Utjecaj zaštitnoga plina i načina prijenosa metala na svojstva zavarenoga spoja čelika X80

U ovom doktorskom radu obrađena je i analizirana problematika utjecaja zaštitnog plina i novorazvijenog načina prijenosa metala (eng. CBT – Controlled Bridge Transfer) na svojstva zavarenog spoja visokočvrstog čelika API 5L X80. U uvodnom dijelu rada iznesen je pregled dosadašnjih spoznaja i istraživanja na području proizvodnje TMCP (eng. Thermo Mechanical Controlled Process) čelika, MAG zavarivanja visokočvrstih čelika (eng. Metal Active Gas) s posebnim naglaskom na CBT način prijenosa metala te utjecaja zaštitnih plinova na mikrostrukturu zavarenog spoja. Također su postavljene hipoteze i definirani ciljevi rada. U eksperimentalnom dijelu rada opisan je plan provedbe zavarivanja, ispitivanja i analize rezultata. Zavarivanje uzoraka u eksperimentalnom dijelu rada izvedeno je prema plošno centriranom centralno kompozitnom planu pokusa (eng. CCF – Face Centered Composite Design), te je prema tome definirano 22 stanja pokusa, s 3 ponavljanja u centru. Prema planu pokusa definirane su 3 varijable koje su bile varirane na 2 i 3 razine. Od spomenute 3 varijable, dvije su numeričke (brzina dodavanja žice, m/min i udio CO2 u zaštitnom plinu, %) i jedna je kategorijska (način prijenosa metala). Za svako stanje pokusa su iz sučeljeno zavarenih ploča izrađeni uzorci za kemijsku i mikrostrukturnu analizu. Karakterizacijom su definirani kemijski sastavi zavarenih spojeva, uključci u zavarenim spojevima i osnovni materijal, mikrostrukturni sastav tj. udio konstituenata u zavarenim spojevima kao i mikrotvrdoće pojedinih prolaza i faza. Cijeli eksperimentalni dio rada proveden je u Laboratoriju za zavarivanje, Laboratoriju za tribologiju, Laboratoriju za analizu materijala i Laboratoriju za materijalografiju na Fakultetu strojarstva i brodogradnje, Sveučilište u Zagrebu. Dobiveni rezultati i podaci o kemijskom i mikrostrukturnom sastavu zavarenog spoja statistički su analizirani pomoću programskog paketa Design Expert. Izrađeni su matematički modeli iz kojih je vidljiva značajnost utjecaja variranih faktora i njihovih interakcija na ispitivana svojstva zavarenog spoja. Također su Monte Carlo simulacijom procijenjeni utjecaji varijacija ulaznih veličina na kvalitetu rezultata mjerenja kemijskog sastava i analize mikrostrukture zavarenog spoja

Determination of ballistic properties on ARMOX 500T steel welded joint

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

PHANTOM EARTHQUAKE SYNDROME - A PILOT STUDY AFTER ZAGREB AND BANOVINA 2020 EARTHQUAKE

Impact of earthquake on mental health is well-documented globally. A number of earthquake survivors after Zagreb and Banovina earthquake in the year 2020 reported a phenomenon of phantom earthquake. Telephone pilot study on phantom earthquake symptoms was conducted with semi-structured interview in earthquake survivors. Phantom earthquake is manifested as a false sense of earthquake-motion, accompanied with vegetative and motor symptoms with psychological distress and behavioral change that interfere with expected daily functioning. We propose an operational model for the phantom earthquake syndrome and discuss possible underlying neurobiological mechanisms to be further investigated in studying of the phantom earthquake syndrome

ATTITUDES TOWARDS OLDER PEOPLE IN CROATIAN AND SLOVENIAN NURSING STUDENTS

Background: Croatia and Slovenia are neighboring countries with marked differences in high school and undergraduate nursing curricula. The aim was to assess and compare attitudes toward the elderly among undergraduate nursing students in Croatia and Slovenia and identify factors associated with positive/negative attitudes. Subjects and methods: This was a cross-sectional survey conducted between September, 2017 and July, 2018 among undergraduate nursing students at five higher education institutions: three in Slovenia and two in Croatia. The following data were gathered: age, sex, year of study, previous education, employment status, previous education in gerontolgy, desired professional role after graduating, previous experience with the elderly. Kogan`s Attitude Towards Old People Scale (KATOPS) score was the primary outcome measure. Pairwise comparisons were conducted between Croatian and Slovenian students. KATOPS score was dichotomized with values above the 3rd quartile considered excellent - the dichotomized score was used as the dependent variable in a binary logistic regression model. Results: Overall, 825 students completed the questionnaire, 85.5% were women, 417 from Slovenia, 408 from Croatia, and 80% were under 22 years of age (80%). The average score on the KATOPS was 127.4, 95% CI 126.6-128.2. Variables associated with excellent scores on the KATOPS, based on the binary regression were: studying in Slovenia (OR=2.05, 95% CI 1.39-3.03), age group 28-32 years (OR=3.9, 95% CI 1.53-9.98); previous education gerontic nursing (OR=2.45, 95% CI 1.34-4.47), and full-time study (OR=2.12, 95% CI 1.38-3.55). Variables not associated with excellent scores were: being married (OR=0.44, 95% CI 0.22- 0.92) and having previous experience in working with the elderly (OR=0.5, 95% CI 0.3-0.86). Conclusion: Attitudes toward old age are mildly positive in Slovenian and Croatian nursing students. Slovenian students have significantly more positive attitudes toward old age and these differences are most probably due to marked differences in undergraduate nursing curricula between the two countries

The Expression of Human Corneal MMP-2, MMP-9, proMMP-13 and TIMP-1 in Bullous Keratopathy and Keratoconus

We aim to find a link between keratokonus (KC) and bullous keratopathy (BK), and extra cellular matrix re-modellation molecules. The activities of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), pro-matrix metalloproteinase-13 (proMMP-13) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) were measured using immunoassay in three human corneal tissue layers (epithelium, stroma and endothelium) supernatants of the patients with KC and BK which underwent the perforative keratoplasty. MPP-2, MMP-9, proMMP-13 and TIMP-1 activity was detected in all samples. The epithelial layer showed significantly higher levels of MMP-9 and proMMP-13 in BK than in KC. Increased levels of MMP-2 (p=0.07) levels were found in bullous keratopathy compared to keratoconus patients. Epithelial TIMP-1 showed no significant difference in activity between KC and BK. All these findings suggest an active degradation of the extra-cellular matrix in epithelial corneal layer in Bullous Keratopathy. No difference in the concentration of MMP-2, MMP-9, proMMP-13 and TIMP-1 between KC and BK in corneal stroma and endothelium suggest that neither of these molecules play important role in KC or BK pathogenesis, at least not in stroma and endothelium

Izrada skale za mjerenje održivosti u visokom obrazovanju

In this study, authors analyze sustainability in higher education (HE), including its theoretical dimensions and linkages to the sustainable development goals (SDGs), in order to develop an initial version of the measurement scale, which could be used in research and practical applications in the HE sector. This is of special importance for public business schools wishing to obtain international accreditation, since the majority of international accreditation schemes put emphasis on social responsibility and sustainability of HEI’s operations. In addition, the presented approach is linked to demonstrating the impact of public HEIs’ contribution to the sustainable development of its broader environment. The empirical part of the study is based on the survey data, obtained from students of a regional public business school in the Republic of Croatia. The initial empirical results show potential dimensions of a measurement scale, which could be used with HEI’s stakeholders. In addition, clustering of the obtained student perceptions suggests how an indicative student sample could interpret a HEI’s efforts to implement the principles of sustainable development in its operations.U ovoj studiji autori analiziraju održivost u visokom obrazovanju, uključujući njezine teorijske dimenzije i poveznice s ciljevima održivoga razvoja, kako bi izradili početnu verziju mjerne skale koja bi se mogla koristiti u istraživanjima i praktično primijeniti u sektoru visokoga obrazovanja. To je iznimno važno za državne poslovne škole koje žele dobiti međunarodnu akreditaciju jer se u većini programa za dobivanje međunarodne akreditacije stavlja poseban naglasak na društvenu odgovornost i održivost u aktivnostima visokoškolskih ustanova. Osim toga, prikazani pristup povezan je s načinom na koji se manifestira učinak državnih ustanova visokoga obrazovanja na održivi razvoj u njihovom širem okružju. Empirijski dio studije temelji se na podatcima dobivenima putem ankete koju su popunili studenti iz regionalne državne poslovne škole u Republici Hrvatskoj. Prvi empirijski rezultati pokazuju potencijalne dimenzije mjerne skale koja bi se mogla koristiti s dionicima visokoškolskih ustanova. K tomu, klasteriranje dobivenih percepcija studenata upućuje na to kako bi indikativan uzorak studenata mogao interpretirati nastojanja visokoškolske ustanove da u svojim aktivnostima provede principe održivoga razvoja

Innovative Conceptual Model of Socio-Cultural Components of Quality of Life in Elderly Persons

Glavni cilj istraživanja je istražiti utjecaj sociokulturnih čimbenika na kvalitetu života starijih osoba u Republici Hrvatskoj. Teorijski cilj istraživanja odnosi se na oblikovanje teorijskog konstrukta utjecaja sociokulturnih čimbenika na kvalitetu života starijih osoba te metodom modeliranja oblikovati model sociokulturnih čimbenika kvalitete života starijih osoba u Republici Hrvatskoj. Pozadina: Problem istraživanja je identifikacija sociokulturnih sastavnica kvalitete života starijih osoba u Republici Hrvatskoj. Osnovna svrha istraživanja je identificirati sastavnice modela sociokulturnih dimenzija koje utječu na kvalitetu života osoba starije životne dobi u Republici Hrvatskoj. Dizajn: U istraživanju je primijenjena kvantitativna istraživačka paradigma. Za postizanje teorijskih ciljeva istraživanja korištene su opće znanstvene metode. Podatci su prikupljeni upitnicima. Metode: Teorijski ciljevi istraživanja ispunjeni su pregledom novije znanstvene literature. U svrhu ovog istraživanja kao mjerni instrumenti primijenjeni su WHOQOL-BREF upitnik i Hofstedeov upitnik. Rezultati: Na temelju obrađenih podataka istraživanja napravljeni su konceptualni multivarijatni regresijski modeli zadovoljavajuće domene kvalitete života osoba starije životne dobi. Načinjeni multivarijatni regresijski modeli predikcije pojedinih domena kvalitete života u kojima prediktorske varijable u multivarijatnom okružju definiraju utjecaj na te domene. Način odabira prediktorskih varijabli uključivao je postavljene ciljeve (dobnu, spolnu, regionalnu, bračnu komponentu te sve domene Hofstedeovog upitnika). Zaključak: U konceptualnom modelu shematski je prikazano da sociokulturne sastavnice kvalitete života ovise o društvenoj nejednakosti, životnim usmjerenjima, kontroli neizvjesnosti, djelovanju pojedinca individualizmom ili kolektivizmom, te odnosom prema muškarcu i ženi. Sve to zajedno određuje nacionalnu kulturu i predstavlja sociokulturni kapital određenog društva. Postoje razlike prema spolu koje su određene kontrolom neizvjesnosti, tjelesnim i psihičkim zdravljem, socijalnim odnosimsa, osobnim stavovima i religioznosti, te okolinom u kojoj osoba živi. Važnost za kliničku praksu: Socijalna gerontologija je mlada znanstvena disciplina i istraživanja na njenom području nalaze svoju primjenu u modernom društvu implementacijom rezultata istraživanja u socijalno i političko okruženje inovativnim modelima u skrbi za starije osobe.The main objective of the study was to investigate the influence of socio-cultural factors on the quality of life in elderly persons in Croatia. The theoretical objective of the study was to form a theoretical construct of the influence of socio-cultural factors on the quality of life of the elderly and to create a model of the socio-cultural factors of the quality of life of the elderly in Croatia using the modelling method. Background: The study problem was to identify the sociocultural components of the quality of life in elderly persons in Croatia. The main purpose of the study was to identify the components of the model of socio-cultural dimensions that have an impact on the quality of life in elderly persons in Croatia. Design: The quantitative research paradigm was applied to the study. To achieve the theoretical objectives of the study, general scientific methods were used. Data were collected through questionnaires. Methods: The theoretical objectives of the study were reached by reviewing recent scientific literature. For the purpose of this study, the WHOQOL- BREF and the Hofstede questionnaires were used as measuring instruments. Findings: The conceptual multivariate regression models of a satisfactory domain of quality of life in elderly persons were created based on processed study data. The multivariate regression models for the prediction of certain domains of quality of life in which predictor variables in a multivariate environment define the impact on these domains were created. The method of selecting predictor variables included the set objectives (age, gender, regional, and marital components and all dimensions of the Hofstede questionnaire). Conclusion: The conceptual model presents a schematic overview of the socio-cultural components of the quality of life that depend on social inequality, life orientations, uncertainty control, acts by individuals through individualism or collectivism, and the attitude towards men and women. All this combined determines a national culture and represents the socio-cultural capital of a certain society. There are differences by gender that were determined by uncertainty control, physical and mental health, social relations, personal attitudes and religiosity, and the environment in which a person lives. Importance for clinical practice: Social gerontology is a young scientific discipline and research in this field finds its application in modern society by implementing research results on the social and political environment with innovative models of care for elderly persons