Effects of Cell Structure on Water Sorption for Wood

Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 213-218 ◽  
Author(s):  
T. Nakano
Keyword(s):  
Cell Wall ◽  
Moisture Content ◽  
Bulk Modulus ◽  
Cross Section ◽  
Water Sorption ◽  
Chemical Potential ◽  
Cell Structure ◽  
Wood Powder ◽  
Swelling Strain ◽  
Thin Crystal

Summary Contributions of the cell structure of wood to water sorption were examined using the chemical potential change induced by restrained swelling. Thermodynamic analysis revealed that this potential was proportional to the product of moisture content and the bulk modulus of the restraining region in the wood. The modulus of the restricting region, which was calculated from isotherm curves of wood powder and block samples by using the thermodynamically derived relationship, was near that obtained from the swelling strain and stress in the cross section for whole wood. These results demonstrated that S1 and S3 layers in the cell wall, where thin crystal threads called microfibrils are wound helically in the circumference, act to resist swelling so that the isotherm curve of the block sample was lower than that of wood powder.

Properties of Gliricidia Wood (Gliricidia sepium) lntercropped with Cocoa (Theobroma cocoa) in Malaysia

2014 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Mohd Helmy Ibrahim ◽  
Mohd Nazip Suratman ◽  
Razali Abd Kader
Keyword(s):  
Cell Wall ◽  
Specific Gravity ◽  
Moisture Content ◽  
Wall Thickness ◽  
Age Groups ◽  
Gliricidia Sepium ◽  
Cell Wall Thickness ◽  
Tree Age ◽  
Lumen Diameter ◽  
Significant Difference

Trees planted from agroforestry practices can become valuable resources in meeting the wood requirements of many nations. Gliricidia sepium is an exotic species introduced to the agricultural sector in Malaysia mainly for providing shade for cocoa and coffee plantations. This study investigates its wood physical properties (specific gravity and moisture content) and fibre morphology (length, lumen diameter and cell wall thickness) of G. sepium at three intervals according to age groups ( three, five and seven years of ages). Specific gravity (0.72) was significantly higher at seven years ofage as compared to five (0.41) and three (0.35) years age group with a mean of 0.43 (p<0.05). Mean moisture content was 58.3% with no significant difference existing between the tree age groups. Fibre diameter (22.4 mm) was significantly lower (p<0.05) for the trees which were three years of age when compared to five and seven years age groups (26.6 mm and 24. 7 mm), respectively. Means of fibre length, lumen diameter and cell wall thickness were 0.83 mm, 18.3 mm, and 6.2 mm, respectively, with no significant differences detected between trees in all age groups. Further calculation on the coefficient of suppleness and runkel ratio suggest that wood from G.sepium may have the potential for insulation board manufacturing and paper making. However, future studies should experiment the utilisation of this species for these products to determine its full potential.

scholarly journals Study on the Moisture Absorption and Thermal Properties of Hygroscopic Exothermic Fibers and Related Interactions with Water Molecules

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 98 ◽  
Author(s):  
Yi Cui ◽  
Shuyi Gao ◽  
Ruiyun Zhang ◽  
Longdi Cheng ◽  
Jianyong Yu
Keyword(s):  
Moisture Content ◽  
Thermal Performance ◽  
Water Sorption ◽  
Moisture Absorption ◽  
Bound Water ◽  
Absorption Process ◽  
Heating Performance ◽  
Hygroscopic Behavior ◽  
Water Sorption Capacity ◽  
Main Factor

The aim of this paper is to study the hygroscopic behavior of hygroscopic exothermic fiber-based materials and to obtain a better understanding of the thermal performance of these fibers during the moisture absorption process. The temperature distribution of different kinds of hygroscopic exothermic fibers in the process of moisture absorption, observed by infrared camera, demonstrated two types of heating performance of these fibers, which might be related to its hygroscopic behavior. Based on the sorption isotherms, a Guggenheim-Anderson-de Boer (GAB) multi-layer adsorption model was selected as the optimal moisture absorption fitting model to describe the moisture absorption process of these fibers, which illustrated that water sorption capacity and the water–fiber/water–water interaction had a significant influence on its heating performance. The net isosteric heats of sorption decreased with an increase of moisture content, which further explained the main factor affecting the heat dissipation of fibers under different moisture contents. The state of adsorbed water and water vapor interaction on the fiber surface were studied by simultaneous thermal analysis (TGA-DSC) measurement. The percentage of bound and unbound water formation at low and high humidity had a profound effect on the thermal performance of fibers. It can therefore be concluded that the content of tightly bound water a strong water–fiber interaction was the main factor affecting the heating performance of fibers at low moisture content, and the content of loosely bound water reflected that water sorption capacity was the main factor affecting the heating performance of fibers at high moisture content. This was further proven by the heat of desorption.

scholarly journals Astringency in ʻGiomboʼ persimmon and its relationship with the harvest time

Revista CERES ◽  
2016 ◽  
Vol 63 (5) ◽  
pp. 646-652
Author(s):  
Magda Andréia Tessmer ◽  
Beatriz Appezzato-da-Glória ◽  
Ricardo Alfredo Kluge
Keyword(s):  
Cell Wall ◽  
Exposure Time ◽  
Fruit Quality ◽  
Cell Structure ◽  
Parenchyma Cell ◽  
Growing Season ◽  
Ethanol Exposure ◽  
Harvest Time ◽  
Intercellular Spaces ◽  
Parenchyma Cell Wall

ABSTRACT ʻGiomboʼ is one of most cultivated persimmon cultivars in Brazil. It is a late-harvest cultivar and requires treatment for astringency removal. The aim of this study was to evaluate the efficiency of ethanol and the effect of harvest time on reducing astringency, physicochemical and anatomical characteristics of 'Giombo' persimmon. Two experiments were carried out, one in each growing season, with five treatments corresponding to exposure to 1.70 mL kg-1ethanol for 0, 12, 24, 36 and 48 hours. At the end of the growing season (2011) the fruits achieved the astringency index and levels of soluble tannins suitable for consumption in 24 hours, and at the beginning of the growing season (2012) in 36 hours, indicating that the efficiency of the treatment is related to harvest time and ethanol exposure time. Astringency removal with ethanol affects the cell structure with accumulation of substances inside the cells and in intercellular spaces, resulting in the degradation of the parenchyma cell wall. To avoid such damage and maintain fruit quality, it is recommended the combination of low ethanol doses with less ethanol exposure time.

scholarly journals Thermodynamic properties and moisture sorption isotherms of two pharmaceutical compounds

2018 ◽  
Author(s):  
Amel Zammouri ◽  
M. Ben Zid ◽  
N. Kechaou ◽  
N. Boudhrioua Mihoubi
Keyword(s):  
Experimental Data ◽  
Thermodynamic Properties ◽  
Moisture Content ◽  
Equilibrium Moisture Content ◽  
Water Sorption ◽  
Pharmaceutical Preparations ◽  
Sorption Isotherms ◽  
Integral Enthalpy ◽  
Isotherm Models ◽  
Water Sorption Isotherms

This investigation examines and compares the water sorption isotherms and the thermodynamic properties of two pharmaceutical preparations (Hypril and Azix) intended to be manufactured with the same process plant and equipment. The moisture equilibrium isotherms were determined at 50, 60 and 70 °C using a gravimetric technique. Five isotherm models were explored for their fitting to the experimental data. Azix showed sigmoid type II isotherms while Hypril showed type III isotherms according to the BET classification. All investigated models fitted well the water sorption isotherms of Hypril. By contrast, only GAB and Adam and Shove equations gave appropriate fit to the experimental data of Azix. For both formulations, the isosteric heat and the differential entropy decreased sharply with the increase of equilibrium moisture content to minimum values and thereafter remain constant. In the case of Azix, the integral enthalpy decreased with equilibrium moisture content while the integral entropy increased until reaching a constant value. Contrariwise, Hypril showed decreasing of the integral enthalpy and entropy with the equilibrium moisture content. Keywords: sorption isotherm, enthalpy, entropy, spreading pressure, pharmaceutical formulations  

scholarly journals The Microstructure and Mechanical Properties of Poplar Catkin Fibers Evaluated by Atomic Force Microscope (AFM) and Nanoindentation

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 938 ◽  
Author(s):  
Wu ◽  
Wu ◽  
Shi ◽  
Chen ◽  
Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Cell Structure ◽  
Large Cell ◽  
Populus Tomentosa ◽  
Thin Wall ◽  
Cell Lumen ◽  
Atomic Force ◽  
Microstructure And Mechanical Properties ◽  
Wall Cell

In this study, the microstructure and mechanical properties of poplar (Populus tomentosa) catkin fibers (PCFs) were investigated using field emission scanning electron microscope, atomic force microscopy (AFM), X-ray diffraction, and nanoindentation methods. Experimental results indicated that PCFs had a thin-wall cell structure with a large cell lumen and the hollow part of the cell wall took up 80 percent of the whole cell wall. The average diameters of the fiber and cell lumen, and the cell wall thickness were 5.2, 4.2, and 0.5 µm, respectively. The crystallinity of fibers was 32%. The AFM images showed that the orientation of microfibrils in cell walls was irregular and their average diameters were almost between 20.6–20.8 nm after being treated with 2 and 5 wt.% potassium hydroxide (KOH), respectively. According to the test of nanoindentation, the average longitudinal-reduced elastic modulus of the PCF S2 layer was 5.28 GPa and the hardness was 0.25 GPa.

scholarly journals Comparison of the Decay Behavior of Two White-Rot Fungi in Relation to Wood Type and Exposure Conditions

2020 ◽  
Vol 8 (12) ◽  
pp. 1931
Author(s):  
Ehsan Bari ◽  
Geoffrey Daniel ◽  
Nural Yilgor ◽  
Jong Sik Kim ◽  
Mohammad Ali Tajick-Ghanbary ◽  
...  
Keyword(s):  
Cell Wall ◽  
Moisture Content ◽  
Wood Species ◽  
White Rot Fungi ◽  
White Rot ◽  
High Mass ◽  
Type I ◽  
Oak Wood ◽  
Mass Losses ◽  
Decay Behavior

Fungal wood decay strategies are influenced by several factors, such as wood species, moisture content, and temperature. This study aims to evaluate wood degradation characteristics of spruce, beech, and oak after exposure to the white-rot fungi Pleurotusostreatus and Trametesversicolor. Both fungi caused high mass losses in beech wood, while spruce and oak wood were more resistant to decay. The moisture content values of the decayed wood correlated with the mass losses for all three wood species and incubation periods. Combined microscopic and chemical studies indicated that the two fungi differed in their decay behavior. While T. versicolor produced a decay pattern (cell wall erosion) typical of white-rot fungi in all wood species, P. ostreatus caused cell wall erosion in spruce and beech and soft-rot type I (cavity formation) decay in oak wood. These observations suggest that P. ostreatus may have the capacity to produce a wider range of enzymes/radicals triggered by the chemical composition of wood cell walls and/or local compositional variability within the cell wall.

scholarly journals Ultrastructure of Cells and Microanalysis in Malus domestica Borkh. ‘Szampion’ Fruit in Relation to Varied Calcium Foliar Feeding

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4622
Author(s):  
Piotr Kowalik ◽  
Tomasz Lipa ◽  
Zenia Michałojć ◽  
Mirosława Chwil
Keyword(s):  
Cell Wall ◽  
Malus Domestica ◽  
Cell Structure ◽  
Middle Lamella ◽  
Apple Fruit ◽  
Malus Domestica Borkh ◽  
X Ray ◽  
Transmission Electron ◽  
Cytoplasmic Membranes

Calcium is one of the most poorly reutilized nutrients. Its deficiencies cause various physiological disturbances and, consequently, reduce the quantity and quality of yields. Reduced content of Ca2+ ions in cells leads to development of, e.g., bitter pit in apples. Efficient and instantaneous mitigation of Ca2+ deficiencies is provided by foliar feeding. There are no detailed data on the effect of foliar feeding with various calcium forms on the cell structure or on the microanalysis and mapping of this element in apple fruit cells. Therefore, we carried out comparative studies of the ultrastructure of epidermis and hypodermis cells, to assess the content and distribution of calcium in the cell wall, cytoplasmic membrane, cytoplasm, and precipitates of Malus domestica Borkh. ‘Szampion’ fruit exposed to four Ca treatments, including the control with no additional Ca supplementation (I) and foliar applications of Ca(NO3)2 (II), CaCl2 (III), and Ca chelated with EDTA (IV). Light and transmission electron microscopy and an X-ray microanalyzer were used and showed a beneficial effect of calcium preparations on the ultrastructure of fruit epidermis and hypodermis cells, manifested in the presence of a normally developed cell wall with a regular middle lamella, preserved continuity of cytoplasmic membranes, and stabilized cell structure. In the selected elements of apical epidermis cells, the highest level of Ca2+ ions was detected in the middle lamella, cell wall, plasmalemma, and cytoplasm. The highest increase in the Ca2+ content in these cell constituents was recorded in treatment IV, whereas the lowest value of the parameters was noted in variant III.

scholarly journals CRISPR/Cas9 Genome Editing Technology: A Valuable Tool for Understanding Plant Cell Wall Biosynthesis and Function

2020 ◽  
Vol 11 ◽  
Author(s):  
Yuan Zhang ◽  
Allan M. Showalter
Keyword(s):  
Cell Wall ◽  
Genome Editing ◽  
Gene Targeting ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Cell Structure ◽  
Higher Order ◽  
Knock Out ◽  
Genetic Crossing ◽  
And Function

For the past 5 years, clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) technology has appeared in the molecular biology research spotlight. As a game-changing player in genome editing, CRISPR/Cas9 technology has revolutionized animal research, including medical research and human gene therapy as well as plant science research, particularly for crop improvement. One of the most common applications of CRISPR/Cas9 is to generate genetic knock-out mutants. Recently, several multiplex genome editing approaches utilizing CRISPR/Cas9 were developed and applied in various aspects of plant research. Here we summarize these approaches as they relate to plants, particularly with respect to understanding the biosynthesis and function of the plant cell wall. The plant cell wall is a polysaccharide-rich cell structure that is vital to plant cell formation, growth, and development. Humans are heavily dependent on the byproducts of the plant cell wall such as shelter, food, clothes, and fuel. Genes involved in the assembly of the plant cell wall are often highly redundant. To identify these redundant genes, higher-order knock-out mutants need to be generated, which is conventionally done by genetic crossing. Compared with genetic crossing, CRISPR/Cas9 multi-gene targeting can greatly shorten the process of higher-order mutant generation and screening, which is especially useful to characterize cell wall related genes in plant species that require longer growth time. Moreover, CRISPR/Cas9 makes it possible to knock out genes when null T-DNA mutants are not available or are genetically linked. Because of these advantages, CRISPR/Cas9 is becoming an ideal and indispensable tool to perform functional studies in plant cell wall research. In this review, we provide perspectives on how to design CRISPR/Cas9 to achieve efficient gene editing and multi-gene targeting in plants. We also discuss the recent development of the virus-based CRISPR/Cas9 system and the application of CRISPR/Cas9 to knock in genes. Lastly, we summarized current progress on using CRISPR/Cas9 for the characterization of plant cell wall-related genes.

A light and electron microscope investigation of the transfer cell region of maize caryopses

1990 ◽  
Vol 68 (3) ◽  
pp. 471-479 ◽  
Author(s):  
Ronald W. Davis ◽  
J. D. Smith ◽  
B. Greg Cobb
Keyword(s):  
Cell Wall ◽  
Cross Section ◽  
Close Association ◽  
Transfer Cells ◽  
Transfer Cell ◽  
Cell Region ◽  
Maternal Tissue ◽  
X Ray ◽  
Numerous Cell ◽  
Electron Microscopes

The transfer cell zones from 23-day postpollination corn caryopses were examined using light and electron microscopes and X-ray elemental analysis. The transfer cells were sectioned in cross and longitudinal planes and were characterized by having numerous cell-wall extensions in the form of anastomosing lamellae. The most basal transfer cells had more cell-wall extensions than those that were successively deeper in the endosperm. Cytoplasm, rich with mitochondria, filled the interstices of cell-wall extensions, and many vesiculate areas could be found along the plasma membrane. Some transfer cells contained crystals within plastids. The crystals were composed of magnesium, phosphorus, calcium, and zinc. Other cells had large aggregations of endoplasmic reticulum that were often in close association with mitochondria or unidentified, single membrane bounded organelles. When viewed in cross section, the cell-wall extensions of contiguous cells tended to originate from common loci. Plasmodesmata were absent in the bottom parts of the basal transfer cells where they contacted the maternal tissue but were abundant in the upper parts of these cells and in the transfer cells found deeper in the endosperm. The plasmodesmata were found in clusters and alternated with the wall extension areas.

Sign in / Sign up

Export Citation Format

Share Document