Jean Arteau

Effect of specimen shape on creep response of a frozen sand

Abstract The stress—strain and strength behavior of frozen soils is most often studied in a conventional uniaxial or triaxial compression test. However, available experimental evidence shows that the results obtained in such a test may be considerably affected by the test conditions, i.e., by the specimen shape and the method of axial load transfer to the specimen ends, both of which affect the uniformity of stress and strain distribution in the sample. The methods proposed for solving the problem of load transfer to the specimen ends differ considerably for brittle and ductile materials, respectively. Since a frozen soil may behave either as a brittle or as a ductile material, depending on strain rate, temperature and confining pressure, it is considered that the load transfer method selected should correspond to the expected sample behavior. In this paper, the results of a series of compression and creep tests are presented, in which the effects of specimen shape and end conditions on the behavior of a frozen sand were systematically investigated and compared. a frozen sand were systematically investigated and compared.

Psychophysical measurements as an effective way of evaluating climbability of wood treated utility poles

Abstract The aim of this study is to evaluate linemens perception of hardness during the climbing of different wood species and treatment combinations in order to determine if psychophysical measurements could be used to evaluate “climbability” of wood treated utility poles. Twenty-four (24) linemen participated in the study. Twelve (12) wood poles, different species, preservative treatments and hardness, were erected inside a large tent. Each lineman was instructed to climb a pole and to record his perception of hardness on a visual analog scale (VAS). The results revealed that linemens perception of hardness, measured using the VAS, can discriminate a difference of 1 mm in Pilodyns penetration. The VAS is also found to be an effective tool to discriminate different species-treatment combinations. It is concluded that the use of a VAS to evaluate linemens perception of hardness could be an effective way to address “climbability” of wood treated poles.

EFFECTIVE LEARNING OF BUCKLING OF COLUMNS IN ENGINEERING PROGRAMS

The objective of this study was to use mentalmaps to analyze the design of higher education students ontheir understanding of technology. The courses wereworked: Computer Science, Technology Systems for InternetTechnology in Computer Networks and Technology Analysisand Systems Development, in particular, was working thirdyearstudents of the Course of Computer Science andstudents of the early years of technological courses. Just asscience, technology is evolving more and more, bothevolving categories irreversible, we must haveunderstandably o of its strengths and weaknesses in society,so we have to think and understand the movement CTS.Index Terms ⎯ mental maps, uniformity and education.

Assessment of wood utility pole climbability using psychophysical and mechanical measurements

The issue of climbability has been raised on several occasions for more than a decade in North America. Presently, climbability is estimated from the pole hardness measured by the Pilodyn measurements (6 J). However, the use of Pilodyn measurements to discriminate the pole hardness value is criticized by climbers, who claim that the Pilodyn hardness measurement is affected by species-treatment combinations and that it does not reflect gaff penetration or climbability. Furthermore, climbability evaluations have been conducted in which test poles were climbed by linemen, and corresponding subjective ratings were recorded. However, the ability of psychophysical measurements to accurately discriminate close hardness pole values and to differentiate species-treatment combinations at specific hardness levels have not yet been fully documented. The aim of this study is to evaluate the psychophysical perception of linemen and the mechanical measurements of gaff penetration and gaff impact during the climbing of different wood species and treatment combinations in order to compare these results with Pilodyn measurements within a precise range of pole hardnesses, to study the relationships between these variables, and, finally, to propose various design guidelines for the development of a better tool for the evaluation of climbability.