Search Results

You are looking at 1 - 10 of 17 items for

  • Author: Michał Dąbrowski x
Clear All Modify Search
Open access

Jacek Paś, Tadeusz Dąbrowski and Michał Wiśnios

Abstract

The article presents a method of teaching the process of diagnosing the technical and functional condition of the fire alarm system (SSP). The fire alarm system’s laboratory model is a representation of a real fire alarm system. The lecturer has the opportunity to inflict several different independent damage. The aim of the laboratory exercise is to familiarize students with the methodology and structure of the fire alarm system diagnosing process.

Open access

Tadeusz Dąbrowski, Marcin Bednarek and Michał Wiśnios

Abstract

The article is devoted to the illustration of the relationship of the operation system state assessment in the reliability and economic aspect on a type of information on the state of the object intended for the implementation of an operational task, on the reliability of this object, on the operational task properties (i.e. on the required effect size and the time for its manufacture), on the nature of relationships between a producer and a recipient of the effect. The proposed model of the operation system, as well as a model of the operation process and models of typical operational situations make it possible to find conclusions on a criterion of reliability and economic usability of the operation system.

Open access

M. Dąbrowski, E. Jakimiuk, M. Gajęcka, M.T. Gajęcki and Ł. Zielonka

Abstract

Deoxynivalenol (DON), one of the most prevalent mycotoxins in the world, and is capable of inducing immune disorders in humans and animals. The aim of this study was to determine the effect of feed contaminated with DON on the number of TLR2- and TLR9-positive cells and their mRNA expression in the porcine large intestine. The experiment was conducted on two equal groups of pigs (n=4). The experimental group (E) was administered feed contaminated with DON (1008 μg/kg of feed) for 6 weeks, and the control group (C) was administered non-contaminated feed over the same period of time. A decrease in the expression of TLR2 mRNA was noted in the cecum. The percentage of TLR9-positive enterocytes increased in the ascending colon and decreased in the cecum. The results of this study indicate that DON can modify the local immune response by changing the expression of TLRs.

Open access

Paweł Dąbrowski, Michał Klugmann and Dariusz Mikielewicz

Abstract

Analysis of the state of-the-art in research of minichannel heat exchangers, especially on the topic of flow maldistribution in multiple channels, has been accomplished. Studies on minichannel plate heat exchanger with 51 parallel minichannels with four hydraulic diameters, i.e., 461 μm, 574 μm, 667 μm, and 750 μm have been presented. Flow at the instance of filling the microchannel with water at low flow rates has been visualized. The pressure drop characteristics for single minichannel plate have been presented along with the channels blockage, which occurred in several cases. The impact of the mass flow rate and channels’ cross-section dimensions on the flow maldistribution were illustrated.

Open access

Zygmunt Domagała, Paweł Dąbrowski, Michał Porwolik, Krystian Porwolik and Bohdan Gworys

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.

Open access

Ewa Labak-Mechowska and Michał Dąbrowski

Abstract

Chełmno is a town in the north-western part of the Chełmno Lakeland. It is one of few towns in Poland to have fully preserved its medieval defensive walls. Its touristic and natural environs make it a popular tourist destination. The town’s location near the escarpment of the Vistula valley mean that the preserved historical structures (including the defensive walls) are under threat. A few years ago a buttress became detached and two sections of the defensive walls collapsed. One part was rebuilt (the site where the studies were conducted), while the second part remains unrestored. Bricks are also progressively coming away. This situation may be the result of several factors, although the authors claim that the most important are the geological structure and the wall foundations (which are shallow, at a depth of 1-2 m, with the wall having been built up higher in the 16th century).

Open access

Michał Jankowski, Michał Dąbrowski, Justyna Jasińska and Adam Michalski

Abstract

The paper presents results of pedological studies of Klembivka site 1 and Prydnistryanske site 1 barrow IV and the reference soil profile Prydnistryanske site 1 in the context of pedostratigraphy, basic soil properties, construction material origin and palaeoenvironmental implications.

Open access

Magdalena Mita, Michał Glazer, Radosław Kaczmarzyk, Michał Dąbrowski and Karolina Mita

Abstract

Mass movements are an ever present threat to building construction, water management, vegetation formation and biodiversity. This paper presents an approach to landslides research based on non-invasive geoelectrical method - Electrical Resistivity Tomography (ERT). Mapping and displacement monitoring of unstable slopes is crucial for the hazards prevention and assessment. The ERT technique is an effective tool to obtain structural differentiation of geological medium through interpretation of 2D electrical resistivity models. The main advantage of the method is a wide range of applicability what makes its useful during field works on a landslide. It is commonly used for measurements of slope instability, determination of shear surface, landslide susceptibility, depth of bedrock, slip plane geometry. The aim of the work is to identify the geological structures underneath three selected landslides in south Poland: in Racibórz, Milówka and Porąbka. Attempts have been focused on determination of the usefulness of the proposed ERT methodology for evaluation of possible further development of mass movements. On two investigation sites two different arrays have been used: Wenner-Schlumberger and dipole-dipole which allowed to prepare combined data set and resistivity models based on them. Forward modelling of synthetic models based on a priori information allowed to understand anomalies present on resistivity models. Applied approach ensured quality increase of final interpretation of resistivity models.

Open access

Grzegorz Wallner, Michał Solecki, Andrzej Dąbrowski, Grzegorz Ćwik, Andrzej Dąbrowski, Andrzej Matyja, Paweł Lampe and Adam Dziki

Open access

Tomasz Guzel, Bohdan Dąbrowski, Michał Mazurkiewicz, Marcin Makiewicz and Ireneusz W. Krasnoębski

Abstract

Solitary fibrous tumour (SFT) is a rare soft tissue tumour which belongs to fibroblastic/myofibroblastic group of tumours. The most often it appears in pleura, also in pericardium, internal organs, peritoneum and extraperitoenal space. SFT was first described as a new type of pleura’s tumour by Klemperer and Rabin in 1931. The histogenesis of SFT’s has been discussed for years suggesting its mesothelial origin. Recently, SFT has been classified as a mesenchymal fibroblastic tumour. We report a very rare case of 71-year old man suffering from gigantic solitary fibrous tumour of extraperitoneal space who underwent curative surgery in the Department of General, Gastroenterological and Oncologic Surgery in 2011