Valvoline has recently launched a pressure-activated cobalt grease that can protect engine parts from damage especially in high temperature environments. The purpose of the grease is to provide a continuous film between moving parts under pressure. Normally under high temperature, the friction between moving parts and the lubricant reduces the viscosity of the film, potentially resulting in metal-to-metal contact. Valvoline’s cobalt grease employs a lithium sulfonate complex thickening system that is effective in dissipating heat and preventing corrosion in extreme conditions.
Whether you work with printed electronics, touch displays, or any of the number of applications working with conductive inks, coatings, paints and pastes, viscosity is one of the key parameters in the development of your process. Over the last few months, RheoSense has released a number of applications related to conductive inks. Our instruments allow for accurate rheological charaterization of these samples between 4°C and 105°C. Check them out!
In this webinar we would cover the basics on whole blood, plasma and serum viscosity and the importance to hemodynamics (blood flow) and related clinical diagnosis applications. We will present the protocols required to test this kind of samples using VROC® (Viscometer/Rheometer-On-a-Chip) powered viscometers.
We demonstrate our technology capability to overcome some of the challenges encountered by conventional methods to measure viscosity when dealing with blood samples. Our instruments are able to characterize the viscosity of blood and its derivatives as a function of shear rate, temperature, vessel size and red blood cell content. If you want to learn more:
Every event we go to, we get asked for the viscosity of bunch of different common fluids. What is the viscosity of honey? Have you measured motor oil? Was it used oil? What about paints and inks? In this last post of the year, right before the holiday break, we ask you: What would you like us to measure?
You can always check our application library to see what fluids we have already tested:
Viscosity is a fundamental material property when studying fluid flow for any application. The two most common types of viscosity are dynamic and kinematic. The relationship between these two properties is quite straightforward.
In a recent post, we discussed how some liquids containing bacteria swimmers can display negative viscosity. This can be a misleading since the apparent negative viscosity occurs due to swimmers pushing the surrounding fluid so that the overall system shows negative resistance to flow (i.e. it flows by itself!). One of the best examples of super fluidity is super cooled helium.
Scientists from Trinity College Dublin captured the falling drop of very high viscosity bitumen or asphalt in a pitch-drop experiment. As Rheologists say, “Everything flows”. Well…in the case of pitch, you need to be extremely patient. This material appears to be an elastic solid to the naked eye. As the drops from these experiments show, however, it is actually an extremely viscous fluid! The Dublin pitch-drop experiment was set up in 1944. This drop took so long to form and fall (1 drop/10 years) that the scientists actually forgot about the experiment and only recently, started recording it with a webcam. Viscosity estimates from the last drop put it at 2 x 107 Pa-s or twenty billion times greater than water. Imagine sitting in front of the funnel with your notebook and your stop watch. Now imagine that you fall asleep and then the drop finally falls!