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Dangers when transporting bulk cargo on bulk carriers
No full textBrodovi za prijevoz rasutih tereta specijalizirani su brodovi koji su se razvili 60-ih godina kao uzrok povećanja potražnje za prijevozom većih količina suhog rasutog tereta. Glavne značajke tih brodova su jedna glavna paluba s velikim otvorima skladišta, vlastita prekrcajna sredstva na manjim brodovima te nadgrađe, strojarnica i zapovjedni most na krmi broda. Skladištni prostor tereta najvažniji je element broda. Sustav balasta ima veliku ulogu u održavanju pozitivne stabilnosti broda tijekom plovidbe praznog broda. Brodove pogone sporohodni dizelski motori s fiksnim krilima te postižu brzinu između 13 i 15 čvorova. Brodove za prijevoz rasutih tereta dijelimo po veličini i vrsti. Glavni problem kod ovih brodova su sile i momenti koji dijeluju na brod pod utjecajem tereta. Ugradnjom HMSS-Hull Stress Monitoring System sustava smanjila se opasnost. Glavni uzroci strukturnih problema su korozija, pad tereta na oplatu dna skladišta, prijevoz korozivnog tereta, oštećenja prouzročena teretnom opremom, zamor metala te operativni faktori. Svaki od tih uzroka na svoj način šteti brodu i čvrstoći brodske konstrukcije. Glavni uzrok svih nesreća i dalje je ljudski faktor. Svaki brod mora imati izrađen plan ukrcaja/iskrcaja tereta koji će zadovoljiti pozitivnu stabilnost tijekom operacija i koji će zadovoljiti sigurnosne zahtjeve vezane za sile i momente savijanja. Sekvence ukrcaja/iskrcaja moraju biti usklađene s krcateljem te mora biti osigurana dovoljna količina tereta za završni trim broda. Svaki rasuti teret donosi određene opasnosti prilikom prijevoza morem. Teški tereti neravnomjerno opterećuju dno skladišta. Pomak tereta u navigaciji može drastično ugroziti stabilnost, kako bi se to spriječilo određene terete se poravnava ili ih se ukrca do vrha skladišta. Problem likvifikacije kod tereta s velikom količinom vlage, a koja pod utjecajem vibracija i valjanja broda, pretvara teret u tekuće stanje. Samozapaljenje i samozagrijavanje tereta može izazvati ozbiljne probleme na brodu osobito na otvorenom moru. Određeni tereti mogu izazvati kemijske reakcije te se prema IMSBC kodu svrštavaju u opasne terete. Ostali problemi izazvani teretom su manjak kisika, prašina nastala rukovanjem teretom te neke ostale kemijske reakcijeBulk carriers are specialized ships that developed in the 1960s as a result of increased demand for the transportation of larger quantities of dry bulk cargo. The main features of these ships are one main deck with large storage hatches, own cargo handling gear on smaller ships and a superstructure, engine room and command bridge at the stern of the ship. The cargo hold is the most important element of the ship. The ballast system plays a major role in maintaining the positive stability of the ship during the navigation of the empty ship. The ships are powered by slow-moving diesel engines with fixed wings and reach a speed of between 13 and 15 knots. Bulk carriers are divided by size and type. The main problem with these ships are the forces and bending moments acting on the ship under the influence of the load. By installing the HMSS-Hull Stress Monitoring System, the danger was reduced. The main causes of structural problems are corrosion, load falling on the double bottom tank, transportation of corrosive cargo, damage caused by cargo equipment, metal fatigue and operational factors. Each of these causes damages, in its own way, to the ship and the strength of the ship's structure. The main cause of all accidents is still the human factor. Each ship must have a cargo loading/unloading plan designed to ensure positive stability during operations and to meet safety requirements related to forces and bending moments. Loading/unloading sequences must be coordinated with the shipper and a sufficient amount of cargo must be provided for the final trim of the ship. Every bulk cargo carries certain risks during sea transportation. Heavy loads unevenly load the bottom of the holds. The movement of the load in the navigation can drastically threaten the stability, in order to prevent this, certain loads are leveled or loaded to the top of the hold. The problem of liquefaction in cargo with a large amount of moisture, which under the influence of vibrations and rolling, turns the cargo into a liquid state. Self-ignition and self-heating of cargo can cause serious problems on board, especially on the open sea. Certain cargoes can cause chemical reactions and are classified as dangerous cargoes according to the IMSBC code. Other problems caused by cargo are lack of oxygen, dust created by cargo handling and some other chemical reactions
Organizational and nautical segments of exceptionally long cruise voyages
No full textOvaj rad namijenjen je svima koje zanimaju kružna putovanja, osobito ona dugotrajna, i žele znati više o samom procesu kreacije takvog putovanja, od ideje za stvaranje ponude preko organizacije prije, tijekom i nakon putovanja, do krajnje točke podmirivanja svih troškova i uvid u ostvarenu dobit. Rad se dotiče segmenata i komponenti organizacije i nautičke djelatnosti koje se javljaju putem do realizacije jednog izuzetno dugog kružnog putovanja. Opseg rada omogućava uvid samo u bitne elemente svake od obrađenih tema, uz detaljnije pojašnjenje onih najvažnijih. Samim time, rad pruža temelj za dobivanje osnovnih informacija o kompleksnosti koju predstavlja tema rada te služi kao podloga za daljnje informiranje i istraživanje teme. Rad je potaknut relativno malim brojem literature i publikacija koje obrađuju temu izuzetno dugih kružnih putovanja.This paper is intended for anyone interested in cruise voyages, especially the lengthy ones, and wishes to learn more about the process of creating such a voyage, from the initial offer idea, through the organization before, during, and after the trip, to the final settlement of all costs and insight into the generated profit. The paper addresses the segments and components of organization and nautical activities that arise along the way to the realization of an exceptionally long cruise voyage. Scope of the paper provides insights into only the essential elements of each discussed topic, with more detailed explanations of the most important ones. Therefore, the paper provides a foundation for obtaining basic information about the complexity of the topic and serves as a basis for further research on the subject. The paper was inspired by the relatively small amount of literature and publications that deal with the paper’s title
Ecological garbage disposal on ships
No full textNepravilno zbrinjavanje otpada i smeća na brodovima rezultiralo je povećanim onečišćenjem i zagađenjem mora i oceana. Brojna istraživanja osvijestila su čovjeka na potrebu pravilnog rukovanja otpadom i smećem kao bi se zaštitilo zdravlje ljudi te flora i fauna podvodnog svijeta. Postupanje sa smećem i otpadom na brodu regulirano je prema Međunarodnoj konvenciji o sprječavanju onečišćenja mora s brodova (engl. International Convention for the Prevention of Pollution from Ships – u daljnjem tekstu skraćeno „MARPOL konvencija“) koja se u Prilogu V bavi sprječavanjem onečišćenja mora smećem. Novi brodovi opremljeni su uređajima za smanjenje volumena otpada, incineratorima za spaljivanje smeća, spremnicima za pravilno razvrstavanje otpada te uređajima za usitnjavanje hrane.
Od svih onečišćivača, plastika predstavlja najveću opasnost za mora i oceane zbog nepovoljnog ekološkog utjecaja uslijed vrlo dugotrajne razgradnje. Čovjek je svojim neodgovornim i nemarnim ponašanjem najveći krivac dospijeća plastike u mora i oceane. Poštivanjem donesenih propisa u pomorstvu, znatno se smanjio udio onečišćenja mora smećem s brodova.Unregulated waste disposal on ships led to pollution and contamination of the seas and oceans. Various researches have urged people to properly dispose of garbage and waste to protect human health and underwater life. Waste disposal on ships is governed by the International Convention for the Prevention of Pollution from Ships (MARPOL Convention), which addresses the prevention of marine pollution from waste in Annex V. New ships are equipped with various devices to reduce the volume of waste on board, incinerators to burn garbage, food shredders, and containers to properly sort garbage for easier delivery to reception centers. Plastic poses the greatest threat of pollution to the seas and oceans when it decomposes due to its ecological impact. Humans are the biggest contributors to plastic in the ocean due to their irresponsible and careless behavior. Compliance with maritime laws and regulations has reduced marine litter pollution
Digital speech processing
No full textOvaj završni rad bavi se proučavanjem metoda i tehnika digitalne obrade govora te prikaza govornih signala. Opisane su Z-transformacije i Fourierove transformacije kao tehnike analize govornih signala kojima se određuju određene karakteristike tog signala, te njihov grafički prikaz u vidu spektrogramske analize glasovnog signala. Obrađene su jednostavnije metode digitalnog enkodiranja poput PCM-a, DPCM-a i ADPCM-a. Prikazan je i razvoj LPC-a i CELP-a kao tehnologija za rekreiranje i kompresiju govornog signala. Za sam kraj obrađene su moderne tehnike digitalne obrade govora poput VoIP-a, HMM-a i ANN-ova te njihova uloga u svakidašnjem životu ljudi.This thesis studies the methods and techniques of digital speech signal processing and representation of speech signals. Z-transformations and Fourier's transformations are described as techniques for analysis of speech signals that determine specific characteristics of those signals, and allow for a graphical representation in form of a spectrogram. Then it elaboretes elementary methods of digital speech encoding such as PCM, DPCM and ADPCM. Furthermore, LPC and CELP are represented as techonologies for recreating and compressing of speech signals. Lastly, VoIP, HMM and ANNs are depicted as modern techniques for digital speech processing and their role in everyday human lives is described
Testing quality of electrical insulation
No full textElektrična izolacija je nezamjenjiva komponenta svih modernih elektroenergetskih sustava. Dobro poznavanje i razumijevanje značajki izolacije ali i samog sustava od iznimne je važnosti sa siguran i neometan rad sustava, kako kopnenih tako i sustava na brodovima. Zbog značajnog razvoja i zahtjeva za boljom i većom količinom električne energije u svijetu sve više su zastupljeniji visoko naponski sustavi, zbog kojih inženjeri biti u mogućnosti efikasnije rješavati i kontrolirati probleme sa izolacijom i visokim naponima u sustavima. Osnovna ideja ovog rada je opisati što je to električna izolacija i koliko je ona značajna u elektroenergetskim sustavima. Zatim je vrlo važno razumjeti koje vrste izolacijskih materijala postoje, kod kojih sustava ili dijelova sustava se primjenjuju te njihova svojstva. Na samom kraju opisane su metode ispitivanja električne izolacije te načini i zahtjevi koji trebaju biti ispunjeni tijekom ispitivanja, kontrole i nadzora.Electrical insulation is an indispensable component of all modern power systems. Good knowledge and understanding of the features of isolation but also of the system itself is extremely important for the safe and unobstructed operation of the system, both onshore and on-board systems. Due to the significant development and demand for quality and better electricity transmission in the world, high-voltage systems are increasingly represented, creating more demanding problems for engineers in terms of efficiently and solving problems with insulation and high voltages in systems. The basic idea of this paper is to describe what electrical insulation is and how significant it is in power systems. Then it is very important to understand what insulation materials exist, which systems or parts of systems are applied and their properties. At the very end there will be described methods of electrical insulation testing and also requirements which need to be met during testing, control and monitoring
Short sea shipping and trends in the world
No full textMeđuobalnim prometnim povezivanjem ostvaruje se prometna povezanost na kraćim obalnim relacijama, između geografski bliskih država. Radi se o transportnom modelu koji spaja više različitih prometnih grana u jedinstvenu cjelinu s posebnim naglaskom na pomorstvo i visokorazvijene luke. Pomoću ostalih prometnih grana, teret pristigao pomorskim putem moguće je prevesti do unutrašnjosti zemalja u kojima se luke nalaze te država koje nemaju dostupan izlaz na more. U svrhu lakših prekrcajnih i prijevoznih operacija, osmišljeni su i različiti prijevozni modeli što ubrzava cjelokupan transportni proces. Uz visoke tehnološke zahtjeve, međuobalno prometno povezivanje karakteriziraju i različiti politički te ekonomski faktori. Korištenje međuobalnog prometnog povezivanja vidljivo je u cijelome svijetu s Europom kao primjerom. Države članice EU imaju razvijene pomorsko-prometne veze što je i jedna od glavnih odlika samog transportnog modela.Inter-coastal transport links provide transport connections on shorter coastal routes, between geographically close countries. It is a transport model that combines several different transport branches into a single entity with a special emphasis on shipping and highly developed ports. With the use of other transport branches, cargo arrived by sea can be transported to the interior part of the countires where ports are located and countries which do not have access to the sea. For the purpose of easier transshipment and transport operations, various transport models have been designed, which speeds up the entire transport process. In addition to high technological requirements, inter-coastal transport connections are characterized by various political and economic factors. The use of intercoastal transport links is seen all over the world with Europe as an example. The EU member states have highly developed maritime transport links, which is one of the main features of the transport model itself
The role of the port in the supply chain
No full textLuka omogućava obavljanje lučkih djelatnosti uz minimalni rizik koji se odnosi na
oštećenje tereta te cjelokupnog broda. Veoma je bitno da luke posjeduju odgovarajuće
akvatorije, prometne infrastrukture, lučke infrastrukture, suprastrukture, pretovarnu opremu te
postrojenja kroz koja se omogućuje osiguravanjem sigurnog pristajanja broda te potom sigurno
skladištenje kao i rukovanje teretom. Sukladno operativnim i administrativnim funkcijama luke
ona predstavlja složen i dinamičan sustav. Osim toga pojedine luke, u okviru svog sastava,
imaju sve operativne funkcije ili samo dio tih funkcija. Učinkovit opskrbni lanac oslanja se na
optimizirane odnose, učinkovitu tehnologiju, izvrsno dijeljenje informacija i moderniziranu
infrastrukturu. Iako postoji mnogo toga što organizacije mogu učiniti kako bi smanjile kašnjenja
i osigurale točnost u vlastitoj otpremnoj, prijamnoj i transportnoj infrastrukturi, postoji veliko
područje koje se može pokazati kao značajan izazov – luke. Učinkovitost luke utječe na
organizacije u cijelom opskrbnom lancu – dobavljače, proizvođače, pružatelje logističkih
usluga, špeditere, prijevoznike tereta i druge. Svatko može imati koristi od boljeg uvida u rad
portova. Luke igraju ključnu ulogu u olakšavanju globalne trgovine i logistike služeći kao
ključna čvorišta koja povezuju zemlje i kontinente. Oni su vitalne komponente međunarodnog
opskrbnog lanca, služe kao pristupnici za kretanje robe i olakšavaju besprijekornu povezanost
između različitih načina prijevoza. Sve veći opseg prijevoza u kontejnerima postavlja
infrastrukturne izazove, zahtijevajući od luka da unaprijede svoje objekte za rukovanje većim
plovilima i većim količinama tereta.The port enables the performance of port activities with minimal risk related to damage
to the cargo and the entire ship. It is very important that ports have adequate water areas, traffic
infrastructures, port infrastructures, superstructures, transshipment equipment and facilities
through which it is possible to ensure the safe docking of the ship and then the safe storage and
handling of cargo. In accordance with the operational and administrative functions of the port,
it represents a complex and dynamic system. In addition, certain ports, within their composition,
have all operational functions or only a part of these functions. An effective supply chain relies
on optimized relationships, efficient technology, excellent information sharing and modernized
infrastructure. While there is much that organizations can do to reduce delays and ensure
accuracy in their own shipping, receiving and transportation infrastructure, there is one big area
that can prove to be a significant challenge – the ports. Port efficiency affects organizations
throughout the supply chain – suppliers, manufacturers, logistics service providers, freight
forwarders, freight carriers and others. Everyone can benefit from better insight into port
performance. Ports play a key role in facilitating global trade and logistics by serving as key
hubs connecting countries and continents. They are vital components of the international supply
chain, serving as gateways for the movement of goods and facilitating seamless connectivity
between different modes of transport. The increasing volume of container shipping poses
infrastructural challenges, requiring ports to upgrade their facilities to handle larger vessels and
larger volumes of cargo
Three-phase marine alterators SR4B
No full textZadatak ovog rada je bio dati detaljan pregled SE i PMPE inačica Caterpillarovog SR4B generatora te opisati njihovo servisiranje i održavanje. Uzbuda generatora ostvaruje se metodom preduzbude s permanentnim magnetima (PMPE) ili metodom samouzbude (SE). SE verzija generatora je osjetljivija na fluktuacije opterećenja nego PMPE verzija. Za kvalitetnu regulaciju napona važna je točnost napona, brzina odziva i stabilnost napona. Automatski regulatori napona (AVR) stalno nadziru i podešavaju napon generatora kako bi ga održavali konstantnim. Tijekom prvog puštanja generatora u pogon važno je nadzirati parametre generatora i pogonskog stroja. Posebno treba pratiti: napon, struju, frekvenciju, tlak ulja i temperaturu pogonskog stroja.The task of this paper was to provide a detailed overview of the SE and PMPE versions of the Caterpillar SR4B generator and to describe their servicing and maintenance. Excitation of the generator is achieved through either the permanent magnet pilot exciter (PMPE) method or the self-excitation (SE) method. The SE version of the generator is more sensitive to load fluctuations than the PMPE version. Voltage regulation relies on voltage accuracy, response speed, and voltage stability. Automatic voltage regulators (AVR) constantly monitor and adjust the generator voltage to maintain it constant. During the initial startup of the generator, it is important to monitor the generator and prime mover parameters. Specifically, voltage, current, frequency, oil pressure, and prime mover temperature should be closely monitored
The appearance of static electricity during the crude oil washing
No full textPrilikom transporta sirove nafte tankerima u tankovima ostaju ostaci ili talog nafte koji se sastoji od parafinskih i asfaltnih tvari. Pranje tankova sirovom naftom izvodi se na način da se uzme dio tereta koji se iskrcava u luci iskrcaja i provede kroz sustav za pranje tankova. Tijekom pranja tankova može doći do stvaranja statičkog elektriciteta i eksplozije pogotovo ako postoji mješavina nafte i vode koja može proizvesti električki nabijenu vodenu maglu tijekom čišćenja tankova.
Statički elektricitet nastaje kada gorivo niske vodljivosti poput benzina teče kroz nevodljivu cijev. Negativni naboji se nakupljaju na stijenci cijevi, a pozitivni naboji se odnose s gorivom.During the transportation of crude oil by tankers, residues or sediments of oil, consisting of paraffinic and asphaltic substances, remain in the tanks. Crude oil tank washing is performed by taking part of the cargo that is unloaded at the port of unloading and passing it through the tank washing system. During tank washing, static electricity and explosions can occur, especially if there is a mixture of oil and water that can produce an electrically charged water mist during tank cleaning.
Static electricity occurs when a low-conductivity fuel such as gasoline flows through a non-conductive pipe. Negative charges accumulate on the pipe wall, and positive charges relate to the fuel
Inflation
No full textU ovom radu analizira se tema inflacije. Objašnjava se sami pojam inflacije, te njezine glavne karakteristike kao što su intenzitet, trajanje, uzroci i sl. Također, proučavaju se njezini učinci na državno gospodarstvo i ekonomiju, te njezina povezanost sa stopom nezaposlenosti. Prikazuje se način računanja intenziteta inflacije, te koji se sve parametri uzimaju u obzir. Analizira se pozicija Republike Hrvatske, kako povijesna tako i sadašnja, te kako i tko kontrolira inflaciju i provodi antiinflacijske mjere. Naposljetku, proučava se inflacija u 2023. godini, te utjecaj pandemije koronavirusa i rata u Ukrajini na inflaciju u svijetu i Hrvatskoj.This bachelor's thesis analyzes the topic of inflation. The concept of inflation is explained, and it´s main characteristics such as intensity, duration, causes, etc. Also, its effects on the national economy and economy, and its connection with the unemployment rate, are studied. It shows the method of calculating the intensity of inflation, and which parameters are taken into account. The position of the Republic of Croatia, both historical and current, is analyzed, as well as how and who controls inflation and implements anti-inflationary measures. Finally, inflation in 2023 is studied, as well as the impact of the coronavirus pandemic and the war in Ukraine on inflation in the world and in Croatia