Thermal expansion of Ti-substituted barium hexaferrite

Thermal expansion measurements in the range of 20–500 °C were carried out on both poly- and single crystalline samples of the hexagonal magnetoplumbite ferrite with composition BaTiFe11O19. The continuous scanning of the thermal expansion reveals the existence of a -type anomaly near the Curie temperature. In contrast to the usual observed anisotropic behavior for magnetoplumbite hexaferrites, the averaged thermal expansion coefficient for the a direction is larger than for the c direction, i.e., 12.8×10–6 and 9.5×10–6 °C–1, respectively

Harmonic index and harmonic polynomial on graph operations

Some years ago, the harmonic polynomial was introduced to study the harmonic topological index. Here, using this polynomial, we obtain several properties of the harmonic index of many classical symmetric operations of graphs: Cartesian product, corona product, join, Cartesian sum and lexicographic product. Some upper and lower bounds for the harmonic indices of these operations of graphs, in terms of related indices, are derived from known bounds on the integral of a product on nonnegative convex functions. Besides, we provide an algorithm that computes the harmonic polynomial with complexity O(n 2 ).This work was supported in part by two grants from Ministerio de Economía y Competititvidad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) (MTM2016-78227-C2-1-P and MTM2017-90584-REDT), Spain

Surgical clavicle reconstruction after aneurysmal bone cyst resection in a child: A simple method

The clavicle is an infrequent location for primary tumors in general, and aneurysmal bone cyst (ABC) of the clavicle is particularly rare. The challenge of the functional and esthetic result in the treatment of these lesions in the pediatric population is high when considering the reconstruction of critical bone defects. In this article, we present the case of a seven -year -old boy with an ABC in the middle third of the clavicle, treated by resection and reconstruction with free autograft of the fibula stabilized by using an intramedullary titanium nail. We offer a description of the used technique, considerations about treatment options in children, and a follow-up of more than two -and -a -half years

Proper motions of the HH1 jet

We describe a new method for determining proper motions of extended objects, and a pipeline developed for the application of this method. We then apply this method to an analysis of four epochs of [S~II] HST images of the HH~1 jet (covering a period of $\sim 20$~yr). We determine the proper motions of the knots along the jet, and make a reconstruction of the past ejection velocity time-variability (assuming ballistic knot motions). This reconstruction shows an "acceleration" of the ejection velocities of the jet knots, with higher velocities at more recent times. This acceleration will result in an eventual merging of the knots in $\sim 450$~yr and at a distance of $\sim 80"$ from the outflow source, close to the present-day position of HH~1.Comment: 12 pages, 8 figure