140 research outputs found
Wastewater treatment and resource recovery for poverty alleviation: a combined duckweed and water hyacinth pond system
No full textFloating macrophyte pond systems, with the ability to produce nutrient
enriched plants simultaneously with wastewater treatment, are a sustainable
solution to contribute to environmental protection and safe nutrient recovery
from domestic wastewater. However, to meet the requirements for reuse with
high strength wastewater containing high levels of metal pollution generated in
developing countries, an adequate combination of water hyacinth and
duckweed ponds is proposed in order to take advantage of the best
characteristics of each of these macrophyte ponds.
This research focused on the advancing of the understanding of the effectiveness
of treatment and resource recovery under the effect of changing operational
parameters such as pH, light intensity, influent metal content and fluctuating
pollutants loading rate on pond performance and recycling ability in order to fill
the noticed gap of knowledge.
Experiments conducted in water hyacinth ponds (WHP), under batch and
tropical natural weather conditions, revealed that pH between 6.4 and 7.1, full
sunlight and seven days hydraulic retention time were optimum for plant
biomass production and pollutant removal in WHP. WHP was able to regulate
pH when the initial pH values moved outside this interval with a drop in
biomass production as a side effect. These ponds showed a first order kinetic for
the removal of iron, zinc and copper from aqueous solution and their
accumulation in plants biomass with a preferential sequence Fe>Zn>Cu.
However the presence of metals in water hyacinth biomass led to the reduction
in ponds performances and a risk of re-pollution of the effluent through the
release of metals into water.
A comparative study carried out over sixty-two weeks in a pilot scale combined
water hyacinth and duckweed ponds (DWP) channel and waste stabilization
ponds channel working under fluctuating loading rates showed different
environmental conditions occurred these ponds. The fluctuating loading rate
was also found to have a reduced effect on the combined WHP/DWP channel
performance and effluent quality stability with the effluents meeting the entire
reuse requirement at high hydraulic flow rate (retention time greater than 20
days). Fish was able to grow in the WHP/DWP channel.
Results suggested some guidelines on WHP/DWP system design, operation and
maintenance. The overall outcome of this research is a significant contribution to
the development of integrated combined WHP/DWP technology for treatment
of wastewater and resource recovery on site
Evaluation of a risk assessment system for heritage railway earthworks
No full textThere are currently over 100 heritage railways in the UK carrying 6.8 million passengers on 15 million passenger journeys and contributing an estimated £579 million to the UK economy. Many of these lines include significant earthworks, which present a considerable risk to their safe operation. In the last decade there have been major slips at several heritage railways causing major disruption to operations and a serious threat to business continuity.
This research describes the application of a risk assessment system based on that used by Network Rail but specifically adapted for heritage railway conditions. Adaptations include significant alterations to the consequence categories used in prioritization of earthwork issues and a simple low-cost method of implementation based on paper forms and Excel spreadsheets.
Use of the system on two heritage railways, the Bo’ness and Kinneil Railway and the Strathspey Railway is evaluated by means of discussion with railway engineering staff and civil engineering volunteers.
It is concluded that whilst the system represents a realistic and useful approach to management of earthwork assets, the system could not be used by heritage railway volunteer staff without targeted training. Such training, however, would be straightforward to provide, perhaps under the auspices of the Heritage Railway Association
Safety and volunteer construction workers
No full textThe construction industry is dangerous, with 39 fatalities at work in the UK in 2012/13 and comparable and even larger figures reported worldwide. People also take part in construction on a voluntary basis; most volunteers have limited training and no technical qualification, whilst safety regulation frameworks range from being comparable to professional sectors to zero regulation in some international contexts. Unstructured interviews were undertaken with volunteer construction workers from two areas: those returning from international development projects and those regularly volunteering on UK heritage railways. Taking a social constructionist perspective, data was explored using discourse analysis to illuminate ‘safety’ within this unique construction ‘industry’. Those with engineering or technical backgrounds developed more tangible constructions of safety, around risks and hazards, within their activities, yet volunteers without this experience also acknowledged a wider context of danger. Volunteers on overseas projects developed discourses of ‘difference’ between safety at home and safety outside the UK, associated with negative practices overseas yet with acceptance of their inevitability as part of the voluntary experience. Further work is proposed to determine whether these insights can contribute to improved safety management within the voluntary construction context
A Novel Immersed Boundary Method for Direct Numerical Simulations of Solid-Fluid Flows
No full textThis thesis has been submitted in fulfilment of the requirements for a postgraduate degree (e.g. PhD, MPhil, DClinPsychol) at the University of Edinburgh. Please note the following terms and conditions of use: • This work is protected by copyright and other intellectual property rights, which are retained by the thesis author, unless otherwise stated. • A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. • This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author. • The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author. • When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given
Analysis of the c-FOS gene on chromosome 14 and the promoter of the amyloid precursor protein gene in familial Alzheimer's disease
No full textThe c-FOS gene product, a putative transacting transcriptional regulator of the amyloid precursor protein (APP) gene, is a candidate locus for the familial Alzheimer's disease (FAD) mutation on chromosome 14 (FAD14). In light of this functional relationship, we investigated the nucleotide sequence and segregation of c-FOS and the nucleotide sequence of the 5' APP promoter. Single-stranded conformational polymorphisms (SSCPs) in the c-FOS gene revealed that c-FOS closely cosegregates with the FAD14 gene but does not show allelic association with FAD. A conservative third-position T-->C mutation was demonstrated in exon 2 (codon 84) of c-FOS, and a C-->G substitution was detected at -209 bp in the 5' promoter of APP. Neither were unique to FAD and are unlikely to be pathogenic or secondary modifiers of the FAD phenotype. We conclude that the c-FOS open reading frame is probably not the site of the FAD14 locus, but we cannot exclude the existence of modifier loci on chromosome 21
The application of integrated constructed wetlands for contaminant treatment and diffusion
No full textThe sediment accumulation is an important characteristic in the ageing process of
integrated constructed wetlands (ICW). Retained nutrient and other contaminants in
wetland sediments have the potential to be remobilized and released to the overlying
water column when environmental conditions change. In this study, mesocosms
which filled with saturated sediments and planted with Phragmites australis and
Agrostis stolonifera were set up to examine nutrient and other contaminants retention
and/or release by wetland sediment and substrates. The effects of physico-chemical
parameters on sediment-water contaminant exchange were also investigated through
the application of multiple regression models, principal component analysis (PCA),
redundancy analysis (RDA), and self-organizing map (SOM) model. The results
demonstrated an average net release of chemical oxygen demand (COD), ammonianitrogen
(NH3-N), nitrate-nitrogen (NO3-N) and molybdate reactive phosphorus
(MRP) to the overlying water column, indicating that the ICW sediment and
substrates acted as new contaminant sources. According to statistical analysis,
electrical conductivity (EC) and redox potential (RP) values affected COD treatment
efficiency. Chloride (Cl) concentration and RP value had an impact on NH3-N
treatment performance. NO3-N removal was influenced by dissolved oxygen (DO)
concentration and RP value. MRP treatment efficiency was related to DO
concentration and EC value. The SOM model was selected as prediction tool to
provide numerical estimations for the performance of ICW mesocosms. The model
was validated, indicating that NH3-N, NO3-N, MRP, and COD treatment efficiencies could be predicted by input variables which are quick and cost-effective to measure.
The SOM model can be seen as an appropriate method for monitoring the
performance of mature ICWs.
The type of vegetation played a minor role in releasing nutrients and other
contaminants. However, the mesocosm planted with Phragmites australis
outperformed the one planted with Agrostis stolonifera.
No water reached bottom outlet of the mesocosm suggesting that there was
little potential risk to contaminate groundwater. The clay liner and the
biogeochemical processes taking place within sediments proved to be effective in
preventing surface water from infiltration.
Although no reduction in the overall performance has been observed for the
full-scale ICW sites 7 and/or 11, this laboratory-scale study provided valuable
warning signs regarding the loss of contaminant sequestration which may contribute
to decline in wetland treatment performance over time.
The impacts of hydraulic loading rate (HLR) and seasonal temperature
fluctuations on contaminant removal efficiencies of a new ICW system receiving
domestic wastewater were also assessed. The system showed good overall treatment
performance in terms of effluent quality and removal efficiency. The influence of
ICW removal efficiencies of the hydraulic loading rate, which was based on overall
water balance, was negligible due to large footprint and multi-cellular configuration
of the studied system. Relatively low temperature in autumns and winters resulted in
decreased biological activities and lower contaminant removal efficiency.
The long-term trends in nutrient removal have been investigated to five
Wildfowl & Wetlands Trust constructed wetland systems. The results showed less effective removal even release of NO3-N, total oxidised nitrogen (TON), orthophosphate-
phosphorus (PO4-P) and total phosphorus (TP) in many of the systems as
a result of wetland aging and lack of sediment management
The development of the user interface of an innovative sanitation solution targeted at developing countries
No full textCase Study Impact Statement.
Around the World, 2.6 billion people do not have access to a toilet, leading to
the deaths of 1.5 million children per year through associated diseases (Kone,
2012). Novel approaches to this problem are needed that utilise the latest
research and technology to safely deal with human waste in developing
countries. These new sanitation methods have to be carefully developed to
meet the needs and aspirations of their target audience.
The Bill and Melinda Gates Foundation are seeking to address this with an
international competition called the ‘Reinvent the Toilet Challenge’. The winning
entries from different universities will employ the latest technology and research
to safely deal with the waste and to utilise the potential of the waste.
Executive Summary.
This thesis will provide academics and new product development (NPD)
practitioners with a strategic methodology for a design-thinking based approach
to design products for developing countries. This transfer of knowledge will be
possible by discussing potential methods before selecting the most appropriate
to utilise with the use of a Case Study to give context.
The research will commence with a scoping phase to show methods of gaining
understanding of the wider problem followed by approaches to down select and
synthesise this information into appropriate project requirements. When clear
direction has been established, the implementation and development can take
place to produce an outcome to meet the project requirements. Suitable
validation techniques will be used to ensure the success of the research.
The Case Study that will be used is focused on the development of a user
interface for a new sanitation system for developing countries. The system is
being developed by Cranfield University, as part of the Reinvent the Toilet
Challenge funded by the Bill and Melinda Gates Foundation
X-ray absorption fine structure of adsorbates on metal surfaces
No full textThe structural techniques of SEXAFS. NEXAFS and photoelectron diffraction have been applied to several adsorption systems. In combination they have allowed detailed surface structural studies to be achieved and the usefulness of these complementary techniques (which employ the same experimental geometry) has been demonstrated.
SEXAFS studies have been carried out for atomic and molecular adsorption systems. It has been found that for several systems the (usual) Fourier filtering analysis method is not applicable due to the superposition of EXAFS from different shells. Some systems have been successfully analysed by the Fourier method, however. In particular, EXAFS from the Cu(111) [ √3x√3] R30°-Cl adsorption system yield the same result when analysed by both the Fourier filtering method and a multiple shell simulation routine. Adsorption occurs in the three-fold hollow with a Cl-Cu bond length of 2.39±0.02Ǻ. This is in contrast with earlier analysis of I chemisorbed on Ni(100) where it was found that only the multi-shell method was applicable. Photoelectron diffraction measurements for both normal and off-normal geometries confirmed the site found by SEXAFS and further revealed that adsorption was in the fcc-like three-fold hollow (as opposed to the hcp-like one).
A study of the formate intermediate on Cu(110) using NEXAFS revealed that the molecule is adsorbed with it’s plane parallel to the [1ī0] azimuth. Single shell SEXAFS analysis determined the adsorption site to be atop a Cu atom on the 'ridges' with the 0 atoms in the pseudo bridge sites. The average O-Cu distance being l.98±0.O7Ǻ.
Reanalysis of the SEXAFS data of formate adsorbed on Cu(110) and Cu(100) using the multi-shell method revealed that the 'anomalous chemisorption bond' proposed for the latter was erroneous. A misleading result had been obtained with the Fourier filtering method because of the superposition of EXAFS from two similar bond lengths.
NEXAF studies of the reaction of ethanol and oxygen on Cu(110) revealed that ethanol and an ethoxy intermediate were coadsorbed with the 0-C bond effectively parallel to the surface in the ethanol and perpendicular in the ethoxy
Conceptual Design Of Instrumentation To Measure The Diffraction Profile Of A Single Crystal At Bragg Angle Near π 2 By Using Synchrotron Radiation
No full textX-ray diffraction at nearly normal incidence is becoming an increasing important tool in several applications. Because the source of synchrotron radiation, an electron beam in a magnetic field in vacuum, is transparent to X-rays back-reflected through it, one can measure X-ray profiles at normal and near-normal incidence. A back-tangent port must be provided to allow a back-reflected beam to leave the storage ring. The concept can be applied to a bending-magnet or insertion-device source. Since the back-reflected beam is a low-power monochromatic beam, the front end, beryllium window, and other components of the back-tangent port can be simplified. It may be possible to merely drill a hole through the concrete shielding wall leading into a hutch for the detector. Possible arrangements for the SPEAR and Positron-Electron Project rings at the Stanford Synchrotron Radiation Laboratory (SSRL) are presented. © 1990.2911-2132134Woodruff, Seymour, McConville, Riley, Crapper, Prince, Jones, (1987) Phys. Rev. Lett., 58, p. 1460Woodruff, Seymour, McConville, Riley, Crapper, Prince, Jones, (1988) Surf. Sci., 195, p. 237Caticha, Caticha-Ellis, (1982) Phys. Rev., 25 B, p. 971Caticha, Caticha-Ellis, Free Electron Generation of Extreme Ultraviolet Coherent Radiation (1984) AIP Conf. Proc., 118, p. 220. , J.M.J. Madey, C. Pellegrini, AIP, New YorkCaticha, Caticha, Caticha-Ellis, (1989) Appl. Phys. Lett., 54, p. 887Graeff, Materlik, (1982) Nucl. Instr. and Meth., 195, p. 97Kushnir, Suvorov, (1986) JEPT Lett., 44, p. 262Caticha-Ellis, (1983) Anais do Encontro Tecnicas e aplic\̃~aoes da Radiac\̃~ao Sincrotron, pp. 240-257. , (in Portuguese), CBPF, Rio de JaneiroHoyer, A new wiggler beam line for SSRL (1983) Nuclear Instruments and Methods in Physics Research, 208, p. 117A. Bienenstock, G. Brown, H. Wiedemann and H. Winick, Rev. Sci. Instr. to be publishe
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