Volume 114 (2017): Issue 3 (March 2017)

Since the beginning of the twentieth century, Finland has been a ground for experiments in the field of the housing environment. A low population density, as well as the unique natural and landscape values of the country have led to a clear trend of respect for nature in its architectural tradition. The paper, based on the theory of the Modern Movement – represented by, among others, Alvar Aalto, as well as on the tenets of Finnish the garden city of Tapiola – provides a characteristic of the role of natural elements in the composition of urban recreational spaces. The paper also discusses the structure of modern building complexes on the basis of the latest residential districts of Helsinki – as well as other cities of southern Finland, focusing on the compositional and functional role played by elements of nature within recreational spaces of a place of residence.

Diffusion with a first-order chemical reaction in a spherical pellet of a catalyst with third-type boundary conditions was considered; such a process can be described by a kinetic model based on the continued fraction approximation. Results of calculations obtained from an approximate kinetic model were compared with the exact solution. It was found that the application of this approximate model provides a good level of accuracy and requires short calculation times.

In this work, a new preparation method is proposed to obtain high temperature monolithic structures for catalytic applications. A commercial 3D printer was used to synthesise polymeric templates that were utilised in the designing of channel structures in monolithic catalysts. New materials with manganese and sodium tungstate supported on corundum with macropores of well-defined shapes and sizes were prepared; their catalytic performance was investigated in the process of the oxidative coupling of methane.

An unified method of designing molecular formulae for all types hydrocarbons is proposed in this paper. The developed formula provides the molecular composition of hydrocarbons regardless of the number of chemical bonds and bond types or the number of rings they contain. Moreover, a small modification to that formula makes it suitable for deriving the molecular composition of hydrocarbons with oxygen atoms bound to carbon atoms with single and double bonds.

Spectroscopic studies of the fluorescence emission of selected 1,3,4-thiadiazoles in organic solvents and an aqueous solution were carried out. An interesting effect of pH-induced dual fluorescence was observed in the aqueous solution. The use of organic solvents resulted either in a single fluorescence maximum, double fluorescence (two well-resolved emission bands), or the dual fluorescence effect. The results obtained suggest that the fluorescence emission effects in 1,3,4-thiadiazoles are associated with both the conformational isomerism and the chromophore aggregation phenomena.

This paper paper the results of the stationary characteristics of CSTR bioreactor cascades with a modifiable structure, obtained by the way of numerical experiments. As a technological example, the biodegradation of phenol was chosen.

The process of interaction between the ground and screw displacement columns (SDC) in transferring loads has not yet been sufficiently investigated. This paper presents the results of pioneering tests in this field, carried out with the application of a long-term structural health monitoring system.

The primary aim of this study is the analysis of the influence of multi-seam coal mining on a specific 110 kV overhead high-voltage power line. The paper presents the results of geodesic measurements of surface deformation in the area of the analysed location. The study also analyses mining-induced changes in the construction and the inclination of the transmission pylons. Some proposals for the reinforcement of the pylons are suggested. Additionally, pressing issues are identified indicating the necessity for the replacement of the existing pylon system of the overhead high-voltage power line.

In the building industry, polymeric matrix composites filled with glass, carbon, graphite, polypropylene, or Kevlar filaments are commonly used. However, it is notable that the wider use of composites is limited by a lack of sound knowledge regarding their properties their responses to exposure to various environments. In this respect, the alkaline and acid environments may have a significant influence on the response of epoxy-glass composites which are most commonly in use. They may undergo stress corrosion and the resulting cracks reduce the strength of the composite. Within this work, a method based on acoustic emission measurement is devised which allows the determination of the beginning of cracking and of the intensity of the corrosive cracking of filaments in a loaded composite. This is substantial in terms of the diagnosing of the functioning structures.

The objective of this paper is to analyse the time reserves in scheduling periods for conducting processes that ensure construction deadlines can be met. By using the probability account and numerical analyses methods, including ‘Monte Carlo’, execution cycles have been analysed, as well as summary stoppage times for executing teams and working areas. On the basis of calculations made using data from studies made during the construction office building in Krakow it was stated that in order to keep to the planned deadline, must be smaller periods of performance of works by individual brigades, an average of 0,103 times of rhythm.

Over recent years in Poland, there has been a rapid accumulation of sewage sludge – a by-product of the treatment of urban wastewater. This has come about as a result of infrastructure renewal, specifically, the construction of modern sewage treatment plants. As a consequence, the amount of fly ash resulting from the thermal treatment of municipal sewage sludge has grown significantly. The aim of this experiment was to evaluate the possibility of using the fly ash that results from municipal sewage sludge thermal treatment (SSTT) as an additive to hardening slurries. The article presents the technological and functional parameters of hardening slurries with the addition of fly ash obtained by SSTT. Moreover, the usefulness of these slurries is analysed on the basis of their basic properties. The mandated requirements for slurries employed in the construction of cut-off walls in flood embankments are listed as a criterion of usefulness. On the basis of this experiment, the usefulness of fly ash obtained through SSTT as an addition to hardening slurries was identified.

This article presents a comprehensive analysis of the technical condition of the sewage collector located under Krakowska Avenue in Warsaw. The cross section of the collector is an extended ovoid with the dimensions of 1400 × 800 mm. Current operational problems as well as the reasons for specific faults and failures were discussed. The numerical models generated according to the collected data and the technical documentation were presented. Boundary and initial conditions taken into account in the analysis process and the assumed calculation scenarios were also described. The results obtained as well asthe considered modernization projects, along with selected optimal technical solutions, were discussed.

This paper is a wide review of literature concerning the presence of flame retardants in sediments, treated wastewater, sewage sludge and the possibilities of their biodegradation. These compounds are widely applied in, for example, the textile and electronics industries. Flame retardants (FRs) are hydrophobic with very low solubility in water; however, they are released slowly during the washing of clothing, and as a result of the discarding of waste electronic products, etc. FRs show low mobility in the environment and can accumulate in wastewater, sewage sludge, in sediments in the beds of rivers and lakes, and in soil. Total concentrations of polybrominated diphenyl ethers (PBDEs) ranged from 0.59 to 48.000 ng/g d.w and decaBDE (BDE 209) concentrations from 0.4 to 47,400 ng/g d.w. BDE 209 dominated the congener profile.

The current work consisted of performing tests on the prototype airlift reactor, examining the efficiency of oxygenation in an airlift reactor equipped with an airlift pump and an additional nozzle to aerate and mix water in the tank. In particular, the objective was to find the optimal submergence of the nozzle which would allow achieving the best possible oxygenation of water with adequate lift efficiency. The testing was performed in two series: with a tank fully filled with water; with a tank filled with 80% water and 20% moving bed. The use of a moving bed with a high specific surface area significantly improved aeration conditions and decreased mixture flow velocity thus causing an increase of gas and liquid contact time. The research has shown the effect of nozzle position on the aeration and circulation conditions in the reactor.

This article presents an application of the kinetostatic method. The kinetostatic method is a universal method for determining optimum control of unit components in a multisource drive system with regard to selected energetic or ecological criteria. The method’s algorithm and mathematical models for components with descriptions are presented. Example results of this method when applied to a hydrostatic multisource drive system composed of hydrostatic transmission, gas-loaded accumulator and IC engine as the primary source of energy, are presented.

The mathematical simulation of a plate fin and tube heat exchanger is presented in this paper. The simulation of the transient operation of the heat exchanger was carried out using a general numerical model that was previously developed by the authors. The Reynolds number of the water flowing inside the tubes varied in the range from 4000 to 12000. A detailed analysis of the transient response of a heat exchanger to sudden increase in water mass flow rate and the simultaneous reduction in air flow velocity was modelled. Heat transfer correlations for air and water were determined based on the experimental data. Unknown parameters appearing in the relationships for the Nusselt numbers on the airand water-sides were estimated using the least squares method. A set of partial differential equations for the temperature of water, air, tube wall, and fins was solved using the finite volume method. The results of the numerical simulations of a heat exchanger using experimentally determined air and water-side heat transfer formulas for the calculation of heat transfer coefficients were compared with the experimental data. Excellent agreement between computation results (air and water temperatures at the outlet of the heat exchanger) and experimental results was obtained.

This paper presents the results of a thermodynamic analysis and a method of selecting individual devices and their components to design a zero-emission power plant project in Pomerania. Another aim of the paper is to present the technological abilities of the application of gas-steam turbines with a particular emphasis on enhanced energy conversion in the construction of a wet combustion chamber using cooling water transpiration and a gas-steam expander.