392 research outputs found

    An experimental apparatus for measuring the Casimir effect at large distances

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    An experimental set-up for the measurement of the Casimir effect at separations larger than a few microns is presented. The apparatus is based on a mechanical resonator and uses a homodyne detection technique to sense the Casimir force in the plane-parallel configuration. First measurements in the 3-10 micrometer range show an unexpected large force probably due to patch effects.Comment: Proceedings of the workshop On the 60 Years on Casimir Effec

    The Casimir force of Quantum Spring in the (D+1)-dimensional spacetime

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    The Casimir effect for a massless scalar field on the helix boundary condition which is named as quantum spring is studied in our recent paper\cite{Feng}. In this paper, the Casimir effect of the quantum spring is investigated in (D+1)(D+1)-dimensional spacetime for the massless and massive scalar fields by using the zeta function techniques. We obtain the exact results of the Casimir energy and Casimir force for any DD, which indicate a Z2Z_2 symmetry of the two space dimensions. The Casimir energy and Casimir force have different expressions for odd and even dimensional space in the massless case but in both cases the force is attractive. In the case of odd-dimensional space, the Casimir energy density can be expressed by the Bernoulli numbers, while in the even case it can be expressed by the ζ\zeta-function. And we also show that the Casimir force has a maximum value which depends on the spacetime dimensions. In particular, for a massive scalar field, we found that the Casimir force varies as the mass of the field changes.Comment: 9 pages, 5 figures, v2, massive case added, refs. adde

    Ultra high level liquid argon purification using electron emission from a tip array

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    Abstract An array of 148 sharp tips was used to inject large quantities of free electrons in liquid argon and to purify it at a level · 0.09 ppb in few hours. We also evaluated the gettering capability of the stainless steel surface and measured the I–V characteristic of the array

    Measurement of the Casimir force between parallel metallic surfaces

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    We report on the measurement of the Casimir force between conducting surfaces in a parallel configuration. The force is exerted between a silicon cantilever coated with chromium and a similar rigid surface and is detected looking at the shifts induced in the cantilever frequency when the latter is approached. The scaling of the force with the distance between the surfaces was tested in the 0.5 - 3.0 ÎĽ\mum range, and the related force coefficient was determined at the 15% precision level.Comment: 4 Figure

    Beyond lockdown: The potential side effects of the sars-cov-2 pandemic on public health

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    Lockdowns to contain the spread of the SARS-CoV-2 have disrupted routines and behaviors, which could lead to a worsening of lifestyle and an increase in the burden of non-communicable diseases. This study aimed to describe the changes in physical activity, diet, alcohol drinking, and cigarette smoking during lockdown. A self-administered online survey addressing adults living in a province in northern Italy was advertised through websites and social media. Citizens could access the survey in anonymity from 4 May until 15 June 2020. A total of 1826 adults completed the survey, with a worsening of physical activity (35.1%), diet (17.6%), alcohol drinking (12.5%), and cigarette smoking (7.7%) reported. In contrast, 33.5% reported an improvement in diet, 12.6% in alcohol drinking, 5.3% in physical activity and 4.1% in cigarette smoking. Female sex, young adult age, suspension of work activity, and symptoms of psychological distress were the factors associated with a greater likelihood of change, which was frequently for the worse. Lockdown had an impact on lifestyle, with some net beneficial effects on diet and mostly negative effects on physical activity. Public health measures should be implemented to avoid long-term negative effects of the lockdown, supporting individuals more prone to change for the worse

    T-Odd Correlations in pi->e nu_e gamma and pi->mu nu_mu gamma Decays

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    The transverse lepton polarization asymmetry in pi_l2gamma decays may probe T-violating interactions beyond the Standard Model. Dalitz plot distributions of the expected effects are presented and compared to the contribution from the Standard Model final state interactions. We give an example of a phenomenologically viable model, where a considerable contribution to the transverse lepton polarization asymmetry arises.Comment: 19 pages, 5 figures. To be published in Phys.Rev.D. Fixed sign in FSI contribution figure, fixed formulas in K-bar{K} mixing analysis, added some minor comment

    A novel experimental approach for the detection of the dynamic Casimir effect

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    The Casimir effect is a well-known macroscopic consequence of quantum vacuum fluctuations, but whereas the static effect (Casimir force) has long been observed experimentally, the dynamic Casimir effect is up to now undetected. From an experimental viewpoint a possible detection would imply the vibration of a mirror at gigahertz frequencies. Mechanical motions at such frequencies turn out to be technically unfeasible. Here we present a different experimental scheme where mechanical motions are avoided, and the results of laboratory tests showing that the scheme is practically feasible. We think that at present this approach gives the only possibility of detecting this phenomenon.Comment: Submitted to the Physical Review Letters. RevTeX. 4 pages, 2 figure

    Idiopathic sensorineural hearing loss is associated with endothelial dysfunction

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    Hearing impairment is the most prevalent sensory deficit [1]. Sensorineural hearing loss (SNHL) is the most common type of permanent hearing loss and it occurswhen there is damage to the inner ear (cochlea), or to the nerve pathways fromthe inner ear to the brain.Most of the time, SNHL cannot be medically or surgically corrected. SNHL can result from genetic, environmental, or combined etiologies that prevent normal function of hearing, but, despite detailed investigation, the main cause remains usually unknown. Clinical and experimental studies have shown that ischemia contributes to several SNHL [2], suchas sudden sensoneural hearing loss, presbyacusis and noise-induced hearing loss. All of these SNHL can be related to alteration in blood flow [3]. The aim of the study is finding a relationship between idiopathic SNHL and endothelial dysfunction
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