Infrared spectroscopy of model tropospheric aerosols as a function of relative humidity: Observation of deliquescence and crystallization

1997 ◽  
Vol 102 (D15) ◽  
pp. 18843-18850 ◽  
Author(s):  
D. J. Cziczo ◽  
J. B. Nowak ◽  
J. H. Hu ◽  
J. P. D. Abbatt
Keyword(s):  
Infrared Spectroscopy ◽  
Relative Humidity ◽  
Tropospheric Aerosols

Plasma Polymerization of Hexamethyldisiloxane and Tetraethoxysilane Thin Films for Humidity Sensing Application

2014 ◽  
Vol 354 ◽  
pp. 41-47 ◽  
Author(s):  
N. Guermat ◽  
A. Bellel ◽  
Salah Sahli ◽  
Yvan Segui ◽  
Patrice Raynaud
Keyword(s):  
Thin Films ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Relative Humidity ◽  
Plasma Polymerization ◽  
Humidity Sensing ◽  
Response And Recovery ◽  
Sensing Application ◽  
Higher Sensitivity ◽  
Humidity Sensing Properties

Humidity sensitive layers elaborated from pure HMDSO and TEOS by PECVD technique have been studied. Humidity sensing properties including impedance relative humidity (RH) and current RH characteristics were investigated. TEOS films show higher sensitivity and excellent linearity over the explored range of humidity (20–95% RH). However, HMDSO films exhibits a small response and recovery of about 8 and 34 s for humidification and desiccation, respectively, in addition to very low hysteresis (2%). Structural analyses of sensitive layers were characterized by Fourier transform infrared spectroscopy (FTIR).

scholarly journals Growth of upper tropospheric aerosols due to uptake of HNO<sub>3</sub>

2004 ◽  
Vol 4 (1) ◽  
pp. 121-140
Author(s):  
S. Romakkaniemi ◽  
H. Kokkola ◽  
A. Petzold ◽  
A. Laaksonen
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Relative Humidity ◽  
Low Temperatures ◽  
Size Distributions ◽  
Mixing Ratios ◽  
Equilibrium Size ◽  
Tropospheric Aerosols ◽  
Sulfuric Acid Aerosols ◽  
Equilibrium Calculations

Abstract. The effect of nitric acid on the equilibrium size distributions of upper tropospheric aerosols is calculated as a function of relative humidity. It is shown that HNO3 concentrations above a few tenths of a ppb can cause substantial increases in haze mode particle concentrations at relative humidities at about 60% and above. The effect can be strongly magnified when letovicite particles are present in addition to sulfuric acid aerosols. This is mainly due to the lowering of the deliquescence RH of letovicite in the presence of gaseous nitric acid at low temperatures. We have also compared equilibrium calculations of the HNO3 effect with observations of increased haze mode concentrations at relative humidities above 50% (Petzold et al., 2000). Nitric acid mixing ratios on the order of 0.5–2 ppb may explain the observed increase of haze mode particles at least partially.

scholarly journals Growth of upper tropospheric aerosols due to uptake of HNO<sub>3</sub>

2004 ◽  
Vol 4 (2) ◽  
pp. 549-556 ◽  
Author(s):  
S. Romakkaniemi ◽  
H. Kokkola ◽  
A. Petzold ◽  
A. Laaksonen
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Relative Humidity ◽  
Low Temperatures ◽  
Size Distributions ◽  
Mixing Ratios ◽  
Equilibrium Size ◽  
Tropospheric Aerosols ◽  
Sulfuric Acid Aerosols ◽  
Equilibrium Calculations

Abstract. The effect of nitric acid on the equilibrium size distributions of upper tropospheric aerosols is calculated as a function of relative humidity. It is shown that HNO3 concentrations above a few tenths of a ppb can cause substantial increases in haze mode particle concentrations at relative humidities at about 60% and above. The effect can be strongly magnified when letovicite particles are present in addition to sulfuric acid aerosols. Letovicite particles are less acidic than the sulfuric acid particles and so more nitric acid can be absorbed. This effect can be seen even at RH below 50% due to the lowering of the deliquescence RH of letovicite in the presence of gaseous nitric acid at low temperatures. We have also compared equilibrium calculations of the HNO3 effect with observations of increased haze mode concentrations at relative humidities above 50% (Petzold et al., 2000). Nitric acid mixing ratios on the order of 0.5-2ppb may explain the observed increase of haze mode particles at least partially.

Understanding the responses of Saccharomyces cerevisiae yeast strain during dehydration processes using synchrotron infrared spectroscopy

The Analyst ◽  
2017 ◽  
Vol 142 (19) ◽  
pp. 3620-3628 ◽  
Author(s):  
T. D. Nguyen ◽  
S. Guyot ◽  
C. Pénicaud ◽  
S. Passot ◽  
C. Sandt ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Infrared Spectroscopy ◽  
Relative Humidity ◽  
Real Time ◽  
Yeast Strain ◽  
Dehydration Processes ◽  
First Time

For the first time, synchrotron infrared spectroscopy was performed on yeast during dehydration processes in real time with simultaneously controlled relative humidity and temperature.

Millimetre-wave and infrared spectroscopy of Br13 CN: anharmonic force field of cyanogen bromide from spectroscopic data and ab initio calculations

1997 ◽  
Vol 90 (3) ◽  
pp. 495-497
Author(s):  
CLAUDIO ESPOSTI ◽  
FILIPPO TAMASSIA ◽  
CRISTINA PUZZARINI ◽  
RICCARDO TARRONI ◽  
ZDENEK ZELINGER
Keyword(s):  
Infrared Spectroscopy ◽  
Force Field ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Spectroscopic Data ◽  
Cyanogen Bromide ◽  
Millimetre Wave ◽  
Anharmonic Force
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