The big problem of small particles : a comparison of methods for determination of particle size in nanocrystalline anatase powders

We compare different methods for particle size determination in nanocrystalline anatase (TiO2) powders: transmission electron microscopy (TEM), nitrogen adsorption measurements, mercury porosimetry, and X-ray diffraction(XRD). The main source of errors in TEM is the sampling of the powder population, whereas in XRD the deconvolution of peak broadening due to instrument, microstrains, and crystalline domain size is delicate and can lead to unreliable results. Different approaches including Scherrer and Williamson-Hall equations are discussed. The presence of mesopores due to agglomerate formation is clearly revealed in adsorption measurements and porosimetry

Materials requirements for improved design and operation in high temperature

Internet address: http://www.cram.enel.it target=NewWindow>www.cram.enel.itConsiglio Nazionale delle Ricerche - Biblioteca Centrale CNR, 7, Rome; ENEL S.p.A., Via A. Volta, 1 Cologno Monzese / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Value of CT scanning in the diagnosis of CNS mycotic involvement : report of 3 cases

Fungal infections of the CNS are becoming an increasingly serious problem in immunosuppressed patients. We describe three patients with malignant blood disease who in the course of systemic fungal infection presented cerebral involvement. The nature, site and extent of the cerebral involvement were defined by computed tomography (CT). Further, in one patient it was possible to follow the course of the lesion and assess the effectiveness of antimycotic therapy by CT because of its noninvasiveness and repeatability