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Tlačna čvrstoća kompozitnih cijevi ojačanih ugljičnim vlaknima izloženih morskim uvjetima
No full textThis study investigates the effects of seawater exposure on the crashworthiness of two types of carbon/epoxy composite tubes under quasi-static compression. Carbon/epoxy composites, widely used in maritime structures due to their high strength-to-weight ratio and corrosion resistance, may experience altered mechanical properties when exposed to harsh marine conditions. To evaluate these effects, quasi-static crushing tests were conducted on composite tubes after a one-month exposure to natural seawater. Composite tubes were manufactured using hand layup and prepreg technique. By analyzing the behavior of these composite structures under controlled compression, the study aims to provide insights into their structural integrity in marine environments. Results indicate a significant impact of seawater exposure on the crashworthiness of carbon/epoxy composites. The maximum compression force is considerably lower after the exposure, and hand layup specimens generally withstand the exposure much better than prepregs. The findings contribute to a deeper understanding of material behavior in marine applications, offering practical guidelines for designing and maintaining composite-based maritime infrastructure.Ova studija istražuje učinke izloženosti morskom okolišu na tlačnu čvrstoću dviju vrsta cijevi od ugljika/epoksi kompozita pod kvazistatičkom kompresijom. Ugljik/epoksidni kompoziti, naširoko korišteni u pomorskim strukturama zbog visokog omjera čvrstoće i težine i otpornosti na koroziju, mogu doživjeti izmijenjena mehanička svojstva kada su izloženi teškim morskim uvjetima. Kako bi se procijenili ti učinci, provedena su kvazistatička ispitivanja drobljenja na kompozitnim cijevima nakon jednomjesečnog izlaganja prirodnoj morskoj vodi. Kompozitne cijevi proizvedene su tehnikom ručnog laminiranja i preprega. Analizom ponašanja ovih kompozitnih struktura pod kontroliranom kompresijom, studija ima za cilj pružiti uvid u njihov strukturni integritet u morskom okruženju. Rezultati pokazuju značajan utjecaj izloženosti morskoj vodi na otpornost ugljika/epoksi kompozita na udar. Maksimalna sila kompresije znatno je niža nakon izlaganja, a uzorci izrađeni ručnom laminacijom općenito podnose izlaganje mnogo bolje od preprega. Rezultati pridonose dubljem razumijevanju ponašanja materijala u pomorskim primjenama, nudeći praktične smjernice za projektiranje i održavanje pomorske infrastrukture temeljene na kompozitima
Flywheel energy storage system
No full textU ovom diplomskom radu opisan je pojam sustava pohrane energije zamašnjakom. Razrađen je osnovni koncept skladišta energije, što uključuje i njihovu podjelu s obzirom na tehnologiju pohrane energije, te su grafički uspoređeni u kontekstu njihovih prednosti i
nedostataka. Nadalje, govoreći o sustavu pohrane energije zamašnjakom, opisan je princip rada, građa sustava, te su navedene
i opisane komponente koje čine sustav: kućište, rotor, motor/generator, ležajevi, energetska elektronika, a isto tako su navedeni gubici, kvarovi i sigurnosni standardi koji se primjenjuju uz ovaj sustav. U završnom dijelu, navedene su neke primjene sustava: unutar brodskog elektroenergetskog sustava, uz obnovljive izvore energije i u transportnoj industriji. Diplomski rad sažima se u zaključku, gdje se sintetizira obrađena tematika i daje generalna slika sustava pohrane energije zamašnjakom.In this thesis, the concept of flywheel energy storage system is described. First, the basic concept of energy storage, including its subgroups, are elaborated based on energy storing technology and graphically compared in the context of their advantages and disadvantages. Furthermore, speaking about the flywheel energy storage system, this thesis describes the working principle, structure of the system and its components: housing, rotor, motor/generator, bearings, and power electronics. Losses, common failures, and safety regulations, that are applied with such system, are also listed. In the final part of the thesis, some applications of the system are mentioned: within the ship power system, with renewable energy sources and in the transport industry. The thesis is summarized in the conclusion section, where the discussed topics are synthesized, and a general picture of the flywheel energy storage is given
Forecast of freight and passenger traffic in The European Union
No full textCilj završnog rada je identificirati i dati odgovore na važna pitanja koja se odnose na promet tereta i putnika u Europskoj uniji. Razmotrena su sljedeća pitanja: je li se povećao promet tereta i putnika u Europskoj uniji u zadnjih nekoliko godina, na koji način je reguliran promet u Europskoj uniji, koje mjere su donesene a koje se tek planiraju donijeti u svrhu regulacije prometa tereta i putnika u Europskoj uniji da ne bi došlo do zagušenja i povećanog zagađenja. Težište rada je na statističkoj analizi prometa putnika i tereta u EU.The goal of the final paper is to identify and provide answers to important questions related to the traffic of cargo and passengers in the European Union. The following questions were considered: has the traffic of cargo and passengers in the European Union increased in the last few years, how is traffic in the European Union regulated, what measures have been adopted and which are still planned to be adopted for the purpose of regulating the traffic of cargo and passengers in the European Union to avoid congestion and increased pollution. The focus of the work is on the statistical analysis of passenger and cargo traffic in the EU
Hydraulic cylinders
No full textHidrauličke cilindre definiramo kao mehaničke aktuatore koji iskorištavaju hidraulički fluid kako bi generirali linearnu silu i pokret. Možemo ih naći u širokom spektru primjene u svakodnevnom životu. U ovom radu opisivat će se vrste, izvedbe te upotreba hidrauličkih cilindara u pomorstvu, što je danas vrlo širok i opširan pojam. U prvom dijelu rada opisuje se izvedba samog cilindra, njegove komponente te vrste izvedbi. Drugi dio rada opisivat će vrste koje su u čestoj općoj primjeni. Na kraju rada navest će se primjer koji nam ukazuje na važnost hidrauličkih cilindara u razvitku i poboljšanju performansi broda kao cjeline.We define hydraulic cylinders as mechanical actuators that use hydraulic fluid to generate linear force and movement. We can find them in a wide range of applications in everyday life. This paper will describe the types, performance and use of hydraulic cylinders in maritime, which today is a very broad and comprehensive term. The first part of the paper describes the performance of the cylinder itself, its components and types of performance. The second part of the paper will describe the species that are frequently used in maritime affairs. At the end of the paper, an example will be given that indicates the importance of hydraulic cylinders in the development and improvement of the performance of the ship as a whole
The Recent and Submerged Tombolos—Unique Phenomena on the Adriatic Sea
No full textPrvić Island (Kvarner area in the NE channel part of the Adriatic Sea) is a part of the Natura 2000 protected area network. A recent tombolo is located on the SW coast of Prvić Island, and much larger submerged tombolos are located on the shoal towards the south. Both phenomena are unique to the Croatian coast of the Adriatic Sea. The inland part of the tombolo was surveyed using an Unmanned Aerial Vehicle, and a 3D point cloud was created using Structure from Motion with Multi-View Stereo photogrammetry. The body of the talus breccia behind the tombolo has a triangular form. Large collapsed rocky blocks form the cape vertex. This cape is in a state of equilibrium in the present oceanographic conditions but might be eroded due to predicted rises in sea level. The submarine zone was explored using scuba-diving equipment and Remotely Operated Vehicles. A large triangle-shaped shoal consists of flysch. Parallel vertical sandstone layers that look like artificially built walls are more than a hundred metres long. The carbonate breccia is located at the end of the shallow zone. The conditions for the final formation of the submerged shoal were created during the sea level stagnation in the Holocene
Legal regulation of transport of goods by rail
No full textŽeljeznica je važan aspekt za rast gospodarstva ima svoje propise i zakone proučavat ćemo nacionalne i međunarodne.U temeljnim obilježjima govori se o vrsti pruga o modernizaciji komunikacijskih sustava,prijevozu robe,uslugama HŽ carga najvećeg prijevoznika u Republici Hrvatskoj.Analizom dokumenata nastojat će se objasniti više o samoj dokumentaciji.Tereni list kao glavni dokument za prijevoz željezničke kompozicije,kod komunikacijskog sustava moći ćemo viditi tehnologiju koja se implementira u komunikacijski sustav željeznice.Povezivanje same prakse sa zakonima i pravilnicima prilikom carinskih prekršaja,upoznavanje sa vrstama carinjenja robe.The railway is an important aspect for the growth of the economy, it has its own regulations and laws about the documentation itself. The field sheet as the main document for the transport of railway composition, with the communication system we will be able to see the technology that is implemented in the communication system of the railway. Connecting the practice itself with laws and rules in case of customs violations, familiarization with the types of customs clearance of goods
Management aspects of safety of LNG ships
No full textLNG je prirodni plin (uglavnom metan) koji je pretvoren u tekućinu hlađenjem na -161°C. Kao
tekućina zauzima puno manje prostora te se ne mora skladištiti pod pritiskom i samim time
lakši je za transport i može biti siguran za isporuku na tržišta diljem svijeta. Kao tekućina, LNG
je bez mirisa, bez boje, nije zapaljiv i brzo isparava kada je izložen zraku. Također, nije
korozivan niti toksičan i brzo isparava ako se izlije na vodu što znači da ne zagađuje zemlju ili
vodu u slučaju izlijevanja. LNG se prevozi specijaliziranim modernim brodovima koji su
posebno dizajnirani i konstruirani da se spriječi curenje ili puknuće cijevi i tankova. LNG se
skladišti u posebnom sustavu unutar trupa plovila, koji je dizajniran za zaštitu tereta u slučaju
nesreća. Kako bi prijevoz i skladištenje LNG – a prošlo bez ikakve opasnosti potrebno je
poštivati određene standarde, propise i zakone. Kada je riječ o propisima i zakonima, oni se
istovremeno definiraju na međunarodnoj razini i na razini svake države pod čijom se zastavom
plovi.LNG is natural gas (mainly methane) that is converted into liquid by cooling at -161°C. As a
liquid, it takes up significantly less space and does not have to be stored under pressure.
Therefore, it is easier to transport and can be delivered safely to markets all around the world.
As a liquid, LNG is odorless, colorless, non-flammable, and it evaporates quickly if exposed to
air. It is also non-corrosive and non-toxic and evaporates quickly if spilled on water so in the
event of a spill, there is no risk for land ot water pollution. LNG is transported by specialized
ships, i.e. LNG ships. LNG ships are modern ships specially designed and constructed to
prevent leaks or ruptures. LNG is stored in a special containment system inside the vessel's
inner hull which is designed to protect cargo in the case of an accident. In order for the
transportation and storage of LNG to take place without any danger, it is necessary to comply
with certain standards, regulations and laws
Transition model of cargo seaports into smart ports
No full textTranzicija teretnih morskih luka u pametne luke moguća je samo ukoliko su luke visoke razine digitalne zrelosti. Postizanje visoke razine digitalne zrelosti teretnih morskih luka i tranzicija u pametne luke ostvaruje se primjenom digitalnih tehnologija i sustava. Proces tranzicije teretnih morskih luka u pametne luke je postupan, s obzirom da se nove digitalne tehnologije i sustavi ne primjenjuju odjednom u lukama. Iako je koncept pametna luka praktično potvrđen kroz primjere vodećih svjetskih luka, još uvijek nije primijenjen u većini teretnih morskih luka. U doktorskom radu detaljno su istražene i analizirane Tradicionalne digitalne tehnologije i sustavi te Disruptivne digitalne tehnologije koje se koriste u teretnim morskim lukama. Detaljno je elaboriran koncept pametna luka te su analizirani relevantni primjeri teretnih morskih luka uspješnih u primjeni digitalnih tehnologija i sustava i tranziciji u pametnu luku. Identificirani su kriteriji za evaluaciju scenarija tranzicije teretnih morskih luka u pametne luke. Analizirani kriteriji definirani su sukladno TOE okviru. U radu je primijenjeno više Metoda višekriterijskog odlučivanja te Deskriptivna statistička analiza i Multivarijatna statistička analiza, a u istraživanje su involvirani stručnjaci iz područja primjene digitalnih tehnologija i sustava u lukama. Primjenom DEX metode višekriterijskog odlučivanja, na primjerima luka (Ploče, Split, Rijeka, Bar, Port of Adria, Kopar, Ravena) analizirana je digitalna zrelost luka, kao prvi korak u izradi modela tranzicije teretnih morskih luka u pametne luke s identifikacijom tranzicijskih scenarija. Primjenom Deskriptivne statističke analize i Multivarijatne statističke analize ̶ metoda aglomerativno hijerarhijsko klasteriranje, interpretirani su rezultati istraživanja provedenog ispitivanjem mišljenja stručnjaka iz područja primjene digitalnih tehnologija i sustava u lukama. Provedenim istraživanjem utvrđeno je koje Tradicionalne digitalne tehnologije i sustave te Disruptivne digitalne tehnologije stručnjaci smatraju najvažnijima za tranziciju teretnih morskih luka u pametne luke te koje kriterije stručnjaci smatraju najvažnijim za evaluaciju scenarija tranzicije teretnih morskih luka u pametne luke. Temeljem rezultata istraživanja značaja digitalnih tehnologija i sustava za tranziciju teretnih morskih luka u pametne luke izrađen je model tranzicije teretnih morskih luka u pametne luke s identifikacijom tranzicijskih scenarija. Identificirana su tri scenarija: Digitalno liderstvo u teretnim poslovnim procesima, Digitalno liderstvo u administrativnim poslovnim procesima i Digitalno liderstvo u internim poslovnim procesima. Sukladno istraženim i analiziranim digitalnim tehnologijama i sustavima te kriterijima za evaluaciju scenarija tranzicije teretnih morskih luka u pametne luke, primjenom AHP metode višekriterijskog odlučivanja provedena je evaluacija, odnosno odabir scenarija tranzicije teretne morske luke u pametnu luku, na primjeru luke Rijeka koja je odabrana zbog dostupnosti podataka. Evaluacija scenarija tranzicije rezultirala je III odabirom scenarija tranzicije luke Rijeka u pametnu luku: Digitalno liderstvo u teretnim poslovnim procesima. Provedenim istraživanjem u doktorskom radu dokazane su glavna hipoteza i pomoćne hipoteze.The transition of cargo seaports into smart ports is only possible if ports have a high level of digital maturity. A high level of digital maturity of cargo seaports and the transition of seaports into smart ports is achieved by applying digital technologies and systems. The process of transition of cargo seaports into smart ports is gradual, given that new digital technologies and systems are not applied in ports all at once. Although the concept of a smart port has been confirmed in practice based on the examples of the world's leading ports, it has not yet been applied in the most cargo seaports. An in-depth study and analysis of traditional digital technologies and systems, as well as disruptive digital technologies used in cargo seaports, was conducted in this doctoral thesis. The concept of a smart port was elaborated in detail, and relevant examples of cargo seaports that have successfully applied digital technologies and systems and made the transition to a smart port were analyzed. The criteria for evaluating the scenario of the transition of cargo seaports to smart ports were identified. The analyzed criteria were defined according to the TOE framework. Several Multi-criteria decision-making methods and Descriptive statistical analysis as well as Multivariate statistical analysis were applied in the work, and experts from the field of application of digital technologies and systems in ports were involved in the research. By applying the DEX method of multi-criteria decision-making, the digital maturity of the ports was analyzed on the examples of specific ports (Ploče, Split, Rijeka, Bar, Port of Adria, Kopar, Ravena) and digital maturity of ports was analyzed as the first step in creating a model of transition of cargo seaports into smart ports with the identification of transition scenarios. The results of the research conducted by studying the opinions of experts in the field of application of digital technologies and systems in ports were interpreted using Descriptive statistical analysis and Multivariate statistical analysis - the agglomerative hierarchical clustering method. The conducted research showed which "traditional digital technologies and systems", as well as "disruptive digital technologies", are considered by experts to be the most important in the transition of cargo seaports into smart ports and which criteria are considered to be the most important for evaluating the scenario of the transition of cargo seaports into smart ports. Based on the results of studying the importance of digital technologies and systems for the transition of cargo seaports into smart ports, a model of the transition of cargo seaports into smart ports with the identification of transition scenarios was created. Three scenarios were identified: "Digital leadership in cargo business processes", "Digital leadership in administrative business processes" and "Digital leadership in internal business processes". In accordance with the researched and analyzed digital technologies and systems, as well as the criteria for evaluating the scenario of the transition of cargo seaports into smart ports using the AHP method of multi-criteria decision-making, an evaluation was V carried out, the scenario of the transition of a cargo seaport into smart port was selected based on the example of the port of Rijeka, which was chosen due to the availability of data. The evaluation of the transition scenario resulted in the selection of the following transition scenario of the port of Rijeka into a smart port: "Digital leadership in cargo business processes". The research described in the doctoral thesis proved the main hypothesis and auxiliary hypotheses
Sustainable development and passenger traffic flows in urban areas
No full textPrometni tokovi putnika obuhvaćaju širok spektar karakteristika, oblika i čimbenika koji utječu na održivi razvoj urbanih područja. Naglasak se stavlja na analizu i optimizaciju različitih oblika urbanog prijevoza gdje se posebna pažnja posvećuje integraciji različitih prijevoznih modaliteta i njihovoj ulozi u postizanju održivog razvoja gradova kroz smanjenje emisija štetnih plinova, uštedu energije i poboljšanje socio-ekonomskih uvjeta. U fokusu istraživanja su različiti oblici prometa, od javnog prijevoza do individualnih prijevoznih sredstava, kao i njihova uloga u održivom razvoju gradova. Na praktičnom primjeru grada Londona prikazani su aspekti organiziranosti, modaliteti, struktura, te strategije razvoja koje doprinose održivom razvoju urbanog prometa u gradu Londonu, a koje su kao takve primjenjive u održivom prometnom planiranju i drugih gradova.Passenger traffic flows encompass a wide spectrum of characteristics, forms and factors that influence the sustainable development of urban areas. Emphasis is placed on the analysis and optimization of different forms of urban transport, where special attention is paid to the integration of different transport modalities and their role in achieving sustainable development of cities through the reduction of harmful gas emissions, energy saving and improvement of social-economic conditions. The research focuses on different forms of transport, from public transport to individual means of transport, as well as their role in the sustainable development of cities. On the practical example of the city of London, aspects of organization, modalities, structure, and development strategies are presented that contribute to the sustainable development of urban traffic in the city of London, and which are applicable in sustainable traffic planning in other cities as well
Motivation of employees in logistics companies
No full textU diplomskom radu istražena je motivacija zaposlenika, kao jedan od bitnijih čimbenika uspješnosti poduzeća. U radu je pojašnjen pojam motivacije kao i glavne teorije motivacije kojima se može objasniti ponašanje zaposlenika. Nadalje, u radu je pojašnjen pojam ljudskih potencijala. Kroz rad je naglašena važnost ljudskih potencijala kao i važnost kvalitetnog pristupa i upravljanja ljudskim potencijalima u poduzeću. U svrhu provedbe istraživanja napravljen je anketni upitnik kojim je analizirana motivacija zaposlenika logističkog odjela unutar poduzeća koje u ovome radu ostaje anonimno. Istraživanje je provedeno u svrhu dobivanja rezultata o motiviranosti zaposlenika prema poslu i svakodnevnim radnim zadacima koje obavljaju. Rezultati dobiveni istraživanjem služe kao uvid u stanje motiviranosti zaposlenika kao i pomoć menadžmentu poduzeća u budućem poslovanju i budućoj primjeni strategija motivacije.In the diploma thesis, employee motivation was investigated as one of the most important factors in the success of the company. The paper explains the concept of motivation as well as the main theories of motivation that can explain employee behavior. Furthermore, the concept of human potential is clarified in the paper. The paper emphasized the importance of human resources as well as the importance of quality access and management of human resources in the company. In order to carry out the research, a survey questionnaire was made which analyzed the motivation of employees of the logistics department within the company, which remains anonymous in this paper. The research was conducted in order to obtain results about employee motivation towards work and the daily work tasks they perform. The results obtained from the research serve as an insight into the state of employee motivation as well as help to the management of the company in future operations and the future application of motivation strategies