4,541 research outputs found

    Status of Designs of Lunar Surface Vehicles

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    This report summarizes the activities of the various organizations that have been giving some thought and design effort to producing a lunar surface traversing vehicle. It is a state-of-the-art rather than a technical report. It's purpose is to show where we are in this effort and to survey the trend of the various designers

    O\u27Connor v. Donaldson: The Death of the Quid Pro Quo Argument for a Right to Treatment

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    On June 26, 1975, the Supreme Court was confronted with the controversial issue of whether there is a constitutionally guaranteed right to treatment for nondangerous persons who have been involuntarily and civilly committed to mental institutions. The Court avoided this long advocated issue and created the potential for future litigation by holding that a state cannot constitutionally confine a nondangerous individual solely for custodial care if such person can live safely in the outside world, without a finding of more than mere mental illness. This comment will discuss the decision in terms of the most volatile and frequently urged constitutional argument -a right to treatment based on a quid pro quo concept

    O\u27Connor v. Donaldson: The Death of the Quid Pro Quo Argument for a Right to Treatment

    Get PDF
    On June 26, 1975, the Supreme Court was confronted with the controversial issue of whether there is a constitutionally guaranteed right to treatment for nondangerous persons who have been involuntarily and civilly committed to mental institutions. The Court avoided this long advocated issue and created the potential for future litigation by holding that a state cannot constitutionally confine a nondangerous individual solely for custodial care if such person can live safely in the outside world, without a finding of more than mere mental illness. This comment will discuss the decision in terms of the most volatile and frequently urged constitutional argument -a right to treatment based on a quid pro quo concept

    Stability of Magneto-optical Traps with Large Field Gradients: Limits on the Tight Confinement of Single Atoms

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    We report measurements of the stability of magneto-optical traps (MOTs) for neutral atoms in the limit of tight confinement of a single atom. For quadrupole magnetic field gradients at the trap center greater than ∼1 kG/cm, we find that stochastic diffusion of atoms out of the trapping volume becomes the dominant particle loss mechanism, ultimately limiting the MOT size to greater than ∼5 μm. We measured and modeled the diffusive loss rate as a function of laser power, detuning, and field gradient for trapped cesium atoms. In addition, for as few as two atoms, the collisional loss rates become very high for tightly confined traps, allowing the direct observation of isolated two-body atomic collisions in a MOT

    Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer

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    CONTEXT: In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer. OBJECTIVES: To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial. METHODS: Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made. RESULTS: The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients. CONCLUSIONS: This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions
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