Desmonte de rochas com explosivos em áreas próximas a residenciais têm ocorrido com frequência em várias localidades em todo o Brasil. Atividades relacionadas a mineração e em especial as detonações causam muitos problemas visto que geram incômodo às comunidades vizinhas resultante de níveis elevados de pressão acústica (ruído) na atmosfera e reclamações de rachaduras em paredes das residências associadas com a propagação de vibrações no terreno. A necessidade de se obter uma melhor compreensão de como estruturas típicas da construção civil nacional respondem as vibrações geradas pelas detonações se torna evidente, bem como uma avaliação conjunta da influência de outras forças, tais como, condições meteorológicas (variações diárias de temperatura e umidade relativa do ar) que começam a agir sobre os materiais constituintes das estruturas desde o momento da construção e durante toda sua vida útil. Nesse contexto, definiu-se como meta dessa pesquisa investigar a resposta deformacional de construções de alvenaria frente aos estímulos provocados por diferentes níveis de vibração e pressão acústica gerados pelo desmonte de rochas com explosivos em diferentes condições geológicas, comparando-as com os efeitos das variações climáticas de temperatura e umidade. Visando o atendimento desta demanda, a resposta de três estruturas, duas residenciais e uma comercial, a diferentes operações com desmonte de rochas (mineração de carvão e pedreira) foram avaliadas. A movimentação das paredes de estruturas de alvenaria, comumente encontradas no entorno de empreendimentos mineiros, foi registrada com sensores de velocidade instalados nas paredes e os resultados foram correlacionados com os níveis de vibração no terreno e pressão acústica (ruído) na atmosfera que provocaram esta movimentação. A partir dos resultados das medições da movimentação das estruturas, deformações induzidas nas paredes, geradas durante trações no plano e flexões fora do plano das paredes, foram computadas e comparadas com os limites de ruptura do material mais fraco que constitui as paredes das estruturas. Em conjunto com o monitoramento da movimentação das estruturas, variações na abertura de rachaduras existentes no reboco no interior ou exterior das estruturas induzidas por forças dinâmicas (detonações) e estática (variações climáticas) foram registradas por meio de sensores de deslocamento instalados em ambos lados das rachaduras. As respostas das estruturas apresentaram excelente acoplamento da fundação com o terreno e nenhuma movimentação livre (ressonância) das paredes das estruturas foi observada após a passagem das ondas sísmicas, indicando que as estruturas seguem muito perto as excitações provocadas pelas vibrações no terreno do terreno e param de movimentar junto com o mesmo. Devido às ondas sísmicas e acústicas atingirem quase que ao mesmo tempo as estruturas, foi difícil separar a influência de cada estímulo. As deformações calculadas foram inferiores as necessárias para induzir rachaduras na argamassa utilizada como reboco nas paredes, considerada como o material mais frágil dentre os constituintes das paredes das estruturas. A resposta deformacional das rachaduras frente às variações climáticas diárias de temperatura e humidade relativa do ar foi superior as variações resultantes da influência das vibrações geradas pelas detonações. / Blasting near residential areas has become frequent in many locations throughout Brazil. Activities related to mining and in especial blasting have become a problem as they generate a potential nuisance to nearby communities resulting from high air sound pressure levels and can result in claims of wall cracking associated with ground vibrations. It was deemed necessary to have a better understanding of how structures of typical national construction respond to blast vibrations and compare this response to other forces, such as, environmental forces that naturally act on these structures since the moment they are constructed and throughout the entire life of the structure. The response of three structures, two residential and one office building, to different blasting activities (coal and quarry blasting) were evaluated in this study. Whole structure motions and the movement of existing cracks were measured in masonry built structures commonly found near mining operations. Whole structure and mid-wall motions were measured at upper and lower corners and on mid-walls using single-axis velocity transducers and compared with ground motions and air sound pressure excitations, measured next to the structures using a tri-axial geophone and microphone. Dynamic (blast-induced) and static (weather-induced) changes in crack width of existing interior and exterior wall cracks in the cement grout, typically used as wall coverage, were recorded. Dynamic structure and crack motions during blasting were time-correlated with ground vibrations and air sound pressure levels. Wall strains generated during out-of plane bending and in-plane tensile strains were computed and compared with the failure strains for the weakest material comprising the wall construction. Long-term crack movement with variations in temperature and humidity were compared with blast-induce peak crack displacements. The structures response showed good coupling of the foundations with the ground and no free-response was observed after the cessations of the ground excitations, indicating the structures are rigid following very close the ground excitation. Because air sound pressure levels and ground motions arrived at the same time in the structures, it was difficult to separate the influence of each stimulus. Calculated strains were lower than the required to induce cracks in the cement grout and environmental-induced crack response, resultant from daily changes in temperature and humidity, were greater than the response caused by blast-induced ground motions and air sound pressure levels in crack aperture.

Desmonte de rochas com explosivos em áreas próximas a residenciais têm ocorrido com frequência em várias localidades em todo o Brasil. Atividades relacionadas a mineração e em especial as detonações causam muitos problemas visto que geram incômodo às comunidades vizinhas resultante de níveis elevados de pressão acústica (ruído) na atmosfera e reclamações de rachaduras em paredes das residências associadas com a propagação de vibrações no terreno. A necessidade de se obter uma melhor compreensão de como estruturas típicas da construção civil nacional respondem as vibrações geradas pelas detonações se torna evidente, bem como uma avaliação conjunta da influência de outras forças, tais como, condições meteorológicas (variações diárias de temperatura e umidade relativa do ar) que começam a agir sobre os materiais constituintes das estruturas desde o momento da construção e durante toda sua vida útil. Nesse contexto, definiu-se como meta dessa pesquisa investigar a resposta deformacional de construções de alvenaria frente aos estímulos provocados por diferentes níveis de vibração e pressão acústica gerados pelo desmonte de rochas com explosivos em diferentes condições geológicas, comparando-as com os efeitos das variações climáticas de temperatura e umidade. Visando o atendimento desta demanda, a resposta de três estruturas, duas residenciais e uma comercial, a diferentes operações com desmonte de rochas (mineração de carvão e pedreira) foram avaliadas. A movimentação das paredes de estruturas de alvenaria, comumente encontradas no entorno de empreendimentos mineiros, foi registrada com sensores de velocidade instalados nas paredes e os resultados foram correlacionados com os níveis de vibração no terreno e pressão acústica (ruído) na atmosfera que provocaram esta movimentação. A partir dos resultados das medições da movimentação das estruturas, deformações induzidas nas paredes, geradas durante trações no plano e flexões fora do plano das paredes, foram computadas e comparadas com os limites de ruptura do material mais fraco que constitui as paredes das estruturas. Em conjunto com o monitoramento da movimentação das estruturas, variações na abertura de rachaduras existentes no reboco no interior ou exterior das estruturas induzidas por forças dinâmicas (detonações) e estática (variações climáticas) foram registradas por meio de sensores de deslocamento instalados em ambos lados das rachaduras. As respostas das estruturas apresentaram excelente acoplamento da fundação com o terreno e nenhuma movimentação livre (ressonância) das paredes das estruturas foi observada após a passagem das ondas sísmicas, indicando que as estruturas seguem muito perto as excitações provocadas pelas vibrações no terreno do terreno e param de movimentar junto com o mesmo. Devido às ondas sísmicas e acústicas atingirem quase que ao mesmo tempo as estruturas, foi difícil separar a influência de cada estímulo. As deformações calculadas foram inferiores as necessárias para induzir rachaduras na argamassa utilizada como reboco nas paredes, considerada como o material mais frágil dentre os constituintes das paredes das estruturas. A resposta deformacional das rachaduras frente às variações climáticas diárias de temperatura e humidade relativa do ar foi superior as variações resultantes da influência das vibrações geradas pelas detonações. / Blasting near residential areas has become frequent in many locations throughout Brazil. Activities related to mining and in especial blasting have become a problem as they generate a potential nuisance to nearby communities resulting from high air sound pressure levels and can result in claims of wall cracking associated with ground vibrations. It was deemed necessary to have a better understanding of how structures of typical national construction respond to blast vibrations and compare this response to other forces, such as, environmental forces that naturally act on these structures since the moment they are constructed and throughout the entire life of the structure. The response of three structures, two residential and one office building, to different blasting activities (coal and quarry blasting) were evaluated in this study. Whole structure motions and the movement of existing cracks were measured in masonry built structures commonly found near mining operations. Whole structure and mid-wall motions were measured at upper and lower corners and on mid-walls using single-axis velocity transducers and compared with ground motions and air sound pressure excitations, measured next to the structures using a tri-axial geophone and microphone. Dynamic (blast-induced) and static (weather-induced) changes in crack width of existing interior and exterior wall cracks in the cement grout, typically used as wall coverage, were recorded. Dynamic structure and crack motions during blasting were time-correlated with ground vibrations and air sound pressure levels. Wall strains generated during out-of plane bending and in-plane tensile strains were computed and compared with the failure strains for the weakest material comprising the wall construction. Long-term crack movement with variations in temperature and humidity were compared with blast-induce peak crack displacements. The structures response showed good coupling of the foundations with the ground and no free-response was observed after the cessations of the ground excitations, indicating the structures are rigid following very close the ground excitation. Because air sound pressure levels and ground motions arrived at the same time in the structures, it was difficult to separate the influence of each stimulus. Calculated strains were lower than the required to induce cracks in the cement grout and environmental-induced crack response, resultant from daily changes in temperature and humidity, were greater than the response caused by blast-induced ground motions and air sound pressure levels in crack aperture.

Os fatores físicos que envolvem a incubação artificial são determinantes no desenvolvimento embrionário, eclosão e desempenho das aves. Muitos deles são bem-conceituados, mas acredita-se que ainda existem questões que possam prover melhorias ou adaptar este processo as novas demandas da produção animal. Nesta pesquisa, a bioacústica é colocada como uma dessas questões, motivando a investigação da estimulação sonora na incubação artificial, dados os efeitos do ruído dos incubatórios comerciais e a adição de vocalizações da espécie em respostas fisiológicas, produtivas e comportamentais de pintos de corte. Inicialmente, o Capítulo 3 apresenta a mensuração do nível de pressão sonora (NPS) no interior dos ovos. Para isso, desenvolveu-se um sensor de tamanho reduzido (decibelímetro-miniaturizado) utilizando a plataforma Arduíno®. O sensor foi calibrado e testado, o que forneceu informações como o isolamento da onda sonora pela casca dos ovos e valores de NPS próximos aos embriões. Em sequência realizaram-se incubações experimentais com a aplicação de tratamentos determinados pela associação de dois NPS do ruído de incubadoras [70 ou 90 dB (A)] com ou sem a adição de vocalizações da espécie (estímulos naturais). Estes tratamentos foram avaliados no crescimento embrionário e em respostas da eclosão (Capítulo 4) e no desempenho de pintos de corte na primeira semana (Capítulo 5). Diferente do esperado, a exposição ao maior NPS, que simulava o ruído de incubatórios comerciais, adiantou o tempo para o início das eclosões, aumentou a eclodibilidade e a qualidade do umbigo e jarretes dos pintos. Todavia, as vocalizações da espécie só se mostraram influentes se associadas ao NPS de 70 dB (A). Nas respostas de desempenho a exposição ao NPS inferior resultou em um maior consumo de ração e em uma pior conversão alimentar, com melhores resultados na exposição a 90 dB (A) ou na presença das vocalizações. Por fim, no Capítulo 6, testes comportamentais como o de imobilidade tônica, isolamento social e campo aberto foram realizados com os pintos eclodidos dos tratamentos de incubação descritos anteriormente. Na realização destes testes consideraram-se três períodos no pós-eclosão (24, 72 e 120 horas) e duas condições (testes em silêncio ou com vocalizações ao fundo). Os efeitos da estimulação sonora foram verificados somente em 24 horas pós-eclosão, de modo que a exposição às vocalizações no desenvolvimento embrionário reduziu a movimentação e o nível de vocalização dos pintos, o que foi associado ao menor estresse. Conclui-se que a estimulação sonora na incubação artificial é capaz de alterar respostas produtivas e o comportamento de pintos após a eclosão. / The physical factors that involve artificial incubation are determinant to the embryonic development, hatching and performance of chicks. Although many of them are highly regarded, there are other issues capable of improving or adapting the process to new animal-production demands. The current research addresses the bioacoustics as one of such issues, which motivated the investigation of the sound stimuli in artificial incubation, relating the noise of the commercial hatcheries and the addition of vocalizations of the species with physiological, productive and behavioral of chicks. Initially, the Chapter 3 presents the measuring the sound pressure level (SPL) inside eggs. To do so, a small sensor (miniaturized decibel meter) was developed in the Arduino® platform. The sensor was calibrated and tested under specific conditions to collect information, such as sound wave isolation by egg shells and SPL values close to the embryos. Experimental incubations with treatments based on the association between two noise SPLs of the hatcheries [70 or 90 dB (A)] with, or without, the addition of species-specific vocalizations (natural stimulus). These treatments were evaluated on embryo growth and hatch responses (Chapter 4) and chicks performance in the first week of life (Chapter 5). Against all expectations, egg exposure to the highest SPL, which simulated the noise of commercial hatcheries, reduced the time necessary for hatching, besides increasing the hatchability, as well as the quality of the navel and hocks, of chicks. On the other hand, species-specific vocalizations were only influential when they were associated with 70 dB SPL (A). The exposure to lower NPS resulted in higher feed intake and lower feed conversion with better results in exposure to 90 dB (A) or in the presence of vocalizations. Finally, in Chapter 6, behavioral tests such as tonic immobility, social isolation and open field tests applied to chicks hatching from the incubation treatments described above. The tests comprised three post-hatching periods (24, 72 and 120 hours) and two conditions (silence or species-specific vocalizations in the background). The effects of incubation treatments were just observed in some responses and 24 hours after hatching. The exposure to the vocalizations during embryonic development reduced chicks\' movement and vocalization level, which was associated with lower stress. It is concluded that sound stimulation in hatcheries can alter productive responses and behavior of chicks after hatching.

Noise is a circumstance of ordinary life and mainly originated by continually growing dynamic and the rapid development of society. In the industrial environment there are noise-intensive parts that influence the condition of present operators negatively. Thus, measures of noise abatement have been investigated intensely by industrial companies as well as federal agencies. As a subdomain of fluid power pneumatics is especially known for characteristic noise emission by the use of air as power transmission. The transient decompression of air from pressure levels up to 8 bar and partly high flow rates nearby sonic speed cause the emergence of direct airborne noise at vent ports of pneumatic components. The following paper outlines the mechanisms that induce the emission of high sound pressure levels. In order to achieve reproducible results a test bench for varying pneumatic standard components is introduced. Based on a selection of those components results are compared to standardized measurement procedures whether fulfilling the standardizations’ requirements. In conclusion, two benefits are achieved. Firstly, standardization is derived enabling neutral comparison of standard pneumatic components’ noise emission. Secondly, the measures can be evaluated to determine the most promising way to redesign pneumatic components of lower noise emissions.

Behovet av en mer mobil granatkastare har resulterat i en utredning av möjliga koncept som sedan ska gallras bort och resultera i en investering i ett nytt fordonsmonterat granatkastarsystem. Denna rapport beskriver utredningen av en potentiell risk med ett av de potentiella koncepten. Konceptet består av att placera en granatkastare i personalutrymmet i en stridsfordon90-vagn och avfyra den med öppna takluckor. Detta koncept har använts av andra länder och deras arméer, bland dem finns USA som använder sig av fordonsplattformen Stryker. Säkerheten för soldaterna i Försvarsmakten är högt prioriterat och strängt reglerat av standarder och reglementen som ständigt revideras. Den största potentiella risken med det aktuella konceptet har identifierats att vara ljudtrycksnivån som soldaterna utsätts för vid avfyrning. Om en undersökning av ljudtrycksnivåerna skulle visa att konceptet inte är säkert så finns därmed inget behov att vidare utreda konceptet och det skulle därmed bli uteslutet. För att fastställa vilka nivåer som kan förväntas av denna lösning så planerades och genomfördes en testskjutning med hjälp av FMV Test och Evaluering i Karlsborg samt representanter från BAE Systems Hägglunds. Provskjutningen genomfördes genom att placera den svenska 120mm granatkastaren M/41 i ett testchassi, som i stora drag motsvarar Strf90 chassiet, och sedan skjuta granater i flera olika testscenarion för att undersöka parametrarna elevation, laddning, riktning, användning av tratt, vinkel på takluckor öppen/stängd bakre lucka samt upphöjt chassi.Provet visade att dubbla hörselskydd kommer att behövas inne i fordonet och att potentiellt kommer personal längst in i fordonet att klara sig med enkla hörselskydd. Högst troligt är att det slutgiltiga konceptet kommer att ha en begränsning på 30-50 avfyrningar per dag med högsta laddning, 40-50 med laddning 7 och 70-80 med laddning 5. Användning av en tratt visade sig effektivt och minskade ljudtrycksnivån med 5-10 dB och därmed ökar antalet tillåtna avfyrningar till över 100 skott per dag för högsta laddningen. / The need of a more mobile mortar has led to an investigation of possible concepts which will be narrowed down and end in a purchase of a self-propelled mortar system. This report describes the exploration of a possible risk with one of these concepts. The concept is to place a mortar in the back storage area of a CV90 where it will be fired with open hatches. This concept has been used by other countries armies, amongst them the US Army which uses the Stryker vehicle platform.The safety of the personnel in the Swedish Army is prioritized and strictly regulated by set standards and regulations which are frequently revised. The largest potential risk with the concept in question has been identified to be the sound pressure acting on the personnel. If the concept would indicate levels over the permissible levels it would not have any potential and would not be further investigated.To conclude which levels a concept like this would have, a test shooting was planned and conducted with the help from FMV Test and Evaluation centre in Karlsborg and representatives from BAE Systems HägglundsThe shooting was conducted by placing the Swedish 120 mm mortar GRK M/41 inside a CV90 chassis mock-up and firing grenades in several scenarios which would test the different parameters; elevation, charge, direction, BAD, angle of roof hatches, open/closed rear door and elevated chassis.The test showed that double ear protectors will be needed in the vehicle and with the potential that it will suffice with single ear protectors for personnel furthest in the vehicle. It is most likely that it will be restrictions on number of permissible rounds fired per day of 30-50 firings for charge 9, 40-50 with charge 7 and 70-80 with charge 5.The use of BAD resulted in the sound level decreasing between 5-12 dB which would increase the restrictions to a maximum of 100 rounds per day for maximum charge.

In the advent of increasing the number of operable unmanned aerial systems (UAS) over the next years, a challenge exists in regard to the noise signature that these machines may generate. In this work, we perform advanced computational simulations to study the flow around an airfoil and the associated noise radiating to the near- and farield. The airfoil size and the freestream velocity are representative of a typical UAS. The study is aimed at investigating the characteristics of the aerodynamic noise radiating from an airfoil at various angles of attack, Reynolds number and Mach number. The numerical tool is a high-order compressible Navier-Stokes solver, using Runge-Kutta explicit time integration and dispersion-relation-preserving spatial discretization. Various results in terms of velocity and pressure distribution around the airfoil, and sound pressure level spectra calculated from different probe points located in the near- and farield are compared to each other and discussed.

Closer attention has been given to the acoustic noise performance of electric motors as electrified powertrains penetrate into the transportation system. Particularly, switched reluctance machines (SRMs) introduce a new challenge to the acoustic noise aspects given that the radial force harmonics can excite the natural frequencies of the main circumferential modes. A practical understanding of the radial force density decomposition is crucial in identifying the primary source of acoustic noise at different operating points, and it is one of the contributions of this thesis. An analytical expression is introduced to identify the temporal harmonic orders that excite different spatial mode shapes. The mode excitation is investigated along with the sound pressure level (SPL) produced by the primary vibrating mode shapes. Acoustic noise characteristics for each mode and the corresponding natural frequency at different speeds have been analyzed by using a waterfall plot. The acoustic noise generation by conventionally controlled SRMs prevents its use on applications where acoustic comfort is required. Acoustic noise is radiated by the stator frame when a vibration mode is excited by the respective spatial order at a forcing frequency that is close to the stator's modal natural frequency. The excitation surface wave is the radial force density waveform as a function of time and spatial position. From the harmonic content analysis, a phase radial force shaping method is for switched reluctance machines is proposed. A generic function for the radial force shape is identified, whose parameters are calculated by an optimization algorithm to minimize the torque ripple for a given average torque. From the phase radial force, a current reference is obtained. The proposed methodology is experimentally validated, with a four-phase 8/6 SRM, by acoustic noise measurements at different speeds and load torque conditions. / Thesis / Doctor of Philosophy (PhD)

The acoustic source structure, acoustic farfield, and duct terminating impedances fully describe the acoustics of a source within a duct. A main goal in the study of noise generated by turbulent combustion is to characterize the structure of the flame as an acoustic source. Data describing the farfield and duct terminating conditions allow for the testing of combustion noise models. The acoustic farfield of a premixed flame burner is documented for various power levels and air-to-fuel ratios. The terminating impedance of the burner exhaust is determined by a method using the transfer function between two microphones that communicate with the acoustic field inside the duct. High temperature probes isolate the microphones from extreme temperatures within the duct while only slightly distorting the results. The real part of the terminating impedance agrees with a correlation in the literature for hot flow leaving a duct. / M.S.

Une limitation fondamentale du problème inverse acoustique est déterminée par la taille et la densité de l'antenne de microphones. Une solution pour atteindre une grande antenne et / ou à forte densité de microphones est de scanner l'objet d'intérêt en déplaçant séquentiellement une antenne de petites dimensions (mesures dites séquentielles). La différence entre des mesures séquentielle et une mesure simultanée en tous points est que dans ce dernier cas, l'intégralité de la matrice interpectrale peut être estimée, contrairement au cas des mesures séquentielles qui ne permettent l'estimation que d'une partie réduite de cette matrice; les éléments croisés (interspectres) entre deux points de mesures n'appartenant pas à la même séquence ne sont pas estimés. Néanmoins, ces données restent nécessaires pour la reconstruction acoustique. Dans l'approche classique, une ou plusieurs références sont utilisées pour retrouver les données manquantes. L'objet de cette thèse est de récupérer les éléments manquants de la matrice interspectrale sans capteurs de référence, dans le cas où le champ acoustique est suffisamment cohérent pour mettre en œuvre les mesures séquentielles. Deux modèles de spectre de valeurs propres parcimonieux sont proposés pour résoudre ce problème, le premier impose une valeur faible de rang, tandis que le second repose sur la minimisation de la norme nucléaire (recherche d'une solution faiblement parcimonieuse). / A fundamental limitation of the inverse acoustic problem is determined by the size of the array and the microphone density. A solution to achieve large array and/or high microphone density is to scan the object of interest by moving sequentially a small prototype array, which is referred to as sequential measurements. In comparison to a large array and/or high microphone density array that can acquire simultaneously all the information of the spectral matrix, in particular all cross-spectra, sequential measurements can only acquire a block diagonal spectral matrix, while the cross-spectra between the sequential measurements remain unknown due to the missing phase relationships between consecutive positions. Nevertheless, these unknown cross-spectra are necessary for acoustic reconstruction. The object of this thesis is to recover the missing elements of the spectral matrix in the case that the acoustical field is highly coherent so as to implement the sequential measurements. Sparse eigenvalue spectrum are assumed to solve this problem, which lead to a structured low rank model and a weakly sparse eigenvalue spectrum model.

Comparisons were made between changes in the audibility of bone-conduction stimuli to differences in the sound pressure present in the external auditory canal when ears were occluded. Fifteen listeners with normal middle ear function were tested using pure tones of 250, 500, and 1000 Hz, delivered via a bone-conduction oscillator placed on the mastoid process and the frontal bone. At all three frequencies, and both sites of stimulation, ear canal sound pressures were greater in the occluded than in the unoccluded conditions. Concurrently, the test signals were detected at lower intensities, although the changes in audibility and external canal sound pressure levels were not unity. The occlusion effect was attenuated slightly when the skull was vibrated from the frontal bone.