Transport Numbers for Hydrochloric Acid at Elevated Temperatures

1973 ◽  
Vol 51 (16) ◽  
pp. 2747-2749 ◽  
Author(s):  
DiGBY D. Macdonald ◽  
D. Owen
Keyword(s):  
Hydrochloric Acid ◽  
Temperature Dependence ◽  
Liquid Water ◽  
Infinite Dilution ◽  
Thermal Destruction ◽  
Elevated Temperatures ◽  
Transport Number ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Transport Numbers

Transport numbers for H+ and Cl− have been measured as a function of concentration and temperature to 200 °C using electrolyte concentratio cells. The infinite dilution transport number for H+ decreases with temperature while that for Cl− increases. This temperature dependence is discussed in terms of thermal destruction of the three dimensional structure of liquid water.

High Temperature Aqueous Electrolyte Concentration Cells and the Ionization of Liquid Water to 200 °C

1973 ◽  
Vol 51 (15) ◽  
pp. 2590-2595 ◽  
Author(s):  
Digby D. MacDonald ◽  
P. Butler ◽  
D. Owen
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Thermodynamic Parameters ◽  
Liquid Water ◽  
Infinite Dilution ◽  
Electrolyte Concentration ◽  
Aqueous Electrolyte ◽  
Ionization Constant ◽  
Liquid Junction ◽  
Concentration Cells

High temperature aqueous electrolyte concentration cells with and without liquid junction are described. These cells were used to measure the ionization constant of water in 0.1, 0.25,0.5, and]1.0 mol/kg KCl solutions at temperatures to 200 °C. Extrapolation to infinite dilution yielded the following functions for the temperature dependence of log Kw0 and the thermodynamic parameters for ionization: log Kw0 = −4046.16/T + 3.537 − 0.01323T; ΔG0 = 77458.0 − 67.71T + 0.253187T2 J/mol; ΔH0 = 77458.0 − 0.253187T2 J/mol; ΔS0 = 67.71 − 0.5063T J/K mol; ΔCp0 = −0.5063T J/K mol.

scholarly journals The role of lignin in wood working processes using elevated temperatures: an abbreviated literature survey

2020 ◽  
Author(s):  
Zoltán Börcsök ◽  
Zoltán Pásztory
Keyword(s):  
Cell Walls ◽  
Elevated Temperatures ◽  
Three Dimensional ◽  
Solid Wood ◽  
Literature Survey ◽  
Industrial Processes ◽  
Dimensional Structure ◽  
Advantages And Disadvantages ◽  
Surface Densification

AbstractThe lignin, cellulose and hemicelluloses in wood are polymers that behave similarly to the artificial polymers and are bonded together in wood. Lignin differs from the other two substances by its highly branched, amorphous, three-dimensional structure. Under appropriate conditions, the moist lignin incorporated in the wood softens at about 100 °C and allows the molecules of it to deform in the cell walls. There are many advantages and disadvantages to this phenomenon. If we know this process accurately and the industrial areas where it matters, we may be able to improve these industrial processes. This article provides a brief theoretical summary of lignin softening and the woodworking processes where it plays a role: wood welding, pellet manufacturing, manufacturing binderless boards, solid wood bending, veneer manufacturing, and solid wood surface densification.

scholarly journals Temperature Dependence of the Fracture Toughness JC of Random Fibrous Material

2020 ◽  
Vol 10 (3) ◽  
pp. 941
Author(s):  
Datao Li ◽  
Yan Li ◽  
Wenshan Yu
Keyword(s):  
Fracture Toughness ◽  
Temperature Dependence ◽  
Fracture Strength ◽  
Elevated Temperatures ◽  
Three Dimensional ◽  
Compact Tension ◽  
Fe Model ◽  
The Finite Element Method ◽  
Silica Fibers ◽  
Different Temperatures

The temperature dependence of the fracture toughness JC of a three-dimensional (3D) random fibrous (RF) material, with a porosity of 87% along the through-the-thickness (TTT) direction, was investigated using experiments and the finite element method (FEM) in this study. The temperature considered ranges from 299 to 1273 K. The experimental observations revealed the fracture toughness JC with crack length-to-width ratios of 0.4 and 0.5, which increased from 47.32 to 328.28 J/m2 and from 44.92 to 280.09 J/m2, respectively, as the temperature increased. Then, a 3D FE model, considering the meso-morphology characteristics of the 3D RF material, was developed to simulate a size-scaled compact tension (CT) specimen with a single edge crack. Using the elastic modulus and the fracture strength of the silica fibers at room temperature, we verified the effectiveness of the FE model, then predicted the fracture strength of the silica fibers and the bonding between the fibers at elevated temperatures. In addition, our developed FE model proved to successfully simulate the fracture toughness JC from 299 to 1273 K and reveal the deformation mechanism of the 3D RF material at different temperatures.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

Electron Microscopy of Cytoplasmic Contractile Proteins

1978 ◽  
Vol 36 (3) ◽  
pp. 606-614 ◽  
Author(s):  
T.D. Pollard ◽  
P. Maupin
Keyword(s):  
Electron Microscopy ◽  
Actin Filaments ◽  
Three Dimensional ◽  
Uranyl Acetate ◽  
Contractile Proteins ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
Cytoplasmic Matrix ◽  
Computer Image Processing ◽  
Nonmuscle Cells

In this paper we review some of the contributions that electron microscopy has made to the analysis of actin and myosin from nonmuscle cells. We place particular emphasis upon the limitations of the ultrastructural techniques used to study these cytoplasmic contractile proteins, because it is not widely recognized how difficult it is to preserve these elements of the cytoplasmic matrix for electron microscopy. The structure of actin filaments is well preserved for electron microscope observation by negative staining with uranyl acetate (Figure 1). In fact, to a resolution of about 3nm the three-dimensional structure of actin filaments determined by computer image processing of electron micrographs of negatively stained specimens (Moore et al., 1970) is indistinguishable from the structure revealed by X-ray diffraction of living muscle.

A New 1000kv Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 100-101
Author(s):  
J.L. Williams ◽  
K. Heathcote ◽  
E.J. Greer
Keyword(s):  
Electron Microscope ◽  
Direct Observation ◽  
High Voltage ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Specimen Thickness ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
Dynamic Experiments ◽  
Conventional Instrument

High Voltage Electron Microscope already offers exciting experimental possibilities to Biologists and Materials Scientists because the increased specimen thickness allows direct observation of three dimensional structure and dynamic experiments on effectively bulk specimens. This microscope is designed to give maximum accessibility and space in the specimen region for the special stages which are required. At the same time it provides an ease of operation similar to a conventional instrument.

High-voltage electron microscopy of maxillary gland of spirochete-infected brine shrimp: lesion of efferent tubule

1988 ◽  
Vol 46 ◽  
pp. 362-363
Author(s):  
G. E. Tyson ◽  
M. J. Song
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Brine Shrimp ◽  
Natural Populations ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Infected Adult

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.

Mitochondrial Reconstructions Based on Serial Thick Sections and HVEM

1975 ◽  
Vol 33 ◽  
pp. 286-287
Author(s):  
Jerome J. Paulin
Keyword(s):  
Imaging Techniques ◽  
Three Dimensional ◽  
Posterior Pole ◽  
Dimensional Structure ◽  
Stereo Imaging ◽  
Thin Sections ◽  
Anatomical Features ◽  
The Past ◽  
Cellular Components ◽  
Mitochondrial Reticulum

Within the past decade it has become apparent that HVEM offers the biologist a means to explore the three-dimensional structure of cells and/or organelles. Stereo-imaging of thick sections (e.g. 0.25-10 μm) not only reveals anatomical features of cellular components, but also reduces errors of interpretation associated with overlap of structures seen in thick sections. Concomitant with stereo-imaging techniques conventional serial Sectioning methods developed with thin sections have been adopted to serial thick sections (≥ 0.25 μm). Three-dimensional reconstructions of the chondriome of several species of trypanosomatid flagellates have been made from tracings of mitochondrial profiles on cellulose acetate sheets. The sheets are flooded with acetone, gluing them together, and the model sawed from the composite and redrawn.The extensive mitochondrial reticulum can be seen in consecutive thick sections of (0.25 μm thick) Crithidia fasciculata (Figs. 1-2). Profiles of the mitochondrion are distinguishable from the anterior apex of the cell (small arrow, Fig. 1) to the posterior pole (small arrow, Fig. 2).

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