2,893 research outputs found

    Regenerable biocide delivery unit

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    A method and apparatus are disclosed for maintaining continuous, long-term microbial control in the water supply for potable, hygiene, and experimental water for space activities, as well as treatment of water supplies on Earth. The water purification is accomplished by introduction of molecular iodine into the water supply to impart a desired iodine residual. The water is passed through an iodinated anion exchange resin bed. The iodine is bound as I-(sub n) at the anion exchange sites and releases I(sub 2) into the water stream flowing through the bed. The concentration of I(sub 2) in the flowing water gradually decreases and, in the prior art, the ion-exchange bed has had to be replaced. In a preferred embodiment, a bed of iodine crystals is provided with connections for flowing water therethrough to produce a concentrated (substantially saturated) aqueous iodine solution which is passed through the iodinated resin bed to recharge the bed with bound iodine. The bed of iodine crystals is connected in parallel with the iodinated resin bed and is activated periodically (e.g., by timer, by measured flow of water, or by iodine residual level) to recharge the bed. Novelty resides in the capability of inexpensively and repeatedly regenerating the ion-exchange bed in situ

    Wireless Acoustic Measurement System

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    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/ Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in the article on page 8. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro- ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that provides an intuitive graphical user interface through which an operator at the control server can control the operations of the field stations for calibration and for recording of measurement data. A test engineer positions and activates the WAMS. The WAMS automatically establishes the wireless network. Next, the engineer performs pretest calibrations. Then the engineer executes the test and measurement procedures. After the test, the raw measurement files are copied and transferred, through the wireless network, to a hard disk in the control server. Subsequently, the data are processed into 1.3-octave spectrograms

    Thermodiffusion in model nanofluids by molecular dynamics simulations

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    In this work, a new algorithm is proposed to compute single particle (infinite dilution) thermodiffusion using Non-Equilibrium Molecular Dynamics simulations through the estimation of the thermophoretic force that applies on a solute particle. This scheme is shown to provide consistent results for simple Lennard-Jones fluids and for model nanofluids (spherical non-metallic nanoparticles + Lennard-Jones fluid) where it appears that thermodiffusion amplitude, as well as thermal conductivity, decrease with nanoparticles concentration. Then, in nanofluids in the liquid state, by changing the nature of the nanoparticle (size, mass and internal stiffness) and of the solvent (quality and viscosity) various trends are exhibited. In all cases the single particle thermodiffusion is positive, i.e. the nanoparticle tends to migrate toward the cold area. The single particle thermal diffusion 2 coefficient is shown to be independent of the size of the nanoparticle (diameter of 0.8 to 4 nm), whereas it increases with the quality of the solvent and is inversely proportional to the viscosity of the fluid. In addition, this coefficient is shown to be independent of the mass of the nanoparticle and to increase with the stiffness of the nanoparticle internal bonds. Besides, for these configurations, the mass diffusion coefficient behavior appears to be consistent with a Stokes-Einstein like law

    High Resolution HST-STIS Spectra of CI and CO in the Beta Pictoris Circumstellar Disk

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    High resolution FUV echelle spectra showing absorption features arising from CI and CO gas in the Beta Pictoris circumstellar (CS) disk were obtained on 1997 December 6 and 19 using the Space Telescope Imaging Spectrograph (STIS). An unsaturated spin-forbidden line of CI at 1613.376 A not previously seen in spectra of Beta Pictoris was detected, allowing for an improved determination of the column density of CI at zero velocity relative to the star (the stable component), N = (2-4) x 10^{16} cm^{-2}. Variable components with multiple velocities, which are the signatures of infalling bodies in the Beta Pictoris CS disk, are observed in the CI 1561 A and 1657 A multiplets. Also seen for the first time were two lines arising from the metastable singlet D level of carbon, at 1931 A and 1463 A The results of analysis of the CO A-X (0-0), (1-0), and (2-0) bands are presented, including the bands arising from {13}^CO, with much better precision than has previously been possible, due to the very high resolution provided by the STIS echelle gratings. Only stable CO gas is observed, with a column density N(CO) = (6.3 +/- 0.3) x 10^{14} cm{-2}. An unusual ratio of the column densities of {12}^CO to {13}^CO is found (R = 15 +/- 2). The large difference between the column densities of CI and CO indicates that photodissociation of CO is not the primary source of CI gas in the disk, contrary to previous suggestion.Comment: 13 pages, including 6 figures. LaTex2e (emulateapj5.sty). Accepted for publication in Ap

    Demonstration of the Zero-Crossing Phasemeter with a LISA Test-bed Interferometer

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    The Laser Interferometer Space Antenna (LISA) is being designed to detect and study in detail gravitational waves from sources throughout the Universe such as massive black hole binaries. The conceptual formulation of the LISA space-borne gravitational wave detector is now well developed. The interferometric measurements between the sciencecraft remain one of the most important technological and scientific design areas for the mission. Our work has concentrated on developing the interferometric technologies to create a LISA-like optical signal and to measure the phase of that signal using commercially available instruments. One of the most important goals of this research is to demonstrate the LISA phase timing and phase reconstruction for a LISA-like fringe signal, in the case of a high fringe rate and a low signal level. We present current results of a test-bed interferometer designed to produce an optical LISA-like fringe signal previously discussed in the literature.Comment: find minor corrections in the CQG versio

    Early markers of prolonged hospital stay in demented inpatients: A multicentre and prospective study

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    Background: Dementia is a serious, chronic, and costly public health problem. Prior studies have described dementia as increasing length of hospital stay, but so far no explanations have been proposed. Methods: To identify early markers for prolonged hospital stay in demented elderly inpatients, 178 community-dwelling or institutionalized subjects aged 75+, hospitalized through an emergency department in 9 teaching hospitals in France, were analyzed. Prolonged hospital stays were defined according a limit adjusted for Diagnosis Related Group. All patients underwent a comprehensive geriatric assessment at admission. Logistic regression multifactorial mixed model was performed. Center effect was considered as a random effect. Results: Of the 178 stays, 52 were prolonged. Most concerned community-dwelling patients (86%). Multifactor analysis demonstrated that demographic variables had no influence on the length of stay, while diagnosis of delirium (OR 2.31; 95% CI 1.77-2.91), walking difficulties (OR 1.94; 95% CI 1.62-2.43) and report by the informal caregiver of moderate or severe burden (OR 1.52; 95% CI 1.19-1.86) or low social quality-of-life score (OR 1.25; 95% CI 1.03-1.40), according to the Zarit's Burden Inventory short scale (12 items) and the Duke's Health Profile respectively, were identified as early markers for prolonged hospital stays. Conclusion: At the time of the rising incidence of cognitive disorders, these results suggest that preventive approaches might be possible. In a hospital setting as well as in a community-dwelling population, more specific, specialized and coordinated care, using the expertise of multiple disciplines appears as a probable effective measure to limit prolonged hospital stay. Such approaches require (i) clear patient-oriented goal definition, (ii) understanding and appreciation of roles among various health care and social disciplines and, (iii) cooperation between partners in patient's management. However, the cost- and health-effectiveness of such approaches should be evaluate

    Principles And Practices Fostering Inclusive Excellence: Lessons From The Howard Hughes Medical Institute’s Capstone Institutions

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    Best-practices pedagogy in science, technology, engineering, and mathematics (STEM) aims for inclusive excellence that fosters student persistence. This paper describes principles of inclusivity across 11 primarily undergraduate institutions designated as Capstone Awardees in Howard Hughes Medical Institute’s (HHMI) 2012 competition. The Capstones represent a range of institutional missions, student profiles, and geographical locations. Each successfully directed activities toward persistence of STEM students, especially those from traditionally underrepresented groups, through a set of common elements: mentoring programs to build community; research experiences to strengthen scientific skill/identity; attention to quantitative skills; and outreach/bridge programs to broaden the student pool. This paper grounds these program elements in learning theory, emphasizing their essential principles with examples of how they were implemented within institutional contexts. We also describe common assessment approaches that in many cases informed programming and created traction for stakeholder buy-in. The lessons learned from our shared experiences in pursuit of inclusive excellence, including the resources housed on our companion website, can inform others’ efforts to increase access to and persistence in STEM in higher education

    Lifecycle, culture, and maintenance of the emerging cephalopod models Euprymna berryi and Euprymna morsei

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    Cephalopod research remains limited by the inability to culture species under laboratory conditions for multiple generations to provide continuous access to animals at all stages of the life cycle. Here, we describe a multi-generational laboratory culture system for two emerging cephalopod models: the hummingbird or Berry’s bobtail squid, Euprymna berryi Sasaki, 1929, and Morse’s bobtail squid, Euprymna morsei Verrill, 1881, which are primarily found off mainland Japan. E. berryi wild adults were spawned and raised to the third filial generation, and E. morsei wild adults were spawned and raised to the second filial generation in a closed system at 20°C. We report growth and survivorship data for a cohort of 30 individuals across the first generation raised in captivity. E. berryi and E. morsei grew exponentially during the first 90 and 60 days post-hatching, respectively. Survivorship at the first spawning event for E. berryi and E. morsei was 90% and 77%. E. berryi and E. morsei females spawned after days 112 and 71 days post-hatching, respectively. We describe the life history of each species and how to distinguish sexes. We discuss the challenges of cephalopod culture and how culturing these species address those problems

    Study protocol:the effectiveness and cost effectiveness of a brief behavioural intervention to promote regular self-weighing to prevent weight regain after weight loss: randomised controlled trial (The LIMIT Study)

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    BACKGROUND: Although obesity causes many adverse health consequences, modest weight loss reduces the incidence. There are effective interventions that help people to lose weight but weight regain is common and long term maintenance remains a critical challenge. As a high proportion of the population of most high and middle income countries are overweight, there are many people who would benefit from weight loss and its maintenance. Therefore, we need to find effective low cost scalable interventions to help people achieve this. One such intervention that has shown promise is regular self-weighing, to check progress against a target, however there is no trial that has tested this using a randomised controlled design (RCT). The aim of this RCT is to evaluate the effectiveness and cost effectiveness of a brief behavioural intervention delivered by non-specialist staff to promote regular self-weighing to prevent weight regain after intentional weight loss. METHODS: A randomised trial of 560 adults who have lost ≄5 % of their initial body weight through a 12 week weight loss programme. The comparator group receive a weight maintenance leaflet, a diagram representing healthy diet composition, and a list of websites for weight control. The intervention group receive the same plus minimally trained telephonists will ask participants to set a weight target and encourage them to weigh themselves daily, and provide support materials such as a weight record card. The primary outcome is the difference between groups in weight change from baseline to 12 months. DISCUSSION: If effective, this study will provide public health agencies with a simple, low cost maintenance intervention that could be implemented immediately. TRIAL REGISTRATION: ISRCTN52341938 Date Registered: 31/03/201
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