Fluxes of Sporadic Meteoroids from Optical Measurements

The purpose of this study was to develop a process to measure the mass distribution index, the speed distribution, and the flux of the sporadic meteor sources using an electro-optical system. Data was recorded on two nights, April 27 and May 6, 2006, and the system was tested by measuring the flux of the eta Aquariid meteor shower. Eta Aquariid fluxes yielded ZHRs of 14.3 ± 4.5 meteors hr\u271and 65 ± 10 meteors hr\u271 on the measured nights in agreement with literature values (Rendtel, 1997). The mass index of sporadic meteors was s = 2.14 ± 0.12 and the speed distributions were found to be in agreement with radar measurements by Campbell- Brown (2008). The estimated total annual flux from all sporadic sources was: 0.226 ± 0.018 meteors km\u272hr\u27! and 0.151 ± 0.023 meteors km^hr 1brighter than magnitude 4.72 ±0.19 for April 27 and May 6 respectively

Contamination by respiratory viruses on outer surface of medical masks used by hospital healthcare workers

© 2019 The Author(s). Background: Medical masks are commonly used in health care settings to protect healthcare workers (HCWs) from respiratory and other infections. Airborne respiratory pathogens may settle on the surface of used masks layers, resulting in contamination. The main aim of this study was to study the presence of viruses on the surface of medical masks. Methods: Two pilot studies in laboratory and clinical settings were carried out to determine the areas of masks likely to contain maximum viral particles. A laboratory study using a mannequin and fluorescent spray showed maximum particles concentrated on upper right, middle and left sections of the medical masks. These findings were confirmed through a small clinical study. The main study was then conducted in high-risk wards of three selected hospitals in Beijing China. Participants (n = 148) were asked to wear medical masks for a shift (6-8 h) or as long as they could tolerate. Used samples of medical masks were tested for presence of respiratory viruses in upper sections of the medical masks, in line with the pilot studies. Results: Overall virus positivity rate was 10.1% (15/148). Commonly isolated viruses from masks samples were adenovirus (n = 7), bocavirus (n = 2), respiratory syncytial virus (n = 2) and influenza virus (n = 2). Virus positivity was significantly higher in masks samples worn for > 6 h (14.1%, 14/99 versus 1.2%, 1/49, OR 7.9, 95% CI 1.01-61.99) and in samples used by participants who examined > 25 patients per day (16.9%, 12/71 versus 3.9%, 3/77, OR 5.02, 95% CI 1.35-18.60). Most of the participants (83.8%, 124/148) reported at least one problem associated with mask use. Commonly reported problems were pressure on face (16.9%, 25/148), breathing difficulty (12.2%, 18/148), discomfort (9.5% 14/148), trouble communicating with the patient (7.4%, 11/148) and headache (6.1%, 9/148). Conclusion: Respiratory pathogens on the outer surface of the used medical masks may result in self-contamination. The risk is higher with longer duration of mask use (> 6 h) and with higher rates of clinical contact. Protocols on duration of mask use should specify a maximum time of continuous use, and should consider guidance in high contact settings. Viruses were isolated from the upper sections of around 10% samples, but other sections of masks may also be contaminated. HCWs should be aware of these risks in order to protect themselves and people around them

Optical and Thermal Design and Analysis of Phase-Change Metalenses for Active Numerical Aperture Control

This is the final version. Available on open access from MDPI via the DOI in this recordThe control of a lens's numerical aperture has potential applications in areas such as photography and imaging, displays, sensing, laser processing and even laser-implosion fusion. In such fields, the ability to control lens properties dynamically is of much interest, and active meta-lenses of various kinds are under investigation due to their modulation speed and compactness. However, as of yet, meta-lenses that explicitly offer dynamic control of a lens's numerical aperture have received little attention. Here, we design and simulate active meta-lenses (specifically, focusing meta-mirrors) using chalcogenide phase-change materials to provide such control. We show that, operating at a wavelength of 3000 nm, our devices can change the numerical aperture by up to a factor of 1.85 and operate at optical intensities of the order of 1.2 × 109 Wm-2. Furthermore, we show the scalability of our design towards shorter wavelengths (visible spectrum), where we demonstrate a change in NA by a factor of 1.92.Engineering and Physical Sciences Research Council (EPSRC)Margarita Salas fellowshi

Lens numerical aperture control with phase-change metasurfaces

This is the author accepted manuscript.The control of lens numerical aperture has many applications, including photography, imaging, and laser processing. Here we introduce active control of numerical aperture via a focusing phase-change meta-mirror. This can potentially operate at high speed in a low cost, light and compact format. We demonstrate designs for both infrared (3000 nm) and visible (632.8 nm) wavelengths.Engineering and Physical Sciences Research Council (EPSRC)Atomic Weapons Establishment (AWE

Switching of Phase-Change Optical Metasurfaces via Remote Thermal Sources

This is the final version.Atomic Weapons Establishment (AWE) plcEngineering and Physical Sciences Research Council (EPSRC

Remote Thermal Sources for Switching Phase-Change Material-Based Metasurfaces

This is the final version.Atomic Weapons Establishment (AWE) plcEngineering and Physical Sciences Research Council (EPSRC

Phase-Change Metasurfaces for the Active Control of Lens Numerical Aperture

This is the author accepted manuscript. Available from META Conference via the link in this recordLens numerical aperture (NA) control has applications in many fields, such as photography, imaging, andlaser processing. Active metasurfaces offer the prospect for dynamic control of numerical aperture, in a flat,compact and low-cost format. Here, we design and simulate an active focusing meta-mirror using phase-change materials to provide this control. Designs for use in both the infrared (3000 nm) and visible (632.8nm) are shown.Engineering and Physical Sciences Research Council (EPSRC

Far From \u27Easy\u27 Spectroscopy with the 8π and GRIFFIN Spectrometers at TRIUMF-ISAC

The 8π spectrometer, installed at the TRIUMF-ISAC facility, was the world\u27s most sensitive γ-ray spectrometer dedicated to β-decay studies. A description is given of the 8π spectrometer and its auxiliary detectors including the plastic scintillator array SCEPTAR used for β-particle tagging and the Si(Li) array PACES for conversion electron measurements, its moving tape collector, and its data acquisition system. The recent investigation of the decay of 124Cs to study the nuclear structure of 124Xe, and how the β-decay measurements complemented previous Coulomb excitation studies, is highlighted, including the extraction of the deformation parameters for the excited 0+ bands in 124Xe. As a by-product, the decay scheme of the (7+) 124Cs isomeric state, for which the data from the PACES detectors were vital, was studied. Finally, a description of the new GRIFFIN spectrometer, which uses the same auxiliary detectors as the 8π spectrometer, is given

The energy-related inventions program: Continuing benefits to the inventor community

This report provides information on the economic, energy, and environmental impacts of inventions supported by the Energy-Related Inventions Program (ERIP) - a technology commercialization program jointly operated by the U.S. Department of Energy (DOE) and the National Institute of Standards and Technology (NIST). It describes the results of the latest in a series of ERIP evaluation projects that have been completed since 1980. The period of interest is 1980 through 1994. The evaluation is based on data collected in 1995 through mail and telephone surveys of 211 program participants, and historical data collected during previous evaluations for an additional 253 participants. As of September 1993, a total of 609 inventions had been recommended to DOE by NIST, which screens all submitted inventions for technical merit, potential for commercial success, and potential energy impact. By the end of 1994, at least 144 (or 24%) of these inventions had entered the market, generating total cumulative sales of $961 million (in 19944). It is estimated that in 1994 ERIP inventors earned royalties of$2.3 million, and over the lifetime of the program, royalties total $28.2 million. With$47.5 million in grants awarded from 1975 through 1994 and $124 million in program appropriations over the same period, ERIP has generated a 20:1 return in terms of sales values to grants, and an 8:1 return in sales versus program appropriations. Further, it is estimated that at least 757 job-years of employment were supported by ERIP technologies in 1994, and that this resulted in a return of approximately$3.4 million in individual income taxes to the U.S. Treasury. Finally, approximately $334 million of energy expenditures were saved in 1994 as a result of the commercial success of five ERIP projects. These energy savings resulted in reduced emissions of 2.1 million metric tons of carbon in 1994 alone

Professionalism, Golf Coaching and a Master of Science Degree: A commentary

As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues