Relation of the Sound Insulating and Reflecting Properties With Noise Dampening Effect of the Construction With Coatings

1995 ◽  
Author(s):  
Michail N. Kouzmitchev
Keyword(s):  
Frequency Range ◽  
Damping Effect ◽  
Negative Effect ◽  
External Coating

Abstract Calculated evaluation of the relation of the sound insulating and reflecting properties taking into account noise damping effect of an external coating put on construction elements in water is presented by the example of a measurement made using “Underwater Measuring Tubes” installation. The expressions permitting to determine first frequency range and the frequency of largest negative effect in dependence on the parameters of a construction and coating and their materials are obtained.

scholarly journals Evaluation and Substantiation of the Necessity to Revise Guidelines for Measuring Electromagnetic Radiation of Cellular Base Stations

2020 ◽  
pp. 29-35
Author(s):  
N.V. Zaitseva ◽  
T.S. Ulanova ◽  
A.L. Ponomarev ◽  
O.A Molok ◽  
A.A. Odegov
Keyword(s):  
Radio Frequency ◽  
Electromagnetic Radiation ◽  
Mobile Communications ◽  
Biological Effects ◽  
Current Method ◽  
Base Stations ◽  
Measuring Instruments ◽  
Frequency Range ◽  
Residential Areas ◽  
Negative Effect

Introduction: Measurements of electromagnetic radiation of the radio frequency range are of great relevance due to the increasing number of transmitting radio facilities in the densely populated territories, constant cell site upgrades, and emerging communication standards. The paper presents a brief description of the biological effects of radio frequency electromagnetic radiation and shows basic mechanisms of the negative effect on the most vulnerable organs and systems. Our objective was to evaluate valid guidelines for measuring electromagnetic radiations of the radio frequency range in residential areas, in houses and public buildings. Materials and methods: We reviewed specific characteristics of cellular base and radio relay stations, compared and described electromagnetic radiation measuring devices. The provided recommendations for their selection were based on frequencies at which the communication equipment operates. We also analyzed the current guidelines with account for characteristics of transmitting radio equipment of cellular base stations and the applied measuring instruments. Results: The results of assessing established significant differences are discussed. The analysis of the requirements for measurements demonstrated significant discrepancies and contradictions between the valid documents. The evaluation results demonstrated impossibility of simultaneous measurements of electromagnetic radiation from cellular BS and RRS due to violations of requirements for measurement procedures. We concluded that, according to the current method documents, measurements of electromagnetic radiation from the fourth (4G) and fifth (5G) generation mobile communications systems were not possible. Conclusions: We revealed the necessity to revise the compared guidelines МUК 4.3.1167–02 and МUК 4.3.1677–03, to harmonize regulatory requirements for measurements, and to develop a single document guiding measurements of radio frequency electromagnetic radiation. Recommendations for taking measurements are provided.

scholarly journals Urban background noise affects breeding song frequency and syllable-type composition in the Northern Mockingbird

The Condor ◽  
2019 ◽  
Vol 121 (2) ◽  
Author(s):  
Mitchell J Walters ◽  
Robert P Guralnick ◽  
Nathan J Kleist ◽  
Scott K Robinson
Keyword(s):  
Background Noise ◽  
Peak Frequency ◽  
Frequency Range ◽  
Noise Levels ◽  
Syllable Type ◽  
Urban Background ◽  
Type Composition ◽  
Negative Effect ◽  
Song Frequency ◽  
Positive Effect

AbstractThe Northern Mockingbird (Mimus polyglottos) is a successful urban adaptor known to display flexibility in foraging, nesting, and anti-predator behavior. Its vocal behavior is also complex, with a breeding song composed of a wide variety of non-mimetic and mimetic elements, or “syllable types.” We tested the hypothesis that Northern Mockingbird adaptation to urban settings includes changes in its vocal behavior in noisy urban environments. We studied an urban/suburban mockingbird population to test the effect of urban background noise on breeding song frequency and syllable-type composition. Given that urban noise overlaps most strongly with low-frequency vocalizations, a phenomenon known as “signal masking,” we predicted a positive association between noise levels and mockingbird average peak frequency (a measure of vocalization power). We further predicted a positive effect of noise levels on the peak frequency of the lowest-pitched syllable type in a mockingbird’s song, no effect on the peak frequency of the highest-pitched syllable type, and thus a negative effect on mockingbird peak frequency range. Lastly, we predicted a negative effect of background noise on the use of syllable types experiencing heavy signal masking and, conversely, a positive effect on the use of syllable types experiencing minimal signal masking. We found a significant positive effect of noise levels on both average peak frequency and peak frequency of the lowest-pitched syllable type, but no effect on the peak frequency of the highest-pitched syllable type and peak frequency range. In addition, as background noise levels increased, we found significant declines in the percentages of heavily masked syllable types (1–3 kHz) and significant increases in the percentages of syllable types in the 3–5 kHz range; percentages of syllable types >5 kHz were, however, unaffected by background noise. These results were consistent with the hypothesis that Northern Mockingbird breeding songs change in pitch and syllable-type composition in noisy settings, providing further evidence that songs of urban-adapting species differ in noisy environments.

scholarly journals PSS Parameter Optimization Based on Comprehensive Damping Effect Method Aiming at Actual Grid Characteristics in Northern China

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xiang-Yu Liu ◽  
Yu-Ling He ◽  
Xiao-Ming Li ◽  
Peng Lu ◽  
Lun Cheng ◽  
...  
Keyword(s):  
Parameter Optimization ◽  
Northern China ◽  
Optimization Method ◽  
Frequency Range ◽  
Grid Data ◽  
Commercial Software ◽  
Damping Effect ◽  
Frequency Optimization ◽  
Frequency Properties ◽  
Effect Method

In this paper, we proposed the comprehensive damping effect method to optimize the PSS parameters. Different from other studies, the optimization in this paper is based on both the amplitude-frequency and the phase-frequency properties, while other studies mainly focus on the phase-frequency characteristics. The actual grid data in Northern China are employed to verify the optimization effect in the multimachine system. The proposed method is compared with the engineering method, the existing optimization method, and the commercial software. The comparison shows that the PSS parameters obtained by the proposed method in this paper are superior to those obtained by the engineering experience, the phase-frequency optimization method, and the commercial software. In the cases of different phase-frequency range requirements, the wider the phase-frequency range is, the better the damping effect of the obtained parameters will be.

Density-based discrimination of protein and RNA in the ribosome

1992 ◽  
Vol 50 (1) ◽  
pp. 464-465
Author(s):  
Joachim Frank
Keyword(s):  
Transfer Function ◽  
Spatial Frequency ◽  
Three Dimensional ◽  
Wiener Filter ◽  
Dark Field Image ◽  
Dark Field ◽  
Frequency Range ◽  
Bright Field ◽  
Contrast Transfer Function ◽  
Pass Filter

Cryo-electron microscopy combined with single-particle reconstruction techniques has allowed us to form a three-dimensional image of the Escherichia coli ribosome.In the interior, we observe strong density variations which may be attributed to the difference in scattering density between ribosomal RNA (rRNA) and protein. This identification can only be tentative, and lacks quantitation at this stage, because of the nature of image formation by bright field phase contrast. Apart from limiting the resolution, the contrast transfer function acts as a high-pass filter which produces edge enhancement effects that can explain at least part of the observed variations. As a step toward a more quantitative analysis, it is necessary to correct the transfer function in the low-spatial-frequency range. Unfortunately, it is in that range where Fourier components unrelated to elastic bright-field imaging are found, and a Wiener-filter type restoration would lead to incorrect results. Depending upon the thickness of the ice layer, a varying contribution to the Fourier components in the low-spatial-frequency range originates from an “inelastic dark field” image. The only prospect to obtain quantitatively interpretable images (i.e., which would allow discrimination between rRNA and protein by application of a density threshold set to the average RNA scattering density may therefore lie in the use of energy-filtering microscopes.

Evaluation of Special Hearing Aids for Deaf Children

1971 ◽  
Vol 36 (4) ◽  
pp. 527-537 ◽  
Author(s):  
Norman P. Erber
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Hearing Aid ◽  
Low Frequency ◽  
Acoustic Stimulation ◽  
Deaf Children ◽  
Frequency Range ◽  
Frequency Limit ◽  
Unpublished Studies ◽  
Published Research

Two types of special hearing aid have been developed recently to improve the reception of speech by profoundly deaf children. In a different way, each special system provides greater low-frequency acoustic stimulation to deaf ears than does a conventional hearing aid. One of the devices extends the low-frequency limit of amplification; the other shifts high-frequency energy to a lower frequency range. In general, previous evaluations of these special hearing aids have obtained inconsistent or inconclusive results. This paper reviews most of the published research on the use of special hearing aids by deaf children, summarizes several unpublished studies, and suggests a set of guidelines for future evaluations of special and conventional amplification systems.

Social Motives Predict Loneliness During a Developmental Transition

2017 ◽  
Vol 76 (4) ◽  
pp. 145-153 ◽  
Author(s):  
Jana Nikitin ◽  
Alexandra M. Freund
Keyword(s):  
Social Relationships ◽  
Well Being ◽  
Social Avoidance ◽  
Social Approach ◽  
Social Motives ◽  
Developmental Transitions ◽  
Avoidance Motivation ◽  
Negative Effect ◽  
Low Levels

Abstract. Establishing new social relationships is important for mastering developmental transitions in young adulthood. In a 2-year longitudinal study with four measurement occasions (T1: n = 245, T2: n = 96, T3: n = 103, T4: n = 85), we investigated the role of social motives in college students’ mastery of the transition of moving out of the parental home, using loneliness as an indicator of poor adjustment to the transition. Students with strong social approach motivation reported stable and low levels of loneliness. In contrast, students with strong social avoidance motivation reported high levels of loneliness. However, this effect dissipated relatively quickly as most of the young adults adapted to the transition over a period of several weeks. The present study also provides evidence for an interaction between social approach and social avoidance motives: Social approach motives buffered the negative effect on social well-being of social avoidance motives. These results illustrate the importance of social approach and social avoidance motives and their interplay during developmental transitions.

A Longitudinal Study of Mental Health in Emerging Adults

2014 ◽  
Vol 73 (3) ◽  
pp. 135-141 ◽  
Author(s):  
Monica S. Bachmann ◽  
Hansjörg Znoj ◽  
Katja Haemmerli
Keyword(s):  
Mental Health ◽  
Longitudinal Study ◽  
Emerging Adults ◽  
Poor Mental Health ◽  
Need Satisfaction ◽  
Computer Assisted ◽  
Consistency Model ◽  
Negative Effect ◽  
The Cross ◽  
Health Model

Emerging adulthood is a time of instability. This longitudinal study investigated the relationship between mental health and need satisfaction among emerging adults over a period of five years and focused on gender-specific differences. Two possible causal models were examined: (1) the mental health model, which predicts that incongruence is due to the presence of impaired mental health at an earlier point in time; (2) the consistency model, which predicts that impaired mental health is due to a higher level of incongruence reported at an earlier point in time. Emerging adults (N = 1,017) aged 18–24 completed computer-assisted telephone interviews in 2003 (T1), 2005 (T2), and 2008 (T3). The results indicate that better mental health at T1 predicts a lower level of incongruence two years later (T2), when prior level of incongruence is controlled for. The same cross-lagged effect is shown for T3. However, the cross-lagged paths from incongruence to mental health are marginally associated when prior mental health is controlled for. No gender differences were found in the cross-lagged model. The results support the mental health model and show that incongruence does not have a long-lasting negative effect on mental health. The results highlight the importance of identifying emerging adults with poor mental health early to provide support regarding need satisfaction.

Working Memory, Mental Prospection, Time Orientation, and Cognitive Insight

2013 ◽  
Vol 34 (3) ◽  
pp. 159-169 ◽  
Author(s):  
Sevtap Cinan ◽  
Aslı Doğan
Keyword(s):  
Working Memory ◽  
Structural Equation ◽  
Factor Model ◽  
Time Orientation ◽  
Equation Modeling ◽  
Cognitive Insight ◽  
Confirmatory Factor ◽  
Negative Effect ◽  
Positive Effect ◽  
Three Factor

This research is new in its attempt to take future time orientation, morningness orientation, and prospective memory as measures of mental prospection, and to examine a three-factor model that assumes working memory, mental prospection, and cognitive insight are independent but related higher-order cognitive constructs by using confirmatory factor analysis (CFA). The three-factor model produced a good fit to the data. An alternative one-factor model was tested and rejected. The results suggest that working memory and cognitive insight are distinguishable, related constructs, and that both are distinct from, but negatively associated with, mental prospection. In addition, structural equation modeling (SEM) showed that working memory had a strong positive effect on cognitive insight and a moderate negative effect on mental prospection.

A Negative Effect of Repetition On Free Recall

2011 ◽  
Author(s):  
Daniel Peterson ◽  
Knox College ◽  
Neil W. Mulligan
Keyword(s):  
Free Recall ◽  
Negative Effect
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