On the Multimomentum Bundles and the Legendre Maps in Field Theories

We study the geometrical background of the Hamiltonian formalism of first-order Classical Field Theories. In particular, different proposals of multimomentum bundles existing in the usual literature (including their canonical structures) are analyzed and compared. The corresponding Legendre maps are introduced. As a consequence, the definition of regular and almost-regular Lagrangian systems is reviewed and extended from different but equivalent ways.Comment: LaTeX file, 19 pages. Replaced with the published version. Minor mistakes are correcte

Multivector Field Formulation of Hamiltonian Field Theories: Equations and Symmetries

We state the intrinsic form of the Hamiltonian equations of first-order Classical Field theories in three equivalent geometrical ways: using multivector fields, jet fields and connections. Thus, these equations are given in a form similar to that in which the Hamiltonian equations of mechanics are usually given. Then, using multivector fields, we study several aspects of these equations, such as the existence and non-uniqueness of solutions, and the integrability problem. In particular, these problems are analyzed for the case of Hamiltonian systems defined in a submanifold of the multimomentum bundle. Furthermore, the existence of first integrals of these Hamiltonian equations is considered, and the relation between {\sl Cartan-Noether symmetries} and {\sl general symmetries} of the system is discussed. Noether's theorem is also stated in this context, both the ``classical'' version and its generalization to include higher-order Cartan-Noether symmetries. Finally, the equivalence between the Lagrangian and Hamiltonian formalisms is also discussed.Comment: Some minor mistakes are corrected. Bibliography is updated. To be published in J. Phys. A: Mathematical and Genera

Non-standard connections in classical mechanics

In the jet-bundle description of first-order classical field theories there are some elements, such as the lagrangian energy and the construction of the hamiltonian formalism, which require the prior choice of a connection. Bearing these facts in mind, we analyze the situation in the jet-bundle description of time-dependent classical mechanics. So we prove that this connection-dependence also occurs in this case, although it is usually hidden by the use of the ``natural'' connection given by the trivial bundle structure of the phase spaces in consideration. However, we also prove that this dependence is dynamically irrelevant, except where the dynamical variation of the energy is concerned. In addition, the relationship between first integrals and connections is shown for a large enough class of lagrangians.Comment: 17 pages, Latex fil

Remote Laboratories for Teaching and Training in Engineering

Typical mechatronic systems are a combination of advanced technologies involving several disciplines. This multidisciplinary approach to the development of industrial applications provides great opportunities for the implementation of e-learning environments and collaborative schemes. Engineering education, in particular, benefits from many of these advances, among which, virtual instrumentation is a useful tool for the development of virtual environments, e-learning spaces and, particularly, remote laboratories. This chapter describes the implementation of web-based laboratories that allow the remote operation of experiments used as training exercises in undergraduate engineering courses. The remote laboratories were developed using LabVIEW® software, and they enable remote control and monitoring of laboratory equipment, allowing engineering students to perform experiments in real time, at their own pace, from anywhere, and whenever is suitable for them. Besides the experimental training that the web-based laboratories provide to students, the system is also a powerful teaching tool since real-time demonstrations of the experiments can be performed, and they also can be simultaneously monitored by a group of students. This approach is highly beneficial for engineering schools in developing countries, as resources can be shared through the Internet. A description of the system and three proposed experiments is presented, together with the experimental results

The host of the Type I SLSN 2017egm: A young, sub-solar metallicity environment in a massive spiral galaxy

Here we present an integral-field study of the massive, high-metallicity spiral NGC 3191, the host of SN 2017egm, the closest SLSN Type I to date. We use data from PMAS/CAHA and the public MaNGA survey to shed light on the properties of the SLSN site and the origin of star-formation in this non-starburst spiral galaxy. We map the physical properties different \ion{H}{II} regions throughout the galaxy and characterize their stellar populations using the STARLIGHT fitting code. Kinematical information allows to study a possible interaction with its neighbouring galaxy as the origin of recent star formation activity which could have caused the SLSN. NGC 3191 shows intense star-formation in the western part with three large SF regions of low metallicity. The central regions of the host have a higher metallicity, lower specific star-formation rate and lower ionization. Modeling the stellar populations gives a different picture: The SLSN region has two dominant stellar populations with different ages, the youngest one with an age of 2-10 Myr and lower metallicity, likely the population from which the SN progenitor originated. Emission line kinematics of NGC 3191 show indications of interaction with its neighbour MCG+08-19-017 at $\sim$45 kpc, which might be responsible for the recent starburst. In fact, this galaxy pair has in total hosted 4 SNe, 1988B (Type Ia), SN 2003ds (Type Ic in MCG+08-19-017), PTF10bgl (SLSN-Type II) and 2017egm, underlying the enhanced SF in both galaxies due to interaction. Our study shows that one has to be careful interpreting global host and even gas properties without looking at the stellar population history of the region. SLSNe seem to still be consistent with massive stars ($>$ 20 M$_\odot$) requiring low ($< 0.6Z_{\odot}$) metallicity and those environments can also occur in massive, late-type galaxies but not necessarily starbursts.Comment: Accepted for publication in A&A, 13 pages, 11 figures, 7 tables. Abstract has been reduced to match arXiv form requirement

Significado de la celularidad peritoneal basal: más allá del diagnóstico de infección peritoneal en diálisis peritoneal

Resume

Estado ergonómico de los reincorporados laborales por patología osteomuscular en una empresa del sector avícola

Objetive: The ergonomic condition between worker and work station can generate musculoskeletal pathologies. Those who suffer these pathologies must make a reincorporation process in order to return to their labor responsibilities avoiding and minimizing future negative health consequences. Objective: Determine the ergonomic state of the relocated employees for musculoskeletal pathologies in the poultry industry of Valle del Cauca 2014. Methods: Comparative analytic study of three groups: 20 relocated employees, 20 relocated employees with restrictions, 20 relocated employees without restrictions, in a company of the poultry sector of Valle del Cauca between 2000 to 2014. The recollection of information was through the Nordic and LEST method. Results: The most prevalent musculoskeletal pathologies are carpal tunnel syndrome and non-specified lumbago. The presence of ergonomic risk was observed in the dimensions: physical environment, psicosociological aspects and working time, with prevalence from 65% to 90%; in the physical load dimension it was found a low-risk level with prevalence from 55% to 80. Conclusions: Ergonomic risk is especially evident in psicosociological aspects, working time and physical environment (exposure to low temperatures); which when considered as risk factors could aggravate the symptoms of underlying pathology of labor reinstated. In the work station of stock packaging of section of benefit and added value, is where we find the largest number of reinstated workers with restrictions and relocated and where the most common positions are seating and standing, the rate does not depend on the production line.Objetivo:&nbsp;Determinar el estado ergonómico entre trabajador y puesto de trabajo puede generar patologías osteomusculares, quienes las padecen deben realizar un proceso de reincorporación laboral evitando o minimizando la posibilidad de consecuencias negativas en su salud. Metodología: Estudio analítico comparativo de tres grupos de 20 reubicados, 20 reintegrados con restricciones y 20 reintegrados sin restricciones en una empresa del sector avícola del Valle del Cauca desde el año 2000. Se efectuó la recolección de información a través de cuestionario Nórdico y método LEST. Resultados: Las patologías osteomusculares más prevalentes son síndrome del túnel carpiano y lumbago inespecífico. Hay presencia de riesgo ergonómico representativo en las dimensiones: entorno físico, aspectos psicosociológico y tiempo de trabajo, con prevalencias desde 65% hasta el 90%, en la dimensión carga física se encontró en bajo nivel de riesgo con prevalencias desde el 55% hasta el 80%. Conclusiones: Se evidencia riesgo ergonómico especialmente en las dimensiones aspectos psicosociológicos, tiempo de trabajo y entorno físico (exposición a bajas temperaturas), que se consideran factores de riesgo los cuales podrían agravar la sintomatología de la patología de base de los reincorporados laborales. El puesto de trabajo almacén de empaque de la sección beneficio y valor agregado es donde se encuentra el mayor número de trabajadores reintegrados con restricciones y reubicados, donde las posturas más frecuentes son sedente y de pie y el ritmo no depende de la cadena de producción

Higher-order Mechanics: Variational Principles and other topics

After reviewing the Lagrangian-Hamiltonian unified formalism (i.e, the Skinner-Rusk formalism) for higher-order (non-autonomous) dynamical systems, we state a unified geometrical version of the Variational Principles which allows us to derive the Lagrangian and Hamiltonian equations for these kinds of systems. Then, the standard Lagrangian and Hamiltonian formulations of these principles and the corresponding dynamical equations are recovered from this unified framework.Comment: New version of the paper "Variational principles for higher-order dynamical systems", which was presented in the "III Iberoamerican Meeting on Geometry, Mechanics and Control" (Salamanca, 2012). The title is changed. A detailed review is added. Sections containing results about variational principles are enlarged with additional comments, diagrams and summarizing results. Bibliography is update

Properties of Multisymplectic Manifolds

This lecture is devoted to review some of the main properties of multisymplectic geometry. In particular, after reminding the standard definition of multisymplectic manifold, we introduce its characteristic submanifolds, the canonical models, and other relevant kinds of multisymplectic manifolds, such as those where the existence of Darboux-type coordinates is assured. The Hamiltonian structures that can be defined in these manifolds are also studied, as well as other important properties, such as their invariant forms and the characterization by automorphisms.Comment: 10 pp. Changes in Sections 5 and 7 (where brief guides to the proofs of theorems have been added). Lecture given at the workshop on {\sl Classical and Quantum Physics: Geometry, Dynamics and Control. (60 Years Alberto Ibort Fest), Instituto de Ciencias Matem\'aticas (ICMAT)}, Madrid (Spain), 5--9 March 201