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Adding a small amount of cysteine to bioleaching solution in contact with gold ores, largely enhanced the leaching rate of Fe, while cysteine inhibited the extraction of As. Xray diffraction (XRD), Scanning electron microscope and Energy-dispersive X-ray spectroscopy (SEM/EDS) observations of residues without cysteine showed bio-leaching products were mainly jarosite and sulfur. Yet, the peak densities of sulfur disappeared in the XRD patterns of residues with cysteine added. Furthermore, Fourier transform infrared spectroscopy (FTIR) led to the conclusion that more bacteria had adsorbed on the bioleached residues surface in media with cysteine than without cysteine. Combining the results of the bioleaching experiment and the analysis of SEM/EDS, FTIR and XRD leads us to conclude that cysteine addition just facilitates the electron transfer but does not change the gold ore oxidation mechanism. [ABSTRACT FROM AUTHOR]

Introduction. This is a study of hierarchical navigation; how users browse a taxonomy-based interface to an organizational repository to locate information resources. The study is part of a project to develop a taxonomy for an library and information science department to organize resources and support user browsing in a digital repository. Method. The data collection was carried out using task-based navigation exercises with twenty-two participants. A cognitive framework of hierarchical navigation is proposed, involving the cognitive process of matching context, topic and/or resource type concepts to taxonomy categories. Analysis. The analysis was mainly qualitative, supplemented with simple statistics and measures of prevision and recall, and error analysis. Results. Though users often use the topic concept in making navigation choices, they sometimes make use of context and resource-type concepts. Users infer a variety of relationships between a task concept and a taxonomy category, including the application area, associated tool, associated process/procedure/technique, associated institution and academic discipline. Conclusions. Users prefer to use common or generic associations in selecting categories to browse, rather than formal disciplinary relations. Some users prefer to search by people groups, contexts and institutions, rather than by subject categories. Users have difficulty distinguishing between various kinds of document and resource types. [ABSTRACT FROM AUTHOR]

A study was conducted to investigate the capability of a general classification scheme and domain thesauri to support the construction of an organizational taxonomy to be used for navigation, and to develop steps and guidelines for constructing the hierarchical structure and categories. The study was conducted in the context of a graduate department in information studies in Singapore that offers Master's and PhD programs in information studies, information systems, and knowledge management. An organizational taxonomy, called Information Studies Taxonomy, was built for learning, teaching and research tasks of the department using the Dewey Decimal Classification and three domain thesauri (ASIS&T, LISA, and ERIC). The support and difficulties of using the general classification scheme and domain thesauri were identified in the taxonomy development process. Steps and guidelines for constructing the hierarchical structure and categories were developed based on problems encountered in using the sources. [ABSTRACT FROM AUTHOR]

Purpose - This paper seeks to examine attitudes toward the use of clickers, as well as practicalities and pedagogical considerations that inform them. Drawing on interviews from a variety of viewpoints at one institution of higher education, this paper aims to situate a librarian perspective among those of teaching faculty, administration, and students. Design/methodology/approach - This paper is a case study of a single institution of higher education in which the experiences of teaching faculty, an administrator, and a library faculty member are gathered using semi-structured interviews. Student opinions are obtained through the use of a focus-group interview. Findings - This paper provides attitudes and experiences of nursing teaching faculty who use clickers in their instruction, an administrator who purchased clickers for his department, and a library faculty member who uses clickers in bibliographic instruction, as well as those of nursing students who used the technology in class. Research limitations/implications - Because of the nature of the research method employed, reported results may not be universally generalizable. Practical implications - This paper may help inform the choices of those deciding to use clickers in their instruction. Originality/value - This paper fulfills an identified need to analyze reactions to clicker use in instruction among students, instructors, and other program participants, including librarians. [ABSTRACT FROM AUTHOR]