Perceptions of the taste of colors in children and adults

Taste is an acquired phenomenon. The tastes of colors are related to people's perceptions and assumptions, as well as their personal experiences. In other words, there is a meaningful correlation between taste and color. However, this correlation requires extensive investigation before general patterns of taste perceptions can be determined. In addition, multiple studies of a range of different populations are necessary. This study investigated the responses of 56 male and 56 female Iranian participants aged 2 to 6 years to 11 colors commonly used in food and food packaging. Data analysis revealed significant correlations between perceptions of the taste of colors and the relationships between primary and secondary colors in Itten's color wheel. The data were also compared with data from an earlier and identical survey of the taste perceptions of adult Iranians. Participants in both groups perceived the taste of secondary colors as the taste common to their two constituent primary colors. In addition, the basic color rules set out in Itten's color wheel in relation to secondary and achromatic colors also affected how the taste of each color was perceived.     

Viscoelastic properties of architected foams based on the Schoen IWP triply periodic minimal surface

Abstract

In this article, we studied the viscoelastic properties of an architected foam based on the mathematically-known Schoen IWP triply periodic minimal surface (TPMS) under both time and frequency domains. IWP-based architectures possess unique multifunctional attributes when used as a three-dimensional (3D) reinforcement in composites. The 3?D representative volume elements (RVEs) of different relative densities (i.e., the ratio of the foam’s density to the density of its solid counterpart) were generated and studied using the finite element method in order to predict the effective uniaxial, shear, and bulk viscoelastic responses of IWP-foams as a function of relative density and/or frequency. The principle of time-temperature superposition principle was used to create the master curve of the observed relative-density dependent mechanical responses (loss tangent, storage and loss moduli) in frequency domains. Reduced uniaxial, bulk, and shear stiffness-loss map results suggested that the IWP-foam possesses strongest uniaxial viscoelastic response while highest damping can be achieved under shear responses. Relaxation behavior of IWP-foam was compared with other six different types of open-cell periodic foams. It was found that IWP-foam uniaxial response is similar to simple cubic foam, bulk relaxation response is similar to primitive-foam while shear response follows the behavior of body centered cubic foam. Among these foams, we found that IWP-foam is the best candidate to use as a damper under uniaxial and hydrostatic loading conditions.     

Modes of failure under creep/fatigue loading of a nickel-based superalloy

Crack growth experiments have been carried out under combined creep and fatigue loading at 700° C on a hot isostatically pressed powder nickel alloy. A fractographic investigation has been undertaken of the modes of failure over a frequency range of 0.001 to 10 Hz. The observations indicate that under static loading and at low frequencies failure is intergranular and controlled by creep processes, whereas at high frequencies a transgranular fatigue fracture is obtained. The transition from creep to fatigue behaviour is found to be progressive, and to begin at a lower frequency the higher the ratio of cyclic to mean load. In the transition region a mixed intergranular and transgranular fracture surface is observed, which correlates well with the recorded proportion of creep to fatigue crack growth.     

Production Lot-Sizing Under Learning Effects: An Efficient Solution Technique

In this paper, we consider a production-inventory model which assumes that learning occurs as a function of the number of units produced. We analyze two cases: the first case allows for no forgetting between production runs and the second case (a generalization of the first case) allows for some given degree of forgetting between production runs. In the first case, we show that learning only has an impact on initial lot-sizes for large order quantities and that steady state lot-sizes will approach the traditional EOQ amount. In addition, we show that succeeding lot-sizes are always nonincreasing. Applying these results to the second case when forgetting occurs, we develop efficient heuristic algorithms with complexity O(N logN) to determine order quantities. Results from our algorithms are compared to optimal solutions; these comparisons indicate that our algorithms usually provide solutions within one percent of the optimal cost.     

Combined deadbeat control of a series-parallel convertercombination used as a universal power filter

This paper presents the notion of combined control of a system of interconnected power electronic converters. The concept is demonstrated using a three-phase series-parallel active power filter as an example. The described active power filter consists of a series-parallel combination of two full bridge VSIs capable of arbitrarily controlling the input current and output voltage. The proposed control scheme treats the converter combination as a single unit and uses the inverse system model to generate deadbeat control response for both input current and output voltage. A full-order predictive state observer is used to reduce the number of sensors. Simulation results show better disturbance rejection characteristics of the proposed control when compared to the separately controlled converter scheme     

Determination of an unknown radiation term in an inverse problem of heat equation

A linear conduction equation with radiative boundary condition is considered, in which the function representing radiative flux is unknown, and is to be determined from overspecified data. Exact and approximate explicit solutions are presented for the temperature and radiation term. Some uniqueness and stability results are presented. Finally some numerical results will be given.     

A fast on-line neural-network training algorithm for a rectifierregulator

This paper addresses the problem of deadbeat control in fully controlled high-power factor rectifiers. Improved deadbeat control can be achieved through the use of neural network-based predictors for the input current reference to the rectifier. In this application, online training is absolutely required. In order to achieve sufficiently fast online training, a new random search algorithm is presented and evaluated. Simulation results show that this type of network training yields equivalent performance to standard backpropagation training. Unlike backpropagation, however, the random weight change method can be implemented in mixed digital/analog hardware for this application. The paper proposes a very large-scale integration implementation which achieves a training epoch as low as 8 μs     

Numerical assessment of the mechanical stability in vertical,directional and horizontal wellbores

In this research the stability of wellbore is evaluated in seven different stress regimes and diverse orientations using FLAC3D software. The normalized yielded zone area (NYZA, i.e., the ratio of surrounding yielded cross-sectional area to initial area of wellbore) is determined for different mud pressures as well as diverse orientations of wellbore. By means of MATLAB software the best curve is fitted to the recorded points and then the optimized mud pressure is calculated using these plots. The optimized orientation is selected considering these data. Finally the mud pressure resulted from this method was compared with the mud pressure obtained from the Mogi-Coulomb criterion and then with the fields data. The minimum allowable mud pressure obtained from the NYZA criterion is close to actual data and the value obtained from the Mogi-Coulomb criterion. Hence, the NYZA is considered to be an appropriate criterion for wellbore stability analysis.     

A novel heteropolyacid-doped carbon nanotubes/Nafion nanocomposite membrane for high performance proton-exchange methanol fuel cell applications

A novel proton-exchange polymer composite membrane was synthesized using Nafion^®, tetraethoxysilane-modified carbon nanotubes (CNTs) and phosphotungstic acid-modified carbon nanotubes with the aim of using direct methanol fuel cells (DMFCs). Physicochemical properties of the modified CNTs and fabricated composite membranes were investigated by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, water uptake, thermogravimetric analysis, ion exchange capacity, proton conductivity and methanol permeability tests. It was demonstrated that chemical surface modification of CNTs and introduction of the phosphotungstic acid (PWA) groups effectively improved the performance of DMFC. It was found that the presence of PWA groups on the surface of CNTs led to the formation of strong electrostatic interactions between the PWA groups and clusters of sulfonic acid in Nafion^® macromolecules. Hence, the incorporation of inorganic phosphotungstic super-acid-doped silicon oxide-covered carbon nanotubes (CNT@SiO₂-PWA) into Nafion^® matrices enhanced the proton conductivity of the prepared membranes. Moreover, the methanol permeability was reduced to 2.63 × 10^?7 cm² s^?1 in comparison with the recast Nafion^® membrane (2.25 × 10^?6 cm² s^?1). Enhancing the proton conductivity and reducing the methanol permeability, the selectivity of the prepared nanocomposite membranes was enhanced to a greater value of 330,700 S s cm^?3 as compared to the value of 38,222 S s cm^?3 for recast Nafion^®.