Experimental manufacture of a pneumatic cushion made of etfe foils and OPV cells

This paper presents the preliminary activity from which the fabrication of a new kind of ETFE foil fully integrated with a Smart, Organic, Flexible and Translucent Photovoltaic building component (named SOFT-PV) begins. A prototype of SOFT-PV cushion will be the object of optical, mechanical and thermal tests to preview all problematic aspects of the fabrication process and the environmental impact evaluation with LCA methodology

An overview of transparent and translucent 3D-printed façade prototypes and technologies

3D-printing has transformed traditional manufacturing by enabling the fabrication of individually designed complex systems. The building’s façade is one of the most challenging systems because it affects the control of the built indoor environment and allows to provide energy-saving. The objective of this research is to distinguish 3Dprinting technologies and applied materials in them that improve transparency in the façade to decrease artificial lighting consumption, to control solar energy, and to improve energy-savings. A literature study was performed, firstly, different 3Dprinting techniques and their materials for producing transparent outcomes were reviewed from academic databases. Then, transparent 3D-printed façade prototypes were identified. The outcomes indicated that most of the prototypes used the FDM 3D-printing technique and Polyethylene Terephthalate Glycol as a material. These prototypes didn’t consider the disadvantages of the FDM technique for the lighting transmission. Additionally, some prototypes have control over daylighting discomforts but some of them not. Prototypes tried to improve energy-saving which ranged from applying recyclable materials to controlling solar gain.publishedVersio

Hissin nappikonstruktion suunnittelu lisääville valmistusmenetelmille

Additive manufacturing, with its recent technological developments, has increasingly disrupted how products are designed and manufactured. Within additive manufacturing, there has been a shift from the production of visual models and rapid prototyping applications to direct digital manufacturing of end products. Additive manufacturing provides intriguing possibilities in the design of new and existing products. These radical, pioneering designs have already redefined whole industries. This thesis provides a practical case study for an additive manufacturing redesign together with a literature review of the current additive manufacturing technologies and applications. The target of the redesign was a low volume elevator button assembly. Concepts were prototyped and tested in contrast to the current industry specification. As a result of the thesis, a functional button assembly was produced and tested. The part count, material usage, and costs were reduced compared to the original. However, all industry requirements were not met. A need for a more systematic material and process selection was identified. Nevertheless, additive manufacturing was proven to be a serious alternative in the production of low volume plastic products and should be researched further.Lisäävien valmistusmenetelmien teknologinen kehitys vaikuttaa enenevissä määrin siihen, miten fyysisiä tuotteita valmistetaan. Visuaalisten- sekä pikamallien tulostuksesta ollaan siirtymässä lopputuotteiden suoraan valmistukseen. Geometristen rajoitusten vähyys luo kiinnostavia mahdollisuuksia uusien ja olemassa olevien tuotteiden suunnittelussa. Uudet radikaalit ja uraauurtavat tuotteet ovat jo määrittäneet uudelleen kokonaisia toimialoja. Tämän diplomityön käytännön osuudessa suunnittellaan hissin nappikonstruktio täysin uusiksi lisäävien valmistusmenetelmien näkökulmasta. Työ tarjoaa myös kirjallisen läpileikkauksen lisääviin valmistusteknologioihin sekä käyttökohteisiin. Käytännön työssä etsittiin lisäävien valmistusmenetelmien etuja hyödyntäviä konsepteja, prototypoitiin, sekä testattiin kehiteltyjä ratkaisuja suhteessa toimialan vaatimuksiin. Työn tuloksena valmistettiin ja testattiin toiminnallinen nappikonstruktio. Kokoonpanon osamäärää, materiaalinkäyttöä sekä hintaa saatiin vähennettyä suhteessa alkuperäiseen. Kaikkia vaatimuksia ei kuitenkaan saatu täytettyä. Prosessin aikana tunnistettiin tarve systemaattisemmalle materiaali- sekä valmistusprosessivalinnalle. Tästä huolimatta lisäävät valmistusmenetelmät todettiin vakavasti otettavaksi vaihtoehdoksi matalan volyymin muovituotteiden valmistuksessa

Innovative Dental Technologies and Restorative Materials in Prosthodontics: New Perspectives and Future Developments

Digital technology is advancing rapidly in dentistry. Computers are making what were previously manual tasks easier, faster, cheaper and more predictable. Layered manufacturing processes can produce complex shapes at affordable prices with little or no waste. The challenge for the dental materials research community is to mach the new technology with materials that are suitable for use in dentistry. This can potentially take dental materials research in a totally different direction. The new generation of ceramic materials presents interesting options, both in terms of material selection and in terms of fabrication techniques. A closer understanding of the dynamics of the materials with respect to design of the restoration and the intended use is required to enable these restorations to perform productively

Optical properties Of CAD-CAM lithium disilicate glass-ceramic in different firing temperatures and thicknesses

Indiana University-Purdue University Indianapolis (IUPUI), Indiana University School of DentistryBackground: With the emerging of digital dentistry, IPS e.max® CAD lithium disilicate (LD) glass-ceramic material has become one of the most popular esthetic restorative materials in digital assisted dental esthetic restoration. The mechanical and optical properties of this material have been investigated in several studies. However, there is a lack of information and consensus regarding the optical properties of IPS e.max® LD glass-ceramic materials. Objectives: 1) To investigate the optical properties as translucency parameters (TP), Contrast ratio (CR), light transmissions (Lt) and color changes (CC) between high-translucent (HT) and low-translucent (LT) IPS e.max® CAD LD glass-ceramic materials with different crystalline phases and thickness in different firing stages. 2) To investigate the optical properties as TP, CR, Lt and CC of each translucent (HT and LT) IPS e.max® CAD LD glass-ceramic materials with different crystalline phases and thickness in different firing stages. 3) To determine the mathematical relationships of thicknesses of IPS e.max® CAD LD glass-ceramics materials with TP and Lt. Materials and methods: The total of 120 of shade A2 IPS max CAD samples (HT and LT) were prepared into square shape (15.25 mm X 15.25 mm) and were divided into two main groups according to the material translucency (HT and LT) (n=60). Each main group was further divided into 5 sub-groups according to the thickness (1.00, 1.25, 1.5, 1.75, and 2.00 mm) (n=12). Each thickness group was assigned into three groups based on different crystallization (firing) temperatures (750, 820 °C in single stage heating schedule with 1 second and 10 second holding times, respectively, and 840 °C with two-stage heating schedule (RECOM) (820°C, 840 °C with 10 second and 7 min holding time, respectively) as recommended by manufacturer (n=4). CIEL*a*b*, TP, CR, and Lt were measured and calculated for all samples. Statistical analysis: The effects of the test results were evaluated using 3-way ANOVA with factors for Translucency (HT and LT), Firing Temperature (750, 850, and RECOM) and Thickness (1, 1.25, 1.5, 1.75, and 2), as well as all two-way and three-way interactions among the factors. Pair-wise comparisons were made using Least Significant Differences to control the overall significance level at 5%. Results: The mean irradiance and TP for both HT and LT decrease as the thickness of the samples increases from 1 to 2mm with significant difference between the thickness groups within each material translucency groups (HT and LT) and between both HT and LT. The coefficients of absorption (c) of the two materials were calculated. The effective incidence irradiance when material thickness approaches zero (Ie) was also calculated. There is an unexpected spectral peak shift as the thickness of the samples increases. There is no statistically significant difference in Ie at 750˚C and 820 ˚C between the HT and LT. However, there is a statistically significant higher Ie in HT at the recommended firing temperature as expected. Coefficients of translucency parameter (p) of the materials in various firing temperature were defined and the TP of the material as the thickness approaches zero were calculated (TP0). The TP of the materials is directly correlated to the mean irradiance passing through the samples. There is no statistically significant difference in the TP0 and Ie of the HT and LT groups at the recommended firing temperature. Conclusion: In this project we developed modified Beer-Lambert law to describe the parameters governing the effect of thickness on light transmission in dental ceramic material. We also applied the same equation to describe the translucency parameter. The parameters defined in these equations allow us to compare the optical property of dental ceramic material independent of the thickness of the samples

Inflatable pillow system as a glass substitute in terms of building envelope

Thesis (Master)--İzmir Institute of Technology, Architecture, İzmir, 2003Includes bibliographical references (leaves: 169-171)Text in English; Abstract: Turkish and Englishxiii, 174 leavesIn the line with the increasing energy demand, there have been many investigations related with the conservation of energy used in buildings. The systems and materials used in buildings have an important role in consumption of energy. Transparent materials and the systems occupies transparent materials contributes this consumption in positive and negative way due to their design and properties. Nevertheless, the transparent materials used in buildings as glazing have importance in order to increase comfort, decrease cost and environmental harm.This study aims to investigate a contemporary construction system; ETFE foil pillow system, which is also known as, Inflatable Pillow System made of ETFE Foil. In the scope of the study, pneumatic pillow system investigated in detail and its performance evaluated due to environmental control criteria, which can be compared with other conventional glass glazing products. The study also involves cost analysis and brief knowledge about contemporary cases that have been completely or partially constructed with this system. The increase in the amount of transparent surfaces in contemporary buildings, pointed out that the conventional glazing system are no more appropriate. Therefore, in specific cases, usage of conventional glass glazing systems results as a cost increase and loss of comfort. The alternatives of the conventional glazing systems don.t have appropriate performance or don.t meet the need of the consumer. Inflatable ETFE foil pillows have better optical properties than glass glazing systems. Generally, thermal properties of this system equal to the advanced double-glazing. Light and heat transmission values vary by changing the foil type and number of layer. Low sound reduction index can be an obstacle or a chance for designers that should be given attention in design phase. The pillow system that relatively provides fire and earthquake protection is also lightweight and flexible. Thus, includes many criteria that are expected in contemporary constructions. The inflatable pillow system made of ETFE foil can be considered as a safe construction method due to mechanical properties of the system and the membrane material that is used as pillows. System reduces operational and maintenance cost for the building. Considerable amount of expenses for lighting and heating can also be reduced by the usage of the pillow system. The lightweight nature of the pillow system affects the construction of the whole building, which also results as a cost reduction.Pillow system is commonly used for greenhouses and botanical gardens and also used for sports and leisure halls as well as institutions ands museums. Addition to its usage as a skylight or façade cover, pillow system can be used as a total envelope that covers the whole construction underneath.As a result, this study investigates ETFE foil pillows and their environmental control properties against conventional glass glazing systems. The results are evaluated in the line with the information gained. The advantages and disadvantages of the system as a glazing are given in detail. Although it.s not expected that ETFE pillow system totally be replaced with the conventional glass glazing system, it constitutes an alternative glazing system in specific cases.Keywords: pillow system, pneumatic membrane, glazing, ETFE foil, glass, fluoropolymer, environmental control criteria

Advanced Materials for Oral Application

This book consists of one editorial, 12 original research articles and two review papers from scientists across the world, with expertise in materials for dental application. The main subjects covered are: biomaterials and techniques for oral tissue engineering and regeneration; biomaterials for surgical reconstruction; CAD/CAM technologies and dedicated materials; novel restorative and endodontic materials and instruments

Transparent polycrystalline ceramics at visible and infrared wavelenghts

Tato práce se zabývá přípravou průhledných keramických plátů vyrobených ze sub-µm prášku oxidu hlinitého. Zhutnělá keramická tělesa jsou připraveny ultrafialovým (UV) vytvrzováním UV vytvrzovací pryskyřice obsahující keramický prášek s následným vypálením organické složky za zvýšené teploty. Vysoká relativní hustota takto vypálených těles je nezbytná ke snížení smršťování během následujícího slinovacího procesu. Proto jsou použity vysoce plněné disperse obsahující > 57 obj.% keramických částic. K dosažení transparentního chování, porozita uvnitř plátů musí být úplně odstraněna. Proto jako závěrečné operace je použito isostatického stlačování za zvýšené teploty. Nakonec jsou prezentovány měření světelné propustnosti a tvrdosti. Možnosti výroby mikrostruktur s vysokým rozlišením za použití bezmaskové litografie a návrhy na použití UV vytvrzovací metody pro produkci tvarově náročných 3D struktur jsou krátce zmíněny.his thesis deals with preparation of transparent ceramic sheets made out of sub-µm alumina powder. Green bodies are prepared by ultraviolet (UV) curing of UV curable resin containing ceramic powder followed by debinding of organic parts at elevated temperature. High relative density of green bodies is essential for reduction of shrinkage during subsequent sintering process. Therefore high solids loading dispersions containing > 57 vol% ceramic particles are used. To reach transparent behaviour, porosity within the sheets must be reduced completely. Therefore hot isostatic pressing (HIP) is used as a final operation. Finally, light transmission and hardness measurements are presented. Possibilities of making high resolution microstructures using maskless lithography and some suggestions for use of the UV curing technique for production of complex-shaped 3D structures are briefly mentioned.

THE IMPORTANCE OF ETHYLENE-TETRAFLUOROETHYLENE FOR BUILDING DAYLIGHTING

Nowadays, it is possible to implement and realize solutions that once seemed inconceivable. Namely, the development of novel technologies allows the implementation of creative ideas, as well as new approach to building design. The use of the state of the art technology offers the application of functional high-tech coatings and building claddings. Hence, a new generation of plastic - ethylene tetrafluoroethylene (ETFE) is increasingly used in buildings and architectural structures. The use of ETFE is increased due to its very low weight, high transparency potential and possibility to control the utilization of daylight in buildings, as well as due to self-sufficient performances and low environmental load. Therefore, it is necessary to overcome a lack of information on some advantages of this environmentally friendly material. In this paper, the properties and possibilities of applications of ETFE are presented. It increasingly replaces traditional glazing and enables the implementation of creative solutions due to its performance and possibility of advancing sustainable construction. This could contribute to sustainable development and to the prevention of the negative influence to climate change