scholarly journals Assessment of Noise Level Pollution from Powered Generators – A Case Study of UTC Commercial Business Area Abuja, Nigeria

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Nathaniel Mopa Wambebe ◽  
Xiaoli Duan
Keyword(s):  
Noise Level ◽  
Business Area

Optimum Airflow Management for Multi-Board Rack-Mount Equipment

2003 ◽  
Author(s):  
Bhalchandra Puranik ◽  
Younes Shabany
Keyword(s):  
Design Process ◽  
Noise Level ◽  
Vacuum System ◽  
Air Velocity ◽  
Air Filter ◽  
Pull System ◽  
Geometrical Constraints ◽  
System Configurations

The airflow management for multi-board rack-mount equipment has to meet certain requirements including a minimum air velocity over the boards, uniform air velocity from board to board and from front to rear, and fan redundancy. These requirements have to be met within certain size, noise level and reliability constrains. Several configurations are usually considered: “push” or pressurized system, “pull” or vacuum system, and “push-pull” system. The purpose of this article is to demonstrate the airflow management design process for the three system configurations mentioned above, and to compare their optimum designs with each other given a set of geometrical constraints such as the overall dimensions of the equipment chassis, the card cage, and the type and thickness of the air filter. The design process is explained as a case study involving a typical multi-board rack mounted telecommunication chassis.

scholarly journals ECONOMIC ASPECTS OF THE CITY TRAFFIC NOISE: CASE STUDY // EKONOMSKI ASPEKTI BUKE OD GRADSKOG SAOBRAĆAJA: STUDIJA SLUČAJA

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Jelena Božić ◽  
Predrag Ilić ◽  
Ljiljana Stojanović Bjelić
Keyword(s):  
Noise Level ◽  
Road Traffic ◽  
Scientific Evidence ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Common Denominator ◽  
Economic Implications ◽  
The Impact ◽  
The City

Noise pollution is one of the main environmental problems today.The main source of environmental noise is traffic noise, especially the noise of road vehicles. The continuing expansion of motorized transport in Europe and Republic of Srpska today, and especially the sharp increase in the use of private cars raises concerns about the health risks.The aim of the case study was to determine the noise level at the location „Borik“ in Banja Luka. The measured values indicate that the noise level in this street is alarming. This paper discusses health and well-being related impacts of traffic noise pollution as well as the economic and social benefits associated with its reduction. It summarizes the latest scientific evidence on the impact of road traffic-induced noise on physical and mental health as a reaction to the high level of traffic noise risks. According to the scientific evidence, road traffic is the main source of noise pollution in Europe that cause harmful health such as impaired communication and disturbed sleep, as well as adverse after effects such as fatigue and decreased performance, annoyance, hearing impairment, ischemic heart disease and hypertension. The effects of unhealthy noise level are reflected on living and working conditions, consequently affecting the economy.This paper highlights economic implications and health benefits linked to cross-functionalities in the process of noise reduction in urbanism, architecture and vehicle design and methods for its evaluation. Cost-benefit analysis would be a pivotal decision-making tool for the city road traffic and land-use decisions. Economic valuation is about identifying all preferences and translating them into a money measure, to create a common denominator for comparing the pros and cons. Any decision implicitly include a money value into health effects. A holistic approach is crucial, considering the various health and economic consequences together.

scholarly journals Development of Airport Noise Mapping using Matlab Software (Case Study: Adi Soemarmo Airport – Boyolali, Indonesia)

2018 ◽  
Vol 31 ◽  
pp. 12007
Author(s):  
Pertiwi Andarani ◽  
Haryono Setiyo Huboyo ◽  
Diny Setyanti ◽  
Wiwik Budiawan
Keyword(s):  
Noise Level ◽  
Noise Exposure ◽  
Model Simulation ◽  
Develop Model ◽  
Noise Power ◽  
Noise Levels ◽  
Noise Mapping ◽  
Matlab Software ◽  
International Airport

Noise is considered as one of the main environmental impact of Adi Soemarmo International Airport (ASIA), the second largest airport in Central Java Province, Indonesia. In order to manage the noise of airport, airport noise mapping is necessary. However, a model that requires simple input but still reliable was not available in ASIA. Therefore, the objective of this study are to develop model using Matlab software, to verify its reliability by measuring actual noise exposure, and to analyze the area of noise levels‥ The model was developed based on interpolation or extrapolation of identified Noise-Power-Distance (NPD) data. In accordance with Indonesian Government Ordinance No.40/2012, the noise metric used is WECPNL (Weighted Equivalent Continuous Perceived Noise Level). Based on this model simulation, there are residence area in the region of noise level II (1.912 km2) and III (1.16 km2) and 18 school buildings in the area of noise levels I, II, and III. These land-uses are actually prohibited unless noise insulation is equipped. The model using Matlab in the case of Adi Soemarmo International Airport is valid based on comparison of the field measurement (6 sampling points). However, it is important to validate the model again once the case study (the airport) is changed.

Acoustics in South African classrooms: Regulations versus reality

2021 ◽  
pp. 1351010X2110369
Author(s):  
Coralie van Reenen ◽  
Chrisna du Plessis
Keyword(s):  
Urban Schools ◽  
South African ◽  
Noise Level ◽  
Small Body ◽  
Design Guidelines ◽  
National Standard ◽  
Mitigation Measures ◽  
Reverberation Time ◽  
Acoustic Conditions

This research set out to broaden the pool of evidence regarding the acoustic conditions at schools in South Africa. A review of local and international literature, standards and design guidelines shows that the ideal classroom acoustic conditions of 35 dBA ambient and 0.7 s reverberation time are required to enable a suitable environment for teaching and learning. A review of local literature revealed a very small body of knowledge regarding actual acoustic conditions and monitoring of classroom acoustics and that these cases demonstrated ambient noise levels in classrooms (whether occupied or unoccupied) to be above the recommendations of the relevant South African National Standard (SANS 10103). The limited local research promted the need for this case study. The findings of a province-wide survey of urban schools showed that traffic noise is the main source of noise disturbance in schools. A case study of five schools showed that the average outdoor noise level at schools exposed to traffic throughout the day is 63.3 dBA and the average indoor noise level at these schools when classrooms are unoccupied is approximately 58 dBA, which is significantly higher than the requirement. The reverberation time in classrooms was between 0.6 and 1.75 s. It is concluded that the current acoustic conditions in South African urban schools is poor when evaluated against the South African National Standards. However, since this is based on only five case studies, a broader study is required to understand the general conditions and establish suitable mitigation measures.

scholarly journals Improving retrieval quality for airborne limb sounders by horizontal regularisation

2013 ◽  
Vol 6 (1) ◽  
pp. 15-32 ◽  
Author(s):  
J. Ungermann
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Noise Level ◽  
Large Scale ◽  
Image Noise ◽  
Detailed Case ◽  
Near Future

Abstract. Modern airborne infrared limb sounders are capable of measuring profiles so fast that neighbouring profiles are very similar to one another. This can be exploited by retrieving whole 2-D cross-sections instead of simple 1-D profiles. This paper presents algorithms that are able to perform such a large-scale retrieval and that efficiently produce typical diagnostic quantities. The characteristics and capabilities of the proposed method are analysed and demonstrated in a detailed case study using a series of profiles that were measured by CRISTA-NF (Cryogenic Infrared Spectrometers and Telescope for the Atmosphere–New Frontiers). It is shown that cross-section retrievals can either reduce noise-induced artefacts or produce finer vertical structures while maintaining the same image noise level. Further, it is discussed how the presented methodology can also be applied to improve the retrievals for other instrument types including current satellite-borne nadir-sounders and near-future satellite-borne limb sounders.

scholarly journals Application of Acceptable Noise Level to Confirm Fitting Strategy for Bone-Anchored Hearing Aid

2020 ◽  
Vol 16 (1) ◽  
pp. 70-76
Author(s):  
Sunghwa You ◽  
Jihyun Lee ◽  
Woojae Han ◽  
Young Joon Seo
Keyword(s):  
Noise Level ◽  
Hearing Aid ◽  
Self Report ◽  
Fitting Procedure ◽  
Permissible Range ◽  
Acceptable Noise Level ◽  
Fitting Procedures ◽  
Bone Anchored Hearing Aid ◽  
Present Case Study

Since there is no standardized fitting procedure for bone-anchored hearing aid (BAHA) patients, many clinics have failed to perform their successful fitting. The present case study tried to identify whether acceptable noise level (ANL) was clinically applied as one of fitting procedures for the BAHA users. Four hearing-impaired adults with BAHA (3 female and 1 male) who had a period of hearing deprivation for at least 8 years and the BAHA experience of more than 1 year participated. They conducted ANL in their unaided and aided BAHA conditions after being familiar with the ANL instruction. Also, the subjects responded to a self-report of Korean version of Profile of Hearing Aid Benefit (K-PHAB) to subjectively check amount of satisfaction with BAHA. Compared to the unaided condition, two out of four BAHA users showed a decreased ANL in the aided condition whereas the other users had a slightly increased ANL. Regardless, their levels were examined within the permissible range except for one subject. Their K-PHAB scores were similar to the ANL results in the aided condition. Although measured ANLs were slightly differed from the users, the current results suggest that ANL might be a tool to measure individual’s inherent value when the BAHA fitting being appropriated while also supported by K-PHAB scores. In the following study, we need to confirm a typical pattern of many BAHA users with longitudinal measures of ANL.

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