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Table 6. Appropriate Statistical Significances of Differences in Fig. 6 T = 20°C,
T = 20°C, RH = 85%
T = 20°C, RH = 65%, Desorption
T = 103°C, Desorption
RH = 65%, Absorption
R A B
R A B
R A B
R A B
R n.s. s.
R
s.
s. s.
R
s.
s. s.
R
n.s.
s. s.
A n.s.
n.s.
A s. B s.
A s. B s.
A n.s. B s.
B s. n.s.
s.
s.
s.
Note: s. = statistically significant, n.s. = not significant, and α = 0.05 %HQGLQJVWUHQJWKDQGLQWHUQDOERQGLQJ
Table 7 shows the average values with basic descriptive statistics for the bending strength of boards. Figure 7 shows the bending strength variation analysis and Table 8 shows data on the statistical significance of the differences. The results show that in both cases of plasma treatment of the particles there was an increase in flexural strength compared to the reference material, but the increase was only statistically significant for modification A. There was also no statistically significant difference in the flexural strength between the two different plasma treatments. Table 7. Average Values with Basic Bending Strength Descriptive Statistics Bending Strength Ref. Modification A B Mean (MPa) 4.9 5.5 5.1 Median (MPa) 4.8 5.5 5.4 Standard Deviation (MPa) 0.5 0.3 0.7 Minimum (MPa) 4.2 5.0 3.9 Maximum (MPa) 5.6 6.0 5.9 Table 8. Appropriate Statistical Significances of Differences in Fig. 7 R A B R s. n.s. A s. n.s. B n.s. n.s. Note: s. = statistically significant, n.s. = not significant, and α = 0.05 Table 9 shows the average values with the basic descriptive statistics for the internal bonding of the boards. Figure 8 shows the internal bonding variation analysis and Table 10 shows data on the statistical significance of the differences. The results showed that in both cases of plasma treatment there was a statistically significant increase in internal bonding. There was no statistically significant difference between the different plasma treatments. Both observed mechanical properties reached lower values than the boards made form rapeseed stalk particles, where internal bonding was 0.34 MPa to 0.50 MPa and the bending strength was 5 MPa to 10 MPa (Hýsek HWDO 2018). However, in previous research, boards with an average density of 600 kg/m 3 and with an inverse vertical density profile (maximal density in the middle of the board) were produced.
5075
Hýsek et al . (2018). “Cold plasma & straw board,” B io R esources 13(3), 5065-5079.
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