Frequency of origin: 2 issues per year (April and November). Editor-in-chief: Mitja Slavinec (University of Maribor, Slovenia) Print ISSN: 2232-416X Online ISSN: 2820-364X The journal ANALI PAZU is an openly accessible, international journal dedicated to the study of natural sciences, engineering, medicine and biotechnistuals. The main purpose of publishing the journal is to publish peer-reviewed scientific and professional articles aimed at interdisciplinary or transdisciplinary topics considered, which go beyond disciplinary frameworks and include all scientific and professional fields of those scientific disciplines. The core of the magazine (80%) is represented by the original scientific research articles. ANALI PAZU: study of natural sciences, engineering, medicine and biotechnistuals. Indexing: COBISS.si, dLib.si (Digital Library of Slovenia), Ulrich's Periodicals Directory, BIBLIO-B. License: CC BY-NC-ND
Modeling the topographic properties of 3D printed metal materials
This research presents a groundbreaking method that combines fractals, network theory, and genetic programming to analyze the surface topography of metal additive parts. Specifically, it focuses on the selective laser melting of EOS MS1 maraging steel processed with the EOS M 290 3D printer. The findings show a significant improvement in the accuracy of surface roughness characterization using genetic programming. The use of fractal geometry and machine learning has improved our understanding of the complexity of selective laser melting of surfaces. This study not only contributes to the field of additive manufacturing by offering a more efficient and accurate approach to quality control, but also lays the foundation for future research into other materials and the refinement of analytical techniques. The potential of this method in supporting metal 3D printing practices is considerable, indicating a promising future for the industry in terms of both innovation and application.
Simulations of dynamical responses of electric motor drives with induction machines
The paper presents the simulations of dynamical responses of electric motor drives with induction machines working in various motor-, generator- and brake- regimes. For modeling of the electric motor drives with induction machines the arbitrary qd0 reference frame and stationary reference frame are used. The governing differential and algebraic equations of the induction machine are derived and coupled by the governing equations of the mechanical load, where the mathematical models of the entire drives are implemented in the programming system Mathematica®.
THE IMPACT OF COMPLEX INTERACTIONS ON THE EVOLUTION OF COOPERATION IN THE PUBLIC GOODS GAME
The emergence and persistence of cooperation among selfish individuals remain one of the most significant challenges that continues to intrigue scientists across various research fields. Evolutionary game theory has become a key tool in these studies, providing a robust theoretical framework to describe the evolutionary dynamics of strategies in social dilemmas. Simultaneously, advances in network science have significantly enhanced our understanding of numerous complex systems in the real world, including the development of cooperation in group decision-making and collective actions. A critical factor in this context is how individuals are embedded within society. Research over the past decades has showed that social network structure critically impacts cooperation. Moreover, as individuals are often mobile in most real-world scenarios, mobility and population mixing also play a crucial role in the evolution of cooperation. The primary aim of our study was to examine how different interaction networks and player mixing influence the evolution of cooperation in the public goods game.
The attitudes of healthcare professionals in surgical operations on the use of artificial intelligence and its integration into the operating room
Artificial intelligence has significant potential to improve the quality and efficiency of healthcare in surgical operations. A study conducted in the General Hospital Murska Sobota in 2023 examined the attitudes of healthcare professionals in surgical operations towards the use of artificial intelligence. The survey included 120 respondents (response rate 64.1%). One-third supported the integration of artificial intelligence in operating rooms. The main advantage they see in its use is the absence of emotional exhaustion (41.6%). However, they highlighted its limited ability to adapt and solve unexpected situations as a disadvantage (57.1%). In the next ten years, they expect its development in support services for operating rooms (39%). Ethical dilemmas focus on the responsibility for its use. The majority of respondents (54.5%) believe that legal responsibility will be assumed by the employed healthcare professionals in surgical operations. According to the respondents (63.7%), artificial intelligence cannot replace the role of a healthcare professional in the operating room. Further research could explore education about artificial intelligence and the development of ethical guidelines for its use.
In this study, we developed bioink for 3D printing incorporating human skin cells, composed of alginate, methylcellulose, and nanofibrillar cellulose in a cell medium. The 3D bioprinter allows the creation of multilayer scaffolds that simulate the natural cellular microenvironment of the skin. Due to the need for reproducibility, we stored the bioink in a freezer and thawed it later. The rheological properties of the material after thawing significantly affect its viscosity, impacting the feasibility of 3D printing and the stability of the printed scaffolds. We found that the freezing temperature notably influences these properties, which is crucial for the further development of an in vitro skin model, promising for preclinical and clinical research.
Pharmacist Prescriber: Abroad Experiences and Possible Implementation in Slovenia
The pharmacist prescriber represents a clinical pharmacist's most advanced role in drug prescription and therapy optimization. This collaborative practice initially emerged in the United Kingdom and the United States of America and later extended to other countries. Research findings indicate that this collaborative model yields positive outcomes, positively impacting clinical, humanistic, and economic outcomes while notably enhancing healthcare accessibility, particularly in the absence of family physicians. In Slovenia, pharmacist consultant settings have already been successfully integrated into the existing healthcare framework, laying a solid foundation for advancing collaboration in the form of prescribing pharmacists. This enhancement promises improved service accessibility, reduced physician workload, and heightened work quality. The reasons behind this collaborative approach in Slovenia are described in the paper.
it depends and independent prescribing medicines
State of the art and development of gold dental alloys
The article discusses the history, development, and properties of gold dental alloys. Alloys produced by Zlatarna Celje d.o.o. are certified medical devices in class IIa according to Regulation (EU) 2017/745, indicating a moderate level of risk. Alloys for porcelain crowns and bridges have a special status, requiring specific chemical composition and processing. Future development should aim to minimize biological risks and corrosion, achievable with highly noble alloys with stable microstructure. Dental alloys must not be ferromagnetic. Correct chemical composition is crucial for each patient, as the market offers various alloys suitable for individuals with different allergies and specific conditions in their oral cavity. It is important to follow the manufacturer's recommendations to ensure the quality fabrication and installation of dental prosthetic constructions.
Development of biomimetic sensors to determine the functionality of in vitro cell models
Advances in biomedical science have enabled the development of in vitro models that mimic human tissues. Non-invasive real-time monitoring of these models would provide valuable insights without disrupting the cellular environment. This study explores the use of molecularly imprinted polymers (MIPs) for this purpose, focusing on insulin and lactate as biomarkers of cellular metabolism. MIP sensors were created by electropolymerizing pyrrole around insulin or lactate templates on carbon electrodes. The sensors showed high sensitivity and selectivity, with detection ranges of 20.0–70.0 pM for insulin (LOD: 2.41 pM) and 0.5–3.0 mM for lactate. These findings highlight MIPs’ potential for personalized diagnostics and therapy monitoring.
Implementation of seamless care in a hospital: A qualitative study focused on clinical pharmacists
In Slovenia, the notion of seamless care has been relatively new in the recent past. It suggests that clinical pharmacists have a significant role in working closely with patients and enhancing their safety. The perspective of clinical pharmacists in a novel work environment piqued our curiosity. We conducted a qualitative research. We obtained the necessary information through interviews conducted with four clinical pharmacists who have the most theoretical and practical knowledge in the field of seamless care. The interviewees believe that the implementation of seamless care in clinical practice is important and positive. However, they are distracted by administrative obstacles in carrying out seamless care. The detection of clinical pharmacists is appropriate and enables the development of the method to other professional groups.
Features in recognizing activities of daily life in smart homes
The question arises of how to ensure a safe stay for the elderly in their home environment. Development in sensor technology, machine learning, and artificial intelligence can contribute to achieving this goal. Activities of daily life recognition systems recognize the activities of residents in smart homes with high accuracy. They can consequently detect anomalies in the daily functioning of the elderly, which may indicate health problems. Systems of this type are based on sensor networks and recognize the activities of residents based on the activation of various sensors. The accuracy of activity recognition depends primarily on the quality of the features that are compiled from sensor data and the classification model, which is built from the collection of data in the learning phase. In the presented research, we mainly focus on selecting and extracting features and studying how different features affect the final result of activity recognition. We analyze which activities have the best and which have the worst recognition accuracy. In the latter's case, we also show which activities are most often misidentified.
Experimental Spray Characterization and Numerical Modeling of Suspension Spraying in a Spray Dryer
Drying is one of the most important and at the same time the oldest areas of process technology. One of the most established forms of drying is spray drying, which is very often present in the food, pharmaceutical and chemical industries. In this paper, we discuss the characterization of the spray formation on the spray nozzle and the implementation of numerical simulation with included secondary breakup of the spray. The characterization of the spray on the nozzle was performed on the Oxfor laser system, while the Ansys Fluent software package was used to perform the numerical simulations. A comparison of the results showed a good agreement between the particle size distribution obtained in the experiment and in the numerical simulation.
Good clinical practice for investigators conducting clinical trials
Drug development is a long and expensive process. Before a particular drug receives the appropriate marketing authorization, it is necessary to prove its efficacy and safety in addition to its quality. Clinical trials are necessary to prove the effectiveness and safety of the drug. A clinical trial of a drug is research conducted on healthy individuals and patients, in which the principles of good clinical practice (GCP) must be followed. Compliance with this standard provides public assurance that the rights, safety and wellbeing of trial subjects are protected and that clinical-trial data are credible. A clinical trial of a drug involves investigators, sponsors, and participants. In this paper, we focus on the investigator in the clinical trial of a drug, who must be well aware of the principles of GCP in order to be able to comply with his obligations and responsibilities. By showing examples of deficiencies identified during clinical trial site inspection (at the investigator), we aim to help investigators to achieve compliance with good clinical practice.
Influence of Metal Surface Finishing on Porcelain Microstructure Failures in Porcelain-Fused-to-Metal Dental Restoration
Although the current trend in fixed prosthetics is the use of full-ceramic dental restorations, research has shown that most commonly used are still metal-ceramic dental restorations. The purpose of the research presented in this paper is to find out how different techniques of mechanical treatment of the surface of the metal frame affect the occurrence of defects in the porcelain layer and the metal-porcelain interface. As part of the research, we produced samples from Co-Cr alloy using various surface treatment methods and techniques, followed by the preparation of metallographic tablecloths, with the help of which we analyzed the influence of surface treatments on the change in the macro- and microstructure of the metal framework, the porcelain veneer and the interface between them. The results of the conducted research showed that the occurence of defects in samples whose metal surface was treated with an abrasive in one direction is minimal, the surface of the metal framework is uniformly rough with an average thickness of the oxide layer of 3.5 µm. In samples with a metal framework treated with an abrasive in several directions, we observed a rougher surface of the metal framework with the presence of plastic deformation of the surface of the metal framework, which forms a thinner oxide layer
Implementation of the Savvy portable ECG body monitor for cardiac arrhythmia screening at the primary health care level: an interventional randomized controlled trial
At the Jožef Štefan Institute, in cooperation with doctors, they developed a personal portable EKG meter Savvy, which works in combination with a smartphone and can be used in patients who complain of heart rhythm disorders. The aim of the study was to analyze the utility of telecardiology at the primary health care level using the Savvy portable ECG body monitor. Methods: We included 400 patients with a suspected heart rhythm disorder who visited their family doctor in the Ljubljana Health Center and the Murska Sobota Health Center from October 2016 to January 2018. The patients were divided into a test group, where they received a portable ECG body meter, and a control group, where they did not. Results: The study showed that there was no statistically significant difference between the test and control groups regarding detected rhythm disturbances and measures to treat patients, either by observation or by administering a new drug. In the test group, there were significantly fewer referrals to a cardiologist than in the control group (p <0.001).
MULTISTABLE NETWORKS OF TOPOLOGICAL DEFECTS
Topological defects are a consequence of symmetry-breaking phase transitions and are ubiquitous in nature. An environment where they most easily studied, are nematic liquid crystals. We describe nematic structures at the mesoscopic scale with a tensor order parameter and we determine equilibrium states by numerically minimizing free energy. We enforce defects through boundary conditions at enclosing surfaces. First we show that there are multiple equilibrium states possible by just enforcing one defect, depending on the thickness of the cell. While enforcing multiple defects at the bottom surface we can create equilibrium states with “chargeless” line defects. By enforcing a 4x4 network of defects we can create complex patterns of chargeless line defects, where 18 are quantitatively and 7 are qualitatively different. We also demonstrate how to rewire the line defects to transition from one pattern to another and back. Our system could lead to multistable optical displays and rewirable nanowires.
IMPACT OF THE ORIGINATING MARTENSITIC PHASE ON THE CHARACTER OF MARTENSITIC PHASE TRANSFORMATION
In the article, we discuss the influence of the locally perturbed order parameter in austenitic-martensitic phase transformation on the character of the phase transformation. We choose Landau type mean field approximation which covers the most important features of the proposed theoretical description.
austenitic-martensitic phase transformation
MONITORING THE INTERVENTIONS OF CLINICAL PHARMACISTS IN MURSKA SOBOTA GENERAL HOSPITAL
Clinical pharmacists have been part of the health care team for many years. The number of employed clinical pharmacists varies widely among hospitals. Still the question remains, how to evaluate work of clinical pharmacists. In Murska Sobota General Hospital, we evaluated the work of clinical pharmacists by different departments from 1/1/2020 to 31/12/2020. The services of three clinical pharmacists in SBMS were included in the analysis. In one year, 8,523 different interventions were introduced. 30 different interventions were monitored, as well as attendance at reports and/or rounds with other medical staff. Among the interventions, the most frequently was: therapy review of the hospitalized patient’s (1,979 times), review of interactions between examined drugs (1,859 times) and review of the history of treatment with drugs and food supplements upon admission (1,785 times). Evaluation of the work of clinical pharmacists in hospitals is an important step towards work monitoring, also an upgrade of this system with subsequent measurement of the quality of the services provided would be welcome.
COMPUTATION OF DISPERSION CURVES OF RAYLEIGH-LAMB WAVES BY NEWTON-RAPHSON METHOD
The paper treats the numerical construction of dispersion curves which belong to the propagation of Rayleigh-Lamb waves in isotropic elastic media. The Newton-Raphson method.is applied for computation of real, imaginary and complex wavenumbers in dependence on the frequency of the wave. Due to multivaluedness, unexpected jumps between modes of dispersion curves occur in branch tracing, which prevents successful direct application of the method. This shortcoming is eliminated in the article by introducing the arc-length continuation method. The efficiency of this supplement to the Newton-Raphson method is shown on the example of an aluminum plate with constructions of dispersion curves for real, imaginary and complex wave numbers.
Thermoanalysis of Smart Heating Textiles for Car Seats
In this paper, we focus on active smart textiles that detect a temperature change and respond to it by turning the heating on or off. In the development of such products, it is important to know the temperature-time dynamics of heating and cooling to control and prevent overheating. Thermoanalysis proves to be an appropriate method. An infrared camera enables a non-contact study of the temperature distribution on the surface of a textile product and the identification of hot spots. We present the results of thermoanalsyis of two samples of heating textiles in combination with two samples of melamine textiles, which is considered a good thermal insulator. In analysis and results interpretation we focus on the possibility of using individual samples of heating textiles and their combinations with melamine for heated car seats.
The model of conjugate heat and mass transfer between a particle and a fluid flow in spray drying based on the boundary element method
Drying is one of the oldest process technologies, which is used in different industrial applications. Drying process is complex physical process that involves coupled multiphase heat, mass and momentum transfer. As for example by spray drying process, local drying conditions inside the dryer affect to total drying time of porous particles. For this reason, the influence between particle and drying gas is very important. Through the drying process heat and mass exchange between particles and drying gas occurs, which results in local change of drying conditions. Two-way interaction (drying air to particle and particle to drying air) need to be considered to obtain accurate results. Fully coupled model for heat and mass transfer between particles and drying gas on the base of the Boundary Elements Method was developed in the present work, were particles were modelled as points. The results presented in this work show that two-way coupling between particles and drying gas is important in order to provide accurate results.
Numerical simulations of particles and fluid flow in a fluidized bed granulator
The objective of this study was to determine the distribution of air flow on a distributor plate of a laboratory fluid bed granulator. The uniform spatial distribution of particles is important for the granulation process. Instead of the current approaches to scaling the process parameters for air flow rate based on the concept of apparent air velocity, it would be desirable to also consider the distribution of air flow above the distributor, since the flow is not uniform. We have performed several numerical simulations of the air flow using computational fluid dynamics (CFD) and several two-way coupled simulations using CFD and the discrete element method (DEM), motivated by our confirmed assumption that particles affect the air flow distribution. We found that the air flow rate through the granulator affects the distribution of the air flow on the distributior, especially in the case of a loaded granulator.
Bonding of wood with the adhesive from waste polystyrene
Each year the world produces more and more durable plastic waste, which is accumulating in nature. One of the solutions to ease its impact is to recycle and reuse it for new products and intermediate products. Recycled plastic, especially thermoplastic, has great potential in the wood industry. In our research, we have used waste coffee cups and spoons made of polystyrene to make two adhesive mixtures, using dimethylformamide as a solvent. To establish the shear strength of adhesive bonds, we made bonded wood panels according to the instructions by standard SIST EN 205:2016. The idea was to optimize the temperature of hot pressing and to add a cooling procedure to ensure better shear strength of the bond, which is needed to reach the minimum criteria of the SIST EN 204:2016 standard. We used two temperatures for hot pressing (150 °C and 120 °C) and four ways of panel cooling in a closed press. After trying out different procedures, we came to the conclusion that the best way to use a coffee cup adhesive is to cool it down to 75 °C, while for the spoon-based adhesive the best bonding method is to cool the joints down to 100 °C or 25 °C. We also found that by cooling the panels in a closed press the consistency of the results increases, which makes the adhesive bonds more reliable. We managed to reach standard criteria with a sample which had been glued with coffee cup adhesive, hot pressed at 150 °C and cooled down to 75 °C before being taken out of the press.
Analysis topography of robot laser hardened materials by using machine learning method
Laser treatment of materials, including heat treatment, is based on the use of laser radiation, which allows you to create, on a very small surface, the high thermal field densities required for intense heating or melting. The article presents the influence of the robot laser cell parameter on the material topography. Machine learning methods show how the parameters of a robot laser cell affect the hardness and roughness of the hardened material, and the relationship between hardness and roughness.
Optimal determination of stability domains of vibrations in gear drives
The article deals with the optimization of stable vibration zones of a two-stage gearbox with parametric excitation as a consequence of periodically variable tooth stiffness during meshing. In order to ensure a calm running of the gearbox and to reduce noise, we want to minimize the vibration instability zone in the gearbox design process. The reduction of individual instability zone is largely influenced by the contact ratio of each gear pair and their phase shift. Unfortunately, as one unstable area decreases, other unstable areas can increase. This raises the need to find the optimal solution that can be provided by solving the multi-criteria optimization problem. The article presents the multi-criteria optimization of gear vibration stability zones by using the Weighted Sum Method and the ε-Constraint Method, respectively. The results of multicriteria optimization of stability zones in the article are analytically explained. Both multi-criteria optimization methods are presented in the article for a two-stage, three-gear gearbox with the same meshing frequencies.
optimization of parametric instability domains
Development of an advanced tool steel for the most demanding applications in the knife industry
This paper presents the starting points and an approach for the development of an advanced tool steel for the most demanding applications in the knife industry, which is carried out by SIJ Ravne Systems in collaboration with the University of Maribor Faculty of Mechanical Engineering. On one hand, the development is related to the identification of key features of tool steels that present a competitive advantage over other conventional steels, such as toughness, hardness, strength and cutting ability. On the other hand, the development also represents the implementation of appropriate technologies for the production and subsequent thermal or mechanical treatment of tool steels, in order to achieve key properties of the final products - knives.
Nanotechnology as the technology of the future, nanowaste problems
In this paper, we present Nanotechnology, which is a branch of science and engineering focused on materials with at least one dimension below 100 nm. It involves the understanding of materials or processes on the "nano" scale. Nanomaterials, in the form of nanoparticles, nanotubes, nanopyramids, etc., have different properties compared to materials with ordinary dimensions. They have altered physical and chemical properties, which come from the large surface-to-volume ratio. This is reflected in their high surface activity and, because of this, they are useful in various fields (Electronics, Chemistry, Biotechnology, Medicine). Based on this fact, Nanotechnology is a broad term that covers many areas of science, research and technology.
Diabetic foot is the most common cause of non-traumatic amputation. The consequences of diabetes such as peripheral neuropathy, poor blood circulation, limited joint mobility, foot deformity, and consequently altered pressures on the sole are known as some of the risk factors for the development of diabetic foot. During the treatment of diabetic foot, preventive surgical procedures are used to prevent amputation, traumatic surgical procedures are used to remove damaged parts of the foot and corrective surgical procedures are used to achieve wound healing.
Application of mathematical analysis in the design of permanent magnet motors
The development of permanent magnets with high energy density and their availability on the market affect the increased use of magnets in synchronous motors. The efficiency of the permanent magnet machine is highly influenced by the magnetic field in the air-gap between the rotor and the stator, which is generated by the rotor with its permanent magnets during rotation. The magnetic field in the air gap and in the permanent magnets of the rotor is obtained as the solution of a system of partial differential equations describing the magnetic properties of the machine. This system is not always fully analytically solvable.
Are multiple-choice tests a sufficient tool for the assessment of knowledge?
How best to assess students’ knowledge is still an unsolved dilemma among educational researchers. Multiple-choice questions become a popular assessment tool at all stages of education. But, many researchers are sceptical if such assessment is sufficient for the determination of students’ knowledge. In this paper, we present our study, in which 167 students of Physiotherapy were involved. Students had to complete a multiple-choice test after completing the physics course. The multiple-choice test incorporated questions, which covered domains of physics that were part of the course, and questions from the field of modern physics that were not part of the course. The results of this study indicate that multiple-choice questions can be a successful assessment tool for the determination of students’ knowledge.
Ultra-fast laser pulses induced phase changes in ηǦMo4O11 crystals
The article presents the experimental result of fluence dependence of the transient reflectivity response to ultra-fast laser pulses in η-Mo4O11 crystals. Results of the experiment show that at certain fluences at low temperatures phase changes can be induced in the crystals which are not seen inthe temperature phase diagram.