Michael McCarthy
Title Integration of Tomographic Data in Process Analysis, Modeling and Control
Abstract Tomographic experimental data provides detailed information that is in general both spatially and temporally resolved. Examples of tomographic techniques include magnetic resonance imaging, ultrasound reflection tomography, electrical resistance tomography and gamma ray imaging. Application of these experimental techniques to validating or constructing mathematical models of physical processes requires data processing and acquisition of the data on an appropriate length scale. Consider the case of characterizing moisture transport in a heterogeneous food. If the goal of the experiment is to calculate the concentration dependence of the diffusivity, all that is needed is a well-defined measurement of the concentration profile and the mass flux for the profile. The calculated diffusivity is tied to the concentration and the length scale on which that concentration is measured. To produce data that is intrinsic to the physical process of interest the measurement must be made on the appropriate length scale. Examples in application of magnetic resonance imaging to measure moisture diffusivity, component concentrations and fluid viscosity will be described detailing the selection of experimental conditions and data processing.
Authors Michael J. McCarthy
Speaker Michael McCarthy
web page
 http://www.engr.ucdavis.edu/~bae/People/McCarthyM'98.html
  Professor McCarthy's research program is focused on developing and utilizing nuclear magnetic resonance and ultrasonic tomographic techniques to determine the physical and transport properties of food systems and consumer products. Magnetic resonance imaging and ultrasonics are capable of rapidly characterizing material properties as well as for use as process analytical instruments.

Viscometry: In the application of MRI or ultrasonics as a viscometer, measurements of the fluid velocity profile in tube flow are coupled with a pressure drop measurement to yield shear viscosity. The range of shear rates for a measurement is set by the fluid flow rate and tube geometry, and ranges from zero at the tube center to a maximum at the tube wall (typically two to three orders of magnitude). This technique has the potential to significantly enhance process control of industrial processes.

Mixing quality: The goal of this work is to develop MRI to measure the effectiveness of industrial mixing operations. The focus of the work is to obtain both concentration and velocity data for the materials during processing. Our initial studies have focused on evaluating the mixing of power law fluids in a scraped surface heat exchanger, mixing of fluids in static mixers and characterizing colloidal batch mixing.

Fresh Produce: Internal disorders in fresh fruits and vegetables result in significant losses to growers, packers, sellers and consumers. We have been developing MRI as an in-line sensor for detecting defects in and measuring the quality of fruits and vegetables. The development of a nondestructive imaging sensor would be beneficial to packinghouses, as it would facilitate testing of representative samples or sorting of entire lots of apples and other agricultural products before marketing or further storage.

Institution Department of Biological and Agricultural Engineering, University of California
web page
 http://www.engr.ucdavis.edu/~bae/

 

The Department of Biological and Agricultural Engineering integrates engineering principles with biological systems. The Department belongs to both the College of Engineering and the College of Agricultural and Environmental Sciences.

Undergraduate Biological Systems Engineering Major, courses in biology and engineering in the analysis and design of biological systems. Graduate programs: the Master of Science (M.S.) and Doctor of Philosophy (Ph.D.), Master of Engineering (M.E.) and Doctor of Engineering (D.E.) degrees. In the College of Agricultural and Environmental Sciences, three minors—Applied Biological Systems Technology, Geographic Information Systems, and Precision Agriculture.

In research, the department enjoys the strategic advantage of being located in the state of California, which leads the nation in agricultural production and in the diversity of its crops and is the growing center of biotechnology. Over the past 84 years of the department’s existence, the following research programs have evolved: Agricultural Engineering, Aquacultural Engineering, Bioenvironmental Engineering, Bioinstrumentation Engineering, Biomedical Engineering, Biotechnical Engineering, Energy Systems Engineering, Food Engineering, Forest and Fiber Engineering, and Postharvest Engineering. Each of these areas is described in the research section of this website.

Our department is recognized as the leading department of its kind in the western United States and is consistently viewed as one of the top biological/agricultural engineering departments in the world.