Thermodynamic Relation between Silicon and Aluminum in Liquid Iron

The thermodynamic relation between silicon and aluminum in liquid iron was studied by measuring the effect of silicon on the solubility product of AlN in liquid Fe-Si-Al-N alloys containing silicon up to 1.5?mass pct in the temperature range from 1823?K to 1923?K (1550 °C to 1650 °C). The effects of aluminum and silicon on nitrogen solubility in liquid iron were separately determined in the same temperature range. The experimental results were thermodynamically analyzed using Wagner??s interaction parameter formalism to determine the first-order interaction parameters of silicon on nitrogen and aluminum in liquid iron as follows: $ e_{\text{N}}^{\text{Si}} = 0. 0 6 7 3, \;e_{\text{Al}}^{\text{Si}} = 0.009 $ (1823?K to 1923?K (1550 °C to 1650 °C), Si ?? 1.5?mass pct)     

All-optical inverter with one picojoule switching energy

An ultrafast inverter based on soliton dragging in optical fibres with a switching energy of only 1 pJ, which is the lowest switching energy of any all-optical device, is demonstrated. The inverter consists of a 30 m length of moderately birefringent fibre followed by a 2 km length of a polarisation-maintaining fibre. The switching energy is lowered by separating the soliton dragging mechanisms in two different fibres and optimising the parameters in a time domain chirp switch that is based on time shift keying logic.<>     

Characteristics of SrTiO3 thin films deposited under various oxygen partial pressures

SrTiO₃ thin films were deposited by rf-magnetron sputtering under various sputtering conditions followed by conventional furnace annealing at 600 and 700 °C. The amorphous SrTiO₃ thin films crystallized into polycrystals at 600 °C. The leakage current of the SrTiO₃ thin films decreased with increasing oxygen partial pressure in the sputtering gas. On the contrary, the dielectric constant increased with increasing the oxygen content in the sputtering gas. The leakage current and dielectric constant increased with increasing substrate temperature and post-annealing temperature. The ratio of SrTi approached 11 with increasing oxygen content in the sputtering gas and substrate temperature during deposition. The oxygen content in the film decreased with increasing the substrate temperature. The capacitance-voltage (C-V) curves showed that the capacitance was nearly independent of the applied voltage. Scanning electron microscopy (SEM) micrographs showed that interdiffusion between the bottom electrode (Pt) and the buffer layer (Ti) occurred during post-annealing, but that the interface between SrTiO₃ and Pt was stable.     

Multiscale Modulation of Nanocrystalline Cellulose Hydrogel via Nanocarbon Hybridization for 3D Neuronal Bilayer Formation

Bacterial biopolymers have drawn much attention owing to their unconventional three‐dimensional structures and interesting functions, which are closely integrated with bacterial physiology. The nongenetic modulation of bacterial (Acetobacter xylinum) cellulose synthesis via nanocarbon hybridization, and its application to the emulation of layered neuronal tissue, is reported. The controlled dispersion of graphene oxide (GO) nanoflakes into bacterial cellulose (BC) culture media not only induces structural changes within a crystalline cellulose nanofibril, but also modulates their 3D collective association, leading to substantial reduction in Young's modulus (≈50%) and clear definition of water–hydrogel interfaces. Furthermore, real‐time investigation of 3D neuronal networks constructed in this GO‐incorporated BC hydrogel with broken chiral nematic ordering revealed the vertical locomotion of growth cones, the accelerated neurite outgrowth (≈100 µm per day) with reduced backward travel length, and the efficient formation of synaptic connectivity with distinct axonal bifurcation abundancy at the ≈750 µm outgrowth from a cell body. In comparison with the pristine BC, GO‐BC supports the formation of well‐defined neuronal bilayer networks with flattened interfacial profiles and vertical axonal outgrowth, apparently emulating the neuronal development in vivo. We envisioned that our findings may contribute to various applications of engineered BC hydrogel to fundamental neurobiology studies and neural engineering.     

A multidimensional Rasch analysis of gender differences in PISA mathematics

Since the 1970s, much attention has been devoted to the male advantage in standardized mathematics tests in the United States. Although girls are found to perform equally well as boys in math classes, they are consistently outperformed on standardized math tests. This study compared the males and females in the United States, all 15-year-olds, by their performance on the PISA 2003 mathematics assessment. A multidimensional Rasch model was used for item calibration and ability estimation on the basis of four math domains: Space and Shape, Change and Relationships, Quantity, and Uncertainty. Results showed that the effect sizes of performance differences are small, all below .20, but consistent, in favor of boys. Space and Shape displayed the largest gender gap, which supports the findings from many previous studies. Quantity showed the least amount of gender difference, which may be explained by the hypothesis that girls perform better on tasks that they are familiar with through classroom practice.     

Effect of Yarn Type and Twist Factor on Air Permeability,Absorbency, and Hand Properties of Open-end and Ring-spun Yarn Fabrics

The paper investigates the effects of yarn type, i.e. open-end yarn (OE) and ring-spun yarn (RS) and the twist factors of the warp (W) and filling (F) of the OE yarns on the permeability to air and moisture and the hand properties of various test fabrics woven from both OE and RS yarns. A comparison is made of the effect of yarn types and various twist levels of warp and filling of the OE yarns on the air permeability, absorbency, coefficient of friction and flexural rigidity of fabrics woven from such yarns.

It is intended that future studies will explore a wider range of twist levels and different yarn types than those investigated on this initial exercise.