Relationships Between Prospective Middle Grades Mathematics Teachers' Beliefs and TPACK

As technology become more ubiquitous in the classroom, teachers need to overcome two types of barriers to use it effectively: access to resources (including the development of knowledge) and the development of appropriate beliefs. To assist teachers in overcoming these barriers, we must understand the relationships that exist among them. We examined relationships between middle grade prospective teachers' beliefs and their technology, pedagogy, and content knowledge framework (TPACK). We found possible relationships between their beliefs about the nature of mathematics, learning and teaching mathematics, and the use of technology and their content knowledge, pedagogical content knowledge, and technological pedagogical content knowledge, respectively.     

Ionic conductivities for poly(ethylene oxide) complexes with lithium salts of monobasic and dibasic acids and blends of poly(ethylene oxide) with lithium salts of anionic polymers

Lithium salts of two polyanionic addition polymers containing alkyl sulphonic acid and perfluoroalkyl carboxylic acid side groups were prepared. Blends of these polymers were formed with poly(ethylene oxide) (PEO). The blend containing alkyl sulphonate units showed some phase separation but this was not observed for the blend containing perfluoroalkyl carboxylate groups. In the latter case a comparatively high conductivity of $\text{～10}{}^{\mathrm{?5}}\text{Ω}{}^{\mathrm{?1}}$ cm^?1 at 374 K was obtained. The anionic units in these blends are expected to be virtually immobile. Complexes formed from PEO and the Li-salt of hexafluoroglutaric acid had similar high ionic conductivities and there are grounds for supposing that the anions in these complexes may also be substantially immobilized. In addition, conductivity values were obtained for some PEO complexes containing lithium salts of some monobasic acids and it was found that the complex formed from the Li-salt of the strongest acid gave the highest conductivity ($\text{～4 × 10}{}^{\mathrm{?4}}\text{Ω}{}^{\mathrm{?1}}$ cm^?1 at 373 K for a PEO-LiSO₃CF₃ complex).     

Limit analysis of a pad reinforced flush nozzle in a spherical pressure vessel

Using the one moment limited interaction shell yield surface and a three hinge-circle mechanism, the limit pressure is found for a flush radial cylindrical nozzle in a spherical pressure vessel where the vessel near the intersection is reinforced by a pad. The pad is welded to the nozzle/vessel junction and at its outer circumference to the vessel.The limit pressure is calculated for a range of geometrical parameters including, in particular, the length of the pad measured along the circumference of the vessel from the nozzle/vessel junction.A lower bound and an approximate upper bound to the limit pressure are calculated.     

Mass filter and focusing ion detector for use with time-of-flight velocity distribution measurements

A novel mass filter and focusing ion detector for time-of-flight studies of dissociative ionization fragments is described. The filter-dector combination is particularly suited for measuring the kinetic energy released in the molecular dissociation process. The mass filter utilizes a computer-controlled, time-dependent retarding potential synchronized with, and located a distance L from, a pulsed electron-bombardment ion source. Ions arriving at the filter at time t have a kinetic energy of mL(2)/2t(2). The retarding potential varies with time as mL(2)/2et(2), thus deflecting ions with masses less than m. Operation of the filter in a mode which provides unity mass resolution at 16 amu has been demonstrated. The detector consists of a channel electron multiplier and a focusing electrode configuration approximating that of a charged sphere above a grounded conducting plane. The planar input aperture of the detector is located just behind the mass filter along the ion flight path. The detector features high efficiency, large input aperture, low background, and simple operation. Ion transit times through the detector are small and essentially independent of the initial ion kinetic energy.     

The study of stress application and corrosion cracking on Ni-16 Cr-9 Fe (Alloy 600) C-ring samples by polychromatic X-ray microdiffraction

Microscopic strains associated with stress corrosion cracks have been investigated in stressed C-rings of Ni-16 Cr-9 Fe (Alloy 600) boiler tubing. Polychromatic X-ray microdiffraction was used to measure deviatoric strain tensors and the distribution of dislocations near cracks that had been propagated in electrochemically accelerated corrosion tests. An associated investigation of the C-ring-induced strains prior to corrosion showed significant tensile strain in the stress axis direction by the torsional closure of the alloy tube section in the C-ring test. Significant grain lattice rotation and pronounced plastic strain at some grain boundaries were noted. Stress-corrosion-cracking-generated intergranular cracks were produced in two Alloy 600 specimens after 6 h and 18 h tests. The diffraction patterns and resultant strain tensors were mapped around the cracked area to a 1 μm spatial resolution. The strain tensor transverse to the crack growth direction showed tensile strain at the intergranular region just ahead of the crack tip for both specimens. Both cracks were found to follow grain boundary pathways that had the lowest angle of misorientation. Dislocation distributions within each grain were qualitatively obtained from the shapes of the diffraction spots and the effect of “hard” and “soft” grains on the crack pathway was explored for both 6 h and 18 h specimens. The Schmid factor of one of the grains adjacent to the crack at the 6 h and 18 h initiation sites was found to be the lowest, compared to Schmid factors calculated for surface grains away from the initiation site, and also along the crack path into the bulk.     

An experimental investigation of consistency in female undergraduates' reports of coping efforts for the same versus different stressful situations.

For each of 3 event categories (harm/loss, threat, challenge), with a 6-week test-retest time interval, female undergraduates were randomly assigned to report on coping efforts (problem- vs. emotion-focused coping) for the same stressful event or a different stressful event across the 2 sessions. For problem-focused coping and each category of stressor, test-retest correlations were strongest when subjects reported on coping efforts for the same situation but were still of moderate size and significant for reports of coping with different stressful situations. This difference between conditions was found only for the challenge stressor for emotion-focused coping. These findings imply that stressor context, type of coping, and response tendencies across different stressors relate to the reliability of self-reported coping efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)