Influence of characteristics on combined sewer performance

2012 ◽  
Vol 66 (5) ◽  
pp. 1052-1060 ◽  
Author(s):  
M. Möderl ◽  
M. Kleidorfer ◽  
W. Rauch
Keyword(s):  
Automatic Generation ◽  
Negative Influence ◽  
Positive Influence ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Different Characteristics ◽  
Further Development ◽  
Storage Units ◽  
System Characteristics

Elements of combined sewer systems are among others sub-catchments, junctions, conduits and weirs with or without storage units. The spatial distribution and attributes of all these elements influence both system characteristics and sewer performance. Until today, little work has been done to analyse the influence of such characteristics in a case unspecific approach. In this study, 250 virtual combined sewer systems are analysed by defining groups of systems, which are representative for their different characteristics. The set was created with a further development of the case study generator (CSG), a tool for automatic generation of branched sewer systems. Combined sewer overflow and flooding is evaluated using performance indicators based on hydrodynamic simulations. The analysis of system characteristics, like those presented in this paper, helps researchers to understand coherences and aids practitioners in designing combined sewers. For instance, it was found that characteristics that have a positive influence on emission reduction frequently have a negative influence on flooding avoidance and vice versa.

Sediment transport under dry weather conditions in a small sewer system

1998 ◽  
Vol 37 (1) ◽  
pp. 155-162
Author(s):  
Flemming Schlütter ◽  
Kjeld Schaarup-Jensen
Keyword(s):  
Sediment Transport ◽  
Field Data ◽  
Field Measurements ◽  
Weather Conditions ◽  
Sewer System ◽  
Transport Models ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Initial Results

Increased knowledge of the processes which govern the transport of solids in sewers is necessary in order to develop more reliable and applicable sediment transport models for sewer systems. Proper validation of these are essential. For that purpose thorough field measurements are imperative. This paper renders initial results obtained in an ongoing case study of a Danish combined sewer system in Frejlev, a small town southwest of Aalborg, Denmark. Field data are presented concerning estimation of the sediment transport during dry weather. Finally, considerations on how to approach numerical modelling is made based on numerical simulations using MOUSE TRAP (DHI 1993).

scholarly journals Assessing the efficiency of different CSO positions based on network graph characteristics

2013 ◽  
Vol 67 (7) ◽  
pp. 1574-1580 ◽  
Author(s):  
R. Sitzenfrei ◽  
C. Urich ◽  
M. Möderl ◽  
W. Rauch
Keyword(s):  
Treatment Plant ◽  
Spatial Layout ◽  
Construction Costs ◽  
Sewer Systems ◽  
Significant Difference ◽  
Combined Sewer ◽  
The Impact ◽  
And Storage ◽  
Storage Units ◽  
Sewer Networks

The technical design of urban drainage systems comprises two major aspects: first, the spatial layout of the sewer system and second, the pipe-sizing process. Usually, engineers determine the spatial layout of the sewer network manually, taking into account physical features and future planning scenarios. Before the pipe-sizing process starts, it is important to determine locations of possible weirs and combined sewer overflows (CSOs) based on, e.g. distance to receiving water bodies or to a wastewater treatment plant and available space for storage units. However, positions of CSOs are also determined by topological characteristics of the sewer networks. In order to better understand the impact of placement choices for CSOs and storage units in new systems, this work aims to determine case unspecific, general rules. Therefore, based on numerous, stochastically generated virtual alpine sewer systems of different sizes it is investigated how choices for placement of CSOs and storage units have an impact on the pipe-sizing process (hence, also on investment costs) and on technical performance (CSO efficiency and flooding). To describe the impact of the topological positions of these elements in the sewer networks, graph characteristics are used. With an evaluation of 2,000 different alpine combined sewer systems, it was found that, as expected, with CSOs at more downstream positions in the network, greater construction costs and better performance regarding CSO efficiency result. At a specific point (i.e. topological network position), no significant difference (further increase) in construction costs can be identified. Contrarily, the flooding efficiency increases with more upstream positions of the CSOs. Therefore, CSO and flooding efficiency are in a trade-off conflict and a compromise is required.

scholarly journals PENGARUH ADOPSI AKUNTANSI TRANSAKSI ASURANSI SYARIAH BERDASARKAN PSAK 108 TERHADAP KINERJA KEUANGAN PERUSAHAAN (STUDI KASUS PADA AJB BUMIPUTERA 1912 WILAYAH SYARIAH JAKARTA)

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Nuro Sholihah
Keyword(s):  
Data Collection ◽  
Financial Performance ◽  
Measurement System ◽  
Random Sampling ◽  
Technical Analysis ◽  
Likert Scale ◽  
Negative Influence ◽  
Positive Influence ◽  
Sampling Techniques

This study aims to identify and analyze "Insurance Transaction Accounting Influence Adoption of PSAK 108 Against Sharia Based Financial Performance (Case Study At AJB Bumiputera 1912 Jakarta Regional Sharia)". The population in this study were all employees of all branches of sharia region of Jakarta as many as 84 people. The samples were set at 70 sample respondents with random sampling techniques, and data collection by questionnaire. Technical analysis of data using SPSS 20 to process the data from respondents who provide an assessment of the questionnaire stated in figures in the Likert Scale. Based on the results of the analysis showed that the presence of a negative influence between the application of the system in the early engakuan PSAK 108 on financial performance at the company AJB Bumiputera Sharia Jakarta region. This research proved the positive influence between the application of the measurement system in PSAK 108 on financial performance at the company AJB Bumiputera Sharia Jakarta region. This research proved the positive influence between the application of PSAK 108 in a presentation system on financial performance at the company AJB Bumiputera Sharia Jakarta region. This research proved the positive influence between the application of the system disclosure under PSAK 108 on financial performance at the company AJB Bumiputera Sharia Jakarta region

Design of self-cleansing sanitary sewer systems with the use of flushing devices

2009 ◽  
Vol 60 (4) ◽  
pp. 901-908 ◽  
Author(s):  
T. Goormans ◽  
D. Engelen ◽  
R. Bouteligier ◽  
P. Willems ◽  
J. Berlamont
Keyword(s):  
Surface Waters ◽  
Sewer System ◽  
Sewer Pipes ◽  
Hydrodynamic Simulations ◽  
Sanitary Sewer ◽  
Sewer Systems ◽  
Increased Risk ◽  
Combined Sewer ◽  
Maintenance Requirements

Many European countries tend to shift from constructing combined sewer systems to separate ones, in order to optimise wastewater treatment efficiency and reduce CSO impact on surface waters. An economic design minimises maintenance requirements by aiming at self-cleansing pipes. However, providing the necessary slopes for self-cleansing sanitary sewer pipes often is unfeasible in flat regions, resulting in an increased risk of loss of hydraulic capacity or blocking. To reduce these risks, flushing tanks can be installed in the sewer system. Where most other researchers contribute to a better understanding of the hydraulics of flushing, this paper rather tries to formulate a methodology to design and test flushing devices in sanitary sewer systems using standards and hydrodynamic simulations. Therefore, several aspects that require consideration when incorporating flushing devices into a sanitary sewer system are discussed. For instance, when flushing sanitary sewers the increase in discharge has to be explicitly considered. A Belgian case study is used to investigate the suitability of the developed methodology. Although the pipe slopes in the methodology are derived assuming uniform flow, the simulation results comply with it. Furthermore, pressurisation of the conduits due to multiple flushing waves remains within acceptable limits.

scholarly journals ANALYSIS OF FACTORS AFFECTING THE IMPORT OF DAIRY MILK (CASE STUDY: THE IMPORT OF DAIRY MILK IN INDONESIA)

2021 ◽  
Vol 5 (1) ◽  
pp. 27-33
Author(s):  
Kustopo Budiraharjo ◽  
Budi Raharjo ◽  
Solikhin Solikhin
Keyword(s):  
Milk Production ◽  
Secondary Data ◽  
Negative Influence ◽  
Positive Influence ◽  
Gdp Per Capita ◽  
Milk Consumption ◽  
Factors Affecting ◽  
Per Capita ◽  
Dairy Milk

The supply of fresh dairy milk in the country (SSDN) has not been able to meet the needs of domestic dairy milk consumption so that the fulfillment of dairy milk consumption needs is also done byimporting dairy milk. This study aims to analyze the factors that influence milk imports in Indonesia.The research method uses quantitative analysis techniques, namely multiple linear regression. This research was conducted in Indonesia using secondary data from 2006-2016 obtained at the Central Statistics Agency and the Ministry of Agriculture and other literature related to research. Research variables include exchange rates, GDP per capita, milk exports, and milk production. The results showed that variables GDP per capita, milk exports, and milk production have positive influence. Meanwhile, exchange rate has negative influence for milk imports.  

scholarly journals Analysis of The Influence of Motivation, Environment, and Work Stress on Employee Performance Through Job Satisfaction As Intervening Variable (Case Study Of PT. XYZ)

2020 ◽  
Vol 2 (1) ◽  
pp. 43-50
Author(s):  
Kukuh Eska Yanuar ◽  
Suparto Suparto
Keyword(s):  
Job Satisfaction ◽  
Structural Equation Modeling ◽  
Significant Influence ◽  
Structural Equation ◽  
Employee Performance ◽  
Negative Influence ◽  
Positive Influence ◽  
Equation Modeling ◽  
Environment Stress

PT. XYZ is a company engaged in construction specifically steel fabrication. The problem encountered by company was frequent overtimes with low remuneration but cannot meet production target. The objective of study was to know the influence of motivation, environment,stress on employee performance through job satisfaction as intervening variable. The method used was Structural Equation Modeling with IBS SPSS AMOS software. The results of study indicated that motivation had positive influence of 0.229, environment had positive influence of 2.746, and stress had significant influence of 0.139 on job satisfaction. Motivation had positive influence of 0.910, environment had positive influence of 2.526, and stress had negative influence of -0.221 on employee performance. Motivation had positive influence of 0.093, environment had positive influence of 1.120, and stress had positive and significant influence of 0.056 on employee performance through job satisfaction as intervening variable. Job satisfaction had positive influence of 0.408 on employee performance.Keywords: motivation, environment, stress, structural, equation, modeling

An agent-based approach for generating virtual sewer systems

2010 ◽  
Vol 62 (5) ◽  
pp. 1090-1097 ◽  
Author(s):  
C. Urich ◽  
R. Sitzenfrei ◽  
M. Möderl ◽  
W. Rauch
Keyword(s):  
Population Distribution ◽  
Automatic Generation ◽  
Data Sets ◽  
Urban Structure ◽  
Sewer System ◽  
Agent Based ◽  
Sewer Systems ◽  
Virtual Infrastructure ◽  
Sewer Networks

The application of artificial case studies is a well established technique in urban drainage to test measures, approaches or models. However, the preparation of a virtual case study for a sewer system is a tedious task. Several algorithms have been presented in the literature for an automatic generation of virtual sewer systems. Applying the approach of generating virtual cities by means of the software VIBe (Virtual Infrastructure Benchmarking) the urban structure (including elevation map, land use and population distribution) is generated firstly and the infrastructure is designed meeting the requirements of the urban structure. The aim of this paper is the development of an agent based approach for generating virtual sewer systems. This new algorithm functions as module of the software VIBe but can of course also be applied to a real city in order to get information on possible/optimal sewer placement. Here hundred virtual VIBe cities and for each twelve virtual sewer networks are generated and calibrated based on data of an alpine region. It is revealed that with the approach presented virtual sewer networks which are comparable with real world sewer networks can be generated. The agent based method provides data sets for benchmarking and allows case independent testing of new measures.

A conceptual model for sediment transport in combined sewer systems

1999 ◽  
Vol 39 (9) ◽  
pp. 39-46 ◽  
Author(s):  
Flemming Schlütter
Keyword(s):  
Sensitivity Analysis ◽  
Sediment Transport ◽  
Conceptual Model ◽  
Qualitative Information ◽  
Sewer System ◽  
Erosion And Deposition ◽  
Sewer Systems ◽  
Hydraulic Conditions ◽  
Combined Sewer

This paper presents a numerical model capable of simulating sediment transport in combined sewer systems. The main objectives of the model are to model mass transport rates at the outlet from a catchment and at the same time obtaining qualitative information on erosion and deposition going on at different locations in the sewer system. The model is conceptual but based on deterministic computations of hydraulic conditions. The formulations used in the conceptual model (STSim) are presented as well as results from a sensitivity analysis. Finally, an example is given of a calibration event from a case study.

Combined sewer overflow over an oblique weir at Rat Creek in Edmonton, Alberta

2010 ◽  
Vol 37 (3) ◽  
pp. 477-488
Author(s):  
Elizabeth Valentine ◽  
Kurt Kronebusch ◽  
David Z. Zhu ◽  
N. Rajaratnam ◽  
Sid Lodewyk ◽  
...  
Keyword(s):  
Urban Drainage ◽  
Combined Sewer Overflow ◽  
Rating Curve ◽  
Flow Conditions ◽  
Sewer System ◽  
Sewer Systems ◽  
Model Study ◽  
Combined Sewer ◽  
Sewer Overflow

Oblique weirs are commonly used in urban drainage systems to remove excess flow from a sewer, in particular, a combined sewer system that has limited conveyance capacity. It is important to understand the hydraulics of these weirs to properly monitor the amount of the overflows as well as to design and improve sewer systems. The Rat Creek structure in Edmonton, Alberta, is a combined sewer overflow structure with a weir at an oblique alignment to the centerline of the sewer. A physical model study of the structure was conducted. The results show that both the approach flow conditions and the chamber geometry can significantly affect the hydraulic performance of the weir and invalidate the application of standard weir equations. A unique flow regime with a linear head–discharge rating curve was observed. The effects of modifying the weir and the hanging baffle wall downstream of the weir were also studied and reported. The results of this case study help to improve the understanding of the hydraulics of oblique weirs in sewer systems.

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