Varying paths for learning to revise

The paper draws on the Vygotskyan view of instruction, advocating the support of learners within their individual Zones of Proximal Development. It describes an instructional design developed iteratively—gradually building in scaffolding techniques to support the use of the procedural facilitation of text evaluation during revision—and the open-ended management of its provision to students, so that they could fade it out themselves.The study took place in a writing class for students at basic writing levels. The present, post hoc analysis is concerned with individual differences among three members of the class identified as weak, intermediate and more advanced novices while learning to revise within that program.     

Research mathematicians as teacher educators: focusing on mathematics for secondary mathematics teachers

We believe that professional mathematicians who teach undergraduate mathematics courses to prospective teachers play an important role in the education of secondary school mathematics teachers. Thus, we explored the views of research mathematicians on the mathematics that should be taught to prospective mathematics teachers, on how the courses they teach can serve teachers in their work with school students, and on the changes they would implement if their courses were designed specifically for prospective teachers. We constructed profiles of the four mathematicians based on their responses to a clinical interview. We employed the construct of mathematics teacher-educators’ triad in the reflective analysis of our findings and extended the construct based on the results of this study. In conclusion, we commented on potential ways to draw stronger connections between university mathematics and the mathematics taught in schools.     

Three-phase slug flow in microchips can provide beneficial reaction conditions for enzyme liquid-liquid reactions

Here, we introduce a solution to low stability of a two-phase slug flow with a chemical reaction occurring at the phase interface in a microfluidic reactor where substantial merging of individual reacting slugs results in the loss of uniformity of the flow. We create a three-phase slug flow by introducing a third fluid phase into the originally two-phase liquid-liquid slug flow, which generates small two-phase liquid slugs separated by gas phase. Introduction of the third phase into our system efficiently prevents merging of slugs and provides beneficial reaction conditions, such as uniform flow pattern along the whole reaction capillary, interfacial area with good reproducibility, and intensive water-oil interface renewal. We tested the three-phase flow on an enzyme hydrolysis of soybean oil and compared the reaction conversion with those from unstable two-phase slug flows. We experimentally confirmed that the three-phase slug flow arrangement provides conversions and pressure drops comparable or even better with two-phase liquid-liquid arrangements.     

Multiple solution methods and multiple outcomes—is it a task for kindergarten children?

Engaging students with multiple solution problems is considered good practice. Solutions to problems consist of the outcomes of the problem as well as the methods employed to reach these outcomes. In this study we analyze the results obtained from two groups of kindergarten children who engaged in one task, the Create an Equal Number Task. This task had five possible outcomes and five different methods which may be employed in reaching these outcomes. Children, whose teachers had attended the program Starting Right: Mathematics in Kindergartens, found more outcomes and employed more methods than children whose teachers did not attend this program. Results suggest that the habit of mind of searching for more than one outcome and employing more than one method may be promoted in kindergarten.     

Future climate-induced pressures on painted wood

A broad category of cultural heritage objects are multilayer structures composed of organic, humidity-sensitive materials – wood, animal glue, paper, leather, bone or paints. They respond to variations in relative humidity (RH) in their environment by cyclically gaining and losing moisture, and consequently swelling and shrinking. Differences in the moisture response of the materials induce internal stresses in the individual layers of the structures, which cause objects to deform and crack. Polychrome wood is examined in detail. The cumulative physical damage of the design layer on wood due to repeated RH variations is quantified in terms of their magnitude and number of times they occur. The climatological risk index for accumulated, ‘fatigue’ damage is established, using a procedure to reduce irregular real-world climate histories into simple RH cycles of known damage impact. Using output from the Hadley Model (HadCM3) and simple transfer functions predicting indoor temperature and RH from outdoor climate, changes in the indoor climate through to 2100 were forecast for unheated buildings. European maps highlighting the areas in which painted wood may be significantly affected by climate change are presented.     

The ability-track glass ceiling of Israeli schooling: lessons from a comparative analysis of Israeli and Australian PISA 2012 data

Israeli students ranked in the bottom third of the countries surveyed by PISA 2012 in mathematical literacy, while the gap between the highest and lowest scores was the second largest in the OECD. This paper explores which variables led to disparities in mathematical literacy between different socioeconomic levels and between Israeli Arabs and Jews as well as in comparison with Australian students. Different instructional approaches that are known in the literature to have a positive impact on students’ achievement are not observed in the relationship between teachers and students in Israel. In Israel, schools contribute to the perpetuation of socioeconomically driven educational inequality by using tracks that are characterised by different teaching pedagogies and different content, with little or no upward mobility between tracks, leading to structural exclusion. By comparison, in Australia, ability tracking is less rigid and mathematical literacy far higher than in Israel. The policy implication is that either teachers must work differently in a track-based system to overcome the process of exclusion dictated by the structure itself or the system must reduce the use of tracking.     

History

EDISON'S ELECTRIC LIGHT: BIOGRAPHY OF AN INVENTION by Robert Friedel, et al. (New Brunswick, NJ: Rutgers University Press, 1986—$27.95 until July 1st, then $35)

ENGINEERS & ELECTRONS: A CENTURY OF ELECTRICAL PROGRESS by John D. Ryder and Donald G. Fink (IEEE Press, 345 East 47th St., New York 10017—price not given)

THE MAKING OF A PROFESSION: A CENTURY OF ELECTRICAL ENGINEERING IN AMERICA by A. Michal McMahon (New York: IEEE Press, see address to left, 1984—price not given)

IBM'S EARLY COMPUTERS by Charles J. Bashe, et al (Cambridge, MA: MIT Press, 1986—$27.50)

THE POWER OF THE PRESS: THE BIRTH OF AMERICAN POLITICAL REPORTING by Thomas C. Leonard (New York: Oxford, 1986—$22.50)     

Crack Saturation as a Mechanism of Acclimatization of Panel Paintings to Unstable Environments

ABSTRACT

This paper analyzes the process of crack saturation, which is fundamental to understanding why panel paintings have survived remarkably well in the uncontrolled environments of historic houses or places of worship for several centuries. The process of crack saturation was analyzed using finite element modeling. A double layer elastic model with fractured overlying paint layer was subjected to uniaxial tension. The critical separation between cracks was determined and compared with patterns observed in real paintings. In addition, the generation and propagation of delamination were studied to elucidate the effect of their propagation on the saturation distance of cracks, as well as the load carrying ability of the paint layer. Contributing modes of crack propagation and their significance are also discussed. The results demonstrate that shearing fracture mode dominates the process of delamination. The impact of crack saturation on the degree of relative humidity variation that is allowable is also discussed.