EFFICIENCY EVALUATION OF A NOISE BARRIER

Author(s):  
Pranas Baltrėnas ◽  
Donatas Butkus ◽  
Vytautas Nainys ◽  
Raimondas Grubliauskas ◽  
Jurgita Gudaitytė

Mechanization of industrial and agricultural production, increase of urban and rural traffic flows, modernization of domestic facilities cause a rapid expansion of acoustic discomfort zones. Since the noise level in any environment is one of the basic factors determining the human comfort indicator, investigation into noise processes is given special attention by researchers. Seaport freight discharge terminals are also connected with noise problems. Noise from AB KLASCO fertilizer discharge terminal of Klaipeda seaport cause great concern to local people. There is a noise barrier installed near the terminal. The present paper describes the efficiency evaluation of the noise barrier according to the noise level measurements performed, modelling of noise spread and mathematical calculations. The investigation was performed with noise measuring equipment Bruel&Kjaer mediator 2260. According to measurements, it is obvious that the noise level in the residential zone is 3–4 dBA above the limits (limits are given in HN 33–1:2003) in the daytime, and by 7 dBA at night. The modelling of noise spread was performed by CadnaA program which allowed to make different models according to variations of the noise level caused by changing conditions.

2018 ◽  
Vol 169 ◽  
pp. 01012
Author(s):  
Chaddanai Jiradecha ◽  
Pruethipong Singhatiraj

Highway Route No. 9 is a Bangkok bypass motorway that aims to alleviate traffic congestion in greater Bangkok areas. Presently, it is found a rapid expansion of new communities residing along both side of Highway No. 9. To lessen the noise level, Department of Highways installed the noise barrier on the sensitive locations. However, people from communities living on both sides of highway still demand some additional noise pollution improvement. To improve the efficiency of using noise barriers and to promote environmental and social quality for the people on the sensitive communities along the highway route, the Department of Highways, therefore, designs a new technique for installing noise barrier on the sensitive areas, i.e. education institutions, temple, residential area. In addition, the mathematic model is applied to 12 selected locations of sensitive areas for monitoring the effectiveness of the new installation technique. The mathematic model is used for predict the future noise level after installation of noise barrier in year 2037. The results confirm that the appropriate height and width of noise barrier can improve the comfortable of the people on the sensitive area.


Author(s):  
A.D Rawlins

In the following work, we solve the problem of the best orientation of a rigid noise barrier, which has one face lined with absorbent material, between a noise source and a receiver point in the shadow region of the barrier. By the ‘best orientation’, we mean that positioning of the barrier which yields the least noise level at the receiving point for a given barrier and source position.


Author(s):  
Tomas Vilniškis ◽  
Tomas Januševicius

In this article was analyzed acoustic efficiency of two different construction noise barriers. Field measurements of noise tests were carried out before and behind a wooden barrier, which height was 2.9 meters and a wooden wall with equipped roof, which height was 3.2 m. As is known the length of the wall, height, surface roughness, shape and material of the wall – key aspects of determining the effectiveness of noise barrier. Different materials, depending on their characteristics of the hard or soft, porous or dense, interact differently with the sound of waves. Article contains research results of noise measurements at positive and negative air temperature. There analyzing wooden noise barrier acoustic efficiency at different temperatures and the effects of temperature to the diffraction of sound waves through the peak of the barrier. Test results show, that noise barrier without structural changes reduced noise level to 14–22 dB, noise barrier with structural changes reduced noise level to 20–23,1 dB, when air temperature was positive. When air temperature was negative, noise barrier without structural changes reduced noise level to 15,5–21,4 dB, noise level with structural changes to 19–26,6 dB.


1956 ◽  
Vol 10 (3) ◽  
pp. 508-510

Annual Report:The fifth annual report of the Managing Board of the European Payments Union (EPU) covered the period July I, 1954 to June 30, 1955. The financial year 1954—1955, the report noted, had been one of considerable economic expansion in member countries, although with some variation between them; the progress of the previous year, which had followed upon a period of relative stagnation, had continued and gathered momentum. The report noted that in some countries the rapid expansion had had repercussions both internally and externally which had required corrective measures. During 1954–1955 industrial production had increased greatly, the increase being most marked in base metal manufacturing, metal products and in chemical manufacturing. However, agricultural production of member countries, as a whole, had not changed from the previous year. The report stated that the greater industrial production had been the result of both increased employment and productivity; in a number of countries unemployment had been reduced to new low levels and in certain countries, the number of unfilled vacancies exceeded that of the registered unemployed. Concurrently, and in connection with the rapid economic expansion, salaries and wages had increased in practically all member countries to a much greater extent than in previous years.


2018 ◽  
Vol 7 (4.35) ◽  
pp. 11 ◽  
Author(s):  
Helmi A Halim ◽  
Gasim Hayder

This research is an acoustical performance study in an open cycle peaking gas turbine power plant located at the southern coast of Peninsula Malaysia. Referring to its location at the middle of residence and tourism area, throughout its operation years, several complains from public has been lodged about the excessive operational noise at the perimeter of the plant and statistically from the last decade, twenty-four (24) noise related public complains were recorded. This issue has initiated a study to determine the current operational noise level as well as the effectiveness of the existing noise barriers. Based on EIA approval, the boundary noise for the operation should be limited to 55 dB(A) at any time. The field measurement of noise level at two (2) different locations are assessed in-situ and continuously noise monitoring covering all the plant’s operational regime and at different plant operational pattern. These results are compared with the initial noise report during its early year of operation in 1999. Finally the hypotheses then compared with the referenced legislations. Results from all the methodologies show the current operational noise level of the plant are within the permissible limit, however the overall operational noise of the plant is increasing compared with 1999 report due to the increasing of surrounding activities as well as deteriorating of current engineering and natural noise barrier arrangement. Mitigation plans has been recommended to the management to minimize the impact of the excessive noise to surrounding residence and to the plant workers. On top of that, the theoretical and commercial implication of the research is also discussed.


Author(s):  
Hanna Holovanova

The research is devoted to the scientific analysis of the rational choice principles of commodity specialization taking into account the functioning specifics of agricultural enterprises. The main tasks are identified, the solution of which has the potential to improve the internal specialization. There are among them: the maximum production increase in each unit, effi-cient use of production funds and work-force, improving the production efficiency. The adaptation process of commodity specialization of agricultural enterprises to market conditions is structured. Eight stages of it are distinguished: from deter-mining the change volume related to the enterprise adaptation to the external environment, to adjusting the system of opera-tional, tactical and strategic planning. In the factor analysis framework of the internal and external environment of agrarian enterprise, the determinants of its product specialization are systematized. The author's vision of the organizational and economic mechanism of managing the specialization of agricultural enterprises is outlined. The tendency to update the re-search of the risk system in the managing process the specialization of agricultural enterprises has been noted. This system has included the following risks: market, personnel, financial, legal, natural-climatic, logistical, agro-technological, the only mechanism for regulation in many branches of agriculture. The conclusion is made that substantiation of construction con-ceptual bases of organizational and economic mechanism of commodity specialization management of agrarian enterprise allows to realize adaptation development strategies of production and commercial activity. The basis is a comprehensive consideration of the factors of external and internal environment in the components mobilization of production and economic potential, as well as determining the configuration of management systems of commodity specialization in enterprise man-agement. Keywords: agricultural production, specialization, commodity specialization, commodity structure, agrarian enter-prise.


Author(s):  
Aulia Ramandha ◽  
Wisnu Eka Yulyanto ◽  
Sandra Madonna

<strong>Aim:</strong> The aim of this study is to design noise barrier shapes and to investigate its effectiveness in reducing traffic noise at one public school in Indonesia. <strong>Methodology and Results:</strong> Two types of barriers were designed on a laboratory scale using plywood materials and the noise level was measured using Noise Analyzer Briiel and Kjaer Type 2250. Noise reduction was analyzed by using the Insertion Loss method based on the difference of the noise level before and after implementing the barrier. The results show that the barrier Type II with a length of 200 cm, a receiver height of 30 cm, and a curved shape of 45° angle (Type L) is more effective in reducing the noise than the other variation of barrier shape and length. Barrier Type L (Type II) can reduce the noise at high frequency between 1–8 kHz with an Insertion Loss value of 6.9–27.9 dB. <strong>Conclusion, significance and impact study:</strong> The noise barrier Type II, with specifications of 20 m length, 3 m height, and barrier material of reinforced concrete, is recommended to be used at the high school to reduce the road traffic noise.


Author(s):  
Florin SALA ◽  
Marius BOLDEA ◽  
Isidora RADULOV ◽  
Florin CRISTA ◽  
Adina BERBECEA

Assuming that the production increase is proportional to the saturation superdeficit, we get the differential equation: where A is the saturation production, and a is the initial production. The equation above has the solution , where is the hyperbolic tangent of . It is possible to generate nomograms based on the equation determined. These nomograms can help prognosticate the agricultural production for the situations in which people choose to use only nitrogen fertilizers


Noise Mapping ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 268-280
Author(s):  
Francesco Centracchio ◽  
Lorenzo Burghignoli ◽  
Umberto Iemma

Abstract The present work deals with the multiobjective, multidisciplinary optimisation of takeoff and approach operations of a commercial aircraft aimed at the mitigation of the impact of aviation noise on the population. The innovative approach used here couples the minimisation of the aircraft noise level at the certification points with the improvement of the sound quality. The latter objective represents the main novelty of the present work and is addressed using a spectral–matching approach to make the aircraft noise as close as possible to a target sound. The rationale underlying the research is the development of a community–oriented approach to the assessment airport operations in view of the complete redefinition of the future airport scenarios. Indeed, the air traffic growth, the rapid expansion of urban areas around airports, and the expected advent of urban air mobility, are transforming the aviation noise into a serious hazard to the sustainable development of society. The sound–quality–based objective imposes a comprehensive multidisciplinary approach also in the procedural optimisation, due to the detail required to estimate the noise spectrum composition. Two merit factors are minimised, specifically the EPNL at the noise certification points and the Lp –norm of the difference between the noise produced by the configuration under analysis and a target sound. The target sounds are obtained by using sound engineering techniques aimed at the sound quality improvement, on the basis of the results of the psychometric tests campaigns performed within the projects SEFA and COSMA. The minimisation is achieved adopting a global evolution method, and the results are presented in terms of approximated Pareto frontiers for a single–aisle aircraft in both takeoff and landing conditions.


2010 ◽  
Vol 18 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Pranas Baltrėnas ◽  
Egidijus Petraitis ◽  
Tomas Januševičius

Noise is a relevant problem faced not only by Lithuania but across the world. With motor traffic flow increase, the noise caused by them is also growing and in particular noisy are heavy vehicles and motorcycles. Noise measurements were taken near the main streets in the southern part of Panevežys. Measurements were made during three time periods of the day: in the daytime (from 6 a.m. to 6 p.m.), in the evening (from 6 p.m. to 10 p.m.) and at night (from 10 p.m. to 6 a.m.). In this part of the city noise is mainly generated by cars. The measured noise levels were compared with the noise level limit (NLL) in the measurement places where the NLL is most often exceeded. Noise level analysis and traffic flows are presented in the work. As the performed measurements show, the NLL in the daytime was exceeded by 65%, in the evening by 88%, and at night by 71% of all the total measurements made. The equivalent NLL was exceeded by up to 14 dBA and the maximum NLL – by up to 17 dBA. The highest excess of the NLL was recorded by streets with the heaviest traffic. Santrauka Triukšmas – ne tik Lietuvoje, bet ir visame pasaulyje aktuali problema. Automobiliu srautams vis labiau didejant, dideja ir ju keliamas triukšmas, ypač triukšmingi yra sunkvežimiai ir motociklai. Triukšmo tyrimai atlikti Panevežio pietineje dalyje prie pagrindiniu gatviu. Matavimai vyko skirtingu paros laiku: diena 6–18 val., vakare 18–22 val. ir nakti 22–6 valandomis. Šioje miesto dalyje pagrindine triukšmo priežastis – automobiliai. Triukšmo lygis, išmatuotas vietose, kuriose dažniausiai viršijamas, lyginamas su leidžiamosiomis normomis. Atlikta triukšmo lygiu ir transporto srautu analize. Iš duomenu matyti, kad leidžiamasis triukšmo lygis diena viršytas 65 %, vakare 88 %, o nakti – 71 % atliktu matavimu. Ekvivalentinis triukšmo lygis viršytas iki 14 dBA, o maksimalusis leidžiamasis – iki 17 dB. Labiausiai triukšmo lygis viršijamas prie gatviu, kuriose pravažiuoja daugiausia automobiliu. Резюме Шум является актуальной проблемой не только в Литве, но и во всем мире. С увеличением автомобильных потоков неизбежно увеличивается и вызываемый ими (особенно грузовиками и мотоциклами) шум. Исследования шума проводились в южной части города Паневежиса, вблизи основных улиц в разное время суток: днем с 6 до 18 часов, вечером с 18 до 22 часов и ночью с 22 до 6 часов утра. В этой части города основным источником шума являются автомобили. Измеренные уровни шума были сравнены с допустимыми уровнями для мест, в которых он чаще всего превышен. Произведен анализ уровней шума и транспортных потоков. Из данных измерений видно, что допустимый уровень шума в дневное время был превышен в 65%, вечером – в 88%, а ночью – в 71% проведенных измерений. Эквивалентный уровень шума превышен до 14 дБа, а максимально допустимый – до 17 дБа. Уровни шума особенно увеличены вблизи улиц, по которым проезжает больше всего автомобилей.


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