Predicting structure and property relations in polymeric photovoltaic devices

Plastic solar cells are attractive candidates for providing cheap, clean, and renewable energy. However, such devices are critically dependent on the internal structure, or morphology, of the polymer constituents. We have developed a model that enables us to predict photovoltaic behavior for arbitrary morphologies, which we also generate from numerical simulations. We illustrate the model by showing how diblock copolymer morphologies can be manipulated to optimize the photovoltaic effect in plastic solar cells. In this manner, we can correlate photovoltaic properties with device structure and hence guide experiments to optimize polymer morphologies to meet photovoltaic needs

Actin dynamics and the elasticity of cytoskeletal networks

The structural integrity of a cell depends on its cytoskeleton, which includes an actin network. This network is transient and depends upon the continual polymerization and depolymerization of actin. The degradation of an actin network, and a corresponding reduction in cell stiffness, can indicate the presence of disease. Numerical simulations will be invaluable for understanding the physics of these systems and the correlation between actin dynamics and elasticity. Here we develop a model that is capable of generating actin network structures. In particular, we develop a model of actin dynamics which considers the polymerization, depolymerization, nucleation, severing, and capping of actin filaments. The structures obtained are then fed directly into a mechanical model. This allows us to qualitatively assess the effects of changing various parameters associated with actin dynamics on the elasticity of the material

The status of continuous improvement in ICiPS members in 2015

This report was commissioned following discussions in 2014, between the authors of this report and staff members from ICiPS about the paucity of relevant research about the current status of continuous (CI) in the UK. The purpose of this report is therefore, to examine the status of CI in ICiPS members in 2015, with a view to helping ICiPS serve the needs of its members, and also to provide an agenda for research organisations such as the Centre for Service Management (CSM) at Loughborough University. This report covers seven case studies and draws out common themes. In this report, CI is understood to mean: ‘where all members of the organisation work together on an ongoing basis improving processes and reducing errors to improve overall performance for the customer’ (Fryer, Antony, and Douglas, 2007, p. 498). This report is required, because although CI has been on the agenda for many years for Public Services Organisations there has not been a review as to how this has progressed recently

Kondo physics in a dissipative environment

We report nonperturbative results for the interacting quantum-critical behavior in a Bose-Fermi Kondo model describing a spin-1/2 coupled both to a fermionic band with a pseudogap density of states and to a dissipative bosonic bath. The model serves as a paradigm for studying the interplay between Kondo physics and low-energy dissipative modes in strongly correlated systems.Comment: 2 pages, 2 figures. Proceedings of The International Conference on Strongly Correlated Electron Systems (SCES'07), accepted for publication in Physica

The use of RGB Imaging and FTIR Sensors for mineral mapping in the Reiche Zeche underground test mine, Freiberg

The application of sensor technologies for raw material characterization is rapidly growing, and innovative advancement of the technologies is observed. Sensors are being used as laboratory and in-situ techniques for characterization and definition of raw material properties. However, application of sensor technologies for underground mining resource extraction is very limited and highly dependent on the geological and operational environment. In this study the potential of RGB imaging and FTIR spectroscopy for the characterization of polymetallic sulphide minerals in a test case of Freiberg mine was investigated. A defined imaging procedure was used to acquire RGB images. The images were georeferenced, mosaicked and a mineral map was produced using a supervised image classification technique. Five mineral types have been identified and the overall classification accuracy shows the potential of the technique for the delineation of sulphide ores in an underground mine. FTIR data in combination with chemometric techniques were evaluated for discrimination of the test case materials. Experimental design was implemented in order to identify optimal pre-processing strategies. Using the processed data, PLS-DA classification models were developed to assess the capability of the model to discriminate the three material types. The acquired calibration and prediction statistics show the approach is efficient and provides acceptable classification success. In addition, important variables (wavelength location) responsible for the discrimination of the three materials type were identified

Allocating Public Spending Efficiently: Is There a Need for a Better Mechanism to Inform Decisions in the UK and Elsewhere?

In the UK few if any regular processes explicitly address comparisons of value for money between spending in different government departments, despite the existence of mechanisms that could in principle achieve that. This leaves a very important gap in evidence and means that decisions about public spending allocations are likely to miss opportunities to improve social welfare from existing budgets. Greater attention to the development of methods and evidence to better inform the allocation of public sector spending between departments is therefore urgently needed. We identify a number of possible approaches to this—some of which are being used in different countries—and highlight their strengths and weaknesses. We propose a new, pragmatic approach that incorporates a generic descriptive system to measure the disparate outcomes produced by public sector activities in a commensurate manner. Discrete-choice experiments could be used to generate evidence of the relative importance placed on different aspects of public sector outcomes by members of the general public. The proposed approach would produce evidence on value for money across departments, and the generation of evidence on public preferences to support that

Real-Time Mining Control Cockpit: a framework for interactive 3D visualization and optimized decision making support

Real-Time Mining is a research and development project within the European Union\'s Horizon 2020 initiative and consists of a consortium of thirteen European partners from five countries. The overall aim of Real-Time-Mining is to develop a real-time framework to decrease environmental impact and increase resource efficiency in the European raw material extraction industry. The key concept of the research conducted is to promote a paradigm shift from discontinuous to a continuous process monitoring and quality management system in highly selective mining operations. The Real-Time Mining Control Cockpit is a framework for the visualization of online data acquired during the extraction at the mining face as well as during material handling and processing. The modules include the visualization of the deposit-model, 3D extraction planning, integrated data of the positioning-system as well as the visualization of sensor and machine performance data. Different tools will be developed for supporting operation control and optimized decision making based on real-time data from the centralized database. This will also integrate results from the updated resource model and optimized mine plan. The developed Real-Time Mining cockpit software will finally be integrated into a wider central control and monitoring station of the whole mine

Modeling photo-generated charge extraction in bulk heterojunction nanoparticles

We present a drift-diffusion model for predicting currents generated through the absorption of solar energy inside bulk heterojunction organic nanoparticles, which are, for example, promising nanomaterials for photo-catalytic water splitting. By coupling a model of the internal microstructure of the nanoparticle with the electronic properties, we show how different characteristics of the microstructure influence the efficiency of the conversion of solar energy into electrical energy. Our model provides a foundation for using computational modeling to optimize the design of photocatalytic nanoparticles

Ground State Properties of Anderson Impurity in a Gapless Host

Using the Bethe ansatz method, we study the ground state properties of a $U\to\infty$ Anderson impurity in a ``gapless'' host, where a density of band states vanishes at the Fermi level $\epsilon_F$ as $|\epsilon-\epsilon_F|$. As in metals, the impurity spin is proven to be screened at arbitrary parameters of the system. However, the impurity occupancy as a function of the bare impurity energy is shown to acquire novel qualitative features which demonstrate a nonuniversal behavior of the system. The latter explains why the Kondo screening is absent (or exists only at quite a large electron-impurity coupling) in earlier studies based on scaling arguments.Comment: 5 pages, no figure, RevTe