The incompatibility of knowledge regimes: consequences of the material world for cross-domain work

In this paper, we argue that successful integration of knowledge across work domains in the short-term can mask the generation of long-term consequences. We explore a setting, the introduction of environmental considerations into semiconductor manufacturing, where the eventual adoption of common measurement artifacts and associated practices enabled knowledge integration, but failed to address significant underlying consequences. Drawing from observational, interview, and archival data we develop an understanding of the work practices of the Tech and EnviroTech groups as structured by the material world and broader collective conventions. We introduce the concept of knowledge regime to outline the differences in knowledge across these work domains. More specifically, we find that differences in the causal specificity and developmental time horizon of knowledge and the measurement artifacts that result contribute to the relative power of one knowledge regime over another. Understanding these sources of incompatibility provides insight into the design requirements of information systems as boundary objects for knowledge integration, but also specifies the potential limits to any design effort.     

Perceived risk and trust associated with purchasing at electronic marketplaces

Understanding consumer behaviour is of vital importance to consumer-oriented e-business models today. In this paper, we study the relationships between consumer perceptions of risk and trust and the attitude towards purchasing at a consumer-to-consumer electronic marketplace (EM). Typical for EM settings is that consumer behaviour is subject to perceptions of the selling party as well as of the institutional structures of the intermediary that is operating the EM. Building upon the well-established literature of trust, we consider the concepts of intermediary trust and seller trust. We extend this categorisation by introducing the concepts of intermediary risk and seller risk. We developed measurement instruments for intermediary risk and seller risk. All measurement scales have acceptable alphas and are unidimensional. An empirical study is conducted to explore the relationships between the risk and trust types and consumer purchase attitude. The results reveal significant, direct effects of seller trust and seller risk. Second-order effects of intermediary trust and intermediary risk are investigated and reported. The paper concludes with general observations and recommendations for research and practice.     

Nutzung unterschiedlicher Streulichtanteile zur Partikelgrößen-Bestimmung in dispersen Systemen

Utilisation of Different Components of Scattered Light for Particle Size Determination in Dispersed Systems . Light scattered by finely and coarsely dispersed particles can be used in variety of ways for characterization of sprays, emulsions, or suspensions. The characteristic of greatest interest is the particle size or the particle size distribution. While homogeneous, coarsely dispersed particles at sufficient dilutions and randomly distributed in a transparent continuous phase are generally amenable to particle size analysis, finely dispersed particles at higher concentrations or coarsely dispersed particles containing finely dispersed components are often difficult to measure. This article discusses ways of overcoming such difficulties on the basis of examples taken mainly from phase Doppler anemometry.     

Determination of carbon black fillers in vulcanizates of natural rubber by metathesis degradation

A method for the determination of carbon black fillers in peroxide vulcanizates or sulfur vulcanizates of natural rubber (NR, cis-1,4-polyisoprene) by metathesis degradation with 1-octene was developed using the catalyst WCl₆? (C₂H₅)₃Al₂Cl₃. The carbon black was separated from the reaction mixture by centrifuging and determined by weighing. In this connection, investigations were also performed with the catalyst WCl₆? C₂H₅Al₂Cl₃ which was less suitable for filler determination. The rate of degradation of crosslinked NR with (E)-4-octene was measured. Metathesis reactions of 2-methyl-2-pentene (low-molecular-weight model compound of NR) with 7-tetradecene showed the importance of double bond shift for the degradation of NR.     

Electrical properties and positron annihilation study of (Ba<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Ho<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>)TiO<Subscript>3</Subscript> ceramics

DC resistivity, dielectric constant, dielectric loss and positron annihilation spectra of (Ba_1−x Ho _x )TiO₃ ceramics have been measured as a function of holmium concentration x. It has been found that the DC resistivity of (Ba_1−x Ho _x )TiO₃ is strongly dependent on the Ho content: it decreases three orders of magnitude and reaches a minimum at x = 0.4%. Doping with 0.6% holmium increases the permittivity of BaTiO₃ by approximately three times (from ∼1,300 to ∼4,000), with only a slight increase in the corresponding dielectric loss. The local electron density and defect concentration estimated using positron annihilation technique conforms well to the features found in the dielectric and resistivity measurements. The results have been discussed in terms of a mixed compensation model.