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232. The chronology of the silver fir (Abies alba Mill.) from Pohorje, SloveniaTom Levanič, Katarina Čufar, 1998, original scientific article Abstract: Dendrochronological investigations were made in silver fir (Abies alba Mill.) from Lovrenc, Pohorje, in the NE Slovenia. Tree ring analyses were made in discs of 25 healthy, adult, dominant or co-dominant silver firs and in cores from roof construction of two older rustic buildings from the same region using a LINTAB measuring device nad a TSAP/X of F. Rinn. We constructed the chronology of trees spanning the period of 1785-1996. The chronology of the old house is spanning the period of 1713-1852 and the chronology of barn 1745-1887. It was shown that the last considerable reconstruction of the house roof took place after the end of the growing period of 1952. The dating of the cores containining the outer ring 1887 confirmed the dating based on the carved inscription "1888". The three chronologies were joined into 284 years long silver fir chronology for Pohorje spanning the period of 1713-1996. It was compared with the Slovene silver fir chronology of the Dinaric region. Despite distance and great differences between the two regions there was shown a statistically confirmed similarity of two chronologies with tBP=9.8, GLK=71% and CDI=398. The chronologies have 21 common negative, 21 positive signature years and one common signature interval. Based on this the constructed chronology may be considered as representative for the whole Pohorje. The two chronologies are expected to be a good base to construct a regional Slovene Silver-fir chronology for dating in whole Slovenia. Two Slovene chronologies were compared with the following European silver fir chronologies: South German, stand 1993 (Becker and Siebenlist 1970; Spurk and Friedrich , pers. com.), Bavarian Forest - Germany (Eckstein, Sass 1988), Abetone - Italy (Schweingruber, ITRDB), Bannwald - Switzerland (Schweingruber, ITRDB). Both Slovene chronologies proved to be statistically similar with the two German and the Italian silver fir chronology, but showed no similarity with the Swiss one. The Pohorje chronology correlates better with both German ones and the Dinaric chronology correlates better with the Italian one.
Keywords: jelka, Abies alba, datiranje objektov, dendrokronologija, Silver fir, Abies alba, dating of the object, dendrochronology, Slovenia
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237. Nastanek lesa pri beli jelki (Abies Alba Mill.) in navadni bukvi (Fagus sylvatica L.) - diferenciacija terminalnih celic v ksilemski branikiJožica Gričar, Peter Prislan, Gerald Koch, Katarina Čufar, 2009, independent scientific component part or a chapter in a monograph Keywords: bela jelka, Abies alba Mill., bukev, Fagus sylvatica L., nastanek lesa, diferenciacija, svetlobna mikroskopija, UV mikrospektrofotometrija
Published in DiRROS: 12.07.2017; Views: 3304; Downloads: 960
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239. Elemental composition of wheat, common buckwheat, and tartary buckwheat grains under conventional productionLea Orožen, Katarina Vogel-Mikuš, Matevž Likar, Marijan Nečemer, Peter Kump, Marjana Regvar, 2012, original scientific article Keywords: dietary reference intake, energy dispersive X-ray fluorescence spectrometry, metals, minerals, trace elements, total reflection X-ray fluorescence spectrometry
Published in DiRROS: 11.07.2017; Views: 4226; Downloads: 1434
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240. Fizikalne in mehanske lastnosti svežega in osušenega lesa v bukovih deblih, izruvanih med žledolomomŽeljko Gorišek, Denis Plavčak, Dominika Gornik Bučar, Maks Merela, Katarina Čufar, Aleš Straže, 2017, original scientific article Abstract: V raziskavi smo preučevali fizikalne in mehanske lastnosti lesa v deblih navadnih bukev (Fagus sylvatica L.), izruvanih med žledolomom. Lastnosti smo preučevali na vzporednih preizkušancih sveže in osušene bukovine, ki smo jih sistematično vzorčili po radialni in vertikalni smeri dreves. Določili smo gostoto, togost, upogibno trdnost, strižno trdnost v smeri lesnih vlaken ter tlačno trdnost lesa v vseh anatomskih smereh. Togost smo primerjalno vrednotili med statično 4-točkovnim upogibom in nedestruktivno z merjenjem hitrosti ultrazvoka ter z določanjem frekvenčnega odziva. V drevesih, ki so izruvana obležala v gozdu od februarja do konca vegetacijske dobe 2014 in so imela delno ohranjen koreninski sistem, aktivno krošnjo in zadosten kapilarni tok, nismo zaznali sprememb gostote in mehanskih lastnosti, ki bi bile posledica razkroja lesa. Tako v svežem kot osušenem stanju smo ugotovili značilni vzorec porazdelitve gostote in trdnosti. Gostota lesa je po višini dreves naraščala, v radialni smeri od stržena proti periferiji debla pa smo zaznali rahel trend zmanjševanja. Mehanske lastnosti z izjemo prečne tlačne trdnosti se povečujejo tako po višini debla kot tudi od stržena proti kambiju in so bile vedno boljše pri osušenem kot pri svežem lesu. Zanesljivost nedestruktivnih metod za določanje togosti je večja pri ocenjevanju osušenega lesa. Za oceno upogibne trdnosti z nedestruktivnimi metodami še vedno priporočamo vzporedno vizualno opredelitev značilnosti lesa.
Keywords: bukev, Fagus sylvatica, gostota, mehanske lastnosti, nedestruktivno testiranje, žledolom
Published in DiRROS: 03.07.2017; Views: 6227; Downloads: 3460
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