What is the Difference between Motor Oil and Grease?

Technology, Transportation
[caption id="attachment_15935" align="alignright" width="440"] Silhouette of working oil pumps on sunset background.[/caption] Lubricants are slippery substances that coat mechanical parts having tight tolerances so they can slide against each other with minimal friction. This is very important, since friction heats up the component parts, which lowers their lifetime. Sometimes oil may used to achieve satisfactory results. Sometimes grease is necessary. What is the difference between motor oil and grease? Oil Composition Refined oil is derived, as one would expect, from crude oil. Its composition varies due to the source of the crude as well as the processing needed to create the finished product. Oils are viscous, non-polar organic substances of biotic and/or abiotic origin. They do not readily adhere to other surfaces. That being the case, they afford a high…
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Why is Soapstone Slippery?

Geology
[caption id="attachment_8570" align="alignright" width="440"] A 12th century soapstone Byzantine relief.[/caption] Most rocks are rough to the touch. Some are smooth. Asbestos is stringy. Sulfur is brittle. One very interesting rock variety is soapstone. It is called smooth and slippery. What makes soapstone slippery? I was raised in the North then moved to the South to where soapstone is is mined, Nelson County, Virginia. I take special interest in the stuff. As a young child, I watched spellbound as my father took a handheld soapstone and used it to sharpen our enormous carving knife. General Rock Types As kids we were taught there are three types of rock, sedimentary, igneous, and metamorphic rock. Sedimentary rock forms from mineral and organic materials near at earth's surface. These deposits form rock deposits over…
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Water Coolant in Internal Combustion Engines

Physics
[caption id="attachment_7705" align="alignright" width="440"] Most internal combustion engine radiators use water as coolant.[/caption] Automobile manufacturers almost invariably design their automobiles to use radiator cooling. Within the radiator, the fluid of choice is water coolant. A few additives in small quantities help minimize the formation of rust and reduce the freezing point. Why do they use radiators, and why is water the liquid of choice? As you might expect, it is the physical and chemical properties of water that dictate its use. What properties? Fluid Choice Common fluids include free moving solid-particles, liquids, and gases. As an example of fluid solids, black molybdenum sulfide is a solid lubricant used on certain moving automotive parts. That gases can cool should be intuitive. One blows on a forkful of hot food to keep…
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