scholarly journals Synthesis of Hierarchical Dorsal SpineAg2SStructures by a Solid-Vapor Reaction: The Effect of Reagent Gas Composition

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
J. A. Muñiz-Lerma ◽  
J. F. Hernández-Paz ◽  
J. R. Farias-Mancilla ◽  
P. E. García Casillas ◽  
C. A. Rodriguez González
Keyword(s):  
Carbon Monoxide ◽  
Plastic Deformation ◽  
Hierarchical Structures ◽  
Silver Sulfide ◽  
Dorsal Spine ◽  
Gas Composition ◽  
Spine Morphology ◽  
Sulfur Atmosphere ◽  
High Plastic

Silver sulfide hierarchical structures with unique dorsal spine morphology were successfully synthesized on mechanically deformed silver substrates by simple solid-vapor reactions. It has been found that it is possible to change the structures morphology by changing the reagent gas composition. The carbon monoxide (CO) presence in a reactive sulfur atmosphere was found to be the key for growing the dorsal spine structures. In all cases, theAg2Sstructures grew on the edge of the silver substrates where high plastic deformation occurred.

scholarly journals A comparative morphological study of the ligamentum lamina nuchae and ligamenta interspinalia reveals enthesis patterns at the sites of attachment from the second to seventh cervical vertebrae in four extant species of Equus

2020 ◽  
Vol 8 ◽  
Author(s):  
Sharon May-Davis ◽  
Robert Hunter ◽  
Wendy Brown
Keyword(s):  
Comparative Study ◽  
Morphological Variation ◽  
Morphological Study ◽  
Cervical Vertebrae ◽  
Environmental Influences ◽  
Dorsal Spine ◽  
Spine Morphology ◽  
Size And Shape ◽  
Attachment Sites ◽  
Extant Species

Morphological variation in the attachment sites of the ligamentum lamina nuchae and ligamentainterspinalia to the 2nd to 7th cervical vertebrae is described in four species of Equus, and enthesis patterns inrelation to these attachment sites are explored. This comparative study provides new insights with respect tothis variation in the zebrine and asinine clades within Equus. In zebrines (Equus caballus, E. quagga boehmiand E. przewalskii), the ligamentum lamina nuchae attaches to the eminence of the cervical dorsal spinesfrom either the 2nd to 5th, and or 2nd to 7th. These attachments resemble digits and between each digit anaperture is apparent. The ligamenta interspinalia attach to the base of each cervical dorsal spine from the 2ndto 7th before progressing caudally onto the thoracic dorsal spines. Three enthesis patterns per cervical dorsalspine correspond to the size and shape of these ligaments. In contrast, in asinines (as represented by Equusasinus), the ligamentum lamina nuchae attaches without digitation to the complete sagittal ridge of the cervicalvertebra including the dorsal spine and exhibits no ligamenta interspinalia. Consequently, the enthesispattern is represented by a raised sagittal ridge only, excluding the 7th cervical dorsal spine. These differencesbetween the ligamentum lamina nuchae and ligamenta interspinalia attachment sites create distinct enthesispatterns that differentiate zebrines from asinines. Findings include: differing ligamentous morphology; associatedenthesis patterns corresponding to attachment sites of the ligaments to the cervical vertebrae; influencesin dorsal spine morphology subject to the presence or absence of the ligaments; and the postulation ofevolutionary functional adaptions in response to environmental influences between the two Equus clades.These results may be useful for palaeontologists in the identification of isolated cervical vertebrae.

Obtaining of Coatings from Ni-Al by Electro Spark Deposition and Surface Smoothing by Ultrasonic Plastic Deformation

2021 ◽  
Vol 1037 ◽  
pp. 473-478
Author(s):  
Sergey N. Khimukhin ◽  
Kseniia P. Eremina ◽  
Sergey V. Nikolenko
Keyword(s):  
Plastic Deformation ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Intermetallic Alloys ◽  
Surface Smoothing ◽  
Complex Composition ◽  
Electrospark Deposition ◽  
Plastic Properties ◽  
High Plastic ◽  
Ultrasonic Surface Treatment

The article presents the research results on obtaining coatings on steels 1030 and AISI 420 by the method of electrospark deposition and subsequent smoothing by means of ultrasonic surface plastic deformation (USPD). Intermetallic alloys consisting mainly of NiAl and Ni3Al phases were used as materials for obtaining coatings. It was found that the coatings consist of columnar crystallites of complex composition and have high plastic properties. To ensure the minimum parameters of the surface roughness of the obtained coatings, it is necessary to carry out 3-6 times of ultrasonic surface treatment.

Development and Commercialization of Large Stationary Engines Utilizing Low BTU Fuel Containing H2/CO

2003 ◽  
Author(s):  
E. Toombs ◽  
T. Stowell ◽  
N. Austin ◽  
P. Danyluk
Keyword(s):  
Carbon Monoxide ◽  
Atmospheric Pressure ◽  
Early Experience ◽  
Low Energy ◽  
Gas Composition ◽  
Pyrolysis Process ◽  
Fuel Gas ◽  
Heating Value ◽  
Cabot Corporation ◽  
Development Cycle

In 1996 Cabot Corporation begun development of engines capable of burning the off-gas from a pyrolysis process used to make carbon black. The fuel gas comes off the process at near atmospheric pressure, high temperature, and saturated with water. After de-watering the gas composition was approximately 16–20% Hydrogen, 16–20% Carbon Monoxide, 1–3% Sulfur compounds and the rest Nitrogen and water. Dewatered heating value of the fuel was around 3350–3720 kJ/nm3. Many engine configurations including both spark and oil ignited were evaluated to utilize this low energy fuel. The paper describes the development cycle and the early experience at commercialization at three sites.

Enhanced Plastic Deformation of Magnesium Alloy Produced through Accumulative Diffusion Bonding

2012 ◽  
Vol 735 ◽  
pp. 87-92 ◽  
Author(s):  
Koichi Kitazono ◽  
Yutaro Shimoda ◽  
Shigeki Kato
Keyword(s):  
Plastic Deformation ◽  
Magnesium Alloy ◽  
Diffusion Bonding ◽  
Alloy Sheet ◽  
Az91 Magnesium Alloy ◽  
Bending Tests ◽  
Random Texture ◽  
Az91 Magnesium ◽  
Hcp Structure ◽  
High Plastic

Plastic deformation of magnesium alloy is limited because of its HCP structure. Though the grain refined magnesium alloy exhibits superplastic deformation at elevated temperature, the strength decreases due to induced cavitation. This study focusses on developing the random texture of magnesium alloy and causes relatively high plastic deformation even at room temperature. Random texture is produced through newly proposed accumulative diffusion bonding process using commercial AZ91 magnesium alloy sheets. Tensile and V-bending tests reveal that the enhanced ductility of the produced magnesium alloy sheet.

Do Load Peaks Cause Breakage, Plastic Deformation or Cracks in Case-Hardened Gears?

2003 ◽  
Author(s):  
R. Kage ◽  
H. Linke ◽  
B. Schlecht
Keyword(s):  
Plastic Deformation ◽  
Crack Initiation ◽  
Load Capacity ◽  
Research Association ◽  
Deformation Limit ◽  
Low Load ◽  
Core Hardness ◽  
Universal Relationship ◽  
High Plastic ◽  
Current Guidelines

Apart from the continuous load over the lifetime, load peaks are critical for the capacity of a gearing. This article focuses on the maximally bearable load peaks in case-hardened gears. The ISO 6336 calculation guideline assesses the load capacity at a low number of load alternations (N less than 100 to 1000). The criterion is crack initiation. However, industrial experience shows that unallowably high plastic deformation can occur even in case-hardened gears. In some cases the allowable deformation is reached at such low load levels that cracks do not yet occur. In order to investigate these problems and improve the calculation method, the institute of the authors carried out a research project in cooperation with the industrial research association “Forschungsvereinigung Antriebstechnik” (FVA; Frankfurt/Main, Germany). This article sums up the theoretical and practical work and a calculation procedure derived from the results. During the project it became evident that the current guidelines need to be amended. For the experimental analyses materials of varying core hardness were used. In addition, the load capacity was tested for a variety of addendum modifications and tooth root fillet radii. Analysis criteria were: breakage, cracking, and plastic deformation. A universal relationship between deformation limit and crack initiation was found.

EFFECTS OF CELL ANATOMY ON THE PLASTIC AND ELASTIC BEHAVIOUR OF DIFFERENT WOOD SPECIES LOADED PERPENDICULAR TO GRAIN

IAWA Journal ◽  
2003 ◽  
Vol 24 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Ulrich Müller ◽  
Wolfgang Gindl ◽  
Alfred Teischinger
Keyword(s):  
Plastic Deformation ◽  
Wood Species ◽  
Small Samples ◽  
Elastic Behaviour ◽  
Radial Compression ◽  
Stress Plateau ◽  
Plastic Deformations ◽  
Euler Buckling ◽  
Compression Behaviour ◽  
High Plastic

In radial compression, the shape of the stress-deformation curve varies for different wood species, particularly at the transition from elastic to plastic deformation and along the stress plateau. Due to differences in anatomy and cell wall microstructure, different responses to perpendicular loads were observed in spruce (ductile plastic deformation), oak (brittle failure), and beech (elastomeric yielding). Beginning plastic deformation was examined by SEM after the application of different compression levels and by dynamic observations during the loading process of small samples under a light microscope. It was demonstrated that radial compression of spruce is limited by the critical Euler buckling load of only a few cells closely behind the ring border. The compression behaviour of oak is determined by the buckling of the earlywood vessels and vasicentric tissue, whereas beech is characterised by the densification of the vessels at high plastic deformations.

scholarly journals Classification of pressure welding methods depending on thermal deformation conditions

2020 ◽  
Vol 329 ◽  
pp. 03014
Author(s):  
Vsevolod Bulychev ◽  
Rashit Latypov ◽  
Svetlana Golubina ◽  
Gyulnara Latypova ◽  
Artem Rodin
Keyword(s):  
Plastic Deformation ◽  
Deformation Rate ◽  
Active Centers ◽  
Pressure Welding ◽  
Mechanical Methods ◽  
Plastic Deformation Rate ◽  
Welding Processes ◽  
High Plastic ◽  
Heat Deformation

In this study, a classification of welding methods is proposed, based on the peculiarities of metal gripping under various heat-deformation conditions for the implementation of welding processes. The theoretical basis of the developed classification is the hypothesis of the critical sizes of active centers. The main approaches to the classification of welding methods are considered, and four groups of pressure welding methods are proposed, depending on the mechanism of formation of stable centres of gripping: mechanical welding methods with low plastic deformation rate; mechanical methods of welding with a high plastic deformation rate; thermo-mechanical welding methods, in which, in addition to heating by deformation, additional sources of thermal energy are used to increase the temperature in the zone of joint formation; thermal pressure welding methods that envisage only a thermal activation channel.

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