Biomimetic Facade Applications for a More Sustainable Future

Mankind has often taken inspiration from the nature to solve problems since nature has sophisticated processes, refined for thousands of years. While manmade systems are unsustainable, natural processes embody sustainability principles; therefore, there are many things to learn from nature in order to solve design problems and create a more sustainable future. This is the promise of a biomimetic design approach. Another design approach is biodesign, and it also involves utilizing natural elements inside the design. The building façade is a problematic research area since it is at the intersection between living spaces and natural environment; thus it faces many problems especially regarding energy-air-water transition between indoors and outdoors. Application of key sustainability concepts in architecture such as energy requirements, form and structure, and sustainability considerations can be enhanced by learning from natural processes. This chapter looks at cutting-edge design principles, materials, and designs in building façades through the lens of biomimetics and biodesign. First, the design principles and then the materials and some cases are explained. The concepts of biomimicry and biodesign are in harmony with the concept of sustainability; however, to reach sustainable façade solutions, the sustainability principles should be at the core of the design problem definition

Comparison of solar output of vertical and inclined solar panels in the high north

Abstract. This thesis presents a comprehensive literature review on the endurance of solar photovoltaic (PV) systems in high north conditions and the optimized setup parameters for maximizing their output. To simulate data, PV panels were considered in the high north region of Oulu, Finland, and their output was measured under various setup parameters. The data was then analyzed using SketchUp simulation with the Skelion plug- in to determine the optimized setup parameters that yield maximum output. The findings of the study highlight the importance of tilt angles and orientation for maximizing energy production. The evaluation of different tilt angles, including vertical panels, roof-mounted panels with varying tilt angles, and inclined panels on a carousel, revealed that tilt angles closer to 45 to 47 degrees contribute to improved solar PV performance. Inclined panels exhibited peak outputs during the summer months, while vertically mounted panels performed better during spring. The optimal tilt angle was determined to be 45–47 degrees, enabling effective energy generation throughout the year. The study also emphasized the significance of south-facing panel orientation, which consistently yielded higher energy production compared to other orientations. Furthermore, the thesis suggests future research directions, including the incorporation of complex weather variables, analysis of regional variation and temperature patterns, and the integration of advanced technologies into solar PV system simulations. Overall, this research contributes valuable insights for the design, installation, and optimization of solar PV systems in high north conditions, promoting the adoption of efficient and sustainable solar energy solutions

SYMMETRY AND DOPANT DIFFUSION IN INVERTED NANOPYRAMID ARRAYS FOR THIN CRYSTALLINE SILICON SOLAR CELLS

In this dissertation, we enhance the efficiency of thin flexible monocrystalline silicon solar cells by breaking symmetry in light trapping nanostructures and improving homogeneity in dopant concentration profile. These thin cells are potentially less expensive than conventional thick silicon cells by using less silicon material and making the cells more convenient to be handled when supported on polymer films. Moreover, these cells are widely applicable due to their flexibility and lightweight. However, for high efficiencies, these cells require effective light trapping and charge collection. We achieve these in cells based on 14-mm-thick free-standing silicon films with light-trapping arrays of nanopyramidal dips fabricated by wet etching. We break the symmetry of nanopyramids by etch mask design and its rotation with respect to a crystallographic direction in silicon substrate. This approach eliminates the need for using expensive off-cut silicon wafers. We also make use of low-cost, manufacturable, wet etching steps to fabricate the nanopyramidal dips. In our experiment, the new symmetry-breaking approach enhances the cell efficiency by 1.1%. In light-trapping nanostructures, the texture size is comparable to or smaller than the characteristic diffusion length of a dopant. In this size regime, strong inhomogeneity in the dopant concentration often develops in the pn-junction of the cells. The strong inhomogeneity creates electrically inactive regions in the texture. We improve the homogeneity by diffusing a dopant through selective surface regions exposed by wet etch masks. Our experiments demonstrate that this dopant diffusion method enhances the cell efficiency by 0.8%. This method would be generally applicable for other micro/nano structures, semiconductor materials, and optoelectronic devices

Nanostructured Materials for Solar Cell Applications

The use of nanomaterials in technologies for photovoltaic applications continues to represent an important area of research. There are numerous mechanisms by which the incorporation of nanomaterials can improve device performance. We invited authors to contribute articles covering the most recent progress and new developments in the design and utilization of nanomaterials for highly efficient, novel devices relevant to solar cell applications. This book covers a broad range of subjects, from nanomaterials synthesis to the design and characterization of photovoltaic devices and technologies with nanomaterial integration

Solar Module Packaging

While global demand for photovoltaic (PV) modules has increased approximately 45 percent per year over the past decade, PV modules must be durable and inexpensive to compete with traditional energy resources. Often overlooked as a means to improve solar technology, polymer packaging is not only the key to protecting fragile solar cells from environmental factors, but is also the critical path for increasing the power performance of a PV module Solar Module Packaging: Polymeric Requirements and Selection explores current and future opportunities in PV polymeric packaging, emphasizing how it can simultaneously reduce cost, increase weatherability, and improve a PV module’s power. The book offers an insider’s perspective on the manufacturing processes and needs of the solar industry and reveals opportunities for future material development and processing. A broad survey of the polymeric packaging of solar cells, the text covers various classifications of polymers, their material properties, and optimal processing conditions. Taking a practical approach to material selection, it emphasizes industrial requirements for material development, such as cost reduction, increased material durability, improved module performance, and ease of processing. Addressing cost and profitability, the author examines the economics behind polymeric packaging and how it influences the selection process used by solar companies. Suitable for nonspecialists in polymer science, the book provides a basic understanding of polymeric concepts, fundamental properties, and processing techniques commonly used in solar module packaging. It presents guidelines for using polymers in commercial PV modules as well as the tests required to establish confidence in the selection process

Materiais para energia: oportunidades em transferência de tecnologia

Mestrado em Engenharia QuímicaEnergy is a current topic and although due to different motivations (rising fuel costs, environmental issues or supply security) the main goals are common, consume less energy and find alternatives to fossil fuel based technologies. Nowadays, significant efforts towards the implementation of sustainable energy technologies, by delineating strategies and priorities, as well as through developing supporting mechanisms and building scenarios. In Europe this efforts are being taken in order to meet the ambitious and binding energy and climate change objectives for 2020. In the form of electricity, heat, light, mechanical, biological or chemical, energy will become an always more expensive commodity, and therefore there is a great need to manage this resource effectively. New products made from new advanced materials can have a large impact on the energy field. It is intended with this dissertation to better understand the energy problem nowadays, to explore applicability of materials science towards sustainable energy technologies with potential to commercial deployment and to understand in each way the positioning of the University of Aveiro associate laboratory CICECO – Centre for Research in Ceramics and Composites Materials, the largest Portuguese institute in the field of materials science and engineering, is fulfilling these assumptions. Therefore, this analysis aims at gathering information in order to create a tool for strategic decision making.A energia é uma temática atual e, apesar das diferentes motivações (o aumento do consumo de combustíveis, as questões ambientais ou de segurança de abastecimento), os principais objetivos são comuns, reduzir o consumo de energia e encontrar formas de energia alternativas aos combustíveis fósseis. Actualmente estão a ser desenvolvidos esforços significativos no sentido da implementação de tecnologias de energia sustentável, delineando para tal estratégias e prioridades, assim como desenvolvendo mecanismos de financiamento e projecção de cenários. Na Europa, estes esforços estão a ser desenvolvidos no sentido de cumprir com os objectivos ambiciosos estabelecidos para 2020, no que respeita a energia e às alterações climáticas. Sob a forma de electricidade, calor, luz, mecânica, biológica ou química, a energia vai se tornar uma comodidade cada vez mais cara e, neste sentido, há uma grande necessidade de gerir este recurso de forma eficaz. Novos produtos resultantes do desenvolvimento de novos materiais avançados poderão ter um impacto significativo na área da energia. Pretende-se com esta dissertação analisar a atual problemática energética, explorar a aplicabilidade da ciência dos materiais em tecnologias energéticas sustentáveis com potencial de comercialização e perceber de que forma o posicionamento do Laboratório Associado da Universidade de Aveiro, CICECO - Centro de Investigação em Materiais Cerâmicos e Compósitos, o maior instituto Português em matéria de engenharia e ciência dos materiais, vai ao encontro desses pressupostos. Deste modo, a presente análise pretende reunir informação de forma a criar uma ferramenta de apoio à decisão em termos de desenvolvimento estratégico

Developing a new generation of neuro-prosthetic interfaces: structure-function correlates of viable retina-CNT biohybrids

PhD ThesisOne of the many challenges in the development of neural prosthetic devices is the choice of electrode material. Electrodes must be biocompatible, and at the same time, they must be able to sustain repetitive current injections in a highly corrosive physiological environment. We investigated the suitability of carbon nanotube (CNT) electrodes for retinal prosthetics by studying prolonged exposure to retinal tissue and repetitive electrical stimulation of retinal ganglion cells (RGCs). Experiments were performed on retinal wholemounts isolated from the Cone rod homeobox (CRX) knockout mouse, a model of Leber congenital amaurosis. Retinas were interfaced at the vitreo-retinal juncture with CNT assemblies and maintained in physiological conditions for up to three days to investigate any anatomical (immunohistochemistry and electron microscopy) and electrophysiological changes (multielectrode array stimulation and recordings; electrodes were made of CNTs or commercial titanium nitride). Anatomical characterisation of the inner retina, including RGCs, astrocytes and Müller cells as well as cellular matrix and inner retinal vasculature, provide strong evidence of a gradual remodelling of the retina to incorporate CNT assemblies, with very little indication of an immune response. Prolonged electrophysiological recordings, performed over the course of three days, demonstrate a gradual increase in signal amplitudes, lowering of stimulation thresholds and an increase in cellular recruitment for RGCs interfaced with CNT electrodes, but not with titanium nitride electrodes. These results provide for the first time electrophysiological, ultrastructural and cellular evidence of the time-dependent formation of strong and viable bio-hybrids between the RGC layer and CNT arrays in intact retinas. We conclude that CNTs are a promising material for inclusion in retinal prosthetic devices

Indirect ties in knowledge networks:a social network analysis with ordered weighted averaging operators

This PhD thesis analyses networks of knowledge flows, focusing on the role of indirect ties in the knowledge transfer, knowledge accumulation and knowledge creation process. It extends and improves existing methods for mapping networks of knowledge flows in two different applications and contributes to two stream of research. To support the underlying idea of this thesis, which is finding an alternative method to rank indirect network ties to shed a new light on the dynamics of knowledge transfer, we apply Ordered Weighted Averaging (OWA) to two different network contexts. Knowledge flows in patent citation networks and a company supply chain network are analysed using Social Network Analysis (SNA) and the OWA operator. The OWA is used here for the first time (i) to rank indirect citations in patent networks, providing new insight into their role in transferring knowledge among network nodes; and to analyse a long chain of patent generations along 13 years; (ii) to rank indirect relations in a company supply chain network, to shed light on the role of indirectly connected individuals involved in the knowledge transfer and creation processes and to contribute to the literature on knowledge management in a supply chain. In doing so, indirect ties are measured and their role as means of knowledge transfer is shown. Thus, this thesis represents a first attempt to bridge the OWA and SNA fields and to show that the two methods can be used together to enrich the understanding of the role of indirectly connected nodes in a network. More specifically, the OWA scores enrich our understanding of knowledge evolution over time within complex networks. Future research can show the usefulness of OWA operator in different complex networks, such as the on-line social networks that consists of thousand of nodes