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2. Comprehensive analysis of different coating materials on the POM substrateTonica Bončina, Srečko Glodež, Brigita Polanec, Lara Hočuršćak, Franc Zupanič, 2023, original scientific article Abstract: This study presents a comprehensive analysis of different coating materials on the POM substrate. Specifically, it investigated physical vapour deposition (PVD) coatings of aluminium (Al), chromium (Cr), and chromium nitride (CrN) of three various thicknesses. The deposition of Al was accomplished through a three-step process, particularly plasma activation, metallisation of Al by magnetron sputtering, and plasma polymerisation. The deposition of Cr was attained using the magnetron sputtering technique in a single step. For the deposition of CrN, a two-step process was employed. The first step involved the metallisation of Cr using magnetron sputtering, while the second step involved the vapour deposition of CrN, obtained through the reactive metallisation of Cr and nitrogen using magnetron sputtering. The focus of the research was to conduct comprehensive indentation tests to obtain the surface hardness of the analysed multilayer coatings, SEM analyses to examine surface morphology, and thorough adhesion analyses between the POM substrate and the appropriate PVD coating. Keywords: POM, PVD coating, metal coating, adhesion analyses, indentation tests Published in DKUM: 15.02.2024; Views: 304; Downloads: 37
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3. Wear Behaviour of Multilayer Al-PVD-Coated Polymer GearsTonica Bončina, Brigita Polanec, Franc Zupanič, Srečko Glodež, 2022, original scientific article Abstract: A comprehensive experimental investigation of the wear behaviour of coated spur polymer gears made of POM is performed in this study. Three different thicknesses of aluminium (Al) coatings were investigated and deposited by the Physical Vapour Deposition (PVD) process. The Al coating was deposited in three steps: By plasma activation, metallisation of the aluminium by the magnetron sputtering process, and plasma polymerisation. The wear of the gears was tested on an in-house developed testing rig for different torques (16, 20, and 24 Nm) and a rotational speed of 1000 rpm. The duration of the experiments was set to 13 h, when the tooth thickness and, consequently, the wear of the tooth flank were recorded. The experimental results showed that the influence of metallisation with aluminium surface coatings on the wear behaviour of the analysed polymer gear is not significantly important. The results also showed that the gears with a thicker aluminium coating showed greater wear than gears with a thinner coating or even without a coating. This is probably due to the fact that the aluminium particles that started to deviate during gear operation represented the abrasive material, which led to the faster wear of the contacting surfaces of the meshing gear flanks. Keywords: polymer gears, aluminium PVD coating, Physical Vapour Deposition process, multilayer coating, wear Published in DKUM: 15.11.2022; Views: 580; Downloads: 80
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4. Education of proper waste management based on non-formal and informal educationBrigita Polanec, Srečko Glodež, Boris Aberšek, 2012, original scientific article Abstract: The present work gives methods on how available information can be presented to as many people as possible in a way that will allow them to assimilate that knowledge. The most appropriate forms of education for the concrete target group are included in informal education. Informal education is divided into informal general education and informal education for the profession or for the professional work. The fact, regarding the method of giving information, has to be considered that people differ from each other, and in accordance with this, it makes a difference as to how they perceive certain information. Regarding this, the forms and methods of education have to be adapted to different types of people. Elements such as people's levels of concentration, motivation, non-linear receipt of information, stability of information and obtaining of knowledge are looked at more closely. The rapid development of science and new technology brings with it many opportunities for those who are learning on the one hand, and for those who are working on programs for education on the other hand. Information technology has also led to the development of various educational methods; one of them is the method of e-learning. This paper will discuss the mechanism of informal education called microtraining. The concept of micro training provides information in short bursts (about 15 to 20 minutes long), concisely and in an interesting way. Knowledge has become the main product of micro training in specific fields. Keywords: informal education, e-learning, microtraining Published in DKUM: 15.12.2017; Views: 1255; Downloads: 150
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5. Postopki priprave za proizvodnjo trdnih goriv iz nenevarnih odpadkovJanez Ekart, Niko Samec, Filip Kokalj, Brigita Polanec, 2013, original scientific article Abstract: Namen raziskovalnega dela v predstavljenem članku je bil z matematičnim modelom poiskati rešitev za pripravo trdnih goriv iz nenevarnih odpadkov, ki se lahko predelajo v trdno gorivo v skladu z veljavno nacionalno zakonodajo. Nenevarni odpadki so definirani z DIREKTIVO 2008/98/ES Evropskega parlamenta in Evropskega sveta (19. 11. 2008) - Priloga III1. Z uporabo matematičnega modela in njegovim orodjem občutljivosti, vezanim na posamezne lastnosti vhodnih odpadnih materialov, smo iz razpoložljivih odpadnih materialov z znanimi parametri njihovega organskega in anorganskega dela poiskali rešitev za njihovo najbolj optimalno izrabo. Iz razpoložljivih odpadnih materialov smo v maksimalnem masnem deležu pripravili zahtevano trdno gorivo z vsemi potrebnimi kakovostnimi lastnostmi z najvišjim mogočim kakovostnim razredom in iz preostanka razpoložljivih masnih tokov ostanek trdnega goriva slabše kakovosti, ki ga pa še vedno lahko plasiramo na trgu z možnostjo sosežiga v cementarnah ali sežigalnicah odpadkov. Pri ugotavljanju kakovosti nenevarnih odpadkov in trdnega goriva je bilo pomembno njihovo pravilno vzorčenje, ki se je izražalo v stopnji homogenizacije vzorcev, ki imajo vsak zase svoje kemijske, fizikalne in energijske lastnosti. Analiza kovinskega dela nenevarnih odpadkov je bila pomembna zaradi podatkov o pričakovanih emisijskih vrednostih v dimnih plinih, letečem pepelu, pepelu in žlindri, ki nastane pri sosežigu trdnega goriva v kurilni napravi. Analiza nekovinskega dela nenevarnih odpadkov je bila pomembna z vidika energijske vrednosti trdnega goriva in tehnoloških ter okoljskih posledic. Rezultati raziskovalnega dela so pokazali, da je mogoče iz razpoložljivih nenevarnih odpadkov doseči sorazmerno majhen masni delež visokokakovostnega trdnega goriva iz odpadkov glede na celotno razpoložljivo maso odpadkov, ki je sedaj v Sloveniji. Keywords: nenevarni odpadki, trdno gorivo, kurilna vrednost, matematični model, razred trdnega goriva Published in DKUM: 10.07.2015; Views: 1741; Downloads: 184
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6. Model za sortiranje odpadkov pri proizvodnji trdnih gorivBrigita Polanec, 2013, doctoral dissertation Abstract: V tej doktorski disertaciji obravnavamo sledeče probleme iz področja gospodarjenja z odpadki: proizvodnja alternativnega trdnega goriva iz nenevarnih odpadkov, razvoj matematičnega modela, idejna zasnova pilotne naprave za proizvodnjo trdnega alternativnega goriva in ozaveščenosti ljudi o pravilnem ravnanju z odpadki. Politika ravnanja z odpadki je v Evropski uniji urejena s hierarhično lestvico ravnanja z odpadki. Ta sistem daje poudarek na preprečevanje nastajanja odpadkov, sledijo priprava odpadkov za ponovno uporabo, recikliranje, energetska izraba in nazadnje odlaganje. Proizvodnja trdnih goriv iz nenevarnih odpadkov je v EU vedno bolj uveljavljena in tudi v Sloveniji pridobiva vedno večji pomen.
V obsegu naših raziskav za proizvodnjo trdnih goriv iz nenevarnih odpadkov je razvit matematični model za pripravo različnih vzorcev trdnega goriva, s katerim lahko poljubno spreminjamo kakovost trdnega goriva v smislu njegovih energijskih, kemijskih in fizikalnih lastnostih. Matematični model je osnova za določitev približne kakovosti trdnega goriva in s tem tudi razreda v katerega je uvrščeno gorivo. Vzorci za gorivo so pripravljeni na tehnološki liniji za obdelavo komunalnih in industrijskih odpadkov in laboratorijsko analizirani. Namen proizvodnje kvalitetnega SRF je: (a) pridobiti gorivo, za katerega v prihodnosti ne bomo več govorili kot o odpadku, ampak produktu, v ta namen je bil podan tudi predlog za standardizacijo trdnih alternativnih goriv iz nenevarnih odpadkov v Sloveniji; (b) zmanjšati negativne vplive na okolje in s tem posredno na ljudi in druge žive organizme; (c) zmanjšati porabo fosilnih goriv; (d) zmanjšati korozijo, ki nastaja pri uporabi goriva z večjo vsebnostjo klora in s tem posredno zmanjšati stroške čiščenja; (e) zmanjšati stroške odvoza in deponiranja pepela/ostanka po sežigu. Glavni problem prekomerne količine odloženih odpadkov na odlagališčih je v zavesti ljudi o ravnanju z odpadki. V petem poglavju je izdelana analiza stanja poznavanja področja ravnanja z odpadki, na osnovi katere bo potrebno razviti izobraževalni koncept, ki bo dvignil ozaveščenost ljudi. Keywords: Gospodarjenje z odpadki, trdno alternativno gorivo, proizvodnja trdnih alternativnih goriv, matematični model, neformalno izobraževanje, osveščenost. Published in DKUM: 30.01.2014; Views: 2643; Downloads: 285
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7. LEIBNIZ-NEWTONOVA FORMULABrigita Polanec, 2009, undergraduate thesis Abstract: V diplomskem delu predstavimo Leibniz-Newtonovo formulo. V prvem delu so definirani osnovni pojmi, ki jih potrebujemo za nadaljnjo razlago. V nadaljevanju so predstavljeni
izreki integralskega računa. V zadnjem delu diplomskega dela je podan življenjepis obeh matematikov in zgodovinski opis odkritja Leibniz-Newtonove formule, kakor tudi razlike
in podobnosti v razvoju.
Zaključimo lahko, da sta Leibniz in Newton razvila pomemben matematičen rezultat, s katerim nam je omogočeno, da hitreje in enostavneje izračunamo vrednost določenega
integrala. Njuno odkritje pa je pripomoglo tudi k nadaljnjim, novim rezultatom v matematiki. Keywords: Matematika, Leibniz-Newtonova formula, nedoločeni integral, določeni integral, osnovni
izrek analize. Published in DKUM: 17.06.2009; Views: 4511; Downloads: 279
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