The random-field specific heat critical behavior at high magnetic concentration: Fe(0.93)Zn(0.07)F2

The specific heat critical behavior is measured and analyzed for a single crystal of the random-field Ising system Fe(0.93)Zn(0.07)F2 using pulsed heat and optical birefringence techniques. This high magnetic concentration sample does not exhibit the severe scattering hysteresis at low temperature seen in lower concentration samples and its behavior is therefore that of an equilibrium random-field Ising model system. The equivalence of the behavior observed with pulsed heat techniques and optical birefringence is established. The critical peak appears to be a symmetric, logarithmic divergence, in disagreement with random-field model computer simulations. The random-field specific heat scaling function is determined.Comment: 9 pages, 4 figures, RevTeX, minor revision

Je li praktična pedagoška obuka studenata tjelesnoga odgoja dovoljno učinkovita?

AbstractPractical pedagogical training (PPT) is a significant element of professional development in the education of physical education teachers. It is important in their professional socialisation while developing teaching competencies and classroom management skills. This paper examines Slovenian physical education students\u27 estimations of their own progress during PPT. In a cross-sectional study, two groups of students (N2007/08=84; N2009/10=82) who participated in PPT in the 2007/08 and 2009/10 academic years were compared. Basic statistics, the T-test, the Mann-Whitney U-test and the Pearson correlation coefficient were used. The results revealed that teacher-educators\u27 encouragement of students for better preparation for PPT and written students\u27 reflections improved the level of their efficiency and made them more certain of their teaching practice. Better preparation for PPT lead to greater progress of students and helped ensure that administrative and/or pedagogical changes lead to changes in teacher behaviour. The correlations between the observed areas showed that the lesson planning had the strongest influence on students\u27 efficiency at PPT.Praktična pedagoška obuka (PPO) važna je sastavnica profesionalnog razvoja u obrazovanju učitelja tjelesnoga odgoja. Važna je u njihovoj profesionalnoj socijalizaciji, istovremeno razvijajući učiteljske kompetencije i vještine upravljanja razredom. U ovom se članku proučavaju procjene slovenskih studenata tjelesnog odgoja u pogledu vlastitog napretka tijekom PPO-a. U ovoj usporednoj studiji uspoređivane su dvije skupine studenata (N2007/08=84; N2009/10=82) koji su sudjelovali u PPO-u akademske godine 2007./2008. i 2009./2010. Upotrijebljena je temeljna statistička analiza, kao i T-test, Mann-Whitney U-test i Pearsonov korelacijski koeficijent. Rezultati otkrivaju da su poticaj za bolju pripremu za PPO profesora metodičara i učitelja mentora, kao i pisane refleksije studenata pridonijeli poboljšanju razine uspješnosti i da im je to ojačalo sigurnost u vlastite vještine. Bolja pripremljenost za PPO vodi prema znatnijem napretku studenata i jamči da će administrativne i/ili pedagoške promjene dovesti do promjena u ponašanju učitelja. Korelacije između proučavanih područja pokazuju da je planiranje nastavnoga sata imalo najveći utjecaj na uspješnost studenata tijekom PPO-a

d=3 random field behavior near percolation

The highly diluted antiferromagnet Mn(0.35)Zn(0.65)F2 has been investigated by neutron scattering for H>0. A low-temperature (T<11K), low-field (H<1T) pseudophase transition boundary separates a partially antiferromagnetically ordered phase from the paramagnetic one. For 1<H<7T at low temperatures, a region of antiferromagnetic order is field induced but is not enclosed within a transition boundary.Comment: 9 pages, 4 figure

Equilibrium random-field Ising critical scattering in the antiferromagnet Fe(0.93)Zn(0.07)F2

It has long been believed that equilibrium random-field Ising model (RFIM) critical scattering studies are not feasible in dilute antiferromagnets close to and below Tc(H) because of severe non-equilibrium effects. The high magnetic concentration Ising antiferromagnet Fe(0.93)Zn(0.07)F2, however, does provide equilibrium behavior. We have employed scaling techniques to extract the universal equilibrium scattering line shape, critical exponents nu = 0.87 +- 0.07 and eta = 0.20 +- 0.05, and amplitude ratios of this RFIM system.Comment: 4 pages, 1 figure, minor revision

Effective and Asymptotic Critical Exponents of Weakly Diluted Quenched Ising Model: 3d Approach Versus ϵ1/2\epsilon^{1/2}-Expansion

We present a field-theoretical treatment of the critical behavior of three-dimensional weakly diluted quenched Ising model. To this end we analyse in a replica limit n=0 5-loop renormalization group functions of the $\phi^4$-theory with O(n)-symmetric and cubic interactions (H.Kleinert and V.Schulte-Frohlinde, Phys.Lett. B342, 284 (1995)). The minimal subtraction scheme allows to develop either the $\epsilon^{1/2}$-expansion series or to proceed in the 3d approach, performing expansions in terms of renormalized couplings. Doing so, we compare both perturbation approaches and discuss their convergence and possible Borel summability. To study the crossover effect we calculate the effective critical exponents providing a local measure for the degree of singularity of different physical quantities in the critical region. We report resummed numerical values for the effective and asymptotic critical exponents. Obtained within the 3d approach results agree pretty well with recent Monte Carlo simulations. $\epsilon^{1/2}$-expansion does not allow reliable estimates for d=3.Comment: 35 pages, Latex, 9 eps-figures included. The reference list is refreshed and typos are corrected in the 2nd versio

Ordering in the dilute weakly-anisotropic antiferromagnet Mn(0.35)Zn(0.65)F2

The highly diluted antiferromagnet Mn(0.35)Zn(0.65)F2 has been investigated by neutron scattering in zero field. The Bragg peaks observed below the Neel temperature TN (approximately 10.9 K) indicate stable antiferromagnetic long-range ordering at low temperature. The critical behavior is governed by random-exchange Ising model critical exponents (nu approximately 0.69 and gamma approximately 1.31), as reported for Mn(x)Zn(1-x)F2 with higher x and for the isostructural compound Fe(x)Zn(1-x)F2. However, in addition to the Bragg peaks, unusual scattering behavior appears for |q|>0 below a glassy temperature Tg approximately 7.0 K. The glassy region T<Tg corresponds to that of noticeable frequency dependence in earlier zero-field ac susceptibility measurements on this sample. These results indicate that long-range order coexists with short-range nonequilibrium clusters in this highly diluted magnet.Comment: 7 pages, 5 figure

ECONOMIC AND TECHNICAL ASPECTS OF ENERGY - EFFICIENT REFURBISHMENT OF A MULTI-STOREY RESIDENTAL BUILDING IN KAMNICA

Diplomsko delo obravnava energetsko učinkovito sanacijo stanovanjskih stavb kot okoljsko upravičeno investicijo in temu primerne ukrepe, s katerimi pozitivno vplivamo na učinkovito rabo energije v stavbah in posredno tudi na kakovost bivanja. V diplomski nalogi je predstavljen večstanovanjski objekt v Kamnici za katerega se na podlagi analiz in ugotovitev izdela predlog energetske sanacije toplotnoizolacijskega ovoja stavbe. Skladno z novim Pravilnikom o učinkoviti rabi energije v stavbah (PURES2) je izračunana energetska bilanca objekta pred in po sanaciji ter predlagana rešitev ogrevanja s koriščenjem obnovljivih virov energije. V primerjavi z obstoječim energetskim stanjem objekta je izdelana ekonomska analiza vseh ukrepov, ki kot rezultat navaja predvideni prihranek energije pri ogrevanju in s tem dokazuje ekonomsko upravičenost investicije.This thesis deals with energy-efficient refurbishment of residental buildings as environmentally justified investment and appropriate actions needed to positively influence on the energy efficiency in buildings and, indirectly, the quality of life. The case study of this thesis presents a multi-storey residential building in Kamnica for which, based on the analysis and findings, a plan of the energy efficient actions on the building envelope is made. In accordance with the new Regulations on energy efficiency in buildings (PURES2) an energy balance of the facility before and after refurbishment is calculated along with the proposed renewable energy heating solution. Based on the current state the cost-analysis of necessary measures has been conducted which has estimated the amount of energy which would have been saved on the account of the energy-efficient refurbishment thus making the investment economically viable

Honey bees and wild bees in an organic apple orchard

Raziskovalno delo je potekalo leta 2019 v ekološkem nasadu jablan (Malus domestica B.) Fakultete za kmetijstvo in biosistemske vede, Univerze v Mariboru. Nasad sorte \u27Topaz\u27 je posajen na lokaciji Log v bližini Maribora. Pestrost opraševalcev na cvetovih jablane smo opazovali tri zaporedne dni v mesecu aprilu. Vzorčenje smo opravljali z lovljenjem opraševalcev s plastičnimi vrečkami in lovljenjem z različnimi barvnimi krožniki (bel, moder, rumen). Rezultati so pokazali, da je najpogostejši opraševalec jablane medonosna čebela (Apis mellifera), velik delež opraševalcev pa predstavljajo divje čebele (čebele samotarke in čmrlji). V rumene barve krožnikov kot vabe se je ulovilo največje število opraševalcev jablan. V to barvo krožnikov se je ulovilo največ čebel samotark.The research took place in 2019 in the organic apple orchard (Malus domestica B.) of the Faculty of Agriculture and Life Sciences, University of Maribor. The \u27Topaz\u27 plantation is located in Log near Maribor. The variety of pollinators on apple blossoms was observed for three consecutive days in the month of April. Sampling was performed by catching the pollinators with plastic bags and with different colored plates (white, blue, yellow). The results showed that the most common pollinator of apple trees is the honey bee (Apis mellifera), and a large proportion of pollinators are wild bees (solitary bees and bumblebees). The largest number of apple pollinators was caught on the yellow plates placed as a bait. On this color of plates solitary bees were caught the most