Repository of Department of Physics in Osijek
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The magnetic field of the Sun
Get PDFSunce je pojam kojeg svakodnevno susrećemo i upotrebljavamo u raznim kontekstima,
no ako želimo nešto više znati o Suncu općenito, ponajviše o Sunčevoj unutrašnjosti i
aktivnostima, onda je magnetsko polje Sunca zasigurno neizostavan pojam.
U ovom završnom radu bit će detaljnog govora o magnetskom polju Sunca. U prvom
dijelu rada teorijski su obrađeni osnovni podaci i razmatranja. U središnjem dijelu rada slijedi
razrada temeljnih pojmova vezanih uz nastanak i ponašanje magnetskog polja općenito i
konkretni učinci u pojedinim područjima. Zanimljive fenomene koje uzrokuje magnetsko polje
na Sunčevoj površini i unutrašnjosti, uz teorijsku obradu sadrže i ilustracijske slike.Sun is a term which we daily encounter and use in different contexts, but if we want to
know something more about the Sun and Sun's interior and activities, then the magnetic field of
the Sun is an indispensable term.
In this bachelor's thesis there will be a detailed discussion about Sun's magnetic field. To
begin with, there are theoretically analyzed basic data followed by elaboration of basic terms
related to occurrence and behavior of magnetic field in general and specific effects in certain
areas. Interesting phenomena which are caused by magnetic filed on Sun's surface and interior,
along with theoretical treatment are illustrated by picture
State of the gas in the gravitational field
Get PDFRad započinje opisom Boltzmannove raspodjele kojom se opisuje stanje plina u gravitacijskom
polju. Zatim ću definirati što je to gravitacijsko polje u kojem se promatrani plin nalazi, što je u
ovom slučaju zrak. Nakon toga upotrebom Boltzmannove raspodjele dolazim do barometarskih
formula kojima se opisuje stanje plina u gravitacijskom polju. Te zatim se opisuje
eksperimentalna potvrda Boltzmannove raspodjele, koju nam je omogućio Perrin.Thesis begins with description of the Boltzmann distribution which describes the state of the gas
in the gravitational field. Then I will define the gravitational field of the observed gas, which is
in this case air . Then I applied the Boltzmann distribution to generate barometric formulas
which describes the state of the gas in the gravitational field. And then we have described the
experimental confirmation of the Boltzmann’s distribution , which was made by Perrin
Dual nature of light
Get PDFJedna od najranijih pojava iz fizike koju je čovjek počeo proučavati, svakako je svjetlost.
Prema nekim istraživanjima, prva lampa napravljena je prije 70 000 godina (u posudu sa
otvorom stavljao se materijal koji je mogao gorjeti i tako stvarati svjetlo). Teško je zamisliti
da pojavu s kojom se čovjek susreo čim je došao na svijet, nije mogao u potpunosti objasniti
do 1905. godine. Od 17. do 20. stoljeća svjetlost je znanstveno proučavana jer neka pitanja
vezana uz nju nikako se nisu mogla objasniti. Preko 350 godina znanstvenici su pokušavali
odgonetnuti kakva je to čudna priroda svjetlosti zbog koje se ona ponaša na sasvim različite
načine u različitim situacijama - nekada kao val, a nekada kao čestica. Danas priznajemo
teoriju po kojoj svjetlost ima dvojnu narav – valnu (undularnu) i čestičnu (korpuskularnu) i
ovisno o tome koje pojave proučavamo, nekada se očituje jedna, a nekada druga priroda.The phenomena of light is one of the phenomena that mankind started to study most
early. According to some researches, first lamp was made 70 000 years ago (it was made of
some materials that could burn and on that way, made light). It is hard to imagine that
mankind could not explain light until the year 1905. From 17th century until the 20th century
light was scientific studied because some question related with light could not be explained.
For over 350 years scientists have been trying to figure out about strange nature of light that
makes it to behave sometimes as wave and sometimes as particle. Today is confirmed The
dual theory of light – wave and corpuscular theory and depending on which phenomena we
study, light can manifest as a wave or as a particle
Continuum mechanics
Get PDFU prvom dijelu diplomskog rada objašnjen je koncept kontinuuma te djelovanje unutarnjih i vanjskih sila. Objašnjen je Cauchyjev princip naprezanja te je uveden pojam tenzora naprezanja. Kroz rad su uvedeni i objašnjeni fundamentalni zakoni mehanike kontinuuma.The continuum concept and interaction of body and surface forces are presented in the first part of this thesis. Concept of stress tensor is introduced and Cauchy's stress principle is explained further on. Fundamental laws of continuum mechanics are introduced and explained in the main part of this thesis
Legendre polynomials
Get PDFLegendreovi polinomi rješenja su Legendreove diferencijalne jednadžbe
\left(1-x^{2}\right)P^{n}-2xP^{'}\left(x\right)+\lambda P\left(x\right)=0.
Pomoću ove diferencijalne jednadžbe također se može dobiti funkcija izvodnica.
Nadalje, ona će nam pomoći u izračunu rekurzivnih relacija. Legendreovi polinomi
imaju široku primjenu u mnogim granama fizike. Nalazimo ih u elektrodinamici te u kvantoj
mehanici.Legendre polynomials are solution to Legendre differential equation \left(1-x^{2}\right)P^{n}-2xP^{'}\left(x\right)+\lambda P\left(x\right)=0.From Legendre differential equation we can calculate generating function.
Further, from generating function we can calculate recurrence formulas. Legendre polynomials
are widely used in many branches of physics. They are used in electrodynamics as well as in
quantum physics
Chernobyl before and after the disaster
Get PDFNuklearna elektrana Černobil nalazila se u blizini ukrajinskog grada Černobila, u gradu
Pripjatu. Sastojala se od četiri reaktora tipa RBMK-1000. Posljednji, četvrti reaktor u rad je
pušten 1983. godine. Nuklearna elektrana Černobil stvarala je energiju pomoću procesa fisije.
Milijuni ljudi su pomoću nuklearne elektrane dobivali struju. 26. travnja 1986. godine, zbog
ljudskih pogrešaka i zbog nedostataka u reaktoru, došlo je do najveće nuklearne katastrofe-
Černobilske katastrofe. Do katastrofe je došlo eksplozijom četvrtog reaktora. Nakon katastrofe
mnogi ljudi su se morali evakuirati iz grada Pripjata, a mnogi su i oboljeli te ubrzo umrli.
Posljedice su se odrazile i na gospodarstvo, ali i na čitav svijet, te se osjećaju još i danas.
Područje Pripjata i danas je još uvijek prazno.The Chernobyl Nuclear Power Plant is located near the Ukrainian city of Chernobyl, in the
city of Pripyat. Nuclear Power Plant had four RBMK reactors. The fourth reactor was in use
since 1983. The Chernobyl Nuclear Power Plant was producing energy using the fission process.
It was a electric energy supplier for milions of people. On April 26, 1986 occured the worst
nuclear disaster - the Chernobyl disaster. It was a combination of RBMK reactor's design flaws
and human handling what caused the explosion of the fourth reactor. The Chernobyl disaster was
led to immediate evacuations, many health problems and thousands of dead people.. Many of
them had health problems and some of them have died. A disaster had a huge impact on the
economy of Ukraine and the consequences of it can be seen eventoday. Today, field of Pripyat
was still empty
Validacija Gating sustava koristeći Gating fantom kućne izrade
Get PDFGating radioterapija jedna je od metoda liječenja tumora pluća. U ovoj vrsti terapije CT
snimanje sinkronizirano je s tretmanom zračenja pomoću disanja pacijenta snimanog sustavom
za praćenje disanja pacjenata (imaging sustav).
Glavna svrha ovog rada je provjera valjanosti dva imaging sustava, Varian RPM i GateRT,
koristeći fantom koji simulira disanje pacjenta. Krivulja disanja fantoma snimana je s oba
sustava te su dobivene krivulje uspoređene. Vrijeme reakcije oba sustava izmjereno je te je
izračunata razlika između položaja očitanog na gating sustavu i stvarnog položaja fantoma.
Krivulja disanja implementirana je u plan zračenja koji je korišten pri zračenju fantoma.
Napravljena je film dozimetrija kako bi se dobilo saznanje o passing rates za oba sustava.
Vrijeme reakcije oba sustava ne utječe značajno na razliku između stvarnog položaja i položaja
koji u tom trenutku snima imaging sustav. Film dozimetrija pokazala je kako je passing rates
najviši za breath-hold terapiju. Za terapiju bez breath-holda passing rates nije dovoljno visok
kako bi se taj tip terapije preporučio u svakodnevnom liječenju tumora pluća.Gated radiation therapy is a method for lung cancer treatment. In this type of therapy CT
imaging and the treatment are synchronized with the patients breathing monitored by imaging
systems.
The main purpose of this work is the validation of two monitoring systems Varian RPM and
GateRT using a homemade gating phantom simulating the patients breathing. The breathing
curve of the phantom was recorded with both systems and compared. The reaction time of both
systems and the difference between the monitored position and the actual phantom position was
calculated. The breathing curve was implemented in the treatment plan used for irradiation of
the phantom. During the gated irradiation film dosimetry was used to gain knowledge about the
passing rates for each system.
The reaction times of both systems do not influence the difference between the monitored
position and the actual phantom position significantly. The film dosimetry showed high passing
rates for breath-hold therapy. For the gated therapy without breath-hold passing rates are not
sufficient to recommend gated therapy in everyday cancer treatment
Fluctuations around the average value
Get PDFU ovom radu nastoji se teorijskim putem pobliže objasniti sam pojam fluktuacije
srednjih vrijednosti te na koji način ona utječe na broj čestica sustava. Na početku rada
objašnjeni su pojmovi koji će nam biti potrebni za razumijevanje rada u cijelosti. Kasnije kroz
konkretne primjere dolazimo do krajnjih rezultata i zaključka samog rada.
Kao mjeru koja će pokazivati kolika je raspršenost oko srednje vrijednosti koristiti
ćemo se relativnom devijacijom, koja se dobiva dijeljenjem srednje vrijednosti sa
standardnom devijacijom. Standardna devijacija označava mjeru raspršenosti podataka u
nekom skupu i osnovni je podatak u statističkoj obradi podataka. Grafički, podaci se prikazuju
Gaussovom krivuljom.In this thesis the term of fluctuation around the average value and its influence on
system particle number wil be discussed. Terms required for comprehension of this thesis will
be explained in the introduction. Later, final results and conclusion will be introduced through
particular examples.
Relative deviation, which is defined as a ratio of mean and standard deviation, will be
used as a measure of mean square distribution. Standard deviation is defined as a measure of
data set distribution and it is basic information in statistical data processing. Data is shown
graphically as Gaussian curve
Marie Curie-life and work
Get PDFU diplomskom radu opisan je životni i profesionalni put poljske znanstvenice Marie Curie. Nakon uvodnog dijela, opisano je djetinjstvo, školovanje i znanstveni rad s posljedicama koje su prouzročile smrt ove iznimne znanstvenice. Zatim su detaljnije prikazani njeni najvažniji doprinosi u području fizike i kemije: otkriće novih elemenata (polonija i radija) te začetka novog znanstvenog područja - radioaktivnosti. Na kraju je prikazana i prokomentirana ostavšina Marie Curie s obzirom da je svojim iznimnim zalaganjem i radom otvorila vrata ženama u znanosti koje su, potaknute njenim primjerom, mukotrpno pronalazile put u znanstvenom svijetu dotad rezerviranom isključivo za muškarce.This bachelor thesis describes a life and work of Polish scientist Marie Curie. After the introductory part, the childhood, education and scientific work as well as the consequences that caused the death of this outstanding scientist is presented. Her most important contributions in the fields of physics and chemistry such as Marie's discovery of new elements (polonium and radium) as well as the beginning of the new scientific area – radioactivity is explained in detail. At the end, Marie Curie's legacy is commented because her exceptional dedication and hard work has opened many doors in science for female scientists who were encouraged by her example to found their way in the scientific world exclusively reserved for men at that time
Alan Turing and His Contribution to Cryptanalysis and Computing
Get PDFPredmet izučavanja ovog diplomskog rada je životni put i doprinos kriptoanalizi i računalstvu znamenitog britanskog matematičara, kriptografa, logičara i vizionara, te čovjeka osebujnog karaktera i uma, Alana Mathisona Turinga. Nakon uvoda, upoznat ćemo se s Turingovim djetinjstvom, školovanjem i profesionalnom karijerom, kao i kontroverzama vezanim uz njegovu smrt. Zatim će se detaljnije ukazati na njegove najvažnije doprinose u području kriptoanalize i računalstva. Pri tome će se posebno istaknuti Turingova uloga u pobjedi Saveznika u Drugom svjetskom ratu. Na kraju će se pokušati odgovoriti kako se prema Turingu i njegovom radu odnosi suvremeno društvo. Alan M. Turing je po mnogočemu bio ispred svog vremena pa tek počinjemo biti svjesni njegove važnosti za svijet u kojem danas živimo.The case study of this thesis is Alan Mathison Turing's life and contribution to cryptanalysis and computing. Alan Turing was famous British mathematician, cryptographer, logician and visionary, and a person of a distinctive character and mind. After the introduction, we will explore Turing's childhood, education, and professional career, as well as the controversies related to his death. In the next section, his most important contributions in the field of cryptanalysis and computing will be discussed in detail. Thereby, a particular emphasis will be put on Turing's role in the Allied victory in World War II. In the end, an attempt will be made to answer how the modern society refers to Turing and his work. Alan M. Turing was in many ways ahead of his time, and we are just starting to realise his importance for the world we live in today