Les je po poseku in uporabi za konstrukcije izpostavljen staranju, ki je med drugim odvisno od pogojev izpostavitve. V času življenjske dobe oz. uporabe je les izpostavljen fotodegradaciji, ...biodegradaciji, površinskim in notranjim strukturnim spremembam in staranju, ki se kaže v spremembi barve, kemijske sestave, higroskopnosti, dimenzijske stabilnosti ter nekaterih mehanskih lastnosti. Podajamo pregled literature, s posebnim poudarkom vpliva pogojev izpostavitve na spremembe lastnosti lesa ter pregled kemijskih in mikrostrukturnih sprememb ter sprememb barve, sorpcijskih in mehanskih lastnosti. V splošnem so spremembe zaradi staranja lahko zelo počasne in jih je težko ovrednotiti tudi zaradi velike naravne variabilnosti lesnih lastnosti. Poznavanje sprememb v naravno staranem lesu je ključno pri ohranjanju kulturne dediščine. Pri načrtovanju vzdrževanja, konzerviranja ter pri obnovi kulturne dediščine, z upoštevanjem staranja konstrukcijskega lesa bolje razumemo strukturne spremembe, vlažnostna in napetostno-deformacijska stanja lesenih konstrukcij ter interakcije z drugimi gradbenimi materiali.
Postupkom hladnog prešanja iz sjemenki lana i jezgre lješnjaka proizvodi se jestivo ulje visoke nutritivne vrijednosti. U ovom radu istraživan je utjecaj dodatka antioksidanasa (prirodni, sintetski) ...i sinergista na oksidacijsku stabilnost mješavine lješnjakovog i lanenog ulja (50:50). Od prirodnih antioksidanasa korišteni su ekstrakt kadulje, ekstrakt ružmarina, ekstrakt nara, mješavina tokoferola, eterično ulje konopljike, lavande, slatkog pelina, divlje mrkve, smilja, a od sintetskih propil galat. Određivanje oksidacijske stabilnosti mješavine ulja te utjecaj dodatka antioksidansa i sinergista provedeno je testom ubrzane oksidacije ulja Schaal Oven testom. Rezultat oksidacije mješavine ulja izražen je peroksidnim brojem. Primjenom standardnih metoda u ulju su određeni osnovni parametri kvalitete (peroksidni broj, slobodne masne kiseline, voda, netopljive nečistoće). Rezultati ispitivanja pokazuju da ekstrakt ružmarina (sa i bez limunske kiseline) efikasnije štiti mješavinu ulja od oksidacijskog kvarenja u odnosu na druge ispitivane antioksidanse. Eterično ulje slatkog pelina ne pokazuje utjecaj na stabilizaciju ove mješavine ulja.
The process of cold pressing linseed and hazelnut kernels produces edible oil of high nutritional value. In this paper, the influence of addition antioxidants (natural, synthetic) and synergists on the oxidative stability of mixture hazelnut and linseed oil (50:50) was investigated. The testing was carried out using the natural antioxidants sage extract, rosemary extract, pomegranate extract, tocopherol mixture, essential oil of hemp, lavender, sweet wormwood, wild carrot, immortelle, and synthetic propyl gallate. The oxidative stability of the oil mixture and the effect of addition of antioxidant and synergists were determined by the accelerated oil oxidation test, the Schaal Oven test. The result of the oil mixture oxidation was expressed by the peroxide value. The basic quality parameters (peroxide value, free fatty acids, water, insoluble impurities) were determined by applying the standard methods to oil. The results of testing indicated that rosemary extract (with and without citric acid) protect the oil mixture from oxidative spoilage more effectively than compared to other tested antioxidants. The essential oil of sweet wormwood shows no effect on the stabilization of this oil mixture.
One of the most important tasks of breeders is to improve the properties of breeding material (varieties, lines) and to create a new genetic variability. The study goals were as follows: during two ...consecutive years (2019 and 2020), to evaluate the agronomic value of nine newly created spring breeding lines of fodder pea, as well as to evaluate the stability of yield components and to select the most promising genotypes for further breeding. The results of the study demonstrate that there are significant differences between the tested genotypes in the tested environments for most of the analyzed properties and that the variation of genotypes within the identified sources of experimental variation exerts the greatest influence . Based on the investigated property values, subsequent to stability evaluation the desirable genotypes L - OSMBK 1, L - OSMBK 3 – for the grain/plant yield L - OSMBK 1, L - OSMBK 8, L - OSMBK 3, L - OSMBK 9 – for the mass of 1,000 grains, and L – OSMBK 9 – for plant height were identified as the stable genotypes, with a high breeding and agronomic properties.
Jedan od najvažnijih zadataka oplemenjivača jest poboljšanje svojstava oplemenjivačkoga materijala (sorata, linija) i stvaranje nove genetske varijabilnosti. Ciljevi ovoga istraživanja bili su sljedeći: tijekom dvije uzastopne godine (2019. i 2020.) procijeniti agronomsku vrijednost devet novostvorenih oplemenjivačkih linija jaroga stočnog graška, kao i procijeniti stabilnost komponenata prinosa te odabrati najperspektivnije genotipove za daljnji oplemenjivački postupak. Rezultati analize varijance pokazali su da postoje značajne razlike između istraživanih genotipova i okolina za većinu istraživanih svojstava i da u okviru identificiranih izvora varijacije najveći utjecaj ima varijacija uslijed utjecaja genotipova. Procjena stabilnosti obavljena je metodom grupiranja prema Francisu i Kannenbergu, na temelju koje su genotipovi L – OSMBK 1, L – OSMBK 3 za prinos zrna/biljci L – OSMBK 1, L – OSMBK 8, L – OSMBK 3, L – OSMBK 9 za masu 1000 zrna i L – OSMBK 9 za visinu biljke bili u skupini I, koja se odlikuje visokim vrijednostima i malim koeficijentom variranja svojstva te predstavljaju najstabilnije, a time i oplemenjivački najperspektivnije, genotipove.
Biljna ulja se osim u prehrani te kao goriva i maziva, mogu koristiti kao dodaci hrani, nutraceutici, u proizvodnji kozmetike i biomedicini, no primjena im je ograničena zbog slabe oksidacijske ...stabilnosti. Mikroinkapsulacija je uobičajena metoda zaštite ulja od razgradnje i vanjskih čimbenika tijekom skladištenja, kojom se kontrolira otpuštanje aktivnih sastojaka i produljuje trajnost ulja. U ovom je radu dan kratki pregled metoda mikroinkapsulacije biljnih ulja, uključujući fizikalne (sušenje raspršivanjem i zamrzavanjem), fizikalno-kemijske (kompleksna koacervacija, ionsko geliranje i slojeviti elektrostatski premazi) i kemijske (međufazna i in situ polimerizacija) postupke. Osim toga, ovaj rad donosi informacije o principima, parametrima, prednostima i nedostacima, te mogućim primjenama ovih metoda.
U ovom radu provedena je analiza izvijanja konstrukcije pješačkog mosta primjenom metode konačnih elemenata. Formulacija uzima u obzir utjecaj velikih pomaka na konstrukciju pod utjecajem ...konzervativnih i statičkih vanjskih opterećenja. Materijal se pretpostavlja linearno elastičnim i izotropnim. Stabilnost analize provodi se na temelju vlastitih vrijednosti (eigenvalue). Linearizirane ravnotežne jednadžbe grednog konačnog elementa izvedene su primjenom principa virtualnih radova i nelinearnog polja pomaka poprečnog presjeka.
In this paper, a buckling analysis of a pedestrian bridge structure was conducted using finite element methods. The formulation considers the effects of large displacements on the structure subjected to conservative and static external loads Material is assumed to be linear elastic and isotropic. Stability analysis is performed in eigenvalue manner. The linearized equilibrium equations are derived by applying the linearized virtual work principle and the non-linear cross-sectional displacement field.
Relationship commitment is one of the key constructsin studies on relationship quality and stability. In this study, the Investment Model (Rusbult, 1980) was used as a theoretical basis, where ...commitment is emphasized as the central construct for relationship maintenance and endurance. The aim of the study was to examine the role of psychological violence in predicting commitment and perceived relationship stability within the aforementioned model. The participants were students of the University of Zagreb (N = 154), with female students (77.9%) being more represented in the sample. The obtained results confirmed the assumptions of the basic model and all regression analyses resulted in a high percentage of explained variance of the examined criteria. The frequency of experiencing psychological violence was a significant negative predictor of commitment and perceived relationship stability, and this relationship was only partially mediated by other examined constructs. Contrary to expectations, more frequent experiencing of psychological violence also had a direct contribution in predicting less perceived relationship stability. The paper discusses the meaning of individual mediation effects and their contribution to explaining the relationships between the investigated constructs. The implications for future studies and for potential practical application of the results are also indicated. Key words: psychological violence; commitment; stability; partner relationships; Investment model
Polifenolni spojevi, zaostali u komini koja je nusproizvod u proizvodnji maslinova ulja, antioksidansi su koji imaju pozitivan učinak na ljudsko zdravlje. Za izdvajanje polifenola sve češće se ...primjenjuju prirodna eutektička otapala koje karakterizira netoksičnost, biorazgradljivost, nezapaljivost te niska cijena. U ovom radu upotrijebljeno je prirodno niskotemperaturno eutektičko otapalo (NADES) pripravljeno od triju komponenti: DL-jabučne kiseline, D-fruktoze i glicerola (MaFruGly) s različitim udjelima vode koji omogućavaju uspješnu ekstrakciju polifenola. Određena je optimalna metoda ekstrakcije, a nakon provedene ekstrakcije, ekstrakti su podvrgnuti mikrobiološkoj analizi te je praćena stabilnost izdvojenih polifenola. Istraživanje je pokazalo da su najuspješnije metode za ekstrakciju polifenola mikrovalno ultrazvučna te ekstrakcija ultrazvučnom sondom, a NADES s 30 % vode optimalno otapalo za održavanje stabilnosti polifenola.
Polyphenols, left in olive pomace, which is a by-product in the production of olive oil, are antioxidants that have a positive effect on human health. For the extraction of polyphenols, the use of natural deep eutectic solvents is increasingly encountered, characterised by non-toxicity, biodegradability, nonflammability, and low price. In this work, a natural deep eutectic solvent (NADES) was prepared from three components: malic acid, D-fructose, and glycerol (MaFruGly) with different water contents that allow successful extraction of polyphenols. The optimal extraction method was determined. Following extraction, the microbial activity was tested and stability of the isolated polyphenols monitored. Research has shown that the most successful methods for polyphenol extraction are microwave ultrasound and ultrasonic probe extraction, and NADES with 30 % water has proven to be the optimal solvent for maintaining the stability of polyphenols.
Autorice u radu analiziraju institucionalizaciju discipline međunarodnih odnosa i sigurnosnih studija na Fakultetu političkih znanosti vodeći se kriterijima stabilnosti, identiteta i autonomije, koji ...se testiraju na osnovi specifičnih pokazatelja njihove manifestacije. Pritom je naglasak na razvoju u posljednjih tridesetak godina, s kraćim osvrtom na ranija razdoblja kada se ponajprije međunarodni odnosi ugrađuju kao jedna od konstitutivnih disciplina na tada novoj sveučilišnoj instituciji, koja je emancipirala politologiju u odnosu na ostala, starija znanstvena polja iz kojih vuče korijene. Pored toga, kako bi se stekao uvid u paralelni razvoj međunarodnih odnosa i sigurnosnih studija od sredine dvadesetog stoljeća, u radu se propituje moguća emancipacija sigurnosnih studija kao zasebne znanstvene discipline i pokušava se odgovoriti na pitanje je li moguće ili pak korisno razdvajati ih s obzirom na međusobnu isprepletenost i preklapanje pojmovno-kategorijalnog aparata, teorija i fenomena koje istražuju. Posebno se komparira razvoj discipline međunarodnih odnosa i sigurnosnih studija u Hrvatskoj s državama u okruženju (Srbija i Slovenija) te se izvode zaključci o međuodnosu sigurnosnih studija i međunarodnih odnosa. U radu se polazi od tvrdnje da je disciplina međunarodnih odnosa i sigurnosnih studija, koja se od druge polovice 1990-ih intenzivnije razvija u pogledu znanstvene produkcije i nastavnih planova i programa, snažno institucionalizirana.
In the paper, the authors analyse the institutionalization of the discipline of international relations and security studies at the Faculty of Political Sciences, guided by the criteria of stability, identity and autonomy, which are tested through specific indicators of their manifestation. In doing so, the emphasis is on the development during the last thirty years, with a brief review of the earlier periods when international relations were primarily incorporated as one of the constitutive disciplines at the then new university institution, which emancipated political science in relation to the other, older scientific fields which it is rooted in. In addition, in order to gain insight into the parallel development of international relations and security studies since the mid-twentieth century, the paper examines the possible emancipation of security studies as a separate scientific discipline and tries to answer the question of whether it is possible or useful to separate them, considering the intertwining and overlapping of the conceptual-categorical apparatus, theories and phenomena they investigate. In particular, the development of the discipline of international relations and security studies in Croatia is compared with neighbouring countries (Serbia and Slovenia), which leads to conclusions about the relationship between security studies and international relations. The paper argues that international relations and security studies, which have been developing more intensely since the second half of the 1990s in terms of scientific production and curricula, represent a strongly institutionalized discipline.
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