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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Paprastosios eglės (Picea abies (L.) Karst.) vidinio puvinio įtaka medienos savybėms / Norway spruce internal root influence to the wood properties

Danielius, Marius 21 June 2013 (has links)
Magistro darbe tiriama paprastosios eglės vidinio puvinio įtaka medienos savybėms . Darbo objektas – eglės mediena, kuri buvo paimta iš VĮ Prienų miškų urėdijos 15 kv 25 skl., 49 kv 15 skl., Veisėjų 3 kv 7 skl., Šilutės 2 kv 7skl., 11 kv 12 skl., 19 kv 6 skl., 33 kv 3 skl., 147 kv 4 skl. Darbo tikslas – ištirti paprastosios eglės vidinio puvinio įtaką medienos tankio ir stiprio savybėms. Darbo metodai – tirtuose eglės bareliuose visi medžiai buvo patikrinti prietaisu „ARBOTOM“, kuris matuoja garso sklidimo greitį medienoje ir pateikia erdvinį garso greičio stiebe vaizdą. Garsas sveikoje ir puvinio pažeistoje medienoje sklinda skirtingu greičiu. Vėliau atsitiktiniu būdu iš visų medžių, kuriuose prietaisas parodė vidinį puvinį, buvo atrinkti ir nupjauti medžiai. Radus puvinį buvo paimta kelminė atpjova 50 cm ilgio tolesniems tyrimams. Ruošiant bandinius, iš atpjovų buvo išpjauta centrinė (einanti išilgai per šerdį) 60 mm storio išpjova, kuri supjaustyta į sluoksnius. Medienos fizinės ir mechaninės savybės nustatytos LAMMC Miškų instituto medienos laboratorijoje ir slėnio „Nemunas“ medienos naudojimo, kokybės ir apdirbimo technologijų laboratorijoje. Vykdant medienos stipruminių savybių bandymus, naudota 5 tonų galios bandymų mašina P – 5. Duomenų sisteminimas ir jų analizė atlikta, naudojant statistinių duomenų tvarkymo paketą Microsoft Excell. Darbo rezultatai: atlikus tyrimus nustatyta, kad Prienų urėdijos eglės branduolio puvinio įtaką medienos tankiui, išryškėjo, jog... [toliau žr. visą tekstą] / In this master thesis was researched internal rot of Norway spruce (Picea abies) and its impact to woods characteristics. The object of this work: wood of Norway spruce (Picea abies), which was taken from Prienai state-owned forest enterprise (therefore SOFE) 15 quarter 25 plot, 49 quarter 15plot,Veisiejai SOFE 3 quarter 7 plot, Šilutė SOFE 2quarter 7plot, 11 quarter 12plot, 19 quarter 6 plot, 33 quarter 3plot, 147 quarter 4 plot. The aim of this work is to research the inner rot influence of picea abies to wood density and strength properties. The methods: all spruce in research area were checked with device called “ARBOTROM”, which measures sound speed in wood and shows spatial sound speed view in a steam. Sound in healthy and rot wood differs. Randomly were selected and cut down all trees, which according to the device had an inner rot. After the rot was found a 50cm length tree stump sample was taken for the further research. During preparation of samples there was prepared the central 60 mm thick cutoff (lengthways the core) and shredded to layers. Physical and mechanical wood properties were defined in LRCAF Forest Institute for timber laboratory and in “Nemunas” valley, timber quality and technology lab. For a wood strength property testing was used 5 ton test machine P-5. All data was systematized and analyzed by using Microsoft Excel. Results: after researching Norway spruce kernel rot effect to wood density, was discovered, that wood samples with inner rot from... [to full text]
2

SLEDOVÁNÍ MÍRY DEFOLIACE LESNÍCH POROSTŮ PROSTŘEDKY DPZ / MONITORING OF DEFOLIATION USING REMOTE SENSING TECHNIQUES

Prokopec, Karel January 2017 (has links)
The aim of this diploma thesis is a proposal of a methodology used for an assessment of the measure of defoliation based on the multispectral satellite images from missions Landsat and Sentinel-2. The first part of the thesis is dedicated to the introduction of the problematics of remote sensing using multispectral sensors and the basics of research into forest vegetation. Following on this part, there is a chapter considering possibilities of monitoring defoliation using resources of remote sensing, and the closely connected problematics of the health condition of forest vegetation. After that comes a description of the used data (the satellite images and the data of ground investigation by VÚLHM) and logically compounded process of transformation of the data from satellite images on the levels of defoliation. Outcomes of the thesis include analysis of the ability of single spectral bands and vegetation indices to predict defoliation of Norway spurce (Picea abeis) and Scots pine (Pius sylvestris) vegetation. The assessment of the measure of defoliation is demonstrated on single band in near-infrared region with used of linear regression model.

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