Investigation of flow uniformity and pressure recovery in a turning diffuser by means of baffles

Turning diffuser is an engineering device that is widely used in the industry to reduce the flow velocity as well as change the direction of the flow. Having a curvature shape causes its performance to decrease in terms of pressure recovery (Cp) and flow uniformity (σu). Therefore, this study presents the work done in designing baffles to be installed in the turning diffuser with ratio of AR=2.16 to improve the flow uniformity and pressure recovery. It also aims to investigate the mechanism of flow structure and pressure recovery in turning diffusers by means of turning baffles. The results with varying inflow Reynolds number (Rein) between 5.786E+04 – 1.775E+05 have been experimentally tested and compared with previous study. Particle image velocimetry (PIV) was used to determine the flow uniformity. On the other hand, a digital manometer provided the average static pressure of the inlet and outlet of turning diffuser. The best produced pressure recovery of Cp=0.526 were recorded when the system were operated at the highest Reynolds number tested Rein=1.775E+05. This result shows an improvement up to 54.625% deviation from previous study with Cp=0.239. The flow uniformity also shows an improvement of 47.127% deviation from previous study at the same Rein with σu=3.235 as compared to previous study σu=6.12

Future filters- A new approach to face coverings

In common with many universities, academics at the University of Lincoln formed groups to help in the struggle against the Covid pandemic. A syndicate drawn from the schools of design, engineering and pharmacy developed an effective virus trapping filter that does not compromise on permeability. The group acknowledged that for a rapid roll-out of results, concurrent engineering involving the whole supply chain from suppliers to producers is necessary, and so worked from the beginning in close association with their industrial partners. The face covering originated in the school of design with a product to protect children from urban particulates. For a face covering to have a significant effect on public health, it must have a high degree of take-up by a volunteer clientele, in this case the general public, so it must be comfortable and stylish. For the wearer, the ideal face covering should offer low resistance to breathing. For a face covering, low permeability is also desirable in that it allows freer passage of breath through the covering rather than around the edges. From a simple engineering view this is awkward: passive filter mechanisms rely on the physical entanglement of particulates. Particulates – the air born viruses must contact a mesh of fibres of sufficiently low porosity to prevent the further passage of the particulates through the filter. Clearly, improvements to efficiency by this method will result in a decrease in porosity and an increase in resistance to flow. Improvements of this type are likely to be of little benefit, if the face covering becomes uncomfortable, and therefore undesirable to wear.The group investigated methods to increase filter efficiency without a disagreeable decrease in filter permeability. The team identified a commonly used neutraceutical called fucoidan, a sulfated water-soluble polysaccharide extracted from brown seaweeds such as Ascopbyllum nodosum, Fucus vesiculosus, and Saccharina japonica, as glue to stick the viruses to the filter fibres. The potential of this material as a virus adherent was proposed by Kwon et al (2020a) and offered a way forward to improve filter efficiency without lowering permeability, because the need for physical entanglement with the filter matrix to occur if a virus particle is to be captured is much reduced. This improved filter concept uses molecular biology and chemical mimicry to attract and entrap the virus on the fibres. The biochemical treated fibre admixtures enhance the propensity for viral binding through developing a molecular-level synergy on the polymer substrate which exploits the COVID-19 spike to hACE2 receptor interaction. This method was perceived to have the advantage that however the virus mutates, it must still stick to a common surface, namely the internal mucosal surfaces of the human respiratory tract.</p

Future filters- A new approach to face coverings

In common with many universities, academics at the University of Lincoln formed groups to help in the struggle against the Covid pandemic. A syndicate drawn from the schools of design, engineering and pharmacy developed an effective virus trapping filter that does not compromise on permeability. The group acknowledged that for a rapid roll-out of results, concurrent engineering involving the whole supply chain from suppliers to producers is necessary, and so worked from the beginning in close association with their industrial partners. The face covering originated in the school of design with a product to protect children from urban particulates. For a face covering to have a significant effect on public health, it must have a high degree of take-up by a volunteer clientele, in this case the general public, so it must be comfortable and stylish. For the wearer, the ideal face covering should offer low resistance to breathing. For a face covering, low permeability is also desirable in that it allows freer passage of breath through the covering rather than around the edges. From a simple engineering view this is awkward: passive filter mechanisms rely on the physical entanglement of particulates. Particulates – the air born viruses must contact a mesh of fibres of sufficiently low porosity to prevent the further passage of the particulates through the filter. Clearly, improvements to efficiency by this method will result in a decrease in porosity and an increase in resistance to flow. Improvements of this type are likely to be of little benefit, if the face covering becomes uncomfortable, and therefore undesirable to wear.The group investigated methods to increase filter efficiency without a disagreeable decrease in filter permeability. The team identified a commonly used neutraceutical called fucoidan, a sulfated water-soluble polysaccharide extracted from brown seaweeds such as Ascopbyllum nodosum, Fucus vesiculosus, and Saccharina japonica, as glue to stick the viruses to the filter fibres. The potential of this material as a virus adherent was proposed by Kwon et al (2020a) and offered a way forward to improve filter efficiency without lowering permeability, because the need for physical entanglement with the filter matrix to occur if a virus particle is to be captured is much reduced. This improved filter concept uses molecular biology and chemical mimicry to attract and entrap the virus on the fibres. The biochemical treated fibre admixtures enhance the propensity for viral binding through developing a molecular-level synergy on the polymer substrate which exploits the COVID-19 spike to hACE2 receptor interaction. This method was perceived to have the advantage that however the virus mutates, it must still stick to a common surface, namely the internal mucosal surfaces of the human respiratory tract.</p

Interfacial study of cell adhesion to liquid crystals using widefield surface plasmon resonance microscopy.

Widefield surface plasmon resonance (WSPR) microscopy provides high resolution imaging of interfacial interactions. We report the application of the WSPR imaging system in the study of the interaction between keratinocytes and liquid crystals (LC). Imaging of fixed keratinocytes cultured on gold coated surface plasmon substrates functionalized with a thin film of liquid crystals was performed in air using a 1.45 NA objective based system. Focal adhesion of the cells adhered to glass and LC were further studied using immunofluorescence staining of the vinculin. The imaging system was also simulated with 2 × 2 scattering matrix to investigate the optical reflection of the resonant plasmonic wave via the glass/gold/cell and glass/gold/LC/cell layers. WSPR imaging indicated that keratinocytes are less spread and formed distinct topography of cell–liquid crystal couplings when cultured on liquid crystal coated substrates. The simulation indicates that glass/LC shifted the surface plasmon excitation angle to 75.39° as compared to glass/air interface at 44°. The WSPR microcopy reveals that the cells remodelled their topography of adhesion at different interfaces

The dilemma of Brexit: hard choices in the narrow context of British foreign policy traditions

Brexit threatens to disrupt the fabric of British foreign policy thinking. For decades, policymakers identified membership of the European Community as one of two pillars of British influence (the other being the ‘Special Relationship’ with the United States). Together, they allowed Britain to exercise power on a global as well as regional scale. These assumptions were repeated so often that the UK was regularly criticised for lacking policy imagination and avoiding hard choices when the interests of Europe and the United States conflicted. Brexit presents an unavoidable dilemma for policymakers as they chart a new course for British foreign policy. Interpretivism, as set out by Bevir and Rhodes (2003), offers a route to understanding how actors interpret and respond to such dilemmas, via reference to traditions. This article uses their approach to examine the expression of beliefs about Brexit and British foreign policy. In particular, it focuses on two datasets, one a ‘control sample’ of commentary since 2016, the other, the parliamentary debates on the first EU Withdrawal Bill in December 2018 and January 2019. We find a contrasting willingness to evoke traditions in a substantive fashion to understand and justify political choices. In particular, parliamentarians utilise one particular tradition, pragmatism, to marginalise the expression of abstract belief. In the process, they reduce discussion to a technocratic exercise that is unable to manage the conflicts Brexit has brought about. Meanwhile, those MPs that are most creative in their expression of traditions tend to be from smaller regional parties or on the political periphery. The resulting deadlock is evidence of the importance of traditions to interpreting and managing dilemmas of social change