance Spectra ◽  
Before And After ◽  
The Difference ◽  
Tropical Woods

Abstract This paper describes the change in diffuse reflectance Fourier transform infrared (DRIFT) and ultraviolet-visible (UV-Vis) diffuse reflectance spectra of the following eight tropical woods during artificial weathering up to 600 h in relation to their color changes, especially to yellowing: Amnurana acreana, Acacia auriculiformis, Dipterocarpus spp., Eucalyptus marginata, Eucalyptus robusta, Shorea spp. and Tabebuia spp. with relatively high and low specific gravity. For A. acreana, A. auriculiformis, Dipterocarpus spp. and both Tabebuia spp., Δb* (yellowing) increased with exposure up to 50 h, and decreased above 50 h. For E. marginata, E. robusta and Shorea spp., on the other hand, both Δa* (shift to red) and Δb* decreased with increased exposure time. For woods in which Δb* increased, the Δb* showed a positive dependence on the difference in relative intensity ratio of a band at 1740 cm–1 to that at 2900 cm–1 (ΔD1740/D2900) in DRIFT spectra of specimens before and after exposure. This result indicated that the increased band at 1740 cm–1 played a significant role in the increased Δb*. Then again, also for woods in which Δb* decreased, the ΔD1740/D2900 increased, but was not related to the Db*. The ΔD1740/D2900 for woods in which Δb* decreased had a positive relationship to the difference in remission function at 410 nm (ΔF(R∞)410) in UV-Vis diffuse reflectance spectra for specimens before and after exposure, while woods in which Δb* increased were independent of the ΔF(R∞)410. Therefore, it is suggested that woods in which Δb* increased and decreased differ from one another in the contribution to the increase in the band at 1740 cm–1, resulting in either an increase or decrease of Δb*.

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