95 research outputs found
Maple River Dam Removal Project
Limnologyhttps://deepblue.lib.umich.edu/bitstream/2027.42/143561/1/Klier_Lugten_2017.pd
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An experimental study on the shielding performance of buildings exposed to aircraft noise comparing measurements near front and rear facades
© 2016, German Acoustical Society (DEGA). All rights reserved. This paper explores the shielding properties of buildings exposed to aircraft noise by comparing sound levels near front and rear facades at two locations in the proximity of Amsterdam Schiphol Airport. The focus of the study lies on an experimental approach to measure the shielding capacity of airplanes as fast moving source passes, but primarily on how the urban environment might contribute to noise attenuation from air traffic. The paper therefore builds on studies about shielding effects of buildings seen from an architectural design perspective. In total three pilot studies 45 fly-overs were recorded by microphones in front and behind buildings. One pilot study focuses on ascending airplanes and two on landings. The shielding effect of the building was calculated by subtracting the OASPL (overall A-weighted sound pressure level) graphs of the microphones for the first four seconds of a stabilized sound peak evoked by the passing airplane. A spectral analysis for these time frames is added to study the shielding effects for octave bands between 31.5 and 4000 Hz. The results show that the two buildings have a mean shielding effect of around 11 dB(A) for landings and 14 dB(A) for ascending airplanes, when taking into account the moment sound levels peak at microphone due to a passing airplane. The results show a large variance between results of single flyovers, mainly at the octave bands between 31.5 and 4000 Hz. For instance, for landings the figures show a range between 0 and 7 dB for eight octave bands below 125 Hz while variance stretches between 8 and 14 dB above 125 Hz. For starts these results were respectively around 4 dB for octave bands below 125 Hz and ranges between 8 and 12 dB for bands between 125 and 4000 Hz.Cambridge Trus
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Tranquillity by design - Architectural and landscape interventions to improve the soundscape quality in urban areas exposed to aircraft noise
The noise emissions from aircraft negatively impact the quality of life for those in areas around airports. Excess noise levels can cause stress-related complaints, leading to adverse health effects. Although newer aircraft are significantly quieter than older models, aircraft noise pollution remains a problem. Literature suggests that the level of aircraft noise annoyance people experience is equally dependent on the level of disturbance induced by the sound and individuals’ perceived level of their own ability to cope with and control it. Traditionally, noise prediction models are used to determine the noise load around airports. If levels are deemed too high, building restrictions are put in place, and house owners are either bailed out or receive funding for acoustic insulation. However, literature on road traffic noise shows that the design of the environment that surrounds individuals has a great impact on their perception of noise annoyance. For instance, the design of buildings, streets and cities influence the propagation of sound around buildings. This can reduce or amplify the sound levels locally. Furthermore, the presence of natural features, such as trees and moving water, can evoke a more positive auditory sensation in areas exposed to traffic noise. Without changing the sound exposure levels, the sight and proximity of vegetation improves the individuals’ assessment of the soundscape quality and reduces the level of noise annoyance. Like landscapes, the perception of the acoustic environment, or soundscape, is the result of design choices.
Nevertheless, the question remains as to whether the design of the built environment can yield a similar effect for aircraft noise. The doctoral research focused on this question, from both an acoustic and soundscape-perception perspective, and comprised four separate studies. The first study presents the results of a systematic in-situ measurement study, in which the sound attenuating effects of buildings exposed to aircraft noise were assessed. In the second chapter, the results from the first study were used to develop and test a method to predict the propagation of aircraft noise around buildings in a numerical acoustic model. The third study used the numerical model to compare the noise attenuation effects of building design parameters, namely height, form and cladding. The fourth chapter explored the perception of aircraft noise in urban areas with or without moving water and vegetation, using virtual-reality. Together, the four studies provide tools that can be used by architects and urban designers to improve the soundscape quality in areas affected by aircraft noise. Depending on the location and local acoustic situation, different alternatives are possible, which are supported by the results presented in this thesis.Cambridge Trust, Dutch Aerospace Centre (NLR), City of Amsterdam, City of Haarlemmermeer, Province of Noord-Hollan
Observations of the rotational transitions of OH from the Orion molecular cloud
A summary of observed rotationally excited, far infrared OH line emissions from Orion-KL made using the Kuiper Airborne Observatory is given, together with a list of the resulting publications, talks, and lectures based on this data. In addition, a paper is appended, particularly addressing the (16)OH and (18)OH emission from Orion-KL. The first detections of the (16)OH (2)pi(1/2) to (2)pi(3/2) J = 3/2(-) to 3/2(+) rotational cross-ladder transition (53.351 micrometer) and the (18)OH (2)pi(3/2) J = 5/2(+) to 3/2(-) rotational ground-state transition (120.1719 micrometer). It is found that both of these lines exhibit a P-Cygni profile
How Entropy Explains the Emergence of Consciousness: The Entropic Theory
Emergentism as an ontology of consciousness leaves unanswered the question as to its mechanism. I aim to solve the Body-Mind problem by explaining how conscious organisms emerged on an evolutionary basis at various times in accordance with an accepted scientific principle, through a mechanism that cannot be understood, in principle. The reason for this cloak of secrecy is found in a seeming contradiction in the behavior of information with respect to the first two laws of thermodynamics. Information, the microstate of particles within an isolated system's macrostate, can, like first law energy, be neither created nor destroyed, yet the information in the system, like second law entropy, will inevitably increase. To explain information increasing without being created, Laplace's demon is invoked, able to predict where each particle is destined. This doesn't work for emerging events like consciousness, which are Unpredictable. This can be understood in terms of the derivation of entropy, and the Emergence of classical physics, from the Relativistic Transactional Interpretation of Quantum Mechanics. I propose that the increased entropy in a time-irreversible, Unpredictable (emergent) isolated system requires the simultaneous deletion of information concerning the steps, or calculations, involved. Thus, the steps leading to consciousness are immediately destroyed and must remain a mystery. Implications include that entropy, not panpsychism, is the Universal principle generative of consciousness, that our being conscious proves that we are not predetermined, and that consciousness requires assuming an "entropy debt" that can only be repaid by living organisms, prohibiting the emergence of conscious machines
Effects of forest features and location on emerald ash borer (Agrilus planipennis) infestation severity of ash (Fraxinus spp.) trees
Forest EcosystemsThe Emerald Ash Borer (Agrilus planipennis; EAB) is a well-studied invasive species that was first discovered in the United States in 2002 (Herms and McCullough, 2014), and has spread quickly since, infesting all ash (Fraxinus sp .) trees native to the U.S (Cappaert et al., 2005). Once symptoms are observed, infested trees die within 3-4 years (Herms and McCullough, 2014). Difficulty in detecting new infestations has made them dffficult to contain. EAB prefers Fraxinus spp. stems grown individually in sunlight (Chen and Poland, 2009). Previous studies have also shown that lakes can act as barriers restricting insect pest dispersal (Kim and McPheron,1993). Additionally, there are conflicting results in previous literature regarding Fraxinus spp. density and EAB 's rate of infestation (Krlight et al., 2013; Chen et al., 2009). In order to further investigate these variables' effects on infestation, we considered three questions: ( 1) Does the density of surrounding Fraxinus spp. stems affect the severity of an individual's EAB infestation; (2) Does the distance between a Fraxinus spp. stem and the shoreline affect the severity of its EAB infestation; (3) Does the level of canopy cover surrounding an individual Fraxinus spp. stem affect the severity of its EAB infestation? We created three transects on the University of Michigan's Biological Station (UMBS) property. In each transect we recorded canopy cover, density, and severity of infestation for each Fraxinus spp. stem. Distance to shoreline and density were mapped in ArcGIS. The three Fraxinus spp. found in northern Michigan, F. americana, F. nigra., and F. pennsylvanica are all affected by EAB equally (Agiuset al., 2005), therefore differentiation by species was deemed irrelevant to this study. We found a significant inverse correlation with a weak R2 value between Fraxinus spp. stem density and severity of infestation on individual stems. Our data support the hypothesis that increased Fraxinus spp. density within a stand is associated with slower mortality due to EAB infestation. We found no significant correlation between EAB infestation severity and canopy cover or distance to shoreline. In forest stands, the canopy cover of each stem does not affect whether or not it suffers more severe infestati6ns. We hypothesize that Douglas and Burt Lakes are either not significant barriers to the spread of EAB, or that they are no longer effective barriers.https://deepblue.lib.umich.edu/bitstream/2027.42/143559/1/Jubera_Kaczmarek_Lugten_McClendon_Soulliere_2017.PD
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