167 research outputs found
Elasto-viscoplastic modelling of unsaturated soils under static and dynamic loading in 3D stress space
No full textConsolidation, dynamic analysis, and wave propagation are some of the topics in geomechanics in which a complete characterization of coupling of the solid skeleton deformation and fluid flows is necessary for an accurate evaluation of material response. Dynamic behavior of soils is widely investigated in the past decades; however, they have mainly concerned the behaviour of dry or fully saturated porous media. Considering a three-phase continuum system which accounts for the interactions between the phases is crucial for investigating dynamic behavior of real soils which are invariably in an unsaturated state. Deposits located near the surface of the earth with relatively low water content, highly plastic clays which undergo changing environment or loose silty sands which collapse under wetting process are examples of unsaturated soils and experience severe situations especially under dynamic conditions.
This thesis presents an elasto-visco-plastic flow-deformation model for dynamic analysis of unsaturated soils including mechanical and hydraulic hysteresis. Governing equations of fluid and solid phases are derived based on theory of continuum mechanics considering phase interaction, and nonlinear deformation of solid skeleton subject to dynamic loading. A numerical scheme is developed using a robust Finite Element method as the global solution to solve various boundary value problems. For the local solution, a comprehensive bounding surface viscoplastic model is presented for unsaturated soils which accounts for suction hardening and rate effects and can simulate monotonic and cyclic loading paths. Consistency condition theory is used to describe the viscosity behaviour of the material. A unique relationship between stress, strain, and strain rate of the material is also defined to perfectly describe the effect of the strain rate hardening. Several examples are solved to validate the model and demonstrate the capability of the proposed framework for investigating behaviour of soils in complex hydro-mechanical conditions
Computational Modelling of Compaction in Asphaltic Mixtures and Geomaterials
No full textAsphaltic mixtures are heterogeneous composite materials consisting of aggregates coated and bound by asphalt binder. The long term performance of asphaltic pavements is highly dependent on the mechanical behaviour of the asphaltic mixture during construction (mixing and compaction) and operation; inadequate mixture compaction leads to faster moisture and oxygen diffusion, ravelling, rutting and poor fatigue life
Corrigendum to “Impact of chronic opioid on cognitive function and spermatogenesis in rat: An experimental study” [Int J Reprod BioMed 2024; 22: 579-592]
No full textThe publisher has been informed of an error that occurred on page 579 in which the last authors affiliation must be changed to Department of Biology, Faculty of Sciences, Malayer University, Malayer, Iran. On behalf of the author, the publisher wishes to apologize for this error. The online version of the article has been updated on October 31, 2024 and can be found at https://doi.org/10.18502/ijrm.v22i7.16971
AN ANOMALY BEHAVIOR ANALYSIS METHODOLOGY FOR NETWORK-CENTRIC SYSTEMS By
No full textRights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Downloaded 3-Mar-2016 23:35:4
Automated Liquid Unloading in Low-Pressure Gas Wells Using Intermittent and Distributed Heating of Wellbore Fluid
No full textParticles Inside Particles: The Flow of Energy in Quarks, Gluons, and Jets
No full textThis thesis presents the author’s work in developing probes of the inner structure of jets in high-energy particle collisions. We begin by introducing QCD and the scattering of partons (quarks and gluons), discussing jets as theoretical and experimental proxies for partonic physics, and presenting the partonic cascade model of jet formation and jet substructure. Noting the ubiquitous presence of low-energy pollution in particle collision events, in the forms of hadronization, detector effects, the underlying event (UE), and pileup (PU), we then move towards the modern research area of developing pollution-insensitive probes of jet substructure. Pollution-insensitive features of jet substructure are often accessed theoretically either through jet grooming or energyweighted correlation functions. We present the basics of the modern theory of jet grooming as well as the work of the author in developing the Piranha paradigm for continuous jet grooming, introduced by the author in Ref. [1], and explore the formal and phenomenological benefits of continuous grooming techniques as pollutioninsensitive probes of jet substructure. We introduce the basics of the simplest energy-weighted correlation function – the energy-energy correlator (EEC), which probes angular correlations between particle pairs – and discuss its multi-particle analogues. We focus on the efficient and visually intuitive projected and resolved energy correlators introduced by the author in Ref. [2], which provide computationally-realistic, pollution-insensitive probes of angular many-body correlations in QCD jets. Finally, we exposit the generic theory of energy-weighted observable correlations (EWOCs), introduced by the author in Ref. [3], which utilizes the energy weighting of the EEC to provide pollution-insensitive probes of non-angular correlations within jets.Ph.D
Empirical Evaluation of Test Coverage for Functional Programs
No full textThe correlation between test coverage and test effectiveness is important to justify the use of coverage in practice. Existing results on imperative programs mostly show that test coverage predicates effectiveness. However, since functional programs are usually structurally different from imperative ones, it is unclear whether the same result may be derived and coverage can be used as a prediction of effectiveness on functional programs. In this paper we report the first empirical study on the correlation between test coverage and test effectiveness on functional programs. We consider four types of coverage: as input coverages, statement/branch coverage and expression coverage, and as oracle coverages, count of assertions and checked coverage. We also consider two types of effectiveness: raw effectiveness and normalized effectiveness. Our results are twofold. (1) In general the findings on imperative programs still hold on functional programs, warranting the use of coverage in practice. (2) On specific coverage criteria, the results may be unexpected or different from the imperative ones, calling for further studies on functional programs
Integration Axiomatic Design with Quality Function Deployment and Sustainable Design for the Satisfaction of an Airplane Tail Stakeholders
No full textAbstractOne of the most important criteria to remain competitive in the marketplace is a suitable product design that satisfy requirements of a diverse range of stakeholders. But, ambiguous, different and general description of customer needs, major technological advance and significant change from traditional requirements (cost, performance etc.) to new requirements such as, economic, environmental, ecological and societal consideration make the design process more complicate. It should be noticed too, while the new requirements have a major effect on the product successfully, the traditional requirement should not be forgotten by designers. Unfortunately, new issues sometimes are deeply coupled with traditional functions, so the current design methodologies are not able to consider them in the product design process. In this regard, the development of new design methods and tools that facilitate design process by consideration new requirements is vital. The Axiomatic Design (AD) approach is one of the most promising design methodology in the field of conceptual design. This method is emerging as a superior method of design, particularly when innovation versus incremental design is needed. This paper focuses on setting up the redesign of the Beech Baron 58 tail, by using AD method that integrate with Quality Function Deployment (QFD) and Eco-Design concepts
- …
