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Influence of soil composition on the content of heavy metals (Bi, Cd, Co, Cr, Ni, Pb, Sn i Tl) in the fruiting body of truffles
No full textU ovom radu određene su ukupne koncentracije 8 teških metala (Bi, Cd,
Co, Cr, Ni, Pb, Sn and Tl) u uzorcima dvije vrste tartufa, uzorcima tla i kore drveta. Za potrebe
istraživanja uzeto je 7 uzoraka vrste Tuber aestivum i 7 uzoraka vrste Tuber melanosporum te
uzorci tla i kore obližnjih stabala, s ukupno 12 lokaliteta i 6 različitih tipova staništa na području
Republike Hrvatske. Svim uzorcima su laboratorijski određene ukupne koncentracije metala
multielementnom analizom. Dobivene koncentracije statistički su obrađene, izračunati su
bioakumulacijski faktori (BAF) za uzorke tartufa te su izračunati geoakumulacijski indeksi
(Igeo) i indeksi zagađenja tla (PI) za uzorke tla. Dobiveni rezultati ukazuju na povećane
vrijednosti bioakumulacijskih faktora za Cd za gotovo sve uzorke tartufa, kao i najveće
vrijednosti geoakumulacijskih indeksa i indeksa zagađenja tla za gotovo sve uzorke tla.In this paper, total concentrations of 8 heavy metals (Bi, Cd, Co, Cr, Ni,
Pb, Sn and Tl) in two truffle species, soil and wood bark samples were determined. For this
research, 7 samples of Tuber aestivum and 7 samples of Tuber melanosporum, as well as soil
samples and adjacent wood bar samples from 12 locations and 6 different types of habitats were
collected. Total concentrations for each sample of mentioned heavy metals were determined
using multi-element analysis and were further statistically processed. Bioaccumulation factor
(BAF) was calculated for truffle samples, while for soil samples were geoaccumulation index
(Igeo) and single pollution index (PI) calculated. Results showed elevated bioaccumulation
factors for almost all of truffle samples of Cd, as well as elevated geoaccumulation index and
elevated single pollution index of Cd for almost all of soil samples
Synthesis and solvatomorphism of ternary coordination compounds of copper(II) with 2,2'-bipyridine and L-homoserine ; Titrimetry and gymnasium chemistry syllabus
No full textOvaj diplomski rad sastoji se od dva dijela, istraživačkog i metodičkog. U istraživačkom dijelu
mehanokemijski su sintetizirana tri ternarna koordinacijska spoja bakra(II) s 2,2'-bipiridinom (bipy) i ʟhomoserinom (L-HHser): [Cu(µ-L-Hser)(H2O)(bipy)]2SO4∙2H2O (1∙2H2O), [Cu(µ-LHser)(H2O)(bipy)]2SO4∙3H2O (1∙3H2O) i [Cu(µ-L-Hser)(H2O)(bipy)]2SO4∙4H2O (1∙4H2O). Prilikom
sinteza, ispitan je utjecaj korištenih reaktanata (CuSO4∙xH2O, x = 0, 1 i 5) i tekućine (vode, metanola ili
smjese vode i metanola) na nastajanje određenog hidrata. Svi produkti mehanokemijskih sinteza su
analizirani metodom difrakcije rendgenskog zračenja na polikristalnom uzorku. Spoj 1∙2H2O dodatno
je analiziran infracrvenom sprektroskopijom i termogravimetrijskom analizom. Ispitana je stabilnost
spoja 1∙2H2O pri različitim relativnim vlažnostima zraka i 20 °C.
Metodički dio rada usmjeren je na mogućnost uključivanja titracije u nastavu kemije. Na temelju
analize osnovnoškolskog i srednjoškolskog programa kemije te starih i novih kemijskih
udžbenika, može se reći da u praksi gimnazijske nastave kemije nema izvođenja titracija. Ipak,
uvođenje ove eksperimentalne aktivnosti moglo bi nastavu kemije značajno unaprijediti, jer u sebe
integrira niz ciljanih obrazovnih ishoda. Titracija kao metoda kvantitativne kemijske analize učenicima
pruža širok spektar znanja, vještina i sposobnosti. Stoga je predložen 90-minutni nastavni sat koji se
temelji na strategiji učenja otkrivanjem, a u kojem će učenici ovladati temeljnom idejom
volumetrijske analze.This Diploma thesis consists of two parts, the research and the methodical. In the research part,
three ternary coordination compounds of copper(II) with 2,2'-bipyridine (bipy) and Lhomoserine (L-HHser) were synthesized by mechanochemical methods: [Cu(µ-LHser)(H2O)(bipy)]2SO4∙2H2O (1∙2H2O), [Cu(µ-L-Hser)(H2O)(bipy)]2SO4∙3H2O (1∙3H2O) and
[Cu(µ-L-Hser)(H2O)(bipy)]2SO4∙4H2O (1∙4H2O). During the synthesis, the influence of the
used reactants (CuSO4∙xH2O, x = 0, 1 and 5) and liquid (water, methanol or a mixture of water
and methanol) on the formation of a certain hydrate were investigated. All products of
mechanochemical syntheses were analyzed by the powder X-ray diffraction method. The
compound 1∙2H2O was additionally analyzed by infrared spectroscopy and thermogravimetric
analysis. The stability of the compound 1∙2H2O in atmospheres of different relative humidities
at 20 °C was investigated.
Methodological part of this thesis is focused on involvment of titrations into gymnasium
chemical lessons. Analysis of primary and secondary chemical syllabuses and of old and new
chemical textbooks indicates that titrations are not part of regular gymnasium chemical
teaching. But, introduction of this experimental activity would be beneficial since it integrates
series of targeted educational goals and achievements. Titration as a method of quantitative
chemical analysis engages a wide spectrum of pupil's content knowledge, skills and abilities. A
90-minute lesson is designed that is based on the guided inquiry-learning strategy during which
students will master fundamental ideas of volumetric analysis
Lithological, sedimentological and chemical characteristics of sediment after earthquake-triggered occurrence of liquefaction and sand volcanos
No full textPrikupljena su 4 uzorka sedimenta na području KAS Sisak koji su likvefakcijom
izašli na površinu. Cilj analiza provedenih na njima je bio odrediti postoji li trag
antropogenog utjecaja u vidu onečišćenja, te ispitati može li se njihov sastav koristiti kao
referentna vrijednost u procjeni antropogenog opterećenja površinskih uzoraka sedimenta
rijeka. Napravljene su analiza veličine zrna, analiza geokemijskog sastava, udio karbonatne
komponente i analiza mineralnog sastava. Sva četiri uzorka su sličnih karakteristika po
pitanju geokemijskog i mineralnog sastava. Dobiveni rezultati i usporedba litoloških,
kemijskih i sedimentoloških karakteristika mjesta u blizini ustanovljeno je da u
analiziranom sedimentu nije detektirano antropogeno onečišćenje. Jedino su elementi
povezani sa aluvijem rijeka Save te Kupe i Odre u povećanim koncentracijama zbog
utjecaja rijeka. Naslage kojemu pripadaju uzorci su aluvij recentnih tokova (a). Dubina s
koje je mogao doći sediment procjenjuje se na 20 do 26 m ili vjerojatnije s 12 -15 m
dubine.Four sediment samples were collected in the area of KAS Sisak, which came to
the surface through liquefaction. The goal of the analyses that were carried out on the
samples was to determine whether there is a trace of anthropogenic influence in the form
of pollution, and to examine whether their composition can be used as a reference value in
the assessment of the anthropogenic load of surface samples of river sediments. Analysis
of grain size, analysis of geochemical composition, proportion of carbonate component and
analysis of mineral composition were made. All four samples have similar characteristics
in terms of geochemical and mineral composition. The obtained results and a comparison
of the lithological, chemical, and sedimentological characteristics of the nearby places
revealed that no anthropogenic pollution was detected in the analysed sediment. The only
elements associated with the alluvium of the Sava and Kupa and Odra rivers are in
increased concentrations due to the influence of the rivers. The deposits to which the
samples belong are of the alluvium of recent flows (a). The depth from which the sediment
could have come is estimated at 20 to 26 m or more likely from 12-15 m deep
Computational and experimental characterization of esterase from Rhodopseudomons palustris for the degradation of polylactic acid
No full textU sklopu diplomskog rada okarakterizirana je α/β hidrolaza RPA1511 iz bakterije Rhodopseudomonas palustris s hidrolitičkom aktivnosti prema polimliječnoj kiselini. Konstruirana je mutirana inačica Arg243Lys, a konstrukcija mutanta motivirana je prethodnim in silico istraživanjem. Hidrolaze su heterologno eksprimirane u bakteriji Escherichia coli, potom su eksprimirani proteini pročišćeni afinitetnom kromatografijom. Aktivnost hidrolize hidrolaza polimliječne kiseline ispitana je na suspenziji polimliječne kiseline uklopljene u agarozi te pomoću turbidimetrijskog testa. Dinamika RPA1511 i njene mutirane inačice ispitana je pomoću simulacija molekularne dinamike, te je procijenjena entalpija vezanja modelnog supstrata dekamera mliječne kiseline. Nadalje, istražen je pojedinačni doprinos aminokiselina entalpije vezanja dekamera mliječne kiseline.In this work, an α/β hydrolase RPA1511 from Rhodopseudomonas palustris with activity towards polylactic acid was characterized experimentally and computationally by means of turibidmetric assays and molecular dynamics simulations. Motivated by in silico studies perfomed on RPA1511, a mutant Arg243Lys with potentially higher hydrolitic acitvity towards polylactic acid was also characterized. Both hydrolazes were expressed heterologously in Escherichia coli and purified by affinity chromatography. Their hydrolitic acitivity towards polylactic acid was assessed on polyester suspension solidified with agarose and by turbidimetric suspension assay. On the other hand, their dynamical properties were studied in silico utilizing molecular dynamics simulations modelled with the decamer of lactic acid. The binding enthalpy was calculated with the use of an end-point method. To assess the importance of amino acid residues involved in binding decameric lactic acid, the per-residue enthalpy decomposition was calculated
Optimal management and applications in economics
No full textIdeja ovog rada je upoznati se s teorijom optimalnog upravljanja, matematičkom pozadinom iste i zatim primijeniti pokazane tvrdnje na primjerima iz ekonomije. Izveli smo nužne uvjete za rješenje te pokazali kada će oni biti i dovoljni pomoću Mangasarianovog teorema. Važan alat koji koristimo u svim primjerima je Hamiltonian. Među ostalim, na početku rada uvodimo i dva primjera iz ekonomije koji se protežu cijelim radom: jedan u kojem tražimo optimalan raspored proizvodnje (u smislu minimalnog troška), a drugi vezan uz investiranje s ciljem maksimizacije profita. Za oba prethodno navedena primjera, kao i mnoge druge, s izgradnjom teorije su nađena optimalna rješenja. Za složenije probleme navodimo primjere u kojima imamo dodatne početne uvjete ili neka ograničenja na upravljačku funkciju te probleme više varijabli (Cobb-Douglas). Rad zaključujemo s opće poznatim Pontrjaginovim principom maksimuma.The idea of this thesis is to get acquainted with the theory of optimal control, mathematical background of the same, and then apply the demonstrated statements to examples from economics. We developed the necessary conditions for a solution and showed when they will be both necessary and sufficient with the help of the Mangasarian theorem. An important tool that we used in all examples is the Hamiltonian. At the beginning of the thesis, among others, we introduced two examples from economics that are extended throughout the thesis: one in which we are looking for an optimal production schedule (in terms of minimum cost), and the other related to investing with the aim of maximizing profit. For both of the above examples, like many others, optimal solutions were found when the whole theory was built. For more complex problems, we mentioned examples in which we have additional initial conditions or some other restrictions on control function, and multi-variable problems like Cobb-Douglas. We concluded the thesis with the well-known Pontryagin maximum principle
Creation of an optimal portfolio with risk modeled by VaR
No full textCilj ovog rada bio je predstaviti te pojasniti dvije bitne strane investiranja - najprije odabir portfelja te zatim kontrolu rizika povezanih s investiranjem. U svrhu optimizacije portfelja predstavili smo optimizaciju portfelja kako ju je zamislio Markowitz u svojoj modernoj teoriji portfelja, raspravljali smo o svrsi diverzifikacije te smo uveli pojam efikasne granice te s njom povezanih efikasnih portfelja. Radi jasnijeg razumijevanja mjere rizika, tzv. rizične vrijednosti (eng. Value-at-Risk), pokazali smo nekoliko načina za njen izračun (povijesna metoda, parametarska metoda te metoda Monte Carlo simulacija) te komentirali prednosti i nedostatke svakog načina. Na kraju, kako bi se odmaknuli od teorijskog pogleda, prikazali smo primjerom kako se može izračunati portfelj minimalne varijance te smo na njemu izračunali VaR koristeći povijesnu metodu.The aim of this paper was to present and clarify two important aspects of investing - firstly, the concept of portfolio selection, and then the control of investment-related risks. For the purpose of portfolio optimization, we introduced portfolio optimization as envisioned by Markowitz in his Modern Portfolio Theory, furthermore, we discussed the purpose of diversification and introduced the concept of the efficient frontier and with it related efficient portfolios. In order to better understand the risk measure Value-at-Risk, we presented several methods for its calculation (historical method, parametric method and Monte Carlo simulation method) and commented on the advantages and disadvantages of each method. Finally, to step away from the theoretical view, we constructed an example of the process to calculate the minimum-variance portfolio and calculated the Value-at-Risk metric on it by implementing the historical method
Interactions of benzyl-4"-macrozone and its nickel(II) complex with biological targets by STD and WaterLOGSY NMR techniques
No full textPovećana rezistencija patogenih bakterija na dosad poznate lijekove i nedostatak razvoja novih antibiotika predstavljaju globalni medicinski problem koji se može riješiti jedino otkrivanjem biološki aktivnih spojeva s izraženim antibakterijskim djelovanjem. Makrolidni antibiotici (makrolidi) imaju široki spektar djelovanja i učinkoviti su na većinu Gram-pozitivnih i Gram-negativnih bakterija. Jedan od najvažnijih predstavnika druge generacije makrolida je azitromicin. Povezivanjem azitromicina i nekih biološki aktivnih tiosemikarbazona dobiveni su njihovi konjugati makrozoni koji su pokazali povećanu učinkovitost i aktivnost na neke višestruko rezistentne sojeve bakterija. Biološka svojstva makrozona mogu se dodatno poboljšati kompleksiranjem s kationima prijelaznih metala. U ovom diplomskom radu istražena je aktivnost benzil-4''-makrozona i kompleksa nikla(II) s makrozonskim 4''- derivatom azitromicina. Interakcije pripravljenih spojeva s ribosomom izoliranim iz bakterije Escherichia coli i s goveđim albuminom iz seruma (BSA) određene su i analizirane pomoću tehnika STD i WaterLOGSY NMR te su određeni epitopi vezanja.An increased resistance of pathogenic bacteria to previously known drugs and the lack of development of new antibiotics represent a global medical problem that can only be solved by discovering biologically active compounds with increased antibacterial activity. Macrolide antibiotics (macrolides) have a broad spectrum of activity and are effective against most Gram-positive and Gram-negative bacteria. One of the most important representatives of the second generation of macrolides is azithromycin. By linking azithromycin and some biologically active thiosemicarbazones, their conjugates, macrozones, were obtained, which showed increased efficiency and activity against some multi-resistant strains of bacteria. The biological properties of macrozones can be further improved by complexing with transition metal cations. In this thesis, the activity of benzyl-4''-macrozone and nickel(II) complex with macrozone 4''-derivative of azithromycin was investigated. The interactions of the prepared compounds with the ribosome isolated from the bacterium Escherichia coli and with bovine albumin (BSA) have been investigated and analysed by using STD and WaterLOGSY NMR techniques and binding epitopes have been determined
Modeling of cardiac muscle biophysics
No full textU radu je predstavljen princip rada srčanog mišića, pojam elektrokardiograma i akcijskog potencijala. Matematički je izveden dvodomenski model te potom i jednodomenski model kao aproksimacija dvodomenskog. Zatim je pokazan algoritam Strangove podjele kojim se modeli mogu numerički riješiti te je izvedena varijacijska/slaba formulacija jednadžbi. Prikazani su dobiveni rezultati za pravokutnu domenu s reparametriziranim FitzHugh-Nagumo modelom, Nobleovim modelom i Beeler-Reuter modelom. Rezultati modela na domeni presjeka srca uspoređeni su s literaturom. Na jednakoj domeni modelirana je lokalna ishemija srca te su prezentirana rješenja takvog modela. Uspoređena su rješenja jednodomenskog i dvodomenskog modela i pokazano je rješenje dvodomenskog modela na trodimenzionalnoj domeni lijeve klijetke.This thesis presents the physiology of the heart muscle, the concept of the electrocardiogram, and action potential. The bidomain model and subsequently the monodomain model, as an approximation of the bidomain model, are mathematically derived. Then, the Strang operator splitting scheme, which is used to solve the models numerically, is shown, and the variational/weak form of the equations is derived. The results obtained for the rectangular domain with the reparameterized FitzHugh-Nagumo model, the Noble model, and the Beeler-Reuter model are presented. The results of the model on the heart cross-section domain are compared with the literature. Local ischemia was added to the same domain, and solutions for such a model are presented. The solutions of the monodomain and bidomain models are compared, and the solutions of the bidomain model on the three-dimensional domain of the left ventricle are shown
Assessment of the dynamic response of the Cathedral of St. Jakov in Šibenik to microseismic noise measurements
No full textIzgrađena tijekom 15. i 16. stoljeća, katedrala sv. Jakova u Šibeniku smatra se jednim od najvažnijih arhitektonskih djela hrvatske kulturne baštine te je uvrštena na popis UNESCO-a 2000. godine. Kako bi se našle ranjive točke katedrale te je se učinilo otpornom na buduće seizmičke učinke, HVSR metodom su mjerene seizmičke ambijentalne vibracije okolnog terena i unutar katedrale. Na osnovi 35 mjerenja na području oko katedrale napravljene su mikrozonacije osnovne frekvencije tla, H/V amplituda, dubine osnovne stijene i Vs30 vrijednosti uskog područja oko katedrale te je određen predominantni smjer gibanja tla.
Mikrozonacijom je utvrđena velika promjena svojstava tla u smjeru jugozapad-sjeveroistok, odnosno od obale prem unutrašnjosti. Iz 19 mjerenja na različitim točkama unutar katedrale određene su frekvencije dominantnih modova za svaki smjer osciliranja.
Prema amplitudi H/V krivulja ustanovljen je predominantni smjer osciliranja katedrale.
Usporedbom mjerenja na terenu i u samoj zgradi određeni su kritični strukturni elementi konstrukcije, koji se nalaze u rezonanciji s tlom; desni bočni zid, lijeva galerija i kupola. Određene strukturne jednice pokazuju i dijagonalne modove osciliranja.
Ovaj rad je prvi rad koji opisuje seizmički odziv katedrale sv. Jakova s obzirom na lokalno tlo te kao takav daje podlogu za daljnja istraživanja i modeliranja odziva, a s konačnim ciljem konstrukcijskog ojačivanja te time očuvanja ovog vrijednog zdanja kulturne baštine.Built during the 15th and 16th centuries, the Cathedral of St. James in Šibenik is considered one of the most important architectural works of Croatian cultural heritage and was included in the UNESCO list in 2000. To identify vulnerable points in the cathedral and enhance its resistance to future seismic effects, seismic ambient vibrations of the surrounding terrain and inside the cathedral were measured using the HVSR method. Based on 35 measurements in the area around the cathedral, microzonation of the ground frequency, H/V amplitude, depth of the base rock, and Vs30 values of the narrow area around the cathedral was performed. The preferred direction of ground movement was also determined. Microzonation revealed a significant change in soil properties in the southwest-northeast direction, i.e., from the coast to the interior. From 19 measurements at different points inside the cathedral, the frequencies of the dominant modes for each direction of oscillation were determined. The predominant direction of oscillation of the cathedral was established based on the amplitude of the H/V curves. By comparing measurements on the ground and within the building itself, critical structural elements were identified: the right side wall, the left gallery, and the dome. Certain structural units also exhibited diagonal modes of oscillation. This paper represents the first documentation describing the seismic response of the Cathedral of St. James concerning the local soil. It serves as a foundational work for further research and modeling of the response, with the ultimate goal of structural strengthening and the preservation of this valuable cultural heritage building
Binding of transition metal ions into human dipeptidyl peptidase III
No full textCilj istraživanja bio je odrediti učinak vezanja različitih dvovalentnih iona metala: Zn2+, Mn2+, Co2+, Cu2+, u različitim koncentracijama, na aktivnost ljudske dipeptidil-peptidaze III (hDPP III), istražiti pretpostavku postojanja inhibitornog veznog mjesta metala i ukoliko je točna, identificirati ga. Istraživanja su provedena kombiniranjem različitih eksperimentalnih i računalnih metoda. Za potrebe eksperimentalnog istraživanja pripremljeni su holoenzimi s ionima Zn2+, Mn2+, Co2+ i Cu2+. U tim uzorcima stehiometrija metal-protein određena je spektrometrijom masa s induktivno spregnutom plazmom (ICP-MS) i izotermalnom titracijskom kalorimetrijom (ITC). Koristeći metodu spektroskopije zaustavljenog protoka, pratilo se smanjenje enzimske aktivnosti hDPP III uzrokovano viškom iona metala. Računalnim metodama, kvantno mehaničkim izračunima i molekulsko dinamičkim simulacijama, određeni su afiniteti različitih kationa metala prema aktivnom mjestu hDPP III, identificirana su inhibitorna vezna mjesta za ione bakra i cinka i određen je mehanizam izmjene metalnih iona vezanih u inhibitorno i katalitičko vezno mjesto.The aim of the study was to determine the binding effect of various divalent ionic metals: Zn2+, Mn2+, Co2+, Cu2+, in different concentrations, on the activity of human dipeptidyl peptidase III (hDPP III), to verify our assumption of the existence of an inhibitory metal binding site and, if correct, to identify this site. The investigations were carried out by combining different experimental and computational methods. For the experimental studies, holoenzymes with Zn2+, Mn2+, Co2+, and Cu2+ ions were prepared. In these samples, the metal-protein stoichiometry was determined by inductively coupled plasma mass spectrometry (ICP-MS) and isothermal titration calorimetry (ITC). Stopped flow spectroscopy was used to monitor the decrease in hDPP-III enzyme activity due to an excess of metal ions. Computational methods, quantum mechanical calculations and molecular dynamics simulations were used to determine the affinities of different metal dications to the active site of hDPP III, to identify the inhibitory binding site for copper and zinc ions and to determine the mechanism of exchange of metal ions bound to the inhibitory and catalytic binding sites