Croatian Digital Thesis Repository
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Ekspresija i pročišćavanje ljudske DNA polimeraze eta u ljudskim stanicama
No full textDNA polymerase eta (POLH) is a translesion synthesis (TLS) polymerase that enables replication across UV-induced DNA lesions. The fat mass and obesity-associated protein (FTO) is an m⁶A demethylase recently linked to the DNA damage response. This thesis aimed to investigate whether FTO physically interacts with POLH and if this interaction is influenced by UV-induced DNA damage. Constructs encoding full-length, N-terminal (catalytic), and C-terminal (non-catalytic) domains of POLH were cloned and expressed in HEK293T cells. A GST-tagged anti-mCherry nanobody was expressed and purified to isolate mCherry-tagged POLH variants via co-immunoprecipitation. Western blotting revealed that FTO co-precipitates with full-length POLH and, upon UV treatment, weakly with the C-terminal domain, suggesting the interaction depends on protein-protein interaction domains. These findings support a novel connection between RNA modifications and TLS, with potential implications for understanding genome maintenance mechanisms.DNA polimeraza eta (POLH) je translezijska polimeraza (TLS) koja omogućuje replikaciju preko UVinduciranih oštećenja DNA. Protein FTO, povezan s pretilošću, je m⁶A demetilaza koja je nedavno povezana s odgovorom na oštećenje DNA. Cilj ovog rada bio je ispitati ostvaruje li FTO fizičku interakciju s POLH i je li ta interakcija uvjetovana UV-induciranim oštećenjem DNA. Konstruirani su plazmidi koji kodiraju za puni, N-terminalni (katalitički) i C-terminalni (nekatalitički) dio POLH, a zatim su eksprimirani u HEK293T stanicama. Za izolaciju mCherry-označenih varijanti POLH proteina, metodom koimunoprecipitacije, anti-mCherry nanotijelo s GST-tagom je eksprimirano i pročišćeno. Western blot analizom pokazano je da FTO koprecipitira s punom duljinom POLH, te prilikom UV zračenja, slabo i sa C-terminalnim dijelom što sugerira da interakcija ovisi o domenama za međuproteinske interakcije. Dobiveni rezultati ukazuju na novu moguću vezu između RNA modifikacije i translezijske sinteze DNA što bi moglo pridonijeti boljem razumijevanju mehanizama očuvanja genomske stabilnosti
Importance of process engineers in automotive industry
No full textKonstantnim i ubrzanim razvojem automobilske industrije kroz uvođenje novih tehnologija i metoda u proizvodnju, procesni inženjeri imaju važniju ulogu nego ikada. Procesni su inženjeri odgovorni za projektiranje, implementaciju, kontrolu i optimizaciju proizvodnih procesa. Oni osiguravaju da svi proizvodi budu proizvedeni na učinkovit i isplativ način, dok su u skladu sa sigurnosnim propisima i standardima kvalitete. Glavni cilj ovog završnog rada je opisati ulogu procesnih inženjera u automobilskoj industriji, fokusirajući se na vitka unapređenja u proizvodnji. Detaljno će biti objašnjen realni primjer implementacije vitkog rješenja redefiniranjem mjerne opreme u procesu sklapanja mjenjačke kutije u poduzeću Rimac Technology. Središte pozornosti bit će na praćenju koraka PDCA metode, izgradnji strukturiranog vremenskog okvira i opravdanju investicije.With the automotive industry constantly and rapidly improving by introducing new technologies and methods in manufacturing, process engineers play a more vital role than ever. Process engineers are responsible for designing, implementing, controlling and optimizing manufacturing processes. They ensure that any products are created in an efficient and cost-effective manner while complying with health and safety regulations and quality standards. The main goal of this bachelor’s thesis is to describe the role of process engineers in automotive industry, mainly focusing on lean improvements in manufacturing. A real example of implementing lean solutions by redefining measuring equipment within Rimac gearbox assembly process will be thoroughly explained. Center of attention will be on following a PDCA method and its steps, building a structured timeline of change and justifying the investment
Indirect cooling system of electric vehicle battery
No full textKako je kupnja električnih automobila posljednjih godina u porastu, sve više pažnje usmjerava
se na poboljšanje njihovih performansi. S obzirom da su performanse vozila kao što su energija,
snaga i velika brzina punjenja moguće samo ukoliko je hlađenje baterije dobro osmišljeno, u
ovom radu analiziran je rashladni sustav baterije. Kod vozila visokih performansi baterija se
hladi s kapljevinom u direktnom ili indirektnom kontaktu, a u ovom radu analiziran je sustav
indirektnog sustava hlađenja. Usmjerila se pažnja na kontaktni otpor između baterije i rashladne
ploče, odnosno ljepilo koje ih drži zajedno. U radu se ispitalo kako prekrivenost ljepila utječe
na prijenos topline – točnije koliko je aksijalni prijenos topline oslabljen ukoliko se ljepilo ne
nanese u dovoljnoj količini na površinu baterije. Ispitivanje je napravljeno za 4 vrste ljepila od
kojih su dva strukturna, a dva su termalna, te su njihovi rezultati međusobno uspoređeni.
Ispitivanje se provodilo na način da se između dviju aluminijskih pločica nanijelo ljepilo u
promjerima od 20 i 80 mm, u debljini od 0,5 mm koja se osigurala postavljanjem mjernih listića
između pločica. Svako ljepilo ispitano je kroz 2 ispitna modela (pokrivenost od 20 i 80 mm) za
koja su korištena po 3 ispitna uzorka. Prijenos topline mjeren je na način da su uzorci stavljeni
na grijač konstante temperature od 60°C mjereći vrijeme u kojem svaki od njih dostigne
ustaljenu temperaturu. Grijač je napravljen pomoću ARDUINO sustava i postavljena mu je PID
regulacija. Prije samog ispitivanja, napravljena je simulacija u Simulinku kako bi se dobili
okvirni rezultati te je opisan matematički model koji je korišten za modeliranje.
Za vrijeme ispitivanja mjerile su se temperatura grijača i gornje pločice te PWM signal u
razmacima od 300 ms, a vrijednosti su im automatski zapisane u Excel tablicu. Obradom tih
podataka dobili su se rezultati koji prikazuju da je prijenos topline svih ljepila značajno bolji
kod uzoraka od 80 mm. Gornja pločica se kod njih zagrijavala puno brže te na više temperature
nego kod uzoraka od 20 mm. Kod uzoraka od 20 mm gornja pločica strukturnih ljepila se
zagrijala na temperaturu od 52°C, dok se kod termalnih ljepila u istom vremenu postigla
temperatura od 55°C. Kod uzoraka od 80 mm strukturna ljepila postigla su temperaturu od
56°C, a termalna 58°C. Tromost ljepila opisana je vremenskom konstantom τ koja daje vrijeme
u kojem se temperatura termopara povisi za 68,3%. Za termalna ljepila prosječan τ kod uzoraka
od 80 mm iznosi 1.34 min, a kod strukturnih je njegova vrijednost 2.00 min. Kod uzoraka od
20 mm vrijednost τ strukturnih ljepila povećala se u prosjeku za 35%, a kod termalnih za 47.5%.As the purchase of electric cars has been on the rise in recent years, more and more attention is
focused on improving their performance. Given that the performance of the vehicle, such as
energy, power, and high charging speed, is possible only if the cooling of the battery is well
thought out, in this paper the cooling system of the battery is analyzed. In high-performance
vehicles, the battery is cooled with liquid in direct or indirect contact, and this paper analyzes
the system of the indirect cooling system. Attention was focused on the contact resistance
between the battery and the cooling plate, the glue that holds them together. The paper examined
how the coverage of the adhesive affects the heat transfer - more precisely, how much the axial
heat transfer is weakened if the adhesive is not applied in sufficient quantity to the surface of
the battery. The test was done for 4 types of glue, two structural and two
thermal, and their results were compared with each other. The test was carried out in such a way
that glue was applied between two aluminum tiles in diameters of 20 and 80 mm, with a thickness
of 0.5 mm, which was ensured by placing measuring sheets between the tiles. Each adhesive
was tested through 2 test models (coverage of 20 and 80 mm), for which 3 test samples were
used. Heat transfer was measured in such a way that the samples were placed on a heater with
a constant temperature of 60°C, measuring the time in which each of them reached the
established temperature. The heater is made using the ARDUINO system and has PID
control. Before the test, a simulation was made in Simulink to obtain preliminary
results, and the mathematical model used for modeling was described.
During the test, the temperature of the heater and the upper plate, and the PWM signal were
measured at intervals of 300 ms, and their values were automatically recorded in an Excel table.
By processing these data, results have shown that the heat transfer of all adhesives
is significantly better with 80 mm samples. In the case of 20 mm samples, the upper plate of
structural adhesives heated up to a temperature of 52°C, while in the case of thermal adhesives,
a temperature of 55°C was reached at the same time. In the case of 80 mm samples, structural
adhesives reached a temperature of 56°C, and thermal 58°C. The inertia of the glue is described
by the time constant τ which gives the time in which the temperature of the thermocouple rises
by 68.3%. For thermal adhesives, the average τ for 80 mm samples is 1.34 min, and for
structural adhesives, its value is 2.00 min. For 20 mm samples, the τ value of structural
adhesives increased by 35% on average, and for thermal adhesives 47.5%
Seismic Analysis of Reinforced Masonry Historic Towers by Finite-Discrete Element Method : Master's Thesis
No full textU ovom radu provedena je analiza utjecaja ojačanja na ponašanje povijesnih zidanih tornjeva izloženih seizmičkom opterećenju. Za numeričku analizu korišten je Y2D numerički program koji se temelji na kombiniraj metodi konačno-diskretnih elemenata. Potres na koji su tornjevi analizirani je zapis potresa u Petrovcu, Crna Gora, 1979. godine. Analiza je izvršena za dvije faze tornjeva: tornjevi s neojačanim i tornjevi s ojačanim karakteristikama materijala. Rezultat analize je prikazati rezultate graničnih stanja tornjeva.In this paper, an analysis of the influence of reinforcement on the behavior of historic masonry towers exposed to seismic load was carried out. For the numerical analysis, the Y2D numerical program based on the combined finite-discrete element method was used. The earthquake for which the towers were analyzed is a record of an earthquake in Petrovac, Montenegro in 1979. The analysis was performed for two phases of towers: towers with unreinforced and towers with reinforced material properties. The result of the analysis is to show the results of the limit states of the towers
Life-cycle assessment of municipal waste management systems in Croatia's leading tourist towns : diploma thesis
No full textHrvatska, popularno turističko odredište, imala je visoku sezonalnost turizma između 2015. i 2021., što je doprinijelo povećanju komunalnog otpada u hrvatskim turističkim gradovima. U ovom radu analizirane su količine komunalnog otpada u pet vodećih hrvatskih turističkih gradova od 2015. do 2021., tj. u Zagrebu, Poreču, Rovinju, Splitu i Dubrovniku te je uočeno da količina prikupljenog komunalnog otpada varira u skladu s promjenom turističkog ekvivalenta stanovništva (TES). Navedeno je izraženije u gradovima s većim vrijednostima TES-a, poput Poreča, Rovinja i Dubrovnika. Također, analiziran je utjecaj na okoliš sustava gospodarenja krutim komunalnim otpadom navedenih gradova u godini s najvećim brojem ostvarenih noćenja turista, tj. u 2019. godini, računalnim programom IWM-EPIC/CSR procjene životnog ciklusa (engl. life-cycle assessment). LCA je pokazala da su sustavi gospodarenja otpadom u Poreču i Rovinju imali manji negativan utjecaj na okoliš u 2019. od onih u većim gradovima poput Zagreba, Splita i Dubrovnika.Croatia, a popular tourist destination, has a high seasonality between 2015 and 2021, which results in increasing municipal waste in Croatian tourist towns. This paper analyzes municipal waste in five major Croatian tourist towns (Zagreb, Poreč, Rovinj, Split, and Dubrovnik) from 2015 to 2021., revealing that the amount of collected municipal waste varies in tandem with the change in tourist population equivalent (TES). This is more prominent in towns with higher TES values, such as Poreč, Rovinj, and Dubrovnik. In addition, the IWM-EPIC/CSR life-cycle assessment software was used to examine the environmental impact of the indicated cities' solid municipal waste management systems in the year with the highest number of tourist overnight stays, namely 2019. The LCA showed that waste management systems in Poreč and Rovinj had a lower negative impact on the environment in 2019 than those in larger towns like Zagreb, Split, and Dubrovnik
Analiza utjecaja parametara modela vozača na izdvojene utjecajne značajke profila vožnje
No full textIn motorsport, minimizing lap time is the ultimate goal, guiding all research and development activities. One common tool used in this pursuit is the Driver-in-the-Loop (DiL) simulator, where a human driver interacts with a virtual environment to test and optimize vehicle systems. However, relying on human drivers for these simulations is time-consuming and limits the potential for automation of the system parameter optimization.
To address this challenge, there is an increasing shift toward replacing human drivers with driver models that can accurately replicate on-track behavior. While current solutions for creating respective digital twins often rely on machine learning techniques, they typically require large amounts of training data, making them resource-intensive and less cost-effective.
This research focuses on identifying the dependencies between driver model parameters and key driving performance indicators defined here as key performance indicators (KPIs). By understanding these parameters and KPIs relationships, it becomes possible to optimize driver models more efficiently, reducing the need for extensive data collection and data-driven training. The study also includes a validation of the identified dependencies, confirming their relevance and practical applicability for future integration into advanced simulation and optimization frameworks
Development and implementation of a lithium battery cell thermal model
No full textOvaj diplomski rad daje pregled tehnologija sekundarnih litijevih baterija, uspoređujući karakteristike pojedinih elektrokemijskih sastava, s naglaskom na litij-titanat bateriju kao najsigurniju i temperaturno najneovisniju vrstu litij-ionske baterije. Nadalje, predstavljeni su strujno-naponski modeli za opisivanje dinamike baterije, zajedno s detaljnijim prikazom Theveninovog modela baterije kao ekvivalentnog modela strujnog kruga baterije korištenog u ovom radu. Razvijen je i odgovarajući matematički model kao osnova za simulacijski model koji opisuje mehanizme zagrijavanja temeljene na reakcijskoj i polarizacijskoj toplini te toplini unutarnjeg otpora. Simulacijski model koristi tehničke specifikacije koje je dao proizvođač i eksperimentalno dobivene parametre za Theveninov model litij-titanat baterije. Nakon što su osigurani svi potrebni podaci na razini modela baterije, cijeli model je implementiran u programskom paketu Matlab/Simulink. Rezultati simulacije prate različite toplinske tokove tijekom punjenja i pražnjenja litij-titanat baterije uz simultano izračunavanje rezultirajućeg zagrijavanja, odnosno povećanja temperature baterije.This master’s thesis provides an overview of lithium secondary battery technologies, comparing the characteristics of individual electrochemical compositions, with an emphasis on the lithium-titanate battery as the safest and most temperature-independent type of lithium-ion battery. Furthermore, current-voltage models are presented to describe battery dynamics, along with a more detailed presentation of the Thevenin battery model as the equivalent battery circuit model used in this work. A corresponding mathematical model has also been developed as a basis for the simulation model which describes the heating mechanisms based on reaction and polarization heat, and internal resistance heat. Simulation model uses the technical specifications provided by the manufacturer and experimentally obtained parameters for the lithium titanate battery Thevenin model. After all the necessary data at the battery model level were provided, the entire model was implemented in the Matlab/Simulink software package. The simulation results track different heat fluxes during charging and discharging of the lithium titanate battery, while calculating the resulting heating, i.e. battery temperature increase
Development of the test bench for irradiation influence on electronic components
No full textNeizbježnost uporabe elektroničkih sklopova u raznim tehničkim sustavima često dovodi do potrebe za ispitivanjem robusnosti i funkcionalnosti sklopova. Primjena u svemirskim, nuklearnim i medicinskim poljima rada dovodi do izloženosti elektronike ionizirajućem zračenju koje može prouzročiti sve od neprimjetnih problema koji se sami isprave do velikih havarija. Iz navedenog razloga u sklopu diplomskog rada razvijen je testni postav za ispitivanje elektroničkih sklopova, u koje ubrajamo aktuatorske (motore), senzoriku (enkodere, krajnje prekidače, senzore tlaka...) te logičke sklopove za upravljanje. Također su razvijene te proizvedene dvije tiskane pločice od kojih jedna ima funkciju ponovnog testiranja funkcionalnosti nakon ispitivanja elektronike na ionizirajuće zračenje i druga koja je zamišljena kao upravljačka tiskana pločica otporna na ionizirajuće zračenje. Kao zadnja faza diplomskog rada provedena su ispitivanja te su analizirani dobiveni podaci iz kojih je moguće interpretirati ukupnu isplativost korištenja dodanih mjera zaštite sustava od zračenja. Testirana oprema je sastavni dio manipulatorskih sustava tvrtke INETEC te je u sklopu europskog projekta RIMA provedeno ispitivanje testnog postava razvijenog u ovom diplomskom radu.The inevitability of using electronic circuits in various technical systems often leads to the need of testing the robustness and functionality of the assemblies. Application such as space, nuclear and medical often leads to exposure of the electronics to the radiation that can cause imperceptible problems but also to the major accidents. For that reason, test set-up was developed as part of the masters thesis for exposing electronic circuits to radiation, which includes actuators (motor), sensors (encoders, limit switches, pressure sensors...) and logic circuits for control. In adition, two printed circuit boards were developed and produced, one of which has the function of retesting the functionality after iradiation testing has been preformed and second which is designed as a control printed circuit board resistant to ionizing radiation. Last stage of the Masters thesis was iradiation test, which was carried out and obtained data was analised from which it is possible to interpret the overall profitability of the radiation hardened electronics. Used test equipment is an integral part of the manipulator systems of the company INETEC and iradiation testing was carried out as part of the European project called RIMA
Reliability analysis and improvement of a system for assisting the positioning of medical instruments in neurosurgery
No full textPri razvoju novih proizvoda se sve veća pozornost pridodaje aspektima pouzdanosti i sigurnosti, što je posljedica sve kraćeg trajanja razvojnih projekata uzrokovana specifičnim potrebama i konkurencijom na tržištu. Posebna pažnja na sigurnost i pouzdanost također se obraća u specifičnim tehnološkim granama, kao što je razvoj medicinskih uređaja. Stoga je cilj ovoga rada dati pregled te provesti i diskutirati različite metode za analizu pouzdanosti i sigurnosti na primjeru medicinskog robota. Prilikom izrade rada, posebna pažnja je posvećena teorijskom uvodu i opisu izabranih metoda. Metode su izabrane na temelju pregleda dostupne literature u područjima sigurnosti medicinskih uređaja. Nakon odabira metoda, svaka je predstavljena i opisana, te je prikazan postupak njihove provedbe. Prema utvrđenim postupcima, provedene su detaljne analize pouzdanosti i sigurnosti NERO sustava. Dobiveni rezultati su prikazani i opisani, te su na temelju njih provedene konstrukcijske promjene kritičnih podsustava. Svrha konstrukcijskih promjena je postizanje veće pouzdanosti i sigurnosti sustava, ali i svojevrsni zapisi znanja u obliku vodilja za daljnji konstrukcijski razvoj sustava. Prilikom provedbe navedenih postupaka, odrađene su sve pripremne radnje koje se izvode na temelju postupka odabranih metoda. Također je prije same provedbe analiza ukratko predstavljen i opisan NERO sustav, za koji su provedene analize pouzdanosti i sigurnosti.When developing new products, more and more attention is paid to reliability and safety aspects, which is a consequence of the shorter duration of development projects caused by specific needs and competition in the market. Special attention to safety and reliability is also paid within specific technological branches, such as the development of medical devices. Therefore, this thesis aims to provide an overview, implementation and discussion of different reliability and safety analysis methods with an example from a medical robot development project. When preparing the work, special attention was given to the theoretical introduction and description of the chosen methods. The methods were selected based on a review of the available literature in the fields of medical device safety. After selecting the methods, each is presented and described, and the procedure for their implementation is laid out. According to established procedures, detailed analyses of the NERO system's reliability and security were carried out. Finally, the obtained results are presented and described, with design changes to critical subsystems made based on them. The design changes aim to achieve higher reliability and safety of the overall system but also to record knowledge needed to guide further system development. During the implementation of the above-mentioned procedures, all preparatory actions were carried out based on the selected methods. Also, before the actual implementation of the analysis, the NERO system is briefly presented and described, for which the reliability and security analyses were carried out
Centrifugal casting of stainless steel tube
No full textPredmet razmatranja rada je tehnologija centrifugalnog vertikalnog lijevanja, razvoj
centrifugalnog vertikalnog lijevanja kroz povijest. U radu je navedena problematika vertikalnog
centrifugalnog lijevanja, tehnološki postupak lijevanja te prednosti i nedostaci lijevanja.
Detaljnije je opisan tehnološki postupak lijevanja, uključujući pripremanje kalupa, lijevanje,
hlađenje te vađenje odljevka. Napravljen je kratki osvrt o skrućivanju materijala nakon lijevanja
što je jedna od najvažnijih pojava pri izradi proizvoda lijevanjem. Opisane su računalne
simulacije kao naophodan alat u industriji i proizvodnji. Eksperimentalni dio temelji se na
simulaciji lijevanja nehrđajućeg čelika EN 1.4301 izvedenoj u programu ProCAST nakon čega
su analizirani rezultati računalne simulacije. Rezultati simulacije su uspoređeni sa stvarnim
stanjem odljevka odlivenim u Laboratoriju za ljevarstvo na Fakultetu strojarstva i brodogradnje.
Napravljena je mikrostrukturna analiza odljevka. Rezultati simulacije podudaraju se sa
rezultatima stvarnog lijevanja.The subject of this paper is the technology of vertical centrifugal casting and the development
of vertical centrifugal casting throughout history. The thesis presents the problems of vertical
centrifugal casting, technological casting process and advantages and disadvantages of casting.
The technological process of casting is described in more detail, including mold preparation,
pouring, cooling and casting removal. A brief review was made of the solidification of the
material after pouring, which is one of the most important phenomena in the manufacture of
products by casting. Computer simulations are described as a necessary tool in industry and
production. The experimental part is based on the simulation of stainless steel EN 1.4301
casting performed in the software ProCAST. The results of computer simulation were analyzed.
The simulation results were compared with the actual condition of the casting cast in the
Foundry Laboratory at the Faculty of Mechanical Engineering and Naval Architecture. A
microstructural analysis of the casting was performed. The simulation results match the actual
casting results