796 research outputs found
Selective spin coupling through a single exciton
We present a novel scheme for performing a conditional phase gate between two
spin qubits in adjacent semiconductor quantum dots through delocalized single
exciton states, formed through the inter-dot Foerster interaction. We consider
two resonant quantum dots, each containing a single excess conduction band
electron whose spin embodies the qubit. We demonstrate that both the two-qubit
gate, and arbitrary single-qubit rotations, may be realized to a high fidelity
with current semiconductor and laser technology.Comment: 5 pages, 3 figures; published version, equation formatting improved,
references adde
Phonon-Induced Rabi-Frequency Renormalization of Optically Driven Single InGaAs/GaAs Quantum Dots
The authors thank the EPSRC (U.K.) EP/G001642, and the QIPIRC U.K. for financial support. A. N. is supported by the EPSRC and B.W. L. by the Royal Society.We study optically driven Rabi rotations of a quantum dot exciton transition between 5 and 50 K, and for pulse areas of up to 14 pi. In a high driving field regime, the decay of the Rabi rotations is nonmonotonic, and the period decreases with pulse area and increases with temperature. By comparing the experiments to a weak-coupling model of the exciton-phonon interaction, we demonstrate that the observed renormalization of the Rabi frequency is induced by fluctuations in the bath of longitudinal acoustic phonons, an effect that is a phonon analogy of the Lamb shift.Peer reviewe
A model for cathodic blister growth in coating degradation using mesomechanics approach
The paper presents a novel theoretical model of blistering initiation and propagation especially useful for coating life assessment. The focus is on initially circular blisters. A two-part theoretical analysis of blistering is conducted using mesomechanics approach coupling diffusion concepts with fracture mechanics concepts. The diffusion concept is used to treat the corrosive species transport, eventually causing corrosion and blistering, while the fracture mechanics concept is used to treat the blister growth as circular crack propagation. Effects of thickness ratio and modulus ratio on blistering propagation are discussed. A simple criterion is identified which excludes the possibility of widespread blister propagation. Furthermore, a comparative study with the existing blistering models is carried out. Experiments are reported for blistering using a model coating-substrate system, chosen to allow visualisation of interface and to permit coupled (diffusion and residual) stresses in the coating over a full range of interest. The predicted limits from theoretical model are expected to be useful for the manufacturers in the design and deposition of coatings
A Unified Mathematical Modelling and Simulation for Cathodic Blistering Mechanism incorporating diffusion and fracture mechanics concepts
A novel mathematical model has been developed to understand the mechanism of blister initiation and propagation. The model employs a two-part theoretical approach encompassing the debondment of a coating film from the substrate, coupled with the design components incorporating diffusion and fracture mechanics, where the latter is derived from equi-biaxial tensile loading. Integrating the two components, a comprehensive mathematical design for the propagation of blister boundaries based on specific toughness functions and mode adjustment parameters has been developed. This approach provided a reliable and efficient prediction method for blister growth rate and mechanisms. The model provided a foundation for holistic design based on diffusion and mechanic components to enable better understanding of the debondment of thin elastic films bonded to a metallic substrate
An Interim Analysis of an Advance Care Planning Intervention in the Nursing Home Setting
Objectives
To describe processes and preliminary outcomes from the implementation of a systematic advance care planning (ACP) intervention in the nursing home setting.
Design
Specially trained project nurses were embedded in 19 nursing homes and engaged in ACP as part of larger demonstration project to reduce potentially avoidable hospitalizations.
Setting
Nursing homes.
Participants
Residents enrolled in the demonstration project for a minimum of 30 days between August 2013 and December 2014 (n = 2,709) and residents currently enrolled in March 2015 (n = 1,591).
Measurements
ACP conversations were conducted with residents, families, and the legal representatives of incapacitated residents using a structured ACP interview guide with the goal of offering ACP to all residents. Project nurses reviewed their roster of currently enrolled residents in March 2015 to capture barriers to engaging in ACP.
Results
During the initial implementation phase, 27% (731/2,709) of residents had participated in one or more ACP conversations with a project nurse, resulting in a change in documented treatment preferences for 69% (504/731). The most common change (87%) was the generation of a Physician Orders for Scope of Treatment form. The most frequently reported barrier to ACP was lack of time.
Conclusion
The time- and resource-intensive nature of robust ACP must be anticipated when systematically implementing ACP in the nursing home setting. The fact that these conversations resulted in changes over 2/3 of the time reinforces the importance of deliberate, systematic ACP to ensure that current treatment preferences are known and documented so that these preferences can be honored
Online monitoring of the impact of language processing on motor processes: prehensile grip-force measures during passive listening of manual action.
A large number of recent behavioural studies have established that processing linguistic descriptions of motor actions affect overt motor behaviour. For instance, when participants are asked to make sensibility judgments on sentences that describe action toward the body (“Mark gave the book to yo
Experimental study of geotechnical characteristics of crushed glass mixed with Kaolinite soil
The Geotechnical properties of adding crushed curbside-collected glass to Kaolinite S300 with various percentages of 10 to 50% were experimentally evaluated. Crushed glass passing the 2.36 mm (#8) sieve, and retaining on 1.18 mm (#16) selected for this study is collected from a different area in Johor Bahru, Malaysia. Measured hydraulic conductivities were on the order of 2.33E-6 and 1.87E-5 for 10% and 50% respectively. The result shows increment in the maximum dry density from 1.615mg/m3 at 10% to 1.908mg/m3 at 50% of addition of crushed glass with the optimum moisture content of 18.35% and 7.4% respectively. Friction angles from the direct shear test were evaluated between 12 to 25 degrees at normal stresses of 56.4 to 219.9 kPa. The result shows that the unconfined compression strength of Kaolinite S300 mixed with crushed glass is increased from 5.26 kPa at 10% addition of crushed glass up to 17.52 kPa at 50%. It can be concluded that the crushed glass is environmentally clean, readily available, and relatively low-cost material that can be one of the replacements for traditional aggregate to enhance the geotechnical properties of soft cohesive soils
Lowering virus attack with improved yield and fiber quality in different cotton genotypes by early sown cotton (Gossypium hirsutum L.)
A three year study with the objective of exploring the possible role of different sowing dates and cotton genotypes on seed cotton yield, fiber quality and virus attack was conducted at the Cotton Research Station (CRS), Multan, Pakistan during three consecutive years (2006, 2007 and 2008). Two cotton genotypes namely: MNH-6070 and CIM-496 were sown on five different sowing dates (15th April, 1st May, 15th May, 1st June and 15th June) during the three consecutive years (2006, 2007 and 2008). The analyzed data indicated that early sown cotton (15th April) resulted in low virus attack (21.06%) and enhanced seed cotton yield (1575%), together with yield components (number of bolls per plant and boll weight), and improved fiber quality (staple length and micronaire) during all the three years as compared with late sown crop (15th June). Likewise, MNH-6070 also resulted in low virus attack (45.79%) and higher seed cotton yield (117.19%), as well as yield components. Regarding fiber quality, MNH-6070 resulted in higher micronarie, while CIM-496 resulted in higher staple length. Early sowing and cotton genotype MNH-6070 also resulted in maximum ginning out turn (GOT). Nonetheless, seed cotton yield and fiber quality were both negatively affected due to late sowing (1st and 15th of June) in both cotton genotypes. In crux, early sowing enhanced seed cotton yield due to increased number of bolls per plant, boll weight and low virus attack. Similarly, cotton genotype MNH-6070 also resulted to higher seed cotton yield, GOT and more resistance against virus attack due to its better genetic makeup. In summary, cotton genotype MNH-6070 should be sown on 15th April in order to obtain maximum seed cotton yield under agro-climatic conditions of Multan, Pakistan.Key words: Sowing time, seed cotton yield, staple length, micronaire
Optimisation of Interface Roughness and Coating Thickness to Maximise Coating-Substrate Adhesion - A Failure Prediction and Reliability Assessment Modelling
This paper addresses a novel modelling technique which is based on a multidisciplinary approach to predict the coating-substrate adhesion. It proposes new equations governing coating debondment that combines material science concepts with and solid mechanics concepts. The effects of two parameters i.e. interface roughness λ and coating thickness h on coating-substrate adhesion has been analysed. The reliability of newly developed technique has been validated by comparison with the experimental results
Decoherence of geometric phase gates
We consider the effects of certain forms of decoherence applied to both
adiabatic and non-adiabatic geometric phase quantum gates. For a single qubit
we illustrate path-dependent sensitivity to anisotropic noise and for two
qubits we quantify the loss of entanglement as a function of decoherence.Comment: 4 pages, 3 figure
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