Search

The demand for wooden raw materials is constantly on the rise. Meeting this interest requires developing new timber supply chains, tackling illegal trade, using timber more efficiently, and enhancing the service life of wood-based products. From this point of view, sweet chestnut wood can be successfully used, alone or mixed with poplar, to manufacture Oriented Strand Board (OSB). This article assesses the fungal resistance of OSB/3 (load-bearing boards for use in humid conditions) made with different fractions of poplar (P) and sweet chestnut (SC) wood, in order to take advantage of the protective action of the tannins contained in the latter. Four types of OSB/3 were manufactured on an industrial scale: 100% P; 80% P and 20% SC; 50% P and 50% SC; 100% SC. The durability of the experimental boards was determined in accordance with the EN 113-3 standard (2023). No significant differences in mass loss were found for OSB/3 with different sweet chestnut wood fractions. Instead, the mass loss of these panels was significantly lower (i.e. fungal resistance was higher) than that of the poplar OSB/3 and poplar plywood tested for comparison. Based on the results, the use of sweet chestnut wood has interesting potential for the manufacturing of OSB/3 made with adequate gluing quality, suitable for applications in environments where fungal decay may occur. [ABSTRACT FROM AUTHOR]

In this study, the ecotoxicological effects of a selected OSB material on three model plants (green freshwater algae Desmodesmus subspicatus, duckweed Lemna minor, and seeds of lettuce Lactuca sativa) were tested. A 24 h and 168 h leachate of the same OSB material was prepared. Mg, Si, Ca, K, Fe, Zn, Mn, and Na were found in the samples. Their higher residues were measured in the 168 h leachate. Biogenic elements (N, P, C) were not detected. The acute effect was relatively slow (for algae up to 26%, for duckweed up to 20%, and for lettuce seeds with stimulation up to 37%). Prolongation of the leaching time did not show any effect on the results of the plant tests. Acute toxicity for the three plant species used was slow. [ABSTRACT FROM AUTHOR]

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of wood-based panels such as Oriented Strand Board has grown in civil construction. This follows the contemporary trend towards low environmental impact materials. However, there is a lack of relevant information about their life cycle assessment, appearing as a current and relevant research topic. Experimental panels made with Eucalyptus wood and castor oil-based polyurethane adhesive already demonstrated great physical-mechanical performance. Therefore, this study aimed to continue the evaluation of this innovative product, estimating their potential environmental impacts using life cycle assessment from a cradle-to-gate perspective and comparing the results with traditional panels and literature data. System boundaries, environmental impacts and environmental hotspots were identified using the ReCiPe H method in terms of ten impact categories. Comparing experimental (heat-treated) and traditional panels, the experimental versions performed better in most categories and showed safer behavior in categories related to human health in addition to not using paraffin, termiticide, and other organic chemicals presented in the traditional panels. Though made of different types of adhesives, the adhesive was the main environmental hotspot for both types. [ABSTRACT FROM AUTHOR]

In this study, five types of Aspen (Populus tremuloides Michx) strands with different widths and percentages were mixed to prepare oriented strand board (OSB) panels and their impacts on the internal bonding strength (IB), stiffness (MOE), and bending strength (MOR) of OSB were investigated. The results showed that strands with different widths at different ratios showed a significant effect on the manufacture process and qualities of the obtained OSB. The influence mechanisms of the width combination of strands on the performance of OSB was also revealed. This study could provide references for further improving the quality of OSB products, improving resource utilization, reducing the carbon footprint of wood-based panel production and reducing manufacturing costs. [ABSTRACT FROM AUTHOR]

The use of wood-based panels such as Oriented Strand Board has grown in civil construction. This follows the contemporary trend towards low environmental impact materials. However, there is a lack of relevant information about their life cycle assessment, appearing as a current and relevant research topic. Experimental panels made with Eucalyptus wood and castor oil-based polyurethane adhesive already demonstrated great physical-mechanical performance. Therefore, this study aimed to continue the evaluation of this innovative product, estimating their potential environmental impacts using life cycle assessment from a cradle-to-gate perspective and comparing the results with traditional panels and literature data. System boundaries, environmental impacts and environmental hotspots were identified using the ReCiPe H method in terms of ten impact categories. Comparing experimental (heat-treated) and traditional panels, the experimental versions performed better in most categories and showed safer behavior in categories related to human health in addition to not using paraffin, termiticide, and other organic chemicals presented in the traditional panels. Though made of different types of adhesives, the adhesive was the main environmental hotspot for both types.

Boron presents an important role in chemistry, biology, and materials science. Diatomic transition-metal borides (MBs) are the building blocks of many complexes and materials, and they present unique electronic structures with interesting and peculiar properties and a variety of bonding schemes which are analyzed here. In the first part of this paper, we present a review on the available experimental and theoretical studies on the first-row-transition-metal borides, i.e., ScB, TiB, VB, CrB, MnB, FeB, CoB, NiB, CuB, and ZnB; the second-row-transition-metal borides, i.e., YB, ZrB, NbB, MoB, TcB, RuB, RhB, PdB, AgB, and CdB; and the third-row-transition-metal borides, i.e., LaB, HfB, TaB, WB, ReB, OsB, IrB, PtB, AuB, and HgB. Consequently, in the second part, the second- and third-row MBs are studied via DFT calculations using the B3LYP, TPSSh, and MN15 functionals and, in some cases, via multi-reference methods, MRCISD+Q, in conjunction with the aug-cc-pVQZ-PPM/aug-cc-pVQZB basis sets. Specifically, bond distances, dissociation energies, frequencies, dipole moments, and natural NPA charges are reported. Comparisons between MB molecules along the three rows are presented, and their differences and similarities are analyzed. The bonding of the diatomic borides is also described; it is found that, apart from RhB(X1Σ+), which was just recently found to form quadruple bonds, RuB(X2Δ) and TcB(X3Σ−) also form quadruple σ2σ2π2π2 bonds in their X states. Moreover, to fill the gap existing in the current literature, here, we calculate the TcB molecule. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Literature & Humanities / Edebiyat ve Beşeri Bilimler Dergisi is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the ecotoxicological effects of a selected OSB material on three model plants (green freshwater algae Desmodesmus subspicatus, duckweed Lemna minor, and seeds of lettuce Lactuca sativa) were tested. A 24 h and 168 h leachate of the same OSB material was prepared. Mg, Si, Ca, K, Fe, Zn, Mn, and Na were found in the samples. Their higher residues were measured in the 168 h leachate. Biogenic elements (N, P, C) were not detected. The acute effect was relatively slow (for algae up to 26%, for duckweed up to 20%, and for lettuce seeds with stimulation up to 37%). Prolongation of the leaching time did not show any effect on the results of the plant tests. Acute toxicity for the three plant species used was slow.

To increase the sustainability of prefabricated timber buildings and constructions, composite timber beams with "box" cross-sections were developed in collaboration with an industry partner. They were constructed from a solid timber frame and from webs made of residual waste wood-particle boards from prefabricated timber buildings production. The developed beams' design concepts presented in this paper were governed by architectural features of prefabricated timber buildings, geometrical limitations, available production technology, and structural demand related to various possible applications. The paper presents the results of experimental bending tests of six variations of the developed composite timber beams constructed by mechanical fasteners only. The developed design concept of composite timber beams without adhesives is beneficial compared to glued beams in terms of design for deconstruction and lower VOC emissions. The tests were conducted to study the influence of the following parameters on the beams' mechanical behavior: (i) web material (oriented strand boards (OSBs) vs. cement-particle boards); (ii) the influence of beam timber frame design (flanges and web stiffeners vs. flanges, web stiffeners, and compressive diagonals), and (iii) the influence of stiffener–flange joint design. Besides the beams' load-bearing capacities, their linear and non-linear stiffness characteristics were the main research interest. While adding compressive timber diagonals did not prove to significantly increase the stiffness of the beams in the case of cement-particle board webs, it increased their load-bearing capacity by enabling the failure of flanges instead of prior webs and stiffener–flange joints failure. For beams with OSB webs, failure of the bottom flange was achieved already with the "basic" timber frame design, but timber diagonals proved beneficial to increase the stiffness characteristics. Finally, mechanical characteristics of the developed beams needed in structural design for their application are provided together with further development guidelines. [ABSTRACT FROM AUTHOR]

Copyright of Mülkiye Dergisi is the property of Mulkiye Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Geodesy & Geodynamics (1671-5942) is the property of Editorial Board Journal of Geodesy & Geodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Particleboards (PB) and oriented strand boards (OSB) are commonly used materials in building structures or building interiors. The surface of boards may hence become directly exposed to fire or radiant heat. The aim of this paper is to evaluate the behaviour of uncoated particleboards and OSB exposed to radiant heat. The following ignition parameters were used to observe the process of particleboard and OSB ignition: heat flux intensity (from 43 to 50 kW.m-2) and ignition temperature. The time-to-ignition and mass loss of particleboards and OSB with thicknesses of 12, 15 and 18 mm were monitored and compared. The experiments were conducted on a modified device in accordance with ISO 5657: 1997. Results confirmed thermal degradation of samples. Heat flux had a significant effect on mass loss (burning rate) and time-to-ignition. OSB had higher ignition time than particleboards and the thermal degradation of OSB started later, i.e., at a higher temperature than that of particleboards, but OSB also had higher mass loss than particleboards. The samples yielded the same results above 47 kW.m−2. Thermal analysis also confirmed a higher thermal decomposition temperature of OSB (179 °C) compared to particleboards (146 °C). The difference in mass loss in both stages did not exceed 1%. [ABSTRACT FROM AUTHOR]

The embedment strength and stiffness of wood products are key parameters in the design of timber structures using dowel-type connections. The embedment behaviour of layered wood products such as hybrid cross-laminated timber (HCLT) will result from a combination of the behaviours of the multiple layers. In this paper, half-hole embedment tests according to ASTM D5764–2013 are presented, evaluating the embedment performance of HCLT made of fast-growing Chinese fir and OSB with self-tapping screws (STS). Six prediction models proposed by current standards and other scholars are compared with the measured data for strength, and two modified models are proposed to predict embedment strength for HCLT. Specimens loaded parallel to the grain of longitudinal layers had a higher bearing capacity, yield and ultimate embedment strength. An increase of STS diameter improved the bearing capacity of specimens but had a negative influence on the embedment strength. The modified models proposed here achieved more accurate prediction of the experimental characteristic values for HCLT than the existing methods, both for yield and ultimate embedment strength. The findings of this study represent progress towards the safe and economical structural design and wider application of innovative CLT products in the construction industry. • Fabrication and investigation of hybrid CLT. • Summary of current embedment models. • Proposal of two modified prediction models. • Comparison between current models and our proposed models. [ABSTRACT FROM AUTHOR]

Black spruce is widely used for lumber production in Eastern Canada, and it has the potential to replace trembling aspen and paper birch for oriented strand board (OSB) manufacturing. This study evaluated the bending modulus of elasticity (MOE) and modulus of rupture (MOR), the internal bond (IB), and the thickness swelling (TS) of OSB panels made from black spruce and trembling aspen strands and how they were affected by strand geometry. All the panels met the CSA O437 (1993) standard for class O-2 properties except for the TS. The strand thickness had a significantly negative effect on the bending properties but a significantly positive effect on the IB and TS properties. The strand length had a significantly positive effect on the parallel bending properties but a significantly negative effect on the perpendicular bending properties and the IB, except for the TS. The OSB panels made from aspen obtained better bending properties, while the IB and TS properties were lower than those of the OSB black spruce panels. The results indicate that black spruce strands obtained from the Eastern Canadian softwood lumber industry are suitable for OSB production, but more work is required to reduce the TS. [ABSTRACT FROM AUTHOR]

bozukluğunun (OSB) yaygınlığının saptanması ve Aile Sağlığı Merkezlerinde (ASM) görev yapan sağlık çalışanlarının OSB farkındalıklarının araştırılması amaçlanmıştır. Gereç ve Yöntem: Çalışmanın örneklemi 18-72 ay arası 752 çocuk ve 90 aile hekimi ile 78 aile sağlığı elemanlarından (ASE) oluştu. Sağlık çalışanlarına OSB Bilgi ve Tutum Ölçeği ve OSB Farkındalık Anketi uygulandı. Çocukların tümüne Değiştirilmiş Erken Çocukluk Dönemi Otizm Tarama Ölçeği (M-CHAT) uygulandı. Bulgular: Aile hekimlerinin OSB Bilgi-Tutum Ölçeği ile OSB Farkındalık Anketi puan ortalamaları ASE'lerinkinden anlamlı olarak daha yüksekti. Taramada OSB için risk oranı %6.25 (n=47); yaygınlık oranı %0.53 olarak saptandı. Riskli saptanan bu çocukların 20’si çocuk ve ergen psikiyatrisi uzmanı tarafından değerlendirildi. Değerlendirilen 20 çocuğun 7’si normal saptanırken, 4’ü OSB tanısı, 9’u başka psikiyatrik tanılar aldı. Sonuç: Bu çalışma Sivas İl Merkezi’nde OSB yaygınlık oranının %0.53 olduğunu ve aile hekimlerinin OSB farkındalıklarının ASE'lerinkinden daha yüksek olduğunu gösterdi. Sağlık çalışanlarının OSB'ye ilişkin farkındalıklarının artmasına yönelik eğitim programlarının OSB’li çocukların erken saptanmasına katkı sağlayabileceği kanaatindeyiz.

The sheathing-to-timber connection (STC) is a critical component of timber-framed shear walls. The STC provides the shear wall system with its racking resistance, while anchors and tiedowns provide resistance to sliding and overturning, respectively. Because building materials are exposed to weathering during construction, this study aims to quantify the influence of weathering on the structural performance of STCs. To achieve this aim, a total of 117 small-scale specimens were fabricated with 5 different sheathing types and 2 different timber species. Each specimen comprised 2 panels of sheathing connected to 2 short lengths of pine timber (90×35 mm cross-section), with a total of 16/2.8ϕ×30 mm (l) galvanised clouts at 45 mm spacings. Some specimens were tested under the EN 594 monotonic loading protocol and others were tested under the ISO 16670 cyclic loading protocol. Some specimens were exposed to the weather for a period of 6 months before being tested, while others were stored in an air-conditioned environment before being tested. The results show that weathering reduces the ultimate and yield capacity of STC connections by 3% and 5% on average, respectively; however, this result is not statistically significant for most sheathing types. The results varied, with some configurations having an ultimate capacity up to 16% higher and others having an ultimate capacity as much as 20% lower for weathered specimens compared to unweathered specimens. However, weathering reduces the stiffness of STCs by 61% and ductility by 50%, a statistically significant result. For most sheathing types, these findings do not support reductions to the design capacity of STCs that have been exposed to weathering.

This study aims to investigate the feasibility of producing OSB from softwood species used in the Eastern Canadian softwood lumber industry in the context of the overcapacity of softwood chips traditionally produced for the pulp and paper industry. Balsam fir, black spruce, and jack pine logs were used to make 15 mm thick OSB panels with a target density of 600 kg/m3. The panels were manufactured at a temperature of 210 °C during a pressing cycle of 300 s. Strands with different thicknesses were used to obtain a constant specific surface of 6.7 m2/kg for the three species. The bending modulus of the rupture and modulus of elasticity, internal bond, and thickness swelling of the OSB panels were determined and compared to the CSA standard requirements. The species significantly affected the physical and mechanical properties of OSB. The bending properties of OSB decreased with an increase in the species wood density. The internal bond strength of OSB increased with the increase in species wood density. The panels made from softwood species showed physical and mechanical properties exceeding the standard requirements, except for high thickness swelling. The combination of softwood and aspen strands significantly improved the thickness swelling of softwood-based OSB. The reduction in the surface layer density could also be explored to reduce the thickness swelling of the OSB made from the softwoods considered in this study. [ABSTRACT FROM AUTHOR]

To increase the sustainability of prefabricated timber buildings and constructions, composite timber beams with “box” cross-sections were developed in collaboration with an industry partner. They were constructed from a solid timber frame and from webs made of residual waste wood-particle boards from prefabricated timber buildings production. The developed beams’ design concepts presented in this paper were governed by architectural features of prefabricated timber buildings, geometrical limitations, available production technology, and structural demand related to various possible applications. The paper presents the results of experimental bending tests of six variations of the developed composite timber beams constructed by mechanical fasteners only. The developed design concept of composite timber beams without adhesives is beneficial compared to glued beams in terms of design for deconstruction and lower VOC emissions. The tests were conducted to study the influence of the following parameters on the beams’ mechanical behavior: (i) web material (oriented strand boards (OSBs) vs. cement-particle boards); (ii) the influence of beam timber frame design (flanges and web stiffeners vs. flanges, web stiffeners, and compressive diagonals), and (iii) the influence of stiffener–flange joint design. Besides the beams’ load-bearing capacities, their linear and non-linear stiffness characteristics were the main research interest. While adding compressive timber diagonals did not prove to significantly increase the stiffness of the beams in the case of cement-particle board webs, it increased their load-bearing capacity by enabling the failure of flanges instead of prior webs and stiffener–flange joints failure. For beams with OSB webs, failure of the bottom flange was achieved already with the “basic” timber frame design, but timber diagonals proved beneficial to increase the stiffness characteristics. Finally, mechanical characteristics of the developed beams needed in structural design for their application are provided together with further development guidelines.

This study found that the substitution of 6% unbleached cellulose nanofibers (LCNF) into pMDI allowed for a reduction in density of 0.09 and 0.08 g/cm3 for equivalent performance in modulus of elasticity and modulus of rupture respectively; while, all other properties except internal bond were maintained. For panels made above 0.60 g/cm3, it was found that blows would consistently occur due to additional steam pressure from LCNF addition. However, below 0.60 g/cm3 and at 210°C press temperature, all blows at the laboratory scale were eliminated. Industrially, these findings suggests that a company could possibly make a lower density oriented strand board (OSB) of equivalent or better dry mechanical properties while reducing panel weight and avoiding blows. Moving forward, future studies will need to tackle viscosity issues at the sprayer. Our qualitative observation during spraying found that it may be possible to spray up to 3% LCNF without clogging, but at 6% clogging was a mild problem. More research should be performed to improve the homogeneity of spraying at higher substitution rates to assist with industrial commercialization. [ABSTRACT FROM AUTHOR]

Particleboards (PB) and oriented strand boards (OSB) are commonly used materials in building structures or building interiors. The surface of boards may hence become directly exposed to fire or radiant heat. The aim of this paper is to evaluate the behaviour of uncoated particleboards and OSB exposed to radiant heat. The following ignition parameters were used to observe the process of particleboard and OSB ignition: heat flux intensity (from 43 to 50 kW.m-2) and ignition temperature. The time-to-ignition and mass loss of particleboards and OSB with thicknesses of 12, 15 and 18 mm were monitored and compared. The experiments were conducted on a modified device in accordance with ISO 5657: 1997. Results confirmed thermal degradation of samples. Heat flux had a significant effect on mass loss (burning rate) and time-to-ignition. OSB had higher ignition time than particleboards and the thermal degradation of OSB started later, i.e., at a higher temperature than that of particleboards, but OSB also had higher mass loss than particleboards. The samples yielded the same results above 47 kW.m−2. Thermal analysis also confirmed a higher thermal decomposition temperature of OSB (179 °C) compared to particleboards (146 °C). The difference in mass loss in both stages did not exceed 1%.

Copyright of Afyon Kocatepe University Journal of Social Sciences / Afyon Kocatepe Üniversitesi Sosyal Bilimler Dergisi is the property of Afyon Kocatepe University (AKU) Sosyal Bilimler Enstitusu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An experimental study on sheathed cold‐formed steel C‐lipped columns (studs) with service holes in the web subjected to compression and major axis bending is presented in this paper. A total of 17 experiments was performed with both oriented strand board (OSB) and plasterboard used as the sheathing material and with varying connector spacing employed between the sheathing and the steel members. Material tests and geometric imperfection measurements were also undertaken. The tested specimens comprised a single 2.4 m long cold‐formed steel member sheathed on both sides and secured at its ends to top and bottom tracks. Eight pure compression tests with plasterboard and OSB sheathing and with the spacing of the connectors varying between 75 mm and 600 mm were initially performed. Specimens with OSB were then tested under pure bending and also under combined loading, by first applying a compressive load corresponding to the 75%, 50% or 25% of the predetermined axial resistance and then laterally loaded until failure. Reducing the spacing of the connectors from 600 mm to 75 mm resulted in up to 20% and 30% increases in capacity for the studs sheathed with OSB and plasterboard respectively. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to determine the prevalence of autism spectrum disorder (ASD) in Sivas City Center and to investigate the ASD awareness of healthcare professionals working in Family Health Centers (FHC). Materials and Methods: The sample of the study consisted of 752 children aged between 18-72 months, 90 family physicians and 78 family health personnel (FHPs). The ASD Knowledge-Attitudes Scale and the ASD Awareness Questionnaire were administered to healthcare professionals. The Modified Checklist for Autism in Toddlers (M-CHAT) was applied to all of the children. Results: The mean scores of the ASD Knowledge- Attitude Scale and ASD Awareness Questionnaire of the family physicians were significantly higher than FHPs. The risk rate for ASD in screening was 6.25% (n=47), and the prevalence rate was 0.53%. Twenty of these children who were found to be at risk were evaluated by a child and adolescent psychiatrist. Of the 20 evaluated children, 7 were found to be normal, while 4 had a diagnosis of ASD, and 9 had other psychiatric diagnoses. Conclusion: This study showed that the prevalence rate of ASD in Sivas City Center is 0.53% and that the ASD awareness of family physicians is higher than that of FHPs. We believe that training programs to increase the awareness of healthcare professionals about ASD can contribute to the early detection of children with ASD. [ABSTRACT FROM AUTHOR]

This study investigated the ballistic properties of oriented strand board panels supported by different proportions of woven glass fiber and waste polypropylene. In the ballistic tests, galvanized metal plates of three different thicknesses (M1, M2, and M3) were used to absorb the initial velocity of the projectile. The materials forming the ballistic panel were arranged using the hand lay-up method. The waste polypropylene plates were melted on the upper and lower surfaces of the lay-up forming the panel. Production conditions were applied at 170‒175°C and 3.5‒4.0 N/mm2 for 10 min. Ballistic tests were performed on the panels according to the Level IIA category of the US National Institute of Justice standard. As a result of the ballistic test firing, the ballistic panel consisting of 1.5-mm-thick metal plate, 50 woven glass fibers, and OSB exhibited the best strength. As a result of the study, it was determined that the mechanical properties of the material that absorbed the initial velocity of the projectile were effective in the ballistic performance of the panels. [ABSTRACT FROM AUTHOR]

This study investigated the feasibility of substituting core layer strands of randomly oriented strand boards (OSB) with waste wood particles with respect to CSA 0437–Series 93 Standards on OSB and Waferboard requirements. Standard core layer strands have been substituted with four different levels (0, 25, 50 and 100%) of waste wood particles. Several mechanical properties of the OSB have been tested. Overall, it could be demonstrated that waste wood particles can successfully be used in the core layer of OSB. All properties met the requirements of CSA 0437-Series 93, except for thickness swell (TS) and water absorption (WA). From a mechanical and physical board properties perspective, it is possible to substitute up to 100% of the core layer strands in randomly OSB panels with unsorted contaminated waste wood particles. However, results showed high density variability within boards and between different core compositions. Internal bond (IB) met the standard's requirements, showed significant differences between the waste wood proportions and increased with the level of waste wood particles. The modulus of elasticity (MOE) and modulus of rupture (MOR) also met the requirements, and decreased with increasing waste wood particle levels. [ABSTRACT FROM AUTHOR]

This work investigated the feasibility of using western juniper (Juniperus occidentalis) as a material to manufacture oriented strandboard (OSB) panels. Four different material combinations of juniper sapwood, heartwood, and fibrous bark were compared with regular southern yellow pine (Pinus sp.) strands. The OSB panels were made at an oven-dry density of 560 kg/m3. One pine control panel was also made at a higher density of 650 kg/m3 with a 5% addition of phenol formaldehyde (PF) resin and a 0.5% addition of wax. The single-layer panels were formed with a hot press, and the physical and mechanical properties were tested according to the ASTM standard D1037 (2020). The testing indicated that western juniper is a potential material for manufacturing of OSB panels. The properties of the juniper panels were equivalent or slightly better than those of the southern yellow pine panels at the same density level, except for the modulus of elasticity (MOE). The lower density of the juniper OSB panels may have benefits in construction applications and can decrease transportation costs. [ABSTRACT FROM AUTHOR]

This paper presents the fire resistance results of 6 full-scale exterior wall assemblies study conducted at the National Research Council of Canada jointly with the North American construction industry and other Canadian government departments. The parameters investigated include: cavity insulation types (rock, glass and cellulose fibre) in exterior wall assemblies with oriented strand board sheathing; cavity insulation types (glass fibre and cellulose fibre) in exterior wall assemblies with Type X gypsum glass mat sheathing; and assemblies with different screw spacing of standard 400 mm o.c. and non-standard 200 mm o.c. for attaching the Type X gypsum board on the fire-exposed side and glass mat sheathing board on unexposed side to wood studs using glass fibre insulation in wall cavity. The impact of the investigated parameters on the fire resistance of exterior wall assemblies is discussed. Also, Further research recommendations on design changes to enhance the fire resistance of exterior wall assemblies are proposed. Results of the parameters studied showed that the effect of insulation types on the fire resistance of exterior wall assemblies with OSB sheathing can be considered significant when gypsum board on the fire-exposed side is attached to wood studs with screws spaced at 406 mm o.c., however, the effect insulation types on fire resistance when the gypsum board on fire-exposed side and gypsum glass mat sheathing are attached to wood studs with screw spaced at 203 mm o.c. can be considered insignificant. Also, results showed the use of non-standard screw spacing at 203 mm o.c. for attaching the gypsum board on the fire-exposed side increased the fire resistance by 37% compared to screw spacing at 406 mm o.c. Therefore, the effect of screw spacing on the fire resistance of exterior wall is significant. [ABSTRACT FROM AUTHOR]

In this study, a new apparatus for measuring the air permeability of wood-based panel specimens without using water displacement was developed with the aim of decreasing the influence of variation in atmospheric pressure on permeability measurement. Validation experiments were conducted using plywood, oriented strand board (OSB), particleboard, and medium-density fiberboard (MDF) panels and a control specimen sealed with an epoxy resin. The background (leakage) flow of the apparatus was evaluated based on the experimental results of the control specimen. A methodology for the determination of air permeability based on Darcy’s law for gases and the evaluated background flow rate was proposed. The results of the current study were compared with those obtained in a previous study, indicating that the new method provides valid measurements for wood-based panels with high and low air permeability. No significant influence of variation in atmospheric pressure on the experimental results was observed, suggesting that the proposed method is suitable for a long-term continuous experiment for evaluating a specimen with extremely low permeability.

This study aims to investigate the feasibility of producing OSB from softwood species used in the Eastern Canadian softwood lumber industry in the context of the overcapacity of softwood chips traditionally produced for the pulp and paper industry. Balsam fir, black spruce, and jack pine logs were used to make 15 mm thick OSB panels with a target density of 600 kg/m3. The panels were manufactured at a temperature of 210 °C during a pressing cycle of 300 s. Strands with different thicknesses were used to obtain a constant specific surface of 6.7 m2/kg for the three species. The bending modulus of the rupture and modulus of elasticity, internal bond, and thickness swelling of the OSB panels were determined and compared to the CSA standard requirements. The species significantly affected the physical and mechanical properties of OSB. The bending properties of OSB decreased with an increase in the species wood density. The internal bond strength of OSB increased with the increase in species wood density. The panels made from softwood species showed physical and mechanical properties exceeding the standard requirements, except for high thickness swelling. The combination of softwood and aspen strands significantly improved the thickness swelling of softwood-based OSB. The reduction in the surface layer density could also be explored to reduce the thickness swelling of the OSB made from the softwoods considered in this study.

Objective: Aim of this study was to explore the screen characteristics of children who have been newly diagnosed with Autism Spectrum Disorder (ASD) and context of initial concerns of parents at the time of the first diagnosis. Method: Fifty-seven ASD and 63 typically developing children were included. Data retrieved from families such as concerns at the time of referal and characteristics that comprised use of electronics were recorded. The Childhood Autism Rating Scale and Autism Behavior Checklist was administered by the clinician to evaluate the symptom severity of ASD. Furthermore, the Ankara Development and Screening Inventory were applied to the children to evaluate the general developmental level. Results: ASD was generally diagnosed around 36th month and parents of these children were found to have suspected of something going wrong regarding developmental characteristics of their children approximately 14 months prior formal diagnosis. Age at index use of electronics was smaller and screen time was higher in children with ASD. It has also been found that families most frequently were referred to the clinician due to problems in communication. Discussion: Our findings suggest children with ASD might be more prone to problematic use of electronics. Smaller index age for initiating use of electronic devices might predominantly affect socioemotional processes negatively. The clinicians should evaluate screen characteristics in these children. Lastly, It is important to encourage parents to report concerns to clinicians for early detection of ASD. [ABSTRACT FROM AUTHOR]

An experimental and analytical approach to the relaxation problem of wood-based materials—OSB (Oriented Strand Boards—pressed wood-based composite panels) beams, including beams with CFRP (Carbon fiber reinforced polymer) tape composite reinforcement, is presented. It is a relevant engineering and scientific problem due to the fact that wood and wood-based materials, as well as composite reinforcements, are widely used in building constructions. Their rheological properties are very important and complicated to estimate. A 10 day long relaxation test of thick OSB beams without reinforcement and with CFRP tape was performed. A four-point bending test with five different bending levels was performed, during which the reduction of the loading force was measured. A five-parameter rheological model was used to describe the rheology of the beams. The equations of this model were calculated with the use of Laplace transform, whereas the values of the parameters were calculated based on the experimental relaxation curves. A high correlation between experimental and theoretical results was obtained. A beam reinforced with CFRP tape was treated as a system with a viscoelastic element (OSB) and an elastic element (CFRP), joined together without the possibility of slipping. The equations of the mathematical model were calculated based on the assumptions of the linear theory of viscoelasticity and the convolution integral. A good correlation between experimental and theoretical results was obtained. A significant redistribution of stresses was observed during the relaxation of the reinforced beam. The reinforced beams show a higher stiffness of approximately 63% and carry proportionally higher loads than unreinforced beams at the same deflection values.

INTRODUCTION: The aim of the current study was to investigate the sociodemographic characteristics, prenatal and postnatal history, and dysmorphic findings of children and adolescents diagnosed with Autism spectrum disorder (ASD) and the pregnancy history of the mothers of these cases. MATERIALS and METHODS: The prospective descriptive study included 74 children and adolescents aged 5-17 years, diagnosed with ASD. The Wechsler Intelligence Scale for Children- Revised (WISC)-R was used to determine intelligence level of these children. Childhood Autism Rating Scale (CARS) was used to evaluate the severity of autistic symptoms. The cases were evaluated in respect of the pregnancy history of the mothers, the prenatal and postnatal histories of the cases, family anamnesis with any imaging reports of that time if available, and epicrisis records. In the physical examination of the cases, head circumference was measured, and dysmorphic findings were determined according to the Surface Evaluation for Minor Congenital Anomalies scale. RESULTS: Prenatal, postnatal risk factors, dysmorphology and pregnancy history of mothers were found to be effective in the etiology of ASD in children with ASD. CONCLUSIONS: Although the etiology of ASD is complex and has not been fully elucidated, the data obtained in this study from the evaluation of the risk factors of this spectrum have contributed to the clarification of the etiopathogenesis, and identified the preventable risk factors of ASD. [ABSTRACT FROM AUTHOR]

Wood-particle-based panels are versatile materials, which can be used for packaging, furniture and construction. Their usability ranges from non-load-bearing to load-bearing purposes. Since they are used over long periods of time, it is important to know their behaviour under load over long periods. Three different particle-based panels: Oriented Strand Board - OSB type 3, P5 and P2 grade particleboard - PB) where exposed to different bending loads. The load was applied to the upper and bottom sides of the panel for 24h. The behaviour of panels was correlated to density profile. During this experiment, it was determined that deformation in bending depends on the type of composite and the side of the panel exposed to the load. The lowest deflection was observed in OSB. At 40% of maximum load, the highest deflection was determined in P5 grade PB, while at 60% of maximum load, the highest deflection was determined in P2 grade PB. The wood particle type did not play an essential role when analysing deflection, because OSB type 3 and PB grade P2 values were about 10% lower than that of the P5 structural panel. A possible reason why the deflection was 10% higher in the case of structural PB P5 could be related to the actual load applied, namely for PB P2 the load was 176 N, whereas for PB P5 the load was almost 45% higher (253 N). The deflections increased linearly corresponding to stress levels of 40% and 60% of the maximum load. [ABSTRACT FROM AUTHOR]

INTRODUCTION: The aim of the current study was to investigate the sociodemographic characteristics, prenatal and postnatal history, and dysmorphic findings of children and adolescents diagnosed with Autism spectrum disorder (ASD) and the pregnancy history of the mothers of these cases. MATERIALS and METHODS: The prospective descriptive study included 74 children and adolescents aged 5-17 years, diagnosed with ASD. The Wechsler Intelligence Scale for Children-Revised (WISC)-R was used to determine intelligence level of these children. Childhood Autism Rating Scale (CARS) was used to evaluate the severity of autistic symptoms. The cases were evaluated in respect of the pregnancy history of the mothers, the prenatal and postnatal histories of the cases, family anamnesis with any imaging reports of that time if available, and epicrisis records. In the physical examination of the cases, head circumference was measured, and dysmorphic findings were determined according to the Surface Evaluation for Minor Congenital Anomalies scale. RESULTS: Prenatal, postnatal risk factors, dysmorphology and pregnancy history of mothers were found to be effective in the etiology of ASD in children with ASD. CONCLUSIONS: Although the etiology of ASD is complex and has not been fully elucidated, the data obtained in this study from the evaluation of the risk factors of this spectrum have contributed to the clarification of the etiopathogenesis, and identified the preventable risk factors of ASD. [ABSTRACT FROM AUTHOR]

Wood structural panels are commonly subjected to short-term accelerated weathering (AW) procedures to determine relative moisture durability for quality control and product development purposes. The panel edges contribute heavily to moisture uptake since edges represent the least resistant pathway for moisture intrusion. In full-size panels, the edge area to total surface area ratio is small, and moisture intrusion is primarily limited to panel faces. When small specimens are used, such as those in AW procedures, the ratio of edge area to total surface area increases and moisture intrusion at the edges may dominate, which is referred to as the edge effect. The purpose of this study was to determine if physical and mechanical properties of oriented strand board (OSB) and plywood after AW are influenced by specimen size. Specimen width was varied while thickness and length remained constant to understand if edge effects were present in small specimens with different edge area to total surface area ratios. Three AW procedures were evaluated to determine if the effect of specimen size depends on weathering method. No clear effect of specimen size on physical and mechanical properties of either composite type was found. Differences in flexural properties between specimen widths were observed for unweathered OSB, but similar property retention between specimen widths after AW indicated the same trend as the unweathered control. Plywood results were influenced by natural defects, resulting in high variability and absence of statistically significant differences. Lateral nail resistance connection properties of both OSB and plywood were highly variable for all treatment groups and were unaffected by weathering. [ABSTRACT FROM AUTHOR]

Three fast-growing wood species in Romania, namely birch, willow, and poplar, were considered in this work. These species may have potential to replace softwoods or mixtures of wood species frequently used in the production of oriented strand boards (OSB). This study evaluated some physico-mechanical properties of these wood species that influence the performance of OSB boards made using 100% of strands from each individual species. Wood strands were cut, dried, screened, and sorted in order to form the core and surface layers of OSB boards. They were blended with a polymeric diphenyl methane diisocyanate adhesive (pMDI) and compressed with the help of a hydraulic press. The mechanical tests were performed under standard laboratory conditions. The obtained OSB boards made of each of the wood species met the EN standard of minimum requirements for OSB/2 properties, except the MOE of poplar-OSB, while its MOR was higher than that obtained for OSB made of birch even for small differences in board density. The birch-OSB presented superior elastic properties. Results of this experimental work can have industrial applications for an efficient use of low-grade raw material. [ABSTRACT FROM AUTHOR]

Organize Sanayi Bölgelerinin (OSB’ler) atıksu arıtma sorunu, çoğunlukla alıcı ortama deşarj standartlarını sağlayan geleneksel bir biyolojik atıksu arıtma tesisinin işletmeye alınmasıyla çözülmektedir. Ancak, alıcı ortamların artan kirlilik yükleri, havza bazlı yönetim hedefleri ve su kaynaklarının kısıtlı olmasından dolayı yeni çözümlere ihtiyaç duyulmaktadır. Membran biyoreaktörler (MBR), geleneksel arıtma sistemlerine göre avantajlı olması ve gün geçtikçe azalan maliyetlerinden dolayı daha tercih edilir hale gelmektedir. Bu çalışmada, batık aerobik membran biyoreaktör kullanılarak Kayseri OSB atıksu arıtma tesisi ön çöktürme çıkış suyunun 2 farklı membran türü ile arıtma performansı incelenmiştir. Bu amaçla ön çalışmalar yapılmış olup; membran tıkanması, çamur yaşının sağlanması, akının ve hidrolik bekletme sürelerinin membran işletimine etkileri incelenmiştir. Ayrıca, modül boyutunun membran tıkanmasıyla ilişkisi ortaya konmuştur. MBR sistemi veri tabanlı kontrol ve izleme sistemiyle sürekli izlenmekte olup ayrıca giriş ve çıkış temel parametreleri incelenmiştir. Yapılan tüm analizler standart yöntemlere göre yapılmıştır. Yapılan ön çalışmalarda sistem, reaktörde istenen askıda katı madde (MLSS) konsantrasyonuna ve giderim verimine ulaşması için sürekli olarak izlenmiştir. Bu süreçte MLSS konsantrasyonunun zamanla arttığı ancak düşük akılarda artışın devam etmediği gözlenmiştir. MLSS artışı ve çamur yaşının sağlanması için sistemin daha yüksek akılarda çalışması ve sistemden teorik olarak atılması gereken miktarda çamurun atılması gerektiği görülmüştür. Ancak, bu aşamada sistemde kullanılan modül boyutunun gerekli akıyı tıkanmadan dolayı sağlayamadığı görülmüştür. Sonuç olarak, MBR sistemi için düşük transmembran basıncı (TMP) ve membran tıkanmasının önüne geçilmesi ile istenen akı, çamur yaşı, modül alanı ve membran türleri belirlenerek sistem optimize edilmiştir.

• Water sorption/desorption can linearly increase the deflection of OSB. • Strain transferal plays a crucial role in the mechanical performance of OSB. • Recommendations for OSB application in dynamic moisture conditions were drafted. Oriented strand board (OSB) is used as in-service loadbearing material. The impact of water sorption/desorption on the fatigue deflection is not fully understood yet. In this study, fatigue deflection of two types of OSB was studied when exposed to cyclic loading using the three point bending static method for 12 cycles. During cyclic loading, the specimens were wetted and dried before cycle 4, 7 and 10 respectively. Deflection and strain distributions were continuously recorded with digital image correlation (DIC) during the bending test. The results show that both recoverable and residual deflection mainly occurs in the first cycle. Water sorption/desorption can linearly increase the deflection of the specimens. Both large deflection and strain are prone to occur in a region 1–3 mm beneath the top surface. Large strains along the thickness direction induced during water sorption/desorption can be transferred from the top to the bottom surface of the specimens. Strain accumulation is an important factor of the decreasing loading capacity of OSB. Structural changes induced with shear strain could hurdle strain transferal along the thickness direction. Increasing water resistance and reducing structural defects are essential to guarantee proper strain transfer in OSB aiming at in-service loading conditions. [ABSTRACT FROM AUTHOR]

Oriented strand board (OSB) is a commonly used structural wood-based panel for walls and roof siding, but recently the industry has become interested in OSB as a substrate for indoor and outdoor furniture. Particleboard is mainly used in furniture productions and has become popular as a construction material due to its numerous usage possibilities and inexpensive cost. Moisture is one of the most important factors affecting wood-based panel performance and the post-treatment conditions affected their affinity to water. When OSB and particleboard are used as substrates for coatings, their surface characteristics play an important role in determining the quality of the final product. Furthermore, roughness can significantly affect the interfacial phenomena such as adsorption, wetting, and adhesion which may have an impact on the coating performance. In this research particleboard and OSB panels were sanded, re-pressed and IR heated and the influence of surface treatments on hardness, roughness, wetting, water, and water vapour absorption was studied. Results showed that sanding improved the wetting of particleboard and OSB with water. Moreover, studied surface treatments increased water absorption and water penetration depth of OSB panels, and re-pressing had a positive effect on reducing the water vapour absorption of particleboard and OSB panels.

In this study, the effects of mat moisture content and press temperature on physical and mechanical properties of three layered oriented strand boards were evaluated. Two levels of mat moisture content 7% and 10% and three levels of press temperature 180 ˚c , 200 ˚c and 220 ˚c were applied and 12 mm in nominal thickness laboratory boards were made from mixture of three clones of ten-year-old hybrid poplar ( populous euramericana vernirubensis, p. e. I-214, P. e. 561/41) while the strands on the surface layers are aligned in the long direction of the board and the middle layer strands are cross aligned to the surface layers. In all treatments, board targeted density of 0/7 g/cm3 and press time of 8 min and phenol-formaldehyde resin (PF) content of 7% based on the oven dry weight of the strands were held constant. The mechanical and physical properties of the boards were measured as defined in relevant European standards EN 300 for OSB/1 and OSB/2. Overall results showed that all boards made from above mentioned conditions exceed the EN 300 standards for MOR, MOE, IB and TS24. The bending properties (MOR and MOE) of boards were significantly improved as the mat moisture content increased from 7 to 10%. The highest MOR was achieved at 10% mat moisture content and 220 ˚c press temperature and the highest MOE was achieved at 10% mat moisture content and 180 ˚c press temperature. The Modulus of Rupture (MOR) and Thickness swelling (TS24) were significantly improved as the press temperature increased from 180 ˚c to 220 ˚c. The lowest TS24 was achieved at 7% mat moisture content and 220 ˚c press temperature and the highest IB was achieved at 7% mat moisture content and 200 ˚c press temperature.