• Iron therapy for preoperative anaemia

      Ng, Oliver; Keeler, Barrie D; Mishra, Amitabh; Simpson, JA; Neal, Keith; Al-Hassi, Hafid Omar; Brookes, Matthew J; Acheson, Austin G (Wiley, 2019-12-07)
      Preoperative anaemia is common and occurs in 5% to 76% of patients preoperatively. It is associated with an increased risk of perioperative allogeneic blood transfusion, longer hospital stay, and increased morbidity and mortality. Iron deficiency is one of the most common causes of anaemia. Oral and intravenous iron therapy can be used to treat anaemia. Parenteral iron preparations have been shown to be more effective in conditions such as inflammatory bowel disease, chronic heart failure and postpartum haemorrhage due to rapid correction of iron stores. A limited number of studies has investigated iron therapy for the treatment of preoperative anaemia. The aim of this Cochrane Review is to summarise the evidence for iron supplementation, both enteral and parenteral, for the management of preoperative anaemia. Objectives To evaluate the effects of preoperative iron therapy (enteral or parenteral) in reducing the need for allogeneic blood transfusions in anaemic patients undergoing surgery. Search methods We ran the search on 30 July 2018. We searched the Cochrane Injuries Group's Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library), Ovid MEDLINE(R), Ovid MEDLINE(R) In‐Process & Other Non‐Indexed Citations, Ovid MEDLINE(R) Daily and Ovid OLDMEDLINE(R), Embase Classic and Embase (Ovid), CINAHL Plus (EBSCO), PubMed, and clinical trials registries, and we screened reference lists. We ran a top‐up search on 28 November 2019; one study is now awaiting classification. Selection criteria We included all randomised controlled trials (RCTs) that compared preoperative iron monotherapy to placebo, no treatment, standard care or another form of iron therapy for anaemic adults undergoing surgery. We defined anaemia as haemoglobin values less than 13 g/dL for males and 12 g/dL for non‐pregnant females. Data collection and analysis Two review authors collected data and a third review author checked all collected data. Data were collected on the proportion of patients who receive a blood transfusion, the amount of blood transfused per patient (units), quality of life, ferritin levels and haemoglobin levels, measured as continuous variables at the following predetermined time points: pretreatment (baseline), preoperatively but postintervention, and postoperatively. We performed statistical analysis using the Cochrane software, Review Manager 5. We summarised outcome data in tables and forest plots. We used the GRADE approach to describe the quality of the body of evidence. Main results Six RCTs, with a total of 372 participants, evaluated preoperative iron therapy to correct anaemia before planned surgery. Four studies compared iron therapy (either oral (one study) or intravenous (three studies)) with no treatment, placebo or usual care, and two studies compared intravenous iron therapy with oral iron therapy. Iron therapy was delivered over a range of periods that varied from 48 hours to three weeks prior to surgery. The 372 participants in our analysis fall far short of the 819 required ‐ as calculated by our information size calculation ‐ to detect a 30% reduction in blood transfusions. Five trials, involving 310 people, reported the proportion of participants who received allogeneic blood transfusions. Meta‐analysis of iron therapy versus placebo or standard care showed no difference in the proportion of participants who received a blood transfusion (risk ratio (RR) 1.21, 95% confidence interval (CI) 0.87 to 1.70; 4 studies, 200 participants; moderate‐quality evidence). Only one study that compared oral versus intravenous iron therapy measured this outcome, and reported no difference in risk of transfusion between groups. There was no difference between the iron therapy and placebo/standard care groups for haemoglobin level preoperatively at the end of the intervention (mean difference (MD) 0.63 g/dL, 95% CI ‐0.07 to 1.34; 2 studies, 83 participants; low‐quality evidence). However, intravenous iron therapy produced an increase in preoperative postintervention haemoglobin levels compared with oral iron (MD 1.23 g/dL, 95% CI 0.80 to 1.65; 2 studies, 172 participants; low‐quality evidence). Ferritin levels were increased by intravenous iron, both when compared to standard care ((MD 149.00, 95% CI 25.84 to 272.16; 1 study, 63 participants; low‐quality evidence) or to oral iron (MD 395.03 ng/mL, 95% CI 227.72 to 562.35; 2 studies, 151 participants; low‐quality evidence). Not all studies measured quality of life, short‐term mortality or postoperative morbidity. Some measured the outcomes, but did not report the data, and the studies which did report the data were underpowered. Therefore, uncertainty remains regarding these outcomes. The inclusion of new research in the future is very likely to change these results. Authors' conclusions The use of iron therapy for preoperative anaemia does not show a clinically significant reduction in the proportion of trial participants who received an allogeneic blood transfusion compared to no iron therapy. Results for intravenous iron are consistent with a greater increase in haemoglobin and ferritin when compared to oral iron, but do not provide reliable evidence. These conclusions are drawn from six studies, three of which included very small numbers of participants. Further, well‐designed, adequately powered, RCTs are required to determine the true effectiveness of iron therapy for preoperative anaemia. Two studies are currently in progress, and will include 1500 randomised participants.
    • Electronic regulation of data sharing and processing using smart ledger technologies for supply-chain security

      Epiphaniou, Gregory; Pillai, Prashant; Bottarelli, Mirko; Al-Khateeb, Haider; Hammoudeh, Mohammad; Maple, Carsten (IEEE, 2020-03-31)
      Traditional centralised data storage and processing solutions manifest limitations with regards to overall operational cost and the security and auditability of data. One of the biggest issues with existing solutions is the difficulty of keeping track of who has had access to the data and how the data may have changed over its lifetime; while providing a secure and easyto-use mechanism to share the data between different users. The ability to electronically regulate data sharing within and across different organisational entities in the supply-chain (SC), is an open issue, that is only addressed partially by existing legal and regulatory compliance frameworks. In this work, we present Cydon, a decentralised data management platform that executes bespoke distributed applications utilising a novel search and retrieve algorithm leveraging metadata attributes. Cydon utilises a smart distributed ledger to offer an immutable audit trail and transaction history for all different levels of data access and modification within a SC and for all data flows within the environment. Results suggest that Cydon provides authorised and fast access to secure distributed data, avoids single points of failure by securely distributing encrypted data across different nodes while maintains an "always-on" chain of custody.
    • Effect of nano-Al2O3 addition on the microstructure and erosion wear of HVOF sprayed NiCrSiB coatings

      Praveen, AS; Arjunan, Arun (IOP Publishing, 2019-12-09)
      Development of nanostructured high velocity oxy-fuel (HVOF) coatings with low porosity, high strength and increased wear resistance is still in its infancy. Combining nanoparticles with conventional microscale powders are increasingly being investigated to use with feedstock materials for thermal spray processes. Accordingly, this work investigates the addition of nano-Al2O3 particles on the microstructure and erosion wear of NiCrSiB HVOF coating in a stainless steel (AISI 304) substrate. Particle analysis of the NiCrSiB feedstock was conducted and the maximum allowable addition of Al2O3 nanoparticles have been identified using the 'mass mixture ratio' model considering both the particle size and density. Consequently, two cases are considered and their performance analysed: a maximum allowable case of 1.4 wt%, followed by a 0.17 wt% addition of nano-Al2O3 with NiCrSiB. Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and x-ray Diffraction (XRD) analysis were employed to inform the microstructure, material composition and phase spectrum of the resulting coatings. Subsequently, the nanostructured coating was exposed to both a pull-off adhesion strength test and hot air jet (450 °C) hard particle erosion to characterise its performance. It was found that the microhardness of the HVOF NiCrSiB coating improved from 576 HV0.3 to 748 HV0.3 with the addition of 1.4 wt% nano-Al2O3. Furthermore, the nanostructured coating also exhibited high erosion resistance at a 90° erodent impact angle. The increase in erosion wear resistance was due to the increase in the hardness as a result of the nano-Al2O3 addition.
    • UK landscape ecology: trends and perspectives from the first 25 years of ialeUK

      Young, Christopher; Bellamy, Chloe; Burton, Vanessa; Griffiths, Geoff; Metzger, Marc J; Neumann, Jessica; Porter, Jonathan; Millington, James DA (Springer Nature, 2019-12-03)
      Context The 25th anniversary of the founding of the UK chapter of the International Association for Landscape Ecology (ialeUK) was marked in 2017. Objectives To assess trends in UK landscape ecology research over ialeUK’s first 25 years, to compare these trends to changes elsewhere in the world, and to consider how ialeUK can continue to support landscape ecology research and practice. Methods A database of conference abstracts was compiled and examined in combination with a questionnaire that surveyed existing and former active members of ialeUK. Results Across 1992–2017 we observe noticeable trends including the declining roles of statutory bodies, the development of the ecosystem services concept, and a decrease in use of empirical methods. Analysis of questionnaire results highlighted four key areas: Developing new researchers; Facilitating conferences for networking, learning and discussion; Linking policy with practice; and Driving the continued growth of landscape ecology as a discipline. Challenges were also noted, especially regarding the adoption of a wider understanding of landscape ecological principles in management. Conclusions Increases in qualitative research, decreases in studies explicitly examining connectivity/fragmentation and an absence of landscape genetics studies in the UK are seemingly distinct from US landscape ecology and elsewhere around the world, based on published accounts. ialeUK has had success in increasing the role of landscape ecology in policy and practice, but needs to continue to aim for improved collaboration with other landscape-related professional bodies and contributions to wider sustainability agendas.
    • Developing work breakdown structure matrix for managing offsite construction projects

      Sutrisna, M; Ramanayaka, CDD; Goulding, JS (Informa UK Limited, 2018-05-29)
      © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group. Offsite construction techniques continue to receive considerable attention in academic/research discourse. Whilst discourse in seminal literature critique the positive and negative aspects of offsite; on balance, the benefits outweigh the barriers, especially when fully integrated and managed. From a project management perspective, the techniques applied to construction projects typically commence in determining the project’s work breakdown structure (WBS). Whilst the WBS is applicable to offsite deliverables, reflecting site-based construction activities and concomitant dependencies with the manufacturing processes, there are slight discrepancies in processes, and equally, some areas of repetition and duplication. This mismatch has a fundamental impact on integration, creating pockets of confusion, where less seamless (sub-optimal) synergy between offsite and onsite works is lost. This is an acknowledged challenge. There is, therefore, a real need to retain the product breakdown structure, whilst ensuring a seamless interface with the onsite works is maintained. This is a challenge. Whilst the WBS-matrix has been implemented in the project management domain to bridge the ‘products’ and ‘activities’, this arrangement has not yet been developed for offsite building construction projects. This paper reports an on-going research project set up to implement WBS-matrix for offsite construction projects. Two cases of recently completed offsite construction building projects were studied to analyse current practices–to inform the way forward to further develop the WBS-matrix. Findings from this research provide clear guidance for practitioners involved in offsite construction projects; particularly on the development of the WBS-matrix for manufacturing deliverables/activities in order to more effectively manage offsite construction projects.
    • Investigating the cost of offsite construction housing in Western Australia

      Sutrisna, M; Cooper-Cooke, B; Goulding, J; Ezcan, V (Emerald, 2019-02-04)
      © 2018, Emerald Publishing Limited. Purpose: Offsite construction approaches and methodologies have been proffered a potential solution for controlling “traditional” projects, especially where high levels of complexity and uncertainty exist. Given this, locations such as Western Australia (WA), where there are unique housing provision challenges, offsite construction method was considered a potential solution for not only addressing the complexity/uncertainty challenges but also alleviating the housing shortage. However, whilst acknowledging the benefits of offsite construction, recognition was also noted on perceived barriers to its implementation, primarily relating to cost uncertainty. This recognition is exacerbated by very limited offsite construction cost data and information available in the public domain. In response to this, this paper sims to provide detailed cost analysis of three offsite construction projects in WA. Design/methodology/approach: To hold parameters constant and facilitate cross-case comparative analysis, data were collected from three embedded case studies from three residential housing projects in WA. These projects represent the most contemporary implementation of offsite in WA; where two were completed in 2016/2017 and the third project was still ongoing during the data collection of this research. The research methodological approach and accompanying data analysis component engaged a variety of techniques, which was supported by archival study of project data and evidence gathered from the offsite construction provider. Findings: Core findings revealed three emerging themes from residential offsite construction projects pertinent to cost. Specifically, the overall cost of delivering residential housing project with offsite construction techniques, the cost variability of offsite construction residential housing projects as impacted by uncertainties and the cash flow of residential offsite construction projects based on the payment term. These three major cost drivers are elucidated in this paper. Originality/value: This research presents new cost insights to complement the wider adoption of offsite construction techniques. It presents additional information to address the limited cost data and information of offsite construction projects available in the public domain particularly for residential housing projects (within the bounded context of WA). It also highlights the further stages needed to enhance data validity, cognisant of universal generalisability and repeatability, market maturity and stakeholder supply chains.
    • Managing information flow and design processes to reduce design risks in offsite construction projects

      Sutrisna, M; Goulding, J (Emerald, 2019-03-18)
      © 2019, Emerald Publishing Limited. Purpose: Following the increasing need for faster construction, improved quality and evidence value propositions, offsite construction is increasingly being proffered as a viable contender to “traditional” construction approaches. However, whilst evidence supports the move towards offsite, its uptake has been lower than expected. Whilst the precise reasons for this seem to be influenced by a number of issues, including contextual drivers and market maturity; some project stakeholders also view offsite as carrying greater risks. The purpose of this paper is to report on the quality of information flow, in particular, the impact and influence of this on design risks in offsite construction projects. Design/methodology/approach: An existing design risk framework is used as the point of departure for this research. This is further expanded into a specific model for evaluating offsite construction projects design risks, the rubrics of which were informed by two case studies of offsite construction projects in Australia and the UK analysed with a process-tracing technique. Whilst these cases were geographically separated, the constructs were aligned to uncover fundamental design information requirements and concomitant risks associated with offsite. Findings: The findings of the research reported in this paper include the crucial information feeding into the design process emanating from the lifecycle of offsite construction projects, namely, design, offsite (manufacturing), handling and transporting, site works and installation and also occupancy. These are contextualised within the four categories, namely, client requirements, project requirements, regulation aspects and social aspects and the final outcomes were summarised into a holistic diagram. Originality/value: Given that the offsite construction has shifted the working paradigm into assigning a significant level of efforts and emphasis at the front end of the construction projects, the importance of its design process and hence design risks management has gone up significantly in construction projects delivered using this technique. This research and paper contributes significantly to the built environment domain by identifying the crucial aspects along the project lifecycle to be considered to minimise the potential occurrence of design risks and hence increasing the confidence of project stakeholders in adopting offsite construction techniques in their projects.
    • Securing the embeddedness of psychosocial diffusion indicators into the Turkish construction industry: Silence is no longer golden

      Goulding, JS; Ezcan, V; Sutrisna, M (Emerald, 2018-04-03)
      © 2018, Emerald Publishing Limited. Purpose: The paper aims to investigate the employee–stakeholder engagement on business performance. A psychosocial approach was used to evaluate employees’ perception and role engagement on organisational performance, cognisant of: strategy development; leadership; fiscal acuity; employees’ skills, empowerment; supply chain relationships; external stakeholders and wider societal beneficiaries. Design/methodology/approach: This research is context-bound to the Turkish construction industry. Findings generated from literature established a set of evidenced-based priorities for further investigation. A case study approach was conducted with three large architecture, engineering and construction (AEC) organisations to define psychosocial diffusion indicators and priorities for future uptake. Findings: Initial findings on psychosocial diffusion indicators and their impact on business performance are presented through a psychosocial diffusion model. Three interconnected facets are proffered for future uptake: capability (responsiveness), capability (flexibility) and capability (competence). Research limitations/implications: Findings are exclusively bound to the sample frame in question. No attempt has been made to undertake detailed cross-analysis/correlation to support internal/external consistency, validity or reliability. Practical implications: Organisations are able to reflect on their core business strategy to appreciate how psychosocial diffusion can be operationalised. Social implications: This work impinges on social factors embedded within (and across) organisational boundaries, including the AEC supply chain. It also relates to employer/employee relationships, psychological functioning and employee well-being. Originality/value: Originality rests with the identification of construction-related psychosocial indicators. It contributes to the wider body of knowledge on embedding psychosocial indicators into organisational systems and processes, adding further insight into systems thinking and business transformation.
    • Challenges for managing smart cities initiatives: An empirical study

      Abdalla, Wala; Renukappa, Suresh; Suresh, Subashini; Al-Janabi, Razan (IEEE, 2019-11-21)
      Extensive urbanisation is increasing on a global scale. The urban population is estimated to rise to 66 per cent by 2050. This significant urbanisation growth drives the consumption of resources causing resource shortages and posing significant environmental and social concerns. To manage these concerns municipal decision makers' attempt to leverage the smart city concept with collaboration between external actors as a means to maintain the prepossessed living standard in the city. The philosophy of smart cities is to see challenges as opportunities and take advantage of other trends such as digitalization. Smart cities may offer a major market opportunity that can be easily exploited by information and communication technologies providers and their telecom equipment partners. However, although the opportunity exits, capitalizing on it is not as straightforward as it seems. This paper investigates the predominant challenges in smart city initiatives from the municipal decision makers' perspective. The study is based on the findings of a survey conducted via 65 participants from various small and medium enterprises and large organisations. The results show that smart cities decision makers mainly perceive challenges with various technical and non-technical issues such as collaboration, economical, governance, social acceptance, and awareness of technology, as well as high technological risk, security and privacy of users and cyber-crimes issues.
    • Innovative business models for smart cities – A systematic review

      Suresh, Subashini; Renukappa, Suresh; Shetty, Nisha (Blue Eyes Intelligence Engineering & Sciences Publication, 2019-11-21)
      Cities are the engines of growth for a nation. Smart technologies can help address the urban challenges and improve quality of life, economic opportunity, and liveability for citizens. Cities benefit from a transparent overview of best practice solutions to become smarter and from identifying best-suited solution providers. Companies that make cities smarter benefit from becoming more visible to cities around the globe with their newly developed or proven solutions. Innovative business models help accelerate the adoption of smart technologies. Various funding mechanisms have been used by cities to develop smart city projects. However, it has been revealed that the literature does not provide enough thoughts on these concepts. This paper provides an insight to the concept of innovative business models and the adoption of these in smart cities. Further the paper advances the understanding on the evolving business models and city procurement policies that could be used to accelerate smart city development. The paper seeks to address the question: What are the challenges faced by organisations and smart cities to develop a successful innovative business model? Cities have designed well defined strategies and are in the process of developing strategies for smart city. The paper address the challenges and functions of an innovative business model for development of smart cities
    • Review of motivations, success factors, and barriers to the adoption of offsite manufacturing in Nigeria

      Rahimian, FP; Goulding, J; Akintoye, A; Kolo, S (Elsevier, 2017-08-24)
      © 2017 The Authors. Despite several mitigation attempts, Nigeria is still facing a deficit of 17 million houses. Seminal literature argues that this problem is predominantly due to a myriad of issues, including high construction costs, skills shortages, the slow pace of construction, lack of infrastructure and logistics, poor quality of available housing stock etc. Given these issues, offsite manufacturing has been proffered as an innovative method for addressing these challenges. This paper reports on the findings of a substantial literature review investigated the needs, promises and barriers of adopting offsite manufacturing in Nigeria. Seminal literature elaborating on offsite construction and Nigerian construction industry has been thoroughly reviewed and results were analysed using thematic analysis, and Nvivo software was used to code and analyse the research data. Findings highlighted that the housing deficit in Nigeria is on the increase and nothing significant was being done at the moment. The results also posited that although OSM could improve housing delivery efforts in Nigeria, the prevalence of this is still considerably low; and that this was influenced by many factors, such as negative local perception about OSM, client resistance, lack of infrastructure and skills shortage. This study concludes that for OSM to be adopted in Nigeria, there is a need for greater awareness, collaboration, training and encouragement from Government. This study presents additional understanding of OSM in Nigeria based on expert opinion, the results of which were used to develop a framework for the effective adoption of OSM in Nigeria. It is concluded that the adoption of OSM could help support housing delivery efforts in Nigeria, and leverage wider benefits to the industry and associated supply chain.
    • Smart city business models – A systematic literature review

      Shetty, Nisha; Renukappa, Suresh; Suresh, Subashini; Algahtani, Khaled (IEEE, 2019-11-21)
      Business models have routed its way through smart cities. This, being an important phenomenon for an organisations success the concept has not been defined accurately. Literature review defines this as fuzzy and vague concept despite its importance to organisations is tremendous. This paper advances our understanding of the business model concept by reviewing the different types of business models and business model definitions following a systematic literature review approach. The paper progresses with a comparison between the businesses models developed for the smart cities domain. The paper seeks to address the question - How are smart cities going to generate economic value?
    • Acoustic leading-edge receptivity for supersonic/hypersonic flows over a blunt wedge

      Cerminara, Adriano; Sandham, Neil D (American Institute of Aeronautics and Astronautics (AIAA), 2017-09-11)
      Leading-edge receptivity to fast and slow acoustic waves of boundary layers on a cylinder–wedge geometry is investigated for a set of six different cases with Mach number ranging from 3.0 to 7.3, through direct numerical simulations of the Navier–Stokes equations. The structure of the disturbance field transmitted downstream of the shock by the imposed freestream waves is analyzed, as well as the characteristics of the wall response and its sensitivity to the angle of attack and the freestream-wave inclination angle. The results show that different postshock wave structures are formed for fast and slow acoustic waves, consisting of high-amplitude dragged and reflected waves for the fast-wave case and of low-amplitude convected waves for the slow-wave case. A good agreement is found with linear interaction theory. The wall response for fast waves shows a strong resonant amplification of mode F in the nose region and a modulated long-wavelength behavior farther downstream. In contrast, the response to slow waves shows an initial decay in the leading-edge region and an overall lower amplitude. The simulation results enable freestream disturbances, which are difficult to measure directly in experiments, to be related to wall pressure fluctuations.
    • Design, synthesis, pharmacological evaluation and molecular docking studies of substituted oxadiazolyl-2-oxoindolinylidene propane hydrazide derivatives

      Kerzare, D; Chikhale, R; Bansode, R; Amnerkar, N; Karodia, N; Paradkar, A; Khedekar, P (Sociedade Brasileira de Quimica (SBQ), 2016-03-22)
      ©2016 Sociedade Brasileira de Química. The manuscript describes design and synthesis of novel oxadiazolyl-2-oxoindolinylidene propane hydrazides as amide tethered hybrids of indole and oxadiazole and their evaluation for antiinflammatory and analgesic activity. The compounds were synthesized following five step reaction to yield fifteen derivatives as 3-(5-substituted-1,3,4-oxadiazol-2-yl)-N′-[2-oxo-1,2-dihydro-3Hindol-3-ylidene]propane hydrazides. The final derivatives 3-[5-(4-hydroxyphenyl)-1,3,4-oxadiazol-2-yl]-N′-[2-oxo-1,2-dihydro-3H-indol-3-ylidene]propane hydrazide and 3-[5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl]-N′-[2-oxo-1,2-dihydro-3H-indol-3-ylidene]propane hydrazide were found to be highly promising molecules with severity index of 0.35 and 0.56, respectively, which is promising for an analgesic compound. The hydroxy and methyl substitution on phenyl ring system provided with active anti-inflammatory compounds having increase in reaction time of 84.11 and 83.17%, respectively compared to standard drug at 85.84%. Molecular docking studies exhibit comparable interaction with synthesized derivatives and standard drug having a dock score of -4.44 by the K-nearest neighbour genetic algorithm method.
    • Individuals in urban dwelling primate species face unequal benefits associated with living in an anthropogenic environment

      Marty, Pascal R; Balasubramaniam, Krishna N; Kaburu, Stefano; Hubbard, Josephine; Beisner, Brianne; Bliss-Moreau, Eliza; Ruppert, Nadine; Arlet, Małgorzata E; Sah, Shahrul Anuar Mohd; Mohan, Lalit; et al. (Springer Nature, 2019-11-26)
      In primates, living in an anthropogenic environment can significantly improve an individual’s fitness, which is likely attributed to access to anthropogenic food resources. However, in non-professionally provisioned groups, few studies have examined whether individual attributes, such as dominance rank and sex, affect primates’ ability to access anthropogenic food. Here, we investigated whether rank and sex explain individual differences in the proportion of anthropogenic food consumed by macaques. We observed 319 individuals living in nine urban groups across three macaque species. We used proportion of anthropogenic food in the diet as a proxy of access to those food resources. Males and high-ranking individuals in both sexes had significantly higher proportions of anthropogenic food in their diets than other individuals. We speculate that unequal access to anthropogenic food resources further increases within-group competition, and may limit fitness benefits in an anthropogenic environment to certain individuals.
    • Combined free-stream disturbance measurements and receptivity studies in hypersonic wind tunnels by means of a slender wedge probe and direct numerical simulation

      Wagner, Alexander; Schülein, Erich; Petervari, René; Hannemann, Klaus; Ali, Syed RC; Cerminara, Adriano; Sandham, Neil D (Cambridge University Press (CUP), 2018-03-13)
      Combined free-stream disturbance measurements and receptivity studies in hypersonic wind tunnels were conducted by means of a slender wedge probe and direct numerical simulation. The study comprises comparative tunnel noise measurements at Mach 3, 6 and 7.4 in two Ludwieg tube facilities and a shock tunnel. Surface pressure fluctuations were measured over a wide range of frequencies and test conditions including harsh test environments not accessible to measurement techniques such as Pitot probes and hot-wire anemometry. A good agreement was found between normalized Pitot pressure fluctuations converted into normalized static pressure fluctuations and the wedge probe readings. Quantitative results of the tunnel noise are provided in frequency ranges relevant for hypersonic boundary-layer transition. Complementary numerical simulations of the leading-edge receptivity to fast and slow acoustic waves were performed for the applied wedge probe at conditions corresponding to the experimental free-stream conditions. The receptivity to fast acoustic waves was found to be characterized by an early amplification of the induced fast mode. For slow acoustic waves an initial decay was found close to the leading edge. At all Mach numbers, and for all considered frequencies, the leading-edge receptivity to fast acoustic waves was found to be higher than the receptivity to slow acoustic waves. Further, the effect of inclination angles of the acoustic wave with respect to the flow direction was investigated. An inclination angle was found to increase the response on the wave-facing surface of the probe and decrease the response on the opposite surface for fast acoustic waves. A frequency-dependent response was found for slow acoustic waves. The combined numerical and experimental approach in the present study confirmed the previous suggestion that the slow acoustic wave is the dominant acoustic mode in noisy hypersonic wind tunnels.
    • Receptivity to freestream acoustic noise in hypersonic flow over a generic forebody

      Cerminara, Adriano; Durant, Antoine; André, Thierry; Sandham, Neil D; Taylor, Nigel J (American Institute of Aeronautics and Astronautics (AIAA), 2018-11-12)
      Direct numerical simulations of the Navier–Stokes equations have been performed to investigate the receptivity and breakdown mechanisms in a Mach 6 flow over a generic forebody geometry with freestream acoustic disturbances. The simulations are based on transition experiments carried out in April 2015 in the Boeing/U.S. Air Force Office of Scientific Research Mach 6 facility at Purdue University. A three-dimensional model for both fast and slow freestream acoustic waves with multiple frequencies and spanwise wave numbers has been adopted in the numerical simulations, for which high-amplitude disturbances have been considered in order to simulate noisy wind-tunnel conditions. The numerical results revealed similarities in comparison to the experimental observations, especially when slow acoustic waves were considered as freestream disturbances. In particular, slow acoustic waves have been found to induce the breakdown process via crossflow instabilities located in the off-centerline region, with formation of streamwise streaks. Fast acoustic waves, in contrast, appeared more efficient in inducing earlier nonlinear growth through destabilization of the boundary layer along the symmetry plane of the body.
    • Numerical analysis on thermal crack initiation due to non-homogeneous solder coating on the round strip interconnection of photo-voltaic modules

      Eslami Mjad, Alireza; Ekere, Nduka Nnamdi (Elsevier, 2019-11-13)
      Solar energy is one of the most widely used renewable energy sources, with photo-voltaic (PV) solar cells/panels now utilized as an important energy source. The strip interconnection between solar cells (used for collecting current from solar cells) is a key PV module component; as poor interconnection reliability can lead to PV module failure. Multi-Busbar is a new type of interconnection which incorporates several round copper wires to help increase the energy conversion and transmission efficiency of PV modules and also to reduce the material costs. The non-homogeneity of the solder coating on the wires (resulting from manufacturing process faults), is one of the main factors that is responsible for the poor connections between the wire and the silver pads; which adversely impacts on the interconnection strength and long term reliability. This paper concerns an investigation of the effect of solder coating non-homogeneity on the thermo-mechanical response of round wires used for PV module interconnections. The study evaluates the two main parameters of non-homogeneity (out of centre value and direction), and also investigates the effect of geometrical parameters. The Extended Finite Element Method in ABAQUS software was used to determine the micro-crack initiation temperature and location for a given joint design. The results show that the cracking temperature is most affected by the direction of solder coating non-homogeneity and the downward vertical direction of out of centre positioning of copper in the solder coating leads to the most reduction in cracking temperature (up to 21%).
    • Antibiotics utilization patterns and direct cost in an emergency treatment unit in Sri Lanka

      Morrissey, Hana; Ball, PATRICK A; ABERATHNA, ACHINI; Zawahir, Shukry (Innovare Academic Sciences, 2019-11-15)
      Objective: Anecdotal evidence suggested that antibiotics are frequently used in the Emergency Treatment Units in Sri Lanka, mostly for the respiratory tract, soft tissue or urinary tract infections. This study aimed to describe the utilization patterns of antibiotics in terms of most common type, indication and associated direct cost in ETU at the Teaching Hospital Karapitiya, Sri Lanka. Methods: In this study, utilization patterns and the direct cost of antibiotics in an emergency treatment unit was evaluated by checking the bed-head tickets of all patients admitted to the unit from 1/5/16 to 15/5/16. Out of the 414 bed-head tickets checked 156 patients were receiving antibiotic treatment. Socio-demographic characteristics were analyzed. The prices of antibiotics in SriLankan government hospitals were taken from the hospital medical supply division price list. Data were analyzed by Microsoft Excel™. Results: In this study, 45.5% (out of 156 patients) were aged between 61-80years. The most used antibiotic was amoxicillin/clavulanic acid (18.1%) and clarithromycin (15.5%). Generic antibiotics were used for most patients (95.58%). Fixed-dose combinations were used in 18.5% of cases, including amoxicillin/clavulanic acid and piperacillin/tazobactam. The common indications for prescribing antibiotics were respiratory tract infections (31.2%) and soft tissues injuries (12.1%). Conclusion: This study revealed that there is apparent overuse of antibiotics and reveals that antibiotic stewardship programme could reduce antibiotic use, antibiotic resistance, and cost. Improved understanding of the rationale for antibiotic use would contribute optimising their use. Further studies are needed to establish the extent of sub-optimal prescribing of antibiotics in Sri Lankan hospitals.
    • Janus kinase enzyme (JAK) inhibitors and rheumatoid arthritis: a review of the literature

      Morrissey, Hana; Ball, Patrick A; Askari, Ayman; NOURI, ABDULLA KHALID (Innovare Academic Sciences, 2019-11-15)
      Cytokines play an essential role in normal cell growth and the regulation of immune function. The emergence of Janus Kinase Enzyme inhibitors promises the start of a revolution in the treatment of several chronic diseases. Their efficacy and safety profile have been demonstrated in multiple trials and they have been licensed for the treatment of a number of diseases including RA and PsA. Moreover, the use of highly selective Janus Kinase Enzyme inhibitors is currently being studied aiming to reduce side effects compared with traditional JAKinibs, an example of that would be the recent FDA approved upadacitinib. The Janus Kinase Enzyme inhibitorsmay supplant the classical biologic agents in the treatment of autoimmune diseases, since they exhibitthe advantages of oral administration, simultaneous blockade of multiple cytokines, reversibility and the lack of immunogenicity.