Guides “bimorphes” d''ondes ultrasoniques “bimorph” ultrasonic wave guides”

An analysis of the dispersion of elastic waves is presented for two types of long ultrasonics wave-guides that we qualify of “bimorph”: (i) a “three-layer” guide made of two different materials and (ii) a “clad core” guide built up of a rectangular core surrounded by a cladding, the materials of the rod and cladding having different properties. An analytical model is proposed to describe the extensional, flexural and torsional motions in “bimorph” wave guides having two geometrical and material symmetry axes. The asymptotic behaviour of the model allows one to select the material properties which lead to modes guided essentially either in the central layer or in the core of the bimorph guide. Moreover, the dispersive properties of a “bimorph” can be controlled through the choice of geometrical and material parameters.     

“Engineering Graduate Teaching Assistant Instructional Programs: Training Tomorrow's Faculty Members”

Although there has been increased interest in graduate teaching assistant (GTA) training programs recently, few examples of programs specifically for engineering GTA's are found in the technical literature. A survey of engineering schools in Western Canada and the Pacific Northwest region of the United States has been conducted to determine the extent of instructional programs. The results of this survey and the literature indicate that there are large differences in the amount of training that GTA's in different engineering schools receive. While some are involved in extensive training programs, many receive little or no instruction in teaching, and/or inadequate feedback to help improve their teaching skills. These findings are discussed, along with details of innovative instructional programs found in the literature, and suggestions for improving the state of engineering GTA instruction.     

“Low-Tech” Innovations

This paper is about an industrial sector which, according to the usual socio-scientific indicators, is referred to as “low-tech”, respectively as non-research intensive and which mostly comprises “traditional” industries. The interest in this sector is motivated by the contradictory situation that, on the one hand, the debate about the perspectives of modern societies focuses on the rapidly growing importance of technological innovations, knowledge and research-intensive economic sectors while, on the other hand, traditional industries make up a considerable fraction of employment and production, especially also in developed economies. On the basis of the results of extensive empirical research, this contribution tries to find answers to the basic question, whether one can speak of an innovation mode typical of the low-tech sector. The institutional based innovation systems approach forms the categorical basis of the analysis. In order to elucidate the specific features of low-tech innovations, they are, in conclusion, compared to the general characteristics of high-tech-based innovation processes.     

Fullerenes in Chinese Ink Sticks (“Sumi”)

Small amounts (up to 0.1%) of C₆₀ and C₇₀ have been detected by high-pressure liquid chromatographic (HPLC) analysis of toluene extracts from soots used to manufacture Chinese ink sticks, or Sumi. These soots have been prepared by slow burning of pine wood, and later various seed oils. Turpentine oil, the major constituent of pine wood oil, have been found to produce twice as much fullerenes as does toluene when used as the combustion material. The yields of fullerene from unsaturated combustion materials decrease with the iodine number, reaching zero in the saturated compounds. Possible role of fullerenes as the effective gloss enhancer for black color is suggested in reference to the known technique of adding a natural red pigment to Sumi practiced in Japan.     

“Style” and technology

A rational approach to dealing with the problems created by developing technologies requires a new account of what is involved in proper management. A tripartite distinction is introduced between being reasonable, being rational, and having style. These notions are based on the commonsense principle of rationality (CPR), to be rational one must learn from experience. The proper management of technology requires more than learning from experience (being rational) and having the proper goals (being reasonable); it requires style, which entails being reasonable and acting in accordance with a given standard systematically over time.     

Use of “Studio” Methods in the Introductory Engineering Design Curriculum

A number of themes, including interest in first year design courses, commitment to active learning approaches, and desires for changes in course structures and costs have come together in a variety of teaching approaches. Some of these approaches have been referred to as using “studio” methods, although the particular pedagogy appears to vary greatly. In this paper, some of these experiments are briefly reviewed and placed in a larger context of studio education in other disciplines. The paper seeks to differentiate studio education from other active learning approaches. An introductory engineering design course was taught using an architecture studio model for two semesters. The experiment demonstrated that the studio method can be very effective in teaching design concepts, but because students are likely to be unfamiliar with this approach, care must be taken to reassure students regarding grades and expectations.