Host, Sarah Rutan: When it comes to fastening wood materials, there are many instances where screws are preferable to nails. Today we’re in San Rafael with Diamond Certified Expert Contributor Luis Baldenebro of Baldenebro Construction to learn more.
Diamond Certified Expert Contributor, Luis Baldenebro: Here is a tip from Baldenbro Construction. We’re using a siding, cedar. A T&G 1’x6’. It’s a tongue and groove. This is the tongue and this is the groove. We’re using it for a siding between this frame. We have a sliding door, you know, and the screen as well, that this goes into the track between this frame.
And the main reason we’re using this material, you know, just to get access in the future. So, that’s why we choose a flat head stainless steel screw. But this was the nail. You know, the screw, we’re going to be able to pull the screw with the screw gun. And be able to reduce the board back without any damage. But this is using a galvanized nail. And pulling the nail will make it damaged on the board. So, that’s why we’re using a screw. In case somebody needs to get, to replace the wheels or do any maintenance on these doors, they can get to it without making any damage. Thank you.
Host, Sarah Rutan: To learn more from local, top rated companies, visit our Diamond Certified Expert Reports at experts.diamondcertified.org.
Freshman Organic Chemistry II (CHEM 125B)
Isoprenoid or terpene natural products, that seem to be made from isoprene (2-methylbutadiene), are formed by oligomerization of electrophilic isopentenyl pyrophosphate (IPP). Latex, the polymer of IPP, became commercially important when Charles Goodyear, a New Haven native, discovered how to vulcanize rubber. Statistical mechanics explains such curious properties of rubber as contraction upon heating when tightly stretched. Specific chemical treatment confers useful properties on a wide variety of polymers, including hair, synthetic rubber, and plastics. The structure of copolymers demonstrates non-Hammond behavior and ionic character in the transition state for free-radical polymerization.
00:00 – Chapter 1. IPP as the Carbon Electrophile in Isoprenoid Biosynthesis
13:56 – Chapter 2. Latex, Rubber, and Vulcanization
20:14 – Chapter 3. Understanding Vulcanization – Polymer Properties and Statistical Mechanics
35:34 – Chapter 4. Other Polymers and Their Properties
38:22 – Chapter 5. Synthetic Polymers and Free-Radical Copolymerization
Complete course materials are available at the Open Yale Courses website: https://oyc.yale.edu
This course was recorded in Spring 2011.