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Teorijske simulacije kvazičestičnih spektara u dopiranom grafenu
No full textThis thesis covers several aspects of the electronic and electromagnetic properties of doped
graphene; peculiar properties of the 2D plasmon, strong quasi-particle interactions with these
plasmons and finally the possibility of transforming these plasmons into radiative modes. The
thesis is imbued with comparisons with available experiments and offers a solution to the longstanding problem of plasmon emission prosess seen in ARPES experiments.
A graphene is a 2D single-layer hexagon crystal, with two atoms in the unit cell. The
electrostatic doping fills its π∗ / π bands with the electrons / holes, enabling the well known
intraband Dirac plasmon. When the graphene is doped with alkali metals, its band structure
introduces a metallic σ band, which profusely fills the graphene π∗ band with the electrons.
In this way, two 2D electron gases interplay, which makes the plasmonic properties of doped
graphene even more interesting.
Moreover, the simulated spectra of electronic excitations in the graphene intercalated with
potassium [KC8 (2x2)] and caesium [CsC8 (2x2)] atoms exhibit very intensive Dirac plasmon,
which dominates the IR frequency range of the electron excitations spectra. On the other hand,
the acoustic plasmon also dominates the IR frequency range of the KC8 spectra, unlike in the
CsC8. More precisely, the acoustic plasmon does not appear at all in the CsC8 spectra of, and a
mechanism responsible for its disappearance is based on the interlayer interband screening due
to the electronic excitations.
In addition to plasmons in the infrared region, we shall also study interband plasmons in
the ultraviolet region, in various graphene intercalates such as KC8, CsC8, LiC2 and LiC6. A
comparative analysis with electrostatically doped graphene will also be done. Furthermore,
when these systems are electrostatically doped with electrons / holes, their spectra of electronic
excitations change drastically as a function of doping.
Here we also study the intercation between electrons / holes in π / π ∗ bands in electrostatically or chemically doped graphene (KC8) with the electronic excitations (focused to the Dirac
plasmon). The electron / hole spectra were calculated using a newly developed G0W0 approximation, which corrects the DFT Green’s function in terms of the induced correlation self energy, which simulates ARPES measurements. In this thesis, we shall see how the electron doping of the graphene π∗ band affects the renormalization of Fermi and Dirac group velocites, kinks at
the Fermi energy and widths of the hole decays in the π and π∗ bands. Finally, we shall see
that both deformation and abrupt increase in the decay width of the π band just below the Dirac
point is due to the Dirac plasmon emission. These theoretical observations will be compared
with the results of other theoretical and experimental studies.
In this thesis, we also investigate the electromagnetic properties of doped graphene and the
intensities of IR active plasmons in graphene nanoribbons. Plasmons in the doped graphene are
non-radiative (evanescent) modes that cannot be excited directly by photons, but only indirectly,
e.g. by scattering of the IR photon stream. In this way the photons scattered in the near-field
region couple to the plasmons and excite them. Yet another way to excite plasmons is to slice
the graphene into nanoribbons that support dipole-active plasmons. In the end, we shall study
the IR active plasmonic resonances in the 1D array of the KC8 nanoribbons, and compare them
with experimental measurements. Also, the synthesis of the KC8 nanoribbons will be discussed.Ova doktorska disertacija istražduje nekoliko aspekata elektronskih i elektromagnetskih svojstava dopiranog grafena; neobicna svojstva 2D plazmona, jake kvazičestične interakcije sa plazmonima te konačno mogućnost transformiranja plazmona u radijativne modove. Disertacija je prožeta usporedbama teorijskih rezultata s dostupnim eksperimentima, te nudi rješenje dugogodišnjeg problema razumijevanja procesa plazmonske emisije u ARPES eksperimentima.
Grafen je 2D jednoslojni heksagonski kristal, koji sadrži dva atoma u jediničnoj ćeliji. Elektrostatsko dopiranje puni njegove π∗ / π vrpce elektronima / šupljinama, omogucavajući dobro znani unutar vrpcani Diracov plazmon. Pri dopiranju grafena alkalijskim metalima, u vrpčastu strukturu ulazi metalna σ vrpca, koja obilato puni grafenovu π∗ vrpcu elektronima. Time počinje međuigra dva 2D elektronska plina, koja čini plazmonska svojstva dopiranog grafena još zanimljivijima.
Štoviše, teorijske simulacije spektara elektronskih pobudenja u grafenu interkaliranog kalijevim [KC8 (2x2)] i cezijevim [CsC8 (2x2)] atomima pokazuju Diracov plazmon visokog intenziteta, koji dominira IR frekvencijskim podrucjem spektara elektronskih pobuđenja. S druge strane, akustični plazmon također dominira IR frekvencijskim podrucjem KC ˇ 8 spektara , ali to nije slučaj i za CsC8. Tocnije, akustični plazmon se uopće ne pojavljuje u CsC8 spektrima, a
mehanizam koji je zaslužan za njegov nestanak se bazira na meduvrpčanom zasjenjenju između razlicitih slojeva radi elektronskih pobuđenja.
Osim plazmona u IR frekvencijskom podrucju, u ovoj disertaciji ćemo se također baviti i međuvrpčanim plazmonima u ˇ UV području. Proučavat će se grafeni interkalirani alkalijskim atomima, poput KC8, CsC8, LiC2 i LiC6, uz usporedbu sa rezultatima za elektrostatski dopirani grafen. Štoviše, pri elektrostatskom dopiranju sustava elektronima / šupljinama, njihovi spektri elektronskih pobudenja se drastično mijenjaju kao funkcija dopiranja.
Proucavat će se i interakcija šupljina / elektrona u ´ π / π∗ vrpcama elektrostatski ili kemijski dopiranog grafena (KC8) sa elektronskim pobudenja (s fokusom na Diracov plazmon). Spektri elektrona / šupljina su izracunati koristeći novorazvijenu G ´ 0W0 aproksimaciju, koja popravlja DFT Greenovu funkciju koristeci induciranu korelacijsku ´ self energiju, a oni su zapravo simulacija ARPES (Angle-resolved photoemission spectroscopy) mjerenja. U ovoj disertaciji pokazat
ću kako dopiranje grafenske ´ π ∗ vrpce utjece na renormalizaciju Fermijevih i Diracovih grupnih brzina, kinkove na Fermijevoj energiji, te širine raspada šupljina u π i π∗ vrpcama. Na koncu, vidjet ćemo i da se deformacija i nagli porast širine raspada ´ π vrpce odmah ispod Diracove točke pojavljuje radi emisije Diracovog plazmona. Teorijska opažanja će se također usporediti sa rezultatima drugih teorijskih i eksperimentalnih istraživanja.
U ovoj disertaciji istraživana su i elektromagnetska svojstva dopiranog grafena, kao i intenziteti IR aktivnih plazmona u grafenskim nanovrpcama. Plazmoni u dopiranom grafenu su neradijativni modovi, koji se ne mogu pobuditi direktno fotonima vec samo indirektno, npr. raspršenjem IR fotonskog snopa. Tako se fotoni raspršeni u near-field području vežu na plazmone, te ih pobuđuju. Drugi način da se pobude plazmoni je da se grafen nareže na nanovrpce koje podržavaju dipolno-aktivne plazmone. Naposljetku, analizirati ćemo ´ IR aktivne plazmone u 1D nizu nanovrpci izrezanih iz KC8, te ih usporediti sa eksperimentalnim mjerenjima, a baviti ćemo se i sintezom KC ´ 8 nanovrpci
Maintance of hydraulic systems
No full textRad se bavi održavanjem hidrauličkih sustava i ključnih komponenti u mnogim
industrijskim procesima. Fokusira se na preventivno i korektivno održavanje, važnost
preciznih mjernih instrumenata te studiju slučaja s Bosch Automation. Rad naglašava da
pravilno održavanje smanjuje rizik od kvarova, produžava vijek trajanja opreme,
poboljšava učinkovitost te smanjuje operativne troškove. Također, istražuje inovacije u
mjernim instrumentima, posebno u kontekstu digitalizacije, i analizira specifične metode
održavanja korištene u Bosch sustavima.The paper discusses the maintenance of hydraulic systems, which are essential
components in many industrial processes. It focuses on preventive and corrective
maintenance, the importance of precise measuring instruments, and a case study with
Bosch Automation. The paper emphasizes that proper maintenance reduces the risk of
failures, extends equipment life, improves efficiency, and lowers operating costs. It also
explores innovations in measuring instruments, particularly in the context of digitalization,
and analyzes specific maintenance methods used in Bosch systems
Risks and risk assessment in crude oil ship-to-ship (STS) transfer operations
No full textOvaj završni rad obrađuje operacije prekrcaja sirove nafte s jednog tankera na drugi (STS – Ship-to-Ship transfer), s naglaskom na prepoznavanje i procjenu rizika povezanih s takvim postupcima. STS operacije predstavljaju važan dio međunarodnog pomorskog prijevoza nafte, ali istovremeno donose određene sigurnosne i okolišne izazove. U radu su analizirani ključni tehnički, organizacijski i ljudski čimbenici koji mogu utjecati na sigurnost tijekom STS operacija, kao i međunarodni propisi i preporučene prakse koje ih reguliraju. Poseban naglasak stavljen je na proces procjene rizika, uključujući analizu mogućih nezgoda, njihovih posljedica te mjera za prevenciju i odgovor. Cilj rada je dati jasan i sveobuhvatan pregled sigurnosnih zahtjeva potrebnih za kvalitetno planiranje i provođenje STS operacija, uz nastojanje da se smanji rizik po ljude, okoliš i brodove.This final thesis explores the operations of crude oil transfer between tankers (STS – Ship-to-Ship transfer), with a particular focus on identifying and assessing the risks associated with this process. STS operations represent a significant part of international maritime oil transportation but also pose various safety and environmental challenges. The paper analyzes the key technical, organizational, and human risk factors, as well as international regulations and best practices that govern these types of operations. Special attention is given to the risk assessment process, including the analysis of potential incidents, their consequences, and the preventive and response measures. The aim of this work is to provide a clear and comprehensive overview of the safety requirements necessary for effective planning and execution of STS operations, while minimizing potential hazards to people, the environment, and property
Influence of a Zombie-like State of the Liver on Drugs and Its Medico-Legal Implications: A Scoping Review
No full textWhen cells remain permanently trapped in a particular cell cycle stage, they are in senescence. This also occurs in the liver. Such cells are often referred to as “zombie cells”, and an entire organ filled with these “zombie cells” is said to be in a “zombie-like” state, characterized by a lack of function. The senescence-associated secretory phenotype (SASP) encompasses the substances these “zombie cells” release, which can significantly affect nearby cells and tissues. While cellular senescence and SASP are related concepts, they are distinct. This scoping review aims to clarify the role of hepatocyte senescence and hepatocyte SASP in the administration of pharmaceuticals, as well as their relevance to medico-legal practice, disability claims, and insurance coverage. In this context, the effects of pharmaceuticals on senescent hepatocytes are discussed, particularly regarding the medico-legal implications of substances likely to be abused. In conclusion, hepatocyte senescence may be relevant in clinical or medico-legal work because it sheds a new light on interpreting clinical findings and expert witness statements
Actor and Partner Effects of Rumination and Reflection on Mood in Romantic Couples
No full textCilj ovog istraživanja bio je ispitati aktorske i partnerske efekte ruminiranja i refleksije na pozitivno i negativno raspoloženje kod romantičnih parova. Ispitanici su uživo ispunili skup upitnika te je prikupljen uzorak od 188 heteroseksualnih parova. Kao mjere raspoloženja korištene su samoprocjene te procjene od strane partnera. Za obradu podataka korišten je ,,Actor-Partner Interdependence Model'' (APIM). Dobiveni rezultati ukazuju na više razine ruminiranja i refleksije kod žena nego kod muškaraca. Za refleksiju su dobiveni pozitivni aktorski efekti na samoprocijenjen osjećaj prihvaćanja, negativni partnerski efekti na pozitivno raspoloženje žena i pozitivni partnerski efekti na negativno raspoloženje žena kada ih je procjenjivao partner. Kod ruminiranja su dobiveni negativni aktorski efekti na pozitivno raspoloženje žena te pozitivni aktorski efekti na negativno raspoloženje muškaraca i žena. Aktorski efekti ruminiranja bili su slični kod samoprocjena raspoloženja i raspoloženja koje je procijenio partner. Dobiveni su negativni partnerski efekti ruminiranja na pozitivno raspoloženje žena te pozitivni partnerski efekti na negativno raspoloženje i kod žena i kod muškaraca. Partnerski efekti ruminiranja dobiveni su kod partnerovih procjena raspoloženja, ali ne i kod samoprocjena.The aim of this study was to examine actor and partner effects of rumination and reflection on positive and negative mood in romantic couples. Participants completed a set of questionnaires in person. Mood was measured by self-reports and partner-reports and data were analyzed using the Actor-Partner Interdependence Model (APIM). The study included a total of 188 heterosexual couples. The results indicate significant differences in rumination and reflection between men and women, while women exhibiting higher levels of both rumination and reflection. For reflection, positive actor effects were found on self-reported feelings of acceptance, negative partner effects on women's positive mood and positive partner effects on women's negative mood when assessed by their partners. For rumination, negative actor effects were found on women's positive mood and positive actor effects were found on both men's and women's negative mood. Actor effects of rumination were similar for self-reports and partner-reports of mood. Negative partner effects of rumination were found on women's positive mood and positive partner effects were observed on negative mood in both men and women. Partner effects of rumination were found when using partner-reports but not self-reports of mood
Gender stereotypical attitudes of primary school teachers
No full textOvim se radom nastojalo ispitati rodno stereotipne stavove i rodno stereotipne postupke u poučavanju i odgojno-obrazovnoj praksi učitelja i učiteljica razredne nastave. Rad sadrži teorijski i empirijski dio. Teorijski dio obuhvaća teme održivog razvoja, rodnih stereotipa te rodnih stereotipa u obrazovanju kao temeljnih konstrukta za empirijski dio rada. U empirijskom dijelu predstavljeni su metodologija, rezultati i zaključci istraživanja provedenog s učiteljima i učiteljicama razredne nastave na području Republike Hrvatske, a s ciljem ispitivanja njihovih rodno stereotipnih stavova i postupaka u poučavanju i odgojno-obrazovnoj praksi. Rezultati istraživanja prikupljeni na uzorku od 434 ispitanika pokazuju da, iako su ispitanici izrazili relativno egalitarnije stavove i postupke u poučavanju i odgojno-obrazovnoj praksi, rodni stereotipi te rodno stereotipni postupci u poučavanju i praksi u određenoj su mjeri ipak prisutni. Nadalje, stariji učitelji i učiteljice, kao i učitelji i učiteljice s duljim radnim stažem imaju manje izražene rodno stereotipne stavove te su u manjoj mjeri primjenjivali rodno stereotipne postupke u poučavanju i odgojno-obrazovnoj praksi. Uz to, utvrđeno je da učitelji i učiteljice s izraženijim rodno stereotipnim stavovima češće primjenjuju rodno stereotipne, a rjeđe rodno egalitarne postupke u vlastitoj praksi. Na temelju dobivenih rezultata, navedene su preporuke za unapređenje odgojno-obrazovne prakse u kontekstu rodne jednakosti u obrazovanju.This paper examines gender-stereotypical attitudes and practices among primary school teachers within their teaching and educational activities. It comprises two main sections: a theoretical and an empirical part. The theoretical section outlines the conceptual framework, focusing on sustainable development, gender stereotypes, and the manifestation of gender stereotypes in educational contexts, serving as the foundational constructs for the empirical section. The empirical section presents the research methodology, results, and conclusions of a study conducted with primary school teachers in the Republic of Croatia. The study aims to examine the prevalence and nature of gender-stereotypical attitudes and behaviours in their professional practice. The findings collected from a sample of 434 participants indicate that, although respondents generally expressed more egalitarian attitudes and reported egalitarian practices, gender stereotypes and associated behaviours are still present to a certain extent. Furthermore, the results suggest that older teachers and those with longer professional experience tend to show less pronounced gender-stereotypical attitudes and are less likely to implement such practices in their teaching. Additionally, the study finds a correlation between strongly held gender-stereotypical attitudes and the increased application of gender-stereotypical practices, alongside a reduced use of gender-egalitarian approaches. Based on these findings, the paper proposes recommendations aimed at improving educational practice through the promotion of gender equality in education
Thyroid Autoimmunity Impairs Oocyte Maturation, Fertilization, and Embryo Development in Assisted Reproductive Technology in Euthyroid Infertile Patients
No full textBackground: Thyroid autoimmunity (TAI) has been widely associated with reduced fertility; however, its impact on assisted reproductive technology (ART) outcomes in euthyroid women remains controversial. Ovarian reserve (OR) and anti-Müllerian hormone (AMH) are considered to be the most reliable predictors of controlled ovarian hyperstimulation (COH) and ART outcome. This study aims to evaluate whether TAI affects COH outcomes depending on the OR, or if TAI is an independent negative factor affecting COH outcomes. Methods: This study includes 341 infertile euthyroid participants under 38 years old undergoing ART at a single reproductive medicine center. The serum concentrations of sex hormones, thyrotropin (TSH), AMH, and antithyroid antibodies (ATAbs) were measured before COH. Ovarian response to COH, assessed by oocyte number and maturation (percentage of mature MII oocytes), fertilization rate (FR), and early embryo development (cleavage and blastocyst rate), were assessed in 191 participants with TAI and 150 TAI negative age-matched controls with normal ORs. The TAI group was further divided into two subgroups: the TAI1 group with normal OR (n = 120) and the TAI2 group with diminished ORs (n = 71). Results: The mean of the retrieved oocytes was significantly lower in TAI1 (p = 0.015) and expectedly significantly lower in TAI2 (p < 0.001) compared to the control. The percentage of MII oocytes was significantly lower in the TAI1 (p < 0.001) and TAI2 (p = 0.009) groups compared to the control group. We observed significantly lower FR (p = 0.002), cleavage rate (p = 0.020), and blastocyst rate (p < 0.001) in the TAI1 group compared to control. In the TAI2 group, there was a lower cleavage rate (p < 0.001) and blastocyst rate (p < 0.001) compared to the control. There was no difference in the mean percentage of MII oocytes, FR, and cleavage rate between the TAI1 and TAI2 groups, but the blastocyst rate was significantly lower (p < 0.001) in the TAI2 group. Conclusions: TAI may represent a negative predictor of in vitro fertilization outcomes by impairing oocyte maturation, fertilization rate, and embryo development in ART cycles, regardless of ORs
Job Satisfaction as a Factor in Nursing Staff's Work Wellbeing and Retention: A Comparative Study of Central and Eastern Europe and Other Global Regions
No full textBackground: Prior international collaborative studies indicated that job satisfaction, a factor of nursing work wellbeing (WWB), is closely linked to retention, with notable cross-country differences. However, limited regional comparisons, especially between Central and Eastern Europe (CEE), North America, and the Middle East and North Africa (MENA), restrict understanding of nurse wellbeing and retention regional impacts, limiting tailored strategy development. Aims: This secondary analysis study compared the effects of region on nursing WWB and job satisfaction factors in CEE, MENA, and North America, aiming to identify those CEE region-specific predictors associated with and effects on job satisfaction and, in turn, WWB. Methods: CEE (n = 1616), MENA (n = 1562), and North America (n = 1386) data were analyzed using descriptive and linear regression analytics (p < 0.001). The CEE sample included nursing staff from Croatian (n = 301), Polish (n = 215), Serbian (n = 489), and Slovenian (n = 611) nurses and nursing assistants. Six job satisfaction factors were examined: coworkers, patient care, participative management, autonomy, professional growth, and organizational rewards. Results: The CEE region reported statistically significant lower mean scores and negative effects across all six job satisfaction factors compared to MENA and North America. Satisfaction with coworkers had the largest effect within the CEE region when compared to MENA and North America (ϐ = −0.26), while satisfaction with participative management had the smallest regional effect (ϐ = −0.10). Findings informed operational discussions for CEE-targeted retention interventions. Linking Evidence to Action: Job satisfaction subscale factors facilitate the identification of empirically- and theoretically-informed operational actions to improve CEE nursing job satisfaction as an important factor of WWB and contribute to nursing retention
Eurovision Song Contest: Can juries assess the quality of songs objectively?
No full textThis paper analyses the role of jury votes in the Eurovision Song Contest (ESC). We analysed the results of the six ESCs (from 2017 to 2023) in terms of the differences (1) between public and jury votes, (2) among jury votes, and (3) among public votes at the national and ESC levels. We applied 15,251 Spearman rank correlations. The role (mission) of the jury return in the competition, as explained by the organiser, is to ensure objectivity since it was concluded that the public is not entirely capable of objectively evaluating songs. Considering the mission of the jury return and the assumption that juries can fulfil it, we expected that the correlations between each national jury and ESC jury and among national juries would be high. Furthermore, it was expected that the correlations between each national public and ESC public and among the national public would be low or at least lower than those in the jury cases. However, the results are different and are the opposite of expectations. Additionally, the influence of juries on the results is equal to that of the public (without the rest of the world). Consequently, with the current voting system, the jury mission is only partly achieved, and the inclusion of juries highly influences the winner such that the winner is different from what the public thinks it should be. The situation becomes even more severe when the public has to accept a winner that was their only fifth choice (as in ESC 2024). The final conclusion is that the (jury) voting system still needs to be upgraded in the future, and our research proposals include establishing two awards, a jury award and a public award, among others
Economic justification of sailing tourism
No full textOvaj rad obrađuje jedriličarski turizam kao specifičan i sve značajniji segment nautičkog
turizma u Republici Hrvatskoj, s posebnim naglaskom na njegovo gospodarsko iskorištavanje.
Analiziran je zakonodavni i tehnički okvir registracije jedrilica za gospodarske svrhe,
uključujući proces izrade potrebne dokumentacije, tehničke preglede te proračun stabiliteta s
jedrima. Posebna pažnja posvećena je tržištu Istre kao jednoj od najrazvijenijih regija za
nautički turizam te je obrađen konkretan primjer poslovanja jedrilice Nelson 46. U radu su
također predstavljeni najnoviji statistički podaci o prihodima luka nautičkog turizma,
popunjenosti kapaciteta i strukturi plovila u tranzitu. Rezultati ukazuju na stabilan rast prihoda
i povećanje interesa za jedriličarskim aktivnostima, pri čemu se naglašava potreba za daljnjim
ulaganjem u infrastrukturu, modernizaciju usluga i održivi razvoj sektora. Jedriličarski turizam
pokazuje visoki gospodarski potencijal te značajno doprinosi produljenju turističke sezone,
zapošljavanju i jačanju lokalnih ekonomija.This paper explores sailing tourism as a specific and increasingly significant segment of
nautical tourism in the Republic of Croatia, with a particular emphasis on its economic
utilization. The legislative and technical framework for registering sailboats for commercial
purposes is analyzed, including the process of preparing the necessary documentation,
conducting technical inspections, and calculating sail stability. Special attention is given to the
market of the Istrian region, one of the most developed areas for nautical tourism, with a case
study of the business operations of the sailboat Nelson 46. The paper also presents the latest
statistical data on the revenues of nautical tourism ports, berth occupancy rates, and the structure
of vessels in transit. The results indicate a stable increase in revenue and growing interest in
sailing activities, highlighting the need for further investment in infrastructure, service
modernization, and sustainable sector development. Sailing tourism demonstrates high
economic potential and significantly contributes to the extension of the tourist season,
employment, and the strengthening of local economies