Distribution of elements in Ni-Mo-TiC alloy processed under microgravity conditions

Ni-Mo-TiC particle-strengthened alloy was processed through melting-pressing treatment of hot-pressed samples under microgravity environments by sounding rocket flight. The distributions of titanium carbide particles and elements in the alloy sample obtained were analysed using microscopy and micro Auger electron spectroscopy. The objective of this analysis was mainly to clarify the elemental distribution in the titanium carbide particle. Analysis was also carried out on the melting-pressing treated and hot-pressed samples for comparison. Analytical results showed that titanium carbide particles are uniformly distributed by the processing under microgravity and that stable mutual diffusion reaction had progressed there.     

A Novel Stacked Array Antenna with Uni-planar Compact EBG Reflector

Most broadband microstrip antennae are implemented in the form of slot structure or laminate structure,which provide a broad impedance bandwidth and meanwhile bring large sidelobes and backlobes. A novel uni-planar compact electromagnetic band-gap( EBG) structure is proposed, which shows excellent performance when applied to broadband stacked or aperture coupled microstrip array antennae. The test results indicate that,the directivity is effectively improved,and the front-to-back ratio is increased,and the thickness of the antenna is reduced. These improvements make this structure better used in airborne antennae.     

An approach for ergonomic design of mouse wheel

A new method for ergonomic design of a computer mouse is proposed in this paper.In the method,the movements of joints and tip of the forefinger during operating a mouse was captured by a high-speed video camera.The captured videos were analyzed and an algorithm was developed to decide the size and location of the mouse wheel according to ergonomic principles.The algorithm was then coded in a software package with Visual C++ and OpenGL languages.Results of the calculation and simulation agreed well with those of the experiments.The software can also be used for shape design of mouse body,buttons and their layouts.     

New amphoteric surfactants containing a 2-hydroxyalkyl group VIII. Synthesis and surface activities for amphoteric oligomeric or polymeric surfactants of β-alanine type

A series of amphoteric oligomeric and polymeric surfactants of poly(iminoethylene) (PIE) containing both a 2-hydroxyalkyl group (C₁₂-HA or C₁₄-HA) and a 2-carboxyethyl (CE) group as N-substituents was studied as follows: PIE having 1,000 or 20,000 molecular weight was treated with 1,2-epoxydodecane or 1,2-epoxytetradecane and subsequently methyl acrylate. The adducts were saponified to obtain amphoteric oligomeric surfactants (AO) or amphoteric polymeric surfactants (AP), poly{[N-(2-carboxyethyl)-N′-(2-hydroxyalkyl)]iminoethylene}. Various adducts of which the ratios of CE/HA for one unit of iminoethylene group are 2, 3.5, 8, 17 and 89 were synthesized. Surface activities such as surface tension, solubilization of orange OT, and foaming power, and physicochemical properties such as turbidity, isoelectric point, and the dissociation constant, were studied. Particular attention was paid to the dependence of solubilization, viscosity and turbidity on pH value.     

Autonomous reconfiguration of robot shape by using Q-learning

A modular robot can be built with a shape and function that matches the working environment. We developed a four-arm modular robot system which can be configured in a planar structure. A learning mechanism is incorporated in each module constituting the robot. We aim to control the overall shape of the robot by an accumulation of the autonomous actions resulting from the individual learning functions. Considering that the overall shape of a modular robot depends on the learning conditions in each module, this control method can be treated as a dispersion control learning method. The learning object is cooperative motion between adjacent modules. The learning process proceeds based on Q-learning by trial and error. We confirmed the effectiveness of the proposed technique by computer simulation.     

On cavitation occurrence in perforated plates

The hydraulics of perforated plates has a large impact on the design of water systems; particularly, estimating the inception of cavitation is fundamental for correctly assessing the performances of these devices. The work is focused on the onset of cavitation, as defined by means of the incipient cavitation number. Objects of discussion are the experimental evidences collected in two large laboratory campaigns, in which different plates with equivalent diameter ratio between 0.17 and 0.60, relative thickness between 0.11 and 4.40, and number of holes between 1 and 15 were tested. Literature experimental data, previously checked for consistency, have been added to ours in order to enlarge the experimental database. Such database was firstly employed for investigating the dependence of the incipient cavitation number upon the most relevant parameters and then for providing a formula for its estimation. In details, we propose a new correlation – based on the formula of Tullis (1993) – relating the incipient cavitation number to the discharge coefficient showing a satisfactory agreement with all the available data and therefore having a quite large applicability.     

Long-term irradiation effects of visible light on amorphous carbon nitride films

The effect of long-term visible-light irradiation on the photo-induced deformation of amorphous carbon nitride (a-CN_x) films was investigated. a-CN_x films were deposited on SiO₂ substrates (30 × 2 × 0.05 mm³) using reactive radio frequency magnetron sputtering. Deformation of the a-CN_x films was measured using continuous wave (CW) or pulsed monochromatic light with a wavelength of 470 nm. Pulsed light irradiation was applied for a total of 60 min with an on/off pulse period of 60 s, while CW light irradiation was performed for 120, 190, and 759 min with different light intensities so that the total photon flux remained constant. In all cases, the extent of photo-induced deformation of the a-CN_x films before and after irradiation did not change. The chemical bonding states determined from X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy analyses indicated no significant changes after illumination. In addition, electron spin resonance (ESR) spectroscopy measurements indicated that there was no increase in the defect density after illumination. The long-term stability of a-CN_x films is one of the main advantages for their use in light-driven microactuator systems.     

A rigorous calculation of the critical point from the fundamental equation of state for the water + ammonia mixture

The critical point of the water + ammonia mixture was calculated directly from the Helmholtz free energy formulation. The calculation was performed according to the critical point criteria expressed in terms of the derivatives of the Helmholtz free energy with respect to mole numbers. Smooth critical locus linking between the critical points of pure water and ammonia was obtained. The critical locus showed a good agreement with the most reliable experimental data. Simple correlations for the critical temperature, pressure, and molar volume for a given composition were developed. The information obtained in this study is helpful for design and simulation of the cycles using the water + ammonia mixture as working fluid.