4,615 research outputs found
Stability of Magneto-optical Traps with Large Field Gradients: Limits on the Tight Confinement of Single Atoms
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
Nucleosynthesis of elements between Sr and Ag in neutron- and proton-rich neutrino-driven winds
Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer
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
Strengthening Oklahoma’s Aviation Maintenance Workforce Pipeline through Collaborative Efforts of CareerTech, Educational Institutions and Industry Partners
As the needs of the 21st century aviation/aerospace workforce change and in-demand job skills evolve, it becomes increasingly important to cohesively bring industry and education together to produce a well-trained, qualified aviation maintenance technical workforce for the state of Oklahoma. The primary focus of this FAA-funded project is to establish a sustainable pipeline that addresses the needs and priorities of the aviation maintenance workforce, a significant sector of the aviation/aerospace industry that drives Oklahoma’s economic growth. This sustainable pipeline will be built with a broad array of educational and industry partners. This pipeline will be designed to recruit, train, and retain a diverse and talented workforce, including underrepresented and disadvantaged populations, into the aviation maintenance industry. This workforce group will consist of high school students and adult learners, including military personnel and aviation/aerospace workers displaced as a result of the coronavirus pandemic. As the students matriculate through the pipeline, each one of them will have various learning opportunities to obtain maintenance certificates, academic scholarships, industry apprenticeships and internships, and an associate degree in applied technology and a bachelor’s degree in aviation management; ensuring that all students receive the academic and professional experiences required for industry employment and advancement. When successfully created and maintained, the use of collaborative agreements among high schools, career techs and colleges/universities will reduce the cost of skills training and higher education opportunities and enable students to graduate with little or no debt and the pipeline of skilled aviation maintenance technicians is increased within the state of Oklahoma
Current Concepts and Trends in Human-Automation Interaction
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The purpose of this panel was to provide a general overview and discussion of some of the most current and controversial concepts and trends in human-automation interaction. The panel was composed of eight researchers and practitioners. The panelists are well-known experts in the area and offered differing views on a variety of different human-automation topics. The range of concepts and trends discussed in this panel include: general taxonomies regarding stages and levels of automation and function allocation, individualized adaptive automation, automation-induced complacency, economic rationality and the use of automation, the potential utility of false alarms, the influence of different types of false alarms on trust and reliance, and a system-wide theory of trust in multiple automated aids
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