This button makes you go up: three-year-olds and the Nintendo controller

Forty three-year-old children used the Nintendo controoler in a simple cursor-placement task, with two different software interfaces. The directional interface required children to map specific directions of movement on to specific buttons on the controller. The non-directional interface simply advanced the cursor in a clockwise direction to the next placement location, regardless of the specific directional button pressed. Results indicate that while the youngest three-year-old children find the non-directional interface slightly easier to use, older three-year-olds are more successful with the directional interface. In addition, all three-year-olds actually experienced problems using the simpler, non-directional interface - and problems increased with age. The results are discussed with reference to designing appropriate interfaces for the wide variety of skill levels present in the pre-school population.     

Template synthesis of zinc oxide nanoparticles entrapped in the zeolite Y matrix and applying them for thermal control paint

Zinc oxide nanoparticles within faujasite zeolites have been synthesized by a procedure comprising of (i) ion-exchange of zinc ions into the zeolite, (ii) precipitation of zinc ions with sodium hydroxide within the supercage of the zeolite, and (iii) calcination. The products were characterized by XRD, SEM, TEM, EDX and FTIR techniques. The size of the ZnO particles was in the range of 24±4 nm. Finally, ZnO@zeolite was used as a pigment and its optical properties were studied.     

Rheological properties of Lepidium sativum seed extract as a function of concentration, temperature and time

The seeds of Lepidium sativum (Garden Cress) were selected as a new source of hydrocolloid and its chemical composition and molecular parameters were determined. The macromolecular component of the extract had a molecular weight of 540 kDa, and was nearly as rigid as xanthan with regard to chain conformation. The main rheological features were investigated as a function of shear rate, concentration and temperature. The extract exhibited strong shear-thinning behaviour, which was even more pronounced than for xanthan. An increase in concentration or temperature led to an increase in pseudoplasticity. The Arrhenius model was applied to the temperature dependence of viscosity, and the activation energy (E_a) was found to decrease with increasing concentration. The extract solutions showed thixotropic behaviour at all the concentrations and temperatures studied, and the first-order stress decay model with a non-zero equilibrium stress fairly described the time-dependent behaviour. The rheological characteristics found indicated a potential application of the extract as a novel thickener.     

Correlation of Microstructure and Magnetotransport Properties of Epitaxially Grown La2/3Ca1/3MnO3 Thin Films

Using the technique of pulsed laser deposition, we have studied the correlation of the film deposition conditions with the microstructure and magnetotransport properties of La_2/3Ca_1/3MnO₃ thin films. Detailed TEM microstructure studies revealed the dependence of the local microstructure with the deposition temperature. The TEM studies reveal a distortion of the La_2/3Ca_1/3MnO₃ lattice leading to a breakdown of the symmetry from orthorhombic to monoclinic. At high deposition temperatures (T<800°C), the substrate/film interface is perfectly coherent, suggesting that the film is strained due to the lattice mismatch. Effects of hydrostatic pressure on the resistivity of the films reveal an increase in temperature of the metal–insulator transition and a colossal change in resistivity qualitatively comparable to the magnetoresistance effect. The data are interpreted in terms of microstructure sensitive changes of the contraction and alignment of the Mn–O–Mn bonds.     

Piezoelectric hollow cylinder with thermal gradient

The coupling nature of piezoelectric materials has acquired wide applications in electric-mechanical and electric devices. Recent advances in smart structures technology have led to a resurgence of interest in piezoelectricity, and in particular, in the solution of fundamental boundary value problems. In this paper, an analytic solution to the axisymmetric problem of a radially polarized, radially orthotropic piezoelectric hollow cylinder with thermal gradient is developed. An analytic solution to the governing equilibrium equations (a coupled system of second-order ordinary differential equations) is obtained. On application of the boundary conditions, the problem is reduced to solving a system of linear algebraic equations. The stress and potential field distributions in the cylinder are obtained numerically for two piezoceramics. It is shown that the hoop stresses in a cylinder composed of these materials can be decreased throughout the cross-section by applying an appropriate set of boundary conditions. This paper was recommended for publication in revised form by Associate Editor Jeong Sam Han Mahdi Saadatfar received a B. S. degree in Mechanical Engineering from University of Kashan 2006. He is currently a M.S student at the School of Mechanical Engineering at University of Tehran, Iran. He is currently researching about modeling of nanoindentation process in nanocomposites. Mr. Saadatfar’s research interests are in the area of piezoelectric Materials, Polymer/Clay nanocomposites and Finite element modeling. He has several published paper about piezoelectric materials and Finite element modeling of nanocomposites. Amin Shariat Razavi received a B.S degree in Mechanical Engineering from Kashan University in 2006. He is currently testing and examining an specific type of intelligent plasma cutting machine for process equipment that is designed by himself. Mr. Razavi’s research interests are smart materials and design of mechanical system.     

A 125-MHz mixed-signal echo canceller for Gigabit Ethernet oncopper wire

A discrete-time analog echo canceller is described that reduces the echo in the front end of Gigabit Ethernet twisted-pair interfaces. Echo cancellation in the analog domain by means of four taps reduces the complexity of the digital echo canceller and crosstalk cancellers. Designed in a 0.4-μm CMOS technology, the circuit employs an LMS algorithm to adapt to the cable length and impedance discontinuities, providing an echo suppression of 10 dB. The design operates at 125 MHz while consuming 43 mW from a 3-V supply     

Rheology of Al-Cu-Mg pre-alloyed powder in supersolidus liquid phase sintering process

Sintering process was performed on cylindrical consolidates in dry nitrogen atmosphere at various temperatures ranging from the solidus-to-liquidus temperatures for 30?min at a heating rate of 10°C?min^?1. Beam bending technique has been used to measure the macroscopic apparent viscosity of Al-Cu-Mg pre-alloyed powder (2024 Al alloy). Slumping test has been used to measure the yield strength at temperatures above solidus temperature. Wetting angle and capillary stress were calculated. Results showed that the rheological behaviour of this system follows as Bingham model. The yield stress varies from 0.37?kPa at 580°C to 0.3?kPa at 610°C on air atomised Al-Cu-Mg having 0.1% Sn. The correlation between variations of viscosity as function of temperature has been derived. The activation energy of viscous flow was estimated to 15.164?kJ?mol^?1. Capillary and yield stress decrease by increasing temperature. Maximum densification with minimum distortion is obtained at 600–610°C.     

Rheological Characterization of Low Fat Sesame Paste Blended With Date Syrup

In this paper, the time-dependent flow behavior of reduced fat sesame paste with date syrup were assessed using Brookfield rotational viscometer as a function of fat substitutes (guar gum, xanthan, and starch) at three levels and shearing time. Two models were used to predict the time-dependent behavior, known as, first-order stress decay with a zero equilibrium stress and Weltman models. It was found that time-dependent behavior of samples was adequately fitted with these models. All blends exhibited the thixotropic behavior and thixotropy of samples increased with increasing shear rate. For Weltman model, the A and B constants appeared in the range of 189.2–730.6 Pa and 0.090–1.571 Pa, respectively. While for first-order stress decay model, the initial shear stress (τ₀) was in the range of 197–794 Pa, and the breakdown rate constant (K) varied in the range of 0.002–0.018 s^?1. The presence of fat substitutes generally resulted in an increase of viscosity and thixotropy of blends in comparison with the blank.     

Effect of Trisodium Citrate Concentration and Soy Cheese on Meltability of Pizza Cheese

The objective of this study was to determine the effect of soy cheese (tofu) and trisodium citrate (TSC) concentration on physicochemical properties of pizza cheese. The results indicated that fat and FDM contents of pizza cheese increased significantly with increased proportion of TSC, while moisture and protein decreased but not significantly (P < 0.05). On the other hand, the fat, FDM, and protein content decreased with increased proportion of tofu, while moisture increased. The melting area and melting degree indicated that melting properties of pizza cheese decreased significantly, as the concentration of TSC increased. Furthermore, increase approximately 5 and 10% tofu in the blends with 0.5% TSC or 10% tofu in the blends with 1% TSC affected notable decrease in melting properties. Among each level of tofu, oiling off area showed significant increase with increasing TSC. Increase in tofu proportion as well as different TSC concentration resulted in decrease in free oil. The control cheese with 1% TSC (CC2C) had maximum oiling off, and with increase in tofu proportion there was a corresponding reduction (P < 0.05) in the oiling off area. It was observed that increase approximately 10% tofu in the blends with 0.5% TSC cause marked reduction in oiling off area by approximately 47%. There was rapid increase in oiling off area during the early stage of cooking. According to observation, free oil formation of cheese with 1% TSC (C2C) was higher than that of the cheese with 0.5% TSC (C1C), especially during 2.5 to 10 min (P > 0.05). Oiling off area of treatments decreased independently of trisodium citrate prolong cooking as the proportion of tofu increased.