96 research outputs found
Prelog\u27s Zagreb School of Organic Chemistry (1935 - 1945)
This article on Vladimir Prelog and his contribution to the development of organic chemistry in Croatia presents data on his scientific work done in the Department of Organic Chemistry of the Technical Faculty in Zagreb, as well as the scientific research work carried out in collaboration with the Science Laboratory of the pharmaceutical factory »Kaštel« in Zagreb. All the resulting papers were prepared by joint engagement of Professor Prelog\u27s enthusiastic co-workers from the Faculty and »Kaštel«, thus establishing »Prelog\u27s Zagreb School of Organic Chemistry«. It continued its activities even after Professor Prelog\u27s departure for Zürich and had a vital influence on the further development of organic chemistry and biochemistry at the University of Zagreb, research institutions and scientific research laboratories of the chemical and pharmaceutical industries in Croatia
Estimation of the stands’ arithmetic mean diameter using manual method of digital photogrammetry
Background and Purpose: The development of digital photogrammetry
during the last twenty years has reopened the question of the possibility of its application in forest inventory. The focus of this paper is to research the potential of the manual method of digital photogrammetry for the estimation of diameter at breast height (DBH) at stand level.
Material and Methods: The results (stands\u27 arithmetic mean diameter)
obtained by classical terrestrial measurement and photogrammetric measurement were compared for the selected part of the \u27Donja Kup~ina – Pisarovina\u27 management unit. Photogrammetric measurements of tree variables (height, crown diameter), necessary for DBH estimation, were carried out in the stereomodels of colour infrared digital images of 30 cmand 10 cm spatial resolution, i.e. ground sample distance (GSD) using digital photogrammetric workstation.
Results: The repeated measures ANOVA testing determined statistically
significant differences between the results obtained by terrestrial and photogrammetric measurements (GSD 10 cm and GSD 30 cm) of the arithmetic mean DBH of subcompartments. Furthermore, the testing determined no statistically significant differences between the \u27trends\u27 of estimating DBH by different methods. In other words, a \u27pattern of constant overestimation\u27 of DBH, taken by the photogrammetric measurement in relation to terrestrial measurement, was noted for all subcompartments. The value of overestimation was lesser in case of aerial images of GSD 10 cm(1.45–3.90 cm) and greater in case of images of GSD 30 cm (2.55–5.29 cm).
Conclusions: Considering the obtained results, it can be concluded that
the method used in this research may find its practical application primarily in forests of less intensive management (protective forests, forests with special purposes, privately-owned forests), where a compromise between the data collection costs and utilization value is necessary
Forest biomass and sequestered carbon estimation according to main tree components on the forest stand scale
Background and Purpose: The estimation of forest woody biomass has a significant role in forestry due to several reasons. One of the reasons is that good woody biomass estimation is important for the planning of forest woody assortments production, for main commercial roundwood assortment and for assortments like »waste wood« or »recovered wood« as a potential for electricity (heat) generation (firewood, wood bricks, wood pellets etc.). Economic and political meaning of woody biomass estimation is important to know forest biomass resources in the country and present these
facts to international institutions or in treaties as needed. The estimation is also important for strategic planning of the use of renewable energy sources from woody biomass. On the other hand, estimation of the carbon content in forest woody biomass has importance in global climatemitigation policy and processes (Kyoto- and post-Kyoto period). The purpose of this paper is to present methodology applied for estimation of forest woody biomass and its
carbon content according to main tree components, on the forest stand scale.
Material and Methods: As research area, two representative Croatian
forest communities/stands were selected. The one represents flooded lowland pedunculate oak forest of Pokupski Basin, and the other represents mountain fir-beech forest of the Gorski Kotar region. Emphasis in the paper is on themethodology which was developed for the purpose of research. The methods applied in this study consist of: a) dendrometrical measurements on selected forest stands (research sites), b) sampling of main tree components and sample analyses in laboratory, and c) calculation of forest woody biomass and its carbon content according to main tree components.
Results: General result of the laboratory analyses of the samples of main tree componets is that the carbon content in biomass was around 50,0% of the dry matter of a component. In line with volume allocation of main tree components are the biomass of tree components and the content of carbon sequestered in these components. Stem had the largest share in total tree biomass
while foliage or needle biomass had the smallest share. The shares of
main tree components in total biomass of the tree depend on morphology each of tree species.
Conclusion: This research was a pilot and pioneering research of forest biomass in Croatian forestry, and it should be continued to acquire better knowledge of relations in forest woody biomass in main forest communities in Croatia
Die Einstellung von Studenten zu sexueller Belästigung
Cilj istraživanja bio je provjeriti postojanje razlika u
percepciji seksualnoga uznemiravanja između spolova,
ovisno o spolu i reakciji žrtve. Ispitivanje je provedeno na
uzorku 159 studenata i studentica Sveučilišta u Zagrebu.
Nađene su razlike u percepciji seksualnoga uznemiravanja
između muških i ženskih ispitanika, kao i razlike u percepciji
s obzirom na spol žrtve. Te razlike dobivene su procjenama
hipotetskih priča koje opisuju seksualno uznemiravanje.
Muški i ženski ispitanici su se razlikovali i po kaznama koje
bi odredili za napadača te po onome što bi osjećali i učinili
u takvoj situaciji.The goal of this study was to explore differences between
male and female perceptions of sexual harassment,
depending on the sex and the reaction of the victim. The
participants in the study were 159 male and female students
from the University of Zagreb. They assessed a hypothetical
sexual harassment story on five 4-point Likert scales. The
significant differences between men and women were found
in their perception of the incident as well as differences
concerning the sex of the victim. Women generally assessed
the stories more negatively. The assessment was generally
more negative if the victim was female. Male and female
participants also differed in the kind of punishment they
would see as just for the perpetrator, and in the way they
would feel and act in such a situation.Ziel dieser Untersuchung war festzustellen, ob das Phänomen
der sexuellen Belästigung von Männern und Frauen unterschiedlich
wahrgenommen wird, d.h. je nach Geschlechtszugehörigkeit
und Reaktion des Opfers. Grundlage dieser Studie
ist eine Meinungsumfrage, die unter 159 StudentInnen der
Universität Zagreb durchgeführt wurde. Es konnten Unterschiede
in der Wahrnehmung sexueller Belästigung festgestellt werden,
und zwar hinsichtlich der Geschlechtszugehörigkeit des Opfers.
Die Angaben wurden mittels hypothetischer Beschreibungen
ermittelt, die Fälle sexueller Belästigung zum Gegenstand hatten.
Die Unter-schiede in den Sichtweisen männlicher und weiblicher
Um-frageteilnehmer beziehen sich sowohl auf die suggerierten
Strafen für den Angreifer als auch auf die Art und Weise, wie die
Befragten, wenn sie selbst betroffen gewesen wären, empfunden
und reagiert hätten
Litters Health Status and Growth Parameters in the Sows Feeding Diets Supplemented with Probiotic Actisaf Sc 47® within Pregnancy Or Lactation
The aim of this study was to investigate the effect of supplementing standard diets for pregnant and lactating sows with live yeast culture (Saccharomyces cerevisiae) on their health status, as well as the health status and growth parameters of their litters during lactation. A total of 120 sows were divided into three groups: the first group was fed diets supplemented with probiotics during pregnancy (G+P, n=40), the second group was fed these diets during lactation (L+P, n=40), and the third group was the control group which was not fed diets supplemented with probiotics (C, n = 40). During the lactation period, a significantly (p<0.01) smaller proportion of probiotic treated sows (G+P=7.5%, L+P=12.5%) manifested clinical signs of the uterus and/or the udder disease in comparison with the control sows (22.5%). The incidence of infectious diarrhea in the nursing piglets was significantly (p<0.05) lower in the treated sows (12.5%) compared to the control sows (27.5 %). The average number of weaned piglets per litter (p/l) and average litter weight at weaning (lw) (G+P=11.6 p/l and 103.6 kg lw, L+P=11.1 p/l and 102.8 kg lw, C=10 p/l and 79 kg lw) were significantly higher (p<0.01 or p<0.05) in sows treated with probiotic compared to the control sows. These results clearly show that the use of probiotic significantly improves the health status of sows and nursing piglets, as well as the piglets growth parameters
Vladanje krmača 24 sata prije odbića
A number of 30 sows of different age and breed composition, accommodated in farrowing crates with piglets aged 27-28 days were observed, 24 hours before weaning. The partitions bars were removed from one side of the crate at 8th to 10th day after farrowing. Five sows’ body positions were observed (lying on the left side, on the right side, on stomach, the sitting position and the standing position). Statistical analysis showed differences between the observed sow groups regarding the duration of the lying position on the right side (the 1st group differed from the 2nd, 3rd and 4th, while there was none for the 5th and 6th group) and the sitting position (only group 2 and 3 differed). The sows were lying for a shorter period of time than the sows with suckling piglets and spent longer time in the sitting and standing position. Sitting was the dominant position of all noted positions, while the remaining observed activities (drinking, urinating, sniffing, rooting, scratching) were only short and happened, mostly, before and after feeding. It would be convenient to enable the sows some space where they can remove from the piglets when they wish to do so, improving thus to their welfare and, although, earlier return of the sow to estrus would, enable a more successful production.Promatrano je 24 sata prije odbića 30 krmača, različite starosti i pasminskog sastava, smještenih u bokseve s prasadi starom 27-28 dana. Krmače su raskliještene 8. do 10. dana nakon prasenja, kod čega je bila skinuta jedna pregrada. Praćeno je 5 položaja (ležanje na lijevom boku, desnom boku, trbuhu, sjedenje i stajanje) i 6 aktivnosti krmača (jedenje, pijenje, uriniranje, grizenje predmeta, rovanje i čohanje). Statistička analiza je pokazala razlike između šest promatranih grupa krmača u trajanju položaja ležanja na desnom boku (razlika prve grupe od 2., 3. i 4., dok je nema za 5. i 6. grupu) i sjedenja (razlika samo između 2. i 3. grupe). Krmače su ležale kraće nego što to leže krmače s mlađom prasadi, te su duže sjedile i stajale. Od uočenih aktivnosti dominantno je bilo jedenje, dok su ostale uočene aktivnosti (pijenje, uriniranje, njušenje, rovanje, čohanje) bile kratkotrajne i događale su se uglavnom prije i nakon hranjenja. Poželjno bi bilo omogućiti krmačama prostor u koji bi se mogle odvojiti od prasadi kada to žele, čime bi se povećala njihova dobrobit, a ranije vraćanje krmača u estrus omogućilo bi i uspješniju proizvodnju
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