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SUNSPOTS
No full textUvodni dio započinje s opisom ranih zapažanja Sunčevih pjega prije izuma teleskopa i nakon.
Nadalje, dana je definicija pjega te opis njihove građe i veličine. Također, u radu je opisan i
mehanizam njihova nastanka.
Tijekom daljnjeg izlaganja obrađena je tema Sunčevog ciklusa u kojoj su opisana važna otkrića
vezana za Sunčev ciklus. Tema Sunčevog ciklusa obuhvaća i opis brojnosti pjega i njihove
položaje na Suncu. Uz to opisan je 24. Sunčev ciklus te predviđanja za 25. Sunčev ciklus.
Na kraju rada, obrađuje se tema o sondama i novim spoznajama do kojih se došlo pomoću njih.The introductory part begins with a description of the early observations of sunspots before and
after the invention of the telescope. Furthermore, the definition of spots and a description of their
structure and size is given. Also, the paper describes the mechanism of their occurrence.
During the further presentation, the topic of the solar cycle was discussed, in which important
discoveries related to the solar cycle were described. The topic of the solar cycle includes a
description of the number of spots and their positions on the Sun. In addition, the 24th solar
cycle and predictions for the 25th solar cycle are described. At the end of the paper, the topic of
probes and new insights gained with them is discussed
Linearization of equations of motion
No full textUvod u linearizaciju jednadžbi gibanja tijela započinjemo teorijskim dijelom gdje predstavljamo
uvjete ravnoteže te potrebne korake za dobivanje jednadžbi gibanja u okviru analitičke mehanike.
Osim teorijskog dijela obrađene su i matematičke definicije potrebne za pronalaženje jednadžbe
gibanja, te njenu linearizaciju. U nastavku slijedi nekoliko primjera sustava s jednim i više
stupnjeva slobode u kojima su pronađene i linearizirane jednadžbe gibanja.The introduction to the linearization of the equations of motion begins with a theoretical part where
we present the conditions of equilibrium and all necessary steps for obtaining the equations of
motion in the form of analytical mechanics. In addition to the theoretical part, the mathematical
definitions for finding the equations of motion and its linearized forms are also processed. In
addition there are some examples of systems with one or more degrees of freedom in which the
equations of motion are found and linearized
MOMENT OF INERTIA OF A REGULARLY GEOMETRIC BODIES
No full textUvod u moment tromosti pravilnih geometrijskih tijela započinjemo osnovnim definicijama
potrebnih za bolje razumijevanje gradiva. Nakon upoznavanja s općenitim teorijskim dijelom
ulazimo u matematičke definicije i objašnjenja koja su potrebna za izračun momenta tromosti.
U daljnjem izlaganju slijedi rješavanje primjera. Na kraju rada nalaze se ukratko sažeti izrazi za
momente tromosti standardnih geometrijskih tijela oko glavnih osi.We begin our thesis about moment of inertia of a regularly geometric bodies with basic definitions
needed for better understanding of the material. After familiarising ourselves with the general
theoretical part, we enter into mathematical definitions and explanations which are required for
the moment of inertia. In addition, we move on to solving examples. At the end, there are briefly
summarized expressions of moment of inertia of standard geometric bodies around the main axis
COSMIC IONIZING RADIATION AT FLIGHT ALTITUDES
No full textPovećanjem broja niskotarifnih zračnih prijevoznika i pristupačnijim cijenama karata,
komercijalni zračni prijevoz bilježi rast broja putnika. Otvaraju se nova odredišta, flote se
povećavaju, što također zahtijeva i veći broj letačke posade. Putnici i posada su tijekom leta
izloženi povećanoj dozi ionizirajućeg kozmičkog zračenja, a iznos doze zračenja koju će oni
primiti ovisi o nadmorskoj visini, geografskoj širini, trajanju leta i Sunčevoj aktivnosti. Prvi dio
ovog rada opisuje povijest i vrste ionizirajućeg zračenja, a daljnju tematiku usmjeravam na
kozmičko ionizirajuće zračenje. U drugom dijelu su predstavljene dopuštene doze za članove
posade koje izdaju ICRP, EU i FAA s potrebnim metodama mjerenja doza i izračunima pomoću
prihvaćenih računalnih programa kao što su CARI, EPCARD.Net ili SIEVERT. Primjer
provedenog mjerenja doza zračenja na letovima IBERIA airlines daje nam usporedbu s gore
spomenutim programima. Rad završavam biološkim utjecajem ionizirajućeg zračenja i
mogućim povećanim rizikom od razvoja malignih bolesti.With an increased number of low-cost airlines and more affordable ticket prices,
commercial air transport is experiencing growing passenger numbers. New destinations are
opening and fleets are increasing, which requires a larger number of aircrew too. Passengers
and aircrew are exposed to an increased dose of ionizing cosmic radiation during the flight and
the amount of radiation dose which they will receive depends on altitude, latitude, flight
duration and solar activity. The first part of this paper describes the types of ionizing radiation
and it's history, further I focus only on cosmic ionizing radiation. In the second part, the
permitted annual doses for crew members issued by the ICRP, EU and FAA is presented with
required flight measurement methods and calculations using accepted computer programs such
as CARI, EPCARD.Net or SIEVERT. The example of measuring radiation doses on IBERIA
airlines flights provides a comparison with the programs mention above. Lastly, I conclude with
biological effects of ionizing radiation and possible increased risk of developing malignant
diseases
EXPERIMENTAL VERIFICATION OF NEWTON'S LAW OF COOLING
No full textMjerenja su izvršena u praktikumu na Odjelu za fiziku u Osijeku. Za vrijeme mjerenja uvjeti u
prostoriji su stalno bili kontrolirani. Jednim termometrom CATT2 uređaja je praćena
temperatura tvari tijekom njezinog hlađenja, a drugim je praćena temperatura okoline. Pomoću
teorijskog izraza za Newtonov zakon hlađenja dobivena je temperatura na koju bi se tijelo
trebalo ohladiti u određenom vremenu te je grafički prikazana njezina usporedba s
temperaturom dobivenom eksperimentom.Measurements were performed in a practicum at the Department of Physics in Osijek. During
the measurement, the conditions in the room were constantly controlled. One thermometer of
CATT 2 device measured the temperature of the substance during its cooling and the other one
measured the ambient temperature. Theoretical expression for Newton's law of cooling was
used to obtain the temperature at which the body should cool down in a certain time and its
comparation with the temperature to which the body actually cooled down at that time is shown
graphically
THERMOPHOTOVOLTAICS
No full textReprezentativni i glavni dio fotonaponskih sustava je fotonaponska ćelija. Ona se može
definirati kao poluvodič pomoću kojeg se svjetlost Sunčevog zračenja izravno pretvara u
električnu energiju , odnosno dolazi do pojave kod koje se na krajevima prikladno oblikovanog
poluvodičkog elementa, kod izloženja svjetlosti, inducira elektromotorna sila, čime fotonaponska
ćelija postaje izvor istosmjerne električne struje. Uz objašnjene vrste termovotovoltaika, u radu
su objašnjene primjene te princip rada.Representative and main part of photovoltaic systems is photovoltaic cell. It can be defined
as a semiconductor by which the light of solar radiation is directly cpnverted into electricity, or
there is a phenomenon in whch an electromotive force is generated at the ends of suitably shaped
semiconductor element during light exposure, and photovoltaic cells becomes the source of
direct electric current. In addition to the types of thermovoltaics, the thesis explains the
applications and the principle of operation
BEHAVIOR OF MATERIALS IN MAGNETIC FIELD - DIAMAGNETS AND PARAMAGNETS
No full textPočetni dio rada obuhvaća povijesni razvoj magnetizma, teoriju kojom se objašnjava
podrijetlo magnetizma u tvarima i objašnjenje magnetizacije, a zatim su opisana svojstva
pojedinih skupina tvari koje dijelimo prema ponašanju u vanjskom magnetskom polju, odnosno
dijamagneta, paramagneta, feromagneta, antiferomagneta te ferimagneta. Središnji dio rada
posvećen je jednostavnim demonstracijskim pokusima koji prikazuju ponašanje dijamagneta i
paramagneta u prisustvu magnetsko polja. Nakon toga, u završnom dijelu, priložena je
metodička jedinica u kojoj su uklopljeni slični demonstracijski pokusi kojima bi učenici mogli
nadopuniti znanje o dijamagnetima i paramagnetima koji se rijetko detaljnije obrađuju u nastavi
fizike.The first part of master thesis includes historical development of magnetism, theory that
describes origin of magnetism and explanation of properties in individual groups of substances
that can be divided according to their behaviour in the external magnetic field, which are
diamagnets, paramagnets, ferromagnets, antiferromagnets and ferrimagnets. Simple
demonstration experiments that are showing behaviour of diamagnets and paramagnets in the
presence of magnetic field are contained in main part. After that, in the final part of master
thesis, we have methodical unit that contains similar demonstration experiments in which
students could supplement their knowledge of diamagnets and paramagnets, which are rarely
discussed details in physics class
1D Ising model and transfer matrix
No full textIsingov jednodimenzijski model je model čiji su sastavni elementi magnetski momenti spina ±1/2. Spinovi
međudjeluju silama kratkog dosega ograničenog samo na prve susjede. Particijska funkcija ovog modela
računa se pomoću matrice transfera (odjeljak 4.1). Iz poznate particijske funkcije lako se računa slobodna
energija, magnetizacija i ostale termodinamičke funkcije. Za magnetizaciju se pokazuje da je analitička
funkcija temperature za sve T > 0, što ukazuje da u ovom Isingovom modelu ne postoji fazni prijelaz za
T > 0.Ising’s one-dimensional model is a model whose constituent elements are magnetic moments of spin ±1/2.
Spins interact with short-range forces limited only to the first neighbours. The partition function of this model is easy to calculate using transfer matrix (section 4.1). From the known partition function, free energy,
magnetization and other thermodynamic functions can be easily obtained. It shows that the magnetization
is analytical function of the temperature for all T > 0, which shows that in this Ising model, there is no
phase transition for T > 0
INFLUENCE OF SUBSTRATE MORPHOLOGY ON 2D MATERIAL STRUCTURES
No full textCilj ovog rada bio je proširiti već postojeću bazu znanja o svojstvima 2D materijala. Struktura
aluminena (dvodimenzionalni alotrop aluminija) ispitana je na nekoliko određenih supstrata.
Aluminen je pretpostavljen u tri različite alotropske modifikacije (ravninska saćasta, svijena
saćasta i ravninska trokutasta) čije su jedinične ćelije relaksirane na supstratima: Cu, Ag, Au,
Ge, PdTe2, Pt i Ir. Ideja rada je otkriti utjecaj supstrata na strukturu 2D aluminija (aluminena).
Za sve račune koristili smo softver Quantum ESPRESSO, programski paket namijenjen za
izračune elektronskih struktura i modeliranje materijala. Na kraju, kroz ovaj rad pokušali smo
utvrditi poveznicu između morfologije i konstante rešetke supstrata i postavljene 2D strukture.
To znanje će biti od iznimnog značaja za buduće eksperimentalne pokušaje sinteze aluminena.The focal point of this thesis, which centres on the expansion of an existing knowledge about
the properties of 2D materials, is the structure of aluminene (two-dimensional allotrope of
aluminium) paired with specifically chosen substrates. Aluminene is proposed in three different
allotropic modifications (planar honeycomb, buckled honeycomb and planar triangular) with
its unit cell relaxed onto several different substrates: Cu, Ag, Au, Ge, PdTe2, Pt and Ir. The aim
of this thesis is to determine which of these metallic surfaces can serve as a synthesis substrate
as well as to examine their impact on the crystal structure of aluminene. In order to do this,
software Quantum ESPRESSO, a suit for ab initio quantum chemistry methods of electronicstructure calculation and materials modelling, is used. Furthermore, another aim of this study
is, to establish relations and find patterns between the morphology and lattice constant of the
substrates and the proposed 2D structure. This knowledge will be of great importance for future
experimental attempts of aluminene synthesis
Ambient dose equivalent rate on Kopački rit
Get PDFU teorijskom dijelu rada opisana je osnovna teorija građe atoma, svojstva ionizirajućeg zračenja, podjela
ionizirajućeg zračenja i djelovanje ionizirajućeg zračenja na ljudsko tijelo. Nadalje, opisane su osnovne
dozimetrijske veličine i vrste detektora kojim se detektira zračenje. Osim toga navedeni su i izvori zračenja i
njihova osnovna podjela.
U eksperimentalnom dijelu rada opisani su korišteni uređaji i računalni programi. Opisane su lokacije
mjerenja i razlog zašto su provedena mjerenja na točno određenom području. Rezultati mjerenja su podijeljeni u
dvije skupine uzoraka te statistički obrađeni. Osim uvida u brzinu ambijentalnog doznog ekvivalenta na području
Kopačkog rita, željelo se utvrditi postoji li utjecaj Dunava na brzinu ambijentalnog doznog ekvivalenta.Theoretical part od this thesis describes fundamental theory: built of an atom, the properties of ionizing
radiation, classification of ionizing radiation and effects from ionizing radiation on human body . Furthermore,
basic dosimetric quantities and types of detectors for detecting radiation are described. Also, sources of radiation
and their classsification are listed.
In the experimental part of this thesis are described used devices and softwares as well as the area of
measurement and the reason why measurements were carried out in specific area. The results of the measurements
were divided into two groups of samples and statistically processed. Apart from the insight into the velocity of
the ambient dosage equivalent in the Kopački rit field, it was desirable to determine whether the influence of the
Danube River on the velocity of the ambient dosage equivalent was present