Biomimetic materials and design

El campo interdisciplinario de la biomimética ha sido objeto de creciente atención en los últimos años. La comunidad científica e industrial entiende que el daño que hemos estado haciendo a la naturaleza puede ser resuelto por la naturaleza misma. El diseño biomimético también ha ido ganando impulso gracias a las nuevas investigaciones y tecnologías. La biomimética no se limita a la forma y la estética solamente, sino que también hace uso de una comprensión más profunda de los aspectos funcionales, procesos y sistemas encontrados en la naturaleza. Este artículo desarrolla cinco enfoques biomimé- ticos: imitación, inspiración, funcionalidad, basado en procesos y basado en ecosistemas. Los estudios de casos cortos explican cómo la investigación biomimética puede ayudar a resolver diferentes problemas en el diseño.The interdisciplinary field of biomimetics has been enjoying increasing attention in recent years. The scientific and industrial community understands that the harm we have been doing to nature can actually be solved by nature herself. Biomimetic design has also been gaining impetus thanks to new research and technologies. Biomimetics is not limited to form and aesthetics only but also makes use of a deeper understanding of functional aspects, processes and systems found in nature. This paper elaborates on five biomimetic approaches: imitation, inspiration, functional, process-based, and ecosystem-based. Short case studies explain how biomimetic research can help solve different problems in design.O campo interdisciplinar de biomimética tem recebido atenção crescente nos últimos anos. A comunidade científica e industrial entende que os danos que temos feito à natureza podem ser resolvidos pela própria natureza. O design biomimético também vem ganhando força graças a novas pesquisas e tecnologias. Biomimética não está limitado a apenas a forma e estética, mas também faz uso de uma compreensão mais profunda dos aspectos funcionais, processos e sistemas encontrados na natureza. Este artigo tem cinco abordagens biomiméticos: imitação, inspiração, funcionalidade, com base em processos e com base nos ecossistemas. Os estudos de caso explicam como a pesquisa biomimética pode ajudar a resolver problemas diferentes em design

İstanbul Kent Ormanında Arazi Kullanım Yoğunluğuna Bağlı Toprak Özelliklerinin Değişimi

Bu çalışmada rekreasyon alanlarında orman toprağının farklı kullanım koşullarına bağlı fiziksel ve kimyasal özelliklerindeki değişim araştırılmıştır. Bu kapsamda İstanbul Hekimbaşı Kent Ormanı içerisinde bulunan farklı kullanım şekillerinin olduğu alanlardan iki farklı toprak derinliğinde toprak örneklemesi ve toprak yüzeyinden ölü örtü örneklemesi yapılmıştır. Sahadaki yoğun kullanıma bağlı olarak toprak hacim ağırlığı, iskelet miktarı, toprak reaksiyonu (pH) ve kum oranının arttığı, topraktaki inorganik karbon (IOC), organik karbon (OC), organik madde (OM), azot (N) oranları ve hektardaki toplam miktarları ile birlikte katyon değişim kapasitesinin (KDK) ve ölü örtü miktarının azaldığı tespit edilmiştir. Sonuç olarak insan kullanımının daha yoğun olduğu alanlarda toprağın verimliliği ve sürdürülebilirliği üzerinde olumsuz etkilere neden olduğu belirlenmiştir. Bu etkilerin en aza indirilmesi için alanın taşıma kapasitesinin toprak özelliklerine en az düzeyde zarar verecek şekilde planlanması gerekmektedir. İnsanların tam alan yerine sahadaki belirli noktaları kullanması, yürüyüş yolları dışındaki alanlara insan girişlerinin azaltılması en başta alınacak önlemler olarak düşünülmektedir

Engineering ceramics

This is a comprehensive book applying especially to junior and senior engineering students pursuing Materials Science/ Engineering, Ceramic Engineering and Mechanical Engineering degrees. It is also a reference book for other disciplines such as Chemical Engineering, Biomedical Engineering, Nuclear Engineering and Environmental Engineering. Important properties of most engineering ceramics are given in detailed tables. Many current and possible applications of engineering ceramics are described, which can be used as a guide for materials selection and for potential future research. While covering all relevant information regarding raw materials, processing properties, characterization and applications of engineering ceramics, the book also summarizes most recent innovations and developments in this field as a result of extensive literature search

Reactive Joining of Alumina by Oxidation of Al Interlayers

Al2O3 bars were butt-joined by brazing with thin Al interlayers. After brazing, an attempt was made to oxidize the Al interlayers to convert the metal to a crystalline ceramic. While pure Al interlayers did not oxidize significantly even under severe conditions (pure O2, 1600°C for 4 hours), addition of MgO in the joint or alloying the interlayers with Si and Fe dramatically increased the oxidation of the interlayer according to SEM analysis. Heat treatment under pure O2 resulted in more complete oxidation compared to similar treatments in air. The highest strength as measured with four-point bending of Al-brazed and oxidized joints was 112 MPa. The advantages offered by this approach include its relative simplicity and its ability to form a fully ceramic joined assembly

Effect of Long-term Heating and Thermal Cycling on Thermal Expansion, Phase Distribution and Microhardness of Lithium Aluminosilicate Glass-ceramics

Lithium aluminosilicate glass-ceramics prepared by two different devitrification procedures were subjected to thermal cycling and heat treatment at 700 and 800 °C for up to 16 days in air. Changes in microstructure, phase distribution, microhardness, and thermal expansion behavior were monitored. Glass-ceramics prepared with a 950 °C nucleation step were observed to have various advantages over those prepared with a 1000 °C nucleation treatment. These advantages include finer microstructure, higher microhardness, and an almost linear thermal expansion behavior in the as-devitrified state. Additionally, no significant changes in physical properties were detected in the 950 °C-devitrified samples, while 1000 °C-devitrified glass-ceramics were found to be thermally unstable, causing important property changes, jeopardizing their reliability

Kinetic Materials Experience

Shape memory alloys and polymers respond to changes in temperature, light or other environmental stimuli by changing their shape. This paper shows new kinetic experiences with objects and surfaces that apply memory shape materials, describing some case histories based on design experimentations that open up new frontiers in design. This article investigates how the shape memory effect can add useful features to everyday objects, create unusual user experiences, and how this new potential has been tapped by designers so far. The authors present considerations on design methods, describing the convergence of product design, interaction design and experience design in the new scenario of smart materials. They discuss models from literature to understand and describe the emotional aspects of interaction design with shape-changing materials. Such models could be useful reference points for designers of interactive products that offer kinetic experiences

Materials that Change ColorSmart Materials, Intelligent Design /

VII, 139 p. 86 illus.online resource

Effect of the geometry on the structural performance of high-density polyethylene small craft joints

In today's marine industry, high-density polyethylene (HDPE) material has gained popularity due to its recyclability that relieves the concerns for sustainability of the products and its lightweight, resistance to environmental effects, such as moisture, corrosion, organisms, UV, etc. its sufficient mechanical properties. HDPE material may be combined with other light materials for structural optimisation. In this work, the performances of three joints - one T-joint and two L-joints - designed by the authors and representing the assembly of HDPE hull and Glass Reinforced Polyester (GRP) composite sandwich superstructure were studied experimentally and numerically. Adhesively bonded, bolted and welded joints were subjected to tensile load. Due to the maximum strain and the failure loads, Type A shows promising performance followed by Type C and B. Type C is more cost-effective while providing a moderate strength followed by Type B and A. Results also affirm the utility of the 2D-FE models for the strain distribution in such joints