1,869 research outputs found

    Pass-by characterization of noise emitted by different categories of seagoing ships in ports

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    In the light of sustainability, satisfactory living conditions is an important factor for people's positive feedback in their own living environment. Acoustic comfort and noise exposure should then be carefully monitored in all human settlements. Furthermore, it is already well-known that high or prolonged noise levels may lead to unwanted health effects. Unfortunately, while in the last decades scientists and public authorities have investigated the noise produced by roads, trains, and airports, not enough efforts have been spent in studying what happens around the coastal and port areas. Following the attention brought to the subject by recent European projects on noise in port areas, the present paper characterizes the sound power level and 1/3 octave band sound power spectrum of seagoing ships while moving at low speeds. Five different categories have been distinguished: Roll-on/roll-off (RORO), container ship, oil tanker, chemical tanker, and ferry. The analysis is based on a continuous noise measurement lasting more than three months, performed in the industrial canal of the port of Livorno (Italy). The resulting noise emissions are new and useful data that could be inserted in acoustic propagation models to properly assess the noise in the areas affected by port activities. Thus, the present work can act as a supporting tool in planning ship traffic in ports towards better sustainability

    Port noise and complaints in the North Tyrrhenian sea and framework for remediation

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    Compared to the other relevant noise sources such as railways, roads, and airplanes, the regulation regarding port noise is lagging behind. The absence of specific laws is likely one of the main causes of the increasingly high number of complaints reported by the citizens living nearby the ports. At the same time, scientific literature concerning the impact of port noise and its mitigation is not so widespread and only a few studies are available at the moment. However, the volume of maritime traffic has increased in the last years and consequently, Port Authorities are required to assess the impact of port operations on the city soundscape without using specific directives or guidelines. In this context, the INTERREG Maritime programme projects RUMBLE, MON ACUMEN, and REPORT aim to fill this gap, by investigating the state-of-the-art of port noise in the north Tyrrhenian sea and developing helpful instruments. Data were collected via a survey sent to the Port Authorities, local environmental protection agencies and universities involved in the projects. The survey was focused on monitoring systems, previous measurement campaigns, noise maps, and citizens’ complaints already taken. The results confirmed both a lack of awareness among residents and authorities and the absence of actions aimed at reducing port noise. In this framework, the difficulties encountered by the Port Authorities in managing the ports sustainably are highlighted. An underestimation of citizens’ exposure to noise in port areas could be expected

    Plasduino: an inexpensive, general purpose data acquisition framework for educational experiments

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    Based on the Arduino development platform, Plasduino is an open-source data acquisition framework specifically designed for educational physics experiments. The source code, schematics and documentation are in the public domain under a GPL license and the system, streamlined for low cost and ease of use, can be replicated on the scale of a typical didactic lab with minimal effort. We describe the basic architecture of the system and illustrate its potential with some real-life examples.Comment: 11 pages, 10 figures, presented at the XCIX conference of the Societ\`a Italiana di Fisic

    Parameters affecting noise emitted by ships moving in port areas

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    Only recently has noise been considered in the assessment of the sustainability of port infrastructures, after decades of unawareness. INTERREG Maritime projects unveiled problems that have been neglected so far, such as the lack of proper regulation and noise exposure assessments for citizens. While it is true that a port area includes a huge variety of possible noise sources, very few of them have been characterized from an acoustical point of view. INTERREG projects have boosted research in the field, and previous studies have dealt with noise produced by moving ships in ports. The present work starts from a previous measurement campaign used to obtain broadband and 1/3-octave-band noise emissions of moving ships, and it aims to explain their uncertainties. More than a month’s worth of continuous acoustic measurements and video recordings were deeply analyzed in order to obtain an input database that is as precise as possible. A multiple regression analysis was performed in order to understand the influence that parameters such as minimum distance, speed, and draught have on ships’ noise emissions, which were calculated using pass-by measurements, with a special focus on ferries. The minimum distance of each ship’s passage from the microphone was measured using a video recording with an innovative methodology, providing results with 3 m of uncertainty. Knowing which parameter is more influential would help in planning proper measurements for monitoring or for drafting correct guidelines. Draught was determined to be uninfluential in ferries’ noise emissions, while the minimum distance and speed relations were estimated and accounted for in the calculation of a refined sound power level. From a spectrum point of view, the frequencies from 500 Hz to 2.5 kHz were determined to be those that contributed the most to the noise produced by the transit of a ship, and they vary with speed. With the studied corrections, different ferry models resulted in similar noise emissions. The standard deviation of noise emitted was reduced by 0.5 dB (A), and the average was also improved by positioning the ships’ flow at the correct average minimum distance. Furthermore, the right placement of a source is also important in the acoustic mapping phase for a correct evaluation of the propagation of noise at a distance. The use of more precise input data is important for improving the output of acoustic propagation models during the assessment of port noise in the surrounding areas

    Updated Report Acceleration of Polarized Protons to 120-150 GeV/c at Fermilab

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    The SPIN@FERMI collaboration has updated its 1991-95 Reports on the acceleration of polarized protons in Fermilab's Main Injector, which was commissioned by Fermilab. This Updated Report summarizes some updated Physics Goals for a 120-150 GeV/c polarized proton beam. It also contains an updated discussion of the Modifications and Hardware needed for a polarized beam in the Main Injector, along with an updated Schedule and Budget.Comment: 30 pages, 12 figure

    Source characterization guidelines for noise mapping of port areas

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    Maritime transport for both passengers and freight is continuously increasing and, consequently, the global attention toward its sustainability is growing. Ships offer advantages in terms of environmental impact compared to other transportation systems but the increasing traffic volume is expected to increase pollutants. Noise produced in port areas has been neglected for too long, until the INTERREG Maritime programme Italy-France 2014\u20132020 has brought to light how citizen complaints are emerging for some of the main ports in the Mediterranean. However, port noise prevention and management is difficult as knowledge on specific sources is very limited in the literature. Furthermore, on field measurements are difficult to be performed given the complexity of the port area, where multiple types of sound emitters mix and confuse each other. Noise maps represent the first important step in order to align ports to the requirements set by the Environmental Noise Directive to the transportation infrastructures. Once computed, they are an excellent tool supporting port management towards the reduction of citizens\u2019 noise exposure while ensuring traffic growth. The present paper reports a guideline for the characterization of noise sources needed as inputs for the noise maps, as developed in the framework of the INTERREG Maritime programme Italy-France 2014\u20132020. On the basis of the current state of the art, a procedure has been elaborated for different categories of noise sources acting in port, ranging from stationary to moving ships, from mooring operations to loading/unloading operations, from industrial activities to road and railway traffic

    MECHANICAL SHOT NOISE INDUCED BY CREEP IN SUSPENSION DEVICES

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    Abstract The sensitivity curve of a gravitational wave interferometric detector like VIRGO might be seriously limited by the mechanical shot noise induced by stationary creep in the heavily loaded mechanical suspension components (wires, spring blades, etc.). We quantify this effect and discuss possible improvements which could be implemented without major design alterations

    Demonstration of K-Kbar, B-Bbar, and D-Dbar Transitions with a Pair of Coupled Pendula

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    A setup of two coupled and damped pendula is used to demonstrate the main features of transitions beween neutral K, D, B mesons and their respective antiparticles, including CP violation in K Kbar transitions. The transitions are described by two-state Schr\"odinger equations. Since the real parts of their solutions obey the same differential equations as the pendula coordinates, the pendulum motions can be used to represent the meson transitions. Video clips of the motions are attached as supplementary material.Comment: 15 pages, 6 figure

    Displacement power spectrum measurement of a macroscopic optomechanical system at thermal equilibrium

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    The mirror relative motion of a suspended Fabry-Perot cavity is studied in the frequency range 3-10 Hz. The experimental measurements presented in this paper, have been performed at the Low Frequency Facility, a high finesse optical cavity 1 cm long suspended to a mechanical seismic isolation system identical to that one used in the VIRGO experiment. The measured relative displacement power spectrum is compatible with a system at thermal equilibrium within its environmental. In the frequency region above 3 Hz, where seismic noise contamination is negligible, the measurement distribution is stationary and Gaussian, as expected for a system at thermal equilibrium. Through a simple mechanical model it is shown that: applying the fluctuation dissipation theorem the measured power spectrum is reproduced below 90 Hz and noise induced by external sources are below the measurement.Comment: 11 pages, 9 figures, 2 tables, to be submitte

    GWITCHHUNTERS – A CITIZEN SCIENCE PROJECT FOR THE IMPROVEMENT OF GRAVITATIONAL WAVE DETECTORS

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    Gravitational wave detectors are complex instruments devoted to the formidable task of measuring spacetime deformations as small as a thousandth of the size of the atomic nucleus, like those produced by the signals originating from the coalescence of compact stars. GWitchHunters is a citizen science project aimed at promoting the study of the Universe carried out with these detectors and the ongoing activities to improve their sensitivity to newer and further sources of gravitational waves. In order to reach the vastest possible audience, we have developed new strategies to present detector data in the form of images and sounds. Moreover, citizens are invited to contribute themselves to the improvement of these detectors by completing simple tasks, inspired by those actually carried out by researchers, that consist in identifying relations and patterns in the data. This constitutes an important aid to the detector characterization activity conducted by the scientists. All of this is proposed via the Zooniverse web platform, where citizens can get to know about the research on gravitational waves and enjoy giving their contribution to this field
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