Search results for "STRENGTH"

Application of linear friction welding for joining ultrafine grained aluminium

2020

Abstract Ultrafine grained (UFG) materials are of great potential in industry due to their enhanced mechanical strength and other promising features, such as ability to superplastic deformation or excellent corrosion resistance. Nevertheless, one of the main limitations lies in their low thermal stability, which leads to excessive grain growth at elevated temperature. It influences mainly further processes performed at high temperature, such as joining. It causes detrimental problems during conventional fusion welding, as significant grain growth is observed and therefore the advantages as a result of small average grain size disappear. Therefore, the idea of applying solid state joining pr…

Aluminum to titanium laser welding-brazing in V-shaped grooveI

2017

International audience; Laser assisted joining of AA5754 aluminum alloy to T40 titanium with use of Al-Si filler wires was carried out. Continuous Yb:YAG laser beam was shaped into double spot tandem and defocalized to cover larger interaction zone in V shaped groove. Experimental design method was applied to study the influence of operational parameters on the tensile properties of the joints. Microstructure examination and fractography study were carried out to understand the relation between local phase content and fracture mode.Within defined window of operational parameters, statistically important factors that influenced the strength of T40 to AA5754 joints in V groove configuration w…

When Is an Affordance? Outlining Four Stances

2016

Part 3: Exploring Affect and Affordance; International audience; Affordance has emerged as a core concept in information systems (IS) research during the last decade. This relational concept is applied to understand and theorize the relationship between the social and the technical. In the works of the concept originator James Gibson, the relation was mainly portrayed as an ever-existing fact between the natural environment and an animal. In contrast, IS research focuses on relationships in-the-making between artificial things and human beings. In the IS context, we have identified vagueness in temporal and relational ontology: when do affordances exist and between whom or what? In this pap…

The shear strength of Opalinus Clay shale in the remoulded state

2020

Abstract The Opalinus Clay shale formation is considered as a potential host geomaterial for the Swiss deep geological repository for radioactive waste. It presents different facies and it is characterised by a multi-scale heterogeneous composition, by a typical fissile structure with well-defined bedding planes and by anisotropic hydro-mechanical behaviour. This peculiar complexity makes it difficult to assign a unique set of geomechanical parameters to the material. This paper presents an experimental study aimed at characterising the lowest values of the shear strength parameters. In this sense, the shear behaviour was investigated on remoulded samples where the fabric and the diagenetic…

Procedure for a Temperature-Traffic Model on Rubberized Asphalt Layers for Roads and Railways

2017

The impact of temperature on the mechanical properties and thermal susceptibility of the railway bituminous sub-ballast layer, has served as motivation to develop the advanced measurement of thermal cycles in this layer and, an evaluation of the average seasonal temperatures interpolated by sinusoidal functions, of which characteristic parameters are determined. According to weather situation, Barber’s temperature model was used to prove the effectiveness for the railway superstructure. It is included the assessment of improved modified asphalt mixes performed with coarse rubber from scrap tires, having 1.5 to 3 percent of crumb rubber (particle size 0.2-4 mm) by weight of the total mix, as…

Kinetic, isotherm and thermodynamic studies of the adsorption of methylene blue dye onto agro-based cellulosic materials

2015

AbstractThe purpose of this work is to establish the optimal experimental conditions for the removal of methylene blue (MB-as model basic dye) from aqueous solution by adsorption onto four agro-based materials, namely, cedar sawdust, pine sawdust, wheat straw, and Provence cane Arundo donax. Results show that an increase in acidity or ionic strength of the medium has generally a negative effect on the discoloration yield. From the data of pH effect, there is no need to change the initial pH of the MB solution to be treated. Equilibrium was reached after 20−30 min of agitation when cedar sawdust, pine sawdust, and Provence cane are used as adsorbents. However, in the case of wheat straw, an …

2020

A soldier’s occupational physical task requirements are diverse and varied. However, the type of physical training that most effectively improves soldiers’ occupational task requirements has not been studied previously. The purpose of this study was to determine the important strength characteristics for soldiers during a repeated simulated military task course, and the type of training that may be effective to improve these abilities during a specialized military training period. Forty-two (n = 42) soldiers participated in the study. They were divided into three training groups; a soldier task-specific training group (TSG, n = 17), a strength training group (STG, n = 15), and a control gro…

Experimental study of a naturally weathered stiff clay

2016

Studying the shear strength of a naturally weathered clay is important to understand rain-induced slope failures in weathered soils. However, experimental studies on naturally weathered soils are limited. The paper focuses on the laboratory experimental investigation carried out to analyse the shear strength of a naturally weathered stiff clay that can be found in unsaturated conditions in situ. This has an important practical relevance in the evaluation of the stability conditions of natural slopes at clay outcrops. Different experimental techniques of suction measurement were used to obtain the soil-water retention curve of the clay over a wide range of suctions. Scanning electronic micr…

A risk assessment proposal for underground cavities in Hard Soils-Soft Rocks

2018

Abstract Underground calcarenite quarries in Marsala (Sicily) have been involved in a number of collapses that have, seriously damaged numerous buildings. The stability conditions were therefore examined in order to assess risk conditions within the historical centre of the town and the surrounding areas, which are subject to urban expansion. Starting with an extensive collection of historical information, the research was carried out through surveys of the cavities, systematic sampling of material, petrographic analysis and geotechnical testing. The results of laboratory tests and in situ investigations provided a geotechnical characterization of both the intact material and the rock mass.…

On the reactivation of a large landslide induced by rainfall in highly fissured clays

2018

Abstract The paper discusses the field investigations, geotechnical characterization and time evolution of horizontal displacements in a wide landslide. The latter, triggered by an earthquake occurring in September 2002, is located in Sicily and involves a thick body of stiff and highly fissured clays belonging to a Varicoloured Clay formation. In order to characterise the reactivation of landslide mechanisms induced by rainfall, a three-year monitoring programme (2008–2011) was implemented to measure rain, pore water pressures, and deep and superficial displacements. The monitoring data made it possible to recognize three distinct landslides, which evolve at variable rates in different dir…