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Influence of the filler material on crack appearance during MAG welding of structural and high alloyed austenitic steel
No full textZavarivanje konstrukcijskih i austenitnih nehrđajućih čelika često se primjenjuje prilikom proizvodnje konstrukcija s ciljem smanjenja troškova, a zadržavanja antikorozivnih svojstava ili osiguravanja nemagnetičnosti dijelova konstrukcije. Zavarivanje takve kombinacije predstavlja brojne izazove zbog nepravilnosti koje se mogu pojaviti poput toplih pukotina, korozijskih pukotina uzrokovanih interkristalnom ili napetosnom korozijom, pojave martenzita na granici staljivanja, bandinga i makrosegregacije. Nečistoće poput sumpora i fosfora u dodatnom i osnovnom materijalu glavni su utjecajni faktor na podložnost nastanka toplih pukotina u materijalu zavara zbog niske topivosti tih elemenata u austenitu. Nizak stupanj miješanja dodatni je faktor koji treba osigurati tijekom zavarivanja raznorodnih čelika kako bi se smanjio prijelazni sloj između materijala i tako spriječilo smanjenje korozijske postojanosti i pojavu nepoželjnog martenzita. Zavarivanje konstrukcijskog i austenitnog čelika najčešće se provodi MAG postupkom zavarivanja s dodatnim materijalom austenitne mikrostrukture i zaštitnim plinom visokog udjela Ar i malog udjela CO2 ili O2. U eksperimentalnom dijelu rada ispitan je utjecaj 3 vrste dodatnog materijala (ESAB ER309LSi, Oerlikon ER309LSi i ER307) na nastanak pukotina i nepravilnosti u 3 kombinacije spojeva konstrukcijskih i austenitnih nehrđajućih čelika: S355J2+N zavaren za X2CrNi18-9, X5CrNi18-10 i X6CrNiMoTi17-12-2. Zavarivanje je provedeno na robotskoj stanici uz konstantne parametre kako bi se eliminiralo što više utjecajnih parametara na kvalitetu zavarenih spojeva. Mjerenjem feritnog broja zavara te makrostrukturnom i mikrostrukturnom analizom ispitnih uzoraka zaključeno je da bi sve tri vrste dodatnog materijala uz daljnju optimizaciju parametara bile pogodne za postizanje kvalitetnog zavarenog spoja. Makrostrukturnom i mikrostrukturnom analizom nisu uočene značajne greške i nepravilnosti u metalu zavarenog spoja, ali su primijećene pukotine i nepravilnosti na liniji staljivanja osnovnih materijala iza korijena zavara što je posljedica nepravilne tehnologičnosti spoja.Welding of structural and austenitic stainless steels is commonly used in the production of structures to reduce costs while maintaining corrosion resistance or ensuring the non-magnetic properties of certain parts. Welding of dissimilar steels is often challenging due to various difficulties that may arise, such as hot cracks, corrosion cracks caused by intergranular or stress corrosion, the formation of martensite at the fusion boundary, banding, and macrosegregation. Impurities like sulphur and phosphorus in the filler and base materials are the main influencing factors on the susceptibility to hot cracks in the weld metal due to their low solubility in austenite. A low degree of mixing is another factor that must be ensured during dissimilar welding to reduce the transition zone between materials and thus prevent a decrease in corrosion resistance and the appearance of unwanted martensite. For welding of structural and austenitic steels, MAG welding process is most commonly used with austenitic filler materials and a shielding gas mixture with a high proportion of argon and a small amount of CO2 or O2. In the experimental part of the study, the influence of three types of filler materials (ESAB ER309LSi, Oerlikon ER309LSi and ER307) on crack formation and defects were tested in three combinations of joints between structural and austenitic stainless steels: S355J2+N welded to X2CrNi18-9, X5CrNi18-10, and X6CrNiMoTi17-12-2. Welding was performed on a robotic station with constant parameters to eliminate as many influencing factors on the quality of the welded joints as possible. By measuring the ferrite number of the welds and performing macrostructural and microstructural analyses of the test samples, it was concluded that all three types of filler materials, with further parameter optimization, would be suitable for achieving high-quality welded joints. No significant defects or irregularities were observed in the weld metal through macro and microstructural analysis, but some issues were detected at the fusion line of the base materials behind the root of the weld. These issues can be attributed to improper joint design
The Relationship Between the Strategic Role of the Supervisory Board and the Integration of Sustainability Goals
No full textIstraživački problem predmetne disertacije odnosi se na ispitivanje povezanosti načina preuzimanja strateške uloge nadzornog odbora i integracije ciljeva održivosti u poslovanje poduzeća. Nadalje, disertacija ispituje moderacijski efekt veličine i određenih obilježja sastava nadzornog odbora na navedenu povezanost. Na koncu, ispituje se signifikantnost određenih procesa grupne dinamike u nadzornom odboru kao antecedenata razine uključenosti nadzornog odbora u strateška pitanja poduzeća. Rezultati empirijskog istraživanja koje je provedeno među-metodnom triangulacijom potvrđuju povezanost strateške uloge nadzornog odbora i integracije ciljeva održivosti. Pritom je moderacijski efekt na navedenu povezanost potvrđen samo za raznolikost znanja i vještina u nadzornom odboru. Na koncu, rezultati potvrđuju utjecaj kognitivnog konflikta, normi truda te primjene znanja i vještina u nadzornom odboru na razinu strateške uključenosti nadzornog odbora. Mapirajući znanstveni prostor na sjecištu korporativnog upravljanja i korporativne održivosti, uz navedeni empirijski doprinos, disertacija kroz bibliometrijsko istraživanje ostvaruje i znanstveni doprinos. Disertacija na temelju empirijskog doprinosa pruža i niz preporuka za unaprjeđenje zakonskog i regulatornog okvira čime ostvaruje i važan aplikativni doprinos.This doctoral thesis is grounded in theoretical assumptions of stakeholder theory and investigates the relationship between the level of supervisory board involvement in the company's strategy and the integration of sustainability goals. Also, this dissertation aims to examine the moderating effects of board size and certain board composition characteristics on the aforementioned relationship. Finally, this thesis aims to determine if certain group dynamics processes influence the level of supervisory board involvement in strategic issues.
Therefore, this thesis is based on three major hypotheses: (H1) group dynamics in the supervisory board is positively related to the strategic role of the supervisory board; (H2) strategic role of the supervisory board is positively related to the integration of sustainability goals, and (H3) size and composition of the supervisory board positively moderate the relationship between the strategic involvement of the supervisory board and the integration of sustainability goals. In order to investigate these assumption, a mixed-method triangulation empirical study is conducted.
The results of this empirical research largely corroborate the initial assumptions. Both quantitative and qualitative research phases confirm the existance of significant positive relationship between the level of supervisory board involvement in the company's strategy and the integration of sustainability goals, thereby confirming H2. This relationship is however only moderated by the diversity in knowledge and experience of board members, while quantitative data failed to establish such an effect for both board independence and gender diversity, and qualitative data failed to confirm initial quantitative research finding for board size. Therefore, H3 was only partially supported. Finally, empirical research confirmed the positive effects of cognitive conflict, effort norms and the use of knowledge and experience of board members on the level of board inveolvement in strategic issues, fully confirming H1.
The scientific contribution of this doctoral thesis encompasses also the bibliometric analysis of the research space at the nexus of corporate sustainability and corporate governance. Finally, the applicative contribution of the dissertation consists of several legislative and regulatory proposals aimed to increase the contributions of corporate governance to corporate sustainability adoption
Characterisation of silicon dioxide nanoparticles of different sizes and their modification by polyelectrolyte
No full textNanočestice silicijeva dioksida pokazuju veliki potencijal za primjenu u raznim područjima te je za njihovu primjenu važno razumjeti kako veličina utječe na njihova ostala svojstva. Nadalje, modificiranjem nanočestica adsorpcijom polielektrolita moguće je promijeniti njihova svojstva. Polielektroliti su makromolekule čije podjedinice sadrže ionske ili lako ionizirajuće skupine te ih je moguće adsorbirati na površine suprotnog naboja. U ovome radu istražen je utjecaj veličine nanočestica silicijeva dioksida na njihova svojstva te su korištene čestice promjera od 10 nm do 100 nm. Veličina čestica određena je mikroskopijom atomskih sila te pretražnom elektronskom mikroskopijom. Dinamičkim i elektroforetskim raspršenjem svjetlosti određeni su hidrodinamički promjer i ζ-potencijal nanočestica pri različitim koncentracijama natrijeva klorida. Površinski naboj određen je titracijom nanočestica otopinom polielektrolita. Zatim je na nanočestice adsorbiran poli(N-etil-4-vinilpiridinijev) bromid te je određeno kako maksimalna koncentracija polielektrolita ovisi o veličini čestica. Također su određeni veličina čestica, hidrodinamički promjer te ζ-potencijal i uspoređeni s nemodificiranim česticama.Silicon dioxide nanoparticles show great potential for application so it’s important to understand how their size affects their other properties. It is possible to modify nanoparticle properties my adsorbing polyelectrolytes on them. Polyelectrolytes are macromolecules which contain ionic or easily ionisable groups, and they can be adsorbed on oppositely charges surfaces. The influence of silicon dioxide nanoparticle size on their properties was studied for nanoparticles with a diameter of 10 nm to 100 nm. Particle size was determined by atomic force microscopy and scanning electron microscopy. Dynamic and electrophoretic light scattering was used to determine the hydrodynamic radius and ζ-potential of the particles at different concentrations of sodium chloride. Surface charge was determined by titrating nanoparticles with polyelectrolyte. Then, poly(N-ethyl-4-vinylpyridinium) bromide was adsorbed and the dependence of maximum polyelectrolyte concentration on particle diameter was shown. Particle size, hydrodynamic radius and ζ-potential were also determined and compared to unmodified particles
Reliability analysis and improvement of a device for non-destructive testing of reactor pressure vessel welds
No full textKoncepti pouzdanosti i analize pouzdanosti sve više dobivaju na važnosti povećanjem složenosti proizvoda i porastom zahtjeva krajnjih korisnika. To je posebice izraženo u postrojenjima visokih rizika, poput nuklearnih elektrana, gdje je pouzdanost ključan aspekt u očuvanju integriteta postrojenja, ali i sprječavanja dugotrajnog zastoja rada elektrane do kojeg može doći uslijed kvarova uređaja kojima se vrši inspekcija pojedinih dijelova postrojenja. Upravo iz tog razloga cilj ovoga rada bio je provesti analizu pouzdanosti uređaja za ispitivanje zavara tlačnih posuda reaktora i predložiti konstrukcijske promjene kojima će se povećati pouzdanost komponenti i podsustava kod kojih postoji povećani rizik od kvara.
Radi upoznavanja s problematikom inženjerstva pouzdanosti, najprije su definirani pojmovi poput kvara, rizika, pouzdanosti i raspoloživosti sustava, te je definirana metodologija provedbe analize pouzdanosti. U metodologiji je poseban naglasak stavljen na ispravnu i temeljitu provedbu funkcijske analize, kao i na odabir i primjenu različitih metoda za analizu pouzdanosti. Kako bi se za konkretni slučaj omogućio odabir najprimjerenije metode, te postigli bolji rezultati i točnija primjena metode, prvo je dan pregled njihovih karakteristika, prednosti i nedostataka. U sljedećem koraku je provedena FMEA analiza, kao odabrana metoda za analizu pouzdanosti, na spomenutom uređaju za inspekciju zavara posude reaktora, kojeg razvija tvrtka INETEC. Najprije su opisani sam uređaj, njegov princip rada i interakcija s drugim podsustavima, nakon čega su provedbom funkcijske analize identificirane glavne i pomoćne funkcije uređaja, kao osnova za izradu FMEA tablica u kojima su potom definirani svi mogući načini, uzroci i posljedice otkazivanja. Pri njihovom definiranju, kao i kvantifikaciji ozbiljnosti i učestalosti, pomoglo je prijašnje iskustvo tvrtke te podaci od dobavljača i proizvođača. FMEA analizom identificirano je 1067 malih i srednjih rizika, 141 visokih te 29 kritičnih rizika u sustavu. Visoki rizici su u najvećoj mjeri posljedica prekida tokova zraka i energije kroz sustav, kao i mogućeg prodiranja vode unutar uređaja. Kvarovi, odnosno greške koje mogu nastati u sustavu najčešće su rezultat neadekvatne ulazne kontrole dijelova, pogrešnog proračuna, neadekvatne konstrukcije, kao i grešaka na softveru, instrumentu, kontrolnoj kutiji ili uslijed rukovanja operatera. Za sve rizike predložene su mjere za njihovo smanjenje, dok su za one kritične napravljene odgovarajuće konstrukcijske promjene, pri čemu su se najkritičnijim pokazali podsustavi za vakuumsko prianjanje uređaja za stijenku posude. Na samom kraju dan je kritički osvrt na upotrebu navedenih metoda te su dani prijedlozi za budući rad.Reliability and reliability analysis concepts are increasingly gaining importance with the increase in product complexity and end-user requirements. This is particularly noticeable in high-risk facilities, such as nuclear power plants, where reliability is a crucial aspect not only in preserving the plant's integrity but also preventing the prolongation of the outage phase of power plants that can occur due to in-service inspection device failures during the inspection of the plant parts. For this reason, aim of this paper was to analyze the reliability of a device for ultrasonic testing of reactor pressure vessel welds and propose required design changes that will increase the reliability of components and subsystems where an increased risk of failure has been identified. In order to get acquainted with the issue of reliability engineering, terms such as failure, risk, reliability, availability, maintainability, and quality were addressed, after which the methodology for conducting reliability analysis was defined. Within the methodology, great emphasis was placed on the correct and thorough implementation of functional analysis and the selection and application of different methods for reliability analysis. An overview of the characteristics, advantages, and disadvantages of each of the methods is given in order to select the most appropriate methods for the respective case and to ensure correct application and better results. In the next step, an FMEA analysis was performed on said in-service inspection device, currently being developed by the INETEC company. First, the device itself, its principle of operation and interaction with other subsystems were described, after which the main and auxiliary functions of the device were collected through the functional decomposition process. Based on the decomposition, the FMEA table was created in which all failure modes, causes and effects for said functions are defined. In defining them, as well as quantifying their severity and occurrence, the company's previous experience and data from suppliers and manufacturers helped. FMEA analysis identified 1067 minor and medium risks, 141 high and 29 critical risks in the system. The high risks are largely due to the interruption of air and energy flows through the system, as well as the possible penetration of water inside the device. Malfunctions and errors that can occur in the system, are most often the result of inadequate input control of parts, incorrect calculation, inadequate construction, as well as errors in software, instrument, control box or due to operator handling. For all risks, suggestions for their mitigation have been proposed, while for those critical, appropriate design changes have been made. At the very end, a critical review of the use of these methods is given as well as future work suggestions
Electrochemical characterization of dimeric metallosurfactants
No full textPovršinski aktivne tvari, zahvaljujući svojim amfifilnim svojstvima, nalaze široku primjenu u različitim područjima, uključujući i elektrokemiju. U ovom radu provedena je elektrokemijska karakterizacija staklaste ugljikove elektrode (GC) u prisutnosti dimerne kationske površinski aktivne tvari (12-2-12) (PAT) te u prisutnosti PAT-a koji u protuionu sadrži različite prijelazne metale (12-2-12)[MBr4] pri čemu je M = Co, Ni, Zn, Cu (PAT M). Ispitivanja su provedena u otopini elektrolita, Na2SO4, pri koncentracijama ispod (PAT 1/PAT 1 M) i iznad (PAT 2/PAT 2 M) kritične micelizacijske koncentracije (cmc) korištenjem elektrokemijske impedancijske spektroskopije (EIS) i cikličke voltammetrije (CV). Rezultati su pokazali da dodatak PAT 1 u otopinu elektrolita ne uzrokuje značajne promjene u elektrokemijskom odzivu GC elektrode dok dodatak PAT 2 dovodi do povećanja kapaciteta elektrode. U prisutnosti PAT M spojeva (M = Co, Ni, Zn), osobito u koncentracijama iznad cmc-a (PAT 2 M), zabilježen je porast specifičnih struja i nastanak novih strujnih vrhova u CV-u GC elektrode, kao i složeniji odgovori u EIS-u (više od jedne vremenske konstante). To ukazuje na prisutnost dodatnih elektrokemijskih procesa osim čistog nabijanja/izbijanja električnog dvostrukog sloja. Najizraženiji efekti zabilježeni su u prisutnosti PAT-a koji sadrži Cu, osobito pri višoj koncentraciji (PAT 2 Cu). Voltamogrami i impedancijski spektri (IS) GC elektrode u tim slučajevima pokazuju značajne elektrokemijske promjene unutar ispitivanog sustava. One se manifestiraju kroz dodatne strujne vrhove u CV-u te kao dodatne vremenske konstante u IS-u ukazujući na postojanje brojnijih redoks procesa i kompleksniju elektrokemijsku dinamiku unutar ispitivanog sustava.Surfactants are widely used in many different areas, including electrochemistry owing to their amphiphilic properties. In this work, the electrochemical characterization of glassy carbon electrode (GC) was carried out in the presence of a dimeric surfactants (12-2-12) (PAT) and in the presence of PAT with modified transition metal counterion (12-2-12)[MBr4], i.e., M = Co, Ni, Zn, Cu (PAT M). The electrochemical behavior of GC was carried out in an electrolyte solution, Na2SO4, containing different concentrations of PAT/PAT M solutions: pre-micellar (PAT 1/PAT 1 M) and post-micellar (PAT 2/PAT 2 M). The electrochemical techniques used were electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The results showed that the addition of PAT 1 to the electrolyte solution does not lead to any significant changes in the electrochemical response of the GC electrode. On the other hand, the addition of PAT 2 leads to an increase in electrode capacity. In the presence of PAT M solutions (M = Co, Ni, Zn), an increase in the specific currents and the formation of new current peaks can easily be observed in the CV, while new time constants can be recognized in the impedance spectra (IS). This indicates that in addition to the pure charging/discharging of the electrical double layer, more complex electrochemical process are also taking place. These changes become even clearer when PAT 2 M is added to the electrolyte solution. The most pronounced effects in both CV and EIS were observed in the presence of PAT Cu, especially at post-micellar concentrations (PAT 2 Cu). In these cases, the voltamograms and IS of the GC electrode show clear electrochemical changes within the tested system. These are reflected in additional current peaks in the CVs and additional time constants in the IS, indicating additional redox processes and more complex electrochemical dynamics in the tested system
Synthesis and spectroscopic characterization of novel iminocoumarine benzoxazole derivatives as potential sensors for pH in solutions
No full textU ovom radu provedena je sinteza novih iminokumarinskih derivata benzoksazola 9-12. Polazni spoj, etil-2-cijano-acetamidat-hidroklorid 3, sintetiziran je aktivacijom malonitrila 1 u prisutnost trimetilsilil-klorida (TMSCl) i etanola. Ključni međuprodukt,
2-cijanometilbenzoksazol 4, dobiven je reakcijom spoja 2 i 2-aminofenola 3, primjenom dviju sintetskih metoda: konvencionalne te mikrovalovima potpomognute sinteze. Ciljani iminokumarinski derivati 9-12 dobiveni su kondenzacijom 2-cijanometilbenzoksazola 4 s odgovarajućim supstituiranim 2-hidroksibenzaldehidima 5-8 u prisutnosti piperidina i etanola u reaktoru za paralelnu sintezu. Strukture spojeva 9-12 potvrđene su 1H i 13C NMR spektroskopijom. Radi ispitivanja njihove potencijalne primjene kao optičkih pH senzora u otopinama, spojevi 9, 10 i 12 spektroskopski su okarakterizirani UV/Vis spektroskopijom u šest organskih otapala različitih polarnosti. Provedene su i UV/Vis pH titracije u puferskim otopinama različitih pH vrijednosti. Promjene u apsorpcijskim spektrima, ovisno o polarnosti otapala i pH vrijednosti medija, ukazuju na potencijalnu primjenjivost spojeva 9, 10 i 12 kao optičkih pH senzora.In this work, the synthesis of new iminocoumarine derivatives of benzoxazoles 9-12 was carried out. The starting compound, ethyl-2-cyano-acetamidate hydrochloride 60, was synthesized by activation of malonitrile 1 in the presence of trimethylsilyl chloride (TMSCl) and ethanol. The key intermediate, 2-cyanomethylbenzoxazole 4, was obtained by reaction of compound 2 with 2-aminophenol 3, using two synthetic methods: conventional and microwave-assisted synthesis. The targeted iminocoumarine derivatives 66, 67 and 69 were obtained by condensation of 2-cyanomethylbenzoxazole 4 with the corresponding substituted 2- hydroxybenzaldehydes 5-8 in the presence of piperidine and ethanol in a parallel synthesis reactor. The structures of compounds 9-12 were confirmed by 1H and 13C NMR spectroscopy. To investigate their potential application as optical pH sensors in solutions, compounds 9, 10 and 12 were spectroscopically characterizedby UV/Vis spectroscopy in six organic solvents of different polarities, as well as by UV/Vis pH titrations in a buffered solutions of different pH values. Changes in absorption spectra, depending on the polarity of the solvent and the pH value of the medium, indicate the potential applicability of compounds 9, 10 and 12 as optical pH sensors
Application of electrospun membranes in "lung-on-a-chip" models for simulating the alveolar barrier
No full textRazvoj funkcionalnog "lung-on-a-chip" modela, koji na vjerodostojan način oponaša kompleksnu strukturu i funkciju alveolarno-kapilarne barijere, središnja je tema ovoga rada. Inspiriran fiziologijom ljudskih pluća, model je osmišljen kao multifunkcionalna platforma za istraživanje prijenosa tvari kroz plućno tkivo, ispitivanje djelovanja inhalacijskih pripravaka te evaluaciju toksičnosti aerosola i drugih inhalacijskih agensa. Ključni korak u njegovoj izradi bila je primjena metode elektroispredanja za dobivanje tankih, biokompatibilnih membrana od polikaprolaktona, pri čemu je posebna pažnja posvećena optimizaciji uvjeta izrade kako bi se što bolje reproducirale mehaničke i morfološke karakteristike plućnog tkiva. Osim toga, u sustav su integrirani hidrogelovi na bazi natrijeva alginata, koji omogućuju kontroliranu difuziju i upotpunjuju model pluća. Cilj istraživanja je izraditi dinamički model koji „diše“, odnosno simulira mehaničke sile disanja, čime se dobiva realistični prikaz respiratorne funkcije u in vitro uvjetima. Takav sustav otvara mogućnosti za unapređenje inhalacijskih terapija, provedbu toksikoloških ispitivanja te razvoj alternativnih metoda za analizu plućnih funkcija bez upotrebe životinjskih modela. Model predstavlja značajan napredak u području biomedicine i kemijskog inženjerstva, jer omogućuje ubrzanje procesa razvoja lijekova i terapija. Njegova primjena omogućuje bržu i etički prihvatljiviju evaluaciju novih terapija, osobito u područjima pulmologije i farmacije, čime postaje vrijedan alat doprinoseći razvoju sigurnijih i učinkovitijih terapijskih rješenja za respiratorne bolesti.The development of a functional lung-on-a-chip model that accurately mimics the complex structure and function of the alveolar-capillary barrier is the central focus of this work. Inspired by the physiology of the human lung, the model is designed as a multifunctional platform for studying substance transport across pulmonary tissue, evaluating the effects of inhaled formulations, and assessing the toxicity of aerosols and other inhalable agents. A key step in the fabrication of the model involved the application of electrospinning to produce thin, biocompatible membranes made of poly(ε-caprolactone), with particular attention given to optimizing fabrication conditions to best replicate the mechanical and morphological properties of lung tissue. Additionally, the system incorporates sodium alginate-based hydrogels, which enable controlled diffusion and complement the lung model. The aim of the research is to develop a dynamic, “breathing” model that simulates the mechanical forces of respiration, thereby providing a realistic representation of respiratory function under in vitro conditions. Such a system offers new opportunities for improving inhalation therapies, conducting toxicological testing, and developing alternative methods for analyzing lung function without the use of animal models. This model represents a significant advancement in the fields of biomedicine and chemical engineering, as it accelerates the process of drug and therapy development. Its application enables faster and more ethically acceptable evaluation of new therapies, particularly in the fields of pulmonology and pharmaceutical sciences, making it a valuable tool in the pursuit of safer and more effective therapeutic solutions for respiratory diseases
TBM modeli predviđanja napredovanja. Usporedba napredovanja predviđenog u natječaju i u stvarnosti. Projekt: Anneberg–Skanstull tunel (Stockholm, Švedska) : diplomski rad
No full textThe most widely used prediction model for hard rock is the Colorado School of Mines (CSM) model, which was used for tender prediction in the Anneberg - Skanstull Tunnel (AST) project. However, during the construction phase, the TBM penetration rate was lower than predicted in the model. Intact rock strength is usually the first rock mechanic parameter obtained from geological investigation for tunnelling projects. This is one of the key parameters used in the Tunnel Boring Machine (TBM) prediction model. The most common rock mechanic test for intact rock strength determination is the Uniaxial Compressive Strength (UCS). After core sampling from the tunnel, new UCS values were obtained, analysed, filtered, and implemented in the CSM model to generate new penetration rates for different lithologies.Za stijene visoke čvrstoće, najčešće korišteni TBM model predviđanja je Colorado School of Mines (CSM), koji je i korišten u natječaju za izradu Anneberg-Skanstull tunela (AST). Međutim, tijekom konstrukcije tunela, uočeno je sporije napredovanje nego što je predviđeno u modelu. Svojstva stijena obično su prva informacija dobivena iz geoloških istraživanja kod izrade tunela. Ovo je jedan od ključnih parametara korištenih kod izrade modela za predviđanje napredovanja stroja za bušenje tunela (eng. TBM). Najčešća metoda ispitivanja stijenske mase je Jednoosna Tlačna Čvrstoća (eng. UCS). Nakon jezgrovanja u tunelu, nove UCS vrijednosti su dobivene, analizirane i uvrštene u CSM model s ciljem generiranja novih stopa napredovanja za druge litologije
Položaj kromosoma 1 i 9, obilježenih pomoću tehnologije CRISPR/Cas9, u odnosu na jezgrinu ovojnicu i centrosome
No full textHuman chromosomes occupy specific territories in the cell nucleus. Chromosomes that are
localized at the periphery of the cell nucleus at the onset of mitosis show increased missegregation
rates, in compromised mitosis conditions, than the chromosomes that are
localized centrally. I specifically labeled subtelomeric region of chromosome 1 and
pericentromeric region of chromosome 9 using technology CRISPR/Cas9 (clustered regularly
interspaced short palindromic repeats and CRISPR-associated protein 9). I determined their
position in the cell nucleus, during early prometaphase, with respect to the nuclear envelope
and centrosomes. Chromosome 1 is localized at the periphery, whereas chromosome 9 is
equally distributed in the cell nucleus during early prometaphase. Furthermore, chromosome 1
and chromosome 9 are both equally polar (closing the angle of >90º with the spindle pole)
during early prometaphase. Also, there is no difference in the distance between chromosome 1
and chromosome 9 from the centrosome in early prometaphase and the average distance of
the centrosome to the former nuclear envelope in early prometaphase is 2.79 μm. The position
of centrosomes during early prometaphase is important from the point of mitotic fidelity. The
results of this thesis further support future research of specific chromosome position during
early prometaphase.Kromosomi ljudskih stanica zauzimaju specifične teritorije u jezgri. Kromosomi koji se
nalaze na periferiji jezgre prije početka mitoze skloniji su pogrešnoj podjeli, u uvjetima
narušene mitoze, u odnosu na kromosome koji su pozicionirani centralno. Specifično sam
obilježila subtelomernu regiju kromosoma 1 i pericentromernu regiju kromosoma 9
upotrebom tehnologije CRISPR/Cas9 (engl. clustered regularly interspaced short palindromic
repeats and CRISPR-associated protein 9). Odredila sam položaj navedenih kromosoma u
jezgri, tijekom rane prometafaze, u odnosu na jezgrinu ovojnicu i centrosome. Kromosom 1
zauzima periferni položaj, dok je kromosom 9 podjednako distribuiran u svim dijelovima
jezgre tijekom rane prometafaze. Nadalje, kromosom 1 i kromosom 9 su podjednako polarni
(zatvaraju kut >90º s polom diobenog vretena) tijekom rane prometafaze. Također, ne postoji
razlika u udaljenosti kromosoma 1 i kromosoma 9 od centrosoma u ranoj prometafazi te
prosječna udaljenost centrosoma od nekadašnje jezgrine ovojnice tijekom rane prometafaze
iznosi 2,79 μm. Pozicija centrosoma tijekom rane prometafaze važna je za pravilnu diobu.
Rezultati proizašli iz ovoga rada podupiru buduća istraživanja položaja specifičnih
kromosoma tijekom rane prometafaze
A contribution on the knowledge of the horticultural flora of Croatia
No full textUresna flora Hrvatske se razlikuje na kopnenom i obalnom dijelu zbog utjecaja reljefa, klime, dostupnosti biljnog materijala i kreativnosti stanovništva. Analizirano je osam ranijih florističkih istraţivanja s područja kontinentalne (Donja Stubica, Karlovac, Posavski Bregi, Virovitica) i obalne (Dubrovnik, Opatija, Susak, Veli Lošinj) Hrvatske. Dokumentirano je 457 svojti iz 106 porodica kontinentalne, te 473 svojte iz 123 porodice obalne Hrvatske. Najzastupljenije porodice kontinentalnog dijela su Asteraceae, Ranunculaceae, Rosaceae i Pinaceae, a obalnog dijela su Rosaceae, Asteraceae, Lamiaceae i Fabaceae. U kontinentalnom području najzastupljenije su euroazijske i hortikulturne svojte, dok u obalnom području dominiraju svojte azijskog, zatim euroazijsko-sjevernoafričkog (tj. sredozemnog) podrijetla. Najzastupljeniji ţivotni oblik je zeljasta trajnica, ali se u velikom broju pojavljuju i listopadni/zimzeleni grm te listopadno/zimzeleno drvo. S obzirom na status u Hrvatskoj prevladavaju alohtone svojte u kulturi i autohtone svojte, ali zabiljeţeno je i deset invazivnih svojti na obalnom te sedam na kontinentalnom području Hrvatske.The horticultural flora of Croatia differs on the mainland and the coastal part due to the influence of relief, climate, availability of plant material and the creativity of the population. Eight earlier floristic surveys from continental (Donja Stubica, Karlovac, Posavski Bregi, Virovitica) and coastal (Dubrovnik, Opatija, Susak, Veli Lošinj) areas of Croatia were analyzed. 457 taxa from 106 families of continental Croatia and 473 taxa from 123 families of coastal Croatia were documented. The most represented families of the continental part are Asteraceae, Ranunculaceae, Rosaceae and Pinaceae, and of the coastal part are Rosaceae, Asteraceae, Lamiaceae and Fabaceae. In the continental area, Euro-Asian and horticultural taxa are most represented, while in the coastal area taxa of Asian, then Euro-Asian-North African (ie Mediterranean) origin dominate. The most common life form is a herbaceous perennial, but there are also deciduous/evergreen shrubs and deciduous/evergreen trees in large numbers. Regarding the status in Croatia, allochthonous taxa in culture and autochthonous taxa predominate, but ten invasive taxa were also recorded on the coastal and seven on the continental area of Croatia