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Editorial
Get PDFThis editorial introduces the Special Issue of the Strojniški vestnik - Journal of Mechanical Engineering dedicated to the 30th anniversary of the Faculty of Mechanical Engineering as an independent member of the University of Maribor, and the 50th anniversary of the University of Maribor. The Faculty of Mechanical Engineering is one of the most successful members at the University of Maribor and is recognised for its excellence in education, research and collaboration with industry. Its history of development, from its early beginnings in 1959 to becoming an internationally active and research-driven institution, reflects a continuous commitment to technological progress and societal impact. The Special Issue presents a selection of articles covering applied fluid mechanics, advanced materials and metamaterials, manufacturing science, and biomedical modelling. The collected works combine experimental, numerical, and review-based approaches to address contemporary challenges in mechanical engineering. This publication not only highlights the scientific excellence achieved at the Faculty of Mechanical Engineering, University of Maribor, but also celebrates its enduring mission to connect knowledge, innovation and human creativity in shaping a sustainable and technologically advanced future
Self-limiting the Use of Social Networking Sites
Get PDFSpletna socialna omrežja (SSO) predstavljajo vseprisoten, dinamičen in pomemben del sodobnega življenja, saj bistveno vplivajo na oblikovanje identitete, medosebne odnose in vsakodnevno komunikacijo. V magistrski nalogi so predstavljeni teoretični pristopi k razumevanju motivacije za (ne)problematično rabo, razvoj kognitivnih, čustvenih in vedenjskih vzorcev ter možne negativne posledice uporabe. Glavni namen dela je bil s pomočjo enotedenske intervencije samoomejevanja uporabe preučiti vpliv na različne psihološke konstrukte, vlogo zasvajajoče rabe ter motivacijo sodelovanja in samega procesa samoomejevanja. Končni vzorec je zajemal 24 udeležencev, pri katerih so bile ugotovljene pozitivne spremembe pri FoMO, anksioznosti, depresivnih simptomih, stresu in psihološkem blagostanju. Pri osamljenosti, socialni povezanosti, samospoštovanju, zadovoljstvu z življenjem in kakovosti spanja ni bilo statistično značilnih sprememb. Zasvajajoča uporaba ni imela vpliva na učinkovitost intervencije, najbolj izražen motiv uporabe je bila zabava, najmanj pa motiv negativne družbene moči. Sodelovanje so motivirali radovednost, samoraziskovanje, optimalnejša raba časa ter pomoč raziskovalki, proces samoomejevanja pa je bil večinoma opisan kot pozitiven. V diskusiji so predstavljene možne razlage (ne)dobljenih učinkov. Povezane so z zmanjšano izpostavljenostjo obvestilom in stresorjem, prekinitvijo avtomatiziranega pregledovanja vsebin, zmanjšanjem socialnih primerjav, osredotočenostjo na druge dejavnosti, refleksijo, čustveno oporo, začetno odsotnost težav, kompenzacijo, kratkotrajnostjo intervencije in podobno.Social networking sites (SNS) represent a ubiquitous, dynamic, and significant part of modern life, as they have a substantial impact on identity formation, interpersonal relationships, and everyday communication. This master\u27s thesis presents theoretical approaches to understanding the motivation behind (non)problematic use, the development of cognitive, emotional, and behavioural patterns, and the potential negative consequences of use. The main aim of the study was to examine the impact on various psychological constructs, the role of addictive use, the motivation for participation, and the self-limitation process itself, using a one-week self-limitation intervention. The final sample included 24 participants, who showed positive changes in FoMO, anxiety, depressive symptoms, stress, and psychological well-being. No statistically significant changes were found in loneliness, social connectedness, self-esteem, life satisfaction, or sleep quality. Addictive use did not influence the effectiveness of the intervention. The most prominent motive for using social networking sites was entertainment, while negative social potency was the least prominent motive. Participants were primarily motivated to take part out of curiosity, self-exploration, more optimal use of time, and a willingness to assist the researcher. The process of self-restraint was mostly described as positive. The discussion outlines possible explanations for the (non)significant effects, including reduced exposure to notifications and stressors, the interruption of habitual content browsing, decreased social comparison, increased focus on other activities, reflection, emotional support, an initial lack of problems, compensation, short duration of the intervention, and other similar factors
Podeželje in odpornost, ruralno kriminološki diskurz
No full textEvropska unija je v okviru drugega stebra skupne kmetijske politike leta 2023 uvedla politiko na področju razvoja podeželja za obdobje 2023–2027. Le-ta je namenjena podpori podeželskim območjem v Evropski uniji za naslavljanje ekonomskih, okoljskih, podnebnih in družbenih izzivov 21. stoletja. Države članice so ukrepe za razvoj podeželja zapisale v obliki nacionalnih strateških načrtov skupne kmetijske politike 2023–2027, ki se delijo v štiri sklope: 1) Pospeševanje konkurenčnosti kmetijstva, živilstva in gozdarstva2) Skrb za okolje in prilagajanje na podnebne spremembe3) Uravnotežen razvoj podeželskih območijin 4) Prenos znanja in inovacij. Ključni cilj politike je dvig kakovosti življenja in krepitev gospodarske aktivnosti na podeželju. Avtorica v prispevku analizira prednostne naloge kmetijske politike razvoja podeželja in skozi prizmo ruralne kriminologije razpravlja o povečanju konkurenčnosti, zagotavljanju trajnostnega gospodarjenja z naravnimi viri in ukrepi na področju podnebnih sprememb ter doseganju uravnoteženega teritorialnega razvoja podeželskih gospodarstev in skupnosti ter izpostavlja prednosti in slabosti.The European Union introduced a rural development policy for the period 2023–2027 under the second pillar of the Common Agricultural Policy in 2023. It is intended to support rural areas in the European Union in addressing the economic, environmental, climate, and social challenges of the 21st century. Member States have written down rural development measures in the form of national strategic plans, which are divided into four strands: 1) Promoting the competitiveness of agriculture, food and forestry2) Caring for the environment and adapting to climate change3) Balanced development of rural areasand 4) Transfer of knowledge and innovation. The key objective of the policy is to improve the quality of life and strengthen economic activity in rural areas. The author analyses the priorities of agricultural policy for rural development and, through the prism of rural criminology, discusses increasing competitiveness, ensuring sustainable management of natural resources and climate change measures, and achieving balanced territorial development of rural economies and communities, highlighting advantages and disadvantages
Macromolecular inks of nanocellulose-alginate for direct-ink-writing
Get PDFWe present a scalable platform for the fabrication of multifunctional bioactive materials by integrating, polysaccharide-based matrices, green extraction and additive manufacturing. In this work, bioactive 3D-printed structures were fabricated using inks composed of nanofibrillated cellulose (NFC), alginate (Alg), and curcumin extracts. Bioactive compounds were efficiently recovered from turmeric via solvent-free supercritical carbon dioxide extraction, yielding up to 6.57 mg/100 g curcuminoids and 232.45 mg/100 g total phenols. The extracts exhibited robust antioxidant activity (DPPH• IC50: 23.24 mg/mLABTS+• IC50: 3.59 mg/mL) and broad-spectrum antimicrobial efficacy against Staphylococcus aureus, Escherichia coli, Candida albicans, and Pseudomonas aeruginosa (MIC: 9.38 mg/mL). Incorporation into NFC-Alg inks exhibited excellent shear-thinning properties suitable for direct-ink-writing 3D printing. Post-printing CaCl2 crosslinking further reinforced the hydrogel network, enhancing mechanical robustness and shape fidelity. The resulting constructs featured a highly porous, grid-like architecture with intricate surface morphology, highlighting significant potential for biomedical and tissue engineering applications
Numerical solving of dynamic thermography inverse problem for skin cancer diagnosis based on non-Fourier bioheat model
No full textThis paper presents numerical solving of the inverse bioheat problem to estimate four skin cancer parametersdiameter, thickness, blood perfusion rate and thermal relaxation time, based on the thermal response on the skin surface obtained by dynamic thermography and numerical skin cancer model, which can greatly enhance dynamic thermography diagnostics. To describe the heat transfer inside biological tissue and thermal behavior during the dynamic thermography process as realistic as possible, the non-Fourier dual-phase-lag bioheat model was used, as well as skin cancer model has been composed of multilayered healthy skin, embedded skin tumor and subcutaneous fat and muscle. Boundary element method has been used to solve a complex non-Fourier bioheat model to simulate dynamic thermography based on the skin cancer model and guessed searched parameters to obtain the thermal response on the skin surface during the cooling and rewarming phase using a cold air jet provocation, which is needed for the solution of the inverse bioheat problem. The inverse problem has been solved by optimization approach using the hybrid Levenberg-Marquardt optimization method, while the measurement data has been generated numerically with known exact tumor parameters and added noise, to evaluate the accuracy and sensitivity of the solution. Inverse problem solution has been tested for two different thermal responsesabsolute temperature and temperature difference response, as well as for two different tumor stagesearly stage or Clark II and later stage or Clark IV tumor. All important tumor parameters were successfully retrieved, especially the diameter and relaxation time, even for the high level of noise, while the accuracy of obtained parameters is slightly better using absolute temperature response. The results demonstrate the robustness of the method and a promising way for early diagnosis. The findings contribute to improving bioheat modeling in biological tissues, solving inverse bioheat problems and advancing dynamic thermography as a non-invasive tool for early skin cancer diagnosis.Članek obravnava numerično reševanje inverznega problema prenosa toplote za določitev štirih parametrov kožnega raka: premer, debelino, perfuzijski pretok krvi in relaksacijski čas. Določitev temelji na toplotnem odzivu kože pridobljenim z dinamično termografijo ter numeričnim modelom kožnega raka ki lahko bistveno izboljša diagnostično vrednost termografije. Za čim bolj realističen opis prenosa toplote v tkivu med procesom dinamične termografije je bil uporabljen nefourierov model z dvojnim faznim zamikom. Model kožnega raka je sestavljen iz večplastne kože, podkožne maščobe in mišice ter kožnega raka oziroma tumorja. Za rešitev kompleksnega nefourierovega modela ter simulacije dinamične termografije je bil razvit programski paket na osnovi metode robnih elementov. Simulacija dinamične termografije, ki za temperaturno vzbujanje uporablja curek hladnega zraka, je pomembna za rešitev inverznega problema, saj z njo pridemo do termičnega odziva oziroma temperaturnega kontrasta na površini kože pri predpostavljenih iskanih parametrih ter njene primerjave z meritvijo. Tako je bil inverzni problem rešen s pristopom optimizacije, pri čemer je bil uporabljen Levenberg–Marquardt algoritem. Meritve so bili pri tem generirane numerično z vnaprej znanimi parametri tumorja in dodanim šumom za ovrednotenje natančnost in občutljivost inverzne rešitve. Rešitev inverznega problema je bila pri tem testirana za dva različna temperaturna odziva, in sicer absolutno temperaturo in temperaturno razliko, kakor tudi za dve različni stadija tumorja kot je Clark II, ki predstavlja zgodnji stadij in Clark IV, ki predstavlja pozni stadij. Vsi pomembni parametri tumorja so bili uspešno določeni tudi pri visoki stopnji šuma, zlasti premer in relaksacijski čas, pri čemer je bila natančnost ovrednotenih parametrov nekoliko boljša z uporabo absolutnega temperaturnega odziva. Rezultati kažejo na robustno in obetavno metodo za zgodnjo diagnostiko kožnega raka in pomembno prispevajo na področju modeliranja prenosa toplote v bioloških tkivih, reševanju inverznih problemov ter razvoju dinamične termografije
Advancing intelligent toolpath generation: A systematic review of CAD–CAM integration in Industry 4.0 and 5.0
Get PDFThis systematic literature review investigates advancements in intelligent computer-aided design and computer-aided manufacturing (CAD–CAM) integration and toolpath generation, analyzing their evolution across Industry 4.0 and emerging Industry 5.0 (I5.0) paradigms. Using the theory–contextcharacteristics–methodology framework, the study synthesizes 51 peer-reviewed studies (from 2000 to 2025) to map theoretical foundations, industrial applications, technical innovations, and methodological trends. Findings reveal that artificial intelligence (AI) and machine learning dominate research, driving breakthroughs in feature recognition, adaptive toolpath optimization, and predictive maintenance. However, human-centric frameworks central to I5.0, such as socio-technical collaboration, remain underexplored. High-precision sectors (aerospace, biomedical) lead adoption, while small and medium enterprises (SMEs) lag due to resource constraints. Technologically, AI-driven automation and STEP-NC standards show promise, yet interoperability gaps persist due to fragmented data models and legacy systems. Methodologically, AI-based modeling prevails (49 % of studies), but experimental validation and socio-technical frameworks are sparse. Key gaps include limited real-time adaptability, insufficient AI training datasets, and slow adoption of sustainable practices. The review highlights the urgent need for standardized data exchange protocols, scalable solutions for SMEs, and human-AI collaboration models to align CAD–CAM integration with I5.0’sPregled literature raziskuje napredek na področju integracije računalniško podprtega konstruiranja in računalniško podprte proizvodnje (CAD–CAM) ter generiranja poti orodja, pri čemer analizira razvoj v okviru Industrije 4.0 in Industrije 5.0 (I5.0). S pomočjo pristopa po teoriji–kontekstuznačilnostih–metodologiji (TCCM) študija sintetizira 51 recenziranih raziskav (v obdobju 2000–2025) ter analizira teoretične osnove, industrijske aplikacije, tehnične inovacije in metodološke trende. Ugotovitve razkrivajo, da raziskave močno zaznamujejo umetna inteligenca (UI) in strojno učenje, ki poganjata preboje na področju prepoznavanja značilnosti, adaptivne optimizacije poti orodja in napovednega vzdrževanja. Vendar pa človeškousmerjene rešitve, ki so osrednjega pomena za I5.0, kot je sociotehnično sodelovanje, ostajajo premalo raziskana. Panoge z visoko natančnostjo (letalska in vesoljska, biomedicinska) vodijo pri uvajanju, medtem ko mala in srednja podjetja (MSP) zaostajajo zaradi omejenih virov. S tehnološkega vidika obetajo avtomatizacija, ki temelji na UI in standardi STEP-NC, a vrzeli v interoperabilnosti ostajajo zaradi razdrobljenih podatkovnih modelov in zastarelih sistemov. Metodološko prevladuje modeliranje na osnovi UI (49 % raziskav), eksperimentalna validacija in sociotehnična ogrodja pa ostajata redka. Ključne vrzeli, ki so bile zaznane v študiji, vključujejo omejeno sprotno prilagodljivost, pomanjkanje zadostnih učnih podatkovnih zbirk za učenje modelov UI, ter počasno uvajanje trajnostnih praks. Pregled poudarja nujnost standardiziranih protokolov za izmenjavo podatkov, razširljivih rešitev za malo serijsko proizvodnjo ter razvoj modelov sodelovanja med človekom in UI, ki bi CAD–CAM integracijo uskladili s trajnostnimi in odpornimi cilji I5.0. Z odpravljanjem teh vrzeli prispeva pregled k oblikovanju n
Fusion behavior of pure magnesium during selective laser melting
Get PDFThis study examined the melting behavior and flowability of pure magnesium during selective laser melting. The potential to increase product density was also investigated. Various combinations of manufacturing parameters were considered. The laser power was gradually increased in different machine runs, with different scanning speeds for each run to vary the energy density (ED). The laser power ranged from 10 W to 75 W, and the scanning speed ranged from 100 mm/s to 800 mm/s. Lower laser powers resulted in poor melting, while higher laser powers produced better melting, with significant differences even when the ED was the same. High EDs between 3.50 J/mm² and 4.30 J/mm² led to a lack of melting at low laser power and to an unstable melt pool with significant spattering at high laser power. In contrast, moderate EDs in the range of 1.40 J/mm² to 2.90 J/mm² resulted in better density at high laser power. Higher scanning speeds helped to avoid the formation of a dense smog cloud and provided sufficient energy in a short time with the aid of higher laser power. Therefore, increasing both laser power and scanning speed improved melting performance and increased product density. The relative product density ranged from 80 % to 96.5 %. Reducing the layer thickness from 50 µm to 25 µm at a laser power of 40 W resulted in the formation of a well-formed melt pool in some areas and significant melt spattering in others, which led to a deterioration in density.V raziskavi smo proučevali obnašanje taljenja čistega magnezija in pretočnost njegove taline med selektvinim laserskim taljenjem. Raziskali smo tudi vpliv različnih kombinacij procesnih parametrov na povečanje gostote izdelka. Moč laserja smo postopoma povečevali in pri tem spreminjali hitrosti skeniranja za vsako serijo izdelkov, s čimer smo vplivali na vnos energije v talilni process (ED). Moč laserja se je gibala od 10 W do 75 W, hitrost skeniranja pa od 100 mm/s do 800 mm/s. Z nižjimi močmi laserja nismo dosegli zadovoljivega taljenja materiala, medtem ko so višje moči laserja povzročile boljše taljenje, z znatnimi razlikami tudi pri enakih vnosih energije - ED. Visoka energijska gostota - ED med 3,50 J/mm² in 4,30 J/mm² je povzročila pomanjkljivo taljenje pri nizki moči laserja oziroma nestabilen talilni bazen z znatnim pršenjem materiala pri visoki moči laserja. Nasprotno pa so zmerne ED v območju od 1,40 J/mm² do 2,90 J/mm² povzročile boljšo gostoto pri visoki moči laserja. Višje hitrosti skeniranja so pomagale preprečiti nastanek gostega oblaka smoga in s pomočjo večje laserske moči zagotovile zadostno energijo v kratkem času. Zato je povečanje tako laserske moči kot hitrosti skeniranja izboljšalo učinkovitost taljenja in povečalo gostoto vzorca. Relativna gostota vzorcev se je gibala od 80 % do 96,5 %. Zmanjšanje debeline plasti s 50 µm na 25 µm pri laserski moči 40 W je na nekaterih območjih povzročilo nastanek dobro oblikovanega bazena taline, na drugih pa znatno brizganje taline, kar je povzročilo poslabšanje gostote
PAMPS PolyHIPEs
Get PDFIn this study, the adsorption performance of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS)-based polymerizedhigh internal phase emulsion (polyHIPE) for the removal of Zn 2+, Fe3+, and Al 3+ ions from water is investigated. The triple-factoranalysis includes the role of shape, porosity, and sulfonate group density. By systematically comparing different forms of PAMPS,that is, polyHIPE beads and monoliths (shape effect), PAMPS homopolymers and copolymers ( SO3− group density effect), andporous polyHIPEs compared to commercially available gel-type, non-macroporous beads (porosity effect), we determine howstructure–function relationships govern metal ion uptake. The results show ion-specific effects: The high charge density of Fe3+and Al 3+ generates a strong electrostatic driving force for multipoint binding to SO3− groups, which leads to fast adsorption. Incontrast, Zn 2+ adsorption is slower due to its lower charge density and the relatively stable hydration sphere. It therefore appearsto be diffusion-limited compared to Fe3+ and Al 3+. These results show how the polymer architecture can be tuned to optimizeadsorption efficiency, selectivity, and robustness. Such a design principle of PAMPS-based polyHIPEs demonstrates a strategy tocustomize adsorbents for advanced water treatment applications
Protection of product appearances assisted or generated by artificial intelligence
Get PDFVpliv vse večje razširjenosti tehnologije umetne inteligence se odraža na številnih pravnih področjih, med drugim tudi na področju modelov, ki predstavljajo eno od pravic intelektualne lastnine, s katerimi se varuje videz izdelka. Umetna inteligenca je lahko v proces oblikovanja videza izdelka vključena kot orodje, lahko pa je tudi neodvisni oblikovalec videza izdelka. Kadar se uporablja zgolj kot orodje, rezultat oblikovanja nazivamo kot videz izdelka, ustvarjen s pomočjo umetne inteligence, medtem ko tisti, ki ga umetna inteligenca samostojno razvije, nazivamo kot videz izdelka, ustvarjen z umetno inteligenco. To poglavje izpostavlja pravna vprašanja glede umetne inteligence kot oblikovalca videza izdelka oziroma kot imetnika modela. Nadalje obravnava možnosti varstva tistega videza izdelka, ki je ustvarjen z umetno inteligenco ali njeno pomočjo, ter t. i. vhodne in izhodne kršitve obstoječih modelov z videzi izdelkov, ustvarjenih z umetno inteligenco ali njeno pomočjo.The impact of the increasing prevalence of artificial intelligence technology is reflected in many legal areas, including the field of designs, which represents one of the intellectual property rights that protect the appearance of a product. Artificial intelligence can be included in the design process as a tool, or it can be an independent designer. When used solely as a tool, the result is called an artificial intelligence-assisted design, while the one that artificial intelligence independently develops is called an artificial intelligence-generated design. This chapter highlights legal issues regarding the possibility of artificial intelligence acting as a designer or as a holder of a design. It further discusses the possibilities of protecting the appearance of a product created by or with the help of artificial intelligence, as well as the so-called input and output infringements of existing designs with product appearances created by or with the help of artificial intelligence