Dr K R (Ken) Davey
Senior Lecturer
B.E. (Chem.) RMIT, M.Eng.Sc., (Melb.) Ph.D., (Melb).
FIChemE., FIEAust., FAIFST, MSAM(UK).
Location: Room 212b Engineering North
Email: kdavey@chemeng.adelaide.edu.au
Phone: + 61 8 8303 5457
FAX: + 61 8 8303 4373
Interests
Our research interests lie mainly in the area of biochemical engineering
and presently cover five principal areas. These are outlined below.
Through our Food
Safety Alliance we collaborate closely with government and industry.
Quantitative Risk Assessments:
We are particularly interested in researching the notion that no
matter how good the design and operation of process plant there
is an occasional, and usually catastrophic, failure - or Friday
13th event. In the food and pharmaceutical industries this is a
serious risk to public health. Often there is too small a data set
for detailed analyses, especially if failure is simply put down
to human error. New approaches have emerged that offer insight to
the (bio) chemical engineer into process failure. In contrast to
traditional approaches, which we have titled Single Value Assessment
(SVA), process simulation is based on a distribution of values or
Monte Carlo Assessment (MCA). A Quantitative Risk Assessment (QRA)
is a statement of the probability of plant failure. It is hoped
this research will lead to a greater understanding of process failure
- and to an increased confidence and reliability in the design and
performance of unit operations.
Modelling of Chemical Residuals of Polychlorinated Dibenzo-p-dioxins,
Polychlorinated Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls
(PCBs) in Tuna:
Because of high lipophilicity, PCDD/Fs (dioxins) and PCBs can bioaccumulate
in the fatty tissue of fish. Feed baitfish is believed to be a major
source of dioxins and PCBs. The aim of this research is to develop
a quantitative through-chain predictive model for dioxins and PCBs
in tuna. Southern Bluefin Tuna (SBT) is an economically important
ranched marine finfish in South Australia. The framework for modelling
dioxins and PCBs in ranched SBT is being developed from a Quantitative
Risk Assessment (QRA). This is a first step to documenting residue
traceability for ranched SBT. A validated model derived from this
framework will provide increased confidence in international market
acceptance
Biological Filtration of Algal Metabolites:
The aim of this research is to develop a biological filter for removal
of cyanobacterial metabolites from drinking water. Focus is on 2-methylisoborneol
(MIB) and hepatotoxin microcystin. These commonly occur in surface
waters. Understanding the origin of the acclimatisation, or lag,
period of the filter and ways to minimise it are important in a
practical situation. We are looking at ways of seeding the filter
with selected degrading bacteria and introducing compounds which
are known to promote the degradation of the metabolites.
Filtration of Liquid Foods:
Diatomaceous earth is a form of volcanic clay that is widely used
as a filter-medium for the polishing of wines and the clarification
of beers. We are interested in the development of practical substitute
filter media as possible replacements. Our work continues to involve
extensive experimental investigations with both wine and beer. We
are interested in the development of alternative media, protocols
for media preparation and in the adequate simulation of process
conditions and practices using pilot plant.
Modelling the Effect of Combined Process Parameters on the Growth
and Death of Contaminating Bacteria:
An adequate mathematical model is an essential step to longer-term
process control and optimisation. Mathematical models therefore
have a central place in planning and design. We are interested in
the synthesis and application of kinetic models that include the
combined effect of a number of environmental factors in addition
to time, principally, T, pH and aw, to describe the behaviour of
contaminant micro-organisms. We are currently investigating the
thermal processing of liquids and the optimisation of models for
microorganism growth during packaging, storage and handling of foods.
Ultra High Pressure - Cold Pasteurisation:
Ultra High Pressure-Cold Pasteurisation (UHP-CP) (< 700 MPa,
< 35 0C) of microbial contaminants in vacuum-packed foods is
an emerging alternative to commercial thermal processing. Present
operating conditions however have evolved empirically. An over-estimate
of treatment will mean that there are actually more microbial survivors
than expected. This is potentially a serious risk to public health.
Our research focuses on the synthesis and validation of an adequate
mathematical process model. The research can be justified by an
increased reliability of operation and is a necessary first step
in the optimisation of UHP-CP technology.
UV Disinfection of Water:
Irradiation with ultraviolet light is an effective means for disinfection
of contaminating micro-organisms in potable water and wastewater.
We are interested in the performance characteristics of existing
equipment and in the geometry of reactor design for optimal processing.
This type of research can involve extensive experimental investigations
to help assess the value of key parameters characterising a particular
flow system. We are interested in the synthesis of mathematical
models which can describe the experimental results and which can
be used in computer simulations for appraisal of design and optimisation.
Value-Adding to Food Industry Wastes:
We are interested in investigating possible options to value add
to food-industry wastes, especially those derived from marine sources.
Nutraceuticals derived from marine sources have a commercial premium,
in contrast to synthesised alternatives. We are currently involved
in optimising supercritical CO2 extractions of material and in the
development of a process and economics model. This work is carried
out as a commercial and in confidence study in co-operation with
industry.
Previous Research Interests
Specialised instrument development
Textural and sensory measurement
Meat and related food chilling
Heavy metal contamination of water
Recent Publications
- Davey, K.R., Phua, S.T.G., "Letter to the Editor", Food
Microbiology, 22 2005) 483-487.
- 17. Patil, R. A., Davey, K. R. and Daughtry, B. J., "A New Quantitative
Risk Assessment Model of a Fermenter for Friday 13th Syndrome" Chemeca
2005, Smart Solutions - Doing More with Less" 25-28 September 2005,
Brisbane Queensland.
- 18. Phua, S.T.G., Davey, K.R., D.J. Daughtry, "Application of
a Modified Davey-Linear Arrhenius Model for high pressure (= 600
MPa) - Cold Pasteurisation of Vacuum Packed/Liquid Foods", Chemeca
2005, Smart Solutions - Doing More with Less 25-28 September 2005,
Brisbane Queensland.
- 19. Phua, S.T.G., Davey, K.R., D.J. Daughtry, "Framework for modelling
chemical residuals of Polychlorinated Dibenzo-p-dioxins, Polychlorinated
Dibenzofurans (PCDD/Fs) and Polychlorinated Biphenyls (PCBs) in
Australian Ranched Southern Bluefin Tuna (Thunnus maccoyii)", Chemeca
2005, Smart Solutions - Doing More with Less" 25-28 September 2005,
Brisbane Queensland
- Davey K R & Phua S T G 2005 Kinetic analysis of Escherichia
coli inactivation by high hydrostatic pressure in broth and foods.
Food Microbiology 22, 483-7.
- Amos S A, Davey K R & Thomas C J 2004 A new Weibull model
for prediction of tailing in UV disinfection survivor data. In:
Proc. 32nd Australasian Chemical Engineering Conference (Sustainable
Processes), CHEMECA 2004, Australian Technology Park, Sydney,
NSW, Australia, September 26-29, paper 106 (ISBN 1 877040126).
Selected Book Reviews
Davey K R 2005 Food Microbiology 22, 489-90.
McKellar R C and Lu X (Eds) 2004
Modelling Microbial Responses in Food
CRC Series in Contemporary Food Science, CRC Press, 343 pages
(ISBN 0 8493 1237 X)
Davey K R 2002 The Chemical Engineer October (2002), 57.
Venables J 2002
Communication Skills for Engineers and Scientists
3rd Edn, The Institution of Chemical Engineers, 99 pages (ISBN
0 85295 455 7)
Davey K R 2000 Transactions of the Institution of Chemical Engineers,
Part C, Food and Bio products Processing 78, 105.
Sharma S K, Mulvaney S J and Rizvi S S H 2000
Food Process Engineering - Theory and Laboratory Experiments
John Wiley & Sons, 348 pages (ISBN 0 471 32241 5)
Davey K R 1998 Transactions of the Institution of Chemical Engineers,
Part C, Food and Bio products Processing 76, 170.
Gardner J F and Peel M M (1988)
Sterilization, Disinfection and Infection Control
3rd Edn, Churchill Livingston, 267 pages (ISBN 0 443 05435 5)
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