Scale model testing and calibration of City of Ottawa sewer weirs

2001 ◽  
Vol 28 (4) ◽  
pp. 627-639 ◽  
Author(s):  
J Bettez ◽  
R D Townsend ◽  
A Comeau

This paper reports the results of a laboratory study of the effects of (i) manhole proximity to installation site, (ii) pipe slope (i.e., approach velocity), (iii) upstream head measurement location, and (iv) submergence on the "hydraulics" of two types of sewer weirs used by the City of Ottawa. The City's streamlined form of broad-crested weir and its compound-shaped sharp-crested weir were initially calibrated for a "pipe straight"-arrangement (no upstream manhole is present) for a wide range of flow conditions at 0.2%, 0.4%, and 1.0% pipe slopes. The calibration tests were then repeated with the weirs positioned immediately downstream of a model manhole structure ("manhole"-arrangement). Corresponding data sets were compared to determine the effects of (i) approach velocity and (ii) manhole proximity (for two different shapes of manhole "benching") on the respective weir discharge coefficients.Key words: sewer weirs, broad-crested weir, compound sharp-crested weir, calibration, sewer benching, discharge coefficients.

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 794 ◽  
Author(s):  
Rita F. Carvalho ◽  
Pedro Lopes ◽  
Jorge Leandro ◽  
Luis M. David

Gullies are sewer inlets placed in pavements usually covered by bar grates. They are the most common linking-element used to drain a wide range of flows from surface runoff into the buried drainage system. Their hydraulic behavior and their overall hydraulic performance is dependent on the flow conditions, the gully dimension, geometry, and location of the outlet device. Herein a numerical research based on Volume Of Fluid ( V O F ) to detect the interface, and on the Shear Stress Transport S S T k - ω turbulence model was conducted to study the importance of the outlet location and characterize flows through them in drainage conditions. Results provided detailed information about flow features, discharge coefficients, and efficiencies for different outlet locations. The authors identified three different regimes, R 1 , R 2 , and R 3 , and concluded that the outlet location influences the velocity field along the gully, the discharge coefficient, and the drainage efficiency. This allows for the estimation of uncertainty and its variation for different outlet positions.


Author(s):  
M. Gritsch ◽  
A. Schulz ◽  
S. Wittig

This paper presents the discharge coefficients of three film-cooling hole geometries tested over a wide range of flow conditions. The hole geometries include a cylindrical hole and two holes with a diffuser shaped exit portion (i.e. a fanshaped and a laidback fanshaped hole). The flow conditions considered were the crossflow Mach number at the hole entrance side (up to 0.6), the crossflow Mach number at the hole exit side (up to 1.2), and the pressure ratio across the hole (up to 2). The results show that the discharge coefficient for all geometries tested strongly depends on the flow conditions (crossflows at hole inlet and exit, and pressure ratio). The discharge coefficient of both expanded holes was found to be higher than of the cylindrical hole, particularly at low pressure ratios and with a hole entrance side crossflow applied. The effect of the additional layback on the discharge coefficient is negligible.


Author(s):  
Kathryn A. Sloan

Popular culture has long conflated Mexico with the macabre. Some persuasive intellectuals argue that Mexicans have a special relationship with death, formed in the crucible of their hybrid Aztec-European heritage. Death is their intimate friend; death is mocked and accepted with irony and fatalistic abandon. The commonplace nature of death desensitizes Mexicans to suffering. Death, simply put, defines Mexico. There must have been historical actors who looked away from human misery, but to essentialize a diverse group of people as possessing a unique death cult delights those who want to see the exotic in Mexico or distinguish that society from its peers. Examining tragic and untimely death—namely self-annihilation—reveals a counter narrative. What could be more chilling than suicide, especially the violent death of the young? What desperation or madness pushed the victim to raise the gun to the temple or slip the noose around the neck? A close examination of a wide range of twentieth-century historical documents proves that Mexicans did not accept death with a cavalier chuckle nor develop a unique death cult, for that matter. Quite the reverse, Mexicans behaved just as their contemporaries did in Austria, France, England, and the United States. They devoted scientific inquiry to the malady and mourned the loss of each life to suicide.


2019 ◽  
Vol 9 (4) ◽  
pp. 193-198
Author(s):  
Lyudmila S. Timofeeva ◽  
Albina R. Akhmetova ◽  
Liliya R. Galimzyanova ◽  
Roman R. Nizaev ◽  
Svetlana E. Nikitina

Abstract The article studies the existence experience of historical cities as centers of tourism development as in the case of Elabuga. The city of Elabuga is among the historical cities of Russia. The major role in the development of the city as a tourist center is played by the Elabuga State Historical-Architectural and Art Museum-Reserve. The object of the research in the article is Elabuga as a medium-size historical city. The subject of the research is the activity of the museum-reserve which contributes to the preservation and development of the historical look of Elabuga and increases its attractiveness to tourists. The tourism attractiveness of Elabuga is obtained primarily through the presence of the perfectly preserved historical center of the city with the blocks of integral buildings of the 19th century. The Elabuga State Historical-Architectural and Art Museum-Reserve, which emerged in 1989, is currently an object of historical and cultural heritage of federal importance. Museum-reserves with their significant territories and rich historical, cultural and natural heritage have unique resources for the implementation of large partnership projects. Such projects are not only aimed at attracting a wide range of tourists, but also stimulate interest in the reserve from the business elite, municipal and regional authorities. The most famous example is the Spasskaya Fair which revived in 2008 in Elabuga. It was held in the city since the second half of the 19th century, and was widely known throughout Russia. The process of the revival and successful development of the fair can be viewed as the creation of a special tourist event contributing to the formation of new and currently important tourism products.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Eleanor F. Miller ◽  
Andrea Manica

Abstract Background Today an unprecedented amount of genetic sequence data is stored in publicly available repositories. For decades now, mitochondrial DNA (mtDNA) has been the workhorse of genetic studies, and as a result, there is a large volume of mtDNA data available in these repositories for a wide range of species. Indeed, whilst whole genome sequencing is an exciting prospect for the future, for most non-model organisms’ classical markers such as mtDNA remain widely used. By compiling existing data from multiple original studies, it is possible to build powerful new datasets capable of exploring many questions in ecology, evolution and conservation biology. One key question that these data can help inform is what happened in a species’ demographic past. However, compiling data in this manner is not trivial, there are many complexities associated with data extraction, data quality and data handling. Results Here we present the mtDNAcombine package, a collection of tools developed to manage some of the major decisions associated with handling multi-study sequence data with a particular focus on preparing sequence data for Bayesian skyline plot demographic reconstructions. Conclusions There is now more genetic information available than ever before and large meta-data sets offer great opportunities to explore new and exciting avenues of research. However, compiling multi-study datasets still remains a technically challenging prospect. The mtDNAcombine package provides a pipeline to streamline the process of downloading, curating, and analysing sequence data, guiding the process of compiling data sets from the online database GenBank.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yance Feng ◽  
Lei M. Li

Abstract Background Normalization of RNA-seq data aims at identifying biological expression differentiation between samples by removing the effects of unwanted confounding factors. Explicitly or implicitly, the justification of normalization requires a set of housekeeping genes. However, the existence of housekeeping genes common for a very large collection of samples, especially under a wide range of conditions, is questionable. Results We propose to carry out pairwise normalization with respect to multiple references, selected from representative samples. Then the pairwise intermediates are integrated based on a linear model that adjusts the reference effects. Motivated by the notion of housekeeping genes and their statistical counterparts, we adopt the robust least trimmed squares regression in pairwise normalization. The proposed method (MUREN) is compared with other existing tools on some standard data sets. The goodness of normalization emphasizes on preserving possible asymmetric differentiation, whose biological significance is exemplified by a single cell data of cell cycle. MUREN is implemented as an R package. The code under license GPL-3 is available on the github platform: github.com/hippo-yf/MUREN and on the conda platform: anaconda.org/hippo-yf/r-muren. Conclusions MUREN performs the RNA-seq normalization using a two-step statistical regression induced from a general principle. We propose that the densities of pairwise differentiations are used to evaluate the goodness of normalization. MUREN adjusts the mode of differentiation toward zero while preserving the skewness due to biological asymmetric differentiation. Moreover, by robustly integrating pre-normalized counts with respect to multiple references, MUREN is immune to individual outlier samples.


Author(s):  
Francisco Arcas-Tunez ◽  
Fernando Terroso-Saenz

The development of Road Information Acquisition Systems (RIASs) based on the Mobile Crowdsensing (MCS) paradigm has been widely studied for the last years. In that sense, most of the existing MCS-based RIASs focus on urban road networks and assume a car-based scenario. However, there exist a scarcity of approaches that pay attention to rural and country road networks. In that sense, forest paths are used for a wide range of recreational and sport activities by many different people and they can be also affected by different problems or obstacles blocking them. As a result, this work introduces SAMARITAN, a framework for rural-road network monitoring based on MCS. SAMARITAN analyzes the spatio-temporal trajectories from cyclists extracted from the fitness application Strava so as to uncover potential obstacles in a target road network. The framework has been evaluated in a real-world network of forest paths in the city of Cieza (Spain) showing quite promising results.


1979 ◽  
Author(s):  
P.D. Richardson

Thrombocyte adhesion and aggregation in a vessel or on a chamber wall can be measured most readily if the flow is controlled and steady, and continuous observation is used. Videotape recording is very helpful for subsequent quantification of the dynamics. The adhesion of each thrombocyte can occur for a finite time interval:this interval has been observed to have a wide range. Platelets which escape often leave open a site which attracts other platelets preferentially. The rate of change of adhesion density (platelets/mm2) is affected by the local shear rate and the shear history upstream. Aggregation is affected similarly, and also proceeds with some platelet turnover. The role of erythrocytes in facilitating cross-stream migration of thrombocytes (which can enhance the growth rate of large thrombi) appears due in part to convective flow fields induced by the motion of erythrocytes in a shear flow, which can be demonstrated theoretically and experimentally. Observations of the phenomenlogy of adhesion and aggregation under controlled flow conditions and comparison with fLu id-dynamically based theory allows representation in terras of a small number of parameters with prospects of prediction of behaviour over a wide range of haemodynamic conditions; biochemical changes lead to changes in values of the parameters, so that activating agents and inhibiting agents modify values in different directions.


Transport ◽  
2012 ◽  
Vol 26 (4) ◽  
pp. 418-424 ◽  
Author(s):  
Valentina Basarić ◽  
Jadranka Jović

The research presented in this paper is aimed at defining a model that enables the management of the relationship between private vehicles and public transport applying the available instruments of city transport policy such as parking policy and public transport policy measures. Statistical data used for modelling is sourced from the database in a wide range of EU cities. The target model was developed in the form of stepwise regression analysis. Very favourable statistical results were obtained, and the subsequent tests on the city of Novi Sad (250000 inhabitants) led to the conclusion that the obtained results were suitable for implementation in practice. The results of the implemented procedure are of great importance for the enhancement of the existing transport policies in cities, as they enable the development of strategies for finding combinations of instruments that would bring the transport system and urban environment into a desired-viable rather than consequential condition.


1995 ◽  
Vol 15 (1) ◽  
pp. 59-81 ◽  
Author(s):  
G. Clare Wenger

AbstractThis paper compares findings on the distribution of support networks in the City of Liverpool and in rural communities in North Wales. It demonstrates that while support network type is highly correlated with a wide range of demographic and social variables in both urban and rural samples, the nature of the relationships are not always comparable. The paper shows how cultural, migration and socio-economic factors interact to affect the formation of different types of support networks. As a result of a more stable elderly population, more old people in Liverpool have network types able to provide a high level of informal care and support.


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