Multilayer refractory nozzles produced by plasma-spray process

Multilayer rocket nozzles formed by plasma spraying have good thermal shock resistance and can be reheated in an oxidizing environment without loss of coating adherence. Suggested application of this process are for the production of refractory components, which can be formed as surfaces of revolution

\u3ci\u3eEchinococcus vogeli\u3c/i\u3e sp. n. (Cestoda: Taeniidae) from the Bush Dog, \u3ci\u3eSpeothos venaticus\u3c/i\u3e (Lund)

Echinococcus vogeli sp. n., from a bush dog, Speothos venaticus (Lund), captured in the Province of Esmeraldas, Ecuador, differs morphologically from the three species of Echinococcus recognized as valid. E. vogeli sp. n. is distinguished from E. granulosus (Batsch 1786) by its larger rostellar hooks, different proportions of the strobila, tubular, sac-like gravid uterus, and different arrangement of the female genital ducts. from E. multilocularis Leuckart 1863 by its larger rostellar hooks, different proportions of the strobila, position of genital pore, and greater number of testes; from E. oligarthrus (Diesing 1863) by different proportions of the strobila, position of genital pore, and greater number of testes. Characters that separate E. vogeli sp. n. from E. granulosus and E. oligarthrus differentiate it respectively from two species of uncertain status, E. patagonicus Szidat 1960 and E. pampeanus Szidat 1967

The Acanthocephalan Parasites of Eider Ducks

Because of their wide geographical distribution through arctic and subarctic regions of the northern hemisphere, the eider ducks offer some unusual opportunities for the study .of distribution and hostrelations of their parasites. When the Acanthocephala from eider ducks were first studied, the fauna of each continent was regarded as distinct, because it had been reasonably well established that the majority of species of these parasites encounter~d in the United States were distinct from those found in central Europe. This belief failed to take into account the fact that in the arctic the usual distributional bartl:ers to both the definitive and the intermediate hosts are lacking. Recent studies -in northern Europe, especially by Lundstrom (1941, 1942), and Dew collections. on the American continent have added significantly to an understanding, of .:this fauna. The new evidencesmake it seem apparent that for water\u27 birds of the arctic region the acanthocephalan parasites are very widely distrilmted -geographically. This statement does not contradict the generalization that migratory birds have little influence on inter-continental distribution of acanthocephalan parasites. It seems more probable that suitable intermediate hosts for Acanthocephala are widely dispersed in the arctic and subarctic regions and that local bird populations, even though they may have undergone subspecific or specific differentiation, are by food habits and habitat exposed to infection by identical species of parasites on the two continents. This condition of birds under ecologically similar conditions is a direct parallel to that described for fishes of the same regions where numerous species on the two continents serve as definitive hosts for Neoechinorhynchus rutili (Mueller) as demonstrated by Van Cleave and Lynch (1950)

The Acanthocephalan Parasites of Eider Ducks

Because of their wide geographical distribution through arctic and subarctic regions of the northern hemisphere, the eider ducks offer some unusual opportunities for the study .of distribution and hostrelations of their parasites. When the Acanthocephala from eider ducks were first studied, the fauna of each continent was regarded as distinct, because it had been reasonably well established that the majority of species of these parasites encounter~d in the United States were distinct from those found in central Europe. This belief failed to take into account the fact that in the arctic the usual distributional bartl:ers to both the definitive and the intermediate hosts are lacking. Recent studies -in northern Europe, especially by Lundstrom (1941, 1942), and Dew collections. on the American continent have added significantly to an understanding, of .:this fauna. The new evidencesmake it seem apparent that for water\u27 birds of the arctic region the acanthocephalan parasites are very widely distrilmted -geographically. This statement does not contradict the generalization that migratory birds have little influence on inter-continental distribution of acanthocephalan parasites. It seems more probable that suitable intermediate hosts for Acanthocephala are widely dispersed in the arctic and subarctic regions and that local bird populations, even though they may have undergone subspecific or specific differentiation, are by food habits and habitat exposed to infection by identical species of parasites on the two continents. This condition of birds under ecologically similar conditions is a direct parallel to that described for fishes of the same regions where numerous species on the two continents serve as definitive hosts for Neoechinorhynchus rutili (Mueller) as demonstrated by Van Cleave and Lynch (1950)

Toward a spatial understanding of staple food and nonstaple food production in Brazil

Brazilian agricultural census data at the municipal level are used to develop and map a simple index of staple food versus nonstaple food agriculture for Brazil over time (1996-2006). The results show spatial variation in the direction and degree of the shift toward or away from staple food cropping across Brazil. The index is presented as an important methodological step toward a systematic geographic understanding of crop share changes surrounding food versus fuel and other nonfood crop production. (1996 ?? 2006 ?) Los datos del censo agropecuario brasileno a nivel municipal se utilizan para desarrollar y cartografiar un indice simple de la agricultura de alimentos esenciales versus la de alimentos no esenciales del Brasil durante un tiempo (1996-2006). Los resultados muestran variacion espacial en la direccion y grado del cambio hacia cultivos para alimentacion esencial, o lo contrario, en Brasil. El indice se presenta como un paso metodologico importante hacia un entendimiento geografico sistematico de cambios hacia un tipo de cosecha compartida que privilegia la produccion de alimentos, contra las cosechas para combustibles y otra produccion no alimentaria66224925

Recent Enhancements to the Development of CFD-Based Aeroelastic Reduced-Order Models

Recent enhancements to the development of CFD-based unsteady aerodynamic and aeroelastic reduced-order models (ROMs) are presented. These enhancements include the simultaneous application of structural modes as CFD input, static aeroelastic analysis using a ROM, and matched-point solutions using a ROM. The simultaneous application of structural modes as CFD input enables the computation of the unsteady aerodynamic state-space matrices with a single CFD execution, independent of the number of structural modes. The responses obtained from a simultaneous excitation of the CFD-based unsteady aerodynamic system are processed using system identification techniques in order to generate an unsteady aerodynamic state-space ROM. Once the unsteady aerodynamic state-space ROM is generated, a method for computing the static aeroelastic response using this unsteady aerodynamic ROM and a state-space model of the structure, is presented. Finally, a method is presented that enables the computation of matchedpoint solutions using a single ROM that is applicable over a range of dynamic pressures and velocities for a given Mach number. These enhancements represent a significant advancement of unsteady aerodynamic and aeroelastic ROM technology

On the ternary complex analysis and its applications

Previouly a possible extension of the complex number, together with its connected trigonometry was introduced. In this paper we focuss on the simplest case of ternary complex numbers. Then, some types of holomorphicity adapted to the ternary complex numbers and the corresponding results upon integration of differential forms are given. Several physical applications are given, and in particuler one type of holomorphic function gives rise to a new form of stationary magnetic field. The movement of a monopole type object in this field is then studied and shown to be integrable. The monopole scattering in the ternary field is finally studied.Comment: LaTeX 28 page

Application of the FUN3D Unstructured-Grid Navier-Stokes Solver to the 4th AIAA Drag Prediction Workshop Cases

FUN3D Navier-Stokes solutions were computed for the 4th AIAA Drag Prediction Workshop grid convergence study, downwash study, and Reynolds number study on a set of node-based mixed-element grids. All of the baseline tetrahedral grids were generated with the VGRID (developmental) advancing-layer and advancing-front grid generation software package following the gridding guidelines developed for the workshop. With maximum grid sizes exceeding 100 million nodes, the grid convergence study was particularly challenging for the node-based unstructured grid generators and flow solvers. At the time of the workshop, the super-fine grid with 105 million nodes and 600 million elements was the largest grid known to have been generated using VGRID. FUN3D Version 11.0 has a completely new pre- and post-processing paradigm that has been incorporated directly into the solver and functions entirely in a parallel, distributed memory environment. This feature allowed for practical pre-processing and solution times on the largest unstructured-grid size requested for the workshop. For the constant-lift grid convergence case, the convergence of total drag is approximately second-order on the finest three grids. The variation in total drag between the finest two grids is only 2 counts. At the finest grid levels, only small variations in wing and tail pressure distributions are seen with grid refinement. Similarly, a small wing side-of-body separation also shows little variation at the finest grid levels. Overall, the FUN3D results compare well with the structured-grid code CFL3D. The FUN3D downwash study and Reynolds number study results compare well with the range of results shown in the workshop presentations