deletions | additions       diff --git a/paragraph_textbf_Self_healing_Glassy__.tex b/paragraph_textbf_Self_healing_Glassy__.tex  index ccac5a1..80a9613 100644  --- a/paragraph_textbf_Self_healing_Glassy__.tex  +++ b/paragraph_textbf_Self_healing_Glassy__.tex 
...
\paragraph{\textbf{Self-healing Glassy Composites}}  The self-healing property is an important feature for materials of great strength and reliability by damage management. Materials with Some materials have  the ability to self-heal the damages and defects incurred during functional use or inevitable changes in physical properties such as stress and volume expansion. The self-healing mechanism can be intrinsic or extrinsic. Intrinsic healing requires the phase transition (softening, melting or chemical decomposition) of the materials itself triggered by external environmental parameters, such as temperature and pressure. Extrinsic self-healing involves the elements encapsulated in the material and their reactivity is controlled by either mechanical, chemical or physical constraints. This work on self-healing process was extrinsic and the healing processes was were  recorded by in situ ESEM ESD images under high temperature $T \approx 730^{\circ} C$ without deformation of the glassy composites. The extrinsic healing source was vanadium boride (VB) which was mixed with standard glass powder and the whole sample was situated in the sample chamber of an ESEM. The sample chamber then worked as a reactor when heated up. VB would be decomposed under high temperature at $730^{\circ} C$. Both vanadium and boron form the oxides which would gradually flow and fill the cracks and defects due to the low viscosity. The healing took place at a temperature lower than the softening temperature for the glass so the self-healing did not change the formation of the glass composites. The ESEM primary beam was of the energy $24KeV$ with the working distance $d = 8mm$ and the sample chamber was kept at pressure of $450 \space Pa$. The ESD images taken every 2 to 5 minutes indicated that the cracks were repaired after 60-minute treating time, shown in Fig.4. The spatial resolution was as good as $0.5 \mu m$ while the temporal resolution was about several-minute range.