R. Mitchell – författare

Earth structures engineering involves the analysis, design and construction of structures, such as slopes and dams, that are composed mainly of earth materials, and this is a growth area in geotechnical engineering practice. This growth is due largely to increased involvement in designing various types of earth structures for the resources industries (slopes, impoundment structures, offshore islands, mine backfills), to the development of increas­ ingly large hydroelectric projects, to the need for more freshwater storage and diversion schemes, and to the need for transportation, communications and other facilities in areas where the natural earth materials are occasionally subject to mass instabilities. Although geotechnical engineering transects traditional disciplinary boundaries of civil, geological and mining engineering, the majority of geotechnical engineers are graduates from civil engineering schools. Here the geotechnical instruction has been concentrated on soil mechanics and foundation engineering because foundation engineering has traditionally been the major component of geotechnical practice. Geotechnical special­ ists, however, generally have acquired considerable formal or informal training beyond their first engineering degree, and an advanced degree with considerable cross-discipline course content is still considered an advantage for a young engineer entering a career in geotechnical engineering. Practical job experience is, of course, a necessary part of professional development but is readily interpreted and assimilated only if the required background training has been obtained.

usage of the terms substrate and substratum. A substrate (pI.: substrates) is a material utilized by microorganisms, generally as a source of energy. A substratum (pI.: substrata) is asolid surface to which a microorganism mayattach. REFERENCES (1) Marshall, K.C. 1976. Interfaces in Microbial Ecology. Cambridge, MA: Harvard University Press. (2) ZoBell, C.E. 1943. The effect of solid surfaces upon bacterial activity. J. Bacteriol. 46: 39-56. Standing, left to right: Paul Rutter, Rolf Freter, Mike Silverman, lan Robb, Hinrich Mrozek, Frank Dazzo, David Gingell Seated, left to right: Garth Jones, Stanislawa Tylewska, Staffan Kjelleberg, Ellen Rades-Rohkohl, Kevin Marshall Microbial Adhesion and Aggregation, ed. K.C. Marshall, pp. 5-19. Dahlem Konferenzen 1984. Berlin, Heidelberg, New York, Tokyo: Springer-Verlag. Mechanisms of Adhesion Group Report P.R. Rutter, Rapporteur F.B. Dazzo H. Mrozek R. Freter E. Rades-Rohkohl D. GingeIl I.D. Robb G.W. Jones M. Silverman 8. Kjelleberg 8. Tylewska K.C. Marshall INTRODUCTION The subject, Mechanisms of Microbial Attachment, has proved to be a fertile sour ce of argument between both microbiologists and physical chemists.In order to find common ground for discussion, the group endeavored to come to a consensus regarding a number of definitions pertinent to the subject. Some of these are described in the text and others will be found at the end of this report.