Definition - What does Positive Displacement Pump mean? Positive Displacement Pump is a type of pump used to displace or force oil and petroleum products into pipelines or into various equipment installed in refineries.
A brain looks like a walnut because our minds are constantly making comparisons and finding similarities to help us understand the world around us. Here's an activity that can help you see more such things. Try to find faces.
Report Abuse. They don't really look like brains, people have decided to describe walnut meats as looking like brains. Pecan halves also resemble what most people think brains look like.