Combined analysis of static and dynamic extinction characteristics of microbial spores and mycelia as a mid-infrared extinction material
TL;DR: In this article, a method via combined static and dynamic analysis extinction performance is presented, combining with the reflection spectra measured by a Nicolet FT-IR spectrometer, and transmittance determined by smoke box test of microbial materials in 3 ∼ 5 μ m.
About: This article is published in Optik.The article was published on 2019-01-01. It has received 6 citations till now. The article focuses on the topics: Extinction (optical mineralogy) & Extinction event.
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TL;DR: In this article, the complex refractive indices of traditional smoke materials and bio-aerosols in the 2.5-15 μm wavebands were calculated and the IR transmittances of different smoke materials in the smoke box experiment were measured to calculate their mass extinction coefficients.
12 citations
TL;DR: In this paper, the authors used the cluster-cluster aggregation model to establish the structures of aggregated particles at different stages in the aggregation of bioaerosols and calculated the extinction parameters of the aggregated particle by using the discrete dipole approximation method.
9 citations
TL;DR: In this article, the spectral reflectance of three eukaryotic bio-smoke materials and three prokaryotic BioSmoke materials in the waveband from 0.25 μm to 14 μm was measured based on the Kramers-Kroning algorithm.
Abstract: At present, research into optical properties of bio-smoke materials mostly concentrates on single band or single germplasm. Herein, we measured the spectral reflectance of three eukaryotic bio-smoke materials and three prokaryotic bio-smoke materials in the waveband from 0.25 μm to 14 μm. Based on the Kramers–Kroning algorithm, the complex refractive index m(λ) was calculated and the Fourier-transform infrared (FTIR) spectra of materials were analyzed. The results show that n(λ) of bio-smoke materials varies between 1.1–2, and n(λ) values in the visible light to near-infrared wavebands are significantly larger than those in other wavebands. The k(λ) of bio-smoke materials varies between 0–0.4. At 6–6.5 μm, k(λ) of prokaryotic materials is 3 times that of eukaryotic materials, which is caused by C=O stretching vibration of amide I and C–N stretching vibration of amide II in proteins. At 2.5–3 μm and 9.75 μm, k(λ) values of eukaryotic bio-smoke materials are nearly 2 times that of prokaryotic ones. The absorption peak at 2.5–3 μm is mainly triggered by C–H stretching vibration in lipid and O–H stretching vibration in bound water. The absorption peak at 9.75 μm is mainly caused by symmetric stretching vibration of in nucleic acids.
8 citations
01 Jan 2011
TL;DR: In this paper, the complex refractive index of expanded graphite (EG) pellet in the 0.24~2.6 μm and 2.5~25 μm waveband was calculated by Kramers-Kronig(K-K) relation and Bruggeman effective medium theory.
Abstract: The expanded graphite(EG) with good extinction performance can be used as electro-optical passive jamming materials,and its complex refractive index is an important parameter for study on its extinction property.The reflection spectra of EG pellet in the 0.24~2.6 μm and 2.5~25 μm waveband were measured respectively.Based on the measured data,the complex refractive index of EG in the wavelength band 5 to 10 μm were calculated by Kramers-Kronig(K-K) relation and Bruggeman effective medium theory,and calculation errors were analyzed.The results indicate that it is practicable to calculate the complex refractive index of EG based on its reflection spectra data.
6 citations
TL;DR: The simulation results and experimental data from an aerosol chamber experiment show that as the relative humidity values above 70%, the broadband extinction performance of bioaerosol will be increased with humidity, and the variation law of broadband extinction performances in different humidity conditions was obtained by simulation.
Abstract: Bioaerosol, a significant constituent of the atmosphere, exhibits excellent broadband extinction performance and has attracted increasing attentions in the fields of atmospheric science, environmental science and electromagnetic field, et al. Relative humidity of the atmosphere has obvious diurnal and seasonal variation characteristics, and the frequent variation of relative humidity has a significant impact on bioaerosol in the atmosphere. However, the influence of relative humidity on broadband extinction performance of bioaerosol is unclear. Herein, we present the humidity growth model of bioaerosol. And the variation law of broadband extinction performance of bioaerosol in different humidity conditions was obtained by simulation. The simulation results and experimental data from an aerosol chamber experiment show that as the relative humidity values above 70%, the broadband extinction performance of bioaerosol will be increased with humidity. As the relative humidity increases from 70% to 90%, the extinction performance of AN0913 spores increase about 30% in visible and mid-infrared bands, about 20% in ultraviolet and far-infrared bands. And the extinction performance of AO0907 spores increase about 23% in the all four bands.
5 citations
References
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Book•
01 Jan 1983
TL;DR: In this paper, a Potpourri of Particles is used to describe surface modes in small Particles and the Angular Dependence of Scattering is shown to be a function of the size of the particles.
Abstract: BASIC THEORY. Electromagnetic Theory. Absorption and Scattering by an Arbitrary Particle. Absorption and Scattering by a Sphere. Particles Small Compared with the Wavelength. Rayleigh--Gans Theory. Geometrical Optics. A Potpourri of Particles. OPTICAL PROPERTIES OF BULK MATTER. Classical Theories of Optical Constants. Measured Optical Properties. OPTICAL PROPERTIES OF PARTICLES. Extinction. Surface Modes in Small Particles. Angular Dependence of Scattering. A Miscellany of Applications. Appendices. References. Index.
16,859 citations
Book•
10 Jun 2002
TL;DR: In this paper, the basic theory of Electromagnetic Scattering, Absorption, and Emission was presented, and the T-matrix method and Lorenz-Mie theory were used to calculate and measure the scattering and absorption properties of small particles.
Abstract: Preface Acknowledgements Part I. Basic Theory of Electromagnetic Scattering, Absorption, and Emission: 1. Polarization characteristics of electromagnetic radiation 2. Scattering, absorption, and emission of electromagnetic radiation by an arbitrary finite particle 3. Scattering, absorption and emission by collections of independent particles 4. Scattering matrix and macroscopically isotropic and mirror-symmetric scattering media Part II. Calculation and Measurement of Scattering and Absorption Characteristics of Small Particles: 5. T-matrix method and Lorenz-Mie theory 6. Miscellaneous exact techniques 7. Approximations 8. Measurement techniques Part III. Scattering and Absorption Properties of Small Particles and Illustrative Applications: 9. Scattering and absorption properties of spherical particles 10. Scattering and absorption properties of nonspherical particles Appendices References Index.
1,816 citations
TL;DR: A surfactant-assisted nonaqueous route to anisotropic copper sulfide nanocrystals, selectively trapped in the covellite phase, which can exhibit intense, size-tunable LSPR at near-infrared wavelengths despite their stoichiometric, undoped structure is demonstrated.
Abstract: In the realm of semiconductor nanomaterials, a crystal lattice heavily doped with cation/anion vacancies or ionized atomic impurities is considered to be a general prerequisite to accommodating excess free carriers that can support localized surface plasmon resonance (LSPR). Here, we demonstrate a surfactant-assisted nonaqueous route to anisotropic copper sulfide nanocrystals, selectively trapped in the covellite phase, which can exhibit intense, size-tunable LSPR at near-infrared wavelengths despite their stoichiometric, undoped structure. Experimental extinction spectra are satisfactorily reproduced by theoretical calculations performed by the discrete dipole approximation method within the framework of the Drude–Sommerfeld model. The LSPR response of the nanocrystals and its geometry dependence are interpreted as arising from the inherent metallic-like character of covellite, allowed by a significant density of lattice-constitutional valence-band free holes. As a consequence of the unique electronic pr...
298 citations
TL;DR: In this paper, a modified Lorentz-Drude model with frequency-dependent damping was proposed to model the optical constants of graphite for ordinary and extraordinary waves with an acceptance probability-controlled simulated annealing algorithm.
Abstract: Optical constants of graphite for ordinary and extraordinary waves are modeled with a modified Lorentz–Drude model with frequency-dependent damping. The model enables the shape of the spectral line to vary over a range of broadening functions with similar kernels and different wings, the broadening type being its adjustable parameter. The model parameters are determined by the acceptance-probability-controlled simulated annealing algorithm. Good agreement with the experimental data is obtained in the entire investigated spectral range (0.12–40 eV for ordinary wave and 2.1–40 eV for extraordinary wave). The significant discrepancies between the experimental data obtained by the reflectance measurements and the electron-energy-loss spectroscopy data are analyzed in details. Inconsistency in terms of unsatisfied Kramers–Kronig relations is discovered in the index of refraction data derived from reflectance measurements, and a method for correcting the data is proposed.
241 citations
TL;DR: It is shown that copper telluride NCs with well-defined morphologies (spheres, rods, tetrapods) can be prepared via cation exchange of preformed CdTe NCs while retaining their original shape, suggesting that holes in the valence band of Cu(2-x)Te cannot be described as fully free particles and that the effects of localization of holes are important.
Abstract: Size- and shape-controlled synthesis of copper chalcogenide nanocrystals (NCs) is of paramount importance for a careful engineering and understanding of their optoelectronic properties and, thus, for their exploitation in energy- and plasmonic-related applications. From the copper chalcogenide family copper telluride NCs have remained fairly unexplored as a result of a poor size-, shape-, and monodispersity control that is achieved via one-step syntheses approaches. Here we show that copper telluride (namely Cu2–xTe) NCs with well-defined morphologies (spheres, rods, tetrapods) can be prepared via cation exchange of preformed CdTe NCs while retaining their original shape. The resulting copper telluride NCs are characterized by pronounced plasmon bands in the near-infrared (NIR), in analogy to other copper-deficient chalcogenides (Cu2–xS, Cu2–xSe). We demonstrate that the extinction spectra of the as-prepared NCs are in agreement with theoretical calculations based on the discrete dipole approximation and ...
192 citations