3,653 research outputs found
On-line process analysis innovation: DiComp (tm) shunting dielectric sensor technology
The DiComp Shunting Dielectric Sensor (SDS) is a new patent-pending technology developed under the Small Business Innovation Research Program (SBIR) for NASA's Kennedy Space Center. The incorporation of a shunt electrode into a conventional fringing field dielectric sensor makes the SDS uniquely sensitive to changes in material dielectric properties in the KHz to MHz range which were previously detectable only at GHz measurement frequencies. The initial NASA application of the SDS for Nutrient Delivery Control has demonstrated SDS capabilities for thickness and concentration measurement of Hoagland nutrient solutions. The commercial introduction of DiComp SDS technology for concentration and percent solids measurements in dispersions, emulsions and solutions represents a new technology for process measurements for liquids in a variety of industries
Restoring Acipenser sturio L., 1758 in Europe: Lessons from the Acipenser oxyrinchus Mitchill, 1815 experience in North America
Acipenser sturio L., 1758 estuvo ampliamente distribuido y fue común en Europa, pero ahora persiste precariamente en estado silvestre sólo en poblaciones relictas. Su especie hermana, el morfológica y ecológicamente similar Acipenser oxyrinchus Mitchill, 1815, existe en el Atlántico norte occidental. Aunque ambas formas han padecido los mismos tres riesgos —sobrepesca, modificación del hábitat y contaminación— sus efectos netos han sido mucho mayores en A. sturio. Históricamente hubo, al menos, 35 poblaciones de A. oxyrinchus en América del Norte; su estado actual varía entre moderadamente abundante a posiblemente extirpado. Sin embargo, el interés por la conservación de A. oxyrinchus ha crecido importantemente durante las dos últimas décadas y se han dado grandes pasos hacia su recuperación. Las técnicas utilizadas han incluido inspecciones de información anecdótica, revisiones directas de las pescas, análisis genético detallado, mejora del cultivo en criadero, sueltas experimentales de juveniles producidos en criadero e investigación básica de la historia natural. Además, la gravedad de los bruscos declives frente a los repentinos aumentos de las pescas reunió la voluntad política para proteger a A. oxyrinchus de la pesca directa en las aguas estadounidenses por un periodo de hasta 40 años (aunque la captura ocasional continúa siendo un problema). Debido a que su tasa intrínseca de crecimiento es muy lenta, tendrán que pasar décadas antes de que poblaciones particulares sean de nuevo abundantes. No obstante, el futuro para A. oxyrinchus parece prometedor. A. sturio es tan escaso que cada ejemplar es precioso; así, es arriesgado experimentar con ellos. Pero dadas las similitudes entre las dos especies, los que pretenden recuperar A. sturio serían capaces de adaptar mucha de la información aprendida de los gestores de A. oxyrinchus.Acipenser sturio L., 1758 was once wide-ranging and common in Europe, but it now persists precariously in the wild only in relict populations. Its sister species, the morphologically and ecologically similar Acipenser oxyrinchus Mitchill, 1815, exists in the western North Atlantic. Although both forms have suffered from the same three liabilities -overharvest, habitat modification, and pollution- their net effects have been far greater for A. sturio. Historically, there were at least 35 populations of A. oxyrinchus in North America; their present statuses range from moderately abundant to possibly extirpated. However, interest in conservation of A. oxyrinchus has increased greatly over the past two decades and great strides have been made toward their restoration. Techniques used have included surveys of anecdotal information, directed fisheries surveys, comprehensive genetic analysis, hatchery culture improvements, experimental stockings of hatcheryproduced young, and fundamental life history research. Moreover, the seriousness of sharp declines in the face of suddenly enlarged fisheries mustered the political will to protect A. oxyrinchus from directed fisheries in U.S. waters for a period of up to 40 years (although by-catch remains a concern). Because their intrinsic rate of increase is very protracted, it will be decades before particular populations are once again abundant. Nonetheless, the future for A. oxyrinchus appears promising. A. sturio is so scarce that each specimen is precious; thus, it is risky to experiment with them. But given the similarities between the two species, those seeking to restore A. sturio should be able to adapt much of the information learned from managers of A. oxyrinchus.Instituto Español de Oceanografí
Instrument to collect fogwater for chemical analysis
An instrument is presented which collects large samples of ambient fogwater by impaction of droplets on a screen. The collection efficiency of the instrument is determined as a function of droplet size, and it is shown that fog droplets in the range 3–100-µm diameter are efficiently collected. No significant evaporation or condensation occurs at any stage of the collection process. Field testing indicates that samples collected are representative of the ambient fogwater. The instrument may easily be automated, and is suitable for use in routine air quality monitoring programs
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Coccidioidomycosis Complement Fixation Titer Trends in the Age of Antifungals.
Coccidioidomycosis is associated with a broad spectrum of illness severity, ranging from asymptomatic or self-limited pulmonary infection to life-threatening manifestations of disseminated disease. Serologic studies before the widespread availability of antifungals established current understanding of serologic kinetics and dynamics. Chart histories and complement fixation (CF) titer trends were analyzed for 434 antifungal-treated coccidioidomycosis patients, who were classified by three infectious disease physicians as having either pulmonary uncomplicated coccidioidomycosis (PUC) (n = 248), pulmonary chronic coccidioidomycosis (PCC) (n = 64), disseminated coccidioidomycosis (DC) not including meningitis (n = 86), or coccidioidal meningitis (CM) (n = 36). The median maximal CF titers were 1:4 for PUC patients, 1:24 for PCC patients, 1:128 for DC patients, and 1:32 for CM patients. Approximately 25.4% of PUC patients, 6.2% of PCC patients, 2.3% of DC patients, and 8.3% of CM patients did not develop detectable titers during the study period. Maximal titers developed a mean of 31 days (95% confidence interval [CI], 13 to 50 days) after initial serologic positivity, with no significant differences between groups. Serologic recurrence occurred in 9% of PUC patients, 36% of PCC patients, 50% of DC patients, and 52% of CM patients. Median titer improvement rates were 91 days/dilution for PUC patients, 112 days/dilution for PCC patients, 136 days/dilution for DC patients, and 146 days/dilution for CM patients. Receiver operating characteristic (ROC) analysis revealed that CF testing retains moderate classification value for disseminated infections (area under the curve [AUC], 0.82 [95% CI, 0.78 to 0.87]) and complicated infections (AUC, 0.82 [95% CI, 0.77 to 0.86]). A suitable cutoff value for complicated infections is ≥1:32. Findings update serologic parameters that are relevant for clinical assessment of coccidioidomycosis patients in the triazole era
Carbon-poor stellar cores as supernova progenitors
Exploring stellar models which ignite carbon off-center (in the mass range of
about 1.05 - 1.25 Msun, depending on the carbon mass fraction) we find that
they may present an interesting SN I progenitor scenario, since whereas in the
standard scenario runaway always takes place at the same density of about 2 X
10^9 gr/cm^3, in our case, due to the small amount of carbon ignited, we get a
whole range of densities from 1 X 10^9 up to 6 X 10^9 gr/cm^3. These results
could contribute in resolving the emerging recognition that at least some
diversity among SNe I exists, since runaway at various central densities is
expected to yield various outcomes in terms of the velocities and composition
of the ejecta, which should be modeled and compared to observations.Comment: 49 pages, 20 figure
New separation protocol reveals spray painting as a neglected source of microplastics in soils
Microplastics are recently discovered contaminants, yet knowledge on their sources and analysis is limited. For instance, paint microplastics are poorly known because soil separation protocols using flotation solutions cannot separate paint microplastics due to the higher density of paint microplastic versus common microplastics. Here, we designed a new two-step density separation protocol for paint microplastics, allowing paint microplastics to be separated from the soil without digestion. Paint particles were separated from soil samples collected around the graffiti wall at the Mauerpark, Berlin, then quantified according to their shape and color characteristic. The presence of polymers as binders in the paint particles was verified by Fourier transform infrared spectroscopy. Results show concentrations from 1.1 × 105 to 2.9 × 105 microplastics per Kg of dry soil, representing the highest microplastic concentration ever reported in the literature. Particle concentrations decreased and the median size increased with soil depth. Our results provide first evidence that spray painting, a technique with a wide range of applications from industry to art, leaves a legacy of environmental microplastic in soils that has so far gone unnoticed
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