Energy efficiency of propulsion systems in LNG ships

Rad će obuhvatiti i opisati najnovije trendove u pomorskoj industriji usmjerene na smanjenje emisija stakleničkih plinova s brodova, što je postalo ključno pitanje u kontekstu globalnih napora za očuvanje okoliša i borbe protiv klimatskih promjena. Poseban naglasak biti će stavljen na sve širu primjenu prirodnog plina u pomorskom prometu, koji se više ne koristi isključivo na brodovima namijenjenima prijevozu ukapljenog prirodnog plina, već i na drugim vrstama brodova, poput tankera za prijevoz sirove nafte, brodova za prijevoz rasutog tereta, kontejnera i slično. Uporaba prirodnog plina značajno smanjuje emisije ugljikovog dioksida (CO₂) i dušikovih oksida (NOₓ), dok su emisije sumporovih oksida (SOₓ) gotovo neznatne, čime se postiže pozitivan utjecaj na okoliš i ispunjavaju stroži ekološki standardi. Glavni dio rada biti će usmjeren na detaljnu usporedbu različitih vrsta brodskih propulzijskih sustava s obzirom na njihove performanse i razinu emisija. Analizirati će se brodovi s novim i postojećim tehnologijama za prijevoz ukapljenog prirodnog plina, uz fokus na identificiranje trenutno učinkovitije propulzijske tehnologije s aspekta emisija CO₂ i energetske učinkovitosti. U obzir će biti uzete različite vrste propulzija, uključujući: parno-turbinske sustave, DFDE sustave, dvotaktne sustave poput „ME-GI“ i „X-DF“ te dvotaktne sustave bez izgaranja plinskog goriva. Također, analizirati će se „Sayaringo STaGE“ propulzija. Usporedba ovih tehnologija temeljiti će se na pokazateljima, uključujući pokazatelje učinkovitosti novih i postojećih brodova (EEDI i EEXI), operativni indikator energetske učinkovitosti (EEOI) na razinama opterećenja propulzije od 80 do 100%, te godišnji indikator intenziteta ugljika (CII). Uz tehničke analize, rad će opisati i relevantne inicijative i regulative Međunarodne pomorske organizacije (IMO) i Europske unije koje se odnose na smanjenje emisija u pomorskom sektoru, smanjenja intenziteta ugljika u operacijama samih brodova te implementaciju novih tehnologija. Uz tehničke aspekte, rad će također pružiti uvid u mjere i strategije koje brodski operateri i posada mogu implementirati kako bi dodatno smanjili emisije ugljika tijekom svakodnevnih operacija. Biti će prikazani praktični primjeri, poput optimizacije rute, prilagodbe brzine plovidbe, smanjenja potrošnje goriva, itd. Na temelju provedenih analiza i usporedbi, donijet će se zaključci o najperspektivnijim tehnologijama i praksama koje mogu pridonijeti održivijem razvoju pomorskog sektora.The paper will cover and describe the latest trends in the maritime industry aimed at reducing greenhouse gas emissions from ships, which has become a key issue in the context of global efforts to protect the environment and combat climate change. Special emphasis will be placed on the increasing use of natural gas in maritime transport, which is no longer used exclusively on ships designed for transporting liquefied natural gas but also on other types of vessels, such as crude oil tankers, bulk carriers, container ships, and others. The use of natural gas significantly reduces carbon dioxide (CO₂) and nitrogen oxide (NOₓ) emissions, while sulfur oxide (SOₓ) emissions are almost negligible, resulting in a positive environmental impact and compliance with stricter ecological standards. The main part of the paper will focus on a detailed comparison of different types of ship propulsion systems in terms of their performance and emission levels. An analysis will be conducted on ships equipped with both new and existing technologies for liquefied natural gas transportation, with a focus on identifying the most efficient propulsion technology currently available in terms of CO₂ emissions and energy efficiency. Various types of propulsion systems will be considered, including steam turbine systems, DFDE systems, two-stroke systems such as „ME-GI“ and „X-DF“, as well as two-stroke systems without gas fuel combustion. Additionally, the „Sayaringo STaGE“ propulsion system will be analyzed. The comparison of these technologies will be based on indexes such as the efficiency index of new and existing ships (EEDI and EEXI), the operational energy efficiency indicator (EEOI) at propulsion load levels ranging from 80% to 100%, and the annual carbon intensity indicator (CII). In addition to technical analyses, the paper will also describe relevant initiatives and regulations by the International Maritime Organization (IMO) and the European Union concerning emission reduction in the maritime sector, carbon intensity reduction in ship operations, and the implementation of new technologies. Beyond the technical aspects, the paper will also provide insights into measures and strategies that ship operators and crews can implement to further reduce carbon emissions during daily operations. Practical examples will be presented, such as route optimization, speed adjustment, and fuel consumption reduction. Based on the conducted analyses and comparisons, conclusions will be drawn on the most promising technologies and practices that can contribute to the sustainable development of the maritime sector

Design of a Conceptual Underwater Wireless Communication System Integrating Electromagnetic and Optical Technologies

Underwater wireless communication is pivotal for advancing maritime technology, supporting applications such as underwater exploration, autonomous underwater vehicles (AUVs), diver communication, search-and-rescue operations, and military systems. Traditional acoustic communication systems, while effective over long distances, are constrained by low bandwidth and high latency, limiting their suitability for data-intensive operations. Electromagnetic (EM) and optical communication technologies offer promising alternatives, providing higher data rates, greater bandwidth, and lower latency, but face challenges such as signal attenuation, scattering, and environmental interference. To address these challenges, this paper explores the potential of an integrated wireless communication and navigation system combining EM and optical technologies. Initial experimental measurements of EM wave propagation in freshwater provided valuable insights into signal attenuation and frequency-dependent performance, demonstrating the feasibility of overcoming attenuation in such environments. Building on these observations, this paper proposes a conceptual system comprising three interconnected segments: a space segment utilizing the Galileo High Accuracy Service (HAS) for precise GNSS signals, a waterline segment processing and transmitting GNSS-like signals, and an underwater segment facilitating navigationand communication for divers and AUVs. Preliminary findings highlight the potential of combining EM and optical technologies for reliable, near real-time underwater wireless communication. Future work will focus on extending functionality, validating the system in saltwater environments, and refining the design for practical deployment

Maritime Liquid Cargo Market

Ovaj diplomski rad bavi se analizom pomorskog tržišta tekućeg tereta, s posebnim osvrtom na tankersko brodarstvo i čimbenike koji oblikuju njegovu dinamiku. U radu se razmatraju podjela i karakteristike pomorskog tržišta, uključujući cikličnost i sezonalnost, razrađuje se pojam učinkovitog tržišta. Poseban dio rada namijenjen je brodovima za prijevoz tekućih tereta poput ''prljavih'' i ''čistih'' tankera te LNG/LPG brodova. Analizira se i uloga međunarodnih organizacija poput IMO-a, BIMCO-a i INTERTANKO-a, te se prilažu privitci ugovora koji se koriste u prijevozu tekućih tereta. Završni dio rada posvećen je analizi tržišta tekućeg tereta u 2024. godini, pri čemu se koriste statički podatci i grafikoni za prikaz aktualnih trendova i kretanje vozarina. Rad pruža cjelovit uvid u strukturu i funkcioniranje tržišta tekućeg tereta, uz prikaz glavnih izazova i prednosti koje utječu na njegov razvoj.This thesis focuses on the analysis of the maritime liquid cargo market, with particular emphasis on tanker shipping and the factors that shape its dynamics. The thesis examines the structure and characteristics of the maritime market, including its cyclicality and seasonality, and elaborates on the concept of an efficient market. A dedicated section of the thesis addresses ships used for transporting liquid cargoes, such as ''dirty'' and ''clean'' tankers, as well as LNG and LPG carriers. The role of international organizations such as the IMO, BIMCO and INTERTANKO is also analysed, and attachments of contracts used in liquid cargo transport are included. The final part of the thesis is devoted to an analysis of the liquid cargo market in 2024, using statistical data and charts to illustrate current trends and freight rate developments. The thesis provides a comprehensive overview of the structure and the functioning of the liquid cargo market, highlighting the main challenges and advantages that influence its development

Comparison of static, dynamic and hybrid network load balancing algorithms in a 'cloud' environment

U ovom diplomskom radu obrađena je usporedba statičkih, dinamičkih i hibridnih algoritama raspodjele mrežnog opterećenja u okruženju računalstva u oblaku. Nakon teorijskog prikaza interneta i računalstva u oblaku, provedene su simulacije za svaku vrstu algoritama. Analizom rezultata potvrđena je radna hipoteza da hibridni algoritmi pružaju optimalnu ravnotežu performansi i fleksibilnosti, te se pokazuju kao najpogodniji za dinamička okruženja. Rad pridonosi boljem razumijevanju učinkovitosti algoritama u kontekstu modernih mrežnih sustava.This master thesis compares static, dynamic, and hybrid network load balancing algorithms in a cloud computing environment. Following a theoretical overview of the internet and cloud technologies, simulations were conducted for each type of algorithm. The analysis confirmed the working hypothesis that hybrid algorithms provide an optimal balance of performance and flexibility, proving to be the most suitable for dynamic environments. The thesis contributes to a better understanding of algorithm efficiency in modern network systems

Components of the ECDIS system and its integration in maritime navigation

ECDIS (Electronic Chart Display and Information System) sustav integracija je većeg broja sustava u funkcionalnu cjelinu koja donosi korisniku mogućnost brzog pristupa svim željenim informacijama u svrhu pomorske površinske navigacije. ECDIS sustav sastoji se od više dijelova. Ti dijelovi su zasebni sustavi koji se koriste u navigaciji, u radiokomunikaciji, te satelitski i ultrazvučni sustavi poput elektroničkih navigacijskih karata, odgovarajućeg programskog rješenja s prikazom informacija u zadovoljavajućoj rezoluciji, pozicijskih sustava, žirokompasa, senzora brzine, AIS-a (Automatski indetifikacijski sustav) i RADAR-a (Radio Detecting and Ranging). Glavne karakteristike i funkcije su mu brza obrada podataka i njihov prikaz na zaslonu koji omogućuje upravitelju broda brzo i točno informiranje uz jednostavno korištenje. Koristi se na svim trgovačkim i vojnim brodovima jer je tako određeno SOLAS (Safety of Life at Sea) konvencijom pa se da zaključiti da je osim u eksploatacijske svrhe, koristan u svrhu sigurnosti plovidbe i posade broda.The ECDIS (Electronic Chart Display and Information System) system is an integration of a number of systems into a functional unit that gives the user the ability to quickly access all desired information for the purpose of maritime surface navigation. The ECDIS system consists of several parts. These parts are separate systems used in navigation, radio communication, satellite and ultrasonic systems such as electronic navigation charts, appropriate software solutions with information display in satisfactory resolution, positioning systems, gyrocompasses, speed sensors, AIS (Automated Indetification System) and RADAR. Its main characteristics and functions are fast data processing and their display on the screen, which enables the ship captain to be informed quickly and accurately as it is simple to use. It is used on all commercial and military vessels, as mandated by the SOLAS (Safety of Life at Sea) convention, which indicates that, in addition to its operational role, it is also important for the safety of navigation and the ship’s crew

Greenwashing or sustainable environmental practices? The case of cruise tourism

Cruise tourism is a highly environmentally damaging form of tourism, causing various environmental degradation. This study aims to characterise cruise tourism, frame it technically and legally within international legal instruments, particularly concerning environmental policies and practices, and assess if companies' sustainability measures are steps towards sustainability or greenwashing practices. These practices are operationalised to respond to the demands of public opinion and an increasingly demanding demand in these matters, the so-called green consumers. To achieve these objectives, a comprehensive range of qualitative and quantitative data was gathered and analysed. As conclusion, cruise lines have made significant changes towards the sustainability commitments established by international organisations and the public. Nevertheless, due to their distinctive characteristics, dimensions, and intricacies, there is still a dearth of technological and logistical alternatives that are commensurate with the scale of cruise ships, despite the advancement that has been made in this direction

Risks and risk assessment in crude oil ship-to-ship (STS) transfer operations

Ovaj završni rad obrađuje operacije prekrcaja sirove nafte s jednog tankera na drugi (STS – Ship-to-Ship transfer), s naglaskom na prepoznavanje i procjenu rizika povezanih s takvim postupcima. STS operacije predstavljaju važan dio međunarodnog pomorskog prijevoza nafte, ali istovremeno donose određene sigurnosne i okolišne izazove. U radu su analizirani ključni tehnički, organizacijski i ljudski čimbenici koji mogu utjecati na sigurnost tijekom STS operacija, kao i međunarodni propisi i preporučene prakse koje ih reguliraju. Poseban naglasak stavljen je na proces procjene rizika, uključujući analizu mogućih nezgoda, njihovih posljedica te mjera za prevenciju i odgovor. Cilj rada je dati jasan i sveobuhvatan pregled sigurnosnih zahtjeva potrebnih za kvalitetno planiranje i provođenje STS operacija, uz nastojanje da se smanji rizik po ljude, okoliš i brodove.This final thesis explores the operations of crude oil transfer between tankers (STS – Ship-to-Ship transfer), with a particular focus on identifying and assessing the risks associated with this process. STS operations represent a significant part of international maritime oil transportation but also pose various safety and environmental challenges. The paper analyzes the key technical, organizational, and human risk factors, as well as international regulations and best practices that govern these types of operations. Special attention is given to the risk assessment process, including the analysis of potential incidents, their consequences, and the preventive and response measures. The aim of this work is to provide a clear and comprehensive overview of the safety requirements necessary for effective planning and execution of STS operations, while minimizing potential hazards to people, the environment, and property

Information and Communication Technology, and Supply Chains as Economic Drivers in the European Union

Background: The adoption of information and communication technology (ICT) is transforming supply chains in the European Union, affecting logistical performance, economic integration and sustainability. This study examines the extent to which ICT adoption affects logistics efficiency in the 27 EU Member States. Methods: Using panel data from the World Bank and UNCTAD (2008–2018), the analysis applies the Arellano–Bond Generalized Method of Moments estimator to assess the impact of ICT indicators, broadband penetration, mobile connectivity and digital skills on logistics performance. GDP per capita and trade openness are included as control variables. Results: The results show that a 1% increase in ICT usage correlates with a 0.12-point increase in the Logistics Performance Index. Higher ICT usage leads to more efficient supply chains, lower costs and higher customer satisfaction. However, there are still differences in digitalization: the ICT usage rate of SMEs is 28% in Bulgaria and 27% in Romania, compared to the EU average of 59%. Conclusions: Bridging the digital divide requires targeted investments in ICT infrastructure, harmonized regulatory frameworks and stronger public–private cooperation to foster regional economic cohesion. This study provides policy recommendations to drive digital transformation, strengthen the resilience of logistics and improve the sustainability of supply chains in the EU

The Relationship between Ports and Regional Development - a Bibliometric and Visualization Analysis

Interest in ports and their impact on regional development can be traced back to the early days of industrialization and world trade, but has become more important in recent decades due to changes in global economic patterns, technological advances and the increasing importance of sustainable development. Although the economic impact of ports has been explored in the literature, there is a lack of studies dedicated to analyzing the popularity of this topic in academic papers. This research aims to fill this gap by employing a bibliometric analysis to capture the evolution of academic work on the relationship between ports and regional development and to identify research patterns and emerging areas of interest. Bibliometric analysis and visualization tools are used for the analysis. Based on the Web of Science Core Collection database, the most important research areas, journals and author keywords are identified. The results of the analysis are visualized with the VOSviewer software. The findings show that the topic is popular and that there is a growing trend in publications on the relationship between ports and regional development. Authors from port countries dominate the field. In addition, major publishers such as Elsevier and Taylor & Francis publish the most on this topic. The results of the co-occurrence analysis show the dominance of the keywords ports, management, port performance, logistics, which indicates that these keywords are of central importance for the research area under investigation

FLNG Facilities as a Solution for Natural Gas Liquefaction

U završnom radu analizirani su dizajn, koncept i operativni segmenti plutajućih postrojenja za ukapljivanje prirodnog plina. Obrađen je povijesni razvoj FLNG tehnologije te razlozi prihvaćanja takve tehnologije u industriji. Opisane su ključne tehnološke komponentne od samog dizajna, spremnika, sustava za iskrcaj LNG-a do sustava sidrenja. Naročita pažnja je posvećena procesu ukapljivanja prirodnog plina na FLNG postrojenjima, uključujući pripremu plina za ukapljivanje i same tehnologije ukapljivanja. U radu su dodatno razmotrene prednosti FLNG postrojenja, poput efikasnosti, manjeg utjecaja na kopnenu infrastrukturu, tehnička ograničenja i utjecaja na okoliš. Peto poglavlje donosi pregled trenutnih FLNG postrojenja u svijetu i nakon toga dolazi analiza FLNG postrojenja u zaključku.The final paper analyzes the design, concept and operational segments of floating liequefied natural gas (FLNG) facilities. It covers the historical development of FLNG technology and the reasons for the adoption of FLNG in the industry. Key technological components are disracebed, from the design itself, storage tanks, LNG offloading systems, to mooring systems. Particular attention is given to the process of natural gas liquefaction on FLNG units, including gas pre-treatment and liquefaction technologies. The advantages of FLNG facilities are discussed, such as efficiency, reduced impact on onshore infrastructure, technical limitations and enviromental impact. Chapter five provides an overview of current FLNG facilities in the world, followed by an analysis of the entire content in the conclusion