Case study: Noise reduction of a vacuum-assisted toilet

2020 ◽  
Vol 68 (4) ◽  
pp. 294-302
Author(s):  
Michael T. Rose ◽  
B. Dagan Pielstick ◽  
Zach T. Jones ◽  
Scott D. Sommerfeldt ◽  
Kent L. Gee ◽  
...  

Flushing a vacuum-assisted toilet generates noise levels that can be disturbing both to users and those nearby. Peak radiated noise levels correlate with the time when the valve opens and closes, while the noise levels when the valve is com- pletely open are also relatively high. Significant noise ranges between 300 Hz and 3000 Hz. It was hypothesized that increasing the in-tube distance between the flush valve and the bowl in addition to increasing the bend radius of the tube would reduce radiated noise levels. These modifications resulted in a reduction of about 14 dB in the radiated noise during the valve opening and closing in ad- dition to a reduction of about 5 dB while the valve is completely opened. Inter- mediate results of varying the tube length and bend radius are presented to show their effects on the radiated sound levels. Two tube inserts were designed to fit (1) underneath and (2) behind the toilet in a compact manner. They were tested to show that they maintain noise control performance without modifying any other part of the toilet.

2014 ◽  
Author(s):  
Raymond W. Fischer ◽  
Louis M. Pettit

There is a price to be paid to achieve compliance with the acoustic requirements imposed by regulatory agencies. Acoustic requirements typically appear in ship specifications as airborne and/or underwater radiated noise limits as the need to preclude hearing loss for crew members and the need to control sound levels experienced by marine mammals receive more recognition. Recent changes and additions to regulatory body requirements addressing compartment airborne noise and underwater radiated noise can be found in IMO Resolution MSC.337(91) Annex 1 and Annex 2 which state that IMO Resolution A.468(XII) “Code on Noise Levels Onboard Ships” shall take effect on 1 July 2014 for all SOLAS compliant vessels. Thus the airborne noise levels in compartments and at on-deck work stations onboard as-built ships seeking a SOLAS certificate will need to be measured, and must demonstrate compliance with noise limits stated in paragraph 4.2 of IMO Resolution A.468(XII). IMO “Guidelines for the Reduction of Underwater Noise from Commercial Shipping to Address Adverse Impacts on Marine Life” dated 7 April 2014 and agencies such as ICES and DNV have established guidance and/or criteria for control of underwater radiated noise from vessels, and these too are now commonly appearing in ship specifications. Specifications referencing such criteria typically require that compliance be demonstrated by at-sea testing of underwater radiated noise. Making the correct decisions during the ship design process will minimize costs for noise control and will provide a positive return on investment. The process of how best to comply with noise limits while minimizing costs through optimization of noise control treatments and design approaches is discussed.


2020 ◽  
Vol 37 (12) ◽  
pp. 841.1-841
Author(s):  
Lucy Hall ◽  
Sophie Dando ◽  
Anthony Hanks

Aims/Objectives/BackgroundIn the Emergency department (ED), noise is a frequent and often unavoidable consequence of work undertaken and levels can often be raised during the day and night. Raised ambient noise levels have potential implications for the workforce, patients and relatives.Investigation into the problem of noise levels in the ED follows feedback from a young patient who couldn’t sleep during a prolonged stay. His complaint focused on loud, irregular banging noises such as those from closing bins that kept him awake.The team felt work should be done to see if it was a wider spread problem or just isolated to his case. A simple sound recording experiment and literature search was conducted.Methods/DesignThe literature search was conducted using electronic/online databases (Medline; Cochrane library) with a fixed date range and specific inclusion criteria.The noise exposure experiment was conducted using a verified phone app to record the sound levels. They were measured at 3 times, during a night shift, in the paediatric emergency department of UHW. All measurements were at a fixed distance and were averaged and compared with WHO recommendations.Results/ConclusionsThere are many sources of noise pollution in the ED, some are unavoidable for safety and clinical reasons.The literature review produced a small number of papers all of which found that sound levels were raised above recommended levels. Similarly, all the sounds measured in the ED also exceeded the recommendations.The most consistent finding across the papers, matched by findings from recordings, was that human behavioural modification is an easy and effective way to reduce noise levels.There are simple steps that can be taken to reduce and eliminate soundsRaising awareness regarding this problem is of great importance and focussing future work on assessing the impact in younger patients within the Emergency Department is paramount.


PEDIATRICS ◽  
1975 ◽  
Vol 56 (4) ◽  
pp. 617-617
Author(s):  
Gōsta Blennow ◽  
Nils W. Svenningsen ◽  
Bengt Almquist

Recently we reported results from studies of incubator noise levels.1 It was found that in certain types of incubators the noise was considerable, and attention was called to the sound level in the construction of new incubators. Recently we had the opportunity to study an improved model of Isolette Infant Incubator Model C-86 where the mechanical noise from the electrically powered motor has been partially eliminated. With this modification it has been possible to lower the low-frequency sound levels to a certain degree in comparison to the levels registered in our study.


2021 ◽  
Vol 69 (4) ◽  
pp. 364-372
Author(s):  
Yalcin Yildirim ◽  
Diane Jones Allen

Noise is one of the most frequent consequences of traffic. Public transportation systems, such as the Dallas Area Rapid Transit (DART) authority provides various modes of transportation. Even though the availability of commuting service for the public is a boon to communities, mass transit systems are potential sources of excessive sound levels in daily urban life. This article examines the nexus between the transit station facilities of light rail train (LRT) stations and noise implications at both station and neighborhood scales by studying selected LRT stations. A multilevel linear analysis was conducted to understand the degree of train station amenities and neighborhood characteristics that affect sound levels. Using a type II sound pressure level (SPL)meter, sound measurements were obtained during the weekdays and weekends over several weeks. Upon examining the station amenities, and built environment and sociodemographic characteristics of the neighborhood, findings of this comprehensive research reveal significant implications for sound levels. Stations with ticket vending machines and informative message boards include a higher degree of significance on SPLs, while shelters, crew rooms, bike lockers, restrooms, and windshields are significantly and negatively associated with the noise levels. Additionally, neighborhoods with dense roads, higher speed limits, more neighborhood facilities, and a higher number of transit routes have an increased likelihood of noise levels. Recommendations include creating transformative policies for implementation, and approaches addressing noise for transit authorities, transportation engineers, and planners are presented. Planning and engineering aspects of comfort, aesthetics, safety, and public health, as train stations are daily use spaces for commuters and surrounding communities, should also be considered.


Author(s):  
Greicikelly Gaburro Paneto ◽  
Cristina Engel de Alvarez ◽  
Paulo Henrique Trombetta Zannin

In contemporary cities, and usually without realizing it, the population has been exposed to high sound pressure levels, which besides causing discomfort, can lead to health problems. Considering that a large part of this noise comes from emission from motor vehicles, this research aims to evaluate the sound behavior in sound environments configured by voids in the urban fabric, in order to identify whether open spaces can act as attenuators of sound levels. To obtain the expected results, the methodology used was structured from a review of the state-of-the-art and computer simulations relating the variables that influence the formation of urban space and sound emission and propagation, taking as a case study an urban portion of the municipality of Vitória/ES. In parallel, questionnaires were applied to evaluate the user's perception of their exposure. The measurement results indicated that the sound pressure levels caused by traffic noise are above the limit tolerated limit by the NBR norm 10151:2000 for the daytime period. In turn, the results obtained from the population indicated that there is little perception of noise by the users of the spaces surveyed.


2018 ◽  
Vol 7 (3.32) ◽  
pp. 127
Author(s):  
Francisco Javier Díaz Perez ◽  
David Chinarro ◽  
M Rosa Pino Otín ◽  
Ricardo Díaz Martín ◽  
Adib Guardiola Mouhaffel

This article presents a management model and control of energy efficiency in hotels adapted to the consumption patterns that ensure the comfort requirements of customers and integrated into the environment of an intelligent tourist complex. The analysis of the hot water system (DHW) of two hotels in the Canary Islands (Spain) in relation to their occupation, yields a solution based on renewable energies using high temperature heat pumps with aerothermal dissipation and supported by boilers of existing LPG propane. The control by programmable automatons (PLC) integrated in a system of control and acquisition of data (SCADA) optimizes the systems to maintain the maximum accumulated energy during the periods of cheapest electric tariff, by means of a system of opening and closing of hydraulic Valves that It manages to adjust the demand of DHW consumption to achieve the highest energy accumulation during the hours with the cheapest electricity tariff. The result after two and a half years of activity registration is a faster return on investment due to the optimized energy management of the system, through the control of operating hours adjusted to the needs of customers and the hourly rate. It has also been predicted that during the estimated 12 years of the system will have saved more than € 1,179,737 and thermal 8,780,005 kWh in a hotel 1 and € 1,315,104 and thermal 9,522,301 kWh in the hotel 2. This model shown can be seen how economically and energetically very efficient.  


2020 ◽  
Vol 10 (1) ◽  
pp. 31-37
Author(s):  
Mohammad Hasan Fuadi

Diesel engines is generally used for industrial and agricultural machines. Few people care about the engine temperature so it is forced to reach temperature of 100oC, which causes overheating of the diesel engine and has an impact on the performance itself. This also uses a hopper cooling system which is certainly not effective, because it's necessary to see that the water in the reservoir is still or not, also not equipped with an engine temperature display so it's difficult to ascertain the temperature inside. This study aims to monitor and control the temperature of cooling water. Operation of temperature control uses a telecontrol system that is connected to network (Internet of Things) so diesel temperature control can be done remotely. Monitoring of temperature and water level in the reserve tank using Web Mobile. In addition, there is a temperature sensor that is used to measure the temperature of the cooling water so that users can monitor the temperature of the diesel engine on Web Mobile. The test results obtained, the temperature sensor has an average temperature reading error of 0.031004%. Diesel engines with controlled solenoid valve cooling systems can produce ideal temperatures compared to when the solenoid valve is open (using the radiator continuously) or when the solenoid valve is Closed (without using a radiator). When the solenoid is controlled the engine temperature can be ideal because the solenoid valve opening and closing system has the lowest temperature of 56.34oC and the highest temperature of only 80.85oC.


2017 ◽  
Vol 42 (3) ◽  
pp. 423-432 ◽  
Author(s):  
Satish K. Lokhande ◽  
Satyajeet A. Dhawale ◽  
Samir S. Pathak ◽  
Rakesh Gautam ◽  
Mohindra C. Jain ◽  
...  

Abstract Noise mapping is a well-established practice among the European nations, and it has been follow for almost two decades. Recently, as per guidelines of the Directorate General of Mines Safety (DGMS), India, noise mapping has been made mandatory in the mining expanses. This study is an effort to map the noise levels in nearby areas of mines in the northern Keonjhar district. The motive of this study is to quantify the existing A-weighted time-average sound level (LAeq,T ) in the study area to probe its effects on the human dwellings and noise sensitive areas with the probability of future development of the mines, roads, and industrial and commercial zone. The LAeq,T was measured at 39 identified locations, including industrial, commercial, residential, and sensitive zones, 15 open cast mines, 3 major highways, and 3 haulage roads. With the utilisation of Predictor LimA Software and other GIS tools, the worked out data is mapped and noise contours are developed for the visualisation and identification of the extent and distribution of sound levels across the study area. This investigation discloses that the present noise level at 60% of the locations in silence and residential zone exposed to significantly high noise levels surpasses the prescribed limit of Central Pollution Control Board (CPCB), India. The observed day and night time LAeq, T level of both zones ranged between 43.2-62.2 dB(A) and 30.5-53.4 dB(A), respectively, whereas, the average Ldn values vary between 32.7 and 51.2 dB(A). The extensive mobility of heavy vehicles adjoining the sensitive areas and a nearby plethora of open cast mines is the leading cause of exceeded noise levels. The study divulges that the delicate establishments like schools and hospitals are susceptible to high noise levels throughout the day and night. A correlation between observed and software predicted values gives R2 of 0.605 for Ld, 0.217 for Ln, and 0.524 for Ldn. Finally, the mitigation measure is proposed and demonstrated using a contour map showing a significant reduction in the noise levels by 0-5.3 dB(A).


2021 ◽  
Vol 10 (1) ◽  
pp. 113-140
Author(s):  
Francisco Javier Fernández Polo

Abstract There are few studies on backchannels in ELF and none concerns computer-mediated conversations. Backchannelling has been associated with good listenership and enhanced cooperativeness, an intrinsic feature of ELF. They would also play a key role in computer-mediated communication, maintaining a sense of affective equilibrium among participants and compensating for medium-related limitations. We analyze backchanneling in an ELF conversation between a Spanish female and a German male student from the Corpus of Video-Mediated English as a Lingua Franca Conversations (ViMELF). Backchanneling seems to be particularly intense in the opening and closing sections of the exchange, where interpersonal work is the most needed. While significant idiolectal differences are observed between the two participants, both show a marked preference for and a tendency to concentrate realizations on a few weak backchanneling forms, conferring the exchange a general impression of monotony and emotional flatness. Some backchanneling features in the exchange may be described as typical of ELF: backchannels tend to occur in moments when speakers sense that understanding may be compromised and are frequently complemented by supportive material reinforcing the speaker’s point. The analysis also reveals some characteristic awkward usage, with tokens which are clearly “overdone,” while others are too weak and disappointing or behave disruptively by occurring in unexpected positions and interrupting the flow of the conversation. Research on ELF video conversations is particularly timely given the recent surge in videoconferencing propitiated by the COVID pandemic, a tendency which is likely to stay in post-pandemic times.


PEDIATRICS ◽  
1979 ◽  
Vol 63 (1) ◽  
pp. 100-106 ◽  
Author(s):  
Fred H. Bess ◽  
Barbara Finlayson Peek ◽  
Judy J. Chapman

The purpose of this study was to conduct an acoustic analysis of incubator noise under two conditions: when the incubator was associated with different types of life-support equipment; and when impulse noise was created by striking the side of the incubator or by opening and closing the doors of the storage unit. It was found that the life-support equipment increased the overall noise levels of incubators by as much as 15 to 20 dB. Much of this increased energy was in the high frequency region. Impulse signals created by striking the side of the incubator ranged from 130 to 140 dB. A representative impulse for opening the incubator was 92.8 dB, whereas closing the door produced a peak amplitude of 114 dB.


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