Technical Transactions. Vol. 2

Technical Transactions. Vol. 2

Type: Collection of magazine numbers
Release date

Collection items (11)


Comparison of results of stress cycle counting by the direct spectral method and the Fu-Cebon method for bi-modal type stress processes

Kozień, Marek S., Smolarski, Dariusz
Article
2017
This article compares the results of a high cycle fatigue analysis obtained through the application of the two methods dedicated to analysis of response of the structure of the bi-modal type – the direct spectral method and the Fu-Cebon one. The compared parameter is the lifetime for an assumed material S–N curve and stress spectrum defined in an article by Fu & Cebon.

The production and properties of micro-extruded low-density polyethylene microtubes

Głogowska, Karolina, Sikora, Janusz W.
Article
2017
Micro-extrusion is the process of obtaining microtubes with either simple or complex cross-sections which are used for the high-precision transport and protection of various of media. Through this process, it is possible to create tubing with interior diameters and wall thicknesses as small as 0.1 mm and 0.05 mm respectively. Micro-extruded tubing such as micro catheters and peripheral intravenous cannulas are employed in microfluidics, paediatrics and micro-analytics. This article presents the results of granulometric tests of micropellets produced by micro-extrusion with cold pelletizing and results of tensile strength tests of microrods of different diameters. The trials were performed using a standard twin-screw extruder and low-density polyethylene.

Analysis, modelling and verification of the phenomena occurring in a hydraulic prop during dynamic load

Domagała, Zygmunt, Kędzia, Krzysztof
Article
2017
The paper describes the working conditions of hydraulic prop in particular issues related to their dynamics. On this basis, mathematical model was developed for given simplif ying assumptions. The paper includes description of simulation model as well as an experimental verification performed in HSW Stalowa Wola.

Design of a decentralised intelligent network for five wet pit pumping stations

Poehler, Michael, Thamsen, Paul Uwe
Article
2017
This paper presents a design for a decentralised intelligent network of five wet pit pumping stations in a rural area. This enables the network to automatically respond to inflow conditions divergent to the base flow and use the storage capacity of the system to prevent sewer overflows. First results for the base flow and a simulation of the network in EPANET are presented.

Stress state laboratory verification in masonry structures according to the flat jack method

Łątka, Dawid
Article
2017
In the article, the value of compressive stress defined according to the flat jack method with a theoretical value of the stress was compared. The test was performed in a laboratory using part of the 38 cm thick masonry wall according to the procedure described in the A STM C1196 – 14a Standard. Significant correspondence between the obtained results confirms that this diagnostic method is useful in Polish conditions as well as it allows one to estimate approximately how accurate it is.

Characteristics of selected methods for the synthesis of nanometric zirconium oxide – critical review

Kwaśny, Justyna, Balcerzak, Wojciech
Article
2017
High chemical stability, resistance to changes in the pH, pressure and temperature meant that zirconium oxide is widely used in many fields. It is used in water treatment and waste water treatment processes, as well as air purification. In this paper, selected methods of nano-zirconia synthesis in liquid phase were characterized. These methods include, among others, the microemulsion method. Based on literature data, the advantages and difficulties associated with the use of each method are presented, in order to answer the question of which method of nanometric zirconium oxide synthesis in the liquid phase is the most advantageous. The authors also pointed out some directions of development for the discussed methods, which relate to, among others, solvent change and the use of additives in the form of polymers.

Comparison of temperature and displacements of a gravity section and a buttress section illustrated with the example of concrete dam in Rożnów

Kasprzak, Adam, Popielski, Paweł
Article
2017
This paper presents the results and the process of numerical analysis of a selected section of the concrete dam in Rożnów. The calculations were carried out for two different variants: the gravity section and the buttress section. The effects of the geometry on the temperature distribution inside the section, and the effect of the temperature on displacements, were examined.

Numerical modelling of gabion joints

Grodecki, Michał
Article
2017
This paper presents results of a numerical analysis of the stability of a gabion retaining wall. The main objective of the paper is to identify how different methods of the modelling of gabion joints affect the stability of the structure.

Study of oxidative coupling of methane integrated with CO oxidation

Michorczyk, Barbara, Hędrzak, Elżbieta
Article
2017
In this work, the process of OCM carried out over Mn-Na2WO4/SiO2 integrated with selective oxidation over Ag/support was investigated. The effect of feed gas composition and OCM bed temperature as well as the position of Ag/support bed and additional oxygen injection before this bed were investigated. At optimal OCM conditions for the Mn-Na2WO4/SiO2 catalyst (CH4/O2 = 3.75; Vtot = 77 cm3/min; T = 780°C), the injection of additional 4 cm3/min of oxygen into the bed of Ag/support (working at 250–300°C) leads to a preferential oxidation of CO to CO2.

Eight city types and their interactions: the “eight-fold” model

Salingaros, Nikos A.
Article
2017
A model for understanding the city in terms of eight characteristic “city types” is proposed. The most human cities consist of adaptive city types that act in a congruent manner. Any city can be analyzed as a particular mixture of these eight types. Competing city types combine and interact in different ways, and users feel the result as an essential quality of the environment. Some types either add to, or cancel and destroy each other, whereas others can juxtapose without interacting. This eight-fold model of city types helps us to predict the success or failure of distinct urban regions in promoting urban life. It also suggests how to repair declining or non-existent pedestrian activity, and how architectural projects could affect the city adversely or positively. One section of this paper is devoted to techniques for designing urban spaces that invite human engagement, and another to designing a campus.