This paper presents a comprehensive experimental and numerical investigation of the mechanical behaviour and failure mechanisms of a non-standardised C-column and Z-purlin clip connection employed in thin-walled cold-formed steel photovoltaic support structures. The study is motivated by documented structural failures occurring at wind speeds approximately 30% below the design value, attributable to assembly non-conformities at the clip joint. Full-scale (1:1) quasi-static and cyclic laboratory tests were conducted in two loading configurations: tensile loading applied perpendicularly to the Z-purlin axis and sliding friction loading applied parallel to it. Three assembly schemes were examined, representing code-compliant and non-compliant installation conditions, to characterise joint resistance, deformation capacity, and failure mode. The tests revealed two qualitatively distinct failure mechanisms. In the compliant assembly, failure is governed by progressive plasticisation of the clip wings. In non-compliant assemblies, an additional deformation mechanism activates at the clip-to-gusset plate attachment, resulting in complete loss of joint integrity upon unloading. Although peak forces across the three assembly schemes differ by no more than approximately 15%, the post-failure behaviour diverges fundamentally, demonstrating the critical sensitivity of joint performance to geometric imperfections introduced by assembly errors. A three-dimensional continuum FEM model of the individual joint was implemented in Abaqus using C3D4 solid elements and calibrated against the experimental friction data with a Coulomb friction coefficient μ = 0.5. The model accurately reproduces both the failure force and the governing failure mode. Extension of the validated model to a full 1:1 scale structural model of the entire PV canopy reveals that clip wing plasticisation initiates at approximately 70% of the design wind load according to EN 1991–1-4, confirming the connection as the critical load-bearing component. Four joint strengthening variants were evaluated numerically. The most effective solution consists of an additional unequal-sided angle bar 50 × 95 × 3 mm connecting the C-column flange to the Z-purlin web. This variant eliminates yielding of both the clip and the Z-purlin at the full design wind load and increases global structural stiffness by approximately 90%.

This study investigated materials intended for use in porous bearings, incorporating selected layered materials. Previous research has demonstrated that layered compounds, such as molybdenum disulfide (MoS2), tungsten disulfide (WS2), and hexagonal boron nitride (h-BN), can significantly enhance tribological performance. However, these improvements in tribological properties may be accompanied by undesirable characteristics that could limit the practical application of such materials. Therefore, further investigation was necessary to gain a better understanding of their behavior. To this end, composite materials containing iron (Fe) and varying amounts (0.5, 2.5, and 5 wt%) of layered materials were fabricated using powder metallurgy and sintering techniques. The study evaluated the impact of compaction pressure applied before sintering on the tribological properties and hardness of the materials. Additionally, the long-term stability of the composites was assessed after six years of storage under ambient conditions. The results confirmed that incorporating layered materials into the structure of porous bearing materials improves operating conditions and reduces the coefficient of friction by more than 20%. However, after six years of ambient storage, only the samples containing h-BN remained unchanged. Samples containing WS2 or MoS2 exhibited partial degradation, with evident signs of corrosion and grain fragmentation.

Ceramic brick masonry elements constitute the largest number of structural systems of historic buildings, especially sacral and public utility buildings. In the past, they were also very commonly used as a material for the construction of military facilities. Historic buildings and masonry structures undergo destructive processes over time, the course of which can be very diverse and depends, among other things, on the physicochemical properties of the materials, the type of structure, the age of the building, working conditions and random conditions and events. The paper is an engineering review of the causes of damage to masonry structures and indicates the need for cooperation between representatives of various specialties of science and technology, in particular architectural historians, specialists in the field of conservation of monuments, structural engineers and specialists in the field of geotechnics, geology, hydrogeologists and meliorators in order to ensure the protection of masonry structures in historic

Lubricants are substances that reduce friction and heat dissipation between operating machine parts. The purpose of the paper is to investigate the possibility of improving the tribological properties of biodegradable vegetable oils. The objects of the research were lubricating oils produced based on selected plant oils (rapeseed, sunflower, corn, soybean) and Priolube ester oil containing nanoparticle hexagonal boron nitride (h-BN) and a dispersant. The research assesses the physicochemical properties, the wear load limit, the welding load, and the friction coefficient of the prepared oil compositions. The article compares the results with those obtained during the CB30 engine and PAO4 oil tests. The test results confirm that lubricating oils prepared in this way are characterized by promising tribological properties, are easy to prepare, and are environmentally friendly. The appropriate method of preparation has a significant impact on the quality of the obtained oils.

The article presents selected results of the analysis of the comprehensive monitoring of the historical building of the "Sala BHP" in Gdansk. The necessity of monitoring was caused by scratches on its structural and finishing elements that occurred in the previous period. A preliminarily assumed factor that could cause the expansion of existing damages and the possible formation of new ones was the planned implementation of an investment consisting of the erection of multi-storey buildings on adjacent plots. As part of the preventive work, a comprehensive monitoring of the facility was proposed, consisting of geodetic determination of vertical and horizontal displacements of measurement points, measurement of changes in the width of existing cracks, and control of the height of the water table in piezometers located in the area adjacent to the ,,Sala BHP" building. As part of the technical condition inspection, the collected data was analyzed, and the measurement data was compared. In the course of the studies, no strong correlations between displacements and individual factors were observed, and thus the preliminary thesis on the direct impact of the investment carried out on the neighboring ,,Sala BHP" building on the formation of scratches was not confirmed. To confirm the conclusion that the current technical condition of the structure is a consequence of the typical operation of a building with a flexible structure, and most importantly, the occurring defects and damages do not threaten the safety of its structure and use, an additional analysis of the uniformity of the obtained displacements occurrence was carried out, using the transformation method for the purpose. The method shows the non-uniformity of the occurrence of the displacements of the control point network. The results of the analysis confirmed the previously formulated conclusions.

W artykule przedstawiono opis uszkodzeń płyty fundamentowejgarażu podziemnego, która została błędnie zaprojektowana,a następnie wykonana w sposób niezgodny z zasadamiwiedzy technicznej. Bezpośrednio po zakończeniu realizacji płyty fundamentowejna jej powierzchni wystąpiły intensywne zarysowania,które miały charakter nieustabilizowany i ulegały dalszemu rozwojowiw czasie. Wykonana na płycie fundamentowej w ramach pracwykończeniowych posadzka również uległa zarysowaniu. W pracyprzedstawiono propozycje zakresu prac naprawczych zarówno samejpłyty fundamentowej, jak i uszkodzonej posadzki, tj. górnej powierzchniwykończonej zasypką utwardzoną powierzchniowo

Wolna Wszechnica Polska była pierwszą instytucją w okresie międzywojennym otwierała możliwość dla uprawiania humanistyki w Łodzi jako mieście przemysłowym. Działalność Stefanii Skwarczyńskiej w tamtych latach w Łodzi pokazuje, że ukształtowane wówczas nowe style myślenia teoretycznego i formy kształtowania wspólnoty badań odbiegały od wzorców akademickich właściwych dla tradycyjnych ośrodków uniwersyteckich. Powstała wówczas społeczność nauczycieli i badaczy będzie od podstaw budować Uniwersytet Łódzki po 1945 roku, przenosząc w okres powojenny idee „kolektywu myślowego”. Do kręgu bezpośrednich współpracowników Skwarczyńskiej w tym okresie należeli m.in. Tadeusz Czapczyński, Wilhelm Fallek i Zygmunt Hajkowski, których prace miały wiele wspólnego z wypracowaną przez Skwarczyńską ideą „literatury stosowanej”.

The paper describes the case of monitoring the technical condition of a historic sacral building after a failure and during renovation works. In order to monitor the condition of the building, safely conduct diagnostic work, identify the causes of failures and safely carry out renovation works, a detailed Facility Monitoring Program has been developed, which has been implemented, is operational and is a source of valuable data used to assess the current condition of the facility.

The research paper reviews issues associated with the impact of groundwater flow on soil characteristics and parameters, hence, the entire structure of a building set on it. Water seepage through the ground, building subsoil or structural elements of buildings made of soil affects the soil skeleton and may lead to changes in the arrangement of individual grains relative to each other, i.e., a modified soil structure. Soil solid phase (soil skeleton) deformations resulting from seepage forces are called seepage-induced deformations. The article characterizes typical seepage-induced deformations and specifies a criterion defining the beginning of the phenomenon. The case study involved using data on cracks and deformations in a historic building, as well as water seepage in its subsoil. Seepage was analysed, and zones where the seepage process initiation criterion was exceeded, were determined based on subsoil water level monitoring data. The determined zones coincide with the location of building cracks and scratches and confirm the possible cause behind building damage.

Wiedza kulturowa to wiedza umiejscowiona, to rozumienie „od wewnątrz” wartości, zwyczajów, zasad i praktyk, które są wspólne dla danego społeczeństwa lub grupy. W jej ramach istnieją wspólne, podzielane przez wszystkich reguły interpretacyjne, konstrukcje rzeczywistości i światopoglądy. Wiedza kulturowa jest ściśle powiązana z wiedzą ukrytą, której nie da się w pełni wyartykułować ani wyjaśnić, w przeciwieństwie do wiedzy jawnej. W odwrotnym kierunku wydaje się zmierzać teoria kulturowa i wiedza propozycjonalna na temat kultury, które pozorują uniwersalne „spojrzenie znikąd”. Autor artykułu zastanawia się nad relacją typów idealnych „wiedzy kulturowej” i „wiedzy kulturoznawczej” w ramach projektowanej „ekologii form wiedzy”. Pyta, jak ta relacja była modelowana u początków instytucjonalizacji kulturoznawstwa jako dyscypliny naukowej w latach siedemdziesiątych ubiegłego wieku. Wymiar poznawczy spotyka się tutaj z wymiarem praktycznym. Rodzi się zatem pytanie, czy możliwe jest takie modelowanie tej relacji, aby kulturoznawstwo odnalazło się współcześnie w roli dyscypliny badawczej oferującej wglądy we własną „partykularną wiedzę kulturową” jako wiedzę poznawczo wartościową i jako dyskurs terapeutyczny dla patologii, dysfunkcji i nadużyć ideologicznych związanych z „kulturowym światem pojęć własnych”.

The paper presents the Complex of Buildings which was created in Gdańsk as a result of the reconstruction and development of the remains of the defensive fortifications of Redita Napoleońska. Some of the buildings of the Building Complex, after many years of operation, were in an emergency condition and required urgent renovation and repair work. The paper contains a detailed analysis of the technical condition of individual buildings of the Building Complex and analyzes the impact of the current use and the lack of regular periodic repairs on the technical efficiency of these facilities. Conceptual solutions in the field of renovation and repair works were also presented, the purpose of which was to bring the objects in question to the proper technical condition.

This paper aims to assess the quality of composite joints made with the Fused Filament Fabrication (FFF) additive manufacturing technique through strength tests. The first part of this paper details the design of different test sample versions with standardised geometry and the methods of joining plastics by application of 3D printing. The details cover the test apparatus used in the research, sample preparation methodology, as well as tensile and impact testing methodology. The test sample versions were selected according to the test types to have the results fully reproduce the mechanical response of the composite materials to the input forces. The second part of this paper analysis of the test results, presenting the fabrication accuracy of the test samples and their mechanical response recorded during the tests. Five test specimens of each version were produced to enable statistical analysis of the test results, which was indispensable for a reliable data analysis. The tests made it possible to determine how the proposed joints of plastic materials responded to the input forces, the maximum transmitted force limit, and the flaws of each version’s design. The test results made it possible to adapt the suggested solutions in the design engineering of programmable energy-absorbing structures.

The article presents a description of the technical condition of the Grain Elevator building situated on the port quay, which after many years of operation has been decommissioned. The immediate reason for the cessation of operation was the change in the use profile of the port quay, which caused the handling of other goods at the quay than the bulk materials originally stored in Elewator Zbożowy. The work contains a detailed analysis of the technical condition of the building, also taking into account the functional and utility aspect as well as the economics of renovation works. The article showed that despite the location of the building in the conservation protection zone, the optimal solution was the demolition of Grain Elevator and its reconstruction of a new warehouse facility with parameters adapted to the current needs and target handling capacity of the port quay.

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

The paper presents a description of the technical condition of the Bunker building located at the port quay, which has been out of use for several decades. The direct reason for the cessation of exploitation was the deletion of Bunker from the Civil Defense records. The paper contains a detailed analysis of the Bunker's technical condition, also taking into account the national defense, functional and utility aspects and the issues of economics of carrying out renovation works. The paper shows that despite the location of the Bunker in the conservation protection zone, the optimal solution was its demolition and the final use of the area where the Bunker was located as a place for the construction of warehouse buildings with parameters adapted to the current needs and target transshipment capabilities of the port quay.

Our experiments aimed to study the influence of layered materials with nanometric-scale particles, which are part of lubricant oils, on their tribological properties. The object of this study was a lubricant oil made using base oil PAO4, which contained nanoparticle hexagonal boron nitride (nano h-BN) and a dispersant based on succinic acid imide. Comparative tests for engine oil (CB30) were also performed. The paper presents the method of preparing the test material and the tribological test results, including wear spot diameter (wear mark), limit wear load, and seizure load. The test results obtained demonstrate that nano-hexagonal boron nitride improves the tribological properties of lubricant oils. However, oil preparation and the quantitative selection of components markedly influence the results.

W artykule przedstawionopsi dzialn podjetych po pozarze dachu zabytkowego Kciola pw. Świetych Apostolow Piotra i Pawla w Gdansku

This paper presents the results of preliminary tests on specimens made from mixtures of dendritic copper powder (CuE) with the graphene-coated copper powder (CuG) in a range from 20% to 100% (CuG). The properties of the powder mixtures, green compacts and sinters were determined. To study the properties of the powder mixtures, the following tests were carried out: a measurement of the CuG powder grain size after the grinding process, measurements of the bulk density and tap density of the prepared powder mixtures. The porosity of the produced green compacts and the sinters was calculated as well as the densification capabilities of the powder mixtures by die pressing, cold isostatic pressing and sintering in a reducing atmosphere were tested. Moreover, the nature of the porosity formation was analysed using an optical microscope and the Brinell hardness was determined. The measured Brinell hardness was in the range of 17 HB for sinters made from CuG to 34 HB for sinters made from a 20% CuG powder mixture. More than six hundred measurements that were made in this study show that the high CuG content in the powder mixture reduce the hardness of the sinters as well increase their porosity.