Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1995
ABSTRACT Synchrotron radiation is used routinely for diffraction measurements on crystalline powd... more ABSTRACT Synchrotron radiation is used routinely for diffraction measurements on crystalline powders and amorphous materials. The usual method of data collection is to use a diffractometer to scan a detector over a wide angular range, step-wise building up a 1-D diffraction pattern at an appropriate angular resolution. There are a number of drawbacks to this approach: there may well be 2-D information which is being ignored (or confused), and when collecting data at one point the diffracted intensity at all other scan intervals is not being recorded, ie. it is wasted. A 1-D, or preferably 2-D, position sensitive detector is obviously required to optimise data collection. image-plates offer a solution and we report here recent investigations of their use for both powder diffraction and amorphous materials. Gains of 100 in data collection time could be achieved in principle and this suggests the technology could not only improve the efficiency of use of expensive central resources, but could also open up new possibilities for studying materials processing in situ.
Journal of Water Supply: Research and Technology—AQUA, 2009
ABSTRACT Computational fluid dynamics (CFD) can be applied to the advancement of dissolved air fl... more ABSTRACT Computational fluid dynamics (CFD) can be applied to the advancement of dissolved air flotation (DAF) plant design. The use of CFD in design and predictive analysis, in particular here with reference to the upgrading of an existing DAF plant from 30 to 60 Ml/d and associated diagnostics, while still developing, helped by the emergence of ever more powerful computational systems, can be regarded as an established tool providing beneficial and useful data, although on occasions care may be required in the interpretation of results. The initial CFD studies were undertaken using the existing and upgraded works flows and structures at both 'low' and 'high' temperatures, i.e. 2 and 20 degrees C, while the modelling results are reported using graphical representations of 'contours of flow velocity' and 'velocity vectors'. In addition the degree of short circuiting based on T(10) together with other retention parameters T(50) and T(50)/m are reported. Further modifications were also considered: how changes to the incline baffle and tank depth can impact on the predicted distribution, vorticity and in practice on the actual subnatant water quality measured in terms of turbidity. Finally applying CFD to DAF plant design is shown to be a beneficial tool for the designer.
Models of the atomic and magnetic structures of Fe0.91Zr0.09 metallic glass have been produced by... more Models of the atomic and magnetic structures of Fe0.91Zr0.09 metallic glass have been produced by RMC modelling of neutron diffraction and x-ray diffraction data at temperatures between 10 and 300 K. The magnetic structure at all T is predominantly ferromagnetic but a weak peak in the neutron structure factor at 1.2 A-1 is identified as being due to magnetic `defects'. It is found that the average local density of Fe atoms around these defects tends to be higher than around `normal' moments. This supports the idea of magnetic frustration in such systems due to competing ferromagnetic and antiferromagnetic interactions. Assuming that Fe and Zr substitute isomorphously in Fe1-xZrx glasses, and that Fe moments with more than 12 neighbouring Fe atoms behave antiferromagnetically, the composition dependence of the magnetic phase diagram can be explained on the basis of the RMC structural model for Fe0.91Zr0.09 glass.
Water science and technology : a journal of the International Association on Water Pollution Research
Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), wit... more Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), with application to almost all unit processes. This paper provides an overview of CFD applied to a wide range of unit processes in water and WWT from hydraulic elements like flow splitting to physical, chemical and biological processes like suspended growth nutrient removal and anaerobic digestion. The paper's focus is on articulating the state of practice and research and development needs. The level of CFD's capability varies between different process units, with a high frequency of application in the areas of final sedimentation, activated sludge basin modelling and disinfection, and greater needs in primary sedimentation and anaerobic digestion. While approaches are comprehensive, generally capable of incorporating non-Newtonian fluids, multiphase systems and biokinetics, they are not broad, and further work should be done to address the diversity of process designs. Many units ...
Water science and technology : a journal of the International Association on Water Pollution Research
Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), wit... more Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), with application to almost all unit processes. This paper provides an overview of CFD applied to a wide range of unit processes in water and WWT from hydraulic elements like flow splitting to physical, chemical and biological processes like suspended growth nutrient removal and anaerobic digestion. The paper's focus is on articulating the state of practice and research and development needs. The level of CFD's capability varies between different process units, with a high frequency of application in the areas of final sedimentation, activated sludge basin modelling and disinfection, and greater needs in primary sedimentation and anaerobic digestion. While approaches are comprehensive, generally capable of incorporating non-Newtonian fluids, multiphase systems and biokinetics, they are not broad, and further work should be done to address the diversity of process designs. Many units ...
Tony Amato Enpure Ltd, Enpure House, Woodgate Business Park, Kettleswood Drive, Birmingham B323DB... more Tony Amato Enpure Ltd, Enpure House, Woodgate Business Park, Kettleswood Drive, Birmingham B323DB, UK E-mail: tamato@enpure.co.uk Jim Wicks The Fluid Group, Magdalen Centre, The Oxford Science Park, Oxford OX44GA, UK E-mail: jim.wicks@thefluidgroup.com Computational fluid dynamics (CFD) can be applied to the advancement of dissolved air flotation (DAF) plant design. The use of CFD in design and predictive analysis, in particular here with reference to the upgrading of an existing DAF plant from 30 to 60Ml/d and associated diagnostics, while still developing, helped by the emergence of ever more powerful computational systems, can be regarded as an established tool providing beneficial and useful data, although on occasions care may be required in the interpretation of results. The initial CFD studies were undertaken using the existing and upgraded works flows and structures at both ‘low’ and ‘high’ temperatures, i.e. 2 and 208C, while the modelling results are reported using graphic...
The purpose of this paper will be to report on the potential impact on the clarified water qualit... more The purpose of this paper will be to report on the potential impact on the clarified water quality produced by a Dissolved Air Flotation (DAF) plant, designed and built on the basis of conventional rates (i.e. ~10 m/h Net, excluding recycle) and assessing when using the same structures loaded at higher rates how the product quality may change or online monitoring such as turbidity may be affected. The assessment has been based on the use of both Computational Fluid Dynamics (CFD) and a small number of full scale site trials.
This outline paper aims to provide a critical review of secondary settling tank (SST) modelling a... more This outline paper aims to provide a critical review of secondary settling tank (SST) modelling approaches used in current wastewater engineering and develop tools not yet applied in practice. We address the development of different tier models and experimental techniques in the field with a particular emphasis on works published since the reference work by Ekama et al. (1997). We give insight into the current engineering practice, identify how recent developments can be transferred to engineering practice and pinpoint limitations and potential pathways for further development of models and measurement techniques. As a follow-up to the present work, we believe there is a need for the development of a protocol for systematic clarifier modelling depending on the modelling objective and in line with good modelling practice.
Modelling has been used frequently for both system understanding and optimization. However, the c... more Modelling has been used frequently for both system understanding and optimization. However, the challenges put on the models are constantly growing. This entails new regulations for effluent, more accurate energy consumption predictions, predictions of greenhouse gas emissions, enlarging the scale towards urban water systems, to name but a few. Hence, simulations are being pushed into ranges where the models currently in use have greater uncertainty. This is exacerbated by the fact that the submodels in use may lack sufficient detail or may not be in proper balance with the full model when coupled solutions are attempted. In this contribution we want to highlight how computational fluid dynamics models can assist in resolving some of these issues.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1995
ABSTRACT Synchrotron radiation is used routinely for diffraction measurements on crystalline powd... more ABSTRACT Synchrotron radiation is used routinely for diffraction measurements on crystalline powders and amorphous materials. The usual method of data collection is to use a diffractometer to scan a detector over a wide angular range, step-wise building up a 1-D diffraction pattern at an appropriate angular resolution. There are a number of drawbacks to this approach: there may well be 2-D information which is being ignored (or confused), and when collecting data at one point the diffracted intensity at all other scan intervals is not being recorded, ie. it is wasted. A 1-D, or preferably 2-D, position sensitive detector is obviously required to optimise data collection. image-plates offer a solution and we report here recent investigations of their use for both powder diffraction and amorphous materials. Gains of 100 in data collection time could be achieved in principle and this suggests the technology could not only improve the efficiency of use of expensive central resources, but could also open up new possibilities for studying materials processing in situ.
Journal of Water Supply: Research and Technology—AQUA, 2009
ABSTRACT Computational fluid dynamics (CFD) can be applied to the advancement of dissolved air fl... more ABSTRACT Computational fluid dynamics (CFD) can be applied to the advancement of dissolved air flotation (DAF) plant design. The use of CFD in design and predictive analysis, in particular here with reference to the upgrading of an existing DAF plant from 30 to 60 Ml/d and associated diagnostics, while still developing, helped by the emergence of ever more powerful computational systems, can be regarded as an established tool providing beneficial and useful data, although on occasions care may be required in the interpretation of results. The initial CFD studies were undertaken using the existing and upgraded works flows and structures at both 'low' and 'high' temperatures, i.e. 2 and 20 degrees C, while the modelling results are reported using graphical representations of 'contours of flow velocity' and 'velocity vectors'. In addition the degree of short circuiting based on T(10) together with other retention parameters T(50) and T(50)/m are reported. Further modifications were also considered: how changes to the incline baffle and tank depth can impact on the predicted distribution, vorticity and in practice on the actual subnatant water quality measured in terms of turbidity. Finally applying CFD to DAF plant design is shown to be a beneficial tool for the designer.
Models of the atomic and magnetic structures of Fe0.91Zr0.09 metallic glass have been produced by... more Models of the atomic and magnetic structures of Fe0.91Zr0.09 metallic glass have been produced by RMC modelling of neutron diffraction and x-ray diffraction data at temperatures between 10 and 300 K. The magnetic structure at all T is predominantly ferromagnetic but a weak peak in the neutron structure factor at 1.2 A-1 is identified as being due to magnetic `defects'. It is found that the average local density of Fe atoms around these defects tends to be higher than around `normal' moments. This supports the idea of magnetic frustration in such systems due to competing ferromagnetic and antiferromagnetic interactions. Assuming that Fe and Zr substitute isomorphously in Fe1-xZrx glasses, and that Fe moments with more than 12 neighbouring Fe atoms behave antiferromagnetically, the composition dependence of the magnetic phase diagram can be explained on the basis of the RMC structural model for Fe0.91Zr0.09 glass.
Water science and technology : a journal of the International Association on Water Pollution Research
Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), wit... more Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), with application to almost all unit processes. This paper provides an overview of CFD applied to a wide range of unit processes in water and WWT from hydraulic elements like flow splitting to physical, chemical and biological processes like suspended growth nutrient removal and anaerobic digestion. The paper's focus is on articulating the state of practice and research and development needs. The level of CFD's capability varies between different process units, with a high frequency of application in the areas of final sedimentation, activated sludge basin modelling and disinfection, and greater needs in primary sedimentation and anaerobic digestion. While approaches are comprehensive, generally capable of incorporating non-Newtonian fluids, multiphase systems and biokinetics, they are not broad, and further work should be done to address the diversity of process designs. Many units ...
Water science and technology : a journal of the International Association on Water Pollution Research
Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), wit... more Computational fluid dynamics (CFD) is a rapidly emerging field in wastewater treatment (WWT), with application to almost all unit processes. This paper provides an overview of CFD applied to a wide range of unit processes in water and WWT from hydraulic elements like flow splitting to physical, chemical and biological processes like suspended growth nutrient removal and anaerobic digestion. The paper's focus is on articulating the state of practice and research and development needs. The level of CFD's capability varies between different process units, with a high frequency of application in the areas of final sedimentation, activated sludge basin modelling and disinfection, and greater needs in primary sedimentation and anaerobic digestion. While approaches are comprehensive, generally capable of incorporating non-Newtonian fluids, multiphase systems and biokinetics, they are not broad, and further work should be done to address the diversity of process designs. Many units ...
Tony Amato Enpure Ltd, Enpure House, Woodgate Business Park, Kettleswood Drive, Birmingham B323DB... more Tony Amato Enpure Ltd, Enpure House, Woodgate Business Park, Kettleswood Drive, Birmingham B323DB, UK E-mail: tamato@enpure.co.uk Jim Wicks The Fluid Group, Magdalen Centre, The Oxford Science Park, Oxford OX44GA, UK E-mail: jim.wicks@thefluidgroup.com Computational fluid dynamics (CFD) can be applied to the advancement of dissolved air flotation (DAF) plant design. The use of CFD in design and predictive analysis, in particular here with reference to the upgrading of an existing DAF plant from 30 to 60Ml/d and associated diagnostics, while still developing, helped by the emergence of ever more powerful computational systems, can be regarded as an established tool providing beneficial and useful data, although on occasions care may be required in the interpretation of results. The initial CFD studies were undertaken using the existing and upgraded works flows and structures at both ‘low’ and ‘high’ temperatures, i.e. 2 and 208C, while the modelling results are reported using graphic...
The purpose of this paper will be to report on the potential impact on the clarified water qualit... more The purpose of this paper will be to report on the potential impact on the clarified water quality produced by a Dissolved Air Flotation (DAF) plant, designed and built on the basis of conventional rates (i.e. ~10 m/h Net, excluding recycle) and assessing when using the same structures loaded at higher rates how the product quality may change or online monitoring such as turbidity may be affected. The assessment has been based on the use of both Computational Fluid Dynamics (CFD) and a small number of full scale site trials.
This outline paper aims to provide a critical review of secondary settling tank (SST) modelling a... more This outline paper aims to provide a critical review of secondary settling tank (SST) modelling approaches used in current wastewater engineering and develop tools not yet applied in practice. We address the development of different tier models and experimental techniques in the field with a particular emphasis on works published since the reference work by Ekama et al. (1997). We give insight into the current engineering practice, identify how recent developments can be transferred to engineering practice and pinpoint limitations and potential pathways for further development of models and measurement techniques. As a follow-up to the present work, we believe there is a need for the development of a protocol for systematic clarifier modelling depending on the modelling objective and in line with good modelling practice.
Modelling has been used frequently for both system understanding and optimization. However, the c... more Modelling has been used frequently for both system understanding and optimization. However, the challenges put on the models are constantly growing. This entails new regulations for effluent, more accurate energy consumption predictions, predictions of greenhouse gas emissions, enlarging the scale towards urban water systems, to name but a few. Hence, simulations are being pushed into ranges where the models currently in use have greater uncertainty. This is exacerbated by the fact that the submodels in use may lack sufficient detail or may not be in proper balance with the full model when coupled solutions are attempted. In this contribution we want to highlight how computational fluid dynamics models can assist in resolving some of these issues.
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