scholarly journals Aerosol Charging with a Piezoelectric Plasma Generator

Plasma ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 377-388
Author(s):  
Helmut Krasa ◽  
Mario A. Schriefl ◽  
Martin Kupper ◽  
Alexander Melischnig ◽  
Alexander Bergmann
Keyword(s):  
Charge Distribution ◽  
Size Range ◽  
Aerosol Particles ◽  
Plasma Generator ◽  
High Reproducibility ◽  
X Ray ◽  
N2 Atmosphere ◽  
First Results ◽  
Aerosol Charging

A novel piezoelectric plasma generator developed by TDK Electronics GmbH & Co OG, the CeraPlas®, was investigated for its feasibility as a charger for aerosol particles. The CeraPlas® charger was directly compared to a commercially available bipolar X-ray charger regarding its efficiency of charging atomized NaCl particles in a size range from 30nm–100nm. First results show the ability of the CeraPlas® to perform bipolar aerosol charging with high reproducibility, and measurements of the charge distribution in the Nit product yielded about E12/m3s for our experimental charging configuration. Unwanted generation of ozone was suppressed by a dedicated charging chamber and operation in N2 atmosphere.

On tungstates of divalent cations (III) – Pb5O2[WO6]

2020 ◽  
Vol 235 (8-9) ◽  
pp. 311-317
Author(s):  
Stephan G. Jantz ◽  
Florian Pielnhofer ◽  
Henning A. Höppe
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Quantum Chemical ◽  
Density Functional ◽  
Divalent Cations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
First Results ◽  
Electrostatic Calculations

Abstract${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ was discovered as a frequently observed side phase during our investigation on lead tungstates. Its crystal structure was solved by single-crystal X-ray diffraction ($P{2}_{1}/n$, $a=7.4379\left(2\right)$ Å, $b=12.1115\left(4\right)$ Å, $c=10.6171\left(3\right)$ Å, $\beta =90.6847\left(8\right)$°, $Z=4$, ${R}_{\text{int}}=0.038$, ${R}_{1}=0.020$, $\omega {R}_{2}=0.029$, 4188 data, 128 param.) and is isotypic with ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{Te}}_{6}\right]$. ${\text{Pb}}_{5}{\text{O}}_{2}\left[{\text{WO}}_{6}\right]$ comprises a layered structure built up by non-condensed [WO6]${}^{6-}$ octahedra and ${\left[{\text{O}}_{4}{\text{Pb}}_{10}\right]}^{12+}$ oligomers. The compound was characterised by spectroscopic measurements (Infrared (IR), Raman and Ultraviolet–visible (UV/Vis) spectra) as well as quantum chemical and electrostatic calculations (density functional theory (DFT), MAPLE) yielding a band gap of 2.9 eV fitting well with the optical one of 2.8 eV. An estimation of the refractive index based on the Gladstone-Dale relationship yielded $n\approx 2.31$. Furthermore first results of the thermal analysis are presented.

scholarly journals Low-Temperature Synthesis of Solution Processable Carbon Nitride Polymers

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1646
Author(s):  
Junyi Li ◽  
Neeta Karjule ◽  
Jiani Qin ◽  
Ying Wang ◽  
Jesús Barrio ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Spatial Organization ◽  
Surface Display ◽  
Liquid Media ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
X Ray ◽  
N2 Atmosphere ◽  
Carbon Nitride Materials

Carbon nitride materials require high temperatures (>500 °C) for their preparation, which entails substantial energy consumption. Furthermore, the high reaction temperature limits the materials’ processability and the control over their elemental composition. Therefore, alternative synthetic pathways that operate under milder conditions are still very much sought after. In this work, we prepared semiconductive carbon nitride (CN) polymers at low temperatures (300 °C) by carrying out the thermal condensation of triaminopyrimidine and acetoguanamine under a N2 atmosphere. These molecules are isomers: they display the same chemical formula but a different spatial distribution of their elements. X-ray photoelectron spectroscopy (XPS) experiments and electrochemical and photophysical characterization confirm that the initial spatial organization strongly determines the chemical composition and electronic structure of the materials, which, thanks to the preservation of functional groups in their surface, display excellent processability in liquid media.

Formation of Graphite Encapsulated Nickel Nanoparticles by Ball Milling and Annealing of Expanded Graphite with Nickel

2011 ◽  
Vol 80-81 ◽  
pp. 217-220 ◽  
Author(s):  
Xue Qing Yue ◽  
Hai Jun Fu ◽  
Da Jun Li
Keyword(s):  
Electron Microscope ◽  
Ball Milling ◽  
Transmission Electron Microscope ◽  
Nickel Nanoparticles ◽  
Size Range ◽  
Expanded Graphite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Powders ◽  
Transmission Electron

Graphite encapsulated nickel nanoparticles were prepared by ball milling andsubsequently annealing a mixture of expanded graphite with nickel powders. The products were characterized by transmission electron microscope and X-ray diffraction. The formation mechanism of the products was discussed. Results show that the products have a size range of 20-150 nm. The graphite and nickel in the products all exhibit a high crystallinity.

The phosphatase domains of LAR, CD45, and PTP1B: structural correlations with peptide-based inhibitors1

2000 ◽  
Vol 78 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Nicholas R Glover ◽  
Alan S Tracey
Keyword(s):  
Insulin Receptor ◽  
Charge Distribution ◽  
T Cell Activation ◽  
Active Site ◽  
Cell Activation ◽  
Cell Function ◽  
Protein Tyrosine Phosphatases ◽  
Surface Topology ◽  
X Ray ◽  
Protein Tyrosine

PTP1B is a cytosolic protein tyrosine phosphatase that is a regulator of the kinase activity of the insulin receptor; the two protein tyrosine phosphatases LAR and CD45 are receptor type phosphatases crucially important to cell function. LAR also is involved in regulation of the insulin receptor while CD45 is critical for T-cell activation. Although LAR and CD45 are both transmembrane phosphatases, these enzymes manifest their phosphatase activity through a catalytic cytosolic domain. We have utilized X-ray coordinates of related phosphatases (RPTPalpha and RPTPµ) and comparative protein modeling to obtain molecular models of the D1 catalytic domains of CD45 and LAR. The models were tested using established protocols and found to be comparable to low resolution X-ray structures. The structure obtained for LAR was compared with the recently reported X-ray structure. Both the CD45-D1 and LAR-D1 structures were then compared to and contrasted with PTP1B. The active site of pockets of the three enzymes were found to be very uniform in structure and charge distribution. Also, the gross surface topology around the active site was found to be somewhat similar for the 3 phosphatases. However, there were significant differences in surface topology, and, more importantly, large changes in surface charge distribution. The differences between the surface features of these enzymes provide an explanation for the selectivity of inhibition by a number of peptides.

A muonic X-ray study of the charge distribution of 144, 148, 150, 152, 154Sm

1979 ◽  
Vol 316 (3) ◽  
pp. 295-316 ◽  
Author(s):  
R.J. Powers ◽  
P. Barreau ◽  
B. Bihoreau ◽  
J. Miller ◽  
J. Morgenstern ◽  
...  
Keyword(s):  
Charge Distribution ◽  
X Ray

scholarly journals Laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF): performance, reference spectra and classification of atmospheric samples

2018 ◽  
Vol 11 (4) ◽  
pp. 2325-2343 ◽  
Author(s):  
Xiaoli Shen ◽  
Ramakrishna Ramisetty ◽  
Claudia Mohr ◽  
Wei Huang ◽  
Thomas Leisner ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Aerosol Particle ◽  
Mass Spectrometer ◽  
Size Range ◽  
Aerosol Particles ◽  
Time Of Flight ◽  
Polystyrene Latex ◽  
Dust Particles ◽  
Data Set ◽  
Flight Mass Spectrometer

Abstract. The laser ablation aerosol particle time-of-flight mass spectrometer (LAAPTOF, AeroMegt GmbH) is able to identify the chemical composition and mixing state of individual aerosol particles, and thus is a tool for elucidating their impacts on human health, visibility, ecosystem, and climate. The overall detection efficiency (ODE) of the instrument we use was determined to range from  ∼  (0.01 ± 0.01) to  ∼  (4.23 ± 2.36) % for polystyrene latex (PSL) in the size range of 200 to 2000 nm,  ∼  (0.44 ± 0.19) to  ∼  (6.57 ± 2.38) % for ammonium nitrate (NH4NO3), and  ∼  (0.14 ± 0.02) to  ∼  (1.46 ± 0.08) % for sodium chloride (NaCl) particles in the size range of 300 to 1000 nm. Reference mass spectra of 32 different particle types relevant for atmospheric aerosol (e.g. pure compounds NH4NO3, K2SO4, NaCl, oxalic acid, pinic acid, and pinonic acid; internal mixtures of e.g. salts, secondary organic aerosol, and metallic core–organic shell particles; more complex particles such as soot and dust particles) were determined. Our results show that internally mixed aerosol particles can result in spectra with new clusters of ions, rather than simply a combination of the spectra from the single components. An exemplary 1-day ambient data set was analysed by both classical fuzzy clustering and a reference-spectra-based classification method. Resulting identified particle types were generally well correlated. We show how a combination of both methods can greatly improve the interpretation of single-particle data in field measurements.

scholarly journals Unipolar Charging of Nanosized Aerosol Particles Using Soft X-ray Photoionization

2003 ◽  
Vol 37 (4) ◽  
pp. 330-341 ◽  
Author(s):  
Bangwoo Han ◽  
Manabu Shimada ◽  
Mansoo Choi ◽  
Kikuo Okuyama
Keyword(s):  
Aerosol Particles ◽  
X Ray
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