scholarly journals II.—The microscopical features of mechanical strains in timber and the bearing of these on the structure of the cell-wall in plants

1921 ◽  
Vol 210 (372-381) ◽  
pp. 49-82 ◽  
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Cell Walls ◽  
Research Laboratory ◽  
Permanent Deformation ◽  
Structure And Properties ◽  
Mode Of Failure ◽  
The University ◽  
University Of Manchester ◽  
The Relationship

When wood is subjected to increasing mechanical stress its component parts ultimately undergo changes resulting in permanent deformation or failure. This paper deals with the minute microscopic changes upon which the permanent deformation of wood depends, and with the relationship between the microscopic structure of wood and some of its more important mechanical properties. The work has provided abundant material for a study of the structure of the walls of the cells of which wood is composed. Considerable light has been thrown on the structure and properties of the vegetable cell-wall in general, and it has been possible, from the facts for wood, to frame a hypothesis which seems to explain satisfactorily most of the properties of cell-walls. The examination of the mode of failure in timber, which has led to the work described in this paper, was begun at the request of Lt.-Col. Jenkin, R. A. F. I am deeply indebted to him for the original suggestion of this line of work and for his continued interest during its course. I have derived great advantage throughout the work by discussing various engineering questions, as they have arisen, with Major Robertson, R. A. F., and I desire to thank him for many helpful suggestions. I am further indebted to him for the supply of many fractured specimens of wood. The research has been carried out, in the course of more definitely applied work for the Air Ministry, in the Barker Cryptogamic Research Laboratory of the University of Manchester. I have to thank Prof. W. H. Lang, F. R. S., for encouraging me to attempt to relate the facts of the mechanical properties of wood to fundamental botanical questions bearing on the structure of cell-walls in plants.

scholarly journals Investigation of the Mechanical Properties of Flax Cell Walls during Plant Development: The Relation between Performance and Cell Wall Structure

Fibers ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 6 ◽  
Author(s):  
Camille Goudenhooft ◽  
David Siniscalco ◽  
Olivier Arnould ◽  
Alain Bourmaud ◽  
Olivier Sire ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Plant Development ◽  
Cell Walls ◽  
Cell Wall Structure ◽  
Wall Structure

Relationship of wood cell wall ultrastructure to bacterial degradation of wood

IAWA Journal ◽  
2019 ◽  
Vol 40 (4) ◽  
pp. 845-870 ◽  
Author(s):  
Adya P. Singh ◽  
Yoon Soo Kim ◽  
Ramesh R. Chavan
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Wood Cell Wall ◽  
Bacterial Degradation ◽  
Cell Wall Components ◽  
Degrading Bacteria ◽  
Wall Ultrastructure ◽  
Relationship Of ◽  
The Relationship ◽  
Wall Components

ABSTRACT This review presents information on the relationship of ultrastructure and composition of wood cell walls, in order to understand how wood degrading bacteria utilise cell wall components for their nutrition. A brief outline of the structure and composition of plant cell walls and the degradation patterns associated with bacterial degradation of wood cell walls precedes the description of the relationship of cell wall micro- and ultrastructure to bacterial degradation of the cell wall. The main topics covered are cell wall structure and composition, patterns of cell wall degradation by erosion and tunnelling bacteria, and the relationship of cell wall ultrastructure and composition to wood degradation by erosion and tunnelling bacteria. Finally, pertinent information from select recent studies employing molecular approaches to identify bacteria which can degrade lignin and other wood cell wall components is presented, and prospects for future investigations on wood degrading bacteria are explored.

Eniac in Action

2016 ◽  
Author(s):  
Thomas Haigh ◽  
Mark Priestley ◽  
Crispin Rope
Keyword(s):  
Research Laboratory ◽  
Electronic Computer ◽  
Historical Memory ◽  
General Purpose ◽  
University Of Pennsylvania ◽  
Patent Rights ◽  
The University ◽  
Relationship Of ◽  
The Relationship ◽  
Design Construction

This book explores the conception, design, construction, use, and afterlife of ENIAC, the first general purpose digital electronic computer. ENIAC was created and tested at the University of Pennsylvania from 1943 to 1946, then used at the Ballistic Research Laboratory in Aberdeen, Maryland until 1955. Unlike most discussion of early computers, this book focuses on ways in which ENIAC was used, and the relationship of its design to computational practice, particularly its use between 1948 and 1950 to conduct the first computerized Monte Caro simulations for Los Alamos. ENIAC’s first team of operators were all women, and the book probes their contribution to the machine’s achievements and the development of computer programming practice. ENIAC’s users changed its hardware and transformed its configuration over time, so that it eventually became the first computer to execute a modern program, defined by the authors as one following the “modern code paradigm” introduced in John von Neumann’s seminal 1945 “First Draft of a Report on the EDVAC.” They draw on new archival evidence to document the development of this idea and its relationship to work on ENIAC. They also use ENIAC to probe the construction of historical memory, looking at ways in which a bitter succession of legal battles around patent rights shaped later perceptions.

Microdistribution of copper in copper-ethanolamine (Cu-EA) treated southern yellow pine (Pinus spp.) related to density distribution

Holzforschung ◽  
2005 ◽  
Vol 59 (1) ◽  
pp. 82-89 ◽  
Author(s):  
Jinzhen Cao ◽  
D. Pascal Kamdem
Keyword(s):  
Cell Wall ◽  
Density Distribution ◽  
Cell Walls ◽  
Middle Lamella ◽  
Treated Wood ◽  
Yellow Pine ◽  
Using Data ◽  
Pinus Spp ◽  
Southern Yellow Pine ◽  
The Relationship

Abstract The relationship between copper absorption and density distribution in wood cell walls was investigated in this study. The density distribution on layer level was obtained from two approaches: (1) calculation by using data obtained from literature; (2) microdistribution of carbon and oxygen atoms in the wood cell. The microdistribution of carbon and oxygen in untreated southern yellow pine (Pinus spp.) sapwood, as well as copper in cell walls of copper-ethanolamine (Cu-EA) treated wood was determined by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDXA). Both approaches for density distribution led to the same result: the density was higher in the compound middle lamella and cell corners than in the secondary wall. The concentration/intensity of Cu, C and O in the cell wall follow the same trend as the density distribution; suggesting that density may play a major role in SEM-EDXA study of the distribution of metal-containing wood preservatives within the wood cell wall.

The fate of acetyl groups and sugar components during the digestion of grass cell walls in sheep

1977 ◽  
Vol 89 (2) ◽  
pp. 327-340 ◽  
Author(s):  
E. Jane Morris ◽  
J. S. D. Bacon
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Sodium Ethoxide ◽  
Mesophyll Cell ◽  
Cell Types ◽  
Gas Liquid Chromatography ◽  
Cell Wall Preparation ◽  
The Relationship ◽  
Isolated Cell

SummaryThe digestibilities of grass cell wall constituents determined in a digestion trial were compared with those obtained by suspending various isolated cell wall preparations in nylon bags in the rumen of a sheep. Particular attention was paid to acetyl groups and to individual sugars, which were determined in both cases by gas liquid chromatography.For dried grass and hay in the digestion trial the cell wall constituents showed digestibilities decreasing in the following order: arabinose, galactose, glucose, xylose, acetyl, lignin.For a leaf cell wall preparation derived from all cell types except mesophyll, the nylon bag technique allowed the same order of digestibilities; rhamnose and uronic acids were also measured and found to be rapidly digested. Mesophyll cell walls placed in nylon bags were more readily digested than non-mesophyll. All the sugars, and also acetyl groups, were digested to the same extent.In a grass cell wall preparation isolated from sheep faeces, tested similarly, xylose and glucose were digested to the same extent, but acetyl groups were less digested.Removal of acetyl groups, using sodium ethoxide, which left the sugar composition and lignin content unchanged, increased the digestibility particularly of the cell walls from faeces.The results are discussed with reference to the relationship between cell wall composition and digestibility.

Fabrication of Porous Polyethylene by Two-Stepped Heat Treatment and Powder Printing Technique

2010 ◽  
Vol 93-94 ◽  
pp. 165-168 ◽  
Author(s):  
Jintamai Suwanprateeb ◽  
Kitiya Wasoontararat ◽  
Waraporn Suvannapruk
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Density Polyethylene ◽  
Physical And Mechanical Properties ◽  
High Density ◽  
Processing Conditions ◽  
Structure And Properties ◽  
Porous Polyethylene ◽  
Printing Technique ◽  
The Relationship

In this study, a combination of powder printing technique and two-stepped heat treatment was utilized as a mean to prepare porous high density polyethylene structure. Physical and mechanical properties of the resulting structure were then characterized by porosity measurement and monotonic tensile test. It was found that the relationship between structure and properties was strongly influenced by processing conditions including compositions, treatment times and treatment temperatures. This process could increase the properties of porous high density polyethylene significantly over the single-stepped heat treatment without destroying porous structure. Porous high density polyethylene bodies having a porosity ranging from 46-58 percents with tensile strength up to approximately 4 MPa could be successfully prepared in this study.

A SEROLOGICAL STUDY OF CELL WALLS OF CERTAIN LACTIC ACID BACTERIA

1962 ◽  
Vol 8 (5) ◽  
pp. 629-637
Author(s):  
K. L. Chung ◽  
Roma Z. Hawirko
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Intact Cell ◽  
Synthetic Medium ◽  
Specific Cell ◽  
Intact Cells ◽  
Common Antigens ◽  
Species Specific ◽  
Relationship Of ◽  
The Relationship

From three species of Lactobacillus and three species of Streptococcus, cultured in a synthetic medium, cell walls were isolated following sonic disintegration and purified by washing. Sera against each species were prepared by injecting three rabbits with cell walls, and three with intact cells. Reciprocal agglutination tests were carried out with unabsorbed and absorbed antisera. More kinds of antibodies were detected with cell-wall antisera than with intact-cell antisera. Many species in the two genera shared common antigens. S. faecalis was the exception. Certain antigens believed to be complex haptens in nature reacted with heterologous antisera. Haemagglutination of tanned erythrocytes sensitized with a particulate cell-wall suspension showed fewer cross reactions than agglutination of intact-cell suspensions.The evidence presented shows the possibility of using antisera against species-specific cell-wall antigens for the identification of these species. The relationship of these species is discussed.

scholarly journals Multi-Scale Evaluation of the Effect of Phenol Formaldehyde Resin Impregnation on the Dimensional Stability and Mechanical Properties of Pinus Massoniana Lamb.

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 646 ◽  
Author(s):  
Wang ◽  
Chen ◽  
Xie ◽  
Cai ◽  
Yuan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Dimensional Stability ◽  
Cell Walls ◽  
Phenol Formaldehyde ◽  
Pinus Massoniana ◽  
Swelling Properties ◽  
Masson Pine ◽  
Pine Wood ◽  
Pinus Massoniana Lamb

The local chemistry and mechanics of the control and phenol formaldehyde (PF) resin modified wood cell walls were analyzed to illustrate the modification mechanism of wood. Masson pine (Pinus massoniana Lamb.) is most widely distributed in the subtropical regions of China. However, the dimensional instability and low strength of the wood limits its use. Thus, the wood was modified by PF resin at concentrations of 15%, 20%, 25%, and 30%, respectively. The density, surface morphology, chemical structure, cell wall mechanics, shrinking and swelling properties, and macro-mechanical properties of Masson pine wood were analyzed to evaluate the modification effectiveness. The morphology and Raman spectra changes indicated that PF resin not only filled in the cell lumens, but also penetrated into cell walls and interacted with cell wall polymers. The filling and diffusing of resin in wood resulted in improved dimensional stability, such as lower swelling and shrinking coefficients, an increase in the elastic modulus (Er) and hardness (H) of wood cell walls, the hardness of the transverse section and compressive strength of the wood. Both the dimensional stability and mechanical properties improved as the PF concentration increased to 20%; that is, a PF concentration of 20% may be preferred to modify Masson pine wood.

scholarly journals The Implication of Benzene–Ethanol Extractive on Mechanical Properties of Waterborne Coating and Wood Cell Wall by Nanoindentation

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 449 ◽  
Author(s):  
Yan Wu ◽  
Yingchun Sun ◽  
Feng Yang ◽  
Haiqiao Zhang ◽  
Yajing Wang
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Wood Surface ◽  
Cell Walls ◽  
Wood Cell Wall ◽  
Coating Layer ◽  
Waterborne Coating ◽  
Average Value ◽  
Wood Surfaces ◽  
Extraction Treatment

The waterborne coating uses water as its solvent, which will partially dissolve wood extractives when it is applied to wood surfaces. This influences both the coating curing process and the mechanical properties of the cured coating. To investigate these influences, the mechanical properties of waterborne polyacrylic coating on control and extractive-free wood surfaces were investigated by nanoindentation. Reductions to elastic modulus (Er) and hardness (H) of the coating layer was observed in the wood cell walls adjacent to or away from coating layers. Extraction treatment resulted in significant decrease of the Er and H of the coating layer on extractive-free wood surface comparing with control wood, but the values slightly increased for extractive-free wood cell walls compared to a control. Er and H of coating in wood cell lumen were higher than the average value of coating layer on wood surface in both the control and extractive-free wood. The Er of wood cell wall without coating filled in lumen was significantly higher than those of filling with coating. However, there was no distinct difference of H. The Er and H of CCML in extractive-free wood were 15% and 6% lower than those in control ones, respectively.

The estimation of the metabolizable energy of forage from its cell-wall content and digestible cell wall

1974 ◽  
Vol 82 (3) ◽  
pp. 423-426 ◽  
Author(s):  
K. W. Moir
Keyword(s):  
Cell Wall ◽  
Organic Matter ◽  
Cell Walls ◽  
Metabolizable Energy ◽  
Published Data ◽  
Energy Value ◽  
Image Position ◽  
The Relationship

SUMMARYPublished data are used in support of a hypothesis that equal amounts of digestible cell walls and digestible non-cell walls do not contribute equally to the energy value of forages. The relationship between the concentration in the organic matter of metabolizable energy (kcal/g organic matter) determined at the maintenance level of feeding, and the percentages of cell wall and digestible cell wall in the forage organic matter is defined by:This equation derived from published data on 12 grasses appears to be applicable to both grasses and legumes.

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