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.     

A New “Contact-Based” First Year Engineering Course*

A new first year, engineering orientation course has been put in place at NCSU. The course stresses integration with other first year courses, writing, team building, critical thinking, disciplinary thinking, and has a strong problem-solving component. Students were randomly selected to participate in the course. Students' attitudes about engineering and the first year experience were assessed using an instrument developed at the University of Pittsburgh and compared with the normal introduction to engineering course. Students in this course were more positive about their learning experience in the first semester, reported a higher satisfaction with all their courses, and were less likely to think that the first year courses were designed to “weed” students out of the program.     

Differentiation between the terms ”confined masonry“ and ”infill masonry“

This publication concerns the differentiation between the terms ”confined masonry“ and ”infill masonry“ using the example of the national technical approval Z‐17.1‐1145 – POROTON S9 MW –vertically perforated clay units with integrated thermal insulation using thin layer mortar [1].     

“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.     

“Smart” Surface Capsules for Delivery Devices

This review describes emerging trends, basic principles, applications, and future challenges for designing next generation responsive “smart” surface capsules. Advances and importance of “surface” capsules which are not deposited onto the surface but are built into the surface are highlighted for selective applications with specific examples of surface sponge structures formed by high intensity ultrasonic surface treatment (HIUS). Surface capsules can be adapted for biomedical applications, membrane materials, lab‐on‐chip, organ‐on‐chip, and for template synthesis. They provide attractive self‐healing anticorrosion and antifouling prospects. Nowadays delivery systems are built from inorganic, organic, hybrid, biological materials to deliver various drugs from low molecular weight substances to large protein molecules and even live cells. It is important that capsules are designed to have time prolonged release features. Available stimuli to control capsule opening are physical, chemical and biological ones. Understanding the underlying mechanisms of capsule opening by different stimuli is essential for developing new methods of encapsulation, release, and targeting. Development of “smart” surface capsules is preferable to respond to multiple stimuli. More and more often a new generation of “smart” capsules is designed by a bio‐inspired approach.