Koszalin University of Technology
  • Koszalin, West Pomeranian Voivodeship, Poland
Recent publications
This article describes the technology of organic recycling of polylactide/halloysite biocomposites using the sugar- protein condensation theory. For this purpose, polymer biocomposites were produced with a polylactic acid structure and reinforced in the form of halloysite nanoparticles by 1; 2.5; and 5% by mass. A new method of decomposition of the produced biocomposites was developed. For this purpose, the composting process uses complex sugars in the form of beet molasses. This action is based on Stevenson’s theory of protein-sugar condensation. Thus, the validity of this theory was confirmed, as research showed that this modification significantly influences the acceleration of the composting process of the produced biomaterials. For each phase of the process, the parameters of accelerated composting were defined by determining the temperature, degree of humidity, and quantitative scale of acidity and alkalinity. The degree of decomposition of biocomposites was assessed based on microbiological tests, hardness, weight loss, viscosity-average molecular weight tests, and structure assessment using macro and microscopic examinations (SEM). Based on the microbial tests, it was shown that composting also seems to be an alternative method of infectious waste disposal in the case of using biocomposites for products, e.g., medical product.
Full manuscript #### https://authors.elsevier.com/c/1f65R3IhXMtgTE ### Terrestrial Laser Scanning (TLS) is an ideal, non-invasive remote sensing technology for all measurements related to examining the condition of building walls. Based on the point clouds, users can carry out dimensioning and 3D modeling of bas-reliefs. TLS gives the opportunity to obtain point clouds with high resolution, which allows for accurate mapping of objects, but on the other hand is troublesome during data processing. Therefore, this paper presents a methodology of TLS point cloud optimization based on a modified Optimum Dataset method (OptD v.A). OptD v.A allows the number of observations to be reduced. The reduction does not happen in a random manner, the points are examined for their usefulness and relevance. The research was carried out using real walls with bas-reliefs. The tests showed that the OptD v.A method did not disturb the nature of the tested objects. Optimized TLS point clouds were used for 3D modeling.
This study aimed to determine whether the wind zone that characterizes a given area of the country in open area is reflected in the built-up area lying within the zone. Analysis included four Polish cities located in different wind zones. The two-parameter Weibull density distribution function was used to present the wind conditions at each location. Two 3 kW VAWT devices were selected to evaluate the productivity of wind turbines at the locations analyzed. It was shown that the wind zones characterizing the wind potential of a region in an open area have no significant influence on the wind conditions in the built-up area located in that area. It was determined that the study location’s did not exhibit wind potential that could be economically justified by a wind turbine. WTs in the city do not reach their nominal productivity. A decisive advantage of very light winds was observed (up to 2 m/s) and a large proportion of so-called atmospheric calms. It was shown that the installation of small wind turbines in an urbanized area requires a minimum of annual wind measurements at the exact location and height of each future turbine planned.
A method for the evaluation of experimental data from spectroscopic ellipsometry is proposed which combines the global-search optimization algorithm with statistical model selection criteria. The hybrid genetic-gradient search algorithm (HGGA) is applied to find the optical parameters and thickness of a diamond-like carbon (DLC) coating deposited on SW7M stainless steel. Akaike and Bayesian information criteria are used to evaluate the different dielectric function models. The method is able to find optical model parameters even in case of a limited initial knowledge about the material optical constants. At the same time, the optimal dielectric function model for the description of the material optical properties can be selected unambiguously from the set of candidate models.
Background The approach to the education and professional advancement of physiotherapists is particularly relevant today. To date, no studies have compared the perceptions of physiotherapists regarding professional issues in geographically close European countries such as Poland and Germany. Therefore, this study’s purpose was to compare Polish and German physiotherapists’ perceptions related to their profession, entry-level education, and career opportunities. Methods We recruited 565 physiotherapists from Poland and 560 physiotherapists from Germany. An opinion polling method based on a questionnaire was applied in the study. The survey was conducted in 48 facilities located throughout the territories of the two countries. The assessment focused on the following three issues: 1) professional education (form and content of educational programs, organizational aspects, and effects of education); 2) professional development and career opportunities; and 3) the relationship between years of service and perceptions of professional education, career satisfaction and advancement opportunities. Results German respondents rated specific aspects of their education, development opportunities and professional careers more highly than their Polish counterparts ( p = 0.001). A highly significant negative correlation was identified in both groups between all the assessed aspects of professional education and years of service (0.9 ≤ |R| < 1, p = 0.001). Conclusions Opinions on their professions expressed by physiotherapists from closely neighboring countries, namely, Poland and Germany, were surprisingly disparate. Compared to their Polish colleagues, German physiotherapists viewed their experiences more favorably vis-a-vis entry-level education, career opportunities, and professional status. Further study is needed to establish whether these findings reflect actual differences, sampling bias, or other factors.
This paper describes the results of experimental studies on heat transfer in a shell and tube heat exchanger during the phase changes of the HFE 7000 refrigerant. The studies were performed using a mixture of water and a microencapsulated phase change material as a coolant. HFE 7000 refrigerant condenses on the external surface of the copper tube, while a mixture of water and phase change materials flows through the channels as coolant. Currently, there is a lack of research describing cooling using phase change materials in heat exchangers. There are a number of publications describing the heat exchange in heat exchangers during phase changes under air or water cooling. Therefore, the research hypothesis was adopted that the use of mixed water and microencapsulated material as a heat transfer fluid would increase the heat capacity and contribute to the enhancement of the heat exchange in the heat exchanger. This will enable an increase in the total heat transfer coefficient and the heat efficiency of the exchanger. Experimental studies describe the process of heat transfer intensification in the above conditions by using the phase transformation of the cooling medium melting. The test results were compared with the results of an experiment in which pure water was used as the reference liquid. The research was carried out in a wide range of refrigerant and coolant parameters: ṁr = 0.0014–0.0015 kg·s−1, ṁc = 0.014–0.016 kg·s−1, refrigerant saturation temperature Ts = 55–60 °C, coolant temperature at the inlet Tcin = 20–32 °C, and heat flux density q = 7000–7450 W·m−1. The obtained results confirmed the research hypothesis. There was an average of a 13% increase in the coolant heat transfer coefficient, and the peak increase in αc was over 24%. The average value of the heat transfer coefficient k increased by 5%, and the highest increases in the value of k were noted at Tin = 27 °C and amounted to 9% in relation to the reference liquid.
Surface engineering is an interdisciplinary topic thatcontains many branches of science related to materials science, chemistry, and physics [...]
Entrepreneurs in peripheral areas need to fully utilize a multidimensional regional environment in order to reduce regional innovation gaps. To gain a deeper theoretical and empirical understanding of the determinants of innovation processes in peripheral areas, this article sheds light not only on hard infrastructure and financial factors, but also on institutional, social, and relational factors. Studies of innovation in peripheral areas were conducted with the classic concept of regional innovation systems. Based on the results of a survey among 300 entrepreneurs in Polish peripheral regions, it was found that peripheral regions suffer from a deficit of human and social capital, particularly local leaders and mentoring and networking assistance. In addition, the analysis shows that peripheral regions do not have an effective innovation development strategy, lack institutional capital, and local authorities are not working to remove local barriers.
Sustainabletransportationhasasignificantimpactonfactorsrelatedtourbandevelopment and economic development. Therefore, much research is being undertaken to select the best strategies to manage sustainable transportation. Transportation requires a carefully designed method to manage the development of mobility modes in terms of the pollution they produce or the use of renewable energy sources. However, due to numerous preferences of decision-makers and data uncertainty problems, it is challenging to select the optimal strategy. In this paper, we focus on creating a framework for determining the best strategy for sustainable transportation management. For this purpose, T-spherical fuzzy graphs will be used, which, together with the combination of Laplacian Energy, can accurately represent decision-makers’ preferences in an uncertain environment. Due to the lack of limitations of T-spherical fuzzy graphs and its numerous membership functions, decision-makers can decide which factor seems most important for selecting the optimal sustainable transportation strategy. Additionally, due to the applicability, the SFS TOPSIS approach has been used in this approach. The obtained results demonstrate the high performance of the proposed approach and the applicability of the approach in management and sustainable transport problems.
The article presents research on using the adsorption process of aldrin (a chloro-organic pesticide that most often occurs in the environment near expired pesticide burials). The research used three sorbents: two activated carbons and compost from sewage sludge as a low-cost sorbent. Obtained adsorption isotherms belong to the L group according to the Giles classification. The test results and their analysis confirm that the IZO application facilitates the analysis of the adsorption process. The study results also confirm that compost can be a cost-effective alternative to commercial activated carbons to build barriers protecting the environment against existing leaking expired pesticide burials.
In this paper, we introduce the idea of the ‘visibility matrix’ for automated data entry form generation in low-code development platforms. We then focus on the problem of software development productivity in the area of automated software generation as the main factor of the Industry 4.0 concept in the area of business information. In our study, two different approaches to user interface development in a business process management low-code platform were evaluated. The first, the multi-form model, assumes that input forms are prepared separately for each user task in the business process being automated. The second approach, the single-form model, assumes that there is one global input form for every task in the business process. Since users have access to different data in different process tasks, it is necessary to prepare the visibility matrix to define which data are relevant to which tasks. The experiments presented in this paper help to answer the following question: which approach yields better results in terms of productivity, which is measured as costs and time required to prepare the application? Several dozen real business processes were analysed to examine the properties of their visibility matrix. Additionally, the real project team members were evaluated to determine their productivity. Then, the productivity parameters were calculated for real business processes and real project teams. The results show which approach is better suited for real-world business process development.
This paper describes a stability study in plastic injection molding process. There is a need - underpinned by economic considerations - to continuously improve and lead to a maximum reduction in the level of deficiencies in production processes. One of the methods that can help to improve the process is SPC (Statistical Process Control). One of the SPC tools are process capability indicators (Cp, Cpk) or performance indicators such as Pp, Ppk. In this paper, on a mass measuring station, a study was conducted on three types of products manufactured in a company, and the measurements concerned each piece of product manufactured during one work shift. The collected data were used to calculate the process capability and evaluate these processes.
The paper presents the modeling and analysis algorithm as well as the results of simulation tests with the use of FEM of the process of punching aluminum sheets used for casings. The first part presents the results enabling the correct selection of the die clearance on production lines depending on the thickness of the sheet metal. The second shows how to prepare the punch geometry in the FEM environment, taking into account the typical defects that occur as the work cycles increase. Thanks to this, it was possible to determine their influence on the state of stresses and deformations as well as the quality of the cut edge. The developed numerical applications and the obtained test results can be used to design tools and optimize the punching process.
The measure of the energy efficiency of the non-adiabatic two-phase condensation process of refrigerants in mini-channels is both the value of the heat transfer coefficient α and the flow resistance expressing the external energy input required to realize the flow. The modelling of this very complex process is effective if the condensation mechanism in mini-channels is correctly identified. It has been proven that the effects of changes in the condensation mechanism are the different structures of the two-phase flow resulting from process interactions both in the channel cross-section and along the flow path. The research aimed to connect the value of the heat transfer coefficient with the flow structures occurring during condensation. Thermal and visualization studies of the condensation process of low-pressure refrigerants were carried out: Novec649, HFE7100 and HFE7000 in tubular mini-channels with diameters dh = 0.5; 0.8; 1.2; 2.0 mm. Based on visualization studies, flow structures were proposed to be divided into 3 main groups: dispersive, stratified and intermittent. Based on this, a computational correlation was derived for determining the heat transfer coefficient and frictional resistance depending on the type of flow structure. The research shows that the highest values of the heat transfer coefficient occur during the mist flow and the lowest during the bubble flow.
A phase change material (PCM) is used as a substance filling in a heat store, due to the possibility of accumulating a significant amount of latent heat—the heat of phase transformation. Knowledge about the practical use of the working fluid, with the addition of a phase change substance, in heat exchange systems is limited The paper presents the results of preliminary research aimed at determining the possibility of using microencapsulated phase change material slurry (mPCM) as a working fluid in installations with a flat liquid solar collector, and the potential benefits as a result. The following were used as the working fluid during the tests: water (reference liquid), and a slurry of microencapsulated PCM. The mass fraction of mPCM in the working liquids is 4.3% and 8.6%, respectively. The research was carried out in laboratory conditions, in the range of radiation intensity G = 270–880 W/m2. The mass flux of each of the three working fluids in the collector is 30 kg/h, 40, kg/h, 60 kg/h, and 80 kg/h. Two main advantages of using mPCM as an additive to the working liquid are found: 1. in the entire range of thermal radiation intensity, the increase in the thermal efficiency of the collector fed with slurries is 4% with 4.3% mPCM in the slurry, and 6% with 8.6% mPCM in the slurry (for = 80 kg/h); 2. the slurry is characterized by a lower temperature at the outlet from the collector as compared to the water with the same thermal and flow parameters, which reduces heat losses to the environment both from the collector and other elements of the installation, as a result of excessive heating of the working liquid.
The urban transport system based on trams as the basic means of transport is one of the oldest systems of human transport in urban agglomerations. A tram is a more efficient, cheaper-to-operate, and greener means of transport compared to a bus. Striving to enable the use of this means of transport by elderly and disabled people, constructors and manufacturers of tram vehicles began to consider the requirements of the ordering parties—organizers of municipal public transport—in their solutions. The basic condition for disabled and elderly people to use tram transport is the possibility of safe and efficient entry and exit from the vehicle at tram stops. The fulfillment of this condition is possible only in the case of tram vehicles with a low 100% floor, and this, in turn, requires the replacement of trolleys with traditional wheelsets, that is, trolleys with independently rotating wheels, in the construction of the running gear. A wheelset with independently rotating wheels (IRW) does not have self-centering properties, and, thus, problems may arise with excessive wear of wheel and rail profiles and with continuous contact of the wheel flange with the rail, which may, consequently, lead to derailment. Driving a vehicle on the track in this case is governed by different laws. To prevent such phenomena, it is required to use the wheel drive control system, which allows for the stabilization of the vehicle movement on the track. Both the introduction of independently rotating wheels in the construction of the bogie and the drive connected to the wheel control system requires research and analysis to confirm the correctness of the assumptions made. The innovative solution of the control system in the case of a tram vehicle was patented and then the patent was implemented to produce a low-floor tram with 100% low floor by a Polish tram manufacturer. This article presents the results of the work carried out on the adoption of the concept of a running gear and drive solution for a low-floor tram vehicle with independently rotating wheels and the results of simulation analysis of the drive control of such a system, using mathematical models of the mechanical system (running gear) and the electrical system (motor drive control system).
This paper presents an aspect of asset tracking and storage conditions. This paper aims to fill the gap in the development of Industry 4.0 in terms of fully digital asset tracking to be implemented by medium and large-size manufacturing and logistics facilities. The article presents an innovative technology for the remote monitoring of chemical raw materials, including fertilizers, during their storage and transport from the place of manufacture to the local distributor or recipient. Methods: The method assumes the monitoring and identification of special transport bags, so-called “big-bags,” through embedded RFID tags or LEB labels and monitoring the key parameters of their content, i.e., temperature, humidity, insolation, and pressure, using a measuring micro-station that is placed in the transported raw material. Results: The automation of inference based on the collected information about the phenomenon in question (the distribution of parameters: pressure, temperature, and humidity), and expert knowledge, allows the creation of an advisory system prototype indicating how to manage the measuring devices. Conclusions: No similar solution in the field of monitoring environmental parameters has been implemented in the Polish market. The developed system enables the monitoring of 10,000 pieces of big bags in at least 30 locations simultaneously.
The fact that personality traits play an important role when it comes to predicting people’s entrepreneurial behavior is currently indisputable. However, so far, the majority of subject literature has focused on employee characteristics in developed countries. To address this gap, research was conducted, including 188 entrepreneurs of small and medium enterprises (SME) and 21 highest-level employees in Poland—one of the countries with the most hostile and turbulent environment for entrepreneurial operations in the world. The five personality traits (Big Five) were evaluated using the 60-item scale. There were three objectives of this study: to identify the differences between entrepreneurs and the most effective, highest-level employees, in the context of personality trait intensities, to determine the level of specific trait(s) intensities (OCEAN) of an effective entrepreneur. Finally, to determine whether it is possible to construct a model based on BIG5 to estimate the probability of success as an entrepreneur. The research results imply there are significant differences between successful entrepreneurs and highly effective employees and their personality trait intensities, described in the BIG5 model. Moreover, it is possible to distinguish trait intensity ranges, determining the success as an entrepreneur. Finally, we constructed the empirically based model, which allows us to estimate the chances of an individual succeeding as an entrepreneur with only a 5% error rate. The main factor and common denominator of entrepreneurial effectiveness is the trait of extraversion. The findings of our study are particularly important for the renewable energy sector in Poland, as the last part of green energy implementing blockchain (e.g., the installation and maintenance of wind turbines and solar panels) is being undertaken, in vast majority, by independent contractors and SME owners (entrepreneurs).
In this paper we present results of research on the transformation of chemical forms of two elements (Cu, Zn) that occurred at the highest concentration in sewage sludge being processed in a composting process. The factor that had impact on the direction of the observed transformation was the amount of straw added to the mix with sewage sludge at the batch preparation stage including elimination of an additional source of organic carbon (straw). The analysis of contents of Cu and Zn chemical forms was performed applying Tessiere’s methodology. It was ascertained that reduction of supplementation has positive impact on the allocation of tested elements in organic (IV) and residual (V) fractions with a simultaneous decrease of heavy metals mobile forms share in bioavailable fractions, mostly ion exchangeable (I) and carbonate (II). Using an artificial neural network (ANN), a tool was developed to classify composts based on Austrian standards taking into account only I ÷ IV fractions treated as a labile, potentially bioavailable, part of heavy metals bound in various chemical forms in compost. The independent variables that were predictors in the ANN model were the composting time, C/N, and total content of the given element (total Cu, Zn). The sensitivity coefficients for three applied predictors varied around 1, which proves their significant impact on the final result. Correctness of the predictions of the generated network featuring an MLP 3-5-3 structure for the test set was 100%.
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370 members
Mariusz Ruchwa
  • Faculty of Civil Engineering, Environmental and Geodetic Sciences
Dariusz Jacek Jakóbczak
  • Department of Electronics and Computer Science
Zbigniew Antoni Banaszak
  • Department of Management and Computer Science
Sebastian Glowinski
  • Department of Mechanical Engineering
P. Myśliński
  • Faculty of Technology and Education
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Śniadeckich 2, 75-453, Koszalin, West Pomeranian Voivodeship, Poland
Website
http://www.tu.koszalin.pl/eng/