The paper deals with determination of flexural resistance buckling curves for welded I-section steel members made of high strength steel (S 690). In the paper the previously proposed BF analytical model is used for approximation of FEM results obtained using moderately large deformation shell theory and ABAQUS/Standard software. Final formulation of flexural resistance buckling curves is possible through the use of the Merchant-Rankine-Murzewski approach adopted extensively in the authors’ previous papers. For nonlinear optimization, which is needed for analytical model parameters determination, the Wolfram Mathematica package is used. Obtained results for S 690 steel are presented against the results for S 355 steel.

Construction work on buildings covered by the revitalization program of historic urban development represents a special type of construction project in which, in the execution phase, difficult technical situations and other risk sources are being encountered. An important source of risk is the necessity to preserve a part of the historic substance, which results, among others, from the recommendations of the conservator, legal regulations or from the vision of the architect/investor. The risk is also associated with difficulties and complications in construction works resulting from the location of these objects in dense urban development. The aim of the article is to identify risk factors and reactions of contractors, i.e. applied risk management methods and techniques, based on the example of a complex of buildings constructed in the historic district of Krakow. The elimination of sources of risk, especially of a technical nature, requires the construction management to be highly skilled and experienced, to carefully prepare the construction work and to design additional solutions to ensure safety at work. The experience gained may serve as a basis for risk analysis and identification during the implementation of projects involving the use of an existing building and historic substance in areas subject to revitalization programs.

The article presents the results of tests of the application of magnetic fuel activators, which improve the efficiency of metallurgical furnaces and positively affect the ecological aspects of their work. Energy indicators for metallurgical furnaces during operation before and after installation of magnetic fuel activators as well as the results of composition and concentration of emitted pollutants are included in the paper. The magnetic activation of liquid and gaseous fuels modifies their structure. As a result of the activation, the fuel mixture is selectively saturated with oxygen in the zone of free fuel flow. The combustion conditions were close to optimal, which is confirmed by the reduction of pollutants in the exhaust gases. Fuel saving in the combustion process is also a measurable economic effect. The tests included ovens of several types: pusher furnace, one and two chamber furnaces and a furnace with a rotary shaft. Several-month measurement cycles were carried out on each of them. The experiments consisted in the analysis of gas and heat consumption per month in individual furnaces before and after the use of magnetic fuel activators. The effectiveness of using activators was determined on the basis of the results of the tests carried out. As a result of a twelve-month test cycle on the pusher type furnace, a 36% reduction in gas consumption and a 22% reduction in heat consumption were achieved. After a seventeen-month measurement cycle on chamber furnaces, a 35% reduction in gas consumption and 6% in heat consumption were achieved. The tests on furnaces with a rotary shaft lasted fourteen months and showed a reduction in gas consumption by 8%. An improvement in the composition of fumes in the furnace atmosphere was achieved in all units with magnetic activators installed, as well as a reduction in the emission of harmful pollutants into the atmosphere from the installation.

The paper presents the effectiveness of waste heat recovery regenerators equipped with innovative ceramic matrix forming an integral part of a real glass furnace. The paper full description of the regenerators’ matrix structure with its dimensions, thermo-physical properties and operating parameters is included experimentally determined was the effectiveness of the regenerators has been descrbed using the obtained experimental data such as the operating temperature, gas flows as well as the gases generated during the liquid glass manufacturing process. The effectiveness values refer not only to the heating cycle when the regenerator matrix is heated by combustion gases but also to the cooling cycle in which the matrix is cooled as a result of changes in the direction of the flowing gas. On the basis of the determined effectiveness values for both cycles and measurement uncertainties it was possible, to calculate the weighted average efficiency for each of the regenerators.

The term of melancholy has left the domain of human psyche becoming a contemporary philosophical experience. In contemporaneity it appears as such in creating architectural space, showing its diverse faces – melancholic subjects, poetics of space associated with an issue of duration – melancholy of monuments or melancholic ruins. Examples of the phenomenon of melancholy in architecture, described in the article, show its various incarnations, both in built and drawn space – architecture widely understood as: buildings, urban spaces, land art and artistic interventions in built environment.