scholarly journals Field characterization of the PM<sub>2.5</sub> Aerosol Chemical Speciation Monitor: insights into the composition, sources, and processes of fine particles in eastern China

2017 ◽  
Vol 17 (23) ◽  
pp. 14501-14517 ◽  
Author(s):  
Yunjiang Zhang ◽  
Lili Tang ◽  
Philip L. Croteau ◽  
Olivier Favez ◽  
Yele Sun ◽  
...  
Keyword(s):  
Chemical Speciation ◽  
Fine Particles ◽  
Eastern China ◽  
Temporal Variations ◽  
Inorganic Aerosols ◽  
Mass Fractions ◽  
Highly Correlated ◽  
First Time

Abstract. A PM2.5-capable aerosol chemical speciation monitor (Q-ACSM) was deployed in urban Nanjing, China, for the first time to measure in situ non-refractory fine particle (NR-PM2.5) composition from 20 October to 19 November 2015, along with parallel measurements of submicron aerosol (PM1) species by a standard Q-ACSM. Our results show that the NR-PM2.5 species (organics, sulfate, nitrate, and ammonium) measured by the PM2.5-Q-ACSM are highly correlated (r2 > 0.9) with those measured by a Sunset Lab OC  /  EC analyzer and a Monitor for AeRosols and GAses (MARGA). The comparisons between the two Q-ACSMs illustrated similar temporal variations in all NR species between PM1 and PM2.5, yet substantial mass fractions of aerosol species were observed in the size range of 1–2.5 µm. On average, NR-PM1−2.5 contributed 53 % of the total NR-PM2.5, with sulfate and secondary organic aerosols (SOAs) being the two largest contributors (26 and 27 %, respectively). Positive matrix factorization of organic aerosol showed similar temporal variations in both primary and secondary OAs between PM1 and PM2.5, although the mass spectra were slightly different due to more thermal decomposition on the capture vaporizer of the PM2.5-Q-ACSM. We observed an enhancement of SOA under high relative humidity conditions, which is associated with simultaneous increases in aerosol pH, gas-phase species (NO2, SO2, and NH3) concentrations and aerosol water content driven by secondary inorganic aerosols. These results likely indicate an enhanced reactive uptake of SOA precursors upon aqueous particles. Therefore, reducing anthropogenic NOx, SO2, and NH3 emissions might not only reduce secondary inorganic aerosols but also the SOA burden during haze episodes in China.

scholarly journals Field characterization of the PM<sub>2.5</sub> Aerosol Chemical Speciation Monitor: insights into the composition, sources and processes of fine particles in Eastern China

2017 ◽  
Author(s):  
Yunjiang Zhang ◽  
Lili Tang ◽  
Philip L. Croteau ◽  
Olivier Favez ◽  
Yele Sun ◽  
...  
Keyword(s):  
Chemical Speciation ◽  
Fine Particles ◽  
Eastern China ◽  
Particle Surface ◽  
Temporal Variations ◽  
Particle Surface Area ◽  
Inorganic Aerosols ◽  
Mass Fractions ◽  
Highly Correlated ◽  
First Time

Abstract. A PM2.5-capable aerosol chemical speciation monitor (ACSM) was deployed in urban Nanjing, China for the first time to measure in-situ non-refractory fine particle (NR-PM2.5) composition from October 20 to November 19, 2015 along with parallel measurements of submicron aerosol (PM1) species by a standard ACSM. Our results show that the NR-PM2.5 species (organics, sulfate, nitrate, and ammonium) measured by the PM2.5-ACSM are highly correlated (r2 > 0.9) with those measured by a Sunset Lab OC/EC Analyzer and a Monitor for AeRosols and GAses (MARGA). The comparisons between the two ACSMs illustrated similar temporal variations in all NR species between PM1 and PM2.5, yet substantial mass fractions of aerosol species were observed in the size range of 1–2.5 μm. On average, NR-PM1–2.5 contributed 53 % of the total NR-PM2.5 with sulfate and secondary organic aerosols (SOA) being the two largest contributors (26 % and 27 %, respectively). Rapid formation and thereafter growth of secondary inorganic aerosols (SIA) were observed under fog processing in NH3-rich environments. Positive matrix factorization of organic aerosol showed similar temporal variations in both primary and secondary OA between PM1 and PM2.5 although the mass spectra were slightly different due to more thermal decomposition on the capture vaporizer of PM2.5-ACSM. We observed an enhancement of SOA under high relative humidity conditions, which is associated with simultaneous increases in particle surface area, gas-phase species (NO2, SO2, and NH3) concentrations and aerosol water content driven by anthropogenic SIA. These results likely indicate an enhanced reactive uptake of SOA precursors upon aqueous particles. Therefore, reducing anthropogenic NOx, SO2, and NH3 emissions might not only reduce SIA but also SOA burden during haze episodes in China.

scholarly journals Identification and Characterization of a Rhodopsin Kinase Gene in the Suckers of Octopus vulgaris: Looking around Using Arms?

Biology ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 936
Author(s):  
Al-Sayed Al-Soudy ◽  
Valeria Maselli ◽  
Stefania Galdiero ◽  
Michael J. Kuba ◽  
Gianluca Polese ◽  
...  
Keyword(s):  
3D Structure ◽  
Complete Characterization ◽  
Octopus Vulgaris ◽  
Kinase Gene ◽  
Light Sensing ◽  
Rhodopsin Kinase ◽  
First Time ◽  
Identification And Characterization

In their foraging behavior octopuses rely on arm search movements outside the visual field of the eyes. In these movements the environment is explored primarily by the suckers that line the entire length of the octopus arm. In this study, for the first time, we report the complete characterization of a light-sensing molecule, Ov-GRK1, in the suckers, skin and retina of Octopus vulgaris. We sequenced the O. vulgaris GRK1 gene, defining a phylogenetic tree and performing a 3D structure model prediction. Furthermore, we found differences in relative mRNA expression in different sucker types at several arm levels, and localized it through in situ hybridization. Our findings suggest that the suckers in octopus arms are much more multimodal than was previously shown, adding the potential for light sensing to the already known mechanical and chemical sensing abilities.

Molecular beam homoepitaxial growth of MgO(001)

1994 ◽  
Vol 9 (11) ◽  
pp. 2944-2952 ◽  
Author(s):  
S.A. Chambers ◽  
T.T. Tran ◽  
T.A. Hileman
Keyword(s):  
Electron Spectroscopy ◽  
High Speed ◽  
Molecular Beam ◽  
Step Flow ◽  
Homoepitaxial Growth ◽  
Crystallographic Order ◽  
Step Flow Growth ◽  
First Time

We describe homoepitaxial growth and detailed in situ characterization of MgO(001). We have used, for the first time, high-speed Auger electron spectroscopy as a real-time probe of film composition during growth. Excellent short-range and long-range crystallographic order are achieved in films grown to a thickness of several hundred angstroms in the substrate temperature range of 450 °C to 750 °C. Moreover, the films become more laminar as the growth temperature increases, suggesting that MgO grows homoepitaxially by the step-flow growth mechanism at elevated temperature. The surfaces of films grown at 650°and 750 °C are smoother than those obtained by cleaving MgO(001).

Elucidating the structure of a high-spin σ-phenyliron(iii) species in a live FeCl3–PhZnCl reaction system

2018 ◽  
Vol 54 (12) ◽  
pp. 1481-1484 ◽  
Author(s):  
Zhiliang Huang ◽  
Dongchao Zhang ◽  
Jyh-Fu Lee ◽  
Aiwen Lei
Keyword(s):  
Density Functional ◽  
Reaction System ◽  
Paramagnetic Resonance ◽  
Functional Theory ◽  
System P ◽  
First Time ◽  
X Ray Absorption ◽  
Electron Paramagnetic

Characterization of σ-aryliron(iii) species in a live reaction system: an unknown sextet Ph(THF)FeCl2 species was well-characterized in a live FeCl3–PhZnCl reaction system for the first time by Raman, in situ IR, electron paramagnetic resonance (EPR), X-ray absorption spectroscopic (XAS) and density functional theory (DFT) calculations.

scholarly journals Fiber-integrated Brillouin microspectroscopy: Towards Brillouin endoscopy

2017 ◽  
Vol 10 (06) ◽  
pp. 1742002 ◽  
Author(s):  
Irina V. Kabakova ◽  
YuChen Xiang ◽  
Carl Paterson ◽  
Peter Török
Keyword(s):  
Optical Fiber ◽  
Brillouin Scattering ◽  
Region Of Interest ◽  
The Body ◽  
Propagation Model ◽  
Micromechanical Characterization ◽  
First Time

Brillouin imaging (BI) for micromechanical characterization of tissues and biomaterials is a fast-developing field of research with a strong potential for medical diagnosis of disease-modified tissues and cells. Although the principles of BI imply its compatibility with in vivo and in situ measurements, the integration of BI with a flexible catheter, capable of reaching the region of interest within the body, is yet to be reported. Here, for the first time, we experimentally investigate integration of the Brillouin spectroscope with standard optical fiber components to achieve a Brillouin endoscope. The performance of single-fiber and dual-fiber endoscopes are demonstrated and analyzed. We show that a major challenge in construction of Brillouin endoscopes is the strong backward Brillouin scattering in the optical fiber and we present a dual-fiber geometry as a possible solution. Measurements of Brillouin spectra in test liquids (water, ethanol and glycerol) are demonstrated using the dual-fiber endoscope and its performance is analyzed numerically with the help of a beam propagation model.

scholarly journals Spatiotemporal characterization of periocular mesenchyme heterogeneity during anterior segment development

2019 ◽  
Author(s):  
Kristyn L. Van Der Meulen ◽  
Oliver Vöcking ◽  
Megan L. Weaver ◽  
Jakub K. Famulski
Keyword(s):  
Expression Patterns ◽  
Anterior Segment ◽  
Critical Event ◽  
Transgenic Zebrafish ◽  
Anterior Segment Dysgenesis ◽  
Heterogenous Population ◽  
First Time

ABSTRACTEstablishment of the ocular anterior segment (AS) is a critical event during development of the vertebrate visual system. Failure in this process leads to Anterior Segment Dysgenesis (ASD), which is characterized by congenital blindness and predisposition to glaucoma. The anterior segment is largely formed via a neural crest-derived population, the Periocular Mesenchyme (POM). In this study, we aimed to characterize POM behaviors and identities during zebrafish AS development. POM distributions and migratory dynamics were analyzed using transgenic zebrafish embryos (Tg[foxC1b:GFP], Tg[foxD3:GFP], Tg[pitx2:GFP], Tg[lmx1b.1:GFP], and Tg[sox10:GFP] throughout the course of early AS development (24-72hpf). In vivo imaging analysis revealed unique AS distribution and migratory behavior among the reporter lines, suggesting AS mesenchyme (ASM) is a heterogenous population. This was confirmed using double in situ hybridization. Furthermore, we generated ASM transcriptomic profiles from our reporter lines and using a four-way comparison analysis uncovered unique ASM subpopulation expression patterns. Taken together, our data reveal for the first time that AS-associated POM is not homogeneous but rather comprised of several unique subpopulations identifiable by their distributions, behaviors, and transcriptomic profiles.

Polarimetry: a primary tool for the physical characterization of asteroids

2014 ◽  
Vol 10 (S305) ◽  
pp. 313-318
Author(s):  
A. Cellino ◽  
S. Bagnulo
Keyword(s):  
Solar System ◽  
First Generation ◽  
Ground Truth ◽  
Preliminary Evidence ◽  
Physical Characterization ◽  
New Class ◽  
Solid Bodies ◽  
First Time

AbstractAsteroid polarimetry has taken profit in recent years of a renewed interest triggered by exciting results from observing campaigns and theoretical studies. One of the most important applications of polarimetry to asteroid studies is the derivation of the geometric albedo and of the typical sizes of the particles forming the regolith layer covering the surface. Moreover, the serendipitous discovery of a new class of asteroids displaying unusual polarimetric properties, the so-called “Barbarians”, has been followed by increasing evidence that these objects can be extremely primitive and may be interpreted as remnants of the very first generation of solid bodies accreted in the inner Solar System. In addition, some results of asteroid polarimetry are going to be interpreted, for the first time, in terms of some “ground truth” evidence, made possible by in situ observations of the surface of the asteroid (4) Vesta by the Dawn space probe. Finally, some preliminary evidence suggests that spectro-polarimetry is going to become a major tool for the physical characterization of the small bodies of the solar system.

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