scholarly journals Bird song and anthropogenic noise: vocal constraints may explain why birds sing higher-frequency songs in cities

2013 ◽  
Vol 280 (1754) ◽  
pp. 20122798 ◽  
Author(s):  
Erwin Nemeth ◽  
Nadia Pieretti ◽  
Sue Anne Zollinger ◽  
Nicole Geberzahn ◽  
Jesko Partecke ◽  
...  
Keyword(s):  
High Frequency ◽  
Life Histories ◽  
Vocal Communication ◽  
Traffic Noise ◽  
Low Frequency ◽  
Noise Pollution ◽  
Frequency Shifts ◽  
Severe Constraint ◽  
The Common ◽  
Common Blackbird

When animals live in cities, they have to adjust their behaviour and life histories to novel environments. Noise pollution puts a severe constraint on vocal communication by interfering with the detection of acoustic signals. Recent studies show that city birds sing higher-frequency songs than their conspecifics in non-urban habitats. This has been interpreted as an adaptation to counteract masking by traffic noise. However, this notion is debated, for the observed frequency shifts seem to be less efficient at mitigating noise than singing louder, and it has been suggested that city birds might use particularly high-frequency song elements because they can be produced at higher amplitudes. Here, we present the first phonetogram for a songbird, which shows that frequency and amplitude are strongly positively correlated in the common blackbird ( Turdus merula ), a successful urban colonizer. Moreover, city blackbirds preferentially sang higher-frequency elements that can be produced at higher intensities and, at the same time, happen to be less masked in low-frequency traffic noise.

scholarly journals Solving Noise Pollution Issue Using Plenum Window with Perforated Thin Box

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 614
Author(s):  
Hsiao Mun Lee ◽  
Andi Haris ◽  
Kian Meng Lim ◽  
Jinlong Xie ◽  
Heow Pueh Lee
Keyword(s):  
White Noise ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Experimental Results ◽  
Frequency Range ◽  
Noise Mitigation ◽  
Noise Sources ◽  
Acoustic Performance ◽  
Common Noise ◽  
The Common

In the present study, a conventional plenum window was incorporated with perforated thin box in order to enhance its performance at frequency range which centralized at 1000 Hz as most of the common noise sources at city nowadays are centralizing around this frequency. The entire studies were conducted in a reverberation room. The effectiveness of jagged flap on mitigating diffracted sound was also studied. Three types of noises were examined in the current study—white noise, traffic noise and construction noises. The experimental results showed that the plenum window with perforated thin box could reduce 8.4 dBA, 8.7 dBA and 6.9 dBA of white, traffic and construction noises, respectively. The jagged flaps did not have significant effect on the plenum window’s noise mitigation performance. When frequencies were ranging from 800 Hz to 1250 Hz, when compared with the case of without perforated thin box, it was found that the perforated thin box had good acoustic performance where it was able to reduce additional 1.6 dBA, 1.6 dBA and 1.2 dBA of white, construction and traffic noises, respectively.

The A2Π–X2Σ+ system of MgCl

1987 ◽  
Vol 65 (12) ◽  
pp. 1594-1603 ◽  
Author(s):  
M. Singh ◽  
G. S. Ghodgaonkar ◽  
M. D. Saksena
Keyword(s):  
High Resolution ◽  
Structure Analysis ◽  
Vibrational Level ◽  
High Frequency ◽  
Low Frequency ◽  
Rotational Structure ◽  
Rotational Analysis ◽  
The Common ◽  
Π State

The A2Π–X2Σ+ system of MgCl has been photographed at high resolution and analyzed for the rotational structure. Analysis of the low-frequency sub-bands of the 0–0, 0–1, and 0–2 bands showed that there is a nonzero Λ doubling in the common vibrational level ν′ = 0, thereby indicating that the A2Π state is regular and not inverted as presumed by earlier workers. Spin-doubling has been seen in the ν = 1 and 2 levels of the X2Σ+ state. Rotational analysis of the high-frequency sub-band has also been done for the 0–0 band.

scholarly journals A Review of the Impacts of Roads on Wildlife in Semi-Arid Regions

Diversity ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 81 ◽  
Author(s):  
W. Richard J. Dean ◽  
Colleen L. Seymour ◽  
Grant S. Joseph ◽  
Stefan H. Foord
Keyword(s):  
Genetic Diversity ◽  
Arid Regions ◽  
Vocal Communication ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Mitigation Measures ◽  
Obvious Effect ◽  
Long Term Impact ◽  
The Impact ◽  
Semi Arid

Roads now penetrate even the most remote parts of much of the world, but the majority of research on the effects of roads on biota has been in less remote temperate environments. The impacts of roads in semi-arid and arid areas may differ from these results in a number of ways. Here, we review the research on the impacts of roads on biodiversity patterns and ecological and evolutionary processes in semi-arid regions. The most obvious effect of roads is mortality or injury through collision. A diversity of scavengers are killed whilst feeding on roadkill, a source of easily accessed food. Noise pollution from roads and traffic interferes with vocal communication by animals, and birds and frogs living along noisy roads compensate for traffic noise by increasing the amplitude or pitch of their calls. Artificial light along roads impacts certain species’ ability to navigate, as well as attracting invertebrates. Animals are in turn attracted to invertebrates at streetlights, and vulnerable to becoming roadkill themselves. Genetics research across taxa confirms a loss of genetic diversity in small populations isolated by roads, but the long-term impact on the fitness of affected populations through a reduction in genetic diversity is not yet clear. Roads may rapidly cause genetic effects, raising conservation concerns about rare and threatened species. We assess mitigation measures and collate methods to identify the impact of roads on wildlife populations and their associated ecosystems, with a particular focus on recent advances.

scholarly journals Vibrational Cooling After Photo Isomerisation: First Application of a Novel Intramolecular Thermometer

1999 ◽  
Vol 19 (1-4) ◽  
pp. 45-49 ◽  
Author(s):  
P. Hamm ◽  
S. Ohline ◽  
M. Zurek ◽  
T. Röschinger
Keyword(s):  
Experimental Data ◽  
Schiff Base ◽  
Time Resolution ◽  
High Frequency ◽  
Low Frequency ◽  
Frequency Range ◽  
Frequency Shifts ◽  
Absorption Change ◽  
Vibrational System ◽  
Anharmonic Coupling

Femtosecond VIS-pump-IR-probe experiments (time resolution: 300fs, detectable absorption change: 5.10-5 , frequency range: 1000–1800 cm-1) were applied to the ultrafast photo isomerisation of azobenzene and the protonated Schiff base of retinal. The energy of the pump photon heats the vibrational system of the molecule, leading to pronounced anharmonic frequency shifts which are dominated by the anharmonic coupling between the investigated high frequency modes to hot low frequency modes. A model taking into account this intramolecular anharmonicity and assuming a well defined intramolecular temperature gives a good fit of the experimental data.

scholarly journals Time-domain aliasing and anti-aliasing effects in differentiating a band-unlimited signal

2018 ◽  
Vol 210 ◽  
pp. 05005 ◽  
Author(s):  
Vairis Shtrauss
Keyword(s):  
Time Domain ◽  
High Frequency ◽  
Filter Design ◽  
Low Frequency ◽  
Nyquist Frequency ◽  
Processing Mode ◽  
Type Iv ◽  
Full Band ◽  
The Common ◽  
Derivatives Of

In this paper, we investigate time-domain errors occurring in the two extreme discrete-time differentiation modes of band-unlimited signals: in the full-band processing mode and in the processing mode with ideal anti-aliasing filtering (AAF) with a cut-off at the Nyquist frequency. We disclosed that regardless sampling frequency the error from AAF is greater than the aliasing error. It is found that type IV differentiators designed by three commonly known digital filter design methods approximately equally process the high frequency portion of the signal above the Nyquist frequency with nearly equal aliasing errors having a weak dependence on differentiator length. In contrast, the differentiators very differently compute the derivatives of the low frequency portion bellow the Nyquist frequency providing rather dissimilar the common differentiation accuracy. The results show that the differentiators derived by using maximal linearity constraints are more accurate than those designed by the Parks-McClellan algorithm and the impulse response truncation method.

A Frequency-Specific Factorization to Identify Commonalities with an Application to the European Bond Markets*

2020 ◽  
Author(s):  
Simona Boffelli ◽  
Jan Novotny ◽  
Giovanni Urga
Keyword(s):  
Financial Distress ◽  
High Frequency ◽  
Low Frequency ◽  
High Frequency Data ◽  
Bond Markets ◽  
Government Bond ◽  
Bond Yields ◽  
Common Features ◽  
Exogenous Factors ◽  
The Common

Abstract We propose a frequency-specific framework to link the common features in the multivariate high-frequency price jumps with the low-frequency exogenous factors. We introduce the measure of commonality and the measure of multiplicity based on high-frequency data and define the notions of coarrivals and cojumps to explore the contribution of individual assets. We employ the framework to study the 10-year high-frequency European government bond yields over June 2009–April 2019 as a function of macrofactors, macroannouncements, bond auctions, and unconventional monetary policy announcements. Both idiosyncratic and common jump arrivals are significant, with the idiosyncratic arrivals being more sensitive to financial distress as characterized by a low level of commonality in jump arrivals.

scholarly journals VLBI Observations of Compact Extragalactic Radio Sources with Steep Spectra

1988 ◽  
Vol 129 ◽  
pp. 123-124
Author(s):  
V. K. Kulkarni ◽  
J. D. Romney
Keyword(s):  
High Frequency ◽  
Angular Size ◽  
Low Frequency ◽  
Compact Objects ◽  
Radio Sources ◽  
Structural Differences ◽  
The Common ◽  
Symmetric Structures ◽  
High Degree ◽  
Separate Class

In recent years it has become clear that the common practice of dividing radio sources into two classes, compact flat-spectrum sources and extended steep-spectrum sources is too simplistic and that compact steep-spectrum sources (CSS) sources which seem to form a separate class in themselves, need to be taken into consideration. A majority of flat-spectrum sources are known to show asymmetric or D2 structures. In contrast to this many CSS sources when observed with subarcsecond resolution show symmetric structures typical of extended steep-spectrum sources. However, further high resolution observations of CSS objects are clearly needed to establish the structural differences, if any, between the two types of compact objects and to understand the interrelationship between the three classes of objects. In this connection we have undertaken a program to observe a sample of 18 CSS sources using the European VLBI network. The sample was selected from the compilation by Peacock and Wall (1982), according to the following criteria: (1) flux density > 1.8 Jy; (2) largest angular size < 1 arc sec; and (3) steep high frequency spectral index (> 0.5) and high degree of low frequency spectral curvature. Our aim was to find out the structures common to these sources and their relation to more commonly observed “centimetre excess” compact objects. Here we will present the preliminary results.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

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