1. Comparison study of four commercial SARS-CoV-2-rapid antigen tests : characterisation of the individual componentsŽiga Jelen, Ivan Anžel, Rebeka Rudolf, 2022, original scientific article Abstract: During the corona virus (COVID-19) pandemic, there was a sharp increase in the need for diagnostic tests that could detect the presence of SARS-CoV-2 virus or its antibodies quickly and reliably. An important type in the group of diagnostic tests are rapid antigen lateral flow immuno-assay (LFIA) tests, which operate on the immuno-chromatographic principle with the lateral flow of analyte. Clinical practice in the last year has shown that such diagnostic tests can be effective in preventing the spread of the SARS-CoV-2 virus.The development, and, thus, the production of the rapid antigen LFIA tests, is influenced by a number of factors that determine their sensitivity and accuracy indirectly. These factors are directly dependent on the type of antibody produced, which is formed as an immune response when infected with the virus. The production of the rapid antigen LFIA tests is associated with the appropriate selection of basic components that determine the type and quality of these tests. The basic components include: substrates and membranes, antigens, antibody labels and compatible buffers. The correct choice of membranes and their materials is crucial to compiling an effective rapid antigen LFIA test. This study therefore presents a comparative analysis of four commercially available SARS-CoV-2-rapid LFIA tests using state-of-the-art characterisation techniques scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectrometry (ICP-OES), environmental scanning electron microscope / energy-dispersive X-ray spectroscopy (ESEM/EDX), Fourier-transform infrared spectroscopy / attenuated total reflection (FTIR/ATR) for the individual components. The obtained results were the starting point for the development and assembling of our own rapid antigen LFIA test based on gold nanoparticles as antibody labels.
Keywords: hitri antigenski testi, komponente, karakterizacija, analize, rapid antigen test, components, characterisation, analysis
Published in DKUM: 26.03.2025; Views: 0; Downloads: 3
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2. Modeling of tensile test results for low alloy steels by linear regression and genetic programming taking into account the non-metallic inclusionsMiha Kovačič, Uroš Župerl, 2022, original scientific article Abstract: Štore Steel Ltd. is one of the biggest flat spring steel producers in Europe. The main
motive for this study was to study the influences of non-metallic inclusions on mechanical properties
obtained by tensile testing. From January 2016 to December 2021, all available tensile strength data
(472 cases–472 test pieces) of 17 low alloy steel grades, which were ordered and used by the final
user in rolled condition, were gathered. Based on the geometry of rolled bars, selected chemical
composition, and average size of worst fields non-metallic inclusions (sulfur, silicate, aluminium
and globular oxides), determined based on ASTM E45, several models for tensile strength, yield
strength, percentage elongation, and percentage reduction area were obtained using linear regression
and genetic programming. Based on modeling results in the period from January 2022 to April 2022,
five successively cast batches of 30MnVS6 were produced with a statistically significant reduction
of content of silicon (t-test, p < 0.05). The content of silicate type of inclusions, yield, and tensile
strength also changed statistically significantly (t-test, p < 0.05). The average yield and tensile strength
increased from 458.5 MPa to 525.4 MPa and from 672.7 MPa to 754.0 MPa, respectively. It is necessary
to emphasize that there were no statistically significant changes in other monitored parameters.
Keywords: mechanical properties, tensile test, tensile strength, yield strength, percentage elongation, percentage reduction area, low alloy steel, modeling, linear regression, genetic programming, industrial study, steel making, optimization
Published in DKUM: 24.03.2025; Views: 0; Downloads: 2
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3. Study on the compression effect of clothing on the physiological response of the athleteMarianna Halász, Jelka Geršak, Péter Bakonyi, Gabriella Oroszlány, András Koleszár, Orsolya Nagyné Szabó, 2022, original scientific article Abstract: The study aimed to analyze whether the high compression of unique, tight-fitting sportswear
influences the clothing physiology comfort of the athlete. Three specific sportswear with different
compression were tested on four subjects while they were running on a treadmill with increasing
intensity. The compression effect of the sportswear on the body of the test persons, the temperature
distribution of the subjects, and the intensity of their perspiration during running were determined.
The results indicate that the compression effect exerted by the garments significantly influences the
clothing physiology comfort of the athlete; a higher compression load leads to more intense sweating
and higher skin temperature.
Keywords: clothing physiology, tight-fitting sportswear, running test on a treadmill, thermal comfort, skin temperature, perspiration
Published in DKUM: 21.03.2025; Views: 0; Downloads: 2
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4. The international energy security risk index in sustainable energy and economy transition decision making - a reliability analysisIztok Podbregar, Goran Šimić, Mirjana Radovanović, Sanja Filipović, Damjan Maletič, Polona Šprajc, 2020, original scientific article Abstract: The world economy and society are in a complex process of transition characterized by a high degree of uncertainty. Therefore, further development and management of the transition will largely depend on the quality of the decisions made and, accordingly, on the decision-making process itself. The main goal of this study is to analyze the reliability of International Energy Security Risk Index as a tool to support the process of energy and economy transition decision making, as closely related and highly interdependent phenomena. The index is composed of 29 aggregated variables (grouped into eight categories), and the research is conducted on a research sample of 25 countries over a period of 36 years. The reliability assessment is performed by using Multiple Regression Analysis. Multicollinearity test, plus Multicollinearity test with Variance Inflation Factors, is used for methodological verification. The test results indicate a high degree of unreliability of the Index, as is concluded based on the observed errors in its methodological settings. These errors primarily relate to a high degree of multicollinearity in all 29 variables, whereby independent variables lose their independence and thus jeopardize reliability of the total Index. Out of the eight groups of variables, the fuel imports group is the only one that does not show big methodological errors. The paper presents a recommendation for the improvement of the observed Index (review of the role of individual variables found to be particularly methodologically indicative), as well as a recommendation for different distribution of weighting coefficients.
Keywords: energy and economy transition, decision making, international energy security risk index, multiple regression analysis, multicollinearity test, multicollinearity test with variance inflation factors
Published in DKUM: 04.02.2025; Views: 0; Downloads: 7
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5. Micelarne strukture za stabilizacijo terapevtskih encimov : diplomsko delo visokošolskega strokovnega študijskega programa I. stopnjeAnja Zirdum, 2024, undergraduate thesis Abstract: Encimi so biološke molekule, sestavljene iz enega ali več polipeptidnih verig, ki se zvijejo v specifične tridimenzionalne oblike. Njihova specifična tridimenzionalna struktura omogoča vezavo substratov na aktivna mesta, kjer se izvajajo katalitične reakcije. Specifičnost encimov izhaja iz natančnega prileganja med encimom in substratom, kar pogosto opisujemo s pojmom "ključ-ključavnica". Vsak encim je tako usmerjen k določenemu substratu ali vrsti reakcije, kar omogoča visoko stopnjo regulacije in učinkovitosti v bioloških sistemih. Veliko prednost predstavlja imobilizacija encimov na trdne nosilce, kar omogoča njihovo ponovno uporabo in izboljša stabilnost ter učinkovitost encima. Uporaba imobiliziranih encimov je zaradi lažjega ločevanja od reakcijskih zmesi in posledično nižjih stroškov procesa vse bolj zaželena v industrijskih in biotehnoloških panogah. Encim transglutaminaza (TGM) se uporablja v različnih panogah, veliko vlogo ima predvsem v medicini in živilski panogi, kjer ga pogosto uporabljajo za izboljšanje teksture mesa, mlečnih izdelkov in drugih prehrambenih izdelkov.
Diplomsko delo najprej zajema proizvodnjo micelarnih struktur z gojenjem medicinske gobe Ganoderma lucidum v tekočem hranilnem mediju s sladnim in kvasnim ekstraktom pri 28 °C pri statičnih pogojih. Za tvorbo micelarnih struktur je bilo potrebno gojiti G. lucidum 14 dni. Povprečna debelina micelarnih struktur je bila 0,493 mm, povprečna masa pa 3,961 g. Proizvedene micelarne strukture so izkazale visoko sposobnost absorbiranja vode z doseženim odstotkom nabrekanja po 24 h 579,3 %. S FTIR analizo smo potrdili prisotnost proteinov, lipidov in polisaharidov, s SEM analizo pa prisotnost por in hif v micelarnih strukturah. Povprečni premer por je znašal 40 µm, povprečni premer hif pa 425 nm.
V nadaljevanju študije smo izvedli stabilizacijo terapevtskega encima TGM z imobilizacijo na sintetizirane micelarne strukture z metodo adsorpcije in določili učinkovitost in zmogljivost ujetja encima. Najvišja učinkovitost imobilizacije TGM v micelarne strukture je znašala 41,98 % , kar ustreza masi vgrajenega encima 8,97 g. S študijo sproščanja smo ugotovili, da se je encim uspešno adosrbiral, saj se encim niti po 24 h ni sprostil iz micelarnih struktur. Najverjetneje je adsorbirana TGM v micelarne strukture katalizirala tvorbo kavalentnih vezi med proteini in je prišlo do zamreženja TGM v notranjosti micelarnih struktur, ki vsebuje tudi proteine. Zato smo proučili potek encimske reakcije z imobiliziranim encimom v micelarne strukture pri različnih koncentracijah substrata in kinetiko imobiliziranega encima primerjali s kinetiko prostega encima. Določili smo kinetična parametra, kot sta Michaelis-Mentenova konstanta (KM) in maksimalna reakcijska hitrost (vmax) za prostiin imobilizirani encim z Lineweaver-Burkovim diagramom. Pri tem smo ugotovili, da ima sicer imobiliziran encim slabšo afiniteto do substrata kot prosti encim, zaradi višje izračunane vrednosti KM in nižje vmax.
Sledilo je proučevanje vpliva mase ujetega encima na potek encimske reakcije v odvisnosti od časa. Ugotovili smo, da z naraščanjem mase imobiliziranega encima, reakcija, torej pretvorba substrata v produkt, poteka hitreje. Pri najvišji možni ujeti masi encima (8,97 mg ) v micelarne strukture smo dosegli plato, saj ni bilo zaznati signifikantnih razlik med profilom poteka encimske reakcije med 8,97 mg (13 mg/mL) in 8,76 mg ujetega encima (10 mg/mL).
Imobilizacija encima na trdni nosilec je primerna za številne aplikacije. Z uspešno imobilizacijo encima TGM v micelarne strukture medicinske gobe G. lucidum, smo pripravilli stabilen funkcionalizirani naravni biokompozit, ki se lahko uporabi za različne biomedicinske aplikacije, predvsem za celjenje ran.
Keywords: Ganoderma lucidum, micelarne strukture, encimi, transglutaminaza, imobilizacija, encimski test
Published in DKUM: 26.09.2024; Views: 0; Downloads: 15
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6. Analiza bralne pismenosti in spremljajočih dejavnikov pri 15-letnikih v mariborskih srednjih šolah : magistrsko deloKatarina Grosek, 2024, master's thesis Abstract: Temeljni namen magistrskega dela je bil ugotoviti, kakšno je stanje bralne pismenosti in spremljajočih dejavnikov učne uspešnosti pri 15-letnikih v mariborskih srednjih šolah. V teoretičnem delu naštejemo in opišemo mednarodno primerljive raziskave o znanju in dosežkih učencev ter opredelimo merske značilnosti vprašalnikov in testov znanja. Osredotočimo se tudi na spremljajoče dejavnike učne uspešnosti, in sicer odnos s starši in učitelji, počutje v šoli in zadovoljstvo z življenjem. Nato podrobneje opredelimo bralno pismenost, tako da naštejemo in predstavimo njene gradnike. Empirični del temelji na kvantitativnem pristopu, v okviru katerega so dijaki šestih mariborskih srednjih šol reševali test znanja bralne pismenosti, in kvalitativnem pristopu, v okviru katerega smo opravili polstrukturirane intervjuje s petimi učitelji slovenščine na mariborskih srednjih šolah. Kombinacija obeh pristopov nam je omogočila, da bolje razumemo rezultate testa bralne pismenosti, hkrati pa smo z intervjuji dobili vpogled v mnenja, ki jih s kvantitativnim pristopom nismo mogli dobiti, saj tako pridobljene informacije dopolnjujejo in nadgrajujejo kvantitativne ugotovitve. Rezultati so pokazali, da je naš sklop vprašanj v primerjavi s tistim iz predraziskave PISA z vidika veljavnosti podrobnejši, saj zajema več različnih taksonomskih stopenj in gradnikov bralne pismenosti. Ugotovili smo še, da so 15-letniki večinoma zadovoljni s svojim življenjem in se v šoli dobro počutijo, dejavnika odnos s starši in počutje v šoli pa sta povezana z rezultati bralne pismenosti.
Keywords: bralna pismenost, spremljajoči dejavniki, srednja šola, gradniki, test znanja
Published in DKUM: 11.09.2024; Views: 52; Downloads: 75
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7. Suitability of test procedures for determining the compatibility of seal materials with ionic hydraulic fluidsDarko Lovrec, Vito Tič, 2024, original scientific article Abstract: The compatibility of seal materials with the working fluid is crucial for the flawless, energysaving, environmentally sustainable, and safe operation of any technical system. This is especially
true for hydraulic systems operating under high operating pressure. The problem of materials
compatibility comes into play when either a new type of seal material or a new type of fluid comes
into use. The paper discusses the research findings regarding material compatibility testing of new
high-tech ionic hydraulic fluids with commonly used seal materials. Due to the completely different
chemical composition of these new fluids compared to the classical mineral-based oil, for these fluids,
there are no standardized testing procedures. In these cases, we can only lean on the Standards
that apply to classical fluids, which can lead to incorrect results. In the forefront of the paper is the
discrepancy between the results obtained by the standardized test, and the test under real operating
conditions. FKM, an excellent material for seals, proved to be the most suitable in the case of using
ionic hydraulic fluid, according to a standardized test. However, it failed in the comparison test
under real operating conditions, as the cylinder leaked. NBR seals proved to be a better solution.
Keywords: ionic hydraulic fluids, seal material compatibility, static and dynamic test, comparison of results, differences, test suitability
Published in DKUM: 10.09.2024; Views: 59; Downloads: 33
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8. Spodbujanje razvoja ritmičnih sposobnosti učencev 1. razreda osnovne šole : magistrsko deloSara Šiftar, 2024, master's thesis Abstract: Magistrsko delo je razdeljeno na teoretični in empirični del. Teoretični del obravnava strokovne izsledke s področja glasbenih (ritmičnih) sposobnosti: njihov razvoj, Gordonov test Osnovne mere glasbene avdiacije (tudi za merjenje ritmičnih sposobnosti) ter dejavnosti, ki spodbujajo ritmični razvoj. V empiričnem delu predstavimo raziskavo, v kateri je sodelovalo 16 učencev prvega razreda izbrane osnovne šole. Njen namen je bil ugotoviti stopnjo razvitosti ritmičnih sposobnosti pri učencih pred in po izvedbi glasbenih delavnic ter ugotoviti, ali bodo vpeljane ritmične dejavnosti prispevale k boljšim ritmičnim sposobnostim učencev ter pri tem opazovati njihove odzive na dejavnosti. Za testiranje stopnje razvitosti ritmičnih sposobnosti pred in po izvedbi delavnic smo uporabili Gordonov test Osnovne mere glasbene avdiacije. Na osnovi dosedanjih znanstvenih spoznanj smo načrtovali in izvedli 10 glasbenih delavnic z dejavnostmi, ki spodbujajo razvoj ritmičnih sposobnosti. Pri analizi rezultatov smo ugotovili, da so učenci po izvedbi delavnic imeli povprečno nekoliko boljši rezultat na testu, ki pa ni bil statistično značilen. Ugotovili smo, da pri nobenem testiranju ni bilo razlik med dosežki dečkov in deklic ter da sta učenca, ki sta obiskovala glasbeno pripravnico, imela v obeh primerih slabše rezultate kot ostali učenci. Pri sprotnem spremljanju delavnic smo opazili, da so učenci pokazali napredek v ritmičnih sposobnostih.
Keywords: Razvoj ritmičnih sposobnosti, Gordonov test Osnovne mere glasbene avdiacije, dejavnosti za spodbujanje ritmičnega razvoja
Published in DKUM: 21.08.2024; Views: 104; Downloads: 53
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9. Critical review of the use of the Rorschach in European courtsIgor Areh, Fanny Verkampt, Alfred Allan, 2022, original scientific article Abstract: In relation to the admissibility of evidence obtained using projective personality tests arose in F v. Bevándorlási és Állampolgársági Hivatam (2018). The Court of Justice of the European Union has held that an expert's report can only be accepted if it is based on the international scientific community's standards, but has refrained from stipulating what these standards are. It appears timely for European psychologists to decide what standards should be applied to determine whether or not a test is appropriate for psycholegal use. We propose standards and then apply them to the Rorschach because it was used in this case and is an exemplar of projective tests. We conclude that the Rorschach does not meet the proposed standards and that psychologists should abstain from using it in legal proceedings even in the absence of a clear judicial prohibition.
Keywords: psychology, law, forensic assessment, courts, professional standard, ethics, evidential value, acceptability, projective test, Rorschach
Published in DKUM: 06.08.2024; Views: 87; Downloads: 12
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10. Vloga gozdnega vrtca pri motoričnem razvoju otrok, starih 2-3 letaKaja Hovnik, 2024, undergraduate thesis Abstract: Diplomsko delo z naslovom Vloga gozdnega vrtca pri motoričnem razvoju 2–3 leta starih otrok je sestavljena iz dveh delov. Prvi del je teoretični, kjer smo predstavili dejavnike, ki vplivajo na motorični razvoj in kako se spremlja motoričen razvoj otrok. Predstavili smo program gozdnega vrtca, kaj je njegova vloga, ter Denverski razvojni presejalni test. Na koncu teoretičnega dela smo omenili in predstavili tudi dosedanje raziskave, ki so bile ugotovljene na podlagi dobrih praks s sodelovanjem gozdnega vrtca. Drugi del predstavlja empirično raziskavo, kjer smo ugotavljali razliko v motoričnem razvoju med dvema vrtcema – Vrtec Ravne na Koroškem, ki izvaja program gozdnega vrtca, in Vrtec Otona Župančiča Maribor, ki tega programa ne izvaja. Uporabili smo neslučajnostni vzorec iz konkretne populacije 2–3 leta starih otrok. Na podlagi rezultatov, pridobljenih s pomočjo Denverskega razvojno presejalnega testa, smo ugotovili, da otroci, ki so vključeni v program gozdnega vrtca, dosegajo boljše rezultate Denverskega presejalnega testa kot otroci, ki v program gozdnega vrtca niso vključeni.
Keywords: Motorični razvoj otroka, Gozdni vrtec, Denverski razvojni presejalni test
Published in DKUM: 05.08.2024; Views: 116; Downloads: 78
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