Study of Ceramic Slurries for Investment Casting with Ice Patterns

Ice patterns generated by rapid freeze prototyping or a molding process can be used to make ceramic investment molds for metal castings. Due to the use of ice, the ceramic slurries must be poured around the pattern and cured at sub-freezing temperatures. Success of this process depends greatly on the mold strength after the gelation of the slurries. This paper describes the experimental results of the mold strength after the gelation of the slurries under different compositions. The parameters considered include mixing time, alumino-silicate vs. fused silica ratio, volume of binder, and volume of catalyst. The strength of the gelled slurries is examined by breaking test bars on a four-point bending apparatus. Weibull modulus for each trial is calculated based on the breaking strength from four-point bend tests. Analysis of variance for breaking strength and Weibull analysis is performed to evaluate the significance of the effect of each parameter. The casting of a bolt is used to demonstrate that metal castings of complex geometry can be fabricated using investment casting with ice patterns.Mechanical Engineerin

Rapid Freezing Prototyping with Water

Rapid Freezing Prototyping (RFP) with water is a novel solid freeform fabrication technique that can generate three-dimensional ice objects by depositing and rapidly freezing water layer by layer. The support where necessary is made of brine whose. freezing point is lower than. pure water. After building the part, the support can be removed by utilizing the melting temperature difference between brine and water. Preliminary experiments have shown that the ice patterns produced by this technique can be used for design visualization and silicone molding. This paper will present the concept and some experimental results of the RFP process as well as potential applications

China's absorptive State: research, innovation and the prospects for China-UK collaboration

China's innovation system is advancing so rapidly in multiple directions that the UK needs to develop a more ambitious and tailored strategy, able to maximise opportunities and minimise risks across the diversity of its innovation links to China. For the UK, the choice is not whether to engage more deeply with the Chinese system, but how. This report analyses the policies, prospects and dilemmas for Chinese research and innovation over the next decade. It is designed to inform a more strategic approach to supporting China-UK collaboration

Geometric Modeling of Cellular Materials for Additive Manufacturing in Biomedical Field: A Review

Advances in additive manufacturing technologies facilitate the fabrication of cellular materials that have tailored functional characteristics. The application of solid freeform fabrication techniques is especially exploited in designing scaffolds for tissue engineering. In this review, firstly, a classification of cellular materials from a geometric point of view is proposed; then, the main approaches on geometric modeling of cellular materials are discussed. Finally, an investigation on porous scaffolds fabricated by additive manufacturing technologies is pointed out. Perspectives in geometric modeling of scaffolds for tissue engineering are also proposed

A Bibliometric Analysis in Industry 4.0 and Advanced Manufacturing: What about the Sustainable Supply Chain?

During the last decade, different concepts, methodologies, and technologies have appeared, evolving industry toward what we know today as the fourth industrial evolution or Industry 4.0 (I4.0) and Advanced Manufacturing (AM). Based on both, Supply Chain (SC) is presented as the relevant process that sets the sustainability of manufacturing and, therefore, is defined as a key term in a sustainable approach to I4.0. However, there are no studies that analyze the evolution of science in the fields of I4.0 and AM together. In order to fill this gap, the aim of this research work is to analyze the tendencies of science research related to I4.0 and AM by conducting a bibliometric and network analysis and also to generate a new contribution through the analysis of scientific trends related to SC and Sustainable Supply Chain (SSC) within this scientific context, for the time span 2010–2019. The results show that the number of publications is growing exponentially and the most active countries are Germany and the U.S., with Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University being the most productive organization and Tecnologico de Monterrey the most collaborative. The analysis of the scientific terms allows us to conclude that the research field is in a growth phase, generating up to almost 4500 new terms in 2019

Study of Ceramic Slurries for Investment Casting with Ice Patterns

Ice patterns generated by rapid freeze prototyping or a molding process can be used to make ceramic investment molds for metal castings. Due to the use of ice, the ceramic slurries must be poured around the pattern and cured at sub-freezing temperatures. Success of this process depends greatly on the mold strength after the gelation of the slurries. This paper describes the experimental results of the mold strength after the gelation of the slurries under different compositions. The parameters considered include mixing time, alumino-silicate vs. fused silica ratio, volume of binder, and volume of catalyst. The strength of the gelled slurries is examined by breaking test bars on a four-point bending apparatus. Weibull modulus for each trial is calculated based on the breaking strength from four-point bend tests. Analysis of variance for breaking strength and Weibull analysis is performed to evaluate the significance of the effect of each parameter. The casting of a bolt is used to demonstrate that metal castings of complex geometry can be fabricated using investment casting with ice patterns

Starting up biology in China: performances of life at BGI

BGI (hua da ji ying; 华大基因; “China Great Gene”) counts among the world’s largest and wealthiest institutions for biomedical research. Located in Shenzhen, the new megacity in southern China, BGI is now a critical site for understanding the relationship between biomedicine and the economic development of China. This essay uses performance studies and the notion of shanzhai (“copycatting”) to understanding how this laboratory poses a challenge to traditional modes of understanding technoscience. This marks an attempt to understand BGI, its work, and its workers on their own terms, or at least on local terms. Just as shanzhai challenges our notions of originality, BGI’s hybridity challenges our notions of where and how scientific knowledge is produced. Performing not merely as a “laboratory,” but also, and at the same time, as a “factory,” and a “company,” BGI is an unfamiliar kind of hybrid scientific-industrial-commercial-governmental-philanthropic space that draws its repertoire from its very particular regional, national, and local-urban circumstances

Digital factory – virtual reality environments for industrial training and maintenance

This study evaluates the use of virtual reality (VR) platforms, which is an integrated part of the digital factory for an industrial training and maintenance system. The digital factory-based VR platform provides an intuitive and immersive human–computer interface, which can be an efficient tool for industrial training and maintenance services. The outcomes from this study suggested that use of the VR platform for training and maintenance of complex industrial tasks should be encouraged and use of the VR platform for that purpose should be further evaluated. This paper highlighted the generic concept of the application of virtual reality technique within the digital factory to industrial maintenance and to build a low-cost VR application for a training and maintenance system. An application case on virtual reality technique in a power plant operations and maintenance is demonstrated within the scope of this research. Overall research implications on virtual reality concept in industrial applications are concluded with future research directions.fi=vertaisarvioitu|en=peerReviewed

Optimising additive manufacturing for fine art sculpture and digital restoration of archaeological artefacts

Additive manufacturing (AM) has shown itself to be beneficial in many application areas, including product design and manufacture, medical models and prosthetics, architectural modelling and artistic endeavours. For some of these applications, coupling AM with reverse engineering (RE) enables the utilisation of data from existing 3D shapes. This thesis describes the application of AM and RE within sculpture manufacture, in order to optimise the process chains for sculpture reproduction and relic conservation and restoration. This area poses particular problems since the original artefacts can often be fragile and inaccessible, and the finishing required on the AM replicas is both complex and varied. Several case studies within both literature and practical projects are presented, which cover essential knowledge of producing large scale sculptures from an original models as well as a wide range of artefact shapes and downstream finishing techniques. The combination of digital technologies and traditional art requires interdisciplinary knowledge across engineering and fine art. Also, definitions and requirements (e.g. ‘accuracy’), can be applied as both engineering and artistic terms when specifications and trade-offs are being considered. The thesis discusses the feasibility for using these technologies across domains, and explores the potential for developing new market opportunities for AM. It presents and analyses a number of case study projects undertaken by the author with a view to developing cost and time models for various processes used. These models have then been used to develop a series of "process maps", which enable users of AM in this area to decide upon the optimum process route to follow, under various circumstances. The maps were validated and user feedback obtained through the execution of two further sculpture manufacturing projects. The thesis finishes with conclusions about the feasibility of the approach, its constraints, the pros and cons of adopting AM in this area and recommendations for future research

Will Beijing Achieve Global City Status? An Assessment to the Year 2030

abstract: Beijing, in its Twelfth Five-Year Plan for the National Economic and Social Development of Beijing (2011 – 2015), affirmed its intention to become a leading “World City with Chinese characteristics.” This research is based on an assessment of the proposed strategies contained within the 12th Five-Year plan that are grounded in the set of indicators (variables) closely associated with world city status. Indicator selection (e.g., percentage of foreign born population) is based on review of shared characteristics of world cities (e.g., Tokyo, New York, Singapore) constrained by availability of Beijing data; plus the significant academic literature on the topic from leading scholars such as Peter Hall. Using these indicators, Beijing’s baseline conditions and associated trends are established for assessment in a Status-Quo Scenario. Thereafter, interventions proposed by the Beijing Municipality to achieve world city status are evaluated. The results of this assessment will inform Beijing’s policy-makers regarding potential obstacles, pitfalls, or potential disruptions on the road to premier ‘World City’ status, and emphasize the need to undertake peremptory interventions and/or prepare contingency responses, as well as, inform stakeholders and decision-makers of critical and non-critical interventions recommended to achieve World City status by the year 2030.Dissertation/ThesisDoctoral Dissertation Urban and Environmental Planning 201