32,568 research outputs found
Deep-sea habitat characterization using acoustic data and underwater imagery in Gazul mud volcano (Gulf of Cádiz, NE Atlantic)
Gazul is the shallowest mud volcano (MV) within the Shallow Field of Fluid Expulsion (SFFE) of the northeastern Gulf of Cádiz (NE Atlantic; 300–1200 m depth). The SFFE represents an important geo- and biodiversity area that was designated as a Site of Community Importance under the European Habitats Directive in 2014. In this study, geological features, habitats and associated biodiversity, as well as anthropogenic impacts, were characterized at Gazul MV from underwater imagery and multibeam bathymetry. Multivariate methods using the Bray-Curtis similarity index identified six main habitats, each of which harbored a characteristic faunal assemblage that included: (1) sandy ripple bottoms typified by the actiniarian Actinauge richardi; (2) sandy, muddy, coarse sand and bioclastic bottoms dominated by the solitary coral Flabellum chunii; (3) coarse sand and bioclastic bottoms, together with soft sediments covered by scattered methane-derived authigenic carbonates (MDACs) (mixed bottoms), characterized by the echinoid Cidaris cidaris; (4) hard bottoms comprising MDACs dominated by a wide variety of sponges and gorgonians; (5) coral-rubble bottoms typified by the presence of colonial scleractinian communities dominated by Madrepora oculata; and (6) mixed bottoms characterized by the presence of a styelid ascidian. Slope and water depth were the main factors explaining assemblages’ distribution, which was also supported by the presence of MDACs such as slabs, crusts and chimneys on the seafloor, as well as by the geomorphologic diversity of Gazul MV. The results highlight Gazul MV as an eco-biologically important area harboring different vulnerable marine ecosystem (VME) elements with indicator taxa such as scleractinians, sponges, gorgonians and black corals. ROV images revealed abandoned or lost fishing gears and marine debris on the seafloor, indicating anthropogenic impacts in Gazul MV and adjacent areas. Indeed trawling fisheries activities have also been detected in Vessel Monitoring System datasets. A fishery restricted area is recommended in Gazul MV due to the occurrence of diverse VMEs and species included in different conservation directives and conventions.Postprin
Exploring the Impact of Living with Fanconi Anaemia & Diamond-Blackfan Anaemia: A Systemic Consideration
Aims: Amidst a growing body of medical research, little is yet known about the psychological impact of living with two rare life-limiting conditions, Fanconi Anaemia (FA) and Diamond Blackfan Anaemia (DBA). One might expect some level of impact on well-being as indicated by wider literature on other childhood illnesses. At present, understanding of this impact is limited in being generalised from other research, as therefore are the supports available. This research seeks to begin a consideration of the psychological impact, and to consider how support has been deemed.
Method: Using semi-structured interviews, parents and individuals living with FA or DBA were interviewed regarding their experiences. Thematic analysis was used to achieve an overview of these experiences.
Results: Themes identified for individuals included: 1. ‘Knowledge’, which outlined the impact of lack of knowledge and 2. ‘Illness Concept’ relating to one’s relationship to FA/DBA and how this is socially mediated. For parents, themes identified were: 1. ‘Knowledge’, which centered on uncertainty and 2. ‘Social Responses’ which related to areas of support and strain. These themes indicated an impact on individual well-being. Two joint themes were identified: 1. ‘Family Dynamics’ which outlined how relationships and family well-being may be impacted and 2. ‘Mental Health Care as Necessary but Inadequate’.
Conclusion: There was a clear impact articulated regarding the well-being of family members, individually and collectively in concerns regarding relational dynamics. There was also clear demand for psychological support which, in its current form, was generally considered inadequate. Research must be responsive in furthering efforts to establish clear and adequate pathways and a standard of care for the well-being of all families living with FA/DBA
Bank managers in Jordan: a study of motivation, job satisfaction and comparative organizational practices
This thesis is an attempt to fill a gap in research in the area of motivation and job satisfaction in the Jordanian/Arab managerial context. It is basically built on a representative sample of 266 Jordanian managers taken from 21 Jordanian/Arab and Western (Anglo-American) banks in Jordan. The thesis is an exploratory and comparative organizational behaviour and management study. It implements two instruments of investigation, a standardized questionnair and in-depth interviews.
The major findings of the thesis that Jordanian bank managers' patterns of motivation and job satisfaction and their interpretation of the 'higher goals of the job' (for example, autonomy) are similar to Western managers'. The assessmentf about 20 related factors on bank managers' motivation and job satisfaction reveal that different demographic and social and other organizational factors contribute to the significant impact on bank managers' motivation and job satisfaction. However, the significant impact of job related factors is more noticeable compared with other factors.
The thesis, with consideration to the recommendation and the implications of relevant research, extends the study beyond managers' attitudes and includes relevant managerial practices and systems. It also attemps to reflect on the interaction of the organization within the wider environment.
The comparison of the managerial practices and systems (for example, delegation of authority) and other organizational variables (for example, specialization) relevant to bank managers' motivation and job satisfaction reveal that major and significant differences are found between Western (Anglo-American) and Jordanian/Arab banks. It also reveals that the type of managerial practices and systems in the Jordanian/Arab banks is, by and large, traditional and less bureaucratic compared with the managerial practices in Western (Anglo-American) banks. The thesis addresses the main managerial implications Jordanian/Arab banks could consider when designing their motivational and job satisfaction systems.
In an attempt to interpret the traditional managerial practices in the Jordanian/Arab banks, pertinent factors are discussed. These relate to particular factors of the Jordanian/Arab banks and to specific cultural and social factors in the Jordanian/Arab societies
A Narrative Study of the Emotional Processing of a Female Victim of Stalking by an Ex-Intimate Partner
Background: There is a body of literature which already suggests that being stalked is associated with an increased risk of mental health difficulties, such as elevated anxiety, depression and post-traumatic stress disorder (PTSD) symptoms. However, the current research lacks a detailed picture of the emotional toll that being stalked can take on its victims. Aim: This research aimed to investigate the emotional impact of stalking behaviours on five females by their ex-intimate partners, using a qualitative approach to shed light on emotional experiences embedded in their stories and experiences. Methodology, Methods and Analysis: An in-depth investigation was conducted, using semi-structured interviews with five female students and staff members from the University of Kent. Each was identified as victims of stalking by their ex-intimate partners using a stalking checklist. A narrative inquiry was chosen as the ideal qualitative approach in order to gain insight into how a person experiences a particular phenomenon. The interviews were analysed and interpreted, taking into account the themes and plots that constructed the participants’ stories. The researcher used narrative inquiry based on a thematic approach to study events as described in the words of the participants. The interviews were transcribed and coded, and subsequently organised into themes chosen to best describe the information given. Findings: The findings from this research illustrated that being stalked has an impact on the victim’s ability to process and regulate their emotions in a functional and appropriate manner. Three themes identified were: Stalker Behaviour, Impact of Stalking on the Victim, and Victim Response. Additionally, the use and impact of coercive control by ex-intimate partners during the period of stalking, were important components affecting the emotional responses of victims, as illustrated through the stories they told. The findings support previous theories that being stalked can have a significant detrimental impact on a person’s mental health. The findings offer further insight into the manner in which that emotional impact can occur, and may pave the way for future research into victim response, coercive control and possible deficits in emotional processing and difficulties with emotional regulation, during and after a stalking experience. Limitations and Recommendations: Narrative research is suited to a small sample size, and this study was limited due to the small amount of participants involved. It was also restricted geographically to one location and to a female gender. Further research will be valuable to move beyond these limitations and provide additional insight into an area where there remains much to be discovered about the emotional impact of stalking
Unsupervised automated retinal vessel segmentation based on Radon line detector and morphological reconstruction
Abstract Retinal blood vessel segmentation and analysis is critical for the computer‐aided diagnosis of different diseases such as diabetic retinopathy. This study presents an automated unsupervised method for segmenting the retinal vasculature based on hybrid methods. The algorithm initially applies a preprocessing step using morphological operators to enhance the vessel tree structure against a non‐uniform image background. The main processing applies the Radon transform to overlapping windows, followed by vessel validation, vessel refinement and vessel reconstruction to achieve the final segmentation. The method was tested on three publicly available datasets and a local database comprising a total of 188 images. Segmentation performance was evaluated using three measures: accuracy, receiver operating characteristic (ROC) analysis, and the structural similarity index. ROC analysis resulted in area under curve values of 97.39%, 97.01%, and 97.12%, for the DRIVE, STARE, and CHASE‐DB1, respectively. Also, the results of accuracy were 0.9688, 0.9646, and 0.9475 for the same datasets. Finally, the average values of structural similarity index were computed for all four datasets, with average values of 0.9650 (DRIVE), 0.9641 (STARE), and 0.9625 (CHASE‐DB1). These results compare with the best published results to date, exceeding their performance for several of the datasets; similar performance is found using accuracy
Co-registration of eye movements and fixation-related potentials in natural reading: Practical issues of experimental design and data analysis
A growing number of studies are using co-registration of eye movement (EM) and fixation-related potential (FRP) measures to investigate reading. However, the number of co-registration experiments remains small when compared to the number of studies in the literature conducted with EMs and event-related potentials (ERPs) alone. One reason for this is the complexity of the experimental design and data analyses. The present paper is designed to support researchers who might have expertise in conducting reading experiments with EM or ERP techniques and are wishing to take their first steps towards co-registration research. The objective of this paper is threefold. First, to provide an overview of the issues that such researchers would face. Second, to provide a critical overview of the methodological approaches available to date to deal with these issues. Third, to offer an example pipeline and a full set of scripts for data preprocessing that may be adopted and adapted for one's own needs. The data preprocessing steps are based on EM data parsing via Data Viewer (SR Research), and the provided scripts are written in Matlab and R. Ultimately, with this paper we hope to encourage other researchers to run co-registration experiments to study reading and human cognition more generally
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Experiences of People with Multiple Sclerosis and Their Use of Assistance Dogs: An Interpretative Phenomenological Analysis
In this thesis, findings are reported from a qualitative study of eleven people living with multiple sclerosis (MS) who between them have used nineteen assistance dogs for more than two decades.
The first recorded use of dogs specifically trained to help people living with physical impairments undertake practical tasks aimed at increasing their independence and quality of life was in North America in 1975. In recent decades, the use of such dogs by people living with a wide range of physical, sensory, and intellectual disabilities and mental illness has rapidly expanded in many countries of the global north. Research from the field of human-animal interactions and disability studies raises issues concerning both the quality and quantity of evidence in this area. Recently, this has led researchers to urge caution regarding the benefits and challenges of assistance dog use by those living with disabilities. In this study, participants were recruited from two of the four accredited charities who train assistance dogs for people with physical disabilities across the United Kingdom (UK). Single in-depth, semi-structured interviews were undertaken. Interpretative Phenomenological Analysis (IPA) was applied to the data resulting in three super-ordinate themes: VISIBILITY, (UN)CERTAINTY and IDENTITY.
Key findings were that the use of an assistance dog was perceived to transform participants’ self-identity to one which was shared with their dog. Experiences of interactions between participants and society in which their assistance dog served to misdirect negative public gaze away from visible impairment were understood to amplify shared human-ness and minimise difference. This interspecies relationship was however, revealed to be vulnerable to the uncertainties of ageing (human and canine) intertwined with the unpredictability of living with a degenerative condition. The findings and conclusions offered in this thesis enhance and inform both critical disability studies and human-animal interaction studies through its exploration of new understandings of identity
3D Printing ceramic materials for energy and environmental applications.
New activities that arose during the Industrial Revolution caused the development of novel production sector, changes in the organisation of production, new forms of capital business, development of a global market and the use of new energy sources. However, it also led to the use of fossil fuels that in the long-term brought severe environmental issues due to diverse activities carried out during the revolution. Nowadays, it is known that these activities are the cause of the current environmental crisis involving a fast climate change and global warming. Most of the environmental problems, i.e. degradation of the ozone layer, acid rain, air and water pollution or waste reduction, cannot be managed by a single nation. Consequently, a lot of countries have implemented many agreements last decades with the purpose of the Zero Emission concept, trying to promote synergistic processes with very low impact on the environment and reducing the volume of waste and harmful emission without affecting the industrial benefits.
Over the last years, a lot of research groups have been focused on the development of new materials and new manufacturing techniques in order to achieve this environmental goal. This thesis is focused on the introduction of new manufacturing methods using well-known materials saving energy, time and money while reducing waste. More precisely, this work complements the current state-of-the-art of rapid prototyping of ceramics, covering the key aspect of microstructural control to improve the performance of different devices, such as Solid Oxide Fuel Cells and catalytic reactors for wastewater cleaning and for solar fuels generation.
On one hand, this thesis employed the binder jetting technique to produce ceramic support of CaSO4 which acts as support of the catalyst for the removal of contaminants from wastewater. Different routes were explored regarding the functionalisation of the support. Thanks to the porosity of the support, the TiO2 catalyst was synthesised in situ via TiCl4 hydrolysis, which was the most adequate strategy for the activation of the 3D printed ceramic support. Then, an exhaustive study on the microstructure (SEM), composition (TGA and XDR) and performance (photodegradation test employing methylene blue as contaminant) of the monolith were carried out. Finally, target values of photodegradation test were obtained achieving a nearly complete, i.e. 92%, conversion of methylene blue after 24 hours.
However, another route was explored as well, printing directly the catalyst avoiding the use of supports. For this purpose, during this thesis a ceramic TiO2 filament compatible with fused deposition modelling printers was developed in collaboration with Print3D Solutions. An exhaustive study on the composition of the filament and the optimisation of the printing parameters was carried out. In order to compare the results, the design of the monoliths was the same than that employed for the printed supports. TiO2 porous and dense structures were achieved and their photocatalytic performance tested. In this case, similar conversion of methylene blue conversion was achieved, 89% for the porous structure and 87% using the dense monolith. The recyclability of the catalyst was evaluated, with a clear difference between both monoliths as the re-activated porous catalyst lost 8% of the original efficiency, while the re-activated dense catalyst lost 72%.
On the other hand, related to the energy application, this thesis is focused ceramic electrolyte fabrication for solid oxide fuel cell via additive manufacturing as a contrast to traditional technologies. These devices are considered as Zero Emission technology because they only produce heat and water as final products when hydrogen is used as fuel. In, this work a prototype of digital light processing (DLP) printer was used for electrolyte manufacturing that were compared with electrolytes obtained by a commercial stereolithography printer. A thorough research of this work was dedicated to the production of 8% YSZ printable slurries. Once the slurry and the printing parameters were optimised, plane and structured electrolytes were obtained with a thickness average of 500 µm and an active area of 2.42 cm2 which were sintered at 1350°C. The cathode electrochemical performance was tested on symmetrical cells, LSM-YSZ/YSZ/YSZ-LSM, to study the ionic conductivity. The highest ionic conductivity 0.054 S/cm was achieved at 900°C for the cathode fixed at 1100°C, being its specific area resistance 1.762 Ω·cm2. Thus, these results confirmed that 3D printing technology can be employed for reduce the number steps, the time and the cost of solid oxide fuel cell.
Las nuevas actividades que surgieron durante la Revolución Industrial provocaron el desarrollo de un sector novedoso de producción, cambios en la organización de la producción, nuevas formas de negocio, desarrollo de un mercado global y el uso de nuevas fuentes de energía. Sin embargo, también propició el uso de combustibles fósiles que, a largo plazo, trajeron graves problemas ambientales debido a las diversas actividades realizadas durante la revolución. Hoy en día se sabe que estas actividades son la causa de la actual crisis ambiental que involucra un rápido cambio climático y calentamiento global. La mayoría de los problemas ambientales, como, por ejemplo, la degradación de la capa de ozono, la lluvia ácida, la contaminación del aire y el agua o la reducción de desechos, no pueden ser gestionados por una sola nación. En consecuencia, muchos países han implementado muchos acuerdos en las últimas décadas con el propósito del concepto Emisión Cero, tratando de promover procesos sinérgicos con muy bajo impacto en el medio ambiente y reduciendo el volumen de residuos y emisiones nocivas sin afectar los beneficios industriales.
Durante los últimos años, muchos grupos de investigación se han centrado en el desarrollo de nuevos materiales y nuevas técnicas de fabricación para lograr este objetivo medioambiental. Esta tesis se centra en la introducción de nuevos métodos de fabricación, utilizando materiales conocidos, que ahorran energía, tiempo y dinero y reducen los residuos. Concretamente, este trabajo complementa el estado actual de la técnica de prototipado rápido de cerámicas, abarcando el control microestructural como punto clave para mejorar el rendimiento de diferentes dispositivos, como las pilas de combustible de óxido sólido y los reactores catalíticos para la limpieza de aguas residuales y para generación de combustibles solares.
Por un lado, en esta tesis se utilizó la técnica de Binder Jetting para producir un soporte cerámico de CaSO4 que actúa como soporte del catalizador, con el fin de remover contaminantes de las aguas residuales. Se exploraron diferentes rutas en cuanto a la funcionalización del soporte. Gracias a la porosidad del soporte, el catalizador de TiO2 se sintetizó in situ mediante hidrólisis de TiCl4, la cual fue la estrategia más adecuada para la activación del soporte cerámico impreso en 3D. A continuación, se realizó un estudio exhaustivo sobre la microestructura (SEM), composición (TGA y XDR) y rendimiento (ensayo de fotodegradación empleando azul de metileno como contaminante) del monolito. Finalmente, se obtuvieron los valores objetivo de la prueba de fotodegradación logrando una conversión casi completa, es decir, 92%, de azul de metileno después de 24 horas.
Sin embargo, también se exploró otra ruta, imprimir directamente el catalizador evitando el uso de soportes. Para ello, durante esta tesis se desarrolló en colaboración con Print3D Solutions un filamento cerámico de TiO2 compatible con impresoras de modelado de deposición fundida (FDM). Se realizó un estudio exhaustivo sobre la composición del filamento y la optimización de los parámetros de impresión. Para comparar los resultados, el diseño de los monolitos fue el mismo que el empleado para los soportes impresos. Se lograron estructuras densas y porosas de TiO2 y se estudió su rendimiento fotocatalítico. En este caso, se logró una conversión similar de conversión de azul de metileno, 89% para la estructura porosa y 87% usando el monolito denso. Se evaluó la reciclabilidad del catalizador, con una clara diferencia entre ambos monolitos ya que el catalizador poroso reactivado perdió un 8% de la eficiencia original, mientras que el catalizador denso reactivado perdió un 72%.
Por otro lado, en relación con la aplicación energética, esta tesis se centra en la fabricación de electrolitos cerámicos para pilas de combustible de óxido sólido mediante impresión 3D como contraste con las tecnologías tradicionales. Estos dispositivos se consideran tecnología de emisión cero porque solo producen calor y agua como productos finales cuando se utiliza hidrógeno como combustible. En este trabajo, se utilizó un prototipo de impresora de procesamiento de luz digital (DLP) para la fabricación de electrolitos, que se compararon con electrolitos obtenidos por una impresora de estereolitografía comercial (SLA). Se realizó un estudio exhaustivo en este trabajo a la producción de pastas imprimibles de 8% YSZ. Una vez optimizados la pasta y los parámetros de impresión, se obtuvieron electrolitos planos y estructurados con un espesor promedio de 500 µm y un área activa de 2,42 cm2 que se sinterizaron a 1350°C. El rendimiento electroquímico del cátodo se probó en celdas simétricas, LSM-YSZ/YSZ/YSZ-LSM, para estudiar la conductividad iónica. La conductividad iónica más alta fue de 0.054 S/cm la cual se obtuvo a 900°C, para el cátodo fijado a 1100°C, siendo su resistencia de área específica 1.762 Ω·cm2. Por lo tanto, estos resultados confirmaron que la tecnología de impresión 3D se puede emplear para reducir el número de pasos, el tiempo y el costo de la celda de combustible de óxido sólido
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