Instrumental neutron activation analysis (INAA) was used to determine the Br and I concentration in the same ten lyophilized and homogenized human thyroid samples prior and after a 20-year storage at room temperature. It was found that long-term storage had no effect on the iodine content. At the same time, the bromine content was about 2-fold lower (p<0.01). It was assumed that possible losses of other halogens can occur under long-term storage of lyophilized biological materials at room temperature.
Authors:J. St-Pierre, R. Kada, G. Kennedy, J. Zayed, and P. Ghadirian
Neutron activation analysis of toenails is often used to monitor body selenium in studies looking for an association between
selenium deficiency and an increased cancer risk. In this study, 87 toenail samples were analyzed for Se four times, using
neutron activation with 17.4-second 77mSe, to determine the possible systematic effects of long-term storage, the washing procedure, and irradiation in a nuclear
reactor. The mean Se concentration found was 0.92 mg/g, standard deviation 0.14 mg/g. The results showed that the Se concentrations
are unaffected by washing and neutron irradiation, but the samples lost moisture during storage causing a 2% increase in the
mean Se concentration.
Authors:Santiago Varga, Carmen Diez, Lina Fernández, Jenny Álvarez, Adelino Katchicualula, Carlos Hidalgo, Carolina Tamargo, and Maite Carbajo
de la Varga, S., Díez, C., Alvarez, E., Fernández, A., Fernández, L. and Carbajo, M. (2005): Freezing or lyophilization as tools for the long-termstorage of a bovine embryo culture medium. Reprod. Domest. Anim. 40 , 384 (Abstr
decomposition of smokeless fireworks made by waste single base propellant are wholly gaseous and these products are pollution free, tasteless, and safe [ 2 ]. However, many problems, like the stabilizer's volatilization during long-termstorage, the probability
Stability of mineral mixed fertilizers processed by effective mixing
and compaction, using extrusion technology, is a subject of this study. As
new products there is a need to learn the possible changes in the phase ratios
and caking processes during long term storage. 7 samples with different nutrient
components ratios are investigated after one year kept in a storage facility
Applying TG-DTA, electron microscopy and
X-ray diffraction methods samples are studied, recording thermal effects and
mass losses, type of crystal structures and phase content in the sample. On
the base of the results obtained the relationships are discussed and conclusions
made about the possibility to safety storage and visible application of the
new products as fertilizers in the agriculture for nut ratio of different
plant. It is confirmed that the investigated samples, produced on the base
of low grade phosphates are stable during long term storage and they could
be successfully recommended for practical use in agriculture, using traditional
or individual method of fertilization.
Authors:E. Dadáková, N. Vrchotová, Š. Chmelová, and B. Šerá
Black elder inflorescence has been traditionally used in Central Europe both in folk and official medicine. This plant material is a rich source of two biologically active components, rutin and chlorogenic acid. Nevertheless, there is a lack of data on the changes of their content during processing.The stability of rutin and chlorogenic acid during drying and the long-term storage of black elder inflorescence were analysed in this study. The rutin content was determined by capillary electrophoresis using solid-phase extraction. HPLC was used for the determination of chlorogenic acid. The dependence of rutin and chlorogenic acid content on the temperature of drying and storage duration were monitored and statistically evaluated by a two-way ANOVA test. The contents of rutin and chlorogenic acid revealed no statistically significant changes when dried at temperatures of 22 °C and 30 °C. The significant decrease in contents of both studied compounds was found at a drying temperature of 50 °C. The decrease in content of rutin was about 20%, in chlorogenic acid about 12%.The content of both studied compounds also decreased after long-term storage (at a temperature of 22 °C for one year). The decrease in content of rutin was greater than that of chlorogenic acid.
Adsorption studies of thorium and uranium radionuclides on 9 different pure clay minerals and 4 local Malaysian soil sediments
were conducted. Solution containing dissolved thorium and uranium at pH 4.90 was prepared from concentrate sludges from a
long term storage facility at a local mineral processing plant. The sludges are considered as low level radioactive wastes.
The results indicated that the 9 clay minerals adsorbed more uranium than thorium at pH ranges from 3.74 to 5.74. Two local
Malaysian soils were observed to adsorb relatively high concentration of both radionuclides at pH 3.79 to 3.91. The adsorption
value 23.27 to 27.04 ppm for uranium and 33.1 to 50.18 ppm for thorium indicated that both soil sediments can be considered
as potential enhanced barrier material for sites disposing conditioned wastes containing uranium and thorium.
Long-term investigations of the phase structure and pore structure of nitrocellulose and sym-diethyldiphenylurea (C1) mixtures were conducted for samples with C1 mass fractions wC1=0.5, 0.6 and 0.8. The distribution of pore sizes and the composition of the nitrocellulose matrix were determined based on
the melting enthalpy of C1. The three kinds of pores was observed with the characteristic size of about 7, 14 and 28 nm. Long-term
storage of mixtures caused an increase in size of the smallest pores and a decrease of C1 concentration in the nitrocellulose
matrix. The mechanism of changes in pore sizes is presented in term of multi-sheet model of NC fiber.
Authors:Silvia Dulanská, Milan Meloun, and Lubomír Mátel
The decommissioning of the nuclear power plant (NPP) A1 Jaslovské Bohunice (Slovakia) is a complicated set of problems that
is highly demanding both technically and financially. The basic goal of the decommissioning process is the total elimination
of radioactive materials from the nuclear power plant area, and radwaste treatment to a form suitable for its safe disposal.
The initial conditions of decommissioning also include elimination of the operational events, preparation and transport of
the fuel from the plant territory, radiochemical and physical–chemical characterization of the radioactive wastes. One of
the problems was and still is the processing of the liquid radioactive wastes. Such media is also the cooling water of the
long-term storage of spent fuel. A suitable scaling model for predicting the activity of hard-to-detect radionuclides 239,240Pu, 90Sr and summary beta in cooling water using a regression triplet technique has been built using the regression triplet analysis
and regression diagnostics.