Development of a Test Method for the Comparative Analysis of Bicycle Saddle Vibration Transmissibility

AbstractVibrational comfort is one of the most important parameters evaluated by cyclists during bicycle riding. A method for measuring the saddle vibration transmissibility was developed with the aim of comparing the comfort properties of bicycle saddles without any influence of the full bicycle frame, using a quantitative approach. Three different bicycle saddles were mounted on a stiff seatpost clamped to the extremity of a vertical servohydraulic cylinder: saddles were loaded by a UNI 10814 standard wooden dummy bottom carrying deadweights. After applying a sinusoidal sweep of 0.6mm amplitude to the cylinder, from 1 to 100Hz, with steps of 2.5Hz, the application of two piezoelectric accelerometers allowed evaluating the magnitude of the transfer function H between the input acceleration at the cylinder shaft and the output acceleration at the dummy, in the range 1-100Hz. The three curves of the transfer function magnitude were compared and analyzed in order to introduce a Vibrational Comfort Index and to rank the tested saddles from the engineering quantitative point of view

Methods for evaluating the radial structural behaviour of racing bicycle wheels

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A method for evaluating the vibrational response of racing bicycles wheels under road roughness excitation

Abstract The aim of the work was the development of a method for measuring and comparing the vibrational response of different racing rear wheels to the excitation caused by riding on irregular road surfaces. Four different rear wheels were selected for the study. Vertical accelerations at rear wheel axis and at the seatpost were measured during field tests performed while cruising on different road surfaces at different constant speeds. Frequency analysis of acceleration signals was performed using random signal analysis methods. The results show that the ranking between comfort properties of different wheels varies with the road surface roughness and the cruising speed considered

Development of integrated methods for the engineering characterization of bicycle components

Aim of this work was the development of integrated methods for the engineering characterization of the bicycle components, following a user-centred approach. The overall methodology was developed through five main stages. The first stage concerned the development of laboratory testing methods for the evaluation of the basic engineering characteristics of the bicycle components. The regarding activities were focused on the study of the vibrational and impulsive comfort properties of bicycle wheels and saddles. New laboratory testing methods were therefore developed for the evaluation of the wheels radial structural behaviour, and for the measurement of the vibration transmissibility of wheels and saddles. The testing methods developed for the evaluation of the radial stiffness and the vibration transmissibility of the wheels were developed in the University laboratory, and then implemented in Campagnolo srl. The second stage of the work regarded the development of a structured and objective method for the identification and organization of wheels quality requirements, evaluated by the cyclists during road cycling. A dedicated subjective evaluation tests session was performed in order to collect the assessment of 33 cyclists among the quality requirements of three different wheelsets. The correlation between them and the basic engineering characteristics of the wheels was then calculated through the adoption of a mathematic method. The adoption of a mathematic method for the computation of the correlation coefficients, represents a significant improvement of the arbitrary method proposed by the widely used QFD [16]. The high differences obtained among the evaluated quality requirements of three different tested wheelsets suggested the development of the engineering complex indexes. Six engineering complex indexes were formulated in the fourth stage with the aim to express a technical measurement of the user quality requirements. The engineering complex indexes were developed through a scientific and rigorous approach, in which the analysis of the subjective evaluation of the cyclists and of the bicycle dynamics is combined. In the fifth stage, an instrumented racing bicycle was developed for measuring, through dedicated field tests, the parameters needed for the computation of the indexes, and for characterizing the braking actions performed by the cyclists during road downhill riding. The engineering complex indexes are the final outcome of the overall method developed. Since they give a technical measurement of the cyclist feelings, they represent the integrated engineering characterization of the wheels. They can assist the product development based on a user-centred approach, the management of the products range, and the definition of the target characteristics of new products. They can also represent a reliable guideline for customers in the product choice, or for marketing communication messages. So, an innovative structured approach for the user-centred characterization of sports equipment is presented in this thesis. The overall methodology was developed mainly considering racing bicycle wheels, but it is suitable also for the characterization of other bicycle components, or other sports equipmen

Development of instrumented downhill bicycle components for field data collection

Abstract A downhill bicycle was equipped with strain gauge bridges at the most significant safety components, stroke sensors at the suspensions and accelerometers at the front axle. A set of 7 channels was applied on the frame, 4 channels were applied to the rear swing arm, 6 channels to the front fork, 2 channels to the front and rear brakes and a customized load cell was connected to the rear damper. Each channel was calibrated during static laboratory tests and the calibration constants or matrices were used to convert the measured signals into functional loads applied to the components. Tests were performed involving an expert downhill racer on a competition track. The peak values collected during the study would allow for the definition of static overload tests on the bicycle safety components; the time histories collected in the field will allow evaluating the field loads spectra to be used in the fatigue life prediction of the components and defining the standard fatigue tests to verify the minimum required fatigue strength of the most important components of such an extreme sport discipline

Ecological risk assessment for contaminated sites in Italy: Guidelines and path forward

Ecological risk assessment (ERA) is defined as an iterative process that evaluates the likelihood of adverse ecological effects resulting from exposure to one or more stressors. Although ERA is recognized as a valuable procedure to better address efforts and strategies for site remediation, in Europe a common framework for the implementation of ERA in the management of contaminated sites is lacking. In Italy, there are no legally binding provisions regulating the direct assessment of potential likelihood of ecological risks. In this context, the main objective of this article was to develop a guideline to facilitate ERA application in support of an effective and sustainable management of contaminated sites in Italy and to facilitate a multistakeholder dialogue. The work was based on a critical review of existing ERA guidelines in the international context, as well as other regulatory documents and technical approaches dealing with the evaluation of ecological effects of chemical contaminants in different environmental compartments. Approaches and tools available in these documents were then used to prepare a proposed guideline for the Italian context; the proposed ERA guideline is meant to represent a flexible but robust approach that can be useful in evaluating existing data (e.g., from past investigations) as well as in the planning of site-specific investigations. To facilitate the direct application of the ERA procedure, the guideline was prepared including several templates of summary tables, checklists, and examples. The proposed ERA guideline could facilitate the decision-making process for contaminated sites with ecological values, although its application would necessarily require, at least in the initial phase, testing of its suitability to the Italian context and setting-up of a close dialogue and collaboration with local authorities and other stakeholders. Integr Environ Assess Manag 2022;00:1-7. (c) 2022 SETA

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI