Longitudinal penetration of silicon dioxide nanosols in wood of Pinus sylvestris

For purposes of wood preservation, stabilization and fire protection, the penetration ability of bio-inspired environmentally friendly Sebosil^® nanosols in axial direction of the pine tracheids were investigated using macroscopic evaluations and EDX microanalysis.     

Properties of oriented strandboard made of wood species from Brazilian planted forests: Part 1: 80 mm-long strands of Pinus taeda L.

This research is part of a general study on the properties of oriented strandboard (OSB) using wood strands of species from Brazilian planted forests. The OSB industry is the latest wood related activity established in Brazil. In this particular part of the study, 80 mm long strands of Pinus taeda L. were bonded using two resin types (urea-formaldehyde and phenol-formaldehyde) at two levels of resin content (5% and 8%) to produce three-layer cross-aligned OSB to a face to core layer ratio of 1:2 and target density of 0.75 g/cm³. Physical and mechanical properties of the boards were evaluated according to ASTM standard D 1037-96a (1997) and the results compared to standards available as requirements for commercial structural panels. The results indicate that all the mechanical properties evaluated were above the requirements set forth by the Canadian standard CSA O437.0 (1993) for structural panels. The results of Janka hardness were in average 4 folds higher than the minimal requirements for Grade R-1 waferboard. Screw withdrawal values were also above the minimum required by grade M-3 of ANSI A208.1 standard (1993). Nevertheless, values of thickness swelling and water absorption were very high. The low dimensional stability may be related to the high density of the boards (“springback” effect) and also to the fact that no wax was used.     

Effects of wood flour modification on the fire retardancy of wood–plastic composites

Wood–plastic composites (WPC) are materials that combine the properties of wood and plastics. Both are flammable organic materials. Fire safety is considered to be an important issue especially in construction applications. In this research, the fire safety of WPC material is improved by using modification chemicals for wood flour treatment. The effectiveness of the modification is studied with a cone calorimeter device. Mechanical properties and water absorption are also examined. Scanning electron microscopy is used for analyzing the interfacial adhesion of the fiber and matrix. The results show that the fire performance of WPC material can be enhanced through wood modification, which can also improve the moisture uptake performance and the interfacial adhesion of the material. However the mechanical properties decrease as a result of modification with the used fire retardants.     

How Maillard Reaction Influences Sensorial Properties (Color,Flavor and Texture) of Food Products?

ABSTRACT

Maillard reaction products are largely responsible for the development of color, taste and especially aroma of thermally treated food. For this reason, our review focused on gathering literature from the last 10 years about the influence of the Maillard reaction products formation on food acceptance in aspects of color, texture and flavor. Maillard reaction products have a characteristic odor note and can significantly positively or negatively influence the sensory acceptance of a product. For example, pyrazines and thiols were found in most cases as the most potential odor compounds formed in MR. Another important aspect of high sensorial acceptability is food color. Color development of thermally treated products is mainly attributed to the formation of brown polymers called melanoidins. It was also noted that the increasing concentration of “probably carcinogenic and mutagenic” acrylamide is related to the darker color of a product. Not much attention is focused on the connection between Maillard reaction products formation and textural properties. Therefore, textural properties have been mostly investigated in meat products. Changes in the texture of meat products were estimated as the difference in linkage formations between proteins and polysaccharides.     

Fatigue strength and design stress of oil palm wood for?furniture?application

Oil palm wood (OPW) and oil palm empty fruit bunches based particleboard (OPEFBP) furniture components were tested on edge in order to determine their resistance to fatigue. Tests were carried out at selected stress levels that corresponded to specific percentages of the material’s ultimate strength (modulus of rupture—MOR). Generally, the materials fatigue life decreased as the levels of stress increased, and the allowable design stresses for the OPW and OPEFBP furniture components could be set at 40% of their respective MOR. The study also showed that OPW does not perform as well as solid Rubberwood in cyclic loading, but the OPEFBP showed similar fatigue performance to the conventional Rubberwood-based particleboard.     

Properties of (Ni-P)–SnO2 (nanometer) electroless composite coating on PET fabrics

The preceding parts of this series detailed a theoretical analysis to predict fabric tensile behaviour, the measurement and mathematical representations of the fibre-orientation angle and curl factor, which are the two principal parameters involved in the treatment, and a complete list of variables essential for computations and procedures to determine their values. This paper presents a comparison of the predicted stress–strain curves, constructed from the computer calculations, and the experimental ones for the nine commercial fabrics studied. After the individual remarks concerning the outcome for each fabric, possible reasons for the discrepancies encountered between the theoretical and experimental curves and the validity of some assumptions made in the analysis are discussed.     

Effect of industrial wood particle size on mechanical properties of?wood-polyvinyl chloride composites

Wood-polyvinyl chloride (PVC) composites were prepared using industrial wood particles used for manufacturing three-layer particleboards. The effect of particle size (0.25–0.5, 0.5–1, 1–2, and 2–4?mm) on the mechanical properties of the composites was investigated. The effect of cross-section size (4×10, 6×15 and 8×20?mm²) of composite pieces made by an injection moulding method was also studied. Both the particle size and specimen cross-section area significantly influenced these properties. The tensile and flexural properties as well as the impact strength in general increased with increasing particle size, and decreased with increasing cross-section size.     

Stiffness of spruce wood – Influence of moisture conditions

3 , from Norway Spruce are presented. The measurements were carried out using a dynamic test method at equilibrium moisture content in 30% and 90% relative humidity. The test material, from two stands, was well defined with respect to growth conditions, material properties as knots and compression wood and position in the tree. Large variations in dynamic modulus of elasticity between the two moisture levels were found. For specimens from some trees, these variations were extremely large. The variations were not systematic within each tree as many other wood parameters. A part of the variations was explained by occurrence of compression wood and knots. A strong individual variation in stiffness between different trees was found. To achieve a more fundamental understanding of the relationships between stiffness and moisture content it appeared that also microscopic characteristics need to be taken into account.

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Steifheit von Fichtenholz – Einflu? der Feuchtebedingungen

     

Enhanced water resistance of extruded wood–polypropylene composites based on alternative wood sources

Polypropylene wood flour composites made from short-rotation coppice (SRC) and low valued beech wood (Fagus sylvatica) were investigated with respect to their suitability for use in the production of wood–polymer composites (WPC). An industrial wood source consisting of spruce wood flour (Picea abies) was used as reference material. All composites were compounded on a co-rotating twin screw extruder containing either 60 or 70 wt% wood flour. Consolidation was done by profile extrusion. Mechanical and physical properties of the composites were investigated. The wood sources were characterized concerning their particle length and shape by the use of a dynamic optical particle analysis system. X-ray microtomography (µ-CT) was used to study the dispersion of wood particles and the internal composite structure. However, all composites based on alternative wood sources showed an equivalent performance regarding mechanical properties compared to the composite reference. Composites containing beech wood flour showed notably reduced water absorption rates, whereas the composites based on SRC wood flour revealed significantly reduced moisture content compared to reference composites. A different particle length distribution was depicted between the industrial wood source and three other investigated wood sources. Moreover, all wood flour sources were characterized by a mean aspect ratio up to 3:1. The X-ray microtomography illustrated morphological differences between composites. Based on the X-ray images, an alignment along the melt flow and a decent encapsulation by polypropylene were shown.     

Bending properties of compressed wood impregnated with?phenolic resin through drilled holes

The effect of drilling on the permeability of Japanese cedar and the bending properties of resin treated compressed wood were examined. Compressed wood was manufactured by impregnating aqueous phenolic resin solutions into the heartwood through drilled holes and polymerizing the impregnated resins using a hot press to maintain the deformation. The compressive deformation was carried out at 150°C for 1 h to one-half of the original specimen thickness. A dye solution permeated the entire specimen when the density of drilled holes exceeded approximately 5000?holes/m². When the compressed wood was manufactured under the drilling condition, the resin type was found to greatly affect the bending strength and the failure mode of the specimens in bending test.     

Effect of High Hydrostatic Pressure (HHP) Treatment on Edible Flowers’ Properties

Edible flowers are increasing worldwide because they can improve the appearance, taste, and aesthetic value of food, aspects that the consumer appreciates. However, some of these are highly perishable and have a short shelf-life. To overcome these problems, high hydrostatic pressure (HHP) food processing might be applied, allowing producing high-quality food with enhanced safety and increased shelf-life. The application of HHP to vegetables has been extensively discussed and is already an industrial reality, but information on edible flowers is scarce and incomplete. Thus, in order to summarize the current knowledge on potential applications of HHP treatment in edible flowers and to determine the effect of this treatment on physical (e.g., color and texture) and nutritional characteristics as well as on microbial and enzymatic inactivation, a literature review was performed. It was stated that broccoli and cauliflower (inflorescences, usually not considered by consumers as flowers) have been the most studied, existing few information for other edible flowers. Thus, much more works are needed to better understand the effect and mechanisms behind HHP, and to define the adequate technological conditions for each flower.     

Bioactive Components and Health-Promoting Properties of Yuzu (Citrus ichangensis × C. reticulate)

Yuzu (Citrus ichangensis × C. reticulate) fruit is an important functional food that possesses several health-promoting properties. It has been widely used in commercial medical products, healthy foods, and cosmetics in many countries. Yuzu is a rich source of wide variety of non-nutritive compounds, such as flavonoids, anthocyanins, phenolic acids, carotenoids, and tannins; as well as nutritive compounds such as sugars, proteins, vitamins, fibers, and minerals. Yuzu fruit (juice, peel, and seeds) and its bioactive compounds have been demonstrated to have numerous functional properties, such as antioxidant, anti-inflammatory, anticancer, antiplatelet, angiogenesis, and antimicrobial properties, both in vitro and in vivo. These diverse applications provided by the yuzu fruit (juice, peel, and seeds) and its bioactive compounds are of great industrial importance. This review summarizes the composition, nutritional values, and functional properties of yuzu fruit, and their biological activity in relation to their potential impact on human health.     

Effects of Different Whey Protein Concentrate Coating on Selected Properties of Rainbow Trout (Oncorhynchus mykiss) During Cold Storage (4°C)

In this study, the effect of different whey protein concentrate coating formulations (with or without glycerol) on the storage of fillets over a period of 15 days at 4ºC was investigated. Fillets were conducted to microbiological, chemical, and sensory analyses. Difference in microbiological and chemical changes between samples was found to be significant (p < 0.05) during storage period. The Y and Z were preferred more by the panellists, while C samples received the lowest scores. According to the results of microbiological analyses, shelf life of fillets was estimated at 6, 9, 12, and 15 days for C, X, Y, and Z samples, respectively.     

Material properties and nondestructive evaluation of laminated veneer lumber (LVL) made from Pinus oocarpa and P. kesiya

This study aimed at evaluating the mechanical, physical and biological properties of laminated veneer lumber (LVL) made from Pinus oocarpa Schiede ex Schltdl (PO) and Pinus kesiya Royle ex Gordon (PK) and at providing a nondestructive characterization thereof. Four PO and four PK LVL boards from 22 randomly selected 2-mm thickness veneers were produced according to the following characteristics: phenol-formaldehyde (190 g/m²), hot-pressing at 150°C for 45 min and 2.8 N/mm² of specific pressure. After board production, nondestructive evaluation was conducted, and stress wave velocity (v ₀) and dynamic modulus of elasticity (E _Md ) were determined. The following mechanical and physical properties were then evaluated: static bending modulus of elasticity (E _M ), modulus of rupture (f _M ), compression strength parallel to grain (f _c,0), shear strength parallel to glue-line (f _v,0), shear strength perpendicular to glue-line (f _v,90), thickness swelling (TS), water absorption (WA), and permanent thickness swelling (PTS) for 2, 24, and 96-hour of water immersion. Biological property was also evaluated by measuring the weight loss by Trametes versicolor (Linnaeus ex Fries) Pilát (white-rot) and Gloeophyllum trabeum (Persoon ex Fries.) Murrill (brown-rot). After hot-pressing, no bubbles, delamination nor warping were observed for both species. In general, PK boards presented higher mechanical properties: E _M , E _Md , f _M , f _c,0 whereas PO boards were dimensionally more stable, with lower values of WA, TS and PTS in the 2, 24, and 96-hour immersion periods. Board density, f _v,0, f _v,90 and rot weight loss were statistically equal for PO and PK LVL. The prediction of flexural properties of consolidated LVL by the nondestructive method used was not very efficient, and the fitted models presented lower predictability.     

The development of wood technology and technology developments in the wood industries—from history to future

The term technology is frequently used in every-day communication and in the specific areas of producing goods and providing services. Technology comprises the science of knowledge and usage of tools and techniques or its systems, methods, organization and material products thereof. The meaning of the word technology itself as well as the specific meaning of the term wood technology has changed over the past centuries of industrialized production systems. The current paper analyses the development of wood technology over a period of about 300 years. Based on various COST Actions and the European Forest-sector Technology Platform current topics of wood technology are addressed and a future outlook is given.