Improving the geometry of manholes designed for separate sewer systems

The design of manholes dates back more than 100 years. However, there have been developments such as the use of new materials for the manufacture of manholes, and advances in inspection and maintenance technologies, allowing improvements to the shape of manholes. This paper presents an innovative design for manholes, created to overcome the challenges associated with the installation of separate sewer systems in narrow streets, common to both UK and EU cities. The traditional separate sewer system has two separate manholes. The proposed manhole combines these two manholes into one structure, with two separate chambers, to allow storm flow and foul flow to pass through the same manhole without mixing. The structural performance of the new design has been tested using mathematical modelling validated by experimental tests. The results are compared with the structural performance of traditional manholes. The new design shows an improved resistance to high live loads

Developing a decision support tool for the positioning and sizing of vortex flow controls in existing sewer systems

12th International Conference on Computing and Control for the Water Industry, CCWI2013This is the final version of the article. Available from Elsevier via the DOI in this record.This paper describes the development of a decision support tool for the positioning and sizing of vortex flow controls in existing sewer systems. The tool aims to prioritise the placement of vortex flow controls primarily within subcatchments with the greatest flood consequence rating and maximise the use of unused inpipe volumes during critical rainfall events. The decision support tool is intended for use in catchments where opportunities to implement SuDS and rainwater harvesting to defend against flooding are limited. The decision support tool is envisaged to identify potential strategies which could enhance flood resistance of sewer systems in a cost effective manner. © 2013 The Authors

Investigation of the structural performance of two flexible pipes set in one trench with a new placement method for separate sewer systems

Substantial research has been conducted on single flexible pipes buried in a trench. In contrast, the objective of this study is to determine the structural performance of two buried flexible sewer pipes positioned one over the other in a single trench. An innovative configuration is designed, based around the use of an innovative manhole structure which can accommodate both foul and surface water, to solve the challenges associated with constructing separate sewer systems in narrow streets while providing additional space for other infrastructure services. The behaviours of the two flexible pipes were tested using a 3D finite element (FE) model validated with experimental data from a laboratory investigation. A modified Drucker–Prager cap soil constitutive model was used to simulate the elasto-plastic soil behaviour. The results show that this approach comprising the use of a large-diameter flexible pipe set above a small-diameter flexible pipe mitigates the strain on the smaller pipe and decreases the total deflections of both pipes and the soil

Experimental data used to validate the FE model of the structural performance of two flexible pipes laid in a single trench.

The objective of the article is to describe the methodology followed to validate the finite element model for the new method of setting pipes in a separate sewer system, using one trench to accommodate the storm pipe over the sanitary pipe "doi.org/10.1016/j.tust.2019.103019" (Abbas et al., 2019). A physical model was established in the Liverpool John Moores University (LJMU) lab to test the structural performance of two PVC pipes buried in one trench. The results of the physical model were used to validate an FE model using the same material properties and boundary conditions used in the physical model. The validation process allowed the FE model to be upgraded to a 3D FE full-scale model for testing the novel method used to place the separate sewer system

Grain quality characteristics of imported rice in Ghana: Implications for breeding for consumer-preferred varieties

ABSTRACTRice is the fastest growing food source in Ghana. The country, however, imports about 70 per cent of its rice requirement due to low volumes of production and poor grain quality of domestic rice compared to imported ones.  In the study, 10 popular imported rice brands on the Ghanaian market were characterised for grain quality traits including grain dimensions, apparent amylose content, gelatinisation temperature, paste viscosity properties, and aroma using physiochemical properties and DNA markers. The rice brands came from Asia and the USA. The rice type from Asia was found to be Jasmine-styled aromatic long grained with low amylose content and gelatinisation temperature, whereas those of USA were conventional long grain with intermediate amylose content and gelatinisation temperature.  These findings were confirmed through DNA marker analyses, with the rice types from Asia and the USA revealing the presence of the TAC and GCC of the waxy gene SNP haplotypes, respectively. The implication for rice breeding in Ghana is discussed.Original scientific paper. Received 29 Oct. 14; revised 03 Aug 15

Photoreactivation of total heterotrophic bacteria in bottled drinking water after inactivation with pulsed ultra-violet light

Bacteria which cause opportunistic infections such as Pseudomonas can self resuscitate incircumstances where effective UV disinfection is compromised and is exposed to sunlight. The study investigated the effect of sub-lethal doses of pulsed ultra-violet (PUV) light on total heterotrophic bacteria (THB) in three brands of bottled water packed in glass and plastic bottles and how photoreactivation and dark repair occurred. The effect of exposure time on photoreactivation of Escherichia coli and Pseudomonas aeruginosa after inactivation with PUV was also investigated. THB in brands 1, 2 and 3 were completely inactivated by 7, 3 and 5 pulses of UV light respectively. Light repair of THB varied in the three brands of bottled water due perhaps to differences in the ionic composition of the three brands. Brands 1, 2 and 3 having 0.4, 0.7 and 1.7 log units of repair. respectively. Evidence of dark repair was not significant. Photo-repair in E. coli and Pseudomonas aeruginosa increased gradually with continual exposure to irradiating light for a period after which there was a decrease, suggesting that for a particular bacterium and illuminating source, an optimum time of exposure exist during which maximum photo-repair occur

Modelling data of an urban drainage design using a Geographic Information System (GIS)database

This paper describes the development of a model to interface a planned urban drainage system with Geographic Information System (GIS)through the introduction of open-source tools; Auto Numbering and Get Elevation to extract essential data from GIS and Excel2GIS to bridge the output data between GIS and the drainage design program. Creating a range of essential data from digital database repositories aids the development of decision-support tools for urban planners in a simulation of different urban drainage scheme scenarios and moderates the interference with other infrastructure utilities. These tools, modelled with design software and GIS platform, are tested in two case studies; the results revealing essential improvements in accuracy of output, time taken to prepare and run the model and model presentation which visualised the hydraulic design results and global location of the drainage layout on an urban master plan. © 2019 Elsevier B.V

Graphics for relatedness research

Studies of relatedness have been crucial in molecular ecology over the last decades. Good evidence of this is the fact that studies of population structure, evolution of social behaviours, genetic diversity and quantitative genetics all involve relatedness research. The main aim of this article is to review the most common graphical methods used in allele sharing studies for detecting and identifying family relationships. Both IBS and IBD based allele sharing studies are considered. Furthermore, we propose two additional graphical methods from the field of compositional data analysis: the ternary diagram and scatterplots of isometric log-ratios of IBS and IBD probabilities. We illustrate all graphical tools with genetic data from the HGDP-CEPH diversity panel, using mainly 377 microsatellites genotyped for 25 individuals from the Maya population of this panel. We enhance all graphics with convex hulls obtained by simulation and use these to confirm the documented relationships. The proposed compositional graphics are shown to be useful in relatedness research, as they also single out the most prominent related pairs. The ternary diagram is advocated for its ability to display all three allele sharing probabilities simultaneously. The log-ratio plots are advocated as an attempt to overcome the problems with the Euclidean distance interpretation in the classical graphics.Peer ReviewedPostprint (published version

Designing a Mechanical System That Will Be Used To Extract and Separate Lemon Grass Oil

ABSTRACT Lemon grass is broadly used in medicine, perfumery industry, vitamin A manufacturing and pharmaceuticals. The need for lemon grass oil, especially in human health and its problem of extracting the oil, have directed this paper in designing a mechanical system that will be used to extract and separate lemon grass oil. The extraction of essential oil from lemon grass was done using direct steam distillation process. In all, three concepts were developed based on the orientation of the condensers, source of power, and method of oil production. The three (3) concepts were evaluated and the best concept was selected as the final design. Design analysis was performed on each part to determine their specification, the material to be used and manufacturing processes for the fabrication. Two tests were performed to determine the performance of machine and the quality of the oil produced. From the results, it can be established that the prototype machine developed can be used to extract lemon grass oil from the leaves. The efficiencies were then computed and favorable results were obtained. Also, the results obtained for the four tests responded positive given an indication of the pureness of the oil. It can then be concluded that the prototype machine developed can be used to extract lemon grass oil from the leaves and its efficiency ranges from 2.37 to 3.95 ml/kg and it is economically viable, effective and efficient