scholarly journals On the perception of Limited Traffic Zones as urban noise mitigation action

Noise Mapping ◽  
2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Luigi Maffei ◽  
Maria Di Gabriele ◽  
Massimiliano Masullo ◽  
Francesco Aletta
Keyword(s):  
Traffic Management ◽  
Noise Control ◽  
Local Population ◽  
Environmental Noise ◽  
Subjective Perception ◽  
City Management ◽  
Noise Mitigation ◽  
Urban Noise ◽  
One Year ◽  
Sonic Environment

AbstractEnvironmental noise is a very important issue in modern urban agglomerations and new policies are being explored in order to reduce high sound-pressure levels from transportation and industry, especially in urban contexts. Considering this issue from the subjective perspective, environmental noise is often related to noise annoyance. Over the years, possible solutions were explored for urban sound planning beyond the mere noise control engineering techniques and a number of international projects proposed innovative approaches to deal with this issue: most of them were traffic-related. In order to support the city management, it is suitable to analyse possible indirect effects of traffic limitations on the perception of the sonic environment. Indeed, it was observed that even traffic management plans with no specific focus on noise mitigation are likely to have acoustic implications. The present study investigated the variations of the sonic environment induced by the implementation of a Limited Traffic Zone (LTZ) in the historic centre of Naples, in terms of objective parameters and perceived quality of the ‘sound’ component by means of noise and social surveys before, immediately after and one year after the LTZ implementation, in order to check for possible time effects. Results show that the sample interviewed immediately after the LTZ implementation reported overall positive opinions on the sonic environment and its variation, while the sample interviewed one year after tended to shift to more neutral opinions. This finding suggests that the LTZ could be considered an effective environmental strategy for the urban noise control, but it should be adequately actuated in order to preserve the achievements in terms of noise reduction and subjective perception by the local population.

scholarly journals A Metawindow with Optimised Acoustic and Ventilation Performance

2021 ◽  
Vol 11 (7) ◽  
pp. 3168
Author(s):  
Gioia Fusaro ◽  
Xiang Yu ◽  
Zhenbo Lu ◽  
Fangsen Cui ◽  
Jian Kang
Keyword(s):  
Natural Ventilation ◽  
Noise Control ◽  
Fem Analysis ◽  
The Finite Element Method ◽  
Noise Mitigation ◽  
Acoustic Performance ◽  
Potential Applications ◽  
Ventilation Performance ◽  
Sound Reduction ◽  
Window Design

Crucial factors in window performance, such as natural ventilation and noise control, are generally conceived separately, forcing users to choose one over the other. To solve this dualism, this study aimed to develop an acoustic metamaterial (AMM) ergonomic window design to allow noise control without dependence on the natural ventilation duration and vice versa. First, the finite element method (FEM) was used to investigate the noise control performance of the acoustic metawindow (AMW) unit, followed by anechoic chamber testing, which also served as the validation of the FEM models. Furthermore, FEM analysis was used to optimise the acoustic performance and assess the ventilation potential. The numerical and experimental results exhibited an overall mean sound reduction of 15 dB within a bandwidth of 380 to 5000 Hz. A good agreement between the measured and numerical results was obtained, with a mean variation of 30%. Therefore, the AMW unit optimised acoustic performance, resulting in a higher noise reduction, especially from 50 to 500 Hz. Finally, most of the AMW unit configurations are suitable for natural ventilation, and a dynamic tuned ventilation capacity can be achieved for particular ranges by adjusting the window’s ventilation opening. The proposed designs have potential applications in building acoustics and engineering where natural ventilation and noise mitigation are required to meet regulations simultaneously.

scholarly journals Analysis of reproductive biology and spawning season of the pink ear emperor Lethrinus lentjan, from marine ecosystem

2020 ◽  
Vol 37 ◽  
pp. 1-10
Author(s):  
Elsayed M. Younis ◽  
Nasser A. Al-Asgah ◽  
Abdel-Wahab A. Abdel-Warith ◽  
Mohamed H. Gabr ◽  
Fozi S. Shamlol
Keyword(s):  
Fish Species ◽  
Gonadosomatic Index ◽  
Marine Ecosystem ◽  
Local Population ◽  
Spawning Season ◽  
Monthly Basis ◽  
Population Sampling ◽  
Maturation Rate ◽  
Maturation Index ◽  
One Year

A total of 593 samples of Lethrinus lentjan (Lacepede, 1802) were collected from the Red Sea, Jeddah, Saudi Arabia, to study their productive biology and spawning season of the local population. Sampling was carried out on a monthly basis for a period of one year. The monthly sex ratios indicated that females were dominant throughout the study period, with an overall male:female sex ratio of 1:7.98, although males were larger than females. The highest monthly performance maturation index (PMI), as well as the male and female gonadosomatic index (GSI) and ovarian maturation rate (OMR) were observed in February and March. Histological examination of the gonads confirmed the process of sexual transformation in this fish species, wherein individuals mature first as female, and then change sex to male (protogynous hermaphroditism). Histological sections also showed that the sexual maturation of males of L. lenjtan comprised three main stages, while the sexual development of females could be classified into four main stages. Extended spawning in the form of batches released during different months throughout the year were recorded for this fish species, with the main spawning season in February and March, and an additional, shorter spawning season in September.

scholarly journals A Balanced Strategy for the FFBS Operator Integrating Dispatch Area, Route, and Depot Based on Multimodel Technologies

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Qingfeng Zhou ◽  
Jun Zhou ◽  
Chun Janice Wong
Keyword(s):  
Traffic Management ◽  
Evaluation Method ◽  
Time Window ◽  
Mean Shift ◽  
City Management ◽  
Optimal Dispatch ◽  
Scheduling Strategy ◽  
Mean Shift Clustering ◽  
Load Action ◽  
Shared Bicycle

Bicycle scheduling is the essential strategy for balancing the demand for the public bicycle system (PBS). Existing literature pays more attention to bike scheduling models and their solutions, but seldom discusses the dispatch area and depot center. Reasonable dockless public bicycle dispatch area and optimal dockless bike dispatch depot location in the service area were discussed from the existing shared bicycle operation data in this paper. We proposed a feasible framework including bike trip network segmentation, mean-shift clustering based on the point position, VRP model, genetic algorithm, and TOPSIS evaluation method. The effectiveness and superiority of the division of the dispatch area are verified. The main evidence for this article is (1) although the cycling networks of bicycles are different at different times of the day, the results of community division are relatively stable and have great similarities. (2) The plan of the dispatch area has impacted on the operation efficiency of the PBS. For a scheduling area, the target value of the optimal scheduling strategy corresponding to different dispatch centers is obviously different. Therefore, the location of the dispatch center has a great impact on the quality of the scheduling strategy. The dispatch area determined by bike trip OD community detection has stable characteristics of scheduling costs. (3) This work is an attempt to combine big data and model technology to assist city management. We build a feasible framework to serve a balanced strategy for FFBS which can provide reasonable dispatch area, optimal dispatch depot location, dispatch truck’s route length, load action, and time window. Our proposed framework provides new ideas for regional traffic dispatching for the traffic management department and FFBS operator, which has certain practical reference significance.

scholarly journals The Present and Future Role of Acoustic Metamaterials for Architectural and Urban Noise Mitigations

Acoustics ◽  
2019 ◽  
Vol 1 (3) ◽  
pp. 590-607 ◽  
Author(s):  
Sanjay Kumar ◽  
Heow Lee
Keyword(s):  
Human Life ◽  
Low Frequency ◽  
Comfort Level ◽  
Frequency Noise ◽  
Acoustic Metamaterials ◽  
Noise Mitigation ◽  
Urban Noise ◽  
Continuous Growth ◽  
Architectural Acoustics

Owing to a steep rise in urban population, there has been a continuous growth in construction of buildings, public or private transport like cars, motorbikes, trains, and planes at a global level. Hence, urban noise has become a major issue affecting the health and quality of human life. In the current environmental scenario, architectural acoustics has been directed towards controlling and manipulating sound waves at a desired level. Structural engineers and designers are moving towards green technologies, which may help improve the overall comfort level of residents. A variety of conventional sound absorbing materials are being used to reduce noise, but attenuation of low-frequency noise still remains a challenge. Recently, acoustic metamaterials that enable low-frequency sound manipulation, mitigation, and control have been widely used for architectural acoustics and traffic noise mitigation. This review article provides an overview of the role of acoustic metamaterials for architectural acoustics and road noise mitigation applications. The current challenges and prominent future directions in the field are also highlighted.

Mexico City urban noise control network.

2009 ◽  
Vol 126 (4) ◽  
pp. 2279 ◽  
Author(s):  
Felipe Rolando Menchaca Garcia ◽  
Luis Pastor Sanchez Fernandez ◽  
Sergio Suarez Guerra
Keyword(s):  
Mexico City ◽  
Noise Control ◽  
Control Network ◽  
Urban Noise

scholarly journals Population structure and one-year dynamics of the endangered tropical tree species Caesalpinia echinata Lam. (Brazilian red-wood): the potential importance of small fragments for conservation

Rodriguésia ◽  
2009 ◽  
Vol 60 (1) ◽  
pp. 211-220 ◽  
Author(s):  
Pablo José Francisco Pena Rodrigues ◽  
Rodolfo Cesar Real de Abreu ◽  
Eduardo M. B. Barcellos ◽  
Haroldo Cavalcante de Lima ◽  
Fabio Rubio Scarano
Keyword(s):  
Size Structure ◽  
Local Population ◽  
Population Expansion ◽  
Plant Distribution ◽  
Matrix Analysis ◽  
Small Fragment ◽  
Potential Importance ◽  
One Year ◽  
Density And Biomass ◽  
Caesalpinia Echinata

ABSTRACT Caesalpinia echinata Lam. an endangered species, occurs in forest fragments of the Cabo Frio region, in Rio de Janeiro, Brazil. Data from four sub-populations were used to describe local population patterns and one-year dynamics. In each subpopulation, 0.1 ha-plots were set up and all C. echinata trees were mapped, and diameter and height were measured. The fragments sampled had different sizes and were subjected to various degrees of man-made disturbance, representing a succession gradient from an earlier (small fragment) to a later stage (large fragment). We compared the sub-populations as regards density, size structure, spatial distribution, germination and mortality, to identify short-term responses to mechanical injuries (broken stems, sand burial and man-made cuts). Matrix analysis considering the four C. echinata sub-populations together showed a slight tendency for population expansion (λ = 1.0211) if injury patterns do not lead to habitat extinction. On the other hand, sub-populations showed aggregated distribution patterns, particularly at forest edges. Diameter size structure varied from a reversed-J pattern, i.e. seedling abundance in the small fragment (more impacted sub-population) to a uniform plant distribution of size classes in the large one (less impacted sub-population). The sub-population in the smallest fragment showed the highest birth and mortality, in contrast to reduced demographic variation in the largest fragment. Moreover, the smallest fragment also showed the largest seedling stand density and biomass. These data indicate the potential importance of small fragments for the conservation of the Brazilian red-wood.

The Abundance and Distribution of the Northern Sea Lion (Eumetopias jubata) on the Coast of British Columbia

1958 ◽  
Vol 15 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Gordon C. Pike ◽  
Brian E. Maxwell
Keyword(s):  
British Columbia ◽  
Local Population ◽  
Sea Otter ◽  
Sea Lion ◽  
Sea Lions ◽  
One Year ◽  
Abundance And Distribution ◽  
Pup Mortality ◽  
First Time ◽  
Sexually Mature

The abundance and distribution of the northern sea lion, Eumetopias jubata, in British Columbia are described chiefly on the basis of a survey conducted during the summer of 1956. Results of surveys and censuses made in the years 1913, 1916, 1938 and 1955 are included for comparison. Most major rookeries and hauling-out sites were visited in 1956. Some which were missed were surveyed by aircraft in 1957.The numbers of sea lions in British Columbia are estimated to be 11,000–12,000 in 1956–57. They have apparently changed little since 1913 and 1916 when the population is estimated less reliably to have been 12,000–13,000. Some changes have occurred in their distribution, mainly as a result of organized destruction of concentrations centred near to fishing areas. Numbers in the Sea Otter Group have been reduced to about one-quarter of their former abundance. Numbers on the Cape St. James rookery, where the population has seldom been molested, have doubled.Present rookeries include: Triangle, Sartine, and Beresford Islands, in the Scott Island group; Kerouard Islands off Cape St. James; and North Danger Rocks. The Virgin and Pearl Rocks in the Sea Otter Group are no longer rookeries. Sartine Island and North Danger Rocks are recorded for the first time as rookeries. The Scott Islands and Kerouard Islands rookeries accommodate approximately 70% of the entire population, and 90% of the pups during the summer breeding season.Destruction of approximately 1,000 sea lions annually, when many of these are pups, is shown to be ineffective in substantially reducing the total population. Where efforts are concentrated in one area such as the Sea Otter Group, however, a local population can be greatly reduced and pupping curtailed or stopped.Pups are born from late May until late June. Soon after giving birth, the cows are serviced by the harem bulls. The harem structure, which averages about 10 cows per harem bull on the rookeries, begins to disintegrate near the end of July when pups take to the water and dominant bulls are replaced by reserve bulls. Some cows, probably not more than 25% at any one time, may forgo the normal annual pregnancy and continue to nurse a pup for more than a year.It is calculated that more than 70% of the sexually mature females in this population are pregnant in any one year. Natural mortality among the pups appears to be slight, but severe storms in some years may cause heavy pup mortality and constitute an important check on population growth.

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