Corrosion Inhibitors for Sour Oilfield Environment (H2S Corrosion)

Lower-grade steel materials are the most commonly used construction materials for oil and gas wells due to their low cost and high performance. However, they are susceptible to corrosion when they come in contact with corrosive environments that are highly acidic. In oil wells, particularly deep oil wells, hydrogen sulfide (H2S) is commonly found. The dissolution of H2S gas in produced water makes the fluid corrosive. The use of corrosion inhibitors is perhaps the most practical and costeffective means of controlling corrosion of low carbon steels in the sour environment. In this chapter, typical corrosion inhibitors used in oil and gas fields to control the internal corrosion of oilfield equipment caused by H2S are being examined. The inhibitors found to be effective are polar functional compounds, with many being based on nitrogen-containing compounds, such as amines, imidazolines, and quaternary ammonium salts. Drawbacks of these compounds in practical applications and potentials of future developments are discussed

Group discussion as interactive dialogue or as serial monologue: The influence of group size

Current models draw a broad distinction between communication as dialogue and communication as monologue. The two kinds of models have different implications for who influences whom in a group discussion. If the discussion is like interactive dialogue, group members should be influenced most by those with whom they interact in the discussion; if it is like serial monologue, they should be influenced most by the dominant speaker. The experiments reported here show that in small, 5-person groups, the communication is like dialogue and members are influenced most by those with whom they interact in the discussion. However, in large, 10-person groups, the communication is like monologue and members are influenced most by the dominant speaker. The difference in mode of communication is explained in terms of how speakers in the two sizes of groups design their utterances for different audiences

Exploring interactive systems using peripheral sounds

Our everyday interaction in and with the physical world, has facilitated the development of auditory perception skills that enable us to selectively place one auditory channel in the center of our attention and simultaneously monitor others in the periphery. We search for ways to leverage these auditory perception skills in interactive systems. In this paper, we present three working demonstrators that use sound to subtly convey information to users in an open office. To qualitatively evaluate these demonstrators, each of them has been implemented in an office for three weeks. We have seen that such a period of time, sounds can start shifting from the center to the periphery of the attention. Furthermore, we found several issues to be addressed when designing such systems, which can inform future work in this area. © 2010 Springer-Verlag

Students' experience of problem-based learning in virtual space

This paper reports outcomes of a study focussed on discovering qualitatively different ways students' experience problem-based learning in virtual space. A well accepted and documented qualitative research method was adopted for this study. Five qualitatively different conceptions are described, each revealing characteristics of increasingly complex student experiences. Establishing characteristics of these more complex experiences assists teachers in facilitating students engagement and encouraging deeper learning