J. S. H. Q. Perera

Purpose: The purpose of this paper is to report on a study of teacher learning through participation in sustained collaborative subject-based professional development groups supported by a facilitator, using a model of teachers’ conceptions of teaching developed from phenomenography to identify what are the critical features of teaching that must be present if teachers are to learn, and using a variation theory of learning to explain how they learn. Design/methodology/approach: The groups engaged in cycles of lesson study action research to improve the learning outcomes of their students. The authors intended to engage the teachers in an exploration of their own and their students’ experiences to understand the relationship between the enactment of the research lesson(s) and the educational outcome. The authors collected over 157 hours of video recorded teachers’ meetings involving 15 groups, 47 hours of follow-up interviews and 97 hours of lessons. In this paper the authors report on the progress of one of those groups. The authors analysed the transcripts to see what, if any, dimensions of variation were opened in discussion, affording the opportunity for learning. The authors sought the simultaneous juxtaposition, the bringing together, of threads that have entered the discussion that have the potential to open dimensions of variation – to add critical features to the “what” and “how” dimensions of teaching. Findings: The authors identified necessary conditions for teacher learning through collaborative subject-based professional development groups. Any member of the group might bring this about. The facilitator or coach might be expected to perform this role in the group, and to sustain the group’s attention on the critical features of the object of learning. Practical implications: The paper provides valuable insights into strategies to change teacher perspectives from a transmission oriented to a construction oriented view of teaching in the face of new and challenging curriculum demands. Originality/value: In the work reported here the authors have used variation theory to design lesson study. This is rather different from a learning study where the teachers engaged in the study use variation theory to design their research lesson(s). It is a learning study of teachers’ professional development.

Purpose: – The purpose of this paper is to explore how web-based science curriculum materials designed to develop autonomous learners can succeed in Brunei. In this instruction, designed to prepare students to independently explore new topics, students and teachers take new roles. Students collaborate with a peer to engage in inquiry and teachers monitor progress and guide students rather than leading the class. Design/methodology/approach: – The authors studied two Web-based Inquiry Science Environment (WISE) units (photosynthesis and cellular respiration) developed using the knowledge integration framework. The framework promotes autonomous learning by building on the diverse ideas that students bring to science lessons and encouraging them to distinguish among their own ideas and those they encounter when using scientific visualizations. In a study on “How People Learn: Brain, Mind, Experience and School”, Bransford et al. (1999) suggest that the students’ preconceptions of how the world works must be engaged, as failing to do so may hinder them from grasping new concepts and information that are taught. Two intact classes of students from two secondary schools in Brunei each studied one of the WISE units. Observations revealed that students could work in pairs to jointly engage in inquiry with encouragement from teachers. Embedded assessments and interviews were analyzed to show how students linked observable events and scientific ideas when explaining the conversion of solar energy to chemical energy in photosynthesis. Findings: – Significant gains in knowledge integration show that Brunei students who collaboratively study WISE inquiry units can autonomously succeed. Specifically, students using WISE were able to construct complex ideas about photosynthesis and cellular respiration by linking observable events and scientific ideas while working autonomously with infrequent teacher monitoring. Originality/value: – The paper provides invaluable insights into ways in which web-based learning supports students to become autonomous learners.

Physics, widely regarded as a difficult subject, is also in nature whereby most of its concepts are intangible and hard to imagine. For instance, the concept of pressure, although it is a difficult concept to learn, it is also an important topic to master. Pressure not only appears in physics but also in other scientific fields such as in chemistry as one of the physical changes in the rate of change of reactions, and in biology or medicine involving blood pressure. In this study, students’ understanding on the topic of pressure will be reported. Specifically, in identifying the students’ misconceptions on manometer reading. A manometer is an instrument that uses a U-tube containing a liquid (either mercury or water) to measure gas pressure. From the interviews conducted with eleven Year 9 students, two main misconceptions were identified. The first misconception was on the existence of air pressure. The students failed to recognise its presence, as the effects of air pressure are often not obvious and undetectable. Additionally, two students on two separate interview occasions had referred to air pressure as vacuum. Another misconception was mistakenly taking the high liquid level of a manometer column as high pressure acting on that side and vice versa. This misconception is caused by again failing to comprehend that air and also gas pressure can cause liquid levels to change. Identifying these misconceptions will indeed assist Physics secondary school teachers to confront the issues relating to the difficulty concerning the pressure concept. DOI: 10.5901/mjss.2015.v6n4s1p27

A series of nanocomposites of polyaniline-montmorillonite have been prepared in which polyaniline is present within the interlayers as well as adsorbed onto the external surfaces of the clay particles (i.e., emeraldine salt-montmorillonite, ES-MMT series). The composite materials show uniform texture as revealed by scanning electron microscopy. The ES-MMT members show high electronic conductivities. Under the identical conditions of sample preparation, the d-spacing enhancement upon the polymer intercallation is the same regardless of whether the polymer is present only within intergalleries or both inside and outside the intergalleries. The FTIR studies reveal that the OH stretching in the Al-Mg-OH infrared band appearing at 840cm^-1 disappears upon polymer loading. Since the OH in Al-Mg-OH moieties are directed outward from the hexagonal cavities, this effect may be attributed to the interaction between the clay particles and the polymer that is present adsorbed to clay surfaces. The polymer present within the intergalleries influences strongly on the 0-H vibrations, which are directing inward to the intergalleries. Cyclic voltammetric studies reveal that the electroactivity of the composite material is limited by the accessibility of solution species into the intergalleries in a diffusion-controlled manner. The electrochemical impedance spectroscopic (EIS) studies reveal that the ES-MMT members have both electronic and ionic conductivities with similar transport numbers even when the polymer is in its fully electronically conducting state. Four different and mutually independent techniques used to characterize the composites give strong evidence to confirm that there is a limit to the repetitive polymer loading within the intergalleries of the clay particles. The limited interspacing with all repeated polymer loading may be due to the saturation of all ion-exchangeable sites of montmorillonite by the cations of the polymer.

This paper describes the preparation and characterization of conducting polyaniline-montmorillonite (PANI-MMT) nanocomposites by the polymerization of anilinium ions within the interlayer space of MMT particles. A procedure for the successive introduction of PANI chains within the interlayer galleries of MMT is developed. The d-spacing, measured after heat treatment at various temperatures serves as a measure of the amount of polymer inserted in the clay intergalleries. The FTIR spectroscopy reveals the presence of host-guest interactions of a hydrogen-bonded nature. The DC conductivities were found to increase with the amount of PANI intercalated. Anilinium ions supported on kaolinite tended to dislodge from the surface upon repeated washings, as shown by the absence of polymer formation on such samples upon treatment with the oxidant. In MMT, however, polymerization is observed even with exhaustively washed samples, thus confirming that the successive polymerization processes occur within the interlayer galleries. Exclusion of the washing stage gives a composite material in which polyaniline is present on both the internal and external surfaces. This material is found to have significantly higher electronic conductivities than the composites where the polymer is restricted to interlayer galleries. The washed samples of the polymer once loaded into the clay (EMS1-MMT), twice loaded into the clay (EMS2-MMT) and thrice loaded into the clay (EMS3-MMT) have electrical conductivities of 4.5 × 10⁻⁵, 3.0 × 10⁻⁴, and 1.0 × 10⁻³ Scm⁻¹, respectively in their dry states. The corresponding samples prepared by excluding the washing procedure had the values of 4.0 × 10⁻⁴, 1.0 × 10⁻², and 1.0 10⁻¹ Scm⁻¹, respectively.

Gas phase x‐ray photoelectron spectra of some transition metal acetylacetonates, M(AcAc)₂, (M=Co,Ni,Cu) are reported. The metal 2p, 3s, and 3p core levels and the O 1s and C 1s binding energies have been obtained. Satellites were observed to higher binding energies from the metal 2p, 3s, and 3p levels and the O 1s levels. From a comparison of the solid phase and the present gas phase results the effects of changes in symmetry upon satellite structure were studied without changing the central metal atom or the ligand. The results suggest that the satellites seen in these transition metal 3s level spectra arise from shakeup mechanisms rather than from multiplet splittings.

X‐ray photoelectron spectra of the Ti 2p and 3p and halogen core levels from titanium tetrahalide vapors have been obtained. Satellites are observed at higher binding energies than the halogen core levels as well as the titanium levels. The origin of these satellites is discussed by comparison with published data on octahedral Ti(IV) compounds. It was also observed that the separation of the Ti 2p spin–orbit doublet in TiF₄ was lower than the separations observed in the other three molecules (5.2 eV in TiF₄ as compared to 6.1 eV).