Impulse Radar for Air Traffic Control

U ovom završnom radu obrađena je tema impulsnog radara koji se koristi za kontrolu zračne plovidbe. U prvom djelu rada opisan je tehnički aspekt impulsnog radara, kako impulsni radar radi, njegove podjele te jednadžba koja definira jakost signala koji se odašilje i odbija od zrakoplova. U drugom djelu navedeni su primjeri radara koji se koriste za kontrolu zračnog plovidbe te njihovi proračuni razlučivosti za određene udaljenosti. Radari kao faktor sigurnosti u zračnom prometu su neophodni te je trenutni broj operacija zrakoplova u svijetu nezamisliv bez primjene radara. Kako bi se dobio jasan prikaz, opisan je način rada radara i njegove podjele prema načinu određivanja zrakoplova te proračuni razlučivosti kako bi se pokazala stvarna korist i prednosti upotrebe radara za kontrolu zračnog prometa.In this thesis, the theme of impulse radar which is used in air traffic control was elaborated. In the first part of this thesis, the technical aspect of impulse radar was described, how impulse radar works, its divisions, and also the equation that defines the strength of the signal that is transmitted and the signal that is reflected from the airplane. In the second part examples of different types of radar were given and their calculation of resolution for certain distances. Radars as a factor of security in air traffic are essentials and serving of the current number of airplane operations would have been impossible without the use of radar. To get a clearer view, the function of the radar was described and the ways it distinguishes airplanes were given for the reasons of showing real benefits and advantages in using radar in air traffic control

Implementation of Standardised European Rules of the Air

Standardizacija Europskih pravila letenje (engl. Standardised European Rules of the Air - SERA) predstavlja propis kojim se objedinjuju pravila letenja, te bi kao takav propis trebao pomoći državama članicama u unificiranju standarda i jedinstvene implementacije procedura u europskom zračnom prometu. Implementacijom se nastoji povećati sigurnost zračnog prometa i minimalizirati opasnosti koje su prouzročene vlastitim nacionalnim pravilima letenja koje provode pojedine članice Europske unije. Ovim radom se vrši komparativna analiza dokumenta SERA-e i zakonodavnog okvira Republike Hrvatske, te se prikazuju odstupanja od nacionalnog zakonodavnog, Međunarodne organizacije civilnog zrakoplovstva (engl. International Civil Aviation Organisation - ICAO) i europskog regulatornog okvira.Standardised European Rules of the Air (SERA) represent document that unites/standardise flight rules and as such regulation should help member states to unify the standards and the implementation of procedures in European air space. Implementation aims to increase air traffic safety and minimize the dangers caused by State implementaed national rules of the air by individual European union members. This thesis will perform a comparative analysis of the SERA document and the legislative framework of the Republic of Croatia, and will present differences that deviate from national legislative, ICAO and European reuglatory framework

Impulse Radar for Air Traffic Control

U ovom završnom radu obrađena je tema impulsnog radara koji se koristi za kontrolu zračne plovidbe. U prvom djelu rada opisan je tehnički aspekt impulsnog radara, kako impulsni radar radi, njegove podjele te jednadžba koja definira jakost signala koji se odašilje i odbija od zrakoplova. U drugom djelu navedeni su primjeri radara koji se koriste za kontrolu zračnog plovidbe te njihovi proračuni razlučivosti za određene udaljenosti. Radari kao faktor sigurnosti u zračnom prometu su neophodni te je trenutni broj operacija zrakoplova u svijetu nezamisliv bez primjene radara. Kako bi se dobio jasan prikaz, opisan je način rada radara i njegove podjele prema načinu određivanja zrakoplova te proračuni razlučivosti kako bi se pokazala stvarna korist i prednosti upotrebe radara za kontrolu zračnog prometa.In this thesis, the theme of impulse radar which is used in air traffic control was elaborated. In the first part of this thesis, the technical aspect of impulse radar was described, how impulse radar works, its divisions, and also the equation that defines the strength of the signal that is transmitted and the signal that is reflected from the airplane. In the second part examples of different types of radar were given and their calculation of resolution for certain distances. Radars as a factor of security in air traffic are essentials and serving of the current number of airplane operations would have been impossible without the use of radar. To get a clearer view, the function of the radar was described and the ways it distinguishes airplanes were given for the reasons of showing real benefits and advantages in using radar in air traffic control

Impulse Radar for Air Traffic Control

U ovom završnom radu obrađena je tema impulsnog radara koji se koristi za kontrolu zračne plovidbe. U prvom djelu rada opisan je tehnički aspekt impulsnog radara, kako impulsni radar radi, njegove podjele te jednadžba koja definira jakost signala koji se odašilje i odbija od zrakoplova. U drugom djelu navedeni su primjeri radara koji se koriste za kontrolu zračnog plovidbe te njihovi proračuni razlučivosti za određene udaljenosti. Radari kao faktor sigurnosti u zračnom prometu su neophodni te je trenutni broj operacija zrakoplova u svijetu nezamisliv bez primjene radara. Kako bi se dobio jasan prikaz, opisan je način rada radara i njegove podjele prema načinu određivanja zrakoplova te proračuni razlučivosti kako bi se pokazala stvarna korist i prednosti upotrebe radara za kontrolu zračnog prometa.In this thesis, the theme of impulse radar which is used in air traffic control was elaborated. In the first part of this thesis, the technical aspect of impulse radar was described, how impulse radar works, its divisions, and also the equation that defines the strength of the signal that is transmitted and the signal that is reflected from the airplane. In the second part examples of different types of radar were given and their calculation of resolution for certain distances. Radars as a factor of security in air traffic are essentials and serving of the current number of airplane operations would have been impossible without the use of radar. To get a clearer view, the function of the radar was described and the ways it distinguishes airplanes were given for the reasons of showing real benefits and advantages in using radar in air traffic control

Implementation of Standardised European Rules of the Air

Standardizacija Europskih pravila letenje (engl. Standardised European Rules of the Air - SERA) predstavlja propis kojim se objedinjuju pravila letenja, te bi kao takav propis trebao pomoći državama članicama u unificiranju standarda i jedinstvene implementacije procedura u europskom zračnom prometu. Implementacijom se nastoji povećati sigurnost zračnog prometa i minimalizirati opasnosti koje su prouzročene vlastitim nacionalnim pravilima letenja koje provode pojedine članice Europske unije. Ovim radom se vrši komparativna analiza dokumenta SERA-e i zakonodavnog okvira Republike Hrvatske, te se prikazuju odstupanja od nacionalnog zakonodavnog, Međunarodne organizacije civilnog zrakoplovstva (engl. International Civil Aviation Organisation - ICAO) i europskog regulatornog okvira.Standardised European Rules of the Air (SERA) represent document that unites/standardise flight rules and as such regulation should help member states to unify the standards and the implementation of procedures in European air space. Implementation aims to increase air traffic safety and minimize the dangers caused by State implementaed national rules of the air by individual European union members. This thesis will perform a comparative analysis of the SERA document and the legislative framework of the Republic of Croatia, and will present differences that deviate from national legislative, ICAO and European reuglatory framework

Polarised emission of galaxies at low radio frequencies

U ovom radu bavimo se potragom za polariziranim zračenjem radiogalaksija koristeći polarimetrijska promatranja na 150 MHz prikupljena LOFAR teleskopom u području centriranom na sjajnoj radiogalaksiji 3C196 (RA = 8h13m36s, DEC = +48°13'03'') koje obuhvaća oko 50 kvadratnih stupnjeva. Ukupno smo pronašli 10 polariziranih radioizvora. Analizom slika iz FIRST kataloga na 1.4 GHz ustanovili smo da su 9 izvora radiogalaksije FR-II tipa koje su luminoznije prema rubovima, a preostali izvor je kvazar. Izračunati postotci polarizacije izvora na 150 MHz pokazuju znatno veću depolarizaciju u odnosu na mjerenja iz NVSS kataloga na frekvencijama oko 1.4 GHz. Za pojedine izvore postoje velike razlike između Faradayevih dubina dobivenih iz LOFAR-ovih mjerenja i onih koje se navode u NVSS katalogu, što pripisujemo niskoj rezoluciji u Faraday prostoru za NVSS-ova mjerenja. Usporedbom dobivenih vrijednosti ukupnog intenziteta s onima na drugim frekvencijama, koje smo pronašli u VLSS (74 MHz), NVSS (1.4 GHz) i WENSS (325 MHz) katalozima, dobili smo vrijednosti spektralnih indeksa koji u prosjeku iznose 0.753. Dobivena je gustoća od jednog izvora na 5 kvadratnih stupnjeva neba.In this Diploma thesis we are searching for polarized emission of the radio galaxies in a field centred at a bight radio galaxy 3C196 (RA = 8h13m36s, DEC = +48°13'03''), covering an area of 50 square degrees. In our analysis we are using LOFAR polarimetric observations at 150 MHz. In total we have found 10 polarized radio sources. By analysing the FIRST images of these sources we concluded that one source is a quasar, while all the others are FR-II radio galaxies, which are the brightest at the edges. Their degree of polarization at 150 MHz is smaller than at 1.4 GHz (NVSS catalogue), due to significantly higher wavelenght dependent depolarization. There is some discrepancy in obtained rotation measures if compared with the ones at 1.4 GHz. This can be attributed to much poorer resolution in Faraday depth at higher radio frequencies. We also compared the amount of emission obtained in total intensity with catalogues at other frequencies (VLSS - 74 MHz, WENSS - 325 MHz, NVSS - 1.4 GH). Based on this comparison we calculated the spectral indices of the sources, mounting to 0.753 in average. We found a density of 1 source per 5 square degrees

Polarised emission of galaxies at low radio frequencies

U ovom radu bavimo se potragom za polariziranim zračenjem radiogalaksija koristeći polarimetrijska promatranja na 150 MHz prikupljena LOFAR teleskopom u području centriranom na sjajnoj radiogalaksiji 3C196 (RA = 8h13m36s, DEC = +48°13'03'') koje obuhvaća oko 50 kvadratnih stupnjeva. Ukupno smo pronašli 10 polariziranih radioizvora. Analizom slika iz FIRST kataloga na 1.4 GHz ustanovili smo da su 9 izvora radiogalaksije FR-II tipa koje su luminoznije prema rubovima, a preostali izvor je kvazar. Izračunati postotci polarizacije izvora na 150 MHz pokazuju znatno veću depolarizaciju u odnosu na mjerenja iz NVSS kataloga na frekvencijama oko 1.4 GHz. Za pojedine izvore postoje velike razlike između Faradayevih dubina dobivenih iz LOFAR-ovih mjerenja i onih koje se navode u NVSS katalogu, što pripisujemo niskoj rezoluciji u Faraday prostoru za NVSS-ova mjerenja. Usporedbom dobivenih vrijednosti ukupnog intenziteta s onima na drugim frekvencijama, koje smo pronašli u VLSS (74 MHz), NVSS (1.4 GHz) i WENSS (325 MHz) katalozima, dobili smo vrijednosti spektralnih indeksa koji u prosjeku iznose 0.753. Dobivena je gustoća od jednog izvora na 5 kvadratnih stupnjeva neba.In this Diploma thesis we are searching for polarized emission of the radio galaxies in a field centred at a bight radio galaxy 3C196 (RA = 8h13m36s, DEC = +48°13'03''), covering an area of 50 square degrees. In our analysis we are using LOFAR polarimetric observations at 150 MHz. In total we have found 10 polarized radio sources. By analysing the FIRST images of these sources we concluded that one source is a quasar, while all the others are FR-II radio galaxies, which are the brightest at the edges. Their degree of polarization at 150 MHz is smaller than at 1.4 GHz (NVSS catalogue), due to significantly higher wavelenght dependent depolarization. There is some discrepancy in obtained rotation measures if compared with the ones at 1.4 GHz. This can be attributed to much poorer resolution in Faraday depth at higher radio frequencies. We also compared the amount of emission obtained in total intensity with catalogues at other frequencies (VLSS - 74 MHz, WENSS - 325 MHz, NVSS - 1.4 GH). Based on this comparison we calculated the spectral indices of the sources, mounting to 0.753 in average. We found a density of 1 source per 5 square degrees

Determination of ballistic properties on ARMOX 500T steel welded joint

In this paper, the effect of different hardness filler materials and sequence of welding on the ballistic performance has been investigated. Also, besides the optimization of the ballistic properties, other mechanical testing was carried out in order to achieve wanted mechanical properties along the entire welded joint. The experimental work includes macrostructure analysis, ballistic testing, and hardness testing of steel welded joint. The base material used in the experiment were ARMOX® 500T plates. In this experiment 3 different filler materials were used. Based on the testing results, it was found out that best ballistic performance of the welded joint is achieved if capping layer is welded with a hardfacing filler material.  This distributes the impact energy to a greater area and transfers it to the lower hardness weld layer underneath which then absorbs the rest of the energy

Finding optimal conditions and investigating the structure & morphology of cobalt/magnesium ferrite based cubic spinels (CoxMg1-xFe2O4) as photocatalysts

Cobalt/magnesium ferrites with various mole percentage ratio of the metals (obtained structures are CoxMg1-xFe2O4 with x being 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1.0) were synthesized by sol-gel combustion synthesis using glycine as fuel, following the rules of propellant chemistry. The powders were then sintered at 700 °C for 3 hours. Obtained powders were characterized by X-Ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, UV/vis diffuse reflectance spectroscopy (DRS). Investigation of the magnetic properties was also conducted by vibrating sample magnetometry (VSM). The obtained powders were proved to be phase-pure cubic spinels which formed agglomerated micrograins. Series of photocatalytic experiments of methylene blue degradation were done. The influence of different experimental conditions was investigated including variations of: pH values, concentrations of the pollutant, masses of the photocatalyst, different light sources and therefore different light irradiation. Interesting results, including enhancement of the degradation rate with the introduction of cobalt into MgFe2O4 and decrease of the degradation rate with further increase of cobalt content and formation of hard agglomerates, open new possibilities for further investigation of the utilisation of Co/Mg ferrites as photocatalysts

Effect of Ag doping on the morphological and magnetic properties of CuO nanostructures

The influence of Ag doping on the crystal structure and magnetic properties of CuO nanopowders was investigated. Nanoparticles of copper–silver oxide solid solutions with composition Cu1-xAgxO (x=0.01–0.05) were successfully produced by using self-propagating room temperature synthesis using reaction between metal nitrates and sodium hydroxide. Prepared powders were calcinated at 700 °C for 2 h. The diffraction pattern was recorded at room temperature and atmospheric pressure without of any re-heating of the sample. A fitting refinement procedure using the Rietveld method was performed which showed the incorporation of Ag3+ ions in the CuO crystal lattice, where they substitute Cu2+ ions. Magnetic behaviour of synthesized materials was investigated by SQUID magnetometer in temperature interval 2–400 K. It is known that copper(II) oxide exhibits ferroelectricity driven by magnetic order at temperature as high as 230 K [1]. Multiferroic phase is present above the first order phase transition at TN1 = 213 K and exists up to the subsequent first order phase transition TN2 = 230 K [1,2]. It was shown that disorder in the form of impurities can stabilize the ferroelectric phase [2] this was our motivation to dope CuO with Ag in order to improve further its multiferroic properties. In Cu1-xAgxO small changes of magnetic properties were observed if compared to CuO. Transmission electron microscopy (TEM) and the scanning electron microscopy (SEM) were used to determine the particle size and morphology.VI Serbian Ceramic Society Conference : program and the book of abstracts; June 28-29, 2022; Belgrad