Sewer solids management using invert traps

1998 ◽  
Vol 37 (1) ◽  
pp. 139-146
Author(s):  
Alasdair G. Fraser ◽  
Richard M. Ashley ◽  
Morven M. Sutherland ◽  
Jes Vollertsen

During the 20th century, the once common practice of trapping sewer sediments at key locations within sewerage systems has lost favour with UK sewerage designers and, to a lesser extent, operators. The reasons for this include the perception of a priori unquantifiable maintenance, and the difficulties of sewer sediment extraction in town centres in an environmentally acceptable fashion. In order to assess the need for and requirements of such trapping systems, a survey of UK sewerage operators was carried out. The results of this survey have been used as a starting point to initiate the development of a design and operational methodology for the utilisation of traps. The survey highlighted the lack of guidance available and the importance of trap monitoring to enhance performance. A fill rate model is proposed for the design and operational aspects of cleaning and monitoring traps, using two of the most recently developed “near bed solids” transport equations. The model has been applied to a trap situated on a trunk sewer in the city centre area of Dundee. The pollution potential of trap and in-pipe sediments has also been assessed by considering the biodegradability of the sediment fractions likely to be released into the flow column during storm events.

Author(s):  
Mihajlo Zinoski ◽  
Igor Medarski ◽  
Stefani Solarska

The modern way of life is conditioned by fast transportation. This, in turn, requires integration of many additional contents that opens the opportunity to the passengers for quick access to their target-food, accommodation, entertainment, communication. The distance of the existing railway station (3.7 km from the city centre) makes it hardly accessible to the population, therefore it is neglected and the rail traffic in the city of Kumanovo is minimized. On the other hand, the bus station has a good location, but the building is in poor condition, which impedes the functioning of the city and intercity bus service. Adjacent to the existing bus station, a segment of the railroad from the proposed "Corridor 8" transits, which opens the question of the importance of rail transport and its impact in the further development of the city. These considerations clearly indicate the need to establish an integrated transport hub, whose proposed location touches the downtown area, but is still in the zone between the city and the suburbia, which includes adjoining contents such as: retail, hospitality and culture, which will help achieve the goal of the transportation hub as a starting point of development of a new city nucleus, a new point in the city.


2017 ◽  
Vol 1 (1) ◽  
pp. 69-73
Author(s):  
Robert Noga

Henryk Jordan – who lived in Cracow at the turn of 19th and 20th century – was a well-known and esteemed medical doctor, social and political activist as well as an art patron and publicist. His most prominent heritage is a city park named after him. At the time it was a location where pioneering work promoting physical culture among youngsters took place. First trainings started in 1889 and instantly became popular. Trainings were carefully organized and combined physical training with a promotion of a patriotism. At the beginning of 1890’s Jordan introduced football which became very popular amongst male teenagers. Football became a part of trainings and competitions, and after a while organized football teams started to play in the park. This was a starting point of the oldest still existing Polish football clubs: Cracovia and Wisła. Jordan’s ideas inspired others, and soon many other cities in Poland. Jordan’s park exists until today, however, it plays a role of a popularizing recreational spot in the city centre. In other cities, so-called “Jordan’s gardens” became playgrounds for children.


2017 ◽  
Vol 14 (1) ◽  
pp. 118-128
Author(s):  
Jason Cohen ◽  
Judy Backhouse ◽  
Omar Ally

Young people are important to cities, bringing skills and energy and contributing to economic activity. New technologies have led to the idea of a smart city as a framework for city management. Smart cities are developed from the top-down through government programmes, but also from the bottom-up by residents as technologies facilitate participation in developing new forms of city services. Young people are uniquely positioned to contribute to bottom-up smart city projects. Few diagnostic tools exist to guide city authorities on how to prioritise city service provision. A starting point is to understand how the youth value city services. This study surveys young people in Braamfontein, Johannesburg, and conducts an importance-performance analysis to identify which city services are well regarded and where the city should focus efforts and resources. The results show that Smart city initiatives that would most increase the satisfaction of youths in Braamfontein  include wireless connectivity, tools to track public transport  and  information  on city events. These  results  identify  city services that are valued by young people, highlighting services that young people could participate in providing. The importance-performance analysis can assist the city to direct effort and scarce resources effectively.


2012 ◽  
pp. 66-80
Author(s):  
Michał Mrozowicki

Michel Butor, born in 1926, one of the leaders of the French New Novel movement, has written only four novels between 1954 and 1960. The most famous of them is La Modification (Second thoughts), published in 1957. The author of the paper analyzes two other Butor’s novels: L’Emploi du temps (Passing time) – 1956, and Degrés (Degrees) – 1960. The theme of absence is crucial in both of them. In the former, the novel, presented as the diary of Jacques Revel, a young Frenchman spending a year in Bleston (a fictitious English city vaguely similar to Manchester), describes the narrator’s struggle to survive in a double – spatial and temporal – labyrinth. The first of them, formed by Bleston’s streets, squares and parks, is symbolized by the City plan. During his one year sojourn in the city, using its plan, Revel learns patiently how to move in its different districts, and in its strange labyrinth – strange because devoid any centre – that at the end stops annoying him. The other, the temporal one, symbolized by the diary itself, the labyrinth of the human memory, discovered by the narrator rather lately, somewhere in the middle of the year passed in Bleston, becomes, by contrast, more and more dense and complex, which is reflected by an increasinly complex narration used to describe the past. However, at the moment Revel is leaving the city, he is still unable to recall and to describe the events of the 29th of February 1952. This gap, this absence, symbolizes his defeat as the narrator, and, in the same time, the human memory’s limits. In Degrees temporal and spatial structures are also very important. This time round, however, the problems of the narration itself, become predominant. Considered from this point of view, the novel announces Gerard Genette’s work Narrative Discourse and his theoretical discussion of two narratological categories: narrative voice and narrative mode. Having transgressed his narrative competences, Pierre Vernier, the narrator of the first and the second parts of the novel, who, taking as a starting point, a complete account of one hour at school, tries to describe the whole world and various aspects of the human civilization for the benefit of his nephew, Pierre Eller, must fail and disappear, as the narrator, from the third part, which is narrated by another narrator, less audacious and more credible.


Author(s):  
Rafael Salas ◽  
María José Pérez Villadóniga ◽  
Juan Prieto Rodríguez ◽  
Ana Russo
Keyword(s):  

2020 ◽  
Vol 46 (1) ◽  
pp. 55-75
Author(s):  
Ying Long ◽  
Jianting Zhao

This paper examines how mass ridership data can help describe cities from the bikers' perspective. We explore the possibility of using the data to reveal general bikeability patterns in 202 major Chinese cities. This process is conducted by constructing a bikeability rating system, the Mobike Riding Index (MRI), to measure bikeability in terms of usage frequency and the built environment. We first investigated mass ridership data and relevant supporting data; we then established the MRI framework and calculated MRI scores accordingly. This study finds that people tend to ride shared bikes at speeds close to 10 km/h for an average distance of 2 km roughly three times a day. The MRI results show that at the street level, the weekday and weekend MRI distributions are analogous, with an average score of 49.8 (range 0–100). At the township level, high-scoring townships are those close to the city centre; at the city level, the MRI is unevenly distributed, with high-MRI cities along the southern coastline or in the middle inland area. These patterns have policy implications for urban planners and policy-makers. This is the first and largest-scale study to incorporate mobile bike-share data into bikeability measurements, thus laying the groundwork for further research.


Urban Science ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 42
Author(s):  
Dolores Brandis García

Since the late 20th century major, European cities have exhibited large projects driven by neoliberal urban planning policies whose aim is to enhance their position on the global market. By locating these projects in central city areas, they also heighten and reinforce their privileged situation within the city as a whole, thus contributing to deepening the centre–periphery rift. The starting point for this study is the significance and scope of large projects in metropolitan cities’ urban planning agendas since the final decade of the 20th century. The aim of this article is to demonstrate the correlation between the various opposing conservative and progressive urban policies, and the projects put forward, for the city of Madrid. A study of documentary sources and the strategies deployed by public and private agents are interpreted in the light of a process during which the city has had a succession of alternating governments defending opposing urban development models. This analysis allows us to conclude that the predominant large-scale projects proposed under conservative policies have contributed to deepening the centre–periphery rift appreciated in the city.


Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 179
Author(s):  
Said Munir ◽  
Martin Mayfield ◽  
Daniel Coca

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.


Urban Studies ◽  
2021 ◽  
pp. 004209802110078
Author(s):  
Romit Chowdhury ◽  
Colin McFarlane

In the history of urban thought, density has been closely indexed to the idea of citylife. Drawing on commuters’ experiences and perceptions of crowds in and around Tokyo’s Shinjuku Station, this article offers an ethnographic perspective on the relationship between urban crowds and life in the city. We advance understandings of the relations between the crowd and citylife through three categories of ‘crowd relations’– materiality, negotiation and inclusivity – to argue that the multiplicity of meanings which accrue to people’s encounters with crowds refuses any a priori definitions of optimum levels of urban density. Rather, the crowd relations gathered here are evocations of citylife that take us beyond the tendency to represent the crowd as a particular kind of problem, be it alienation, exhaustion or a threshold for ‘good’ and ‘bad’ densities. The portraits of commuter crowds presented capture the various entanglements between human and non-human, embodiment and mobility, and multiculture and the civic, through which citylife emerges as a mode of being with oneself and others.


Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 17 ◽  
Author(s):  
Justyna Jaworek-Jakubska ◽  
Maciej Filipiak ◽  
Adam Michalski ◽  
Anna Napierała-Filipiak

Knowledge about urban forests in Poland is still limited, as it is primarily based on aggregate, formal data relating to the general area, ignoring the spatial dimension and informal green areas. This article describes and analyses spatio-temporal changes in the actual urban forest resources in Wrocław in 1944–2017, which covers the first period of the city’s rebuilding after its destruction during World War II and its development during the nationalised, centrally-planned socialist economy, as well as the second period of intensive and only partly controlled growth under conditions of market economy. The study is based on current and historical orthophotomaps, which were confronted with cartographic data, as well as planning documents. We found that between 1944 and 2017, the percentage contribution of informal woodlands increased tenfold (from 0.5 to 4.9% of the present total area of the city). The area occupied by such forests has grown particularly during the most recent years of the city’s intensive development. However, the forests have been increasingly fragmented. During the first period, new forest areas were also created in the immediate vicinity of the city centre, while during the second one, only in its peripheral sections. The post-war plans regarding the urban green spaces (UGS), including the current plan, are very conservative in nature. On the one hand, this means no interference with the oldest, biggest, and most valuable forest complexes, but on the other hand, insufficient consideration of the intensive built-up area expansion on former agriculture areas. Only to a limited extent did the above-mentioned plans take into account the informal woodlands, which provide an opportunity for strengthening the functional connectivity of landscape.


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