Transient Hot-Strip Method for Simultaneous Determination of Thermal Conductivity and Thermal Diffusivity of Refractory Materials

The transient hot-strip method has been used for determining thermal conductivity and thermal diffusivity of a refractory brick. The technique is based on recording the transient temperature increase of a 25-μm-thick, 8-mm-wide, and 70-mm-long iron strip clamped between two sample halves and heated with a constant direct current. The method is accurate to within 5% in the thermal conductivity and to within 10% in the thermal diffusivity in the temperature range 20° to 700°C.     

Derivative free algorithm for solving nonlinear equations

In this work, we develop a simple yet practical algorithm for constructing derivative free iterative methods of higher convergence orders. The algorithm can be easily implemented in software packages for achieving desired convergence orders. Convergence analysis shows that the algorithm can develop methods of various convergence orders which is also supported through the numerical work. Computational results ascertain that the developed algorithm is efficient and demonstrate equal or better performance as compared with other well known methods.     

Transient plane source (TPS) technique for measuring thermal transport properties of building materials

The electrical circuit for the recently developed transient plane source (TPS) technique for fast and precise measurements of thermal transport properties of solids has been modified for more convenient and more automated measurements. The technique has been tested for measurements of thermal conductivity and thermal diffusivity for a series of building materials ranging from thermally insulating materials (extruded polystyrene and PMMA) to good thermal conductors (stainless steel and aluminium). The results obtained in this work agree well with other techniques and international standard materials. This agreement indicates that the TPS method is accurate to within ±5% over a thermal conductivity range of four orders of magnitude (0.02 W m^?1 K^?1 to 200 W m^?1 k^?1).     

Formation of cracks in Soederberg electrodes used in aluminum reduction plants

Shrinkage and crack formation during baking of Soederberg anode paste for aluminum furnaces is discussed, and the authors demonstrate how this shrinkage may be reduced by applying suitable raw materials and paste compositions.     

Results from three models compared to full-scale tunnel fires tests

Information from full-scale fire tests are gathered and systemised. The knowledge from these tests is used as input to three different models, ranging from a simple spreadsheet model to advanced computational fluid dynamics (CFD) modelling, for calculating the temperature in the smoke layer. The deviation between the fire tests and the computed results is described and an evaluation of how this may influence the use of the models is discussed from the point of view of risk analysis.     

Non-isothermal aging of a high-Zn-containing Al–Zn–Mg–Cu alloy: microstructure and mechanical properties

The non-isothermal aging behaviour of a newly developed Al–Zn–Mg–Cu alloy containing 17?wt-% Zn was investigated. Hardness and shear punch tests demonstrated that during non-isothermal aging, the mechanical properties of the alloy first increased and then decreased. The best properties were obtained in a sample which was non-isothermally aged upto 250°C with heating rate of 20°C?min^?1, due to the presence of η′/η (MgZn₂) phases. This was confirmed by differential scanning calorimetery. After homogenisation, residual eutectic phases remained at triple junctions or in a spherical form. During aging, these phases transformed into rodlike S (Al₂CuMg)-phase at 400°C, with sizes ranging from 50 to 250?nm. The precipitation sequence in this high-Zn alloy was similar to that for conventional Al–Zn–Mg–Cu alloys.     

An anisotropic stress based criterion to predict the formability and the fracture mechanism of textured zinc sheets

The Forming Limit Diagram (FLD) of a textured zinc sheet has been identified via tensile and bulge tests. The strong anisotropy of the sheet is reflected in the tensile tests, and even more strikingly in the formability measured from the bulge tests. The dependence of the FLD on the orientation of the sheet is unusual, and is shown to be well captured by an anisotropic stress based criterion. The criterion is also able to predict the observed cracks orientations.     

Sex differences in the connection between need for achievement and school performance.

Hypothesized that in a traditional classroom, only boys of moderate ability and girls of high ability would be strongly motivated to achieve. 138 male and 157 female 7th graders in Norway were tested for need to achieve (n Ach), IQ, and school achievement. Motive to achieve success was measured by the TAT score of n Ach. Results support the hypothesis. It is suggested that bright boys need to be stimulated since they are not inspired to use their motive to achieve and that low-ability boys and low- and average-ability girls are not stimulated to achieve since they probably find the demands too heavy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)