Abstract: The performances of nuclear fuels and materials are qualified at an irradiation system in research reactors operating under the commercial nuclear power plant conditions. Fuel centerline temperature, coolant temperature, neutron flux, deformations of fuel stack and swelling are important parameters needed to analyze the nuclear fuel performances. The dimensional stability of nuclear fuels is a key parameter measuring the fuel densification and swelling. In this study, the fuel stack elongation is measured using a LVDT. A mockup LVDT instrumented fuel rod is developed. The performances of mockup LVDT instrumented fuel rod is evaluated by experiments.
Abstract: Sisal leaves were subjected to enzymatic retting
method to extract the sisal fibre. A portion of the fibre was pretreated
with alkali (NaOH), and further treated with benzoyl chloride
and silane treatment reagents. Both the treated and untreated Sisal
fibre composites were used to fabricate the composite by hand lay-up
technique using unsaturated polyester resin. Tensile, flexural, water
absorption, density, thickness swelling and chemical resistant tests
were conducted and evaluated on the composites. Results obtained
for all the parameters showed an increase in the treated fibre
compared to untreated fibre. FT-IR spectra results ascertained the
inclusion of benzoyl and silane groups on the fibre surface. Scanning
electron microscopy (SEM) result obtained showed variation in the
morphology of the treated and untreated fibre. Chemical modification
was found to improve adhesion of the fibre to the matrix, as well as
physico-mechanical properties of the composites.
Abstract: Cross-linked konjac glucomannan and kappa
carrageenan film were prepared by chemical crosslinking using
glutaraldehyde (GA) as the crosslinking agent. The effect
crosslinking on the swelling degree was investigated. Konjac
glucomannan and its mixture with kappa carrageenan film was
immersed in GA solution and then thermally cured. The obtained
cross-linked film was washed and soaked in the ethanol to remove
the unreacted GA. The obtained film was air dried at room
temperature to a constant weight. The infrared spectra and the value
of swelling degree of obtained crosslinked film showed that
glucomannan and kappa carrageenan was able to be cross-linked
using glutaraldehyde by film immersion and curing method without
catalyst. The cross-linked films were found to be pH sensitive,
indicating a potential to be used in drug delivery polymer system.
Abstract: A finite element analysis was conducted to determine
the effect of moisture diffusion and hygroscopic swelling in rice. A
parallel simple stochastic modeling was performed to predict the
number of grains cracked as a result of moisture absorption and
hygroscopic swelling. Rice grains were soaked in thermally (25 oC)
controlled water and then tested for compressive stress. The
destructive compressive stress tests revealed through compressive
stress calculation that the peak force required to cause cracking in
grains soaked in water reduced with time as soaking duration was
extended. Results of the experiment showed that several grains had
their value of the predicted compressive stress below the von Mises
stress and were interpreted as grains which become cracked and/or
broke during soaking. The technique developed in this experiment
will facilitate the approximation of the number of grains which will
crack during soaking.