ZnO nanomaterials with different shapes were synthesized, characterized and tested in the selective monitoring of low concentration of CO and NO₂ in air. ZnO nanoparticles (NPs) and nanofibers (NFs) were synthesized by a modified sol-gel method in supercritical conditions and electrospinning technique, respectively. CO and NO₂ sensing tests have demonstrated that the annealing temperature and s...

The main purpose of this paper is to analyze some characteristics of gravity waves (GWs), and seasonal variations of atmospheric waves over Istanbul by using wavelet techniques. Daily radiosonda data of Istanbul in the troposphere and lower stratosphere (1000 hPa–30 hPa) between 1993 and 1997 have been considered. Wavelet analysis based on a computer simulation of data is generally close to the...

[1] Tropical convective anvil clouds detrain preferentially near 200 hPa. It is argued here that this occurs because clear-sky radiative cooling decreases rapidly near 200 hPa. This rapid decline of clear-sky longwave cooling occurs because radiative emission from water vapor becomes inefficient above 200 hPa. The emission from water vapor becomes less important than the emission from CO2 becau...

1. introduction the position of iran in the subtropical region that has made its arid and semiarid climate and the topographic diversity changes this trend of climate. therefore, climate hazards such as frost, flood, dust storm, drought, temperature anomalies, heavy rainfall, avalanches, snow, sleet, etc occur in iran. the northwest of iran experiences the above conditions following the arrival...

Effects of temperature and oxygen concentration on decarburization of 55SiCr spring steel were investigated at the temperature range of 500°C–1 200°C by using a Muffle furnace (an atmosphere of ambient air) and a Simultaneous Thermal Analyzer (low oxygen concentration with 2% O2 and 98% N2). In ambient air, the decarburization behavior can be divided roughly into five temperature ranges: T≥1 20...

Both extreme heat and heavy air pollution can cause adverse health impacts on urban inhabitants. To understand stress its relationship with boundary layer structure in Beijing, this study analyzed surface meteorological observations, radiosonde measurements, ground-level PM 2.5 O 3 concentrations summer from 2015 to 2019, conjunction simulated quality MERRA-2 data. We measured the using a index...

This work describes a high temperature corrosion kinetics study of ?30 % porous Fe22Cr alloys. The surface area the alloy (?0.02 m2 g?1) has been determined by tomographic microscopy. weight gain alloys was studied isothermal thermogravimetry in air for 100 h at 700–900 °C. Breakaway oxidation observed after 850 °C (?100 h) and 900 (?30 h). lifetime prediction shows investigated can be used >30...