• Building a consistent parton shower

      Forshaw, Jeffrey R.; Holguin, Jack; orcid: 0000-0001-5183-2673; email: jack.holguin@manchester.ac.uk; Plätzer, Simon (Springer Berlin Heidelberg, 2020-09-01)
      Abstract: Modern parton showers are built using one of two models: dipole showers or angular ordered showers. Both have distinct strengths and weaknesses. Dipole showers correctly account for wide-angle, soft gluon emissions and track the leading flows in QCD colour charge but they are known to mishandle partonic recoil. Angular ordered showers keep better track of partonic recoil and correctly include large amounts of wide-angle, soft physics but azimuthal averaging means they are known to mishandle some correlations. In this paper, we derive both approaches from the same starting point; linking our under- standing of the two showers. This insight allows us to construct a new dipole shower that has all the strengths of a standard dipole shower together with the collinear evolution of an angular-ordered shower. We show that this new approach corrects the next-to-leading- log errors previously observed in parton showers and improves their sub-leading-colour accuracy.
    • Building Information Modelling Diffusion Research in Developing Countries: A User Meta-Model Approach

      Adekunle, Samuel Adeniyi; orcid: 0000-0002-9230-2924; email: sasamuel@uj.ac.za; Ejohwomu, Obuks; orcid: 0000-0001-7098-8999; email: obuks.ejohwomu@manchester.ac.uk; Aigbavboa, Clinton Ohis; email: caigbavboa@uj.ac.za (MDPI, 2021-06-22)
      Building information modelling (BIM) has become a common denominator for information management, efficiency, collaboration, and productivity in the construction industry. The adoption of building information modelling has been assessed to be unequal in the construction industry the world over. It has been observed that developing countries are struggling with BIM adoption and are at a beginner stage in the process. Meanwhile, there have been different research efforts focused on advancing BIM diffusion in developing countries. This study focused on reviewing the research trend and knowledge domains of BIM research in developing countries. The study analysed scholarly publications from selected developing countries sourced from the Scopus database from 2005 to 2019; the study covered BIM research efforts since their commencement in developing countries. The study identified the different research trends and the current focus through visualisations using VOS viewer software. The most influential and productive researchers were also identified. This research contributes to the extant body of knowledge by synthesizing the state of the art of BIM research in developing countries. Furthermore, it provides the pre-COVID-19 BIM diffusion status in developing countries.
    • Building the future of public policy in the Basque Country: Etorkizuna Eraikiz, a metagovernance approach

      Barandiaran, Xabier; Luna, Alvaro; orcid: 0000-0002-1372-1275; Bendall, Mark (Informa UK Limited, 2018-08-02)
    • Bulk and Confined Benzene-Cyclohexane Mixtures Studied by an Integrated Total Neutron Scattering and NMR Method

      Hughes, Terri-Louise; orcid: 0000-0002-6389-8669; email: terri-louise.hughes@manchester.ac.uk; Falkowska, Marta; orcid: 0000-0003-0888-005X; Leutzsch, Markus; orcid: 0000-0001-8171-9399; Sederman, Andrew J.; orcid: 0000-0002-7866-5550; Mantle, Mick D.; Headen, Thomas F.; orcid: 0000-0003-0095-5731; Youngs, Tristan G. A.; orcid: 0000-0003-3538-5572; Bowron, Daniel T.; orcid: 0000-0002-4557-1929; Hardacre, Christopher; orcid: 0000-0001-7256-6765 (Springer US, 2021-04-23)
      Abstract: Herein mixtures of cyclohexane and benzene have been investigated in both the bulk liquid phase and when confined in MCM-41 mesopores. The bulk mixtures have been studied using total neutron scattering (TNS), and the confined mixtures have been studied by a new flow-utilising, integrated TNS and NMR system (Flow NeuNMR), all systems have been analysed using empirical potential structure refinement (EPSR). The Flow NeuNMR setup provided precise time-resolved chemical sample composition through NMR, overcoming the difficulties of ensuring compositional consistency for computational simulation of data ordinarily found in TNS experiments of changing chemical composition—such as chemical reactions. Unique to the liquid mixtures, perpendicularly oriented benzene molecules have been found at short distances from the cyclohexane rings in the regions perpendicular to the carbon–carbon bonds. Upon confinement of the hydrocarbon mixtures, a stronger parallel orientational preference of unlike molecular dimers, at short distances, has been found. At longer first coordination shell distances, the like benzene molecular spatial organisation within the mixture has also found to be altered upon confinement.
    • Burden of illness of progressive familial intrahepatic cholestasis in the US, UK, France, and Germany: study rationale and protocol of the PICTURE study

      Ruiz-Casas, Leonardo; O’Hara, Sonia; orcid: 0000-0002-9119-8336; Mighiu, Claudia; Finnegan, Alan; Taylor, Alison; Ventura, Emily; Dhawan, Anil; Murray, Karen F; Schattenberg, Jorn; orcid: 0000-0002-4224-4703; Willemse, Jose; et al. (Informa UK Limited, 2021-01-07)
    • Burden of illness of progressive familial intrahepatic cholestasis in the US, UK, France, and Germany: study rationale and protocol of the PICTURE study

      Ruiz-Casas, Leonardo; O’Hara, Sonia; orcid: 0000-0002-9119-8336; Mighiu, Claudia; Finnegan, Alan; Taylor, Alison; Ventura, Emily; Dhawan, Anil; Murray, Karen F; Schattenberg, Jorn; orcid: 0000-0002-4224-4703; Willemse, Jose; et al. (Informa UK Limited, 2021-01-07)
    • Burden of illness of progressive familial intrahepatic cholestasis in the US, UK, France, and Germany: study rationale and protocol of the PICTURE study.

      Ruiz-Casas, Leonardo; O'Hara, Sonia; orcid: 0000-0002-9119-8336; Mighiu, Claudia; Finnegan, Alan; Taylor, Alison; Ventura, Emily; Dhawan, Anil; Murray, Karen F; Schattenberg, Jorn; orcid: 0000-0002-4224-4703; Willemse, Jose; et al. (2021-01-07)
      : Progressive familial intrahepatic cholestasis (PFIC) is an ultra-rare disease with a considerable burden on pediatric patients and their caregivers, impacting quality of life (QoL). The mortality rates highlight a significant need for efficacious treatments. Real-world data on associated costs and QoL are needed to gauge the potential impact of new pharmacological treatments. : Clinical and socio-economic burden of PFIC on patients/caregivers, health systems, and society will be assessed. Patient/caregiver- and physician-level retrospective cross-sectional data will be collected from the US, UK, France, and Germany, for PFIC types 1, 2, 3. A representative sample of physicians will provide clinical and resource utilization information using an electronic Case Report Form (eCRF). Patient/caregiver surveys will collect socio-economic and QoL data, enabling assessment of PFIC impact on QoL. Mean costs (direct medical/non-medical, indirect) will be calculated. The study materials were reviewed by medical professionals and patient representatives and received ethical approval from the University of Chester. : The study aims to reveal the unmet medical need, disease burden, resource utilization, and costs of PFIC, to raise awareness with policymakers and healthcare professionals, and provide support for the patient/caregiver community. As novel PFIC therapies recently emerged, this study will yield quantifiable data for health technology assessments.
    • C-H arylation of arenes at room temperature using visible light ruthenium C-H activation.

      Sagadevan, Arunachalam; orcid: 0000-0001-9486-1706; Charitou, Anastasios; orcid: 0000-0002-9100-8950; Wang, Fen; Ivanova, Maria; Vuagnat, Martin; Greaney, Michael F; orcid: 0000-0001-9633-1135 (2020-04-07)
      A ruthenium-catalyzed C-H arylation process is described using visible light. Using the readily available catalyst [RuCl ( -cymene)] , visible light irradiation was found to enable arylation of 2-aryl-pyridines at room temperature for a range of aryl bromides and iodides. [Abstract copyright: This journal is © The Royal Society of Chemistry.]
    • Ca

      Lim, Dmitry; email: dmitry.lim@uniupo.it; Dematteis, Giulia; Tapella, Laura; Genazzani, Armando A; Calì, Tito; Brini, Marisa; Verkhratsky, Alexei; email: alexej.verkhratsky@manchester.ac.uk (2021-08-05)
      Mitochondria-endoplasmic reticulum (ER) contact sites (MERCS) are morpho-functional units, formed at the loci of close apposition of the ER-forming endomembrane and outer mitochondrial membrane (OMM). These sites contribute to fundamental cellular processes including lipid biosynthesis, autophagy, apoptosis, ER-stress and calcium (Ca ) signalling. At MERCS, Ca ions are transferred from the ER directly to mitochondria through a core protein complex composed of inositol-1,4,5 trisphosphate receptor (InsP R), voltage-gated anion channel 1 (VDAC1), mitochondrial calcium uniporter (MCU) and adaptor protein glucose-regulated protein 75 (Grp75); this complex is regulated by several associated proteins. Deregulation of ER-mitochondria Ca transfer contributes to pathogenesis of neurodegenerative and other diseases. The efficacy of Ca transfer between ER and mitochondria depends on the protein composition of MERCS, which controls ER-mitochondria interaction regulating, for example, the transversal distance between ER membrane and OMM and the extension of the longitudinal interface between ER and mitochondria. These parameters are altered in neurodegeneration. Here we overview the ER and mitochondrial Ca homeostasis, the composition of ER-mitochondrial Ca transfer machinery and alterations of the ER-mitochondria Ca transfer in three major neurodegenerative diseases: motor neurone diseases, Parkinson disease and Alzheimer's disease. [Abstract copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.]
    • Cage and maternal effects on the bacterial communities of the murine gut.

      Singh, Gurdeep; Brass, Andrew; Cruickshank, Sheena M; email: sheena.cruickshank@manchester.ac.uk; Knight, Christopher G (2021-05-10)
      Findings from gut microbiome studies are strongly influenced by both experimental and analytical factors that can unintentionally bias their interpretation. Environment is also critical. Both co-housing and maternal effects are expected to affect microbiomes and have the potential to confound other manipulated factors, such as genetics. We therefore analysed microbiome data from a mouse experiment using littermate controls and tested differences among genotypes (wildtype versus colitis prone-mdr1a ), gut niches (stool versus mucus), host ages (6 versus 18 weeks), social groups (co-housed siblings of different genotypes) and maternal influence. We constructed a 16S phylogenetic tree from bacterial communities, fitting random forest models using all 428,234 clades identified. Models discriminated all criteria except host genotype, where no community differences were found. Host social groups differed in abundant, low-level, taxa whereas intermediate phylogenetic and abundance scales distinguished ages and niches. Thus, a carefully controlled experiment treating evolutionary clades of microbes equivalently without reference to taxonomy, clearly identifies whether and how gut microbial communities are distinct across ecologically important factors (niche and host age) and other experimental factors, notably cage effects and maternal influence. These findings highlight the importance of considering such environmental factors in future microbiome studies.
    • Calcium signaling in neuroglia.

      Lim, Dmitry; email: dmitry.lim@uniupo.it; Semyanov, Alexey; Genazzani, Armando; Verkhratsky, Alexei; email: alexej.verkhratsky@manchester.ac.uk (2021-04-10)
      Glial cells exploit calcium (Ca ) signals to perceive the information about the activity of the nervous tissue and the tissue environment to translate this information into an array of homeostatic, signaling and defensive reactions. Astrocytes, the best studied glial cells, use several Ca signaling generation pathways that include Ca entry through plasma membrane, release from endoplasmic reticulum (ER) and from mitochondria. Activation of metabotropic receptors on the plasma membrane of glial cells is coupled to an enzymatic cascade in which a second messenger, InsP is generated thus activating intracellular Ca release channels in the ER endomembrane. Astrocytes also possess store-operated Ca entry and express several ligand-gated Ca channels. In vivo astrocytes generate heterogeneous Ca signals, which are short and frequent in distal processes, but large and relatively rare in soma. In response to neuronal activity intracellular and inter-cellular astrocytic Ca waves can be produced. Astrocytic Ca signals are involved in secretion, they regulate ion transport across cell membranes, and are contributing to cell morphological plasticity. Therefore, astrocytic Ca signals are linked to fundamental functions of the central nervous system ranging from synaptic transmission to behavior. In oligodendrocytes, Ca signals are generated by plasmalemmal Ca influx, or by release from intracellular stores, or by combination of both. Microglial cells exploit Ca permeable ionotropic purinergic receptors and transient receptor potential channels as well as ER Ca release. In this contribution, basic morphology of glial cells, glial Ca signaling toolkit, intracellular Ca signals and Ca -regulated functions are discussed with focus on astrocytes. [Abstract copyright: Copyright © 2021 Elsevier Inc. All rights reserved.]
    • Can common mycorrhizal fungal networks be managed to enhance ecosystem functionality?

      Alaux, Pierre‐Louis; orcid: 0000-0002-2518-7911; email: pierre-louis.alaux@manchester.ac.uk; Zhang, Yaqian; orcid: 0000-0002-7172-4503; Gilbert, Lucy; orcid: 0000-0002-9139-8450; Johnson, David; orcid: 0000-0003-2299-2525 (2021-02-02)
      Societal Impact Statement: Mycorrhizal fungi are key components of soil biodiversity that offer potential to provide sustainable solutions for land management, notably in agriculture and forestry. Several studies conducted in controlled environments show that key functional attributes of common mycorrhizal networks (CMNs), which inter‐link different plants, are influenced by management practices. Here, we highlight the need to consider how land management affects the ubiquity and function of CMNs in nature to maximize the role of mycorrhizal fungi in enhancing ecosystem services. We emphasize that CMNs can sometimes negatively affect aspects of plant performance, but there remain major gaps in understanding before explicit consideration of CMN management can be delivered. Summary: Most mycorrhizal fungi have the capacity to develop extensive extraradical mycelium, and thus have the potential to connect multiple plants and form a ‘common mycorrhizal network’. Several studies have shown that these networks can influence plant establishment, nutrition, productivity and defense, nutrient distribution and storage, and multitrophic interactions. However, many of these studies have focused on the importance of common mycorrhizal networks in ecological contexts and there has been less emphasis in managed systems, including croplands, grassland, agroforestry and forestry, on which humankind relies. Here we review the evidence of the potential importance of common mycorrhizal networks in managed systems, and provide insight into how these networks could be managed effectively to maximize the functions and outputs from managed systems. We also emphasize possible negative effects of common mycorrhizal networks on plant performance and question popular views that mycorrhizal networks may offer a panacea for enhancing ecosystem services. We highlight the need to gain greater insight into the ubiquity, functioning, and response to management interventions of common mycorrhizal networks and, critically, the need to determine the extent to which these networks can add value to the promotion of mycorrhizal colonization.
    • Can molecular flexibility control crystallization? The case of

      Tang, Sin Kim; Davey, Roger J; orcid: 0000-0002-4690-1774; Sacchi, Pietro; orcid: 0000-0001-5066-4508; Cruz-Cabeza, Aurora J; orcid: 0000-0002-0957-4823 (2020-11-16)
      Despite the technological importance of crystallization from solutions almost nothing is known about the relationship between the kinetic process of nucleation and the molecular and crystal structures of a crystallizing solute. Nowhere is this more apparent than in our attempts to understand the behavior of increasingly large, flexible molecules developed as active components in the pharmaceutical arena. In our current contribution we develop a general protocol involving a combination of computation (conformation analysis, lattice energy), and experiment (measurement of nucleation rates), and show how significant advances can be made. We present the first systematic study aimed at quantifying the impact of molecular flexibility on nucleation kinetics. The nucleation rates of 4 substituted benzoic acids are compared, two of which have substituents with flexible chains. In making this comparison, the importance of normalizing data to account for differing solubilities is highlighted. These data have allowed us to go beyond popular qualitative descriptors such 'crystallizability' or 'crystallization propensity' in favour of more precise nucleation rate data. Overall, this leads to definite conclusions as to the relative importance of solution chemistry, solid-state interactions and conformational flexibility in the crystallization of these molecules and confirms the key role of intermolecular stacking interactions in determining relative nucleation rates. In a more general sense, conclusions are drawn as to conditions under which conformational change may become rate determining during a crystallization process. [Abstract copyright: This journal is © The Royal Society of Chemistry.]
    • Can molecular flexibility control crystallization? The case of <i>para</i> substituted benzoic acids.

      Tang, Sin Kim; Davey, Roger J; orcid: 0000-0002-4690-1774; Sacchi, Pietro; orcid: 0000-0001-5066-4508; Cruz-Cabeza, Aurora J; orcid: 0000-0002-0957-4823 (2020-11-16)
      Despite the technological importance of crystallization from solutions almost nothing is known about the relationship between the kinetic process of nucleation and the molecular and crystal structures of a crystallizing solute. Nowhere is this more apparent than in our attempts to understand the behavior of increasingly large, flexible molecules developed as active components in the pharmaceutical arena. In our current contribution we develop a general protocol involving a combination of computation (conformation analysis, lattice energy), and experiment (measurement of nucleation rates), and show how significant advances can be made. We present the first systematic study aimed at quantifying the impact of molecular flexibility on nucleation kinetics. The nucleation rates of 4 <i>para</i> substituted benzoic acids are compared, two of which have substituents with flexible chains. In making this comparison, the importance of normalizing data to account for differing solubilities is highlighted. These data have allowed us to go beyond popular qualitative descriptors such 'crystallizability' or 'crystallization propensity' in favour of more precise nucleation rate data. Overall, this leads to definite conclusions as to the relative importance of solution chemistry, solid-state interactions and conformational flexibility in the crystallization of these molecules and confirms the key role of intermolecular stacking interactions in determining relative nucleation rates. In a more general sense, conclusions are drawn as to conditions under which conformational change may become rate determining during a crystallization process.
    • Can Skin Aging Contribute to Systemic Inflammaging?

      Pilkington, Suzanne M; email: suzanne.pilkington@manchester.ac.uk; Bulfone-Paus, Silvia; Griffiths, Christopher E M; Watson, Rachel E B (2021-10-28)
    • Can we achieve better recruitment by providing better information? Meta-analysis of 'studies within a trial' (SWATs) of optimised participant information sheets.

      Madurasinghe, Vichithranie W; Bower, Peter; orcid: 0000-0001-9558-3349; email: peter.bower@manchester.ac.uk; Eldridge, Sandra; Collier, David; Graffy, Jonathan; Treweek, Shaun; Knapp, Peter; Parker, Adwoa; Rick, Jo; Salisbury, Chris; et al. (2021-09-23)
      <h4>Background</h4>The information given to people considering taking part in a trial needs to be easy to understand if those people are to become, and then remain, trial participants. However, there is a tension between providing comprehensive information and providing information that is comprehensible. User-testing is one method of developing better participant information, and there is evidence that user-tested information is better at informing participants about key issues relating to trials. However, it is not clear if user-testing also leads to changes in the rates of recruitment in trials, compared to standard trial information. As part of a programme of research, we embedded 'studies within a trial' (SWATs) across multiple ongoing trials to see if user-tested materials led to better rates of recruitment.<h4>Methods</h4>Seven 'host' trials included a SWAT evaluation and randomised their participants to receive routine information sheets generated by the research teams, or information sheets optimised through user-testing. We collected data on trial recruitment and analysed the results across these trials using random effects meta-analysis, with the primary outcome defined as the proportion of participants randomised in a host trial following an invitation to take part.<h4>Results</h4>Six SWATs (n=27,805) provided data on recruitment. Optimised participant information sheets likely result in little or no difference in recruitment rates (7.2% versus 6.8%, pooled odds ratio = 1.03, 95% CI 0.90 to 1.19, p-value = 0.63, I<sup>2</sup> = 0%).<h4>Conclusions</h4>Participant information sheets developed through user testing did not improve recruitment rates. The programme of work showed that co-ordinated testing of recruitment strategies using SWATs is feasible and can provide both definitive and timely evidence on the effectiveness of recruitment strategies.<h4>Trial registration</h4>Healthlines Depression (ISRCTN14172341) Healthlines CVD (ISRCTN27508731) CASPER (ISRCTN02202951) ISDR (ISRCTN87561257) ECLS (NCT01925625) REFORM (ISRCTN68240461) HeLP Diabetes (ISRCTN02123133).
    • Can we achieve better recruitment by providing better information? Meta-analysis of ‘studies within a trial’ (SWATs) of optimised participant information sheets

      Madurasinghe, Vichithranie W.; Bower, Peter; orcid: 0000-0001-9558-3349; email: peter.bower@manchester.ac.uk; Eldridge, Sandra; Collier, David; Graffy, Jonathan; Treweek, Shaun; Knapp, Peter; Parker, Adwoa; Rick, Jo; Salisbury, Chris; et al. (BioMed Central, 2021-09-23)
      Abstract: Background: The information given to people considering taking part in a trial needs to be easy to understand if those people are to become, and then remain, trial participants. However, there is a tension between providing comprehensive information and providing information that is comprehensible. User-testing is one method of developing better participant information, and there is evidence that user-tested information is better at informing participants about key issues relating to trials. However, it is not clear if user-testing also leads to changes in the rates of recruitment in trials, compared to standard trial information. As part of a programme of research, we embedded ‘studies within a trial’ (SWATs) across multiple ongoing trials to see if user-tested materials led to better rates of recruitment. Methods: Seven ‘host’ trials included a SWAT evaluation and randomised their participants to receive routine information sheets generated by the research teams, or information sheets optimised through user-testing. We collected data on trial recruitment and analysed the results across these trials using random effects meta-analysis, with the primary outcome defined as the proportion of participants randomised in a host trial following an invitation to take part. Results: Six SWATs (n=27,805) provided data on recruitment. Optimised participant information sheets likely result in little or no difference in recruitment rates (7.2% versus 6.8%, pooled odds ratio = 1.03, 95% CI 0.90 to 1.19, p-value = 0.63, I2 = 0%). Conclusions: Participant information sheets developed through user testing did not improve recruitment rates. The programme of work showed that co-ordinated testing of recruitment strategies using SWATs is feasible and can provide both definitive and timely evidence on the effectiveness of recruitment strategies. Trial registration: Healthlines Depression (ISRCTN14172341) Healthlines CVD (ISRCTN27508731) CASPER (ISRCTN02202951) ISDR (ISRCTN87561257) ECLS (NCT01925625) REFORM (ISRCTN68240461) HeLP Diabetes (ISRCTN02123133)
    • Can Weight Watchers (WW) Help Address Maternal Obesity? An Audit of Weight Change in Women of Childbearing Age and Mothers-To-Be, Referred into a Commercial Slimming Programme.

      Tocque, Karen; Kennedy, Lynne; orcid: 0000-0002-4699-2602; email: l.kennedy@chester.ac.uk (2021-11-05)
      The scale of overweight and obesity amongst women of childbearing age or mothers to be, living in Wales, places a considerable burden on the NHS and public health. High BMI (over 30) during pregnancy increases the health risks for mother and baby. Policy advice recommends weight management services are available to help women lose weight before and whilst planning pregnancy. In parts of Wales, NHS partnerships with commercial companies provide weight management services for women considering or planning pregnancy. This study evaluates whether an established referral Weight Watchers (WW) programme, known to be effective in adults in England, can help mothers-to-be living in North Wales lose weight. Analysis used routine data from 82 referrals to WW between June 2013 and January 2015. Participants received a referral letter inviting them to attend face-to-face group workshops combined with a digital experience. The programme encompassed healthy eating, physical activity and positive mind-set. Trained WW staff measured bodyweight before, during and at 12 weeks. On entry to the course, participants had a median age of 31.4 years (interquartile range (IQR) 28-34) with a median BMI of 36.8 kg/m (IQR 33.3-43.7). Women completing the course (n = 34) had a median weight loss of 5.65 kg (IQR 0.45-10.85), equating to 5.7% (SD 3.46) of initial body weight. Intention-to-treat analysis (last observation carried forward), which included lapsed courses n = 66, showed a median weight loss of 3.6 kg (IQR - 2.53 to 9.73), equating to 3.7% (SD 3.62) of initial body weight. Overall, there was significant weight loss during the WW programme (Wilcoxon signed rank test Z = - 6.16; p < 0.001). Weight loss was significantly correlated with the number of workshops attended (Spearman correlation coefficient 0.61 p < 0.001). The proportion of all 82 participants (intention to treat, baseline observation carried forward) that achieved a weight loss of ≥ 5% initial weight was 30.5%. Referral of obese mothers-to-be into WW can successfully achieve short-term weight loss, at or above 5%, in approximately one third of participants. The dose-response effect supports a causal inference. Successful weight loss at this critical life stage may provide women with the necessary motivation to initiate weight loss for healthy pregnancy, however further research is required. [Abstract copyright: © 2021. The Author(s).]
    • Cancellation of Tollmien–Schlichting waves with surface heating

      Brennan, Georgia S.; orcid: 0000-0002-4914-5716; Gajjar, Jitesh S. B.; orcid: 0000-0001-8744-0102; email: jitesh.gajjar@manchester.ac.uk; Hewitt, Richard E.; orcid: 0000-0003-3056-1346 (Springer Netherlands, 2021-04-22)
      Abstract: Two-dimensional boundary layer flows in quiet disturbance environments are known to become unstable to Tollmien–Schlichting waves. The experimental work of Liepmann et al. (J Fluid Mech 118:187–200, 1982), Liepmann and Nosenchuck (J Fluid Mech 118:201–204, 1982) showed how it is possible to control and reduce unstable Tollmien–Schlichting wave amplitudes using unsteady surface heating. We consider the problem of an oncoming planar compressible subsonic boundary layer flow with a three-dimensional vibrator mounted on a flat plate, and with surface heating present. It is shown using asymptotic methods based on triple-deck theory that it is possible to choose an unsteady surface heating distribution to cancel out the response due to the vibrator. An approximation based on the exact formula is used successfully in numerical computations to confirm the findings. The results presented here are a generalisation of the analogous results for the two-dimensional problem in Brennan et al. (J Fluid Mech 909:A16-1, 2020).