Summary of Activities at WSU in 2002

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Summary of Activities at WSU in 2002 1. Improved
heating block systems 2. Thermal death kinetics
studies (Beetles and Medflies) 3. Dielectric
property measurements 4. Temperature uniformity
study in RF systems 5. Differential heating of
insects in walnuts and almonds 6. Improved IFAFS
website design 7. Cherry work at Yakima and
Wenatchee
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1. Improved WSU heating block system
The improved heating block system developed at WSU
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1. Improved WSU heating block system (cont.)

• Top and bottom plate temperatures of the HBS
  when heated to different final temperatures at a
  rate of 15C/min

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2. Thermal death kinetics studies (Medflies)
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2. Thermal death kinetics studies (Medflies)
TDT curve of 5th-instar Indianmeal moth (IMM),
codling moth (CM) and navel orangeworm (NOW),
3rd-instar and egg medfly
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3. Dielectric property measurements
Dielectric loss factor of grapefruit (?) and
orange (?) at 20C (mean of two replicates)
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3. Dielectric property measurements
Dielectric loss factor of Mexican fruit fly
larvae (?), Medfly larvae (?) and eggs (?) at 20C
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3. Dielectric property measurements
27MHz
915 MHz
Dielectric loss factor of Mexican fruit fly
larvae (?), Medfly larvae (?), and medfly egg
(?) as a function of temperatures at 27 and 915
MHz
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3. Dielectric property measurements
27MHz
915 MHz
Dielectric loss factor of Mexican fruit fly
larvae (?), Medfly larvae (?), and medfly egg
(?) as a function of temperatures at 27 and 915
MHz
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3. Dielectric property measurements
Dielectric loss factor (?) of almonds and
walnuts at 27 MHz as a function of temperature
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4. Temperature uniformity study in RF systems
Temperature uniformity setup of the 24-cups in RF
system
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4. Temperature uniformity study in RF systems
Schematic view of water container for
temperature uniformity study (all units are in
cm)
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4. Temperature uniformity study in RF systems
Temperature uniformity setup of the 24-cups
recorded by a data logger after RF heating
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4. Temperature uniformity study in RF systems
Temperature distribution when the gap was
180mm after 275s RF heating
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4. Temperature uniformity study in RF systems
Temperature distribution for 16 cups when the gap
was 180mm
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4. Temperature uniformity study in RF systems
Temperature distribution for 4 cups when the gap
was 180mm
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4. Temperature uniformity study in RF systems
Improved temperature uniformity in 24 cups for
the new design
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4. Temperature uniformity study in RF systems
Walnut surface temperature distribution in a
container (40X27X12cm) measured by thermal imaging
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4. Temperature uniformity study in RF systems
2 layers with I0.5A
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4. Temperature uniformity study in RF systems
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4. Temperature uniformity study in RF systems
Walnut temperature difference between vertical
and horizontal orientations on a single layer
with I0.6A
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4. Temperature uniformity study in RF systems
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5. Differential heating of insects in walnuts
Temperature profiles of walnut kernels and
codling moth slurry when subjected to 27 MHz RF
system
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5. Differential heating of insects in walnuts
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5. Differential heating of insects in walnuts
915MHz
27MHz
Predicted temperature difference between insects
and walnuts as a function of dielectric loss
factor ratios and heat transfer coefficients
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5. Differential heating of insects in walnuts
Mortality comparison of 5th instar codling moth
between RF treatments on infested walnuts and
heating block tests
Source Wang et al., 2001. Postharvest Bio.
Technol., 22, 29-38.
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Publications in 20021. Wang S., Tang J., Johnson
J.A., Mitcham E., Hansen J.D., Hallman G., Drake
S.R., Wang Y., 2002. Dielectric properties of
fruits and insects as affected by temperatures.
Biosystems Engineering, in review.2. Johnson
J.A., Wang S. and Tang J. 2002. Thermal death
kinetics of fifth-instar Plodia interpunctella
(Lepidoptera Pyralidae). Journal of Economic
Entomology, Accepted.3. Wang S., Tang J.,
Johnson J.A., Mitcham E., Hansen J.D., Cavalieri
R, Bower J., Biasi B., 2002. Process protocols
based on radio frequency energy to control field
and storage pests in in-shell walnuts.
Postharvest Biology and Technology, 26(3)
265-273.4. Wang S., Ikediala J.N., Tang J., and
Hansen J., 2002. Thermal death kinetics and
heating rate effects for fifth-instar codling
moths (Cydia pomonella (L.)). Journal of Stored
Products Research, 38(5) 441-453.5. Wang S.,
Tang J., Johnson J.A. and Hansen J., 2002.
Thermal death kinetics of fifth-instar navel
orangeworms (Lepidoptera Pyralidae). Journal of
Stored Products Research, 38(5) 427-440.6.
Ikediala J.N., Hansen J., Tang J., Drake S.R. and
Wang S., 2002. Development of saline-water-immersi
on technique with RF energy as a postharvest
treatment against codling moth in cherries.
Postharvest Biology and Technology, 24(1) 25-37.
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New people joined WSU group
Dr. Xinming Yin Mr. Sohan Birla
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Thanks!
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Prediction models based on the efficacy study
both in CA and WA cherries (from Jim) as compared
with the model obtained from the HBS log(time)
12.41-0.23xTemp, R20.996
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Relationship between lethal time (LT) and dead
() of CM by observation and kinetic study
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IFAFS work in 2001-2002 -Determined the thermal
death kinetics of insects -Determined the
temperature dependent dielectric
property -Determined the differential heating of
codling moths in walnuts and
almonds -Established the quality curve for
cherries in water bath -Determined codling moth
efficacy in cherries using water bath -Developed
walnut process protocols -Started insect
mortality work on med fruit flies, beetles. ??
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Future IFAFS work proposed in 2003-2004 - Help
industry to implement walnut process protocol -
Develop process protocols for almonds and
pistachios (?) - Determine the temperature
uniformity of fresh fruits in RF system -
Continue the insect thermal death kinetics
studies