نتایج جستجو برای: atmospheric threshold
تعداد نتایج: 198677 فیلتر نتایج به سال:
Changes in cellular O2 levels elicit adaptive responses which can lead to the activation of oxygen-dependent transcription factors such as the hypoxia-inducible factor (HIF). However, our understanding of the determinants of these processes is still incomplete. Using the new intracellular O2 sensing technique, we monitored O2 gradients in static cultures of adherent PC12 cells exposed to graded...
Developing effective strategies for reducing the atmospheric pollutant concentrations below regulatory threshold levels requires identifying the main origins/sources of air pollution. This can be achieved by implementing so called source apportionment methods in atmospheric dispersion models. This study presents the results of a source apportionment module implemented in the SIRANE urban air-qu...
ABSTRACT Field olfactometry is one of the sensory techniques used to determine odour concentration, in atmospheric air, directly in emission sources. A two-dimensional gas chromatography with time of flight mass spectrometer (GC×GC-TOF-MS) allows performing the chemical characterization of various groups of chemical compounds, even in complex mixtures. Application of these techniques enabled de...
We fabricate monolayer MoS2 field effect transistors and study their electric characteristics from 10^-6 Torr to atmospheric air pressure. show that the threshold voltage of transistor increases with growing Hence, we propose device as an pressure sensor, showing it is particularly suitable a low power consumption vacuum gauge. The functions on pressure-dependent O2, N2 H2O molecule adsorption ...
Ultrashort laser pulses have been adapted for use in a variety of applications from micromachining of dielectrics to atmospheric spectrochemistry and multiphoton microscopy. These lasers emit almost exclusively in the retinal hazard wavelength regime, making them potential sources for accidental vision loss, but also candidates for biomedical applications where precise alteration of tissues is ...
Ternary homogeneous nucleation (THN) of H2SO4, NH3 and H2O has been used to explain new particle formation in various atmospheric regions, yet laboratory measurements of THN have failed to reproduce atmospheric observations. Here, we report first laboratory observations of THN made under conditions relevant to the lower troposphere ([H2SO4] of 106–107 cm−3, [NH3] of 0.08–20 ppbv, and a temperat...
From the health stand-point, atmospheric particulate matter (PM) is regulated through PM(10) and PM(2.5) conventions by the Directive 2008/50/EC. The Directive points out the negative impact on human health due to PM(2.5) and recognizes that no threshold has been identified for such pollutant at which no risk is foreseen for the population. Then, the goal is to pursue a general reduction of PM(...
the present research article highlights the metal (cd, cu, pb, zn and fe)distribution pattern in the rspm generated in different hot spot sites located at kochi, thequeen of arabian sea. these sampling sites are categorized under three different zonesas estuarine, riverine, and coastal. two sampling phases are selected in order to check theconsistency in pollution trend after a two year gap and...
Foraminiferal oxygen isotopes from deep-sea sediment cores suggest that a rapid expansion of the Antarctic ice sheet took place in the Middle Miocene around 13.9 million years ago. The origin for this transition is still not understood satisfactorily. One possible cause is a drop in the partial pressure of atmospheric carbon dioxide (pCO2) in combination with orbital forcing. A complication is ...
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