Search results for "Bt"
showing 10 items of 1498 documents
Constraints on the Coupling between Axionlike Dark Matter and Photons Using an Antiproton Superconducting Tuned Detection Circuit in a Cryogenic Penn…
2021
We constrain the coupling between axionlike particles (ALPs) and photons, measured with the superconducting resonant detection circuit of a cryogenic Penning trap. By searching the noise spectrum of our fixed-frequency resonant circuit for peaks caused by dark matter ALPs converting into photons in the strong magnetic field of the Penning-trap magnet, we are able to constrain the coupling of ALPs with masses around $2.7906-2.7914\,\textrm{neV/c}^2$ to $g_{a\gamma}< 1 \times 10^{-11}\,\textrm{GeV}^{-1}$. This is more than one order of magnitude lower than the best laboratory haloscope and approximately 5 times lower than the CERN axion solar telescope (CAST), setting limits in a mass and cou…
The Extratropical Transition of Tropical Cyclones. Part I: Cyclone Evolution and Direct Impacts
2017
Extratropical transition (ET) is the process by which a tropical cyclone, upon encountering a baroclinic environment and reduced sea surface temperature at higher latitudes, transforms into an extratropical cyclone. This process is influenced by, and influences, phenomena from the tropics to the midlatitudes and from the meso- to the planetary scales to extents that vary between individual events. Motivated in part by recent high-impact and/or extensively observed events such as North Atlantic Hurricane Sandy in 2012 and western North Pacific Typhoon Sinlaku in 2008, this review details advances in understanding and predicting ET since the publication of an earlier review in 2003. Methods …
Development of a simulation chamber for the evaluation of dermal absorption of volatile organic compounds
2020
Abstract An exposition chamber has been designed and developed for the production of contaminated atmospheres with fixed and known concentration of volatile organic compounds. The proposed chamber has been evaluated for the determination of in-vitro diffusion parameters, such as flux and lag time for benzene, toluene, ethylbenzene, and xylenes (BTEX). Polydimethylsiloxane (PDMS) and Strat-M® membranes were evaluated, including the effect of membrane thickness, from 0.5 to 3.0 mm, on the diffusion parameters. The obtained flux values and lag times, ranged from 0.2 to 1.5 μg cm−2 h−1 and from 10 to 130 min, respectively, for studies performed at a BTEX concentration of 51 μg L−1 in air. Diffe…
Quasi-decadal signals of Sahel rainfall and West African monsoon since the mid-twentieth century
2013
[1] Sahel rainfall shows pronounced decadal variability and a negative trend between wet conditions in the 1950s–1960s and dry ones in the 1970s–1980s. Using continuous wavelet transform, the quasi-decadal variability (QDV) of rainfall reveals zonal contrasts. The highest QDV is identified in the 1950s–1960s over western Sahel and in the 1970s–1980s over eastern Sahel. The quasi-decadal atmospheric anomalies have been reconstructed using Fourier transform for the 1950s–1960s and the 1970s–1980s, respectively, and assessed by the composite analysis of the QDV phases for the periods before and after 1968. Over western Sahel, the rainfall QDV in the 1950s–1960s is related to the North Atlantic…
Outdoor, indoor and personal distribution of BTEX in pregnant women from two areas in Spain - Preliminary results from the INMA project
2010
Volatile organic compounds (VOCs), which are habitually found in both outdoor and indoor environments, may represent a significant health risk. In this context, pregnancy is a critical period since foetuses are more vulnerable than adults to exposure to toxic compounds. The objective of this study is to present the preliminary results of a series of measurements of outdoor (O), indoor (I) and personal exposure (P) to benzene, toluene, ethylbenzene, o-xylene and m,p-xylene (BTEX) in 107 pregnant women from two areas in Spain, namely Valencia and Sabadell. BTEX samplers were installed for 48 hours both inside and outside of the women’s homes, along with personal samplers. In addition, the tes…
Study on ambient concentrations of PM10, PM10-2.5, PM2.5 and gaseous pollutants. Trace elements and chemical speciation of atmospheric particulates
2010
Abstract This study provides the first comprehensive report on mass concentrations of particulate matter of various sizes, inorganic and organic gas concentrations monitored at three sampling sites in the city of Palermo (Sicily, Italy). It also provides information on the water-soluble species and trace elements. A total of 2054 PM10 (1333) and PM2.5 (721) daily measurements were collected from November 2006 to February 2008. The highest mass concentrations were observed at the urban stations, average values being about two times higher than those at the suburban (control) site. Time variations in PM10 and also PM10–2.5 were observed at the urban stations, the highest concentrations being …
A Lagrangian Climatology of Tropical Moisture Exports to the Northern Hemispheric Extratropics
2010
Abstract Case studies have shown that heavy precipitation events and rapid cyclogenesis in the extratropics can be fueled by moist and warm tropical air masses. Often the tropical moisture export (TME) occurs through a longitudinally confined region in the subtropics. Here a comprehensive climatological analysis of TME is constructed on the basis of seven-day forward trajectories started daily from the tropical lower troposphere using 6-hourly 40-yr ECMWF Re-Analysis (ERA-40) data from the 23-year period 1979–2001. The objective TME identification procedure retains only those trajectories that reach a water vapor flux of at least 100 g kg−1 m s−1 somewhere north of 35°N. The results show fo…
Studies on the impact of winter climate on rubber and wheat cultivation in the mountains of southern China, applying a fuzzy cluster analysis
1992
Data from climatic stations in China, located south of 30° N and > 400 m above sea-level, were analysed in order to study the relationship with winter climate, on the one hand, and with rubber and winter wheat cultivation, on the other. Three relevant agroclimatic parameters were investigated for January, namely mean temperature, precipitation total and sunshine duration. By applying a fuzzy cluster analysis, three agroclimatic regions were found in winter; the boundaries coincide with the macro-scale topography of southern China. In one case the boundary even corresponds with the position of the Kunming quasi-stationary front. Winter climate in the three agroclimatic regions was found to s…
Orographic Effects and Evaporative Cooling along a Subtropical Cold Front: The Case of the Spectacular Saharan Dust Outbreak of March 2004
2012
Abstract On 2 March 2004 a marked upper-level trough and an associated surface cold front penetrated into the Sahara. High winds along and behind this frontal system led to an extraordinary, large-scale, and long-lived dust outbreak, accompanied by significant precipitation over parts of Algeria, Tunisia, and Libya. This paper uses sensitivity simulations with the limited-area model developed by the Consortium for Small-Scale Modeling (COSMO) together with analysis data and surface observations to test several hypotheses on the dynamics of this case proposed in previous work. It is demonstrated that air over central Algeria is cooled by evaporation of frontal precipitation, substantially en…
Dynamics of a local Alpine flooding event in October 2011: moisture source and large‐scale circulation
2014
Alpine heavy precipitation events often affect small catchments, although the circulation pattern leading to the event extends over the entire North Atlantic. The various scale interactions involved are particularly challenging for the numerical weather prediction of such events. Unlike previous studies focusing on the southern Alps, here a comprehensive study of a heavy precipitation event in the northern Alps in October 2011 is presented with particular focus on the role of the large-scale circulation in the North Atlantic/European region. During the event exceptionally high amounts of total precipitable water occurred in and north of the Alps. This moisture was initially transported alon…