Virtual Design and Optimization of Metallic Glass Alloys

Engineering: 2nd Place (The Ohio State University Denman Undergraduate Research Forum)Optimizing a material for a specific application usually requires extensive experimental testing in order to find the best composition. The goal of this work is to greatly reduce the amount of experimentation by introducing a means of testing and selecting materials using only first-principles computational methods. For this work, we have aimed to design a metallic glass with low density, low elastic modulus, and high fracture toughness using molecular dynamics. Metallic glasses are non-equilibrium metallic alloys that lack the long range order characteristic of conventional metals. They are well-suited for testing this design technique because they currently lack methods for tuning properties and have no micron or larger-scale microstructure. This lack of large-scale features allows them to be effectively modeled using atomistic simulation techniques, which are required in order to directly study the influence of changing alloy composition. To manage the design process, we have developed a software system capable of handling the composition optimization automatically. With this tool and the use of high-performance computing, we have been able to identify an alloy composition with an optimal balance of the desired properties. This result was then combined with methods to predict glass-forming ability from atomistic modeling. With these to newly-developed techniques, it was possible to identify both the ideal composition and the closest glass-forming alloy completely from simulation, which will now be fabricated and tested.AFOSR Grant No. FA9550-09-1-0251Ohio Supercomputing CenterAcademic Major: Materials Science and Engineerin

A novel DSM philosophy for building integrated renewable systems

This paper presents an overview of a novel concept in IT network design and power control focused on matching building integrated renewable power generation with local demands. It describes how this is achieved through combination of energy demand reduction and dynamic utilisation of embedded energy storage in a robust, efficient and cost effective manner. A brief overview of the main features of the design is given in terms of its intended benefits as an integrated system. The load components and distribution topology are described for this experimental system within the limits set by the capacity, capabilities and desired function of the network. Power supply to the network is described as including a back-up source to the photovoltaic (PV) source to add functionality and stability with no requirements for undesirable exporting of excess PV generation. The necessary configuration of the renewable array integrating with the network is also highlighted with an example compatible solar module device. A trial of the technology and demand management control in a high profile office building is described. This trial in a live working environment is providing invaluable real world data to compare against modelling and network simulation results

Minimization of Surface Impurities in Anodized Aluminum

Anodized aluminum is commonly used to create wear-resistant parts for process tools used in the semiconductor industry. Sinc microchips require high purity manufacturing environments[1], surface impurities on tooling needs to be minimized. It has been determined that anodized aluminum parts are one source of contamination. This project investigates the source of trace elements in anodized aluminum 6061 parts and ways to reduce them

Urban growth machine

Urban growth machine is an influential thesis of urban politics that suggests the objective of growth unites otherwise pluralistic interests in relation to a city. The thesis is situated within a broader theory about the commodification of place, where place is understood to be socially and economically valued land. Its key premise is that coalitions of actors and organizations (i.e. growth machines), all sharing an interest in local growth and its effects on land values, compete with growth machines elsewhere for scarce mobile capital investment, while simultaneously attempting to gain the tacit support of local publics for such urban growth. Following an introductory overview, this entry discusses the urban growth machine in two main parts. The first part sets out the key concepts underlying the growth machine thesis: use value, exchange value and place; place entrepreneurs; growth machines and their allies; competing for mobile capital; and promoting growth as a public good. The second part identifies core issues and debates in relation to the thesis (particularly those made by human geographers), including critiques of: the property focus; the human agency focus; difficulties with international comparison; the conceptualization of local dependency and scale; and the relationship of political projects with local feeling

Accounts of gender diverse university students who abstain from alcohol use

Gender diverse and transgender people report elevated alcohol use compared with the general population yet no studies have examined motives to abstain or limit alcohol consumption within this vulnerable population. A thematic analysis of interviews with seven gender diverse people identified two overarching themes: Awareness of the safety implications of alcohol and Access to non-drinking spaces. Participants acknowledged that drinking alcohol was a social norm yet were hesitant to drink, especially in public places, due to safety concerns and highlighted a need for non-drinking, LGBTI-friendly spaces. These findings have implications for promoting non-drinking strategies of benefit to gender diverse communities

Determination of Glass-Forming Ability in Metallic Glasses using Atomistic Modeling

Denman Undergraduate Research Forum: Second Place in EngineeringMetallic glasses are a relatively new class of engineered material with many unique properties including high yield strength and easy formability. However, they are currently limited by the fact that only limited compositions are known to form metallic glasses, which often contain expensive components. In this work, a computational tool to assess the glass-forming ability of an alloy was developed to help overcome that issue. Through calculating the viscosity of the liquid state and the fraction of icosahedra, we are able to classify alloys by the relative amount of diffusion and driving force for crystallization in the liquid state. The first test of this system on the copper-zirconium binary system identified Cu-35.7at%Zr and Cu-54at%Zr as the best glass-forming alloys, which is consistent with experimental findings. This tool was designed in such a way to be applicable to many different alloy systems and to be simple enough to enable automated testing of many possible compositions.AFOSR Grant FA9550-09-1-0251The Ohio Supercomputing CenterUndergraduate Research OfficeNo embarg

DNA barcoding unveils skate (Chondrichthyes: Rajidae) species diversity in ‘ray’ products sold across Ireland and the UK

Skates are widely consumed across the globe, but many large species are subject to considerable concern regarding their conservation and management. Within Europe such issues have recently driven policy changes so that, for the first time, reports of skate landings now have to be made under species-specific names. Total allowable catches have also been established for many groups, which have been set to zero for a number of the most vulnerable species (e.g., Dipturus batis, Raja undulata and Rostoraja alba. Whilst accurate species identification has become an important issue for landings, the sale of skates is still usually made under a blanket term of “skate” or “ray”. The matter of identifying species of skate is further complicated by their morphologically conservative nature and the fact that they are commercially valued for their wings. Thus, before sale their bodies are usually discarded (i.e., “winged”) and often skinned, making morphological identification impossible. For the first time, DNA barcoding (of the mitochondrial COI gene) was applied to samples of skate wings from retail outlets across the British Isles, providing insight into which species are sold for consumption. A total of 98 wing samples were analysed, revealing that six species were sold; blonde ray (Raja brachyura), spotted ray (Raja montagui), thornback ray (Raja clavata), cuckoo ray (Leucoraja naevus) small-eyed ray (Raja microocellata) and shagreen ray (Leucoraja fullonica). Statistical testing demonstrated that there were significant differences in the species sold in the distinct retail groups which suggests complex drivers behind the patterns of sale in skates. The results also indicate that endangered species are not commonly being passed on to consumers. In addition, the practice of selling skate wings under ambiguous labels is highlighted as it makes it extremely difficult for consumers to exercise a right to avoid species of conservation concern. Interestingly, a single retailer chain labelled their wings as originating from three smaller-growing species (generally to be considered of lower conservation concern); of the six samples analysed from this company a third were mislabelled and originated from the thornback ray (a larger species that is currently undergoing population declines)