Brzina širenja ultrazvuka kroz drvo razoreno gljivom smeđe truleži

master's thesis

• Title (english): Speed of Ultrasound Propagation through Wood Decayed by Brown Rot Fungi
• Author: Igor Kesak
• Mentor: Marin Hasan (mentor)
• Mentor: Vinko Paulić (komentor)
• Committee member: Marin Hasan (predsjednik povjerenstva)
• Committee member: Vinko Paulić (član povjerenstva)
• Committee member: Tomislav Sedlar (član povjerenstva)
• Granter: University of Zagreb; Faculty of Forestry and Wood Technology; (Institute for Wood Science); Zagreb
• Defense date and country: 2022-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Wood Technology

Abstract

Ultrazvučna ispitivanja danas se vrlo često koriste u dijagnostičke svrhe određivanja zdravosti drva kao nerazorna metoda. Vrlo je malo provedenih ispitivanja utjecaja stupnja biološke razgradnje na brzinu širenja ultrazvuka kroz drvo. Uzorci borovine i bukovine bili su izloženi gljivi smeđe truleži Gloeophyllum trabeum te je određeno nekoliko različitih stupnja razgradnje. Nakon kondicioniranja razorenih uzoraka, izmjerena je brzina širenja ultrazvuka kroz njih u radijalnom i tangentnom smjeru. Povećanjem gubitka mase djelovanjem gljive proporcionalno se smanjuje brzina prolaska ultrazvuka kroz drvo i u radijalnom i u tangentnom smjeru. Bez obzira na vrstu drva i gustoću i najmanji gubitak mase djelovanjem micelija gljive rezultirao je smanjenjem brzine prolaska ultrazvuka kroz drvo u odnosu na zdravo drvo. Porastom gubitka mase djelovanjem micelija gljive brzina prolaska ultrazvuka kroz drvo značajno brže opada u radijalnom nego u tangentnom smjeru.

Abstract (english)

Nowadays, ultrasonic tests are very often used for diagnostic purposes to determine the health of wood as a non-destructive method. Very few studies have been conducted on the influence of the degree of biodegradation on the speed of ultrasound through wood. Pine and beech specimens were exposed to the brown rot fungus Gloeophyllum trabeum and several different levels of degradation were determined. After conditioning the decayed specimens, the speed of ultrasound propagation through them was measured in the radial and tangential directions. By increasing the mass loss due to the action of the fungus, the speed of ultrasound through the wood is proportionally reduced in both the radial and tangential directions. Regardless of the wood species and its density, even the smallest mass loss resulted in a decrease in the speed of ultrasound through the wood compared to healthy wood. With the increase in mass loss, the speed of ultrasound through decayed wood decreases significantly faster in the radial direction than in the tangential direction.

• Keywords: biološka razgradnja; in-situ ispitivanje; nerazorno ispitivanje; zdravost drva
• Keywords (english): biological degradation; in-situ testing; nondestructive testing; helth of wood
• Language: croatian
• URN:NBN: urn:nbn:hr:108:064243
• Study programme: Title: Wood Technology Processes; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka drvne tehnologije (magistar/magistra inženjer/inženjerka drvne tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-12-06 14:44:10