Volume 118 (2021): Issue 1 (January 2021)

This article presents the results of an analysis of the economic viability of using an installation for the treatment of grey water. Economic indicators in the form of simple payback time (SPBT) and net present value (NPV) were used in the analysis. The use of a dual water supply system should theoretically enable the reduction of the costs of both water supply and sewage disposal, ensuring investment profitability. The article presents the impact of the number of residents as well as the impact of water and sewage on the profitability of using example water-recovery systems. It was found that both factors have a huge impact on the result of the economic analysis. For a small number of residents and at a low price of water supply and sewage disposal, it is not profitable to invest in a water-recovery system. This is due to the high price of purification devices.

In recent years, the integration of human-robot interaction with speech recognition has gained a lot of pace in the manufacturing industries. Conventional methods to control the robots include semi-autonomous, fully-autonomous, and wired methods. Operating through a teaching pendant or a joystick is easy to implement but is not effective when the robot is deployed to perform complex repetitive tasks. Speech and touch are natural ways of communicating for humans and speech recognition, being the best option, is a heavily researched technology. In this study, we aim at developing a stable and robust speech recognition system to allow humans to communicate with machines (robotic-arm) in a seamless manner. This paper investigates the potential of the linear predictive coding technique to develop a stable and robust HMM-based phoneme speech recognition system for applications in robotics. Our system is divided into three segments: a microphone array, a voice module, and a robotic arm with three degrees of freedom (DOF). To validate our approach, we performed experiments with simple and complex sentences for various robotic activities such as manipulating a cube and pick and place tasks. Moreover, we also analyzed the test results to rectify problems including accuracy and recognition score.

The article presents an overview of materials which can be employed used to camouflage objects on the modern battlefield in the radar frequency range.

This paper follows the propagation of pollution in a river with a rectangular cross-section of the river bed and a variable cross-sectional velocity. The calculations were made for steady flows and steady pollutant concentrations. To approximate the velocity distribution in the river bed a set of equations for current and vorticity functions was solved. The distribution of pollutant concentrations in the river was calculated from a bidirectional advection and turbulent diffusion equation. Analysis of the distribution of concentrations leads to the conclusion that the effects of transverse advection associated with a lateral inflow of pollutants disappear relatively quickly. Therefore, the distribution of concentrations in cross sections further downstream from the point of pollutant discharge can be determined quite accurately just from an advection-diffusion model, with no transverse advection effects included. Such a level of accuracy is usually sufficient to assess the impact of a pollution source on the aquatic environment. The transverse mixing of pollutants in the stream proceeds slowly and creates a large mixing zone in which the concentrations of pollutants (low but still significant for water quality) can be detected in cross-sections that are remote from the pollutant discharge point. Transverse advection may be ignored while calculating concentrations in remote cross sections at straight watercourse sections and in steady state conditions.

The Pandemic is forcing everyone to become aware of the need for a change in the cultural and socio-economic paradigms of recent decades.

During the twentieth century, on the one hand, entire populations concentrated in urban areas with ever higher population densities, at the same time giving rise to the phenomenon of “urban sprawl” or “suburbanization”.

On the other hand, entire territories have been abandoned (the so-called “inner areas”).

Now, we can define territorial rebalancing strategies based precisely on the reactivation of “inner areas”. Strategies that, in the Post (post) COVID era will have to be not only resilient, but anti-fragile. And the key is precisely in the future of the smaller historical centres.

This article aims to review the strengths and weaknesses of small historic centres, outlining possible scenarios for their “smart” revitalization and for a true sustainable and inclusive development.

The city life cycle is an issue that can be considered from many perspectives. Klaassen’s period cycle is the basic model of city life: urbanisation– suburbanisation–deurbanisation–reurbanisation. In each of these periods, cities develop by, building and transforming their structures. This article presents various approaches to shaping new urban spaces using the city of Rzeszów as an example. In the city’s history, three periods are distinguished during which structures referred to as the ‘new town’ were created in the 16^th and 20^th centuries and continue to be created now. After analysing the site-forming processes, the most important features of new-town urban systems are compared.

In this article, changes occurring in structural steel after exposure to fire are described and discussed. The steel structure before and after fire determines its susceptibility to brittle cracking. The individual phases of cracking are described and interpreted on the basis of a load-displacement graph, directly obtained from the Charpy impact test. The relationship between the intensity of individual fracture energies and the type and appearance of the sample fractures are demonstrated. The program of planned Charpy impact tests and expected hazards after the exposure to fire of selected steel grades are presented. Standard simplified load-displacement graphs are assigned to the steel transition curve. The course of various cracking mechanisms occurring in the case of brittle fractures and plastic fractures are discussed. The aim of this article is to evaluate the possibility of the assessment of structural steel after a fire based on results obtained during the Charpy impact test.

Events related to climate change and the increase in the occurrence of natural disasters, as well as the increasing incidence of new diseases, have all caused the prominence of regional security and crisis management around the world to rise. Three-dimensional printing, which has seen noteworthy developed in recent years, both in terms of print parameters, and the magnitude of the production potential, may prove helpful in this matter. Enormous opportunities have arisen which, if properly directed, can save human life and preserve health in crisis situations, when traditional supply chains could be disrupted or even prevented. The use of additive technologies, however, has its limitations and in order to be able to take full advantage of the opportunities they offer, a legitimate functional system should be created and embedded within proper structures to support crisis management. This paper presents the advantages and disadvantages of using 3D printers and the possibility of their implementation as part of the current crisis-response systems. The article proposes a model for incorporating additive technologies into the crisis-management system.

The kinetics of and mechanism for galvanising low-carbon steel (0.2% C) were examined in powder media which were pre-treated to obtain a fine nanostructured ZnO layer on the surface of zinc powder particles. The effective diffusion coefficient of Zn atoms through the ZnO shell was estimated to be in the order of 1·10⁻¹⁰ m²·s⁻¹. The contribution of the Zn-gas evaporation/condensation microprocesses, which could occur in relation to the above diffusion through a nanostructured surface layer, was evaluated with numerical calculations in the temperature range of 550–950 K and for an average particle size of ZnO up to 100 nm. Our results suggest that the outward diffusion of metallic zinc takes place from the core of powder microparticles across the nano-grain boundaries of their modified surface layer, and can be further intensified by the presence of other inter-phase defects, such as nano-porosity.

The main purpose of the research was the historical study of utility gardens, which are separate functional and spatial sections of the palace and park complex in Klemensów. These include a walled-off garden constituting a unique man-made landscape acting as a fruit and vegetable garden, as well as a tree nursery. The utility gardens in Klemensów were a place of acclimation and reproduction of seeds and saplings imported to Poland. Thanks to the expanding possibilities of obtaining and exchanging them from foreign and domestic garden nurseries, over time, the garden in Klemensów became a unique collector’s garden.

The research introduces rarely discussed problems in the field of conservation, including the adaptation of historic utility gardens. The results include the analyses of archival materials which have not been previously developed.

Human motion analysis is a very important research topic in the field of computer vision, as evidenced by a wide range of applications such as video surveillance, medical assistance and virtual reality. Human motion analysis concerns the detection, tracking and recognition of human activities and behaviours. The development of low-cost range sensors enables the precise 3D tracking of body position. The aim of this paper is to present and evaluate a novel method based on topological data analysis (TDA) for motion capture (kinematic) processing and human action recognition. In contrast to existing methods of this type, we characterise human actions in terms of topological features. The recognition process is based on topological persistence which is stable to perturbations. The advantages of TDA are noise resistance and the ability to extract global structure from local information. The method we proposed in this paper deals very effectively with the task of human action recognition, even on the difficult classes of motion found in karate techniques. In order to evaluate our solution, we have performed three-fold cross-validation on a data set containing 360 recordings across twelve motion classes. The classification process does not require the use of machine learning and dynamical systems theory. The proposed classifier achieves a total recognition rate of 0.975 and outperforms the state-of-theart methods (Hachaj, 2019) that use support vector machines and principal component analysis-based feature generation.

This paper is based on recent articles regarding applications of humic substances (HSs). HSs are natural organic materials, which have a number of potential applications. Furthermore, HSs are cheap, widespread and obtainable from bio-waste materials. HSs can be used as organic compound sorbents or in detoxification. They are applied as organic additives due to their positive effect on soil and plants, even under stress conditions. HSs reduce water consumption and minimise environmental problems. HSs are utilised for the remediation of multi-metal contaminated soils and as substitutes for synthetic washing agents. From an environmental engineering point of view, it is beneficial to remove HSs from municipal management, where they are undesirable (by-products of disinfection) and to utilise them where they are valuable. The aim of this article is to provide a greater insight into research about the applications of HSs.

A typical rack and pinion drive set is comprised of a rack and a pinion. There is an inter-tooth clearance between the mating teeth of the rack and the pinion, which has advantages and disadvantages. The disadvantage of this clearance is the errors that occur in the positioning of the machine tool during set-up. Elimination of clearance between teeth is possible by using a pinion drive with two pinions. This ensures continuous contact between the teeth, regardless of the direction of machine movement.

These are found on new machines, while older machines do not have such a solution. This paper presents a solution with two pinions, which can be used in such older machines and which makes it possible to achieve qualitative parameters that were not possible before.

This paper discusses the long-term vision of the historic city development, where buildings assume a new function over time. The discussion is based on the example of Palazzo Querini Stampalia and Fondaco dei Tedeschi – two monuments restored to Venice in a new, different role. In the comparative analysis of the transformation of the buildings, particular attention was paid to the cultural, social and economic context of the city. This article aims to review the strengths and weaknesses of the new-use scenarios, outlining the renovation of the monuments and its added value for cities. The author concluded that no matter what the new function of the building is, it is worth renovating them, because this way the heritage can survive and this should be the central objective of a long-term vision.

Elements of the tramway track that require special attention in the design and maintenance of the tramway infrastructure are sharp curves (curves with small radii). In such places, there are a number of unfavourable operational problems, which are discussed in the article below. It describes the characteristics of such geometric elements and analyses the interaction of the wheel-rail system. Moreover, the most important operational problems are presented, such as the wear of wheels and tramway rails, the buckling of the rails, and noise and vibrations occurring during the passage of the tram. Methods of reducing unfavourable phenomena occurring on curves in the tramway infrastructure were also highlighted.

The article starts with the short discussion of two geometrical figures, i.e., octagon and ellipse, their genesis in architecture and urban design, and the examples of buildings whose plans were based upon them. Then, the selected octagonal and elliptical city squares are discussed: their genesis, context, layout, architecture surrounding the square, objects appearing in the square and, most specially, urban form and composition. The theory of architectural-landscape interiors has been applied to pinpoint the type of city squares by the assessing of the degree of openings in the square’s perimeter. The review consists of 22 case studies (9 octagonal and 13 elliptical) from the 15^th to the 20^th century. The last discussed case in each group, both atypical created in Krakow in the 20^th century, are discussed even more thoroughly. The conclusions were presented first separately for octagonal and elliptical city squares and finally also for both groups in a comparative way.

The article presents the destructive influence of external factors on building partitions in selected historic buildings made from made full-bodied solid ceramic bricks. The external factors are an additional element that adversely affects the maintaining of historic buildings in a good technical condition, and they are complementary to a number of harmful factors that destructively act upon on such buildings. In order to estimate the range of damage in historic buildings, selected buildings that have been exposed to external factors for a long time in the Podlaskie and Warmińsko-Mazurskie Voivodships were analysed.

Renovation of multi-family residentials, including mainly thermal renovation, which includes adding thermal insulation, contributes to the improvement of living conditions. Above all, it reduces the operating costs of renovated buildings by reducing the consumption of heat energy for central heating. This article discusses the impact of light wet thermal renovation on the temperature distribution in the vertical cross-section of the partition wall and the calculation value of the temperature on the inner surface of the partition wall, as well as on the reduction of thermal energy consumption in buildings. The subject of the research was residentials erected in the large-panel, large- -block, and traditional technology between 1984 and 1994, managed by Łomża Housing Cooperative (ŁSM).

The history of southeastern Poland is inseparably linked with the Jewish community that settled mostly in larger cities located near significant trade routes. Despite limiting privileges, in many cities Jews managed to establish their own quarters, in which synagogues were the most important structures. Only a few cases of historical Jewish religious architecture, in varying states of preservation, have survived to the present. In Przeworsk, to the north of the town hall, an impressive, masonry Jewish synagogue had stood for several centuries. The building was erected at the start of the seventeenth century and up to the Second World War constituted a significant element of the city’s spatial structure. Despite the passage of over eighty years since the demolition of the synagogue, its site has not been commemorated. This paper presents the genesis and architecture of the historical synagogue. The massing of the building, its functional and spatial layout, and its interior décor were investigated. The paper also discusses the commemoration of historical buildings, pointing to the significance of place-based identity and broadly understood cultural heritage.

In recent years, urban spaces all over the world have been effectively staged, sometimes all too obviously, and urban design has often concentrated on the implementation of “beautiful” lighthouse projects and globally oriented lifestyle urbanism. However, beauty – also in the broader sense of a beautiful experience – cannot be an end in itself in urban planning. An urban design of responsibility has to be committed to all residents and address the pressing challenges of our time, for example: the almost unlimited consumption of land, water and energy; floods and heatwaves due to climate change; lack of decent living conditions for large parts of the population. Against this background, five strategic guidelines for the integrated and responsible planning of our cities have been developed. These include “comprehensive” and integrated neighbourhoods, a mobility turnaround, interconnected blue and green infrastructure, a circular resource economy and space sharing, and the exploitation of the opportunities of digitalisation for a social and ecological city.

The article presents the course and results of the procedure for verifying the stability of the cylindrical shell of an oil tank with a floating roof, under wind load. Two dimensioning methods recommended by standard PN-EN 1993-1-6 were used, i.e. dimensioning based on the stress state and the MNA-LBA procedure. The method of determining the critical buckling resistance ratio from the linear bifurcation analysis (LBA) and the plastic reference resistance ratio from the physically nonlinear analysis (MNA) has been presented. Comparison of the results obtained with the use of the indicated design methods revealed significant discrepancies in the stress intensity levels of the analysed shell. When using the stress-based dimensioning method, it was shown that the buckling strength was exceeded by 33%, while the results of the MNA-LBA procedure indicated a 33% reserve of the capacity of the analysed system.

A method for determining the value of the damage to a single-family residential building located near an open-pit mine caused by ground vibrations is presented. The article describes how to objectively determine the degree of actual wear and tear to a residential building (Zr) affected by ground vibrations created during rock mining using blasting. It consists of the method of “weighted average degree of technical wear and tear of individual elements” known from literature and used to calculate the actual wear and tear of the building. The natural wear and tear of the building is then calculated from dependences given in the literature. The percentage of the building’s natural wear and tear (Zn) is subtracted from the percentage of the building’s actual wear and tear. As a result of the subtraction, a percentage of accelerated wear and tear of the building (Zb), which is caused by vibrations of the ground during rock blasting, is obtained. Multiplying the percentage of accelerated wear and tear of the building by the value of a new building gives a value of the damage caused by ground vibrations. Examples of determining the value of the damage caused by ground vibrations in practice are described.

This article presents a detailed analysis of the functioning of municipal sewage treatment plants. The presented findings are based on questionnaires from over seventy wastewater treatment facilities, covering from several hundred to several hundred thousand inhabitants. The required quality of treated sewage and the necessary efficiency level of the treatment plant were determined in the context of the content of the applicable regulations, and were then compared with the actual data obtained from sewage treatment plants. The findings provided the basis for formulating an evaluation of the efficiency of municipal sewage treatment plants and for further analyses of the possibility of the recovery of water from sewage and its reuse.

Unmanned underwater vehicles which use biomimetic mechanisms are becoming increasingly useful in the realisation of tasks requiring silent and efficient propulsion. Complex fish kinematics are simplified to some extent and implemented in such vehicles. One of the essential fish behaviours is their ability to adjust their buoyancy using a swim bladder. This paper covers the issues concerning the implementation of artificial swim bladders as well as depth regulators in two underwater vehicles: biomimetic and hybrid. The control of vehicle depth through buoyancy change was examined in the computer simulation and in the experiment. Two types of artificial swim bladder were tested – a rigid cylinder with a piston and an elastic container with a water pump.

Contemporary armed conflicts reveal that the use of effective mine barriers has a significant impact on the course of hostilities. Therefore, the Polish Armed Forces selected reliable and effective explosive ordnance as a priority, both newly-acquired material and those currently in operation. For this reason, among others, strict supervision over the technical condition of mines is exercised, in particular during their long-term storage. The reasons behind the increased mine unreliability may include physical and chemical changes in the construction materials used (corrosion, deformations, loss of strength properties), deterioration of the physicochemical properties of the main charge, booster and primer-detonator, inadequate technical condition of the safety components, or the failure of mine fuse mechanisms. In order to assess the mine’s operational reliability, each mine fuse subassembly is examined and then a check of the entire assembled mine is performed. This requires proper planning of the full test cycle and the use of inspected and calibrated measuring devices and test stands enabling the precise adjustment of mechanical and climatic stress parameters.

The following article discusses the systems method as an educative tool for teaching sustainable architecture, including environmental design. Based on this method, a systemic model was created which provided a pillar of the learning process that concluded with a solar building project. This method offered a holistic view of the issues of pro-environmental design and led to an understanding of the relationship between the urban scale and the scale of the building. This aspect was considered crucial in teaching sustainable development architecture.

The systems method has been recently used in China as a part of an environmental design course which only lasted for forty-eight lesson hours. The method proved to be an effective educational tool that enabled the obtaining of satisfactory design effects in such a short period of time. Additionally, the method was successful in conditions of cultural and linguistic barriers and a lack of prior preparation of students in the field of architectural design. The created systems model determined a precisely defined path for the teaching process in advance, as the specified issues included only those that were needed to achieve the set project goals. This approach resulted in the optimisation of teaching time, while ensuring the completeness of the assumed results.

Experience gained from the didactic process leads to the conclusions that the systems method can be an adequate educative tool for solving multidisciplinary problems. Based on the example of solar building design, a systems method made it possible to indicate three main external factors that influence the design: macro-scale urban elements (district scale), micro-scale urban development (housing estate) and climatic conditions. The article also presents the possibilities of transforming the system model, in order to facilitate its more universal application, with reference to such issues as the topic of classes, as well as to the required scope and level of detail of the design task.

Planning space around large industrial plants affects urban development and significantly impacts the integration of industrial areas with a city’s structure. Large industrial plants act as functional and spatial barriers within the urban fabric. Their immediate areas undergo transformation and are currently becoming sites of various uses. New manufacturing technologies limit the nuisance caused by industry and the siting of plants aids in using the areas around them. The objective of this paper is t present an analysis of the transformation of the existing function-spatial structure, transport layout and compositional relations in the vicinity of selected large industrial plants in Kraków and Skawina. The study covered areas around the north-eastern territory of the Metallurgy Plant in Kraków and selected industrial plants in Skawina.

This study was based on original analyses of the existing functio-spatial structure, compositional relationships and transport accessibility. The form of development of areas adjacent to large industrial plants was found to be a product of local determinants. Compositional relationships and functional linkages affected the quality of the space and its visual reception, which in many cases is a natural urban development reserve.

Due to the specificity of industrial areas, concentrations of vehicular traffic and dominance within space, it may prove interesting to develop a dedicated form of development for areas near large industrial plants. This form would have to shield against possible nuisances while also offering the potential for a new, attractive and diverse functio-spatial structure. The transformation of and the problems present in these areas are distinctive of many cities in Poland and around the world and require new, cohesive planning principles.

Music school students spend much more time rehearsing than performing in concert halls. Individual and small ensemble exercises are a major part of daily practice. The aim of the article is to verify whether the areas of rehearsal rooms given in functional programs attached to architectural contests for music schools, are sufficient to provide required acoustic conditions inside the chamber such as sound power level (SPL) and reverberation time (RT) which is preferred by musicians. The Norwegian Standard NS 8178:2014 was used to calculate the sound level generated by instruments. In this paper, the author will focus on small rehearsal rooms dedicated to individual practice and small practice groups of two or three members.

The paper presents a new methodology for calculating the optimal linear distribution of braking forces for a three-axle trailer with “walking beam” and “bogie” suspension of the rear axle assembly that will meet the requirements of the new European legislation, EU Directive 2015/68. On this basis, a computer program for selecting the linear distribution of braking forces between axles has been developed. The presented calculations and simulation results of the braking process can be used in the design process to select the parameters of the wheel braking mechanisms and then the characteristics of the pneumatic valves of the braking system. The adaptation of the braking system of agriculture trailers is a very important factor for improving the safety of the transportation systems.

This article presents a numerical analysis of laser-welded flange pipe joints. The presented results concern the welding of low carbon S235JR and stainless 316L steels using a CO₂ laser in lap and fillet joint configurations. The estimation of welding parameters was achieved using Simufact Welding software and numerical simulation, where output power, feed rate, efficiency and intensity distribution (Gaussian parameter) were analysed. In accordance with the established model, a thermo-mechanical simulation was performed. The calculated joint geometries show good agreement with experiments; therefore, the obtained results were used to study selected joint properties of both joint types. Stress-strain distribution was estimated on the basis of thermo-mechanical analysis. Weld bead geometry obtained from numerical simulation was compared with the results from trial joints. The numerical model established for both joint configurations shows good agreement with experimental results and were assumed to be accurate. The results of the performed analysis shown some advantages of the use of this configuration of lap joints in flange pipe joints.