Keyword: boron nitride nanotubesBoron nitride nanotubes (BNNTs) are desired for their exceptional mechanical, electronic, thermal, structural, textural, optical, and quantum properties. Golberg [1] gives an excellent review of possible applications. To date, BNNTs have been grown by a number of techniques which can be divided roughly into two categories based on the class of material produced.One is the high temperature category in which energy is concentrated into a B or BN target at a level which can vaporize elemental boron. BNNTs form in the deposits of the liberated vapors. The energy is input by laser [2][3][4][5][6] or by arc discharge [7][8][9] . Only small quantities (mg's) of material have been produced by this method, but the tubes are high quality. They have one or just a few walls, and most importantly, the tube walls are low in defects and parallel to the axis of the nanotube. The second category is low temperature synthesis, between about 600 C and 1700 C, well below the vaporization temperature of pure boron (~4000 C). These low temperature synthesis methods can be further divided into two catagories. In the first category, ball-milled precursor powders of boron and catalyst are annealed in a nitrogen or ammonia gas atmosphere, sprouting nanostructures on their

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This study investigated the mathematics beliefs and content knowledge of 103 elementary pre‐service teachers in a developmental teacher preparation program that included a two course mathematics methods sequence. Pre‐service teachers' pedagogical beliefs became more cognitively‐oriented during the teacher preparation program with these changes occurring during the two methods courses. Pedagogical beliefs remained stable during student teaching. The pre‐service teachers also significantly increased their personal efficacy for teaching mathematics throughout the program with these shifts occurring across both methods courses and into student teaching. Pedagogical beliefs and teaching efficacy beliefs were not related at the beginning of the program, but, in general, were positively related throughout the program. In addition, the pre‐service teachers' pedagogical beliefs were positively related to their specialized content knowledge for teaching mathematics at the end of the program.

1. The intake of mammary secretion from delivery to day 5 post-partum was determined by test-weighing nine infants using an integrating electronic balance. The mean yield of colostrum for the first 24 h after birth was 37.1 (range 7.0-122.5) g and was 408 (range 98.3-775) and 705.4 (range 452.5-876) g/24 h on days 3 and 5 post-partum respectively.2. The milk yield of mothers on either day 14 or 28 post-partum was determined by test-weighing the mother. The mean milk yield was 1.156 (SD 0.167) kg/24 h. 3. A significant correlation (P < 0.001 ; r 0.85, n 42) was found between milk yield measured by test-weighing the infant and milk yield measured by test-weighing the mother, confirming that it is possible to obtain a similar estimate of milk consumed using either of the two methods of test-weighing.4. There was a significant positive correlation (P < 0.001) between lactose concentration and milk yield for the first 5 d post-partum (r 0.76, n 22); a significant negative correlation (P < 0,001) between protein concentration and milk yield (r -0.74, n 22) and no significant correlation between fat concentration and milk yield for the period studied.5. The calculated energy intake of infants during the first 24 h after birth was only 0.12 (range 0.02-0.29) mJ. This increased to 1.44 (range 0.83-2.18) and 2.99 (range 2.49406) mJ/24 h by days 3 and 14-28 post-partum respectively.

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This mixed methods examination of 710 research articles in mathematics education published in six prominent educational journals during the period 1995-2005 finds that 50% of the studies used qualitative methods only, 21% used quantitative methods only, and 29% mixed qualitative and quantitative methods in various ways. Although the number of mixed methods articles show some variation year to year and journal to journal, there is no discernible trend in the aggregate across this time period for the collection of journals studied. Issues explored include defining research categories and subsequently categorizing studies, balance and dominance between quantitative and qualitative strands, and integration within conclusions.

We investigated the radial mechanical properties of multi-walled boron nitride nanotubes (MW-BNNTs) using atomic force microscopy. The employed MW-BNNTs were synthesized using pressurized vapor/condenser (PVC) methods and were dispersed in aqueous solution using ultrasonication methods with the aid of ionic surfactants. Our nanomechanical measurements reveal the elastic deformational behaviors of individual BNNTs with two to four tube walls in their transverse directions. Their effective radial elastic moduli were obtained through interpreting their measured radial deformation profiles using Hertzian contact mechanics models. Our results capture the dependences of the effective radial moduli of MW-BNNTs on both the tube outer diameter and the number of tube layers. The effective radial moduli of double-walled BNNTs are found to be several-fold higher than those of single-walled BNNTs within the same diameter range. Our work contributes directly to a complete understanding of the fundamental structural and mechanical properties of BNNTs and the pursuits of their novel structural and electronics applications.