The effect of swingarm stiffness on motorcycle stability: Experimental measurements and numerical simulations

This paper focuses on the effect of swingarm deformability on motorcycle stability and in particular on the weave mode. Multibody models for the analysis of stability and handling of single track vehicles require a lumped element representation of the deformability of the critical structural elements of the vehicle. The twist axis method is used to identify lumped stiffness and damping elements able to represent bending and torsion deformability of the swingarm. Experimental tests and identification results dealing with two different swingarms are presented. The identified lumped stiffness and damping elements are implemented in a multibody code and some numerical stability analyses are carried out. Calculated results show that swingarm deformability has a small effect on the stability of super sport motorcycles, whereas the stability of the weave mode of enduro motorcycles is affected by swingarm deformability in a specific range of speeds

On the influence of tyre and structural properties on the stability of bicycles

In recent years the Whipple Carvallo Bicycle Model has been extended to analyse high speed stability of bicycles. Various researchers have developed models taking into account the effects of front frame compliance and tyre properties, nonetheless, a systematic analysis has not been yet carried out. This paper aims at analysing parametrically the influence of front frame compliance and tyre properties on the open loop stability of bicycles. Some indexes based on the eigenvalues of the dynamic system are defined to evaluate quantitatively bicycle stability. The parametric analysis is carried out with a factorial design approach to determine the most influential parameters. A commuting and a racing bicycle are considered and numerical results show different effects of the various parameters on each bicycle. In the commuting bicycle, the tyre properties have greater influence than front frame compliance, and the weave mode has the main effect on stability. Conversely, in the racing bicycle, the front frame compliance parameters have greater influence than tyre properties, and the wobble mode has the main effect on stability

Parametric analysis of the stability of a bicycle taking into account geometrical, mass and compliance properties

Some studies of bicycle dynamics have applied the Whipple Carvallo bicycle model (WCBM) for the stability analysis. The WCBM is limited, since structural elements are assumed to be rigid bodies. In this paper, the WCBM is extended to include the front assembly lateral compliance, and analysis focuses on the study of the open loop stability of a benchmark bicycle. Experimental tests to identify fork and wheel properties are performed, this data is used in the stability analysis for ranking the influence of design parameters. Indexes from the eigenvalues analysis are applied in a full factorial approach. The results show that introducing front assembly compliance generates a wobble mode with little effect on self-stability. The forward displacement of the centre of mass of the rear frame and the increment in trail lead to large increments in the self-stability, whereas increments in front wheel radius and wheelbase reduce stability

Weak Lensing–X-ray Scaling Relations for a High Redshift Galaxy Clusters Sample

Accurate cosmology through large X-ray selected galaxy cluster samples will rely on accurate mass estimates and well-calibrated mass-observable relations. The comparison of independent approaches, such as X-ray and gravitational lensing analysis, yields the most accurate results in tracing the cosmic evolution. This also contributes to improve our understanding of the scaling laws between X-ray luminosity and mass, providing the essential connection between observations and cosmological constraints that will be obtained thanks to the forthcoming eROSITA X-ray space telescope. Our project aims at the mass estimation via the weak lensing follow-up of the cosmological subsample of the 400d Galaxy Cluster Survey: a homogeneous, statistically complete and flux limited X-ray sample of 36 high-redshift (0.35 ≤ z After a brief introduction about cluster cosmology, this thesis presents methods and results of the cluster mass estimation through an homogeneous weak lensing analysis of 18 galaxy clusters. For our purposes we use optical data from archival and granted observations at ground-based instruments: IMACS, WFI and MegaCam wide-field cameras. Given the poor quality of the data format of the IMACS camera, we modify and automatize the THELI data reduction pipeline and implement a method for recovering precious astrometric information. We provide revised scaling relations of weak lensing mass with several X-ray observables integrating the new data with updated masses from the previous works, basing on a total of 25 high-z clusters. We compare our results with the X-ray mass estimates and recent mass comparison projects. We find a hint for a mass-dependent mass bias, with X-ray mass estimates of low-mass clusters (w.r.t. the sample median mass) being biased-high, while they are biased-low at the high-mass end. However, the overall trend is consistent with the zero bias, hence not showing any indication for a strong cluster mass bias which would be needed to alleviate the Planck CMB-cluster tension

Multi-physics phenomena influencing the performance of the car horn

Usually cars are equipped with disk horns. In these devices electromagnetic energy is converted into mechanical energy of two nuclei that vibrate and impact each other \u2013 the impacts excite the disk that radiates sound. This paper aims at understanding the results of acoustic tests carried out on horns with different excitation voltages and different mounting brackets. Since many non-linear phenomena are inherent in the vibrations of the nuclei, a detailed model of the electromechanical system is developed. Results show the dependence of operating frequency on the input voltage and the role played by the various mechanical and electrical parameters on the dynamics of the horn. Particular nonlinear effects, like sub-harmonic excitation, are presented and discussed. A general agreement between experimental results and numerical simulations is found

Development of piezoelectric harvesters with integrated trimming devices

Piezoelectric cantilever harvesters have a large power output at their natural frequency, but in some applications the frequency of ambient vibrations is different fromthe harvester\u2019s frequency and/or ambient vibrations are periodicwith some harmonic components. To copewith these operating conditions harvesters with integrated trimming devices (ITDs) are proposed. Some prototypes are developed with the aid of an analytical model and tested with an impulsive method. Results show that a small trimming device can lower the main resonance frequency of a piezoelectric harvester of the same extent as a larger tip mass and, moreover, it generates at high frequency a second resonance peak. A multi-physics numerical finite element (FE) model is developed for predicting the generated power and for performing a stress-strain analysis of harvesters with ITDs. The numerical model is validated on the basis of the experimental results. Several configurations of ITDs are conceived and studied. Numerical results show that the harvesters with ITDs are able to generate relevant power at two frequencies, owing to the particular shape of the modes of vibration. The stress in the harvesters with ITDs is smaller than the stress in the harvester with a tip mass trimmed to the same frequency

Diseño de un plan de mercadeo que aumente el posicionamiento en el eje cafetero de la empresa Territorio Explora

El turismo es una actividad compleja generadora de divisas y empleo y lo más importante es que mantiene y recupera las manifestaciones culturales que representan nuestra verdadera identidad “amable y acogedora”. Una gestión apropiada el destino turístico puede proporcionar a las empresas ventajas significativas de los costos de la promoción y mercadeo, dos puntos destacan en el análisis de la situación. Primero la falta de coordinación en cuanto a todas las actividades promocionales (precios y paquetes promocionales contra precios y paquetes reales) y segundo, el desconocimiento de un manejo adecuado de un destino turístico en Risaralda. Por un lado se caracterizan las empresas por competir con base en el bajo costo de los factores (salarios bajos y recursos naturales abundantes), usan métodos ineficientes, no innovan e imitan. Aquí surge la necesidad de crear nuevos planes turísticos, potencializando la región del Eje Cafetero. Por esto, es indispensable desarrollar un amplio portafolio que preste toda clase de servicios de la más alta calidad de acuerdo a sus diferentes temáticas. Territorio Explora, es una empresa nueva en la región que busca ser cada día más competitiva, que vela por la seguridad y satisfacción de los clientes, dispuestos a ajustarse a sus necesidades. Actualmente la visión de Territorio Explora es consolidarse como una empresa confiable y ser reconocidos por brindar bienestar, comodidad y buen servicio a todos sus clientes en los diferentes destinos que opera con un equipo de trabajo profesional y amable

A Fragment-Based Approach for the Development of G-Quadruplex Ligands: Role of the Amidoxime Moiety

G-quadruplex (G4) nucleic acid structures have been reported to be involved in several human pathologies, including cancer, neurodegenerative disorders and infectious diseases; however, G4 targeting compounds still need implementation in terms of drug-like properties and selectivity in order to reach the clinical use. So far, G4 ligands have been mainly identified through high-throughput screening methods or design of molecules with pre-set features. Here, we describe the development of new heterocyclic ligands through a fragment-based drug discovery (FBDD) approach. The ligands were designed against the major G4 present in the long terminal repeat (LTR) promoter region of the human immunodeficiency virus-1 (HIV-1), the stabilization of which has been shown to suppress viral gene expression and replication. Our method is based on the generation of molecular fragment small libraries, screened against the target to further elaborate them into lead compounds. We screened 150 small molecules, composed by structurally and chemically different fragments, selected from commercially available and in-house compounds; synthetic elaboration yielded several G4 ligands and two final G4 binders, both embedding an amidoxime moiety; one of these two compounds showed preferential binding for the HIV-1 LTR G4. This work presents the discovery of a novel potential pharmacophore and highlights the possibility to apply a fragment-based approach to develop G4 ligands with unexpected chemical features

Diseño, implementación, administración y enrutamiento avanzado bajo el núcleo IOS CLI (Cisco)

[ES] Descripción del proyecto enviada a la aplicación con menos de 1000 caracteres El proyecto esta basado en el diseño, implementación y administración de una red con conexiones de área local y extensa basada en una simulación de la UPV contempla desde el diseño, implementación y administración en una red virtualizada. Para el proyecto utilizamos los dispositivos de cisco system. Usaremos los routers catalyst 2811, genericos para la interconexión de fibra, inalambricos, switches catalyst s2000 y switches genéricos para la fibra. La finalidad es la creación de una red de la forma correcta, siguiendo los pasos adecuados, la implementación adecuada y la forma de administrarla, explicando detalladamente los pasos y justificando cada uno de ellos.Tejedor Doria, JA. (2014). Diseño, implementación, administración y enrutamiento avanzado bajo el núcleo IOS CLI (Cisco). http://hdl.handle.net/10251/48355.TFG