Theoretical exploration of factors affecting dielectric constants of masson pine

Holzforschung ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 418-422 ◽  
Author(s):  
Z.-Q. Hou ◽  
Z. Chen ◽  
R.S. Wright
Keyword(s):  
Dielectric Constant ◽  
Moisture Content ◽  
Volume Fraction ◽  
Density Ratio ◽  
Longitudinal Direction ◽  
Pinus Massoniana ◽  
Dielectric Constants ◽  
Masson Pine ◽  
Factors Affecting ◽  
Ray Cells

AbstractA theoretical model to calculate the dielectric constant of masson pine (Pinus massoniana) in the longitudinal direction was developed by considering the effect of wood moisture content, density, ratio of earlywood to latewood, and the volume fraction of ray cells. The calculated results were used to explore the relationship between dielectric constant and moisture content, density, and other factors. The results indicated that the dielectric constant of masson pine increased with the moisture content. From 0% to 30% moisture content, the longitudinal dielectric constant increased more than 5 times from 2.3 to 13.3. In the range of density from 0.450 to 0.650 (g cm−3at 15% moisture content, the longitudinal dielectric constant increased from 7.7 to 10.0. However, the longitudinal dielectric constant decreased as the volume fraction of ray cells increased.

Experimental Study on Tensile Properties of Sugarcane Leaves

2021 ◽  
Vol 37 (4) ◽  
pp. 615-621
Author(s):  
Jing Bai ◽  
Shaochun Ma ◽  
Jiwei Hu ◽  
Yi Wei ◽  
Fenglei Wang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Tensile Properties ◽  
Tensile Force ◽  
Testing Machine ◽  
Longitudinal Direction ◽  
Leaf Sheath ◽  
List Type ◽  
Factors Affecting ◽  
Strong Linear Correlation ◽  
Tensile Forces

Highlights This article focuses on the tensile properties of sugarcane leaves. The moisture content and sheath diameter were selected as test factors, and the test index was the stalk-leaf connecting force. The load-displacement curves of stalks and leaves were plotted. Two-way ANOVA was also discussed. Abstract . The tensile properties of sugarcane leaves are critical factors affecting the harvesting quality of sugarcane harvesters. Thus, it is important to investigate the tensile properties of sugarcane stalks and leaves. The selected test factors were leaf moisture content and sheath diameter, and the stalk-leaf connecting force was selected as test index. The tests were conducted with two moisture content levels of 15% and 20%, and three sheath diameters of 22, 26, and 30 mm. The stress-strain curves of stalks and leaves were plotted to show how the tensile force varied during the tensile test. The results showed that there was a strong linear correlation between the stalk-leaf connecting force and diameter of leaf sheath, and the connecting force also increased with the increasing moisture content. In addition, leaf tensile forces in longitudinal direction were much larger than in transverse direction. Two-way ANOVA revealed that both of the moisture contents (A) and sheath diameters (B) had significant effects on the stalk-leaf connecting force (p < 0.01), however, the interaction between A and B was not significant (p > 0.1). This study provides a theoretical reference for the design and improvement of crop dividers of sugarcane harvester. Keywords: Moisture content, Sheath diameter, Stalk-leaf connecting force, Sugarcane leaves, Universal testing machine, Tensile properties.

Preparation, Morphology and Dielectric Properties of Polyamide-6/Poly(Vinylidene Fluoride) Blends

2012 ◽  
Vol 496 ◽  
pp. 263-267
Author(s):  
Rui Li ◽  
Jian Zhong Pei ◽  
Yan Wei Li ◽  
Xin Shi ◽  
Qun Le Du
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Flexible Electronics ◽  
High Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Volume Fraction ◽  
Polyamide 6 ◽  
Dielectric Constants ◽  
Poly Vinylidene Fluoride ◽  
High Dielectric

A novel all-polymeric material with high dielectric constant (k) has been developed by blending poly (vinylidene fluoride) (PVDF) with polyamide-6 (PA6). The dependence of the dielectric properties on frequency and polymer volume fraction was investigated. When the volume fraction of PA6 is 20%, the dielectric property is better than others. The SEM investigations suggest that the enhanced dielectric behavior originates from significant interfacial interactions of polymer-polymer. The XRD demonstrate that the PA6 and PVDF affect the crystalline behavior of each component. Furthermore, the stable dielectric constants of the blends could be tuned by adjusting the content of the polymers. The created high-k all-polymeric blends represent a novel type of material that are simple technology and easy to process, and is of relatively high dielectric constant, applications as flexible electronics.

Microwave properties of saturated reservoirs

Geophysics ◽  
1983 ◽  
Vol 48 (3) ◽  
pp. 367-375 ◽  
Author(s):  
James N. Lange
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Surface Area ◽  
Oil And Gas ◽  
Volume Fraction ◽  
Empirical Relationship ◽  
Dielectric Constants ◽  
Solid Matrix ◽  
Detailed Model

Dielectric properties of saturated, porous geologic materials reflect the large difference in dielectric constant ε of typical saturating fluids such as water (ε = 78) or oil and gas (ε = 1–3). The deconvolution of in‐situ dielectric properties of saturated porous materials into the component parts requires a detailed model of the composite material. Defining aspects of this model in the microwave frequency regime is the primary purpose of this investigation. A model is examined in which the dielectric constant of the composite is equal to the sum of the dielectric constants of the components weighted by the volume fraction occupied by each. That model is compared to measurements at microwave frequencies made on systems consisting of glass beads, quartz, or sand saturated with chlorobenzene, 1,2‐dichloroethane, methanol, or air, and find satisfactory agreement. When water is the saturant an interaction between water and the solid matrix has an important effect on the composite dielectric constant. This interaction is observed to be particularly large for quartz and water and suppresses the composite dielectric constant quite considerably. This interaction is dependent upon the relative surface area per unit volume. An empirical relationship between the surface area and composite dielectric constant is obtained for clean, saturated, unconsolidated reservoirs. The inverse process of determining surface area from in‐situ measurements of the composite dielectric constant may be possible for clean reservoirs of known lithology. In sandstones from cores the dielectric constant is also below the volume fraction model and corrections are needed to evaluate water content.

Preparation and Dielectric Properties of Cu/PVDF Composite Films

2014 ◽  
Vol 1035 ◽  
pp. 417-421 ◽  
Author(s):  
Jian Wen Zhai ◽  
Ya Jun Wang ◽  
Jian Lou Deng ◽  
Chang Gen Feng
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Volume Fraction ◽  
Composite Films ◽  
Interfacial Polarization ◽  
Dielectric Constants ◽  
Pvdf Film ◽  
Continuous Increase ◽  
Better Than

nanoand micro size Cu were employed separately and investigated comparatively. Different volume fraction of Cu was added into PVDF film in order to investigate the content of filler effect on the dielectric properties of polymer composites. XRD and SEM were used to analyze the crystalline phase and microstructure of the films. The results show that two sizes of Cu have the same peak features, and with the continuous increase of the content of Cu, it disperse better in PVDF. The dielectric constant (ε) of the composite containing 16 vol% micro-CCTO filler is 16 at 100 Hz and room temperature, and its dielectric loss (tanδ) is only 0.15, which is substantially better than others. Besides, for 18 vol% nanoCu/PVDF composite tanδis 0.25 andεis 18 at 100 Hz. Moreover,εand tanδof nanoCu/PVDF composite are both higher than those of micro-Cu/PVDF. Analysis shows that the composites with nanoCu have higher dielectric constants, which is mainly from the interfacial polarization.

Dielectric Properties of Blackberries as Related to Microwave Drying Control

2017 ◽  
Vol 13 (12) ◽  
Author(s):  
Chunfang Song ◽  
Tian Sang ◽  
Haiying Chen ◽  
Li Zhenfeng ◽  
Li Jing
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Moisture Content ◽  
Penetration Depth ◽  
Loss Factor ◽  
Large Scale ◽  
Coaxial Line ◽  
Dielectric Constants ◽  
Microwave Drying ◽  
Increasing Temperature

AbstractThe dielectric properties of blackberry samples with a 20.0–80.0 % w.b (web basis) moisture content were determined with a network analyzer and an open-ended coaxial-line probe over a frequency range from 5 to 3000 MHz and a temperature range from 20 to 100 °C. The results showed that the dielectric constant decreased with increasing temperature but increased with increasing moisture content; however, the loss factor increased with increasing temperature and moisture content. The dielectric constant and the loss factor decreased with increasing frequency. The penetration depth decreased with increasing temperature, frequency and moisture content. A large penetration depth at 915 MHz may provide practical large-scale dielectric drying for blackberries. The dielectric constants and loss factors for blackberry by combining the above mathematical model and temperature and moisture of the sample in the microwave drying process were used to analyze and control blackberry drying technology.

scholarly journals Optimization of factors affecting the rooting of pine wilt disease resistant Masson pine (Pinus massoniana) stem cuttings

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0251937
Author(s):  
Ting Pan ◽  
Xue-lian Chen ◽  
Yan-ping Hao ◽  
Chun-wu Jiang ◽  
Song Wang ◽  
...  
Keyword(s):  
Pine Wilt Disease ◽  
Pinus Massoniana ◽  
Wilt Disease ◽  
Stem Cuttings ◽  
Simple Method ◽  
Masson Pine ◽  
Factors Affecting ◽  
Pine Wilt ◽  
Pine Trees ◽  
Root Quality

Pine wilt disease (PWD) is a devastating disease affecting trees belonging to the genus Pinus. To control the spread of PWD in the Masson pine forest in China, PWD resistant Masson pine clones have been selected by the Anhui Academy of Forestry. However, because Masson pine is a difficult-to-root species, producing seedlings is challenging, especially from trees older than 5 years of age, which impedes the application of PWD resistant clones. In this study, we investigated the factors affecting rooting of PWD resistant clones and established a cheap, reliable, and simple method that promotes rooting. We tested the effects of three management methods, four substrates, two cutting materials, two cutting treatments, and three collection times on the rooting of cuttings obtained from 9-year-old PWD resistant clones. Rooting was observed only in stem cuttings treated with the full-light automatic spray management method. Additionally, stem cuttings showed a significantly higher rooting rate and root quality than needles cuttings. Compared with other substrates, stem cuttings planted in perlite produced the longest adventitious root and the highest total root length and lateral root number. Moreover, stem cuttings of PWD resistant clones collected in May showed a significantly higher rooting rate and root quality than those collected in June and July. Moreover, stem cuttings prepared with a horizontal cut while retaining the needles showed significantly higher rooting rate and root quality than those prepared with a diagonal cut while partly removing the needles. This study promotes the reproduction of seedlings of PWD-resistant Masson pine clones which helps control the spread of PWD, meanwhile, provides a technical reference for the propagation of mature pine trees via cuttings.

Longitudinal mechanical properties of cell wall of Masson pine (Pinus massoniana Lamb) as related to moisture content: A nanoindentation study

Holzforschung ◽  
2011 ◽  
Vol 65 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Yan Yu ◽  
Benhua Fei ◽  
Hankun Wang ◽  
Genlin Tian
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Moisture Content ◽  
Pinus Massoniana ◽  
Regression Equations ◽  
Saturation Point ◽  
Masson Pine ◽  
Pinus Massoniana Lamb ◽  
Experimental Values

Abstract The in situ imaging nanoindentation technique was used to investigate how the moisture content (MC) affects the longitudinal mechanical properties of Masson pine cell wall. Furthermore, nanoindentation tests in liquid water were performed. The results indicate that elastic modulus, hardness, and compression yield stress of wood wall are all linearly correlated to the selected MC region in the range from 4.5% to 13.1%. Remarkable differences were found between the experimental values measured in water and the extrapolated values based on regression equations below fiber saturation point.

The Influence Factors of Wood Dielectric Constant

2012 ◽  
Vol 461 ◽  
pp. 779-782
Author(s):  
Xiang Ling Zhang ◽  
Ying Chun Cai ◽  
Qiao Fang Zhou ◽  
Jing Yao Zhao
Keyword(s):  
Dielectric Constant ◽  
Influence Factors ◽  
Longitudinal Direction ◽  
Tangential Direction ◽  
Dielectric Constants ◽  
Exponential Relationship ◽  
Change Trend ◽  
The Difference ◽  
The Relationship ◽  
Frequency Heating

Dielectric constants of Larix gmelinii were measured at 1.1 MHz to 25 MHz (near to frequency of high-frequency heating ), from oven-drying condition to 100％ moisture content, with longitudinal, radial and tangential directions measuring in the experiment. The results showed that: the relationship between MC and dielectric constant can be described as exponential relationship from MC=8% to the fiber saturation point (FSP), above FSP it is linear relationship. The dielectric constant showed decreasing trends when frequency raised. When f﹥10MHz change trend is slow. Permittivity across longitudinal direction is bigger than that across transverse direction，but the difference across tangential direction and that across radial direction is small.

scholarly journals Dielectric Properties of Switchgrass and Corn Stover in the Radio Frequency Range

2021 ◽  
Vol 64 (1) ◽  
pp. 243-252
Author(s):  
Augusto M. Souza ◽  
Stuart J. Birrell ◽  
Brian L. Steward
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Moisture Content ◽  
Radio Frequency ◽  
Corn Stover ◽  
Loss Factor ◽  
Prediction Models ◽  
Dielectric Constants ◽  
Frequency Range ◽  
Loss Factors

HighlightsDielectric permittivities of switchgrass and corn stover in the radio frequency range were calculated.Prediction models achieved R2 > 0.9, except for the switchgrass loss factor for the material in motion.The loss factors were different when static and in motion, but the dielectric constants were similar.Abstract. The dielectric properties of biological materials are relevant when developing moisture content sensors. However, little is known about the permittivities of switchgrass and corn stover in a wider frequency range. The goal of this research was to determine their dielectric constants and loss factors at different moisture contents across a frequency range of 5 Hz to 13 MHz and with the material static and in motion inside a sample container. The permittivity of these materials was calculated by measuring their admittance in a test fixture using an impedance analyzer at three different moisture levels (9.0% to 30.5%). Overall, the materials’ dielectric properties increased with moisture but decreased with frequency. Prediction models were developed using the data in a frequency range of 10 kHz to 5 MHz. Model coefficients of determination were higher than 0.90 in general, except for the model measuring the loss factor of switchgrass in motion. Additionally, the dielectric constant was not different with the materials static or in motion, but the loss factor values were distinct. This work can be used for the development of electrical moisture content sensors for switchgrass and corn stover. Keywords: Corn stover, Dielectric constant, Loss factor, Moisture content, Permittivity, Switchgrass.

A Study of Some Mechanical and Physical Properties for Palm Fiber/Polyester Composite

2020 ◽  
Vol 38 (3B) ◽  
pp. 104-114
Author(s):  
Samah M. Hussein
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Dielectric Constant ◽  
Date Palm ◽  
Volume Fraction ◽  
Unsaturated Polyester ◽  
Dielectric Strength ◽  
Palm Fiber ◽  
Mechanical And Physical Properties ◽  
Polyester Composite

This research has been done by reinforcing the matrix (unsaturated polyester) resin with natural material (date palm fiber (DPF)). The fibers were exposure to alkali treatment before reinforcement. The samples have been prepared by using hand lay-up technique with fiber volume fraction of (10%, 20% and 30%). After preparation of the mechanical and physical properties have been studied such as, compression, flexural, impact strength, thermal conductivity, Dielectric constant and dielectric strength. The polyester composite reinforced with date palm fiber at volume fraction (10% and 20%) has good mechanical properties rather than pure unsaturated polyester material, while the composite reinforced with 30% Vf present poor mechanical properties. Thermal conductivity results indicated insulator composite behavior. The effect of present fiber polar group induces of decreasing in dielectric strength, and increasing dielectric constant. The reinforcement composite 20% Vf showed the best results in mechanical, thermal and electrical properties.

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