Constant of Motion for several one-dimensional systems and outlining the problem associated with getting their Hamiltonians

The constants of motion of the following systems are deduced: a relativistic particle with linear dissipation, a no-relativistic particle with a time explicitly depending force, a no-relativistic particle with a constant force and time depending mass, and a relativistic particle under a conservative force with position depending mass. The problem of getting the Hamiltonian for these systems is determined by getting the velocity as an explicit function of position and generalized linear momentum, and this problem can be solved a first approximation for the first above system.Comment: 15 pages, Te

Los yacimientos del cuarzo-apatito (fosforita) en el Macizo Hespérico español: el caso de Aldea Moret-Zarza la Mayor (Cáceres)

[Resumen] Los filones de Q-Ap se hallan en zona orgánica intracontinental de reactivación de zócalos antiguos. Corresponden a yacimientos plutonogénicos relacionados con granitoides peralumínicos. Poseen estructuras y texturas de relleno, siendo su morfologia filoniana según se deduce de los planos de la mina. El tipo espectral (o tipoquímico) del apatito es característico de yacimientos hidroternales (caracter hipotermal) y su composición es la de fluorapatito. No existe un fondo geoquímico elevado en P, sino que es la presencia de mineralizadores como el F que concentra el P en un modelo halogénico.[Abstract] Since 1961, date of establishment of the firm, the investigations made gave as a result 35,000,000 Tm of reserves, being exploited 120,000 tpa. In this paper a description of benefitiation process and fina1 products is made, appearing that they are mainly for exporte In addition, considerations concerning the significance of magnesium in animal nutrition and its app1ication for it are made. Finally, difficulties and proposed solutions are quote

Large Scale Instrumental Test Embankment on Uranium Tailings

The remediation of an inactive uranium mill tailings pile at the town of Andujar (Spain) has provided an opportunity to investigate the settlement characteristics of hydraulically-deposited uranium mill tailings. A test embankment was constructed on top of the existing tailings deposit and total stresses, settlements and pore pressures were measured. Settlements and pore pressure data were compared with the results obtained using an elastoplastic numerical model which allows the simulation of two dimensional consolidation processes. Backcalculated consolidation parameters were derived to provide agreement between the calculated and measured settlements and pore pressures. These parameters could then be used to predict the post-construction settlement of the remediated pile

El cotilo de impactación en las artroplastias de cadera

Entre los diferentes sistemas de fijación de la cúpula acetabular entre las artroplastias no cementadas, la impactación tiene múltiples ventajas. Permite un mejor contacto entre implante y hueso y no necesita destrucción de la superficie ósea receptora. Los nuevos diseños para impactación están fabricados en aleaciones de titanio y poseen una superficie rugosa recubierta a su vez con hidroxiapatita. Algunos modelos como la artroplatia Bihapro poseen aletas estabilizadoras en su reborde externo para evitar la movilización rotatoria inicial. El sistema de impactación está mostrando buenos resultados de la experiencia conocida y aunque los periodos de seguimiento son aún cortos, la integración ósea conseguida es satisfactoria. Se presentan los resultados de 1107 cúpulas Bihapro con una evolución entre uno y siete años, que han seguido un protocolo de seguimiento informatizado. En sólo un caso se presentó movilización del componente que precisó cirugía de revisión.The acetabular fixation by impaction has advantages on other systems of fixing in the cementless arthroplaties of the hip. Permit a better contact between implant and bone and it does not need destruction of the receiving bony surface. The new designs for fixation by impaction are manufactured in titanium alloys and possess a rugged surface cover at the same time with hyrdoxiapatite-coated. Some models as the arthroplasty Bihapro possess fins for primary stability in your external curbing to avoid the initial rotary mobilization. This system of fixation is showing good results in the known experience and though the periods of follow-up are yet short, the obtained bony integration is satisfactory. We presented the results of 117 Bihapro cups implanted with a follow-up from one to seven years, that they have followed a computed protocol. In only a case was presented loosening of the component that specified review surgery

Effective electronic response of a system of metallic cylinders

The electronic response of a composite consisting of aligned metallic cylinders in vacuum is investigated, on the basis of photonic band structure calculations. The effective long-wavelength dielectric response function is computed, as a function of the filling fraction. A spectral representation of the effective response is considered, and the surface mode strengths and positions are analyzed. The range of validity of a Maxwell-Garnett-like approach is discussed, and the impact of our results on absorption spectra and electron energy-loss phenomena is addressed.Comment: 15 pages, 6 figures, to appear in Phys. Rev.

Census of HII regions in NGC 6754 derived with MUSE: Constraints on the metal mixing scale

We present a study of the HII regions in the galaxy NGC 6754 from a two pointing mosaic comprising 197,637 individual spectra, using Integral Field Spectrocopy (IFS) recently acquired with the MUSE instrument during its Science Verification program. The data cover the entire galaxy out to ~2 effective radii (re ), sampling its morphological structures with unprecedented spatial resolution for a wide-field IFU. A complete census of the H ii regions limited by the atmospheric seeing conditions was derived, comprising 396 individual ionized sources. This is one of the largest and most complete catalogue of H ii regions with spectroscopic information in a single galaxy. We use this catalogue to derive the radial abundance gradient in this SBb galaxy, finding a negative gradient with a slope consistent with the characteristic value for disk galaxies recently reported. The large number of H ii regions allow us to estimate the typical mixing scale-length (rmix ~0.4 re ), which sets strong constraints on the proposed mechanisms for metal mixing in disk galaxies, like radial movements associated with bars and spiral arms, when comparing with simulations. We found evidence for an azimuthal variation of the oxygen abundance, that may be related with the radial migration. These results illustrate the unique capabilities of MUSE for the study of the enrichment mechanisms in Local Universe galaxies.Comment: 13 pages, 7 Figurs, accepted for publishing in A&