scholarly journals Single-particle Raman spectroscopy for studying physical and chemical processes of atmospheric particles

2021 ◽  
Author(s):  
Zhancong Liang ◽  
Yangxi Chu ◽  
Masao Gen ◽  
Chak K. Chan
Keyword(s):  
Raman Spectroscopy ◽  
Single Particle ◽  
Field Measurements ◽  
Chemical Processes ◽  
Atmospheric Particles ◽  
Multiphase Reactions ◽  
Particle Level ◽  
Physical And Chemical ◽  
Non Destructive ◽  
Individual Particles

Abstract. Atmospheric particles experience various physical and chemical processes and change their properties during their lifetime. Most studies on atmospheric particles, both in laboratory and field measurements, rely on analyzing an ensemble of particles. Because of different mixing state of individual particles, only average properties can be obtained from studies using ensembles of particles. To better understand the fate and environmental impacts of atmospheric particles, investigations on their properties and processes at a single-particle level are valuable. Among a wealth of analytic techniques, single-particle Raman spectroscopy provides an unambiguous characterization of individual particles under atmospheric pressure in a non-destructive and in-situ manner. This paper comprehensively reviews the application of such a technique in the studies of atmospheric particles, including particle hygroscopicity, phase transition and separation, and solute-water interactions, particle pH, and multiphase reactions. Investigations on enhanced Raman spectroscopy and bioaerosols on a single-particle basis are also reviewed. For each application, we describe the principle and representative examples of studies. Finally, we present our views on future directions on both technique development and further applications of single-particle Raman spectroscopy in studying atmospheric particles.

Raman Spectroscopy Application to Characterize EVA after UV Exposure

MRS Advances ◽  
2016 ◽  
Vol 1 (17) ◽  
pp. 1191-1196
Author(s):  
Sari Katz ◽  
Aaron Urbas ◽  
Stephanie S. Watson ◽  
Xiaohong Gu
Keyword(s):  
Raman Spectroscopy ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Ethylene Vinyl Acetate ◽  
Crosslinking Density ◽  
Uv Exposure ◽  
Internal Stresses ◽  
Chemical Changes ◽  
Physical And Chemical ◽  
Non Destructive

ABSTRACTEthylene-vinyl acetate (EVA) is the most commonly used photovoltaic (PV) encapsulant material. As such, it is exposed to UV, thermal cycles, temperature gradients between the glass side and the silicon wafer side, and moisture ingress. The combined effect of all these may lead to different physical and chemical changes of EVA including polymer chain alignment, crystallinity, and crosslinking density, as well as the mechanical stresses resulting from coefficient of thermal expansion (CTE) and aging, thus, reducing the adhesion of EVA and eventually lead to failure of the encapsulation. Measuring the effects of UV exposure on EVA can help in understanding the failure mechanism of PV modules. In this work, we suggest a novel and non-destructive way to measure EVA degradation after UV exposure by using Raman spectroscopy (RS). Samples were exposed to NIST SPHERE with UV irradiation, moisture, and elevated temperatures. The physical and chemical changes as well as the internal stresses were monitored by RS, and the intensities of the corresponding Raman peaks ratio were analyzed. The results have indicated that Raman scattering is a sensitive tool to study EVA encapsulant degradation.

Colloidal Plasmonic Nanostar Antennas with Wide Range Resonance Tunability

2019 ◽  
Author(s):  
Theodoros Tsoulos ◽  
Supriya Atta ◽  
Maureen Lagos ◽  
Michael Beetz ◽  
Philip Batson ◽  
...  
Keyword(s):  
Single Particle ◽  
Structural Complexity ◽  
Field Enhancement ◽  
Hot Electron ◽  
Structure Property ◽  
Plasmon Band ◽  
Gold Nanostars ◽  
Wide Range ◽  
Particle Level ◽  
Spectrally Resolved

<div>Gold nanostars display exceptional field enhancement properties and tunable resonant modes that can be leveraged to create effective imaging tags or phototherapeutic agents, or to design novel hot-electron based photocatalysts. From a fundamental standpoint, they represent important tunable platforms to study the dependence of hot carrier energy and dynamics on plasmon band intensity and position. Toward the realization of these platforms, holistic approaches taking into account both theory and experiments to study the fundamental behavior of these</div><div>particles are needed. Arguably, the intrinsic difficulties underlying this goal stem from the inability to rationally design and effectively synthesize nanoparticles that are sufficiently monodispersed to be employed for corroborations of the theoretical results without the need of single particle experiments. Herein, we report on our concerted computational and experimental effort to design, synthesize, and explain the origin and morphology-dependence of the plasmon modes of a novel gold nanostar system, with an approach that builds upon the well-known plasmon hybridization model. We have synthesized monodispersed samples of gold nanostars with finely tunable morphology employing seed-mediated colloidal protocols, and experimentally observed narrow and spectrally resolved harmonics of the primary surface plasmon resonance mode both at the single particle level (via electron energy loss spectroscopy) and in ensemble (by UV-Vis and ATR-FTIR spectroscopies). Computational results on complex anisotropic gold nanostructures are validated experimentally on samples prepared colloidally, underscoring their importance as ideal testbeds for the study of structure-property relationships in colloidal nanostructures of high structural complexity.</div>

Nucleophilicity and its parametrization

1989 ◽  
Vol 54 (1) ◽  
pp. 117-135
Author(s):  
Oldřich Pytela ◽  
Vítězslav Zima
Keyword(s):  
Regression Analysis ◽  
Linear Correlation ◽  
Correlation Equation ◽  
Chemical Processes ◽  
General Tendency ◽  
Orbital Interaction ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Two Parameter ◽  
Better Than

The method of conjugate deviations based on the regression analysis has been suggested for construction of a new nucleophilicity scale. This method has been applied to a set of 28 nucleophiles participating in 47 physical and chemical processes described in literature. The two-parameter nucleophilicity scale obtained represents-in the parameter denoted as ND-the general tendency to form a bond to an electrophile predominantly on the basis of the orbital interaction and-in the parameter denoted as PD-the ability to interact with a centre similar to the proton (basicity). The linear correlation equation involving the ND, PD parameters and the charge appears to be distinctly better than the most significant relations used. The correlation dependences have the physico-chemical meaning. From the position of individual nucleophiles in the space of the ND and PD parameters, some general conclusions have been derived about the factors governing the reactivity of nucleophiles.

The Tree

2018 ◽  
Author(s):  
Andrew Steane
Keyword(s):  
Carbon Capture ◽  
Chemical Processes ◽  
Physical And Chemical

The life of an ordinary tree is described, in terms of the main physical and chemical processes: carbon capture by photosynthesis; entropy and energy; moisture. The information expressed in the tree comes partly from the DNA and partly from the sunlight. The tree does not push upwards from the ground, but solidifies the air.

scholarly journals Control of Physical and Chemical Processes with Nonlocal Metal–Dielectric Environments

ACS Photonics ◽  
2019 ◽  
Vol 6 (12) ◽  
pp. 3039-3056 ◽  
Author(s):  
Vanessa N. Peters ◽  
Srujana Prayakarao ◽  
Samantha R. Koutsares ◽  
Carl E. Bonner ◽  
Mikhail A. Noginov
Keyword(s):  
Chemical Processes ◽  
Physical And Chemical

scholarly journals Role of Single-Particle Energies in Microscopic Interacting Boson Model Double Beta Decay Calculations

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 66
Author(s):  
Jenni Kotila
Keyword(s):  
Beta Decay ◽  
Single Particle ◽  
Field Potential ◽  
Double Beta Decay ◽  
Interacting Boson Model ◽  
Model Calculations ◽  
Single Particle Level ◽  
Particle Level ◽  
Boson Model

Single-particle level energies form a significant input in nuclear physics calculations where single-particle degrees of freedom are taken into account, including microscopic interacting boson model investigations. The single-particle energies may be treated as input parameters that are fitted to reach an optimal fit to the data. Alternatively, they can be calculated using a mean field potential, or they can be extracted from available experimental data, as is done in the current study. The role of single-particle level energies in the microscopic interacting boson model calculations is discussed with special emphasis on recent double beta decay calculations.

scholarly journals Non-Destructive Fuel Volume Measurements Can Estimate Fine-Scale Biomass across Surface Fuel Types in a Frequently Burned Ecosystem

Fire ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 36
Author(s):  
Quinn A. Hiers ◽  
E. Louise Loudermilk ◽  
Christie M. Hawley ◽  
J. Kevin Hiers ◽  
Scott Pokswinski ◽  
...  
Keyword(s):  
Bulk Density ◽  
Pinus Palustris ◽  
Field Measurements ◽  
Complex Surface ◽  
Fuel Type ◽  
Field Methods ◽  
Volume Measurements ◽  
Woody Litter ◽  
Non Destructive ◽  
Surface Vegetation

Measuring wildland fuels is at the core of fire science, but many established field methods are not useful for ecosystems characterized by complex surface vegetation. A recently developed sub-meter 3D method applied to southeastern U.S. longleaf pine (Pinus palustris) communities captures critical heterogeneity, but similar to any destructive sampling measurement, it relies on separate plots for calculating loading and consumption. In this study, we investigated how bulk density differed by 10-cm height increments among three dominant fuel types, tested predictions of consumption based on fuel type, height, and volume, and compared this with other field measurements. The bulk density changed with height for the herbaceous and woody litter fuels (p < 0.001), but live woody litter was consistent across heights (p > 0.05). Our models predicted mass well based on volume and height for herbaceous (RSE = 0.00911) and woody litter (RSE = 0.0123), while only volume was used for live woody (R2 = 0.44). These were used to estimate consumption based on our volume-mass predictions, linked pre- and post-fire plots by fuel type, and showed similar results for herbaceous and woody litter when compared to paired plots. This study illustrates an important non-destructive alternative to calculating mass and estimating fuel consumption across vertical volume distributions at fine scales.

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