Spelling suggestions: "subject:"eonformal"" "subject:"amongnormal""
741 |
Quality aspects in direct shear testing of rock jointsLarsson, Jörgen January 2021 (has links)
The stability of rock masses is influenced by the occurrence of rock joints. Therefore, the shear strength of rock joints must be considered in dimensioning of underground constructions. One way to predict the shear strength is through usage of failure criteria, which are validated from results of direct shear tests under controlled laboratory conditions. Consequently, the quality of the results from the tests are crucial to the accuracy with which the criteria will be able to predict the shear strength. Since rock joints are unique by nature usage of replicas (man-made copies of rock joints) is of importance in parameter studies. The overall objective of this work is to facilitate the development of improved criteria for predictions of the shear strength of rock joints. To support this objective, two sources of uncertainty have been investigated, namely the geometry of replicas and the influence of the normal stiffness of test systems. Two quality assurance parameters for evaluation of geometrical differences between replicas and rock joints based on scanning data have been derived. The first parameter describes the morphological deviations. The second parameter describes the deviations in orientation with respect to the shear plane. The effective normal stiffness approach, which compensates for the influence of the normal stiffness of the test system in direct shear testing, has been developed, validated, and applied. With help of the quality assurance parameters it is demonstrated that it is possible to reproduce replicas within narrow tolerances. Application of the effective normal stiffness approach basically eliminates the normal load error. In all, the results support generation of improved quality of test data and consequently, the development of shear strength criteria with improved accuracy will also be facilitated. / <p>Academic Dissertation which, with due permission of the KTH Royal Institute of Technology, is submitted for public defence for the Degree of Licentiate of Engineering on Wednesday the 9th June 2021, at 9:00 a.m. in M108, Brinellvägen 23, Stockholm.</p><p><strong>Paper A</strong>: Larsson J, Flansbjer M, Portal N W, Johnson E, Johansson F, and Mas Ivars D. (2020) Geometrical Quality Assurance of Rock Joint Replicas in Shear Tests – Introductory Analysis. Paper presented at the ISRM International Symposium - EUROCK 2020, physical event not held. https://onepetro.org/ISRMEUROCK/proceedings-abstract/EUROCK20/All-EUROCK20/ISRM-EUROCK-2020-101/451187 In Diva: http://urn.kb.se/resolve?urn=urn:nbn:se:ri:diva-51987 </p><p><strong>Paper B:</strong> Larsson J, Johansson F, Mas Ivars D, Johnson E, Flansbjer M and Portal N W. (2021) Rock joint replicas in direct shear testing – Part 1: Extraction of geometrical quality assurance parameters. To be submitted to Rock Mechanics and Rock Engineering In DiVA: http://urn.kb.se/resolve?urn=urn:nbn:se:ri:diva-53111 </p><p><strong>Paper C:</strong> Larsson J and Flansbjer M. (2020) An Approach to Compensate for the Influence of the System Normal Stiffness in CNS Direct Shear Tests. Rock Mechancis and Rock Engineering 53, 2185–2199 https://doi.org/10.1007/s00603-020-02051-0 In DiVA: http://urn.kb.se/resolve?urn=urn:nbn:se:ri:diva-44085 </p><p><strong>Paper D:</strong> Larsson J. (2021) Experimental investigation of the system normal stiffness of a 5 MN direct shear test setup and the compensation of it in CNS direct shear tests. Submitted to ISRM International Symposium - EUROCK 2021 In DiVA: http://urn.kb.se/resolve?urn=urn:nbn:se:ri:diva-53112 </p>
|
742 |
Investigation of Novel Turbulence Modeling Techniques for Gas Turbines and Aerospace ApplicationsDhakal, Tej Prasad 11 May 2013 (has links)
Standard eddy-viscosity models lack curvature and system rotation sensitized terms in their formulation. Hence they fail to capture the effects of curvature and system rotation on turbulence anisotropy. As part of this effort, an algebraic expression for a characteristic rotation term is developed and tuned with the help of rotating homogeneous shear flow. This formulation is primarily based upon the rotation and curvature sensitized eddy-viscosity coefficient developed by York et al. (2009). A new scalar transport equation loosely based on Durbin’s wall normal turbulent velocity scale (Durbin, 1991) is introduced to account for the modification in turbulence structure due to system rotation and curvature effects. The added transport equation also introduces history effects and stability in the solution with small increase in computational cost. The eddy-viscosity is redefined based on new turbulent velocity scale and hence the effects of rotation and streamline curvature are introduced into the mean momentum equation. A number of canonical test cases with significant curvature and rotation effects along with a cyclone flow, a representative of complex industrial flows, are considered for model validation. Hybrid modeling framework combines the strength of RANS in boundary layers and LES in separated shear layers to alleviate the weaknesses of RANS and limitations of LES model in some complex flows. A recently proposed hybrid RANS-LES modeling framework uses a weighing parameter that dynamically determines the RANS and LES regions based on solution statistics. The hybrid modeling methodology is implemented on a normal jet in crossflow, and a film cooling case for the purpose of model validation and evaluation. The final goal of the proposed effort is to combine advanced RANS modeling capability with LES using the new hybrid modeling framework. Specifically, the curvature and rotation sensitive RANS model developed here is coupled with commonly used LES models to produce a novel model for complex turbulent flows with the potential to improve accuracy of CFD predictions (versus existing RANS models) as well as significantly reduce the computational expense (versus existing LES models). Performance of the model form hence developed is evaluated on a cyclone flow case.
|
743 |
Bolstering Pine Lumber Value Through Statistical Analysis And Nondestructive TestingOwens, Frank Charles, IV 11 August 2017 (has links)
In or around 2010, a nationwide reevaluation of the allowable properties for southern pine dimension lumber was initiated. This led to a 2013 reduction in the design values of visually graded southern pine dimension lumber and a resulting decrease in its commercial and utility value. This change compelled researchers and industry professionals to ponder what could be done to shore up the value of solid-sawn southern pine products going forward and potentially increase design values if appropriate. In pursuit of this question, this dissertation looks closely at three areas: 1) the possibility this reduction in mechanical performance is not merely limited to southern pine structural lumber but can also be observed in other solid-sawn softwood products and species, 2) flaws that might exist in commonly utilized statistical models for estimating allowable properties in lumber, and 3) the feasibility of using existing technologies to begin to compensate for the economic and/or utility losses attributed to the recent reduction in design values. This work is comprised of an introduction, a conclusion, and three independent content chapters utilizing a variety of statistical techniques to investigate whether strength and stiffness reduction might also be occurring in southern pine (and Douglasir) utility crossarms, evaluate the propriety of using a Weibull distribution model for estimating allowable properties in dimension lumber, and gauge the suitability of nondestructive testing methods for potentially identifying high-value premium grades in solid-sawn softwood products.
|
744 |
Vernacular Forensics: Searching for the Disappeared, Bureaucratic Violence and Communal Exhumations of Clandestine Burials in Contemporary MexicoAlamo-Bryan, Marina January 2023 (has links)
In September 2014, forty-three students were attacked and forcibly disappeared by police in the town of Iguala, Mexico. The Ayotzinapa Case, as it is known, caused international outcry and a domestic political crisis. In the following weeks, the surrounding countryside was discovered to be saturated with clandestine individual and mass graves, and a crisis emerged around bodily remains and their improper burial. As the willingness of the Mexican State to investigate became less and less credible, families of the disappeared —not just families of the students, but families of hundreds of other disappeared people across the country— took on the role of searching for their loved ones and caring for the name-less and unidentified dead they began to find. No longer waiting for authorities to act, kin of the disappeared began to symbolically and materially enact attributes of the State.
What started as groups of people getting together on Sundays in the town of Iguala, to go to the hills in search of bodies in clandestine burials, grew in the following years into a nation-wide social movement. What does it mean to find a murdered body in Mexico today? What does it mean for it to become evidence? What work is done through the discovery by searching families of such bodies? The result of 32 months of ethnographic fieldwork in Mexico, between 2015 and 2021, this dissertation builds on anthropological scholarship on bureaucracy and forensic evidentiary practices to examine the encounters of relatives of the disappeared and State authorities. It analyses current regimes of justice and forensic expertise, interrogating how bodies in the ground are translated into terms legible to the law.
This project investigates social processes of public truth production, forms of violence exerted by the State —through physical violence, forced disappearance, and bureaucratic violence— by bringing into conversation forensics alongside recent critical perspectives on bureaucracy, bearing in mind longstanding approaches to the anthropology of death and the anthropology of the State, to address how dead bodies become evidence and how truth claims circulate around and through them.
|
745 |
On the Automorphism Groups of Almost All Circulant Graphs and DigraphsBhoumik, Soumya 17 August 2013 (has links)
We attempt to determine the structure of the automorphism group of a generic circulant graph. We first show that almost all circulant graphs have automorphism groups as small as possible. Dobson has conjectured that almost all of the remaining circulant (di)graphs (those whose automorphism groups are not as small as possible) are normal circulant (di)graphs. We show this conjecture is not true in general, but is true if we consider only those circulant (di)graphs whose orders are in a “large” subset of integers. We note that all non-normal circulant (di)graphs can be classified into two natural classes (generalized wreath products, and deleted wreath type), and show that neither of these classes contains almost every non-normal circulant digraph.
|
746 |
Chemical Information Based Elastic Network Model: A Novel Way To Identification Of Vibration Frequencies In Proteins.Raj, Sharad K 01 January 2009 (has links) (PDF)
A novel method of analysis of macromolecules has been worked upon through this research. In an effort to understand the dynamics of macromolecules and to further our knowledge, pertaining specifically to the low frequency domain and also to elucidate certain important biological functions associated with it, a theoretical technique of chemical information based Normal Mode Analysis has been developed. These simulations render users with the ability to generate animations of modeshapes as well as key insight on the associated vibration frequencies. Harmonic analysis using atomistic details is performed taking into account appropriate values of masses of constituent atoms of a given macromolecule. In order to substantiate the applicability of such a technique, simple linear molecules were first worked upon. Subsequently, this technique has been applied to relatively more complex structures like amino acids, namely Cysteine. Consequently, this approach was extended to large macromolecules like Lactoferrin. Animations of modeshapes from simulations suggest a one to one correspondence with other computational techniques reported by other researchers. Computed β-factors are also in close agreement with the experimentally observed values of the same. Hence, as opposed to a simple Cα coarse grained model, our method with right masses and reasonable force fields yields not only the correct modeshapes but also provides us with useful information on wavenumbers that can be used to extract useful information about the frequency domain. Moreover, as opposed to conventional Molecular Dynamics’ simulations and Laser spectroscopy, the proposed methodology is significantly faster, cheaper and efficient.
|
747 |
Structural and biological analysis of faults in basalts in Sheepshead Mountains, Oregon as an Earth analogue to MarsBohanon, Allison 13 May 2022 (has links) (PDF)
Microbial life on Mars is not visible from orbit or by rover cameras, but the fracture networks and scarp morphologies associated with fractures they could live in are measurable. We conducted a field analogue study of 92 normal fault scarps in the Sheepshead Mountains, Oregon to examine the correlation between scarp morphology and vegetation growth in the Steens Basalt. While vegetation is not expected on Mars, the fracture networks that sustain vegetation offer the same micro-environment that would support and protect endoliths. Structural variables were measured in the field and infrared spectra of fault scarps were measured using a handheld multispectral camera and vegetation indices were calculated from these images. Statistical analysis of the scarp morphologic parameters indicate that interconnectedness of fractures is key for elevated vegetation and is represented by a range of parameters. Results support a model for ideal slopes to investigate for preserved biological activity on Mars.
|
748 |
A model for estimating the brainstem volume in normal healthy individuals and its application to diffuse axonal injury patients / 正常健常者における脳幹の体積推定モデルの開発及びびまん性軸索損傷患者への応用Fujimoto, Gaku 23 May 2023 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第24797号 / 医博第4989号 / 新制||医||1066(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 花川 隆, 教授 髙橋 良輔, 教授 高橋 淳 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
|
749 |
The New Normal: An Examination of Home Working Environments in Post-Pandemic AmericaLeshnak, Shelby 29 September 2021 (has links)
No description available.
|
750 |
Bézout Domains and Elementary Divisor Domains: Are They the Same?Walton, Michael D. 18 April 2023 (has links) (PDF)
This thesis examines the connections between Bézout domains and elementary divisor domains. I establish what both of these domains are, and I provide some clarifying examples of each. I state and prove some key results that have been established already in the literature. I describe a process by which I tried to show a distinction between Bézout domains and elementary divisor domains, and then provide an explicit example which shows that this process as formulated would not lead to an example of a Bézout domain which is not an elementary divisor domain. Throughout the thesis, I also state open questions that could lead to future research in this area.
|
Page generated in 0.0463 seconds