scholarly journals Brown carbon absorption in the red and near infrared spectral region

2017 ◽  
Author(s):  
András Hoffer ◽  
Ádám Tóth ◽  
Mihály Pósfai ◽  
Chul Eddy Chung ◽  
András Gelencsér
Keyword(s):  
Absorption Coefficient ◽  
Near Infrared ◽  
Infrared Region ◽  
Infrared Light ◽  
Carbonaceous Particles ◽  
Aerosol Absorption ◽  
Tar Balls ◽  
Infrared Spectral ◽  
Carbon Aerosols ◽  
Significant Mass

Abstract. Black carbon aerosols (BC) have been conventionally assumed to be the only light-absorbing carbonaceous particles in the red and near-infrared spectral regions of solar radiation in the atmosphere. Here we report that contrary to the conventional belief tar balls (a specific type of organic aerosol particles from biomass burning) do absorb red and near infrared radiation significantly. Tar balls were produced in a laboratory experiment and their chemical and optical properties were measured. The absorption of these particles in the range between 470 and 950 nm was measured with an aethalometer which is widely used to measure atmospheric aerosol absorption. We find that the absorption coefficient of tar balls at 880 nm is more than 10 % of that at 470 nm. The considerable absorption of red and infrared light by tar balls also follows from their relatively low absorption Ångström coefficient (and significant mass absorption coefficient) in the spectral range between 470 and 950 nm. Our results support previous finding that tar balls may play an important role in global warming. Due to the non-negligible absorption of tar balls in the infrared region the absorption measured in the field at higher wavelengths may not solely due to soot particles.

scholarly journals Brown carbon absorption in the red and near-infrared spectral region

2017 ◽  
Vol 10 (6) ◽  
pp. 2353-2359 ◽  
Author(s):  
András Hoffer ◽  
Ádám Tóth ◽  
Mihály Pósfai ◽  
Chul Eddy Chung ◽  
András Gelencsér
Keyword(s):  
Absorption Coefficient ◽  
Near Infrared ◽  
Infrared Region ◽  
Infrared Light ◽  
Carbonaceous Particles ◽  
Aerosol Absorption ◽  
Tar Balls ◽  
Infrared Spectral ◽  
Infrared Wavelengths ◽  
Significant Mass

Abstract. Black carbon (BC) aerosols have often been assumed to be the only light-absorbing carbonaceous particles in the red and near-infrared spectral regions of solar radiation in the atmosphere. Here we report that tar balls (a specific type of organic aerosol particles from biomass burning) do absorb red and near-infrared radiation significantly. Tar balls were produced in a laboratory experiment, and their chemical and optical properties were measured. The absorption of these particles in the range between 470 and 950 nm was measured with an aethalometer, which is widely used to measure atmospheric aerosol absorption. We find that the absorption coefficient of tar balls at 880 nm is more than 10 % of that at 470 nm. The considerable absorption of red and infrared light by tar balls also follows from their relatively low absorption Ångström coefficient (and significant mass absorption coefficient) in the spectral range between 470 and 950 nm. Our results support the previous finding that tar balls may play an important role in global warming. Due to the non-negligible absorption of tar balls in the near-infrared region, the absorption measured in the field at near-infrared wavelengths cannot solely be due to soot particles.

scholarly journals Brown carbon absorption in the red and near infrared spectral region

2016 ◽  
Author(s):  
A. Hoffer ◽  
A. Tóth ◽  
M. Pósfai ◽  
C. E. Chung ◽  
A. Gelencsér
Keyword(s):  
Optical Properties ◽  
Absorption Coefficient ◽  
Biomass Burning ◽  
Near Infrared ◽  
Global Network ◽  
Infrared Light ◽  
Brown Carbon ◽  
Carbonaceous Particles ◽  
Tar Balls ◽  
Infrared Spectral

Abstract. Black carbon aerosols have been conventionally assumed to be the only light-absorbing carbonaceous particles in the red and near-infrared spectral regions of solar radiation in the atmosphere. Here we report that contrary to the conventional belief tar balls (a specific type of organic aerosol particles from biomass burning) do absorb red and near infrared radiation significantly. Tar balls were produced in a laboratory experiment and their chemical and optical properties were measured. The absorption of these particles in the range between 470 and 950 nm was measured with an aethalometer, which is widely used to measure aerosol absorption in the field. We find that the absorption coefficient of tar balls at 880 nm exceeds 10 % of that at 470 nm. This substantial absorption of red and infrared light is also evident from a relatively low Ångström coefficient (and a significant mass absorption coefficient) of tar balls between 470 and 950 nm. Retrievals of aerosol column optical properties from a global network of surface stations over vast tropical areas dominated by biomass burning suggest that tar balls are the predominant light-absorbing species of organic aerosols over acetone/methanol-soluble BrC or HULIS. Our results also infer that the role of BC (including Diesel soot) in global climate forcing has likely been overestimated at the expense of brown carbon (BrC) from biomass burning.

scholarly journals Phenotypic and genetic variation of ultraviolet–visible-infrared spectral wavelengths of bovine meat

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Giovanni Bittante ◽  
Simone Savoia ◽  
Alessio Cecchinato ◽  
Sara Pegolo ◽  
Andrea Albera
Keyword(s):  
Meat Quality ◽  
Genetic Improvement ◽  
Near Infrared ◽  
Infrared Region ◽  
Phenotypic Variance ◽  
Quality Traits ◽  
Meat Quality Traits ◽  
Infrared Spectral ◽  
Portable Spectrometers ◽  
Absorbance Spectra

AbstractSpectroscopic predictions can be used for the genetic improvement of meat quality traits in cattle. No information is however available on the genetics of meat absorbance spectra. This research investigated the phenotypic variation and the heritability of meat absorbance spectra at individual wavelengths in the ultraviolet–visible and near-infrared region (UV–Vis-NIR) obtained with portable spectrometers. Five spectra per instrument were taken on the ribeye surface of 1185 Piemontese young bulls from 93 farms (13,182 Herd-Book pedigree relatives). Linear animal model analyses of 1481 single-wavelengths from UV–Vis-NIRS and 125 from Micro-NIRS were carried out separately. In the overlapping regions, the proportions of phenotypic variance explained by batch/date of slaughter (14 ± 6% and 17 ± 7%,), rearing farm (6 ± 2% and 5 ± 3%), and the residual variances (72 ± 10% and 72 ± 5%) were similar for the UV–Vis-NIRS and Micro-NIRS, but additive genetics (7 ± 2% and 4 ± 2%) and heritability (8.3 ± 2.3% vs 5.1 ± 0.6%) were greater with the Micro-NIRS. Heritability was much greater for the visible fraction (25.2 ± 11.4%), especially the violet, blue and green colors, than for the NIR fraction (5.0 ± 8.0%). These results allow a better understanding of the possibility of using the absorbance of visible and infrared wavelengths correlated with meat quality traits for the genetic improvement in beef cattle.

Optical enzymatic detection of glucose based on hydrogen peroxide-sensitive HiPco carbon nanotubes

2006 ◽  
Vol 21 (11) ◽  
pp. 2817-2823 ◽  
Author(s):  
Chulho Song ◽  
Pehr E. Pehrsson ◽  
Wei Zhao
Keyword(s):  
Carbon Nanotubes ◽  
Hydrogen Peroxide ◽  
Carbon Nanotube ◽  
Near Infrared ◽  
Sodium Dodecyl ◽  
Enzymatic Reaction ◽  
Infrared Region ◽  
Infrared Spectral ◽  
Sensitivity And Selectivity ◽  
Enzymatic Detection

We recently observed that surfactant sodium dodecyl sulfate (SDS)-encased HiPco single-walled carbon nanotubes (SWNTs) respond optically to hydrogen peroxide (H2O2) in the near-infrared region. In this report, we demonstrate that SDS-encased SWNTs immobilized with glucose oxidase (GOx) can be used to optically detect an enzymatic reaction of glucose based on their H2O2 sensitivity as well as pH sensitivity. Only the enzymatic product H2O2 induces the SWNT near-infrared spectral changes in buffer solutions (pH = 6.0), but both H2O2 and gluconic acid products do this in unbuffered solutions. The SWNT optical response to glucose possesses sensitivity and selectivity similar to an electrochemical method using carbon nanotube nanoelectrode arrays. Our results suggest possible carbon nanotube-based optical tools for molecular recognition applications.

Optical Spectroscopy as a Tool for Observation of Porous SiC Graphitization

2005 ◽  
Vol 483-485 ◽  
pp. 261-264
Author(s):  
V.B. Shuman ◽  
N.S. Savkina
Keyword(s):  
Thermal Treatment ◽  
Absorption Coefficient ◽  
Porous Layer ◽  
Spectral Range ◽  
Optical Transmission ◽  
Near Infrared ◽  
Wet Oxidation ◽  
Infrared Spectral Range ◽  
Infrared Spectral ◽  
Porous Sic

We have studied effects of thermal treatment in vacuum and wet oxidation on the optical transmission of SiC samples with porous layer on the Si face in the visible and near infrared spectral range. An analysis of changes in the absorption coefficient shows that the process of graphitization in vacuum begins at a temperature below 700°C and can be observed at wet oxidation at 1000°C.

scholarly journals Surface Plasmon Resonances in Sn: In2O3 Thin Films with Diffraction Grating

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1034
Author(s):  
Noriyuki Hasuike ◽  
Saito Ochiai ◽  
Ryotaro Iwakiri ◽  
Minoru Takeda ◽  
Woo Sik Yoo ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Spectral Region ◽  
Diffraction Grating ◽  
Near Infrared ◽  
Transparent Conductive Oxide ◽  
Infrared Region ◽  
Reflection Spectra ◽  
Surface Plasmon Resonances ◽  
Infrared Spectral Region ◽  
Infrared Spectral

We newly proposed transparent conductive oxide with diffraction grating structure as an excitation field of surface plasmon resonance working at near-infrared spectral region. We experimentally demonstrated the excitation of SPR using Sn-doped In2O3 films with micro-meter pitched diffraction grating. In this study, we considered the correlation between the grating pitch and the optical reflection spectra. Reflection spectra showed clear polarization properties in infrared spectral region, and the reflection edge has also correlation with the pitch of grating. From these results, the excitation of SPR grating was successfully demonstrated and the wavelength can be tuned by changing the grating pitch in infrared region.

scholarly journals Solution-processed near-infrared Cu(In,Ga)(S,Se)2 photodetectors with enhanced chalcopyrite crystallization and bandgap grading structure via potassium incorporation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joo-Hyun Kim ◽  
Hyemi Han ◽  
Min Kyu Kim ◽  
Jongtae Ahn ◽  
Do Kyung Hwang ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Grain Growth ◽  
Carrier Mobility ◽  
Near Infrared ◽  
Low Cost ◽  
Charge Carrier Mobility ◽  
Infrared Region ◽  
Infrared Light ◽  
Large Area ◽  
Solution Processed

AbstractAlthough solution-processed Cu(In,Ga)(S,Se)2 (CIGS) absorber layers can potentially enable the low-cost and large-area production of highly stable electronic devices, they have rarely been applied in photodetector applications. In this work, we present a near-infrared photodetector functioning at 980 nm based on solution-processed CIGS with a potassium-induced bandgap grading structure and chalcopyrite grain growth. The incorporation of potassium in the CIGS film promotes Se uptake in the bulk of the film during the chalcogenization process, resulting in a bandgap grading structure with a wide space charge region that allows improved light absorption in the near-infrared region and charge carrier separation. Also, increasing the Se penetration in the potassium-incorporated CIGS film leads to the enhancement of chalcopyrite crystalline grain growth, increasing charge carrier mobility. Under the reverse bias condition, associated with hole tunneling from the ZnO interlayer, the increasing carrier mobility of potassium-incorporated CIGS photodetector improved photosensitivity and particularly external quantum efficiency more than 100% at low light intensity. The responsivity and detectivity of the potassium-incorporated CIGS photodetector reach 1.87 A W−1 and 6.45 $$\times$$ ×  1010 Jones, respectively, and the − 3 dB bandwidth of the device extends to 10.5 kHz under 980 nm near-infrared light.

Carbon dioxide in pollucite, a feldspathoid with the ideal composition (Cs, Na)16Al16Si32O96·nH2O

2012 ◽  
Vol 76 (4) ◽  
pp. 903-911 ◽  
Author(s):  
F. Bellatreccia ◽  
G. Della Ventura ◽  
G. D. Gatta ◽  
M. Cestelli Guidi ◽  
S. Harley
Keyword(s):  
Absorption Coefficient ◽  
Single Crystal ◽  
Near Infrared ◽  
Secondary Ion Mass Spectrometry ◽  
Infrared Region ◽  
Sharp Peak ◽  
Molar Absorption Coefficient ◽  
X Ray Diffraction ◽  
Bending Vibration ◽  
Ideal Composition

AbstractWe report a single-crystal Fourier-transform infrared (FTIR) study of a sample of pollucite from Maine, USA. Prior to our work, the sample had been characterized by single-crystal X-ray diffraction, neutron diffraction and electron-probe microanalysis. It is cubicIa3d, with a crystal-chemical formula Na1.93(Cs10.48Rb0.31K0.04)Σ=10.83(Al14.45Si33.97)Σ=48.42O96·3.92H2O, and an H2O content, determined by thermogravimetric analysis, of 1.6 wt.%. The single-crystal FTIR spectrum has a doublet of intense bands at 3670 and 3589 cm–1, which are assigned to the ν3and ν1stretching modes of the H2O molecule, respectively. A very intense and sharp peak at 1620 cm–1is assigned to the ν2bending vibration. In the near-infrared region there is a relatively intense peak at 5270 cm–1, which is assigned to a combination (ν2+ ν3) mode of H2O, and a weak but well defined doublet at 7118 and 6831 cm–1, which is assigned to the first overtones of the fundamental stretching modes. A relatively weak but extremely sharp peak at 2348 cm–1shows that the pollucite contains CO2molecules in structural cavities. Mapping the sample using FTIR indicates that both H2O and CO2are homogeneously distributed. Secondary ion mass spectrometry yielded an average CO2content of 0.09±0.02 wt.%. On the basis of this value, we determined the integrated molar absorption coefficient for the spectroscopic analysis of CO2in pollucite to be εiCO2= 11,000±3000 l mol–1cm–2; the linear molar absorption coefficient for the same integration range is εlCO2= 1600±500 l mol–1cm–1.

scholarly journals Eye Safety Related to Near Infrared Radiation Exposure to Biometric Devices

2011 ◽  
Vol 11 ◽  
pp. 520-528 ◽  
Author(s):  
Nikolaos Kourkoumelis ◽  
Margaret Tzaphlidou
Keyword(s):  
Infrared Radiation ◽  
Near Infrared ◽  
Biological Effects ◽  
Infrared Region ◽  
Infrared Light ◽  
Near Infrared Radiation ◽  
Potential Threat ◽  
Incoherent Light ◽  
Light Emitting ◽  
Living Tissues

Biometrics has become an emerging field of technology due to its intrinsic security features concerning the identification of individuals by means of measurable biological characteristics. Two of the most promising biometric modalities are iris and retina recognition, which primarily use nonionizing radiation in the infrared region. Illumination of the eye is achieved by infrared light emitting diodes (LEDs). Even if few LED sources are capable of causing direct eye damage as they emit incoherent light, there is a growing concern about the possible use of LED arrays that might pose a potential threat. Exposure to intense coherent infrared radiation has been proven to have significant effects on living tissues. The purpose of this study is to explore the biological effects arising from exposing the eye to near infrared radiation with reference to international legislation.

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