The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Liu Guanfeng - One of the best experts on this subject based on the ideXlab platform.
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effect of glass fiber fineness on the Sound Insulation property of glass fabric pvc composite material
Textile Research Journal, 2008Co-Authors: Liu GuanfengAbstract:In order to study the Sound Insulation of glass fabric/PVC composite material and improve its property,the glass fabric/PVC composites were manufactured from glass fibers with different diameters and PVC resin with high damp.The two-channel acoustic analyzer,SEM,etc were used to analyze the Sound Insulation property and micro-structure of the samples.The results showed that glass fiber′s fineness has great influence on the Sound Insulation property of both fabric and composite material.With the same density and thickness,the finer the glass fiber,the better the Sound Insulation of the fabric and composite material.
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study on Sound Insulation property of lead fiber epvc composite material
Journal of Zhejiang Institute of Science and Technology, 2004Co-Authors: Liu GuanfengAbstract:Lead fiber/EPVC composite material, which is a very thin, lightweight and flexible material is fabricated to improve Sound Insulation at low and middle frequencies efficiently according to some molding process parameters. The Sound Insulation property is investigated and analyzed, and its structure and noise resistant principles is also discussed. The test result shows that the Sound Insulation index of this kind of material at low and middle frequencies obtains over 15dB.
Valtteri Hongisto - One of the best experts on this subject based on the ideXlab platform.
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Optimized reference spectrum for rating the impact Sound Insulation of concrete floors.
The Journal of the Acoustical Society of America, 2019Co-Authors: Mikko Kylliäinen, Petra Virjonen, Valtteri HongistoAbstract:It has been long recognized that the single-number quantities presented in the standard ISO 717-2 [(2013) International Organization for Standardization] do not correlate especially well with the subjective judgment of living impact Sound sources directed to the floors. The aim of this study was to find single-number quantities which are well associated with the subjective annoyance caused by different impact Sounds. Experimental data of laboratory measurements of impact Sound Insulation of floors and a psychoacoustic experiment was used [Kylliainen et al. (2017). Acta Acust. Acust. 103, 236–251]. The five studied impact Sound types were walking with hard shoes, socks, and soft shoes, super ball bouncing, and chair moving. A fundamental requirement was that the single-number quantities can be expressed as the sum of L′n,w or L′nT,w and a spectrum adaptation term. Reference spectra were derived by the means of a mathematical optimization method. Reference spectra for each Sound type were defined separately. An optimized reference spectrum based on all five Sound types explained the annoyance of these Sound types reasonably well (r2 = 0.93) and better than any of the standardized single number quantities (e.g., r2 = 0.86 for L′n,w + CI,50-2500).It has been long recognized that the single-number quantities presented in the standard ISO 717-2 [(2013) International Organization for Standardization] do not correlate especially well with the subjective judgment of living impact Sound sources directed to the floors. The aim of this study was to find single-number quantities which are well associated with the subjective annoyance caused by different impact Sounds. Experimental data of laboratory measurements of impact Sound Insulation of floors and a psychoacoustic experiment was used [Kylliainen et al. (2017). Acta Acust. Acust. 103, 236–251]. The five studied impact Sound types were walking with hard shoes, socks, and soft shoes, super ball bouncing, and chair moving. A fundamental requirement was that the single-number quantities can be expressed as the sum of L′n,w or L′nT,w and a spectrum adaptation term. Reference spectra were derived by the means of a mathematical optimization method. Reference spectra for each Sound type were defined separately...
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work performance in private office rooms the effects of Sound Insulation and Sound masking
Building and Environment, 2016Co-Authors: Valtteri Hongisto, Johanna Varjo, Henri Leppamaki, David Oliva, Jukka HyonaAbstract:Abstract Our purpose was to examine whether present Sound Insulation guidelines of private office rooms provide optimal cognitive performance and acoustic satisfaction. 32 voluntary students participated in our laboratory experiment. The experiment simulated two adjacent office rooms. Speaker was in room 1 and listener in room 2. Both Sound Insulation between the rooms and the background noise level (Sound masking) in room 2 were investigated at two levels so that the speech intelligibility between the rooms was significantly changed. Condition A corresponded with the present Finnish Sound Insulation guidelines according to which the weighted Sound reduction index should be at least 35 dB R ' w and background noise level from building services should not exceed 33 dB L Aeq . Conditions B and D had a 10 dB greater Sound Insulation than condition A. Conditions C and D had 9 dB larger background noise level in room 2 than condition A. Cognitive performance was the worst in condition A. Acoustic satisfaction and several other subjective measures showed that conditions B-D were better than condition A. The present Sound Insulation guidelines need to be reconsidered to provide better acoustic satisfaction and less distraction for employees in private office rooms.
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justification of standardized level differences in rating of airborne Sound Insulation between dwellings
Applied Acoustics, 2016Co-Authors: Mikko Kylliäinen, David Oliva, Joose Takala, Valtteri HongistoAbstract:Abstract It has long been recognized that single-number quantities R′w, DnT,w or Dn,w result in different conclusions in objective rating of airborne Sound Insulation between dwellings. The difference between the values of these single-number quantities (SNQ), however, does not prove which of them describes the Sound transmission between rooms most correctly. The main object of this article was to study which SNQ correspond best with transmitted living Sound levels in buildings when reverberation time, volume of receiving room and Sound Insulation are taken into account. Data of 100 field measurements of airborne Sound Insulation were collected as well as 207 reverberation times of furnished rooms. The transmitted Sound levels of living Sounds were evaluated on the basis of known living Sound spectra and measured level differences D. The results show that the SNQs standardized to reference reverberation time of 0.5 s lead in all cases to best correlation between the SNQs and the Sound levels of transmitted living Sounds. It was also checked whether the rating by DnT,w would lead to higher transmitted Sound levels of living Sounds in larger rooms, but this was not detected. The use of DnT,w makes rooms of different volumes equal in regard to required Sound Insulation between them. It is thus justified to replace R′w with DnT,w as the SNQ for rating the airborne Sound Insulation. Widening the frequency range down to 50 Hz or up to 5000 Hz did not give noteworthy improvement in the correlation.
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satisfaction with Sound Insulation in residential dwellings the effect of wall construction
Building and Environment, 2015Co-Authors: Valtteri Hongisto, Maria Makila, Maija SuokasAbstract:Abstract Aim The aim of this study was to compare the acoustic satisfaction in residential multi-storey buildings with different wall constructions with a similar weighted Sound reduction index R ′ w : Heavy construction (monolithic concrete walls) and Light construction (staggered double walls). Light constructions are known to have a lower Sound Insulation especially at low frequencies. Our research question was does this difference affect the overall acoustic satisfaction among occupants. Materials and methods Four and two residential multi-storey buildings were chosen to represent building types Heavy and Light, respectively. A questionnaire was distributed to each dwelling. Seventy-two and eighty-seven respondents were obtained, respectively, with response rates of 62% and 54%. Some Sound Insulation measurements were carried out for verification purposes. Results As expected, the airborne Sound Insulation was worse below 160 Hz in building type Light, while the R ′ w values were nearly equal, 56–57 dB. The satisfaction with Sound Insulation did not differ between the two building types. All neighbour noise sources were rated equally disturbing in both building types. The building types did differ from each other with respect to the effects of noise on sleep. Conclusions The results suggest that when the airborne Sound Insulation is close to 55 dB R ′ w , the construction type does not necessarily affect the acoustic satisfaction. The results also suggest that R ′ w explains better the subjective rating of Sound Insulation than R ′ w + C 50–3150 .
Carin Johansson - One of the best experts on this subject based on the ideXlab platform.
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an investigation of Sound Insulation measurements on wooden joist floors by multivariate data analysis part ii airborne Sound Insulation
International Congress on Noise Control Engineering : 25 08 1997 - 27 08 1997, 1997Co-Authors: Carin JohanssonAbstract:An investigation of Sound Insulation measurements on wooden joist floors by multivariate data analysis. Part II : Airborne Sound Insulation
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an investigation of impact Sound Insulation measurements on wooden joist floors by multivariate data analysis part i impact Sound Insulation
International Congress on Noise Control Engineering : 25 08 1997 - 27 08 1997, 1997Co-Authors: Carin JohanssonAbstract:An investigation of impact Sound Insulation measurements on wooden joist floors by multivariate data analysis : Part I. Impact Sound Insulation.
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predicting impact Sound Insulation of wooden joist floors an application of european models
International Congress on Noise Control Engineering : 30 07 1996 - 02 08 1996, 1996Co-Authors: Carin Johansson, Ulrik SundbackAbstract:Predicting impact Sound Insulation of wooden joist floors : an application of European models
Rajesh D Anandjiwala - One of the best experts on this subject based on the ideXlab platform.
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thermal and Sound Insulation materials from waste wool and recycled polyester fibers and their biodegradation studies
Energy and Buildings, 2015Co-Authors: Asis Patnaik, Mlando Mvubu, Sudhakar Muniyasamy, Anton F Botha, Rajesh D AnandjiwalaAbstract:Abstract This paper reports a study on thermal and Sound Insulation samples developed from waste wool and recycled polyester fibers (RPET) for building industry applications. Waste wool fiber is a potential source of raw material for thermal and Sound Insulation applications, but its quantities are limited. In order to overcome the above problems, waste wool fibers were mixed with RPET fibers in 50/50 proportions in the form of a two layer mat. Another set of three samples from 100% waste wool and 100% RPET fibers were also prepared. All samples were tested for thermal Insulation, acoustic, moisture absorption and fire properties. Also, behavior of the samples under high humidity conditions was evaluated. An extensive biodegradability study was conducted to analyze the conversion of organic carbon into carbon dioxide by composting method for 50 days. Two layer 50% waste wool and 50% RPET mat provided the best Insulation, acoustic, moisture absorption and fire properties. The RPET/waste wool mats were absorbing more than 70% incident noise in the frequency range of 50–5700 Hz. The RPET/waste wool mats have adequate moisture resistance at high humidity conditions without affecting the Insulation and acoustic properties. 65–70% biodegradation was achieved for wool/RPET mats for 50 days composting period.
Paul Sas - One of the best experts on this subject based on the ideXlab platform.
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vibro acoustic analysis procedures for the evaluation of the Sound Insulation characteristics of agricultural machinery cabins
Journal of Sound and Vibration, 2003Co-Authors: Wim Desmet, Bert Pluymers, Paul SasAbstract:Abstract Over the last few years, customer demands regarding acoustic performance, along with the tightening of legal regulations on noise emission levels and human exposure to noise, have made the noise and vibration properties into important design criteria for agricultural machinery cabins. In this framework, both experimental analysis procedures for prototype testing as well as reliable numerical prediction tools for early design assessment are compulsory for an efficient optimization of the cabin noise and vibration comfort. This paper discusses several numerical approaches, which are based on the finite element and boundary element method, in terms of their practical use for airborne Sound Insulation predictions. To illustrate the efficiency and reliability of the various vibro-acoustic analysis procedures, the numerical procedures are applied for the case of a harvester driver's cabin and validated with experimental results.
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vibro acoustic analysis procedures for the evaluation of the Sound Insulation characteristics of agricultural machinery cabins
Proceedings of SPIE the International Society for Optical Engineering, 2001Co-Authors: Wim Desmet, Bert Pluymers, Paul SasAbstract:Over the last few years, customer demands regarding acoustic performance, along with the tightening of legal regulations on noise emission levels and human exposure to noise, have made the noise and vibration properties into important design criteria for agricultural machinery cabins. In this framework, both experimental analysis procedures for prototype testing as well as reliable numerical prediction tools for early design assessment are compulsory for an efficient optimisation of the cabin noise and vibration comfort. This paper describes an experimental procedure for the in-situ assessment of the air-borne Sound Insulation characteristics of a cabin using a two-microphone Sound intensity probe. In addition, several numerical approaches, which are based on the finite-element and boundary element method, are discussed in terms of their practical use for air-borne Sound Insulation predictions. To illustrate the efficiency and reliability of the various vibro-acoustic analysis procedures, all experimental and numerical procedures are applied and evaluated for the case of a cabin scale model.