diff --git a/Materials_science_and_engineering_an_introduction/CH10.ipynb b/Materials_science_and_engineering_an_introduction/CH10.ipynb
index b7fb2351..b7fb2351 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH10.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH10.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH12.ipynb b/Materials_science_and_engineering_an_introduction/CH12.ipynb
index b2774698..b2774698 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH12.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH12.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH14.ipynb b/Materials_science_and_engineering_an_introduction/CH14.ipynb
index e860f213..e860f213 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH14.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH14.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH16.ipynb b/Materials_science_and_engineering_an_introduction/CH16.ipynb
index 02f6165f..02f6165f 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH16.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH16.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH17.ipynb b/Materials_science_and_engineering_an_introduction/CH17.ipynb
index 889d524a..889d524a 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH17.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH17.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH18.ipynb b/Materials_science_and_engineering_an_introduction/CH18.ipynb
index cae50c36..cae50c36 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH18.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH18.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH19.ipynb b/Materials_science_and_engineering_an_introduction/CH19.ipynb
index 1da6512a..1da6512a 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH19.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH19.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH20.ipynb b/Materials_science_and_engineering_an_introduction/CH20.ipynb
index b3d2e8d5..b3d2e8d5 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH20.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH20.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH21.ipynb b/Materials_science_and_engineering_an_introduction/CH21.ipynb
index 38c06f2e..38c06f2e 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH21.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH21.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH3.ipynb b/Materials_science_and_engineering_an_introduction/CH3.ipynb
index eeb7447f..eeb7447f 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH3.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH3.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH4.ipynb b/Materials_science_and_engineering_an_introduction/CH4.ipynb
index 253ffd46..253ffd46 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH4.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH4.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH5.ipynb b/Materials_science_and_engineering_an_introduction/CH5.ipynb
index caf36165..caf36165 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH5.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH5.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH6.ipynb b/Materials_science_and_engineering_an_introduction/CH6.ipynb
index 490f5d5d..490f5d5d 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH6.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH6.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH7.ipynb b/Materials_science_and_engineering_an_introduction/CH7.ipynb
index 262231ec..262231ec 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH7.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH7.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH8.ipynb b/Materials_science_and_engineering_an_introduction/CH8.ipynb
index b5a32873..b5a32873 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH8.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH8.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/CH9.ipynb b/Materials_science_and_engineering_an_introduction/CH9.ipynb
index 0ddab2a7..0ddab2a7 100644..100755
--- a/Materials_science_and_engineering_an_introduction/CH9.ipynb
+++ b/Materials_science_and_engineering_an_introduction/CH9.ipynb

diff --git a/Materials_science_and_engineering_an_introduction/README.txt b/Materials_science_and_engineering_an_introduction/README.txt
index 5f1056e2..5f1056e2 100644..100755
--- a/Materials_science_and_engineering_an_introduction/README.txt
+++ b/Materials_science_and_engineering_an_introduction/README.txt

diff --git a/Materials_science_and_engineering_an_introduction/screenshots/10_2.png b/Materials_science_and_engineering_an_introduction/screenshots/10_2.png
index 2ab2bcc8..2ab2bcc8 100644..100755
--- a/Materials_science_and_engineering_an_introduction/screenshots/10_2.png
+++ b/Materials_science_and_engineering_an_introduction/screenshots/10_2.png

diff --git a/Materials_science_and_engineering_an_introduction/screenshots/8_1.png b/Materials_science_and_engineering_an_introduction/screenshots/8_1.png
index 6d576bb0..6d576bb0 100644..100755
--- a/Materials_science_and_engineering_an_introduction/screenshots/8_1.png
+++ b/Materials_science_and_engineering_an_introduction/screenshots/8_1.png

diff --git a/Materials_science_and_engineering_an_introduction/screenshots/9_3.png b/Materials_science_and_engineering_an_introduction/screenshots/9_3.png
index d332d145..d332d145 100644..100755
--- a/Materials_science_and_engineering_an_introduction/screenshots/9_3.png
+++ b/Materials_science_and_engineering_an_introduction/screenshots/9_3.png