Articles de revues : « Aerosol deposition (ADM) »

1

Mihara, Kensuke, Takuya Hoshina, Hirofumi Kakemoto, Hiroaki Takeda et Takaaki Tsurumi. « Effects of Pretreatments on Deposition Rate of Films in Aerosol Deposition Method ». Key Engineering Materials 421-422 (décembre 2009) : 165–68. http://dx.doi.org/10.4028/www.scientific.net/kem.421-422.165.

Texte intégral

Résumé :

In the aerosol deposition method (ADM), we investigated an influence of pre-treatments for barium titanate powders as raw material on the deposition rate of thick films. By sieving and drying the powder, deposition rate of the films fabricated by ADM was effectively enhanced. On the other hand, heating the powders at 400-800°C, the resulting powders caused low deposition rate of the films. When a planetary milling was performed prior to charge aerosol chamber, the deposition rate of the films was four times higher than that in deposition using the powder without milling. By changing the milling rotation rate, we control size of agglomerated particles consisting of powders, which results in the control of deposition rate of the films.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Akedo, Jun. « Aerosol Deposition Method for Fabrication of Nano Crystal Ceramic Layer ». Materials Science Forum 449-452 (mars 2004) : 43–48. http://dx.doi.org/10.4028/www.scientific.net/msf.449-452.43.

Texte intégral

Résumé :

Aerosol deposition method (ADM) for shock-consolidation of fine ceramics powder to form dense and hard layers is reported. Submicron ceramic particles were accelerated by gas flow in the nozzle up to velocity of several hundred m/s. During interaction with substrate, these particles formed thick (10 ~ 100 µm), dense, uniform and hard ceramics layers. Depositions were fulfilled at room temperature. Every layer has polycrystalline structure with nano-meter order scale.􀀂 The results of fabrications, microstructure, mechanical and electrical properties of oxides (α-Al2O3; Pb(Zr0.52,Ti0.48)O3 etc.) and non-oxides materials are presented.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Uemichi, Yuta, Koji Nishikawa, Yuuki Sato et Shinzo Yoshikado. « Fabrication and Evaluation of Al₂O₃ Films Using the Aerosol Deposition Method ». Key Engineering Materials 485 (juillet 2011) : 211–14. http://dx.doi.org/10.4028/www.scientific.net/kem.485.211.

Texte intégral

Résumé :

Equipment was designed for the application of Al2O3 thin films by the aerosol deposition method (ADM) at room temperature. Al2O3 film could be deposited on Pyrex-glass, indium tin oxide (ITO), polyvinyl chloride (PVC) plastic, single crystal silicon, and sapphire substrates. The films had the same crystal structure as the raw material particles and were highly transparent. The breakdown electric field of the Al2O3 film for the ADM was more than 35 kV/mm.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Leupold, Nico, Michael Schubert, Jaroslaw Kita et Ralf Moos. « Influence of high temperature annealing on the dielectric properties of alumina films prepared by the aerosol deposition method ». Functional Materials Letters 11, n^o 02 (avril 2018) : 1850022. http://dx.doi.org/10.1142/s1793604718500224.

Texte intégral

Résumé :

The aerosol deposition method (ADM) is a novel coating technique that allows to fabricate dense and nanocrystalline ceramic films at room temperature. To investigate the dielectric properties of aerosol deposited alumina films at high temperatures and the influence of annealing on them, the temperature was increased in steps of 100[Formula: see text]C from 200[Formula: see text]C to 900[Formula: see text]C and subsequently cooled down stepwise again. At each step, the dielectric properties were measured by impedance spectroscopy between 50[Formula: see text]mHz and 200[Formula: see text]kHz. During the heating steps, the relative permittivity and also the loss tangent showed a disordered behavior with various maxima in the loss tangent. After reaching 900[Formula: see text]C, during cooling, the behavior was more ordered, and the loss tangent exhibited only one maximum that appeared at lower frequencies. Overall, the annealing reduces the loss tangent at low frequencies and low temperatures. The origin of this behavior could lie in the annealing of defects, which are incorporated into the layer when the particles hit the surface of the substrate and crack while being deposited via ADM following the room temperature impact consolidation mechanism (RTIC).

Styles APA, Harvard, Vancouver, ISO, etc.

5

Ma, Ji Feng, Yuan Hua Lin, Ce Wen Nan et Takaaki Tsurumi. « Preparation and Properties of CaCu₃Ti₄O₁₂ Thick Film by Aerosol Deposition Method ». Key Engineering Materials 368-372 (février 2008) : 126–28. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.126.

Texte intégral

Résumé :

CaCu3Ti4O12 (CCTO) ceramic thick films have been prepared on Copper substrate, using ceramic powders by an aerosol deposition method (ADM). The ceramic powders are prepared by traditional solid state reaction processing at 1100 oC for 5 h. X-ray diffraction and scanning electron microscopy are used to investigate the microstructure and the phase composition of the deposited films. The results indicate that thick films are pure CCTO phase and homogenous. The dielectric impedance spectra indicate that the dielectric constant of CCTO thick film can reach 3×103.

Styles APA, Harvard, Vancouver, ISO, etc.

6

Schubert, Michaela, Jaroslaw Kita, Christian Münch et Ralf Moos. « Analysis of the characteristics of thick-film NTC thermistor devices manufactured by screen-printing and firing technique and by room temperature aerosol deposition method (ADM) ». Functional Materials Letters 10, n^o 06 (décembre 2017) : 1750073. http://dx.doi.org/10.1142/s1793604717500734.

Texte intégral

Résumé :

The study compares thick-film NTC thermistor devices, produced by the screen-printing (and firing) technique and by the Aerosol Deposition Method (ADM) at room temperature. The devices are compared with respect to film quality (optical, mechanical) and to the negative temperature coefficient of resistance (NTCR) parameters [Formula: see text] and [Formula: see text]. While the screen-printed films are porous, the Aerosol Deposited (AD) films are characterized by high tightness, mechanical stability, and a production at room temperature. The electrical analysis shows that the AD films reach the [Formula: see text]- and [Formula: see text]-values of bulk NTCRs from literature after a moderate tempering step below 400[Formula: see text]C in air. The screen-printed films show [Formula: see text]-values that are comparable to the values of bulk NTCRs from literature and [Formula: see text]-values that are significantly higher.

Styles APA, Harvard, Vancouver, ISO, etc.

7

SONG, WOOJIN, KYUBONG JUNG, DOO-MAN CHUN, SUNG-HOON AHN et CAROLINE SUNYONG LEE. « DEPOSITION OF Al2O3 POWDERS USING NANO-PARTICLE DEPOSITION SYSTEM ». Surface Review and Letters 17, n^o 02 (avril 2010) : 189–93. http://dx.doi.org/10.1142/s0218625x10013710.

Texte intégral

Résumé :

In this paper, alumina film was deposited using supersonic micronozzle in nano-particle deposition System (NPDS). Powder deposition at room temperature is important in the field of film deposition since high processing temperature can be a serious limitation for the deposition on flexible substrate. Previously, many studies have been reported on particle deposition, such as aerosol deposition method (ADM) or cold spray method. However, these deposition methods cannot be applied to various types of powders. Recently, NPDS using aluminum nozzle was designed to resolve these problems but it cannot deposit precise patterns less than 1 mm. In this study, alumina particles were deposited using Silicon-based micronozzle in NPDS. Three-dimensional silicon micronozzle was fabricated using semiconductor processing method, specifically deep reactive ion etching (DRIE) method. The silicon micronozzle fabricated by Bosch process is advantageous over the conventionally used nozzle, since the hardness of silicon is higher than that of aluminum and the lifetime can be increased. In this study, alumina nano-particles were accelerated to supersonic level at the neck of micronozzle and deposited on the substrate in a low vacuum condition. The film characteristics were evaluated using field-emission scanning electronic microscope (FE-SEM) and alpha step to measure its thickness of the deposited layer. The deposition result showed that alumina powders were successfully deposited using the fabricated micronozzle by means of NPDS.

Styles APA, Harvard, Vancouver, ISO, etc.

8

Isaza-Ruiz, Marllory, Joseph Henon, Olivier Durand-Panteix, Gregory Etchegoyen, Fabrice Rossignol et Pascal Marchet. « Elaboration of lead-free Na 0.5 Bi 0.5 TiO 3 –BaTiO 3 (NBT-BT) thick films by aerosol deposition method (ADM) ». Ceramics International 42, n^o 13 (octobre 2016) : 14635–41. http://dx.doi.org/10.1016/j.ceramint.2016.06.084.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

9

Donker, Nils, Daniela Schönauer-Kamin et Ralf Moos. « Mixed-Potential Ammonia Sensor Based on a Dense Yttria-Stabilized Zirconia Film Manufactured at Room Temperature by Powder Aerosol Deposition ». Sensors 24, n^o 3 (26 janvier 2024) : 811. http://dx.doi.org/10.3390/s24030811.

Texte intégral

Résumé :

Powder aerosol deposition (often abbreviated as PAD, PADM, or ADM) is a coating method used to obtain dense ceramic films at room temperature. The suitability of this method to obtain ammonia mixed-potential sensors based on an yttria-stabilized zirconia (YSZ) electrolyte that is manufactured using PAD and a V2O5–WO3–TiO2 (VWT)-covered electrode is investigated in this study. The sensor characteristics are compared with data from sensors with screen-printed YSZ solid electrolytes. The PAD sensors outperform those in terms of sensitivity with 117 mV/decade NH3 compared to 88 mV/decade. A variation in the sensor temperature shows that the NH3 sensitivity strongly depends on the sensor temperature and decreases with higher sensor temperature. Above 560 °C, the characteristic curve shifts from exponential to linear dependency. Variations in the water and the oxygen content in the base gas (usually 10% oxygen, 2% water vapor in nitrogen) reveal a strong dependence of the characteristic curve on the oxygen content. Water vapor concentration variations barely affect the sensor signal.

Styles APA, Harvard, Vancouver, ISO, etc.

10

Kim, C. S., M. A. Eldridge, L. Garcia et A. Wanner. « Aerosol deposition in the lung with asymmetric airways obstruction : in vivo observation ». Journal of Applied Physiology 67, n^o 6 (1 décembre 1989) : 2579–85. http://dx.doi.org/10.1152/jappl.1989.67.6.2579.

Texte intégral

Résumé :

Both the total and regional aerosol deposition were measured in six adult sheep before and after an induction of asymmetric airway obstructions, either by local instillation of carbachol solution (CS, 0.1%) distal to the right main bronchus or inhalation challenge of the right lung with carbachol aerosol (CA, 10 breaths). Total lung deposition was determined by monitoring inert monodisperse aerosols [1.0 micron mass median aerodynamic diam (MMAD)] breath-by-breath, at the mouth, by means of a laser aerosol photometer. Cumulative aerosol deposition over the first five breaths as a percent of the initial aerosol concentration (AD5) was used as a deposition index. Regional deposition pattern was determined by scintigraphic images of sulfur-colloid aerosol (1.5 microns MMAD) tagged with 99mTc. Radioactivity counts in the right (R) and left lung (L) were expressed as a percent of the whole lung count. Half-lung AD5 was then determined by multiplying AD5 by fractional radioaerosol depositions in R or L. Pulmonary airflow resistance (RL mean +/- SE), as determined by an esophageal balloon technique, increased by 111 +/- 28 and 250 +/- 96% after CA and CS, respectively (P less than 0.05). AD5 also increased in all the sheep tested by 29 +/- 3 and 52 +/- 8%, respectively, after CA and CS (P less than 0.05). Radioaerosol deposition pattern was even at base line (R/L = 51:49) but shifted toward the unchallenged L after CS (R/L = 40:60). Deposition pattern after CA was variable: a shift toward L in three, no change in one, and a shift toward the R lung in two sheep.(ABSTRACT TRUNCATED AT 250 WORDS)

Styles APA, Harvard, Vancouver, ISO, etc.

11

Bektas, Murat, Thomas Stöcker, Angelika Mergner, Gunter Hagen et Ralf Moos. « Combined resistive and thermoelectric oxygen sensor with almost temperature-independent characteristics ». Journal of Sensors and Sensor Systems 7, n^o 1 (16 avril 2018) : 289–97. http://dx.doi.org/10.5194/jsss-7-289-2018.

Texte intégral

Résumé :

Abstract. The present study is focused in two directions. In the first part, BaFe(1-x)-0.01Al0.01TaxO3−δ (BFATx) thick films with a Ta content between 0.1 and 0.4 were manufactured using the novel room temperature coating method “aerosol deposition” (ADM), and its material properties were characterized to find the best composition of BFATx for temperature-independent oxygen sensors. The material properties “Seebeck coefficient” and “conductivity” were determined between 600 and 800 ∘C at different oxygen partial pressures. BaFe0.69Al0.01Ta0.3O3−δ (BFAT30) was found out to be very promising due to the almost temperature-independent behavior of both the conductivity and the Seebeck coefficient. In the second part of this study, films of BFAT30 were prepared on a special transducer that includes a heater, equipotential layers, and special electrode structures so that a combined direct thermoelectric/resistive oxygen sensor of BFAT30 with almost temperature-independent characteristics of both measurands, Seebeck coefficient and conductance could be realized. At high oxygen partial pressures (pO2 > 10−5 bar), the electrical conductance of the sensor shows an oxygen sensitivity of m = 0.24 (with m being the slope in the logσ vs. logpO2 representation according to the behavior of σαpO2m), while the Seebeck coefficient changes with a slope of −38 µV K−1 per decade of pO2 at 700 ∘C. However, at low pO2 (pO2 < 10−14 bar) the conductance and the Seebeck coefficient change with pO2, with a slope of m = −0.23 and −21.2 µV K−1 per decade pO2, respectively.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Yang, Chu-Hao, Chun-Ping Hsiao, Jerry Chang, Hsin-Yu Lo et Yun-Chien Cheng. « Large area, rapid, and protein-harmless protein–plasma-polymerized-ethylene coating with aerosol-assisted remote atmospheric-pressure plasma deposition ». Journal of Physics D : Applied Physics 55, n^o 19 (15 février 2022) : 195203. http://dx.doi.org/10.1088/1361-6463/ac5148.

Texte intégral

Résumé :

Abstract Our goal is to establish a remote-plasma-based aerosol-assisted atmospheric-pressure plasma deposition (RAAPD) system for depositing protein–plasma-polymerized-ethylene coatings. The method of RAAPD is using plasma to polymerize ethylene and add protein aerosol at downstream region to coat protein–plasma-polymerized-ethylene on substrate. We investigated effects of different mixing, mesh, deposition distance, gas flow, voltage, and frequency. Results showed that downstream-mixing method reduced heat effects on protein. The optimal coating was achieved when using mesh, at a close deposition distance, with high flow rate of protein aerosol, and under high voltage. Compared with current methods, impacts of RAAPD include reducing effects of plasma generated heat, reactive species, and UV on protein, and deposition will not be limited by electrode area and substrate material.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Möhler, O., P. R. Field, P. Connolly, S. Benz, H. Saathoff, M. Schnaiter, R. Wagner et al. « Efficiency of the deposition mode ice nucleation on mineral dust particles ». Atmospheric Chemistry and Physics Discussions 6, n^o 1 (23 février 2006) : 1539–77. http://dx.doi.org/10.5194/acpd-6-1539-2006.

Texte intégral

Résumé :

Abstract. The deposition mode ice nucleation efficiency of various dust aerosols was investigated at cirrus cloud temperatures between 196 K and 223 K using the aerosol chamber facility AIDA (Aerosol Interaction and Dynamics in the Atmosphere). Arizona test dust (ATD) as a reference material and two dust samples from the Takla Makan desert in Asia (AD1) and Sahara (SD2) were used for the experiments at simulated cloud conditions. The dust particle sizes were almost lognormally distributed with mode diameters between 0.3 µm and 0.5 µm and geometric standard deviations between 1.6 and 1.9. Deposition ice nucleation was most efficient on ATD particles with ice-active particle fractions of about 0.6 and 0.8 at an ice saturation ratio Si<1.15 and temperatures of 223 K and 209 K, respectively. No significant change of the ice nucleation efficiency was found in up to three subsequent cycles of ice activation and evaporation with the same ATD aerosol. The desert dust samples SD2 and AD1 showed a significantly lower fraction of active deposition nuclei, about 0.25 at 223 K and Si<1.35. For all samples the ice activated aerosol fraction could be approximated by an exponential equation as function of Si. This formulation of ice activation spectra may be used to calculate the formation rate of ice crystals in models, if the number concentration of dust particles is known. More experimental work is needed to quantify the variability of the ice activation spectra as function of the temperature and dust particle properties.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Möhler, O., P. R. Field, P. Connolly, S. Benz, H. Saathoff, M. Schnaiter, R. Wagner et al. « Efficiency of the deposition mode ice nucleation on mineral dust particles ». Atmospheric Chemistry and Physics 6, n^o 10 (21 juillet 2006) : 3007–21. http://dx.doi.org/10.5194/acp-6-3007-2006.

Texte intégral

Résumé :

Abstract. The deposition mode ice nucleation efficiency of various dust aerosols was investigated at cirrus cloud temperatures between 196 and 223 K using the aerosol and cloud chamber facility AIDA (Aerosol Interaction and Dynamics in the Atmosphere). Arizona test dust (ATD) as a reference material and two dust samples from the Takla Makan desert in Asia (AD1) and the Sahara (SD2) were used for the experiments at simulated cloud conditions. The dust particle sizes were almost lognormally distributed with mode diameters between 0.3 and 0.5 μm and geometric standard deviations between 1.6 and 1.9. Deposition ice nucleation was most efficient on ATD particles with ice-active particle fractions of about 0.6 and 0.8 at an ice saturation ratio Si<1.15 and temperatures of 223 and 209 K, respectively. No significant change of the ice nucleation efficiency was found in up to three subsequent cycles of ice activation and evaporation with the same ATD aerosol. This indicates that the phenomenon of preactivation does not apply to ATD particles. The desert dust samples SD2 and AD1 showed a significantly lower fraction of active deposition nuclei, about 0.25 at 223 K and Si<1.35. For all samples the ice activated aerosol fraction could be approximated by an exponential equation as function of Si. This indicates that deposition ice nucleation on mineral particles may not be treated in the same stochastic sense as homogeneous freezing. The suggested formulation of ice activation spectra may be used to calculate the formation rate of ice crystals in models, if the number concentration of dust particles is known. More experimental work is needed to quantify the variability of the ice activation spectra as function of the temperature and dust particle properties.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Kim, C. S., L. Garcia, M. A. Eldridge et A. Wanner. « Persistence of enhanced aerosol deposition in the lung after recovery from carbachol-induced airway obstruction ». Journal of Applied Physiology 69, n^o 6 (1 décembre 1990) : 2104–12. http://dx.doi.org/10.1152/jappl.1990.69.6.2104.

Texte intégral

Résumé :

Time course recovery from induced airway obstruction by carbachol infusion (CI; 0.2 microgram.kg-1.min-1 for 40 min), carbachol aerosol (CA; 10 breaths of 2% solution), and histamine aerosol (HA; 25-50 breaths of 5% solution) challenge was investigated in conscious sheep (n = 6 each). Total lung aerosol deposition and airway caliber as assessed by pulmonary airflow resistance (RL) were measured every 20-30 min up to 4 h after the challenges. Aerosol deposition was measured by monitoring aerosol concentration continuously with a laser aerosol photometer while the sheep rebreathed 1.0-micron-diam inert oil droplets delivered by a 0.25-liter bag-in-box system driven by a respiratory pump at a breathing frequency of 30 breaths/min. Total accumulated deposition at the fifth breath (AD5) as percentage of the initial aerosol concentration was determined and used as an aerosol deposition index. Percent changes in AD5 from baseline were compared with corresponding changes in RL. Both RL and AD5 increased after Cl, CA, and HA: 192-477% for RL and 23-44% for AD5 (P less than 0.05). Mean RL return to baseline values 1 h after CI and HA and 2 h after CA. Mean AD5 returned to baseline at 1 h post-HA. In contrast, mean AD5 remained elevated for 2-4 h after CI and CA (P less than 0.05), and the increased AD5 could not be reversed by a bronchodilator aerosol. The persistence of enhanced aerosol deposition long after the return of RL to baseline suggests that complete recovery of airway conditions after CI and CA takes much longer than predicted by RL.(ABSTRACT TRUNCATED AT 250 WORDS)

Styles APA, Harvard, Vancouver, ISO, etc.

16

Tricoli, Antonio, Markus Graf, Felix Mayer, Stéphane Kuühne, Andreas Hierlemann et Sotiris E. Pratsinis. « Micropatterning Layers by Flame Aerosol Deposition-Annealing ». Advanced Materials 20, n^o 16 (18 août 2008) : 3005–10. http://dx.doi.org/10.1002/adma.200701844.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

17

Garcia, L., C. S. Kim, R. Forteza et A. Wanner. « Systemic pilocarpine increases deposition of and decreases responsiveness to inhaled carbachol in sheep ». Journal of Applied Physiology 73, n^o 6 (1 décembre 1992) : 2343–48. http://dx.doi.org/10.1152/jappl.1992.73.6.2343.

Texte intégral

Résumé :

The purpose of this study was to determine whether excessive airway secretions could serve as a barrier function against inhaled particulate matter. To increase airway secretions, six conscious sheep were treated with pilocarpine (0.8 mg/kg i.v.). Pilocarpine increased pulmonary resistance (RL) and total aerosol deposition within five breaths (AD5) as determined by the rebreathing of an inert monodisperse aerosol. When RL had returned to baseline, AD5 remained elevated [21 +/- 2% (SE), P < 0.05] and tracheal secretions were increased (237 +/- 77%, P < 0.05) above the values before pilocarpine administration. A carbachol aerosol dose-response curve was carried out at this time and compared with a control carbachol dose-response curve by calculating the dose of carbachol required to increase RL by 400% (PD400). Mean PD400 was increased postpilocarpine by 53 +/- 18 (P < 0.05) and 85 +/- 25% (P < 0.05) when normalized for increased aerosol deposition. Thus, pilocarpine decreased airway responsiveness to inhaled carbachol despite increasing aerosol deposition. The pilocarpine-induced airway hyporesponsiveness to inhaled carbachol is consistent with the hypothesis that excessive secretions have a protective role in the airways.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Zar, H. J. « Lung deposition of aerosol---a comparison of different spacers ». Archives of Disease in Childhood 82, n^o 6 (1 juin 2000) : 495–98. http://dx.doi.org/10.1136/adc.82.6.495.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

19

Kim, C. S., M. A. Eldridge et A. Wanner. « Airway responsiveness to inhaled and intravenous carbachol in sheep : effect of airway mucus ». Journal of Applied Physiology 65, n^o 6 (1 décembre 1988) : 2744–51. http://dx.doi.org/10.1152/jappl.1988.65.6.2744.

Texte intégral

Résumé :

Excessive airway mucus can alter both the mass and site of aerosol deposition, which, in turn, may affect airway responsiveness to inhaled materials. In six prone sheep, we therefore measured pulmonary airflow resistance (RL) and cumulative aerosol deposition during five standard breaths (AD5) at base line and 3 min after inhalation challenge with 2% carbachol in buffered saline (10 breaths, tidal volume = 500 ml) or after an intravenous loading dose of carbachol (3 micrograms/kg) followed by a constant infusion of 0.3 micrograms.kg-1.min-1 with and without instillation of 20 ml of a mucus simulant (MS) into the distal end of each of the main bronchi or 30 ml of MS into the right main bronchus only by means of a flexible fiber-optic bronchoscope. Before carbachol challenge, RL did not change with MS into either both lungs or one lung only. AD5 increased from 36 +/- 2% (SE) before to 42 +/- 2% after MS instillation into both lungs (P less than 0.05) but remained unchanged after MS into one lung. After carbachol inhalation, RL increased significantly by 154 +/- 20 before and 126 +/- 25% after MS into both lungs and 162 +/- 24 before and 178 +/- 31% after MS into one lung (P less than 0.05). When the percent increase in RL was normalized for total aerosol deposition (% delta RL/AD5), the normalized values were lower after MS (3.0 +/- 0.5) than before MS (4.4 +/- 0.3) into both lungs (P less than 0.05) but were not significantly different before and after MS into the right lung only.(ABSTRACT TRUNCATED AT 250 WORDS)

Styles APA, Harvard, Vancouver, ISO, etc.

20

Hu, Jun, Masahiro Hosoda et Shinji Tokonami. « Parameter sensitivity analysis of the theoretical model of a CR-39-based direct 222Rn/220Rn progeny monitor ». Nukleonika 65, n^o 2 (1 juin 2020) : 95–98. http://dx.doi.org/10.2478/nuka-2020-0014.

Texte intégral

Résumé :

AbstractThe deposition-based direct indoor 222Rn and 220Rn progeny measurement techniques are mostly affected by the indoor environmental conditions, such as the ventilation, concentration of condensation nuclei, and reactions with the structure and its furnishings. In this study, a theoretical model of a direct 222Rn and 220Rn progeny monitor based on allyl diglycol carbonate (ADC or CR-39) was established to analyse the factors that influence the detection process by using the parameter sensitivity analysis. The aerosol parameters contributed the highest to the variance, followed by the aerodynamic parameters. With respect to the result of the Spearman’s correlation analysis, the aerosol-related and the room-related parameters are positive, whereas the aerodynamic parameters – which affect the turbulence of indoor deposition – are negative. It means that both the attachment process and the deposition process of 222Rn and 220Rn progenies are important to the performance of the progeny monitor.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Song, Guanyu, Jesse Adamczyk, Yensil Park, Eric S. Toberer et Christopher J. Hogan. « Spray Pyrolysis‐Aerosol Deposition for the Production of Thick Yttria‐Stabilized Zirconia Coatings ». Advanced Engineering Materials 23, n^o 8 (mai 2021) : 2100255. http://dx.doi.org/10.1002/adem.202100255.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

22

Wang, Wendong, Daniel Grozea, Ara Kim, Douglas D. Perovic et Geoffrey A. Ozin. « Vacuum-Assisted Aerosol Deposition of a Low-Dielectric-Constant Periodic Mesoporous Organosilica Film ». Advanced Materials 22, n^o 1 (5 janvier 2010) : 99–102. http://dx.doi.org/10.1002/adma.200901498.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

23

Kim, Sunghoon, Myung‐Yeon Cho, Ik‐Soo Kim, Won‐Jung Kim, Sung‐Han Park, Seungmin Baek, Jong‐Min Oh et Sang‐Wook Kim. « Solvent‐Free Aerosol Deposition for Highly Luminescent and Thermally Stable Perovskite‐Ceramic Nanocomposite Film ». Advanced Materials Interfaces 6, n^o 13 (12 mai 2019) : 1900359. http://dx.doi.org/10.1002/admi.201900359.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

24

NEWMAN, STEPHEN P., et MICHAEL T. NEWHOUSE. « Effect of Add-on Devices for Aerosol Drug Delivery : Deposition Studies and Clinical Aspects ». Journal of Aerosol Medicine 9, n^o 1 (janvier 1996) : 55–70. http://dx.doi.org/10.1089/jam.1996.9.55.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

25

Cho, Myung‐Yeon, Sunghoon Kim, Ik‐Soo Kim, Eun‐Seong Kim, Zhi‐Ji Wang, Nam‐Young Kim, Sang‐Wook Kim et Jong‐Min Oh. « Perovskite‐Induced Ultrasensitive and Highly Stable Humidity Sensor Systems Prepared by Aerosol Deposition at Room Temperature ». Advanced Functional Materials 30, n^o 3 (20 novembre 2019) : 1907449. http://dx.doi.org/10.1002/adfm.201907449.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

26

Nazarenus, Tobias, Jaroslaw Kita, Ralf Moos et Jörg Exner. « Laser‐Annealing of Thermoelectric CuFe 0.98 Sn 0.02 O 2 Films Produced by Powder Aerosol Deposition Method ». Advanced Materials Interfaces 7, n^o 22 (5 octobre 2020) : 2001114. http://dx.doi.org/10.1002/admi.202001114.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

27

Salata, Oleg V., Peter J. Dobson, Peter J. Hull et John L. Hutchison. « Fabrication of PbS nanoparticles embedded in a polymer Film by a gas-aerosol reactive electrostatic deposition technique ». Advanced Materials 6, n^o 10 (octobre 1994) : 772–75. http://dx.doi.org/10.1002/adma.19940061013.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

28

Sagu, Jagdeep S., Kahagala Gamage Upul Wijayantha, Mallika Bohm, Siva Bohm et Tapan Kumar Rout. « Aerosol-Assisted Chemical Vapor Deposition of Multi-Walled Carbon Nanotubes on Steel Substrates for Application in Supercapacitors ». Advanced Engineering Materials 18, n^o 6 (29 décembre 2015) : 1059–65. http://dx.doi.org/10.1002/adem.201500585.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

29

Li, Tian-tian, Ren-rong Zheng, Hui Yu, Ying Yang, Ting-ting Wang et Xiang-ting Dong. « Synthesis of highly sensitive disordered porous SnO2 aerogel composite material by the chemical deposition method : synergistic effect of a layer of CuO thin film ». RSC Advances 7, n^o 62 (2017) : 39334–40. http://dx.doi.org/10.1039/c7ra06415b.

Texte intégral

Résumé :

In this study, a new chemical deposition method was innovatively used to prepare disordered porous CuO/SnO₂ aerogel composite material (CuO/SnO₂-ACM). The prepared material has the excellent gas sensing property.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Crick, Colin R., Joseph C. Bear, Andreas Kafizas et Ivan P. Parkin. « Superhydrophobic Photocatalytic Surfaces through Direct Incorporation of Titania Nanoparticles into a Polymer Matrix by Aerosol Assisted Chemical Vapor Deposition ». Advanced Materials 24, n^o 26 (18 juin 2012) : 3505–8. http://dx.doi.org/10.1002/adma.201201239.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

31

Denjean, C., F. Cassola, A. Mazzino, S. Triquet, S. Chevaillier, N. Grand, T. Bourrianne et al. « Size distribution and optical properties of mineral dust aerosols transported in the western Mediterranean ». Atmospheric Chemistry and Physics Discussions 15, n^o 15 (10 août 2015) : 21607–69. http://dx.doi.org/10.5194/acpd-15-21607-2015.

Texte intégral

Résumé :

Abstract. This study presents in situ aircraft measurements of Saharan mineral dust transported over the western Mediterranean basin in June–July 2013 during the ChArMEx/ADRIMED (the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region) airborne campaign. Dust events differing in terms of source region (Algeria, Tunisia and Morocco), time of tranport (1–5 days) and height of transport were sampled. Mineral dust were transported above the marine boundary layer, which conversely was dominated by pollution and marine aerosols. The dust vertical structure was extremely variable and characterized by either a single layer or a more complex and stratified structure with layers originating from different source regions. Mixing of mineral dust with pollution particles was observed depending on the height of transport of the dust layers. Dust layers carried higher concentration of pollution particles at intermediate altitude (1–3 km) than at elevated altitude (> 3 km), resulting in scattering Angstrom exponent up to 2.2 within the intermediate altitude. However, the optical properties of the dust plumes remained practically unchanged with respect to values previously measured over source regions, regardless of the altitude. Moderate light absorption of the dust plumes was observed with values of aerosol single scattering albedo at 530 nm ranging from 0.90 to 1.00 ± 0.04. Concurrent calculations from the aerosol chemical composition revealed a negligible contribution of pollution particles to the absorption properties of the dust plumes that was due to a low contribution of refractory black carbon in regards to the fraction of dust and sulfate particles. This suggests that, even in the presence of moderate pollution, likely a persistent feature in the Mediterranean, the optical properties of the dust plumes could be assimilated to those of native dust in radiative transfer simulations, modeling studies and satellite retrievals over the Mediterranean. Measurements also showed that the coarse mode of mineral dust was conserved even after 5 days of transport in the Mediterranean, which contrasts with the gravitational depletion of large particles observed during the transport of dust plumes over the Atlantic. Simulations with the WRF mesoscale meteorological model highlighted a strong vertical turbulence within the dust layers that could prevent deposition of large particles during their atmospheric transport. This has important implications for the dust radiative effects due to surface dimming, atmospheric heating and cloud formation. The results presented here add to the observational dataset necessary for evaluating the role of mineral dust on the regional climate and rainfall patterns in the western Mediterranean basin.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Denjean, C., F. Cassola, A. Mazzino, S. Triquet, S. Chevaillier, N. Grand, T. Bourrianne et al. « Size distribution and optical properties of mineral dust aerosols transported in the western Mediterranean ». Atmospheric Chemistry and Physics 16, n^o 2 (1 février 2016) : 1081–104. http://dx.doi.org/10.5194/acp-16-1081-2016.

Texte intégral

Résumé :

Abstract. This study presents in situ aircraft measurements of Saharan mineral dust transported over the western Mediterranean basin in June–July 2013 during the ChArMEx/ADRIMED (the Chemistry-Aerosol Mediterranean Experiment/Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region) airborne campaign. Dust events differing in terms of source region (Algeria, Tunisia and Morocco), time of transport (1–5 days) and height of transport were sampled. Mineral dust were transported above the marine boundary layer, which conversely was dominated by pollution and marine aerosols. The dust vertical structure was extremely variable and characterized by either a single layer or a more complex and stratified structure with layers originating from different source regions. Mixing of mineral dust with pollution particles was observed depending on the height of transport of the dust layers. Dust layers carried a higher concentration of pollution particles below 3 km above sea level (a.s.l.) than above 3 km a.s.l., resulting in a scattering Ångström exponent up to 2.2 below 3 km a.s.l. However, the optical properties of the dust plumes remained practically unchanged with respect to values previously measured over source regions, regardless of the altitude. Moderate absorption of light by the dust plumes was observed with values of aerosol single scattering albedo at 530 nm ranging from 0.90 to 1.00. Concurrent calculations from the aerosol chemical composition revealed a negligible contribution of pollution particles to the absorption properties of the dust plumes that was due to a low contribution of refractory black carbon in regards to the fraction of dust and sulfate particles. This suggests that, even in the presence of moderate pollution, likely a persistent feature in the Mediterranean, the optical properties of the dust plumes could be assumed similar to those of native dust in radiative transfer simulations, modelling studies and satellite retrievals over the Mediterranean. Measurements also showed that the coarse mode of mineral dust was conserved even after 5 days of transport in the Mediterranean, which contrasts with the gravitational depletion of large particles observed during the transport of dust plumes over the Atlantic. Simulations with the WRF mesoscale meteorological model highlighted a strong vertical turbulence within the dust layers that could prevent deposition of large particles during their atmospheric transport. This has important implications for the dust radiative effects due to surface dimming, atmospheric heating and cloud formation. The results presented here add to the observational data set necessary for evaluating the role of mineral dust on the regional climate and rainfall patterns in the western Mediterranean basin and understanding their atmospheric transport at global scale.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Xu, Chongying, Mark J. Hampden-Smith et Toivo T. Kodas. « Aerosol-assisted chemical vapor deposition (AACVD) of silver, palladium and metal alloy (Ag1?xPdx, Ag1?xCux and Pd1?xCux) Films ». Advanced Materials 6, n^o 10 (octobre 1994) : 746–48. http://dx.doi.org/10.1002/adma.19940061005.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

34

Gibson, Phil, et Heidi Schreuder-Gibson. « Patterned Electrospray Fiber Structures ». International Nonwovens Journal os-13, n^o 2 (juin 2004) : 1558925004os—13. http://dx.doi.org/10.1177/1558925004os-1300211.

Texte intégral

Résumé :

Electrospun fibers have useful filtration properties for chemical protective clothing and filter masks. Techniques for the patterned deposition of these fibers have been developed based on varying the conductivity of the target substrate. We are investigating multilayer arrangements of patterned fibers deposited in single layers, and onto air-permeable substrates. Patterning through the depth and across the area of the deposited layers has an effect on membrane strength. These materials are possible add-on solutions to provide complete biological and chemical aerosol particle protection for air permeable garments. Enhanced filtration efficiency of woven and nonwoven fabrics will improve individual soldier protection without compromising air flow characteristics or comfort of air-permeable garments.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Cho, Myung‐Yeon, Sunghoon Kim, Ik‐Soo Kim, Eun‐Seong Kim, Zhi‐Ji Wang, Nam‐Young Kim, Sang‐Wook Kim et Jong‐Min Oh. « Humidity Sensor Systems : Perovskite‐Induced Ultrasensitive and Highly Stable Humidity Sensor Systems Prepared by Aerosol Deposition at Room Temperature (Adv. Funct. Mater. 3/2020) ». Advanced Functional Materials 30, n^o 3 (janvier 2020) : 2070017. http://dx.doi.org/10.1002/adfm.202070017.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

36

Wang, Zhong-Min, Endalkachew Sahle-Demessie et Ashraf Aly Hassan. « Selective Oxidation Using Flame Aerosol Synthesized Iron and Vanadium-Doped Nano-TiO2 ». Journal of Nanotechnology 2011 (2011) : 1–11. http://dx.doi.org/10.1155/2011/209150.

Texte intégral

Résumé :

Selective photocatalytic oxidation of 1-phenyl ethanol to acetophenone using titanium dioxide (TiO2) raw and doped with Fe or V, prepared by flame aerosol deposition method, was investigated. The effects of metal doping on crystal phase and morphology of the synthesized nanostructured TiO2were analyzed using XRD, TEM, Raman spectroscopy, and BET nitrogen adsorbed surface area measurement. The increase in the concentration of V and Fe reduced the crystalline structure and the anatase-to-rutile ratios of the synthesized TiO2. Synthesized TiO2became fine amorphous powder as the Fe and V concentrations were increased to 3 and 5%, respectively. Doping V and Fe to TiO2synthesized by the flame aerosol increased photocatalytic activity by 6 folds and 2.5 folds, respectively, compared to that of pure TiO2. It was found that an optimal doping concentration for Fe and V were 0.5% and 3%, respectively. The type and concentration of the metal dopants and the method used to add the dopant to the TiO2are critical parameters for enhancing the activity of the resulting photocatalyst. The effects of solvents on the photocatalytic reaction were also investigated by using both water and acetonitrile as the reaction medium.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Khansur, Neamul H., Udo Eckstein, Hana Ursic, Matej Sadl, Martin Brehl, Alexander Martin, Kevin Riess, Dominique de Ligny et Kyle G. Webber. « Enhanced Electromechanical Response and Thermal Stability of 0.93(Na 1/2 Bi 1/2 )TiO 3 ‐0.07BaTiO 3 Through Aerosol Deposition of Base Metal Electrodes ». Advanced Materials Interfaces 8, n^o 11 (7 mai 2021) : 2100309. http://dx.doi.org/10.1002/admi.202100309.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

38

Vallejos, Stella, Polona Umek, Toni Stoycheva, Fatima Annanouch, Eduard Llobet, Xavier Correig, Patrizia De Marco, Carla Bittencourt et Chris Blackman. « Single-Step Deposition of Au- and Pt-Nanoparticle-Functionalized Tungsten Oxide Nanoneedles Synthesized Via Aerosol-Assisted CVD, and Used for Fabrication of Selective Gas Microsensor Arrays ». Advanced Functional Materials 23, n^o 10 (15 octobre 2012) : 1313–22. http://dx.doi.org/10.1002/adfm.201201871.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

39

Xing, Jia, Jiandong Wang, Rohit Mathur, Shuxiao Wang, Golam Sarwar, Jonathan Pleim, Christian Hogrefe et al. « Impacts of aerosol direct effects on tropospheric ozone through changes in atmospheric dynamics and photolysis rates ». Atmospheric Chemistry and Physics 17, n^o 16 (22 août 2017) : 9869–83. http://dx.doi.org/10.5194/acp-17-9869-2017.

Texte intégral

Résumé :

Abstract. Aerosol direct effects (ADEs), i.e., scattering and absorption of incoming solar radiation, reduce radiation reaching the ground and the resultant photolysis attenuation can decrease ozone (O3) formation in polluted areas. One the other hand, evidence also suggests that ADE-associated cooling suppresses atmospheric ventilation, thereby enhancing surface-level O3. Assessment of ADE impacts is thus important for understanding emission reduction strategies that seek co-benefits associated with reductions in both particulate matter and O3 levels. This study quantifies the impacts of ADEs on tropospheric ozone by using a two-way online coupled meteorology and atmospheric chemistry model, WRF-CMAQ, using a process analysis methodology. Two manifestations of ADE impacts on O3 including changes in atmospheric dynamics (ΔDynamics) and changes in photolysis rates (ΔPhotolysis) were assessed separately through multiple scenario simulations for January and July of 2013 over China. Results suggest that ADEs reduced surface daily maxima 1 h O3 (DM1O3) in China by up to 39 µg m−3 through the combination of ΔDynamics and ΔPhotolysis in January but enhanced surface DM1O3 by up to 4 µg m−3 in July. Increased O3 in July is largely attributed to ΔDynamics, which causes a weaker O3 sink of dry deposition and a stronger O3 source of photochemistry due to the stabilization of the atmosphere. Meanwhile, surface OH is also enhanced at noon in July, though its daytime average values are reduced in January. An increased OH chain length and a shift towards more volatile organic compound (VOC)-limited conditions are found due to ADEs in both January and July. This study suggests that reducing ADEs may have the potential risk of increasing O3 in winter, but it will benefit the reduction in maxima O3 in summer.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Nemitz, E., M. A. Sutton, G. P. Wyers et P. A. C. Jongejan. « Gas-particle interactions above a Dutch heathland : I. Surface exchange fluxes of NH3, SO2, HNO3 ; and HCl ». Atmospheric Chemistry and Physics Discussions 4, n^o 2 (15 mars 2004) : 1473–517. http://dx.doi.org/10.5194/acpd-4-1473-2004.

Texte intégral

Résumé :

Abstract. A field measurement campaign was carried out over a Dutch heathland to investigate the effect of gas-to-particle conversion and ammonium aerosol evaporation on surface/atmosphere fluxes of ammonia and related species. Continuous micrometeorological measurements of the surface exchange of NH3, SO2, HNO3 and HCl were made and are analyzed here with regard to average fluxes, deposition velocities (Vd), canopy resistances (Rc) and canopy compensation point for NH3. Gradients of SO2, HNO3 and HCl were measured with a novel wet-denuder system with online anion chromatography. Measurements of HNO3 and HCl indicate an Rc of 100 to 200 s m−1 during warm daytime periods, probably at least partly due to non-zero acid partial pressures above NH4NO3 and NH4Cl on the leaf surfaces. Although it is likely that this observation is exacerbated by the effect of the evaporation of airborne NH4+ on the gradient measurements, the findings nevertheless add to the growing evidence that HNO3 and HCl are not always deposited at the maximum rate. Ammonia (NH3) fluxes show mainly deposition, with some periods of significant daytime emission. The net exchange could be reproduced both with an Rc model (deposition fluxes only) using resistance parameterizations from former measurements, as well as with the canopy compensation point model, using parameterizations derived from the measurements. The apoplastic ratio of ammonium and hydrogen concentration (Γs=[NH4+]/[H+]) of 1200 estimated from the measurements is large for semi- natural vegetation, but smaller than indicated by previous measurements at this site.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Nemitz, E., M. A. Sutton, G. P. Wyers et P. A. C. Jongejan. « Gas-particle interactions above a Dutch heathland : I. Surface exchange fluxes of NH3, SO2, HNO3 ; and HCl ». Atmospheric Chemistry and Physics 4, n^o 4 (2 juillet 2004) : 989–1005. http://dx.doi.org/10.5194/acp-4-989-2004.

Texte intégral

Résumé :

Abstract. A field measurement campaign was carried out over a Dutch heathland to investigate the effect of gas-to-particle conversion and ammonium aerosol evaporation on surface/atmosphere fluxes of ammonia and related species. Continuous micrometeorological measurements of the surface exchange of NH3, SO2, HNO3 and HCl were made and are analyzed here with regard to average fluxes, deposition velocities (Vd), canopy resistances (Rc) and canopy compensation point for NH3. Gradients of SO2, HNO3 and HCl were measured with a novel wet-denuder system with online anion chromatography. Measurements of HNO3 and HCl indicate an Rc of 100 to 200 s m-1 during warm daytime periods, probably at least partly due to non-zero acid partial pressures above NH4NO3 and NH4Cl on the leaf surfaces. Although it is likely that this observation is exacerbated by the effect of the evaporation of airborne NH4+ on the gradient measurements, the findings nevertheless add to the growing evidence that HNO3 and HCl are not always deposited at the maximum rate. Ammonia (NH3) fluxes show mainly deposition, with some periods of significant daytime emission. The net exchange could be reproduced both with an Rc model (deposition fluxes only) using resistance parameterizations from former measurements, as well as with the canopy compensation point model, using parameterizations derived from the measurements. The apoplastic ratio of ammonium and hydrogen concentration (Γs=[NH4+]/[H+]) of 1200 estimated from the measurements is large for semi-natural vegetation, but smaller than indicated by previous measurements at this site.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Vallejos, Stella, Polona Umek, Toni Stoycheva, Fatima Annanouch, Eduard Llobet, Xavier Correig, Patrizia De Marco, Carla Bittencourt et Chris Blackman. « Sensors : Single-Step Deposition of Au- and Pt-Nanoparticle-Functionalized Tungsten Oxide Nanoneedles Synthesized Via Aerosol-Assisted CVD, and Used for Fabrication of Selective Gas Microsensor Arrays (Adv. Funct. Mater. 10/2013) ». Advanced Functional Materials 23, n^o 10 (7 mars 2013) : 1226. http://dx.doi.org/10.1002/adfm.201370049.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

43

Zheng, J., R. Zhang, E. C. Fortner, R. M. Volkamer, L. Molina, A. C. Aiken, J. L. Jimenez et al. « Measurements of HNO3 ; and N2O5 ; using ion drift-chemical ionization mass spectrometry during the MILAGRO/MCMA-2006 campaign ». Atmospheric Chemistry and Physics 8, n^o 22 (28 novembre 2008) : 6823–38. http://dx.doi.org/10.5194/acp-8-6823-2008.

Texte intégral

Résumé :

Abstract. An ion drift-chemical ionization mass spectrometer (ID-CIMS) was deployed in Mexico City between 7 and 31 March to measure gas-phase nitric acid (HNO3) and dinitrogen pentoxide (N2O5 during the Mexico City Metropolitan Area (MCMA)-2006 field campaign. The observation site was located at the Instituto Mexicano del Petróleo in the northern part of Mexico City urban area with major emissions of pollutants from residential, vehicular and industrial sources. Diurnally, HNO3 was less than 200 parts per trillion (ppt) during the night and early morning. The concentration of HNO3 increased steadily from around 09:00 a.m. central standard time (CST), reached a peak value of 0.5 to 3 parts per billion (ppb) in the early afternoon, and then declined sharply to less than half of the peak value near 05:00 p.m. CST. An inter-comparison between the ID-CIMS and an ion chromatograph/mass spectrometer (ICMS) showed a good agreement between the two HNO3 measurements (R2=0.75). The HNO3 mixing ratio was found to anti-correlate with submicron-sized aerosol nitrate, suggesting that the gas-particle partitioning process was a major factor in determining the gaseous HNO3 concentration. Losses by irreversible reactions with mineral dust and via dry deposition also could be important at this site. Most of the times during the MCMA 2006 field campaign, N2O5 was found to be below the detection limit (about 30 ppt for a 10 s integration time) of the ID-CIMS, because of high NO mixing ratio at the surface (>100 ppb) during the night. An exception occurred on 26 March 2006, when about 40 ppt N2O5 was observed during the late afternoon and early evening hours under cloudy conditions before the build-up of NO at the surface site. The results revealed that during the MCMA-2006 field campaign HNO3 was primarily produced from the reaction of OH with NO2 and regulated by gas/particle transfer and dry deposition. The production of HNO3 from N2O5 hydrolysis during the nighttime was small because of high NO and low O3 concentrations near the surface.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Xu, Jiayu, Jiachen Zhang, Junfeng Liu, Kan Yi, Songlin Xiang, Xiurong Hu, Yuqing Wang, Shu Tao et George Ban-Weiss. « Influence of cloud microphysical processes on black carbon wet removal, global distributions, and radiative forcing ». Atmospheric Chemistry and Physics 19, n^o 3 (7 février 2019) : 1587–603. http://dx.doi.org/10.5194/acp-19-1587-2019.

Texte intégral

Résumé :

Abstract. Parameterizations that impact wet removal of black carbon (BC) remain uncertain in global climate models. In this study, we enhance the default wet deposition scheme for BC in the Community Earth System Model (CESM) to (a) add relevant physical processes that were not resolved in the default model and (b) facilitate understanding of the relative importance of various cloud processes on BC distributions. We find that the enhanced scheme greatly improves model performance against HIPPO observations relative to the default scheme. We find that convection scavenging, aerosol activation, ice nucleation, evaporation of rain or snow, and below-cloud scavenging dominate wet deposition of BC. BC conversion rates for processes related to in-cloud water–ice conversion (i.e., riming, the Bergeron process, and evaporation of cloud water sedimentation) are relatively smaller, but have large seasonal variations. We also conduct sensitivity simulations that turn off each cloud process one at a time to quantify the influence of cloud processes on BC distributions and radiative forcing. Convective scavenging is found to have the largest impact on BC concentrations at mid-altitudes over the tropics and even globally. In addition, BC is sensitive to all cloud processes over the Northern Hemisphere at high latitudes. As for BC vertical distributions, convective scavenging greatly influences BC fractions at different altitudes. Suppressing BC droplet activation in clouds mainly decreases the fraction of column BC below 5 km, whereas suppressing BC ice nucleation increases that above 10 km. During wintertime, the Bergeron process also significantly increases BC concentrations at lower altitudes over the Arctic. Our simulation yields a global BC burden of 85 Gg; corresponding direct radiative forcing (DRF) of BC estimated using the Parallel Offline Radiative Transfer (PORT) is 0.13 W m−2, much lower than previous studies. The range of DRF derived from sensitivity simulations is large, 0.09–0.33 W m−2, corresponding to BC burdens varying from 73 to 151 Gg. Due to differences in BC vertical distributions among each sensitivity simulation, fractional changes in DRF (relative to the baseline simulation) are always higher than fractional changes in BC burdens; this occurs because relocating BC in the vertical influences the radiative forcing per BC mass. Our results highlight the influences of cloud microphysical processes on BC concentrations and radiative forcing.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Blanchet, Cécile L. « A database of marine and terrestrial radiogenic Nd and Sr isotopes for tracing earth-surface processes ». Earth System Science Data 11, n^o 2 (24 mai 2019) : 741–59. http://dx.doi.org/10.5194/essd-11-741-2019.

Texte intégral

Résumé :

Abstract. The database presented here contains radiogenic neodymium and strontium isotope ratios measured on both terrestrial and marine sediments. The main purpose of this dataset is to help assess sediment provenance and transport processes for various time intervals. This can be achieved by either mapping sediment isotopic signature and/or fingerprinting source areas using statistical tools. The database has been built by incorporating data from the literature and the SedDB database and harmonizing the metadata, especially units and geographical coordinates. The original data were processed in three steps. Firstly, specific attention has been devoted to providing geographical coordinates to each sample in order to be able to map the data. When available, the original geographical coordinates from the reference (generally DMS coordinates) were transferred into the decimal degrees system. When coordinates were not provided, an approximate location was derived from available information in the original publication. Secondly, all samples were assigned a set of standardized criteria that help split the dataset into specific categories. For instance, samples were distinguished according to their location (“Region”, “Sub-region” and “Location” that relate to locations at continental to city or river scale) or the sample type (terrestrial samples – “aerosols”, “soil sediments”, “river sediments”, “rocks” – or marine samples – “marine sediment” or “trap sample”). Finally, samples were distinguished according to their deposition age, which allowed us to compute average values for specific time intervals. Graphical examples illustrating the functionality of the database are presented and the validity of the process was tested by comparing the results with published data. The dataset will be updated bi-annually in order to add more data points to increase the sampling density or provide new types of samples (e.g. seawater signature) and/or integrate additional information regarding the samples. It is publicly available (under CC4.0-BY Licence) from the GFZ data management service at https://doi.org/10.5880/GFZ.4.3.2019.001.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Coburn, Sean, Barbara Dix, Eric Edgerton, Christopher D. Holmes, Douglas Kinnison, Qing Liang, Arnout ter Schure, Siyuan Wang et Rainer Volkamer. « Mercury oxidation from bromine chemistry in the free troposphere over the southeastern US ». Atmospheric Chemistry and Physics 16, n^o 6 (21 mars 2016) : 3743–60. http://dx.doi.org/10.5194/acp-16-3743-2016.

Texte intégral

Résumé :

Abstract. The elevated deposition of atmospheric mercury over the southeastern United States is currently not well understood. Here we measure partial columns and vertical profiles of bromine monoxide (BrO) radicals, a key component of mercury oxidation chemistry, to better understand the processes and altitudes at which mercury is being oxidized in the atmosphere. We use data from a ground-based MAX-DOAS instrument located at a coastal site ∼ 1 km from the Gulf of Mexico in Gulf Breeze, FL, where we had previously detected tropospheric BrO (Coburn et al., 2011). Our profile retrieval assimilates information about stratospheric BrO from the WACCM chemical transport model (CTM), and uses only measurements at moderately low solar zenith angles (SZAs) to estimate the BrO slant column density contained in the reference spectrum (SCDRef). The approach has 2.6 degrees of freedom, and avoids spectroscopic complications that arise at high SZA; knowledge about SCDRef further helps to maximize sensitivity in the free troposphere (FT). A cloud-free case study day with low aerosol load (9 April 2010) provided optimal conditions for distinguishing marine boundary layer (MBL: 0–1 km) and free-tropospheric (FT: 1–15 km) BrO from the ground. The average daytime tropospheric BrO vertical column density (VCD) of ∼ 2.3 × 1013 molec cm−2 (SZA < 70°) is consistent with our earlier reports on other days. The vertical profile locates essentially all tropospheric BrO above 4 km, and shows no evidence for BrO inside the MBL (detection limit < 0.5 pptv). BrO increases to ∼ 3.5 pptv at 10–15 km altitude, consistent with recent aircraft observations. Our case study day is consistent with recent aircraft studies, in that the oxidation of gaseous elemental mercury (GEM) by bromine radicals to form gaseous oxidized mercury (GOM) is the dominant pathway for GEM oxidation throughout the troposphere above Gulf Breeze. The column integral oxidation rates are about 3.6 × 105 molec cm−2 s−1 for bromine, while the contribution from ozone (O3) is 0.8 × 105 molec cm−2 s−1. Chlorine-induced oxidation is estimated to add < 5 % to these mercury oxidation rates. The GOM formation rate is sensitive to recently proposed atmospheric scavenging reactions of the HgBr adduct by nitrogen dioxide (NO2), and to a lesser extent also HO2 radicals. Using a 3-D CTM, we find that surface GOM variations are also typical of other days, and are mainly derived from the FT. Bromine chemistry is active in the FT over Gulf Breeze, where it forms water-soluble GOM that is subsequently available for wet scavenging by thunderstorms or transport to the boundary layer.

Styles APA, Harvard, Vancouver, ISO, etc.

47

Vasudevan, Aswathy. « Single Step Metal Nanoparticle Fabrication Using Atmospheric Pressure Plasma Jets ». ECS Meeting Abstracts MA2022-02, n^o 19 (9 octobre 2022) : 898. http://dx.doi.org/10.1149/ma2022-0219898mtgabs.

Texte intégral

Résumé :

The interaction of atmospheric pressure plasma discharges with liquid or vapour phases is a hot-topic in plasma science and technology. Synthesis and processing of nanomaterials using atmospheric pressure plasma jets attracts more attention because of its simplicity and cost effectiveness. The plasma containing reactive electrons and active chemical species activates physical processes and reduction reaction of metal salts which leads to the formation of metal nanoparticles. Among the unique features of atmospheric pressure plasmas, the chemical non-equilibrium environment produces highly reactive radicals and ions from the precursors as well as inside the plasma. Thus the energy transfer could be initiated with high energy electrons and excited species from plasma and could be achieved by the reactions with reactive species of the precursors. Plasma compliments the production of nanomaterials in vapour phase or from aerosols and in solutions of the precursors. The interface between plasmas and vapors can be employed for rapid, simultaneous reduction and deposition of metal nanoparticles from metal salts, for instance gold nanoparticles from chloroauric acid (HAuCl4). We have employed an atmospheric pressure plasma jet setup operating with a mixture of He and Ar gases to produce gold nanocrystals onto a silicon wafer substrate. In this study, it reveals an easy and reliable synthesis mechanism of gold nanoparticles from chloroauric acid using atmospheric pressure plasma jet working with a high voltage source. A solution of the precursor in water acts as the feed solution for the process which is introduced to plasma in the form of microdroplets and metal nanoparticles were formed inside the plasma from the vapours containing the precursor molecules. Since the plasma-liquid/vapour chemistry allows the lead of accelerated reactions and instantly reduce the metal ions to metal atoms skipping the intermediate steps in the reduction process. The nanoparticles were collected on to a Si wafer substrate downstream of the plasma jet and characterized via scanning electron microscopy, Raman spectroscopy, transition electron microscopy etc. The polygonal nanoparticles sized 40-100 nm were obtained and they do not tend to agglomerate or fuse onto the substrate. Due to the low volatility of the precursor solution and the presence of comparatively larger microdroplets inside the plasma the nanoparticles tend to deposit in a pattern like galaxies on the silicon wafer substrate. These results would lead to the development of low cost and mobile, user-friendly atmospheric pressure plasma devices for the synthesis of nanoparticles without any toxic chemicals for the reduction of metal salt. The challenge in this process is in creating a vapour-plasma interface directly. This problem has been solved by incorporating a vaporizer directly to plasma. The vaporizer would introduce a new phase which would be a combination of gaseous plasma and plasma-liquid interface. To ease the transportation and diffusion of precursor molecules at the interface an inert gas has been introduced to the vaporizer as a carrier. At the interface, high energy electrons are introduced to the vapors containing the precursor metal ions and these wet electrons play the key role as initiators for the reduction process inside the plasma. Nanoparticles are formed inside the plasma by simple reduction mechanism carried out by short-lived reducing species formed at the interface. From the qualitative analysis carried our during the process implies the formation of short-lived reducing agents like hydrogen peroxide (H2O2) which is known as a reducing agent for chloroaurate ions in water medium. The size and shape of the nanoparticles are controlled by the residence time of the particles inside the plasma and the population density of the metal ions. Whereas the purity in turn the reduction rate of metal ions are dependent upon the feed gas flow as well as the applied voltage, i.e. plasma power. Concisely, atmospheric pressure plasma jets are outstanding choice for the synthesis of gold nanoparticles from chloroauric acid without any external reducing agents. The synthesized gold nanoparticles are promising for different applications because of its geometry and shape. Because of its polygonal geometries the particles are plasmonic active surfaces, the functional for highly specific sensing applications and nanoelectronics devices. However, the low-temperature plasma-vapour interphases containing droplets, the evaporation may add new complexities such as quantitative analysis of non-equilibrium chemistry to plasma chemistry which is yet to be understood and developed.

Styles APA, Harvard, Vancouver, ISO, etc.

48

Akedo, Jun, Maxim Lebedev, Atsushi Iwata, Hisato Ogiso et Shizuka Nakano. « Aerosol Deposition Method (Adm) For Nano-Crystal Ceramics Coating Without Firing ». MRS Proceedings 778 (2003). http://dx.doi.org/10.1557/proc-778-u8.10/w7.10.

Texte intégral

Résumé :

AbstractAerosol deposition method (ADM) for shock-consolidation of fine ceramics powder to form dense and hard layers is reported. Submicron ceramic particles were accelerated by gas flow in the nozzle up to velocity of several hundred m/s. During interaction with substrate, these particles formed thick (10 ∼ 100 μm), dense, uniform and hard ceramics layers. Experiments were fulfilled at room temperature. The results of fabrications, microstructure and mechanical properties of oxides (Al2O3; (Ni,Zn)Fe2O3; Pb(Zr0.52,Ti0.48)O3 and non-oxide (AlN; MgB2) materials are presented. Every layer has polycrystalline structure with nano-meter order scale.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Akedo, Jun, Maxim Lebedev, Atsushi Iwata, Hisato Ogiso et Shizuka Nakano. « Aerosol Deposition Method (ADM) for Nano-Crystal Ceramics Coating Without Firing ». MRS Proceedings 779 (2003). http://dx.doi.org/10.1557/proc-779-w7.10/u8.10.

Texte intégral

Résumé :

AbstractAerosol deposition method (ADM) for shock-consolidation of fine ceramics powder to form dense and hard layers is reported. Submicron ceramic particles were accelerated by gas flow in the nozzle up to velocity of several hundred m/s. During interaction with substrate, these particles formed thick (10 ∼ 100 μm), dense, uniform and hard ceramics layers. Experiments were fulfilled at room temperature. The results of fabrications, microstructure and mechanical properties of oxides (Al2O3; (Ni,Zn)Fe2O3; Pb(Zr0.52,Ti0.48)O3 and non-oxide (AlN; MgB2) materials are presented. Every layer has polycrystalline structure with nano-meter order scale.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Takagi, H., J. H. Park, M. Mizoguchi, K. Nishimura, H. Uchida, M. Lebedev, J. Akedo et M. Inoue. « PZT-Driven Micromagnetic Optical Devices ». MRS Proceedings 785 (2003). http://dx.doi.org/10.1557/proc-785-d6.10.

Texte intégral

Résumé :

ABSTRACTA magneto-optic spatial light modulator (MOSLM) driven by electric field is presented. Using finite element method simulation, the parameters of the MOSLM are decided including the 1 μm piezoelectric lead zirconate titanate (PZT)-based layer, the 200 nm bottom electrode, and the 8V electrical applied voltage. A flat surface magneto-optical bismuth-substituted iron garnet (Bi:YIG) based film having an array-pixels structure was created by a site-selected epitaxial method on a SGGG-based substrate. In order to avoid high temperature annealing process which may damage the Bi:YIG film, the PZT film was deposited by the aerosol deposition method (ADM) on the Bi:YIG film. By stress field induced by the PZT film to the Bi:YIG film with an external magnetic field, the pixels of the device were successfully switched.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Aerosol deposition (ADM) »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres