Microaggressions are daily insults to minority individuals such as people with disabilities (PWD) that communicate messages of exclusion, inferiority, and abnormality. In this study, we developed a ...new scale, the Ableist Microaggressions Impact Questionnaire (AMIQ), which assesses ableist microaggression experiences of PWD. Data from 245 PWD were collected using Amazon’s Mechanical Turk (MTurk) platform. An exploratory factor analysis of the 25-item AMIQ revealed a three-factor structure with internal consistency reliability ranging between .87 and .92. As a more economical and psychometrically sound instrument assessing microaggression impact as it pertains to disability, the AMIQ offers promise for rehabilitation counselor research and practice.
Polyvinyl acetate (PVA) is commonly used to bond wood materials, but it generally exhibits poor performance when used in composites that require resistance to water and creep. However, it can be ...reinforced with different particles to improve its performance, making it useful for various applications. In this study, PVA was reinforced with cellulose fibers (CFs) at different loadings (1%, 2%, and 4%). A mixer was used to blend the PVA and CFs. Thermal properties and morphological structure of CF-reinforced PVA adhesive were studied by thermogravimetric analysis (TGA/DTG) and scanning electron microscopy (SEM). The lap joint shear strength of woods bonded by CF reinforced PVA adhesive was tested on poplar and Scots pine woods that had 12% moisture content. The addition of CFs to PVA increased the thermal stability of PVA to different extents depending on the degree of loading on the CFs. The results of morphological studies indicated that some fluctuations on the SEM pictures were observed due to the dispersion of the CFs in the PVA matrix. The results showed that lap joint shear strength of the two different species of wood increased in all states after CFs were added to the PVA.
Epoxy resins have gained attention as important adhesives because they are structurally stable, inert to most chemicals, and highly resistant to oxidation. Different particles can be added to ...adhesives to improve their properties. In this study, cellulose nanofibrils (CNFs), which have superior mechanical properties, were used as the reinforcing agent. Cellulose nanofi brils were added to epoxy in quantities of 1 %, 2 % and 3 % by weight to prepare nanocomposites. Morphological characterization of the composites was done with scanning electron microscopy (SEM). Thermal properties of the nanocomposites were investigated with Thermogravimetric Analyzer (TGA/DTG) and Differential Scanning Calorimeter (DSC). SEM images showed that the cellulose nanofibrils were dispersed partially homogenous throughout the epoxy matrix for 1 % CNF. However, it was observed that the cellulose nanofibrils were aggregated (especially for 2 and 3 % CNFs) in some parts of the SEM images, and the ratios of the aggregated parts increased as the loading rate of the cellulose nanofi brils increased. The TGA curve showed that DTG and decomposition temperature of pure epoxy was higher than that of the nanocomposites. The DSC curve showed that the glass transition temperature (Tg ) value of pure epoxy was found to be similar with Tg of the nanocomposites.
Effects of adding microcrystalline cellulose (MCC) and cellulose nanocrystals (CNC) were evaluated relative to the mechanical, thermal, morphological, and structural properties of rigid polyurethanes ...(rPUs). The composites were prepared with the blending of polyols/isocyanates and the cellulosic fillers at 0.25%, 0.5%, and 1% loadings. Scanning electron microscopic images showed that the samples had micro-scaled porosity, with cell sizes ranging from 250 to 800 nm. The fillers improved the mechanical strengths and modulus of neat rPUs due to the presence of the nano-sized cells in rPUs matrix. The addition of both fillers generally did not provide a positive effect on the thermal properties, and the weight loss generally increased while the loading rate of the fillers was increased from 0.25% to 1%. The samples had two small crystalline peaks at 18° and 19° according to the X-ray diffraction analysis. From the results, it can be said that the presence of both fillers generally improved all properties of the neat rPUs, and the effects of CNC on the properties were higher than MCC due to both lower particle size and the higher crystallinity of CNC.
The aim of this paper was to investigate the effects of wood flour on the mechanical, morphological and thermal properties of poly (L-lactic acid) (PLA)-chitosan biopolymer composites produced by ...compression molding. The composites were characterized by a combination of mechanical properties, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The addition of chitosan to PLA matrix reduced the tensile strength from 57,1 MPa for pure PLA to 34,3 MPa for 5% chitosan and 11,5 MPa for 10% chitosan, and the flexure strength from 72,3 MPa for pure PLLA to 30,4 MPa for 5% chitosan and 24,6 MPa for 10% chitosan. The change trend in the young’s modulus was found to be similar as compare with the tensile strength. However, the flexure modulus generally increased with the addition of the chitosan as comparison with pure PLA. The mechanical properties of the PLA-chitosan blends with wood flour were found to be lower than theirs of the pure PLA. According to SEM images, some holes and small voids at various diameters on the fractured section of the all composites were seen. Tonset, T10%, T50%, T85% of the pure PLA decreased with the addition of both chitosan and wood flour. Thermal stability of the PLA-chitosan blends was determined to be better than the PLA-chitosan composites with wood flour.
This study investigated the material characterization with the fuzzy theory of particleboards bonded by urea formaldehyde with nanofillers including nanofibrillated cellulose (NFC) and titanium ...dioxide (TiO2). The density, water absorption, thickness swelling, and mechanical tests (which included flexure and internal bonding strength tests) were considered. The fuzzy sets theory addressed the ambiguity and subjectivity of language using triangular fuzzy numbers to assess the interests of decision maker’s (DMs). The addition of nanofillers slightly decreased water absorption values due to possible good interactions between nanofillers and urea formaldehyde. Thickness swelling ranged from 0.4 to 17.5%, and water absorption ranged from 0.4 to 10.7% compared to the control sample. The physical properties of the samples were generally improved by urea formaldehyde with NFC/TiO2, and the densities of the test panels were found to be similar. The modulus of rupture of the panels with urea formaldehyde with nanofillers were under the EN 312 standard’s requirements, and the highest flexural strength and flexural modulus of elasticity were 11.1 and 1.3 GPa, respectively. Internal bond values were between 0.55 and 0.89 MPa. According to EDAS method rankings, 2C2T-8 was the best material, followed by 2C1T-8 and 2C-8. The samples coded with Control-4 and Control-8 were the lowest-performing materials.
Road traffic pollution and industrial plant-induced pollution affect negatively the development of forest trees. How forest trees are affected by their growing environment is important for ...sustainable environment. The study aimed to investigate the physical, mechanical, chemical, and morphological properties of the Pinus nigra (black pine) tree which grows under different conditions. Tree samples were chosen from three different lands where were inside the forest (O), near the roadside (Y), and near the factory (F). It was studied whether there were any significant differences among the “O”, “Y” and “F” in terms of their wood properties such as physical, mechanical, chemical, and morphological. As a result, the “O” samples demonstrated more regular annual ring structure. On the other hand, it was observed that the “Y” samples had longer and wider tracheid cells. In addition, “Y” samples had better mechanical strength than “O” and “F”. Environmental pollution caused the presence of some different elements (chlorine and iron) in “Y” and “F”. As a result, it was determined that the trees growing near the roadside or near industrial plants have significant differences from forest trees which are far away from pollutions. It is possible to say that Pinus nigra (black pine) is resistant to environmental stress. For this reason, it can be recommended to use it as a barrier to reduce air pollution on the roadsides.
It was found that Microwave (MW) assisted wood preservative (WP) treatments effects further lowering swelling and water absortion values for selected hardwoods and softwood species in this study. It ...is clear that the post MW treated woods effects further reaction or bonding to hydroxyl group (–C-OH) of cell wall constituents to create further water repellent (hyrophobic) surfaces with WP applications. However, the water absorptiveness was found to be lowered extensively on all WP treated samples. The further lowering water absortiveness values calculated for all post MW treated samples. The calculated values have indicated approximately further reducing of 14.9% for Eucalyptus, 6.9% for Poplar, 6.8% Chestnut samples, 7.9% for Cedrus and 18.1% for Pine samples respectively. It has also found that MW treated samples clear evidence on increasing bonding strength for all post MW treated wood species. The MW treatments effects increasing bonding strengths of wood in the range of 6.5-20.2% for hardwoods and 5.5-10.4% for softwood species.
Bu çalışmanın amacı ahşap materyalin hidrofilikliği ve yapışma direnci üzerinde mikrodalga muamelesinin etkilerini araştırmaktır. Elde edilen sonuçlar mikrodalga (MW) yardımıyla odun koruyucu (WP) muamelelerin seçilen iğne yapraklı ve yapraklı türler için daha düşük su alma ve şişme değerleri göstermiştir. MW muameleli ahşaplar, WP uygulamalarında su itici (hidrofobik) yüzeylerin oluşumunda hüçre duvarı bileşenlerinin hidroksil gruplarına (–C-OH) bağlanması yada reaksiyon oluşumunu etkilediği açıktır. Fakat su emiciliği tüm MP muameleli örnekler üzerinde önemli ölçüde düşürdüğü bulundu buna karşın çok daha fazla su su emiciliğindeki azalma MW muameleli örnekler için elde edilmiştir. Hesaplanan değerler Ekaliptus için 14.9%, Kavak için 6.9%, Kestane için 6.8%, Sedir için 7.9% ve Çam için 18.1% oranında azalma göstermiştir. MW muameleli örnekler yüksek yapışma direnci üzerinde açık bir kanıt gösterdiği bulundu. MW muameleleri yapraklı ağaç odunları için %6,5-20 ve yapraklı ağaç türleri için %5,5-10,4 arasında yapışma direncini artırdı.
Digital image correlation (DIC) was used to examine the strain distribution of heat-treated beech and Uludag fir woods in mechanical testing. It also evaluated the effects of the heat treatment ...process on the properties of the wood samples. The physical (mass/density loss, dimensional stability, color change, and surface roughness), mechanical (flexure test and compressive strength), morphological, thermal, and structural properties of the heat-treated wood were examined. It was determined that the heat treatment parameters can be optimized using the DIC method. The test results showed that although heat treatment can provide improved physical and thermal properties, it caused micro-crack formations and collapses in the wood cells. As a consequence, the mechanical properties of the heat-treated wood materials decreased with the heat treatment process. There were slight differences in the curves of the samples according to Fourier infrared and X-ray diffraction analyses. Morphological characterization showed that the heat treatment triggered large cracks in the cell wall and lumens and the morphological structure of heat-treated wood was affected at large percentages.
The aim of this study was to investigate the properties of lignin obtained from black liquors of Scots pine (Pinus sylvestris L.) and European aspen (Populus tremula L.) woods cooked by Kraft method. ...In the study, the cooking process was carried out according to parameters such as: 1/4 of wood/liquor ratio, cooking temperature at (170±2) °C, and cooking time of 90 min. After the cooking process, the black liquor was taken to a beaker from the digester, and lignin was recovered in different ways from the black liquor with methyl alcohol (MeOH) and ethyl alcohol (EtOH). The material properties of the recovered lignin were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD), and thermogravimetric analysis (TGA). Commercial lignin (cml-lignin) was used to compare the properties of lignin obtained from black liquor. SEM images showed that the particle sizes of lignin obtained with EtOH and MeOH were similar. In FT-IR, it was detected that the recovered lignin types have similar functional groups, while some differences were observed in intensities of the peaks. XRD results revealed that all lignin types were found to have a similar structure with the cml-lignin, and that alcohol types used during the recovery process of lignin do not have an important effect on the structural properties of lignin. The TGA results indicated that the thermal stability of recovered lignin has better thermal stability than cml-lignin. The results showed that the recovered lignin was similar to commercial lignin and that it can be recovered from the liquor leftover from Kraft pulping by the method described and used in industry.
Cilj rada bio je istražiti svojstva lignina dobivenog od crnog luga drva bijelog bora (Pinus sylvestris L.) i jasike (Populus tremula L.), kuhanoga kraft metodom. Proces kuhanja u ovom je istraživanju proveden uz ove parametre: omjer drva i luga 1 : 4, temperatura kuhanja 170 ± 2 °C, vrijeme kuhanja 90 min. Nakon procesa kuhanja crni je lug premješten iz digestora u čašu te je lignin metilnim alkoholom (MeOH) i etilnim alkoholom (EtOH) na različite načine izdvojen iz crnog luga. Svojstva izdvojenog lignina analizirana su skenirajućim elektronskim mikroskopom (SEM), infracrvenom spektroskopijom s Fourierovom transformacijom (FT-IR), difrakcijom X-zraka (XRD) i termogravimetrijskom analizom (TGA). Za usporedbu svojstava lignina dobivenog iz crnog luga poslužio je komercijalni lignin (cml-lignin). SEM slike pokazale su da su veličine čestica lignina dobivenog uz pomoć EtOH i MeOH bile slične. FT-IR analizom utvrđeno je da izdvojeni tipovi lignina imaju slične funkcionalne grupe te da su se pojavile neke razlike u intenzitetu pikova. Rezultati XRD-a otkrili su da svi tipovi lignina imaju sličnu strukturu kao i cml-lignin i da vrsta alkohola upotrijebljenog tijekom procesa izdvajanja lignina nema bitan učinak na strukturna svojstva lignina. Rezultati TGA analize pokazali su da je toplinska stabilnost izdvojenog lignina bolja od toplinske stabilnosti cml-lignina. Prema rezultatima istraživanja može se zaključiti da je izdvojeni lignin sličan komercijalnom ligninu, da može biti izdvojen iz tekućine koja je preostala od proizvodnje celuloze opisanom kraft metodom te da se može rabiti u industriji.
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