Database of rocking shallow foundation performance: Slow-cyclic and monotonic loading

2020 ◽  
Vol 36 (3) ◽  
pp. 1585-1606 ◽  
Author(s):  
Manouchehr Hakhamaneshi ◽  
Bruce L. Kutter ◽  
Andreas G. Gavras ◽  
Sivapalan Gajan ◽  
Angelos Tsatsis ◽  
...  

Many physical model tests have examined the performance of rocking foundations during cyclic and seismic loading. These tests varied in model size, testing equipment, superstructure properties, footing shape, supporting soil environment, and loading protocol. “FoRCy, Foundation Rocking database of Cyclic and Monotonic Loading” is a new database (published at https://datacenterhub.org/ ), summarizing the results of monotonic and slow-cyclic loading tests of rocking foundations. The database consists of columns identifying testing equipment and facility, soil, superstructure, and system properties, as well as loading protocol and results. The database contains 456 records (rows), each one being unique in either model configuration or loading amplitude. To illustrate its value, this article shows correlations between (1) settlement, rotation, and factor of safety with respect to bearing capacity and (2) moment and cumulative rotation for shallow footings. Data indicate that the rotation required to mobilize the moment capacity is surprisingly constant (about 0.01 radians) for a wide range of experiments.

Author(s):  
Cyprian Gil ◽  
Knut Tørnes ◽  
Per Damsleth

A study has been performed to better understand ultimate bending moment and strain capacities of pipelines in relation to criteria defined in the design codes. An 18″ HPHT flowline was designed to undergo global buckling on uneven seabed and to resist trawl gear interference. The high temperature (155 degC) and pressure (300 bar) posed considerable design challenges for material selection and design criteria. A CRA-lined X60 CMn pipeline was selected for the project. The pipeline was of seamless manufacture for which the stress/strain characteristics are subject to the effect of Lüders bands. The DNV-OS-F101 code covers a wide range of D/t but does not specifically address Lüder’s material behaviour which could significantly reduce the bending moment capacity of pipe. The global buckling and trawl pull-over FE analysis results indicated the pipe was highly utilized, requiring excessive amounts of seabed intervention at great cost to meet the DNV LCC criteria. Detailed FE simulation of limit states for local buckling and strain localization of a 3D solid element pipe model was performed, with both Roundhouse and Lüders material properties, to investigate pipe capacity in relation to that stipulated by the design codes. The pipe moment capacity was established by obtaining the moment curvature relationship by bending the local pipe section subject to internal pressure until the maximum resistance was reached. Imperfections were introduced to initiate local buckling at the desired location. To determine strain concentration factors and strain localization, the effects of thickness changes and weld misalignment were also studied. The DNV OS-F101 LCC moment criterion formulation computes a decreasing moment capacity for increasing internal pressure. It has been suggested in the literature that this is correct for higher D/t but the criterion may be conservative for pipes with lower D/t. The combination of Lüders material with low D/t is not specifically addressed by any design code. Clarification of these aspects will provide a better understanding of the risk of failure for highly utilized seamless pipelines and allow for modified design criteria that will reduce seabed intervention costs. The results of the study showed that a higher bending moment criterion and associated strain criterion could be adopted for the design that allows for the higher initial strain caused by Lüder’s plateau. The ultimate bending moment capacity of low D/t pipe with Lüder’s material was found to be similar to that of Roundhouse material due to work hardening. In addition, it was demonstrated that the potential strength of the CRA liner could enhance the moment capacity of the seamless pipe.


2020 ◽  
pp. 431-449
Author(s):  
Oleg V. Shekatunov ◽  
Konstantin G. Malykhin

The article is devoted to the specifics of studying the industrial labour force of Russia in the 1920s - 1930s in Russian historiography. The various stages of study from the 1920s through the 1930s and up to the last years are concerned. The relevance of the study is due to several factors. These include contradictions in the assessments of Bolshevik modernization of the 1920s and 1930s; projected labour force shortages in modern Russia; as well as the existing labour force shortage in industry at the moment. This determines the relevance of studying the historical period, which was characterized by the most acute personnel problems in the country. The novelty of the study is due to the fact that in modern Russian historiography there is no holistic, integrated view of the problems of the labour force potential formation of Russian industry in the 1920s and 1930s. It is noted that there is no research aimed at analyzing the historiography of these problems. The main stages of the study of industrial labour force are highlighted. The analysis of scientific works correlated with each stage of the study of the topic is performed. The problems and methodology of each stage are considered. A review of a wide range of scientific papers both articles and thesis is presented.


Author(s):  
Lakshmi Thangasamy ◽  
◽  
Gunasekaran Kandasamy ◽  

Many researches on double skin sandwich having top and bottom steel plates and in between concrete core called as steel-concrete-steel (SCS) were carried out by them on this SCS type using with different materials. Yet, use of coconut shell concrete (CSC) as a core material on this SCS form construction and their results are very limited. Study investigated to use j-hook shear studs under flexure in the concept of steel-concrete-steel (SCS) in which the core concrete was CSC. To compare the results of CSC, the conventional concrete (CC) was also considered. To study the effect of quarry dust (QD) in its place of river sand (RS) was also taken. Hence four different mixes two without QD and two with QD both in CC and CSC was considered. The problem statement is to examine about partial and fully composite, moment capacity, deflection and ductility properties of CSC used SCS form of construction. Core concrete strength and the j-hook shear studs used are influences the moment carrying capacity of the SCS beams. Use of QD in its place of RS enhances the strength of concrete produced. Deflections predicted theoretically were compared with experimental results. The SCS beams showed good ductility behavior.


2019 ◽  
Vol 26 (23) ◽  
pp. 4403-4434 ◽  
Author(s):  
Susimaire Pedersoli Mantoani ◽  
Peterson de Andrade ◽  
Talita Perez Cantuaria Chierrito ◽  
Andreza Silva Figueredo ◽  
Ivone Carvalho

Neglected Diseases (NDs) affect million of people, especially the poorest population around the world. Several efforts to an effective treatment have proved insufficient at the moment. In this context, triazole derivatives have shown great relevance in medicinal chemistry due to a wide range of biological activities. This review aims to describe some of the most relevant and recent research focused on 1,2,3- and 1,2,4-triazolebased molecules targeting four expressive NDs: Chagas disease, Malaria, Tuberculosis and Leishmaniasis.


2021 ◽  
pp. 002224372110329
Author(s):  
Nicolas Padilla ◽  
Eva Ascarza

The success of Customer Relationship Management (CRM) programs ultimately depends on the firm's ability to identify and leverage differences across customers — a very diffcult task when firms attempt to manage new customers, for whom only the first purchase has been observed. For those customers, the lack of repeated observations poses a structural challenge to inferring unobserved differences across them. This is what we call the “cold start” problem of CRM, whereby companies have difficulties leveraging existing data when they attempt to make inferences about customers at the beginning of their relationship. We propose a solution to the cold start problem by developing a probabilistic machine learning modeling framework that leverages the information collected at the moment of acquisition. The main aspect of the model is that it exibly captures latent dimensions that govern the behaviors observed at acquisition as well as future propensities to buy and to respond to marketing actions using deep exponential families. The model can be integrated with a variety of demand specifications and is exible enough to capture a wide range of heterogeneity structures. We validate our approach in a retail context and empirically demonstrate the model's ability at identifying high-value customers as well as those most sensitive to marketing actions, right after their first purchase.


Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 73
Author(s):  
Marina Garcia-Cardosa ◽  
Francisco-Javier Granados-Ortiz ◽  
Joaquín Ortega-Casanova

In recent years, additive manufacturing has gained importance in a wide range of research applications such as medicine, biotechnology, engineering, etc. It has become one of the most innovative and high-performance manufacturing technologies of the moment. This review aims to show and discuss the characteristics of different existing additive manufacturing technologies for the construction of micromixers, which are devices used to mix two or more fluids at microscale. The present manuscript discusses all the choices to be made throughout the printing life cycle of a micromixer in order to achieve a high-quality microdevice. Resolution, precision, materials, and price, amongst other relevant characteristics, are discussed and reviewed in detail for each printing technology. Key information, suggestions, and future prospects are provided for manufacturing of micromixing machines based on the results from this review.


Author(s):  
С.А. Свердлов

Проблема понимания текстов и способов его оценки является одной из фундаментальных для современной психологии, педагогики, лингвистики. На настоящий момент имеется большое количество попыток выработки метода оценки понимания текстов, который бы отражал объективную картину интериоризации материала текста читателем, и вместе с тем подходил бы для стандартизации и применения на широком диапазоне текстов различного содержания и структуры, по возможности с минимальными затратами ресурсов оценщика и самого читателя. В настоящей статье раскрываются современные подходы к оценке понимания текстов, их преимущества и недостатки, и формулируется новый перспективный метод оценки понимания текстов, использующий в своём основании модель Латентного размещения Дирихле. Данный метод затем проходит исследование валидности через сравнение результатов его применения и наиболее часто используемых современных методов оценки понимания текстов, делается вывод о его применимости в реальных условиях и перспективах использования в спектре прикладных задач. The problem of understanding texts and methods of assessing it is one of the fundamental for modern psychology, pedagogy, linguistics. At the moment, there are a large number of attempts to develop a method for assessing the understanding of texts, which would reflect an objective picture of the internalization of the material of the text by the reader, and at the same time would be suitable for standardization and application on a wide range of texts of different content and structure, if possible with minimal expenditure of resources of the evaluator and the reader himself. This article reveals modern approaches to assessing text understanding, their advantages and disadvantages, and formulates a new promising method for assessing text understanding, based on the Dirichlet Latent Placement model. This method then goes through a validity study through a comparison of the results of its application and the most commonly used modern methods for assessing text understanding, a conclusion is made about its applicability in real conditions and the prospects for use in a range of applied problems.


Author(s):  
Т. Р. Магомаев

В современных условиях функционирования системы высшего образования целью внедрения дистанционного обучения является организация качественного учебно-воспитательного процесса «на расстоянии» с использованием новейших информационно-коммуникационных средств и открытым доступом к образовательным ресурсам. Именно такая форма обучения может быстро адаптироваться к требованиям информационного общества и подготовить будущего специалиста к вызовам цифровой среды. В сочетании с традиционными формами, дистанционное образование в высшем учебном заведении может предоставить широкий спектр образовательных услуг как для абитуриентов и студентов для приобретения необходимых навыков и умений для будущей профессиональной деятельности, так и для преподавателей с целью повышения квалификации. На данный момент основными проблемами внедрения качественного свободного образовательного пространства является отсутствие технической и финансовой поддержки, законодательной основы дистанционного обучения, и это является ведущим фактором сдерживания развития технологий в вузе. Отсутствуют специально подготовленные к работе в дистанционном режиме квалифицированные преподаватели. Однако, учитывая готовность вузов осуществлять обучение преподавателей для работы в дистанционном режиме, негативное влияние этого фактора в ближайшее время может быть устранено. При условии решения вышеописанных проблем будет создано эффективное дистанционное обучение, которое всесторонне раскроет потенциал студента, учитывая как индивидуальные, так и общечеловеческие потребности. In modern conditions of functioning of the higher education system, the goal of introducing distance learning is to organize a high-quality educational process “at a distance” using the latest information and communication tools and open access to educational resources. It is this form of training that can quickly adapt to the requirements of the information society and prepare the future specialist for the challenges of the digital environment. In combination with traditional forms, distance education in a higher educational institution can provide a wide range of educational services for both applicants and students to acquire the necessary skills for future professional activities, and for teachers to improve their skills. At the moment, the main problems in introducing high-quality free educational space is the lack of technical and financial support, the legislative basis of distance learning, and this is a leading factor in curbing the development of technology at the university. There are no qualified teachers specially prepared for working in remote mode. However, given the willingness of universities to train teachers to work remotely, the negative impact of this factor in the near future can be eliminated. Subject to the solution of the above problems, an effective distance learning will be created that will comprehensively reveal the student’s potential, taking into account both individual and universal needs.


Author(s):  
Tobias Leibner ◽  
Mario Ohlberger

In this contribution we derive and analyze a new numerical method for kinetic equations based on a variable transformation of the moment approximation. Classical minimum-entropy moment closures are a class of reduced models for kinetic equations that conserve many of the fundamental physical properties of solutions. However, their practical use is limited by their high computational cost, as an optimization problem has to be solved for every cell in the space-time grid. In addition, implementation of numerical solvers for these models is hampered by the fact that the optimization problems are only well-defined if the moment vectors stay within the realizable set. For the same reason, further reducing these models by, e.g., reduced-basis methods is not a simple task. Our new method overcomes these disadvantages of classical approaches. The transformation is performed on the semi-discretized level which makes them applicable to a wide range of kinetic schemes and replaces the nonlinear optimization problems by inversion of the positive-definite Hessian matrix. As a result, the new scheme gets rid of the realizability-related problems. Moreover, a discrete entropy law can be enforced by modifying the time stepping scheme. Our numerical experiments demonstrate that our new method is often several times faster than the standard optimization-based scheme.


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