Rheology of hydrocarbon gels

1950 ◽  
Vol 200 (1061) ◽  
pp. 183-188 ◽  
Keyword(s):  
Mechanical Properties ◽  
Experimental Measurement ◽  
Theoretical Basis ◽  
Continuous Media ◽  
Point Of View ◽  
Coarse Grained ◽  
Testing Instrument ◽  
Fine Grained ◽  
Mineral Oils ◽  
Space And Time

Hydrocarbon gels contain a number of materials, such as rubber, greases, saponified mineral oils, etc., of great interest for various engineering purposes. Specific requirements in mechanical properties have been met by producing gels in appropriately chosen patterns of constituent components of visible, colloidal, molecular and atomic sizes, ranging from coarse-grained aggregates, represented by sponges, foams, emulsions, etc.; to fine-grained and apparently homogeneous ones, represented by optically clear compounds. The engineer who has to deal with the whole range of such materials will adopt a macroscopic point of view, based on an apparent continuity of all the material structures and of the distributions in space and time of the displacements and forces occurring under mechanical actions. It has been possible to determine these distributions in the framework of a comprehensive scheme in which the fundamental principles of the mechanics of continuous media provide the theoretical basis, and a testing instrument of new design, termed Rheogoniometer, the means of experimental measurement (Weissenberg 1931, 1934, 1946, 1947, 1948).

High Performance Fine Grained Concrete with Content of Pumice

2020 ◽  
Vol 309 ◽  
pp. 21-25
Author(s):  
Vlastimil Bilek ◽  
Michal Pešata ◽  
Lukáš Procházka
Keyword(s):  
Mechanical Properties ◽  
Volcanic Rock ◽  
High Performance ◽  
Volcanic Glass ◽  
Volume Density ◽  
Point Of View ◽  
Fine Grained ◽  
Low Volume ◽  
Small Elements ◽  
High Absorption

Pumice is a volcanic rock that consists of a highly vesicular rough textured volcanic glass. It is very porous and shows a high absorption - it can contain a lot of water. Thanks to its low volume density, it is sometimes used as a light natural aggregate, especially for some small elements such as chimney blocks. The paper is focused on the development of concretes and mortars for these purposes. The optimum content of pumice was specified from the point of view of mechanical properties. Special attention was paid to absorbed water - it can be a source of self-curing of concrete.

scholarly journals Microstructural and Mechanical Characterization of Multilayered Iron Electrodeposits

2011 ◽  
Vol 409 ◽  
pp. 474-479 ◽  
Author(s):  
C. Chan ◽  
J.L. McCrea ◽  
G. Palumbo ◽  
Uwe Erb
Keyword(s):  
Mechanical Properties ◽  
Columnar Structure ◽  
Multilayered Structure ◽  
Structure Design ◽  
Coarse Grained ◽  
Fine Grained ◽  
Microstructure And Mechanical Properties ◽  
Fine Grained Structure ◽  
Iron Coatings

Monolithic and multilayered iron electrodeposits were successfully synthesized by the pulse plating electrodeposition method. Electron microscopy and Vickers microhardness measurements were used to investigate the microstructure and mechanical properties of the iron electrodeposits produced. Two types of monolithic iron coatings were produced, one with a coarse grained, columnar structure and the other with an ultra-fine grained structure. Hall-Petch type grain size strengthening was observed in these monolithic coatings. Multilayered iron coatings composed of alternating layers of coarse grained and fine grained structures were also produced. The hardness value of the multilayered coatings falls between the hardness values for the two types of monolithic coatings produced. This study has demonstrated the possibility of applying a multilayered structure design to tailor the microstructure and mechanical properties of electrodeposited iron coatings.

Effect of alloy grain size on oxidation resistance of silica-coated stainless steel

1994 ◽  
Vol 52 ◽  
pp. 676-677
Author(s):  
C. S. McDowell ◽  
S. N. Basu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Stainless Steel ◽  
Oxidation Resistance ◽  
Powder Processing ◽  
Hot Isostatic Pressing ◽  
Silica Coating ◽  
Austenitic Steels ◽  
Coarse Grained ◽  
Fine Grained

Oxidation resistance of stainless steels, which rely on the formation of a Cr2O3 (chromia) scale, can be further improved through minor alloying additions such as Al or Si, or by application of coatings to the exposed surfaces. Although, additions of Si to austenitic steels have demonstrated an improvement in oxidation resistance, high Si contents can be detrimental to the mechanical properties of these alloys. The application of a silica coating on the surface of the stainless steel provides improved oxidation resistance without detrimental effects on the mechanical properties. This study examines the effect of the grain size of the stainless steel on the effectiveness of a silica coating as an oxidation barrier.Fully austenitic stainless steel of composition Fe-18(wt%)Cr-20Ni-1.5Mn was produced in both coarsegrained and fine-grained form. The coarse-grained alloy, with a grain size of approximately 100 μm, was produced by casting and hot rolling. The fine-grained alloy, with a grain size of approximately 5 μm, was produced by rapid solidification powder processing, followed by consolidated by hot isostatic pressing and swaging.

FABRICATION AND TRIBOLOGICAL PROPERTIES OF GRADIENT FINE-GRAINED OXYGEN-BOOSTING LAYER ON ECAP-TREATED PURE TITANIUM SURFACE

2019 ◽  
Vol 26 (06) ◽  
pp. 1850199
Author(s):  
BAOSEN ZHANG ◽  
JIYING WANG ◽  
SHUAISHUAI ZHU ◽  
QIANGSHENG DONG ◽  
ZHANGZHONG WANG
Keyword(s):  
Mechanical Properties ◽  
Diffusion Process ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Titanium Surface ◽  
Pure Titanium ◽  
Coarse Grained ◽  
Wear Properties ◽  
Fine Grained ◽  
Equal Channel Angular Processing

The gradient fine-grained oxygen-boosting layer was prepared on equal channel angular processing (ECAP)-treated titanium with thermal oxidation and oxygen boost diffusion process, and tribological properties were systematically characterized. Results show that the as-prepared boosting layer consists of surface coarse-grained region, and inner fine-grained region. The corresponding thickness and mechanical properties further increase compared to those of virgin titanium. The oxygen-boosting layer reveals excellent anti-wear properties, the dominant wear mechanism of which is abrasive.

Effect of Grain Size on Mechanical Properties of Dual Phase Steels Composed of Ferrite and Martensite

MRS Advances ◽  
2016 ◽  
Vol 1 (12) ◽  
pp. 811-816 ◽  
Author(s):  
Myeong-heom Park ◽  
Akinobu Shibata ◽  
Nobuhiro Tsuji
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Tensile Test ◽  
Coarse Grained ◽  
Dual Phase ◽  
Fine Grained ◽  
Grain Sizes ◽  
Dp Structure ◽  
Dp Steels

ABSTRACTIt is well-known that dual phase (DP) steels composed of ferrite and martensite have good ductility and plasticity as well as high strength. Due to their excellent mechanical properties, DP steels are widely used in the industrial field. The mechanical properties of DP steels strongly depend on several factors such as fraction, distribution and grain size of each phase. In this study, the grain size effect on mechanical properties of DP steels was investigated. In order to obtain DP structures with different grain sizes, intercritical heat treatment in ferrite + austenite two-phase region was carried out for ferrite-pearlite structures having coarse and fine ferrite grain sizes. These ferrite-pearlite structures with coarse and fine grains were fabricated by two types of heat treatments; austenitizing heat treatment and repetitive heat treatment. Ferrite grain sizes of the specimens heat-treated by austenitizing and repetitive heat treatment were 47.5 µm (coarse grain) and 4.5 µm (fine grain), respectively. The ferrite grain sizes in the final DP structures fabricated from the coarse-grained and fine-grained ferrite-pearlite structures were 58.3 µm and 4.1µm, respectively. The mechanical behavior of the DP structures with different grain sizes was evaluated by an uniaxial tensile test at room temperature. The local strain distribution in the specimens during tensile test was obtained by a digital image correlation (DIC) technique. Results of the tensile test showed that the fine-grained DP structure had higher strength and larger elongation than the coarse-grained DP structure. It was found by the DIC analysis that the fine-grained DP structure showed homogeneous deformation compared with the coarse-grained DP structure.

Harmonic Structure Design of Co-Cr-Mo Alloy with Outstanding Mechanical Properties

2014 ◽  
Vol 939 ◽  
pp. 60-67 ◽  
Author(s):  
Choncharoen Sawangrat ◽  
Osamu Yamaguchi ◽  
Sanjay Kumar Vajpai ◽  
Kei Ameyama
Keyword(s):  
Mechanical Properties ◽  
Mechanical Milling ◽  
Three Dimensional ◽  
High Strength ◽  
Surface Region ◽  
Structure Design ◽  
Coarse Grained ◽  
Harmonic Structure ◽  
Fine Grained ◽  
Plasma Sintering

Co-Cr-Mo alloy powders were subjected to controlled mechanical milling at room temperature under Ar atmosphere to fabricate bimodal microstructure in the MM powders, having nanosized grains in the surface region and micron-sized coarse grains in the center of the milled powders. Subsequently, the MM powder was compacted by spark-plasma sintering (SPS) process. The sintered compacts indicated two structure areas: (i) ultra-fine grained (UFG) regions, called shell, and (ii) the coarse grained regions called core. The shell and the core correspond to the surface and center of the MM powders, respectively. The shell regions established a continuous three dimensional network of high strength ultra-fine grained regions, which surrounded the discrete coarse grained ductile regions. Such a microstructure is referred as Harmonic Structure. The sintered Co-Cr-Mo alloy compacts exhibited outstanding mechanical properties. The yield strength increased from 605 to 635 MPa, and ultimate tensile strength increased from 1201 to 1283 MPa. Moreover, the elongation was maintained more or less same as that of coarse grained compacts. Therefore, the harmonic structure design leads to the new generation microstructure of Co-Cr-Mo alloy, which demonstrates outstanding mechanical properties, i.e. superior strength and excellent ductility as compared to conventional materials. Keywords: mechanical milling, Co-Cr-Mo alloys, mechanical properties, harmonic structure.

scholarly journals Effect of ion nitriding by glow discharge on the physical and mechanical properties of the plastically deformed tool steel R6M5

2021 ◽  
Vol 2064 (1) ◽  
pp. 012052
Author(s):  
R K Vafin ◽  
A V Asylbaev ◽  
D V Mamontov ◽  
I D Sklizkov ◽  
G I Raab ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Glow Discharge ◽  
Tool Steel ◽  
Physical And Mechanical Properties ◽  
Coarse Grained ◽  
Steel R6m5 ◽  
Ion Nitriding ◽  
Fine Grained ◽  
Fine Grained Structure

Abstract This work is devoted to the study of the effect of the duration of ion nitriding by glow discharge on the physical and mechanical properties of tool steel with different initial structure. We used specimens of R6M5 tool steel with a coarse-grained structure obtained after annealing at a temperature of 850°C and with a fine-grained structure obtained after severe plastic deformation by torsion discharge. With an increase in the duration of ion nitriding, the thickness of the hardened layer and wear resistance increase. The combination of plastic deformation with ion nitriding by glow discharge increases the adsorption and diffusion rate of the saturating element due to the creation of a highly fragmented and disoriented fine-grained structure and contributed to reduction in processing time.

scholarly journals BIOSTRATIGRAPHIC CHARACTERIZATION OF THE CRETACEOUS DEPOSITS OF THE SAN-PEDRO MARGIN OF DRILL HOLES K1 AND K2 OF BLOCK KL: PALEOENVIRONMENT IMPLICATION

2021 ◽  
Vol 9 (11) ◽  
pp. 289-301
Author(s):  
Koffi Chiaye Larissa ◽  
◽  
Djeya Kouame Leger ◽  
Douzo Jolie Wanesse Danielle ◽  
Monde Sylvain ◽  
...  
Keyword(s):  
Water Depth ◽  
Depositional Environment ◽  
Point Of View ◽  
Coarse Grained ◽  
Fine Grained ◽  
San Pedro ◽  
Drill Holes ◽  
Coarse Grained Sand ◽  
Cretaceous Deposits

The KL block studies was carried out the eastern part of the San Pedro margin, it has an area of 2034 km2 with a water depth varying from 500 to 2750 m with two probings (K1 and K2).The objective of this work is to carry out a biostratigraphic and paleoenvironmental study based on the associations of planktonic and palynomorphicmicrofauna in the formations of the KL block boreholes. From a lithological point of view, the base of the boreholes generally comprises alternating limestone and argillite, very fine to fine grained quartz sandstone. Its upper part is overlain by claystoneinterbedded with limestone, silstone and siliceous cemented sandstone and alternating claystone, medium to coarse grained sand and siliceous cemented quartz sandstone. The Albian is determined by the presence of the species Ticinellamadecassiana. The Cenomanian is identified by the micropalaeontological assemblages composed of Globigerinelloides spp., Guembelitria spp., Hedbergella spp., Hedbergelladelrioensis, Globigerinelloides bentonensisandLoeblichella cf. hessi. The Turonian is based mainly on the species Hedbergellaplanispira, Heterohelixmoremani and Whiteinella archaeocretacea. The Early Senonian is characterized by associations of species (Hedbergellasp, Hedbergella cf. delrioensis, Buliminacrassa and Whiteinella baltica) and palynomorphs (Proteaciditestienabaensis, Odontochitinacostata, Odontochitinaporiferaand Tricolpites sp). The roof of the Campanian is known by the association of the palynomorph (Trichodinium castanae) and the microfossil (Gaudryina cretacea) The Maastrichtian is highlighted by the associations composed of species Rzehakina epigona fissistomata, Rzehakina minima, Plectina lenis, Reophax duplex, Reophax pilulifera, Reophax globosus, Gaudryina pyramidata and Afrobolivina afra) and palynomorphic species (Andalusiella gabonensis, Cerodinium granulostriatum and Palaeocystodinium australinium). All the micropalaeontological data coupled with those of the microfaunas make it possible to envisage a depositional environment of the internal platform type with continental influence on an external platform.

Truth and Truthlikeness

2018 ◽  
Author(s):  
Graham Oddie
Keyword(s):  
Point Of View ◽  
Coarse Grained ◽  
Cognitive Value ◽  
Fine Grained

Truth is widely held to be a cognitive value—perhaps because, other things being equal, it is better to believe a proposition if it is true than if it is false. But even if this is a genuine aspect of the value of truth, it is rather coarse-grained. Not all truths are equally valuable, from a cognitive point of view, and neither are all falsehoods equally disvaluable. The concept of truthlikeness, or of closeness to the truth, holds out the promise of a richer, more fine-grained classification of propositions, suitable not just for the up or down evaluation of isolated beliefs, but for the calibrated evaluation of cognitive progress in an inquiry. This chapter reviews approaches to truthlikeness, and some of the problems they face.

Characterizing Granular Material Coarseness and Micromechanical Properties with a Small-Diameter Penetrometer

2000 ◽  
Vol 1714 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Jerome B. Johnson
Keyword(s):  
Mechanical Properties ◽  
Granular Material ◽  
Small Diameter ◽  
Penetration Resistance ◽  
Coarse Grained ◽  
Cross Sectional ◽  
Base Area ◽  
Fine Grained ◽  
Micromechanical Properties ◽  
Microstructural Element

A micromechanical theory and data from a penetrometer with a small base area were used to characterize the average microstructural and micromechanical properties of snow, a granular material composed of ice. The micromechanical theory also was used to describe penetration in soil and successfully explains the dependence of penetration resistance for granular materials on penetrometer base area. Material coarseness (microstructural element dimension), elastic modulus, and compressive strength were determined by interpreting penetration resistance measurements by the micromechanical theory. Predictions of the macroscale (continuum) mechanical properties for the snow were made by the micromechanical measurements and theory. The average microstructural dimensions for snow were 3.6 mm (coarse grained) and 1.45 mm (fine grained). Micromechanical strength and modulus of elasticity of snow depend on internal structure and bonding at grain boundaries; grain size by itself was not a good indicator of the mechanical properties for snow. The accuracy of determining micromechanical and microstructural properties for individual microstructural elements decreases as the ratio of the penetrometer base area to the microstructural element cross-sectional area increases. Average micro-and macroscale structural and mechanical properties of a granular material can be determined by interpreting penetration resistance data with a micromechanical penetration theory. The resolution of measurement of material properties increases as the size of the penetrometer tip decreases.

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