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1.
Appl Radiat Isot ; 67(1): 212-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18789709

RESUMO

Apart from the linear monitoring studies concerning the relationship between radon and earthquake, an artificial neural networks (ANNs) model approach is presented starting out from non-linear changes of the eight different parameters during the earthquake occurrence. A three-layer Levenberg-Marquardt feedforward learning algorithm is used to model the earthquake prediction process in the East Anatolian Fault System (EAFS). The proposed ANN system employs individual training strategy with fixed-weight and supervised models leading to estimations. The average relative error between the magnitudes of the earthquakes acquired by ANN and measured data is about 2.3%. The relative error between the test and earthquake data varies between 0% and 12%. In addition, the factor analysis was applied on all data and the model output values to see the statistical variation. The total variance of 80.18% was explained with four factors by this analysis. Consequently, it can be concluded that ANN approach is a potential alternative to other models with complex mathematical operations.


Assuntos
Terremotos , Redes Neurais de Computação , Radônio/análise , Algoritmos , Tempo
2.
Bioresour Technol ; 84(3): 283-6, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12118707

RESUMO

In this study, the kinetics of disappearance of radioactivity in aerobic composting was investigated. For this purpose, compost materials were prepared by mixing sugar beet wastes, wine factory wastes (grape wastes), straw and biological treatment sludge in different amounts. While alpha-radioactivity was not initially detected in all composting materials, the composting materials had some beta-radioactivity. In the mixtures of sugar beet wastes--straw-biological treatment sludge (1), sugar beet wastes-wine factory wastes (grape wastes)-biological treatment sludge (II) and wine factory wastes (grape wastes)-biological treatment sludge (III), the beta-radioactivity reduced by 82%, 58%, 85% respectively of initial values after 52 d. The beta-radioactivity degradation in the composting process could be represented by first-order kinetics and reaction rate constants of mixtures of I, II and III were k = 0.0693 d(-1) (R2 - 0.84), k = 0.0453 d(-1) (R2 = 0.98), k = 0.0234 d(-1) (R2 = 0.97), respectively.


Assuntos
Biodegradação Ambiental , Radioisótopos , Eliminação de Resíduos/métodos , Beta vulgaris , Biotecnologia/métodos , Concentração de Íons de Hidrogênio , Cinética , Resíduos Radioativos , Radioatividade
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