• Energy Research

The correct operation of the continuous welded track requires diagnosing its condition and preparation of track metrics requiring measurements of displacements of rail under operation. This is required as there are additional thermal stresses in the rails with values depending on the temperature changes of the rails. Therefore, the climatic conditions are important. This paper presents the original effective analytical method for diagnosing the condition of continuous welded track based on experimental research. The method allows for an appropriate repair or maintenance recommendation. In the experimental research, the authors considered track diagnostic conditions for two conditions: track under load and track without load. This paper presents empirical formulas for calculating rail temperature and longitudinal force based on ambient temperature, developed from long-term measurements. The formulas were developed for a track located on a straight section—both for a rail loaded and unloaded with a passing train under the following conditions: 60E1 rail, not on an engineering structure, conventional surface, wooden sleepers and very high train traffic load. The obtained results in the value of the correlation coefficient R2 ≥ 0.995 attest to very high accuracy of the calculations performed with the method proposed by the authors.

Nowadays, apart from travel time and cost, more and more attention is paid to ensuring that ecological footprint of the means of transport used for a journey is as small as possible. Therefore, it is reasonable to look for methods and solutions that will allow planning communication connections according to the principles of sustainable development. The aim of the article was to present mathematical model of the proecological distribution of traffic flow into a network, together with a determination of how the amount of emissions of harmful compounds for rail transport will be calculated (based on amount of energy necessary for movement, calculated on circumference of the wheels). The model has been verified on real data. The traffic flow was distributed over a selected communication route: Warszawa—Gdansk, where the criterion was minimization of total carbon dioxide emissions. An evolutionary method implemented in Microsoft Excel was used to solve the optimization problem. For the analysis of only the fastest connections, the railway one was the optimal from the point of view of the adopted criteria. After the train capacity was exceeded, air and car connections were loaded. Based on the research, a function that represents the amount of carbon dioxide emissions in the analyzed traffic route depending on the size of the traffic flow was developed.

The implementation of Product-Service Systems (PSS) calls for the modification of existing business models. The goal of the paper is to work out an analysis and a classification of PSS design methods used in the development of new business models. Using a systematic review method, we identified 60 PSS design methods. Following the examination of the major business model templates, we selected the Business Canvas Model for further studies. Then, coding rules were adopted to specify what elements of the Business Model Canvas impacts individual PSS design methods and an analysis was performed. In the final stage, methods were broken down by Business Model Canvas domains. Various PSS design methods presented in the literature address different areas of Business Model Canvas. The available PPS methods can be classified into three main groups: Group 1—including infrastructure and offering; Group 2—including infrastructure, offering and customers; and Group 3—including infrastructure, offering, customers and finance. Very few methods consider areas such as Key Partners, Customer Segments, Cost Structure and Revenue Streams. Nevertheless, there is no PPS design method that would address all of Business Model Canvas building blocks. The paper discusses PSS design in business model context. Classification of PSS design methods was proposed together with new possibilities to develop business models based on this classification. The proposed approach illustrates the combination of PSS design methods applied in food processing and agricultural machines industry.

Value Stream Mapping (VSM) is a popular and easy tool for visualizing production processes in enterprise. It allows one to eliminate or reduce waste, i.e., activities that do not create added value for the customer. The versatility of this tool allows it to be used in industry. There are theoretical, methodological, and practical aspects encountered by practitioners in developing Value Stream Mapping (VSM) for a specific manufacturing industry, but they are not fully resolved and require clarification. This paper presents a case study that describes the use of Value Stream Mapping (VSM) in the production of steel pipes. Relevant data from this process were collected and analyzed at the start of the project. An initial process was mapped, associated waste was identified, and then future processes were mapped. The financial results were estimated. Consequently, the process was improved, and savings were achieved. The article should constitute the basis for further development of an improvement project for a selected company aimed at improving the areas identified in a given article.

Nowadays, sustainable development is becoming a model for significant improvements in the modern world. Taking into consideration possible future challenges, transport must have sustainable features. Today, such a type of transportation as intermodal transport (transport that uses more than one mode of transportation) is gaining relevance. It is one of the most promising types of transport from an economic and environmental point of view. In this paper, the importance of sustainable development of intermodal freight transport is analyzed; the state of foreign trade and the trade balance in Ukraine and Poland are examined; and the sustainable development trends and prospects of trade relations between two countries are determined, taking into account the existing product structure. It is noted that the post-war recovery of Ukraine will require the activation of logistical flows with EU countries. The analysis of the state of freight transport by various modes of transport allowed for theoretically justifying the insufficient attention given to the development of intermodal freight transport between Ukraine and Poland for logistics optimization in international trade. From a methodological perspective, it is proposed to describe the subject area in terms of graph theory. The practical contribution involved the testing of the proposed model of intermodal freight transport to optimize logistics flows in international trade between Ukraine and Poland, considering the minimization of transport service costs and time. This required refining the mathematical apparatus based on the method of successive moves and linking their development to specific supply chains.

The evolution of aircraft power systems has been driven by increasing electrical demands and advancements in aviation technology. Background: This study provides a comprehensive review and experimental validation of on-board electrical network development, analyzing power management strategies in both conventional and modern aircraft, including the Mi-24 helicopter, F-22 multirole aircraft, and Boeing 787 passenger airplane. Methods: The research categorizes aircraft electrical systems into three historical phases: pre-1960s with 28.5 V DC networks, up to 2000 with three-phase AC networks (3 × 115 V/200 V, 400 Hz), and post-2000 with 270 V DC networks derived from AC generators via transformer–rectifier units. Beyond theoretical analysis, this work introduces experimental findings on hybrid-electric aircraft power solutions, particularly evaluating the performance of the Modular Power System for Aircraft (MPSZE). The More Electric Aircraft (MEA) concept is analyzed as a key innovation, with a focus on energy efficiency, frequency stability, and ground power applications. The study investigates the integration of alternative energy sources, including photovoltaic-assisted power supplies and fuel-cell-based auxiliary systems, assessing their feasibility for aircraft system checks, engine startups, field navigation, communications, and radar operations. Results: Experimental results demonstrate that hybrid energy storage systems, incorporating lithium-ion batteries, fuel cells, and photovoltaic modules, can enhance MEA efficiency and operational resilience under real-world conditions. Conclusions: The findings underscore the importance of MEA technology in the future of sustainable aviation power solutions, highlighting both global and Polish research contributions, particularly from the Air Force Institute of Technology (ITWL).