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Intelligent Metasurface Layer for Direct Antenna Amplitude Modulation Scheme
Get PDFThis paper proposes a transmitter system based on direct antenna amplitude-shift keying modulation for point-to-point microwave link. The proposed system is formed from a conventional microstrip antenna and a novel reconfigurable metasurface layer (RMSL). The proposed RMSL has two states: OFF (or Logic-0) and ON (or Logic-1) where each switching scenario provides a certain gain level. This is achieved through controlling the proposed RMSL switching configuration to control the amplitude of the transmitted signal. Results show that such a system can modulate electromagnetic signals directly by varying the antenna’s gain from about 2 dBi for Logic-0 to 13.8 dBi for Logic-1. An analytical model-based ray-tracing technique is invoked to explain the operation of the proposed antenna system. To demonstrate the operation of the proposed system, both the antenna and the RMSL structures were fabricated, assembled and tested. Measurements show good agreement with the theoretical model and numerical simulations obtained using CST Microwave Studio software package. The overall system has dimensions of 25×25×7.3 cm
Accounts of women identified as drinking at ‘high risk’ during pregnancy: A meta-ethnography of missing voices
Get PDFBackgroundDrinking alcohol during pregnancy is associated with Foetal Alcohol Spectrum Disorders (FASD), and women who drink at higher levels are more likely to have a baby with FASD. Public health responses focus on population-level approaches to FASD prevention such as promoting abstinence and alcohol brief interventions. Efforts to better understand and respond to ‘high risk’ drinking during pregnancy have been largely ignored. This meta-ethnography of qualitative research aims to inform this policy and practice agenda.MethodsTen health, social care, and social sciences databases were searched for qualitative studies published since 2000 exploring drinking during pregnancy. Studies that included accounts of women who described themselves, or were diagnosed as, alcohol-dependent during pregnancy, or reported drinking during pregnancy at levels considered by the Word Health Organisation to constitute ‘high risk’ drinking, were eligible. Noblit and Hare's analytic approach to meta-ethnography was used to synthesise the studies and eMERGe reporting guidance was followed.ResultsNine diverse studies were included. All explored the impact of social norms and relationships, women's knowledge about the risks involved in drinking during pregnancy, the behaviour of women, and the advice they received. Three key themes were identified: drinking is social and relational, knowledge is not enough, and multiple adversities matter. Multiple adversities were interconnected and primarily related to structural inequalities and oppression. The complex needs of women and the wider context in which their drinking occurred were rarely explored or responded to during pregnancy.ConclusionThis meta-ethnography provides a more nuanced understanding of the complex dynamics involved in women's ‘high risk’ drinking during pregnancy, the contexts in which they drink and their unmet needs. These findings can inform future policy and practice responses to ‘high risk’ drinking during pregnancy. Further research should explore women's experiences in a UK context and consider how services could meet women's needs
FEA-Based Simulation of Accelerated Ageing in a Power Cable Due to Sustained Partial Discharge Activities in a Spherical Cavity
Get PDFThe reliability of electrical assets is greatly influenced by the quality of their insulations. Key power installations such as power cables are manufactured with polymer-based materials as part of their insulation system. However, accelerated ageing of equipment insulations due to manifestation of defect(s), and partial discharges (PDs) can offset the operation of these systems or even lead to breakdowns. In this study, a non-deterministic model to simulate the phenomenon of repetitive discharges in a spherical air-filled cavity within a practical power cable has been investigated. In addition, the work contributes to the understanding of PD behaviour and field distribution under different ageing conditions considering changes in cavity surface conductivity. First, a section of the practical XLPE cable containing the cavity is developed in 2D using COMSOL software, and a finite element analysis (FEA) of the electric field distribution within the cable insulation is performed. The magnitude of the cavity local field, that is enough to ignite a PD, is investigated. Alongside the COMSOL model, the activity of sustained internal PD is simulated in MATLAB by introducing a random sample generating factor and adjusting the model’s parameters to obtain something close to the practical results. Furthermore, the impact of continuous PD in the power cable under different cavity dimensions and surface conductivity is likewise investigated, and a phase resolved PD (PRPD) pattern is established. The result shows that the magnitude and number of PDs per cycle increase as the cavity size and its surface conductivity increase. Finally, when the cavity surface conductivity rises, the amplitude of the electric field generated by the surface charge distribution and the number of PDs per cycle approach their maximum values
Review of recent advances in frequency-domain near-infrared spectroscopy technologies
Get PDFOver the past several decades, near-infrared spectroscopy (NIRS) has become a popular research and clinical tool for non-invasively measuring the oxygenation of biological tissues, with particular emphasis on applications to the human brain. In most cases, NIRS studies are performed using continuous-wave NIRS (CW-NIRS), which can only provide information on relative changes in chromophore concentrations, such as oxygenated and deoxygenated hemoglobin, as well as estimates of tissue oxygen saturation. Another type of NIRS known as frequency-domain NIRS (FD-NIRS) has significant advantages: it can directly measure optical pathlength and thus quantify the scattering and absorption coefficients of sampled tissues and provide direct measurements of absolute chromophore concentrations. This review describes the current status of FD-NIRS technologies, their performance, their advantages, and their limitations as compared to other NIRS methods. Significant landmarks of technological progress include the development of both benchtop and portable/wearable FD-NIRS technologies, sensitive front-end photonic components, and high-frequency phase measurements. Clinical applications of FD-NIRS technologies are discussed to provide context on current applications and needed areas of improvement. The review concludes by providing a roadmap toward the next generation of fully wearable, low-cost FD-NIRS systems
Quality of life of children and young people with anterior chest wall deformity: a systematic review of the literature
Get PDFObjective: The aim of this study was to evaluate the current evidence regarding the Quality of life (QoL) of children and young people with Anterior Chest Wall Deformity (ACWD).Methods: Using a defined search strategy, a systematic review of the literature was performed using PRISMA guidelines.Results: The search identified 305 articles, after refinement, the full text of 51 studies were reviewed and 10 included in the review. A total of eight studies described QoL associated with the correction of ACWD, and two studies reported on QoL without correction. The surgical correction of ACWD was reported in six studies and non-surgical correction in two studies. A total of three disease specific and 24 generic QoL measures were used. The variation in QoL outcome measures, together with a lack of consistency in the time scales of data collection, did not allow for direct comparison between studies. However, the improvement in psychosocial QoL following correction of ACWD is clear. The impact of ACWD on physical QoL is less defined and the influence of age, gender, severity, and type of deformity is uncertain. The literature identified primarily surrounds QoL outcomes in relation to surgical correction and is therefore not representative of all children and young people with ACWD.Conclusions: Correction of ACWD is associated with significant improvement in the psychosocial QoL of children and young people. Further work is required to standardise QoL data collection for all children with ACWD to achieve a greater understanding of the impact and guide future management
Stakeholder perspectives of Internationalisation of Universities in China’s non-first-tier Cities: A Case Study
Get PDFInternationalisation of higher education (IoHE) is used by a growing number of non-first-tier cities in China make their universities more globally competitive. However, we only have limited understandings about the strategies, drivers and challenges involved. This study addresses this knowledge gap through a case study focusing on a non-first-tier city in Pearl River Delta, an industrial city also in the Greater Bay Area, southern China. Analysis of interviews with 16 stakeholders from a local university reveals that in this context, internationalisation is a development strategy of higher education institutions to attract government support. The value of stakeholder analysis approach is considered, and further research directions are proposed
Energy Efficiency and Throughput Optimization in 5G Heterogeneous Networks
Get PDFDevice to device communication offers an optimistic technology for 5G network which aims to enhance data rate, reduce latency and cost, improve energy efficiency as well as provide other desired features. 5G heterogeneous network (5GHN) with a decoupled association strategy of downlink (DL) and uplink (UL) is an optimistic solution for challenges which are faced in 4G heterogeneous network (4GHN). Research work presented in this paper evaluates performance of 4GHN along with DL and UL coupled (DU-CP) access scheme in comparison with 5GHN with UL and DL decoupled (DU-DCP) access scheme in terms of energy efficiency and network throughput in 4-tier heterogeneous networks. Energy and throughput are optimized for both scenarios i.e. DU-CP and DU-DCP and the results are compared. Detailed performance analysis of DU-CP and DU-DCP access schemes has been done with the help of comparisons of results achieved by implementing genetic algorithm (GA) and particle swarm optimization (PSO). Both these algorithms are suited for the non linear problem under investigation where the search space is large. Simulation results have shown that the DU-DCP access scheme gives better performance as compared to DU-CP scheme in a 4-tier heterogeneous network in terms of network throughput and energy efficiency. PSO achieves an energy efficiency of 12 Mbits/joule for DU-CP and 42 Mbits/joule for DU-DCP, whereas GA yields an energy efficiency of 28 Mbits/joule for DU-CP and 55 Mbits/joule for DU-DCP. Performance of the proposed method is compared with that of three other schemes. The results show that the DU-DCP scheme using GA outperforms the compared methods
Participatory rights of older adults at risk in adult protection case conferences
Get PDFPurposeThe Adult Support and Protection (Scotland) Act 2007 (ASP Act) mandates public bodies to investigate situations of harm and to support and protect adults at risk. One of the fundamental principles of the legislation is to involve the person in the adult protection process. Older people are highly represented among those defined as adults at risk and have the right to participate in decisions about their lives. However, contextual factors can impact participatory parity, and participation can be tokenistic. Drawing on the author’s practice experience, this paper aims to explore the supports and barriers to meaningful participation in adult protection.Design/methodology/approachBased on practice during the first decade of the ASP Act, this paper uses amalgamated scenarios involving older adults at risk to illustrate some of the key themes emanating from literature.FindingsDespite Human Rights Conventions and law promoting participatory principles, research evidence and practice experience suggests that ethical principles do not always translate to practice. Within adult protection case conferences (APCCs), participation is nuanced and multifaceted, involving individual and structural facilitators and impediments. APCCs can be inhospitable environments for the adult at risk. But they also have the potential to be collaborative and supportive spaces, promoting the person’s self esteem and agency. The author plans to conduct research with service users and practitioners exploring the extent to which APCCs can facilitate meaningful participation.Originality/valueThis paper contributes to the wider debate about the participatory rights of service users and the value of experiential knowledge
The rationale of non-smoking adolescents’ use of electronic cigarettes (vaping)
Get PDFINTRODUCTION: Although electronic cigarettes are primarily advertised as smoking cessation tools, recent studies found a significant increase of adolescents who are non-smokers initiating the use of electronic cigarettes, and the understanding of the rationale behind those non- smoking adolescents’ use of electronic cigarettes is not yet well-established. Guided by the question “What factors increase the likelihood of non-smoking adolescents’ use of electronic cigarettes?”, this scoping review identifies the current landscape of scholarly explorations on this topic. It aims to provide heuristic implications on shaping the future research agenda that could enlighten social work interventions towards adolescents’ use of electronic cigarettes.METHODS: Nine electronic databases were searched and primary research articles exploring the reasons why adolescents (13–18 years of age) initiated their use of electronic cigarettes were screened. A PRISMA-ScR was used to record the results from the search strategy.FINDINGS: Of the five studies retrieved from the database search, three were qualitative studies, and two were quantitative, with all five articles being from the United States. Thematic analysis was used and identified four key themes for the factors influencing the use of electronic cigarettes in this population of interest: personal relationships, social context, ease of access, and production features.CONCLUSION: There is a significant gap in the literature around the reasons why adolescent non-smokers use electronic cigarettes. Conducting further research into this will expand the knowledge of social work practitioners and inform future, evidence-informed interventions and electronic cigarette cessation programmes to reduce the harm electronic cigarettes may have
Bridging the gap, how interprofessional collaboration can support emergency preparedness for children with disabilities and their families: an exploratory qualitative study
Get PDFBackground: Children with disabilities and their families are at higher risk during emergencies and disasters, which is often attributed to the lack of disability inclusion in emergency response as well as disparities in preparedness. This disparity speaks to a need for emergency preparedness that centers children with disabilities and their families. The purpose of this study was to elicit the perspectives of health professionals (nurses, occupational therapists, social workers), disability advocates, and public safety personnel (e.g., fire fighters, police officers, emergency management administrators) on what would enable these types of professionals to support family-centered emergency preparedness for families who care for children with disabilities. One goal of this research is to provide recommendations for practice and policy to improve safety outcomes for children with disabilities and their families in emergency situations. Methods: This study consisted of 46 qualitative interviews with nurses, occupational therapists, social workers, public safety personnel, and advocacy organization representatives about their role in emergency preparedness for families of children with disabilities. Qualitative content analysis was used to identify themes from participants’ responses. Results: Participants expressed interest in family-centered emergency preparedness, and stated that greater awareness, more education and training, increased networking between professions, and institutional support would enable their involvement. Conclusions: These findings have implications for the importance of interprofessional collaboration in supporting family-centered emergency preparedness for families of children with disabilities. Stronger interprofessional networks would help overcome many of the barriers identified by participants, and advocacy groups appear to be well-positioned to bridge the gap between these professionals and their areas of expertise
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