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  • Author: Michał Zygmunt x
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Abstract

There are a limited number of studies on secular changes in the neonatal period, and the majority of them concern research related to childhood and puberty The objective of our study was to carry out a comparative analysis of body weight and length at birth in neonates born in Wrocław in subsequent decades since 1950 to find out if these parameters are subject to secular trend, and what values they attained during the studied period of 50 years. The study was carried out in the 1950s, 1960s, 1970s, 1980s, 1990s and in 2000 to analyse changes in body length, body weight and Rohrer index over time. The sample studied consisted of 7510 neonates, 3882 males and 3628 females, born in Wroclaw. Secular changes were tested using one-way variance analysis. The values of F statistics were compared to the critical values of the F Snedecor distribution. Changes in the features of neonates in subsequent study years were analysed using the modified z-score. Data were normalised for standard deviation in decade increments. Results demonstrated very slight, though statistically insignificant increase in body weight at birth. Over the 50-year period the mean body weight of neonates was in the range of 3.3-3.4 kg, regardless of sex. Results demonstrated very slight, though statistically insignificant increase in body weight at birth. Over the 50-year period the mean body weight of neonates was in the range of 3.3-3.4 kg, regardless of sex. The acceleration in the body length of neonates caused a gradual decrease in the mean values of the Rohrer index. No secular trend in body weight was found in Wrocław neonates over the 50-year period between 1950 and 2000 With regard to body length at birth, four waves of deceleration and acceleration were found: period 1 (1950s): deceleration in the increase of the analysed body parameters of neonates; period 2 (1960s): acceleration in neonates’ growth; period 3 (1970s and 1980s): economic crisis and political transformations in Poland; this is reflected by the stable mean values of body dimensions in neonates. The secular trend clearly decelerated, and period 4 (1990s and 2000) - very intense acceleration in both body weight and length and the Rohrer index.

Abstract

Steel sheet piles are often used to support excavations for bridge foundations. When they are left in place in the permanent works, they have the potential to increase foundation bearing capacity and reduce displacements; but their presence is not usually taken into account in foundation design. In this article, the results of finite element analysis of a typical abutment foundation, with and without cover of sheet piles, are presented to demonstrate these effects. The structure described is located over the Więceminka river in the town of Kołobrzeg, Poland. It is a single-span road bridge with reinforced concrete slab.

Abstract

The aim of this paper is to present the geological structure of the Vistula river valley floor as the modifying factor of fluvial processes and present the development conditions of the contemporary Vistula river channel, which underwent marked transformation due to bed erosion and lateral erosion below the Włocławek reservoir. The analysis of the geological data and the geological survey conducted at the study reach of the Vistula between Włocławek and Toruń resulted in an image of the geological structure of the channel bed along the longitudinal profile

Abstract

Presented paper is dedicated to problems of deformation of the Earth's crust as a response to the surface loading caused by continental waters. The aim of this study was to specify areas particularly vulnerable to studied deformation and to compare calculated and observed displacements. Information of the continental water volume was taken from the WaterGAP Global Hydrological Model. Calculated values of the deformations were verified with the results obtained with programs SPOTL and grat. Vertical deformations were almost 10 times higher than the deformation in the horizontal plane, for which reason later part of the paper focuses on the former. In order to check agreement of the calculated and observed deformation 23 stations of International GNSS Service (IGS) were selected and divided into three groups (inland, near the shoreline and islands). Before comparison outliers and discontinuities were removed from GNSS observations. Modelled and observed signals were centred. The analysed time series of the vertical displacements showed that only for the inland stations it is possible to effectively remove displacements caused by mass transfer in the hydrosphere. For stations located in the coastal regions or islands, it is necessary to consider additional movement effects resulting from indirect ocean tidal loading or atmosphere loading.