Croatian Digital Thesis Repository
Not a member yet
259189 research outputs found
Sort by
Evaluacija obilježja i trendova potrošačkog ponašanja u sektoru brze prehrane
No full textEvaluacija obilježja i trendova potrošačkog ponašanja u sektoru brze prehrane otkriva kako je brza hrana i dalje široko prisutna u svakodnevnim prehrambenim navikama, osobito medu mlađom populacijom koja cijeni praktičnost, brzinu i pristupačnost. Iako je svijest o negativnim zdravstvenim posljedicama relativno visoka, ona često ne rezultira značajnom promjenom navika zbog psiholoških čimbenika poput kognitivne disonance. Marketinške aktivnosti i promotivne ponude snažno utječu na potrošačke odluke, no postoji i rastući interes za zdravijim alternativama koje zadovoljavaju potrebe brzine i dostupnosti. Demografski čimbenici poput dobi i obrazovanja značajno oblikuju stavove i konzumaciju. Sveukupno, sektor brze prehrane prolazi kroz transformaciju u kojoj zdraviji proizvodi i edukacija igraju ključnu ulogu u oblikovanju budućih potrošačkih trendova.The evaluation of consumer behavior characteristics and trends in the fast food sector reveals that fast food remains a prevalent part of daily dietary habits, especially among younger populations who prioritize convenience, speed, and affordability. Although awareness of the negative health impacts is relatively high, it often does not lead to significant behavior changes due to psychological factors such as cognitive dissonance. Marketing activities and promotional offers strongly influence consumer decisions, yet there is a growing interest in healthier alternatives that meet the demands for speed and accessibility. Demographic factors like age and education significantly shape attitudes and consumption patterns. Overall, the fast food sector is undergoing a transformation where healthier products and education play a crucial role in shaping future consumer trends
Influence of noise from old and new generation commercial aircraft on the health of flight and cabin crew
No full textBuka, kao jedan od rastućih problema u zračnom prometu, negativno utječe ne samo na putnike, stanovništvo i okoliš, već i na zdravlje letačkog i kabinskog osoblja. Cilj ovoga rada je usporediti utjecaj buke zrakoplova stare generacije (pod kojeg se za svrhe ovoga rada smatra zrakoplov Dash 8 - Q400) i nove generacije (zrakoplov Airbus A220 - 300) pomoću provedenih mjerenja razine buke na redovitim linijama Zagreb - Split, Split - Zagreb. Osim provedenih mjerenja, za svrhe ovoga rada je provedena i anketa među djelatnicima letačkog i kabinskog osoblja. Pomoću provedenih mjerenja ustanovilo se kako je zrakoplov Dash 8 - Q400 glasniji od zrakoplova Airbus A220 - 300, te uz pomoć ankete je ustanovljeno kako su negativne posljedice buke prisutne kod letačkog i kabinskog osoblja, gdje su izraženije među kabinskim osobljem.Noise, as one of the growing concerns in air transport, has a negative impact not only on passengers, local communities, and the environment, but also on the health of flight and cabin crew members. The aim of this paper is to compare the impact of aircraft noise generated by older - generation aircraft (represented in this study by the Dash8 - Q400) and newer - generation aircraft (Airbus A220 - 300), based on conducted noise level measurements on regular flight routes between Zagreb and Split. In addition to these measurements, a survey was carried out among flight and cabin crew members for the purposes of this study. Based on the conducted measurements, it was established that the Dash 8-Q400 aircraft is louder than the Airbus A220 - 300. Furthermore, the survey results indicated that the negative effects of noise are present among both flight and cabin crew, with a more pronounced impact observed among cabin crew members
The efficiency of the bovine intrauterine device on suppression of estrus in cow
No full textToday, the animal welfare is an important notion for the customers. In other words, it is
essential to avoid pregnant animals at the abattoirs, where important fines apply in such case.
Different methods can be used as contraception in cattle: surgical, chemical, immunological
and mechanical.
The aim of this study was to evaluate the effectiveness of the DIUB Turin® copperreleasing bovine intrauterine device (BIUD) in suppressing estrus and preventing pregnancy in
cows, as well as to assess its potential impact on uterine health.
A total of 19 animals, 18 cows and 1 heifer of various breeds received a BIUD. All
animals were issued exclusively from the Reprovet Clinic, La Brévine, Switzerland. The
devices were inserted following standard procedures and each animal was examined clinically
by ultrasound twice during the study period. Four uterine samples were sent to pathohistology
examinations to assess the possible lesions caused by the BIUD.
Results showed a high pregnancy prevention rate of 94.7 %, with only one cow
becoming pregnant, similar with the results of TURIN et al. (1996). However, estrus
suppression was observed in only 10.53 % of animals, significantly lower than the 98 %
suppression rate claimed by the commercial instruction.
Pathohistological examinations found mild to moderate localized endometrial changes
such as epithelial erosion, fibrosis, and inflammation, though no cases of uterine perforation or
pyometra were detected.
While the BIUD appears effective in preventing pregnancy its ability to suppress estrus
was not efficient. Also, its long-term impact on uterine tissue can be severe. Further
investigation is needed to evaluate correctly the risk of perforationDobrobit životinja bitan je aspekt suvremenog tržišta. U tom smislu od iznimne je
važnosti da se na liniji klanja ne pojavljuju gravidne životinje, ne samo zbog visokih kazni koje
takve slučajeve prate. U govedarstvu su nam na raspolaganju različite metode kontracepcije:
kirurške, kemijske, imunološke i mehaničke.
Cilj ovog rada bilo je istražiti učinkovitost DIUB Turin® intrauterine spirale s
otpuštajućim bakrom (BIUD) na suprimiranje estrusa (gonjenja) i spriječavanje gravidnosti u
krava kao i ocijeniti učinak iste na stijenku maternice.
BIUD je apliciran 19 grla, od čega 18 krava i jednoj junici. Sve su životinje pacijenti
klinike Reprovet Clinic, La Brevine, Švicarska. Spirale su aplicirane po standardnom postupku
te je svaka životinja klinički ultrazvučno pregledavana dva puta tijekom razdoblja provedbe
istraživanja. Četiri uzorka maternica poslana su na patohistološku pretragu kako bi se ocijenile
moguće lezije u maternici prouzrokovane spiralom.
Rezultati su pokazali visoku učinkovitost u prevenciji gravidnosti (94,7 %), sa samo
jednom gravidnom kravom što je u skladu s rezultatima TURIN i sur. (1996). Ipak, supresija
estrusa ostvarena je u samo 10,53 % životinja što je značajno niže od 98 % kako se navodi u
komercijalnoj uputi proizvođača.
Patohistološkim nalazom utvrđene su blage do umjerene, lokalizirane promjene
endometrija kao što su erozija epitela, fibroza i upala. Nalaz nije utvrdio perforacije maternične
stijenke ili pijometru.
Utvrdili smo da je BIUD učinkovit u spriječavanju gravidnosti, dok nije iskazao takovu
učinkovitost u suprimiranju estrusa (gonjenja). Također, spirala može imati ozbiljan učinak na
tkivo maternice u slučaju dugotrajnog držanja. Potrebna su daljnja istraživanja kako bismo
preciznije procijenili rizik perforacije maternice
Development of solutions for reducing deformations in the production of tools for glass packaging
No full textTijekom procesa tokarenja, kod stezanja obratka u steznoj glavi, često dolazi do pojave deformacija, koje mogu biti elastične i plastične. Te deformacije mogu negativno utjecati na dimenzijsku točnost što izravno utječe na kvalitetu gotovih proizvoda. U ovom radu analiziran je problem deformacija obratka u steznoj glavi tijekom tokarenja dijelova alata koji se koriste u proizvodnji staklene ambalaže u tvrtki OMCO Croatia d.o.o. Predložena su moguća tehnička rješenja za smanjenje ili potpuno uklanjanje tih deformacija te je procijenjena primjenjivost i utjecaj predloženih rješenja na točnost obrade, kvalitetu proizvoda i učinkovitost u stvarnom proizvodnom okruženju.During the turning process, clamping the workpiece in the chuck often leads to deformations, which can be both elastic and plastic. These deformations can negatively affect dimensional accuracy, which directly impacts the quality of the final product. This paper analyzes the problem of workpiece deformation in the chuck during the turning of tool parts used in the production of glass packaging at the company OMCO Croatia d.o.o. Possible tehnical solutions are proposed to reduce or completely eliminate these deformations, and the applicability and impact of the proposed solutions on machining accuracy, product quality, and efficiency in a real production environment are evaluated
Development of a fuel production planning algorithm based on multi-criteria optimization
No full textU ovom diplomskom radu istražuje se pravni i strateški okvir energetske i klimatske tranzicije Europske unije, s posebnim naglaskom na regulaciju korištenja biogoriva i biokomponenti u prometnom sektoru. Analizirani su ključni dokumenti europske pravne stečevine, uključujući Europski zeleni plan i zakonodavni paket „Spremni za 55%”, koji definiraju obveze država članica u pogledu smanjenja emisija stakleničkih plinova i povećanja udjela obnovljivih izvora energije. U radu se zasebno razmatraju vrste biogoriva koje se koriste u prometu, uz prikaz njihovih osnovnih svojstava i uloge u dekarbonizaciji sektora. Direktiva o obnovljivim izvorima energije (RED) propisuje pravni okvir za povećanje udjela biogoriva, kao i kriterije održivosti i kvalitete koje ta goriva moraju ispunjavati. U kontekstu Republike Hrvatske analizirana je implementacija europskih propisa u nacionalno zakonodavstvo te izazovi s kojima se suočavaju gospodarski subjekti u procesu usklađivanja. U završnom dijelu rada razvijen je koncept algoritamskog modela koji omogućuje optimizaciju troškova poslovanja povezanih s primjenom zakonskih obveza u području biogoriva. Algoritam je osmišljen kao podrška poslovnim subjektima u donošenju odluka koje osiguravaju regulatornu usklađenost uz minimalna financijska opterećenja.This thesis explores the legal and strategic framework of the European Union’s energy and climate transition, with a particular focus on the regulation of biofuels and biocomponents in the transport sector. Key legislative and policy documents, such as the European Green Deal and the "Fit for 55" legislative package, are analysed, as they define the obligations of member states regarding the reduction of greenhouse gas emissions and the promotion of renewable energy sources. The study examines the main types of biofuels used in transport, outlining their fundamental characteristics and their role in the decarbonisation process. The Renewable Energy Directive (RED) establishes the legal framework for increasing the share of biofuels, as well as the sustainability and quality criteria they must meet. Within the context of the Republic of Croatia, the thesis analyses the implementation of EU regulations into national legislation and the challenges this presents for economic operators. In the final part of the thesis, a conceptual algorithmic model is developed to support cost optimisation related to compliance with biofuel-related legal obligations. The algorithm is designed as a decision-support tool that assists companies in achieving regulatory compliance while minimising financial burdens
Optimization of mechanised metal flux cored wire welding
No full textZavarivanje kao ključna tehnologija spajanja materijala zahtijeva strogo pridržavanje
propisanih standarda i kvalifikacijskih postupaka kako bi se osigurala mehanička svojstva
zavarenih spojeva i ukupna kvaliteta proizvoda. U ovom radu bit će predstavljene i opisane
norme HRN EN ISO 15614-1 i HRN EN ISO 14732, koje se odnose na kvalifikaciju
zavarivačkog postupka (eng. WPQR – Welding Procedure Qualification Record) i
kvalifikaciju operatera za zavarivanje. Osim toga, rad će ukratko objasniti što norme
predstavljaju te koja je njihova uloga u industrijskoj praksi. Budući da norme uključuju širok
spektar tehničkih i tehnoloških zahtjeva, rad će također pružiti sažet pregled WPQR postupka,
kao i opis traktora za zavarivanje koji se koristi u cilju povećanja razine mehanizacije i
automatizacije, čak i u pojedinačnoj proizvodnji. Bit će obrađen i MCAW postupak
zavarivanja (eng. Metal-Cored Arc Welding) te dodatni materijal koji se koristi u tom
postupku, uz objašnjenja u skladu s važećim normativnim zahtjevima. U eksperimentalnom
dijelu rada prikazat će se izrada dvaju kutnih zavara oznaka A i B, uz pripremu spojeva i
izvođenje potrebnih ispitivanja prema zahtjevima norme HRN EN ISO 15614-1.Welding, as a key technology for joining materials, requires strict adherence to prescribed
standards and qualification procedures in order to ensure the mechanical properties of welded
joints and the overall quality of the product.This paper presents and describes the standards
HRN EN ISO 15614-1 and HRN EN ISO 14732, which refer to the qualification of the
welding procedure (WPQR – Welding Procedure Qualification Record) and the qualification
of welding operators. In addition, the paper briefly explains what standards are and their role
in industrial practice. Since standards encompass a wide range of technical and technological
requirements, the paper also provides an overview of the WPQR process, as well as a
description of the welding tractor used to increase the level of mechanization and automation,
even in small-scale production. The MCAW (Metal-Cored Arc Welding) process and the filler
material used in this process will also be covered, with explanations provided in accordance
with applicable normative requirements.In the experimental part of the work, the production
of two fillet welds marked A and B will be presented, along with joint preparation and the
performance of the required tests according to the requirements of the HRN EN ISO 15614-1
standard
Investigation of the corrosion behaviour of stainless steels in seawater of varying salinity : diploma thesis
No full textU radu je ispitano korozijsko ponašanje nehrđajućih čelika AISI 304L, AISI 316L i 2205 DSS u morskoj vodi različitog saliniteta – boćatoj (BMV), morskoj (MV) i ugušćenoj morskoj vodi (UMV) koja je uzeta iz procesa proizvodnje soli (solane) nakon kristalizacije natrijeva klorida i sadrži nižu koncentraciju Na + i Cl⁻ iona. Ispitivanje je izvršeno primjenom elektrokemijskih metoda (potencijal otvorenog strujnog kruga (E OC ), linearna i potenciodinamička polarizacija) te analizom površine (optička mikroskopija, SEM/EDS, optička profilometrija). Dobiveni rezultati pokazuju da u svim otopinama otpornost na koroziju raste sljedećim redoslijedom: AISI 304L < AISI 316L < 2205 DSS, što se pripisuje sve većem udjelu legirajućih elemenata poput kroma i molibdena koji stabiliziraju pasivni oksidni sloj i povećavaju otpornost na lokalnu (pitting) koroziju. Dupleks čelik 2205 DSS pokazao je najpozitivnije vrijednosti E OC i korozijskog (E kor ) potencijala, najveći polarizacijski otpor (R p ), najnižu korozijsku struju (i kor ), najpozitivniji pitting potencijal (E dp ) te najšire pasivno područje, što ukazuje na njegovu superiornu stabilnost u svim ispitivanim medijima. Posebno je zanimljivo da je u UMV, iako s višim ukupnim salinitetom, otpornost na koroziju bila veća nego u običnoj MV, što se objašnjava smanjenom koncentracijom Cl - iona i prisutnošću Mg²⁺, Ca²⁺ i SO₄²⁻ koji potiču formiranje zaštitnih taloga na površini čelika. Površinske analize potvrdile su izraženu rupičastu koroziju kod AISI 304L u MV, dok su u BMV i UMV oštećenja bila značajno manja, osobito kod 2205 DSS koji je u većini uvjeta ostao gotovo neoštećen. Rezultati jasno upućuju na potrebu odabira čelika otpornijih na lokalnu koroziju za primjenu u morskim okruženjima, pri čemu se 2205 DSS pokazao kao najsigurniji izbor.This study investigated the corrosion behaviour of stainless steels AISI 304L, AISI 316L and 2205 DSS in seawater with different salinity – brackish water (BMV), seawater (MV) and concentrated seawater (UMV) which is taken from the salt production process after NaCl crystallization and contains lower concentration of Na + and Cl - ions. The study was carried out using electrochemical methods (open circuit potential (E OC ), linear and potentiodynamic polarization) and surface analysis techniques (optical microscopy, SEM/EDS, optical profilometry). The results showed that corrosion resistance increased in all tested solutions in the following order: AISI 304L < AISI 316L < 2205 DSS, which is due to the increasing content of alloying elements such as chromium and molybdenum, which stabilize the passive oxide layer and increase the resistance to localized (pitting) corrosion. Duplex steel 2205 DSS exhibited the most positive E OC and corrosion potential (E corr ) values, the highest polarization resistance (R p ), the lowest corrosion current density (i corr ), the most positive pitting potential (E dp ) and the widest passive range, indicating its superior stability in all tested environments. Remarkably, – despite the higher total salt content, corrosion resistance in concentrated seawater was greater than in seawater, which can be explained by the lower concentration of Cl - ions and the presence of Mg²⁺, Ca²⁺ and SO₄²⁻ ions, which promote the formation of protective surface deposits on the steel. Surface analysis confirmed pronounced pitting corrosion in AISI 304L in seawater, while damage was significantly less in brackish and concentrated seawater, especially in 2205 DSS, which remained virtually undamaged under most conditions. These results clearly show the importance of selecting steels with higher resistance to localized corrosion for marine applications, with 2205 DSS proving to be the most reliable choice
Influence of aging on the removal of poly(ethylene terephtalate) microplastics with ferrate (VI)
No full textPlastiku karakterizira visoka kemijska i fizička stabilnost, trajnost i niski troškovi proizvodnje. Zbog tih karakteristika postala je široko korištena u industriji i svakodnevnom životu. Međutim, masovna proizvodnja plastike i loše gospodarenje otpadom rezultirali su njenom sveprisutnošću u okolišu što doprinosi ekološkom problemu mikroplastike. Mikroplastika u okolišu nastaje kroz kemijsku, fizičku i biološku degradaciju, a njezina glavna obilježja uključuju visoku kemijsku stabilnost, sposobnost daljnje fragmentacije u nanoplastiku, te sposobnost adsorpcije drugih onečišćujućih tvari. Zbog potencijala za bioakumulaciju također predstavlja ozbiljan rizik za ekosustave i ljudsko zdravlje. Jedan od glavnih izvora mikroplastike u okolišu su vodeni tokovi koji su prošli sustave pročišćavanja jer se mikroplastika teško uklanja standardnim metodama pročišćavanja. Međutim, istraživanja o učinkovitosti uklanjanja mikroplastike još su u ranoj fazi zbog nemogućnosti pronalaska preciznih metoda kvantifikacije mikroplastike u okolišnim uzorcima. Ferati(VI) poznati su po svojoj multifunkcionalnosti, osobito u pročišćavanju onečišćujućih tvari, gdje zahvaljujući snažnim oksidacijskim svojstvima učinkovito djeluju na širok spektar organskih i anorganskih onečišćujućih tvari, uključujući i mikroplastiku. Poli(etilen-tereftalat) (PET) jedan je od najrasprostranjenijih plastičnih materijala, te je zbog svoje dugovječnosti i otpornosti na razgradnju jedan od glavnih tipova polimera prisutnih u okolišu u obliku mikroplastike. U ovom radu ispitana je mogućnost uklanjanja termički starene i nestarene PET mikroplastike procesom koagulacije feratima(VI) iz vodene otopine u različitim uvjetima pH. Masa istaložene mikroplastike određena je mjerenjem sadržaja organskog ugljika u filtratima uzoraka. Ferati(VI) pokazali su se donekle primjenjivim za uklanjanje mikroplastike, međutim potrebno je ispitati učinkovitost uklanjanja pri istim koncentracijama ali manjim obrocima višekratno.Plastic is characterized by high chemical and physical stability, durability, and low production costs. Due to these properties, it has become widely used in industry and daily life. However, mass production of plastic and poor waste management have led to its ubiquity in the environment, contributing to the ecological problem of microplastics. Microplastics in the environment are formed through chemical, physical, and biological degradation, and their main characteristics include high chemical stability, the ability to further fragment into nanoplastics, and the ability to adsorb other pollutants. Due to their potential for bioaccumulation, microplastics also pose a serious risk to ecosystems and human health. One of the main sources of microplastics in the environment are water bodies that have passed through treatment systems, as microplastics are difficult to remove using standard purification methods. However, research on the effectiveness of microplastic removal is still in its early stages due to the lack of precise methods for quantifying microplastics in environmental samples. Ferrates(VI) are known for their multifunctionality, especially in the treatment of pollutants, where thanks to their strong oxidative properties, they effectively act on a wide range of organic and inorganic contaminants, including microplastics. Polyethylene terephthalate (PET) is one of the most widespread plastic materials, and due to its longevity and resistance to degradation, it is one of the main types of polymers present in the environment in the form of microplastics. This study examines the possibility of removing thermally aged and pristine PET microplastics through a coagulation process with ferrates from aqueous solutions under different pH conditions. The mass of precipitated microplastics was determined by measuring the organic carbon content in the filtrates of the samples. Ferrates(VI) have shown to be somewhat effective in removing microplastics; however, it is necessary to investigate the removal efficiency at the same concentrations but with smaller, repeated doses
Wastewater treatment using a hybrid process of electrocoagulation, zeolite, and ultrasound : diploma thesis
No full textU ovom radu provedena su ispitivanja hibridnog procesa obrade kompostne otpadne vode kombinacijom elektrokoagulacije, sintetskog zeolita granulacije < 40 µm i dvije razine intenziteta ultrazvuka snage od 240 W, minimalnoj i maksimalnoj, a koje odgovaraju razinama 1 i 5. Eksperimenti su izvedeni u elektrokemijskoj ćeliji s aluminijevim, željeznim i cinkovim elektrodama, pri konstantnoj gustoći struje od 0,0182 A/cm 2 , udaljenosti elektroda od 3 cm, brzinom vrtnje miješala 250 okr/min, dodatkom elektrolita 0,5 g/L i zeolita 15 g/L. Tijekom eksperimenta pratili su se parametri poput pH vrijednosti, temperature i električne vodljivosti, dok su mutnoća, ukupni isparni ostatak i kemijska potrošnja kisika određivani na početku i kraju procesa. Nakon provedbe hibridnog procesa ispitane su promjene mase elektroda te test taloživosti suspenzija. Rezultati su pokazali da je za obradu kompostne otpadne vode najbolje upotrijebiti elektrokoagulaciju sa zeolitom i željeznim elektrodama uz primjenu intenziteta snage ultrazvuka razine 5. Izračun operativnih troškova pokazao je da istovremena primjena i zeolita i ultrazvuka u svrhu boljeg otapanja elektroda ne pokazuje sinergijski efekt, osim kod hibridnog procesa EKZ sa Fe elektrodama i intenzitetom snage ultrazvuka razine 5. To ukazuje da odabir materijala elektroda je vrlo bitan čimbenik koji određuje hoće li istovremena primjena zeolita i ultrazvuka imati pozitivan efekt.In this study, a hybrid process for the treatment of compost wastewater was investigated using a combination of electrocoagulation, synthetic zeolite granulation <40 μm and two levels of ultrasonic power intensity of 240 W, minimum and maximum, corresponding to levels 1 and 5. The experiments were carried out in an electrochemical cell with aluminium, iron and zinc electrodes, at a constant current density of 0.0182 A/cm², an electrode distance of 3 cm, a stirring speed of 250 rpm, with the addition of 0.5 g/L electrolyte and 15 g/L zeolite. During the experiment, parameters such as pH value, temperature and electrical conductivity were monitored, while turbidity, total solids and chemical oxygen demand were determined at the beginning and end of the process. After a hybrid process the electrode mass changes and the settling test of the suspension were examined. The results showed that electrocoagulation with zeolite and iron electrodes using a level 5 ultrasonic power intensity is the most suitable for the treatment of composting wastewater. The calculation of operating costs showed that the simultaneous use of zeolite and ultrasound to improve electrode dissolution has no synergistic effect, except in the case of the hybrid ECZ process with Fe electrodes and a level 5 ultrasonic power intensity. This indicates that the choice of electrode material is a decisive factor in determining whether the simultaneous use of zeolite and ultrasound has a positive effect
Influence of storage conditions on the quality of virgin olive oils : diploma thesis
No full textDjevičansko maslinovo ulje najviše razine kvalitete je iznimno vrijedan proizvod ploda masline zbog brojnih zdravstvenih koristi kao i poželjnih senzorskih svojstava pa mu je cijena znatno viša u odnosu na cijenu drugih biljnih ulja. Kako bi se izbjegle potencijalne mogućnosti patvorenja drugim uljima ova ulja su predmet stalnih provjera kvalitete i autentičnosti. Kvaliteta djevičanskih maslinovih ulja ovisi o mnogo čimbenika, a jedan od važnijih je način i uvjeti skladištenja. Da bi se usporile promjene u fizikalno-kemijskom sastavu i senzorskim svojstvima ulja važan je ispravan način čuvanja (skladištenja). U prvom redu ulje treba čuvati od negativnih utjecaja svjetla, temperature, kisika i vlage. Cilj ovog diplomskog rada je utvrditi kako različiti uvjeti čuvanja ulja utječu na kvalitetu djevičanskih maslinovih ulja. Analize su provedene na uljima iz maslinika sa dva lokaliteta. Ulja sorti Oblica i Leccino iz jednog maslinika te ulja sorti Oblica i Levantinka iz drugog maslinika. Ulja su čuvana na dva načina; u tamnoj staklenoj boci, na tamnom mjestu pri sobnoj temperaturi te u inox spremniku s natprostorom dušika odnosno bez natprostora dušika. Ispitivanja kvalitete provodila su se tromjesečno kroz period od 18 mjeseci. Rezultati analiza pokazali su kako protekom vremena skladištenja rastu vrijednosti fizikalno-kemijskih pokazatelja kvalitete, smanjuju se intenziteti pozitivnih osjetilnih svojstava te opada sadržaj ukupnih fenolnih spojeva u uljima.Virgin olive oil of the highest level of quality is an extremely valuable product of olive fruit due to numerous health benefits as well as desirable sensory properties, so its price is significantly higher than the price of other vegetable oils. In order to avoid the potential adulterations with other seed oils, these oils are the subject of constant quality and authentication check. The quality of the virgin olive oils depends on many factors, and one of the most important is storage conditions. In order to slow down changes in the physical- chemical composition and sensory properties of oil, the propriate way of storage is important. In the first place, the oil should be kept from the negative effects of light, temperature, oxygen and humidity. The aim of this diploma thesis is to determine how different conditions of storage affect the quality of virgin olive oils. The analyses were carried out on oils from olive orchards from the two localities. Oils from the Oblica and Leccino variety from same olive orchard and oils from Oblica and Levantinka variety from other olive orchard. The oils were storaged in two ways; in a dark glass bottle in dark place at room temperature and in the stainless steel tank with nitrogen or no nitrogen above. Quality analyzes were conducted every 3 months over a period of 18 months. The results of the analyses have shown that as the storage time progresses, the values of physico-chemical quality indicators increase, the intensities of positive sensory properties decrease and the content of total phenolic compounds in oils decreases