Sequence of phase transformations in metastable ß Zr–12Nb alloy studied in situ by HEXRD and complementary techniques

Phase transformations in a metastable beta Zr–12Nb alloy were investigated by high-energy X-ray diffraction (HEXRD) measured simultaneously with thermal expansion in situ during linear heating from room temperature to 800 °C. Complementary in-situ methods of electrical resistance and differential scanning calorimetry, which were performed using the same heating conditions as in the HEXRD experiment, provided additional information on the transformation sequence occurring in the Zr–12Nb alloy. Two bcc phases with a different lattice parameter, ßZr and ßNb, were observed in the investigated temperature range and identified using the phase diagram of the Zr–Nb system. In the initial solution-treated condition, metastable ßZr phase and athermal ¿ particles are present in the material. At about 300 °C, Nb-rich ßNb phase starts to form in the material and the original ßZr phase gradually disappears. Ex-situ observations of the microstructure using transmission electron microscopy revealed a cuboidal shape of the ¿ particles, which is related to a relatively large misfit between the ¿ and ß phases. At 560 °C, ¿ solvus was observed, identified by an abrupt dissolution of ¿ particles which was followed by growth of the a phase.Peer ReviewedPostprint (published version

Clinical Experience of Stereotactic Radiosurgery at a Linear Accelerator for Intraocular Melanoma Combined with Iridociliary Tumor Resection: A Case Report

Introduction: The treatment of iridociliary and choroidal melanoma relies on the patient’s systemic health, tumor size, location, related features, state of the opposing eye, and personal preferences. The two categories are radiation and surgical techniques. Transpupillary thermotherapy, plaque radiotherapy, charged particle irradiation, local resection, enucleation, orbital exenteration, and experimental nanoparticle therapy are all options for treating choroidal melanoma. Case Presentation: The method that entails creating a partial thickness circular, rectangular, or polyhedral scleral flap in the region covering the tumor after removing a portion of the extraocular muscles is the most popular method for local excision in choroidal or choroidal-ciliary body cancers. We discuss our experience treating iridociliary melanoma using block excision and stereotactic irradiation on a linear accelerator with TD 20.0 Gy. Conclusion: One of the treatment modalities is the combined treatment approach using stereotactic irradiation and tumor resection, and our results 1 year after therapy are comparable to the rates of local control and anatomic eye preservation to those achieved in studies of comparable uveal melanoma treatment modalities

Highly Textured Seed Layers for the Growth of Vertically Oriented ZnO Nanorods

One dimensional ZnO nanostructures prepared by favorable and simple solution growth methods are at the forefront of this research. Vertically oriented ZnO nanorods with uniform physical properties require high-quality seed layers with a narrow size distribution of the crystallites, strong c-axis orientation, and low surface roughness and porosity. It has been shown that high quality seed layers can be prepared by the sol–gel process. The sol–gel process involves three essential steps: preparation of the sol, its deposition by dip coating, and thermal treatment comprising preheating and annealing. We put emphasis on the investigation of the heat treatment on the properties of the seed layers and on the vertical alignment of the nanorods. It was demonstrated that for the vertical alignment of the nanorods, the preheating step is crucial and that the temperatures reported in the literature have been too low. With higher preheating temperatures, conditions for the vertical alignment of the nanorods were achieved in both investigated annealing atmospheres in air and in argon