Showing posts with label viscosity. Show all posts
Showing posts with label viscosity. Show all posts

Wednesday, 30 November 2011

New device measures viscosity of ketchup and cosmetics

ScienceDaily (Oct. 24, 2011) — A device that can measure and predict how liquids flow under different conditions will ensure consumer products -- from make-up to ketchup -- are of the right consistency.

The technology developed at the University of Sheffield enables engineers to monitor, in real time, how the viscous components (rheology) of liquids change during a production process, making it easier, quicker and cheaper to control the properties of the liquid.

The research is a joint project between the University's Department of Chemical and Biological Engineering and the School of Mathematics and Statistics. A paper describing the innovation is published Oct. 24, 2011 in the journal Measurement Science and Technology.

Dr Julia Rees from the University's Department of Applied Mathematics, who co-authored the study, said: "Companies that make liquid products need to know how the liquids will behave in different circumstances because these different behaviours can affect the texture, the taste or even the smell of a product."

The viscosity of most liquids changes under different conditions and designers often use complicated mathematical equations to determine what these changes might be.

The team from Sheffield has now developed a way of predicting these changes using a non-invasive sensor system that the liquid simply flows through. The sensor feeds information back through an electronic device that calculates a range of likely behaviours.

Dr Rees, from the Department of Applied Mathematics, explains: "Measuring the individual components of a liquid's viscosity is called rheometry. We can produce equations to measure a liquid's total viscosity, but the rheology of most liquids is very complicated. Instead, we look at properties in a liquid that we can measure easily, and then apply maths to calculate the viscosity. The sensor device we have developed will be able to make these calculations for companies using a straightforward testing process."

Companies developing new products will be able to incorporate the device into their development process, meaning there will no longer be a need for `grab samples' to be taken away for expensive laboratory testing, providing cost and efficiency savings.

The device can be made to any scale and can even be etched onto a microchip, with channels about the width of a human hair. This will be useful for testing where only small samples of fluid are available, for example in biological samples.

Dr Rees' team have developed a laboratory prototype of the system and are currently working to refine the technology and develop a design prototype.

Will Zimmerman, Professor of Biochemical Dynamical Systems in the Department of Chemical and Biological Engineering at the University of Sheffield, worked on the project alongside Dr Rees. He says: "Because the microrheometer works in real time, materials, time and energy will not be wasted when processing flaws are detected. Conservation is one of the best ways to 'green' industrial processing with greater efficiency. Ben Franklin's maxim, 'waste not, want not' is just as true today."

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Story Source:

The above story is reprinted from materials provided by University of Sheffield.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

H C Hemaka Bandulasena, William B Zimmerman, Julia M Rees. An inverse method for rheometry of power-law fluids. Measurement Science and Technology, 2011; 22 (12): 125402 DOI: 10.1088/0957-0233/22/12/125402

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.


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Monday, 4 July 2011

Using magnets to help prevent heart attacks: Magnetic field can reduce blood viscosity, physicist discovers

ScienceDaily (June 8, 2011) — If a person's blood becomes too thick it can damage blood vessels and increase the risk of heart attacks. But a Temple University physicist has discovered that he can thin the human blood by subjecting it to a magnetic field.

Rongjia Tao, professor and chair of physics at Temple University, has pioneered the use of electric or magnetic fields to decrease the viscosity of oil in engines and pipelines. Now, he is using the same magnetic fields to thin human blood in the circulation system.

Because red blood cells contain iron, Tao has been able to reduce a person's blood viscosity by 20-30 percent by subjecting it to a magnetic field of 1.3 Telsa (about the same as an MRI) for about one minute.

Tao and his collaborator tested numerous blood samples in a Temple lab and found that the magnetic field polarizes the red blood cells causing them to link together in short chains, streamlining the movement of the blood. Because these chains are larger than the single blood cells, they flow down the center, reducing the friction against the walls of the blood vessels. The combined effects reduce the viscosity of the blood, helping it to flow more freely.

When the magnetic field was taken away, the blood's original viscosity state slowly returned, but over a period of several hours.

"By selecting a suitable magnetic field strength and pulse duration, we will be able to control the size of the aggregated red-cell chains, hence to control the blood's viscosity," said Tao. "This method of magneto-rheology provides an effective way to control the blood viscosity within a selected range."

Currently, the only method for thinning blood is through drugs such as aspirin; however, these drugs often produce unwanted side effects. Tao said that the magnetic field method is not only safer, it is repeatable. The magnetic fields may be reapplied and the viscosity reduced again. He also added that the viscosity reduction does not affect the red blood cells' normal function.

Tao said that further studies are needed and that he hopes to ultimately develop this technology into an acceptable therapy to prevent heart disease.

Tao and his former graduate student, Ke "Colin" Huang, now a medical physics resident in the Department of Radiation Oncology at the University of Michigan, are publishing their findings in the journal Physical Review E.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Temple University, via EurekAlert!, a service of AAAS.

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.


View the original article here

Tuesday, 28 June 2011

Using magnets to help prevent heart attacks: Magnetic field can reduce blood viscosity, physicist discovers

ScienceDaily (June 8, 2011) — If a person's blood becomes too thick it can damage blood vessels and increase the risk of heart attacks. But a Temple University physicist has discovered that he can thin the human blood by subjecting it to a magnetic field.

Rongjia Tao, professor and chair of physics at Temple University, has pioneered the use of electric or magnetic fields to decrease the viscosity of oil in engines and pipelines. Now, he is using the same magnetic fields to thin human blood in the circulation system.

Because red blood cells contain iron, Tao has been able to reduce a person's blood viscosity by 20-30 percent by subjecting it to a magnetic field of 1.3 Telsa (about the same as an MRI) for about one minute.

Tao and his collaborator tested numerous blood samples in a Temple lab and found that the magnetic field polarizes the red blood cells causing them to link together in short chains, streamlining the movement of the blood. Because these chains are larger than the single blood cells, they flow down the center, reducing the friction against the walls of the blood vessels. The combined effects reduce the viscosity of the blood, helping it to flow more freely.

When the magnetic field was taken away, the blood's original viscosity state slowly returned, but over a period of several hours.

"By selecting a suitable magnetic field strength and pulse duration, we will be able to control the size of the aggregated red-cell chains, hence to control the blood's viscosity," said Tao. "This method of magneto-rheology provides an effective way to control the blood viscosity within a selected range."

Currently, the only method for thinning blood is through drugs such as aspirin; however, these drugs often produce unwanted side effects. Tao said that the magnetic field method is not only safer, it is repeatable. The magnetic fields may be reapplied and the viscosity reduced again. He also added that the viscosity reduction does not affect the red blood cells' normal function.

Tao said that further studies are needed and that he hopes to ultimately develop this technology into an acceptable therapy to prevent heart disease.

Tao and his former graduate student, Ke "Colin" Huang, now a medical physics resident in the Department of Radiation Oncology at the University of Michigan, are publishing their findings in the journal Physical Review E.

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Temple University, via EurekAlert!, a service of AAAS.

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.


View the original article here