Measurement of the Casimir force between dissimilar metals

The first precise measurement of the Casimir force between dissimilar metals is reported. The attractive force, between a Cu layer evaporated on a microelectromechanical torsional oscillator, and an Au layer deposited on an Al$_2$O$_3$ sphere, was measured dynamically with a noise level of 6 fN/$\sqrt{\rm{Hz}}$. Measurements were performed for separations in the 0.2-2 $\mu$m range. The results agree to better than 1% in the 0.2-0.5 $\mu$m range with a theoretical model that takes into account the finite conductivity and roughness of the two metals. The observed discrepancies, which are much larger than the experimental precision, can be attributed to a lack of a complete characterization of the optical properties of the specific samples used in the experiment.Comment: 6 pages, 4 figure

Fabrication and characterisation of nanocrystalline graphite MEMS resonators using a geometric design to control buckling

The simulation, fabrication and characterisation of nanographite MEMS resonators is reported in this paper. The deposition of nanographite is achieved using plasma-enhanced chemical vapour deposition directly onto numerous substrates such as commercial silicon wafers. As a result, many of the reliability issues of devices based on transferred graphene are avoided. The fabrication of the resonators is presented along with a simple undercutting method to overcome buckling, by changing the effective stress of the structure from 436 MPa compressive, to 13 MPa tensile. The characterisation of the resonators using electrostatic actuation and laser Doppler vibrometry is reported, demonstrating resonator frequencies from 5–640 kHz and quality factor above 1819 in vacuum obtained

Modeling Single Electron Transfer in Si:P Double Quantum Dots

Solid-state systems such as P donors in Si have considerable potential for realization of scalable quantum computation. Recent experimental work in this area has focused on implanted Si:P double quantum dots (DQDs) that represent a preliminary step towards the realization of single donor charge-based qubits. This paper focuses on the techniques involved in analyzing the charge transfer within such DQD devices and understanding the impact of fabrication parameters on this process. We show that misalignment between the buried dots and surface gates affects the charge transfer behavior and identify some of the challenges posed by reducing the size of the metallic dot to the few donor regime.Comment: 11 pages, 7 figures, submitted to Nanotechnolog

Exploring recruitment, willingness to participate, and retention of low-SES women in stress and depression prevention

Contains fulltext : 90907.pdf (publisher's version ) (Open Access)Background Recruitment, willingness to participate, and retention in interventions are indispensable for successful prevention. This study investigated the effectiveness of different strategies for recruiting and retaining low-SES women in depression prevention, and explored which sociodemographic characteristics and risk status factors within this specific target group are associated with successful recruitment and retention. Methods The process of recruitment, willingness to participate, and retention was structurally mapped and explored. Differences between women who dropped out and those who adhered to the subsequent stages of the recruitment and retention process were investigated. The potential of several referral strategies was also studied, with specific attention paid to the use of GP databases. Results As part of the recruitment process, 12.1% of the target population completed a telephone screening. The most successful referral strategy was the use of patient databases from GPs working in disadvantaged neighborhoods. Older age and more severe complaints were particularly associated with greater willingness to participate and with retention. Conclusions Low-SES women can be recruited and retained in public health interventions through tailored strategies. The integration of mental health screening within primary care might help to embed preventive interventions in low-SES communities.8 p