scholarly journals INFLUENCE OF DIFFERENT LOADS ON THE PROPERTIES OF LIGHTWEIGHT COMPOSITE

2012 ◽  
Vol 18 (3) ◽  
pp. 386-392
Author(s):  
Modestas Kligys ◽  
Marijonas Sinica ◽  
Georgijus Sezemanas ◽  
Kęstutis Miškinis ◽  
Saulius Vaitkus
Keyword(s):  
Sound Pressure Level ◽  
Unit Volume ◽  
Sound Pressure ◽  
Dynamic Stiffness ◽  
Point Load ◽  
Expanded Polystyrene ◽  
Pressure Level ◽  
Cement Matrix

The paper describes the study on the operational properties of lightweight composite with density of 150–350 kg/m3. It was established that these properties depend on the ratio of porous cement matrix and inclusions of crushed expanded polystyrene packing tare waste per unit volume of the lightweight composite. Studies have demonstrated that when the density of lightweight composite varies in the above mentioned limits, the compressibility amounts to 2.4–0.8 mm, point load – 0.38–3.39 kN, dynamic stiffness – 35–135 MN/m3, and reduction in normalised impact sound pressure level – 26–17 dB. The dependences between the established properties and the density of lightweight composite are showed in the equations of regression. Possible versions for the use of lightweight composite in different constructions of floors and roofs are also provided.

Estimation of Acoustical Performance of Floating Floors from Dynamic Stiffness of Resilient Layers

2005 ◽  
Vol 12 (2) ◽  
pp. 99-113 ◽  
Author(s):  
Alessandro Schiavi ◽  
Andrea Pavoni Belli ◽  
Francesco Russo
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Dynamic Stiffness ◽  
Damping Ratio ◽  
Pressure Level ◽  
International Standard ◽  
And Performance ◽  
The Impact ◽  
The Relationship ◽  
Over Time

This paper describes a procedure for evaluating the reduction in impact sound pressure level of floating floors by measuring the apparent dynamic stiffness of the resilient layer, according to International Standard EN 29052-1. The impact sound pressure level experimental data, obtained according to International Standard UNI EN ISO 140-8, was compared with estimates obtained from dynamic stiffness measurements. Results confirm the effectiveness of the empirical model. Two questions are addressed. The first concerns the decrease in layer thickness over time. The second concerns the relationship between damping ratio and performance.

Impact sound pressure values - Field measurements for different configurations of concrete slabs on the ground

2021 ◽  
Vol 263 (6) ◽  
pp. 54-65
Author(s):  
Bernt Mikal Larsen
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Concrete Slab ◽  
Field Measurements ◽  
Expanded Polystyrene ◽  
Pressure Level ◽  
Concrete Slabs ◽  
Plastic Film ◽  
Room Volume ◽  
Slabs On Ground

The presentation will summarize and discuss values of field measured normalized impact sound pressure level L'n,w measured sideways with different configurations of concrete slabs on ground within buildings. All results are adjusted to receiving room volume of 100 m3 and with thickness of concrete slab 80-100 mm. Measurement on continuous concrete slab on expanded polystyrene gives L'n,w between adjoining rooms of 74 dB. Different principles of splitting have been investigated to evaluate the effect on L'n,w. The configuration where only the concrete slab is split (and with a plastic film between the concrete base and the upper layer of expanded polystyrene), gives L'n,w of approximately 66 dB which is 8 dB lower than for a continuous bare concrete slab. When both the concrete slab and the upper layer of expanded polystyrene are split, measurements show L'n,w of 58-61 dB for the case of no flooring, which is 13-16 dB lower than for a continuous concrete slab (no split). When both concrete slab and all layers of polystyrene are split down to continuous foundation measurements show L'n,w of 55 dB. The situation with concrete slab and all layers of polystyrene split and with no foundation beneath gives L'n,w of 46 dB. Consequences for airborne sound and R'w will be discussed as well for the above mentioned configurations.

Estimation of the Reduction in Impact Sound Pressure Level of Floating Floors from the Dynamic Stiffness of Insulation Layers

1996 ◽  
Vol 3 (1) ◽  
pp. 33-53 ◽  
Author(s):  
H.A. Metzen
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Dynamic Stiffness ◽  
Measurement Procedure ◽  
Pressure Level ◽  
Sound Insulation ◽  
Relevant Parameter ◽  
Short Term ◽  
Surface Mass ◽  
Acoustical Properties

The most relevant parameter for assessing the acoustical properties of insulation layers for floating floor applications is the dynamic stiffness. Besides the surface mass of the floor plate the dynamic stiffness influences the reduction in impact sound pressure level of a floating floor. According to the formerly German measurement standard DIN 52214 the dynamic stiffness of impact sound insulation materials had to be measured after applying a short-term pre-load of 50 kNm−2. This pre-load does not reflect the conditions in the field and has been withdrawn in EN 29052-I. By comparison of measured field data for floor constructions with estimated data based on measurements with and without pre-load it is shown, that the new measurement procedure in connection with a more detailed estimation of the building element properties leads to a more accurate prediction of impact sound insulation in dwellings.

Contributions of Voice and Nonverbal Communication to Perceived Masculinity–Femininity for Cisgender and Transgender Communicators

2020 ◽  
Vol 63 (4) ◽  
pp. 931-947
Author(s):  
Teresa L. D. Hardy ◽  
Carol A. Boliek ◽  
Daniel Aalto ◽  
Justin Lewicke ◽  
Kristopher Wells ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Vocal Tract ◽  
Presentation Mode ◽  
Pressure Level ◽  
Presentation Modes ◽  
Audiovisual Stimuli ◽  
Vocal Tract Resonance ◽  
Point Light

Purpose The purpose of this study was twofold: (a) to identify a set of communication-based predictors (including both acoustic and gestural variables) of masculinity–femininity ratings and (b) to explore differences in ratings between audio and audiovisual presentation modes for transgender and cisgender communicators. Method The voices and gestures of a group of cisgender men and women ( n = 10 of each) and transgender women ( n = 20) communicators were recorded while they recounted the story of a cartoon using acoustic and motion capture recording systems. A total of 17 acoustic and gestural variables were measured from these recordings. A group of observers ( n = 20) rated each communicator's masculinity–femininity based on 30- to 45-s samples of the cartoon description presented in three modes: audio, visual, and audio visual. Visual and audiovisual stimuli contained point light displays standardized for size. Ratings were made using a direct magnitude estimation scale without modulus. Communication-based predictors of masculinity–femininity ratings were identified using multiple regression, and analysis of variance was used to determine the effect of presentation mode on perceptual ratings. Results Fundamental frequency, average vowel formant, and sound pressure level were identified as significant predictors of masculinity–femininity ratings for these communicators. Communicators were rated significantly more feminine in the audio than the audiovisual mode and unreliably in the visual-only mode. Conclusions Both study purposes were met. Results support continued emphasis on fundamental frequency and vocal tract resonance in voice and communication modification training with transgender individuals and provide evidence for the potential benefit of modifying sound pressure level, especially when a masculine presentation is desired.

Case study: Theoretical calculation model and variable condition analysis research on the water-splashing noise for natural draft wet cooling towers

2020 ◽  
Vol 68 (2) ◽  
pp. 137-145
Author(s):  
Yang Zhouo ◽  
Ming Gao ◽  
Suoying He ◽  
Yuetao Shi ◽  
Fengzhong Sun
Keyword(s):  
Theoretical Model ◽  
Sound Pressure Level ◽  
Water Droplet ◽  
Water Distribution ◽  
Sound Pressure ◽  
Cooling Tower ◽  
Distribution Patterns ◽  
Calculation Model ◽  
Pressure Level ◽  
Cooling Towers

Based on the basic theory of water droplets impact noise, the generation mechanism and calculation model of the water-splashing noise for natural draft wet cooling towers were established in this study, and then by means of the custom software, the water-splashing noise was studied under different water droplet diameters and water-spraying densities as well as partition water distribution patterns conditions. Comparedwith the water-splashing noise of the field test, the average difference of the theoretical and the measured value is 0.82 dB, which validates the accuracy of the established theoretical model. The results based on theoretical model showed that, when the water droplet diameters are smaller in cooling tower, the attenuation of total sound pressure level of the water-splashing noise is greater. From 0 m to 8 m away from the cooling tower, the sound pressure level of the watersplashing noise of 3 mm and 6 mm water droplets decreases by 8.20 dB and 4.36 dB, respectively. Additionally, when the water-spraying density becomes twice of the designed value, the sound pressure level of water-splashing noise all increases by 3.01 dB for the cooling towers of 300 MW, 600 MW and 1000 MW units. Finally, under the partition water distribution patterns, the change of the sound pressure level is small. For the R s/2 and Rs/3 partition radius (Rs is the radius of water-spraying area), when the water-spraying density ratio between the outer and inner zone increases from 1 to 3, the sound pressure level of water-splashing noise increases by 0.7 dB and 0.3 dB, respectively.

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