For the construction company, tendering is the most popular way of acquiring contracts. The decision to participate in the tender needs to be made carefully, as it affects the condition of the company and is an important aspect in its quest for success. The bid/no bid decision making is a complex process involving a number of factors. The research carried out so far has mainly concerned the identification of the various kinds of influences on contractors’ bidding decisions. The researchers, on the basis of contractors’ opinions, created rank lists in an attempt to categorize the factors. In this paper the author employs factor analysis which belongs to basic methods of multi-dimensional data analysis. The paper’s aim is first to depict an output set of observed variables, that is bid/no bid factors, in terms of a smaller set of latent variables which cannot be directly observed and then to interpret the dependencies between them.

Polish photography in the first years after Poland regained independence remains a poorly documented area of research. Studies so far had mostly focused on the interpretation of the works of a few key artists from the avant-garde milieu (Witkacy) or photography (Jan Bułhak). It transpires however, that photography – not only as an artistic practice, but as poetic metaphor or an element of a broader aesthetic reflection – has functioned within the circle of the artistic avant-garde. An analysis of the presence of this medium in the consciousness and creativity of Polish artists allows us to see in a new light certain aspects of their technique and intellectual viewpoint. The article focuses on selected characteristics of this assimilation of modern reflection on photography by the Polish avant-garde artists in the first decade after the country regained independence. For the Formists – Tytus Czyżewski and Leon Chwistek – photography was an important point of reference as a metaphor of a new, cognitively uncertain, but also “deeper” way of seeing reality. It was an important help in defining the relationship between reality and its image and subject within a broader theoretical program (the theory of plurality of realities). For the Constructivists in turn – with Władysław Strzemiński and Mieczysław Szczuka at the forefront – photography became the means that enabled them to go beyond the usual schemes of capturing the external world, and as part of the concept of photomontage, it became a new material for creating an artistic reality. The dynamics of the process of assimilation of photography by the avant-garde artists was analysed in the context of the reception of new artistic trends born outside of Poland, primarily Futurism (the theory of photography by Anton Giulio Bragaglia) and Suprematism (reflection by Kazimierz Malewicz).

One of the contract awarding systems in public sector in Poland is the Design & Build system. In this system, a client concludes a contract agreement with only one company, a contractor, in order to carry out both design and construction of works. While deciding on this form of delivery of a public project, the client is obliged to conduct a single proceeding aiming to select the contractor. In this paper, public works contracts awarded in the D&B system in Poland are analysed, whilst attention was put on the contracting modes and assessment criteria. The results are assessed against the experience of other countries and recommended methods for selection of the Design and Build contractor.

Particular diligence in the preparation of documentation and conducting a tender procedure for construction works must be made by public contracting entities, who are subject to additional restrictions. In Poland, the largest public contracting entities are the sectoral ones. These are the entities (defined in Art. 3 of the Public Procurement Law Act) operating in the sectors of water management, energy, transport and postal services. The paper presents the analysis of tender offers for the execution of construction works or design and execution of construction works related to the reconstruction, construction and revitalization of railway lines, announced after the amendment to the Public Procurement Law on June 22, 2016. The considered examples are selected tender procedures covering the scope of construction and assembly works on railway lines throughout the country. The authors paid particular attention to the tender criteria applied and the requirements for the potential contractors for works in the field of railway infrastructure.

Construction projects, even exemplarily planned and organized, bear a risk of unforeseen events and problems which can result in completion of the works after the deadline, that is delays. The construction of bridges is an inseparable part of road and rail projects and construction and expansion of the transport network. The paper aims at finding a relationship between the independent variables characterizing bridge projects and the delays during their implementation. Two alternative models were proposed to solve the problem: logit and probit. The data set comprising road and rail bridges built in Poland in the last 12 years (2005–2017) was used to build the models. The evaluation, quality and accuracy parameters of proposed models were determined in the final part of the paper.

Anaphylaxis is an increasing problem in public health. Th e food allergens (mainly milk, eggs, and peanuts) are the most frequent cause of anaphylaxis in children and youth. In order to defi ne the cause of anaphylaxis, skin tests, the determination of the concentration of specifi c IgE in the blood and basophil activation test are conducted. In vitro tests are preferred due to the risk of allergic response during in vivo tests. Component-resolved diagnosis (CRD) is an additional tool in allergology, recommended in the third level of diagnostics when there are diagnostic doubts aft er the above mentioned tests have been carried out. The paper presents 3 cases of patients with anaphylactic response, and the application of CRD in these patients helped in planning the treatment. Patient 1 is a 4-year-old boy with diagnosed atopic dermatitis and bronchial asthma reported an anaphylactic shock at the age of seven months caused by cow’s milk and the exacerbation of bronchial asthma aft er eating some fruit. Patient 2 is a 35-year-old woman who has had anaphylactic shock three times: in June 2015, 2016, and 2017 and associates these episodes with the consumption of dumplings with a caramel, bun, and the last episode took place during physical exertion few hours aft er eating waffl e. Patient 3 is a 26-year-old man with one-time loss of consciousness after eating mixed nuts and drinking beer. CRD off ers the possibility to conduct a detailed diagnostic evaluation of patients with a history of anaphylactic reaction.

Traditional methods of mineral exploration are mainly based on very expensive drilling and seismic methods. The proposed approach assumes the preliminary recognition of prospecting areas using satellite remote sensing methods. Maps of mineral groups created using Landsat 8 images can narrow the search area, thereby reducing the costs of geological exploration during mineral prospecting. This study focuses on the identification of mineralized zones located in the southeastern part of Europe (Kosovo, area of Selac) where hydrothermal mineralization and alterations can be found. The article describes all the stages of research, from collecting in-situ rock samples, obtaining spectral characteristics with laboratory measurements, preprocessing and analysis of satellite images, to the validation of results through field reconnaissance in detail. The authors introduce a curve-index fitting technique to determine the degree of similarity of a rock sample to a given pixel of satellite imagery. A comparison of the reflectance of rock samples against surface reflectance obtained from satellite images allows the places where the related type of rock can be found to be determined. Finally, the results were compared with geological and mineral maps to confirm the effectiveness of the method. It was shown that the free multispectral data obtained by the Landsat 8 satellite, even with a resolution of 30 meters, can be considered as a valuable source of information that helps narrow down the exploration areas.

The aim of this paper was to test currently available on the market products for sealing anodic oxide coatings as well as to test the use of other alternative substances improving the sealing process. The ability to seal in 10 different solutions and the quality of the seal has been tested. The influence of the applied preparations on corrosion resistance and resistance to strongly alkaline environment was also investigated.

Based on the results obtained, satisfactory results were archived for the sample sealed in a IMN-OML (Institute of Non-Ferrous Metals in Gliwice, Light Metals Division) solution sealant and in solution of nickel acetate in a medium-temperature process. Sealing by means of nickel acetate solutions is economically justified, and its use allows the process temperature to be lowered. When it comes to resistance to alkalis, samples sealed in IMN-OML sealant are the best. Commercial solutions have also achieved positive results in all tests.

The article presents the results of research carried out in construction companies among employees involved in the organisation and management of construction projects. The research concerned factors and their impact on decisions regarding the planning of quantitative employment workforce at a construction site. Based on individual assessments of individual factors, average assessments were calculated and hierarchies of the factors examined were made. In the second part of the article, the dispersion coefficient of relative classification was used to assess the reliability of the opinions collected. The content presented is a continuation of the work of the authors on the subject of employment planning at the construction site.