Dependence of microstructure of Al-44 at% and Al-48 at% zn alloys on temperature

The temperature dependence of microstructure of the title alloys was studied in situ by XRD. Each alloy had been subjected to two different thermal treatments: (i) rapid quenching from the solid-solution temperature, T_SS, in water at room temperature (RT) and ageing at RT (samples WQ) and (ii) cooling slowly from TSS to RT and ageing at RT (samples SC). As the samples SC were closer to the equilibrium state than the samples WQ, the microstructure of the two sets of samples dependeded on temperature in a different way. The solid solution, aSS, was formed at about 720 K for the samples SC, and at about 880 K for the samples WQ. During the slow cooling to RT the samples SC and WQ behaved in a similar way. Instead of the phase transitions expected according to the phase diagram, the following sequence of transitions was observed for both alloys: α(M/β)+β(Zn) - α¢+β(Zn)+a(M/α¢,β) - α_SS. A similar thermal behaviour was also found for the Zn-rich alloys, Al-54 at% Zn and Al-62 at% Zn

Temperature dependence of microstructure of (1-x)Al-xZn alloys, x = 0.44, 0.48, 0.54 and 0.62

The change of microstructure with temperature of the title alloys has been studied in situ by X-ray powder diffraction. It has been found that the temperature dependence of microstructure of the alloys, rapidly quenched from the solid-solution temperature, T_ss, to room temperature, RT, is quite different from that of the alloys slowly cooled from T_ss to RT. The area between two curves showing that dependence for the given phase during the first heating from RT to Tss and first cooling from T_ss to RT is much smaller for the slowly-cooled alloys than for the rapidly quenched alloys. That area slightly increases with the increase of the Zn content in the alloys. The temperature dependence of microstructure of the alloys during the second heating from RT to Tss and second cooling from Tss to RT differs little from that during the first cooling from T_ss to RT. The ideal equilibrium state cannot be reached either by slow cooling of the alloys from T_ss to RT, or by a prolonged ageing at RT of the rapidly quenched alloys. The observed sequence of phase transitions in alloys during heating from RT to T_ss is different from that which could be expected according to the phase diagram of the system Al-Zn accepted in the literature. During cooling from T_ss to RT, a temperature hysteresis is observed in reversal phase transitions

Ovisnost mikrostrukture slitina Al-44 at% Zn i Al-48 at% Zn o temperaturi

The temperature dependence of microstructure of the title alloys was studied in situ by XRD. Each alloy had been subjected to two different thermal treatments: (i) rapid quenching from the solid-solution temperature, TSS, in water at room temperature (RT) and ageing at RT (samples WQ) and (ii) cooling slowly from TSS to RT and ageing at RT (samples SC). As the samples SC were closer to the equilibrium state than the samples WQ, the microstructure of the two sets of samples dependeded on temperature in a different way. The solid solution, αSS, was formed at about 720 K for the samples SC, and at about 880 K for the samples WQ. During the slow cooling to RT the samples SC and WQ behaved in a similar way. Instead of the phase transitions expected according to the phase diagram, the following sequence of transitions was observed for both alloys: α(M/β)+β(Zn) – α0 +β(Zn)+α(M/α0 ,β) – αSS. A similar thermal behaviour was also found for the Zn-rich alloys, Al-54 at% Zn and Al-62 at% Zn.Primjenom rentgenske difrakcije in situ istraživali smo temperaturnu ovisnost mikrostrukture navedenih slitina. Slitine su bile prethodno podvrgnute različitim termičkim obradama: (i) brzom kaljenju s temperature čvrste otopine, TSS, u vodi pri sobnoj temperaturi (uzorci WQ); (ii) sporom hlađenju od TSS do sobne temperature i starenju pri sobnoj temperaturi (uzorci SC). Budući da su nakon starenja uzorci SC bili bliži ravnotežnom stanju nego uzorci WQ, mikrostruktura dviju skupina uzoraka ovisila je o temperaturi na različit način. Uzorci SC bili su prevedeni u stanje čvrste otopine, αSS, na temperaturi oko 720 K, a uzorci WQ na oko 880 K. Umjesto faznih pretvorbi koje bi se očekivale prema faznom dijagramu, opazili smo ovaj niz pretvorbi za obje slitine: α(M/β)+β(Zn) – α0 +β(Zn)+α(M/α0 ,β) – αSS. Slično ponašanje nađeno je i za slitine bogatije cinkom, Al-54 at% Zn i Al-62 at% Zn

Ovisnost mikrostrukture slitina Al-44 at% Zn i Al-48 at% Zn o temperaturi

The temperature dependence of microstructure of the title alloys was studied in situ by XRD. Each alloy had been subjected to two different thermal treatments: (i) rapid quenching from the solid-solution temperature, TSS, in water at room temperature (RT) and ageing at RT (samples WQ) and (ii) cooling slowly from TSS to RT and ageing at RT (samples SC). As the samples SC were closer to the equilibrium state than the samples WQ, the microstructure of the two sets of samples dependeded on temperature in a different way. The solid solution, αSS, was formed at about 720 K for the samples SC, and at about 880 K for the samples WQ. During the slow cooling to RT the samples SC and WQ behaved in a similar way. Instead of the phase transitions expected according to the phase diagram, the following sequence of transitions was observed for both alloys: α(M/β)+β(Zn) – α0 +β(Zn)+α(M/α0 ,β) – αSS. A similar thermal behaviour was also found for the Zn-rich alloys, Al-54 at% Zn and Al-62 at% Zn.Primjenom rentgenske difrakcije in situ istraživali smo temperaturnu ovisnost mikrostrukture navedenih slitina. Slitine su bile prethodno podvrgnute različitim termičkim obradama: (i) brzom kaljenju s temperature čvrste otopine, TSS, u vodi pri sobnoj temperaturi (uzorci WQ); (ii) sporom hlađenju od TSS do sobne temperature i starenju pri sobnoj temperaturi (uzorci SC). Budući da su nakon starenja uzorci SC bili bliži ravnotežnom stanju nego uzorci WQ, mikrostruktura dviju skupina uzoraka ovisila je o temperaturi na različit način. Uzorci SC bili su prevedeni u stanje čvrste otopine, αSS, na temperaturi oko 720 K, a uzorci WQ na oko 880 K. Umjesto faznih pretvorbi koje bi se očekivale prema faznom dijagramu, opazili smo ovaj niz pretvorbi za obje slitine: α(M/β)+β(Zn) – α0 +β(Zn)+α(M/α0 ,β) – αSS. Slično ponašanje nađeno je i za slitine bogatije cinkom, Al-54 at% Zn i Al-62 at% Zn

Temperaturna ovisnost mikrostrukture slitina (1−x)Al–xZn, x = 0.44, 0.48, 0.54 i 0.62

The change of microstructure with temperature of the title alloys has been studied in situ by X-ray powder diffraction. It has been found that the temperature dependence of microstructure of the alloys, rapidly quenched from the solid-solution temperature, Tss, to room temperature, RT, is quite different from that of the alloys slowly cooled from Tss to RT. The area between two curves showing that dependence for the given phase during the first heating from RT to Tss and first cooling from Tss to RT is much smaller for the slowly-cooled alloys than for the rapidly quenched alloys. That area slightly increases with the increase of the Zn content in the alloys. The temperature dependence of microstructure of the alloys during the second heating from RT to Tss and second cooling from Tss to RT differs little from that during the first cooling from Tss to RT. The ideal equilibrium state cannot be reached either by slow cooling of the alloys from Tss to RT, or by a prolonged ageing at RT of the rapidly quenched alloys. The observed sequence of phase transitions in alloys during heating from RT to Tss is different from that which could be expected according to the phase diagram of the system Al-Zn accepted in the literature. During cooling from Tss to RT, a temperature hysteresis is observed in reversal phase transitions.Istraživali smo ovisnost mikrostrukture navedenih slitina o temperaturi in situ pomoću rentgenske difrakcije u prahu. Pokazali smo da je temperaturna ovisnost mikrostrukture slitina, brzo kaljenih s temperature čvrste otopine, Tss, na sobnu temperaturu, RT, bitno različita od one za slitine, koje su sporo hlađene s Tss na RT. Površina između dviju krivulja, koje pokazuju tu ovisnost tijekom prvog grijanja slitine od RT do Tss i prvog hlađenja od Tss do RT, mnogo je manja za sporo hlađene slitine nego za brzo kaljene slitine. Ta površina lagano raste s udjelom Zn u slitinama. Temperaturna ovisnost mikrostrukture slitina tijekom drugog grijanja od RT do Tss i drugog hlađenja od Tss do RT malo se razlikuje od ovisnosti tijekom prvog hlađenja od Tss do RT. Idealno ravnotežno stanje ne može se postići niti sporim hlađenjem slitina od Tss do RT niti dugim starenjem pri RT slitina brzo kaljenih od Tss na RT. Opaženi niz faznih pretvorbi u slitinama tijekom grijanja od RT do Tss razlikuje se od onoga koji bi se očekivao prema faznom dijagramu sustava Al–Zn, prihvaćnog u literaturi. Tijekom hlađenja slitine od Tss do RT uočili smo temperaturnu histerezu za obrnute fazne pretvorbe

X-ray Diffraction Broadening Analysis

The microstructural parameters of a crystalline sample can be determined by a proper analysis of XRD line profile broadening. The observed XRD line profile, h(e), is the convolution of the instrumental profile, g(e), and pure diffraction profile, f(e), caused by small crystallite (coherent domain) sizes, by faultings in the sequence of the crystal lattice planes, and by the strains in the crystallites. Similarly, f(e) is the convolution of the crystallite size/faulting profile, p(e), and the strain profile, s(e). The derivation of f(e) can be performed from h(e) and g(e) by the Fourier transform method, which does not require mathematical assumptions. The analysis of f(e) can be done by the Warren-Averbach method applied to the obtained Fourier coefficients. Simplified methods based on integral widths may also be used in studies where a good relative accuracy suffices. The relation among integral widths of f(e), p(e) and s(e) can be obtained if one assumes bell-shaped functions for p(e) and s(e). Integral width methods overestimate both strain and crystallite size parameters in comparison to the Warren-Averbach method. The crystallite size parameter is more dependent on the accuracy in the diffraction profile measurement, than it is the strain parameter. The precautions necessary for minimization of errors are suggested through examples. The crystallite size and strain parameters obtained by means of integral widths are compared with those which follow from the Warren-Averbach method. Recent approaches in derivation of microstructure are also mentioned in short

Temperaturna ovisnost mikrostrukture slitina (1−x)Al–xZn, x = 0.44, 0.48, 0.54 i 0.62

The change of microstructure with temperature of the title alloys has been studied in situ by X-ray powder diffraction. It has been found that the temperature dependence of microstructure of the alloys, rapidly quenched from the solid-solution temperature, Tss, to room temperature, RT, is quite different from that of the alloys slowly cooled from Tss to RT. The area between two curves showing that dependence for the given phase during the first heating from RT to Tss and first cooling from Tss to RT is much smaller for the slowly-cooled alloys than for the rapidly quenched alloys. That area slightly increases with the increase of the Zn content in the alloys. The temperature dependence of microstructure of the alloys during the second heating from RT to Tss and second cooling from Tss to RT differs little from that during the first cooling from Tss to RT. The ideal equilibrium state cannot be reached either by slow cooling of the alloys from Tss to RT, or by a prolonged ageing at RT of the rapidly quenched alloys. The observed sequence of phase transitions in alloys during heating from RT to Tss is different from that which could be expected according to the phase diagram of the system Al-Zn accepted in the literature. During cooling from Tss to RT, a temperature hysteresis is observed in reversal phase transitions.Istraživali smo ovisnost mikrostrukture navedenih slitina o temperaturi in situ pomoću rentgenske difrakcije u prahu. Pokazali smo da je temperaturna ovisnost mikrostrukture slitina, brzo kaljenih s temperature čvrste otopine, Tss, na sobnu temperaturu, RT, bitno različita od one za slitine, koje su sporo hlađene s Tss na RT. Površina između dviju krivulja, koje pokazuju tu ovisnost tijekom prvog grijanja slitine od RT do Tss i prvog hlađenja od Tss do RT, mnogo je manja za sporo hlađene slitine nego za brzo kaljene slitine. Ta površina lagano raste s udjelom Zn u slitinama. Temperaturna ovisnost mikrostrukture slitina tijekom drugog grijanja od RT do Tss i drugog hlađenja od Tss do RT malo se razlikuje od ovisnosti tijekom prvog hlađenja od Tss do RT. Idealno ravnotežno stanje ne može se postići niti sporim hlađenjem slitina od Tss do RT niti dugim starenjem pri RT slitina brzo kaljenih od Tss na RT. Opaženi niz faznih pretvorbi u slitinama tijekom grijanja od RT do Tss razlikuje se od onoga koji bi se očekivao prema faznom dijagramu sustava Al–Zn, prihvaćnog u literaturi. Tijekom hlađenja slitine od Tss do RT uočili smo temperaturnu histerezu za obrnute fazne pretvorbe

Dječji igrokaz Ekološka priča u funkciji ekološkog odgoja djece predškolske dobi

Today, the importance of ecological education is often highlighted, although the current National Curriculum for Early and Preschool Education doesn’t even mention it. Although ecological education is not mentioned in this baseline document, various activities in this direction are often carried out in our kindergartens. An example of this is the play The Ecological Story by the author Sanja Seferović-Bosak from her collection of plays Maštarije: Igrokazi za djecu od 3 do 13 godina (eng. Pipe Dreams: Plays for Children of 3-13 years). This paper describes the preparation and performance of this play in 2017 in the kindergarten Radost (eng. Joy) in Novska. The theoretical part of the paper considers the basic settings of ecological education in early and preschool age, with special reference to current practice in Croatian kindergartens. The empirical part of the paper describes the stages of preparation and performance of the play The Ecological Story, with special reference to the compliance of this project with the requirements of the National Curriculum in terms of developing key competences for lifelong learning. The paper also contains an analysis of methodological procedures with particular reference to the preparation of musical numbers in the play.U današnje vrijeme često se naglašava važnost ekološkog odgoja i obrazovanja iako sadašnji Nacionalni kurikulum za rani i predškolski odgoj i obrazovanje nigdje ne spominje ekološki odgoj i obrazovanje. Unatoč tome što se ekološki odgoj i obrazovanje ne spominju u temeljnom dokumentu, različite aktivnosti u tom smjeru često se provode u našim dječjim vrtićima. Primjer toga je i igrokaz Ekološka priča autorice Sanje Seferović-Bosak iz zbirke igrokaza Maštarije: Igrokazi za djecu od 3 do 13 godina. Ovaj rad opisuje pripremu i izvedbu tog igrokaza 2017. godine u Dječjem vrtiću Radost u Novskoj. Teoretski dio rada razmatra temeljne postavke ekološkog odgoja u ranoj i predškolskoj dobi, s posebnim osvrtom na trenutačnu praksu u hrvatskim vrtićima. U empirijskom dijelu rada opisane su etape pripreme i izvedbe igrokaza Ekološka priča s posebnim osvrtom na usklađenost ovog projekta sa zahtjevima Nacionalnog kurikuluma u smislu razvoja ključnih kompetencija za cjeloživotno učenje. Rad sadrži i analizu metodičkih postupaka s naročitim osvrtom na pripremu glazbenih brojeva u igrokazu

Opportunities to improve fire protection systems based on modified some regulations which regulated financing

Često na terenu susrećemo vatrogasce koji vatrogastvo doživljavaju, prije svega, kao poziv, a ne kao posao. Posebice se to odnosi na dobrovoljne vatrogasce. Nerijetki su slučajevi da se ti vatrogasci brinu o funkcioniranju sustava zaštite od požara više nego odgovorne osobe (načelnici općina i gradonačelnici), stoga oni sve organizacijske i financijske probleme sustava zaštite od požara doživljavaju na osobnoj razini. Bez obzira na njihovo htijenje, zbog niza objektivnih i subjektivnih okolnosti nije moguće uspostaviti takav sustav zaštite od požara koji bi zadovoljavao minimalne standarde u pogledu zaštite od požara ljudi i imovine na području jedinice lokalne samouprave. Stanje prividne djelotvornosti sustava održava se dok se ne dogodi požar, posebice ako je u pitanju požar većih razmjera ili ako se radi o većem broju požara. Vatrogasce se tada poziva na odgovornost, ili zbog velikog broja požara (požari otvorenog prostora), ili zbog velikih šteta. Nitko ne pita da li su svi u lancu odgovornosti učinili sve kako bi sustav zaštite od požara bio učinkovit. Ili što je još važnije, da li su izvršili barem zakonom utvrđene obveze kako bi vatrogascima omogućili učinkovito djelovati na intervencijama. Veći broj jedinica lokalne samouprave izvršava svoje, zakonom utvrđene, obveze u pogledu financiranja vatrogastva. Problemi nastaju u onim jedinicama lokalne samouprave gdje su fiskalni kapaciteti mali pa tada i postoci na temelju kojih se izdvajaju sredstva za vatrogastvo malo znače. Zbog toga bi trebalo učiniti dvije stvari. Prvo, propisati nove izvore financiranja za zaštitu od požara i samim time za vatrogastvo. Drugo, propisati određenu preraspodjelu financijskih sredstava kako bismo s viših razina vatrogasne organizacije mogli utjecati na poboljšanje sustava zaštite od požara u slabije razvijenim jedinicama lokalne samouprave. Time bismo postigli ravnomjerniji stupanj zaštite od požara na teritoriju cijele Republike Hrvatske.Often in the field meet firefighters to firefighting experience, primarily as a vocation, not a job. In particular, this applies to volunteer firefighters. Often are cases that these firefighters care about the functioning of the fire more than a responsible person (mayors and mayors), so they all organizational and financial problems of fire protection experience on a personal level. Regardless of their will, because of objective and subjective circumstances it is not possible to establish such a fire protection system that would satisfy the minimum standards in terms of fire protection of people and property in the local government. Condition of the apparent effectiveness of the system is maintained until a fire breaks out, especially when it comes to fire a larger scale or in the case of multiple fires. Firefighters are then called to account or due to the large number of fires (fires of open space) or due to serious damage. Nobody asks whether everyone in the chain of responsibility to do all the fire protection system was effective. Or more importantly, whether they make at least a statutory obligation to allow firefighters to operate effectively in interventions. A number of local governments carry out their own, defined by law, the obligations in respect of funding the fire service. Problems arise in those local governments where the fiscal capacity of small and then the percentages are based on which funds were allocated for the fire a little mean. Therefore, you should do two things. First, lay down new sources of funding for fire protection, and thus for the fire brigade. Second, to prescribe a redistribution of funds to a higher level of fire service organization could affect the improvement of fire protection systems in underdeveloped local government units. Time to achieve uniform distribution of the degree of fire protection throughout the all Republic of Croatia

Some specific procedures of geometrical modelling in the PrESMod language for 2D parameter geometric modelling

U jeziku za modeliranje PrESMod, za opis entiteta i modifikacija rabe se takve linije/naredbe da se u primarnom (geometrijskom) opisu mogu rabiti karakteristične točke, koordinate karakterističnih točaka i drugi geometrijski parametri, relacijski iskazi položaja, opis entiteta funkcijama, kao i tri tipa relacijskih iskaza za izdvajanje jednog od dva moguća skupa točaka. Ovdje se razmatra rešenje problema geometrijskog modeliranja, kada na osnovu jednog dijela postupka modeliranja, nakon specificiranja karakterističnih točaka, koordinata karakterističnih točaka, karakterističnih geometrijskih parametara kao što su promjer, polumjer, kut, dužina, kao i relacija paralelno, okomito, tangencijalno nastaje više rješenja za dani entitet (kako se iz dva ili više rješenja dobiva jedno rješenje). Na kraju se daje izgled dvije naredbe u jeziku PrESMod za 2D parametarsko geometrijsko modeliranje.The PrESMod modelling language uses lines/commands for the description of entities and modifications such that characteristic points, coordinates of characteristic points and other geometric parameters, relational position expressions, functional entity descriptions and also three types of relational statements for selecting one of two possible point sets can be used in the geometric description. In this work solutions have been analysed for problems of geometric modelling when based on one part of the modelling procedure, after specifying characteristic points, coordinates of characteristic points, characteristic geometric parameters, such as diameter, radius, angle, length and also parallel, normal, tangent relations, there are several solutions for the given entity (how to obtain one solution from two or more solutions). Finally, two commands in the PrESMod language for 2D parameter geometric modelling are given