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Chapter 17: X-Ray rheology of liquid crystal polymers
No full textX-ray Rheology is an experimental technique which uses time-ressolved x-ray scattering as probe of the molecular level structural reorganisation which accompanies flow. It provides quantitative information on the direction alignment and on the level of global orientation. This information is very helpful in interpreting the classic rheological data on liquid crystal polymers. In this research we use data obtained from a cellulose derivate which exhibits a thermotropic liquid crystal phase. We show how increased shear rates lead to a rapid rise in the global orientation and we related this to therories of flow in liquid crystal polymers from the literature. We show that the relaxation time is independent of the prior shear rate
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Chapter 4: Simulation of reaction injection moulding
No full textReaction Injection Moulding is a technology that enables the rapid production of complex plastic parts directly from a mixture of two reactive materials of low viscosity. The reactants are mixed in specific quantities and injected into a mould. This process allows large complex parts to be produced without the need for high clamping pressures. This chapter explores the simulation of the complex processes involved in reaction injection moulding. The reaction processes mean that the dynamics of the material in the mould are in constant evolution and an effective model which takes full account of these changing dynamics is introduced and incorporated in to finite element procedures, which are able to provide a complete simulation of the cycle of mould filling and subsequent curing
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Controlling morphology using low molar mass nucleators
Full text linkThis chapter focuses on the use of low molar mass compounds which self-assemble in to fibrillar structures within a polymer melt. Application of modest shear rate to the system will result in a common alignment of these fibrils which can serve as row nuclei for the subsequent crystallisation of the polymer matrix. Thus the combination of small quantities of a low molar mass compound and modest shear flow leads to a semi-crystalline morphology with a well defined anisotropy and morphology
Symptom management in palliative care\ud
No full textPalliative care is a specialized area of healthcare that has emerged to respond to the experiences and needs of people with life-limiting illness. Palliative care has been defined by the World Health Organization (WHO) as:\ud
... an approach that improves thwe quality of life of patients and families facing problems associated with life-threatening illness, through the prevention of suffering by means of early identification and impeccable assessment and treatment of pain and other problems, physical, psychological and spiritual. (World Health Organization(WHO) definition of palliative care, 2004)\ud
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Consistent with thsi definition, a number of key principles can be identified to underpin a person-centred approach to clinical management in palliative care. These principles include: \ud
* the palliative approach is identified as being relevant early in the course of an illness, not just as end-of-life care\ud
* palliative care promites holistic care to ensure physical, psychological social and spiritual well-being\ud
* the family and significant others are included in the care process \ud
* there is an emphasis on impeccable assessment, early identification of problems and implementation of appropriate treatments\ud
* disease-modifying treatments, such as chemotherapy and radiotherapy may have a role\ud
* palliative care can be provided in any setting\ud
* there is an emphasis on a team approach to care.\ud
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In this chapter, Yates and Hardy introduce Adrian, a man dying of disseminated melanoma and show how these principles can be applied to managing some of the more common clinical problems that arise in palliative care. The chapter focuses on managing common symptoms including pain, dyspnoea, nausea, fatigue and anorexia. Management issues associated with other important and related care needs, such as psychological distress and spiritual concerns are addressed elsewhere in this book. \ud
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For clarity, each of the symptoms addressed in this chapter is described separately. As seen in Adrian's case, however, patients are more likely to present with several concurrent symptoms. The complex interrelationships between these various symptoms should be considered when identifying an appropriate management plan
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Chapter 16: Electrospinning of polymer solutions
No full textElectrospinning is a technique that involves the production of nanoscale to microscale sized polymer fibres through the application of an electric field to a droplet of polymer solution passed through a spinneret tip. This chapter considers the optimisisation of the electrospinning process and in particular the variation with solution concentration. We show the strong connection between overlapping chains and the successful spinning of fibres. We use small-angle neutron scattering to evaluate the molecular conformations in the solutions and in the fibres
Design and fabrication of scaffolds via melt electrospinning for applications in tissue engineering
No full textMelt electrospinning is a manufacturing technique that can be adapted into a direct writing process, similar to those based on melt extrusion. The resultant product is a three-dimensional (3D) scaffold with significantly reduced filament resolution compared to melt extrusion direct writing approaches. While the argument for using melt electrospinning in applications such as textiles and membranes is problematic due to scale-up requirements, it has a promising future for tissue and tumour engineering applications, as the scaffolds are cell invasive and provide an environment upon which cells can deposit ECM. This emerging processing technology should prosper with more in-depth research, as early results demonstrate excellent in vitro and in vivo biocompatibility
3D food printing: a comprehensive review and critical analysis on technologies, food materials, applications, challenges, and future prospects
No full text3D (three-dimensional) food printing has emerged as a transformative technology, offering exceptional adaptability and customization across various industries. This review explores its potential to enhance environmental sustainability by minimizing food waste, improving portion control, and promoting eco-friendly practices. Key technological foundations, such as rheological assessments for material fow optimization, colorimetric analysis for accurate color representation, and advanced material handling techniques for consistent texture and nutrition, are critically examined. Moreover, it highlights the synergy between mechanical precision, algorithmic control, and material science, illustrating how these elements collectively ensure adherence to high-quality and safety standards in food engineering. The study also reviews 3D food printing technologies, methods, materials, and applications, emphasizing the pivotal role of customization in addressing diverse dietary, cultural, medical, and aerospace needs. A SWOT (strengths, weaknesses, opportunities, and threats) analysis evaluates the current capabilities and limitations of the technology, identifying challenges and future prospects. This comprehensive analysis underscores the potential of 3D food printing to revolutionize food production, ofering valuable insights for researchers, practitioners, and policymakers
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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