Dissertation
NUMERICAL AND EXPERIMENTAL INVESTIGATION INTO THE THERMAL PROPERTIES OF CELLULOSE NANOCRYSTAL (CNC) DISPERSION FOR IMPROVED COLD HARDINESS
Doctor of Philosophy (PhD), Washington State University
01/2020
Handle:
https://hdl.handle.net/2376/111677
Abstract
The tree fruit industry is an important component of the U.S. agricultural sector, representing about 18% of the total $30.6 billion annual crop production in 2018. The yield of these crops is mainly determined by cross-pollination during the brief, but critical, flowering period. During the transition from bud break to flowering, reproductive buds become increasingly susceptible to cold damage, and sudden low temperatures can cause severe economic losses for fruit growers.
Cellulose nanocrystals (CNC) represent a new generation of renewable nano-biomaterials with many unique physical and chemical properties, including their low thermal conductivity. Our team has synthesized a CNC dispersion that can be sprayed onto trees, forming a thin insulating film on the surface of the buds. Thermal image analysis shows apple and cherry buds treated with 3% CNC dispersions lose 16.5% less thermal energy in cold conditions than the control. Additionally, analysis of internal freezing events in CNC-coated apple buds with digital scanning calorimetry showed that lethal freezing occurred 3.2°C lower than in the control one day after the application of CNC, and 5.5°C lower after three days. Large scale field tests of 2.5% CNC solutions applied using a commercially available orchard sprayer showed that CNC-treated trees are given 5.8°C of protection as long as seven days post-application. The results of this work suggest that the use of CNC could represent an advancement in cold damage prevention in fruit crops due to the significant and long-lasting protection offered by CNC, which could allow for a reduction in economic losses from cold damage.
The CFD simulation results for reproductive bud temperature distribution profiles were compared with the experimental data, with a resulting average relative error of less than 15%. The CFD model was able to estimate the convection heat flux, radiation heat transfer, and latent heat, which were impractical and difficult to investigate by measurements made in lab conditions. The comparisons between the CFD model and the measured experimental data yielded promising results relative to the ability of the model to predict the heat transfer mechanism. The new modeling approach can be applied with benefits to multiple areas of research.
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Details
- Title
- NUMERICAL AND EXPERIMENTAL INVESTIGATION INTO THE THERMAL PROPERTIES OF CELLULOSE NANOCRYSTAL (CNC) DISPERSION FOR IMPROVED COLD HARDINESS
- Creators
- Jassim O Alhamid
- Contributors
- Changki Mo (Advisor)Xiao Zhang (Committee Member)Joseph Iannelli (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 134
- Identifiers
- 99900581613801842
- Language
- English
- Resource Type
- Dissertation