Academic literature on the topic 'General Element Ratio'
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Journal articles on the topic "General Element Ratio"
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Wang, Jian, Wei Zhang, Jin Zhang, and Wen Long Wu. "Element Bearing Ratio Based Integral Safety Evaluation of Penstocks." Advanced Materials Research 671-674 (March 2013): 1604–8. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.1604.
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Though it had been employed for limit analysis and integral safety assessment of pressure pipe and vessel, most of the elastic modulus adjustment procedures were applicable to simple structures because their load multiplier was mainly determined by stress. In this paper, a series of element bearing ratio (EBR) based load multiplier algorithms are given, in which the influence of both stress and material on limit load are included. The EBR based load multiplier algorithms are investigated, and two efficient algorithms are suggested. Then the two algorithms combined with the elastic modulus adjustment procedure of elastic modulus reduction method are applied to limit analysis and integral safety assessment of penstocks.
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Daud, Ruslizam, Ahmad Kamal Ariffin, Shahrum Abdullah, Al Emran Ismail, and A. Zulkifli. "Computation of Stress Intensity Factor for Multiple Cracks Using Singular Finite Element." Advanced Materials Research 214 (February 2011): 75–79. http://dx.doi.org/10.4028/www.scientific.net/amr.214.75.
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The simplification of two dimensional approaches in singular finite elements has promoted the method to be used in the formulation of stress intensity factor (SIF) of multiple cracks in finite body. The effect of shielding and amplification are considered in defining the SIF. As been observed, the current available analytical approximations are more restricted to several assumptions. The more accurate and less restricted method has motivated this study. This paper presents the investigation of singular finite elements applied in two dimensional finite element models subjected to different crack-width ratio and cracks interval ratio. The newly finite element formulations are resulted with good agreement with theoretical statement compared to analytical solution. The weak points of presented analytical solution are discussed regards to the influence of crack width ratio and cracks interval ratio.
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Yang, LuFeng, JingMin Liu, Bo Yu, and JW Ju. "Failure path-independent methodology for structural damage evolution and failure mode analysis of framed structures." International Journal of Damage Mechanics 26, no. 2 (August 3, 2016): 274–92. http://dx.doi.org/10.1177/1056789516662626.
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Traditional methods for structural damage evolution and failure mode analysis usually depend on specific failure path analysis, which is inefficient and time-consuming to implement for complex structures. In this paper, an efficient failure path-independent methodology for structural damage evolution and failure mode analysis of framed structures is proposed based on the elastic modulus reduction method. The element bearing ratio, uniformity of element bearing ratio and reference element bearing ratio are defined in terms of the homogeneous generalized yield function of spatial beam element, while a dynamic criterion is presented to identify the highly stressed elements. Subsequently, a self-adaptive strategy of elastic modulus adjustment is developed to reduce the elastic moduli of the highly stressed elements for simulation of structural damage evolution. Finally, the reduction rate of elastic moduli of the highly stressed elements is presented to determine the failed sections among the failure elements in the last iteration, based on which the potential failure mode is identified. The applicability, computational accuracy and efficiency of the proposed methodology are validated by comparing with the elasto-plastic methods through two numerical examples.
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Jiao, Chun Wang, Jie Liu, and Qian Qian Wang. "Dynamic Analysis of Nonlinear Anti-Resonance Vibration Machine Based on General Finite Element Method." Advanced Materials Research 443-444 (January 2012): 694–99. http://dx.doi.org/10.4028/www.scientific.net/amr.443-444.694.
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The operation principle of anti-resonance vibration machine was analyzed. The dynamic model of anti-resonance vibration machine with nonlinear spring was established. A new method for solving nonlinear equation based on general finite element method was put forward, the solution was compared with numerical solution, the validity of the solving method was validated. Then the affection of nonlinear and dynamics parameters to the amplitude stabilization was analyzed. the conclusion can be drown as: when the anti-resonance frequency ratio is 1~2,increase the nonlinear of spring can improve the amplitude stabilization, when the anti-resonance ratio is bigger than 3,there is less affection to the amplitude stabilization by nonlinear of spring. The amplitude stabilization can be improved by increasing anti-resonance frequency ratio.
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Jia, Xin, Zheng Xiang Huang, Xu Dong Zu, and Xiao Hui Gu. "Computational Analysis of Woven Fabric Impact Based on Hybrid Element Analysis." Advanced Materials Research 680 (April 2013): 119–23. http://dx.doi.org/10.4028/www.scientific.net/amr.680.119.
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In this paper, Finite element modeling of the impact of the Kevlar woven fabric using hybrid element analysis (HEA) method has been carried out to find out a suitable ratio between area of solid elements used at impact region and area of shell elements used away from impact region. Three HEA models: about one time, two times and three times of the projectile’s diameter with 200 m/s impact velocities are constructed. The solid and shell elements with variable nodal thickness are joined together using tied interfaces in order to ensure that there are no artificial reflections of the longitudinal wave at the interface. The effect of the different ratio of local area and global area on the ballistic performance of the fabric is discussed.
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Shi, Wen Long, Jin Man Yan, and Xuan Liu. "Finite Element Analysis of Corrugated Mild Steel Damper." Advanced Materials Research 671-674 (March 2013): 678–83. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.678.
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A new kind of mild steel damper which use corrugated plate as energy-intensive steel plate is proposed in this paper. The structures and energy dissipation principles of the new type damper are presented. The hysteretic performances of corrugated mild steel damper with different height-thickness ratio, or with the same height-thickness ratio but with different thickness are analysed by numerical simulation with ABAQUS platform and then parameter study on this kind of damper in detail. The results show that the corrugated steel damper has good and stable energy dissipation performance. The performance of energy consumption increases with the decreasing of height-thickness ratio. When at the same height-thickness ratio, the performance of energy consumption increases with the thickness of energy-intensive steel plate.
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Nandi, R. "Novel insensitive minimal-grounded-element dual-polarity ratio-type function generation." Microelectronics Journal 16, no. 4 (July 1985): 25–28. http://dx.doi.org/10.1016/s0026-2692(85)80069-0.
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Hashimoto, Ken-ya, Yuji Koseki, and Masatsune Yamaguchi. "Boundary Element Method Analysis of Interdigital Transducers Having Arbitrary Metallisation Ratio." Japanese Journal of Applied Physics 30, S1 (January 1, 1991): 162. http://dx.doi.org/10.7567/jjaps.30s1.162.
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Skrinjar, Olle, and Per-Lennart Larsson. "On discrete element modelling of compaction of powders with size ratio." Computational Materials Science 31, no. 1-2 (September 2004): 131–46. http://dx.doi.org/10.1016/j.commatsci.2004.02.005.
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Mackay, Trudy F. C. "Transposable element-induced polygenic mutations in Drosophila melanogaster." Genetical Research 49, no. 3 (June 1987): 225–33. http://dx.doi.org/10.1017/s0016672300027117.
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SummaryP-element mutagenesis was used to contaminate M-strain second chromosomes with P elements. The effect of P-element transposition on abdominal and sternopleural bristle scores and on female productivity was deduced by comparing the distributions of these quantitative traits among the contaminated second-chromosome lines with a control population of M-strain second-chromosome lines free of P elements. Estimates of P-element-induced mutational variance, Vm, for these characters are very high, and mutational ‘heritabilities’ (Vm/Ve, the ratio of mutational variance to environmental variance) are of the same order as heritabilities of these traits from natural populations. P-element-induced mutational variance of abdominal bristle score is roughly two orders of magnitude greater than spontaneous and X-ray-induced Vm/Ve for this trait.
Dissertations / Theses on the topic "General Element Ratio"
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Konovalenko, Lena. "Element transport in aquatic ecosystems – Modelling general and element-specific mechanisms." Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-110064.
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Radionuclides are widely used in energy production and medical, military and industrial applications. Thus, understanding the behaviour of radionuclides which have been or may be released into ecosystems is important for human and environmental risk assessment. Modelling of radionuclides or their stable element analogues is the only tool that can predict the consequences of accidental release. In this thesis, two dynamic stochastic compartment models for radionuclide/element transfer in a marine coastal ecosystem and a freshwater lake were developed and implemented (Paper I and III), in order to model a hypothetical future release of multiple radionuclides from a nuclear waste disposal site. Element-specific mechanisms such as element uptake via diet and adsorption of elements to organic surfaces were connected to ecosystem carbon models. Element transport in two specific coastal and lake ecosystems were simulated for 26 and 13 elements, respectively (Papers I and III). Using the models, the concentration ratios (CR: the ratio of the element or radionuclide concentration in an organism to the concentration in water) were estimated for different groups of aquatic organisms. The coastal model was also compared with a 3D hydrodynamic spatial model (Paper II) for Cs, Ni and Th, and estimated confidence limits for their modelled CRs. In the absence of site-specific CR data, being able to estimate a range of CR values with such models is an alternative to relying on literature CR values that are not always relevant to the site of interest. Water chemistry was also found to influence uptake of contaminants by aquatic organisms. Empirical inverse relationships were derived between CRs of fish for stable Sr (CRSr) and Cs (CRCs) and water concentrations of their biochemical analogues Ca and K, respectively (Paper IV), illustrating how such relationships could be used in the prediction of more site-specific CRCs and CRSr in fish simply from water chemistry measurements.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.
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Whitbread, Michael Andrew Ian, and n/a. "Lithogeochemichal alteration aound the Century and Elura Zn-Pb-Ag deposits: detecting alteration expressions in deep and near surface environments." University of Canberra. Resource, Environmental & Heritage Sciences, 2004. http://erl.canberra.edu.au./public/adt-AUC20051129.112425.
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Exploration companies commonly rely on geochemistry to identify alteration of
distinctive geochemical and mineralogical character, surrounding metal sulphide
deposits that were precipitated from hydrothermal fluids. However, examination of
raw analytical data is prone to error due to closure effects and the difficulty in
removing the effects of background variation in unaltered rocks from the variations
imposed by later hydrothermal alteration. Closure can be avoided by using ratios, or
by utilising mass balance approaches based on fixing volume, mass or concentration
changes between samples of parent and daughter lithologies. Using a parent-daughter
approach is limiting, because only pairs of samples can be compared at any one time
and because an unaltered equivalent must be produced for each sample examined in
this way. Pearce Element Ratio analysis and General Element Ratio analysis (PER
and GER) are not restricted in this fashion, and are more amenable to interrogation of
large data sets. PER and GER are also capable of decoupling background variation
from that variation due to hydrothermal alteration. Furthermore, these ratio methods
are readily applied to commercially derived lithogeochemical assays.
In this study, various analytical methods and interpretive techniques (including PER
and GER) have been applied to identify alteration in rocks around the Century and
Elura Zn-Pb-Ag deposits, and to assess whether primary ore-related alteration effects
can still be identified once altered rocks have been subjected to weathering.
Ratios of trace elements over a conserved element have been used to generate a suite
of pathfinder elements for each deposit. Elements enriched in host rocks around both
deposits include the economic metals Zn, Pb and Ag, along with Rb and Tl. Sodium is
ubiquitously depleted in altered rocks. Other elements in the pathfinder suites are
distinctive to each deposit type, and include a number of major and trace elements
that are added or removed from the rocks around the mineralised zones. For example,
Sb and As are enriched in rocks around Elura mineralisation while Ge and Cd are
enriched in samples around Century deposit.
Iron carbonate development accompanied by potassic alteration, the destruction of
albite and the absence of chlorite are the dominant mineral alteration effects at both
deposits. PER and GER diagrams have been used to quantify the intensity of this
alteration and allow lithogeochemistry to be used to vector towards high intensity
alteration, which is adjacent to Century and Elura mineralisation. These ratio methods
are applied to both visibly and cryptically altered rocks at both deposits, and have a
very high degree of success in classifying alteration in unweathered rocks.
The following simple PER ratios indicate proximity to Elura mineralisation:
Ca/C, K/Al for shales, K/(Al-Na) for siltstones/sandstones.
The following simple PER ratios indicate proximity to Century mineralisation:
Mn/Ti, Mg/Ti and Fe/Ti vs C/Ti, K/Ti vs Al/Ti, K/Ti vs (Al-Na)/Ti.
Pathfinder elements can be overlain onto PER and GER diagrams to aid in ranking the
prospectivity of samples, and to assess mineral hosts for individual pathfinder
elements.
Weathering destroys most indicators of alteration in the Elura area, while alteration
signatures are better preserved in host rocks around the Century deposit.
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Erdogan, Hakan. "Improvement Of Punching Strength Of Flat Plates By Using Carbon Fiber Reinforced Polymer (cfrp) Dowels." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612728/index.pdf.
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Due to their practical application, flat-plates have been commonly used slab type in constructions in recent years. According to the investigations that were performed since the beginning of the 20th century, the vicinity of the slab-column connection is found to be susceptible to punching failure that causes serious unrepairable damage leading to the collapse of the structures. The objective of this study is to enhance the punching shear strength of slab-column connections in existing deficient flat plate structures. For this purpose, an economical and easy to install strengthening method was applied to ¾scale flat-slab test specimens. The proposed strengthening scheme employs the use of in house-fabricated Carbon Fiber Reinforced Polymer (CFRP) dowels placed around the column stubs in different numbers and arrangements as vertical shear reinforcement. In addition, the effect of column aspect ratio on strengthening method was also investigated in the scope of this study. Strength increase of at least 30% was obtained for the CFRP retrofitted specimens compared to the companion reference specimen. Three-dimensional finite element analyses of test specimens were conducted by using the general purpose finite element analyses program. 3-D finite element models are successful in providing reasonable estimates of load-deformation behavior and strains. The experimental punching shear capacities and observed failure modes of the specimens were compared with the estimations of strength and failure modes given by punching shear strength provisions of ACI 318-08, Eurocode-2, BS8110-97 and TS500. Necessary modifications were proposed for the existing provisions of punching shear capacity in order to design CFRP upgrading.
Books on the topic "General Element Ratio"
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General class: FCC license preparation for element 3, general class theory. 8th ed. Niles, Ill: Master Pub., 2011.
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West, Gordon. General class: FCC license preparation for element 3, general class theory. 6th ed. Lincolnwood, Ill: Master Pub., [c2004], 2004.
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West, Gordon. General class: FCC license preparation for element 3, general class theory. 7th ed. Niles, Ill: Master Pub., 2007.
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General class: FCC license preparation for element 3, general class theory. 7th ed. Niles, Ill: Master Pub., 2007.
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Gordon, West, ed. General class: FCC license preparation for element 3 general class theory. 5th ed. Lincolnwood, Ill: Master Pub., 2000.
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New general class: FCC license preparation : element 3B. 4th ed. Lincolnwood, Ill: Master Pub., 1998.
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Fred, Maia. General radiotelephone operator license: FCC commercial radio license preparation, Element 1 and Element 3 question pools. Richardson, Tex: Master Pub., 1994.
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Maia, Fred. GROL plus: General Radiotelephone Operator License plus Radar Endorsement : FCC commercial radio license preparation element 1, element 3 and element 8 question pools. Richardson, Tex: Master Pub., 1996.
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Fred, Maia. GROL plus: General Radiotelephone Operator License plus Radar Endorsement : FCC commercial radio license preparation element 1, element 3 and element 8 question pools. Niles, Ill: Master Pub., 2003.
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Elements of General Radio-Therapy for Practitioners. Franklin Classics, 2018.
Find full textBook chapters on the topic "General Element Ratio"
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Skrypnik, Oleg Nicolaevich. "Elements of the General Radio Navigation Theory." In Radio Navigation Systems for Airports and Airways, 1–52. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-7201-8_1.
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Walker, James C. G. "How to Calculate Isotope Ratios." In Numerical Adventures with Geochemical Cycles. Oxford University Press, 1991. http://dx.doi.org/10.1093/oso/9780195045208.003.0008.
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The calculation of isotope ratios requires special consideration because isotope ratios, unlike matter or energy, are not conserved. In this chapter I shall show how extra terms arise in the equations for the rates of change of isotope ratios. The equations developed here are quite general and can be applied to most of the isotope systems used in geochemistry. As an example of the application of these new equations, I shall demonstrate a simulation of the carbon isotopic composition of ocean and atmosphere and then use this simulation to examine the influence on carbon isotopes of the combustion of fossil fuels. As an alternative application I shall simulate the carbon isotopic composition of the water in an evaporating lagoon and show how the composition and other properties of this water might be affected by seasonal changes in evaporation rate, water temperature, and biological productivity. Equations for the rates of change of individual isotopes in a reservoir are not essentially different from the equations for the rates of change of chemical species. Isotopic abundances, however, are generally expressed as ratios of one isotope to another and, moreover, not just as the ratio but also as the departure of the ratio from a standard. This circumstance introduces some algebra into the derivation of an isotopic conservation equation. It is convenient to pursue this algebra just once, as I shall in this section, after which all isotope simulations can be formulated in the same way. I shall use the carbon isotopes to illustrate this derivation, but the same approach can be used for the isotopes of other elements, such as sulfur, oxygen, nitrogen, hydrogen, or strontium. The most abundant isotope of carbon has a mass of 12 atomic mass units, 12C. A less abundant stable isotope is 13C. And much less abundant is the radioactive isotope 14C, also called radiocarbon. It is convenient to express the abundances of these rare isotopes in terms of ratios of the number of atoms of the rare isotope in a sample to the number of atoms of the abundant isotope. We call this ratio r, generally a very small number.
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Bianchi, Thomas S. "Characterization of Organic Matter." In Biogeochemistry of Estuaries. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195160826.003.0018.
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In chapter 8, a general overview was provided on the dominant sources of organic matter in estuarine systems. In general, estuarine organic matter is derived from a multitude of natural and anthropogenic allochthonous and autochthonous sources that originate across a freshwater to seawater continuum. Knowledge of sources, reactivity, and fate of organic matter are critical in understanding the role of estuarine and coastal systems in global biogeochemical cycles (Simoneit, 1978; Hedges and Keil, 1995; Bianchi and Canuel, 2001). Due to a wide diversity of organic matter sources and the dynamic mixing that occurs in estuarine systems, it remains a significant challenge in determining the relative importance of these source inputs to biogeochemical cycling in the water column of sediments. Temporal and spatial variability in organic matter inputs adds further to the complexity in understanding these environments. In recent years there have been significant improvements in our ability to distinguish between organic matter sources in estuaries using tools such as elemental, isotopic (bulk and compound/class specific), and chemical biomarker methods. This chapter will provide a general overview of the biochemistry of dominant organic compounds in organic matter and the techniques used to distinguish them in estuarine systems. The abundance and ratios of important elements in biological cycles (e.g., C, H, N, O, S, and P) provide the basic foundation of information on organic matter cycling. For example, concentrations of total organic carbon (TOC) provide the most important indicator of organic matter since approximately 50% of most organic matter consists of C. As discussed in chapter 8, TOC in estuaries is derived from a broad spectrum of sources with very different structural properties and decay rates. Consequently, while TOC provides essential information on spatial and temporal dynamics of organic matter it lacks any specificity to source or age of the material. When bulk C information is combined with additional elemental information, as in the case of the C-to-N ratio, basic source information can be inferred about algal and terrestrial source materials (see review, Meyers, 1997). The broad range of C:N ratios across divergent sources of organic matter in the biosphere demonstrate how such a ratio can provide an initial proxy for determining source information.
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Bianchi, Thomas S. "Organic Matter Cycling." In Biogeochemistry of Estuaries. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195160826.003.0017.
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In this chapter the general processes involved in controlling production and transformation of organic matter will be discussed as well as some of the associated stoichiometric changes of a few key biological elements (e.g., C, N, P, S). Stoichiometry is defined as the mass balance of chemical reactions as they relate to the law of definite proportions and conservation of mass (Sterner and Elser, 2002). For example, if we examine the average atomic ratios of C, N, and P in phytoplankton we see a relatively consistent ratio of 106:16:1 in most marine species. This is perhaps the best example of applied stoichiometric principles in natural ecosystems and is derived from the classic work of Alfred C. Redfield (1890–1983) (Redfield, 1958; Redfield et al., 1963). More specifically, Redfield compared the ratios of C, N, and P of dissolved nutrients in marine waters to that of suspended marine particulate matter (seston) (essentially phytoplankton) and found straight lines with equal slopes (figure 8.1; Redfield et al., 1963). This relationship suggested that marine biota were critical in determining the chemistry of the world ocean, clearly one of the most important historical findings linking chemical and biological oceanography (Falkowski, 2000). Moreover, the Redfield ratio has been further validated with recent data using improved analytical techniques (Karl et al., 1993; Hoppema and Goeyens, 1999). Other work has shown that there are predictable deviations from the Redfield ratio across a freshwater to open ocean marine gradient (figure 8.2; Downing, 1997). For example, N-to-P ratios in estuaries have commonly been shown to be lower and/or higher than the predicted Redfield ratio because of denitrification and anthropogenic nutrient enrichment processes, respectively. Inputs of vascular plant organic matter (e.g., mangroves, salt marshes, seagrasses) to estuarine systems presents another problem in causing deviations of C:N:P from the Redfield ratio. Vascular plants have been shown to deviate from this ratio in part because of relatively high amounts of C and N compared to algae due to a higher abundance of structural support molecules (e.g., cellulose, lignin) and defense antiherbivory (secondary) compounds (e.g., tannins), respectively (Vitousek et al., 1988).
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Kumar Singh, Shailesh, and Vivek K. Singh. "Design and Development of High Entropy Alloys Using Artificial Intelligence." In Advances in High-Entropy Alloys - Materials Research, Exotic Properties and Applications [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.96761.
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The conventional design approach of alloys initiates with one principal element and continues by adding several alloying elements to obtain desired properties. In this method, the intrinsic properties of the designed alloy are governed by the principal element. For example, in steel alloy, iron is the principal element, Aluminium in aluminium alloy, and so on. Compared to the conventional alloy, high entropy alloys do not have any dominating elements; all the elements present in these alloys either have an equal or near-equal ratio of elements. As reported in the literature, these alloys exhibit interesting material properties such as high strength, high hardness, improved elevated temperature strength, and magnetic properties. These characteristics make HEAs a suitable option for high-performance applications in the aero engine, aerospace structures, and machine tools. High entropy alloy has multiple principal elements as shown in schematic diagram 1; it leads to much higher possible compositions than conventional alloys. The huge compositional space provides an opportunity to improve desired mechanical properties. If it is explored through “trial and error,” it will be challenging and cumbersome. Therefore, search schemes that can competently and promptly recognize particular alloys with desired properties are essential. Artificial Intelligence is a useful tool to model, discover, and optimize new alloys that enable predicting individual material properties as a function of composition. While the application of Artificial Intelligence is quite popular in many aspects of society, its usage in material informatics is still in the nascent stage. The algorithm used in artificial intelligence is trained to pick up predictive rules from data and create a material model quicker than a computational model and can even generate the model for which no physical model exists. Artificial Intelligence (AI) allows predicting a set of experiments to be conducted to detect new alloy having desired properties. Thus, AI can be used as a valuable tool to optimize the development of new alloys.
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Herz, Norman, and Ervan G. Garrison. "Applications of Stable Isotopes in Archaeological Geology." In Geological Methods for Archaeology. Oxford University Press, 1998. http://dx.doi.org/10.1093/oso/9780195090246.003.0020.
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Isotopic ratios of elements in natural materials on the earth either have been constant in time and space or have varied as a result of radioactive decay or geochemical fractionation. Elements which show variations in isotopic abundances in different samples and the reasons for these variations have helped resolve many geological and archaeological problems. Radioactive decay has provided absolute dating clocks: for archaeology, the most useful systems have been associated with 14C, 40Ar, and U-disequilibrium series. Variations in isotopic ratios of the stable elements H, C, O, N, S, Sr, and Pb have helped solve problems of provenance, paleoenvironments, and paleodiets. The rationale for isotopic variations of individual elements will determine the types of applications to archaeological geology. The most important applications are the determinations of artifact signatures, paleodiet, and paleoenvironment. Isotopic fractionation of light elements by physical, chemical, and biological processes is controlled by those thermodynamic properties which are determined by atomic weight and electronic configuration. Thermodynamic properties of molecules that are mass and temperature dependent include energy, which decreases with decreasing temperature, and vibrational frequency, which varies inversely in proportion to the square root of the reduced mass. Easily measurable isotopic separation is generally restricted to the lighter elements, that is, with atomic weights less than 40. Because isotopic fractionation is mass dependent, the separation is greater for elements with the greater mass difference between isotopes. The greatest separation is expected for hydrogen (mass 1) versus deuterium (mass 2); the other light elements commonly have isotopic differences closer to 10%. Thus, the lighter isotopes have higher vibrational energy and their chemical bonds are more easily broken. The different reactivity of lighter versus heavier isotopes of an element is responsible for their separation during geochemical and biological processes. Thermodynamic behavior has been considered a principal cause for variations, not in isotopic abundances of the heavier elements Sr and Pb, but rather in abundances of their parent radionuclides: Rb for Sr and U and Th for Pb. Recently, however, P. Budd and others suggested that under nonequilibrium conditions, fractionation could theoretically take place among the lead isotopes.
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Marriwala, Nikhil Kumar, Om Prakash Sahu, and Anil Vohra. "Secure Baseband Techniques for Generic Transceiver Architecture for Software-Defined Radio." In Research Anthology on Recent Trends, Tools, and Implications of Computer Programming, 1961–83. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-3016-0.ch089.
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Software Defined Radio (SDR) systems are the ones which can adapt to the future-proof solution and it covers both existing and emerging standards. An SDR has to possess elements of reconfigurability, intelligence and software programmable hardware. The main interest in any communication group is the sure sending of signals of info from a transmitter to a receiver. The signals are transmitted via a guide who corrupts the signal. To ensure reliable communication forward error-correcting (FEC) codes are the main part of a communication system. This chapter will discuss an SDR system built using LabVIEW for a Generic Transceiver. This chapter has covered emerging software radio standards and the technologies being used to specify and support them.
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Marriwala, Nikhil Kumar, Om Prakash Sahu, and Anil Vohra. "Secure Baseband Techniques for Generic Transceiver Architecture for Software-Defined Radio." In Handbook of Research on Recent Developments in Intelligent Communication Application, 96–117. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-1785-6.ch004.
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Software Defined Radio (SDR) systems are the ones which can adapt to the future-proof solution and it covers both existing and emerging standards. An SDR has to possess elements of reconfigurability, intelligence and software programmable hardware. The main interest in any communication group is the sure sending of signals of info from a transmitter to a receiver. The signals are transmitted via a guide who corrupts the signal. To ensure reliable communication forward error-correcting (FEC) codes are the main part of a communication system. This chapter will discuss an SDR system built using LabVIEW for a Generic Transceiver. This chapter has covered emerging software radio standards and the technologies being used to specify and support them.
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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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H. Altiti, Awwad, Rami O. Alrawashdeh, and Hani M. Alnawafleh. "Open Pit Mining." In Mining Techniques - Past, Present and Future. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.92208.
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Open pit mining method is one of the surface mining methods that has a traditional cone-shaped excavation and is usually employed to exploit a near-surface, nonselective and low-grade zones deposits. It often results in high productivity and requires large capital investments, low operating costs, and good safety conditions. The main topics that will be discussed in this chapter will include an introduction into the general features of open pit mining, ore body characteristics and configurations, stripping ratios and stripping overburden methods, mine elements and parameters, open pit operation cycle, pit slope angle, stability of mine slopes, types of highwall failures, mine closure and reclamation, and different variants of surface mining methods including opencast mining, mountainous mining, and artisan mining.
Conference papers on the topic "General Element Ratio"
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Babaee, Hessam, Xiaoliang Wan, and Sumanta Acharya. "Effect of Uncertainty in Blowing Ratio on Film Cooling Effectiveness." In ASME 2013 Heat Transfer Summer Conference collocated with the ASME 2013 7th International Conference on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/ht2013-17159.
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In this study the effect of randomness of blowing ratio on film cooling performance is investigated by combining direct numerical simulations with a stochastic collocation approach. The geometry includes a 35-degree inclined jet with a plenum attached to it. The blowing ratio variations are assumed to have a truncated Gaussian distribution with mean of 0.3 and the standard variation of approximately 0.1. The parametric space is discretized using Multi-Element general Polynomial Chaos (ME-gPC) with five elements where general polynomial chaos of order 3 is used in each element. A fast convergence of the polynomial expansion in the random space was observed. Direct numerical simulations were carried out using spectral element method to sample the governing equations in space and time. The probability density function of the film cooling effectiveness was obtained and the standard deviation of the adiabatic film cooling effectiveness on the blade surface was calculated. A maximum standard deviation of 15% was observed in the region within a four-jet-diameter distance downstream of the exit hole. The spatially-averaged adiabatic film cooling effectiveness was 0.23 ± 0.02. The calculation of all the statistical properties were carried out as off-line post-processing. Overall the computational strategy is shown to be very effective with the total computational cost being equivalent to solving twenty independent direct numerical simulations that are performed concurrently.
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Khair, K. R., and P. N. Singh. "Non-Linear Stress Analysis of Threaded Connection With High Strength Ratio Materials." In 10th International Conference on Nuclear Engineering. ASMEDC, 2002. http://dx.doi.org/10.1115/icone10-22750.
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When the relative strength ratio of nut-to-bolt thread is high, the weaker of the two threads will deflect under the relatively stiff action of the other. The rules of the ASME B1.1-1989 provide general design rules for designing non-critical threaded joints. Most threaded joint designs are based on these rules. In most cases, the strengths of the stud and the nut are about the same. This paper addresses plastic deformation and strain in the threaded part of a component (stud) whose strength is about 7 times more than the mating threads. An axisymmetric finite element analysis was performed using nonlinear material properties and nonlinear contact elements between the surfaces of the threads. The results were used to calculate the collapse load for the thread following the rules of Appendix F of the ASME B&PV. It was found that the collapse (maximum allowed) load calculated using this nonlinear finite element approach and Appendix F of ASME code is 50% higher than the load calculated using the conventional elastic methods given in the ASME code rules would be acceptable.
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Kar, Vishesh Ranjan, and Subrata Kumar Panda. "Free Vibration Responses of Functionally Graded Spherical Shell Panels Using Finite Element Method." In ASME 2013 Gas Turbine India Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gtindia2013-3693.
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Free vibration responses of functionally graded spherical shell panels are investigated in the present article. A general mathematical model is developed based on higher order shear deformation theory mid-plane kinematics. The effective material properties are graded in the thickness direction according to a power-law distribution and it varies continuously from metal (bottom surface) to ceramic (top surface). The model is discretized using a nine noded quadrilateral Lagrangian element. A convergence test has been done with different mesh refinement and compared with the available published results. In addition to that the present study includes an ANSYS model check with the developed mathematical model to show the efficacy. New results are computed for different parameters such as volume fraction, thickness ratio, curvature ratio and support conditions which indicates the effect of parametric study on non-dimensional frequency parameters.
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Oh, Chang-Sik, Nak-Hyun Kim, Sung-Hwan Min, and Yun-Jae Kim. "Finite Element Damage Analyses for Predictions of Creep Crack Growth." In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25294.
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This paper provides the virtual simulation method for creep crack growth test, based on finite element (FE) analyses with damage mechanics. Creep tests of smooth bars are used to quantify the constants of creep constitutive equation. The reduction of area resulting from creep tests of smooth and notched bar is adopted as a measure of creep ductility under multiaxial stress conditions. The creep ductility exhaustion concept is adopted for calculating creep damage, which is defined as the ratio of creep strain to the multiaxial creep ductility. To simulate crack propagation, fully damaged elements are forced to have nearly zero stresses using user-defined subroutine UHARD in the general-purpose FE code, ABAQUS. The results from 2D or 3D FE analyses are compared with experimental data of creep crack growth. It is shown that the predictions obtained from this new method are in good agreement with experimental data.
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Kasahara, Naoto, Hideki Takasho, Nobuchika Kawasaki, and Masanori Ando. "Effective Stress Ratio of Triangular Pattern Perforated Plates." In ASME 2008 Pressure Vessels and Piping Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/pvp2008-61458.
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Tubesheet structures utilized in heat exchangers have complex perforated portions. For realistic design analysis, axisymmetric models with equivalent solid materials of perforated plate are conventionally adopted to simplify perforated area (figure1). Sec.III Appendix A-8000 (ASME 2004) provides elastic equivalent solid materials for flat tubesheets. Plastic properties were studied by Porowski et al. (1974), Gorden et al. (2002) and so on. Elevated temperature design of tubesheets requires plastic and creep properties in addition. The purpose of this study is to develop a general determination method of non-linear equivalent material properties for perforated plates and to confirm their applicability to both flat and spherical tubesheets. Main loadings of tubesheets in fast reactor heat exchanges are inner pressure and thermal stress at transient operations. Under above conditions, average stress of perforated area becomes approximately equi-biaxial. Therefore, average inelastic behaviors of various perforated plates subjected to equi-biaxial field were investigated by inelastic finite element method. Though above investigations, Authors clarified that perforated plates have their own effective stress ratio (ESR). ESR is a function of geometry and is independent from their materials. ESR can determine non-linear equivalent material properties of perforated plates for any kind of constitutive equations of base metals. For simplified inelastic analysis of perforated plates, the brief equations were proposed to determine equivalent plastic and creep material properties for perforated plates. It is considered that physical meaning of ESR is an effective stress ratio between perforated plates and equivalent solid plates. ESR is a function of geometry and is independent from constitutive equations. ESR can determine non-linear equivalent material properties for perforated plates from any kind of constitutive equations of base materials. Assumptions in ESR are von Mises’s equivalent stress-strain relationship and equi-biaxial loadings. Applicability of ESR was investigated through finite element analyses of various flat and spherical tubesheets.
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Sutharson, B., R. Sarala, and R. Kari Thangarathanam. "Geometric Non Linear Analysis of Composite Shells Under Thermomechanical Loading." In ASME 2005 Pressure Vessels and Piping Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/pvp2005-71074.
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A Geometric non-linear analysis of composite shells under thermomechanical loading has been discussed here. From the literature, it may be seen that the thermal stress analysis of structural elements has continued to remain a research topic for a couple of decades. No one computationally verified the geometric non-linear buckling of composite shells under thermomechanical loading using semiloof element. In this work, linear buckling analysis of Kari Thangaratnam (2) is extended to geometric non-linear analysis of composite shells under thermomechanical loading. A general shell element called the semiloof shell element has been extended to thermal stress analysis of laminated shells. The formulation is based on nonlinear theory and the finite element method using semiloof element. The validation checks on the program are carried out using results on homogeneous isotropic shells available in the literature. The parameters considered in analysis are (1) number of layers in the laminate, (2) Lay-up sequence (symmetry, antisymmetry, cross-ply etc.), (3) Fibre orientation angle, (4) Different aspect ratios, (5) Orthotrophy ratio, (6) Boundary conditions (simply supported, clamped and combination of boundary conditions).
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Sutharson, B., A. Elaya Perumal, and R. Kari Thangarathanam. "Geometric Non Linear Analysis of Composite Shells Under Thermomechanical Load." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61422.
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Geometric nonlinear analysis of composite shells under thermomechanical load is reported here. From the literature, it may be seen that the thermal stress analysis of structural elements has continued to remain a research topic for a couple of decades. No one computationally verified the geometric non-linear buckling of composite shells under thermomechanical load using semiloof element. In this work, linear buckling analysis of Kari Thangaratnam (2) is extended to geometric non-linear analysis of composite shells under thermomechanical load. A general shell element called the semiloof shell element has been extended to thermal stress analysis of laminated shells. The formulation is based on nonlinear theory and the finite element method using semiloof element. The validation checks on the program are carried out using results on homogeneous isotropic shells available in the literature. The parameters considered in analysis are (1) number of layers in the laminate, (2) Lay-up sequence (symmetry, antisymmetry, cross-ply etc.), (3) Fibre orientation angle, (4) Different aspect ratios, (5) Orthotrophy ratio, (6) Boundary conditions (simply supported, clamped and combination of boundary conditions).
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Kataoka, Shunji, Asako Miyakawa, and Takuya Sato. "Study on Collapse Characteristics of Cylinder-to-Cylinder Intersections by Inelastic Finite Element Analysis." In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-77277.
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It is known that the collapse strength of complex three-dimensional structures cannot be evaluated accurately with elastic analysis, and more accurate results require the use of inelastic analysis. A typical example is cylinder-to-cylinder intersection. In this paper, the relationship of collapse loads and local primary membrane stresses of cylinder-to-cylinder intersections was examined. First, elastic analysis of the cylinder-to-cylinder intersections with various combinations of diameter and thickness under internal pressure was conducted. The local primary membrane stress (PL) obtained from the analysis was normalized by the general primary membrane stress (Pm) the ratio of PL/Pm defining the Stress Intensification Factor (SIF). The results revealed that SIF was directly influenced by the geometries. Secondly, limit load analysis was conducted on the same structures and the collapse pressure was obtained. The Collapse Strength Reduction Factor (CSRF) defined as the ratio of the run pipe collapse pressure to the cylinder-to-cylinder collapse pressure was proposed. The CSRF was also found to be influenced by the geometries. Comparing the result of SIF with CSRF, it is clear that the evaluation by SIF is overly-conservative and the proposed concept of CSRF provides more accurate evaluation of the cylinder-to-cylinder intersections. Furthermore, the basic data for the intersections with uniform thickness can also be applied to the reinforced intersections.
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Walter, Matthew C., and Daniel V. Sommerville. "Nozzle Blend Radius Peak Stress Correction Factors for 2-D Axisymmetric Finite Element Models." In ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/pvp2010-25104.
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Two dimensional (2-D) axisymmetric finite element models (FEMs) are often used as a simplified means of modeling cylindrical nozzles that intersect cylindrical pressure vessels. An axisymmetric model represents the vessel as a spherical shell rather than a cylindrical shell. Therefore, analysts must correct the stresses predicted by the 2-D model to account for the three dimensional (3-D) effects caused by the true nozzle geometry, which are not represented by the 2-D axisymmetric simplification. This paper presents total stress correction factors for the nozzle blend radius region of Boiling Water Reactor (BWR) Feedwater, Core Spray and Recirculation Inlet nozzle geometries. The correction factors are defined by taking the ratio of the total hoop stress from the 3-D nozzle FEM to the total hoop stress obtained from the 2-D nozzle FEM. Eighteen (18) separate nozzle designs were evaluated. These cases are considered to span the range of dimensions expected for General Electric type BWR-2 through BWR-6 Feedwater, Core Spray, and Recirculation Inlet nozzles.
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Trinca, Giovan Battista, Nicola Ronchi, Fausto Fusari, and Emanuele Fiordaligi. "Alternative Design Approach by Finite Element Analysis for High Pressure Equipment." In ASME 2020 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/pvp2020-21540.
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Abstract Components that are subject to pressure, typical of the pressure vessel industry, can be designed using such calculation methods as “Design by Rule-DBF” or “Design by Analysis-DBA”. DBA, based on the FEM, is used increasingly often because, in addition to providing a reduction in thickness due to the lower uncertainty on the calculation, it helps to verify and study physical phenomena and complex geometry that are otherwise difficult to research while offering a more intuitive usability of the results. In this paper we wish to offer, in an educative and qualitative manner, a general overview of DBA from the creation of the model to obtaining the results, describing the types of analysis that can be carried out according to the constitutive model of the material used and the degree of accuracy that can be achieved. At the end, we cover some case studies in which DBA has been successfully used to verify design or particular conditions (such as heat treatments) for pressure vessels fabrication. The DBA calculation, described in this paper, is used with the same computational methods for high, medium or low pressure components, but it is clear that the most significant reduction in thickness is for high pressure components such as reactors, which is why the DBA calculation is particularly appreciated for this type of equipment. In the context of this paper “high pressure equipment” means when the ratio of the inner diameter to thickness of the walls is < 30.
Reports on the topic "General Element Ratio"
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Memorias Foro Internacional Neogranadino. ¿Gobernanza global o gobierno globalista? 2020. Universidad Militar Nueva Granada, April 2021. http://dx.doi.org/10.18359/docinst.5696.
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El 23 de julio del 2020, en el marco de la celebración del aniversario treinta y ocho de la Universidad Militar Nueva Granada y en medio de las vicisitudes propias que se despliegan al enfrentar una pandemia como la que ha aquejado al mundo durante más de un año, se desarrolló el Foro Internacional Neogranadino: ¿gobernanza global o gobierno globalista?, con la participación de panelistas de alto nivel tales como el TG (r) Frederick Rudesheim, director del Centro de Estudios Hemisféricos de Defensa William J. Perry; el Dr. Alexis Osvaldo López Tapia, investigador y director de radio y TV; el señor Rafael Nieto Loaiza, abogado, columnista y analista político; el Dr. Joseph Humire Cubides, director del Centro para una Socie- dad Libre Segura (SFS); el Dr. Jaime García Covarrubias, analista internacional; el Dr. Omar Bula Escobar, analista internacional; y la Dra. Celina B. Realuyo, profesora del Centro William J Perry. Además, contó con intervenciones magistrales por parte del Dr. Carlos Holmes Trujillo García (Q. E. P. D.), ministro de Defensa Nacional; el señor BG Adolfo Clavijo Ardila, exrector de la Universidad Militar Nueva Granada; y el señor BG Luis Fernando Puentes Torres, actual rector de este claustro universitario. Entre los temas más relevantes tratados durante el foro se encuentran la pandemia generada por el COVID-19, los desafíos de la gobernanza nacional frente a las amenazas externas, el debilitamiento integral de las Fuerzas Armadas, la política exterior de los Estados Unidos con respecto a elementos de seguridad nacional y cooperación internacional, y la revolución molecular disipada como una explicación a la generalización de la violencia urbana y el anarquismo que, derivados de fenómenos globalizadores, ponen en riesgo a los Estados.