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We have studied the energy recovery effect in high-temperature furnace using a high-emittance fiber (HEF) unit. Previous studies have shown that energy recovery effect occurs as placing the HEF unit perpendicular to the gas flow. However, there are some problems such as clogging and pressure loss. In this study, we examined the energy recovery effect and mechanisms of the effect when HEF unit placed in parallel to the gas stream. In the numerical simulation based on thermo-fluid dynamics, energy recovery effect was also appeared even though the HEF unit placed parallel to the gas flow. The simulation, confirm that most of thermal radiation through the exhausted pipe from the inside of furnace is absorbed by HEF unit and is emitted back to the furnace. This simulation indicated more than 10% input power reduction is expected. We also reveal that amount of energy conservation is depend on the HEF unit’s length, position, and number of plates in a unit. In the experiment using similar furnace to simulation model, we can also obtain the input power reduction by 3.5% at 1073 K.

Single crystals of the title compound, calcium neodymium ruthenate, (CaxNd11-x)Ru4O24 (x = 4.175), have been grown by the flux method. The structure consists of two crystallographically independent RuO6 octahedra, which are isolated from each other and embedded in a matrix composed of the Ca and Nd atoms. There are seven M sites which accommodate the Ca and Nd atoms with different populations. Four M sites at general positions are enriched with Nd, whereas the remaining three M sites on twofold rotation axes are enriched with Ca. The coordination numbers of O atoms to the M sites range from 6 to 9. The mean oxidation state of Ru was estimated at +4.79 from the composition analysis. The title compound is non-centrosymmetric and potentially multiferroic.

Single crystals of the title compound, strontium tetrapraseodymium tris(silicate) oxide, SrPr4(SiO4)3O, have been grown by the self-flux method using SrCl2. The structure is isotypic with the apatite supergroup family having the generic formula IXM12VIIM23(IVTO4)3X, where M = alkaline earth and rare earth metals, T = Si and X = O. The M1 site (3.. symmetry) is occupied by Pr and Sr atoms with almost even proportions and is surrounded by nine O atoms forming a tricapped trigonal prism. The M2 site (m.. symmetry) is almost exclusively occupied by Pr and surrounded by seven O atoms, forming a distorted pentagonal bipyramid. The Si atom (m.. symmetry) is surrounded by two O (m.. symmetry) and two O atoms in general positions, forming an isolated SiO4 tetrahedron. Another O atom at the inversion centre (overline{6}.. symmetry) is surrounded by three M2 sites, forming an equilateral triangle perpendicular to the c axis.