Selection of operative centrifuge radius to minimize stress error in calculations

1991 ◽  
Vol 28 (1) ◽  
pp. 160-161 ◽  
Author(s):  
Brian Cooke
Keyword(s):  
Stress Distribution ◽  
Key Words ◽  
Gravity Field ◽  
Vertical Stress ◽  
Centrifugal Acceleration ◽  
Centrifuge Model ◽  
Definition Of ◽  
Centre Of Rotation ◽  
Selection Of ◽  
Stress Error

In a centrifuge model, the vertical stress distribution is nonlinear because of the variation of the model's "gravity" field with the centrifuge radius from the top to the bottom of the model. Thus in calculating the centrifugal acceleration, and hence the scale of the model, care must be taken to use the definition of centrifuge radius that minimizes the stress error in the model profile. This paper demonstrates that this optimum radius is measured from the centre of rotation to a point 0.59 times the model height from the bottom of the model. Key words: centrifuge, stress, error.

scholarly journals El poder subversivo de la fábula en sus diversas manifestaciones diacrónicas

2015 ◽  
pp. 153
Author(s):  
Gordana Matic
Keyword(s):  
Key Words ◽  
19Th Century ◽  
The Other ◽  
Critical Aspect ◽  
Other Hand ◽  
Palabras Clave ◽  
Moral Aspect ◽  
Definition Of ◽  
Historical Periods ◽  
Selection Of

<div class="WordSection1"><p><strong>Resumen</strong></p><p>La fábula ha tenido desde siempre una función retórica e ilustrativa que se ha manifestado a lo largo de la historia de modo dual: mostraba para enseñar, lo que muchas veces implicaba el componente moralizador, o para criticar. Mientras se empeñaba en conseguir una de las dos intencionalidades, o las dos simultáneamente, ha podido ser revestida de un tono humorístico, burlón, irónico o sarcástico. Partiendo de las observaciones sobre el género de Fedro, Rodríguez Adrados o Mireya Camurati, en este trabajo nos proponemos analizar una selección de fábulas clásicas, medievales, dieciochescas y decimonónicas, para demostrar que el aspecto crítico e incluso subversivo del género se mantiene abiertamente activo aun en las épocas en las que se potencia su intención didáctico-moralizante.</p><p>Palabras clave: fábula, definiciones del género, estudio diacrónico, aspecto crítico, aspecto didáctico-moralizante</p><p> </p><p><strong>Abstract</strong></p><p>The fable has always had a rhetoric and illustrative function that manifested itself during its long history in two different ways: on one hand, it represented an example in order to teach, which usually implied the moral component, or on the other hand, to criticize. While it strived to achieve one of these intentions, or sometimes both simultaneously, it could have been written in a humorous, mocking, ironic or sarcastic tone. In this paper, we analyze a selection of classical and medieval, 18th and 19th century fables written in Spanish, with definitions proposed by Phaedrus, Rodríguez Adrados and Mireya Camurati as starting points, in order to show that the critical aspect of this genre was openly maintained and taken benefit of even in the historical periods when its didactic and moralizing intention was preferred and strongly emphasized.</p></div><p>Key words: fable, definition of genre, diachronic approach, critical aspect, didactic and moral aspect</p><p> </p>

A simple procedure for computation of vertical soil stresses for surface regions of arbitrary shape and loading

1987 ◽  
Vol 24 (1) ◽  
pp. 143-145 ◽  
Author(s):  
J. C. Thompson ◽  
B. Lelievre ◽  
R. D. Beckie ◽  
K. J. Negus
Keyword(s):  
Stress Distribution ◽  
Key Words ◽  
Arbitrary Shape ◽  
Simple Procedure ◽  
Surface Region ◽  
Vertical Stress ◽  
Computer Algorithms ◽  
Computer Solution ◽  
Analysis Technique ◽  
Mathematical Operations

Based on the Boussinesq formula, exact formulae are derived for the vertical stress beneath the corner of an arbitrarily shaped triangular surface region subjected to vertical pressures with a uniform, linear, or quadratic distribution. These formulae are the basis of a proposed analysis technique in which any arbitrarily shaped loading region is approximated by a set of triangular regions. Computer algorithms that take advantage of the highly repetitive, yet simple, mathematical operations can readily be implemented on the computational facilities currently available to most engineers. Key words: triangular or arbitrarily shaped load regions, vertical stress distribution, computer solution.

A chart for estimating the average vertical stress increase in an elastic foundation below a uniformly loaded rectangular area

1984 ◽  
Vol 21 (4) ◽  
pp. 710-713 ◽  
Author(s):  
D. V. Griffiths
Keyword(s):  
Stress Distribution ◽  
Key Words ◽  
Vertical Stress ◽  
Limited Data ◽  
Stress Increment ◽  
Surface Loading ◽  
Stress Increase ◽  
Measured Stress ◽  
Stress Components ◽  
Rectangular Area

In spite of the considerable assumptions involved, stress distribution charts based on elastic theory are still used by engineers to estimate stresses induced in soil masses by surface loading. Although there are limited data comparing calculated and measured stress increments, vertical stress components have been predicted quite reliably by this method. The chart presented here enables the average vertical stress increment beneath a corner of a uniformly loaded rectangular area to be estimated. The results are based on numerical integration of existing solutions for the rectangle problem, and should reduce the need for sublayers when calculating consolidation settlements. Key words: stress distribution, elasticity, design graph, rectangular footing, consolidation.

scholarly journals A knowledge-based framework for construction methods selection

1993 ◽  
Vol 20 (2) ◽  
pp. 236-246 ◽  
Author(s):  
Alan D. Russell ◽  
Ibrahim Al-Hammad
Keyword(s):  
Decision Making ◽  
Expert System ◽  
Key Words ◽  
Operational Definition ◽  
Decision Making Process ◽  
Knowledge Based ◽  
Construction Methods ◽  
Definition Of ◽  
System Prototype ◽  
Selection Of

This paper describes the ingredients of a knowledge-based framework for selection of construction methods. They include an operational definition of construction method, a conceptual model of the decision-making process, an explanation of how project context and construction methods may be represented for methods selection and analysis purposes, the range of criteria that need to be considered, and a representation of construction expertise. These ingredients are illustrated using a prototype expert system, called CMSA (Construction Methods Selection Assistant), to select a shoring system for cut-and-cover tunnelling. Key words: construction methods, decision-making, expert system, prototype.

Selection and Preparation of Specific Tissue Regions For Tem Using Large Epoxy-Embedded Blocks

1973 ◽  
Vol 31 ◽  
pp. 324-325 ◽  
Author(s):  
P. M. Lowrie ◽  
W. S. Tyler
Keyword(s):  
Electron Microscopy ◽  
Anatomical Structures ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Microscopic Evaluation ◽  
Embedded Blocks ◽  
Specific Tissue ◽  
Definition Of ◽  
Areas Of Interest ◽  
Selection Of

The importance of examining stained 1 to 2μ plastic sections by light microscopy has long been recognized, both for increased definition of many histologic features and for selection of specimen samples to be used in ultrastructural studies. Selection of specimens with specific orien ation relative to anatomical structures becomes of critical importance in ultrastructural investigations of organs such as the lung. The uantity of blocks necessary to locate special areas of interest by random sampling is large, however, and the method is lacking in precision. Several methods have been described for selection of specific areas for electron microscopy using light microscopic evaluation of paraffin, epoxy-infiltrated, or epoxy-embedded large blocks from which thick sections were cut. Selected areas from these thick sections were subsequently removed and re-embedded or attached to blank precasted blocks and resectioned for transmission electron microscopy (TEM).

scholarly journals Stress and deformation analysis of gob-side pre-backfill driving procedure of longwall mining: a case study

2021 ◽  
Author(s):  
Rui Wu ◽  
Penghui Zhang ◽  
Pinnaduwa H. S. W. Kulatilake ◽  
Hao Luo ◽  
Qingyuan He
Keyword(s):  
Rock Mass ◽  
Stress Distribution ◽  
Coal Seam ◽  
Abutment Pressure ◽  
Longwall Mining ◽  
Vertical Stress ◽  
Floor Level ◽  
Working Face ◽  
Floor Heave ◽  
Stress And Deformation

AbstractAt present, non-pillar entry protection in longwall mining is mainly achieved through either the gob-side entry retaining (GER) procedure or the gob-side entry driving (GED) procedure. The GER procedure leads to difficulties in maintaining the roadway in mining both the previous and current panels. A narrow coal pillar about 5–7 m must be left in the GED procedure; therefore, it causes permanent loss of some coal. The gob-side pre-backfill driving (GPD) procedure effectively removes the wasting of coal resources that exists in the GED procedure and finds an alternative way to handle the roadway maintenance problem that exists in the GER procedure. The FLAC3D software was used to numerically investigate the stress and deformation distributions and failure of the rock mass surrounding the previous and current panel roadways during each stage of the GPD procedure which requires "twice excavation and mining". The results show that the stress distribution is slightly asymmetric around the previous panel roadway after the “primary excavation”. The stronger and stiffer backfill compared to the coal turned out to be the main bearing body of the previous panel roadway during the "primary mining". The highest vertical stresses of 32.6 and 23.1 MPa, compared to the in-situ stress of 10.5 MPa, appeared in the backfill wall and coal seam, respectively. After the "primary mining", the peak vertical stress under the coal seam at the floor level was slightly higher (18.1 MPa) than that under the backfill (17.8 MPa). After the "secondary excavation", the peak vertical stress under the coal seam at the floor level was slightly lower (18.7 MPa) than that under the backfill (19.8 MPa); the maximum floor heave and maximum roof sag of the current panel roadway were 252.9 and 322.1 mm, respectively. During the "secondary mining", the stress distribution in the rock mass surrounding the current panel roadway was mainly affected by the superposition of the front abutment pressure from the current panel and the side abutment pressure from the previous panel. The floor heave of the current panel roadway reached a maximum of 321.8 mm at 5 m ahead of the working face; the roof sag increased to 828.4 mm at the working face. The peak abutment pressure appeared alternately in the backfill and the coal seam during the whole procedure of "twice excavation and mining" of the GPD procedure. The backfill provided strong bearing capacity during all stages of the GPD procedure and exhibited reliable support for the roadway. The results provide scientific insight for engineering practice of the GPD procedure.

scholarly journals Promotion of Resilience in Migrants: A Systematic Review of Study and Psychosocial Intervention

2021 ◽  
Author(s):  
Maria Ciaramella ◽  
Nadia Monacelli ◽  
Livia Concetta Eugenia Cocimano
Keyword(s):  
Systematic Review ◽  
Psychosocial Intervention ◽  
Life Experiences ◽  
Psychosocial Interventions ◽  
Migrant Population ◽  
Methodological Choices ◽  
Research Questions ◽  
Definition Of ◽  
Selection Of

AbstractThis systematic review aimed to contribute to a better and more focused understanding of the link between the concept of resilience and psychosocial interventions in the migrant population. The research questions concerned the type of population involved, definition of resilience, methodological choices and which intervention programmes were targeted at migrants. In the 90 articles included, an heterogeneity in defining resilience or not well specified definition resulted. Different migratory experiences were not adequately considered in the selection of participants. Few resilience interventions on migrants were resulted. A lack of procedure’s descriptions that keep in account specific migrants’ life-experiences and efficacy’s measures were highlighted.

scholarly journals Getting to Hope: Perspectives from Patients and Caregivers Living with Chronic Childhood Illness

Children ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 525
Author(s):  
Emily von Scheven ◽  
Bhupinder K. Nahal ◽  
Rosa Kelekian ◽  
Christina Frenzel ◽  
Victoria Vanderpoel ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Research Question ◽  
Young Patients ◽  
Future Research ◽  
Childhood Onset ◽  
Virtual Focus Groups ◽  
Definition Of ◽  
Selection Of ◽  
Chronic Childhood ◽  
Research Studies

Promoting hope was identified in our prior work as the top priority research question among patients and caregivers with diverse childhood-onset chronic conditions. Here, we aimed to construct a conceptual model to guide future research studies of interventions to improve hope. We conducted eight monthly virtual focus groups and one virtual workshop with patients, caregivers, and researchers to explore key constructs to inform the model. Discussions were facilitated by Patient Co-Investigators. Participants developed a definition of hope and identified promotors and inhibitors that influence the experience of hope. We utilized qualitative methods to analyze findings and organize the promotors and inhibitors of hope within three strata of the socio-ecologic framework: structural, interpersonal, and intrapersonal. Participants identified three types of interventions to promote hope: resources, navigation, and activities to promote social connection. The hope conceptual model can be used to inform the selection of interventions to assess in future research studies aimed at improving hope and the specification of outcome measures to include in hope research studies. Inclusion of the health care system in the model provides direction for identifying strategies for improving the system and places responsibility on the system to do better to promote hope among young patients with chronic illness and their caregivers.

scholarly journals Examining and Fine-tuning the Selection of Glycan Compositions with GlyConnect Compozitor

2020 ◽  
Vol 19 (10) ◽  
pp. 1602-1618 ◽  
Author(s):  
Thibault Robin ◽  
Julien Mariethoz ◽  
Frédérique Lisacek
Keyword(s):  
Search Engine ◽  
Posttranslational Modifications ◽  
Search Engines ◽  
Web Application ◽  
Contextual Information ◽  
Fine Tuning ◽  
Data Sources ◽  
Web Interface ◽  
Definition Of ◽  
Selection Of

A key point in achieving accurate intact glycopeptide identification is the definition of the glycan composition file that is used to match experimental with theoretical masses by a glycoproteomics search engine. At present, these files are mainly built from searching the literature and/or querying data sources focused on posttranslational modifications. Most glycoproteomics search engines include a default composition file that is readily used when processing MS data. We introduce here a glycan composition visualizing and comparative tool associated with the GlyConnect database and called GlyConnect Compozitor. It offers a web interface through which the database can be queried to bring out contextual information relative to a set of glycan compositions. The tool takes advantage of compositions being related to one another through shared monosaccharide counts and outputs interactive graphs summarizing information searched in the database. These results provide a guide for selecting or deselecting compositions in a file in order to reflect the context of a study as closely as possible. They also confirm the consistency of a set of compositions based on the content of the GlyConnect database. As part of the tool collection of the Glycomics@ExPASy initiative, Compozitor is hosted at https://glyconnect.expasy.org/compozitor/ where it can be run as a web application. It is also directly accessible from the GlyConnect database.

General Schema Theory for Genetic Programming with Subtree-Swapping Crossover: Part II

2003 ◽  
Vol 11 (2) ◽  
pp. 169-206 ◽  
Author(s):  
Riccardo Poli ◽  
Nicholas Freitag McPhee
Keyword(s):  
Genetic Programming ◽  
Schema Theory ◽  
Exact Formulation ◽  
Expected Number ◽  
Size Evolution ◽  
General Schema ◽  
Definition Of ◽  
Effective Fitness ◽  
Selection Of ◽  
Exact Definition

This paper is the second part of a two-part paper which introduces a general schema theory for genetic programming (GP) with subtree-swapping crossover (Part I (Poli and McPhee, 2003)). Like other recent GP schema theory results, the theory gives an exact formulation (rather than a lower bound) for the expected number of instances of a schema at the next generation. The theory is based on a Cartesian node reference system, introduced in Part I, and on the notion of a variable-arity hyperschema, introduced here, which generalises previous definitions of a schema. The theory includes two main theorems describing the propagation of GP schemata: a microscopic and a macroscopic schema theorem. The microscopic version is applicable to crossover operators which replace a subtree in one parent with a subtree from the other parent to produce the offspring. Therefore, this theorem is applicable to Koza's GP crossover with and without uniform selection of the crossover points, as well as one-point crossover, size-fair crossover, strongly-typed GP crossover, context-preserving crossover and many others. The macroscopic version is applicable to crossover operators in which the probability of selecting any two crossover points in the parents depends only on the parents' size and shape. In the paper we provide examples, we show how the theory can be specialised to specific crossover operators and we illustrate how it can be used to derive other general results. These include an exact definition of effective fitness and a size-evolution equation for GP with subtree-swapping crossover.

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