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  • Adult hypoglycaemia; a narrative review on forensic aspects

    Marks, Vincent; Gama, Rousseau (AME Publishing Company, 2021-04-30)
    Forensic hypoglycaemia describes interactions between hypoglycaemia and the law. Hypoglycaemia, or more correctly the neuroglycopenia and associated temporary brain malfunction, may result in a state of automatism during which sufferers are absolved, in law, from responsibility for what would otherwise be a criminal offence. Courts consider hypoglycaemia beyond the experience of the layman and consequently require an expert to explain what it is and how it affects behaviour. Experts on hypoglycaemia are few reflecting the rarity with which hypoglycaemia occurs in all except patients with diabetes treated with hypoglycaemic agents. Experts on hypoglycaemia are drawn from a number of disciplines, toxicology, pharmacology, internal medicine, forensic pathology, endocrinology and clinical biochemistry of which the last three are the most important in the forensic context. Death from hypoglycaemia may be due either to natural underlying causes or from the hypoglycaemia. Hypoglycaemia is produced by accidental or malicious administration of hypoglycaemic agents of which insulin is the commonest. The purported victim may be alive or dead when first brought to medical attention. In the former, investigation is essentially the same as for any case of spontaneous hypoglycaemia. Investigation of suspected death from hypoglycaemia requires collaboration between a forensic pathologist and either a toxicologist or clinical biochemist. The post mortem measurement of blood glucose is of little or no value in the investigation of hypoglycaemia whereas detection and quantification of the pancreatic hormones insulin, C-peptide and proinsulin, preferably by liquid chromatography/mass-spectrometry (LC-MS), is essential. Vitreous humour is most useful fluid for analysis as all three hormones remain measurable for several days after death from insulin poisoning unlike in serum from peripheral blood. Biochemical and immunohistological analysis of tissue surrounding a suspected injection site, if identified, is also valuable.
  • COVID-19 in hematology patients: real world experience in hospitals in the UK West Midlands

    Morrissey, Hana; Ball, Patrick A.; Mandal, Anandadeep; Nevill, Alan M.; Paneesha, Shankara; Basu, Supratik; Karim, Farheen; Hossain, M.I.; Phillips, N.; Khawaja, Jahanzeb; et al. (Hilaris, 2021-06-07)
    Objectives: This study aimed to understand the consequences of coronavirus disease 2019 (COVID-19) in patients diagnosed with haematological conditions, malignant and non-malignant. Method: A detailed insight into the first 112 patients with comorbidity of haematological conditions and COVID-19, admitted into nine National Health Services Trusts in the West Midlands Area of the United Kingdom, between 1st of March 2020 and 31st May 2020. Results: In the study cohort, 82% of patients had a malignant haematological disorder whilst 18% had a non-malignant haematological condition. Increasing age, breathlessness, reduction in oxygen saturation under 90% and abnormal chest x-ray were independently associated with higher mortality. Other long term co-morbidities did not present adverse impacts in this population. Survival analysis demonstrated that the COVID-19 severity score had a significant adverse correlation on patient outcome. COVID-19 patients who were classified as low risk, based on their primary haematological condition, showed significantly shorter survival time than those in the high risk category, which might be due to the shielding strategy for high infection risk patients. Conclusion: The 55% overall mortality in this cohort suggests that patients with haematological conditions had a higher mortality rate than patients with other acute, chronic or long term conditions. Significance: Previous studies have suggested poor outcomes for COVID‐19 infection in patients with haematological cancers, with short‐term mortality rates ranging from 32% to 62%. We report here the outcome of COVID-19 infection in patients with haematological conditions with both malignant and non-malignant, admitted to secondary care in acute care hospitals of the UK West Midlands. This study also examined the impact of chemo immunotherapy on outcomes from COVID-19 infection. This will be useful information to guide decision making during this second UK national lockdown
  • Analysis of current collection in micro-tubular solid oxide fuel cells: An empirical and mathematical modelling approach for minimised ohmic polarisation

    Hodjati-Pugh, O; Andrews, J; Dhir, A; Steinberger-Wilckens, R (Elsevier, 2021-03-19)
    Data from electrochemical impedance spectroscopy (EIS) of a 152 mm long, 6.8 mm outer diameter (OD) segmented-in-series micro-tubular solid oxide fuel cell (μT-SOFC) coupled with equivalent circuit modelling (ECM) support a circuit model and a continuum resistance path model to investigate the ohmic polarisation and current distribution for various current collector configurations on a micro-tube. Minimising the characteristically long axial current conduction pathways of μT-SOFCs is critical to maximise cell performance, particularly of cells more than a few centimetres long. Optimal positioning of a single current collector minimises the performance losses from the electrode. Multiple current collector terminals increase cell performance over a single terminal, but positioning must still be optimised. Sizing of the current collector terminal is critical to limit the loss of active area of the cathode. A trade-off between terminal sizing/spacing and loss of active area can lead to sub-optimal current collection. The models are generalised for all possible current collector configurations. We identify simple criteria to determine the maximum current collection efficiency of single and multiple anode current collectors for a range of cell geometries. The design tool allows early consideration to cell sizing as a function of anode current collection during cell and stack development.
  • Internal current collection and thermofluidynamic enhancement in a microtubular SOFC

    Hodjati-Pugh, O; Dhir, A; Steinberger-Wilckens, R (Elsevier, 2021-04-05)
    A low-cost, durable and simple internal current collector is presented for microtubular SOFCs (µT-SOFC). The internal design does not require removal of external cell layers, and subsequent loss of active area required to expose the interior electrode for contacting. The brush-like, high surface area current collector device is adapted from heat exchanger turbuliser technology produced by CALGAVIN Ltd. The effectiveness of the hiTRAN® turbuliser as a µT-SOFC current collector is explored and its thermofluidynamic effects on the cell described, as well as coating of the hiTRAN® design to reduce electrical contact resistance. The final design achieved a current density at 0.7 V of 0.38 A.cm and peak power density of 0.27 W.cm , 4.3 times higher than the original design and 3.3 times higher than the state-of-the-art with the same base materials.
  • Advancements and prospects of thermal management and waste heat recovery of PEMFC

    Baroutaji, A; Arjunan, A; Ramadan, M; Robinson, J; Alaswad, A; Abdelkareem, MA; Olabi, AG (Elsevier, 2021-01-07)
    Despite that the Proton Exchange Membrane Fuel Cell (PEMFC) is considered to be an efficient power device; around half of the energy produced from the electrochemical reaction is dissipated as heat due to irreversibility of the cathodic reaction, Ohmic resistance, and mass transport overpotentials. Effective heat removal from the PEMFC, via cooling, is very important to maintain the cell/stack at a uniform operating temperature ensuring the durability of the device as excessive operating temperature may dry out the membrane and reduces the surface area of the catalyst hence lowering the performance of the cell. In addition to cooling, capturing the produced heat and repurposing it using one of the Waste Heat Recovery (WHR) technologies is an effective approach to add a great economic value to the PEMFC power system. Global warming, climate change, and the high cost of energy production are the main drivers to improve the energy efficiency of PEMFC using WHR. This paper presents an overview of the recent progress concerning the cooling strategies and WHR opportunities for PEMFC. The main cooling techniques of PEMFCs are described and evaluated with respect to their advantages and disadvantages. Additionally, the potential pathways for PEMFC-WHR including heating, cooling, and power generation are explored and assessed. Furthermore, the main challenges and the research prospects for the cooling strategies and WHR of PEMFCs are discussed.
  • Personal Internet of Things (PIoT): what is it exactly

    Sahoo, BPS; Mohanty, SP; Puthal, D; Pillai, P (IEEE, 2021-05-14)
    The use of Internet of Things (IoT) devices in homes and the immediate proximity of an individual communicates to create Personal IoT (PIoT) networks. The exploratory study of PIoT is in its infancy, which will explore the expansion of new use cases, service requirements, and the proliferation of PIoT devices. This article provides a big picture of PIoT architecture, vision, and future research scope.
  • Nonlinear-based chaotic Harris Hawks Optimizer: algorithm and internet of vehicles application

    Abdollahi Dehkordi, Amin; Sadiq, Ali Safaa; Mirjalili, Seyedali; Ghafoor, Kayhan Zrar (Elsevier, 2021-06-05)
    Harris Hawks Optimizer (HHO) is one of the many recent algorithms in the field of metaheuristics. The HHO algorithm mimics the cooperative behavior of Harris Hawks and their foraging behavior in nature called surprise pounce. HHO benefits from a small number of controlling parameters setting, simplicity of implementation, and a high level of exploration and exploitation. To alleviate the drawbacks of this algorithm, a modified version called Nonlinear based Chaotic Harris Hawks Optimization (NCHHO) is proposed in this paper. NCHHO uses chaotic and nonlinear control parameters to improve HHO’s optimization performance. The main goal of using the chaotic maps in the proposed method is to improve the exploratory behavior of HHO. In addition, this paper introduces a nonlinear control parameter to adjust HHO’s exploratory and exploitative behaviors. The proposed NCHHO algorithm shows an improved performance using a variety of chaotic maps that were implemented to identify the most effective one and tested on several well-known benchmark functions. The paper also considers solving an Internet of Vehicles (IoV) optimization problem that showcases the applicability of NCHHO in solving large-scale, real-world problems. The results demonstrate that the NCHHO algorithm is very competitive, and often superior, compared to the other algorithms. In particular, NCHHO provides 92% better results in average to solve the uni-modal and multi-modal functions with problem dimension sizes of D = 30 and 50, whereas, with respect to the higher dimension problem, our proposed algorithm shows 100% consistent improvement with D = 100 and 1000 compared to other algorithms. In solving the IoV problem, the success rate was 62.5%, which is substantially better in comparison with the state-of-the-art algorithms. To this end, the proposed NCHHO algorithm in this paper demonstrates a promising method to be widely used by different applications, which brings benefits to industries and businesses in solving their optimization problems experienced daily, such as resource allocation, information retrieval, finding the optimal path for sending data over networks, path planning, and so many other applications.
  • BIM for deconstruction: an interpretive structural model of factors influencing implementation

    Obi, Lovelin; Awuzie, Bankole; Obi, Chukwudi; Omotayo, Temitope S; Oke, Adekunle; Osobajo, Oluyomi (MDPI, 2021-05-25)
    Transitioning from demolition to deconstruction practices for end-of-life performances is gaining increasing attention following the need for the construction industry to minimise construction and demolition waste. Building information modelling (BIM) presents an opportunity for sustainable deconstruction. However, the notion of BIM for deconstruction (BIMfD) is still in its infancy in the United Kingdom. Although a few studies on BIMfD are evident, a focus on identifying the underlying factors necessary for successful implementation of BIMfD is lacking. The purpose of this study was to identify and analyse the underlying factors necessary for BIMfD implementation in the UK construction industry. It employed a four-stage research design. The reviewed literature explored extant views on BIM implementation factors to identify an initial list of possible factors influencing BIMfD implementation. Subsequently, a mix of questionnaire, focus group discussions and structured interviews were employed at various stages to refine and contextualise 15 factors necessary for BIMfD implementation in the UK construction industry. The contextual interrelationships among the factors were evaluated using interpretive structured modelling (ISM). This evaluation culminated in a BIMfD implementation factor model. The findings identified BIMfD experts, responsiveness of business models to innovative practices and industry’s acceptance to embrace change as the principal factors influencing BIMfD implementation in the UK. The implications of the findings attest that BIMfD experts and advisors must champion the adoption and implementation of BIMfD in the UK and business models need to become more responsive to accommodate BIMfD innovative practices. A BIMfD framework was conceptualised. Even though the BIMfD framework was designed from the UK perspective, the global construction industry can leverage the outcomes of this study. This paper, therefore, brings to the fore, a hierarchical BIMfD implementation factor model to support improved deconstruction practices in the construction industry.
  • Cures, treatments and vaccines for Covid-19: international differences in interest on Twitter

    Thelwall, Mike (Levy Library Press, 2021-06-08)
    Since the Covid-19 pandemic is a global threat to health that few can fully escape, it has given a unique opportunity to study international reactions to a common problem. Such reactions can be partly obtained from public posts to Twitter, allowing investigations of changes in interest over time. This study analysed English-language Covid-19 tweets mentioning cures, treatments, or vaccines from 1 January 2020 to 8 April 2021, seeking trends and international differences. The results have methodological limitations but show a tendency for countries with a lower human development index score to tweet more about cures, although they were a minor topic for all countries. Vaccines were discussed about as much as treatments until July 2020, when they generated more interest because of developments in Russia. The November 2020 Pfizer-BioNTech preliminary Phase 3 trials results generated an immediate and sustained sharp increase, however, followed by a continuing roughly linear increase in interest for vaccines until at least April 2021. Against this background, national deviations from the average were triggered by country-specific news about cures, treatments, or vaccines. Nevertheless, interest in vaccines in all countries increased in parallel to some extent, despite substantial international differences in national regulatory approval and availability. The results also highlight that unsubstantiated claims about alternative medicine remedies gained traction in several countries, apparently posing a threat to public health.
  • Hybrid QSPR models for the prediction of the free energy of solvation of organic solute/solvent pairs

    Borhani, Tohid N; García-Muñoz, Salvador; Vanesa Luciani, Carla; Galindo, Amparo; Adjiman, Claire S (Royal Society of Chemistry, 2019-06-17)
    Due to the importance of the Gibbs free energy of solvation in understanding many physicochemical phenomena, including lipophilicity, phase equilibria and liquid-phase reaction equilibrium and kinetics, there is a need for predictive models that can be applied across large sets of solvents and solutes. In this paper, we propose two quantitative structure property relationships (QSPRs) to predict the Gibbs free energy of solvation, developed using partial least squares (PLS) and multivariate linear regression (MLR) methods for 295 solutes in 210 solvents with total number of data points of 1777. Unlike other QSPR models, the proposed models are not restricted to a specific solvent or solute. Furthermore, while most QSPR models include either experimental or quantum mechanical descriptors, the proposed models combine both, using experimental descriptors to represent the solvent and quantum mechanical descriptors to represent the solute. Up to twelve experimental descriptors and nine quantum mechanical descriptors are considered in the proposed models. Extensive internal and external validation is undertaken to assess model accuracy in predicting the Gibbs free energy of solvation for a large number of solute/solvent pairs. The best MLR model, which includes three solute descriptors and two solvent properties, yields a coefficient of determination (R2) of 0.88 and a root mean squared error (RMSE) of 0.59 kcal mol−1 for the training set. The best PLS model includes six latent variables, and has an R2 value of 0.91 and a RMSE of 0.52 kcal mol−1. The proposed models are compared to selected results based on continuum solvation quantum chemistry calculations. They enable the fast prediction of the Gibbs free energy of solvation of a wide range of solutes in different solvents.
  • The uptake study: a cross-sectional survey examining the insights and beliefs of the UK population on COVID-19 vaccine uptake and hesitancy

    Sethi, Sonika; Kumar, Aditi; Mandal, Anandadeep; Shaikh, Mohammed; Hall, Claire A; Kirk, Jeremy MW; Moss, Paul; Brookes, Matthew J; Basu, Supratik (BMJ, 2021-12-31)
    Objective: A key challenge towards a successful COVID-19 vaccine uptake is vaccine hesitancy. We examine and provide novel insights on the key drivers and barriers towards COVID-19 vaccine uptake. Design: This study involved an anonymous cross-sectional online survey circulated across the UK in September 2020. The survey was designed to include several sections to collect demographic data and responses on: i) extent of agreement regarding various statements about COVID-19 and vaccinations; ii) previous vaccination habits (e.g. if they had previously declined vaccination); and iii) interest in participation in vaccine trials. Multi-nominal logistic models examined demographic factors that may impact vaccine uptake. We used principle component analysis and text mining to explore perception related to vaccine uptake. Setting: The survey was circulated through various media, including: posts on social media networks (Facebook, Twitter, LinkedIn and Instagram), national radio, news articles, Clinical Research Network (CRN) website and newsletter, and through 150 West Midlands general practices via a text messaging service. Participants: There was a total of 4884 respondents of which 9.44% were BAME (Black Asian Minority Ethnic) group. The majority were females (n=3416, 69·9%) and of White ethnicity (n=4127, 84·5%). Results: Regarding respondents, overall 3873 (79·3%) were interested in taking approved COVID-19 vaccines while 677 (13·9%) were unsure, and 334 (6·8%) would not take a vaccine. Participants aged over 70 years (Odds Ratio (OR)=4·63) and the BAME community (OR=5·48) were more likely to take an approved vaccine. Smokers (OR=0·45) and respondents with no known illness (OR=0·70) were less likely to accept approved vaccines. The study identified 16 key reasons for not accepting approved vaccines, the most common (60%) being the possibility of the COVID-19 vaccine having side effects. Conclusions: This study provides an insight into focusing on specific populations to reduce vaccine hesitancy. This proves crucial in managing the COVID-19 pandemic.
  • Lifestyle information from YouTube influencers: Some consumption patterns

    Thelwall, Michael (Emerald, 2021-05-26)
    Purpose: Despite lifestyle information needs being an important part of our daily lives, little is known about the role of common sources. Whilst magazines and television are traditional providers of lifestyle content, including for fashion, makeup, fitness, and cookery, they have been partly replaced by content-creating online influencers. Design/methodology/approach: To investigate this new resource, this article analyses comments on the videos of 223 UK female lifestyle influencers on YouTube for information about possible viewing patterns. Findings: Three quarters of comments are written during the week of the video being published, consistent with videos being consumed with an information browsing function, rather than treated as an information resource to be searched when needed. Commenting on the videos of multiple influencers occurred often, suggesting that many viewers are not loyal to a single influencer. Thus, influencers seem to primarily support active scanning rather than searching for specific information. Typical viewers of UK female lifestyle influencers can therefore expect to accumulate lifestyle ideas and knowledge for potential future use in addition to gaining timely suggestions for near future routine decision making. Practical implications: Public-facing information professionals, health professionals and counsellors may consider recommending selected videos or influencers to help with lifestyle concerns. Originality: This is the first large scale study of content-creating influencers as a lifestyle information resource.
  • Male or female gender-polarised YouTube videos are less viewed

    Thelwall, Michael; Foster, David (Wiley, 2021-05-29)
    As one of the world’s most visited websites, YouTube is potentially influential for learning gendered attitudes. Nevertheless, despite evidence of gender influences within the site for some topics, the extent to which YouTube reflects or promotes male/female or other gender divides is unknown. This article analyses 10,211 YouTube videos published in 12 months from 2014-15 using commenter-portrayed genders (inferred from usernames) and view counts from the end of 2019. Nonbinary genders are omitted for methodological reasons. Although there were highly male and female topics or themes (e.g., vehicles or beauty) and male or female gendering is the norm, videos with topics attracting both males and females tended to attract more viewers (after approximately five years) than videos in male or female gendered topics. Similarly, within each topic, videos with gender balanced sets of commenters tend to attract more viewers. Thus, YouTube does not seem to be driving male-female gender differences.
  • A novel hybrid automaton framework for multi-phase epidemic modelling

    Navarro Lopez, Eva; Cabukoglu, Nurdan (SCS (The Society of Modeling & Simulation International), 2021-12-31)
    A framework for the multi-phase epidemic modelling of SEIARD (Susceptible-Exposed-symptomatic Infectious-Asymptomatic infectious-Recovered by immunity or by vaccination-Dead due to the disease) subpopulations is produced with switching transmission rate, basic reproduction ratio and vaccination strategy. Thekey novel featureof our modelis that we reproduce the different phasesof theevolutionof the infectious diseasebyusingahybrid automatonwithdifferent discrete locations correspondingtoeachof the phases of the disease. This is a general modelling framework applicable to the spreading of infectious diseases.We showhow the proposed modelworks with the simulationof different scenarios.
  • Non-specific effects of BCG vaccination on neutrophil and lymphocyte counts of healthy neonates from a developed country

    Williamson, SL; Gadd, E; Pillay, T; Toldi, G; Department of Neonatology, Birmingham Women's and Children's NHS Foundation Trust, Birmingham, UK. (Elsevier, 2021-03-06)
    BCG vaccination is known to reduce neonatal mortality from infections in a pathogen-agnostic manner. In this observational study we report on whether an emergency granulopoietic response is elicited in term babies from a developed country following BCG vaccination. We studied a cohort of neonates re-admitted to the hospital from home for feeding support separated into 2 groups dependent on whether they had received BCG vaccination. Clinical data including gender, weight, gestational age, method of feeding and full blood count results were retrieved retrospectively. While lymphocyte counts increase following BCG vaccination irrespective of gender and in proportion with the time elapsed after vaccination, the increase in neutrophil counts, is only observed in boys. This increase appears to be temporary. Our results confirm the presence of emergency granulopoiesis following BCG vaccination in a neonatal cohort from a developed country. However, this effect appears to be gender-specific and is present only in boys.
  • T lymphocytes, multi-omic interactions and bronchopulmonary dysplasia

    Toldi, Gergely; Hummler, Helmut; Pillay, Thillagavathie (Frontiers Media, 2021-06-08)
    Bronchopulmonary dysplasia (BPD) remains a significant clinical challenge in neonatal medicine. BPD is clearly a multifactorial disease with numerous antenatal and postnatal components influencing lung development. Extremely immature infants are born in the late canalicular or early saccular stage and usually receive intensive care until the early alveolar stage of lung development, resulting in varying magnitudes of impairment of alveolar septation, lung fibrosis, and abnormal vascular development. The interactions between T lymphocytes, the genome and the epigenome, the microbiome and the metabolome, as well as nutrition and therapeutic interventions such as the exposure to oxygen, volutrauma, antibiotics, corticosteroids, caffeine and omeprazole, play an important role in pathogenesis and disease progression. While our general understanding of these interactions thanks to basic research is improving, this knowledge is yet to be translated into comprehensive prevention and clinical management strategies for the benefit of preterm infants developing BPD and later during infancy and childhood suffering from the disease itself and its sequelae. In this review, we summarise existing evidence on the interplay between T lymphocytes, lung multi-omics and currently used therapeutic interventions in BPD, and highlight avenues for potential future immunology related research in the field.
  • The mould war: developing an armamentarium against fungal pathogens utilising thymoquinone, ocimene, and miramistin within bacterial cellulose matrices

    Swingler, Sam; Gupta, Abishek; Gibson, Hazel; Heaselgrave, Wayne; Kowalczuk, Marek; Adamus, Grazyna; Radecka, Izabela (MDPI, 2021-05-18)
    An increase in antifungal resistance has seen a surge in fungal wound infections in patients who are immunocompromised resulting from chemotherapy, disease, and burns. Human pathogenic fungi are increasingly becoming resistant to a sparse repertoire of existing antifungal drugs, which has given rise to the need to develop novel treatments for potentially lethal infections. Bacterial cellulose (BC) produced by Gluconacetobacter xylinus has been shown to possess many properties that make it innately useful as a next-generation biopolymer to be utilised as a wound dressing. The current study demonstrates the creation of a pharmacologically active wound dressing by loading antifungal agents into a biopolymer hydrogel to produce a novel wound dressing. Amphotericin B is known to be highly hepatotoxic, which reduces its appeal as an antifungal drug, especially in patients who are immunocompromised. This, coupled with an increase in antifungal resistance, has seen a surge in fungal wound infections in patients who are immunodeficient due to chemotherapy, disease, or injury. Antifungal activity was conducted via Clinical & Laboratory Standards Institute (CLSI) M27, M38, M44, and M51 against Candida auris, Candida albicans, Aspergillus fumigatus, and Aspergillus niger. This study showed that thymoquinone has a comparable antifungal activity to amphotericin B with mean zones of inhibition of 21.425 ± 0.925 mm and 22.53 ± 0.969 mm, respectively. However, the mean survival rate of HEp-2 cells when treated with 50 mg/L amphotericin B was 29.25 ± 0.854% compared to 71.25 ± 1.797% when treated with 50 mg/L thymoquinone. Following cytotoxicity assays against HEp-2 cells, thymoquinone showed a 71.25 ± 3.594% cell survival, whereas amphotericin B had a mean cell survival rate of 29.25 ± 1.708%. The purpose of this study was to compare the efficacy of thymoquinone, ocimene, and miramistin against amphotericin B in the application of novel antifungal dressings.
  • Effect of using slender flanges on EN 1993-1-5 design model of mono-symmetric S460 corrugated web bridge girders

    Hassanein, MF; Elkawas, AA; Bock, Marina; Shao, Yong-Bo; Elchalakani, M (Elsevier, 2021-05-03)
    Eurocode (EC3) bending moment design model of mono-symmetric corrugated web girders (CWGs) is based on the critical failure mode among the tension flange yielding, the compression flange yielding and the lateral-torsional buckling (LTB) of the compression flange. Recently, LTB behaviour of S460 laterally-unrestrained mono-symmetric CWGs with fully-effective flanges has been investigated by the authors, from which EC3 design model has been modified to better represent their actual strength. Nevertheless, the effect of the local buckling (LB) of slender compression flanges on the flexural strength and behaviour of such long girders has not been examined. While the corrugated web potentially makes large contribution to the out-of-plane stiffness, LB of the compression flange is expected to reduce LTB resistance of such girder significantly. Principally, this paper is devoted to exploring such effect on the accuracy of EC3 bending moment design model. Currently, virtual tests, by using ABAQUS software, are generated based on accurate validation. Then, parametric studies, intentionally designed to eliminate the tension flange yielding, are carried out on simply supported girders considering mainly the influences of the flange and web dimensions on the behaviour of S460 mono-symmetric CWGs. The strengths of such girders are compared with EC3 design model, from which it is found to provide unsuitable predictions. Hence, new formula has been proposed to accord better with the FE results. Additionally, several conclusions are provided at the end to assist design engineers in suggesting efficient cross-sections.
  • Metamaterial for crashworthiness applications

    Baroutaji, Ahmad; Arjunan, Arun; Robinson, John; Ramadan, Mohamad; Abdelkareem, Mohammad; Olabi, Abdul-Ghani (Elsevier, 2021-05-03)
    Metamaterials are artificial lattice structures or man-made cellular materials with unique mechanical, thermal, optical, and electromagnetic properties enabling their adoption for a wide range of engineering applications. The macroscopic performance of such metamaterials is dominated by the geometrical configuration of their respective unit cell which is normally engineered at microscale or nanoscale. These novel materials have attracted increased research interests as they offer a set of characteristics and functionalities that cannot normally be realized in conventional materials. High strength-to-density ratio and excellent energy absorption capabilities are among the properties exhibited by these materials making them ideal candidates for crashworthiness applications in automotive, aerospace, and defense engineering sectors. This article aims to review the recent developments concerning the energy absorption and impact responses of the metamaterials. An overview of the mechanical properties and manufacturing techniques of metamaterials is first introduced and then the recent studies on the energy absorption performance of metamaterials under dynamic and quasi-static loading are highlighted.

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