Authors:J. Santos, C. Munita, M. Valério, C. Vergne, and P. Oliveira
Instrumental neutron activation analysis (INAA), have been used for the definition of compositional groups of potteries from
Justino site, Brazil, according to the chemical similarities of ceramic paste. The outliers were identified by means of robust
Mahalanobis distance. The temper effect in the ceramic paste was studied by means of modified Mahalanobis filter. The results
were interpreted by means of cluster, principal components, and discriminant analyses. This work provides contributions for
the reconstruction of the prehistory of baixo São Francisco region, and for the reconstitution of the Brazilian Northeast
ceramist population of general frame.
Authors:J. Kvicala, V. Zamrazil, J. Nemecek, and J. Jiranek
To estimate the status of selenium in seniors of the South Bohemia region, Czech Republic, 481 serum samples from seniors
living in 17 Asylum Houses for seniors in the age between 60 and 99 years were obtained. Samples were analyzed by instrumental
neutron activation analysis with concurrent analysis of 4 reference materials for quality assurance. Average concentration
of serum Se, arithmetic means in individual Asylum Houses, frequency distribution of serum Se concentrations as well as five
years running monitoring of serum Se concentrations of one group of seniors proved selenium deficiency of the elderly population
of the region South Bohemia.
Authors:M. Mason, J. Morris, V. Spate, C. Baskett, T. Nichols, T. Horsman, L. Le Marchand, L. Kolonel, and S. Yukimoto
The measurement of dietary selenium intake in a free-living population using dietary recall techniques has been shown to be
spurious. Consequently, in our laboratory, we have focused on the development of biologic monitors such as blood, nails, hair
and urine. In this paper, we report on the neutron activation analysis of whole blood, plasma and nail specimens collected
from 285 Caucasian subjects, all permanent residents of Hawaii, participating in a malignant melanoma trial. Correlations
between monitors are presented and discussed in the context of selenium determinants and integration of selenium intake.
Authors:J. Morris, R. Ngwenyama, J. Guthrie, J. Brockman, V. Spate, and J. Robertson
Instrumental neutron activation analysis is routinely used at the MURR to quantify selenium in prospectively-collected biologic
markers including blood serum and toenails. These specimens are typically collected from well-defined cohort populations participating
in investigations assessing selenium intake and incidence of chronic disease endpoints. These epidemiological investigations,
whether observational (case-control) or clinical (intervention), typically generate thousands of samples. The purpose of this
paper is to assess, through evaluation of quality control results, if the achievable accuracy and precision in the measurement
of selenium using NAA is adequate to determine a relative risk of 1.2 at high confidence in epidemiological studies.
Authors:A. Delben, F. Menezes, J. Delben, M. Coelho, and R. Ribeiro
Waste compromises environmental preservation as well human health in
many countries. Recycling is an alternative that sometimes represents the
only economical activity for a significant population in the big cities. Almost
3% of waste materials in Brazil are vitreous. Ceramic production adding waste
glass is possible with advantages of costs reduction associated to decrease
on firing temperatures and to the raw material itself. At present paper up
to 80 mass% of waste glass was added to clay. The sintering temperature decreased
linearly and the shrinkage increased with glass content, an effect more pronounced
for high glass amount.
Authors:Sandra Babić, Alka Horvat, and Marija Kaštelan-Macan
A method for optimization of a TLC separation based on use of a genetic algorithm is described. The procedure was tested by optimization of the reversed-phase HPTLC separation of a mixture of six pesticides and satisfactory optimum results were obtained. The performance of the genetic algorithm was tested by measurement of the number of generations, the population size, the mutation probability, and the crossover probability. Three separation criteria (
**) were examined as fitness functions. The genetic algorithm was compared with the simplex method.
Authors:N. Aras, G. Yilmaz, F. Korkusuz, I. Olmez, B. Sepici, F. Eksioglu, and P. Bode
Bone samples from iliac crest were obtained from apparently healthy female (n = 4) and male (n = 8) subjects with ages between 15–50. Cortical and trabecular parts were separated and soft tissues like fat, muscle and blood were removed. Calcium, Mg, Na, Cl, Fe, Zn, Br, Sr, and Cs were determined by instrumental neutron activation analysis and other techniques, and their relations were discussed. Fairly good agreement was obtained with literature data. These values may serve as reference values for subjects from a Turkish population.
Authors:T. Cheng, J. Morris, S. Koirtyohann, V. Spate, and C. Baskett
Toenail samples were collected from 129 carpenters (average age 47). The bone and blood lead data for these carpenters have shown a broad range of lead-level exposure in this population. A total of 28 elements were measured in the sample set by a combination of instrumental neutron activation analysis (INAA) and graphite furnace atomic absorption spectrometry (GFAAS) methods. Of the elements measured, only Co, Cr, Fe, Na, Cd, Cu, F, and Ni were significantly correlated with lead. A statistical treatment of the overall data set, including principal component analysis, was further applied in an attempt to correlate the elements in the samples.
Authors:Tran Thiep, Truong An, Nguyen Khai, Nguyen Vinh, Phan Cuong, I. Gangrski, I. Penhionzkevich, G. Mishinski, and V. Zemenhik
The ratio of the probabilities of population of the isomeric and ground states, so called the isomeric ratio is closely connected
to the angular momentum of the initial fission fragments that is dissipated at the later stages of gamma ray cascade. This
ratio also provides important information on the nuclear level structure as well as the nuclear reaction mechanism involved.
In this work, the isomeric ratio in fission fragment 135Xe from photofission of 233U induced by 23.5 MeV bremsstrahlung has been determined by the method that uses inert gaseous flow. The results have been
discussed and compared with that of other authors.
Authors:R. C. Eerlingen, H. Jacobs, H. Van Win, and J. A. Delcour
Gelatinisation temperatures as a function of moisture content were determined for potato starch. The native starch was then hydrothermally treated at a temperature 3% (Kelvin degrees) below the gelatinisation peak temperature and at moisture levels varying from 20 to 67% (by weight). Gelatinisation temperatures, temperature ranges and enthalpy values were affected for all treated samples. However, two sample populations could be distinguished: those samples treated under ‘limited’ moisture conditions and other samples treated in the presence of ‘extragranular’ moisture. A two-step hydrothermal treatment further increased the gelatinisation temperature, but the effect of the second step was small in comparison to that of the first.