Preparação e caracterização de biovidros dopados com Sr e Zn

Mestrado em Ciência e Engenharia dos MateriaisOs vidros e vitro-cerâmicos do sistema ternário diopsite (CaO·MgO·2SiO2; posteriormente mencionado como Di) – fluorapatite (9CaO·3P2O5·CaF2; posteriormente mencionado como FA) e fosfato tricálcico (3CaO·P2O5; posteriormente mencionado como TCP) são potenciais candidatos para várias aplicações biomédicas incluindo estruturas de suporte para engenharia de tecido ósseo. O presente trabalho teve como objectivo investigar os vidros e os vitrocerâmicos do sistema Di-FA-TCP quanto à sua estrutura e capacidades de formação, sinterização e cristalização. Estudou-se também a influência da variação das razões SrO/CaO e ZnO/MgO na estrutura e em várias propriedades termo-físicas nos mesmos vidros, nos quais o CaO foi parcialmente substituído pelo SrO e o MgO pelo ZnO (0-10 mol.%). Todos os vidros estudados foram preparados pela técnica de fusão-arrefecimento rápido. A análise estrutural dos vidros foi feita por Ressonância Magnética Nuclear 29Si e 31P (NMR) e Espectroscopia de Infra-Vermelho (FTIR). Em todos os vidros a rede de silicato é coordenada predominantemente nas unidades Q2 (Si) enquanto que o fósforo tende a permanecer no ambiente do ortofosfato (Q0). O comportamento dos pós dos vidros na sinterização e cristalização foi estudado por Microscopia de Aquecimento (Hot Stage Microscopy - HSM) e por Análise Térmica Diferencial (DTA), respectivamente, enquanto a evolução das fases cristalinas e da microestrutura dos vitro-cerâmicos foi seguida por Difracção de Raios-X (XRD) e por Microscopia Electrónica de Varrimento (SEM). Na maioria das composições dos vidros investigados, a sinterização precedeu a cristalização tendo a DI e a FA cristalizado como fases primárias em todos os vitro-cerâmicos após sinterização a 850ºC durante 1 h.The glasses and glass-ceramics in ternary system of diopside (CaO·MgO·2SiO2; hereafter referred as Di) – fluorapatite [9CaO·3P2O5·CaF2; hereafter referred as FA] – tricalcium phosphate (3CaO·P2O5; hereafter referred as TCP) system are potential candidates for various biomedical applications including scaffolds for bone tissue engineering. The present work investigates the glass forming ability, structure, sintering ability and crystallization behaviour of some glasses along Di-FA-TCP join. Further, influence of varying SrO/CaO and ZnO/MgO ratio has been studied on structure and various thermo-physical properties of glasses in the above mentioned system where CaO has been partially substituted by SrO and MgO has been partially substituted by ZnO (0 – 10 mol.%). All the glasses have been prepared by melt-quenching technique. The structural analysis of glasses has been made by 29Si and 31P-nuclear magnetic resonance (NMR) and infrared spectroscopy (FTIR). The silicate network in all the investigated glasses is predominantly coordinated in Q2 (Si) units while phosphorus tends to remain in orthophosphate (Q0) environment. The sintering and crystallization behaviour of glass powders has been studied by hot stage microscopy (HSM) and by differential thermal analysis (DTA), respectively while crystalline phase evolution and microstructure of glass-ceramics has been followed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The sintering preceded crystallization in majority of the glass compositions and Di and FA crystallized as the primary crystalline phases in all the investigated glassceramics after sintering at 850ºC for 1 h

Voltage Stability Analysis and Stability Improvement of Power System

The main objective of this research work is to analysis the voltage stability of the power system network and its improvement in the network.voltage stability of a power system. A system enters a state of voltage instability when a disturbance, increase in load demand, or change in system condition causes a progressive and an uncontrollable drop in voltage or voltage collapse. The continuing increase in demand for electric power has resulted in an increasingly complex, interconnected system, forced to operate closer to the limits of the stability. This has necessitated the implementation of techniques for analyzing and detecting voltage collapse in bus bar or lines prior to its occurrence. Simple Newton Raphson algorithm based voltage stability analysis has been carried out. Matlab based simulations for all the factors that causes voltage instability has been implemented and analyzed for an IEEE 30 bus system. The proposed model is able to identify the behavior of the power systems, network under various voltage stability conditions and its possibility of recovery/stability improvement of the power system network has been discussed

Empirical Study on Effect of Employee Engagement to Achieve Maximum Customer Satisfaction in the Airline Industry – A Case Study of Etihad Airlines

As we talk; volume of businesses taking place within the aviation sector is increasing at an overwhelming rate. As a result, competition among various airline organizations across the world is becoming a subject worth not to debate. We all agree that financial strength is a paramount prerequisite for airline companies, being a gate pass to the deepening competition in the market. In the year 2003, Etihad airline kicked off its operations. To a layman, the span duration between 2003 and now might not be ample for this airline company to have secured much financial power. However, financial analysts beg to defer with this acclamation saying that financial strength is mandatory essentiality for airline companies. This particular research paper indentifies the  financial power of an airline company as the specific product being offered. The research paper goes on to highlight that it is impossible for an airline company to realize a successful sale of product supposing the clients are not satisfied. Therefore, airline companies have identified the essentiality of paying close attention to their customer’s grievances along with heeding to them in order to secure a competitive edge in the market

Numerical simulation of heat and mass transport during space crystal growth with MEPHISTO

The MEPHISTO space experiments are collaborative United States and French investigations aimed at understanding the fundamentals of crystal growth. Microgravity experiments were conducted aboard the USMP-1 and -2 missions on STS-52 and 62 in October 1992 and March 1994 respectively. MEPHISTO is a French designed and built Bridgman type furnace which uses the Seebeck technique to monitor the solid/liquid interface temperature and Peltier pulsing to mark the location and shape of the solid/liquid interface. In this paper the Bridgman growth of Sn-Bi and Bi-Sn under terrestrial and microgravity conditions is modeled using the finite element code, FIDAP*. The numerical model considers fully coupled heat and mass transport, fluid motion and solid/liquid phase changes in the crystal growth process. The primary goals of this work are: to provide a quantitative study of the thermal buoyancy-induced convection in the melt for the two flight experiments; to compare the vertical and horizontal growth configurations and systematically evaluate the effects of various gravity levels on the solute segregation. Numerical results of the vertical and horizontal Bridgman growth configurations are presented

CESAME: Culturally Engaged and Sensitive Approaches to Mental health Education – Project Summary

The project is a collaboration between the Glasgow School of Art (GSA), De Montfort University, Centre for Mental Health, and Leaders Unlocked, using a participatory design approach to work with young people from ethnically diverse groups. This work fills a crucial gap in current knowledge and approaches to research, policy and practice across the UK that builds on lived experiences of young people from ethnically diverse groups, explicitly focusing at the intersection of ethnic identity, school transition and mental health. The project aimed to map the experiences of young people from ethnically diverse groups during their transition from primary to secondary school, to: - Understand what mental health support young people need and aspire to during this transition - Identify opportunities to improve approaches to supporting young people’s mental health in schools during this transition - Develop ideas and recommendations for culturally sensitive support for young people. The summary report presents key insights and ideas that have emerged, alongside outlining implications of these for future policy, practice and research

Supporting the mental health of young people from ethnically diverse groups during the transition from primary to secondary school

Background: The transition from primary to secondary school is a pivotal period in young people’s lives and can significantly impact their mental health. However, the experiences of young people from ethnically diverse groups during this crucial period of physical, social and emotional development are under-researched, limiting the evidence base for meaningful support. Objectives: This study explored the experiences of young people from ethnically diverse groups during primary-secondary school transition and co-designed ideas for culturally sensitive support. It explicitly focused on the intersection between ethnic and cultural identity, primary-secondary transition and mental health. Methods: The study employed participatory design to collaborate with seven young people from ethnically diverse groups and a peer researcher. Four online workshops mapped participant experiences and ideas concerning the primary-secondary transition, identity and mental health. These were developed into implications for practice, policy and research. Results: Participants highlighted feeling unprepared for the transition, with some experiencing poor mental health and difficulty navigating their ethnic and cultural identity during this time. Participants’ ideas for future transition experiences included: supporting a longer transition period, schools promoting diversity among students and staff, enabling education on ethnicity and culture, breaking stereotypes, enabling mutual learning among staff and students and enabling an open and caring environment to support mental health. Conclusions: The study provides an in-depth understanding of experiences of young people from ethnically diverse groups during primary-secondary transition and suggests ways of supporting multi-faceted transitions and mental health, with a key focus on ethnic and cultural identity formation

A Study of Probable Submerged Area in the Catchment with the Change in Elevation of Sundarijal Hydropower Dam in Nepal

Sundarijal Watershed in Shivapuri National Park, Nepal has been providing services to Kathmandu Valley population in terms of Hydropower Generation and Drinking Water Supply. In this study, the probable submerged area in the catchment with the change in elevation of Sundarijal Hydropower Dam is calculated with the help of GIS-based tools and land use maps. In addition, assessment of the impacts on the vicinity due to the impounding reservoir is prepared. We hope that this study will be useful in designing of dam of an optimum elevation with minimum effects on the environment and maximum efficiency for sustainable period

Study protocol for a real-world evaluation of an integrated child and family health hub for migrant and refugee women

Introduction Continuity of child and family healthcare is vital for optimal child health and development for developmentally vulnerable children. Migrant and refugee communities are often at-risk of poor health outcomes, facing barriers to health service attendance including cultural, language, limited health literacy, discrimination and unmet psychosocial needs. 'Integrated health-social care hubs' are physical hubs where health and social services are co-located, with shared referral pathways and care navigation. Aim Our study will evaluate the impact, implementation and cost-benefit of the First 2000 Days Care Connect (FDCC) integrated hub model for pregnant migrant and refugee women and their infants. Materials and methods This study has three components. Component 1 is a non-randomised controlled trial to compare the FDCC model of care with usual care. This trial will allocate eligible women to intervention and control groups based on their proximity to the Hub sites. Outcome measures include: the proportion of children attending child and family health (CFH) nurse services and completing their CFH checks to 12 months of age; improved surveillance of growth and development in children up to 12 months, post partum; improved breastfeeding rates; reduced emergency department presentations; and improved maternal well-being. These will be measured using linked medical record data and surveys. Component 2 will involve a mixed-method implementation evaluation to clarify how and why FDCC was implemented within the sites to inform future roll-out. Component 3 is a within-trial economic evaluation from a healthcare perspective to assess the cost-effectiveness of the Hubs relative to usual care and the implementation costs if Hubs were scaled and replicated