Electrical excitation of surface plasmons

We exploit a plasmon mediated two-step momentum downconversion scheme to convert low-energy tunneling electrons into propagating photons. Surface plasmon polaritons (SPPs) propagating along an extended gold nanowire are excited on one end by low-energy electron tunneling and are then converted to free-propagating photons at the other end. The separation of excitation and outcoupling proofs that tunneling electrons excite gap plasmons that subsequently couple to propagating plasmons. Our work shows that electron tunneling provides a non-optical, voltage-controlled and low-energy pathway for launching SPPs in nanostructures, such as plasmonic waveguide

The Concepts of Reliability and Homogeneity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67956/2/10.1177_001316445001000103.pd

On the use of advanced material point methods for problems involving large rotational deformation

The Material Point Method (MPM) is a quasi Eulerian-Lagrangian approach to solve solid mechanics problems involving large deformations. The standard MPM [1] discretises the physical domain using material points which are advected through a standard finite element background mesh. The method of mapping state variables back and forth between the material points and background mesh nodes in the MPM significantly influences the results. In the standard MPM (sMPM), a material point only influences its parent element (i.e. the background element in which it is located), which can cause spurious stress oscillations when material points cross between elements. The instability is due to the sudden transfer of stiffness between elements. It can also result in some elements having very little stiffness or some internal elements loosing all stiffness. Therefore, several extensions to the sMPM have been proposed, each of which replaces the material point with a deformable particle domain. The most notable of these extensions are the Generalised Interpolation Material Point (GIMP), the Convected Particle Domain Interpolation (CPDI1) and Second-order CPDI (CPDI2) methods [2]. In this paper, the sMPM, CPDI1 and CPDI2 approaches are unified for geometrically non-linear elasto-plastic problems using an implicit solver and their performance investigated for large rotational problems. This type of deformation is common in applications in the area of soil mechanics, for example the vane shear test and, specifically of interest here, the installation of screw piles. Screw piles are currently used as an onshore foundation solution and research being undertaken at Durham, Dundee and Southampton universities is exploring their use in the area of offshore renewables. The numerical modelling using the MPM aims to predict the installation torque and vertical force as well as understanding the “state” of the soil around the screw pile which is critical in understanding the long term performance of the foundation. In the analysis, the pile is assumed to be a rigid body and no-slip boundary condition is used at the pile-soil interface. The boundary condition is imposed using the moving mesh concept within an unstructured mesh fixed to the pile. It will be shown that the CPDI2 approach produces erroneous torque due to particle domain distortion, while the CPDI1 approach and sMPM predict physically realistic mechanical responses

Fabric anisotropy & DEM informed two-surface hyperplasticity : constitutive formulation, asymptotic states & experimental validation.

In geotechnical analysis continuum idealisations of the bulk material still provide the most appropriate approach for engineers designing large-scale structures. In this area, the most successful framework for describing the behaviour of soils is Critical State (CS) soil mechanics. However, the findings from discrete element method (DEM) analysis, such as the uniqueness of the CS, can provide invaluable information in the development such models. This paper details the key concepts behind a two-surface hyperplasticity model (?) whose development was informed by recent DEM findings on the uniqueness of the CS. Asymptotic states of the model will be confirmed and the DEM-continuum-experimental loop will be closed through comparison of the developed model with experimental data on coarse-grained particulate media. This will demonstrate, that providing the previous stress history is accounted for, the proposed model is suitable for a variety of particulate media

Non-Competition Agreements and Research Productivity in the Biotechnology Industry

This paper examines the impact of the state-level legal structure, namely the legal support for non-competition agreements, on research productivity. Specifically, we study how California’s unique lack of non-competition agreement laws influences product develop when controlling for local munificence and firm-level technological capability. Our results indicate that California’s unique legal structure is negatively associated with research productivity as measured by the number of products in development at the time a biotechnology firm goes public. Further, firm size moderates this relationship such that the effect is stronger for smaller biotechnology firms

An implicit boundary finite element method with extension to frictional sliding boundary conditions and elasto-plastic analyses

Implicit boundary methods, which enrich the interpolation structure with implicit weight functions, are straightforward methods for the enforcement of Dirichlet boundary conditions. In this article, we follow the implicit boundary method that uses approximate step functions (the step boundary method) developed by Kumar et al. and provide modifications that have several advantages. Roller boundary conditions have wide practical applications in engineering, however, the step boundary method for roller boundary conditions with inclinations has yet to be fully formulated through to the final linear system of equations. Thus we provide a complete derivation that leads to simplified sti↵ness matrices compared to the original approach, which can be implemented directly in fictitious domain finite element analysis. The approach is then extended, we believe for the first time, to the nonlinear cases of frictional boundary conditions and elasto-plastic material behaviour. The proposed formulation and procedures are validated on a number of example problems that test di↵erent aspects of the method

The scale grid: Some interrelations of data models

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45699/1/11336_2005_Article_BF02296299.pd

Statistical estimation of trailing edge noise from finite wall-mounted airfoils

The 2016 Joint Conference of The Australian Acoustical Society and The Acoustical Society of New Zealand. Acoustics2016 - The Second Australasian Acoustical Societies ConferenceIt is important to be able to accurately model the flow and noise generated by finite wall-mounted airfoil flows because of the many engineering applications in which these flows occur. One method for predicting turbulent trailing edge noise is the Reynolds-averaged Navier-Stokes based statistical noise model (RSNM) of Doolan et al. (Proceedings of 20th International Congress on Acoustics, ICA 2010). The RSNM method has previously been used successfully on a range of two-dimensional geometry-flow cases. In this paper a new turbulent velocity cross-spectrum model and improved implementation are proposed to allow the RSNM method to be used to effectively and efficiently predict turbulent trailing edge noise from more complex three-dimensional cases. Reynolds-averaged Navier-Stokes (RANS) simulations of a series of wing-in-junction cases are used in combination with the developed acoustic model to predict the far-field noise and compared against experimental noise measurements.Jesse Coombs, Con Doolan, Anthony Zander, Danielle Moreau and Laura Brook

The Ideology of Stadium Construction: A Historical Sociology Model of Power and Control

Indiana University-Purdue University Indianapolis (IUPUI)The Ideology of Stadium Construction seeks to define the application of community power in the process of building sports stadiums. Using data culled from a literature review, this project examines the recent construction of sports venues and the political, economic, and social ideas driving their proliferation. A three dimensional approach to applied power provides a theoretical tool to illustrate and analyze the blueprint of stadium construction. Taking a more broad view of the culture of business in the United States suggests the public funding of stadium construction arching towards Antonio Gramsci’s sense of hegemony. Beyond attempting to merely define the political process driving stadium construction as a significant social problem, this project introduces potential alternatives to the organizational method currently in place

Contingency contracting and private volunteer organization procurement in Uzbekistan : a comparative analysis

This thesis focuses on the similarities and differences between humanitarian organization procurement and contingency contracting. More specifically, it asks whether there are best practices performed by private volunteer organizations (PVOs) that can be applied to contingency contracting during stability operations. To answer this question, this thesis reviews the procurement processes of two PVOs responding to the humanitarian needs in the Republic of Uzbekistan and compares them to the procedures of contingency contracting officers in Uzbekistan supporting Operation Enduring Freedom. Based on the information collected by interviewing members of several PVOs in Uzbekistan, including in-depth interviews with the staff of two PVOs - Heart to Heart and Samaritan's Purse - as well as contingency contracting officers in Uzbekistan, this thesis identifies and discusses three best practices applicable to contingency contracting. These best practices are: 1) develop hands-on, in-depth contingency contracting training methods including scenario-based training, temporary duty assignments at deployed contingency contracting cells for contingency contracting officer trainees, and contracting officer internships with PVOs; 2) empower contingency contracting officers under Executive Order 10789 with full control of all purchases under $50,000.00; and 3) network with PVOs already operating in country to obtain socio-economic and market data typically unavailable to contingency contracting officers upon initial deployment to a region in crisis.http://archive.org/details/contingencycontr10945594