Chromatic visual evoked potential responses in preschool children

The purpose of the study was to analyze chromatic visual evoked potential (VEP) responses to isoluminant red-green (R-G) and blue-yellow (B-Y) stimuli in 30 preschool children (1.5-6 years). The predominant part of the response consisted of a positive (P) wave, which showed age-related latency changes (linear decrease). P wave latency was shorter when using 21° compared to 7° R-G (p=0.004) and B-Y (p=0.044) stimulus and also when using 21° R-G compared to 21° B-Y stimulus (P=0.000). P wave amplitude did not show age-related changes. However, a lower amplitude was recorded when using 7° R-G stimulus (p=0.0013) and also when using B-Y compared to R-G stimulus. We may conclude that chromatic VEP to R-G and B-Y stimuli is reliably recorded in preschool children and that P wave to R-G stimulation shows a higher amplitude and shorter latency than to B-Y stimulus.     

Mathematical models for water vapour resistance prediction of printed garments

The human body has developed a thermo‐regulatory system that maintains an inner body temperature of approximately 37 °C. At excessive body temperatures, sweat mechanisms activate, resulting in a decrease in body temperature through sweat evaporation. Garments, depending on their characteristics, extensively affect the heat interchange process between the human body and the environment. Different printing processes change the characteristics of textile materials and therefore the garments made from these materials. This paper investigates the influence of digital printing parameters on the thermo‐physiological features of textile materials. The effects of printing parameters on thermo‐physiological characteristics of substrate materials were determined by measuring water vapour resistance. The obtained results show that printing parameters, in combination with material composition and material texture, have a large effect on the thermo‐physiological characteristics of textiles.     

End‐of‐life Solutions for Fibre and Bio‐based Packaging Materials in Europe

Efficient end‐of‐life solutions play an important role in developing sustainable packaging because they contribute to reducing resource wastage and environmental impact, whilst providing economic and social benefits. This paper briefly reviews current end‐of‐life solutions for fibre and bio‐based materials for packaging in Europe. It also addresses current research in the field, as well as standardization, legislation and socio‐economic aspects related to renewable packaging in Europe. This review focuses on the following groups of packaging materials: paper and board and bioplastics. With this hierarchy, recycling, organic recovery and energy recovery are analysed with regard to the processes and technologies that offer the most sustainable end‐of‐life options. Copyright © 2012 John Wiley & Sons, Ltd.     

The thermal decomposition of basic lead styphnate RD 1349 at its ignition temperature

Abstract

Basic lead styphnate RD 1349 forms the primary explosive component of several high temperature fuzehead formulations and percussion primers. A study of its thermal decomposition under controlled conditions near its ignition temperature (521–525 K) shows that it decomposes very rapidly, following a second order autocatalytic rate law. The kinetics of this reaction are initially controlled by the ‘‘nucleation of reactive molecules'’occurring on the crystal surfaces or glide planes, by the growth of these nuclei as the reaction proceeds and, in the rate determining step, by their subsequent reaction in the bulk of the material. The rate determining step in this reaction follows Arrhenius kinetics with an activation energy of 197 kJ mol^?1 and pre-exponential log₁₀ A (s^?1) = 17.9.     

The croatian scientific elite and its socio-professional roots

No matter how strong the intellectual and other psychological predispositions for top scientific achievement and/or a successful scientific career, neither the processes of a general and scientific socialisation nor the socio-cultural or socio-professional environment can be avoided or neglected. Empirical support for the thesis on the impact of the social environment on the formation and the influence of the scientific elite of a country is supported by three analysed research studies: on distinguished Croatian scientists (1995), on the population of Croatian scientists (1990) and on Croatian scientific emigrants (1986).     

Influence of Al(OH)3 nanoparticles on the mechanical and fire resistance properties of poly(methyl methacrylate) nanocomposites

One of the drawbacks of poly(methyl methacrylate) (PMMA) is its flammability. This limits its use in many areas, particularly in constructions. Although there are several fire retardants commercially available, certain disadvantages remain. Introduction of fire retardants into PMMA can change the mechanical properties and transparency can be significantly reduced. Our attention in this study was focused on aluminium trihydroxide (ATH) nanoparticles as the filler for PMMA. To achieve better compatibility and avoid the agglomeration of nanoparticles, 2‐hydroxyethyl methacrylate was used as a co‐monomer for nanocomposite preparation. The characteristics of sheets made with ATH nanoparticles were compared to standard PMMA sheets prepared without additives. Better thermal properties and impact hardness were observed, the speed of burning was significantly lower, while complete transparency of the material was retained. POLYM. COMPOS., 37:1659–1666, 2016. © 2014 Society of Plastics Engineers     

Chemical analysis of mineral aggregates for concretes

A review of standardized methods of chemical analysis of mineral aggregates for concretes is presented. Since sample preparation and testing in the standardized methods, based on gravimetric quantitative analysis, is very time consuming, a faster turbidimetric method of testing for water soluble sulphates is suggested.     

Parametric analysis and yearly performance of a trigeneration system driven by solar‐dish collectors

Solar‐driven polygeneration systems are promising technologies for covering many energy demands with a renewable and sustainable way. The objective of the present work is the investigation of a trigeneration system, which is driven by solar‐dish collectors. The examined trigeneration system includes an organic Rankine cycle (ORC), which operates with toluene, and an absorption heat pump, which operates with LiBr/H₂O. The absorption heat pump is fed with heat by the condenser of the ORC, which operates at medium temperature levels (120°C to 150°C). The absorption heat pump produces both useful heat at 55°C and cooling at 12°C. The ORC produces electricity, and it is fed by the solar dishes. The examined ORC is a regenerative cycle with superheating. The total analysis is performed with a developed model in Engineering Equation Solver (EES). The system is investigated parametrically for different ORC heat‐rejection temperatures, different superheating levels in the turbine inlet, and various solar‐beam irradiation levels. Furthermore, the system is investigated on a yearly basis for the climate conditions of Athens (Greece) and for Belgrade (Serbia). It is found that the yearly system energy and exergy efficiencies are 108.39% and 20.92%, respectively, for Athens, while 111.38% and 21.50%, respectively, for Belgrade. The values over 100% for the energy efficiency are explained by the existence of a heat pump in the examined configuration. For both locations, the payback period is found close to 10 years and the internal rate of return close to 10%. The final results indicate that the examined configuration is a highly efficient and viable system, which operates only with a renewable energy source.     

An anchoring theory of lightness perception.

A review of the field of lightness perception from Helmholtz to the present shows the most adequate theories of lightness perception to be the intrinsic image models. Nevertheless, these models fail on 2 important counts: They contain no anchoring rule, and they fail to account for the pattern of errors in surface lightness. Recent work on both the anchoring problem and the problem of errors has produced a new model of lightness perception, one that is qualitatively different from the intrinsic image models. The new model, which is based on a combination of local and global anchoring of lightness values, appears to provide an unprecedented account of a wide range of empirical results, both classical and recent, especially the pattern of errors. It provides a unified account of both illumination-dependent failures of constancy and background-dependent failures of constancy, resolving a number of long-standing puzzles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)