Hyperfine interaction in the ground state of the negatively charged nitrogen vacancy center in diamond

The N-14, N-15, and C-13 hyperfine interactions in the ground state of the negatively charged nitrogen vacancy (NV-) center have been investigated using electron-paramagnetic-resonance spectroscopy. The previously published parameters for the N-14 hyperfine interaction do not produce a satisfactory fit to the experimental NV- electron-paramagnetic-resonance data. The small anisotropic component of the NV- hyperfine interaction can be explained from dipolar interaction between the nitrogen nucleus and the unpaired-electron probability density localized on the three carbon atoms neighboring the vacancy. Optical spin polarization of the NV- ground state was used to enhance the electron-paramagnetic-resonance sensitivity enabling detailed study of the hyperfine interaction with C-13 neighbors. The data confirmed the identification of three equivalent carbon nearest neighbors but indicated the next largest C-13 interaction is with six, rather than as previously assumed three, equivalent neighboring carbon atoms.

Reaching common ground:A patient-family-based conceptual framework of quality EOL care

Improvement in the quality of end-of-life (EOL) care is a priority health care issue since serious deficiencies in quality of care have been reported across care settings. Increasing pressure is now focused on Canadian health care organizations to be accountable for the quality of palliative and EOL care delivered. Numerous domains of quality EOL care upon which to create accountability frameworks are now published, with some derived from the patient/family perspective. There is a need to reach common ground on the domains of quality EOL care valued by patients and families in order to develop consistent performance measures and set priorities for health care improvement. This paper describes a meta-synthesis study to develop a common conceptual framework of quality EOL care integrating attributes of quality valued by patients and their families. © 2005 Centre for Bioethics, IRCM.

Stability Analysis and Implementation of a Decentralized Formation Control Strategy for Unmanned Vehicles

This paper presents a new methodology for solving the multi-vehicle formation control problem. It employs a unique extension-decomposition-aggregation scheme to transform the overall complex formation control problem into a group of subproblems, which work via boundary interactions or disturbances. Thus, it is proved that the overall formation system is exponentially stable in the sense of Lyapunov, if all the individual augmented subsystems (IASs) are stable. Linear matrix inequality-based H8 control methodology is employed to design the decentralized formation controllers to reject the impact of the formation changes being treated as boundary disturbances and guarantee the stability of all the IASs, consequently maintaining the stability of the overall formation system. Simulation studies are performed to verify the stability, performance, and effectiveness of the proposed strategy.

Shifting Ground:Beyond National Architecture

The Irish Pavilion at the Venice Architecture Biennale 2012 charts a position for Irish architecture in a global culture where the modes of production of architecture are radically altered. Ireland is one of the most globalised countries in the world, yet it has developed a national culture of architecture derived from local place as a material construct. We now have to evolve our understanding in the light of the globalised nature of economic processes and architectural production which is largely dependent on internationally networked flows of products, data, and knowledge. We have just begun to represent this situation to ourselves and others. How should a global architecture be grounded culturally and philosophically? How does it position itself outside of shared national reference points?
heneghan peng architects were selected as participants because they are working across three continents on a range of competition-winning projects. Several of these are in sensitive and/or symbolic sites that include three UNESCO World Heritage sites, including the Grand Egyptian Museum in Cairo, the Giants Causeway Visitor Centre in Northern Ireland, and the new Rhine Bridge near Lorelei.
Our dialogue led us to discussing the universal languages of projective geometry and number are been shared by architects and related professionals. In the work of heneghan peng, the specific embodiment of these geometries is carefully calibrated by the choice of materials and the detailed design of their physical performance on site. The stone facade of the Giant’s Causeway Visitor Centre takes precise measure of the properties of the volcanic basalt seams from which it is hewn. The extraction of the stone is the subject of the pavilion wall drawings which record the cutting of stones to create the façade of the causeway centre.
We also identified water as an element which is shared across the different sites. Venice is a perfect place to take measure of this element which suggests links to another site – the Nile Valley which was enriched by the annual flooding of the River Nile. An ancient Egyptian rod for measuring the water level of the Nile inspired the design of the Nilometre - a responsive oscillating bench that invites visitors to balance their respective weights. This action embodies the ways of thinking that are evolving to operate in the globalised world, where the autonomous architectural object is dissolving into an expanded field of conceptual rules and systems. The bench constitutes a shifting ground located in the unstable field of Venice. It is about measurement and calibration of the weight of the body in relation to other bodies; in relation to the site of the installation; and in relation to water. The exhibit is located in the Artiglierie section of the Arsenale. Its level is calibrated against the mark of the acqua alta in the adjacent brickwork of the building which embodies a liminal moment in the fluctuating level of the lagoon.
The weights of bodies, the level of water, changes over time, are constant aspects of design across cultures and collectively they constitute a common ground for architecture - a ground shared with other design professionals. The movement of the bench required complex engineering design and active collaboration between the architects, engineers and fabricators. It is a kind of prototype – a physical object produced from digital data that explores the mathematics at play – the see-saw motion invites the observer to become a participant, to give it a test drive. It shows how a simple principle can generate complex effects that are difficult to predict and invites visitors to experiment and play with them.

Bord Gais Above Ground Installation:Flow

The objective was to design a treatment that would dematerialise an above ground gas installation on the Liffey quayside while still meeting the functional requirement to ventilate the pressure reducing chamber inside. To do this we wrapped the installation in a skin of glass that allows the air to enter below the skin and to escape behind the parapet. The installation building is covered in plastic sequins and the glass is treated with alternating bands of dichroic film. The flow of air causes the sequins to shimmer reflecting spots of coloured light back onto the glass. At night a similar effect is created by lighting concealed within the outer skin. This project won a commendation in the RIAI Awards 2010, and an AAI award in 2011. It was published in New Irish Architecture 26. The British architectural historian William JR Curtis described it as ‘a beautiful understated little kiosk.’

Day-Ahead Optimal Charging/Discharging Scheduling for Electric Vehicles in Micro-Grids

A micro-grid is an autonomous system which can be operated and connected to an external system or isolated with the help of energy storage systems (ESSs). While the daily output of distributed generators (DGs) strongly depends on the temporal distribution of natural resources such as wind and solar, unregulated electric vehicle (EV) charging demand will deteriorate the imbalance between the daily load and generation curves. In this paper, a statistical model is presented to describe daily EV charging/discharging behaviour. An optimisation problem is proposed to obtain economic operation for the micro-grid based on this model. In day-ahead scheduling, with estimated information of power generation and load demand, optimal charging/discharging of EVs during 24 hours is obtained. A series of numerical optimization solutions in different scenarios is achieved by serial quadratic programming. The results show that optimal charging/discharging of EVs, a daily load curve can better track the generation curve and the network loss and required ESS capacity are both decreased. The paper also demonstrates cost benefits for EVs and operators.