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Retrospective determination of exposure temperature of standing trees during wildfires with Solid-state NMR
Thesis (MSc)--Stellenbosch University, 2024.
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| Format: | Thesis |
| Language: | en_ZA en_ZA |
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Stellenbosch : Stellenbosch University
2024
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| _version_ | 1867613923789766656 |
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| access_status_str | Open Access |
| author | Kutzer, Karl |
| author2 | Meincken, Martina |
| author_browse | Kutzer, Karl Meincken, Martina |
| author_facet | Meincken, Martina Kutzer, Karl |
| author_sort | Kutzer, Karl |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc)--Stellenbosch University, 2024. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/130274 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA en_ZA |
| last_indexed | 2026-06-10T12:43:51.865Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/130274 Retrospective determination of exposure temperature of standing trees during wildfires with Solid-state NMR Kutzer, Karl Meincken, Martina Stellenbosch University. Faculty of AgriSciences. Dept. of Forest and Wood Science. Plantations -- Africa, Southern Wildfires -- Africa, Southern Fynbos ecology -- Africa, Southern Eucalyptus -- Ecology -- Africa, Southern UCTD Thesis (MSc)--Stellenbosch University, 2024. ENGLISH ABSTRACT: Timber plantations across the world are suffering from the effects of increasingly frequent wildfires, which potentially degrade the wood of affected trees, depending on the exposure temperature. However, it is rather complicated to determine the exact temperature of the fire, or the temperature to which the wood behind the bark was exposed. This study aimed to determine the exposure temperature of the wood retrospectively through Solid-state NMR (ssNMR) analysis. Models were developed from softwood and hardwood samples exposed to defined temperatures in a laboratory furnace, which successfully linked the NMR signal to the exposure temperature. Various equations were tested to fit either the half-width or peak area of the NMR signals obtained for different exposure temperatures and the best models were identified. The results show a clear difference between Pine and Eucalyptus wood: for Pine the half-width of the NMR signal yielded the best correlation to exposure temperature, while for Eucalyptus the peak area was a better fit. The results confirmed findings of an earlier pilot study performed on Pine with an increased sample number over a larger temperature range and extended the model to a hardwood species, namely Eucalyptus. This non-destructive method offers a valuable evaluation method to determine, if the wood from burnt trees is still sound and can be further processed. If models are developed for the relevant species used by the South African Forest industry, significant economic gains can be made, by not unilaterally discarding burnt trees where the wood of many trees has not been degraded and can still be utilized. AFRIKAANSE OPSOMMING: Houtplantasies regoor die wêreld gaan gebuk onder die gevolge van toenemende gereelde veldbrande, wat moontlik die hout van geaffekteerde bome afbreek, afhangende van die blootstellingstemperatuur. Dit is egter taamlik ingewikkeld om die presiese temperatuur van die vuur te bepaal, of die temperatuur waaraan die hout agter die bas blootgestel is. Hierdie studie het ten doel gehad om die blootstellingstemperatuur van die hout retrospektief te bepaal deur middel van Vastetoestand KMR (ssKMR) analise. Modelle is ontwikkel uit sagtehout- en hardehoutmonsters wat aan gedefinieerde temperature in 'n laboratoriumoond blootgestel is, wat die KMR-sein suksesvol aan die blootstellingstemperatuur gekoppel het. Verskeie vergelykings is getoets om óf die halfwydte óf piekarea van die KMR-seine wat vir verskillende blootstellingstemperature verkry is te pas en die beste modelle is geïdentifiseer. Die resultate toon 'n duidelike verskil tussen denne- en bloekomhout: vir denne het die halfwydte van die KMR-sein die beste korrelasie met blootstellingstemperatuur gelewer, terwyl vir bloekom die piekarea 'n beter passing was. Die resultate het bevindinge bevestig van 'n vroeëre loodsstudie wat op Pine uitgevoer is met 'n verhoogde monstergetal oor 'n groter temperatuurreeks en het die model uitgebrei na 'n hardehoutspesie, naamlik Eucalyptus. Hierdie nie-vernietigende metode bied 'n waardevolle evalueringsmetode om te bepaal of die hout van gebrande bome nog gesond is en verder verwerk kan word. Indien modelle ontwikkel word vir die betrokke spesies wat deur die Suid-Afrikaanse Bosbedryf gebruik word, kan aansienlike ekonomiese winste gemaak word deur nie eensydig verbrande bome weg te gooi waar die hout van baie bome nie afgebreek is nie en steeds benut kan word. Masters 2024-02-22T14:35:13Z 2024-04-26T11:38:41Z 2024-02-22T14:35:13Z 2024-04-26T11:38:41Z 2024-02 Thesis https://scholar.sun.ac.za/handle/10019.1/130274 en_ZA en_ZA Stellenbosch University v, 48 pages : illustrations. application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Plantations -- Africa, Southern Wildfires -- Africa, Southern Fynbos ecology -- Africa, Southern Eucalyptus -- Ecology -- Africa, Southern UCTD Kutzer, Karl Retrospective determination of exposure temperature of standing trees during wildfires with Solid-state NMR |
| title | Retrospective determination of exposure temperature of standing trees during wildfires with Solid-state NMR |
| title_full | Retrospective determination of exposure temperature of standing trees during wildfires with Solid-state NMR |
| title_fullStr | Retrospective determination of exposure temperature of standing trees during wildfires with Solid-state NMR |
| title_full_unstemmed | Retrospective determination of exposure temperature of standing trees during wildfires with Solid-state NMR |
| title_short | Retrospective determination of exposure temperature of standing trees during wildfires with Solid-state NMR |
| title_sort | retrospective determination of exposure temperature of standing trees during wildfires with solid state nmr |
| topic | Plantations -- Africa, Southern Wildfires -- Africa, Southern Fynbos ecology -- Africa, Southern Eucalyptus -- Ecology -- Africa, Southern UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/130274 |
| work_keys_str_mv | AT kutzerkarl retrospectivedeterminationofexposuretemperatureofstandingtreesduringwildfireswithsolidstatenmr |