Croatian Digital Thesis Repository
Not a member yet
259189 research outputs found
Sort by
Determination of fracture toughness of adhesive bonds
No full textOvaj rad bavi se eksperimentalnim određivanjem energije loma ljepila putem DCB testa te rekreiranjem izvedenog testa u numeričkom modelu. U početnim poglavljima dan je teorijski pregled ljepila, njihovih primjena u autoindustriji, standardiziranih testova za stvaranje materijalne kartice ljepila, kao i kohezivnih elemenata u programu Abaqus u kojem se radio numerički model. Nakon toga je dan pregled eksperimentalno provedenog DCB testa u kojem se opisala procedura testiranja i analizirali dobiveni rezultati. Naposlijetku, zadnje poglavlje bavi se numeričkim modelom u kojem je cilj što je preciznije moguće rekreirati eksperimentalno dobivene rezultate.This thesis deals with determining the fracture energy of an adhesive experimentally by DCB test and recreating the experiment in numerical model. Opening chapters describe the theoretical overview of adhesives, adhesives’ application in automotive industry, standardized tests for creating material cards of adhesives, as well as an overview of cohesive elements in Abaqus software in which numerical model was made. After that, an overview of an experimentally carried out DCB test is provided, along with the test procedure and results analysis. Finally, the last chapter concerns the numerical model with the goal of recreating experimentally obtained results as precise as possible
The effect of propolis extract on the corrosion behavior of Ti and Ti-6Al-4V alloy in simulated oral cavity conditions : diploma thesis
No full textTitanij i njegove legure su, zbog biokompatibilnosti i visoke otpornosti na koroziju, standardni materijali za izradu dentalnih implantata. Korozijska otpornost ovih materijala povezana je s prisutnošću zaštitnog oksidnog sloja na površini. Međutim, tijekom upale nastaju različiti reaktivni spojevi kisika koji mogu oštetiti pasivni oksidni sloj što rezultira degradacijom titanijevih implantata. Jedna od često primjenjivanih metoda zaštite metala od korozije je zaštita metala inhibitorima korozije. U ovom radu istraživan utjecaj etanolnog ekstrakta propolisa na korozijsko ponašanje titanijevih biomaterijala (Ti i Ti-6Al-4V) u simuliranim uvjetima usne šupljine bez upale, s blažom ili s težom upalom. Ispitivanja su provedena elektrokemijskim metodama (metoda mjerenja potencijala otvorenog strujnog kruga, metoda linearne polarizacije i potenciodinamička polarizacijska metoda), a površine uzoraka analizirane su optičkim mikroskopom. Dobiveni rezultati pokazuju kako etanolni ekstrakt propolisa inhibira koroziju Ti u simuliranim uvjetima usne šupljine bez upale i s blažom upalom, a u simuliranim uvjetima usne šupljine s težom upalom etanolni ekstrakt propolisa potiče koroziju Ti. Etanolni ekstrakt propolisa inhibira koroziju Ti-6Al-4V legure u simuliranim uvjetima usne šupljine bez upale i s upalom. Inhibitorska djelotvornost etanolnog ekstrakta propolisa je najveća za Ti-6Al-4V leguru u simuliranim uvjetima usne šupljine bez upale, a smanjuje se s povećanjem stupnja upale. Rezultati istraživanja ukazuju na mogućnost primjene ispitivanog etanolnog ekstrakta propolisa kao korozijskog inhibitora za zaštitu od korozije Ti i Ti-6Al-4V legure u ispitivanim uvjetima.Titanium and its alloys are commonly used for dental implants prosthetics owing to their high biocompatibility and corrosion resistance. The corrosion resistance of these materials is related to the presence of the protective oxide film on the surface. However, various reactive oxygen species are present during inflammation, which can alter the passive film, resulting in the degradation of the titanium implants. Using corrosion inhibitors is one of the most common methods to prevent corrosion in metal and alloys. This research examined the effect of ethanolic extract of propolis on the corrosion behavior of titanium biomaterials (Ti and Ti-6Al-4V) in simulated oral cavity conditions without inflammation, with moderate or strong inflammation. This study was carried out by electrochemical techniques (open circuit potential measurement, linear polarisation, and potentiodynamic polarisation measurement), while the specimen’s surface was examined using an optical microscope. The results show that in simulated conditions of the oral cavity without and with moderate inflammation, the ethanolic extract of propolis inhibits Ti corrosion. In contrast, in simulated conditions of the oral cavity with strong inflammation, it promotes Ti corrosion. The ethanolic extract of propolis reduces corrosion of Ti-6Al-4V alloy in simulated oral cavity conditions, both without and with inflammation. The maximal inhibitory efficiency of ethanolic extract of propolis was for the Ti-6Al-4V alloy in simulated conditions of the oral cavity without inflammation, but inhibition efficiency decreased as the degree of inflammation increased. The results show that the tested ethanolic extract of propolis can be used as a corrosion inhibitor for the protection of Ti and Ti-6Al-4V alloy under the tested conditions
Development of an application for real-time analysis of lower extremity kinematics in daily activities using smartphone sensors
No full textCilj ovog završnog rada je istražiti mogućnost primjene senzora pametnog telefona za analizu kinematike donjih ekstremiteta tijekom svakodnevnih aktivnosti. U radu se detaljno obrađuju izrazi kinematike krutih tijela, koji su ključni za razumijevanje biomehaničkih aspekata ljudskog pokreta, a analiza podataka prikupljenih iz akcelerometra, giroskopa, magnetometra i GPS senzora omogućuje precizno praćenje gibanja u stvarnom vremenu. Posebna je pažnja posvećena razvoju vlastite aplikacije koja osigurava jednostavno prikupljanje, filtriranje i obradu podataka, pri čemu se istražuje utjecaj različitih parametara mjerenja na konačnu točnost rezultata. Rad je logički podijeljen u tri glavna dijela. U prvom dijelu izlaže se teorijska podloga, koja obuhvaća stručni dio biomehaničke analize i kinematike, s detaljnom obradom matematičkih i fizičkih osnova pokreta. Drugi dio rada posvećen je razvoju same aplikacije i izboru korištenog hardvera (eng. hardware), što omogućuje učinkovito prikupljanje i obradu podataka u stvarnom vremenu. U završnom, eksperimentalnom dijelu, provodi se testiranje razvijenog sustava kroz analizu pokreta poput hodanja, trčanja i drugih aktivnosti, pri čemu se dobiveni rezultati uspoređuju s idealnim slučajem snimljenim u kontroliranim uvjetima, kako bi se potvrdila pouzdanost i preciznost pristupa. Dobiveni rezultati ukazuju na visoku točnost i primjenjivost sustava temeljenog na senzorskim podacima pametnih telefona, čime se otvaraju nove mogućnosti za primjenu u rehabilitaciji, sportu i daljnjim znanstvenim istraživanjima kinematike ljudskog pokreta.The objective of this final thesis is to investigate the possibility of using smartphone sensors
for the analysis of lower extremity kinematics during everyday activities. The paper thoroughly
examines the expressions of rigid body kinematics, which are crucial for understanding the
biomechanical aspects of human motion, and analyses data collected from accelerometers,
gyroscopes, magnetometers, and GPS sensors to enable precise real-time movement tracking.
Particular attention is devoted to the development of a custom application that ensures easy
data collection, filtering, and processing, while also exploring the impact of various
measurement parameters on the final accuracy of the results.
The work is logically divided into three main parts. The first part presents the theoretical
background, covering the technical aspects of biomechanical analysis and kinematics with a
detailed treatment of the mathematical and physical fundamentals of movement. The second
part is dedicated to the development of the application and the selection of the utilized
hardware, which enables efficient real-time data collection and processing. In the final
experimental phase, the developed system is tested through the analysis of movements such as
walking, running, and other activities, with the obtained results compared to an ideal case
recorded under controlled conditions, in order to validate the reliability and accuracy of the
approach.
The results indicate a high level of accuracy and applicability of the system based on
smartphone sensor data, thereby opening new possibilities for applications in rehabilitation,
sports, and further scientific research on human movement kinematics
Isolation and analysis of multiply glycosylated desulfoglucosinolates from selected pland species of the Brassicaceae and Moringaceae families : diploma thesis
No full textU ovom radu analizirani su glukozinolati u biljnim vrstama Hesperis laciniata, Thlaspi perfoliatum (Brassicaceae) i Moringa oleifera (Moringaceae). Glavni cilj bio je izolacija i identifilacija desulfoglukozinolata iz različitih biljnih dijelova primjenom modificirane ISO 9167-1 metode te njihova kvalitativna i kvantitativna analiza korištenjem UHPLC-DAD-MS/MS sustava. Identificirano je ukupno 7 različitih desulfoglukozinolata, uključujući nekoliko do sada nepoznatih spojeva. Najveća koncentracija glukozinolata u H. laciniata utvrĎena je u cvijetu (110,08 µmol/g suhog biljnog materijala), dok je kod T. perfoliatum koncentracija bila najviša u komuščici (97,6 µmol/g). Kod sjemenki M. oleifera, dominantni spoj bio je glukomoringin (221,74 µmol/g). U biljci H. laciniata, najzastupljeniji glukozinolat bio je 4´- O-β-D-apiofuranozilglukomatronalin (69,57 µmol/g suhog biljnog materijala), dok je kod T. perfoliatum dominantni spoj bio 4´-O-(β-D-apiofuranoziloksi)benzil-glukozinolat (53,86 µmol/g). Nadalje, provedena je uspješna izolacija pojedinih glukozinolata korištenjem HPLC-DAD sustava sa sakupljačem frakcija. Iz biljke T. perfoliatum izolirane su tri frakcije: desulfoglukosinalbin, desulfo-apiofuranozilglukomatronalin i desulfo-(apiofuranoziloksi)benzil-glukozinolat. Rezultati ukazuju na specifične razlike u profilu glukozinolata meĎu vrstama, a identificirani spojevi predstavljaju značajan doprinos razumijevanju kemijske raznolikosti unutar porodica Brassicaceae i Moringaceae. Posebno se ističe identifikacija višestruko glikoziliranih glukozinolata, što doprinosi daljnjoj karakterizaciji bioloških i kemijskih svojstava ovih biljaka.In this study glucosinolates from the plant species Hesperis laciniata, Thlaspi perfoliatum (Brassicaceae), and Moringa oleifera (Moringaceae) were analyzed. The main goal was the isolation and identification of desulfoglucosinolates from different plant parts using a modified ISO 9167-1 method, followed by their qualitative and quantitative analysis using the UHPLC-DAD-MS/MS system. A total of seven different desulfoglucosinolates were identified, including several previously unknown compounds. The highest concentration of glucosinolates in H. laciniata was found in the flowers (110.08 µmol/g dry plant material), while in T. perfoliatum, the highest concentration was observed in the siliques (97.6 µmol/g). In the seeds of M. oleifera, the dominant compound was glucomoringin (221.74 µmol/g). In H. laciniata, the most abundant glucosinolate was 4´-O-β-D-apiofuranosylglucomatronalin (69.57 µmol/g dry plant material), whereas in T. perfoliatum, the dominant compound was 4´-O-(β-D- apiofuranosyloxy)benzyl-glucosinolate (53.86 µmol/g). Furthermore, successful isolation of individual glucosinolates was achieved using the HPLC-DAD system with a fraction collector. From T. perfoliatum, three fractions were isolated: desulfoglucosinalbin, desulfo-apiofuranosylglucomatronalin, and desulfo- (apiofuranosyloxy)benzyl-glucosinolate. The results highlight specific differences in glucosinolate profiles among the species studied, and the identified compounds represent a significant contribution to understanding the chemical diversity within the Brassicaceae and Moringaceae families. Notably, the identification of multiply glycosylated glucosinolates advances the characterization of the biological and chemical properties of these plants
Modeliranje i simulacija pogona hibridnog električnog vozila na temelju FIA pravilnika Formule 1 za 2026 godinu
No full textPowertrain simulation plays a crucial role in the vehicle development process, particularly for
high-performance vehicles such as those used in Formula 1. It provides a virtual environment for
developing prototypes, enabling performance assessments without the need for excessive time,
cost, and material investments.
Depending on the regulatory requirements, the high-level powertrain model is created and
evaluated on a simulation of a real-life race event. An industry standard simulation tool GT-SUITE
was used to model and simulate the powertrain model. The model has a strong foundation in
Computational Fluid Dynamics (CFD) and Heat Transfer methods to assess both thermal and
racing performance, as the power output of a hybrid electric vehicle is closely tied to internal
temperatures within the electric components of the powertrain unit.
Simulation results demonstrate that powertrain performance is greatly influenced by thermal
management defined by component design and energy restrictions defined in regulations. Also, it
can be concluded that the new powertrain concept for 2026 season will be sufficiently powerful to
keep the pace with the current generation of cars.Simulacija sustava pogona igra ključnu ulogu u procesu razvoja vozila, osobito za vozila visokih
performansi poput onih koja se koriste u Formuli 1. Ona pruža virtualno okruženje za razvoj
prototipova, omogućujući analizu performansi bez potrebe za velikim ulaganjem vremena, novca
i materijala.
Ovisno o regulatornim zahtjevima, model pogonskog sklopa izrađen je i analiziran na primjeru
simulacije stvarne utrke. Za modeliranje i simulaciju pogonskog sklopa korišten je industrijski
standardni alat GT-SUITE kod kojeg modeli imaju snažno uporište u metodama računalne
dinamike fluida i prijenosa topline. Ove metode omogućuju procjenu termalnih i trkaćih
performansi, budući da je izlazna snaga hibridnog električnog vozila usko povezana s
temperaturama unutar elektroničkih komponenti pogonskog sklopa.
Rezultati simulacije pokazuju da performanse pogonskog sklopa uvelike ovise o temperaturnoj
regulaciji definiranoj dizajnom komponenti i energetskim ograničenjima koja propisuju regulacije.
Također, može se zaključiti da će novi koncept pogonskog sklopa za 2026. godinu biti dovoljno
snažan da drži korak s trenutnom generacijom vozila
Aerodynamic model of a modern fighter aircraft for subsonic speeds
No full textU ovom diplomskom radu razvijen je prošireni aerodinamički model dvomotornog borbenog zrakoplova IR-1, temeljen na konfiguraciji sličnog realnom zrakoplovu Dassault Rafale. Cilj rada bio je izraditi vjerodostojan aerodinamički model za podzvučne režime leta, s naglaskom na definiranje i modeliranje aerodinamičkih gradijenata koji utječu na uzdužno i bočno gibanje letjelice.
Na temelju preuzetih geometrijskih značajki definirani svi ključni aerodinamički parametri i koeficijenti sila i momenata. Model uključuje ovisnosti aerodinamičkih koeficijenata o napadnom kutu, kutu klizanja, kutnim brzinama, otklonima upravljačkih površina te Machovom broju, što predstavlja unaprijeđenje postojećeg modela koji je bio ograničene primjene s obzirom na Machov broj. Metodama projektne aerodinamike izračunate su konkretne vrijednosti gradijenata u pet referentnih točaka Machova broja koje su aproksimirane polinomom za cijelo područje podzvučnih brzina. Obrađeni su stacionarni i nestacionarni gradijenti, kao i metode procjene maksimalnog koeficijenta sile uzgona i brzine sloma uzgona te hvatišta normalne sile.
Razvijeni model omogućuje kvalitetnu simulaciju leta zrakoplova u podzvučnom režimu i pruža temelj za precizno predviđanje ponašanja letjelice u različitim režimima leta. Rezultati ovog rada mogu se koristiti za integraciju u simulacijske sustave te kao podloga za daljnji razvoj simulatora leta.This thesis presents the development of an enhanced aerodynamic model for the twin-engine fighter aircraft IR-1, based on the configuration of the real-world Dassault Rafale. The objective was to create a reliable aerodynamic model for subsonic flight regimes, with a focus on defining and modelling the aerodynamic gradients that influence both longitudinal and lateral aircraft motion.
Using the provided geometric characteristics, all key aerodynamic parameters and force and moment coefficients were defined. The model incorporates dependencies of aerodynamic coefficients on angle of attack, sideslip angle, angular rates, control surface deflections, and Mach number, representing an improvement over the previous model, which was limited in terms of Mach number applicability.
Gradient values were calculated using preliminary aerodynamic methods at five reference Mach numbers and approximated with polynomial functions to cover the entire subsonic speed range. Both steady and unsteady aerodynamic gradients were considered, along with methods for estimating maximum lift coefficient, stall speed, and normal force center location.
The developed model enables accurate flight simulation of the aircraft in subsonic conditions and provides a foundation for predicting aircraft behavior across various flight regimes. The results can be applied in flight simulation systems and serve as a basis for further development of flight simulators
Design of a forwarder body
No full textU ovom radu opisana je konstrukcija nadogradnje forvardera, šumskog vozila namijenjenog transportu posječenih trupaca s mjesta sječe do privremenog šumskog stovarišta. Fokus je stavljen na teretni prostor forvardera nosivosti 10 tona, koji uključuje elemente poput zaštitne pregrade, nosača, štica i njihovih međusobnih spojeva. Razvijeno je nekoliko koncepata nadogradnje, koji su zatim ocijenjeni prema više kriterija. Analizirane su funkcionalne potrebe i u obzir uzete tehničke specifikacije. Na temelju ocjena odabran je najpovoljniji koncept koji je modularan i omogućuje potencijalnu ugradnju specijaliziranih rješenja poput hidrauličke hvataljke za trupce, odnosno clambunka. Koncepti su konstrukcijski razrađeni te su provedeni svi potrebni proračuni u svrhu provjere čvrstoće i krutosti konstrukcije tijekom eksploatacije. Osim toga, dan je i prijedlog konceptualnog rješenja clambunka kao alternativne nadogradnje teretnog prostora forvardera.This paper describes the design of a forwarder body; a forestry vehicle intended for transporting
felled logs from the felling site to a temporary forest depot. The focus is on the forwarder’s 10-
ton payload load space, which includes elements such as the log gate, support frame, stanches,
and their mutual connections. Several upgraded concepts were developed and evaluated based
on multiple criteria. Functional requirements were analyzed, and technical specifications were
considered. Based on the evaluation, the most favorable concept was selected. Selected concept
has modular design that enables the potential integration of specialized solutions such as a
hydraulic log grapple, clambunk. The concepts were structurally elaborated, and all necessary
calculations were carried out to verify the strength and rigidity of the structure during operation.
In addition, a conceptual design of the clambunk was proposed as an alternative upgrade for
the forwarder’s load space
ICP-MS analysis of mineral elements in wines from Konavle, Pelješac, Hvar and Korčula : graduate thesis
No full textU ovom radu provedena je analiza 30 mineralnih elemenata u 107 uzoraka različitih sorti crnog, bijelog i rosé vina s područja Konavla, Pelješca, Hvara i Korčule. Analiza je provedena korištenjem analitičke tehnike masene spektrometrije povezane s induktivno spregnutom plazmom (ICP – MS). Prije same analize izmjerena je pH vrijednost uzoraka. Svaki uzorak je prije ICP - MS analize podvrgnut mirovalnoj digestiji u zatvorenim teflonskim posudama uz korištenje HNO 3 i H 2 O 2 . Od 30 analiziranih elemenata, berilij, kobalt, živa i vanadij nisu detektirani ni u jednom od 107 uzorka, a rezultati za olovo nisu razmatrani. Šest uzoraka pokazalo je koncentraciju bakra iznad dopuštene (1000 μg/L), uz istovremeno povišene, ali dopuštene vrijednosti nikla, kadmija, kositra, željeza i antimona, što sugerira mogući zajednički izvor kontaminacije. Cink je pokazao poveznicu sa željezom i bakrom. Svi ostali elementi su unutar dopuštenih granica, ali esencijalni su većinom prisutni u nižim koncentracijama nego u drugim istraživanjima, vjerojatno zbog tla bogatog CaCO₃ koje smanjuje dostupnost minerala zbog visokog pH.This study analyzed 30 mineral elements in 107 samples of various red, white, and rosé wines from the regions of Konavle, Pelješac, Hvar, and Korčula. The analysis was conducted using inductively coupled plasma mass spectrometry (ICP-MS). Prior to the analysis, the pH value of each sample was measured. Each sample underwent microwave digestion in closed Teflon vessels using HNO₃ and H₂O₂ before ICP-MS analysis. Out of the 30 analyzed elements, beryllium, cobalt, mercury, and vanadium were not detected in any of the 107 samples, and lead results were not considered. Six samples showed copper concentrations above the permitted limit (1000 μg/L), along with elevated but still acceptable levels of nickel, cadmium, tin, iron, and antimony, indicating a possible common source of contamination. Zinc showed a correlation with iron and copper. All other elements were within acceptable limits, but essential elements were mostly found in lower concentrations compared to other studies, likely due to CaCO₃-rich soils in Central and Southern Dalmatia, which increase soil pH and reduce mineral availability
Venturi flow meter for multiphase flows
No full textDvofazno strujanje je učestala pojava u industrijskim primjenama, gdje često postoji potreba za točnim i pouzdanim mjerenjem ukupnog masenog protoka fluida. Venturijevi protokomjeri, eng. Venturi flow meters (VFM), su industrijski standard za mjerenje masenog protoka jednofaznog strujanja jer nisu skupi, pouzdani su i uzrokuju nizak gubitak tlaka i imaju mali utjecaj na protok. Razni autori su razvili korelacije koje koriste zabilježeni pad tlaka u VFM-u za određivanje ukupnog masenog protoka dvofaznog strujanja, no one uvijek zahtijevaju i mjerenje udjela pare u struji, što predstavlja značajnu poteškoću kod industrijske primjene. Na Von Karman Institutu za dinamiku fluida u Belgiji [1] je stoga razvijena nova metoda koja se temelji isključivo na izmjerenom padu tlaka u VFM-u. Metoda zahtijeva detaljno baždarenje te je ispitana na smjesi zraka i vode. Za primjenu metodologije na dvofazno strujanje rashladnog sredstva s niskim potencijalom globalnog zatopljenja eng. Global warming potential (GWP), R1234ze(E), su provedena mjerenja na VFM-u s unutarnjim promjerom ulaza od 10 mm i omjerom ulaza i grla od 0,42, koristeći vlastito razvijen ispitni postav ljevokretnog rashladnog ciklusa s tekućinom i parom. Udio pare u strujanju je u rasponu od 13,3 % do 31,23 %, dok je maseni protok bio između 0,0246 kg/s i 0,0543 kg/s. Na prikupljene su podatke primijenjene poznate korelacije: korelacija homogene pretpostavke, Murdockova, Jamesova, Collinsova, Chisholmova, Smith i Leangova, Linova i Zhangova, te su sve osim homogene pretpostavke, Collinsove i Murdockove korelacije, procijenile ukupni maseni protok s točnosti unutar +/-20 %. Za novo razvijenu metodologiju su izrađene krivulje baždarenja, no podudarnost nije bila zadovoljavajuća za nastavak primjene. Umjesto toga je dan pregled mogućnosti računalne simulacije modeliranja dvofaznog strujanja u VFM-u radi boljeg uvida u fiziku fluida uz preporuke za poboljšanje mjerenja i nove metodologije.Multiphase flows refer to the simultaneous flow of matter in two or more thermodynamic phases. They are a common occurrence in industrial applications, such as the left-hand liquid vapor refrigeration cycles. With growing emphasis on energy savings, efficiency improvement starts with flow characterization, for which mass flow is one of the key values needed. The efficiency of the whole cycle depends on the efficiency of each device that the circuit consists of. In evaporators, their efficiency is greatly influenced by the distribution of the liquid phase inside them, as the thermal coefficient changes with phase by orders of magnitude [2]. Accurately determining the multiphase mass flow proved difficult without phase separation. Mass flow measuring methods that do not rely on phase separation have to determine flow quality to resolve mass flow. Most often this is performed by determining the void fraction and measuring or assuming phases slip ratio. This can be done by various instruments, like the capacitance probe or void fraction meter, but they are expensive, cumbersome, fragile, and still in various development stages, used exclusively for scientific purposes. An elegant solution that could see usage in industrial applications was sought in the use of a venturi flow meter (VFM). Their usage for determining mass flow in homogeneous flow is proven and standardized [3] because it is based on the Bernoulli principle. They are inexpensive, easy to implement, in line with the flow, and have a low impact on it. However, adapting it for multiphase mass flow measurement is a challenge tackled by many authors, as it requires at least one other physical property to be known, it most often being flow quality. On this principle, various authors have proposed different modelling techniques. The viability of this approach for industrial application, therefore, fades as the instrumentation used for determining these physical properties is either still in the development phase, like capacitance probes, or very costly, intrusive, and difficult to implement, as is the case with void fraction meters. Apart from making the summary on different multiphase mass flow measurement techniques, Lecardonel in her work therefore proposed a new method that evades measuring any physical property of the flow apart from the pressure difference in the VFM. The broader scope of her research was on features impacting a two-phase flow distribution in a simplified evaporator. As a part of that experiment setup, the pressure drop was recorded in the VFM placed on the tubes through which the air-water mixture was passing. Then, a new methodology using strong calibration was proposed and tested on a simplified isothermal evaporator model.
The scope of this work includes the implementation of this methodology on the liquid-vapor refrigeration cycle using low GWP refrigerant R1234ze(E). The experimental setup was developed in conjunction with Liebherr as a part of the PANTHER (exPerimental And Numerical mulTiscale mulTiphasic Heat exchanger) project at the von Karman Institute for Fluid Dynamics, Belgium. Also, VFM methods from previous authors are tested on the acquired data, along with an overview of the possibilities of numerical simulations
Digitalization of business by introducing information systems
No full textDigitalizacija poslovanja predstavlja ključni faktor suvremenog poslovnog okruženja, oblikujući način na koji organizacije obavljaju svoje aktivnosti i ostvaruju poslovne ciljeve. Uvođenje informacijskih sustava postaje imperativ kako bi se organizacije uspješno prilagodile dinamičnim promjenama i iskoristile prednosti digitalne transformacije. Tema je bitna i aktualna iz dva aspekta, s jedne strane široj javnosti daje uvid u jednu realnu perspektivu malog poduzeća na putu digitalne transformacije uvođenjem informacijskih sustava sa svim prednostima i manama, kao i preprekama i rješenjima, a s druge strane poduzetnicima prijeko potrebna tematika kako bi i sami naučili neke stvari iz navedenog primjera, spoznali možda kada je trenutak za digitalizaciju njihovog poduzeća i koji put izabrati. Ciljevi sveučilišnog specijalističkog rada su istražiti obilježja informacijskih sustava za optimizaciju procesa poslovanja, identificirati konkretne prednosti koje organizacije mogu ostvariti implementacijom informacijskih sustava, identificirati ključne izazove i prepreke s kojima se organizacije suočavaju tijekom procesa digitalne transformacije, analizirati proces digitalizacije malog poduzeća na primjeru iz prakse te Identificirati ključne čimbenike uspjeha procesa digitalne transformacije malog poduzeća. Metodologija koja će se koristiti u svrhu postizanja postavljenih ciljeva: Istraživanje domaće i strane znanstvene i stručne literature te metoda analize studije slučaja kojom će se na stvarnom primjeru iz prakse analizirati sve faze i koraci digitalne transformacije malog poduzeća. Glavni zaključci rada: Studija konkretnog slučaja pokazuje da je uvođenje ERP sustava i sekundarnog aplikacijskog rješenja po mjeri ključan iskorak jednog poduzeća u digitalizaciji te unatoč svim izazovima koje je poduzeće imalo, pozitivan financijski ishod i unaprijeđena kvaliteta usluge svjedoče o dugoročnoj koristi cjelokupne digitalne transformacije. Uspješno proveden projekt je definitivno stvorio temelje za daljnju digitalnu transformaciju poduzeća.Digitalization of business is a key factor in the modern business environment, shaping the way organizations perform their activities and achieve business goals. The introduction of information systems is becoming imperative in order for organizations to successfully adapt to dynamic changes and take advantage of digital transformation. The topic is important and current from two aspects, on the one hand, it gives the general public an insight into a realistic perspective of a small company on the way to digital transformation by introducing information systems with all the advantages and disadvantages, as well as obstacles and solutions, and on the other hand, it is a topic that entrepreneurs desperately need in order to learn some things from the above example, realizing perhaps when is the moment to digitize their company and which path to choose. The goals of the university specialist paper are to investigate the characteristics of information systems for the optimization of business processes, to identify concrete advantages that organizations can realize by implementing information systems, to identify key challenges and obstacles that organizations face during the digital transformation process, to analyze the digitalization process of a small business using an example from practice, and Identify the key success factors of the digital transformation process of a small business. The methodology that will be used in order to achieve the set goals: Research of domestic and foreign scientific and professional literature and the case study analysis method, which will analyze all phases and steps of the digital transformation of a small company on a real example from practice. The main conclusions of the work: The study of the specific case shows that the introduction of an ERP system and a customized secondary application solution is a key step forward for a company in digitalization, and despite all the challenges the company had, the positive financial outcome and improved quality of service testify long-term benefit of the entire digital transformation. The successfully implemented project definitely created the foundations for further digital transformation of the company