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Novel two-step processing route combining mechanical alloying and microwave hyb...

In this work, microwave hybrid sintering at 1300 and 1350 °C was carried out for densification of La9.33Si2Ge4O26 mechanically alloyed powder with apatite structure. The pellets sintered at these two temperatures present the same structure (apatite) with relative densities of 92 and 96%, respectively. Mechanical analysis performed on sintered materials revealed the following results: hardness of 7.1 and 8.0 GPa...

On the influence of silica type on the structural integrity of dense La9.33Si2G...

Apatite-type rare earth based oxides, such as R-doped lanthanum oxides of general formula La9.33(RO4)6O2 with R = Ge, Si, exhibit high ionic conductivity and low activation energy at moderate temperatures, when compared to the yttria-stabilized zirconia electrolyte making them potential materials to be used in the range 500–700 °C, for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this study, d...

Effect of the sintering conditions on the morphology of La9.33Si2Ge4O26 oxyapat...

Solid oxide fuel cells (SOFCs) are devices that allow direct conversion of chemical to electrical energy through an electrochemical reaction in a cleaner and more efficient way than conventional processes (eg. gas turbines). They are characterized by the use of a solid oxide material as the electrolyte. Yttria-stabilised zirconia (YSZ) has traditionally been used in SOFCs electrolytes at temperatures in the ra...

Microscopy techniques for dye distribution in DSCs nanocrystalline TiO2 films

Segmentation of Female Pelvic Organs in Axial Magnetic Resonance Images using C...

The segmentation of pelvic structures in magnetic resonance (MR) images of the female pelvic cavity is a challenging task. This paper proposes the use of three novel geometric deformable models to segment the bladder, vagina and rectum in axial MR images. The different imaging appearances and prior shape knowledge are combined into a level set framework as segmentation cues. The movements of the contours are co...

A level set based algorithm to reconstruct the urinary bladder from multiple views

The urinary bladder can be visualized from different views by imaging facilities such as Computerized Tomography and Magnetic Resonance Imaging. Multi-view imaging can present more details of this pelvic organ and contribute to a more reliable reconstruction. Based on the information from multi-view planes, a level set based algorithm is proposed to reconstruct the 3D shape of the bladder using the cross-sectio...

Synthesis and thermal behavior of La9.33Si2Ge4O26 apatite for SOFCs

Powders of La2O3, GeO2 and SiO2 were dry milled in a planetary ball mill with different rotation speeds (150–350 rpm) and increasing milling times up to 35 h in order to obtain the La9.33Si2Ge4O26 apatite phase at room temperature. The results showed that the higher the rotation speed the lower the time required for the formation of the apatite phase. No reaction between the starting powders was observed at 150...

Mechanical properties of sintered La9.33Si2Ge4O26 oxyapatite materials for SOFC...

Mechanical properties of La9.33Si2Ge4O26 prepared by mechanical alloying and subsequent sintering at 1300–1400 °C for 1 h were evaluated. Hardness and Young's modulus values in the range 7.3–9.6 GPa and 106–135 GPa, respectively, were obtained from nanohardness tests. The fracture toughness values derived from the Palmqvist method varied between 3.5 and 3.9 MPa m1/2 from classical microindentation test with an ...

Segmentation of Female Pelvic Cavity in Axial T2-weighted MR Images towards the...

The anatomies of pelvic structures are critical for the diagnosis of pelvic floor dysfunctions. However, because of the complex background, the imaging appearances of pelvic organs and muscles are frequently distorted by noise and partial volume effect. Magnetic resonance imaging with its clear imaging quality of the female pelvic cavity is preferred for many studies. As such, correct segmentations of the pelvi...

An Approach on Determining the Displacements of the Pelvic Floor during Volunta...

The present study was conducted in order to establish a methodology based on the finite element method to simulate the contraction of the pelvic floor (PF) muscles. In the generated finite element model, a downward pressure of 90 cm H2O was applied, while actively contracting the PF muscles with different degrees of muscular activation (10, 50 and 100%). The finite element methodology of the active contraction ...