It’s often said that you don’t need a drill bit; what you need is a hole. How you make that hole is up to you, but it’s a given that you want to make it as efficiently as possible. The drill bit, ...

Abstract: In this article, a coupled axial-torsional drill-string vibration model is established, which considers the influence of bit balling on rock-breaking and drill-string vibration. First, a bit ...

Eight hundred bucks for a laptop with an older processor isn’t a great deal, but chop that price almost in half and it gets a lot more appealing. Today, Best Buy is offering a 15-inch HP laptop with ...