Science experiments are inseparable and indispensable parts of learning experiences. The experiments provide both acquiring science concepts and learning scientific method for learning experiences. Thus, various studies have been carried out to specify the science teachers’ professional knowledge, attitudes towards aims of science experiments (West, 1972; Lynch & Ndyetabura, 1983; Gayford, 1988...

Abstract This work reports the effect of Eu doping on structural, morphological, linear, and nonlinear optical properties Sn 1− x O 2 ( = 0 to 0.10) thin films prepared using spray pyrolysis. The crystallized in tetragonal structure crystallite size reduced due incorporation. film morphology consisted evenly distributed dense grains with trapezohedron or bipyramidal shape. transmittance energy ...

Hematophanite, ideally Pb~FeaOsC1, is tetragonal, space group P4mm, with a = 3'92 and c = 15"3I/~. The crystal structure, which has been refined to an R-factor of 9"t %, may be described as an interlayering of perovskite-like units with a cesium chloride or, alternatively, a nadoritelike unit. The nadorite-like part consists of a double layer of PbO4CI4 distorted square antiprisms. Iron atoms a...

Using Goffman’s (1981) participation framework and Brown & Levinson’s (1987) politeness theory, this study examines stand-up comedy in the U.S. and Japan and demonstrates pervasive patterns of communication in comedy performance. In the U.S., stand-up acts are comprised of solo comedian’s narrative performance, while stand-up comic narrative in Japan is performed in the form of dialogue between...

A phenomenological treatment of domain walls based on the Ginzburg-Landau-Devonshire theory is developed for uniaxial trigonal ferroelectrics, lithium niobate and lithium tantalate. The contributions to the domainwall energy from polarization and strain as a function of orientation are considered. Analytical expressions are developed that are analyzed numerically to determine the minimum polari...

In this paper we investigate the magnetostrictive [(3/2)λ100 and (3/2)λ111] and elastic (c′and c44) behavior of single crystalline alloys Fe100−xMox for 21 and −b2) are computed from the measurements. Similar to other Fe–X (X = Al, Ga, and Ge) alloys, the tetragonal magnetostriction (3/2)λ100 increases monotonically from ∼ 70×10−6 at ∼ 2.5 at. % Mo to a maximum of either ∼ 100×10−6 at ∼ 8 at. %...

In 1984 Shechtman et al. [lo] discovered alloys with a novel kind of structure, intermediate between crystalline and amorphous. These alloys, called qruzskrystuk [8], exhibit long-range orientational order but no translational symmetry. Since fivefold and even icosahedral symmetry is observed, several authors conjectured that the so-called “golden rhombohedra” yield a geometric explanation, in ...

In situ neutron powder diffraction measurements show that the orthorhombic-to-tetragonal phase transition in YBa2Cu307 —,which occurs near 700 C in a pure oxygen atmosphere, is an order-disorder transition in which the disordering of oxygen atoms into a normally vacant site destroys the one-dimensional Cu-0 chains present in the room-temperature orthorhombic structure. For both structures, the ...

Anyone familiar with the Sonobé module has probably assembled both the augmented octahedron and the augmented icosahedron Instructions for both appear in both Kasahara and Takahama and in Mukerji, and can also be found on most of the innumerable websites discoverable by googling the word “Sonobé”. Kasahara and Takahama give some sketchy instructions on how to build some other polyhedra with the...

Crystal structure and compressibility of potassium azide was investigated by in-situ synchrotron powder X-ray diffraction in a diamond anvil cell at room temperature up to 37.7 GPa. In the bodycentered tetragonal (bct) phase, an anisotropic compressibility was observed with greater compressibility in the direction perpendicular to the plane containing N3 ions than directions within that plane. ...