Academic literature on the topic 'Close die compaction'
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Journal articles on the topic "Close die compaction"
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Tempone, Pamela, Martin Landrø, and Erling Fjær. "4D gravity response of compacting reservoirs: Analytical approach." GEOPHYSICS 77, no. 3 (May 1, 2012): G45—G54. http://dx.doi.org/10.1190/geo2010-0361.1.
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Time-lapse gravity is a technique sensitive to subsurface change in mass and in mass distribution. We attempted to devise a method to predict gravity effects caused by redistribution of subsurface mass induced by reservoir compaction. First, displacements and strains due to compaction were modeled using a geomechanical model. Then, 4D gravity effects were derived from the displacements and the volumetric strains computed in and around the reservoir. A sensitivity study was carried out for geomechanical parameters, such as Poisson’s ratio, as well as for geometrical parameters, such as reservoir radius and depth. Finally, changes in gravity due to compaction were compared to changes induced by reservoir fluid substitution. Given a rigid basement close below a strongly compacting reservoir, our modeling case showed that the deformation itself could give gravity changes comparable to changes caused by reservoir fluid density changes, which are the changes traditionally targeted by gravity monitoring. For a homogeneous subsurface, the compaction gave negligible gravity changes for our modeling case.
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Kurniawan, Eko, Nelvia Nelvia, and Wawan Wawan. "Phisycal And Chemical Properties And Nutrient Content (N, P, K, Mg, B, Cu And Zn ) In Oil Palm Leaf In Various Of Age After Compacting." JURNAL AGRONOMI TANAMAN TROPIKA (JUATIKA) 2, no. 2 (July 4, 2020): 86–100. http://dx.doi.org/10.36378/juatika.v2i2.508.
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Planting of oil palm in peatland has been limited by soil physical, chemical properties, and hydrology, that`s way needed improvement on those matters to increase the productivity of peat and oil palm in peat soil by compacting. The purpose of this compacting is to improve the soil's physical, chemical properties, and soil moisture. A sampling of soil, water, and leaf were done in consecutive block 5,4,3,2,1,0 year after compacting and of planting done 4 years 10 months, 3 years 9 months, 2 years 9 months, 1 year 10 months, 11 months and 2 months, control used in this trial are origin condition (forest). Increasing bulk density was found at compacting block with 30 cm depth from the surface with the lower in 2 years after compacting at 0.09 g/cm3 and highest 4 years after compacting 0.4 g/cm3. In-depth of 60 cm from surface was found no increasing the bulk density 3 years after compacting 0.0 g/cm3 and the highest on 5 years after compacting 0.3 g/cm3 compared to forest. Decreasing on permeability in-depth 30 cm at 4 years after compacting 7.47 cm/jam and close to forest permeability 51.11 cm/hour is 2 years 43.6 cm/hour. As represent rise capillary consistently water content ≥ 80% achieved at depth 20 cm of surfaces on all block. Compaction doesn't regard pH, C organic, basa's saturation, capacity exchange cation. On depth 30 cm P-total lower on s without compaction at 599.6 ppm and above 871.6 ppm on 5 yr than forest 585 ppm. P available most low 58.1 ppm happens on 4 yr afters is compacted and p available forest 53.9 ppm. Nutrient content B, Cu and Zn at soil not influenced by compaction. Fosfor (P) in water increases with added years after compaction lower at 39.1 mg/L in the block without compaction compare of forest that 40.8 mg/L. Leaf nutrient rate on compacted block on optimum until excess where N (2. 69 – 3.15 %) , P (0. 170 – 0.209 %) , K( 0. 952 – 1.11%) , Mg ( 0. 377 – 0.497%) , except on block without compacting K (0. 830 %) and Mg (0. 190%) at deficiency and 0 years afters compaction Mg leaf on level deficiency 0. 230%. Nutrient content of B, Cu and Zn at various level and not influenced by compacting.
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Cabot, Louis, and Jean-Pierre Le Bihan. "Quelques propriétés d'une argile sur la « ligne optimale de compactage »." Canadian Geotechnical Journal 30, no. 6 (December 1, 1993): 1033–40. http://dx.doi.org/10.1139/t93-100.
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This paper deals with the evolution of the texture of the clay during compaction and with the importance of maintaining a close correlation between the degree of compaction and the water content to obtain a sealed fill with a homogeneous texture. The results of laboratory tests show the orderly evolution of some physical and mechanical properties of the compacted clay along this optimal correlation of compaction. Finally, the results of the control tests on the clay of the core of Kompienga dam compacted according to these specifications are presented. Key words : compacted clay, texture, macroporosity, optimal line of compaction, evolution of properties, specifications of compaction.
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Wang, Fuyu, Weichen Pang, Yuan Fang, Yingjun Jiang, Leilei Han, and Yanling Li. "Comparative Research on Mechanical Properties and Void Distribution of Cement Stabilized Macadam Based on Static Pressure and Vibration Compaction." Applied Sciences 10, no. 24 (December 10, 2020): 8830. http://dx.doi.org/10.3390/app10248830.
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Cement stabilized macadam semi-rigid base materials are widely used in road construction in China. However, a traditional static molding method and heavy compaction method cannot guide the design and engineering application of cement stabilized macadam mixture because it often appears that the compaction degree exceeds 100% in the practical engineering. In view of this, this paper carried out the research of an indoor vibration compaction method of cement stabilized macadam mixture, and compared the mechanical properties and void distribution characteristics of two kinds of compositions of mixtures under the vibration compaction method as well as static pressure molding and heavy compaction method and on-site sample after 7 days curing period, which was combined with the physical engineering project of Yu-Song Expressway in Jilin Province, China. The research results show that the maximum dry density of mixture under vibration compaction is larger and the best moisture content is smaller, which has a heavy incomparable advantage on the simulation of on-site compaction. And the compressive strength and splitting strength indexes of vibration compacted specimens are close to those of an on-site sample, which are all larger than static pressure specimen. Moreover, the void distribution characteristics of vibration compacted specimens is much closer to those of the on-site sample and more universal, while static pressure specimens lack in uniformity. In addition, different results caused by the two gradation are compared. All of the above research results can verify that the vibration compaction method has more reliability and accuracy to simulate the actual properties of base material. This study provides a reference for the application of vibration compaction method in road engineering design.
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Hawley, Robert L., and Edwin D. Waddington. "In situ measurements of firn compaction profiles using borehole optical stratigraphy." Journal of Glaciology 57, no. 202 (2011): 289–94. http://dx.doi.org/10.3189/002214311796405889.
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AbstractWe have developed a technique in which we use a borehole video camera and post-processing software to make a record of the optical brightness as a function of depth in polar firn. We call this method borehole optical stratigraphy. To measure firn compaction, we note the positions of optical features on the borehole wall detected by an initial ‘baseline’ log. We track the displacements of these features in subsequent logs. The result provides a measurement of the relative vertical motion and thus compaction of the firn over the survey period. We have successfully used this system at Summit, Greenland, to measure the depth distribution of firn column shortening experienced in a borehole over three 1 year periods. The uppermost 30 m of the firn at Summit is compacting as predicted by a simple steady-state model, implying that the firn density profile at Summit is at or close to steady state over the past ∼70 years.
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Khong, Anthony, and Roy Parker. "mRNP architecture in translating and stress conditions reveals an ordered pathway of mRNP compaction." Journal of Cell Biology 217, no. 12 (October 15, 2018): 4124–40. http://dx.doi.org/10.1083/jcb.201806183.
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Stress granules (SGs) are transient membraneless organelles of nontranslating mRNA–protein complexes (mRNPs) that form during stress. In this study, we used multiple single-molecule FISH probes for particular mRNAs to examine their SG recruitment and spatial organization. Ribosome runoff is required for SG entry, as long open reading frame (ORF) mRNAs are delayed in SG accumulation, indicating that the SG transcriptome changes over time. Moreover, mRNAs are ∼20× compacted from an expected linear length when translating and compact ∼2-fold further in a stepwise manner beginning at the 5′ end during ribosome runoff. Surprisingly, the 5′ and 3′ ends of the examined mRNAs were separated when translating, but in nontranslating conditions the ends of long ORF mRNAs become close, suggesting that the closed-loop model of mRNPs preferentially forms on nontranslating mRNAs. Compaction of ribosome-free mRNAs is ATP independent, consistent with compaction occurring through RNA structure formation. These results suggest that translation inhibition triggers an mRNP reorganization that brings ends closer, which has implications for the regulation of mRNA stability and translation by 3′ UTR elements and the poly(A) tail.
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Czech, Krzysztof R., and Wojciech Gosk. "Impact of the Operation of a Tri-band Hydraulic Compactor on the Technical Condition of a Residential Building." Applied Sciences 9, no. 2 (January 18, 2019): 336. http://dx.doi.org/10.3390/app9020336.
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The study investigates the surface vibrations generated by a new generation, tri-band hydraulic compactor type V8 from Maschinentechnik Schrode AG (MTS), and a reversible plate compactor type DPU 6055 from Wacker Neuson in close proximity to a low-rise residential building. Compaction works were carried out in three stages, at distances: 15 m, 10 m, and 5 m from the building, and at three depths: 0.4 m, 1.2 m, and 1.8–2.0 m. The research was conducted at one measurement point, located on the outer foundation wall of the building, and at three measurement points located on the ground at distances of 1.25–7.5 m from the building. The study analyses the distribution of peak component particle accelerations at the ground, and peak component particle velocities at the foundation wall of the building as a function of the distance of compactors from the building and the depth of compaction works, as well as the mode of work of hydraulic compactor type V8 from MTS. The study contains the comparison of the permissible vibration levels that are recommended by selected European standards (DIN, BS, VSS, and PL) and an approximate assessment of the impact of vibrations on the technical condition of the residential building.
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Han, P., X. Z. An, Y. X. Zhang, and Z. S. Zou. "FEM modeling on the compaction of Fe and Al composite powders." Journal of Mining and Metallurgy, Section B: Metallurgy 51, no. 2 (2015): 163–71. http://dx.doi.org/10.2298/jmmb150210020h.
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The compaction process of Fe and Al composite powders subjected to single action die compaction was numerically modeled by FEM method. The relationship between the overall relative density and compaction pressure of the compacts with various Al contents was firstly identified, and the influences of Al content on the local relative density, stress, and their distributions were studied. Then the compaction pressure effects on the above properties with fixed Al content were discussed. Furthermore, detailed flow behaviors of the composite powders during compaction and the relationship between the compaction pressure and the ejection force/spring back of the compact were analyzed. The results show that: (1) With each compaction pressure, higher relative density can be realized with the increase of Al content and the relative density distribution tends to be uniform; (2) When the Al content is fixed, higher compaction pressure can lead to composite compact with higher relative density, and the equivalent Von Mises stress in the central part of the compact increases gradually; (3) Convective flow occurs at the top and bottom parts of the compact close to the die wall, each indicates a different flow behavior; (4) The larger the compaction pressure for each case, the higher the residual elasticity, and the larger the ejection force needed.
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Smith, James Edward, and Edward Millard Smith-Rowland. "Proposed Model for Shale Compaction Kinetics." Geosciences 11, no. 3 (March 15, 2021): 137. http://dx.doi.org/10.3390/geosciences11030137.
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Shales are the most abundant class of sedimentary rocks, distinguished by being very fine-grained, clayey, and compressible. Their physical and chemical properties are important in widely different enterprises such as civil engineering, ceramics, and petroleum exploration. One characteristic, which is studied here, is a systematic reduction of porosity with depth of burial. This is due increases in grain-to-grain stress and temperature. Vertical stress in sediments is given by the overburden less the pore fluid pressure, σ, divided by the fraction of the horizontal area which is the supporting matrix, (1−φ), where φ is the porosity. It is proposed that the fractional reduction of this ratio, Λ, with time is given by the product of φ4m/3, (1−φ)4n/3, and one or more Arrhenius functions Aexp(−E/RT) with m and n close to 1. This proposal is tested for shale sections in six wells from around the world for which porosity-depth data are available. Good agreement is obtained above 30–40 °C and fractional porosities less than 0.5. Single activation energies for each well are obtained in the range 15–33 kJ/mole, close to the approximate pressure solution of quartz, 24 kJ/mol. Values of m and n are in the range 1 to 0.8, indicating nearly fractal water-wet pore-to-matrix interfaces at pressure solution locations. Results are independent of over- or under-pressure of pore water. This model attempts to explain shale compaction quantitatively. For the petoleum industry, given porosity-depth data for uneroded sections and accurate activation energy, E, paleo-geothermal-gradient can be inferred and from that organic maturity, indicating better drilling prospects.
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Jiao, Ming Hua, Long Sun, Man Gu, De Guang Wang, and Yu Cheng Wu. "Mesoscopic Simulation on the Compression Deformation Process of Powder Particles." Advanced Materials Research 753-755 (August 2013): 896–901. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.896.
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The compression deformation processes of powder particles were investigated by the way of mesoscopic simulation based on finite element method of discrete body. The strain process of the particles in typical position, the deformation difference of the particles in different positions and the strain status of particles were investigated under various compacting pressure. The results show that the deformation process of the compressed powder particles consisted of three stages, which were the initial stage of small deformation, the major stage of the sharply changes of strain and the ultimate stage of strain tending to stable state. The interface friction has a significant influence on the deformation and pressed density of particles close to die wall. The density can not be increased with the increase of compacting pressure of compaction infinitely.
Dissertations / Theses on the topic "Close die compaction"
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Pizette, Patrick. "Simulation de la compaction de poudres céramiques par la méthode des éléments discrets : application à la mise en forme des combustibles nucléaires mixtes." Grenoble INPG, 2009. http://www.theses.fr/2009INPG0190.
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Le combustible nucléaire mixte (MOX) est élaboré sous forme de pastilles par compaction en matrice puis frittage d'un mélange de poudres d'oxydes d'uranium et de plutonium. Du fait de la variabilité des poudres et compte tenu de la nécessité industrielle de maintenir constants les paramètres de fabrication sur des quantités importantes de produit, l'opération de compaction peut être à l'origine de rejets des pastilles lors des contrôles. En particulier, la solidité et la maîtrise dimensionnelle des comprimés sont des enjeux majeurs du procédé. La méthode des éléments discrets (DEM), mise en œuvre ici, offre un outil puissant de compréhension et de simulation. Elle s'appuie sur une modélisation explicite du caractère particulaire des poudres. Deux représentations, à l'échelle des agrégats de cristallites et à l'échelle des cristallites sont considérées pour simuler la consolidation de la poudre. Une méthodologie à partir d'expériences numériques est proposée pour établir des lois de comportement susceptibles de renseigner un code par éléments finis. Enfin, la modélisation à l'échelle des cristallites permet d'identifier les principaux paramètres microstructuraux qui influent sur la solidité des comprimésNuclear mixed oxide fuel (MOX) is formed as pellets by cold compaction of a powder blend of oxides of uranium and plutonium followed by sintering. Because of the variability of incoming powders in the process and taking into account the need to maintain constant industrial settings for processing significant quantities of pellets, the compaction process may generate some rejection during controls. In particular, compact strength and dimensional precision are key features of the industrial process. The Discrete Element Method (DEM), which has been used here, offers a powerful tool for understanding and simulating the compaction stage. It relies on an explicit modeling of the particulate nature of the uranium oxide powders. Two models, at the length scale of the aggregate of crystallites and at the length scale of the crystallites are used to simulate the powder compaction. A methodology, based on numerical experiments, is proposed to generate constitutive laws to feed a finite element code. Finally, the modeling at the crystallite length scale is used to identify the main microstructural parameters that control the compact strength
Book chapters on the topic "Close die compaction"
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Kobayashi, Shiro, Soo-Ik Oh, and Taylan Altan. "Compaction and Forging of Porous Metals." In Metal Forming and the Finite-Element Method. Oxford University Press, 1989. http://dx.doi.org/10.1093/oso/9780195044027.003.0016.
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Powder forming, once considered a laboratory curiosity, has evolved into a manufacturing technique for producing high-performance components economically in the metal-working industry because of its low manufacturing cost compared with conventional metal-forming processes. Generally, the powder-forming process consists of three steps: (1) compacting a precise weight of metal powder into a “green” preform with 10–30% porosity (defined by the ratio of void volume to total volume of the preform); (2) sintering the preform to reduce the metal oxides and form strong metallurgical structures; (3) forming the preform by repressing or upsetting in a closed die to less than 1% residual porosity. Powder forming has disadvantages in that the preform exhibits porosity. Because of this porosity, the ductility of the sintered preform is low in comparison with wrought materials. In forging compacted and sintered powdered-metal (P/M) preforms, where large amount of deformation and shear is involved, pores collapse and align in the direction perpendicular to that of forging and result in anisotropy. However, repressing-type deformation, where very little deformation and shear are present, does not lead to marked anisotropy. A low-density preform will result in more local flow and a higher degree of anisotropy than will a preform of high initial density. These anisotropic structures can lead to nonuniform impact resistances of the forged P/M parts. Also, in forming of sintered preforms, materials are more susceptible to fracture than in forming of solid materials, and the analysis is of particular importance in producing defect-free components by determining the effect of various parameters (preform and die geometries, sintering conditions, and the friction conditions) on the detailed metal flow. In this chapter, the plasticity theory for solid materials is extended to porous materials, applicable to the deformation analysis of sintered powdered-metal preforms. In characterizing the mechanical response of porous materials, a phenomenological approach (introducing a homogeneous continuum model) is employed. For the finite-element formulations of the equilibrium and energy equations based on the infinitesimal theory, the following assumptions are made: the elastic portion of deformation is neglected because the practical forming process involves very large amounts of plastic deformation; the normality of the plastic strain-rates to the yield surface holds; anisotropy that occurs during deformation is negligible; and thermal properties of the porous materials are independent of the temperatures.
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Markart, Gerhard, Michaela Teich, Christian Scheidl, and Bernhard Kohl. "Flood Protection by Forests in Alpine Watersheds: Lessons Learned from Austrian Case Studies." In Protective forests as Ecosystem-based solution for Disaster Risk Reduction (ECO-DRR) [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99507.
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This chapter highlights the influence of mountain forests on runoff patterns in alpine catchments. We discuss the forest impact at different spatial scales and bridge to the requirements for an integrated natural hazard risk management, which considers forest as an efficient protection measure against floods and other water-related natural hazards. We present results from a wide range of research studies from Austria, which all reveal the runoff-reducing effect of forest vegetation in small and medium-size catchments (< 100 km2). Forests also contribute to runoff reduction in heavy rainfall events in macro-scale catchments (> 100 km2), e.g., by reducing surface runoff and delaying interflow, but above all by stabilising slopes and therefore reducing bedload transport during major runoff events. To avoid that forests become a hazard due to enhanced driftwood release, managing of steep riparian slopes for a permanent forest cover (“Dauerbestockung”) is a basic prerequisite. Often protective effects of forests are impaired by man-made impacts like dense forest road networks, insensitive use (e.g., false design of skid roads, compacting machinery, forest operations during adverse weather on wet and saturated soils), and delayed or omitted reforestation and regeneration. Flood risk management in mountain regions should include Ecosystem-based Disaster Risk Reduction measures, with particular emphasis on sustainable and climate change-adapted management of protective forests. This will require integral and catchment-based approaches such as comprehensive management concepts coordinated with spatial planning, and verifiable, practicable and correspondingly adapted legal guidelines as well as appropriate funding of protective forest research to close the existing knowledge gaps.
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Orr, David W. "The Carbon Connection." In Down to the Wire. Oxford University Press, 2009. http://dx.doi.org/10.1093/oso/9780195393538.003.0011.
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Having seen pictures of the devastation did not prepare me for the reality of New Orleans. Mile after mile of wrecked houses, demolished cars, piles of debris, twisted and downed trees, and dried mud everywhere. We stopped every so often to look into abandoned houses in the 9th Ward and along the shore of Lake Pontchartrain to see things close up: mud lines on the walls, overturned furniture, moldy clothes still hanging in closets, broken toys, a lens from a pair of glasses . . . once cherished and useful objects rendered into junk. Each house had a red circle painted on the front to indicate the results of the search for bodies. Some houses showed the signs of desperation, such as holes punched through ceilings as people tried to escape rising water. The musty smell of decay was everywhere, overlaid with an oily stench. Despair hung like Spanish moss in the hot, dank July air. Ninety miles to the south, the Louisiana delta is rapidly sinking below the rising waters of the Gulf. This is no “natural” process but rather the result of decades of mismanagement of the lower Mississippi, which became federal policy after the great flood of 1927. Sediments that built the richest and most fecund wetlands in the world are now deposited off the continental shelf—part of an ill-conceived effort to tame the river. The result is that the remaining wetlands, starved for sediment, are both eroding and compacting, sinking below the water and perilously close to no return. Oil extraction has done most of the rest of the damage by crisscrossing the marshlands with channels that allow the intrusion of saltwater and storm surges. Wakes from boats have widened the original channels considerably, further unraveling the ecology of the region. The richest fishery in North America and a unique culture that once thrived in the delta are disappearing, and with them the buffer zone that protects New Orleans from hurricanes. “Every 2.7 miles of marsh grass,” in Mike Tidwell’s words, “absorbs a foot of a hurricane’s storm surge” (2003, p. 57).
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Bezgodov, Andrei Viktorovich. "Advantages of Growing Field Peas in Mixed Crops With Rapeseed and Mustard." In Culture. Science. Education: modern trends, 226–34. Publishing house Sreda, 2020. http://dx.doi.org/10.31483/r-74741.
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In field experiences studies on growing field peas in single-component and mixed seeding with spring rape and white mustard were conducted in the Middle Urals. The crop capacity was increased by 10,8% as well as the total yield was increased by 2.3 times up to 2.14 t / ha by the use of spring rape as a supporting and compacting crop in sowng peas with a seeding rate at 0.6 million / ha. It was found out that crop productivity of peas was decreased by 19.4% when the seeding rate was established at 0.4 million / ha, and the crop productivity of spring rape remained at the level of pure sowing – 1.23 t / ha. The total yield, in comparison with the pure sowing of peas, increased by 2.1 times from 0.93 to 1.98 t / ha. Mustard is less suitable as a supporting crop, although it ripes earlier and does not thrive in contrast to spring rape. The total yield and ratio of land equivalents in a mixture with spring rape is higher than with mustard and ranged from 1.66 to 1.98. Peas accounts for the bulk of the total yield (LERab = 0.81...1.48). The coefficients of competitiveness and aggressiveness of the studied crops in mixed sowing indicate the dominant role of field peas in the pea-rape and pea-mustard agrocenoses. The awned and foliose morphotype of field peas when grown in a mixture with mustard showed themselves equally, their competitiveness and aggressiveness coefficients were in a close range – Crab = 2.37...4.57; CAab = 0.72...1.87. The awned morphotype of field peas had the greatest aggressiveness and competitiveness when cultivated in a mixture with spring rape – CRab=6.78...17.80; CAab = 3.35...5.79. The foliose morphotype of field peas occupied an intermediate position and had a good competitive ability with less aggressiveness towards spring rape – Crab = 2.64...2.66; CAab = 2.06...2.13.
Conference papers on the topic "Close die compaction"
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Segura, Jose M., Miguel A. Caja, Laura García, Juan M. Jiménez, Jorge Díez, Teresa Polo, Jose Alvarellos Iglesias, and M. R. Lakshmikantha. "An Integrated Numerical and Mineralogical Study of a High Pressure High Temperature Well." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-78152.
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Predicting drilling risks in advance is a major challenge in areas that lack drilling experience, and even when information from offset wells is available. Large overpressure was found at TD of an offshore exploratory well drilled mainly through shale. None of the other two previously drilled offset wells in the area had shown any sign of such a high overpressure. This study presents two complementary approaches to gain insight on the overpressure generation mechanisms. The effect of chemical compaction is first evaluated in terms of well cuttings analysis, including sample washing, high-resolution photo catalog, automated mineralogy and X-ray diffraction clay mineralogy analysis. The obtained mineralogical results confirm the presence of the dehydration diagenetic process involving the transformation of smectite to illite. Consequently, a numerical model is presented which combines the effect of mechanical and chemical compaction to predict pore pressure values very close to the overpressure observed during drilling. The model reproduces the depositional history of the lithological column by coupling mechanical and chemical compaction with fluid flow over geological time, and it allows predicting stress, porosity and pore pressure evolution at different geological ages. Calibration and verification of the results of the pore pressure model is done by comparison to drilling experience and logs (post-drill pore pressure profile, geology tops and density/porosity logs).
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Chen, L. H., P. E. Wood, T. V. Jones, and J. W. Chew. "Detailed Experimental Studies of Flow in Large Scale Brush Seal Model and a Comparison With CFD Predictions." In ASME 1999 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/99-gt-281.
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A five times scale model of an engine brush seal has been manufactured. The bristle stiffness and pressure were chosen to satisfy close similarity of the relevant non-dimensional parameters, and the choice of parameters is described. The comparison of flow characteristics for the model seal and an engine seal confirmed the non-dimensional similarity. Detailed pressure measurements were performed within the bristle pack by employing hollow bristles. This novel measurement allowed insight to be obtained into the operation of both clearance and interference seals. In particular, the measured pressure variation in the region of the bristle tips was significant. The deflection of the bristles was determined by comparing the bristle tip pressures with the static pressures along the shaft. Hence the compaction of the pack in this region was found directly. A numerical modelling of brush seals employing anisotropic flow resistance has been developed. Predictions were compared with the measured pressure distributions within the pack. This enabled sensible selection of the pack resistance distribution to be made. Although uniform anisotropic resistance throughout the pack gave reasonable flow rate characteristics, the pressure distribution was not reproduced. A variation of resistance coefficient consistent with the observed compaction was required to give a solution comparable with the experiments.
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Şengün, Emin, Burhan Alam, Reza Shabani, and İ. Özgür Yaman. "Fracture Energy of Roller Compacted Concrete Pavements." In 12th International Conference on Concrete Pavements. International Society for Concrete Pavements, 2021. http://dx.doi.org/10.33593/zmke32q2.
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This study is set out to examine the bending, toughness and fracture energy of RCC pavements produced by double drum vibratory hand roller (DDVHR) to simulate the real performance of RCC in the laboratory environment. To this end, four different binder dosages (200, 300,400, and 600 kg/m3) and two different aggregate gradations (Dmax 12 and 19 mm) were selected to investigate the effect of mixture design on bending, toughness and fracture energy of RCC mixtures. The different mixtures were poured into a large pavement mold (LPM), which was fabricated in laboratory, and compacted by DDVHR. After that, in order to determine the bending, toughness and fracture energy of RCC mixtures, LPM were cut to beam specimens with sizes according to Japan Concrete Institute (JCI). In addition, cores were taken from LPM to compare 28 days' compressive strengths and compaction ratios of the mixtures. At the end of the study, contrary to expectations, the fracture energies for all RCC mixtures except one combination were very close to each other. The increase in cement dosage or the maximum aggregate size did not lead to a significant change in the fracture energy. The mixture that was developed to obtain a high performance RCC appeared to have the lowest fracture energy. Above all, the compaction ratio of the mixtures was effective in the all results.
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Smith, J. Torquil, Eric L. Sonnenthal, and William J. Milliken. "Continuum Modelling of Cyclic Steam Injection in Diatomite." In SPE Western Regional Meeting. SPE, 2022. http://dx.doi.org/10.2118/209331-ms.
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Abstract Objectives/Scope Steam injection in diatomite reservoirs results in permeability changes owing to fracture propagation, and compaction as a result of thermal effects and pressure changes during injection and production. The purpose of this work is to evaluate these coupled thermal, hydrological, and mechanical (THM) processes over several years of cyclic steam injection and production. A single well model in a diatomite reservoir was created to evaluate these processes at a higher resolution near wellbore than used in a 3-D reservoir-scale model. Methods, Procedures, Process Simulations include tensile failure, shear failure with simultaneous shear on multiple planes, coupling of porosity and permeability changes with multiphase flow, and diatomite compaction with temperature and effective stress. Initial isotropic horizontal stresses are 1.0375 of vertical (azimuthal average, part of San Joaquin Valley). Injection interval (437-528 m) pressure is fixed, 6.3 MPa, 930 psi (injection), and ~4 MPa (production), with a soak period between injection and production. Three degree dilation on shearing is assumed. To the extent that fracture opening is tensile, fractures close on fluid pressure drop, but shear components remain. Permeability changes due to mechanical failure are simulated using a cubic law. Results, Observations, Conclusions During injection over multiple cycles, the diatomite surrounding the well is heated to over 250 °C and pressurized by the injected steam. During soak (shut-in) and subsequent production, pressure drops, dropping the boiling point, inducing further vaporization. Geomechanical changes show tensile opening accompanied by a greater amount of shearing. Total shearing increases with each injection cycle, resulting in a greater porosity increase from shearing than tensile opening. Fracture propagation was limited to the diatomite reservoir and did not penetrate the caprock. Novel/Additive Information Inclusion of an empirical effective stress/temperature diatomite compaction law together with porosity and permeability changes due to mechanical failure more closely models the mechanics of cyclic steaming of diatomite.
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Rollin, Bertrand, and Marie Desenlis. "Interaction of a Shock Wave With a Dense Corrugated Particle Curtain." In ASME 2017 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/fedsm2017-69562.
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A numerical experiment studying the gas-particle variant of the Richtmyer-Meshkov instability is presented. Using an Eulerian-Lagrangian approach, namely point particle simulations, we track trajectories of computational particles composing an initially corrugated particle curtain, after the curtain’s interaction with a shock wave. We solve the compressible multiphase Euler equations in a two-dimensional planar geometry and use state-of-the-art particle force models, including unsteady forces, for the gas-particle coupling. However, additional complexities associated with compaction of the curtain of particles to random close packing limit and beyond are avoided by limiting the simulations to relatively modest initial volume fraction of particles. At a fixed Mach number, we explore the effects of the initial perturbation amplitude, initial particle volume fraction and initial shape on the dispersal of the particle curtain. For this shock strength, our simulations suggests that the amplitude of the initial perturbation does not play a significant role in the late time particle dispersal, contrary to the volume fraction. Higher initial particle volume fraction tend to faster particles dispersal. Finally, higher frequency initial perturbations seem to be absorbed by lower frequency initial perturbations.
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Wu, Yufeng, and Gap-Yong Kim. "Modeling of Semi-Solid Powder Processing for a Closed Die Compaction." In ASME 2011 International Manufacturing Science and Engineering Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/msec2011-50130.
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Semi-solid powder processing (SPP) is a promising technique in the fabrication of composite materials. Former work has experimentally shown that SPP was able to synthesize composite materials with reduced load and high efficiency. However, limited work was found in the modeling of the SPP. In this work, SPP was modeled with Shima-Oyane’s model and compared with experimental data in a closed die compaction setup. The evolution and distribution of the density and stress were analyzed. The model prediction agreed with the experimentally measured values. As the compaction pressure increased, the density gradient in the axial compaction direction decreased, while the stress gradient increased.
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Hon, Vai Yee, M. Faizzudin Mat Piah, Noor 'Aliaa M Fauzi, Peter Schutjens, Binayak Agarwal, and Rob Harris. "Integrated Reservoir Geomechanics Approach for Reservoir Management." In International Petroleum Technology Conference. IPTC, 2021. http://dx.doi.org/10.2523/iptc-21216-ms.
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Abstract An integrated 3D dynamic reservoir geomechanics model can provide a diverse 3D view of depletion-injection-induced field stress changes and the resulting deformation of both reservoir and overburden formations at various field locations. It enables the assessment of reservoir compaction, platform site subsidence, fault reactivation and caprock integrity associated with multiple production and injection reservoirs of the field. We demonstrated this integrated approach for a study field located in the South China Sea, Malaysia, which is planned for water injection for pressure support and EOR scheme thereafter. Reservoir fluid containment during water injection is an important concern because of the intensive geologic faulting and fracturing in the collapsed anticlinal structure, with some faults extending from the reservoirs to shallow depths at or close to the seafloor. Over 30 simulations were done, and most input parameters were systematically varied to gain insight in their effect on result that was of most interest to us: The tendency of fault slip as a function of our operation-induced variations in pore pressure in the reservoir rocks bounding the fault, both during depletion and injection. The results showed that depletion actually reduces the risk of fault slip and of the overburden, while injection-induced increase in pore fluid pressure will lead to a significant increase in the risk of fault slip. Overall, while depletion appears to stabilize the fault and injection appears to destabilize the fault, no fault slip is predicted to occur, not even after a 900psi increase in pore pressure above the pore pressure levels at maximum depletion. We present the model results to demonstrate why depletion and injection have such different effects on fault slip tendency. The interpretation of these geomechanical model results have potential applications beyond the study field, especially for fields with a similar geology and development plan. This is a novel application of 3D dynamic reservoir geomechanics model that cannot be obtained from 1D analytical models alone.
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Zhang, Zhiye, and Michael Philen. "Modeling, Analysis, and Experiments of Interfiber Compaction Effects in FMC Actuators for Bio-Inspired Applications." In ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/smasis2011-5092.
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Recently, flexible matrix composite (FMC) actuators were demonstrated in a robotic fish for swimming. When actuated at a specific frequency in the experiments, the sinusoidal component of the thrust was eliminated, leaving only a constant thrust. This elimination of the sinusoidal component of the thrust is due to the hydroelastic tailoring of the tail stiffness with the actuation frequency. The FMC actuators are pressure-driven muscle-like actuators capable of large displacements as well as large blocking forces. The FMC actuators can also exhibit a large change in stiffness through simple valve control when the working fluid has a high bulk modulus. Several analytical models have been developed that capture the geometrical and material nonlinearities, the compliance of the inner liner, and entrapped air in the fluid. This paper focuses on the inter fiber compaction in the composite laminate, which is shown to reduce the effective closed-valve stiffness. In this paper, a new analytical model considering the inter fiber compaction effect as well as the material and geometric nonlinearities is developed. Analysis and experimental results demonstrate that the new compaction model can improve the prediction of the response behavior of the actuator.
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Zhang, Zhiye, and Michael Philen. "Modeling and Analysis of Interfiber Compaction Effects in FMC Actuators for Bio-Inspired Applications." In ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. ASMEDC, 2010. http://dx.doi.org/10.1115/smasis2010-3842.
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Recently, flexible matrix composite (FMC) actuators were employed in a robotic fish for swimming [1]. The FMC actuators based on flexible matrix composites developed by Philen et al. [2] are pressure driven muscle-like actuators capable of large displacements as well as large blocking forces. The FMC actuators can also exhibit a large change in stiffness through simple valve control when the working fluid has a high bulk modulus [3, 4]. Several analytical models have been developed that capture the geometrical and material nonlinearities, the compliance of the inner liner, and entrapped air in the fluid [2, 4, 5]. But no work has been performed in capturing the fiber compaction in the composite laminate, which can have significant influence on the closed valve FMC stiffness. Therefore the objective of this research is to expand upon the previously developed models and incorporate compliance between the woven fibers.
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Andersen, Pål Østebø, Reidar Inge Korsnes, Andre Tvedt Olsen, and Erik Bukkholm. "Reaction Kinetics Determined from Core Flooding and Steady State Principles for Stevns Klint and Kansas Chalk Injected with MgCl2 Brine at Reservoir Temperature." In SPE Improved Oil Recovery Conference. SPE, 2022. http://dx.doi.org/10.2118/209380-ms.
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Abstract A methodology is presented for determining reaction kinetics from core flooding: A core is flooded with reactive brine at different compositions with injection rates varied systematically. Each combination is performed until steady state, when effluent concentrations no longer change significantly with time. Lower injection rate gives the brine more time to react. We also propose shut-in tests where brine reacts statically with the core a defined period and then is flushed out. The residence time and produced brine composition is compared with the flooding experiments. This design allows characterization of the reaction kinetics from a single core. Efficient modeling and matching of the experiments can be performed as the steady state data are directly comparable to equilibrating the injected brine gradually with time and does not require spatial and temporal modeling of the entire dynamic experiments. Each steady state data point represents different information that helps constrain parameter selection. The reaction kinetics can predict equilibrium states and time needed to reach equilibrium. Accounting for dispersion increases the complexity by needing to find a spatial distribution of coupled solutions and is recommended as a second step when a first estimate of the kinetics has been obtained. It is still much more efficient than simulating the full dynamic experiment. Experiments were performed injecting 0.0445 and 0.219 mol/L MgCl2 into Stevns Klint chalk from Denmark, and Kansas chalk from USA. The reaction kinetics of chalk are important as oil-bearing chalk reservoirs are chemically sensitive to injected seawater. The reactions can alter wettability and weaken rock strength which has implications for reservoir compaction, oil recovery and reservoir management. The temperature was 100 and 130°C (North Sea reservoir temperature). The rates during flooding were varied from 0.25 to 16 PV/d while shut-in tests provided equivalent rates down to 1/28 PV/d. The results showed that Ca2+ ions were produced and Mg2+ ions retained (associated with calcite dissolution and magnesite precipitation, respectively). This occurred in a substitution-like manner, where the gain of Ca was similar to the loss of Mg2+. A simple reaction kinetic model based on this substitution with three independent tuning parameters (rate coefficient, reaction order and equilibrium constant) was implemented together with advection to analytically calculate steady state effluent concentrations when injected composition, injection rate and reaction kinetic parameters were stated. By tuning reaction kinetic parameters, the experimental steady state data could be fitted efficiently. From data trends, the parameters were determined relatively accurate for each core. The roles of reaction parameters, pore velocity and dispersion were illustrated with sensitivity analyses. The steady state method allows computationally efficient matching even with complex reaction kinetics. Using a comprehensive geochemical description in the software PHREEQC, the kinetics of calcite and magnesite mineral reactions were determined by matching the steady state concentration changes as function of (residence) time. The simulator predicted close to identical production of Ca as loss of Mg. The geochemical software predicted much higher calcite solubility in MgCl2 than observed at 100 and 130°C for Stevns Klint and Kansas.
Reports on the topic "Close die compaction"
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Upadhyaya, Shrini, Dan Wolf, William J. Chancellor, Itzhak Shmulevich, and Amos Hadas. Traction-Soil Compaction Tradeoffs as a Function of Dynamic Soil-Tire Interation Due to Varying Soil and Loading Conditions. United States Department of Agriculture, October 1995. http://dx.doi.org/10.32747/1995.7612832.bard.
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The objectives of this study were to investigate soil-pneumatic tire interaction and develop traction-soil compaction prediction model. We have developed an inverse solution technique that employs a response surface methodology to determine engineering properties of soil in-situ. This technique is useful in obtaining actual properties of soil in-situ for use in traction and soil compaction studies rather than using the values obtained in the laboratory by employing remolded and/or disturbed soil samples. We have conducted extensive field tests i the U.S. to develop semi-empirical traction prediction equation for radial ply tires. A user friendly traction-soil compaction program was developed to predict tractive ability of radial ply tires using several different techniques and to estimate soil compaction induced by these tires. A traction prediction model that incorporates strain rate effects on the tractive ability of tires was developed in Israel. A mobile single wheel tester and an in-situ soil test device were developed i Israel to significantly enhance the ability of Israeli investigators to conduct traction-soil compaction research. This project has resulted in close cooperation between UCD, Technion, and ARO, which will be instrumental in future collaboration.