Technical Sciences

Adaptive microclimate control system to regulate conditions in a living-space

Łukasz Dziubiński — 2025-01-17

In recent years, smart home automation has become increasingly accessible, largely due to the availability of affordable and easy-to-implement electronic systems for control and measurement. While ready-made systems are widely available, self-designed solutions offer significant advantages, including tailored adaptation to user needs, low cost, ease of modification and expansion, and the ability for self-maintenance. This article presents a custom system designed for microclimate control in living spaces. The hardware components and control algorithms are thoroughly described, providing a foundation and inspiration for similar installations. Additionally, the article includes sample results demonstrating the system’s effectiveness in adapting the microclimate to the user’s comfort and preferences.

Galvanic skin response during pain pressure threshold tests

Jakub Tytuła — 2025-05-22

This study aims to see the correlation between skin resistance and pain during pain pressure threshold tests. A Galvanic Skin Resistance sensor is used to measure the patient’s skin resistance. Two electrodes are placed on two adjacent fingers. A blunt tipped tool is pressed into the patients median nerve, located between the index finger and thumb. This area is known to usually be tender and with little force can inflict noticeable pain. This ensures no long term physical damage to the patients tissue. Sixty tests were made in total on the test subject, the author. On each test there are two noticeable dips in skin resistance. One, when the tool first contacts the patients skin, and another when pain is actually felt. Graphs depicting the direct correlation between force and skin resistance are made to visualize at what force the patient had the lowest skin resistance.

An experimental and numerical investigation of particles fluid dynamic flow and energy transfer in a heat exchanger. Part 1. An experimental and numerical granular material flowability study

Waldemar Cieslakiewicz — 2025-05-06

Flowability is of great importance to a lot of processes especially granular material handling and heat transfer. In the industry achieving the highest heating efficiency of granular material heat exchanger is the most important factor. Heating/cooling area size is one of the critical factors in heat transfer processes and is highly dependent on flowability. The complexity of optimizing flowability can only be solved in two ways, either through experiment or computational modelling. However, the simulation technique is more time efficient and cost effective compared to the experimental analysis technique. Nonetheless, the CFD methodology requires prior validation of the model with the experiment. This study comprises of the experimental and numerical analysis of granular material flowability, and it aims at establishing a balanced flow of spherical silicon particles in a heat exchanger and developing a validated model that can be used for design optimisation. A Discrete Element Method (DEM) is employed in Simcenter STAR CCM+ to analyse the flow behaviour and is validated qualitatively and quantitatively from the experimental data. The results from both the simulation and the experiment exhibit a similar trend, indicating consistency between the two approaches. In both cases, the particle velocities are not uniform within the heat exchanger, as variations are observed across different regions, from 2 mm/s to 9 mm/s. Specifically, particles near the heat exchanger walls experience lower velocities due to higher frictional resistance, while those in the central flow stream, especially close to the outlet, move at relatively higher speeds. Quantitatively, the percentage difference between the simulation and experimental results is 9.53% for particle velocity and 5.61% for mass flow rate, which falls within an acceptable range for computational modelling of granular flow. This level of accuracy indicates that the simulation effectively captures the key flow dynamics within the heat exchanger, making it a reliable tool for further analysis. The study shows convincingly that the model was validated successfully, however investigated heat exchanger is highly inefficient but using the validated model can be optimized.

The study comprises two parts. The first one presents the experimental and numerical particles flow analysis of the fluid (granular material), while the second one focuses on the experimental and numerical energy transfer (heating/cooling) analysis.

Use of waste in the production of concrete structures

Alicja Szymańska — 2025-06-06

The article describes the possibilities of managing and neutralizing industrial and municipal waste in concrete production, recycling, and forming processes. These possibilities relate to the immobilization of contaminants by creating durable systems using hydraulic binders. This is achievable by converting soluble compounds into insoluble forms through the precipitation of salts, oxides, and toxic metals into sparingly soluble hydroxides, sulfides, or phosphates. A classification of concretes according to their potential areas of structural application has been presented. The strength of this material has been defined based on adopted standards, and potential environmental risks associated with its production have been identified. The processes of leaching heavy metals into the environment have also been addressed. Concrete itself may exhibit varying levels of radioactivity. However, appropriate modification of concrete allows for effective containment of hazardous radioactive waste.

By using fine-grained, inorganic additives such as silica fume, fly ash, ground granulated blast furnace slag or metakaolinite it is possible to improve certain properties of concrete or even obtain special properties. Possible types of municipal waste have been defined, and potential methods of utilizing industrial and municipal waste in concrete production have been presented. The share of recycled substances used during concrete formation has been analysed. Agricultural waste represents a separate waste category with considerable potential for utilization in concrete and cement mortars.

Using deep learning algorithms and a flatbed scanner to assess rice quality

Piotr Zapotoczny — 2025-06-10

This article presents the results of research on the application of deep learning techniques in the automatic assessment of rice grain quality. A measurement methodology and a computer program were developed, which uses a deep learning model to identify individual grains in an image and detect impurities for further qualitative analysis. The program was implemented in Python using the OpenCV 4, Numpy, and Ultralytics YOLO libraries. The study used a flatbed scanner, enabling the identification of approximately 3,000 objects in a single scanner ruler pass.

Theoretical proposition of control and data acquisition system for a test stand for single-cell testing of pem hydrogen fuel cells

Mikołaj Klekowicki — 2025-06-12

Accurate, traceable characterisation of proton-exchange membrane (PEM) fuel cells at the
single-cell level is pivotal for material screening, degradation studies and control-algorithm
development. However, commercial diagnostic benches typically cost €20,000-150,000, limiting access for many research and teaching laboratories. This paper introduces a fully open-hardware, modular test stand that delivers 0.1 mV voltage resolution and a 0-50 A current envelope for a bill of materials of only €14,000. The architecture is split into a measurement & regulation layer built around temperature-controlled shunts and a 12-bit delta-sigma ADC, a control & SCADA layer based on an ESP32-S3 micro-controller and CompactDAQ interface, and a hydrogen-supply layer equipped with SIL-2 safety instrumentation. A rigorously quantified Type-A/Type-B uncertainty budget, prepared in accordance with ISO/IEC Guide 98-3 and validated via a 10,000-run Monte-Carlo simulation, yields an expanded cell-voltage uncertainty of ±0.38 % (k = 2). A built-in
real-time digital twin couples an equivalent-circuit model with reduced-order CFD to enable
what-if analyses and predictive maintenance. Comparative benchmarking against the AVL E-Load 2 and ZSW single-cell rigs shows equal or better metrological performance at ≤ 25% of their cost. A proof-of-
-concept dynamic-load experiment confirms the stand’s fidelity, establishing a low-cost pathway towards scalable, open and safe PEM fuel-cell diagnostics.

Determination of the mass fraction of granular mixture components by means of computer image analysis

Piotr Zapotoczny — 2025-06-12

The objective of this study was to determine the statistical relationship among density, volume, mass, and selected geometric parameters of rice grains. A gas pycnometer was employed for grain volume measurement, while a flatbed scanner and specialized software were utilized for the determination of geometric features. Over 70 geometric parameters were identified. Among these, for whole grains, the most effective shape-describing coefficients were Rb, W5, Nv, and LminE, whereas for broken grains, Lsz, LminE, Maver, and Uw proved to be superior. Correlation coefficients between density and geometric features ranged from 0.895 to 0.995 at a significance level of p<0.007. Based on these findings, it will be feasible to develop a grain quality assessment system utilizing 2D images and to infer the mass fraction of grains belonging to different quality grades

Comparison of the tensile strength of FDM printed specimens with different infill densities made of PA12 and PA12+CF15

Łukasz Miazio — 2025-06-27

The research presented in this article represents a further stage in studies on the strength of components printed using 3D printing technology, specifically FDM (Fused Deposition Modelling). The article presents the results of tensile strength tests on samples printed from PA12 and PA12+CF15 materials, while previous studies by the author focused on PLA material.

Basic material data provided by manufacturers and distributors of materials used in the FDM method, such as tensile strength and Young’s modulus, refer to the most favourable model orientation during printing. However, in additive technologies, particularly FDM, the constructed object shows significant layering differences (in the Z direction). The direction of material deposition (in the XY plane) is also crucial. Additionally, the strength is influenced by the degree and type of infill within the model and the temperature during printing. For these reasons, it is essential to understand the relationship between technological parameters and the resulting strength for specific materials. This study aimed to determine the tensile strength of samples printed with varying infill percentages.

In the context of the new material, PA12+CF15, it is essential to understand how the addition of carbon fibers affects the mechanical properties of prints compared to traditional materials, such as PA12 and PLA. Carbon fibers can significantly increase the strength and stiffness of the composite, potentially leading to applications in producing parts with high strength requirements. Therefore, studying the strength of materials concerning various printing parameters is crucial for developing the potential of FDM technology and its industrial applications.

PA12+CF15 is composed of polyamide 12 (PA12), a thermoplastic material with good chemical resistance, abrasion resistance, and flexibility. The addition of 15% carbon fibers (CF15) reinforces the composite structure, leading to increased stiffness, mechanical strength, and deformation resistance. The study shows that this addition enhances PA12’s strength by approximately 13%, also facilitating printing by reducing shrinkage.

Management and forecasting of road accidents in Poland and Montenegro using neural networks

Piotr Gorzelanczyk — 2025-08-25

Despite a general decline in recent years, road traffic accidents remain a significant public safety concern in both Poland and Montenegro. Although accident rates were affected by the COVID-19 pandemic, the persistent frequency of such incidents underscores the urgent need for further preventive measures to enhance road safety.

The aim of this study is to forecast the number of road traffic accidents in Poland and Montenegro for the period 2024-2030. To achieve this, historical data on annual accident counts were obtained from Monstat (Montenegro) and the Polish Police. These datasets were then analyzed using selected neural network models to generate projections for the specified timeframe.

The results suggest a potential stabilization in the number of traffic accidents in the near future. This forecast is influenced by several factors, including the steady increase in car ownership and ongoing investments in road infrastructure, such as the construction of new motorways and local roads. It should be noted, however, that the inherent uncertainty in data sampling – used for training, testing, and validating the models – places natural limitations on the precision of the forecasts.

Selected aspects of research on advanced states deformation of thin-wall aircraft composite structures

Tomasz Lis — 2025-09-17

The paper concerns the most significant and characteristic stages of manufacturing and testing the properties of aircraft thin-wall composite structures. Structures of this kind, due to the high requirements in terms of safety, durability and economy of aircraft operation, force the emergence of a number of often mutually contradictory design assumptions. The basic problem is to ensure the necessary strength and stiffness of the structure at the lowest possible weight. In a typical thin-wall structure, due to the small thickness of the skin, it is the covering that buckles, while the frame elements do not lose stability. Therefore, when testing thin-wall structures, it is extremely important to properly prepare the model so that the loss of stability is only local. The choice of stiffness of individual elements and the adopted technological process, which directly determines the properties of the system, are of fundamental importance.

The text presents an exemplary solution of this problem, concerning the concept of research model with the given technological process. The model underwent the loading condition, which corresponds to the real conditions occurring during the flight. In the next stage, the characteristic properties of the composite thin-wall structure, which is a representative part of the aircraft, were recorded. The obtained results make it possible to determine the influence of the adopted solution on the character of the skin deformation and provide a basis for modifications and comparative analyses.

Forecasting the number of road accidents in Poland using trend models

Piotr Gorzelanczyk — 2025-09-17

Every year a very large number of people die on the roads. From year to year the value decreases, but it is still a very large number. The purpose of this article is to forecast the number of road accidents in Poland. The study was divided into two parts. The first was the analysis of annual data from police statistics on the number of road accidents in Poland in 2000-2021, and on this basis the forecast of the number of road accidents for 2022-2031 was determined. The second part of the study, dealt with monthly data from 2000-2021. Again, the analyzed forecast for the period January 2022 – December 2023 was determined.

Finite element analysis of the eigenfrequencies of milling machine support structure

Radosław Ciemierkiewicz — 2025-12-05

The publication concerns the selection of dimensions for two support structure models of a woodworking spindle moulder, based on the results of finite element analyses: static structural and modal. Using the ANSYS Workbench software, a linear-elastic material behavior was assumed, and preliminary models of the milling machine frame and housing were analyzed, each assigned a different material – structural steel (S235JR) and gray cast iron (EN-GJL-250), respectively. After completing the Design and Analysis of Computer Experiments stage, optimization was carried out using ANSYS Workbench algorithms: the Response Surface Method and the Direct Optimization Method. As a result, the optimal geometric dimensions of the milling machine’s support structures were identified, satisfying both strength and modal criteria.

Mobile air quality monitoring station - a solution for better pollution control

Seweryn Lipiński — 2025-12-05

The paper presents the design of a mobile air quality monitoring station. Its mobility is defined by a lightweight and compact structure, allowing easy transportation and use without additional equipment. To enhance user convenience, a system for storing and analysing the collected data was implemented on an internet server, connected to a web application. The device includes a PM1.0/PM2.5/PM10 sensor, a barometer and hygrometer both with built-in temperature sensors, and two gas sensors. A GPS module provides precise location data, and a GSM module enables wireless transmission of results. The system is powered by Li-Ion batteries, with extended operation time thanks to a photovoltaic panel. The system was tested by comparing its measurements with air quality data from airly.eu, ensuring time and location consistency. The comparison confirmed the device’s accuracy while further tests in mobile mode, i.e., walking, cycling, and driving showed that the system’s mobility increases the number of measurement points, enhancing local air pollution monitoring. Mobile stations could be beneficial, especially in areas with a low density of monitoring stations, e.g. by using vehicles on fixed routes, such as public transport. This would allow effective air quality control and localization of point-source pollution.

Exploring bee colony dynamics: temperature and humidity monitoring as indicators of colony activity

Wojciech Staszewski — 2025-12-05

Honeybee (Apis mellifera) colonies play a crucial role in supporting both ecological balance and agricultural productivity through their pollination activities. Understanding the internal conditions of a honeybee colony is essential for assessing its health, productivity, and seasonal behavior. In recent years, the concept of precision beekeeping has gained momentum, introducing digital tools and sensor-based methods to continuously monitor hive parameters without disturbing the bees. Temperature and humidity are two key physical variables that have been widely recognized as indicators of colony status. Monitoring these factors provides valuable insights into the hive’s internal microclimate, which can directly affect brood development, metabolism, and the colony’s overall health.

Building upon this understanding, the present study focuses on the continuous monitoring of temperature and humidity both inside and outside the hive, as well as within the brood nest. The goal was to evaluate how the internal thermal dynamics of the hive reflect colony activity and environmental interactions. By tracking these parameters, author aims to explore their potential as non-invasive indicators of colony well-being. These data can help beekeepers better understand how environmental factors influence colony productivity and health, ultimately contributing to more effective management strategies.

Immobilization of environmentally harmful elements in concrete

Alicja Szymańska — 2025-12-05

Concrete is a material widely used in the construction industry. The possibility of waste immobilization generated by modern-day industry in concrete structures sets a viable alternative to conventional waste disposal methods. Most of the existing efforts in the field of waste disposal through introducing them to concrete blends face significant limitations. In this study, research was undertaken on the leachability of selected actual industrial waste, such as volatile ashes, sewage sludge, and water sludges, along with paints and varnish containing organic solvents. The research was undertaken undertaken on both crushed and uncrushed samples. The obtained leachability results for individual contaminants (elements and compounds) were compared with current regulatory standards.