Abstract: Calcium fluoroaluminosilicate glasses (CAS) are used in the formulation of glass ionomer cements for dental applications. However, the cements obtained from CAS glasses were found to be radiolucent. In this study, the influence of substituting Zn, Sr and Mg for Ca of CAS glasses was investigated with respect to the structure and setting characteristics, mechanical properties, and radiopacity of cements designed for luting applications. Three glass compositions based on substitution of Zn, Sr and Mg for Ca at 1:1 molar ratio was synthesized. They were coded as the G 021 (Ca: Zn), G 022 (Ca: Sr), G 023 (Ca: Mg). G 021 and G 022 glasses were processed by conventional melt quench route, whereas G 023 was processed by microwave melt–quench route. Each glass was then mixed with Fuji Type I GIC liquid in order to evaluate the properties of novel cements at different powder/liquid ratios. X-ray diffraction and Fourier Transform-Infrared spectroscopy analysis confirmed the structure of the processed glasses. The average particle size of the processed glass powders was within specification limits for luting applications (<15 μm). The substitution of Zn, Sr and Mg for Ca at 1:1 molar ratio increased the reactivity of the respective glasses. This has been reflected in their respective setting characteristics and mechanical properties. The optimal combination of setting time, strength and radiopacity for the cements examined here was shown by G 022 cements. The microwave melting can be utilized for processing ionomer glasses as it did not alter the structure and properties of G 023 cement.
Abstract: BaTiO3 (BT) and Ni0.5Zn0.5Fe2O4 (NZF) ceramic disc specimens were prepared using commercial grade powders sintering by conventional (CV) and microwave (MW) sintering techniques. In both the sintering techniques the set sintering temperatures were in the range of 850 °C to 1000 °C and time from 0.5 to 2 h. Structure, microstructure, dielectric, ferroelectric and magnetic properties have been compared for the as sintered BT and NZF ceramic specimens. Comparatively large grain size and higher density observed for the samples sintered at same temperature and shorter holding time using microwave. Magnetic properties of the NZF samples sintered using MW at a temperature of 950 °C show a higher saturation magnetization (Ms) value of 88 emu/g.
Abstract: Viability of the continuous-flow synthesis of rhomboidal copper(II) oxide (CuO) micro- and nanonoparticles was demonstrated. It has been shown that ultrasonic mixing of reactants, in the stage of Cu(OH)2 synthesis, followed by microwave irradiation of the resulting suspension, gives very fine particles of CuO at high yield and within minutes. Near optimal parameters for the synthesis of fine particles in the continuous reactor were determined.
Abstract: Imagery-based 3D scanning can be performed by scanners with multiple form factors, ranging from small and inexpensive scanners requiring manual movement around a stationary object to large freestanding (nearly) instantaneous units. Small mobile units are problematic for use in scanning living creatures, which may be unwilling or unable to (or for the very young and animals, unaware of the need to) hold a fixed position for an extended period of time. Alternately, very high cost scanners that can capture a complete scan within a few seconds are available, but they are cost prohibitive for some applications. This paper seeks to assess the performance of a large, low-cost 3D scanner, presented in prior work, which is able to concurrently capture imagery from all around an object. It provides the capabilities of the large, freestanding units at a price point akin to the smaller, mobile ones. This allows access to 3D scanning technology (particularly for applications requiring instantaneous imaging) at a lower cost. Problematically, prior analysis of the scanner’s performance was extremely limited. This paper characterizes the efficacy of the scanner for scanning both inanimate objects and humans. Given the importance of lighting to visible light scanning systems, the scanner’s performance under multiple lighting configurations is evaluated, characterizing its sensitivity to lighting design.
Abstract: Microwave energy can be used for the processing of a wide variety of materials. It is used most commonly for the heating of food and has been increasingly applied for processing of polymers; ceramics; metals; minerals and composites. The use of microwave energy allows rapid and volumetric heating where heat is generated from within the material instead of via radiative heat transfer from external heating elements. This paper aims to provide a review on the use of energy efficient and environment friendly microwave energy route to synthesize magnesium based materials reinforced with various types of metallic and ceramic reinforcements. Magnesium composites are extremely attractive for weight critical applications in automotive; aerospace; electronics and transportation sectors. The magnesium composites were prepared using blend—compact—microwave sintering—extrusion methodology. Microwave sintering allowed a significant reduction of 80% in both processing time and energy consumption over conventional sintering without any detrimental effect on the properties of the synthesized magnesium composites. Physical; microstructure and mechanical properties of microwave sintered magnesium composites will also be discussed and compared with magnesium composites processed by conventional liquid and solid processing techniques.
Abstract: Over the last decade, Medical Imaging has become an essential component in many fields of bio-medical research and clinical practice. Biologists study cells and generate 3D confocal microscopy data sets, virologists generate 3D reconstructions of viruses from micrographs, radiologists identify and quantify tumors from MRI and CT scans, and neuroscientists detect regional metabolic brain activity from PET and functional MRI scans. On the other hand, Image Processing includes the analysis, enhancement, and display of images captured via various medical imaging technologies. Image reconstruction and modeling techniques allow instant processing of 2D signals to create 3D images. In addition, image processing and analysis can be used to determine the diameter, volume, and vasculature of a tumor or organ, flow parameters of blood or other fluids, and microscopic changes that have not previously been discernible.[...]