4,238 research outputs found
Development of a Versatile, Stable Dropletâreactor for High Temperature Nanocrystal Synthesis
Colloidal nanocrystals exhibit interesting and useful size-dependent nanoscale phenomena (e.g.
tunable fluorescence in quantum dots and optical absorptions in gold and silver nanoparticles), large
surface areas and can be used for a variety of high-tech applications. Care must be taken to produce
nanocrystals with well defined size, shape and composition, however, as these parameters directly
affect the properties of the colloidal ensemble. Microreactors offer superior control over reaction
conditions relative to traditional bulk batch methods and as such offer an attractive route to
nanoparticle production. Hence there have been over a hundred papers reporting microfluidic
synthesis of nanocrystalline colloids since the first reports in 2002. The work described in this thesis
focussed on extending and improving the microfluidic method.
Continuous-flow reactors were used initially, however, deposition was found to be a pervading
problem with its severity varying with the material being synthesised. To address this problem a new
capillary-based droplet-flow reactor was developed in which droplets are generated by the direct
injection of confluent reagent streams within a stream of immiscible carrier fluid and, subsequently,
can be heated and optically characterised further downstream.
The reactor produced stable, controllable droplet flow over a wide range of flow rates, with droplet
volumes down to 30 nL, and proved to be highly effective: CdSe quantum dots were synthesised via a
high-temperature pyrolytic synthesis with strong control over particle size and size distribution.
Crucially, unlike previously reported high temperature droplet reactors, the reactor could be operated
indefinitely, without any degradation of the device and minimal variation in the product seen during
24 hours continuous production. To emphasise the versatility and applicability of the droplet reactor,
Ag, TiO2 and InP nanocrystals were synthesised (using both organic and aqueous syntheses) and an
automatic optimisation routine to reduce size distribution was applied to CdSe quantum dot
synthesis
The ethical infrastructure of legal practice in larger law firms: values, policy and behaviour
The article examines the impact of the cultures and organisational structures of large law firms on individual lawyers' ethics. The paper suggests that large law firms in Australia should consciously design and implement 'ethical infrastructures' to both counteract pressures for misbehaviour and positively promote ethical behaviour and discussion. The paper goes on to explain what implementing ethical infrastructures in law firms could and should mean by reference to what Australian law firms are already doing and US innovations in this area. Finally, the paper warns that the 'ethical infrastructure' of a firm should not be seen merely as the formal ethics policies explicitly enunciated by management. Formal and legalistic ethical infrastructures that fail to support or encourage the development of individual lawyers' awareness oftheir own ethical values and ethical judgment in practice will be useless
Webly Supervised Semantic Embeddings for Large Scale Zero-Shot Learning
Zero-shot learning (ZSL) makes object recognition in images possible in
absence of visual training data for a part of the classes from a dataset. When
the number of classes is large, classes are usually represented by semantic
class prototypes learned automatically from unannotated text collections. This
typically leads to much lower performances than with manually designed semantic
prototypes such as attributes. While most ZSL works focus on the visual aspect
and reuse standard semantic prototypes learned from generic text collections,
we focus on the problem of semantic class prototype design for large scale ZSL.
More specifically, we investigate the use of noisy textual metadata associated
to photos as text collections, as we hypothesize they are likely to provide
more plausible semantic embeddings for visual classes if exploited
appropriately. We thus make use of a source-based voting strategy to improve
the robustness of semantic prototypes. Evaluation on the large scale ImageNet
dataset shows a significant improvement in ZSL performances over two strong
baselines, and over usual semantic embeddings used in previous works. We show
that this improvement is obtained for several embedding methods, leading to
state of the art results when one uses automatically created visual and text
features
The Politics of Integration: The Opportunities, Challenges and Successes of Embedding Academic Skills and Literacies Development into an Interdisciplinary, âIntegratedâ Foundation Year Programme
Foundation Years (FY) have proliferated within UK Higher Education in recent years, and their benefits and successes have been well documented (e.g. the enhancement of opportunities for underrepresented students, second-chance education, skills and confidence enhancement, and a pipeline into STEM. However, when managed centrally, their implementation can be a contentious site of interdisciplinary unease and âmutual suspicionâ and as much as a fruitful avenue for innovative collaboration. One of the key issues is the question of how to embed academic skills / literacies development within a meaningful, âintegratedâ, interdisciplinary context effectively whilst utilising expertise from both academic departments and learning development / skills teams, and thus navigating disparate disciplinary agendas, communities of practice and strategic priorities. This paper reports on how this complex terrain was navigated at Royal Holloway, University of London, to successfully embed academic skills (using Universal Design for Learning pedagogy) into an academically authentic, inclusive, interdisciplinary âGlobal Perspectives and Academic Practiceâ unit that facilitated student integration into academic departments. Whilst we report on how the programme led to higher than sector average attainment, retention and progression (the EE described it as a âTEF Gold offeringâ), we critically analyse the challenges of embedding and aligning such provision within the communities of practice of a research-intensive institution. Throughout, we suggest ways forward at both practical and strategic levels to ensure the immense potential of integrated academic literacies development within FYs can be realised
Junzi leadership in Singapore: governance and human capital development
Purpose â This paper provides insights as to how a Confucian-inspired Junzi style of leadership translates into initiatives toward human capital development in Singapore. After reviewing tripartite governance in Singapore, we discuss the character of Confucian leadership: how does this value system inform the moral economy of the Singaporean corporatist model and inherently come to impact upon the conception and significance of human capital.
Design/methodology/approach â The case approach was employed using multiple sources of secondary data, supplemented by interviews with high-profile informants in Singapore. Multiple sources led to data triangulation in presenting a mutually consistent set of evidence. The paper also draws from a longitudinal observation of Singaporeâs industrial relations and human resource development (HRD) policies over the last 10 years since the Global Financial Crisis.
Findings â Organized along two thematic areas: governance and human capital development, this paper proposes and finds that governance in Singapore displays an institutionalized form of Junzi leadership that translates into policymaking toward human capital development.
Originality/value â This paper brings about an Asian perspective of Junzi leadership toward management and governance. The Confucian value system intrinsic to tripartite governance provides an original heuristic lens that helps shed a light on the significance of human capital development in Singapore
Moduli spaces of framed perverse instantons on P^3
We study moduli spaces of framed perverse instantons on P^3. As an open
subset it contains the (set-theoretical) moduli space of framed instantons
studied by I. Frenkel and M. Jardim. We also construct a few counterexamples to
earlier conjectures and results concerning these moduli spaces.Comment: 50 page
A stochastic infection rate model for estimating and projecting national HIV prevalence rates
Measurements of the height of fracturing and height of depressurisation above a longwall panel
This paper presents the findings of a program of work to determine the height of mining induced fracturing and the height of groundwater depressurisation above a longwall panel. The program of work utilised two fully cored boreholes drilled from surface at Tahmoor Colliery, located southwest of Sydney in the Southern Coalfields in New South Wales. The boreholes were drilled adjacent to and over a subcritical longwall panel, one before and one after extraction of the longwall panel.
Field measurements of the geotechnical and hydrological ground conditions in the pre and post mining boreholes were compared. Three geomechanical zones were determined in the overburden above the extracted longwall panel which correlate with ground water and hydraulic conductivity measurements.
The results show that the determined height of caving and the start of a reduced pore pressure profile (from hydrostatic) coincide at the same height above the mining horizon. The reduction in pore pressure from hydrostatic to zero pore pressure is a gradual transition, meaning the height of depressurisation (zero pore pressure) and height of caving do not necessarily coincide.
This work program provides a comprehensive dataset of changes in pore pressure, conductivity and caving for the horizons within the overburden above a longwall panel at Tahmoor Colliery. The results from this program of work reinforce the results from a previous work program at Tahmoor Colliery detailing the height of caving and height of depressurisation.
The outcomes of this program are useful in providing an understanding for groundwater modelling above extracted longwall panels
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