Thumbnail Image

Thesis

Browse

20171
Reset filters
Subject: Agricultural Physics and Meteorology × Author: Harneet Kaur × End date: 2018 × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    ThesisItemOpen Access
    Gamma attenuation studies in selected wood samples at varying moisture level.
    (Punjab Agricultural University, Ludhiana, 2017) Harneet Kaur; Rajeev Kumar
    The moisture content of wood is known to have a significant influence on the wood‟s mechanical properties. Changes in wood moisture content lead to changes of virtually all physical and mechanical properties (e.g. strength and stiffness properties) of wood. Another effect of changes of the wood moisture content is the associated shrinkage or swelling of the material. The present study deals with the determination of mass attenuation coefficients of Dek and Poplar wood samples at varying moisture levels using gamma ray transmission method. Measurements were performed using NaI(Tl) scintillation detector and a radioactive source 137Cs of energy 0.662 MeV. In order to vary moisture content of wood samples they were placed in an oven for fixed durations. A graph was plotted between the measured relative transmitted intensities against the thickness of wood samples and we observed the mass attenuation coefficient from the slopes of the plots at different moisture levels. The obtained mass attenuation coefficients were plotted against the relative moisture content of wood samples and it showed that attenuation coefficient increases with decreasing moisture content, i.e., mass attenuation coefficient is least for completely wet samples and is highest for the oven dried samples. We also measured the densities of both wood samples at different moisture levels by using radiation technique and conventional method and compared the results and found very small percentage difference. Wood density is a vital parameter to have knowledge about anatomical and physical properties of wood and thus it can be a useful parameter for determination of quality of wood.