Multi-Scale Analysis of Changes in Crack-Free Flattened Moso Bamboo After Saturated Steam Treatment and Flattening Process

2021 ◽  
Vol 13 (7) ◽  
pp. 1259-1267
Author(s):  
Tiancheng Yuan ◽  
Xiao Xiao ◽  
Xin-Han ◽  
Yifei Wu ◽  
Xinzhou Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Moisture Content ◽  
Mechanical Analysis ◽  
Moso Bamboo ◽  
Steam Treatment ◽  
Saturated Steam ◽  
Main Peak ◽  
Multi Scale ◽  
Main Chemical Composition ◽  
The Relationship

ABSTRACTIn this study, Moso bamboo was firstly softened by saturated steam and then pressed flat by a machine. The modification effect (high-temperature saturated steam) was characterized by FTIR, XRD, SEM, and wet chemistry. The dynamic mechanical analysis (DMA) was used to investigate the effects of three variables (temperature, time, and moisture content) on the thermal-mechanical properties of Moso bamboo. The results indicated that high-temperature saturated steam can effectively soften bamboo cells under high pressure at high temperature. As expected, in comparison with reference samples, the content of hemicellulose and cellulose decreased, while that of relative lignin increased. The results of the changes in main chemical composition were further confirmed by FTIR, which showed that the intensity of the main peak belongs to hemicellulose decreased, so the polysaccharide such as hemicellulose went through the process of hydrolysis and pyrolysis. An increase in the moisture content of bamboo led to a decrement in storage modulus value, which can be attributed to the plasticizing effect. Both temperature and time had a positive effect on the reduction in glass transition temperature. This conclusion not only helps to understand the relationship between bamboo and water, but also provides guide for the utilization and production process of crack-free flattened bamboo board and its products in the construction and building fields.

scholarly journals Effect of microwave and steam treatment on the thermo-hygro-plasticity of beech wood

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 8338-8352
Author(s):  
Jakub Dömény ◽  
Martin Brabec ◽  
Radim Rousek ◽  
Lauri Rautkari ◽  
Petr Čermák
Keyword(s):  
Moisture Content ◽  
Structural Changes ◽  
Mechanical Performance ◽  
Beech Wood ◽  
European Beech ◽  
Microwave Treatment ◽  
Steam Treatment ◽  
Saturated Steam ◽  
Similar Degree ◽  
Loading Mode

The effects of microwave and steam treatment were analyzed relative to the immediate (thermo-hygro-plasticity) and post-assessed (permanent changes) properties of wood. The study was conducted using European beech (Fagus sylvatica L.) standard and 1.5 times up-scaled (only for microwave-heated and reference samples) bending specimens tested in a static three-point loading mode. The specimens were plasticized by heat and moisture (1) separately and (2) simultaneously by heating moist specimens using (i) various microwave regimes in continuous mode, and (ii) heated saturated steam in discontinuous mode. Oven-dried specimens tested at 20 °C served as references. The thermo-hygro-plasticity was studied immediately after treatment, whereas the permanent changes were assessed after oven-drying of plasticized specimens to 0% moisture content. Permanent structural changes were analyzed using scanning electron microscopy. Microwave treatment increased the plasticity of wood (decreasing the modulus of elasticity by 70%) comparably to steam treatment, when the output moisture content was 30% or higher. A similar degree of plasticity was found in up-scaled specimens heated by microwaves. Further analyses confirmed that microwave treatment did not cause any permanent damage to wood structure or reduce mechanical performance. The results showed that microwave treatment is an efficient alternative to steaming when plasticizing moist wood.

Multi-scale evaluation of the effect of saturated steam on the micromechanical properties of Moso bamboo

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tiancheng Yuan ◽  
Zhaoshun Wang ◽  
Xin Han ◽  
ZhuRun Yuan ◽  
XinZhou Wang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cell Wall ◽  
Lignin Content ◽  
Moso Bamboo ◽  
Saturated Steam ◽  
Cellulose Content ◽  
X Ray ◽  
Multi Scale ◽  
Micromechanical Properties ◽  
Steam Heat

Abstract The changes in chemical composition and micro-mechanical properties of Moso Bamboo fiber cells were evaluated by applying saturated steam heat treatment at 160, 170, and 180 °C for periods of 4, 6, and 8 min, and subsequent analysis by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopic, and nanoindentation methods. The hemicellulose and cellulose content decreased as expected, while the relative lignin content showed an upward trend. Significant changes in the bamboo micro-structure were detected by scanning electron microscope under the action of high-temperature and saturated steam. Both temperature and time were shown to affect micromechanical properties of the bamboo cell wall. In addition, higher cell wall elastic modulus and hardness were observed (a rise from 16.1 to 19.2 GPa and from 0.6 to 0.8 GPa, respectively), as compared with those of the untreated sample. Meanwhile, the creep ratio decreased after saturated steam heat treatment.

scholarly journals Effect of the Temperature on the product yield during the Pyrolysis of Guinea-Corn stalk

2020 ◽  
Author(s):  
Adeyemo Kunle Kazeem ◽  
adekoya oluwaseun
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Moisture Content ◽  
Pyrolysis Product ◽  
Product Yield ◽  
Effect Of Temperature ◽  
Corn Stalk ◽  
Microsoft Excel ◽  
Proximate And Ultimate Analysis ◽  
The Relationship

This study explain the effect of temperature on the product yield of guinea-corn stalk (Char, tar and Gas). Approximately 0.23kg dried Guinea Corn Stalk (GCS) was introduced into the retort in which the retort was rendered airtight. The retort was placed into the chamber of an electric furnace and the GCS was pyrolysed at a temperature of 400OC at a constant time of 20minutes. This was repeated for temperatures 450,500,550 and 600OC and in each cases, the quantities of char, tar and the bio-gas were determined. Proximate and ultimate analysis were carried out on the sample in other to know the level of moisture content in the sample and also to know if GCS has more contribution to global warming by observing the percentage of the Sulphur and Nitrogen content in the ultimate analysis.Using the sigma plot application as well as the Microsoft excel bar chart to illustrate the relationship between the temperature and the pyrolysis product. This application depict and shown how the increase in temperature affect the product yield (Gas, Tar and Char). The Char yields a percentage of approximately 17% at 400OC and drastically decreased to 27% at 600OC, the tar yields a percentage of approximately 28% at 400OC and increased to 39% at 600OC and also the gas yields a percentage of approximately 17% at 400OC and increased to 34% at 600OC.The result shown that GCS can be pyrolyzed at and high temperature to obtaining more yields of bio-gas.

Energetic relationships for crushing of soil clods

2006 ◽  
Vol 2 (1) ◽  
pp. 51-72
Author(s):  
István Patay ◽  
Virág Sándor
Keyword(s):  
Moisture Content ◽  
Specific Energy ◽  
Soil Moisture Content ◽  
Energy Requirement ◽  
Clay Content ◽  
Clay Soils ◽  
Rigid Support ◽  
Soil Plasticity ◽  
Specific Energy Requirement ◽  
The Relationship

Clod crushing is a principal problem with soils of high clay content. Therefore, there is a need for determining the conditions for clod breaking and clod crushing. The objective of the work was to develop a special purpose tool for single clod breaking both by rigid support of the clod and by a single clod supported by soil and to develop a machine for clod crushing. Furthermore, the purpose was to determine the relationship between the specific energy requirement for clod crushing in the function of soil plasticity and the soil moisture content by the means of the developed tool and machine. The main result of the experiments is summarized in a 3D diagram where the specific energy requirement for soil clod crushing is given in the function of the moisture content and the plasticity index for different clay soils.

Barley seed storage under controlled conditions

2019 ◽  
pp. 140-150 ◽  
Author(s):  
O. A. Zadorozhna ◽  
T. P. Shyianova ◽  
M.Yu. Skorokhodov
Keyword(s):  
Hordeum Vulgare ◽  
Moisture Content ◽  
Spring Barley ◽  
Seed Storage ◽  
Growing Season ◽  
Storage Conditions ◽  
Meteorological Conditions ◽  
Hordeum Vulgare L ◽  
The Relationship ◽  
And Storage

Seed longevity of 76 spring barley gene pool samples (Hordeum vulgare L. subsp. distichon, convar. distichon: 56 nutans Schubl., two deficience (Steud.) Koern., two erectum Rode ex Shuebl., two medicum Koern.; convar. nudum (L.) A.Trof.: one nudum L. та subsp. vulgare: convar. vulgare: nine pallidum Ser., three rikotense Regel.; convar. coeleste (L.) A.Trof.: one coeleste (L.) A.Trof.) from 26 countries, 11 years and four places of reproduction was analyzed. Seeds with 5–8% moisture content were stored in chamber with unregulated and 4oC temperature. The possibility of seed storage under these conditions for at least 10 years without significant changes in germination has been established. The importance of meteorological conditions in the formation and ripening of seeds for their longevity is confirmed. The relationship between the decrease of barley seeds longevity and storage conditions, amount of rainfall, temperature regime during the growing season of plants is discussed.

scholarly journals The modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Rui Zhang ◽  
Yujie Meng ◽  
Hejia Song ◽  
Ran Niu ◽  
Yu Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
High Temperature ◽  
Air Pollutants ◽  
Meteorological Data ◽  
Effect Of Temperature ◽  
Distributed Lag ◽  
Modification Effect ◽  
Incidence Risk ◽  
The Impact ◽  
The Relationship

Abstract Background Although exposure to air pollution has been linked to many health issues, few studies have quantified the modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo, China. Methods The data of daily incidence of influenza and the relevant meteorological data and air pollution data in Ningbo from 2014 to 2017 were retrieved. Low, medium and high temperature layers were stratified by the daily mean temperature with 25th and 75th percentiles. The potential modification effect of temperature on the relationship between air pollutants and daily incidence of influenza in Ningbo was investigated through analyzing the effects of air pollutants stratified by temperature stratum using distributed lag non-linear model (DLNM). Stratified analysis by sex and age were also conducted. Results Overall, a 10 μg/m3 increment of O3, PM2.5, PM10 and NO2 could increase the incidence risk of influenza with the cumulative relative risk of 1.028 (95% CI 1.007, 1.050), 1.061 (95% CI 1.004, 1.122), 1.043 (95% CI 1.003, 1.085), and 1.118 (95% CI 1.028, 1.216), respectively. Male and aged 7–17 years were more sensitive to air pollutants. Through the temperature stratification analysis, we found that temperature could modify the impacts of air pollution on daily incidence of influenza with high temperature exacerbating the impact of air pollutants. At high temperature layer, male and the groups aged 0–6 years and 18–64 years were more sensitive to air pollution. Conclusion Temperature modified the relationship between air pollution and daily incidence of influenza and high temperature would exacerbate the effects of air pollutants in Ningbo.

scholarly journals Influence of moisture content on the contact angle and surface tension measured on birch wood surfaces

2021 ◽  
Author(s):  
Rami Benkreif ◽  
Fatima Zohra Brahmia ◽  
Csilla Csiha
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Moisture Content ◽  
Solid Wood ◽  
Contact Angles ◽  
Surface Moisture ◽  
Wood Coatings ◽  
The Relationship ◽  
Wood Surfaces

AbstractSurface tension of solid wood surfaces affects the wettability and thus the adhesion of various adhesives and wood coatings. By measuring the contact angle of the wood, the surface tension can be calculated based on the Young-Dupré equation. Several publications have reported on contact angle measured with different test liquids, under different conditions. Results can only be compared if the test conditions are similar. While the roles of the drop volume, image shooting time etc., are widely recognized, the role of the wood surface moisture content (MC) is not evaluated in detail. In this study, the effect of wood moisture content on contact angle values, measured with distilled water and diiodomethane, on sanded birch (Betula pendula) surfaces was investigated, in order to find the relationship between them. With increasing MC from approximately 6% to 30%, increasing contact angle (decreasing surface tension) values were measured according to a logarithmic function. The function makes possible the calculation of contact angles that correspond to different MCs.

Shear Strength Monitoring System Based on Measurement of Shear Wave Velocity and Moisture Content

2014 ◽  
Vol 635-637 ◽  
pp. 750-754
Author(s):  
Peng Hu ◽  
Qing Li ◽  
Yi Wei Xu ◽  
Nan Ying Shentu ◽  
Quan Yuan Peng
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Shear Wave ◽  
Monitoring System ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Bender Elements ◽  
Strength Measurement ◽  
Soil Shear Strength ◽  
The Relationship

Expound the importance of soil shear strength measurement at mudslide hidden point to release the loss caused by the disaster, explain the relationship between shear wave velocity, moisture content and shear strength, design the shear strength monitoring system combining the shear wave velocity measured by Piezoelectric bender elements and moisture content.

scholarly journals Effects of Ni Additions on the High Temperature Expansion, Melting and Oxidation Behaviors of Cobalt-Based Superalloys

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Patrice Berthod ◽  
Lionel Aranda ◽  
Jean-Paul Gomis
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Beneficial Effects ◽  
Ni Addition ◽  
High Temperature Expansion ◽  
High Fraction ◽  
Thermal Analysis Techniques ◽  
Ni Additions

Nickel is often added to cobalt-based superalloys to stabilize their austenitic structure. In this work the effects of Ni on several high temperature properties of a chromium-rich cobalt-based alloy reinforced by high fraction of TaC carbides are investigated. Different thermal analysis techniques are used: differential scanning calorimetry (DSC), thermo-mechanical analysis (TMA) and thermogravimetry (TG). Results show that the progressive addition of nickel did not induce great modifications of microstructure, refractoriness or thermal expansion. However, minor beneficial effects were noted, including reduction of the melting temperature range and slight decrease in thermal expansion coefficient. The most important improvement induced by Ni addition concerns the hot oxidation behavior. In this way, introducing several tens wt % Ni in this type of cobalt-based alloy may be recommended.

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