4101 research outputs found
Sort by
High-Gain Metasurface in Polyimide On-Chip Antenna Based on CRLH-TL for Sub-Terahertz Integrated Circuits
No full textThis paper presents a novel on-chip antenna using standard CMOS-technology based on metasurface implemented on two-layers polyimide substrates with a thickness of 500 μm. The aluminium ground-plane with thickness of 3 μm is sandwiched between the two-layers. Concentric dielectric-rings are etched in the ground-plane under the radiation patches implemented on the top-layer. The radiation patches comprise concentric metal-rings that are arranged in a 3 × 3 matrix. The antennas are excited by coupling electromagnetic energy through the gaps of the concentric dielectric-rings in the ground-plane using a microstrip feedline created on the bottom polyimide-layer. The open-ended feedline is split in three-branches that are aligned under the radiation elements to couple the maximum energy. In this structure, the concentric metal-rings essentially act as series left-handed capacitances CL that extend the effective aperture area of the antenna without affecting its dimensions, and the concentric dielectric rings etched in the ground-plane act as shunt left-handed inductors LL, which suppress the surface-waves and reduce the substrates losses that leads to improved bandwidth and radiation properties. The overall structure behaves like a metasurface that is shown to exhibit a very large bandwidth of 0.350–0.385 THz with an average radiation gain and efficiency of 8.15dBi and 65.71%, respectively. It has dimensions of 6 × 6 × 1 mm3 that makes it suitable for on-chip implementation
Effectiveness of low-flow high-ozone concentration disinfection of dental impressions: A comparative study to immersion disinfection
No full textAims: To examine the effectiveness of low-flow high-ozone concentration disinfection of dental impressions, by means of an automated prototype device.Methodology: Disc shaped dental addition-cured silicone was inoculated with Klebsiella pneumoniae and Staphylococcus aureus, 10 mm discs were removed and ozone disinfected for different time intervals, immersion disinfected or served as controls.Disinfection success was examined by using the viable plate count method, while the statistical analysis was conducted via one way-ANOVA (p < 0.05). Results: Significant eradication was observed for selected Gram (+) and Gram (-) bacteria after 3 minutes of ozone exposure, leading to complete disinfection of the samples.Conclusion: While immersion disinfection of dental impressions is currently the most widely accepted method of disinfecting dental impressions, low-flow high-ozone concentration disinfection provides a quick, efficient, fully automated alternative method, limiting liquid waste generation. Possible alterations of the materials’ physical and chemical properties, like those of immersion disinfection, are not included in the present manuscript. A precise automated method for impression disinfection is established, relieving the dental team of possible cross-contamination
AI-empowered, blockchain and SDN integrated security architecture for IoT network of cyber physical systems
No full textInternet of things (IoT) is one of the most emerging technologies nowadays and it is one of the key enablers of industrial cyber physical system (CPSs).It has started to participate in almost every aspect of our social life, ranging from financial transactions to the healthcare system, communication to national security, battlefield to smart homes, and so on. However, the wide deployment of IoT suffers certain issues as well, such as interoperability, compatibility, heterogeneity, large amount of data, processing of heterogeneous data etc. Among others, energy efficiency and security are the utmost prominent issues. Scarce computing resources of IoT devices put hindrances on information sharing across edge or IoT network. Indeed, unintentional or malicious interference with IoT data may lead to severe concerns. In this study, the researcher exploits the potential benefits of a blockchain system and integrates it with software-defined networking (SDN) while justifying energy and security issues. More in detail, the researcher proposed a new routing protocol with the cluster structure for IoT networks using blockchain-based architecture for SDN controller. The proposed architecture obviates proof-of-work (PoW) with private and public blockchains for Peer-to-Peer (P2P) communication between SDN controllers and IoT devices. In addition to this, distributed trust-based authentication mechanism makes blockchain even more adoptive for IoT devices with limited resources. The experimental results show that the proposed cluster structure based routing protocol outperforms the state-of-the-art Ad-hoc On-demand Distance Vector (AODV), Destination-Sequenced Distance Vector (DSDV), Secure Mobile Sensor Network (SMSN), Energy efficient secured cluster based distributed fault diagnosis (EESCFD), and Ad-hoc On-demand Multipath Distance Vector (AOMDV), in terms of energy consumption, network throughput, and packet latency. Proposed protocol help overcome the issues especially, energy management and security of the next generation industrial cyber physical system
Understanding 'success' and 'failure' in two case studies of collaborative technology : contexts, narrative and lenses
No full textAfter first setting the scene for the development of IMS Learning Design (LD), this thesis details the creation of a LD test environment, along with interviews carried out with some of those involved in the development, implementation and research use of the specification. The creation of SPONGE (the Simplest Possible ONline Grouping Environment), a new software platform developed in response to the LD interview findings, is then documented. The rejection of SPONGE by teachers in a school environment provides the catalyst for an in-depth exploration of that school and the (largely non-technological) reasons for SPONGE's apparent failure. MegaTech and MiniTech, two explanatory lenses based on the work of van Langenhove and Harré, Heidegger, and Popper, are then created and used to revisit the rejection of LD and SPONGE (as two examples of functionally sound educational technologies) by practitioners.This research uses a multi-methodology (Mingers) approach, informed by Case Study (Yin), Realistic Evaluation (Pawson and Tilley) and Narratives (Clough). In addition, reflective elements are embedded at key moments in the thesis to facilitate a personal discussion of the challenges faced by this author and which prompted a significant change in research direction.This research makes the following contributions to knowledge.C1 A new analysis of why LD has not been widely adopted beyond the research community. [Chapters 5, 7, 8 and 9] C2 The initial validation of the analysis in C1 through its application in a contrasting educational and technical context (Hazelmere School). [Chapters 7, 8 and 9] C3 The in-depth picture of the use of educational technology in an extremely demanding environment (Hazelmere School). [Chapters 7 and 9] C4 The creation of MegaTech and MiniTech as explanatory lenses. [Chapter 8] C5 The application of MegaTech and MiniTech to more clearly explain the fate of LD and SPONGE. [Chapters 8 and 9] C6 The creation of SPONGE as a homogenous and open-standards compliant toolbox that focuses on immediacy and facilitates the spontaneous use of collaborative tools. [Chapter 6] C7 The creation of a self-contained and easily deployed LD test environment.[Chapter 4
The effect of simultaneous heat/fire and impact on carbon fibril and particle release from carbon fibre-reinforced composites
No full textA novel laboratory scale testing equipment has been designed and developed, which combines impact and heat/fire conditions to enable the testing of composite laminates, including the ability to capture debris/particles released during the test. This incorporates a pendulum impactor to create impact whilst the sample is exposed to a cone heater at a particular heat flux for a specified period of time.A protocol for testing samples under different conditions and capturing particles released, both from the front and back faces, along with effluents has been provided. A carbon fibre-reinforced epoxy composite was impacted whilst being exposed to different heat fluxes for a range of time periods. A loss of stiffness related to the heating exposure time was found to affect the damage type. At lower heat fluxes, the captured particles included broken carbon fibres, decomposed resinous particles and resin coated fibres. Quantitative and morphological analyses of captured particles demonstrated that the sizes of decomposed resin particles and fibres reduced with longer exposure time or increased heat flux. This information could be useful to provide insight into potential health hazards of components of the composites
Knowledge-advanced innovative behaviour: a hospitality service perspective
No full textPurpose – The purpose of this paper is to explore the nature and implications of knowledge advanced through service employees’ innovative behaviour and leading to initiating innovation within the hotel service subsector.Design/methodology/approach – A case study research method was applied to achieve the research objectives, which investigated two hotel properties resembling two personal–interactive service systems. In total, 52 semi-structured interviews were conducted along with other qualitative research methods, including the direct observation of employees, review of management archives/literature and the assessment of “micro cases”.Findings – The research outcome highlights the role of knowledge as supplementary to the interlinked process of idea generation and development. A novel classification of two types of knowledge is revealed as pre-encounter and encounter-dependent knowledge, implicating four patterns of service employees’ innovative behaviour. Practical implications – This paper recommends practical measures to nurture service employees’ innovative behaviour, leading to innovation.Originality/value – This study contributes to service innovation research by providing an in-depth assessment at the micro level, overlooked to date, of the nature of knowledge and the service employees’ role in initiating innovation within the hotel service subsector
Skilful surfing online for anxiety reduction (SO-FAR) in pregnancy: application development
No full textThe development of the Skilful surfing Online For Anxiety Reduction (SO-FAR) in pregnancy (SO-FAR) mental health (mHealth) application (app) was supported by previous research which modelled the theory of Skilful Surfing. The model informed the app development, with each facet of the model corresponding to a different intervention included in the app. The aim of this chapter was to report the development of an mHealth app to relieve pregnancy-specific health anxiety. App content inclusion was based on previous literature and recommendations for mHealth app inclusions. Overall, the chapter provides the reader with a comprehensive account of the development of the SO-FAR app which may reduce levels of pregnancy-specific HA by encouraging women to become more adept when navigating through online health information, self-aware, and educated and promoting the ability to identify triggers and understand when and why they are experiencing maladaptive cognition and rumination in a self-guided manner
Digital Innovations for Mental Health Support
No full textGiven the migration to more technologically driven services and resources in today’s world, as well as the range of digital innovations and research that have taken shape throughout the COVID-19 pandemic, it is important to consider the role that such advancements have played in supporting mental health initiatives. Throughout the COVID-19 pandemic, mental health service providers utilized technology and online environments more than ever before to care for people’s mental health and emotional needs, which has forced us to raise questions like how COVID-19 has impacted mental health support and services and how technology has helped people with their mental health through this ongoing crisis, along with outlooks for the future.Digital Innovations for Mental Health Support explores a range of current developments and topics surrounding the application of technology in mental health services including the need to examine the availability and forms of technologies to support mental health, how technology is received by people and the providers of services utilizing technology, how online platforms are increasingly being used for support and how efficacious these are, as well as how they are monitored and the issues that arise from their use. This publication provides an outlet with chapters focusing on empirical studies across a variety disciplines that utilize technologies and online platforms to support mental health and emotional well-being, including psychology, counseling, medicine, education, and psychiatry. Covering topics such as counseling online and computer games to support mental health, it is ideal for researchers, academics, healthcare professionals, and students
A critical analysis of the protection offered to third parties in respect of liabilities and immunities under a bill of lading
No full textTeaching undergraduate psychology students about mental health through student-led case studies: a case example of the celebrity Spike Milligan
No full textPurposeThe purpose of this paper is to suggest that student-led case studies are an important way to learn about mental health problems and to highlight this by presenting a case study of the comedic genius Spike Milligan.Design/methodology/approach Celebrities live their lives in the public eye. In recent years, many have talked about their struggles with mental health. This paper is based on a student-led case study of the celebrity Spike Milligan.Findings This case study suggests one previously under-emphasised issue and argues that Spike Milligan’s wartime experiences may have led to post-traumatic stress disorder. Second, that he may have developed neuro-inflammation, through contracting sandfly fever during the war. This could have been an additional trigger for bipolar disorder.Research limitations/implications While this is a single case study, it draws on a wide variety of research sources to back up the arguments advanced.Practical implications Student-led case studies provide a way of engaging students more actively with mental health problems.Social implications Mental illness is complex, if not more complex, than physical health problems. Case studies of celebrities like Spike Milligan can help develop a public understanding of mental illness, as they already have a working knowledge about the person.Originality/value The case study illustrates how Bipolar 1 disorder is a complex and unique condition and that every individual’s illness has different predisposing characteristics. It suggests that student-led case studies are a helpful learning tool