RESUMEN
The composition of rock-painting pigments from Egypt (Gilf Kebia area) has been analyzed by means of molecular spectroscopy such as Fourier transform infrared and micro-Raman spectroscopy and scanning electron microscopy coupled to an energy dispersive X-ray spectrometer and X-ray fluorescence analysis. Red and yellow pigments were recognized as red and yellow ochre with additional rutile.
Asunto(s)
Colorantes/análisis , Pinturas/historia , Antiguo Egipto , Historia Antigua , Microscopía Electrónica de Rastreo , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Titanio/análisisRESUMEN
Composition of the prehistoric pigments' (from Carriqueo rock shelter, Rio Negro province, Argentina) has been analysed by means of molecular spectroscopy (Fourier transform infrared (FTIR) and micro-Raman) and scanning electron microscopy (SEM) coupled to an energy-dispersive X-ray spectrometer (EDS). Red and yellow pigments were recognized as red and yellow ochre. The matrix of the pigments is composed of one or more substances. According to the matrix composition yellow and red pigments were also divided into two groups-i.e. those containing kaolinite or sulphates. Green pigment was detected as green earth, made up of celadonite as a chromophore.
Asunto(s)
Colorantes/química , Espectrometría por Rayos X/métodos , Argentina , Geografía , Historia Antigua , Microscopía Electrónica de Rastreo , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría RamanRESUMEN
A total of 27 teeth were examined in those subjects having been exposed to ionizing radiation in doses between 0.5 and 2.0 Gy, together with ten teeth of essentially healthy individuals. The enamel, dentine and cement mineral and protein contents were studied versus control with the aid of infrared spectroscopy techniques. It has been ascertained that in the teeth of patients presenting with dose loads there take place changes in the organic matrix. Amide I: amide II ratio tends to diminish toward contribution of Amide I. The mineral composition of the enamel reveals practically no changes under exposure to radiation. The dentine and cement display clear-cut changes in the mineral component. There appear absorption bands that belong to more soluble forms of calcium phosphate, which fact suggests an active destructive process in underlying hard tissues of the teeth, that gets intensified under exposure to ionizing radiation.