10,788 research outputs found

    Electron Spin Resonance at the Level of 10000 Spins Using Low Impedance Superconducting Resonators

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    We report on electron spin resonance (ESR) measurements of phosphorus donors localized in a 200 square micron area below the inductive wire of a lumped element superconducting resonator. By combining quantum limited parametric amplification with a low impedance microwave resonator design we are able to detect around 20000 spins with a signal-to-noise ratio (SNR) of 1 in a single shot. The 150 Hz coupling strength between the resonator field and individual spins is significantly larger than the 1 - 10 Hz coupling rates obtained with typical coplanar waveguide resonator designs. Due to the larger coupling rate, we find that spin relaxation is dominated by radiative decay into the resonator and dependent upon the spin-resonator detuning, as predicted by Purcell

    Effects of Plant Growth Hormones on Plant Development in the Absence of Gravitational Effects. the Effect of Weightlessness on the Growth and Orientation of Roots and Shoots of Monocotyledonous Seedlings

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    Hormone effects on plant growth in absence of gravity, and effect of weightlessness on growth and orientation of roots and shoots of monocotyledenous seedlings in biosatellit

    Computer program to predict noise of general aviation aircraft: User's guide

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    Program NOISE predicts General Aviation Aircraft far-field noise levels at FAA FAR Part 36 certification conditions. It will also predict near-field and cabin noise levels for turboprop aircraft and static engine component far-field noise levels

    Emergency medical dispatch recognition, clinical intervention and outcome of patients in traumatic cardiac arrest from major trauma : an observational study

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    © Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.OBJECTIVES: The aim of this study is to describe the demographics of reported traumatic cardiac arrest (TCA) victims, prehospital resuscitation and survival to hospital rate. SETTING: Helicopter Emergency Medical Service (HEMS) in south-east England, covering a resident population of 4.5 million and a transient population of up to 8 million people. PARTICIPANTS: Patients reported on the initial 999 call to be in suspected traumatic cardiac arrest between 1 July 2016 and 31 December 2016 within the trust's geographical region were identified. The inclusion criteria were all cases of reported TCA on receipt of the initial emergency call. Patients were subsequently excluded if a medical cause of cardiac arrest was suspected. OUTCOME MEASURES: Patient records were analysed for actual presence of cardiac arrest, prehospital resuscitation procedures undertaken and for survival to hospital rates. RESULTS: 112 patients were reported to be in TCA on receipt of the 999/112 call. 51 (46%) were found not to be in TCA on arrival of emergency medical services. Of the 'not in TCA cohort', 34 (67%) received at least one advanced prehospital medical intervention (defined as emergency anaesthesia, thoracostomy, blood product transfusion or resuscitative thoracotomy). Of the 61 patients in actual TCA, 10 (16%) achieved return-of-spontaneous circulation. In 45 (88%) patients, the HEMS team escorted the patient to hospital. CONCLUSION: A significant proportion of patients reported to be in TCA on receipt of the emergency call are not in actual cardiac arrest but are critically unwell requiring advanced prehospital medical intervention. Early activation of an enhanced care team to a reported TCA call allows appropriate advanced resuscitation. Further research is warranted to determine which interventions contribute to improved TCA survival.Peer reviewedFinal Published versio

    Sea-Level and Crustal Movements along the New England-Acadian Shore, 4,500-3,000 B.P

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    Remains of three drowned forests have been investigated at Odiorne Point, New Hampshire, and Fort Lawrence and Grand Pre, west-central Nova Scotia. Carbon-14 ages and altitudes below mean tide levels were determined for four in-place stumps of white pine at each locality. Assuming that each dated stump was killed by rising salt water, and that its C14 age represented its true age at death, it was possible to construct curves showing the sequence of submergence and emergence at each site. A continuous transgression of the sea, approximating 0.31 foot per century, is indicated for the period 4,500-3,200 B.P. This rate corresponds well with Shepard\u27s (1960) estimate of eustatic sea-level rise along the stable Texas coast for this time interval. Interpretation of the submergence-emergence curves in terms of crustal movements yields the following history: 4,500-3,800 B.P.: crustal stability at all three sites; 3,800-3,400 B.P.: crustal downwarping of west- central Nova Scotia at the approximate rate of 2.6 feet per century; slightly greater downwarping at Grand Pre possible, indicating a hinge for the warping lying to the north of Fort Lawrence; slight crustal depression of the New Hampshire coast may have taken place; 3,400-3,250 B.P.: upwarping of west-central Nova Scotia at the approximate rate of 4 feet per century; crustal stability of New Hampshire shore; 3,250-3,000 B.P.: renewed downwarping in west-central Nova Scotia at the approximate rate of 0.88 foot per century; crustal stability of New Hampshire shore

    Addressing spin transitions on 209Bi donors in silicon using circularly-polarized microwaves

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    Over the past decade donor spin qubits in isotopically enriched 28^{28}Si have been intensely studied due to their exceptionally long coherence times. More recently bismuth donor electron spins have become popular because Bi has a large nuclear spin which gives rise to clock transitions (first-order insensitive to magnetic field noise). At every clock transition there are two nearly degenerate transitions between four distinct states which can be used as a pair of qubits. Here it is experimentally demonstrated that these transitions are excited by microwaves of opposite helicity such that they can be selectively driven by varying microwave polarization. This work uses a combination of a superconducting coplanar waveguide (CPW) microresonator and a dielectric resonator to flexibly generate arbitrary elliptical polarizations while retaining the high sensitivity of the CPW

    Oxygen isotopes implanted in the LDEF spacecraft

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    Secondary ion mass spectrometry was used to study oxygen implanted in the surface of copper from the Long Duration Exposure Facility (LDEF). Oxidation that occurred in orbit shows a characteristic oxygen isotope composition, depleted in O-18. The measured depletion is comparable to the predicted depletion (45 percent) based on a model of the gravitational separation of the oxygen isotopes. The anomalous oxygen was contained within 10nm of the surface. Tray E10 was calculated to have received 5.14 x 10(exp 21) atoms of oxygen cm(sup -2) during the LDEF mission and so there is sufficient anomalous implanted oxygen present in the surface to obtain a reliable isotopic profile
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