EVALUATION OF MEASUREMENT UNCERTAINTIES IN THE ASSESSMENT OF THE NOISE IMPACT OF SHIPS

Measurement operations are all inevitably affected by uncertainty, that is defined as the "degree of uncertainty" with which the measurement process obtains the result. It produces a range of values in which the true value of the measurand is present with a certain probability. In the specific case of the evaluation of the acoustic emissions associated with ships, this degree of uncertainty is referable to several causes, better understandable if the measurement procedures indi cated by the reference standards are described (for example ASA (Acoustical Society of America) S12.64-2009/PART 1), adopted for all types of ship (with no limitation in size) that transits at a speed not exceeding 50 kn in deep water. The standard offers three degrees of measurement (A, B or C), which differ in terms of uncertainty, complexity and repeatability. In general, information is given on the characteristics of the instru ments, signal processing and positioning of hydrophones. The standard is valid only in deep water and this represents its main limit: in the case, for example, of very large ships it is difficult to reach the great depths with the instruments. From the analysis of the prescriptions, it clearly follows that noise measurements in water are intrin sically affected by measurement errors that can be reported to the following three macro-types: 1. Error due to the degree of precision of the measurement chain 2. Error due to relative positioning between source and receivers 3. Error due to the characteristics of the measurement environment The 28th International Congress on Sound and Vibration (ICSV28), 24-28 July 2022 2 In the present work, all these possible sources of error have been evaluated on the basis of numerical simulation models whose results have been validated by experimental tests at sea, to arrive at the defi nition of a procedure for estimating the overall error inherent in the measurement and thus defining procedures for the control of the same

Holistic control of ship noise emissions

The sustainability of anthropogenic activities at sea is recently gaining more and more attention. As regards shipping, emissions from ships into the environment of various nature (engine exhaust gases, anti-fouling paints leaching, ballast exchange, releases at sea of oil and other noxious liquid or solid cargoes, of sewage and of garbage) have been recognized as sources of pollution and therefore controlled and limited since a long time. The subject of noise emission has been identified only recently. To study the problem, the EU has funded, among others, the FP7 SILENV (Ship Innovative soLutions to rEduce Noise and Vibrations) project that run from 2010 to 2012. In the present work, the holistic approach followed within the project to characterize and control the ship as a source of noise is presented. Three types of noise emissions (in air, in water and inside the ship) are analyzed highlighting peculiarities and different strategies adopted to characterize the source, the impact on the receiver and the possible solutions to set limits to the ship emissions. The project outcome included a socalled “Green Label”: a set of new prenormative requirements defined for the three main areas mentioned above

CARATTERIZZAZIONE ACUSTICA DI NAVI IN PORTO

Le sorgenti acustiche portuali sono molte e variegate: tra queste, le navi occupano un posto di primo piano. La caratterizzazione della sorgente nave non è molto trattata in letteratura e presenta aspetti problematici legati alle dimensioni del mezzo ed alla sua complessità impiantistica. Il testo riporta i risultati di una campagna sperimentale condotta nel porto di Napoli su diversi tipi di imbarcazione in condizioni transitorie e stazionarie. L’attività è propedeutica alla formulazione di un modello di propagazione verso le zone abitate che circondano il porto

Airborne Noise Prediction of a Ro/Ro Pax Ferry in the Port of Naples

Noise emissions from various transportation modes became in recent years a major concern for environmental and governmental agencies due to their impact on the community. As a result, experimental campaigns and studies have been directed towards the analysis and control of the main noise sources. Only a few analyses, however, have regarded noise exposure due to port activities. In this paper, the focus is on airborne noise emissions from a ferry ship. At first, the main onboard noise sources were identified in terms of their nature and location. Secondly, sources data on the main sources were derived, based on onboard measurements of the ferry berthed in the port of Naples. A geometrical 3D model was created, including all bodies present in the acoustic field of the surrounding area. Finally, by post processing, the consistency between actual acoustic field and numerical model results was checked

On field experimental characterisation of the ship sources of acoustic pollution within a commercial harbour

The noise associated to ship operations within large commercial harbours is an issue because often these infrastructures affect strongly the overall acoustic levels of close residential areas. The dimensions and complexity of the ship noise sources and of the transmission path to the receiver make the sound pressure field particularly complex. In this situation, even an assessment of the acoustic impact of harbours may be particularly difficult to achieve, if based on a purely experimental approach. This situation calls for the use of prediction models that, with a proper calibration, allow exploring with continuity the acoustic field in the areas around the source. Moreover, models become essential when studying corrective actions and comparing their effectiveness. Within this general context, the present work illustrates the preliminary experimental activities carried out in a part of the Naples commercial harbour for the calibration of a numerical model of the noise field associated to the operation of a specific ship. The model, based on a Ray Tracing approach, includes both the main noise sources on board the ship and the surrounding physical structures (buildings and infrastructures characterizing the area). The paper describes the main characteristics of the model and presents the procedure envisaged for its development and calibration. Results of the on-field experimental campaign in a portion of the port of Naples are presented and discussed in view of the identification and characterisation of the ship sources detected and surveyed and of the first part of the propagation path around the ship

personality and survival in older age the role of lifestyle behaviors and health status

Objective We intended to assess the relationship between personality and survival in an older population and to explore the role of lifestyle behaviors and health status as potential mediators. Design Population-based cohort study. Setting Swedish National Study of Aging and Care in Kungsholmen, Sweden. Participants 2,298 adults aged 60 or more years, without dementia or depression, followed for 11 years. Measurements Personality (extraversion, neuroticism, and openness) was assessed with a shortened version of the NEO-Five Factor Inventory. We tested whether personality affected mortality and examined the potential mediating effect of health status (body mass index, number of chronic diseases, impairment in instrumental activities of daily living, and C-reactive protein) and lifestyle behaviors (leisure activities, social network, smoking, and alcohol consumption). Results Over 11 years of follow-up, higher levels of extraversion were associated with a 14% reduction in mortality. Examination of different combinations of personality traits showed that independent of levels of neuroticism and openness, high extraversion were associated with up to 65% lower mortality. Decomposing the effect of extraversion on mortality, we found that the majority (44%) of the beneficial effect was mediated by healthy lifestyle behaviors. Health status accounted for 5% of the association. Conclusions Extroverted people, who are characterized by higher optimism and high self-efficacy, are prone to healthier behaviors and better health, which may result in longer survival. These results highlight the importance of a healthy lifestyle in survival

MODAL RESPONSE OF CABINS AT LOW FREQUENCIES IN A RO-PAX VESSEL

Onboard ship noise represents a complex issue due to the interaction of different contributions such as engines, propellers, HVAC systems, and several propagation pathways throughout the ship structure from these sources to the various occupied spaces. Resonances can occur and strongly affect the acoustical comfort into closed spaces, particularly into cabins used to rest by the crew or passengers. Four different cabin geometries from a real passenger vessel have been simulated using 3D FEM techniques in order to obtain the modal response of each enclosure at low frequencies. The density of the modal frequencies was obtained for each space. Some of those frequencies could cause annoyance and could be caused by the engines or the propellers of the ship. The presence of high acoustic pressure zones in sensible locations of the cabins is evident in all the considered geometries. This approach can represent a valuable tool at design or retrofitting stages to achieve the best possible comfort levels by adopting control measures depending on each cabin geometry

Ship propeller side effects: pressure pulses and radiated noise

The present paper deals with the side effects of propellers cavitation, i.e. pressure pulses and radiated noise. These effects are gaining more and more importance for commercial ships for different reasons. Pressure pulses significantly affect comfort onboard, thus their reduction is of utmost importance for all ships carrying passengers. As regards the underwater radiated noise, in the last decade interest has shifted from navy applications to commercial ships, due to the concern for the rising background noise in the oceans. The propellers, generating noise directly in water, represent one of the main contributions to the overall underwater noise emitted from ships. Due to the complexity of the mechanisms of propeller noise generation, different complementary strategies have to be followed to properly analyze the problem, ranging from induced pressure pulses to broadband noise and cavitation. In the present work, part of the activities carried out in the framework of the collaborative EU FP7 project AQUO (Achieve QUieter Oceans by shipping noise footprint reduction, www.aquo.eu) are reported. The paper presents the investigations carried out on a specific test case represented by a single screw research vessel, which is analyzed with three different strategies: numerical calculations, model scale investigations and full scale measurement

Molecular, cellular and physiological characterization of the cancer cachexia-inducing C26 colon carcinoma in mouse

BACKGROUND: The majority of cancer patients experience dramatic weight loss, due to cachexia and consisting of skeletal muscle and fat tissue wasting. Cachexia is a negative prognostic factor, interferes with therapy and worsens the patients' quality of life by affecting muscle function. Mice bearing ectopically-implanted C26 colon carcinoma are widely used as an experimental model of cancer cachexia. As part of the search for novel clinical and basic research applications for this experimental model, we characterized novel cellular and molecular features of C26-bearing mice. METHODS: A fragment of C26 tumor was subcutaneously grafted in isogenic BALB/c mice. The mass growth and proliferation rate of the tumor were analyzed. Histological and cytofluorometric analyses were used to assess cell death, ploidy and differentiation of the tumor cells. The main features of skeletal muscle atrophy, which were highlighted by immunohistochemical and electron microscopy analyses, correlated with biochemical alterations. Muscle force and resistance to fatigue were measured and analyzed as major functional deficits of the cachectic musculature. RESULTS: We found that the C26 tumor, ectopically implanted in mice, is an undifferentiated carcinoma, which should be referred to as such and not as adenocarcinoma, a common misconception. The C26 tumor displays aneuploidy and histological features typical of transformed cells, incorporates BrdU and induces severe weight loss in the host, which is largely caused by muscle wasting. The latter appears to be due to proteasome-mediated protein degradation, which disrupts the sarcomeric structure and muscle fiber-extracellular matrix interactions. A pivotal functional deficit of cachectic muscle consists in increased fatigability, while the reported loss of tetanic force is not statistically significant following normalization for decreased muscle fiber size. CONCLUSIONS: We conclude, on the basis of the definition of cachexia, that ectopically-implanted C26 carcinoma represents a well standardized experimental model for research on cancer cachexia. We wish to point out that scientists using the C26 model to study cancer and those using the same model to study cachexia may be unaware of each other's works because they use different keywords; we present strategies to eliminate this gap and discuss the benefits of such an exchange of knowledge