Characterizing hydro-thermal compression behavior of aspen wood strands

Holzforschung ◽  
2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Cheng Zhou ◽  
Gregory D. Smith ◽  
Chunping Dai
Keyword(s):  
Elevated Temperatures ◽  
Oriented Strand Board ◽  
Transverse Compression ◽  
Aspen Wood ◽  
Thermal Compression ◽  
Compression Behavior ◽  
End Products ◽  
Regression Approach ◽  
Fundamental Understanding ◽  
Strain Function

Abstract Wood-based composites, such as oriented strand board, are typically manufactured by consolidating mats of resinated wood elements under heat and pressure. During this process, the temperature and moisture content distributions within the mat greatly affect the properties of end products. To improve the fundamental understanding of mat consolidation during hot-pressing, a model is established to investigate the transverse compression behavior of aspen wood strands for a variety of combinations of temperatures (20–200°C) and moisture contents (0–15%). A regression approach is used to obtain the modulus-temperature-moisture relationship. In addition, elevated temperatures and moistures are found to influence the strain function of wood strands, which was previously assumed to be independent of these factors.

scholarly journals Phycobiliproteins from extreme environments and their potential applications

2020 ◽  
Vol 71 (13) ◽  
pp. 3827-3842 ◽  
Author(s):  
Anton Puzorjov ◽  
Alistair J McCormick
Keyword(s):  
Hot Springs ◽  
Elevated Temperatures ◽  
Algal Species ◽  
Extreme Environments ◽  
Fundamental Understanding ◽  
Thermophilic Species ◽  
Red Algal ◽  
Potential Applications ◽  
Thermophilic Organisms ◽  
Photosynthetic Adaptation

Abstract The light-harvesting phycobilisome complex is an important component of photosynthesis in cyanobacteria and red algae. Phycobilisomes are composed of phycobiliproteins, including the blue phycobiliprotein phycocyanin, that are considered high-value products with applications in several industries. Remarkably, several cyanobacteria and red algal species retain the capacity to harvest light and photosynthesise under highly selective environments such as hot springs, and flourish in extremes of pH and elevated temperatures. These thermophilic organisms produce thermostable phycobiliproteins, which have superior qualities much needed for wider adoption of these natural pigment–proteins in the food, textile, and other industries. Here we review the available literature on the thermostability of phycobilisome components from thermophilic species and discuss how a better appreciation of phycobiliproteins from extreme environments will benefit our fundamental understanding of photosynthetic adaptation and could provide a sustainable resource for several industrial processes.

Transverse compression behavior of Kevlar KM2 single fiber

2016 ◽  
Vol 81 ◽  
pp. 271-281 ◽  
Author(s):  
Subramani Sockalingam ◽  
Reid Bremble ◽  
John W. Gillespie ◽  
Michael Keefe
Keyword(s):  
Single Fiber ◽  
Transverse Compression ◽  
Compression Behavior

Impact of drying temperature and pressing time factor on VOC emissions from OSB made of Scots pine

Holzforschung ◽  
2006 ◽  
Vol 60 (4) ◽  
pp. 417-422 ◽  
Author(s):  
Mathias Makowski ◽  
Martin Ohlmeyer
Keyword(s):  
Scots Pine ◽  
Process Parameters ◽  
Elevated Temperatures ◽  
Oriented Strand Board ◽  
Time Factors ◽  
Drying Temperature ◽  
Voc Emissions ◽  
Pressing Time ◽  
Emission Testing ◽  
Volatile Aldehydes

Abstract Correlations between process parameters and VOC emissions from an oriented strand board (OSB) made of Scots pine (Pinus sylvestris L.) were demonstrated. Terpene and aldehyde emissions were affected by the pressing time factors in different ways: terpene emissions were lowered with elevated pressing times, whereas the formation of volatile aldehydes was accelerated. Drying temperature mainly affected the dynamics of aldehyde formation, with a clear rise and fall in aldehyde concentration after drying at elevated temperatures (170°C and >200°C). As a consequence of lower temperatures (120°C), aldehyde emissions from OSB constantly increased over the testing period. In spite of this context, a sustainable reduction in aldehyde emissions by adjusting the relevant process parameters does not seem to be feasible, as the concentrations released from all panels converged during emission testing.

Introduction of a novel tribometer especially designed for scratch, adhesion and hardness investigation up to 1000℃

2016 ◽  
Vol 231 (4) ◽  
pp. 469-478 ◽  
Author(s):  
M Varga ◽  
M Flasch ◽  
E Badisch
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Elevated Temperatures ◽  
Normal Load ◽  
Load Range ◽  
Aisi 304 ◽  
Fundamental Understanding ◽  
The Common ◽  
Scratch Tests ◽  
Application Specific

In order to gain a fundamental understanding of material behaviour at elevated temperatures a unique tribometer was designed which can operate at temperatures up to 1000℃. The test takes place in vacuum in order to avoid oxidation and the normal load range varies from 10 to 500 N. It is thus possible to describe the evolution of hardness over a broad range of temperatures and loads. This can give indications of possible microstructural modifications, which can be investigated afterwards on cross sections. For the characterisation of single abrasive phenomena on a very fundamental level, scratch tests at variable loads are proposed. The interaction of sliding surfaces can be simulated by adhesion testing. To this end an application specific counter body, e.g. taken from a field specimen, can be slid over the specimen surface at variable loads. Finally, it can be stated that this newly designed tribometer offers an enormous potential for deeper understanding of fundamental wear phenomena like ploughing, micro-breaking or adhesion occurring at high temperature. The possibilities of high temperature scratch and hardness testing with the new measurement system are shown on the common austenitic stainless steel 1.4301 (AISI 304).

scholarly journals Investigation of the Dynamic Recovery and Recrystallization of Near-β Titanium Alloy Ti-55511 during Two-Pass Hot Compression

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 359
Author(s):  
Hande Wang ◽  
Jinyang Ge ◽  
Xiaoyong Zhang ◽  
Chao Chen ◽  
Kechao Zhou
Keyword(s):  
Dynamic Recrystallization ◽  
Grain Growth ◽  
Dynamic Recovery ◽  
Peak Stress ◽  
Thermal Compression ◽  
Compression Behavior ◽  
Continuous Dynamic Recrystallization ◽  
First Pass ◽  
Restoration Mechanism ◽  
Continuous Dynamic

The two-pass thermal compression behavior of near-β Ti-55511 alloy was investigated. The first-pass restoration mechanisms changed from dynamic recrystallization (DRX) to dynamic recovery (DRV) as the first-pass deformation temperature increased from 700 °C to 850 °C. The occurrence of recrystallization reduced the dislocation density, resulting in a slower grain growth rate in the subsequent process. Because of the static recrystallization (SRX) and β grain growth, the β grain size increased and the morphology became less uniform during the subsequent β holding process, which also changed the restoration mechanism during second-pass compression. The level of continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) become weaker during second-pass deformation. The changes in the restoration mechanism and the microstructures slightly increased the peak stress during the second-pass deformation.

scholarly journals Análisis experimental del comportamiento mecánico de elementos de madera de pino silvestre de pequeña escuadría sometidos a compresión transversal a las fibras = Experimental analysis of the mechanical behavior of small squad pine wood elements subjected to cross-fiber compression

2016 ◽  
Vol 2 (3) ◽  
pp. 33
Author(s):  
Nuria Llauradó ◽  
Nieves Gónzalez ◽  
Pilar De la Rosa Garcia ◽  
Álvaro Santamaria
Keyword(s):  
Tensile Strength ◽  
Mechanical Behavior ◽  
Experimental Analysis ◽  
Modulus Of Elasticity ◽  
Compression Stress ◽  
Transverse Compression ◽  
Compression Behavior ◽  
Pine Wood ◽  
Mean Values ◽  
Structural Details

ResumenEn numerosos detalles estructurales de construcciones realizadas con madera, el esfuerzo de compresión transversal a las fibras juega un papel muy importante y en muchas ocasiones condiciona su diseño. En este trabajo se analiza el comportamiento a compresión de piezas de madera de pino silvestre de pequeña escuadría sometidas a un esfuerzo de compresión transversal a las fibras y se han obtenido unos valores medios para la tensión de rotura y el módulo de elasticidad de 4,20 MPa y 305,86 MPa, respectivamente.AbstractIn many structural details of buildings made of wood, the transverse compression stress to the fibers plays a very important role and often determines its design. In this work, the compression behavior of small pine wood pieces subjected to a cross - compressive stress to the fibers is analyzed and mean values for the tensile strength and the modulus of elasticity of 4,20 MPa and 305.86 MPa, respectively.

Dynamic compression behavior of 6005 aluminum alloy aged at elevated temperatures

Vacuum ◽  
2018 ◽  
Vol 155 ◽  
pp. 604-611 ◽  
Author(s):  
Long Zhang ◽  
Hong He ◽  
Shikang Li ◽  
Xiaodong Wu ◽  
Luoxing Li
Keyword(s):  
Aluminum Alloy ◽  
Elevated Temperatures ◽  
Dynamic Compression ◽  
Compression Behavior

scholarly journals Experimental Investigation of the Temperature Effect on the Mechanical Properties of Hemp Woven Fabrics Reinforced Polymer

2021 ◽  
Vol 2 (2) ◽  
pp. 239-256
Author(s):  
Sheedev Antony ◽  
Abel Cherouat ◽  
Guillaume Montay
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Natural Fiber ◽  
Compression Molding ◽  
Fiber Composites ◽  
Woven Fabrics ◽  
Thermoplastic Composite ◽  
Analytical Models ◽  
Natural Fiber Composites ◽  
Thermal Compression

Natural fiber composites are widely used in a several industrial applications due to their outstanding biodegradability and recyclability. Thermal compression molding is a rapid and easy method to fabricate composite sheets. To better understand the manufacturing process and evaluate the mechanical properties of hemp woven fabrics reinforced thermoplastic composite at elevated temperatures, a detailed investigation is required. In this study, composite sheets were initially fabricated using hemp fiber fabrics (taffeta and serge 2×1) and polypropylene sheets by the thermal compression molding process. Mechanical tests (uniaxial, shear, and biaxial) were carried out at temperatures ranging from 20 to 160 ∘C in order to estimate the mechanical properties of composite sheets. Non-linear behavior was observed during the loading due to the unbalanced weaving pattern of hemp fabric. The biaxial behavior of the composite was estimated using a theoretical method for fabric strength prediction taking into account the interaction effect between the yarns. The experimental results demonstrate that, at high temperature, the polymer softens and the fiber reinforcements dismantle which resulting in a decrease in the mechanical properties of the composite. Two analytical models (Ha & Springer and thermal expansion coefficient) were also proposed to estimate the thermo-mechanical properties of natural fiber composites subjected to various temperatures.

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