Direct inward dial

src: s-media-cache-ak0.pinimg.com Direct inward dialing ( DID ), also called direct dial-in ( DDI ) in Europe and Oceania, is a telecommun...

Bearing (mechanical)

src: c8.alamy.com A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between m...

Websites blocked in mainland China

src: 1.bp.blogspot.com As of September 2017, more than 3,000 websites were blocked in Mainland China under the country's Internet censor...

Drainage

src: previews.123rf.com Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area. The inte...

H-index

src: s3.amazonaws.com The h -index is an author-level metric that attempts to measure both the productivity and citation impact of the publ...