The Effect of Vuggy Porosity on Straining in Porous Media

SPE Journal ◽  
2019 ◽  
Vol 24 (03) ◽  
pp. 1164-1178 ◽  
Author(s):  
Hasan J. Khan ◽  
Maša Prodanovic ◽  
David A. DiCarlo
Keyword(s):  
Glass Beads ◽  
Surface Forces ◽  
Particle Sizes ◽  
Sintering Process ◽  
The Core ◽  
Maximum Change ◽  
Flow Experiment ◽  
The Matrix ◽  
Flow Configurations ◽  
Shape Changes

Summary A formation-damage experimental study is conducted on synthetic homogeneous and vuggy cores. Glass beads of 1.0 mm are sintered to form a uniform core with a porosity of 42%, and finer-sized glass beads (25 and 100 µm) are used as the infiltrates. Glass beads are used as the matrix and infiltrate to reduce surface forces, and the flow is gravity dominated. Dissolvable inclusions are added during the sintering process to create vugs in the core. The pore-size to vug-size ratio is 1:100. The injected-particle sizes are chosen such that straining is the dominant trapping mechanism during the flow experiment. Infiltrate particles are injected at different flow configurations, and the resultant porosity, permeability, and effluent volume are measured. The results can be summarized as follows: Vugs get up to 32% smaller caused by the flow for the infiltrate, while the maximum change in the porosity is observed at the bottom end of the core, vug shape changes to a smoother and rounded surface, and particles go deeper (8 mm more) into the formation when vugs are present, causing damage deeper inside the formation.

The Structure and Development of Microbodies in the Fat Body and other Tissues of an Insect (Calpodes Ethlius)

1970 ◽  
Vol 28 ◽  
pp. 148-149
Author(s):  
M. Locke ◽  
J. T. McMahon
Keyword(s):  
Electron Microscopy ◽  
Liquid Crystals ◽  
Fat Body ◽  
Competitive Inhibitor ◽  
Dense Core ◽  
Urate Oxidase ◽  
Blood Proteins ◽  
Free Base ◽  
The Core ◽  
The Matrix

The fat body of insects has always been compared functionally to the liver of vertebrates. Both synthesize and store glycogen and lipid and are concerned with the formation of blood proteins. The comparison becomes even more apt with the discovery of microbodies and the localization of urate oxidase and catalase in insect fat body.The microbodies are oval to spherical bodies about 1μ across with a depression and dense core on one side. The core is made of coiled tubules together with dense material close to the depressed membrane. The tubules may appear loose or densely packed but always intertwined like liquid crystals, never straight as in solid crystals (Fig. 1). When fat body is reacted with diaminobenzidine free base and H2O2 at pH 9.0 to determine the distribution of catalase, electron microscopy shows the enzyme in the matrix of the microbodies (Fig. 2). The reaction is abolished by 3-amino-1, 2, 4-triazole, a competitive inhibitor of catalase. The fat body is the only tissue which consistantly reacts positively for urate oxidase. The reaction product is sharply localized in granules of about the same size and distribution as the microbodies. The reaction is inhibited by 2, 6, 8-trichloropurine, a competitive inhibitor of urate oxidase.

In Situ Transformed Carbon Fibers/Al2O3 Nanocomposites Using Cao–MgO–SiO2 Sintering Agent

2021 ◽  
Vol 21 (10) ◽  
pp. 5235-5240
Author(s):  
Hua-Hui Chen ◽  
Jing-Jing Cao ◽  
Hai-Ping Hong ◽  
Nan Zheng ◽  
Jie Ren ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
Axial Direction ◽  
Diffraction Peak ◽  
Sintering Process ◽  
Interface Bonding ◽  
The Core ◽  
Matrix Nanocomposites ◽  
Pan Fibers ◽  
Properties Of Composites

In Situ transformed carbon fibers/Al2O3 ceramic matrix nanocomposites with Cao–MgO–SiO2 sintering agent were prepared by hot-pressed sintering technology in vacuum. In the sintering process, pre-oxidized polyacrylonitrile fibers (below named as pre-oxidized PAN fibers) were used as the precursors of In Situ transformed carbon fibers. The micro/nanostructure of composites and interface between In Situ transformed carbon fibers and matrix were investigated, as well as the properties of composites. The results showed that the composites could be sintered well at a relatively low temperature of 1650 °C. During the sintering, the precursors, pre-oxidized PAN fibers, were In Situ transformed into carbon fibers, and the In Situ transformed carbon fibers had the graphitelike structure along the fiber axial direction. The carbon atoms arrangement in the surface layer of the fiber was more orderly than the core. A typical diffraction peak of carbon fiber at 26°, which corresponded to the (002) crystal plane, was observed, and the inter-planar spacing was approximately 0.34 nm. The CaO–MgO–SiO2 sintering agent formed MgAl2O4 and CaAl2Si2O8 phases in the interface between In Situ transformed carbon fibers and matrix, therefore improving the interface bonding, and thereby modifying the mechanical properties of the composites.

scholarly journals Master sintering curve: A practical approach to its construction

2010 ◽  
Vol 42 (1) ◽  
pp. 25-32 ◽  
Author(s):  
V. Pouchly ◽  
K. Maca
Keyword(s):  
Activation Energy ◽  
Practical Method ◽  
Practical Approach ◽  
Particle Sizes ◽  
Sintering Process ◽  
Cubic Zirconia

The concept of a Master Sintering Curve (MSC) is a strong tool for optimizing the sintering process. However, constructing the MSC from sintering data involves complicated and time-consuming calculations. A practical method for the construction of a MSC is presented in the paper. With the help of a few dilatometric sintering experiments the newly developed software calculates the MSC and finds the optimal activation energy of a given material. The software, which also enables sintering prediction, was verified by sintering tetragonal and cubic zirconia, and alumina of two different particle sizes.

Development of shape memory alloy hybrid yarns for adaptive fiber-reinforced plastics

2018 ◽  
Vol 89 (8) ◽  
pp. 1371-1380 ◽  
Author(s):  
Moniruddoza Ashir ◽  
Andreas Nocke ◽  
Chokri Cherif
Keyword(s):  
Shape Memory ◽  
Technological Development ◽  
Fiber Reinforced ◽  
Material Loss ◽  
Reinforced Plastics ◽  
The Core ◽  
Hybrid Yarn ◽  
Pull Out ◽  
The Matrix ◽  
Fiber Reinforced Plastics

The application of shape memory alloys (SMAs) for the development of adaptive fiber-reinforced plastics has been expanding steadily in recent years. In order to prevent matrix damage and optimize the actuating potential of SMAs during the process of thermally induced activation, a barrier layer between SMAs and the matrix of fiber-reinforced plastics is required. This article approaches the textile technological development of SMA hybrid yarns as a core–sheath structure using friction spinning technology, whereby the SMA serves as the core. Four types of hybrid yarns are produced by varying the number of process stages from one to three, as well as the core and sheath materials. The decoupling of the SMA from fiber-reinforced plastics is crucial for optimizing the actuating potential of SMA, thus it is tested by means of the pull-out test. Although the material loss coefficient increases by raising the number of process stages, the three-stage processing of SMA hybrid yarn with an additional glass roving is found to be the most suitable variation for decoupling SMA from the matrix of fiber-reinforced plastics.

Introduction

2020 ◽  
pp. 1-16
Author(s):  
Beth Van Schaack
Keyword(s):  
Security Council ◽  
Civil Liability ◽  
Sovereign State ◽  
The Core ◽  
The Matrix

This chapter introduces the conflict in Syria, the various impediments to justice, and the book’s broad themes, including the observation that the paralysis in the U.N. Security Council has spurred a form of forced creativity that has generated a number of novel proposals for how to bring justice to Syria. In addition to providing an overview of the text, this introduction also presents the matrix of accountability that will structure the core of the book. This matrix is organized along two axes: the first (x) is premised on the distinction between criminal and civil liability; the second (y) compares the types of justice institutions and legal authorities that are available to bring individual perpetrators and even Syria as a sovereign state to justice. The remainder of the book explores different routes to accountability through this matrix and the various advantages presented by, and the challenges encumbering, the various justice options when it comes to the situation in Syria.

scholarly journals EBSD Analysis of Metal Matrix Nanocomposite Microstructure Produced by Powder Metallurgy

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 878 ◽  
Author(s):  
Íris Carneiro ◽  
Filomena Viana ◽  
Manuel F. Vieira ◽  
José V. Fernandes ◽  
Sónia Simões
Keyword(s):  
Powder Metallurgy ◽  
Advanced Materials ◽  
Sintering Process ◽  
Electron Backscattered Diffraction ◽  
Matrix Microstructure ◽  
Metal Matrix Nanocomposite ◽  
The Matrix ◽  
Dislocation Annihilation ◽  
Metal Nanocomposites ◽  
Matrix Nanocomposite

The development of metal nanocomposites reinforced by carbon nanotubes (CNTs) remains a focus of the scientific community due to the growing need to produce lightweight advanced materials with unique mechanical properties. However, for the successful production of these nanocomposites, there is a need to consolidate knowledge about how reinforcement influences the matrix microstructure and which are the strengthening mechanisms promoting the best properties. In this context, this investigation focuses on the study of the reinforcement effect on the microstructure of an Ni-CNT nanocomposites produced by powder metallurgy. The microstructural evolution was analysed by electron backscattered diffraction (EBSD). The EBSD results revealed that the dispersion/mixing and pressing processes induce plastic deformation in the as-received powders. The dislocation structures produced in those initial steps are partially eliminated in the sintering process due to the activation of recovery and recrystallization mechanisms. However, the presence of CNTs in the matrix has a significant effect on the dislocation annihilation, thus reducing the recovery of the dislocation structures.

Effects of Viscosity, Particle Size, and Particle Shape on Erosion in Gas and Liquid Flows

2011 ◽  
Author(s):  
Risa Okita ◽  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirazi ◽  
Edmund F. Rybicki
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Solid Particle ◽  
Abrasive Particle ◽  
Glass Beads ◽  
Solid Particle Erosion ◽  
Particle Sizes ◽  
Particle Erosion ◽  
Particle Velocities ◽  
Liquid Flows

Although solid particle erosion has been examined extensively in the literature for dry gas and vacuum conditions, several parameters affecting solid particle erosion in liquids are not fully understood and need additional investigation. In this investigation, erosion ratios of two materials have been measured in gas and also in liquids with various liquid viscosities and abrasive particle sizes and shapes. Solid particle erosion ratios for aluminum 6061-T6 and 316 stainless steel have been measured for a direct impingement flow condition using a submerged jet geometry, with liquid viscosities of 1, 10, 25, and 50 cP. Sharp and rounded sand particles with average sizes of 20, 150, and 300 μm, as well as spherical glass beads with average sizes of 50, 150 and 350 μm, were used as abrasives. To make comparisons of erosion in gas and liquids, erosion ratios of the same materials in air were measured for sands and glass beads with the particle sizes of 150 and 300 μm. Based on these erosion measurements in gas and liquids, several important observations were made: (1) Particle size did not affect the erosion magnitude for gas while it did for viscous liquids. (2) Although aluminum and stainless steel have significant differences in hardness and material characteristics, the mass losses of these materials were nearly the same for the same mass of impacting particles in both liquid and gas. (3) The most important observation from these erosion tests is that the shape of the particles did not significantly affect the trend of erosion results as liquid viscosity varied. This has an important implication on particle trajectory modeling where it is generally assumed that particles are spherical in shape. Additionally, the particle velocities measured with the Laser Doppler Velocimetry (LDV) near the wall were incorporated into the erosion equations to predict the erosion ratio in liquid for each test condition. The calculated erosion ratios are compared to the measured erosion ratios for the liquid case. The calculated results agree with the trend of the experimental data.

scholarly journals Vapor-Stripping and Encapsulating to Construct Particles with Time-Controlled Asymmetry and Anisotropy

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1248
Author(s):  
Ting-Ying Wu ◽  
Chendi Gao ◽  
Man-Chen Huang ◽  
Zhi Zhang ◽  
Peng-Yuan Wang ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Hybrid Material ◽  
Simulation Analysis ◽  
Particle Surface ◽  
Chemical Vapor ◽  
Particle Sizes ◽  
Soybean Agglutinin ◽  
The Matrix ◽  
Template Substrate ◽  
Timing Parameter

An innovative chemical vapor sublimation and deposition (CVSD) process was shown to produce nanoscale anisotropic hybrid materials. Taking advantage of controlled thermodynamic properties and the mass transfer of molecules, this process allowed for water vapor sublimation from an iced template/substrate and stagewise vapor deposition of poly-p-xylylene onto the sublimating ice substrate. In this study, the use of sensitive soybean agglutinin (SBA) protein tubes was demonstrated as an example to prepare the anisotropic hybrid material based on the CVSD process. The rationale of a timing parameter, Δt, was controlled to program the sublimation of the SBA-ice templates and the deposition of poly-p-xylylene during the CVSD process. As a result of this control, a stripping stage occurred, during which SBA tubes were exposed on the particle surface, and a subsequent encapsulation stage enabled the transformation of the ice templates into a nanometer-sized anisotropic hybrid material of poly-p-xylylene as the matrix with encapsulated SBA tubes. The timing parameter Δt and the controlled stripping and encapsulating stages during CVSD represent a straightforward and intriguing mechanism stemming from physical chemistry fundamentals for the fabrication of hybrid materials from sensitive molecules and with predetermined sizes and asymmetrical shapes. A simulation analysis showed consistency with the experimental results and controllability of the timing mechanism with predictable particle sizes.

Scanning Electron Microscopy of Rubber Tear

1977 ◽  
Vol 50 (5) ◽  
pp. 875-883 ◽  
Author(s):  
W. D. Bascom
Keyword(s):  
Deformation Zone ◽  
Aging Process ◽  
Simple Technique ◽  
Chain Scission ◽  
Surface Forces ◽  
The Other ◽  
Qualitative Information ◽  
Carbon Filler ◽  
The Matrix ◽  
Initial Appearance

Abstract A relatively simple technique has been described which allows observation of the deformation zone at tear tips in rubber specimens. Investigation of various rubbers revealed qualitative information about the type of yielding that occurs in the deformation zone under different conditions. The initial appearance of the tear tip in nitrile, polybutadiene (both with and without carbon filler), and natural rubber suggests a process of stretching followed by rupture and then relaxation onto the tear walls. Only in the case of a fluoro-elastomer was there evidence of cavitation, although microcavitation (of sizes ≪1 µm) may be occurring in the other rubbers at much higher magnification. On the other hand, aging in laboratory air had the dramatic effect of producing fibrous and nodular networks in the tear tip material of all the rubbers except the fluoroelastomer. In the first few hours, the network structure developed as cavities (Figure 9), but after 24 h the network was fully developed across the tear. The aging process is very likely an ozone attack not only on the rubber under stress at the tear tip, but also on the rubber on the tear wall. It is quite possible that there were residual stresses in the material on the wall which facilitated attack. Chain scission appeared to be allowing the rubber to relax by viscous flow under the action of surface forces. These results point up the need to distinguish between failure controlled by pure stress and failure assisted by oxidation/ozonolysis in studies of slow tear growth in rubbers. The SEM technique also provides information about fillers. Their elemental composition can be determined by XES, and some qualitative information can be gained about their adhesion to the matrix and their effect on tear tip yielding.

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