12508 research outputs found
Sort by
Modelling, Simulation and Optimisation of Multistage Humidification and Dehumidification Desalination Plant Using Solar Energy. Performance Evaluation and Improvement of the Humidification-Dehumidification Desalination Process through Modelling, Simulation and Optimisation Techniques
Get PDFSerious social and economic disruptions are unfolding worldwide over the finite water and energy resources; hence, securing fresh water supply and employing renewable energy sources will help avoid catastrophic conflicts, continue modern lifestyles, and circumvent global warming and pollution. For this reason, a new method known as Humidification-Dehumidification (HDH) desalination process has been developed to address the challenge of water shortage. The aim of this research was to build the detailed mechanistic models with the increased capability to predict more accurately as well as to simulate and optimise the Multistage Humidification-Dehumidification (MHDH) desalination plant which is powered by solar energy.
The poor prediction accuracy is major bottleneck for most of conventional models. Mechanistic models for HDH desalination process derived from non-linear mathematical equations offers a promising solution to overcome this challenge. This study proposes a mechanistic model which is formulated by combining the enthalpy equations with the models which govern the mass and heat transfer across a thin film that separates water and air phases within the humidifier and dehumidifier. The proposed model is validated by using the data which were obtained from the physical experiments. Moreover, an experimental rig was designed and fabricated to specifically generate the physical data.
From the experimental and mathematical analysis, it was observed that the Recovery Ratio (RR) attained was increasing as temperature of the feed water increased. The RR was also increasing with the increase of dehumidifier’s surface area while it decreased with an increase of the packing size. Moreover, through a sensitivity analysis the highly influential parameters to the process model were identified to better understand the energy-efficient design principles and operating strategies for the maximum performance of the system.
Finally, a two stages HDH hybrid system that uses solar and biomass as source of energy is proposed whereby, an optimisation problem is solved to achieve the optimum RR. A maximum of 2 stages were required for a system to operate optimally.Commonwealth Scholarship Commission in the UK (CSC) under PhD Scholarships Plan for Low and Middle Income Countrie
Sparse Representation and its Application to Multivariate Time Series Classification
No full textIn signal processing field, there are various measures that can be employed to analyse and represent the signal in order to obtain meaningful outcome.
Sparse representation (SR) has continued to receive great attention as one of the well-known tools in statistical theory which among others, is used to extract specific latent temporal features that can reveal salient primitive and sparsely represented features of complex data signals, including temporal data analysis. Under reasonable conditions, many signals are assumed to be sparse within a domain, such as spatial, time, or timefrequency domain, and this sparse characteristics of such signals can be obtained through the SR. The ECG signal, for instance, is typically a temporal sparse signal, comprises of various periodic activities such as time delay and frequency amplitudes, plus additive noise and possible interference. Particularly challenging in signal processing, especially time series signals is how to reconstruct and extract the various features that characterized the signal. Many problems (e.g., signal components analysis, feature extraction/selection in signals, signal reconstruction, and classification) can be formulated as linear models and solved using the SR technique
The reconstruction of signals through SR can offer a rich representation of the sparsified temporal structure of the original signal. Due to its numerous advantages, such as noise tolerance and widespread use in various signal processing tasks, this has motivated many researchers to adopt the use of this technique for various signal representation analysis for a better and richer representation of the original input signal. In line with this, therefore, the goal of this study is to propose a SR-based mathematical framework and a coherence function for reconstruction and feature extraction from signals for subsequent analysis. The time embedding principle was first applied to restructure the signal into tine delay vectors and then the proposed approach, referred to as temporal subsequence SR approach was used to reconstruct the noisy signals and provides a sparsified time dependent input signal representation, and then the coherence function is further used to compute and extract the correlational coefficient quantities between the temporal subsequence signals to form the final feature vectors representing the discriminative features for each of the signal. These final feature vectors representing the signal are further used as inputs to machine learning classifiers. Experiments are carried out to illustrate the usefulness of the proposed methods and to assess their impact on the classification performance of the SVM and MLP classifiers using the popular and widely used ECG time series benchmark dataset. This research study supports the general hypothesis that, signal reconstruction methods (datadriven approach) can be valuable in learning compact features from the original signals for classifications
Investigation to Identify the Influence of the Surface Energetics of the Dry Powder Formulations of Budesonide and Theophylline on Their Aerodynamic Dose Emission Characteristics.
Get PDFSurface energetics play a key role in the delivery of a dry powder inhaler
formulation into the lungs, as there must be a sufficient balance of adhesive and
cohesive forces to allow optimal lung delivery. In this study, measuring the
surface energies of a set of single drug and carrier (budesonide or theophylline
with either mannitol or lactose) with different levels of surfactant using Inverse
Gas Chromatography, and comparing them to their lung deposition performance
using a Next Generation Impactor established a relationship between the two. A
1:10 mixing ratio of budesonide with either carrier was found to have the highest
FPF. Coating the carriers with 0.05% sodium lauryl sulphate resulted in a further
increase in the FPF when using either budesonide or theophylline as the API,
and the same results were seen when a sonocrystallised version of the API was
substituted for the micronised form. The calculated IGC values then showed that
the highest performing formulations had the lowest dispersive energy and total
free surface energy. Furthermore, a trend was observed in the work of adhesion
(Wa) and work of cohesion (Wc) for each set of formulations depending on which
API was chosen, where for the less polar drug (budesonide) a higher Wa/Wc
ratio was associated with the highest formulation performance, and for the more polar drug (theophylline) a smaller Wa/Wc ratio was associated with the highest formulation performance, enabling the estimation of lung performance for a set of
single drug and carrier using their surface energy data.Kuwait’s government and the Ministry of Health of Kuwai
Intersections between culture, sociodemographic change and caring: a qualitative study of current and prospective family caregivers in mainland China.
Get PDFAim: As the ageing population in China increases, support required from family caregivers for older relatives living with long-term health conditions also increases. This being so, this thesis explored the experiences and perceptions of current and prospective family caregivers, under the culture of Xiao (孝; filial piety).
Design and Methods: Phase 1 was conducted with 19 Chinese students using 3 focus groups to gain greater familiarity with the culture and inform the main study (Phase 2). Adopting a social constructivist philosophical position, data for Phase 2 were obtained from three generational sub-samples: only-children affected by the One-Child Policy (OCP), parents affected by OCP, and family caregivers in the workforce, totaling 23 participants through virtual in-depth interviews with participants in mainland China. Interviews were translated, transcribed, and analysed using reflective thematic analysis.
Findings and Conclusion: Phase 1 confirmed the centrality of the concept of Xiao to attitudes and beliefs around future caregiving for parents. Phase 2 findings’ overarching theme was ‘Competing pressures’, which comprised of three inextricably linked themes: (i) Caregiving beliefs, (ii) Contextual factors, and (iii) Caregiving conditions. Participants expressed meaningful desires to fulfil obligations, reflecting value-based convictions, stemming from their socio-cultural environment. Stressors experienced reveals structural and personal barriers to seeking support. Ultimately, extensive demands and limited coping strategies could diminish meaning in caregiving. This thesis makes a novel contribution on perceptions and experiences of family caregivers of older relatives within China as a collectivist society. Findings have implications for research, policy, and practice, highlighting the need for culturally attuned services to build resilience
Partial Differential Equations for Geometric Design
No full textNoThis title provides detailed description of how Partial Differential Equations are used in the field of geometric design, and supplies clear and concise explanations of how to implement the techniques described. It also offers extensive discussions (with examples) or practical applications of Partial Differential Equations in geometric design
#DiggingWhileDepressed: A Call for Mental Health Awareness in Archaeology
Get PDFYesDuring the excavation season in 2018, I experienced a depressive episode on site and struggled to maintain productivity with the rest of my team. I felt like I wasn't a "real" archaeologist, and turned to Twitter to vent about my situation using the hashtag #DiggingWhileDepressed. To my surprise, others used the hashtag to express their own feelings about mental wellness (or lack thereof) in archaeology. Now that discussion has started, this paper will propose the next steps for our discipline to tackle this pertinent issue. By challenging the toxic masculinity and ableism inherent in the way we view archaeological labour, I will posit tangible ways in which we, as archaeologists, can support each other on and off the field
Developing an obesity research agenda with British Pakistani women living in deprived areas with involvement from multisectoral stakeholders: Research priority setting with a seldom heard group
Get PDFYesBritish Pakistani women have exceptionally high rates of obesity and yet are seldom heard in a research priority setting concerning weight management. The objectives of this study were (i) to ascertain what multisectoral professionals perceive to be the most pressing unmet obesity needs or topic areas that need more research in relation to Pakistani women living in deprived areas of Bradford and (ii) to determine the top 10 obesity health priorities for this group to develop an obesity research agenda.
Methods: A two‐step process was adopted using the following: (i) a survey of a wide range of multisectoral professional stakeholders (n= 159) and (ii) a ranking exercise involving Pakistani women living in deprived areas of Bradford (n= 32) to select and prioritize their top 10 obesity health concerns and unmet needs from a list of 31statements identified in the survey and previous research. Survey data were analysed using inductive content analysis and themes were identified. Themes were translated into statements to be ranked by Pakistani women. The ranking exercise was conducted by telephone either via voice or video call. Data were analysed using a reverse scoring system.
Results: Survey responses were grouped into statements reflecting the following three categories: education needs; healthy behaviour barriers and mental well‐being. The highest rankings were given by Pakistani women to statements on mental health and the need for education. The top 10 prioritized statements were developed with members of the public into an obesity research agenda that reflected the target population.
Conclusion: Actively engaging British Pakistani women in setting research priorities provided a unique opportunity to understand the key areas they think are important for future research. The culminating research agenda can be used by researchers to advance the field of obesity research in Pakistani communities, thus producing research outputs that are relevant to and have impact in this population.
Patient or Public Contribution: Participants in the ranking exercise collected data. Public contributors were involved in developing the prioritized statements into are search agenda.NIHR, Grant/Award Number: NIHR200166;UKPRP, Grant/Award Number:MR/S037527/
A Security-enabled Safety Assurance Framework for IoT-based Smart Homes
Get PDFYesThe exponential growth of the Internet of Things (IoT) has paved the way for safety-critical cyber-physical systems to enter our everyday activities. While such systems have changed the way of our life, they brought new challenges that can adversely affect our life and the environment. Safety and security are two such challenges that can hamper the widespread adoption of new IoT applications. Due to a large number of connected devices and their ability to control critical physical assets, intended attacks on them and/or unintended failure events such as mechanical failure of devices, communication failure and unforeseen bad interactions between connected devices may cause an IoT-based system to enter into unsafe and dangerous physical states. By considering the importance of safety and security of IoT systems, in this article, we present a security-enabled safety monitoring framework for IoT-based systems. In the proposed framework, we utilise design-time system analysis to create an executable monitoring model that enables run-time safety assurance provision for a system via collecting and analysing operational data and evidence to determine the safety status of the system and then taking appropriate actions and securely communicating the safety status and recommended actions to the system users to minimise the risk of the system entering into an unsafe state
On Liminality: Space, Time, and Identities
Get PDFYesImagine that you’re entering a cave on a sunny, warm summer day. There is a swift, and distinct, change in the temperature as you walk into the darkness – a cold, dampness that cuts through to the bone. The lack of internal light immediately plunges you into darkness as you journey further into the cave, and the inherent stillness and silence means any noise you make is amplified twofold. If the Underworld exists, this is likely where it would be situated. And yet, if you simply turn around to face the entrance of the cave, you are greeted by a completely different setting; you can see the bright sun, the clear blue skies. By walking back to the start, you can already feel the warm air, hear the natural noises that one associates with the outdoors. But stop right in the middle, between the entrance of the cave and its deeper chambers – here, you’re in between what can only be described as two completely different worlds. This is a liminal space – and its where I exist, as a researcher and as a queer, mixed woman