Background: This study investigated the concentration of some heavy metals in plastic housing of televisions produced over three decade (1980-2000) with the aim of providing information and comparing the trend in the concentration of these metals. Methods: The heavy metal concentrations were determined by atomic absorption spectroscopy after acid digestion using a 1:1 mixture of sulphuric an...

Introduction Blue light is a part of the spectrum with the highest energy content, which can reach the retina. The damage that it can cause to the retina is called photochemical or blue-light retinal injury. For the retinal injury assessment of the photochemical and aphakic retinal hazards in the wavelength range of 300-700 nm, use of effective spectral radiance limits (W.m-2.sr-1) seems to be...

In this paper, stability of slopes with a shallow foundation located on top including the shape of the failure mechanism is investigated in static and seismic states. This is a three dimensional problem which is analyzed two dimensionally because 3D analyses are complex and appropriate softwares are not available. The conventional method of bearing capacity evaluation of foundations on top of ...

in this study, the fatigue behavior of alloy steels with different hardness values was tested. results showed that the fatigue limit increases by the increment of hardness up to 400 vickers whereas it drops when the hardness value exceeds 400 vickers. fractographic observations using scanning electron microscopy revealed non-metallic inclusions as the dominant fatigue crack initiation sites. by...

The paper is devoted to the estimation of characteristic limits (statistical criteria) for detection small amounts ionizing radiation by a measuring device under conditions natural radioactivity background environment: decision threshold, limit, minimum detectable activity and confidence interval. assessment procedures were carried out in accordance with national harmonized standard DSTU ISO 11...

We consider a difference equation involving three parameters and a piecewise constant control function with an additional positive threshold λ. Treating the threshold as a bifurcation parameter that varies between 0 and∞, we work out a complete asymptotic and bifurcation analysis. Among other things, we show that all solutions either tend to a limit 1-cycle or to a limit 2-cycle and, we find th...

We study the attractor structure of standard block-sequential threshold dynamical systems. In a block-sequential update, the vertex set of the graph is partitioned into blocks, and the blocks are updated sequentially while the vertices within each block are updated in parallel. There are several notable previous results concerning the two extreme cases of block-sequential update: (i) sequential...

We study the diversity of complex spatio-temporal patterns in the behavior of random synchronous asymmetric neural networks (RSANNs). Special attention is given to the impact of disordered threshold values on limit-cycle diversity and limit-cycle complexity in RSANNs which have 'normal' thresholds by default. Surprisingly, RSANNs exhibit only a small repertoire of rather complex limit-cycle pat...