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Analysis of potential locations for solar power plants in Dubrovnik-Neretva County
No full textPovećanje korištenja obnovljivih izvora energije je ključno u tranziciji Europske unije, a tako i Hrvatske, ka klimatski neutralnom društvu i gospodarstvu. Hrvatska ima veliki potencijal za iskorištavanja Sunčeve energije. Jedan od glavnih izazova je pronalazak
optimalnih lokacija za smještaj solarnih fotonaponskih elektrana jer one moraju biti smještene u području optimalnog iskorištavanja energije Sunca bez narušavanja krajolika. Upravo se višekriterijskom metodom mogu pronaći optimalne lokacije. U ovom radu korištene su dvije metode – analiza osjetljivosti i analiza pogodnosti za pronalazak optimalnih lokacija u Dubrovačko-neretvanskoj županiji. Rezultati analiza pokazuju da Dubrovačko-neretvanska županija ima visoki postotak područja na kojima je zakonski onemogućena gradnja (60,9 %). Izrazito pogodne lokacije nalaze se na 9.002,54 ha te su rasprostranjene po cijeloj županiji.Increasing the use of renewable energy sources is crucial in the transition of the European Union, and thus Croatia, to a climate-neutral society and economy. Croatia has great potential for the use of solar energy. One of the main challenges is to find optimal locations for solar photovoltaic power plants because they must be located in area with optimal use of solar energy without disturbing the landscape. It is the multicriteria method that can be used to find optimal locations. Two methods were used in this paper - sensitivity analysis and suitability analysis for finding optimal locations in Dubrovnik-Neretva County. The results of the analysis show that the Dubrovnik-Neretva County has a high percentage of areas where construction is legally prohibited (60,9 %). Extremely suitable locations are located on 9,002.54 ha and are disseminated throughout the county
Removal of Lanthanides (Y, Er, Dy) and Actinides (U, Th) from Aqueous Solution Using Iron Nanoparticles
No full textElementi skupine lantanoida i aktinoida se učestalo koriste u svim modernim granama
tehnologije. Zbog velike potražnje te problema u proizvodnji, važno je osmisliti efikasnu
metodu za recikliranje ovih elemenata iz vodenih sustava. U te svrhe istražuje se primjena
novih materijala poput nanočestica elementarnog željeza. Površina nanočestica može se
kemijski modificirati kako bi se osigurala bolja selektivnost u sorpciji. U ovom radu
uspoređena je efikasnost sintetiziranih i modificiranih neutralnih nanočestica željeza u sorpciji
iona Y, Dy, Er, Th, i U. Za modifikaciju je korištena piridin-2,6-dikarboksilna kiselina
(PDCA) u molarnom omjeru Fe:PDCA=2:1. Provedena je simultana adsorpcija odabranih
kationa na neutralne i modificirane nanočestice u vodenoj otopini. Pomoću spektrometrije
masa uz induktivno spregnutu plazmu (ICP-MS) određena je koncentracija odabranih kationa
nakon sorpcije. Uspješnost modifikacije nanočestica potvrđena je metodom infracrvene
spektroskopije s Fourierovom transformacijom (FT-IR) te mikroskopijom atomskih sila
(AFM). Iz spektara FTIR možemo zaključiti da je PDCA vezana na površinu čestica, a AFM
analizom utvrđena je promjena veličine modificiranih nanočestica. Nastale manje čestice s
modificiranom površinom pokazuju bolju efikasnost u sorpciji odabranih iona.Rare earth elements and actinides are widely used in modern technologies. Due to high
demand and problems in their production, it is quite important to find an effective method for
recycling these elements from aqueous systems. Novel approach in this field includes the
testing of new materials like zero valent iron nanoparticles (nZVI). To ensure better
selectivity, nanoparticles are often surface modified. In this work, efficiency of two kinds of
nZVI, i.e. neutral and modified, was examined using solutions of ions Y, Dy, Er, Th, and U.
Pyridine-2,6-dicarboxylic acid (PDCA) was used for the surface modification with molar ratio
Fe: PDCA=2:1. The simultaneous adsorption of REE (Rare Earth Elements) cations on
neutral and functionalized nZVI from aqueous solutions was analysed by inductively coupled
plasma mass spectrometry (ICP-MS). In order to confirm the efficiency of surface
modification, nZVI particles were analysed with Fourier-transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). From FT-IR spectra we confirmed bonding of
PDCA onto particle surface. AFM analysis showed a decrease in the size of the modified
nanoparticles. Smaller modified nanoparticles showed better removal efficiency of selected
ions
The effect of polymers on the radiolytic synthesis of magnetic iron oxide nanoparticles
No full textU ovom doktorskom radu istražen je utjecaj različitih polimera i drugih eksperimentalnih čimbenika na γ-radiolitičku sintezu magnetskih nanočestica željezovih oksida. Redukcija Fe3+ do koje dolazi γ-ozračivanjem prekursorske suspenzije praćena je spektrofotometrijski metodom s 1,10-fenantrolinom. Uz dekstran, dietilaminoetil-dekstran i dekstran sulfat moguće je postići 100 %-tnu redukciju te nastaju stabilne suspenzije magnetskih nanočestica. Uz dietilaminoetil-dekstran pri dozama 10 – 36 kGy nastaju superparamagnetske nanočestice magnetita, dok pri dozama 50 – 130 kGy nastaju magnetski nanodiskovi feroksihita. Uz dekstran sulfat nastaju getit i željezov(III) sulfat hidroksid. Uz poli(etilen-oksid) (PEO) i poli(vinil-pirolidon) nastaju magnetski polimerni gelovi ili magnetske suspenzije, a znatno slabija redukcija (~55 %) rezultira nastankom magnetita i getita, čak i pri visokim dozama (300
kGy). Stupanj umreženja i čvrstoća PEO gela rastu s dozom i koncentracijom prekursora, a do umrežavanja dolazi i preko nanočestica. Osim polimera i doze zračenja, važan utjecaj na stupanj redukcije i fazni sastav produkta imaju i koncentracija 2-propanola i Fe3+ prekursora, pH te koncentracija i molekulska masa polimera.In this thesis, the effect of different polymers and other experimental factors on the γ-radiolytic synthesis of magnetic iron oxides nanoparticles (NPs) was investigated. γ-irradiation-induced Fe3+ reduction was monitored spectrophotometrically with the 1,10-phenanthroline method. With dextran, diethylaminoethyl-dextran, and dextran sulfate colloids, it is possible to achieve
a 100 % reduction and formation of stable suspensions of magnetic NPs. With DEAE-dextran, superparamagnetic magnetite NPs form in the dose range of 10 – 36 kGy, while magnetic feroxyhyte nanodiscs form in the 50 – 130 kGy dose range. With dextran sulfate, goethite and iron(III) sulfate hydroxide form. Synthesis with poly(ethylene oxide) (PEO) and poly(vinylpyrrolidone) resulted in the formation of magnetic polymer hydrogels or magnetic suspensions. Significantly lower reduction (~55 %) results in the formation of magnetite and goethite, even at high doses (300 kGy). Degree of crosslinking and strength of PEO gels improve with dose and precursor concentration, while NPs act as additional crosslinkers. Besides the polymer and dose absorbed, 2-propanol and precursor concentrations, pH, polymer concentration and molar mass also affect the reduction and phase composition of the products
Expression of MAO and COMT genes in the brain of Podarcis sicula and Podarcis melisellensis lizards
No full textAgresivnost kao oblik kompetitivnog ponašanja česta je pojava koja uvelike utječe na odnos
između jedinki, populacija i/ili vrsta. Primijećena je i u međusobnom odnosu jedinki vrsta
Podarcis sicula (primorska gušterica) i Podarcis melisellensis (krška gušterica) duž jadranske
obale, pri čemu P. sicula kao agresivnija vrsta aktivno potiskuje P. melisellensis, smanjujući
njezin areal. Poznato je da se agresivnost javlja kao rezultat djelovanja određenih
neurotransmitera u mozgu - dopamina, serotonina i noradrenalina. Cilj ovog rada je analiza
ekspresije gena MAO (monoamin oksidaza) i COMT (katehol-O-metiltransferaza) koji
razgrađuju dopamin i tako mogu djelovati na njegovu koncentraciju u mozgu jedinki vrsta P.
sicula i P. melisellensis. U svrhu istraživanja provedeno je terensko uzorkovanje jedinki na tri
lokacije (Pag, Sinj, Knin), njihovo žrtvovanje i pohrana moždanog tkiva iz kojeg je izolirana
RNA, dizajn početnica specifičnih za vrstu, reverzna transkripcija (RT-PCR) i kvantitativni
PCR (qRT-PCR). Nije pronađena razlika u relativnoj ekspresiji gena MAO i COMT između
istraživanih vrsta.Aggression as a form of competitive behavior is a common occurrence that greatly affects the
relationship between individuals, populations and/or species. It has also been noted in the
relationship between the species Podarcis sicula (coastal lizard) and Podarcis melisellensis
(karst lizard) along the Adriatic coast, where more aggressive P. sicula actively suppresses P.
melisellensis reducing its living area. It is known that aggression occurs as a result of the
action of certain neurotransmitters in the brain - dopamine, serotonin and norepinephrine. The
aim of this study was to analyze the expression of MAO (monoamine oxidase) and COMT
(catechol-O-methyltransferase) genes that degrade dopamine therefore affecting dopamine
levels in the brain of individuals of species P. sicula and P. melisellensis. Field sampling of
individuals at three locations (Pag, Sinj, Knin) was performed, their sacrifice and storage of
brain tissue from which RNA was isolated, species specific primers designed and reverse
transcription (RT-PCR) and quantitative PCR (qRT-PCR) performed. No difference in the
relative expression of MAO and COMT genes was found between the studied species
Preparation of aliphatic triazole derivatives of mannosylated desmuramyl dipeptide
No full textU sklopu diplomskog rada opisana je priprava triju novih alifatskih triazolnih derivata
manoziliranog desmuramil-dipeptida, L-Ala-D-isoGln. U konvergentnom pristupu sintezi
zasebno su pripravljene tri podjedinice: dipeptid, alifatski triazolni amin i manozna podjedinica,
koje su zatim međusobno povezane amidnim vezama. Kao polazni dipeptid iz odgovarajućih
zaštićenih aminokiselina pripravljen je Boc-L-Ala-D-Glu(OBn). Alifatske triazolne podjedinice
pripravljene su klik-reakcijom, bakrom(I) kataliziranom azid-alkinskom cikloadicijom
(CuAAC) Boc-zaštićenog propargilamina i odgovarajućih azida, heksadecil-azida i 2-
(adamant-1-il)etil-azida. Nakon uklanjanja Boc zaštite dobiveni alifatski triazolni amini te
prethodno pripravljen dodecilni analog vezani su amidnom vezom na α-karboksilnu skupinu
dipeptida Boc-L-Ala-D-Glu(OBn). Benzilima zaštićena manozna podjedinica s acetilnom
poveznicom pripravljena je hidrolizom odgovarajućeg estera. Alifatski triazolni derivati
desmuramil-dipeptida nakon uklanjanja Boc zaštite vezani su preko amino-skupine alanina na
karboksilnu skupinu manozne podjedinice. U zadnjem koraku reakcije uklanjanjem svih
benzilnih zaštitnih skupina reakcijom katalitičke hidrogenolize uspješno su pripravljene ciljne
molekule ovog rada kojima je konačni cilj ispitati in vivo adjuvantsku aktivnost.In this diploma thesis, the preparation of three new lipophilic aliphatic triazole derivatives of
manosylated desmuramyl dipeptide, L-Ala-D-isoGln, were described. In the convergent
synthesis approach, three subunits were prepared separately: the dipeptide, the aliphatic triazole
amine, and the mannose subunit, which were then interconnected by amide bonds. Boc-L-AlaD-Glu(OBn) was prepared as the starting dipeptide from the corresponding protected amino
acids. Aliphatic triazole subunits were prepared by click reaction, copper(I) catalyzed azidealkyne cycloaddition (CuAAC) of Boc-protected propargylamine and the corresponding azides,
hexadecyl-azide and 2-(adamant-1-yl)ethyl-azide. After the removal of Boc, the resulting
aliphatic triazole amines and the previously prepared dodecyl analog were attached by an amide
bond to the α-carboxyl group of the dipeptide Boc-L-Ala-D-Glu(OBn). The benzyl-protected
mannose subunit with an acetyl linker was prepared by hydrolysis of the corresponding ester.
After removal of Boc-protection group aliphatic triazole derivatives of desmuramyl dipeptide
were coupled through the carboxyl group of the mannose subunit and the amino groups of
alanine. In the last reaction step, all benzyl protecting groups were removed by the catalytic
hydrogenolysis reaction and the target molecules of this work were successfully prepared with
the final goal of testing their in vivo adjuvant activity
Mesolimbic dopamine pathway
No full textMezolimbički put dopamina jedan je od četiri najvažnija puta dopamina u mozgu. Povezuje
ventralno tegmentalno područje, gdje dopamin prvotno nastaje, i nucleus accumbens u striatumu.
Nakon što je dopamin izlučen, veže se za receptori vezane s G-proteinom. Ovo ne dovodi izravno
do stvaranja akcijskog potencijala otvaranjem ionskih kanala, nego se aktivira signalni put unutar
neurona, čime se mijenja stanična aktivnost, kroz koje može doći do promjene ionskih receptora.
Dopamin se konstantno izlučuje iz dopaminergičnih neurona, a izlučivanje se izmjenjuje u
slučaju nagrade, čime se uči o nagrađujućim podražajima. U slučaju nagrade veće od očekivane
luči se više dopamina, a u slučaje manje nagrade inhibira se lučenje dopamina. Nadalje, lučenjem
dopamina u mezolimbičkom putu nastaje želja za nagradom, a sporijim lučenjem nastaje
motivacija. Ovisnost je jedan od najvećih zdravstvenih problema današnjice, a mezolimbički put
dopamina je ključan za nastanak ovisnosti. Sve droge koje mogu izazvati ovisnost utječu na
lučenje dopamina unutar mezolimbičkog puta dopamina zato jer se u njemu određuje kolika želja
za nagradom nastaje. Najvažnija promjena u mezolimbičkim neuronima koja nastaje tijekom
ovisnosti je promjena omjera različitih tipova dopaminskih receptora. Mezolimbički put
dopamina ima kliničku ulogu u nastanku depresije, ADHD-a i shizofrenije.Mesolimbic dopamine pathway is one of the four main dopamine pathways. It connects ventral
tegmental area, where dopamine is created, and nucleus accumbens in striatum. After dopamine
secretion, it binds to G protein-coupled receptor. This does not directly lead to the creation of an
action potential by opening ion channels, rather it activates a signaling pathway inside the
neuron, which changes cellular activity, through which a change in ion receptors occurs.
Dopamine is constantly secreted from dopaminergic neurons, when reward occurs, the release
changes, thus learning about rewarding stimuli. In the case of a higher-than-expected reward,
more dopamine is secreted, and when the reward is smaller, dopamine secretion is inhibited.
Furthermore, dopamine secretion in the mesolimbic pathway generates wanting for reward, and
slower secretion generates motivation. Addiction is one of the biggest health problems nowadays,
and mesolimbic dopamine pathway is essential for its emergence. Each drug that causes addiction
affects secretion of dopamine within the mesolimbic dopamine pathway because it determines
how much wanting for reward is generated. During addiction, the most important change within
mesolimbic neurons is the change in the dopamine receptors ratio. Mesolimbic dopamine plays a
role in the creation of depression, ADHD and, schizophenia
(2) Suppression in Pb-Pb Collisions at the LHC
No full textThe production of the (2) charmonium state was measured with ALICE in Pb-Pb collisions at √NN=5.02 TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.5<<4). The measurement of the ratio of the inclusive production cross sections of the (2) and J/ resonances is reported as a function of the centrality of the collisions and of transverse momentum, in the region <12 GeV/. The results are compared with the corresponding measurements in collisions, by forming the double ratio [(2)//]Pb−Pb/[(2)//]. It is found that in Pb-Pb collisions the (2) is suppressed by a factor of ∼2 with respect to the /. The (2) nuclear modification factor AA was also obtained as a function of both centrality and . The results show that the (2) resonance yield is strongly suppressed in Pb-Pb collisions, by a factor of up to ∼3 with respect to . Comparisons of cross section ratios with previous Super Proton Synchrotron findings by the NA50 experiment and of AA with higher- results at LHC energy are also reported. These results and the corresponding comparisons with calculations of transport and statistical models address questions on the presence and properties of charmonium states in the quark-gluon plasma formed in nuclear collisions at the LHC
Measurement of the 140Ce(n,) Cross Section at n_TOF and Its Astrophysical Implications for the Chemical Evolution of the Universe
No full text140Ce(n,) is a key reaction for slow neutron-capture (-process) nucleosynthesis due to being a bottleneck in the reaction flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at the n_TOF facility, with an unprecedented combination of a high purity sample and low neutron-sensitivity detectors. The measured Maxwellian averaged cross section is up to 40% higher than previously accepted values. Stellar model calculations indicate a reduction around 20% of the -process contribution to the Galactic cerium abundance and smaller sizeable differences for most of the heavier elements. No variations are found in the nucleosynthesis from massive stars
Electric dipole transitions in the relativistic quasiparticle random-phase approximation at finite temperature
No full textFinite temperature results in various effects on the properties of nuclear structure and excitations of relevance for nuclear processes in hot stellar environments. Here, we introduce the self-consistent finite temperature relativistic quasiparticle random phase approximation (FT-RQRPA) based on relativistic energy density functional with point coupling interaction for describing the temperature effects in electric dipole (1) transitions. We perform a study of 1 excitations in the temperature range =0–2 MeV for the selected closed- and open-shell nuclei ranging from 40Ca to 60Ca and 100Sn to 140Sn by including both thermal and pairing effects. The isovector giant dipole resonance strength is slightly modified for the considered range of temperature, while new low-energy peaks emerge for <12 MeV with non-negligible strength in neutron-rich nuclei at high temperatures. The analysis of relevant two-quasiparticle configurations discloses how new excitation channels open due to thermal unblocking of states at finite temperature. The study also examines the isospin and temperature dependence of electric dipole polarizability (), resulting in systematic increase in the values of with increasing temperature, with a more pronounced effect observed in neutron-rich nuclei. The FT-RQRPA introduced in this work will open perspectives for microscopic calculation of -ray strength functions at finite temperatures relevant for nuclear reaction studies