25 research outputs found

    Integrating Imagery from Hull Mounted Sidescan Sonars with Multibeam Bathymetry

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    Multibeam echo sounders produce high quality bathymetric data, however, for acoustic imaging their alongtrack beamwidth is much wider than what is used on conventional sidescan sonars, so the imagery produced by sidescan sonars are of a better quality and are often preferred. A hullmounted combination instrument package that integrates both the accurate multibeam bathymetry and the high resolution sidescan imagery is an attractive and relatively low cost solution for detailed surveys of harbors, canals, rivers and other shallow areas. Especially in these shallow water areas the sidescan sonar benefits from being hull mounted rather than towed, since this arrangement is easier and safer to handle and the sensor position is known with high accuracy. The paper addresses how the backscatter from the hull-mounted sidescan sonar system can be radiometrically and geometrically corrected, by using the bathymetry from the multibeam echo sounder, and how the 2 data sets can be presented together in 2D and 3D. A practical experiment is described, whereby EM 3002D multibeam echo sounder and a hull mounted EA 400 sidescan sonar system are mounted together and deployed over the bow of a small survey launch. The co-registered data sets are analyzed using the UNH GEOCODER processing scheme, and the results are presented and interpreted in terms of capability to resolve small objects. A comparison is made between the EA 400 sidescan backscatter and the EM 3002D seabed imagery

    Phthalates in Indoor Dust and Their Association with Building Characteristics

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    In a recent study of 198 Swedish children with persistent allergic symptoms and 202 controls without such symptoms, we reported associations between the symptoms and the concentrations of n-butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) in dust taken from the childrens’ bedrooms. In the present study we examined associations between the concentrations of different phthalate esters in the dust from these bedrooms and various characteristics of the home. The study focused on BBzP and DEHP because these were the phthalates associated with health complaints. Associations have been examined using parametric and nonparametric tests as well as multiple logistic regression. For both BBzP and DEHP, we found associations between their dust concentrations and the amount of polyvinyl chloride (PVC) used as flooring and wall material in the home. Furthermore, high concentrations of BBzP (above median) were associated with self-reported water leakage in the home, and high concentrations of DEHP were associated with buildings constructed before 1960. Other associations, as well as absence of associations, are reported. Both BBzP and DEHP were found in buildings with neither PVC flooring nor wall covering, consistent with the numerous additional plasticized materials that are anticipated to be present in a typical home. The building characteristics examined in this study cannot serve as complete proxies for these quite varied sources. However, the associations reported here can help identify homes where phthalate concentrations are likely to be elevated and can aid in developing mitigation strategies

    The Association between Asthma and Allergic Symptoms in Children and Phthalates in House Dust: A Nested Case–Control Study

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    Global phthalate ester production has increased from very low levels at the end of World War II to approximately 3.5 million metric tons/year. The aim of the present study was to investigate potential associations between persistent allergic symptoms in children, which have increased markedly in developed countries over the past three decades, and the concentration of phthalates in dust collected from their homes. This investigation is a case–control study nested within a cohort of 10,852 children. From the cohort, we selected 198 cases with persistent allergic symptoms and 202 controls without allergic symptoms. A clinical and a technical team investigated each child and her or his environment. We found higher median concentrations of butyl benzyl phthalate (BBzP) in dust among cases than among controls (0.15 vs. 0.12 mg/g dust). Analyzing the case group by symptoms showed that BBzP was associated with rhinitis (p = 0.001) and eczema (p = 0.001), whereas di(2-ethylhexyl) phthalate (DEHP) was associated with asthma (p = 0.022). Furthermore, dose–response relationships for these associations are supported by trend analyses. This study shows that phthalates, within the range of what is normally found in indoor environments, are associated with allergic symptoms in children. We believe that the different associations of symptoms for the three major phthalates—BBzP, DEHP, and di-n-butyl phthalate—can be explained by a combination of chemical physical properties and toxicologic potential. Given the phthalate exposures of children worldwide, the results from this study of Swedish children have global implications

    Origins Space Telescope: Baseline mission concept

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    The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid-and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20 μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250 μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588 μm, making wide-area and deep spectroscopic surveys with spectral resolving power R ∼ 300, and pointed observations at R ∼ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins\u27 natural background-limited sensitivity

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    The Origins Space Telescope

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    The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid- and far-infrared wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of Herschel, the largest telescope flown in space to date. After a 3 year study, the Origins Science and Technology Definition Team will recommend to the Decadal Survey a concept for Origins with a 5.9-m diameter telescope cryo cooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (MISC-T) will measure the spectra of transiting exoplanets in the 2.8 20 m wavelength range and offer unprecedented sensitivity, enabling definitive biosignature detections. The Far-IR Imager Polarimeter (FIP) will be able to survey thousands of square degrees with broadband imaging at 50 and 250 m. The Origins Survey Spectrometer (OSS) will cover wavelengths from 25 588 m, make wide-area and deep spectroscopic surveys with spectral resolving power R ~ 300, and pointed observations at R ~ 40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The telescope has a Spitzer-like architecture and requires very few deployments after launch. The cryo-thermal system design leverages JWST technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins natural background limited sensitivity

    Origins Space Telescope: baseline mission concept

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    The Origins Space Telescope will trace the history of our origins from the time dust and heavy elements permanently altered the cosmic landscape to present-day life. How did galaxies evolve from the earliest galactic systems to those found in the Universe today? How do habitable planets form? How common are life-bearing worlds? To answer these alluring questions, Origins will operate at mid- and far-infrared (IR) wavelengths and offer powerful spectroscopic instruments and sensitivity three orders of magnitude better than that of the Herschel Space Observatory, the largest telescope flown in space to date. We describe the baseline concept for Origins recommended to the 2020 US Decadal Survey in Astronomy and Astrophysics. The baseline design includes a 5.9-m diameter telescope cryocooled to 4.5 K and equipped with three scientific instruments. A mid-infrared instrument (Mid-Infrared Spectrometer and Camera Transit spectrometer) will measure the spectra of transiting exoplanets in the 2.8 to 20  μm wavelength range and offer unprecedented spectrophotometric precision, enabling definitive exoplanet biosignature detections. The far-IR imager polarimeter will be able to survey thousands of square degrees with broadband imaging at 50 and 250  μm. The Origins Survey Spectrometer will cover wavelengths from 25 to 588  μm, making wide-area and deep spectroscopic surveys with spectral resolving power R  ∼  300, and pointed observations at R  ∼  40,000 and 300,000 with selectable instrument modes. Origins was designed to minimize complexity. The architecture is similar to that of the Spitzer Space Telescope and requires very few deployments after launch, while the cryothermal system design leverages James Webb Space Telescope technology and experience. A combination of current-state-of-the-art cryocoolers and next-generation detector technology will enable Origins’ natural background-limited sensitivity

    Investigation of mineral water springs of Miercurea Ciuc (Csíkszereda) region (Romania) with cultivation-dependent microbiological methods

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    Water samples of ten mineral water springs at Miercurea Ciuc (Csíkszereda) region (Romania) were examined during 2005–2006 using cultivation-dependent microbiological methods. The results of standard hygienic bacteriological tests showed that the Hargita Spring had perfect and five other springs had microbiologically acceptable water quality (Zsögöd-, Nagy-borvíz-, Taploca-, Szentegyháza- and Lobogó springs). The water of Borsáros Spring was exceptionable (high germ count, presence of Enterococcus spp.).Both standard bacteriological and molecular microbiological methods indicated that the microbiological water quality of the Szeltersz-, Nádasszék- and Délő springs was not acceptable. Bad water quality resulted from inadequate spring catchment and hygiene (low yield, lack of runoff, negligent usage of the springs, horse manure around the spring).The 16S rRNA gene-based identification of strains isolated on standard meat-peptone medium resulted in the detection of typical aquatic organisms such as Shewanella baltica, Aeromonas spp., Pseudomonas veronii, Psychrobacter sp,. Acinetobacter spp. and allochthonous microbes, like Nocardia, Streptomyces, Bacillus, Microbacterium , and Arthrobacter strains indicating the impact of soil. Other allochthonous microbes, such as Staphylococcus spp., Micrococcus sp., Lactococcus sp., Clostridium butyricum, Yersinia spp., Aerococcus sp., may have originated from animal/human sources
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