Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites

PubMed Central

Gagani, Abedin I.; Echtermeyer, Andreas T.

2018-01-01

Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR) spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR) spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer–Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described. PMID:29641451

Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites.

PubMed

Krauklis, Andrey E; Gagani, Abedin I; Echtermeyer, Andreas T

2018-04-11

Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR) spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR) spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer-Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described.

Variable-temperature Fourier transform near-infrared imaging spectroscopy of the deuterium/hydrogen exchange in liquid D₂O.

PubMed

Unger, Miriam; Ozaki, Yukihiro; Siesler, Heinz W

2014-01-01

In the present publication, the deuterium/hydrogen (D/H) exchange of liquid D2O exposed to water vapor of the surrounding atmosphere has been studied by variable-temperature Fourier transform near-infrared (FT-NIR) imaging spectroscopy. Apart from the visualization of the exchange process in the time-resolved FT-NIR images, kinetic parameters and the activation energy for this D/H exchange reaction have been derived from the Arrhenius plot of the variable-temperature spectroscopic data.

Rapid identification of Lonicerae japonicae Flos and Lonicerae Flos by Fourier transform infrared (FT-IR) spectroscopy and two-dimensional correlation analysis

NASA Astrophysics Data System (ADS)

Yan, Rui; Chen, Jian-bo; Sun, Su-qin; Guo, Bao-lin

2016-11-01

Lonicerae japonicae Flos (LJF) and Lonicerae Flos (LF) are widely-used herbs derived from several plants of the genus Lonicera with similar appearances. LF are usually misused or counterfeited as LJF for economically motivated adulteration. However, the saponins in LF may cause serious side-effects. In this research, the infrared spectroscopic tri-step identification approach is used to develop a simple and rapid method to discriminate LJF and LF to ensure the safety and efficacy of these herbal drugs. In the primary identification by Fourier transform infrared spectra, LJF and LF show different peaks near 1534, 1404, and 781 cm-1. In the secondary identification by the second derivative infrared spectra, LJF and LF show more different peaks near 1078, 1050, 988, 923, 855, 815, and 781 cm-1. In the tertiary identification by the two-dimensional correlation infrared spectra, the differences between LJF and LF are shown more remarkably and convincingly. The results show the potential of the infrared spectroscopic tri-step identification approach in the rapid identification of LJF and LF when the samples are too few to build a statistical recognition rule. This should be very helpful to ensure the quality, safety, and efficacy of LJF and LF for clinical applications.

Analysis of structural transformation in wool fiber resulting from oxygen plasma treatment using vibrational spectroscopy

NASA Astrophysics Data System (ADS)

Barani, Hossein; Haji, Aminoddin

2015-01-01

The aim of this study was to investigate the influence of oxygen plasma procedure at different time treatments on wool fiber using the micro-Raman spectroscopy as a non-destructive vibrational spectroscopic technique and Fourier transform infrared spectroscopy. The amide I and III regions, Csbnd C skeletal vibration region, and Ssbnd S and Csbnd S bonds vibration regions were analyzed with the Raman microscope. The Fourier transform infrared spectroscope analysis was employed to find out the effect of oxygen plasma treatment on the cysteic acid residues content of the wool fiber sample. The results indicated that the α-helix structure was the highest component content of wool fiber. Moreover, the protein secondary structure of wool fibers was transformed from α-helical arrangement to the β-pleated sheet configuration during the oxygen plasma treatment. Also, the disulphide bonds content in the treated wool fiber reduced because they were fractured and oxidized during oxygen plasma treatment. The oxygen plasma treated samples presented higher cysteic acid compared to the untreated wool samples due to produce more cleavage of disulfide linkages.

Fourier transform infrared spectroscopic characterisation of heavy metal-induced metabolic changes in the plant-associated soil bacterium Azospirillum brasilense Sp7

NASA Astrophysics Data System (ADS)

Kamnev, A. A.; Antonyuk, L. P.; Tugarova, A. V.; Tarantilis, P. A.; Polissiou, M. G.; Gardiner, P. H. E.

2002-06-01

Structural and compositional features of whole cells of the plant-growth-promoting rhizobacterium Azospirillum brasilense Sp7 under standard and heavy metal-stressed conditions are analysed using Fourier transform infrared (FTIR) spectroscopy and compared with the FT-Raman spectroscopic data obtained previously [J. Mol. Struct. 563-564 (2001) 199]. The structural spectroscopic information is considered together with inductively coupled plasma-mass spectrometric (ICP-MS) analytical data on the content of the heavy metal cations (Co2+, Cu2+ and Zn2+) in the bacterial cells. As a bacterial response to heavy metal stress, all the three metals, being taken up by bacterial cells from the culture medium (0.2 mM) in significant amounts (ca. 0.12, 0.48 and 4.2 mg per gram of dry biomass for Co, Cu and Zn, respectively), are shown to induce essential metabolic changes in the bacterium revealed in the spectra, including the accumulation of polyester compounds in bacterial cells and their enhanced hydration affecting certain IR vibrational modes of functional groups involved.

[Authentication of Trace Material Evidence in Forensic Science Field with Infrared Microscopic Technique].

PubMed

Jiang, Zhi-quan; Hu, Ke-liang

2016-03-01

In the field of forensic science, conventional infrared spectral analysis technique is usually unable to meet the detection requirements, because only very a few trace material evidence with diverse shapes and complex compositions, can be extracted from the crime scene. Infrared microscopic technique is developed based on a combination of Fourier-transform infrared spectroscopic technique and microscopic technique. Infrared microscopic technique has a lot of advantages over conventional infrared spectroscopic technique, such as high detection sensitivity, micro-area analysisand nondestructive examination. It has effectively solved the problem of authentication of trace material evidence in the field of forensic science. Additionally, almost no external interference is introduced during measurements by infrared microscopic technique. It can satisfy the special need that the trace material evidence must be reserved for witness in court. It is illustrated in detail through real case analysis in this experimental center that, infrared microscopic technique has advantages in authentication of trace material evidence in forensic science field. In this paper, the vibration features in infrared spectra of material evidences, including paints, plastics, rubbers, fibers, drugs and toxicants, can be comparatively analyzed by means of infrared microscopic technique, in an attempt to provide powerful spectroscopic evidence for qualitative diagnosis of various criminal and traffic accident cases. The experimental results clearly suggest that infrared microscopic technique has an incomparable advantage and it has become an effective method for authentication of trace material evidence in the field of forensic science.

Rapid measurement of human milk macronutrients in the neonatal intensive care unit: accuracy and precision of fourier transform mid-infrared spectroscopy.

PubMed

Smilowitz, Jennifer T; Gho, Deborah S; Mirmiran, Majid; German, J Bruce; Underwood, Mark A

2014-05-01

Although it is well established that human milk varies widely in macronutrient content, it remains common for human milk fortification for premature infants to be based on historic mean values. As a result, those caring for premature infants often underestimate protein intake. Rapid precise measurement of human milk protein, fat, and lactose to allow individualized fortification has been proposed for decades but remains elusive due to technical challenges. This study aimed to evaluate the accuracy and precision of a Fourier transform (FT) mid-infrared (IR) spectroscope in the neonatal intensive care unit to measure human milk fat, total protein, lactose, and calculated energy compared with standard chemical analyses. One hundred sixteen breast milk samples across lactation stages from women who delivered at term (n = 69) and preterm (n = 5) were analyzed with the FT mid-IR spectroscope and with standard chemical methods. Ten of the samples were tested in replicate using the FT mid-IR spectroscope to determine repeatability. The agreement between the FT mid-IR spectroscope analysis and reference methods was high for protein and fat and moderate for lactose and energy. The intra-assay coefficients of variation for all outcomes were less than 3%. The FT mid-IR spectroscope demonstrated high accuracy in measurement of total protein and fat of preterm and term milk with high precision.

Fourier transform mid-infrared (MIR) and near-infrared (NIR) spectroscopy for rapid quality assessment of Chinese medicine preparation Honghua Oil.

PubMed

Wu, Yan-Wen; Sun, Su-Qin; Zhou, Qun; Leung, Hei-Wun

2008-02-13

Honghua Oil (HHO), a traditional Chinese medicine (TCM) oil preparation, is a mixture of several plant essential oils. In this text, the extended ranges of Fourier transform mid-infrared (FT-MIR) and near infrared (FT-NIR) were recorded for 48 commercially available HHOs of different batches from nine manufacturers. The qualitative and quantitative analysis of three marker components, alpha-pinene, methyl salicylate and eugenol, in different HHO products were performed rapidly by the two vibrational spectroscopic methods, i.e. MIR with horizontal attenuated total reflection (HATR) accessory and NIR with direct sampling technique, followed by partial least squares (PLS) regression treatment of the set of spectra obtained. The results indicated that it was successful to identify alpha-pinene, methyl salicylate and eugenol in all of the samples by simple inspection of the MIR-HATR spectra. Both PLS models established with MIR-HATR and NIR spectral data using gas chromatography (GC) peak areas as calibration reference showed a good linear correlation for each of all three target substances in HHO samples. The above spectroscopic techniques may be the promising methods for the rapid quality assessment/quality control (QA/QC) of TCM oil preparations.

Fourier transform infrared spectroscopic study of gamma irradiated SiO2 nanoparticles

NASA Astrophysics Data System (ADS)

Huseynov, Elchin; Garibov, Adil; Mehdiyeva, Ravan; Huseynova, Efsane

2018-03-01

In the present work, nano SiO2 particles are investigated before and after gamma irradiation (25, 50, 75, 100 and 200 kGy) using Fourier transform infrared (FTIR) spectroscopy method for the wavenumber between 400-4000 cm-1. It is found that as a result of spectroscopic analysis, five new peaks have appeared after gamma radiation. Two of new obtained peaks (which are located at 687 cm-1 and 2357 cm-1 of wavenumber) were formed as a result of gamma radiation interaction with Si-O bonds. Another three new peaks (peaks appropriate to 941, 2052 and 2357 cm-1 values of wavenumber) appear as a result of interaction of water with nano SiO2 particles after gamma irradiation. It has been defined as asymmetrical bending vibration, symmetrical bending vibration, symmetrical stretching vibration and asymmetrical stretching vibration of Si-O bonds appropriate to peaks.

Imaging open-path Fourier transform infrared spectrometer for 3D cloud profiling

NASA Astrophysics Data System (ADS)

Rentz Dupuis, Julia; Mansur, David J.; Vaillancourt, Robert; Carlson, David; Evans, Thomas; Schundler, Elizabeth; Todd, Lori; Mottus, Kathleen

2010-04-01

OPTRA has developed an imaging open-path Fourier transform infrared (I-OP-FTIR) spectrometer for 3D profiling of chemical and biological agent simulant plumes released into test ranges and chambers. An array of I-OP-FTIR instruments positioned around the perimeter of the test site, in concert with advanced spectroscopic algorithms, enables real time tomographic reconstruction of the plume. The approach is intended as a referee measurement for test ranges and chambers. This Small Business Technology Transfer (STTR) effort combines the instrumentation and spectroscopic capabilities of OPTRA, Inc. with the computed tomographic expertise of the University of North Carolina, Chapel Hill. In this paper, we summarize the design and build and detail system characterization and test of a prototype I-OP-FTIR instrument. System characterization includes radiometric performance and spectral resolution. Results from a series of tomographic reconstructions of sulfur hexafluoride plumes in a laboratory setting are also presented.

Imaging open-path Fourier transform infrared spectrometer for 3D cloud profiling

NASA Astrophysics Data System (ADS)

Rentz Dupuis, Julia; Mansur, David J.; Engel, James R.; Vaillancourt, Robert; Todd, Lori; Mottus, Kathleen

2008-04-01

OPTRA and University of North Carolina are developing an imaging open-path Fourier transform infrared (I-OP-FTIR) spectrometer for 3D profiling of chemical and biological agent simulant plumes released into test ranges and chambers. An array of I-OP-FTIR instruments positioned around the perimeter of the test site, in concert with advanced spectroscopic algorithms, enables real time tomographic reconstruction of the plume. The approach will be considered as a candidate referee measurement for test ranges and chambers. This Small Business Technology Transfer (STTR) effort combines the instrumentation and spectroscopic capabilities of OPTRA, Inc. with the computed tomographic expertise of the University of North Carolina, Chapel Hill. In this paper, we summarize progress to date and overall system performance projections based on the instrument, spectroscopy, and tomographic reconstruction accuracy. We then present a preliminary optical design of the I-OP-FTIR.

The optical design of a far infrared imaging FTS for SPICA

NASA Astrophysics Data System (ADS)

Pastor, Carmen; Zuluaga, Pablo; Jellema, Willem; González Fernández, Luis Miguel; Belenguer, Tomas; Torres Redondo, Josefina; Kooijman, Peter Paul; Najarro, Francisco; Eggens, Martin; Roelfsema, Peter; Nakagawa, Takao

2014-08-01

This paper describes the optical design of the far infrared imaging spectrometer for the JAXA's SPICA mission. The SAFARI instrument, is a cryogenic imaging Fourier transform spectrometer (iFTS), designed to perform backgroundlimited spectroscopic and photometric imaging in the band 34-210 μm. The all-reflective optical system is highly modular and consists of three main modules; input optics module, interferometer module (FTS) and camera bay optics. A special study has been dedicated to the spectroscopic performance of the instrument, in which the spectral response and interference of the instrument have been modeled, as the FTS mechanism scans over the total desired OPD range.

Spectroscopic properties in Er3+-doped germanotellurite glasses and glass ceramics for mid-infrared laser materials.

PubMed

Kang, Shiliang; Xiao, Xiudi; Pan, Qiwen; Chen, Dongdan; Qiu, Jianrong; Dong, Guoping

2017-03-07

Transparent Er 3+ -doped germanotellurite glass ceramics (GCs) with variable Te/Ge ratio were prepared by controllable heat-treated process. X-ray diffraction (XRD) and transmission electron microscope (TEM) confirmed the formation of nanocrystals in glass matrix. Raman spectra were used to investigate the evolution of glass structure and photon energy. Fourier transform infrared (FTIR) spectra were introduced to characterize the change of hydroxyl group (OH - ) content. Enhanced 2.7 μm emission was achieved from Er 3+ -doped GCs upon excitation with a 980 nm laser diode (LD), and the influence of GeO 2 concentration and heat-treated temperature on the spectroscopic properties were also discussed in detail. It is found that the present Er 3+ -doped GC possesses large stimulated emission cross section at around 2.7 μm (0.85 × 10 -20  cm 2 ). The advantageous spectroscopic characteristics suggest that the obtained GC may be a promising material for mid-infrared fiber lasers.

Spectroscopic properties in Er3+-doped germanotellurite glasses and glass ceramics for mid-infrared laser materials

PubMed Central

Kang, Shiliang; Xiao, Xiudi; Pan, Qiwen; Chen, Dongdan; Qiu, Jianrong; Dong, Guoping

2017-01-01

Transparent Er3+-doped germanotellurite glass ceramics (GCs) with variable Te/Ge ratio were prepared by controllable heat-treated process. X-ray diffraction (XRD) and transmission electron microscope (TEM) confirmed the formation of nanocrystals in glass matrix. Raman spectra were used to investigate the evolution of glass structure and photon energy. Fourier transform infrared (FTIR) spectra were introduced to characterize the change of hydroxyl group (OH−) content. Enhanced 2.7 μm emission was achieved from Er3+-doped GCs upon excitation with a 980 nm laser diode (LD), and the influence of GeO2 concentration and heat-treated temperature on the spectroscopic properties were also discussed in detail. It is found that the present Er3+-doped GC possesses large stimulated emission cross section at around 2.7 μm (0.85 × 10−20 cm2). The advantageous spectroscopic characteristics suggest that the obtained GC may be a promising material for mid-infrared fiber lasers. PMID:28266570

Spectroscopic imaging of biomaterials and biological systems with FTIR microscopy or with quantum cascade lasers.

PubMed

Kimber, James A; Kazarian, Sergei G

2017-10-01

Spectroscopic imaging of biomaterials and biological systems has received increased interest within the last decade because of its potential to aid in the detection of disease using biomaterials/biopsy samples and to probe the states of live cells in a label-free manner. The factors behind this increased attention include the availability of improved infrared microscopes and systems that do not require the use of a synchrotron as a light source, as well as the decreasing costs of these systems. This article highlights the current technical challenges and future directions of mid-infrared spectroscopic imaging within this field. Specifically, these are improvements in spatial resolution and spectral quality through the use of novel added lenses and computational algorithms, as well as quantum cascade laser imaging systems, which offer advantages over traditional Fourier transform infrared systems with respect to the speed of acquisition and field of view. Overcoming these challenges will push forward spectroscopic imaging as a viable tool for disease diagnostics and medical research. Graphical abstract Absorbance images of a biopsy obtained using an FTIR imaging microscope with and without an added lens, and also using a QCL microscope with high-NA objective.

Melvin P. Tucker | NREL

Science.gov Websites

biomass to biofuels and products, with extensive expertise in high solids pretreatment, high solids techniques, high-performance liquid chromatography, and spectroscopic techniques (Fourier transform infrared , biochemists, chemists, and molecular biologist to deconstruct biomass into high concentration, low toxicity

Renal geology (quantitative renal stone analysis) by 'Fourier transform infrared spectroscopy'.

PubMed

Singh, Iqbal

2008-01-01

To prospectively determine the precise stone composition (quantitative analysis) by using infrared spectroscopy in patients with urinary stone disease presenting to our clinic. To determine an ideal method for stone analysis suitable for use in a clinical setting. After routine and a detailed metabolic workup of all patients of urolithiasis, stone samples of 50 patients of urolithiasis satisfying the entry criteria were subjected to the Fourier transform infrared spectroscopic analysis after adequate sample homogenization at a single testing center. Calcium oxalate monohydrate and dihydrate stone mixture was most commonly encountered in 35 (71%) followed by calcium phosphate, carbonate apatite, magnesium ammonium hexahydrate and xanthine stones. Fourier transform infrared spectroscopy allows an accurate, reliable quantitative method of stone analysis. It also helps in maintaining a computerized large reference library. Knowledge of precise stone composition may allow the institution of appropriate prophylactic therapy despite the absence of any detectable metabolic abnormalities. This may prevent and or delay stone recurrence.

[Application of Fourier transform attenuated total reflection infrared spectroscopy in analysis of pulp and paper industry].

PubMed

Zhang, Yong; Cao, Chun-yu; Feng, Wen-ying; Xu, Ming; Su, Zhen-hua; Liu, Xiao-meng; Lü, Wei-jun

2011-03-01

As one of the most powerful tools to investigate the compositions of raw materials and the property of pulp and paper, infrared spectroscopy has played an important role in pulp and paper industry. However, the traditional transmission infrared spectroscopy has not met the requirements of the producing processes because of its disadvantages of time consuming and sample destruction. New technique would be needed to be found. Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR) is an advanced spectroscopic tool for nondestructive evaluation and could rapidly, accurately estimate the production properties of each process in pulp and paper industry. The present review describes the application of ATR-FTIR in analysis of pulp and paper industry. The analysis processes will include: pulping, papermaking, environmental protecting, special processing and paper identifying.

A photometrically and spectroscopically confirmed population of passive spiral galaxies

NASA Astrophysics Data System (ADS)

Fraser-McKelvie, Amelia; Brown, Michael J. I.; Pimbblet, Kevin A.; Dolley, Tim; Crossett, Jacob P.; Bonne, Nicolas J.

2016-10-01

We have identified a population of passive spiral galaxies from photometry and integral field spectroscopy. We selected z < 0.035 spiral galaxies that have WISE colours consistent with little mid-infrared emission from warm dust. Matched aperture photometry of 51 spiral galaxies in ultraviolet, optical and mid-infrared show these galaxies have colours consistent with passive galaxies. Six galaxies form a spectroscopic pilot study and were observed using the Wide-Field Spectrograph to check for signs of nebular emission from star formation. We see no evidence of substantial nebular emission found in previous red spiral samples. These six galaxies possess absorption-line spectra with 4000 Å breaks consistent with an average luminosity-weighted age of 2.3 Gyr. Our photometric and integral field spectroscopic observations confirm the existence of a population of local passive spiral galaxies, implying that transformation into early-type morphologies is not required for the quenching of star formation.

Methodological effects in Fourier transform infrared (FTIR) spectroscopy: Implications for structural analyses of biomacromolecular samples

NASA Astrophysics Data System (ADS)

Kamnev, Alexander A.; Tugarova, Anna V.; Dyatlova, Yulia A.; Tarantilis, Petros A.; Grigoryeva, Olga P.; Fainleib, Alexander M.; De Luca, Stefania

2018-03-01

A set of experimental data obtained by Fourier transform infrared (FTIR) spectroscopy (involving the use of samples ground and pressed with KBr, i.e. in a polar halide matrix) and by matrix-free transmission FTIR or diffuse reflectance infrared Fourier transform (DRIFT) spectroscopic methodologies (involving measurements of thin films or pure powdered samples, respectively) were compared for several different biomacromolecular substances. The samples under study included poly-3-hydroxybutyrate (PHB) isolated from cell biomass of the rhizobacterium Azospirillum brasilense; dry PHB-containing A. brasilense biomass; pectin (natural carboxylated heteropolysaccharide of plant origin; obtained from apple peel) as well as its chemically modified derivatives obtained by partial esterification of its galacturonide-chain hydroxyl moieties with palmitic, oleic and linoleic acids. Significant shifts of some FTIR vibrational bands related to polar functional groups of all the biomacromolecules under study, induced by the halide matrix used for preparing the samples for spectroscopic measurements, were shown and discussed. A polar halide matrix used for preparing samples for FTIR measurements was shown to be likely to affect band positions not only per se, by affecting band energies or via ion exchange (e.g., with carboxylate moieties), but also by inducing crystallisation of metastable amorphous biopolymers (e.g., PHB of microbial origin). The results obtained have important implications for correct structural analyses of polar, H-bonded and/or amphiphilic biomacromolecular systems using different methodologies of FTIR spectroscopy.

Analysis of the physicochemical properties of post-manufacturing waste derived from production of methyl esters from rapeseed oil

NASA Astrophysics Data System (ADS)

Kachel-Jakubowska, Magdalena; Matwijczuk, Arkadiusz; Gagoś, Mariusz

2017-04-01

The technology of transesterification of biodiesel obtained from many agricultural products, which are often referred to as renewable resources, yields substantial amounts of by-products. They exhibit various properties that prompt scientific research into potential application thereof. Various spectroscopic methods, e.g. Fourier transform infrared spectroscopy, are being increasingly used in the research. In this paper, we present the results of Fourier transform infrared spectroscopy spectroscopy analyses of technical glycerine, distilled glycerine, and matter organic non glycerol, i.e. by-products of biodiesel production. To facilitate the spectroscopic analysis, a number of parameters were determined for all the materials, e.g. the calorific value, water content, sulphated ash content, methanol content, acidity, as well as the contents of esters, heavy metals, aldehydes, nitrogen, and phosphorus. The results indicate that the analysed products are characterised by a comparable calorific value in the range from 11.35 to 16.05 MJ kg-1 in the case of matter organic non glycerol and technical glycerine. Observation of changes in the position of selected peaks in the range of 3700-650 cm-1 in the Fourier transform infrared spectroscopy method facilitates determination of the level of degradation of the analysed material. Changes in the wavelength ranges can be used for monitoring the formation of secondary oxidation products containing carbonyl groups.

Resonant antenna probes for tip-enhanced infrared near-field microscopy.

PubMed

Huth, Florian; Chuvilin, Andrey; Schnell, Martin; Amenabar, Iban; Krutokhvostov, Roman; Lopatin, Sergei; Hillenbrand, Rainer

2013-03-13

We report the development of infrared-resonant antenna probes for tip-enhanced optical microscopy. We employ focused-ion-beam machining to fabricate high-aspect ratio gold cones, which replace the standard tip of a commercial Si-based atomic force microscopy cantilever. Calculations show large field enhancements at the tip apex due to geometrical antenna resonances in the cones, which can be precisely tuned throughout a broad spectral range from visible to terahertz frequencies by adjusting the cone length. Spectroscopic analysis of these probes by electron energy loss spectroscopy, Fourier transform infrared spectroscopy, and Fourier transform infrared near-field spectroscopy corroborates their functionality as resonant antennas and verifies the broad tunability. By employing the novel probes in a scattering-type near-field microscope and imaging a single tobacco mosaic virus (TMV), we experimentally demonstrate high-performance mid-infrared nanoimaging of molecular absorption. Our probes offer excellent perspectives for optical nanoimaging and nanospectroscopy, pushing the detection and resolution limits in many applications, including nanoscale infrared mapping of organic, molecular, and biological materials, nanocomposites, or nanodevices.

TiO2 induced structural modifications in Cs containing borosilicate glasses: Raman and infrared studies

NASA Astrophysics Data System (ADS)

Pandey, M.; Banerjee, D.; Sudarsan, V.; Kshirsagar, R. J.

2018-04-01

Effect of TiO2 addition in Cs containing Sodium-borosilicate glasses is studied using Raman and infrared spectroscopic techniques. As revealed from infrared and Raman studies, TiO2 does not form segregated phase, but instead enters into the borosilicate network. It is further observed that TiO2 addition results in modifications of the borate and silicate structural units by transforming into tetraborates and metasilicate structural units. These structural modifications are responsible for Cs immobilization, leach rate and chemical durability of these glasses.

The investigation of the effect of thermal treatment on bentonites from Turkey with Fourier transform infrared and solid state nuclear magnetic resonance spectroscopic methods.

PubMed

Erdoğan Alver, Burcu; Alver, Ozgür

2012-08-01

There is a great deal of interest in the building industry in burned clays for production of building materials. Therefore, the effect of heat treatment on natural bentonite from Turkey was investigated by Fourier transform infrared (FT-IR) between the region of 4000-400cm(-1) and (29)Si, (27)Al magic angle spinning nuclear magnetic resonance (MAS NMR) measurement techniques at various temperatures between 200 and 700°C for 2h. The structural changes were also investigated upon heat treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

Interaction of cytidine 5'-monophosphate with Au(111): an in situ infrared spectroscopic study.

PubMed

Doneux, Thomas; Fojt, Lukás

2009-07-13

The interaction of cytidine 5'-monophosphate (CMP) with gold surfaces is studied by means of in situ infrared spectroscopy and cyclic voltammetry at the Au(111)|aqueous solution interface. Similar to other nucleic acid components, cytidine 5'-monophosphate is chemisorbed on the surface at positive potentials, and the amount of adsorbed CMP increases with the potential. Subtractively normalized interfacial Fourier-transform infrared spectroscopy (SNIFTIRS) is used to identify the adsorbed and desorbed species. Upon electrochemical desorption, the molecules released in solution are unprotonated on the N3 atom. Striking similarities are found between the spectrum of adsorbed CMP and the solution spectrum of protonated CMP. The origin of such similarities is discussed. The results strongly suggest that chemisorption occurs through the N3 atom of the pyrimidine ring. A comparison is drawn with cytidine, whose electrochemical and spectroscopic behaviors are also investigated.

Practical protocols for fast histopathology by Fourier transform infrared spectroscopic imaging

NASA Astrophysics Data System (ADS)

Keith, Frances N.; Reddy, Rohith K.; Bhargava, Rohit

2008-02-01

Fourier transform infrared (FT-IR) spectroscopic imaging is an emerging technique that combines the molecular selectivity of spectroscopy with the spatial specificity of optical microscopy. We demonstrate a new concept in obtaining high fidelity data using commercial array detectors coupled to a microscope and Michelson interferometer. Next, we apply the developed technique to rapidly provide automated histopathologic information for breast cancer. Traditionally, disease diagnoses are based on optical examinations of stained tissue and involve a skilled recognition of morphological patterns of specific cell types (histopathology). Consequently, histopathologic determinations are a time consuming, subjective process with innate intra- and inter-operator variability. Utilizing endogenous molecular contrast inherent in vibrational spectra, specially designed tissue microarrays and pattern recognition of specific biochemical features, we report an integrated algorithm for automated classifications. The developed protocol is objective, statistically significant and, being compatible with current tissue processing procedures, holds potential for routine clinical diagnoses. We first demonstrate that the classification of tissue type (histology) can be accomplished in a manner that is robust and rigorous. Since data quality and classifier performance are linked, we quantify the relationship through our analysis model. Last, we demonstrate the application of the minimum noise fraction (MNF) transform to improve tissue segmentation.

Applications of QCL mid-IR imaging to the advancement of pathology

NASA Astrophysics Data System (ADS)

Sreedhar, Hari; Varma, Vishal K.; Bird, Benjamin; Guzman, Grace; Walsh, Michael J.

2017-03-01

Quantum Cascade Laser (QCL) spectroscopic imaging is a novel technique with many potential applications to histopathology. Like traditional Fourier Transform Infrared (FT-IR) imaging, QCL spectroscopic imaging derives biochemical data coupled to the spatial information of a tissue sample, and can be used to improve the diagnostic and prognostic value of assessment of a tissue biopsy. This technique also offers advantages over traditional FT-IR imaging, specifically the capacity for discrete frequency and real-time imaging. In this work we present applications of QCL spectroscopic imaging to tissue samples, including discrete frequency imaging, to compare with FT-IR and its potential value to pathology.

High-definition Fourier Transform Infrared (FT-IR) Spectroscopic Imaging of Human Tissue Sections towards Improving Pathology

PubMed Central

Nguyen, Peter L.; Davidson, Bennett; Akkina, Sanjeev; Guzman, Grace; Setty, Suman; Kajdacsy-Balla, Andre; Walsh, Michael J.

2015-01-01

High-definition Fourier Transform Infrared (FT-IR) spectroscopic imaging is an emerging approach to obtain detailed images that have associated biochemical information. FT-IR imaging of tissue is based on the principle that different regions of the mid-infrared are absorbed by different chemical bonds (e.g., C=O, C-H, N-H) within cells or tissue that can then be related to the presence and composition of biomolecules (e.g., lipids, DNA, glycogen, protein, collagen). In an FT-IR image, every pixel within the image comprises an entire Infrared (IR) spectrum that can give information on the biochemical status of the cells that can then be exploited for cell-type or disease-type classification. In this paper, we show: how to obtain IR images from human tissues using an FT-IR system, how to modify existing instrumentation to allow for high-definition imaging capabilities, and how to visualize FT-IR images. We then present some applications of FT-IR for pathology using the liver and kidney as examples. FT-IR imaging holds exciting applications in providing a novel route to obtain biochemical information from cells and tissue in an entirely label-free non-perturbing route towards giving new insight into biomolecular changes as part of disease processes. Additionally, this biochemical information can potentially allow for objective and automated analysis of certain aspects of disease diagnosis. PMID:25650759

Infrared spectroscopic analysis of skin tumor of mice treated with several medicinal plants

PubMed Central

Ali, Huma; Dixit, Savita

2013-01-01

Objective To evaluate the differences between cancerous tissue, drug treated tissue and its corresponding normal tissue by infrared spectroscopic analysis. Methods Methanolic extracts of Azadirachta indica, Ocimum sanctum, Aloe barbandesis, Tinospora cordifolia and Triticum aestivum were assessed for the isolation and purification of active compound. After that, combine crude and combine isolated samples were prepared. Skin tumor was induced by topical application of 7, 12-dimethyl benz (a) anthracene and promoted by croton oil in Swiss albino mice. To assess the chemopreventive potential of different drugs, it was administered at a concentration of 400 mg/kg body weight daily up to 16 weeks. Fourier transform infrared spectroscopy analysis was used to differentiate the drug treated tissues with the normal and cancerous tissue. In the present study, spectra of different tissues were recorded in the range of 400-4 000 cm−1. Results The results of the present study have shown that the remarkable difference exists between the IR spectra of normal, drugs treated and cancerous tissue in terms of frequencies and intensities of prominent bands of cellular biomolecules. Conclusions Fourier transform infrared spectroscopy analysis suggests the chemopreventive effect of above treated drugs and the best result was observed in combine crude sample and in combine isolated sample or synergistic effect of individual crude and isolated extract in 7, 12-dimethyl benz (a) anthracene croton oil induced skin carcinogenesis in Swiss albino mice.

Spectroscopic characterization of nitroaromatic landmine signature explosives

NASA Astrophysics Data System (ADS)

Hernandez-Rivera, Samuel P.; Manrique-Bastidas, Cesar A.; Blanco, Alejandro; Primera, Oliva M.; Pacheco, Leonardo C.; Castillo-Chara, Jairo; Castro, Miguel E.; Mina, Nairmen

2004-09-01

TNT and DNT are important explosives used as base charges of landmines and other explosive devices. They are often combined with RDX in specific explosive formulations. Their detection in vapor phase as well as in soil in contact with the explosives is important in landmine detection technology. The spectroscopic signatures of nitroaromatic compounds in neat forms: crystals, droplets, and recrystallized samples were determined by Raman Microspectroscopy (RS), Fourier Transform Infrared Microscopy (FTIR) and Fiber Optics Coupled - Fourier Transform Infrared Spectroscopy (FOC-FTIR) using a grazing angle (GA) probe. TNT exhibits a series of characteristic bands: vibrational signatures, which allow its detection in soil. The spectroscopic signature of neat TNT is dominated by strong bands about 1380 and 2970 cm-1. The intensity and position of these bands were found remarkably different in soil samples spiked with TNT. The 1380 cm-1 band is split into a number of bands in that region. The 2970 cm-1 band is reduced in intensity and new bands are observed about 2880 cm-1. The results are consistent with a different chemical environment of TNT in soil as compared to neat TNT. Interactions were found to be dependent on the physical source of the explosive. In the case of DNT-sand interactions, shifts in vibrational frequencies of the explosives as well as the substrates were found.

Analysis of Forensic Casework Utilizing Infrared Spectroscopic Imaging.

PubMed

Lanzarotta, Adam

2016-02-24

A search of the current scientific literature yields a limited number of studies that describe the use of Fourier transform infrared (FT-IR) spectroscopic imaging for the analysis of forensic casework, which is likely due to the fact that these instruments are fairly new commodities to the field of analytical chemistry and are therefore not yet commonplace in forensic laboratories. This report describes recent forensic case studies that have used the technique for determining the composition of a wide variety of multi-component sample types, including animal tissue sections for toxic inclusions, drugs/dietary supplements, an antibiotic with an active pharmaceutical ingredient (API) present as several different salt forms, an adulterated bulk API, unknown trace powders for illicit drugs and an ophthalmic solution suspected of being adulterated with bleach.

Analysis of Forensic Casework Utilizing Infrared Spectroscopic Imaging †

PubMed Central

Lanzarotta, Adam

2016-01-01

A search of the current scientific literature yields a limited number of studies that describe the use of Fourier transform infrared (FT-IR) spectroscopic imaging for the analysis of forensic casework, which is likely due to the fact that these instruments are fairly new commodities to the field of analytical chemistry and are therefore not yet commonplace in forensic laboratories. This report describes recent forensic case studies that have used the technique for determining the composition of a wide variety of multi-component sample types, including animal tissue sections for toxic inclusions, drugs/dietary supplements, an antibiotic with an active pharmaceutical ingredient (API) present as several different salt forms, an adulterated bulk API, unknown trace powders for illicit drugs and an ophthalmic solution suspected of being adulterated with bleach. PMID:26927101

Chemical fingerprinting of Arabidopsis using Fourier transform infrared (FT-IR) spectroscopic approaches.

PubMed

Gorzsás, András; Sundberg, Björn

2014-01-01

Fourier transform infrared (FT-IR) spectroscopy is a fast, sensitive, inexpensive, and nondestructive technique for chemical profiling of plant materials. In this chapter we discuss the instrumental setup, the basic principles of analysis, and the possibilities for and limitations of obtaining qualitative and semiquantitative information by FT-IR spectroscopy. We provide detailed protocols for four fully customizable techniques: (1) Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS): a sensitive and high-throughput technique for powders; (2) attenuated total reflectance (ATR) spectroscopy: a technique that requires no sample preparation and can be used for solid samples as well as for cell cultures; (3) microspectroscopy using a single element (SE) detector: a technique used for analyzing sections at low spatial resolution; and (4) microspectroscopy using a focal plane array (FPA) detector: a technique for rapid chemical profiling of plant sections at cellular resolution. Sample preparation, measurement, and data analysis steps are listed for each of the techniques to help the user collect the best quality spectra and prepare them for subsequent multivariate analysis.

Analysis of Counterfeit Coated Tablets and Multi-Layer Packaging Materials Using Infrared Microspectroscopic Imaging.

PubMed

Winner, Taryn L; Lanzarotta, Adam; Sommer, André J

2016-06-01

An effective method for detecting and characterizing counterfeit finished dosage forms and packaging materials is described in this study. Using attenuated total internal reflection Fourier transform infrared spectroscopic imaging, suspect tablet coating and core formulations as well as multi-layered foil safety seals, bottle labels, and cigarette tear tapes were analyzed and compared directly with those of a stored authentic product. The approach was effective for obtaining molecular information from structures as small as 6 μm.

Continuous statistical modelling for rapid detection of adulteration of extra virgin olive oil using mid infrared and Raman spectroscopic data.

PubMed

Georgouli, Konstantia; Martinez Del Rincon, Jesus; Koidis, Anastasios

2017-02-15

The main objective of this work was to develop a novel dimensionality reduction technique as a part of an integrated pattern recognition solution capable of identifying adulterants such as hazelnut oil in extra virgin olive oil at low percentages based on spectroscopic chemical fingerprints. A novel Continuous Locality Preserving Projections (CLPP) technique is proposed which allows the modelling of the continuous nature of the produced in-house admixtures as data series instead of discrete points. The maintenance of the continuous structure of the data manifold enables the better visualisation of this examined classification problem and facilitates the more accurate utilisation of the manifold for detecting the adulterants. The performance of the proposed technique is validated with two different spectroscopic techniques (Raman and Fourier transform infrared, FT-IR). In all cases studied, CLPP accompanied by k-Nearest Neighbors (kNN) algorithm was found to outperform any other state-of-the-art pattern recognition techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

Quantitative analysis of red wine tannins using Fourier-transform mid-infrared spectrometry.

PubMed

Fernandez, Katherina; Agosin, Eduardo

2007-09-05

Tannin content and composition are critical quality components of red wines. No spectroscopic method assessing these phenols in wine has been described so far. We report here a new method using Fourier transform mid-infrared (FT-MIR) spectroscopy and chemometric techniques for the quantitative analysis of red wine tannins. Calibration models were developed using protein precipitation and phloroglucinolysis as analytical reference methods. After spectra preprocessing, six different predictive partial least-squares (PLS) models were evaluated, including the use of interval selection procedures such as iPLS and CSMWPLS. PLS regression with full-range (650-4000 cm(-1)), second derivative of the spectra and phloroglucinolysis as the reference method gave the most accurate determination for tannin concentration (RMSEC = 2.6%, RMSEP = 9.4%, r = 0.995). The prediction of the mean degree of polymerization (mDP) of the tannins also gave a reasonable prediction (RMSEC = 6.7%, RMSEP = 10.3%, r = 0.958). These results represent the first step in the development of a spectroscopic methodology for the quantification of several phenolic compounds that are critical for wine quality.

Spectroscopic analysis of bladder cancer tissues using Fourier transform infrared spectroscopy

NASA Astrophysics Data System (ADS)

Al-Muslet, Nafie A.; Ali, Essam E.

2012-03-01

Bladder cancer is one of the most common cancers in Africa. It takes several days to reach a diagnosis using histological examinations of specimens obtained by endoscope, which increases the medical expense. Recently, spectroscopic analysis of bladder cancer tissues has received considerable attention as a diagnosis technique due to its sensitivity to biochemical variations in the samples. This study investigated the use of Fourier transform infrared (FTIR) spectroscopy to analyze a number of bladder cancer tissues. Twenty-two samples were collected from 11 patients diagnosed with bladder cancer from different hospitals without any pretreatment. From each patient two samples were collected, one normal and another cancerous. FTIR spectrometer was used to differentiate between normal and cancerous bladder tissues via changes in spectra of these samples. The investigations detected obvious changes in the bands of proteins (1650, 1550 cm-1), lipids (2925, 2850 cm-1), and nucleic acid (1080, 1236 cm-1). The results show that FTIR spectroscopy is promising as a rapid, accurate, nondestructive, and easy to use alternative method for identification and diagnosis of bladder cancer tissues.

Built-in hyperspectral camera for smartphone in visible, near-infrared and middle-infrared lights region (second report): sensitivity improvement of Fourier-spectroscopic imaging to detect diffuse reflection lights from internal human tissues for healthcare sensors

NASA Astrophysics Data System (ADS)

Kawashima, Natsumi; Hosono, Satsuki; Ishimaru, Ichiro

2016-05-01

We proposed the snapshot-type Fourier spectroscopic imaging for smartphone that was mentioned in 1st. report in this conference. For spectroscopic components analysis, such as non-invasive blood glucose sensors, the diffuse reflection lights from internal human skins are very weak for conventional hyperspectral cameras, such as AOTF (Acousto-Optic Tunable Filter) type. Furthermore, it is well known that the spectral absorption of mid-infrared lights or Raman spectroscopy especially in long wavelength region is effective to distinguish specific biomedical components quantitatively, such as glucose concentration. But the main issue was that photon energies of middle infrared lights and light intensities of Raman scattering are extremely weak. For improving sensitivity of our spectroscopic imager, the wide-field-stop & beam-expansion method was proposed. Our line spectroscopic imager introduced a single slit for field stop on the conjugate objective plane. Obviously to increase detected light intensities, the wider slit width of the field stop makes light intensities higher, regardless of deterioration of spatial resolutions. Because our method is based on wavefront-division interferometry, it becomes problems that the wider width of single slit makes the diffraction angle narrower. This means that the narrower diameter of collimated objective beams deteriorates visibilities of interferograms. By installing the relative inclined phaseshifter onto optical Fourier transform plane of infinity corrected optical systems, the collimated half flux of objective beams derived from single-bright points on objective surface penetrate through the wedge prism and the cuboid glass respectively. These two beams interfere each other and form the infererogram as spatial fringe patterns. Thus, we installed concave-cylindrical lens between the wider slit and objective lens as a beam expander. We successfully obtained the spectroscopic characters of hemoglobin from reflected lights from human fingers.

The convective noise floor for the spectroscopic detection of low mass companions to solar type stars

NASA Technical Reports Server (NTRS)

Deming, D.; Espenak, F.; Jennings, D. E.; Brault, J. W.

1986-01-01

The threshold mass for the unambiguous spectroscopic detection of low mass companions to solar type stars is defined here as the time when the maximum acceleration in the stellar radial velocity due to the Doppler reflex of the companion exceeds the apparent acceleration produced by changes in convection. An apparent acceleration of 11 m/s/yr in integrated sunlight was measured using near infrared Fourier transform spectroscopy. This drift in the apparent solar velocity is attributed to a lessening in the magnetic inhibition of granular convection as solar minimum approaches. The threshold mass for spectroscopic detection of companions to a one solar mass star is estimated at below one Jupiter mass.

Infrared Microtransmission And Microreflectance Of Biological Systems

NASA Astrophysics Data System (ADS)

Hill, Steve L.; Krishnan, K.; Powell, Jay R.

1989-12-01

The infrared microsampling technique has been successfully applied to a variety of biological systems. A microtomed tissue section may be prepared to permit both visual and infrared discrimination. Infrared structural information may be obtained for a single cell, and computer-enhanced images of tissue specimens may be calculated from spectral map data sets. An analysis of a tissue section anomaly may gg suest eitherprotein compositional differences or a localized concentration of foreign matterp. Opaque biological materials such as teeth, gallstones, and kidney stones may be analyzed by microreflectance spectroscop. Absorption anomalies due to specular dispersion are corrected with the Kraymers-Kronig transformation. Corrected microreflectance spectra may contribute to compositional analysis and correlate diseased-related spectral differences to visual specimen anomalies.

Novel high-temperature and pressure-compatible ultrasonic levitator apparatus coupled to Raman and Fourier transform infrared spectrometers

NASA Astrophysics Data System (ADS)

Brotton, Stephen J.; Kaiser, Ralf I.

2013-05-01

We describe an original apparatus comprising of an acoustic levitator enclosed within a pressure-compatible process chamber. To characterize any chemical and physical modifications of the levitated particle, the chamber is interfaced to complimentary, high-sensitivity Raman (4390-170 cm-1), and Fourier transform infrared (FTIR) (10 000-500 cm-1) spectroscopic probes. The temperature of the levitated particle can be accurately controlled by heating using a carbon dioxide laser emitting at 10.6 μm. The advantages of levitating a small particle combined with the two spectroscopic probes, process chamber, and infrared laser heating makes novel experiments possible relevant to the fields of, for example, planetary science, astrobiology, and combustion chemistry. We demonstrate that this apparatus is well suited to study the dehydration of a variety of particles including minerals and biological samples; and offers the possibility of investigating combustion processes involving micrometer-sized particles such as graphite. Furthermore, we show that the FTIR spectrometer enables the study of chemical reactions on the surfaces of porous samples and scientifically and technologically relevant, micrometer-thick levitated sheets. The FTIR spectrometer can also be used to investigate non-resonant and resonant scattering from small, irregularly-shaped particles across the mid-infrared range from 2.5 μm to 25 μm, which is relevant to scattering from interplanetary dust and biological, micrometer-sized samples but cannot be accurately modelled using Mie theory.

Transformation of the Surface Structure of Marble under the Action of a Shock Wave

NASA Astrophysics Data System (ADS)

Shcherbakov, I. P.; Vettegren, V. I.; Bashkarev, A. Ya.; Mamalimov, R. I.

2018-01-01

The structure of marble fracture fragments formed after the destruction under the action of a shock wave have been analyzed by Raman, infrared, and luminescence spectroscopic techniques. It has been found that calcite I in the surface layer of fragments with thicknesses of about 2 μm is transformed into high-pressure phase calcite III. At the same time, concentrations of Mn2+, Eu3+, and other ions decrease to about onefourth of their initial values.

Synthesis of samarium doped gadolinium oxide nanorods, its spectroscopic and physical properties

NASA Astrophysics Data System (ADS)

Boopathi, G.; Gokul Raj, S.; Ramesh Kumar, G.; Mohan, R.; Mohan, S.

2018-06-01

One-dimensional samarium doped gadolinium oxide [Sm:Gd2O3] nanorods have been synthesized successfully through co-precipitation technique in aqueous solution. The as-synthesized and calcined products were characterized by using powder X-ray diffraction pattern, Fourier transform Raman spectroscopy, thermogravimetric/differential thermal analysis, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-Visible spectrometry, photoluminescence spectrophotometer and X-ray photoelectron spectroscopy techniques. The obtained results are discussed in detailed manner.

Application of second derivative spectroscopy for increasing molecular specificity of Fourier transform infrared spectroscopic imaging of articular cartilage.

PubMed

Rieppo, L; Saarakkala, S; Närhi, T; Helminen, H J; Jurvelin, J S; Rieppo, J

2012-05-01

Fourier transform infrared (FT-IR) spectroscopic imaging is a promising method that enables the analysis of spatial distribution of biochemical components within histological sections. However, analysis of FT-IR spectroscopic data is complicated since absorption peaks often overlap with each other. Second derivative spectroscopy is a technique which enhances the separation of overlapping peaks. The objective of this study was to evaluate the specificity of the second derivative peaks for the main tissue components of articular cartilage (AC), i.e., collagen and proteoglycans (PGs). Histological bovine AC sections were measured before and after enzymatic removal of PGs. Both formalin-fixed sections (n = 10) and cryosections (n = 6) were investigated. Relative changes in the second derivative peak heights caused by the removal of PGs were calculated for both sample groups. The results showed that numerous peaks, e.g., peaks located at 1202 cm(-1) and 1336 cm(-1), altered less than 5% in the experiment. These peaks were assumed to be specific for collagen. In contrast, two peaks located at 1064 cm(-1) and 1376 cm(-1) were seen to alter notably, approximately 50% or more. These peaks were regarded to be specific for PGs. The changes were greater in cryosections than formalin-fixed sections. The results of this study suggest that the second derivative spectroscopy offers a practical and more specific method than routinely used absorption spectrum analysis methods to obtain compositional information on AC with FT-IR spectroscopic imaging. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

A Markov random field based approach to the identification of meat and bone meal in feed by near-infrared spectroscopic imaging.

PubMed

Jiang, Xunpeng; Yang, Zengling; Han, Lujia

2014-07-01

Contaminated meat and bone meal (MBM) in animal feedstuff has been the source of bovine spongiform encephalopathy (BSE) disease in cattle, leading to a ban in its use, so methods for its detection are essential. In this study, five pure feed and five pure MBM samples were used to prepare two sets of sample arrangements: set A for investigating the discrimination of individual feed/MBM particles and set B for larger numbers of overlapping particles. The two sets were used to test a Markov random field (MRF)-based approach. A Fourier transform infrared (FT-IR) imaging system was used for data acquisition. The spatial resolution of the near-infrared (NIR) spectroscopic image was 25 μm × 25 μm. Each spectrum was the average of 16 scans across the wavenumber range 7,000-4,000 cm(-1), at intervals of 8 cm(-1). This study introduces an innovative approach to analyzing NIR spectroscopic images: an MRF-based approach has been developed using the iterated conditional mode (ICM) algorithm, integrating initial labeling-derived results from support vector machine discriminant analysis (SVMDA) and observation data derived from the results of principal component analysis (PCA). The results showed that MBM covered by feed could be successfully recognized with an overall accuracy of 86.59% and a Kappa coefficient of 0.68. Compared with conventional methods, the MRF-based approach is capable of extracting spectral information combined with spatial information from NIR spectroscopic images. This new approach enhances the identification of MBM using NIR spectroscopic imaging.

Fourier transform infrared emission spectra of MnH and MnD

NASA Astrophysics Data System (ADS)

Gordon, Iouli E.; Appadoo, Dominique R. T.; Shayesteh, Alireza; Walker, Kaley A.; Bernath, Peter F.

2005-01-01

Fourier transform infrared emission spectra of MnH and MnD were observed in the ground X7Σ + electronic state. The vibration-rotation bands from v = 1 → 0 to v = 3 → 2 for MnH and from v = 1 → 0 to v = 4 → 3 for MnD were recorded at an instrumental resolution of 0.0085 cm -1. Spectroscopic constants were determined for each vibrational level and equilibrium constants were found from a Dunham-type fit. The equilibrium vibrational constant ( ωe) for MnH was found to be 1546.84518(65) cm -1, the equilibrium rotational constant ( Be) is 5.6856789(103) cm -1 and the eqilibrium bond distance ( re) was determined to be 1.7308601(47) Å.

Molecular recognition of 7-(2-octadecyloxycarbonylethyl)guanine to cytidine at the air/water interface and LB film studied by Fourier transform infrared spectroscopy

NASA Astrophysics Data System (ADS)

Miao, Wangen; Luo, Xuzhong; Liang, Yingqiu

2003-03-01

Monolayer behavior of a nucleolipid amphiphile, 7-(2-octadecyloxycarbonylethyl)guanine (ODCG), on aqueous cytidine solution was investigated by means of surface-molecular area ( π- A) isotherms. It indicates that molecular recognition by hydrogen bonding is present between ODCG monolayer and the cytidine in subphase. The Fourier transform infrared (FTIR) transmission spectroscopic result indicates that the cytidine molecules in the subphase can be transferred onto solid substrates by Langmuir-Blodgett (LB) technique as a result of the formation of Watson-Crick base-pairing at the air/water interface. Investigation by rotating polarized FTIR transmission also suggests that the headgroup recognition of this amphiphile to the dissolved cytidine influence the orientation of the tailchains.

DFT simulation, quantum chemical electronic structure, spectroscopic and structure-activity investigations of 4-acetylpyridine

NASA Astrophysics Data System (ADS)

Atilgan, A.; Yurdakul, Ş.; Erdogdu, Y.; Güllüoğlu, M. T.

2018-06-01

The spectroscopic (UV-Vis and infrared), structural and some electronic property observations of the 4-acetylpyridine (4-AP) were reported, which are investigated by using some spectral methods and DFT calculations. FT-IR spectra were obtained for 4-AP at room temperature in the region 4000 cm-1- 400 cm-1. In the DFT calculations, the B3LYP functional with 6-311G++G(d,p) basis set was applied to carry out the quantum mechanical calculations. The Fourier Transform Infrared (FT-IR) and FT-Raman spectra were interpreted by using of normal coordinate analysis based on scaled quantum mechanical force field. The present work expands our understanding of the both the vibrational and structural properties as well as some electronic properties of the 4-AP by means of the theoretical and experimental methods.

FT-mid-IR spectroscopic investigation of fiber maturity and crystallinity at single boll level and a comparison with XRD approach

USDA-ARS?s Scientific Manuscript database

In previous study, we have reported the development of simple algorithms for determining fiber maturity and crystallinity from Fourier transform (FT) -mid-infrared (IR) measurement. Due to its micro-sampling feature, we were able to assess the fiber maturity and crystallinity at different portions o...

UV-Visible and Infrared Methods for Investigating Lipid-Rhodopsin Membrane Interactions

PubMed Central

Brown, Michael F.

2017-01-01

Summary Experimental UV-visible and Fourier transform infrared (FTIR) spectroscopic methods are described for characterizing lipid-protein interactions for the example of rhodopsin in a membrane bilayer environment. The combined use of FTIR and UV-visible difference spectroscopy monitors the structural and functional changes during rhodopsin activation. Such studies investigate how membrane lipids stabilize the various rhodopsin photoproducts, analogous to mutating the protein. Interpretation of the results entails a non-specific flexible surface model for explaining the role of membrane lipid-protein interactions in biological functions. PMID:22976026

Studies on the binding behavior of prodigiosin with bovine hemoglobin by multi-spectroscopic techniques

NASA Astrophysics Data System (ADS)

Tang, Jing; Yang, Chao; Zhou, Lin; Ma, Fei; Liu, Shuchao; Wei, Shaohua; Zhou, Jiahong; Zhou, Yanhuai

2012-10-01

In this article, the interaction mechanism of prodigiosin (PG) with bovine hemoglobin (BHb) is studied in detail using various spectroscopic technologies. UV-vis absorption and fluorescence spectra demonstrate the interaction process. The Stern-Volmer plot and the time-resolved fluorescence study suggest the quenching mechanism of fluorescence of BHb by PG is a static quenching procedure, and the hydrophobic interactions play a major role in binding of PG to BHb. Furthermore, synchronous fluorescence studies, Fourier transform infrared (FTIR) and circular dichroism (CD) spectra reveal that the conformation of BHb is changed after conjugation with PG.

Infrared and Raman Spectroscopic Studies of the Antimicrobial Effects of Garlic Concentrates and Diallyl Constituents on Foodborne Pathogens

PubMed Central

Lu, Xiaonan; Rasco, Barbara A.; Kang, Dong-Hyun; Jabal, Jamie M.F.; Aston, D. Eric; Konkel, Michael E.

2012-01-01

The antimicrobial effects of garlic (Allium sativum) extract (25, 50, 75, 100, and 200 μl/ml) and diallyl sulfide (5, 10 and 20 μM) on Listeria monocytogenes and Escherichia coli O157:H7 cultivated in tryptic soy broth at 4, 22 and 35°C for up to 7 days were investigated. L. monocytogenes was more resistant to garlic extract and diallyl compounds treatment than E. coli O157:H7. Fourier transform Infrared (FT-IR) spectroscopy indicated that diallyl constituents contributed more to the antimicrobial effect than phenolic compounds. This effect was verified by Raman spectroscopy and Raman mapping on single bacteria. Scanning electron microscope (SEM) and transmission electron microscope (TEM) showed cell membrane damage consistent with spectroscopic observation. The degree of bacterial cell injury could be quantified using chemometric methods. PMID:21553849

Fourier transform infrared spectroscopy to quantify collagen and elastin in an in vitro model of extracellular matrix degradation in aorta.

PubMed

Cheheltani, Rabee; McGoverin, Cushla M; Rao, Jayashree; Vorp, David A; Kiani, Mohammad F; Pleshko, Nancy

2014-06-21

Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues.

Fourier Transform Infrared Spectroscopy to Quantify Collagen and Elastin in an In Vitro Model of Extracellular Matrix Degradation in Aorta

PubMed Central

Cheheltani, Rabee; McGoverin, Cushla M.; Rao, Jayashree; Vorp, David A.; Kiani, Mohammad F.; Pleshko, N.

2014-01-01

Extracellular matrix (ECM) is a key component and regulator of many biological tissues including aorta. Several aortic pathologies are associated with significant changes in the composition of the matrix, especially in the content, quality and type of aortic structural proteins, collagen and elastin. The purpose of this study was to develop an infrared spectroscopic methodology that is comparable to biochemical assays to quantify collagen and elastin in aorta. Enzymatically degraded porcine aorta samples were used as a model of ECM degradation in abdominal aortic aneurysm (AAA). After enzymatic treatment, Fourier transform infrared (FTIR) spectra of the aortic tissue were acquired by an infrared fiber optic probe (IFOP) and FTIR imaging spectroscopy (FT-IRIS). Collagen and elastin content were quantified biochemically and partial least squares (PLS) models were developed to predict collagen and elastin content in aorta based on FTIR spectra. PLS models developed from FT-IRIS spectra were able to predict elastin and collagen content of the samples with strong correlations (RMSE of validation = 8.4% and 11.1% of the range respectively), and IFOP spectra were successfully used to predict elastin content (RMSE = 11.3% of the range). The PLS regression coefficients from the FT-IRIS models were used to map collagen and elastin in tissue sections of degraded porcine aortic tissue as well as a human AAA biopsy tissue, creating a similar map of each component compared to histology. These results support further application of FTIR spectroscopic techniques for evaluation of AAA tissues. PMID:24761431

Ag-doped CdO nanocatalysts: Preparation, characterization and catechol oxidase activity

NASA Astrophysics Data System (ADS)

El-Kemary, Maged; El-Mehasseb, Ibrahim; El-Shamy, Hany

2018-06-01

Silver doped cadmium oxide (Ag/CdO) nanoparticles with an average size of 41 nm have been successfully synthesized via thermal decomposition and liquid impregnation technique. The structural characterization has been performed by using several spectroscopic techniques, e.g., X-ray diffraction (XRD), scanning electron microscopy (SEM) and fourier-transform infrared (FT-IR). The catechol oxidase has been studied by UV-visible absorption spectroscopy and fourier-transform infrared as well as the mechanism has been assured by cyclic voltammetry and fluorescence spectroscopy. The results indicate that the oxidation does not occur in the presence of unsupported cadmium oxide particles by silver and in the same time, the catechol oxidase activity of silver doped CdO nanoparticles were improved by about three orders of magnitude than silver ions.

Molecular recognition of 7-(2-octadecyloxycarbonylethyl)guanine to cytidine at the air/water interface and LB film studied by Fourier transform infrared spectroscopy.

PubMed

Miao, Wangen; Luo, Xuzhong; Liang, Yingqiu

2003-03-15

Monolayer behavior of a nucleolipid amphiphile, 7-(2-octadecyloxycarbonylethyl)guanine (ODCG), on aqueous cytidine solution was investigated by means of surface-molecular area (pi-A) isotherms. It indicates that molecular recognition by hydrogen bonding is present between ODCG monolayer and the cytidine in subphase. The Fourier transform infrared (FTIR) transmission spectroscopic result indicates that the cytidine molecules in the subphase can be transferred onto solid substrates by Langmuir-Blodgett (LB) technique as a result of the formation of Watson-Crick base-pairing at the air/water interface. Investigation by rotating polarized FTIR transmission also suggests that the headgroup recognition of this amphiphile to the dissolved cytidine influence the orientation of the tailchains. Copyright 2002 Elsevier Science B.V.

Application of linear discriminant analysis and Attenuated Total Reflectance Fourier Transform Infrared microspectroscopy for diagnosis of colon cancer.

PubMed

Khanmohammadi, Mohammadreza; Bagheri Garmarudi, Amir; Samani, Simin; Ghasemi, Keyvan; Ashuri, Ahmad

2011-06-01

Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) microspectroscopy was applied for detection of colon cancer according to the spectral features of colon tissues. Supervised classification models can be trained to identify the tissue type based on the spectroscopic fingerprint. A total of 78 colon tissues were used in spectroscopy studies. Major spectral differences were observed in 1,740-900 cm(-1) spectral region. Several chemometric methods such as analysis of variance (ANOVA), cluster analysis (CA) and linear discriminate analysis (LDA) were applied for classification of IR spectra. Utilizing the chemometric techniques, clear and reproducible differences were observed between the spectra of normal and cancer cases, suggesting that infrared microspectroscopy in conjunction with spectral data processing would be useful for diagnostic classification. Using LDA technique, the spectra were classified into cancer and normal tissue classes with an accuracy of 95.8%. The sensitivity and specificity was 100 and 93.1%, respectively.

Microplastics on sandy beaches of the Baja California Peninsula, Mexico.

PubMed

Piñon-Colin, Teresita de Jesus; Rodriguez-Jimenez, Ruben; Pastrana-Corral, Miguel Angel; Rogel-Hernandez, Eduardo; Wakida, Fernando Toyohiko

2018-06-01

Microplastics have become a concern in recent years because of their negative impact on marine and freshwater environments. Twenty-one sandy beach sites were sampled to investigate the occurrence and distribution of microplastics on the sandy beaches of the Baja California Peninsula, Mexico, as well as their spectroscopic characterization and morphology. Microplastics were separated using the density method and identified using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR). The mean abundance of microplastics in the samples was 135 ± 92 particles kg−1, and fiber was the most abundant microplastic found in the samples, comprising 91% of the total microplastics identified. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis of the microplastics showed that the main polymers found in microplastics were polyacrylic, polyacrylamide, polyethylene terephthalate, polyesters, and nylon.

Fourier transform infrared spectral detection of life in polar subsurface environments and its application to Mars exploration.

PubMed

Preston, Louisa J; Johnson, Diane; Cockell, Charles S; Grady, Monica M

2015-09-01

Cryptoendolithic lichen communities of the Dry Valleys, Antarctica, survive in an extremely inhospitable environment, finding refuge in microscopic niches where conditions suitable for life exist. Such "within-rock" communities may have evolved on Mars when conditions for life on the surface deteriorated to such an extent that they could no longer survive. Fourier transform infrared spectroscopy of unprepared whole-rock Antarctic Beacon sandstones was used to vertically profile molecular vibrations of fatty acids, proteins, and carboxylic acids created by endolithic communities. Spectral biosignatures were found localized to lichen-rich areas and were absent in crustal regions and the bulk rock substrate. These cryptoendolithic profiles will aid similar spectroscopic investigations of organic biosignatures during future Martian subsurface studies and will help in the identification of similar communities in other localities across the Earth.

Loading of halloysite nanotubes with BSA, α-Lac and β-Lg: a Fourier transform infrared spectroscopic and thermogravimetric study

NASA Astrophysics Data System (ADS)

Duce, Celia; Della Porta, Valentina; Bramanti, Emilia; Campanella, Beatrice; Spepi, Alessio; Tiné, Maria Rosaria

2017-02-01

Halloysite nanotubes (HNTs) are considered as ideal materials for biotechnological and medical applications. An important feature of halloysite is that it has a different surface chemistry on the inner and outer sides of the tubes. This property means that negatively-charged molecules can be selectively loaded inside the halloysite nanoscale its lumen. Loaded HNTs can be used for the controlled or sustained release of proteins, drugs, bioactive molecules and other agents. We studied the interaction between HNTs and bovine serum albumin, α lactalbumin and β -lactoglobulin loaded into HTNs using Fourier transform infrared spectroscopy and thermogravimetry. These techniques enabled us to study the protein conformation and thermal stability, respectively, and to estimate the amount of protein loaded into the HNTs. TEM images confirmed the loading of proteins into HTNs.

Fourier transform infrared evanescent wave (FTIR-FEW) spectroscopy of tissue

NASA Astrophysics Data System (ADS)

Bruch, Reinhard F.; Sukuta, Sydney; Afanasyeva, Natalia I.; Kolyakov, Sergei F.; Butvina, Leonid N.

1997-05-01

A new Fourier transform infrared fiberoptic evanescent wave (FTIR-FEW) spectroscopy method has been developed for tissue diagnostics in the middle infrared (MIR) wavelength range (3 to 20 micrometers). Specific novel fiberoptical chemical and biological sensors have been studied and used for spectroscopic diagnostic purposes. These nontoxic and nonhygroscopic fiber sensors are characterized by (1) low optical losses (0.05 to 0.2 dB/m at about 10 micrometer) and (2) high flexibility. Our new fiber optical devices can be utilized with standard commercially available Fourier transform spectrometers including attenuated total reflection (ATR) techniques. They are in particular ideally suited for noninvasive, fast, direct, sensitive investigations of in vivo and ex vivo medical diagnostics applications. Here we present data on IR spectra of skin tissue in vivo for various cases of melanoma and nevus in the range of 1480 - 1800 cm-1. The interpretation of the spectra of healthy and different stages of tumor and cancer skin tissue clearly indicates that this technique can be used for precancer and cancer diagnostics. This technique can be designed for real-time and on-line computer modeling and analysis of tissue changes.

Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser

NASA Astrophysics Data System (ADS)

Sun, Juan; Deng, Hao; Liu, Ningwu; Wang, Hongliang; Yu, Benli; Li, Jingsong

2016-12-01

We developed a laser absorption sensor based on a pulsed, broadband tunable external cavity quantum cascade laser (ECQCL) centered at 1285 cm-1. Unlike traditional infrared spectroscopy system, a quartz crystal tuning fork (QCTF) as a light detector was used for laser signal detection. Fast Fourier transform was applied to extract vibration intensity information of QCTF. The sensor system is successfully tested on nitrous oxide (N2O) spectroscopy measurements and compared with a standard infrared detector. The wide wavelength tunability of ECQCL will allow us to access the fundamental vibrational bands of many chemical agents, which are well-suited for trace explosive, chemical warfare agent, and toxic industrial chemical detection and spectroscopic analysis.

Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser.

PubMed

Sun, Juan; Deng, Hao; Liu, Ningwu; Wang, Hongliang; Yu, Benli; Li, Jingsong

2016-12-01

We developed a laser absorption sensor based on a pulsed, broadband tunable external cavity quantum cascade laser (ECQCL) centered at 1285 cm -1 . Unlike traditional infrared spectroscopy system, a quartz crystal tuning fork (QCTF) as a light detector was used for laser signal detection. Fast Fourier transform was applied to extract vibration intensity information of QCTF. The sensor system is successfully tested on nitrous oxide (N 2 O) spectroscopy measurements and compared with a standard infrared detector. The wide wavelength tunability of ECQCL will allow us to access the fundamental vibrational bands of many chemical agents, which are well-suited for trace explosive, chemical warfare agent, and toxic industrial chemical detection and spectroscopic analysis.

Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate tissue perfusion for cardiac surgical patients undergoing cardiopulmonary bypass

NASA Technical Reports Server (NTRS)

Soller, Babs R.; Idwasi, Patrick O.; Balaguer, Jorge; Levin, Steven; Simsir, Sinan A.; Vander Salm, Thomas J.; Collette, Helen; Heard, Stephen O.

2003-01-01

OBJECTIVE: To determine whether near infrared spectroscopic measurement of tissue pH and Po2 has sufficient accuracy to assess variation in tissue perfusion resulting from changes in blood pressure and metabolic demand during cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic medical center. SUBJECTS: Eighteen elective cardiac surgical patients. INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over the hypothenar eminence. Reference Po2 and pH sensors were inserted in the abductor digiti minimi (V). Data were collected every 30 secs during surgery and for 6 hrs following cardiopulmonary bypass. Calibration equations developed from one third of the data were used with the remaining data to investigate sensitivity of the near infrared spectroscopic measurement to physiologic changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and reference pH and Po2 measurements were compared for each subject using standard error of prediction. Near infrared spectroscopic pH and Po2 at baseline were compared with values during cardiopulmonary bypass just before rewarming commenced (hypotensive, hypothermic), after rewarming (hypotensive, normothermic) just before discontinuation of cardiopulmonary bypass, and at 6 hrs following cardiopulmonary bypass (normotensive, normothermic) using mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66) with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6 +/- 3 mm Hg, respectively. The average difference between the invasive and near infrared spectroscopic measurement was near zero for both the pH and Po2 measurements. Near infrared spectroscopic Po2 significantly decreased 50% on initiation of cardiopulmonary bypass and remained depressed throughout the bypass and monitored intensive care period. Near infrared spectroscopic pH decreased significantly during cardiopulmonary bypass, decreased significantly during rewarming, and remained depressed 6 hrs after cardiopulmonary bypass. Diabetic patients responded differently than nondiabetic subjects to cardiopulmonary bypass, with lower muscle pH values (p =.02). CONCLUSIONS: Near infrared spectroscopic-measured muscle pH and Po2 are sensitive to changes in tissue perfusion during cardiopulmonary bypass.

Assessment of recent advances in measurement techniques for atmospheric carbon dioxide and methane observations

NASA Astrophysics Data System (ADS)

Zellweger, Christoph; Emmenegger, Lukas; Firdaus, Mohd; Hatakka, Juha; Heimann, Martin; Kozlova, Elena; Spain, T. Gerard; Steinbacher, Martin; van der Schoot, Marcel V.; Buchmann, Brigitte

2016-09-01

Until recently, atmospheric carbon dioxide (CO2) and methane (CH4) measurements were made almost exclusively using nondispersive infrared (NDIR) absorption and gas chromatography with flame ionisation detection (GC/FID) techniques, respectively. Recently, commercially available instruments based on spectroscopic techniques such as cavity ring-down spectroscopy (CRDS), off-axis integrated cavity output spectroscopy (OA-ICOS) and Fourier transform infrared (FTIR) spectroscopy have become more widely available and affordable. This resulted in a widespread use of these techniques at many measurement stations. This paper is focused on the comparison between a CRDS "travelling instrument" that has been used during performance audits within the Global Atmosphere Watch (GAW) programme of the World Meteorological Organization (WMO) with instruments incorporating other, more traditional techniques for measuring CO2 and CH4 (NDIR and GC/FID). We demonstrate that CRDS instruments and likely other spectroscopic techniques are suitable for WMO/GAW stations and allow a smooth continuation of historic CO2 and CH4 time series. Moreover, the analysis of the audit results indicates that the spectroscopic techniques have a number of advantages over the traditional methods which will lead to the improved accuracy of atmospheric CO2 and CH4 measurements.

Model representations of kerogen structures: An insight from density functional theory calculations and spectroscopic measurements

DOE PAGES

Weck, Philippe F.; Kim, Eunja; Wang, Yifeng; ...

2017-08-01

Molecular structures of kerogen control hydrocarbon production in unconventional reservoirs. Significant progress has been made in developing model representations of various kerogen structures. These models have been widely used for the prediction of gas adsorption and migration in shale matrix. However, using density functional perturbation theory (DFPT) calculations and vibrational spectroscopic measurements, we here show that a large gap may still remain between the existing model representations and actual kerogen structures, therefore calling for new model development. Using DFPT, we calculated Fourier transform infrared (FTIR) spectra for six most widely used kerogen structure models. The computed spectra were then systematicallymore » compared to the FTIR absorption spectra collected for kerogen samples isolated from Mancos, Woodford and Marcellus formations representing a wide range of kerogen origin and maturation conditions. Limited agreement between the model predictions and the measurements highlights that the existing kerogen models may still miss some key features in structural representation. A combination of DFPT calculations with spectroscopic measurements may provide a useful diagnostic tool for assessing the adequacy of a proposed structural model as well as for future model development. This approach may eventually help develop comprehensive infrared (IR)-fingerprints for tracing kerogen evolution.« less

Infrared Spectroscopic Imaging: The Next Generation

PubMed Central

Bhargava, Rohit

2013-01-01

Infrared (IR) spectroscopic imaging seemingly matured as a technology in the mid-2000s, with commercially successful instrumentation and reports in numerous applications. Recent developments, however, have transformed our understanding of the recorded data, provided capability for new instrumentation, and greatly enhanced the ability to extract more useful information in less time. These developments are summarized here in three broad areas— data recording, interpretation of recorded data, and information extraction—and their critical review is employed to project emerging trends. Overall, the convergence of selected components from hardware, theory, algorithms, and applications is one trend. Instead of similar, general-purpose instrumentation, another trend is likely to be diverse and application-targeted designs of instrumentation driven by emerging component technologies. The recent renaissance in both fundamental science and instrumentation will likely spur investigations at the confluence of conventional spectroscopic analyses and optical physics for improved data interpretation. While chemometrics has dominated data processing, a trend will likely lie in the development of signal processing algorithms to optimally extract spectral and spatial information prior to conventional chemometric analyses. Finally, the sum of these recent advances is likely to provide unprecedented capability in measurement and scientific insight, which will present new opportunities for the applied spectroscopist. PMID:23031693

Model representations of kerogen structures: An insight from density functional theory calculations and spectroscopic measurements.

PubMed

Weck, Philippe F; Kim, Eunja; Wang, Yifeng; Kruichak, Jessica N; Mills, Melissa M; Matteo, Edward N; Pellenq, Roland J-M

2017-08-01

Molecular structures of kerogen control hydrocarbon production in unconventional reservoirs. Significant progress has been made in developing model representations of various kerogen structures. These models have been widely used for the prediction of gas adsorption and migration in shale matrix. However, using density functional perturbation theory (DFPT) calculations and vibrational spectroscopic measurements, we here show that a large gap may still remain between the existing model representations and actual kerogen structures, therefore calling for new model development. Using DFPT, we calculated Fourier transform infrared (FTIR) spectra for six most widely used kerogen structure models. The computed spectra were then systematically compared to the FTIR absorption spectra collected for kerogen samples isolated from Mancos, Woodford and Marcellus formations representing a wide range of kerogen origin and maturation conditions. Limited agreement between the model predictions and the measurements highlights that the existing kerogen models may still miss some key features in structural representation. A combination of DFPT calculations with spectroscopic measurements may provide a useful diagnostic tool for assessing the adequacy of a proposed structural model as well as for future model development. This approach may eventually help develop comprehensive infrared (IR)-fingerprints for tracing kerogen evolution.

Model representations of kerogen structures: An insight from density functional theory calculations and spectroscopic measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weck, Philippe F.; Kim, Eunja; Wang, Yifeng

Molecular structures of kerogen control hydrocarbon production in unconventional reservoirs. Significant progress has been made in developing model representations of various kerogen structures. These models have been widely used for the prediction of gas adsorption and migration in shale matrix. However, using density functional perturbation theory (DFPT) calculations and vibrational spectroscopic measurements, we here show that a large gap may still remain between the existing model representations and actual kerogen structures, therefore calling for new model development. Using DFPT, we calculated Fourier transform infrared (FTIR) spectra for six most widely used kerogen structure models. The computed spectra were then systematicallymore » compared to the FTIR absorption spectra collected for kerogen samples isolated from Mancos, Woodford and Marcellus formations representing a wide range of kerogen origin and maturation conditions. Limited agreement between the model predictions and the measurements highlights that the existing kerogen models may still miss some key features in structural representation. A combination of DFPT calculations with spectroscopic measurements may provide a useful diagnostic tool for assessing the adequacy of a proposed structural model as well as for future model development. This approach may eventually help develop comprehensive infrared (IR)-fingerprints for tracing kerogen evolution.« less

Portable device for generation of ultra-pure water vapor feeds

NASA Astrophysics Data System (ADS)

Velin, P.; Stenman, U.; Skoglundh, M.; Carlsson, P.-A.

2017-11-01

A portable device for the generation of co-feeds of water vapor has been designed, constructed, and evaluated for flexible use as an add-on component to laboratory chemical reactors. The vapor is formed by catalytic oxidation of hydrogen, which benefits the formation of well-controlled minute concentrations of ultra-pure water. Analysis of the effluent stream by on-line mass spectrometry and Fourier transform infrared spectroscopy confirms that water vapor can be, with high precision, generated both rapidly and steadily over extended periods in the range of 100 ppm to 3 vol. % (limited by safety considerations) using a total flow of 100 to 1500 ml/min at normal temperature and pressure. Further, the device has been used complementary to a commercial water evaporator and mixing system to span water concentrations up to 12 vol. %. Finally, an operando diffuse reflective infrared Fourier transform spectroscopic measurement of palladium catalysed methane oxidation in the absence and presence of up to 1.0 vol. % water has been carried out to demonstrate the applicability of the device for co-feeding well-controlled low concentrations of water vapor to a common type of spectroscopic experiment. The possibilities of creating isotopically labeled water vapor as well as using tracer gases for dynamic experiments are discussed.

Portable device for generation of ultra-pure water vapor feeds.

PubMed

Velin, P; Stenman, U; Skoglundh, M; Carlsson, P-A

2017-11-01

A portable device for the generation of co-feeds of water vapor has been designed, constructed, and evaluated for flexible use as an add-on component to laboratory chemical reactors. The vapor is formed by catalytic oxidation of hydrogen, which benefits the formation of well-controlled minute concentrations of ultra-pure water. Analysis of the effluent stream by on-line mass spectrometry and Fourier transform infrared spectroscopy confirms that water vapor can be, with high precision, generated both rapidly and steadily over extended periods in the range of 100 ppm to 3 vol. % (limited by safety considerations) using a total flow of 100 to 1500 ml/min at normal temperature and pressure. Further, the device has been used complementary to a commercial water evaporator and mixing system to span water concentrations up to 12 vol. %. Finally, an operando diffuse reflective infrared Fourier transform spectroscopic measurement of palladium catalysed methane oxidation in the absence and presence of up to 1.0 vol. % water has been carried out to demonstrate the applicability of the device for co-feeding well-controlled low concentrations of water vapor to a common type of spectroscopic experiment. The possibilities of creating isotopically labeled water vapor as well as using tracer gases for dynamic experiments are discussed.

The water vapour continuum in near-infrared windows - Current understanding and prospects for its inclusion in spectroscopic databases

NASA Astrophysics Data System (ADS)

Shine, Keith P.; Campargue, Alain; Mondelain, Didier; McPheat, Robert A.; Ptashnik, Igor V.; Weidmann, Damien

2016-09-01

Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, infrared and microwave spectral regions. This is partly because, in some spectral regions, there are rather few laboratory measurements in conditions close to those in the Earth's atmosphere; hence understanding of the characteristics of the continuum absorption is still emerging. This is particularly so in the near-infrared and visible, where there has been renewed interest and activity in recent years. In this paper we present a critical review focusing on recent laboratory measurements in two near-infrared window regions (centred on 4700 and 6300 cm-1) and include reference to the window centred on 2600 cm-1 where more measurements have been reported. The rather few available measurements, have used Fourier transform spectroscopy (FTS), cavity ring down spectroscopy, optical-feedback - cavity enhanced laser spectroscopy and, in very narrow regions, calorimetric interferometry. These systems have different advantages and disadvantages. Fourier Transform Spectroscopy can measure the continuum across both these and neighbouring windows; by contrast, the cavity laser techniques are limited to fewer wavenumbers, but have a much higher inherent sensitivity. The available results present a diverse view of the characteristics of continuum absorption, with differences in continuum strength exceeding a factor of 10 in the cores of these windows. In individual windows, the temperature dependence of the water vapour self-continuum differs significantly in the few sets of measurements that allow an analysis. The available data also indicate that the temperature dependence differs significantly between different near-infrared windows. These pioneering measurements provide an impetus for further measurements. Improvements and/or extensions in existing techniques would aid progress to a full characterisation of the continuum - as an example, we report pilot measurements of the water vapour self-continuum using a supercontinuum laser source coupled to an FTS. Such improvements, as well as additional measurements and analyses in other laboratories, would enable the inclusion of the water vapour continuum in future spectroscopic databases, and therefore allow for a more reliable forward modelling of the radiative properties of the atmosphere. It would also allow a more confident assessment of different theoretical descriptions of the underlying cause or causes of continuum absorption.

Enhancing forensic science with spectroscopic imaging

NASA Astrophysics Data System (ADS)

Ricci, Camilla; Kazarian, Sergei G.

2006-09-01

This presentation outlines the research we are developing in the area of Fourier Transform Infrared (FTIR) spectroscopic imaging with the focus on materials of forensic interest. FTIR spectroscopic imaging has recently emerged as a powerful tool for characterisation of heterogeneous materials. FTIR imaging relies on the ability of the military-developed infrared array detector to simultaneously measure spectra from thousands of different locations in a sample. Recently developed application of FTIR imaging using an ATR (Attenuated Total Reflection) mode has demonstrated the ability of this method to achieve spatial resolution beyond the diffraction limit of infrared light in air. Chemical visualisation with enhanced spatial resolution in micro-ATR mode broadens the range of materials studied with FTIR imaging with applications to pharmaceutical formulations or biological samples. Macro-ATR imaging has also been developed for chemical imaging analysis of large surface area samples and was applied to analyse the surface of human skin (e.g. finger), counterfeit tablets, textile materials (clothing), etc. This approach demonstrated the ability of this imaging method to detect trace materials attached to the surface of the skin. This may also prove as a valuable tool in detection of traces of explosives left or trapped on the surfaces of different materials. This FTIR imaging method is substantially superior to many of the other imaging methods due to inherent chemical specificity of infrared spectroscopy and fast acquisition times of this technique. Our preliminary data demonstrated that this methodology will provide the means to non-destructive detection method that could relate evidence to its source. This will be important in a wider crime prevention programme. In summary, intrinsic chemical specificity and enhanced visualising capability of FTIR spectroscopic imaging open a window of opportunities for counter-terrorism and crime-fighting, with applications ranging from analysis of trace evidence (e.g. in soil), tablets, drugs, fibres, tape explosives, biological samples to detection of gunshot residues and imaging of fingerprints.

Mesures spectroscopiques de constituants et de polluants atmosphériques par techniques in situ et à distance, au sol ou embarquéesSpectroscopic measurements of atmospheric constituents and pollutants by in situ and remote techniques from the ground and in flight

NASA Astrophysics Data System (ADS)

Camy-Peyret, Claude; Payan, Sébastien; Jeseck, Pascal; Té, Yao

2001-09-01

Infrared spectroscopy is a powerful tool for precise measurements of atmospheric trace species concentrations through the use of characteristic spectral signatures of the different molecular species and their associated vibration-rotation bands in the mid- or near-infrared. Different methods based on quantitative spectroscopy permit tropospheric or stratospheric measurements: in situ long path absorption, atmospheric absorption/emission by Fourier transform spectroscopy with high spectral resolution instruments on the ground, airborne, balloon-borne or satellite-borne.

A Raman spectroscopic study of thermally treated glushinskite--the natural magnesium oxalate dihydrate.

PubMed

Frost, Ray L; Adebajo, Moses; Weier, Matt L

2004-02-01

Raman spectroscopy has been used to study the thermal transformations of natural magnesium oxalate dihydrate known in mineralogy as glushinskite. The data obtained by Raman spectroscopy was supplemented with that of infrared emission spectroscopy. The vibrational spectroscopic data was complimented with high resolution thermogravimetric analysis combined with evolved gas mass spectrometry. TG-MS identified two mass loss steps at 146 and 397 degrees C. In the first mass loss step water is evolved only, in the second step carbon dioxide is evolved. The combination of Raman microscopy and a thermal stage clearly identifies the changes in the molecular structure with thermal treatment. Glushinskite is the dihydrate phase in the temperature range up to the pre-dehydration temperature of 146 degrees C. Above 397 degrees C, magnesium oxide is formed. Infrared emission spectroscopy shows that this mineral decomposes at around 400 degrees C. Changes in the position and intensity of the CO and CC stretching vibrations in the Raman spectra indicate the temperature range at which these phase changes occur.

Sculpting narrowband Fano resonances inherent in the large-area mid-infrared photonic crystal microresonators for spectroscopic imaging

PubMed Central

Liu, Jui-Nung; Schulmerich, Matthew V.; Bhargava, Rohit; Cunningham, Brian T.

2014-01-01

Fourier transform infrared (FT-IR) imaging spectrometers are almost universally used to record microspectroscopic imaging data in the mid-infrared (mid-IR) spectral region. While the commercial standard, interferometry necessitates collection of large spectral regions, requires a large data handling overhead for microscopic imaging and is slow. Here we demonstrate an approach for mid-IR spectroscopic imaging at selected discrete wavelengths using narrowband resonant filtering of a broadband thermal source, enabled by high-performance guided-mode Fano resonances in one-layer, large-area mid-IR photonic crystals on a glass substrate. The microresonant devices enable discrete frequency IR (DF-IR), in which a limited number of wavelengths that are of interest are recorded using a mechanically robust instrument. This considerably simplifies instrumentation as well as overhead of data acquisition, storage and analysis for large format imaging with array detectors. To demonstrate the approach, we perform DF-IR spectral imaging of a polymer USAF resolution target and human tissue in the C−H stretching region (2600−3300 cm−1). DF-IR spectroscopy and imaging can be generalized to other IR spectral regions and can serve as an analytical tool for environmental and biomedical applications. PMID:25089433

Hydrolysis of Baltic amber during thermal ageing--an infrared spectroscopic approach.

PubMed

Pastorelli, Gianluca; Shashoua, Yvonne; Richter, Jane

2013-04-01

To enable conservation of amber in museums, understanding of chemical changes is crucial. While oxidation has been investigated particularly well for this natural polymer, further degradation phenomena in relation to humidity and pollutants are poorly studied or still unknown. Attenuated total reflectance-Fourier transform infrared spectroscopy was explored with regard to Baltic amber. A systematic spectroscopic survey of a wide range of thermally aged model amber samples, exposed to different microclimatic conditions, showed significant changes in their spectra. Samples aged in a humid and acidic environment or exposed to a humid and alkaline atmosphere generally exhibited a higher absorbance intensity of carbonyl groups at frequencies assigned to acids than unaged samples, samples aged in drier conditions and samples immersed in an alkaline solution. Baltic amber comprises succinate ester, which may be hydrolysed into communol and succinic acid. The survey thus provided evidence about the progress of hydrolytic reactions during degradation of Baltic amber. Infrared spectroscopy was shown to have significant potential for providing qualitative and quantitative chemical information on hydrolysis of amber, which will be of interest for the development of preventive conservation techniques for museum collections of amber objects. Copyright © 2013 Elsevier B.V. All rights reserved.

Flame: A Flexible Data Reduction Pipeline for Near-Infrared and Optical Spectroscopy

NASA Astrophysics Data System (ADS)

Belli, Sirio; Contursi, Alessandra; Davies, Richard I.

2018-05-01

We present flame, a pipeline for reducing spectroscopic observations obtained with multi-slit near-infrared and optical instruments. Because of its flexible design, flame can be easily applied to data obtained with a wide variety of spectrographs. The flexibility is due to a modular architecture, which allows changes and customizations to the pipeline, and relegates the instrument-specific parts to a single module. At the core of the data reduction is the transformation from observed pixel coordinates (x, y) to rectified coordinates (λ, γ). This transformation consists in the polynomial functions λ(x, y) and γ(x, y) that are derived from arc or sky emission lines and slit edge tracing, respectively. The use of 2D transformations allows one to wavelength-calibrate and rectify the data using just one interpolation step. Furthermore, the γ(x, y) transformation includes also the spatial misalignment between frames, which can be measured from a reference star observed simultaneously with the science targets. The misalignment can then be fully corrected during the rectification, without having to further resample the data. Sky subtraction can be performed via nodding and/or modeling of the sky spectrum; the combination of the two methods typically yields the best results. We illustrate the pipeline by showing examples of data reduction for a near-infrared instrument (LUCI at the Large Binocular Telescope) and an optical one (LRIS at the Keck telescope).

Fourier transform infrared spectroscopic analysis of cell differentiation

NASA Astrophysics Data System (ADS)

Ishii, Katsunori; Kimura, Akinori; Kushibiki, Toshihiro; Awazu, Kunio

2007-02-01

Stem cells and its differentiations have got a lot of attentions in regenerative medicine. The process of differentiations, the formation of tissues, has become better understood by the study using a lot of cell types progressively. These studies of cells and tissue dynamics at molecular levels are carried out through various approaches like histochemical methods, application of molecular biology and immunology. However, in case of using regenerative sources (cells, tissues and biomaterials etc.) clinically, they are measured and quality-controlled by non-invasive methods from the view point of safety. Recently, the use of Fourier Transform Infrared spectroscopy (FT-IR) has been used to monitor biochemical changes in cells, and has gained considerable importance. The objective of this study is to establish the infrared spectroscopy of cell differentiation as a quality control of cell sources for regenerative medicine. In the present study, as a basic study, we examined the adipose differentiation kinetics of preadipocyte (3T3-L1) and the osteoblast differentiation kinetics of bone marrow mesenchymal stem cells (Kusa-A1) to analyze the infrared absorption spectra. As a result, we achieved to analyze the adipose differentiation kinetics using the infrared absorption peak at 1739 cm-1 derived from ester bonds of triglyceride and osteoblast differentiation kinetics using the infrared absorption peak at 1030 cm-1 derived from phosphate groups of calcium phosphate.

Pharmaceutical properties of two ethenzamide-gentisic acid cocrystal polymorphs: Drug release profiles, spectroscopic studies and theoretical calculations.

PubMed

Sokal, Agnieszka; Pindelska, Edyta; Szeleszczuk, Lukasz; Kolodziejski, Waclaw

2017-04-30

The aim of this study was to evaluate the stability and solubility of the polymorphic forms of the ethenzamide (ET) - gentisic acid (GA) cocrystals during standard technological processes leading to tablet formation, such as compression and excipient addition. In this work two polymorphic forms of pharmaceutical cocrystals (ETGA) were characterized by 13 C and 15 N solid-state nuclear magnetic resonance and Fourier transformed infrared spectroscopy. Spectroscopic studies were supported by gauge including projector augmented wave (GIPAW) calculations of chemical shielding constants.Polymorphs of cocrystals were easily identified and characterized on the basis of solid-state spectroscopic studies. ETGA cocrystals behaviour during direct compressionand tabletting with excipient addition were tested. In order to choose the best tablet composition with suitable properties for the pharmaceutical industry dissolution profile studies of tablets containing polymorphic forms of cocrystals with selected excipients were carried out. Copyright © 2017. Published by Elsevier B.V.

Synthesis and characterization of porous CaCO3 micro/nano-particles

NASA Astrophysics Data System (ADS)

Achour, A.; Arman, A.; Islam, M.; Zavarian, A. A.; Basim Al-Zubaidi, A.; Szade, J.

2017-06-01

Porous CaCO3 particles, both micro and nano sized, were synthesized in a mixture of Ca(OH)2, hyaluronic acid (HA), glycine, NaOH and NaCl solution with supercritical carbon dioxide. The particles were characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscope, Raman spectroscope (RS), X-ray photoelectron spectroscope (XPS) and scanning electron microscope techniques. All these techniques showed that the particles crystallize into only one CaCO3 structure, namely the vaterite phase. In addition, FTIR, RS and XPS indicated the presence of residual reactive species i.e. glycine, NaCl, and HA. The XRD results confirmed the presence of NaCl and γ-glycine, which is a crystalline material. Moreover, the HA seems to be mostly embedded in the bulk of the micro-particles. Such materials are promising for biomedical applications such as drug delivery.

Discrimination of healthy and osteoarthritic articular cartilage by Fourier transform infrared imaging and Fisher’s discriminant analysis

PubMed Central

Mao, Zhi-Hua; Yin, Jian-Hua; Zhang, Xue-Xi; Wang, Xiao; Xia, Yang

2016-01-01

Fourier transform infrared spectroscopic imaging (FTIRI) technique can be used to obtain the quantitative information of content and spatial distribution of principal components in cartilage by combining with chemometrics methods. In this study, FTIRI combining with principal component analysis (PCA) and Fisher’s discriminant analysis (FDA) was applied to identify the healthy and osteoarthritic (OA) articular cartilage samples. Ten 10-μm thick sections of canine cartilages were imaged at 6.25μm/pixel in FTIRI. The infrared spectra extracted from the FTIR images were imported into SPSS software for PCA and FDA. Based on the PCA result of 2 principal components, the healthy and OA cartilage samples were effectively discriminated by the FDA with high accuracy of 94% for the initial samples (training set) and cross validation, as well as 86.67% for the prediction group. The study showed that cartilage degeneration became gradually weak with the increase of the depth. FTIRI combined with chemometrics may become an effective method for distinguishing healthy and OA cartilages in future. PMID:26977354

Quantitative characterization of chitosan in the skin by Fourier-transform infrared spectroscopic imaging and ninhydrin assay: application in transdermal sciences.

PubMed

Nawaz, A; Wong, T W

2016-07-01

The chitosan has been used as the primary excipient in transdermal particulate dosage form design. Its distribution pattern across the epidermis and dermis is not easily accessible through chemical assay and limited to radiolabelled molecules via quantitative autoradiography. This study explored Fourier-transform infrared spectroscopy imaging technique with built-in microscope as the means to examine chitosan molecular distribution over epidermis and dermis with the aid of histology operation. Fourier-transform infrared spectroscopy skin imaging was conducted using chitosan of varying molecular weights, deacetylation degrees, particle sizes and zeta potentials, obtained via microwave ligation of polymer chains at solution state. Both skin permeation and retention characteristics of chitosan increased with the use of smaller chitosan molecules with reduced acetyl content and size, and increased positive charge density. The ratio of epidermal to dermal chitosan content decreased with the use of these chitosan molecules as their accumulation in dermis (3.90% to 18.22%) was raised to a greater extent than epidermis (0.62% to 1.92%). A larger dermal chitosan accumulation nonetheless did not promote the transdermal polymer passage more than the epidermal chitosan. A small increase in epidermal chitosan content apparently could fluidize the stratum corneum and was more essential to dictate molecular permeation into dermis and systemic circulation. The histology technique aided Fourier-transform infrared spectroscopy imaging approach introduces a new dimension to the mechanistic aspect of chitosan in transdermal delivery. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

High definition infrared spectroscopic imaging for lymph node histopathology.

PubMed

Leslie, L Suzanne; Wrobel, Tomasz P; Mayerich, David; Bindra, Snehal; Emmadi, Rajyasree; Bhargava, Rohit

2015-01-01

Chemical imaging is a rapidly emerging field in which molecular information within samples can be used to predict biological function and recognize disease without the use of stains or manual identification. In Fourier transform infrared (FT-IR) spectroscopic imaging, molecular absorption contrast provides a large signal relative to noise. Due to the long mid-IR wavelengths and sub-optimal instrument design, however, pixel sizes have historically been much larger than cells. This limits both the accuracy of the technique in identifying small regions, as well as the ability to visualize single cells. Here we obtain data with micron-sized sampling using a tabletop FT-IR instrument, and demonstrate that the high-definition (HD) data lead to accurate identification of multiple cells in lymph nodes that was not previously possible. Highly accurate recognition of eight distinct classes - naïve and memory B cells, T cells, erythrocytes, connective tissue, fibrovascular network, smooth muscle, and light and dark zone activated B cells was achieved in healthy, reactive, and malignant lymph node biopsies using a random forest classifier. The results demonstrate that cells currently identifiable only through immunohistochemical stains and cumbersome manual recognition of optical microscopy images can now be distinguished to a similar level through a single IR spectroscopic image from a lymph node biopsy.

Co-treatment of fruit and vegetable waste in sludge digesters: Chemical and spectroscopic investigation by fluorescence and Fourier transform infrared spectroscopy.

PubMed

Provenzano, Maria Rosaria; Cavallo, Ornella; Malerba, Anna Daniela; Di Maria, Francesco; Cucina, Mirko; Massaccesi, Luisa; Gigliotti, Giovanni

2016-04-01

In a previous work co-digestion of food waste and sewage sludge was performed in a pilot apparatus reproducing operating conditions of an existing full scale digester and processing waste mixed sludge (WMS) and fruit and vegetable waste (FVW) at different organic loading rates. An analysis of the relationship among bio-methane generation, process stability and digestate phytotoxicity was conducted. In this paper we considered humification parameters and spectroscopic analysis. Humification parameters indicated a higher not humified fraction (NH) and a lower degree of humification (DH) of FVW with respect to WMS (NH=19.22 and 5.10%; DH=36.65 and 61.94% for FVW and WMS, respectively) associated with their different chemical compositions and with the stabilization process previously undergone by sludge. FVW additions seemed to be favourable from an agronomical point of view since a lower percentage of organic carbon was lost. Fourier transform infrared spectra suggested consumption of aliphatics associated with rising in bio-methane generation followed by accumulation of aliphatics and carboxylic acids when the biogas production dropped. The trend of peaks ratios can be used as an indicator of the process efficiency. Fluorescence intensity of peak B associated with tryptophan-like substances and peak D associated with humic-like substances observed on tridimensional Excitation Emission Matrix maps increased up to sample corresponding to the highest rate of biogas production. Overall spectroscopic results provided evidence of different chemical pathways of anaerobic digestion associated with increasing amount of FVW which led to different levels of biogas production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spectroscopic planetary detection

NASA Technical Reports Server (NTRS)

Deming, Drake

1991-01-01

One of the most promising methods for the detection of extra-solar planets is the spectroscopic method, where a small Doppler shift (approx. 10 meter/sec) in the spectrum of the parent star reveals the presence of planetary companions. However, solar type stars may show spurious Doppler shifts due to surface activity. If these effects are periodic, as is the solar activity cycle, then they may masquerade as planetary companions. The goal of this study was to determine whether the solar cycle affects the Doppler stability of integrated sunlight. Observations of integrated sunlight were made in the near infrared (approx. 2 micron), using the Kitt Peak McMath Fourier transform spectrometer, with a N2O gas absorption cell for calibration. An accuracy of approx. 5 meter/sec was achieved.

Morphological and spectroscopic analysis of cellulose nanocrystals extracted from oil palm empty fruit bunch fiber

NASA Astrophysics Data System (ADS)

Dasan, Y. K.; Bhat, A. H.; Faiz, A.

2015-07-01

This work evaluates the use of oil palm empty fruit bunch (OPEFB) fiber as a source of cellulose to obtain nanocrystalline cellulose (CNC) by acid hydrolysis reaction. The raw OPEFB fibers were pretreated with aqueous Sodium hydroxide at 80°C followed by bleaching treatment and further hydrolyzed with Sulphuric acid at 45°C with limited range of hydrolysis time and acid concentration. The resulting CNC's were characterized for spectroscopic, crystallographic and morphological properties using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometer (XRD), Transmission Electron Microscope (TEM) and Atomic Force Microscopy (AFM). Finding of this study shows that the properties of CNC's are strongly dependent on the hydrolysis time and acid concentration.

Spectroscopic evidence for organic diacid complexation with dissolved silica in aqueous systems—I. Oxalic acid

USGS Publications Warehouse

Marley, N.A.; Bennett, P.; Janecky, D.R.; Gaffney, J.S.

1989-01-01

Increased solubility of quartz and mobilization in contaminated groundwater due to the complexation with dissolved organic acids has been recently proposed [Bennett and Siegel, Nature326, 684–686 (1987)]. Using laser Raman and Fourier transform infrared spectroscopies, we have examined mixed solutions of oxalic and silicic acids at near neutral pH in the tenth molar concentration ranges in an attempt to directly observe the proposed organo-silicate complexes.In both laser Raman and infrared spectra, product bands were observed that indicate an oxalate/silicic acid ester is being formed in the reaction. These data support the observation that organic diacids can lead to enhanced solubility of quartz in hydrogeological systems.

Vibrational structure of the polyunsaturated fatty acids eicosapentaenoic acid and arachidonic acid studied by infrared spectroscopy

NASA Astrophysics Data System (ADS)

Kiefer, Johannes; Noack, Kristina; Bartelmess, Juergen; Walter, Christian; Dörnenburg, Heike; Leipertz, Alfred

2010-02-01

The spectroscopic discrimination of the two structurally similar polyunsaturated C 20 fatty acids (PUFAs) 5,8,11,14,17-eicosapentaenoic acid and 5,8,11,14-eicosatetraenoic acid (arachidonic acid) is shown. For this purpose their vibrational structures are studied by means of attenuated total reflection (ATR) Fourier-transform infrared (FT-IR) spectroscopy. The fingerprint regions of the recorded spectra are found to be almost identical, while the C-H stretching mode regions around 3000 cm -1 show such significant differences as results of electronic and molecular structure alterations based on the different degree of saturation that both fatty acids can be clearly distinguished from each other.

Importance of tissue preparation methods in FTIR micro-spectroscopical analysis of biological tissues: 'traps for new users'.

PubMed

Zohdi, Vladislava; Whelan, Donna R; Wood, Bayden R; Pearson, James T; Bambery, Keith R; Black, M Jane

2015-01-01

Fourier Transform Infrared (FTIR) micro-spectroscopy is an emerging technique for the biochemical analysis of tissues and cellular materials. It provides objective information on the holistic biochemistry of a cell or tissue sample and has been applied in many areas of medical research. However, it has become apparent that how the tissue is handled prior to FTIR micro-spectroscopic imaging requires special consideration, particularly with regards to methods for preservation of the samples. We have performed FTIR micro-spectroscopy on rodent heart and liver tissue sections (two spectroscopically very different biological tissues) that were prepared by desiccation drying, ethanol substitution and formalin fixation and have compared the resulting spectra with that of fully hydrated freshly excised tissues. We have systematically examined the spectra for any biochemical changes to the native state of the tissue caused by the three methods of preparation and have detected changes in infrared (IR) absorption band intensities and peak positions. In particular, the position and profile of the amide I, key in assigning protein secondary structure, changes depending on preparation method and the lipid absorptions lose intensity drastically when these tissues are hydrated with ethanol. Indeed, we demonstrate that preserving samples through desiccation drying, ethanol substitution or formalin fixation significantly alters the biochemical information detected using spectroscopic methods when compared to spectra of fresh hydrated tissue. It is therefore imperative to consider tissue preparative effects when preparing, measuring, and analyzing samples using FTIR spectroscopy.

Spectroscopic studies on the conformational transitions of a bovine growth hormone releasing factor analog

NASA Astrophysics Data System (ADS)

Sarver, Ronald W.; Friedman, Alan R.; Thamann, Thomas J.

1997-10-01

The secondary structure of the bovine growth hormone releasing factor analog, [Ile 2, Ser 8,28, Ala 15, Leu 27, Hse 30] bGRF(1-30)-NH-Ethyl, acetate salt (U-90699F) was studied in solution by Fourier transform infrared and Raman spectroscopies. Spectroscopic studies revealed that concentrated aqueous solutions of U-90699F (100 mg ml -1) undergo a secondary structure transition from disordered coil/α-helix to intermolecular β-sheet. Disordered coil and α-helical structure were grouped together in the infrared and Raman studies since the amide I vibrations are close in frequency and overlap in assignments was possible. Before the conformational transition, the facile exchange of the peptide's amide hydrogens for deuterium indicated that the majority of amide hydrogens were readily accessible to solvent. The kinetics of the conformational transition coincided with an increase in solution viscosity and turbidity. An initiation phase preceded the conformational transition during which only minor spectral changes were observed by infrared spectroscopy. The initiation phase and reaction kinetics were consistent with a highly cooperative nucleation ultimately leading to a network of intermolecular β-sheet structure and gel formation. Increased temperature accelerated the conformational transition. The conformational transition was thermally irreversible but the β-sheet structure of aggregated or gelled peptide could be disrupted by dilution and agitation.

Nanoantenna-Enhanced Infrared Spectroscopic Chemical Imaging.

PubMed

Kühner, Lucca; Hentschel, Mario; Zschieschang, Ute; Klauk, Hagen; Vogt, Jochen; Huck, Christian; Giessen, Harald; Neubrech, Frank

2017-05-26

Spectroscopic infrared chemical imaging is ideally suited for label-free and spatially resolved characterization of molecular species, but often suffers from low infrared absorption cross sections. Here, we overcome this limitation by utilizing confined electromagnetic near-fields of resonantly excited plasmonic nanoantennas, which enhance the molecular absorption by orders of magnitude. In the experiments, we evaporate microstructured chemical patterns of C 60 and pentacene with nanometer thickness on top of homogeneous arrays of tailored nanoantennas. Broadband mid-infrared spectra containing plasmonic and vibrational information were acquired with diffraction-limited resolution using a two-dimensional focal plane array detector. Evaluating the enhanced infrared absorption at the respective frequencies, spatially resolved chemical images were obtained. In these chemical images, the microstructured chemical patterns are only visible if nanoantennas are used. This confirms the superior performance of our approach over conventional spectroscopic infrared imaging. In addition to the improved sensitivity, our technique provides chemical selectivity, which would not be available with plasmonic imaging that is based on refractive index sensing. To extend the accessible spectral bandwidth of nanoantenna-enhanced spectroscopic imaging, we employed nanostructures with dual-band resonances, providing broadband plasmonic enhancement and sensitivity. Our results demonstrate the potential of nanoantenna-enhanced spectroscopic infrared chemical imaging for spatially resolved characterization of organic layers with thicknesses of several nanometers. This is of potential interest for medical applications which are currently hampered by state-of-art infrared techniques, e.g., for distinguishing cancerous from healthy tissues.

Analysis of biofluids in aqueous environment based on mid-infrared spectroscopy.

PubMed

Fabian, Heinz; Lasch, Peter; Naumann, Dieter

2005-01-01

In this study we describe a semiautomatic Fourier transform infrared spectroscopic methodology for the analysis of liquid serum samples, which combines simple sample introduction with high sample throughput. The applicability of this new infrared technology to the analysis of liquid serum samples from a cohort of cattle naturally infected with bovine spongiform encephalopathy and from controls was explored in comparison to the conventional approach based on transmission infrared spectroscopy of dried serum films. Artifical neural network analysis of the infrared data was performed to differentiate between bovine spongiform encephalopathy-negative controls and animals in the late stage of the disease. After training of artifical neural network classifiers, infrared spectra of sera from an independent external validation data set were analyzed. In this way, sensitivities between 90 and 96% and specificities between 84 and 92% were achieved, respectively, depending upon the strategy of data collection and data analysis. Based on these results, the advantages and limitations of the liquid sample technique and the dried film approach for routine analysis of biofluids are discussed. 2005 Society of Photo-Optical Instrumentation Engineers.

Accumulating the hydride state in the catalytic cycle of [FeFe]-hydrogenases

NASA Astrophysics Data System (ADS)

Winkler, Martin; Senger, Moritz; Duan, Jifu; Esselborn, Julian; Wittkamp, Florian; Hofmann, Eckhard; Apfel, Ulf-Peter; Stripp, Sven Timo; Happe, Thomas

2017-07-01

H2 turnover at the [FeFe]-hydrogenase cofactor (H-cluster) is assumed to follow a reversible heterolytic mechanism, first yielding a proton and a hydrido-species which again is double-oxidized to release another proton. Three of the four presumed catalytic intermediates (Hox, Hred/Hred and Hsred) were characterized, using various spectroscopic techniques. However, in catalytically active enzyme, the state containing the hydrido-species, which is eponymous for the proposed heterolytic mechanism, has yet only been speculated about. We use different strategies to trap and spectroscopically characterize this transient hydride state (Hhyd) for three wild-type [FeFe]-hydrogenases. Applying a novel set-up for real-time attenuated total-reflection Fourier-transform infrared spectroscopy, we monitor compositional changes in the state-specific infrared signatures of [FeFe]-hydrogenases, varying buffer pH and gas composition. We selectively enrich the equilibrium concentration of Hhyd, applying Le Chatelier's principle by simultaneously increasing substrate and product concentrations (H2/H+). Site-directed manipulation, targeting either the proton-transfer pathway or the adt ligand, significantly enhances Hhyd accumulation independent of pH.

Spectroscopic detection of pharmaceutical compounds from an aflatoxigenic strain of Aspergillus parasiticus.

PubMed

Basaran, P; Demirbas, R M

2010-08-20

Polar and non-polar secondary metabolites as well as phenolic compounds of Aspergillus parasiticus grown on hazelnut were analyzed by high-resolution high performance liquid chromatography-mass spectroscopy and fourier transform infrared spectroscopy. Several novel and beneficial compounds such as dibutyl phthalate, pyrogallol, fumagillol, italicic acid and sorbicillin were identified from A. parasiticus for the first time. Some of these compounds have the potential to be used in pharmaceutical industry. Copyright 2009 Elsevier GmbH. All rights reserved.

Comparing paraffined and deparaffinized breast cancer tissue samples and an analysis of Raman spectroscopy and infrared methods

NASA Astrophysics Data System (ADS)

Depciuch, J.; Kaznowska, E.; Szmuc, K.; Zawlik, I.; Cholewa, M.; Heraud, P.; Cebulski, J.

2016-05-01

Breast cancer makes up a quarter of all cancer in women, which is why research into new diagnostic methods and sample preparations need to be developed at an accelerated pace. Researchers are looking for diagnostic tools to detect when an individual has cancer cells and use that information to see what measurements and approaches can be used to take further diagnostic steps. The most common method of sample preparation is the imbibing of tumor tissue in paraffin, which can produce a background for spectroscopic measurements in the range of 500-3500 cm-1. In this study we demonstrated that proper preparation of paraffin-embedded specimens and the measurement methodology can eliminate paraffin vibration, as was done in the work Depciuch et al. 2015. Thanks to this spectroscopic technique there may become a reliable and accurate method of diagnosing breast cancer based on the evidence found from the prepared samples. The study compared the results obtained through Raman spectroscopy and FTIR (Fourier Transform Infrared) measurements of healthy and cancerous breast tissues that were either embedded in paraffin or deparaffinized. The resulting spectrum and accurate analysis led to the conclusion that the appropriate measurement of the background and the elimination of peaks from the paraffin had the greatest impact on the reliability of results. Furthermore, after the accurate, detailed studies FTIR and Raman spectroscopy on samples of breast tissue that were deparaffinized or embedded in paraffin, including a complete analysis of the peak after transformation Kramers-Kröning (KK), it was found that sample preparation did not affect the result obtained by measuring the reflectance in the mid-infrared range, and that this only had a minimal effect relating to the intensity obtained by the measurement of the Raman peak. Only in special cases, when Raman spectroscopic methods are used for research to find the peculiarities of the spectra, are deparaffinization recommended, in order to attain more detailed results that could be crucial in understanding the process of carcinogenesis.

Setting the Record Straight: Bottom-Up Carbon Nanostructures via Solid-State Reactions

NASA Astrophysics Data System (ADS)

Jordan, Robert Stanley

Chapter 1 describes the development and spectroscopic investigation of a novel synthetic route to N = 8 armchair graphene nanoribbons from polydiacetylene polymers. Four distinct diphenyl polydiacetylene polymers are produced from the crystal-phase topochemical polymerization of their corresponding diphenyl-1,4-butadiynes. These polydiacetylene polymers are transformed into spectroscopically indistinguishable N = 8 armchair graphene nanoribbons via simple heating in the bulk, solid-state. The stepwise transformation of polydiacetylenes to graphene nanoribbons is examined in detail by the use of complementary spectroscopic methods, namely solid-state nuclear magnetic resonance, infrared, Raman and X-ray photoelectron spectroscopy. The final morphology and width of the nanoribbons is established through the use of high-resolution transmission electron microscopy. Chapter 2 chronicles the implementation of a similar approach to N = 12 armchair graphene nanoribbons from a dinaphthyl substituted polydiacetylene polymer. The mild nature of the process and pristine structure of the nanoribbons is again confirmed with the use of spectroscopic and microscopic methods. The chapter concludes with preliminary electrical measurements of the nanoribbons confirming that they are indeed conductive. Chapter 3 details the development of a synthetic route to diaryl trans-enediynes as structural models of individual reactive units within a polydiacetylene polymer. The trans-enediynes described are found to undergo three distinct annulation reactions depending on reaction conditions. Finally, the synthetic routes developed are utilized to access diethynyl [5]helicenes and phenanthrenes which fueled studies on the mechanism of the Bergman polymerization reaction.

Analysis of the Maillard reaction in human hair using Fourier transform infrared spectroscopic imaging and a focal-plane array detector.

PubMed

Jung, In-Keun; Park, Sang-Chul; Bin, Sung-Ah; Roh, Young Sup; Lee, John Hwan; Kim, Boo-Min

2016-03-01

The Maillard reaction has been well researched and used in the food industry and the fields of environmental science and organic chemistry. Here, we induced the Maillard reaction inside human hair and analyzed its effects by using Fourier transform infrared spectroscopy with a focal-plane array (FTIR-FPA) detector. We used arginine (A), glycine (G), and D-xylose (X) to generate the Maillard reaction by dissolving them in purified water and heating it to 150 °C. This label-free process generated a complex compound (named AGX after its ingredients) with a monomer structure, which was determined by using nuclear magnetic resonance (NMR) and FTIR-FPA. This compound was stable in hair and substantially increased its tensile strength. To our knowledge, we are the first to report the formation of this monomer in human hair, and our study provides insights into a new method that could be used to improve the condition of damaged or aging hair.

Morphological and spectroscopic analysis of cellulose nanocrystals extracted from oil palm empty fruit bunch fiber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dasan, Y. K., E-mail: aamir.bhat@petronas.com.my; Bhat, A. H., E-mail: aamir.bhat@petronas.com.my; Faiz, A., E-mail: faizahmad@petronas.com.my

2015-07-22

This work evaluates the use of oil palm empty fruit bunch (OPEFB) fiber as a source of cellulose to obtain nanocrystalline cellulose (CNC) by acid hydrolysis reaction. The raw OPEFB fibers were pretreated with aqueous Sodium hydroxide at 80°C followed by bleaching treatment and further hydrolyzed with Sulphuric acid at 45°C with limited range of hydrolysis time and acid concentration. The resulting CNC’s were characterized for spectroscopic, crystallographic and morphological properties using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometer (XRD), Transmission Electron Microscope (TEM) and Atomic Force Microscopy (AFM). Finding of this study shows that the properties of CNC’s aremore » strongly dependent on the hydrolysis time and acid concentration.« less

Spectroscopic analysis of roman wall paintings from Casa del Mitreo in Emerita Augusta, Mérida, Spain.

PubMed

Edreira, M C; Feliu, M J; Fernández-Lorenzo, C; Martín, J

2003-05-01

The use of visible spectroscopy, applied to chromatic characterization of Roman wall paintings, allows an easy and trustworthy grouping of the samples studied. The use of other spectroscopic techniques such as Fourier transform infrared spectroscopy (FTIR) and energy-dispersive X-ray spectroscopy (EDS) in conjunction with X-ray diffraction (XRD) allows a good identification of the substances present in the pictorial layers that define and differentiate each chromatic group. In this paper, a study of 40 Roman wall painting samples, from Pinturas Báquicas of Casa del Mitreo in Emerita Augusta (Mérida, Spain), is described. In these samples, some pigments of high quality and cost, as well as some unusual mixtures, not described in the bibliography, have been found.

The effects of biological buffers TRIS, TAPS, TES on the stability of lysozyme.

PubMed

Pannuru, Pavani; Rani, Anjeeta; Venkatesu, Pannuru; Lee, Ming-Jer

2018-06-01

To explore the mechanism of lysozyme stabilization in buffer system, we have investigated the interactions between lysozyme and the biological buffers (TRIS, TAPS, and TES) using spectroscopic techniques, including ultraviolet-visible (UV-Vis), fluorescence, thermal fluorescence, dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR) and circular dichroism (CD) spectroscopy. From the series of spectroscopic studies, it is found that the native structure of the protein remains intact in the different concentrations (0.05, 0.1, 0.25, 0.5, and 1.0M) of the biological buffer aqueous solutions at pH7.0. Moreover, all these three investigated buffers are able to protect lysozyme against thermal denaturation, particularly in high concentration (1.0M) of the buffer aqueous solutions. Copyright © 2018 Elsevier B.V. All rights reserved.

Monitoring light-induced structural changes of Channelrhodopsin-2 by UV-visible and Fourier transform infrared spectroscopy.

PubMed

Ritter, Eglof; Stehfest, Katja; Berndt, Andre; Hegemann, Peter; Bartl, Franz J

2008-12-12

Channelrhodopsin-2 (ChR2) is a microbial type rhodopsin and a light-gated cation channel that controls phototaxis in Chlamydomonas. We expressed ChR2 in COS-cells, purified it, and subsequently investigated this unusual photoreceptor by flash photolysis and UV-visible and Fourier transform infrared difference spectroscopy. Several transient photoproducts of the wild type ChR2 were identified, and their kinetics and molecular properties were compared with those of the ChR2 mutant E90Q. Based on the spectroscopic data we developed a model of the photocycle comprising six distinguishable intermediates. This photocycle shows similarities to the photocycle of the ChR2-related Channelrhodopsin of Volvox but also displays significant differences. We show that molecular changes include retinal isomerization, changes in hydrogen bonding of carboxylic acids, and large alterations of the protein backbone structure. These alterations are stronger than those observed in the photocycle of other microbial rhodopsins like bacteriorhodopsin and are related to those occurring in animal rhodopsins. UV-visible and Fourier transform infrared difference spectroscopy revealed two late intermediates with different time constants of tau = 6 and 40 s that exist during the recovery of the dark state. The carboxylic side chain of Glu(90) is involved in the slow transition. The molecular changes during the ChR2 photocycle are discussed with respect to other members of the rhodopsin family.

Monitoring Light-induced Structural Changes of Channelrhodopsin-2 by UV-visible and Fourier Transform Infrared Spectroscopy*

PubMed Central

Ritter, Eglof; Stehfest, Katja; Berndt, Andre; Hegemann, Peter; Bartl, Franz J.

2008-01-01

Channelrhodopsin-2 (ChR2) is a microbial type rhodopsin and a light-gated cation channel that controls phototaxis in Chlamydomonas. We expressed ChR2 in COS-cells, purified it, and subsequently investigated this unusual photoreceptor by flash photolysis and UV-visible and Fourier transform infrared difference spectroscopy. Several transient photoproducts of the wild type ChR2 were identified, and their kinetics and molecular properties were compared with those of the ChR2 mutant E90Q. Based on the spectroscopic data we developed a model of the photocycle comprising six distinguishable intermediates. This photocycle shows similarities to the photocycle of the ChR2-related Channelrhodopsin of Volvox but also displays significant differences. We show that molecular changes include retinal isomerization, changes in hydrogen bonding of carboxylic acids, and large alterations of the protein backbone structure. These alterations are stronger than those observed in the photocycle of other microbial rhodopsins like bacteriorhodopsin and are related to those occurring in animal rhodopsins. UV-visible and Fourier transform infrared difference spectroscopy revealed two late intermediates with different time constants of τ = 6 and 40 s that exist during the recovery of the dark state. The carboxylic side chain of Glu90 is involved in the slow transition. The molecular changes during the ChR2 photocycle are discussed with respect to other members of the rhodopsin family. PMID:18927082

Profiles of stratospheric chlorine nitrate (ClONO2) from atmospheric trace molecule spectroscopy/ATLAS 1 infrared solar occultation spectra

NASA Technical Reports Server (NTRS)

Rinsland, C. P.; Gunson, M. R.; Abrams, M. C.; Zander, R.; Mahieu, E.; Goldman, A.; Ko, M. K. W.; Rodriguez, J. M.; Sze, N. D.

1994-01-01

Stratospheric volume mixing ratio profiles of chlorine nitrate (ClONO2) have been retrieved from 0.01/cm resolution infrared solar occultation spectra recorded at latitudes between 14 deg N and 54 deg S by the atmospheric trace molecule spectroscopy Fourier transform spectrometer during the Atmospheric Laboratory for Applications and Science (ATLAS) 1 shuttle mission (March 24 to April 2, 1992). The results were obtained from nonlinear least squares fittings of the ClONO2 nu(sub 4) band Q branch at 780.21/cm with improved spectroscopic parameters generated on the basis of recent laboratory work. The individual profiles, which have an accuracy of about +/- 20%, are compared with previous observations and model calculations.

Discourse for slide presentation: An overview of chemical detection systems

NASA Technical Reports Server (NTRS)

Peters, Randy Alan; Galen, Theodore J.; Pierson, Duane L.

1990-01-01

A brief overview of some of the analytical techniques currently used in monitoring and analyzing permanent gases and selected volatile organic compound in air are presented. Some of the analytical considerations in developing a specific method are discussed. Four broad groups of hardware are discussed: compound class specific personal monitors, gas chromatographic systems, infrared spectroscopic systems, and mass spectrometric residual gas analyzer systems. Three types of detectors are also discussed: catalytic sensor based systems, photoionization detectors, and wet or dry chemical reagent systems. Under gas chromatograph based systems five detector systems used in combination with a GC are covered: thermal conductivity detectors, photoionization detectors, Fourier transform infrared spectrophotometric systems, quadrapole mass spectrometric systems, and a relatively recent development, a surface acoustic wave vapor detector.

Proposal of AAA-battery-size one-shot ATR Fourier spectroscopic imager for on-site analysis: Simultaneous measurement of multi-components with high accuracy

NASA Astrophysics Data System (ADS)

Hosono, Satsuki; Qi, Wei; Sato, Shun; Suzuki, Yo; Fujiwara, Masaru; Hiramatsu, Hiroyuki; Suzuki, Satoru; Abeygunawardhana, P. K. W.; Wada, Kenji; Nishiyama, Akira; Ishimaru, Ichiro

2015-03-01

For simultaneous measurement of multi-components on-site like factories, the ultra-compact (diameter: 9[mm], length: 45[mm], weight: 200[g]) one-shot ATR (Attenuated Total Reflection) Fourier spectroscopic imager was proposed. Because the proposed one-shot Fourier spectroscopic imaging is based on spatial-phase-shift interferometer, interferograms could be obtained with simple optical configurations. We introduced the transmission-type relativeinclined phase-shifter, that was constructed with a cuboid prism and a wedge prism, onto the optical Fourier transform plane of infinity corrected optical systems. And also, small light-sources and cameras in the mid-infrared light region, whose size are several millimeter on a side, are essential components for the ultra-compact spectroscopic configuration. We selected the Graphite light source (light source area: 1.7×1.7[mm], maker: Hawkeye technologies) whose radiation factor was high. Fortunately, in these days we could apply the cost-effective 2-dimensional light receiving device for smartphone (e.g. product name: LEPTON, maker: FLIR, price: around 400USD). In the case of alcoholic drinks factory, conventionally workers measure glucose and ethanol concentrations by bringing liquid solution back to laboratories every day. The high portable spectroscopy will make it possible to measure multi-components simultaneously on manufacturing scene. But we found experimentally that absorption spectrum of glucose and water and ethanol were overlapped each other in near infrared light region. But for mid-infrared light region, we could distinguish specific absorption peaks of glucose (@10.5[μm]) and ethanol (@11.5[μm]) independently from water absorption. We obtained standard curve between absorption (@9.6[μm]) and ethanol concentration with high correlation coefficient 0.98 successfully by ATR imaging-type 2-dimensional Fourier spectroscopy (wavelength resolution: 0.057[μm]) with the graphite light source (maker: Hawkeye technologies, type: IR-75).

Applications of Quantum Cascade Laser Spectroscopy in the Analysis of Pharmaceutical Formulations.

PubMed

Galán-Freyle, Nataly J; Pacheco-Londoño, Leonardo C; Román-Ospino, Andrés D; Hernandez-Rivera, Samuel P

2016-09-01

Quantum cascade laser spectroscopy was used to quantify active pharmaceutical ingredient content in a model formulation. The analyses were conducted in non-contact mode by mid-infrared diffuse reflectance. Measurements were carried out at a distance of 15 cm, covering the spectral range 1000-1600 cm(-1) Calibrations were generated by applying multivariate analysis using partial least squares models. Among the figures of merit of the proposed methodology are the high analytical sensitivity equivalent to 0.05% active pharmaceutical ingredient in the formulation, high repeatability (2.7%), high reproducibility (5.4%), and low limit of detection (1%). The relatively high power of the quantum-cascade-laser-based spectroscopic system resulted in the design of detection and quantification methodologies for pharmaceutical applications with high accuracy and precision that are comparable to those of methodologies based on near-infrared spectroscopy, attenuated total reflection mid-infrared Fourier transform infrared spectroscopy, and Raman spectroscopy. © The Author(s) 2016.

Direct measurement of the effective infrared dielectric response of a highly doped semiconductor metamaterial.

PubMed

Al Mohtar, Abeer; Kazan, Michel; Taliercio, Thierry; Cerutti, Laurent; Blaize, Sylvain; Bruyant, Aurélien

2017-03-24

We have investigated the effective dielectric response of a subwavelength grating made of highly doped semiconductors (HDS) excited in reflection, using numerical simulations and spectroscopic measurement. The studied system can exhibit strong localized surface resonances and has, therefore, a great potential for surface-enhanced infrared absorption (SEIRA) spectroscopy application. It consists of a highly doped InAsSb grating deposited on lattice-matched GaSb. The numerical analysis demonstrated that the resonance frequencies can be inferred from the dielectric function of an equivalent homogeneous slab by accounting for the complex reflectivity of the composite layer. Fourier transform infrared reflectivity (FTIR) measurements, analyzed with the Kramers-Kronig conversion technique, were used to deduce the effective response in reflection of the investigated system. From the knowledge of this phenomenological dielectric function, transversal and longitudinal energy-loss functions were extracted and attributed to transverse and longitudinal resonance modes frequencies.

Insights on diagnosis of oral cavity pathologies by infrared spectroscopy: A review

NASA Astrophysics Data System (ADS)

Giorgini, Elisabetta; Balercia, Paolo; Conti, Carla; Ferraris, Paolo; Sabbatini, Simona; Rubini, Corrado; Tosi, Giorgio

2013-11-01

Fourier-Transform Infrared microspectroscopy, a largely used spectroscopic technique in basic and industrial researches, offers the possibility to analyze the vibrational features of molecular groups within a variety of environments. In the bioclinical field, and, in particular, in the study of cells, tissues and biofluids, it could be considered a supporting objective technique able to characterize the biochemical processes involved in relevant pathologies, such as tumoral diseases, highlighting specific spectral markers associable with the principal biocomponents (proteins, lipids and carbohydrates). In this article, we review the applications of infrared spectroscopy to the study of tumoral diseases of oral cavity compartments with the aim to improve understanding of biological processes involved during the onset of these lesions and to afford to an early diagnosis. Spectral studies on mouth, salivary glands and oral cystic lesions, objectively discriminate normal from dysplastic and cancer states characterizing also the grading.

All-photonic drying and sintering process via flash white light combined with deep-UV and near-infrared irradiation for highly conductive copper nano-ink

PubMed Central

Hwang, Hyun-Jun; Oh, Kyung-Hwan; Kim, Hak-Sung

2016-01-01

We developed an ultra-high speed photonic sintering method involving flash white light (FWL) combined with near infrared (NIR) and deep UV light irradiation to produce highly conductive copper nano-ink film. Flash white light irradiation energy and the power of NIR/deep UV were optimized to obtain high conductivity Cu films. Several microscopic and spectroscopic characterization techniques such as scanning electron microscopy (SEM), a x-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy were employed to characterize the Cu nano-films. Optimally sintered Cu nano-ink films produced using a deep UV-assisted flash white light sintering technique had the lowest resistivity (7.62 μΩ·cm), which was only 4.5-fold higher than that of bulk Cu film (1.68 μΩ•cm). PMID:26806215

All-photonic drying and sintering process via flash white light combined with deep-UV and near-infrared irradiation for highly conductive copper nano-ink.

PubMed

Hwang, Hyun-Jun; Oh, Kyung-Hwan; Kim, Hak-Sung

2016-01-25

We developed an ultra-high speed photonic sintering method involving flash white light (FWL) combined with near infrared (NIR) and deep UV light irradiation to produce highly conductive copper nano-ink film. Flash white light irradiation energy and the power of NIR/deep UV were optimized to obtain high conductivity Cu films. Several microscopic and spectroscopic characterization techniques such as scanning electron microscopy (SEM), a x-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy were employed to characterize the Cu nano-films. Optimally sintered Cu nano-ink films produced using a deep UV-assisted flash white light sintering technique had the lowest resistivity (7.62 μΩ·cm), which was only 4.5-fold higher than that of bulk Cu film (1.68 μΩ•cm).

Synthesis, characterization, and application of novel biodegradable self-assembled 2-(N-phthalimido) ethyl-palmitate nanoparticles for cancer therapy

NASA Astrophysics Data System (ADS)

Kasoju, Naresh; Bora, Debajeet K.; Bhonde, Ramesh R.; Bora, Utpal

2010-03-01

We report the synthesis of novel biodegradable nanoparticles (NPs) which can kill the cancer cells without any additional drug loading. The NP was a self-assembled form of a phthalimide based conjugate, in which the phthalimide moiety was responsible for the anticancer activity. We describe the synthesis of a novel 2-(N-phthalimido) ethyl palmitate (PHEP-Pal) conjugate and subsequent preparation of NPs by a simple self assembly process. The successful synthesis of conjugate was confirmed by various characterization studies including nuclear magnetic resonance spectroscope, Fourier transform infrared spectroscope, TOF-liquid chromatography mass spectroscope, differential scanning calorimetry, and X-ray diffraction unit. The synthesis, shape, size, and size distribution of PHEP-Pal NPs were determined by transmission electron microscope, atomic force microscope, and dynamic light scattering technique. Finally, cell culture studies using A549 and HeLa cells were done to evaluate the anticancer effect of PHEP-Pal NPs, which demonstrated the potency of these NPs for use in cancer chemotherapy.

Low-loss Ca{sub 5-x}Sr{sub x}A{sub 2}TiO{sub 12} [A=Nb,Ta] ceramics: Microwave dielectric properties and vibrational spectroscopic analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bijumon, Pazhoor Varghese; Sebastian, Mailadil Thomas; Dias, Anderson

2005-05-15

Complex perovskite-type Ca{sub 5-x}Sr{sub x}A{sub 2}TiO{sub 12} [A=Nb,Ta] (0{<=}x{<=}5) ceramics were prepared by conventional solid-state ceramic route. The crystal structure, microwave dielectric properties, and vibrational spectroscopic characteristics of these materials are reported. The structure and microstructure were investigated by x-ray diffraction and scanning electron microscopy techniques. The microwave dielectric properties were measured in the 3-5-GHz frequency range by the resonance method. Structural evolutions from orthorhombic to an averaged pseudocubic phase, with associated changes in dielectric properties, were observed as a function of composition. The structure-property relationships in these ceramics were established using Raman and Fourier transform infrared spectroscopic techniques. Ramanmore » analysis showed characteristic bands of ordered perovskite materials, with variation in both intensity and frequency as a function of composition.« less

A glutamate is the essential proton transfer gate during the catalytic cycle of the [NiFe] hydrogenase.

PubMed

Dementin, Sébastien; Burlat, Bénédicte; De Lacey, Antonio L; Pardo, Alejandro; Adryanczyk-Perrier, Géraldine; Guigliarelli, Bruno; Fernandez, Victor M; Rousset, Marc

2004-03-12

Kinetic, EPR, and Fourier transform infrared spectroscopic analysis of Desulfovibrio fructosovorans [NiFe] hydrogenase mutants targeted to Glu-25 indicated that this amino acid participates in proton transfer between the active site and the protein surface during the catalytic cycle. Replacement of that glutamic residue by a glutamine did not modify the spectroscopic properties of the enzyme but cancelled the catalytic activity except the para-H(2)/ortho-H(2) conversion. This mutation impaired the fast proton transfer from the active site that allows high turnover numbers for the oxidation of hydrogen. Replacement of the glutamic residue by the shorter aspartic acid slowed down this proton transfer, causing a significant decrease of H(2) oxidation and hydrogen isotope exchange activities, but did not change the para-H(2)/ortho-H(2) conversion activity. The spectroscopic properties of this mutant were totally different, especially in the reduced state in which a non-photosensitive nickel EPR spectrum was obtained.

A rapid Fourier-transform infrared (FTIR) spectroscopic method for direct quantification of paracetamol content in solid pharmaceutical formulations

NASA Astrophysics Data System (ADS)

Mallah, Muhammad Ali; Sherazi, Syed Tufail Hussain; Bhanger, Muhammad Iqbal; Mahesar, Sarfaraz Ahmed; Bajeer, Muhammad Ashraf

2015-04-01

A transmission FTIR spectroscopic method was developed for direct, inexpensive and fast quantification of paracetamol content in solid pharmaceutical formulations. In this method paracetamol content is directly analyzed without solvent extraction. KBr pellets were formulated for the acquisition of FTIR spectra in transmission mode. Two chemometric models: simple Beer's law and partial least squares employed over the spectral region of 1800-1000 cm-1 for quantification of paracetamol content had a regression coefficient of (R2) of 0.999. The limits of detection and quantification using FTIR spectroscopy were 0.005 mg g-1 and 0.018 mg g-1, respectively. Study for interference was also done to check effect of the excipients. There was no significant interference from the sample matrix. The results obviously showed the sensitivity of transmission FTIR spectroscopic method for pharmaceutical analysis. This method is green in the sense that it does not require large volumes of hazardous solvents or long run times and avoids prior sample preparation.

Infrared Spectroscopic Imaging of Latent Fingerprints and Associated Forensic Evidence

PubMed Central

Chen, Tsoching; Schultz, Zachary D.; Levin, Ira W.

2011-01-01

Fingerprints reflecting a specific chemical history, such as exposure to explosives, are clearly distinguished from overlapping, and interfering latent fingerprints using infrared spectroscopic imaging techniques and multivariate analysis. PMID:19684917

Investigating the biochemical progression of liver disease through fibrosis, cirrhosis, dysplasia, and hepatocellular carcinoma using Fourier transform infrared spectroscopic imaging

NASA Astrophysics Data System (ADS)

Sreedhar, Hari; Pant, Mamta; Ronquillo, Nemencio R.; Davidson, Bennett; Nguyen, Peter; Chennuri, Rohini; Choi, Jacqueline; Herrera, Joaquin A.; Hinojosa, Ana C.; Jin, Ming; Kajdacsy-Balla, Andre; Guzman, Grace; Walsh, Michael J.

2014-03-01

Hepatocellular carcinoma (HCC) is the most common form of primary hepatic carcinoma. HCC ranks the fourth most prevalent malignant tumor and the third leading cause of cancer related death in the world. Hepatocellular carcinoma develops in the context of chronic liver disease and its evolution is characterized by progression through intermediate stages to advanced disease and possibly even death. The primary sequence of hepatocarcinogenesis includes the development of cirrhosis, followed by dysplasia, and hepatocellular carcinoma.1 We addressed the utility of Fourier Transform Infrared (FT-IR) spectroscopic imaging, both as a diagnostic tool of the different stages of the disease and to gain insight into the biochemical process associated with disease progression. Tissue microarrays were obtained from the University of Illinois at Chicago tissue bank consisting of liver explants from 12 transplant patients. Tissue core biopsies were obtained from each explant targeting regions of normal, liver cell dysplasia including large cell change and small cell change, and hepatocellular carcinoma. We obtained FT-IR images of these tissues using a modified FT-IR system with high definition capabilities. Firstly, a supervised spectral classifier was built to discriminate between normal and cancerous hepatocytes. Secondly, an expanded classifier was built to discriminate small cell and large cell changes in liver disease. With the emerging advances in FT-IR instrumentation and computation there is a strong drive to develop this technology as a powerful adjunct to current histopathology approaches to improve disease diagnosis and prognosis.

Spectral Mining for Discriminating Blood Origins in the Presence of Substrate Interference via Attenuated Total Reflection Fourier Transform Infrared Spectroscopy: Postmortem or Antemortem Blood?

PubMed

Takamura, Ayari; Watanabe, Ken; Akutsu, Tomoko; Ikegaya, Hiroshi; Ozawa, Takeaki

2017-09-19

Often in criminal investigations, discrimination of types of body fluid evidence is crucially important to ascertain how a crime was committed. Compared to current methods using biochemical techniques, vibrational spectroscopic approaches can provide versatile applicability to identify various body fluid types without sample invasion. However, their applicability is limited to pure body fluid samples because important signals from body fluids incorporated in a substrate are affected strongly by interference from substrate signals. Herein, we describe a novel approach to recover body fluid signals that are embedded in strong substrate interferences using attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy and an innovative multivariate spectral processing. This technique supported detection of covert features of body fluid signals, and then identified origins of body fluid stains on substrates. We discriminated between ATR FT-IR spectra of postmortem blood (PB) and those of antemortem blood (AB) by creating a multivariate statistics model. From ATR FT-IR spectra of PB and AB stains on interfering substrates (polyester, cotton, and denim), blood-originated signals were extracted by a weighted linear regression approach we developed originally using principal components of both blood and substrate spectra. The blood-originated signals were finally classified by the discriminant model, demonstrating high discriminant accuracy. The present method can identify body fluid evidence independently of the substrate type, which is expected to promote the application of vibrational spectroscopic techniques in forensic body fluid analysis.

CF2 Detection in Radio-Frequency Ar/CHF3 Plasmas by Fourier Transform Infrared Spectroscopy

NASA Technical Reports Server (NTRS)

Kim, J. S.; Rao, M. V. V. S.; Cappelli, M. A.; Sharma, S. P.

1999-01-01

CFx radicals, in particular CF2, are instrumental in anisotropic etching of SiO2. In order to optimize the CFx radical population in a given process environment, it is imperative that we understand their production mechanism. Towards this goal, we have conducted a series of quantitative measurements of CF2 radicals in low pressure RF plasmas similar to those used in SiO2 etching. In this study, we present preliminary results for Ar/CHF3 plasmas operating at pressures ranging from 10-50 mTorr and powers ranging from 100-500 W in the GEC reference cell, modified for inductive (transformer) coupling. Fourier transform infrared (FTIR) spectroscop) is used to observe the absorption features of the CF2 radical in the 1114 cm-1 and 1096 cm-1 spectral regions. The FTIR spectrometer is equipped with a high-sensitivity mercury cadmium telluride (MCT) detector and has afixed resolution of 0.125 cm- 1. The CF2 concentrations are measured for a range of operating pressures and discharge power levels, and are compared to measurements of the relative CF2 concentrations made by mass spectrometry using the method of appearance potential for radical selectivity.

Spectroscopic data for thermal infrared remote sensing

NASA Technical Reports Server (NTRS)

Varanasi, P.; Nemtchinov, V.; Li, Z.

1995-01-01

There has been extensive world-wide use of chloro-fluoro-carbons (CFC's), especially CFC-11 (CFCl3) and CFC-12 (CF2Cl2), hydro-chloro-fluoro-carbons (HCFC's), HCFC-22 (CHFCl2) in particular, and sulphur hexaflouride (SF6) in numerous many industrial applications. These chemicals possess either a strong ozone-depletion potential or a global-warming potential, or both, and pose a threat to the inhabitability of our planet. Recognition of this fact has led to significant curtailment, if not total banishment, of their use globally. However, as recent satellite observations have shown, decline in their atmospheric concentrations may not be immediate. The marked depletion of ozone which has been observed in recent years at high latitudes has made infrared remote sensing of the atmosphere an activity of high priority. The success of any infrared remote sensing experiment conducted in the atmosphere depends upon the availability of accurate, high-resolution, spectroscopic data that are applicable to that experiment. This paper presents a preliminary phase of a multi-faceted work using a Fourier-transform spectrometer (FTS) which is in progress in our laboratory. The concept of how laboratory-borne measurements can be geared toward obtaining a database that is directly applicable to satellite-borne remote sensing missions is the main thrust of this paper which addresses itself to ongoing or planned international space missions. Spectroscopic data on the unresolvable bands of the above mentioned as well as several other man-made gases and on the individual spectral lines of such naturally present trace gases as CO2, N2O, NH3, and CH4 are presented. There is often significant overlap between the isolated lines of better known bands of the more abundant species and the weaker absorption features identifiable as bands of the currently less abundant CFC's, HCFC's, and SF6.

Performance assessment and beamline diagnostics based on evaluation of temporal information from infrared spectral datasets by means of R Environment for statistical analysis.

PubMed

Banas, Krzysztof; Banas, Agnieszka; Gajda, Mariusz; Kwiatek, Wojciech M; Pawlicki, Bohdan; Breese, Mark B H

2014-07-15

Assessment of the performance and up-to-date diagnostics of scientific equipment is one of the key components in contemporary laboratories. Most reliable checks are performed by real test experiments while varying the experimental conditions (typically, in the case of infrared spectroscopic measurements, the size of the beam aperture, the duration of the experiment, the spectral range, the scanner velocity, etc.). On the other hand, the stability of the instrument response in time is another key element of the great value. Source stability (or easy predictable temporal changes, similar to those observed in the case of synchrotron radiation-based sources working in non top-up mode), detector stability (especially in the case of liquid nitrogen- or liquid helium-cooled detectors) should be monitored. In these cases, recorded datasets (spectra) include additional variables such as time stamp when a particular spectrum was recorded (in the case of time trial experiments). A favorable approach in evaluating these data is building hyperspectral object that consist of all spectra and all additional parameters at which these spectra were recorded. Taking into account that these datasets could be considerably large in size, there is a need for the tools for semiautomatic data evaluation and information extraction. A comprehensive R archive network--the open-source R Environment--with its flexibility and growing potential, fits these requirements nicely. In this paper, examples of practical implementation of methods available in R for real-life Fourier transform infrared (FTIR) spectroscopic data problems are presented. However, this approach could easily be adopted to many various laboratory scenarios with other spectroscopic techniques.

Evaluating the freezing impact on the proximate composition of immature cowpea (Vigna unguiculata L.) pods: classical versus spectroscopic approaches.

PubMed

Machado, Nelson; Oppolzer, David; Ramos, Ana; Ferreira, Luis; Rosa, Eduardo As; Rodrigues, Miguel; Domínguez-Perles, Raúl; Barros, Ana Irna

2017-10-01

Freezing represents a common conservation practice regarding vegetal foodstuffs. Since compositional features need to be monitored during storage, the development of rapid monitoring tools suitable for assessing nutritional characteristics arises as a pertinent issue. In this study, cowpea (Vigna unguiculata L.) pods, both fresh and after 6 and 9 months of freezing at -18 °C, were evaluated by high-performance liquid chromatography for their content of protein as well as of essential and nonessential amino acids, while their Fourier transform infrared spectra in the mid infrared (MIR) and near infrared (NIR) ranges were concomitantly registered to assess the feasibility of this approach for the traceability of these frozen matrices. For the NIR interval, the application of the 1st derivative to the spectral data retrieved the best results, while for lower concentrations the application of the Savitzky-Golay algorithm was indispensable to achieve quantification models for the amino acids. MIR is also suitable for this purpose, though being unable to quantify amino acids with concentrations below 0.07 mmol g -1 dry weight, irrespective of the data treatment used. The spectroscopic approach constitutes a methodology suitable for monitoring the impact of freezing on the nutritional properties of cowpea pods, allowing accurate quantification of the protein and amino acid contents, while NIR displayed better performance. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Fingerprinting malathion vapor: a simulant for VX nerve agent

NASA Astrophysics Data System (ADS)

Song, Renbo; Ding, Yujie J.; Zotova, Ioulia B.

2008-04-01

Being motivated by the possibility of fingerprinting and detecting VX nerve agent, we have investigated its stimulant, i.e. malathion vapor, which is less toxic and commercially available, in the far-infrared/THz transition region and THz frequency range. Such a spectroscopic study was carried out by using Fourier transform infrared spectroscopy (FTIR). Our intention is to obtain a specific spectroscopic signature of VX nerve agent as a chemical warfare agent. Following our experimental result, we have successfully observed eleven new absorption peaks from malathion vapor in the spectral ranges from 15 cm -1 to 68 cm -1 and from 75 cm -1 to 640 cm -1. Specifically, in the far-infrared/THz transition region, we have observed eight peaks and whereas in the THz region we have identified three relatively weak transition peaks. In addition, we have investigated the dependence of the absorption spectra on temperature in the range from room temperature to 60°C. In both of the frequency ranges, we have found that absorption coefficients significantly increase with increasing temperature. By comparing the transition peaks in the two frequency ranges, we have concluded that the frequency range of 400-640cm -1 is an optimal range for fingerprinting this chemical specie. We have designated two peaks for effectively and accurately identifying the VX nerve agents and one peak for differentiating between malathion and VX nerve agent.

Rapid authentication and identification of different types of A. roxburghii by Tri-step FT-IR spectroscopy

NASA Astrophysics Data System (ADS)

Chen, Ying; Huang, Jinfang; Yeap, Zhao Qin; Zhang, Xue; Wu, Shuisheng; Ng, Chiew Hoong; Yam, Mun Fei

2018-06-01

Anoectochilus roxburghii (Wall.) Lindl. (Orchidaceae) is a precious traditional Chinese medicinal herb and has been perennially used to treat various illness. However, there were unethical sellers who adulterated wild A. roxburghii with tissue cultured and cultivated ones. Therefore, there is an urgent need for an effective authentication method to differentiate between these different types of A. roxburghii. In this research, the infrared spectroscopic tri-step identification approach including Fourier transform infrared spectroscopy (FT-IR), Second derivative infrared spectra (SD-IR) and two-dimensional correlation infrared spectra (2D-IR) was used to develop a simple and rapid method to discriminate between wild, cultivated and tissue cultivated A. roxburghii plant. Through this study, all three types of A. roxburghii plant were successfully identified and discriminated through the infrared spectroscopic tri-step identification method. Besides that, all the samples of wild, cultivated and tissue cultivated A. roxburghii plant were analysed with the Soft Independent Modelling of Class Analogy (SIMCA) pattern recognition technique to test and verify the experimental results. The results showed that the three types of A. roxburghii can be discriminated clearly as the recognition rate was 100% for all three types and the rejection rate was more than 60%. 70% of the validated samples were also identified correctly by the SIMCA model. The SIMCA model was also validated by comparing 70 standard herbs to the model. As a result, it was demonstrated that the macroscopic IR fingerprint method and the classification analysis could discriminate not only between the A. roxburghi samples and the standard herbs, it could also distinguish between the three different types of A. roxburghi plant in a direct, rapid and holistic manner.

Rapid determination of sugar level in snack products using infrared spectroscopy.

PubMed

Wang, Ting; Rodriguez-Saona, Luis E

2012-08-01

Real-time spectroscopic methods can provide a valuable window into food manufacturing to permit optimization of production rate, quality and safety. There is a need for cutting edge sensor technology directed at improving efficiency, throughput and reliability of critical processes. The aim of the research was to evaluate the feasibility of infrared systems combined with chemometric analysis to develop rapid methods for determination of sugars in cereal products. Samples were ground and spectra were collected using a mid-infrared (MIR) spectrometer equipped with a triple-bounce ZnSe MIRacle attenuated total reflectance accessory or Fourier transform near infrared (NIR) system equipped with a diffuse reflection-integrating sphere. Sugar contents were determined using a reference HPLC method. Partial least squares regression (PLSR) was used to create cross-validated calibration models. The predictability of the models was evaluated on an independent set of samples and compared with reference techniques. MIR and NIR spectra showed characteristic absorption bands for sugars, and generated excellent PLSR models (sucrose: SEP < 1.7% and r > 0.96). Multivariate models accurately and precisely predicted sugar level in snacks allowing for rapid analysis. This simple technique allows for reliable prediction of quality parameters, and automation enabling food manufacturers for early corrective actions that will ultimately save time and money while establishing a uniform quality. The U.S. snack food industry generates billions of dollars in revenue each year and vibrational spectroscopic methods combined with pattern recognition analysis could permit optimization of production rate, quality, and safety of many food products. This research showed that infrared spectroscopy is a powerful technique for near real-time (approximately 1 min) assessment of sugar content in various cereal products. © 2012 Institute of Food Technologists®

Characterizing Nanophase Materials on Mars: Spectroscopic Studies of Allophane and Imogolite

NASA Technical Reports Server (NTRS)

Jeute, Thomas; Baker, Leslie; Bishop, Janice; Rampe, Elizabeth; Abidin, Zaenal

2017-01-01

Allophane is an amorphous or poorly crystalline hydrous aluminosilicate material. Allophane's chemical structure represents a hollow nanosphere, 5-6 nm in diameter with 4-7 large pores in the structure. Identification of allophane and other amorphous and nanophase minerals on Mars has provided clues about the aqueous geochemical environment there. These materials likely represent partially altered or leached basaltic ash and therefore, could represent a geologic marker for where water was present on the Martian surface; as well as indicate regions of climate change, where surface water was not present long enough or sufficiently warm to form clays. Characterization of these materials is important for increasing spectral recognition capabilities using visible/near-infrared (VNIR) and thermal infrared (TIR) spectra of Mars. A suite of synthetic allophane samples was created using a method that has been modified to produce allophane with Fe isomorphically substituted for Al in octahedral coordination. Compositions of the materials range from high-Si allophane (molar Al:Si = 1:2) to protoimogolite (Al:Si = 2:1), with Fe(3+) and Fe(2+) isomorphically substituted for Al from 0-10 mol% of total Al. These compositions span the range observed in natural terrestrial allophanes. Fe K-edge X-ray absorption spectroscopy provided information on the speciation and electrochemical and structural position of Fe in the framework. Fourier transform infrared spectroscopy confirmed syntheses and demonstrated changes in infrared spectroscopic signature with Fe substitution. VNIR reflectance spectra and TIR Thermal infrared emissivity spectra were also collected for direct comparison to Martian data. By increasing spectral recognition capacities of nanophase materials, more accurate estimates can be made on the aqueous geochemical environment of Mars.

Rapid authentication and identification of different types of A. roxburghii by Tri-step FT-IR spectroscopy.

PubMed

Chen, Ying; Huang, Jinfang; Yeap, Zhao Qin; Zhang, Xue; Wu, Shuisheng; Ng, Chiew Hoong; Yam, Mun Fei

2018-06-15

Anoectochilus roxburghii (Wall.) Lindl. (Orchidaceae) is a precious traditional Chinese medicinal herb and has been perennially used to treat various illness. However, there were unethical sellers who adulterated wild A. roxburghii with tissue cultured and cultivated ones. Therefore, there is an urgent need for an effective authentication method to differentiate between these different types of A. roxburghii. In this research, the infrared spectroscopic tri-step identification approach including Fourier transform infrared spectroscopy (FT-IR), Second derivative infrared spectra (SD-IR) and two-dimensional correlation infrared spectra (2D-IR) was used to develop a simple and rapid method to discriminate between wild, cultivated and tissue cultivated A. roxburghii plant. Through this study, all three types of A. roxburghii plant were successfully identified and discriminated through the infrared spectroscopic tri-step identification method. Besides that, all the samples of wild, cultivated and tissue cultivated A. roxburghii plant were analysed with the Soft Independent Modelling of Class Analogy (SIMCA) pattern recognition technique to test and verify the experimental results. The results showed that the three types of A. roxburghii can be discriminated clearly as the recognition rate was 100% for all three types and the rejection rate was more than 60%. 70% of the validated samples were also identified correctly by the SIMCA model. The SIMCA model was also validated by comparing 70 standard herbs to the model. As a result, it was demonstrated that the macroscopic IR fingerprint method and the classification analysis could discriminate not only between the A. roxburghi samples and the standard herbs, it could also distinguish between the three different types of A. roxburghi plant in a direct, rapid and holistic manner. Copyright © 2018 Elsevier B.V. All rights reserved.

Pressure Sounding of the Middle Atmosphere from ATMOS Solar Occultation Measurements of Atmospheric CO(sub 2) Absorption Lines

NASA Technical Reports Server (NTRS)

Abrams, M.; Gunson, M.; Lowes, L.; Rinsland, C.; Zander, R.

1994-01-01

A method for retrieving the atmospheric pressure corresponding to the tangent point of an infrared spectrum recorded in the solar occultation mode is described and applied to measurements made by the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer. Tangent pressure values are inferred from measurements of isolated CO(sub 2) lines with temperature-insensitive intensities. Tangent pressures are determined with a spectroscopic precision of 1-3%, corresponding to a tangent point height precision, depending on the scale height, of 70-210 meters.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tiwari, Pragya; Srivastava, A. K.; Khattak, B. Q.

Polymethyl methacrylate (PMMA) is characterized for electron beam interactions in the resist layer in lithographic applications. PMMA thin films (free standing) were prepared by solvent casting method. These films were irradiated with 30keV electron beam at different doses. Structural and chemical properties of the films were studied by means of X-ray diffraction and Fourier transform infra-red (FTIR) spectroscopy The XRD results showed that the amorphization increases with electron beam irradiation dose. FTIR spectroscopic analysis reveals that electron beam irradiation promotes the scission of carbonyl group and depletes hydrogen and converts polymeric structure into hydrogen depleted carbon network.

THESIS: terrestrial and habitable zone infrared spectroscopy spacecraft

NASA Astrophysics Data System (ADS)

Vasisht, G.; Swain, M. R.; Akeson, R. L.; Burrows, A.; Deming, D.; Grillmair, C. J.; Greene, T. P.

2008-07-01

THESIS is a concept for a medium class mission designed for spectroscopic characterization of extrasolar planets between 2-14 microns. The concept leverages off the recent first-steps made by Spitzer and Hubble in characterizing the atmospheres of alien gas giants. Under favourable circumstances, THESIS is capable of identifying biogenic molecules in habitable-zone planets, thereby determining conditions on worlds where life might exist. By systematically characterizing many worlds, from rocky planets to gas-giants, THESIS would deliver transformational science of profound interest to astronomers and the general public.

Novel Molecular Spectroscopic Multimethod Approach for Monitoring Water Absorption/Desorption Kinetics of CAD/CAM Poly(Methyl Methacrylate) Prosthodontics.

PubMed

Wiedemair, Verena; Mayr, Sophia; Wimmer, Daniel S; Köck, Eva Maria; Penner, Simon; Kerstan, Andreas; Steinmassl, Patricia-Anca; Dumfahrt, Herbert; Huck, Christian W

2017-07-01

Water absorbed to poly(methyl methacrylate) (PMMA)-based CAD/CAM (computer-assisted design/computer-assisted manufacturing) prosthodontics can alter their properties including hardness and stability. In the present contribution, water absorption and desorption kinetics under defined experimental conditions were monitored employing several supplementary and advanced Fourier transform infrared (FT-IR) spectroscopic techniques in combination with multivariate analysis (MVA). In this synergistic vibrational spectroscopic multimethod approach, first a novel near-infrared (NIR) diffuse fiber optic probe reflection spectroscopic method was established for time-resolved analysis of water uptake within seven days under controlled conditions. Near-infrared water absorbance spectra in a wavenumber range between 5288-5100 cm -1 (combination band) and 5424-5352 cm -1 (second overtone) were used establishing corresponding calibration and validation models to quantify the amount of water in the milligram range. Therefore, 14 well-defined samples exposed to prior optimized experimental conditions were taken into consideration. The average daily water uptake conducting reference analysis was calculated as 22 mg/day for one week. Additionally, in this study for the first time NIR two-dimensional correlation spectroscopy (2D-COS) was conducted to monitor and interpret the spectral dynamics of water absorption on the prosthodontics in a wavenumber range of 5100-5300 cm -1 . For sensitive time-resolved recording of water desorption, a recently developed high-temperature, high-pressure FT-IR reaction cell with water-free ultra-dry in situ and operando operation was applied. The reaction cell, as well as the sample holder, was fully made of quartz glass, with no hot metal or ceramic parts in the vicinity of the high temperature zone. Applying a temperature gradient in the range of 25-150 ℃, mid-infrared (MIR) 2D-COS was successfully conducted to get insights into the dynamic behavior of O-H (1400-1800 cm -1 ) absorption bands with increasing temperature over time and the release of CO 2 (2450 cm -1 ) from the polymers. In addition, an ATR FT-IR imaging setup was optimized in order to investigate the surface homogeneity of the PMMA-based resins with a spatial resolution to 2 µm. From this vibrational spectroscopic multimethod approach and the collection of several analytical data, conclusions were drawn as to which degree the surface structure and/or its porosity have an impact onto the amount of water absorption.

Effect of Tourmaline-Doped on the Far Infrared Emission of Iron Ore Tailings Ceramics.

PubMed

Liu, Jie; Meng, Junping; Liang, Jinsheng; Zhang, Hongchen; Gu, Xiaoyang

2016-04-01

Iron ore tailings as secondary resources have been of great importance to many countries in the world. Their compositions are similar to that of infrared emission ceramics, but there are few reports about it. In addition, tourmaline has high infrared emission properties due to its unique structure. With the purpose of expanding functional utilization of iron ore tailings, as well as reducing the production cost of far infrared ceramics, a new kind of far infrared emission ceramics was prepared by using iron ore tailings, calcium carbonate, silica, and natural tourmaline. The ceramics powders were characterized by Fourier transform infrared spectroscope, X-ray diffraction and scanning electron microscopy, respectively. The results show that after being sintered at 1065 °C, the percentage of pseudobrookite and lattice strain of samples increased with increasing the elbaite content. Furthermore, the added tourmaline was conducive to the densification sintering of ceramics. The appearance of Li-O vibration at 734.73 cm-1, as well as the strengthened Fe-O vibration at 987.68 cm-1 were attributed to the formation of Li0.375Fe1.23Ti1.4O5 solid solution, which led the average far infrared emissivity of ceramics increase from 0.861 to 0.906 within 8-14 µm.

Near infrared cavity enhanced absorption spectra of atmospherically relevant ether-1, 4-Dioxane.

PubMed

Chandran, Satheesh; Varma, Ravi

2016-01-15

1, 4-Dioxane (DX) is a commonly found ether in industrially polluted atmosphere. The near infrared absorption spectra of this compound has been recorded in the region 5900-8230 cm(-1) with a resolution of 0.08 cm(-1) using a novel Fourier transform incoherent broadband cavity-enhanced absorption spectrometer (FT-IBBCEAS). All recorded spectra were found to contain regions that are only weakly perturbed. The possible combinations of fundamental modes and their overtone bands corresponding to selected regions in the measured spectra are tabulated. Two interesting spectral regions were identified as 5900-6400 cm(-1) and 8100-8230 cm(-1). No significant spectral interference due to presence of water vapor was observed suggesting the suitability of these spectral signatures for spectroscopic in situ detection of DX. The technique employed here is much more sensitive than standard Fourier transform spectrometer measurements on account of long effective path length achieved. Hence significant enhancement of weaker absorption lines above the noise level was observed as demonstrated by comparison with an available measurement from database. Copyright © 2015 Elsevier B.V. All rights reserved.

Spectroscopic signature of mouse embryonic stem cell-derived hepatocytes using synchrotron Fourier transform infrared microspectroscopy

NASA Astrophysics Data System (ADS)

Thumanu, Kanjana; Tanthanuch, Waraporn; Ye, Danna; Sangmalee, Anawat; Lorthongpanich, Chanchao; Parnpai, Rangsun; Heraud, Philip

2011-05-01

Stem cell-based therapy for liver regeneration has been proposed to overcome the persistent shortage in the supply of suitable donor organs. A requirement for this to succeed is to find a rapid method to detect functional hepatocytes, differentiated from embryonic stem cells. We propose Fourier transform infrared (FTIR) microspectroscopy as a versatile method to identify the early and last stages of the differentiation process leading to the formation of hepatocytes. Using synchrotron-FTIR microspectroscopy, the means of identifying hepatocytes at the single-cell level is possible and explored. Principal component analysis and subsequent partial least-squares (PLS) discriminant analysis is applied to distinguish endoderm induction from hepatic progenitor cells and matured hepatocyte-like cells. The data are well modeled by PLS with endoderm induction, hepatic progenitor cells, and mature hepatocyte-like cells able to be discriminated with very high sensitivity and specificity. This method provides a practical tool to monitor endoderm induction and has the potential to be applied for quality control of cell differentiation leading to hepatocyte formation.

Infrared and laser-Raman spectroscopic studies of thermally-induced globular protein gels.

PubMed

Clark, A H; Saunderson, D H; Suggett, A

1981-03-01

Infrared and laser-Raman spectroscopy have been used to follow secondary structure changes during the heat-set gelation of a number of aqueous (D2O) globular protein solutions. Measurements of the infrared Amide I' absorption band around 1650 cm-1, for BSA gels of varying clarity and texture, have shown that the very considerable variations in network structure underlying these materials are not reflected in obvious differences in secondary structure. In all cases aggregation is accompanied by development of beta-sheet of a kind common in fibrous protein systems, but for BSA at least this does not appear to vary significantly in amount from one gel type to another. Infrared studies of gels formed from other protein systems have confirmed this tendency for beta-sheet to develop during aggregation, and the tendency is further substantiated by laser-Raman evidence which provides the extra information that in most of the examples studied alpha-helix content simultaneously falls. From these, and other observations, some generalisations are made about the thermally-induced sol-to-gel transformations of globular proteins.

Spectroscopic Investigation of the Primary Reaction Intermediates in the Oxidation of Levitated Droplets of Energetic Ionic Liquids.

PubMed

Brotton, Stephen J; Lucas, Michael; Chambreau, Steven D; Vaghjiani, Ghanshyam L; Yu, Jiang; Anderson, Scott L; Kaiser, Ralf I

2017-12-21

The production of the next generation of hypergolic, ionic-liquid-based fuels requires an understanding of the reaction mechanisms between the ionic liquid and oxidizer. We probed reactions between a levitated droplet of 1-methyl-4-amino-1,2,4-triazolium dicyanamide ([MAT][DCA]), with and without hydrogen-capped boron nanoparticles, and the nitrogen dioxide (NO 2 ) oxidizer. The apparatus exploits an ultrasonic levitator enclosed within a pressure-compatible process chamber equipped with complementary Raman, ultraviolet-visible, and Fourier-transform infrared (FTIR) spectroscopic probes. Vibrational modes were first assigned to the FTIR and Raman spectra of droplets levitated in argon. Spectra were subsequently collected for pure and boron-doped [MAT][DCA] exposed to nitrogen dioxide. By comparison with electronic structure calculations, some of the newly formed modes suggest that the N atom of the NO 2 molecule bonds to a terminal N on the dicyanamide anion yielding [O 2 N-NCNCN] - . This represents the first spectroscopic evidence of a key reaction intermediate in the oxidation of levitated ionic liquid droplets.

Integrated photonics for infrared spectroscopic sensing

NASA Astrophysics Data System (ADS)

Lin, Hongtao; Kita, Derek; Han, Zhaohong; Su, Peter; Agarwal, Anu; Yadav, Anupama; Richardson, Kathleen; Gu, Tian; Hu, Juejun

2017-05-01

Infrared (IR) spectroscopy is widely recognized as a gold standard technique for chemical analysis. Traditional IR spectroscopy relies on fragile bench-top instruments located in dedicated laboratory settings, and is thus not suitable for emerging field-deployed applications such as in-line industrial process control, environmental monitoring, and point-ofcare diagnosis. Recent strides in photonic integration technologies provide a promising route towards enabling miniaturized, rugged platforms for IR spectroscopic analysis. Chalcogenide glasses, the amorphous compounds containing S, Se or Te, have stand out as a promising material for infrared photonic integration given their broadband infrared transparency and compatibility with silicon photonic integration. In this paper, we discuss our recent work exploring integrated chalcogenide glass based photonic devices for IR spectroscopic chemical analysis, including on-chip cavityenhanced chemical sensing and monolithic integration of mid-IR waveguides with photodetectors.

Predictive evaluation of pharmaceutical properties of direct compression tablets containing theophylline anhydrate during storage at high humidity by near-infrared spectroscopy.

PubMed

Otsuka, Yuta; Yamamoto, Masahiro; Tanaka, Hideji; Otsuka, Makoto

2015-01-01

Theophylline anhydrate (TA) in tablet formulation is transformed into monohydrate (TH) at high humidity and the phase transformation affected dissolution behavior. Near-infrared spectroscopic (NIR) method is applied to predict the change of pharmaceutical properties of TA tablets during storage at high humidity. The tablet formulation containing TA, lactose, crystalline cellulose and magnesium stearate was compressed at 4.8 kN. Pharmaceutical properties of TA tables were measured by NIR, X-ray diffraction analysis, dissolution test and tablet hardness. TA tablet was almost 100% transformed into TH after 24 hours at RH 96%. The pharmaceutical properties of TA tablets, such as tablet hardness, 20 min dissolution amount (D20) and increase of tablet weight (TW), changed with the degree of hydration. Calibration models for TW, tablet hardness and D20 to predict the pharmaceutical properties at high-humidity conditions were developed on the basis of the NIR spectra by partial least squares regression analysis. The relationships between predicted and actual measured values for TW, tablet hardness and D20 had straight lines, respectively. From the results of NIR-chemometrics, it was confirmed that these predicted models had high accuracy to monitor the tablet properties during storage at high humidity.

The spectroscopic (FT-IR, FT-Raman, UV) and first order hyperpolarizability, HOMO and LUMO analysis of 3-aminobenzophenone by density functional method

NASA Astrophysics Data System (ADS)

Karabacak, M.; Kurt, M.; Cinar, M.; Ayyappan, S.; Sudha, S.; Sundaraganesan, N.

In this work, experimental and theoretical study on the molecular structure and the vibrational spectra of 3-aminobenzophenone (3-ABP) is presented. The vibrational frequencies of the title compound were obtained theoretically by DFT/B3LYP calculations employing the standard 6-311++G(d,p) basis set for optimized geometry and were compared with Fourier transform infrared spectrum (FTIR) in the region of 400-4000 cm-1 and with Fourier Transform Raman spectrum in the region of 50-4000 cm-1. Complete vibrational assignments, analysis and correlation of the fundamental modes for the title compound were carried out. The vibrational harmonic frequencies were scaled using scale factor, yielding a good agreement between the experimentally recorded and the theoretically calculated values.

Estimate of Radiosonde Dry Bias From Far-Infrared Measurements on the Antarctic Plateau

NASA Astrophysics Data System (ADS)

Rizzi, R.; Maestri, T.; Arosio, C.

2018-03-01

The experimental data set of downwelling radiance spectra measured at the ground in clear conditions during 2013 by a Far-Infrared Fourier Transform Spectrometer at Dome-C, Antarctica, presented in Rizzi et al. (2016, https://doi.org/10.1002/2016JD025341) is used to estimate the effect of solar heating of the radiosonde humidity sensor, called dry bias. The effect is quite evident comparing residuals for the austral summer and winter clear cases and can be modeled by an increase of the water vapor concentration at all levels by about 15%. Such an estimate has become possible only after a new version of the simulation code and spectroscopic data has become available, which has substantially improved the modeling of water vapor absorption in the far infrared. The negative yearly spectral bias reported in Rizzi et al. (2016, https://doi.org/10.1002/2016JD025341) is in fact greatly reduced when compared to the same measurement data set.

Thermal infrared near-field spectroscopy.

PubMed

Jones, Andrew C; Raschke, Markus B

2012-03-14

Despite the seminal contributions of Kirchhoff and Planck describing far-field thermal emission, fundamentally distinct spectral characteristics of the electromagnetic thermal near-field have been predicted. However, due to their evanescent nature their direct experimental characterization has remained elusive. Combining scattering scanning near-field optical microscopy with Fourier-transform spectroscopy using a heated atomic force microscope tip as both a local thermal source and scattering probe, we spectroscopically characterize the thermal near-field in the mid-infrared. We observe the spectrally distinct and orders of magnitude enhanced resonant spectral near-field energy density associated with vibrational, phonon, and phonon-polariton modes. We describe this behavior and the associated distinct on- and off-resonance nanoscale field localization with model calculations of the near-field electromagnetic local density of states. Our results provide a basis for intrinsic and extrinsic resonant manipulation of optical forces, control of nanoscale radiative heat transfer with optical antennas, and use of this new technique of thermal infrared near-field spectroscopy for broadband chemical nanospectroscopy. © 2012 American Chemical Society

Amino Acid and Peptide Immobilization on Oxidized Nanocellulose: Spectroscopic Characterization

PubMed Central

Barazzouk, Saïd; Daneault, Claude

2012-01-01

In this work, oxidized nanocellulose (ONC) was synthesized and chemically coupled with amino acids and peptides using a two step coupling method at room temperature. First, ONC was activated by N-ethyl-N’-(3-dimethylaminopropyl) carbodiimide hydrochloride, forming a stable active ester in the presence of N-hydroxysuccinimide. Second, the active ester was reacted with the amino group of the amino acid or peptide, forming an amide bond between ONC and the grafted molecule. Using this method, the intermolecular interaction of amino acids and peptides was avoided and uniform coupling of these molecules on ONC was achieved. The coupling reaction was very fast in mild conditions and without alteration of the polysaccharide. The coupling products (ONC-amino acids and ONC-peptides) were characterized by transmission electron microscopy and by the absorption, emission, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectroscopic techniques. PMID:28348303

Interaction of Sulforaphane with DNA and RNA

PubMed Central

Abassi Joozdani, Farzaneh; Yari, Faramarz; Abassi Joozdani, Parvaneh; Nafisi, Shohreh

2015-01-01

Sulforaphane (SFN) is an isothiocyanate found in cruciferous vegetables with anti-inflammatory, anti-oxidant and anti-cancer activities. However, the antioxidant and anticancer mechanism of sulforaphane is not well understood. In the present research, we reported binding modes, binding constants and stability of SFN–DNA and -RNA complexes by Fourier transform infrared (FTIR) and UV–Visible spectroscopic methods. Spectroscopic evidence showed DNA intercalation with some degree of groove binding. SFN binds minor and major grooves of DNA and backbone phosphate (PO2), while RNA binding is through G, U, A bases with some degree of SFN–phosphate (PO2) interaction. Overall binding constants were estimated to be K(SFN–DNA)=3.01 (± 0.035)×104 M-1 and K(SFN–RNA)= 6.63 (±0.042)×103 M-1. At high SFN concentration (SFN/RNA = 1/1), DNA conformation changed from B to A occurred, while RNA remained in A-family structure. PMID:26030290

A comparison of microscopic and spectroscopic identification methods for analysis of microplastics in environmental samples.

PubMed

Song, Young Kyoung; Hong, Sang Hee; Jang, Mi; Han, Gi Myung; Rani, Manviri; Lee, Jongmyoung; Shim, Won Joon

2015-04-15

The analysis of microplastics in various environmental samples requires the identification of microplastics from natural materials. The identification technique lacks a standardized protocol. Herein, stereomicroscope and Fourier transform infrared spectroscope (FT-IR) identification methods for microplastics (<1mm) were compared using the same samples from the sea surface microlayer (SML) and beach sand. Fragmented microplastics were significantly (p<0.05) underestimated and fiber was significantly overestimated using the stereomicroscope both in the SML and beach samples. The total abundance by FT-IR was higher than by microscope both in the SML and beach samples, but they were not significantly (p>0.05) different. Depending on the number of samples and the microplastic size range of interest, the appropriate identification method should be determined; selecting a suitable identification method for microplastics is crucial for evaluating microplastic pollution. Copyright © 2015 Elsevier Ltd. All rights reserved.

Supramolecular interactions of nonsteroidal anti-inflammatory drug in nanochannels of molecular containers: a spectroscopic, thermogravimetric and microscopic investigation.

PubMed

Maity, Banibrata; Chatterjee, Aninda; Ahmed, Sayeed Ashique; Seth, Debabrata

2014-11-10

Supramolecular host-guest complexation between the nonsteroidal anti-inflammatory drug indomethacin (IMC) and molecular containers were investigated. The weakly fluorescent drug molecule becomes highly fluorescent on complexation with different molecular containers, and time-resolved fluorescence emission spectroscopy reveals that the lifetime components of IMC significantly increase in the presence of molecular containers, compared with the lifetimes in neat water. The respective solid host-guest complexes were synthesised and characterised by Fourier transform infrared and (1) H nuclear magnetic resonance spectroscopic analysis. Microscopy techniques were used to analyse modifications of the surface morphology, owing to the formation of supramolecular complexes. The effect of the molecular container on the optical properties of IMC has also been investigated to determine the effect of nanochannels of different size and structure. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study of the interaction of deoxynivalenol with human serum albumin by spectroscopic technique and molecular modelling.

PubMed

Li, Yuqin; Wang, Hao; Jia, Baoxiu; Liu, Caihong; Liu, Ke; Qi, Yongxiu; Hu, Zhide

2013-01-01

The mechanism of interaction between deoxynivalenol (DON) and human serum albumin (HSA) was studied using spectroscopic methods including fluorescence spectra, UV-VIS, Fourier transform infrared (FT-IR) and circular dichroism (CD). The quenching mechanism was investigated in terms of the association constants, number of binding sites and basic thermodynamic parameters. The distance between the HSA donor and the acceptor DON was 2.80 nm as derived from fluorescence resonance energy transfer. The secondary structure compositions of free HSA and its DON complexes were estimated by the FT-IR spectra. Alteration of the secondary protein structure in the presence of DON was confirmed by UV-VIS and CD spectroscopy. Molecular modelling revealed that a DON-protein complex was stabilised by hydrophobic forces and hydrogen bonding. It was potentially useful for elucidating the toxigenicity of DON when combined with biomolecular function effect, transmembrane transport, toxicological testing and the other experiments.

Study of DNA-emodin interaction by FTIR and UV-vis spectroscopy.

PubMed

Saito, Samuel T; Silva, Givaldo; Pungartnik, Cristina; Brendel, Martin

2012-06-04

Emodin, a plant- and fungus-derived anthraquinone, exerts genotoxic and antioxidative effects and shows promise in antitumor and antibacterial therapies. The aim of this study was to examine the molecular interactions of emodin with DNA in aqueous solution at physiological pH using spectroscopic methods. Fourier Transform Infrared (FTIR) Spectroscopy and UV absorption spectra were used to determine the structural features, the binding mode and the association constants. Our UV-spectroscopic results indicate that emodin interacts with DNA by intercalation and by external binding. FTIR results suggest that emodin interaction occurs preferably via adenine and thymine base pairs and also weakly with the phosphate backbone of the DNA double helix. The binding constant for emodin-DNA complex formation is estimated to be K=5.59×10(3)M(-1). No significant changes of DNA conformation were observed upon emodin-DNA complexation. Copyright © 2012 Elsevier B.V. All rights reserved.

Chemical factor analysis of skin cancer FTIR-FEW spectroscopic data

NASA Astrophysics Data System (ADS)

Bruch, Reinhard F.; Sukuta, Sydney

2002-03-01

Chemical Factor Analysis (CFA) algorithms were applied to transform complex Fourier transform infrared fiberoptical evanescent wave (FTIR-FEW) normal and malignant skin tissue spectra into factor spaces for analysis and classification. The factor space approach classified melanoma beyond prior pathological classifications related to specific biochemical alterations to health states in cluster diagrams allowing diagnosis with more biochemical specificity, resolving biochemical component spectra and employing health state eigenvector angular configurations as disease state sensors. This study demonstrated a wealth of new information from in vivo FTIR-FEW spectral tissue data, without extensive a priori information or clinically invasive procedures. In particular, we employed a variety of methods used in CFA to select the rank of spectroscopic data sets of normal benign and cancerous skin tissue. We used the Malinowski indicator function (IND), significance level and F-Tests to rank our data matrices. Normal skin tissue, melanoma and benign tumors were modeled by four, two and seven principal abstract factors, respectively. We also showed that the spectrum of the first eigenvalue was equivalent to the mean spectrum. The graphical depiction of angular disparities between the first abstract factors can be adopted as a new way to characterize and diagnose melanoma cancer.

Infrared spectroscopic ellipsometry of micrometer-sized SiO2 line gratings

NASA Astrophysics Data System (ADS)

Walder, Cordula; Zellmeier, Matthias; Rappich, Jörg; Ketelsen, Helge; Hinrichs, Karsten

2017-09-01

For the design and process control of periodic nano-structured surfaces spectroscopic ellipsometry is already established in the UV-VIS spectral regime. The objective of this work is to show the feasibility of spectroscopic ellipsometry in the infrared, exemplarily, on micrometer-sized SiO2 line gratings grown on silicon wafers. The grating period ranges from 10 to about 34 μm. The IR-ellipsometric spectra of the gratings exhibit complex changes with structure variations. Especially in the spectral range of the oxide stretching modes, the presence of a Rayleigh singularity can lead to pronounced changes of the spectrum with the sample geometry. The IR-ellipsometric spectra of the gratings are well reproducible by calculations with the RCWA method (Rigorous Coupled Wave Analysis). Therefore, infrared spectroscopic ellipsometry allows the quantitative characterization and process control of micrometer-sized structures.

Applications of infrared photo-acoustic spectroscopy for wood samples

Treesearch

Mon-Lin Kuo; John F. McClelland; Siquan Luo; Po-Liang Chien; R.D. Walker; Chung-Yun Hse

1988-01-01

Various infrared (IR) spectroscopic techniques for the analysis of wood samples are briefly discussed. Theories and instrumentation of the newly developed photoacoustic spectroscopic (PAS) technique for measuring absorbance spectra of solids are presented. Some important applications of the PAS technique in wood science research are discussed. The application of the...

Infrared spectroscopic characterization of monocytic microvesicles (microparticles) released upon lipopolysaccharide stimulation.

PubMed

Lee, Joonsup; Wen, Beryl; Carter, Elizabeth A; Combes, Valery; Grau, Georges E R; Lay, Peter A

2017-07-01

Microvesicles (MVs) are involved in cell-cell interactions, including disease pathogenesis. Nondestructive Fourier-transform infrared (FTIR) spectra from MVs were assessed as a technique to provide new biochemical insights into a LPS-induced monocyte model of septic shock. FTIR spectroscopy provided a quick method to investigate relative differences in biomolecular content of different MV populations that was complementary to traditional semiquantitative omics approaches, with which it is difficult to provide information on relative changes between classes (proteins, lipids, nucleic acids, carbohydrates) or protein conformations. Time-dependent changes were detected in biomolecular contents of MVs and in the monocytes from which they were released. Differences in phosphatidylcholine and phosphatidylserine contents were observed in MVs released under stimulation, and higher relative concentrations of RNA and α-helical structured proteins were present in stimulated MVs compared with MVs from resting cells. FTIR spectra of stimulated monocytes displayed changes that were consistent with those observed in the corresponding MVs they released. LPS-stimulated monocytes had reduced concentrations of nucleic acids, α-helical structured proteins, and phosphatidylcholine compared with resting monocytes but had an increase in total lipids. FTIR spectra of MV biomolecular content will be important in shedding new light on the mechanisms of MVs and the different roles they play in physiology and disease pathogenesis.-Lee, J., Wen, B., Carter, E. A., Combes, V., Grau, G. E. R., Lay, P. A. Infrared spectroscopic characterization of monocytic microvesicles (microparticles) released upon lipopolysaccharide stimulation. © FASEB.

Non-opioid analgesic drug flupirtine: Spectral analysis, DFT computations, in vitro bioactivity and molecular docking study

NASA Astrophysics Data System (ADS)

Leenaraj, D. R.; Hubert Joe, I.

2017-06-01

Spectral features of non-opioid analgesic drug flupirtine have been explored by the Fourier transform infrared, Raman and Nuclear magnetic resonance spectroscopic techniques combined with density functional theory computations. The bioactive conformer of flupirtine is stabilized by an intramolecular Csbnd H⋯N hydrogen bonding resulting by the steric strain of hydrogen atoms. Natural bond orbital and natural population analysis support this result. The charge redistribution also has been analyzed. Antimicrobial activities of flupirtine have been screened by agar well disc diffusion and molecular docking methods, which exposes the importance of triaminopyridine in flupirtine.

Effect of γ-irradiation on commercial polypropylene based mono and multi-layered retortable food packaging materials

NASA Astrophysics Data System (ADS)

George, Johnsy; Kumar, R.; Sajeevkumar, V. A.; Sabapathy, S. N.; Vaijapurkar, S. G.; Kumar, D.; Kchawahha, A.; Bawa, A. S.

2007-07-01

Irradiation processing of food in the prepackaged form may affect chemical and physical properties of the plastic packaging materials. The effect of γ-irradiation doses (2.5-10.0 kGy) on polypropylene (PP)-based retortable food packaging materials, were investigated using Fourier transform infrared (FTIR) spectroscopic analysis, which revealed the changes happening to these materials after irradiation. The mechanical properties decreased with irradiation while oxygen transmission rate (OTR) was not affected significantly. Colour measurement indicated that Nylon 6 containing multilayer films became yellowish after irradiation. Thermal characterization revealed the changes in percentage crystallinity.

Spectroscopic characterization of nanohydroxyapatite synthesized by molten salt method.

PubMed

Gopi, D; Indira, J; Kavitha, L; Kannan, S; Ferreira, J M F

2010-10-01

Hydroxyapatite (HAP) nanopowders were synthesized by molten salt method at 260 degrees C. The as-prepared powders were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermo gravimetric analysis (TGA). With the aid of the obtained results the effect of calcining time on the crystallinity, size and morphology of HAP nanopowders is presented. The HAP nanopowders synthesized by molten salt method consist of pure phase of HAP without any impurities and showed the rod-like morphology without detectable decomposition up to 1100 degrees C. Copyright 2010 Elsevier B.V. All rights reserved.

Critical insight into the interaction of naringenin with human haemoglobin: A combined spectroscopic and computational modeling approaches

NASA Astrophysics Data System (ADS)

Maity, Subhajit; Chakraborty, Sandipan; Chakraborti, Abhay Sankar

2017-02-01

The present study demonstrates critical insight into the binding of a bioactive flavanone naringenin with normal human haemoglobin (NHb). Both spectrophotometric and spectrofluorimetric studies reveal that naringenin interacts with NHb. The binding affinity constant and number of binding sites appear to be approximately (1.5 ± 0.2) × 104 M-1 and 1, respectively. Static quenching seems to be an important factor in binding process, as evident from steady-state and time-resolved fluorescence spectroscopic studies. Far UV circular dichroism spectroscopy depicts that binding of naringenin to NHb causes no change in the secondary structure of the protein, which is also evident from Fourier transform infrared spectroscopic study. Free energy change (ΔG0) for naringenin-NHb interaction, determined by spectroscopic and isothermal calorimetric method, appears to be -5.67 kcal/mol and -6.90 kcal/mol, respectively, and is close to the docking energy -6.84 kcal/mol. Molecular docking suggests that naringenin binds near the cavity of the tetrameric heme protein, forming hydrogen bonds with surrounding amino acid residues. The binding site is away from the heme moieties, implicating naringenin binding does not affect the oxygen binding capacity of NHb, which makes the protein a suitable carrier of the flavonoid.

A NEAR-INFRARED SPECTROSCOPIC SURVEY OF COOL WHITE DWARFS IN THE SLOAN DIGITAL SKY SURVEY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kilic, Mukremin; Kowalski, Piotr M.; Von Hippel, Ted

2009-07-15

We present near-infrared photometric observations of 15 and spectroscopic observations of 38 cool white dwarfs (WDs). This is the largest near-infrared spectroscopic survey of cool WDs to date. Combining the Sloan Digital Sky Survey photometry and our near-infrared data, we perform a detailed model atmosphere analysis. The spectral energy distributions of our objects are explained fairly well by model atmospheres with temperatures ranging from 6300 K down to 4200 K. Two WDs show significant absorption in the infrared, and are best explained with mixed H/He atmosphere models. Based on the up-to-date model atmosphere calculations by Kowalski and Saumon, we findmore » that the majority of the stars in our sample have hydrogen-rich atmospheres. We do not find any pure helium atmosphere WDs below 5000 K, and we find a trend of increasing hydrogen to helium ratio with decreasing temperature. These findings present an important challenge to understanding the spectral evolution of WDs.« less

Separating and stabilizing phosphate from high-level radioactive waste: process development and spectroscopic monitoring.

PubMed

Lumetta, Gregg J; Braley, Jenifer C; Peterson, James M; Bryan, Samuel A; Levitskaia, Tatiana G

2012-06-05

Removing phosphate from alkaline high-level waste sludges at the Department of Energy's Hanford Site in Washington State is necessary to increase the waste loading in the borosilicate glass waste form that will be used to immobilize the highly radioactive fraction of these wastes. We are developing a process which first leaches phosphate from the high-level waste solids with aqueous sodium hydroxide, and then isolates the phosphate by precipitation with calcium oxide. Tests with actual tank waste confirmed that this process is an effective method of phosphate removal from the sludge and offers an additional option for managing the phosphorus in the Hanford tank waste solids. The presence of vibrationally active species, such as nitrate and phosphate ions, in the tank waste processing streams makes the phosphate removal process an ideal candidate for monitoring by Raman or infrared spectroscopic means. As a proof-of-principle demonstration, Raman and Fourier transform infrared (FTIR) spectra were acquired for all phases during a test of the process with actual tank waste. Quantitative determination of phosphate, nitrate, and sulfate in the liquid phases was achieved by Raman spectroscopy, demonstrating the applicability of Raman spectroscopy for the monitoring of these species in the tank waste process streams.

Mauna Kea Observatory infrared observations

NASA Technical Reports Server (NTRS)

Jefferies, J. T.

1974-01-01

Galactic and solar system infrared observations are reported using a broad variety of radiometric and spectroscopic instrumentation. Infrared programs and papers published during this period are listed.

High Resolution Spectroscopy to Support Atmospheric Measurements

NASA Technical Reports Server (NTRS)

Venkataraman, Malathy Devi

2003-01-01

Spectroscopic parameters (such as line position, intensity, broadening and shifting coefficients and their temperature dependences, line mixing coefficients etc.) for various molecular species of atmospheric interest are determined. In order to achieve these results, infrared spectra of several molecular bands are obtained using high-resolution recording instruments such as tunable diode laser spectrometer and Fourier transform spectrometers. Using sophisticated analysis routines (Multispectrum nonlinear least squares technique) these high-resolution infrared spectra are processed to determine the various spectral line parameters that are cited above. Spectra were taken using the McMath-Pierce Fourier transform spectrometer (FTS) at the National Solar Observatory on Kitt Peak, Arizona as well as the Bruker FTS at the Pacific Northwest National Laboratory (PNNL) at Richland, Washington. Most of the spectra are acquired not only at room temperature, but also at several different cold temperatures. This procedure is necessary to study the variation of the spectral line parameters as a function of temperature in order to simulate the Earth's and other planetary atmospheric environments. Depending upon the strength or weakness of the various bands recorded and analyzed, the length(s) of the absorption cells in which the gas samples under study are kept varied from a few centimeters up to several meters and the sample temperatures varied from approximately +30 C to -63 C. Research on several infrared bands of various molecular species and their isotopomers are undertaken. Those studies are briefly described.

Vibrational and spectroscopic investigation on the structure of 5H-dibenzo[b,f]azipine-5-carboxamide

NASA Astrophysics Data System (ADS)

Muthu, S.; Renuga, S.

2013-10-01

Fourier transform Raman and Fourier transform infrared spectra of 5H-dibenzo[b,f]azepine-5-carboxamide were recorded in the regions 4000-100 cm-1 and 4000-400 cm-1 respectively in the solid phase. 5H-dibenzo[b,f]azepine-5-carboxamide is typically used for the treatment of seizure disorders and neuropathic pain. The equilibrium geometry harmonic vibrational frequencies, infrared intensities and Raman scattering activities were calculated by density functional B3LYP/6-31G(d,p) method. A detailed interpretation of the vibrational spectra of this compound has been made on the basis of the calculated Potential energy distribution (PED). The thermodynamic functions of the title compound were also performed at the above methods and basis set. A detailed interpretation of the infrared and Raman spectra of 5H-dibenzo[b,f]azepine-5-carboxamide is reported. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The linear polarizability (α) and the first order hyperpolarizability (β) values of the investigated molecule have been computed using DFT quantum mechanical calculations. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The observed and calculated wave numbers are found to be in good agreement. The experimental spectra also coincide satisfactorily with those of theoretically constructed spectra.

Mid-infrared spectroscopic analysis of saccharides in aqueous solutions with sodium chloride.

PubMed

Kanou, Mikihito; Kameoka, Takaharu; Suehara, Ken-Ichiro; Hashimoto, Atsushi

2017-04-01

The infrared spectral characteristics of three different types of disaccharides (trehalose, maltose, and sucrose) and four different types of monosaccharides (glucose, mannose, galactose, and fructose) in aqueous solutions with sodium chloride (NaCl) were determined. The infrared spectra were obtained using the FT-IR/ATR method and the absorption intensities respected the interaction between the saccharide and water with NaCl were determined. This study also focused on not only the glycosidic linkage position and the constituent monosaccharides, but also the concentration of the saccharides and NaCl and found that they have a significant influence on the infrared spectroscopic characterization of the disaccharides in an aqueous solution with NaCl. The absorption intensities representing the interaction between a saccharide and water with NaCl were spectroscopically determined. Additionally, the applications of MIR spectroscopy to obtain information about saccharide-NaCl interactions in foods and biosystems were suggested.

Fourier transform infrared spectroscopic imaging parameters describing acid phosphate substitution in biologic hydroxyapatite.

PubMed

Spevak, Lyudmila; Flach, Carol R; Hunter, Tracey; Mendelsohn, Richard; Boskey, Adele

2013-05-01

Acid phosphate substitution into mineralized tissues is an important determinant of their mechanical properties and their response to treatment. This study identifies and validates Fourier transform infrared spectroscopic imaging (FTIRI) spectral parameters that provide information on the acid phosphate (HPO4) substitution into hydroxyapatite in developing mineralized tissues. Curve fitting and Fourier self-deconvolution were used to identify subband positions in model compounds (with and without HPO4). The intensity of subbands at 1127 and 1110 cm(-1) correlated with the acid phosphate content in these models. Peak height ratios of these subbands to the ν3 vibration at 1096 cm(-1) found in stoichiometric apatite were evaluated in the model compounds and mixtures thereof. FTIRI spectra of bones and teeth at different developmental ages were analyzed using these spectral parameters. Factor analysis (a chemometric technique) was also conducted on the tissue samples and resulted in factor loadings with spectral features corresponding to the HPO4 vibrations described above. Images of both factor correlation coefficients and the peak height ratios 1127/1096 and 1112/1096 cm(-1) demonstrated higher acid phosphate content in younger vs. more mature regions in the same specimen. Maps of the distribution of acid phosphate content will be useful for characterizing the extent of new bone formation, the areas of potential decreased strength, and the effects of therapies such as those used in metabolic bone diseases (osteoporosis, chronic kidney disease) on mineral composition. Because of the wider range of values obtained with the 1127/1096 cm(-1) parameter compared to the 1110/1096 cm(-1) parameter and the smaller scatter in the slope, it is suggested that this ratio should be the parameter of choice.

High Resolution Far Infrared Fourier Transform Spectroscopy of the NH_2 Radical.

NASA Astrophysics Data System (ADS)

Martin-Drumel, M. A.; Pirali, O.; Balcon, D.; Vervloet, M.

2011-06-01

First identified toward Sgr B2, the NH_2 radical has recently been detected in the interstellar medium by the HIFI instrument on board of Herschel. Despite the fact that this radical has not been detected in brown dwarfs and exoplanets yet, it is already included in physical and chemical models of those environments (temperature higher than 2000 K expected in several objects). Its detection in those objects will depend on the existence of a reliable high temperature and high resolution spectroscopic database on the NH_2 radical.The absorption spectrum of NH_2 has been recorded between 15 and 700 Cm-1 at the highest resolution available using the Bruker IFS125HR Fourier transform interferometer connected to the far infrared AILES beamline at SOLEIL (R=0.001 Cm-1). The radical was produced by an electrical discharge (DC) through a continuous flow of NH_3 and He using the White-type discharge cell developped on the beamline (optical path: 24m). Thanks to the brilliance of the synchrotron radiation, more than 700 pure rotational transitions of NH_2 have been identified with high N values (NMax=25) in its fundamental and first excited vibrational modes. By comparison to the previous FT spectroscopic study on that radical in the FIR spectral range, asymmetric splitting as well as fine and hyperfine structure have been resolved for several transitions. E. F. Van Dishoeck, D. J. Jansen, P. Schilke, T. G. Phillips The Astrophysical Journal 416, L83-L86 (1993) C. M. Persson, J. H. Black, J. Cernicharo et al. Astronomy and Astrophysics 521, L45 (2010) K. Lodders and B. Fegley, Jr Icarus 155, 393-424 (2002) I. Morino and K. Kawaguchi Journal of Molecular Spectroscopy 182, 428-438 (1997)

In-line Fourier-transform infrared spectroscopy as a versatile process analytical technology for preparative protein chromatography.

PubMed

Großhans, Steffen; Rüdt, Matthias; Sanden, Adrian; Brestrich, Nina; Morgenstern, Josefine; Heissler, Stefan; Hubbuch, Jürgen

2018-04-27

Fourier-transform infrared spectroscopy (FTIR) is a well-established spectroscopic method in the analysis of small molecules and protein secondary structure. However, FTIR is not commonly applied for in-line monitoring of protein chromatography. Here, the potential of in-line FTIR as a process analytical technology (PAT) in downstream processing was investigated in three case studies addressing the limits of currently applied spectroscopic PAT methods. A first case study exploited the secondary structural differences of monoclonal antibodies (mAbs) and lysozyme to selectively quantify the two proteins with partial least squares regression (PLS) giving root mean square errors of cross validation (RMSECV) of 2.42 g/l and 1.67 g/l, respectively. The corresponding Q 2 values are 0.92 and, respectively, 0.99, indicating robust models in the calibration range. Second, a process separating lysozyme and PEGylated lysozyme species was monitored giving an estimate of the PEGylation degree of currently eluting species with RMSECV of 2.35 g/l for lysozyme and 1.24 g/l for PEG with Q 2 of 0.96 and 0.94, respectively. Finally, Triton X-100 was added to a feed of lysozyme as a typical process-related impurity. It was shown that the species could be selectively quantified from the FTIR 3D field without PLS calibration. In summary, the proposed PAT tool has the potential to be used as a versatile option for monitoring protein chromatography. It may help to achieve a more complete implementation of the PAT initiative by mitigating limitations of currently used techniques. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Non linear optical studies on semiorganic single crystal: L-arginine 4-nitrophenalate 4-nitrophenol dihydrate (LAPP)

NASA Astrophysics Data System (ADS)

Mahadevan, M.; Sankar, P. K.; Vinitha, G.; Arivanandhan, M.; Ramachandran, K.; Anandan, P.

2017-07-01

L-arginine 4-nitrophenalate 4-nitrophenol dihydrate (LAPP) has been synthesized and grown by solution growth at room temperature using deionized water as a solvent. The various functional groups of the sample were identified by Fourier transform infra-red and Fourier transforms - Raman spectroscopic analyses. The Laser damage threshold of LAPP has been studied. Refractive index of LAPP single crystal was measured using Metricon prism coupler Instrument. The etching studies were carried out to study the quality of the grown crystals. The third order nonlinear optical properties of LAPP sample was analyzed by the Z-scan technique using 532 nm diode pumped CW Nd: YAG laser. The LAPP material exhibits negative optical nonlinearity. The results show that LAPP sample has potential applications in nonlinear optics and it can be exploited for optical limiting or switching.

Development of Single-Seed Near-Infrared Spectroscopic Predictions of Corn and Soybeans Constituents Using Bulk Teference Values and Mean Spectra

USDA-ARS?s Scientific Manuscript database

Near-Infrared reflectance spectroscopic prediction models were developed for common constituents of corn and soybeans using bulk reference values and mean spectra from single-seeds. The bulk reference model and a true single-seed model for soybean protein were compared to determine how well the bul...

High-Resolution Infrared Spectroscopy of Carbon-Sulfur Chains: II. C_5S and SC_5S

NASA Astrophysics Data System (ADS)

Thorwirth, Sven; Salomon, Thomas; Dudek, John B.

2016-06-01

Unbiased high-resolution infrared survey scans of the ablation products from carbon-sulfur targets in the 2100 to 2150 cm-1 regime reveal two bands previously not observed in the gas phase. On the basis of comparison against laboratory matrix-isolation work and new high-level quantum-chemical calculations these bands are attributed to the linear C_5S and SC_5S clusters. While polar C_5S was studied earlier using Fourier-transform microwave techniques, the present work marks the first gas-phase spectroscopic detection of SC_5S. H. Wang, J. Szczepanski, P. Brucat, and M. Vala 2005, Int. J. Quant. Chem. 102, 795 Y. Kasai, K. Obi, Y. Ohshima, Y. Hirahara, Y. Endo, K. Kawaguchi, and A. Murakami 1993, ApJ 410, L45 V. D. Gordon, M. C. McCarthy, A. J. Apponi, and P. Thaddeus 2001, ApJS 134, 311

Infrared Spectroscopic Study on Structural Change and Interfacial Interaction in Rubber Composites Filled with Silica-Kaolin Hybrid Fillers

NASA Astrophysics Data System (ADS)

Chen, Y.; Guan, J.; Hu, H.; Gao, H.; Zhang, L.

2016-07-01

A series of natural rubber/styrene butadiene rubber/polybutadiene rubber composites was prepared with nanometer silica and micron kaolin by a dry modification process, mechanical compounding, and mold vulcanization. Fourier transform infrared spectroscopy and a scanning electron microscope were used to investigate the structural changes and interfacial interactions in composites. The results showed that the "seesaw" structure was formed particularly with the incorporation of silica particles in the preparation process, which would be beneficial to the dispersibility of fillers in the rubber matrix. The kaolinite platelets were generally arranged in directional alignment. Kaolinite with smaller particle size and low-defect structure was more stable in preparation, but kaolinite with larger particle size and high defect structure tended to change the crystal structure. The composite prepared in this research exhibited excellent mechanical and thermal properties.

Raman and infrared spectroscopic investigations of a ferroelastic phase transition in B a2ZnTe O6 double perovskite

NASA Astrophysics Data System (ADS)

Moreira, Roberto L.; Lobo, Ricardo P. S. M.; Ramos, Sérgio L. L. M.; Sebastian, Mailadil T.; Matinaga, Franklin M.; Righi, Ariete; Dias, Anderson

2018-05-01

The low-temperature vibrational properties of B a2ZnTe O6 double-perovskite ceramics obtained by the solid-state route were investigated by Raman scattering and Fourier-transform infrared reflectivity. We found that this material undergoes a reversible ferroelastic phase transition at around 140 K, well compatible with a recently proposed rhombohedral-to-monoclinic structural change that would occur below 165 K. Complementary calorimetric measurements showed that the phase transition has a first-order character, with an entropy jump compatible with a displacive mechanism. The vibrational spectra show clearly the splitting of the doubly degenerate E modes into nondegenerate representations of the low-symmetry phase. In particular, the lowest-frequency Raman mode presents soft-mode behavior and splits below the critical temperature, confirming the in-plane ferroelastic deformation in the low-temperature phase.

Infrared spectroscopic investigation of erythrocyte membrane-smoke interactions due to chronic cigarette smoking.

PubMed

Sherif, Mahmoud S; Mervat, Ali A; Eman, Aly M

2017-07-01

Cigarette smoking is a serious health problem throughout the world, with a complicated and not totally clear bio-effect. In this study, erythrocytes were obtained from healthy male volunteers aged 22 ± 2 years and, the possible effects of three cigarette smoking rates namely 10, 15 and 20 cigarette/day on erythrocytes membrane characteristics were examined by Fourier transform infrared spectroscopy (FTIR). The results of this study indicate many smoking-dependent variations on erythrocytes membrane without an obvious dose-response relationship. There was disruption in the acyl chain packing; changes in membrane order and phases as well as membrane proteins becoming more folded. These physico-chemical changes should have an impact on the function of erythrocytes and may explain the complex interaction of cigarette smoke mainstream with erythrocyte membrane and to some extent clarify the pathological processes associated with cigarette smoking.

Pressure-induced polymerization of P(CN) 3

DOE PAGES

Gou, Huiyang; Yonke, Brendan L.; Epshteyn, Albert; ...

2015-05-21

Motivated to explore the formation of novel extended carbon-nitrogen solids via well-defined molecular precursor pathways, we studied the chemical reactivity of highly pure phosphorous tricyanide, P(CN) 3, under conditions of high pressure at room temperature. Raman and infrared (IR) spectroscopic measurements reveal a series of phase transformations below 10 GPa, and several low-frequency vibrational modes are reported for the first time. Synchrotron powder Xray diffraction (PXRD) measurements taken during compression show that molecular P(CN) 3 is highly compressible with a bulk modulus of 10.0±0.3 GPa and polymerizes into an amorphous solid above ~10.0 GPa. Raman and infrared (IR) spectra, togethermore » with first-principles molecular-dynamics simulations, show that the amorphization transition is associated with polymerization of the cyanide groups into CN bonds with predominantly sp 2 character, similar to known carbon nitrides, resulting in a novel PCN polymeric phase, which is recoverable to ambient pressure.« less

The Soleil View on Prototypical Organic Nitriles: Selected Vibrational Modes of Ethyl Cyanide, C_2H_5CN, and Spectroscopic Analysis Using AN Automated Spectral Assignment Procedure (asap)

NASA Astrophysics Data System (ADS)

Endres, Christian; Caselli, Paola; Martin-Drumel, Marie-Aline; McCarthy, Michael C.; Pirali, Olivier; Wehres, Nadine; Schlemmer, Stephan; Thorwirth, Sven

2016-06-01

Vibrational spectra of small organic nitriles, propionitrile and n-butyronitrile, have been investigated at high spectral resolution at the French national synchroton facility SOLEIL using Fourier-transform far-infrared spectroscopy (< 700 cm-1). The Automated Spectral Assignment Procedure (ASAP) has been used for line assignement and accurate determination of rotational level energies, in particular, of the ν20=1 and the ν12=1 states of propionitrile. The analysis does not only confirm the applicability of the ASAP in the treatment of (dense) high-resolution infrared spectra but also reveals some of its limitations which will be discussed in some detail. M. A. Martin-Drumel, C. P. Endres, O. Zingsheim, T. Salomon, J. van Wijngaarden, O. Pirali, S. Gruet, F. Lewen, S. Schlemmer, M. C. McCarthy, and S. Thorwirth 2015, J. Mol. Spectrosc. 315, 72

Potential of mid-infrared spectroscopy as a non-invasive diagnostic test in urine for endometrial or ovarian cancer.

PubMed

Paraskevaidi, Maria; Morais, Camilo L M; Lima, Kássio M G; Ashton, Katherine M; Stringfellow, Helen F; Martin-Hirsch, Pierre L; Martin, Francis L

2018-06-07

The current lack of an accurate, cost-effective and non-invasive test that would allow for screening and diagnosis of gynaecological carcinomas, such as endometrial and ovarian cancer, signals the necessity for alternative approaches. The potential of spectroscopic techniques in disease investigation and diagnosis has been previously demonstrated. Here, we used attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy to analyse urine samples from women with endometrial (n = 10) and ovarian cancer (n = 10), as well as from healthy individuals (n = 10). After applying multivariate analysis and classification algorithms, biomarkers of disease were pointed out and high levels of accuracy were achieved for both endometrial (95% sensitivity, 100% specificity; accuracy: 95%) and ovarian cancer (100% sensitivity, 96.3% specificity; accuracy 100%). The efficacy of this approach, in combination with the non-invasive method for urine collection, suggest a potential diagnostic tool for endometrial and ovarian cancers.

AKARI Infrared Camera Survey of the Large Magellanic Cloud

NASA Astrophysics Data System (ADS)

Shimonishi, Takashi; Kato, Daisuke; Ita, Yoshifusa; Onaka, Takashi

2015-08-01

The Large Magellanic Cloud (LMC) is one of the closest external galaxies to the Milky Way and has been playing a central role in various fields of modern astronomy and astrophysics. We conducted an unbiased near- to mid-infrared imaging and spectroscopic survey of the LMC with the infrared satellite AKARI. An area of about 10 square degrees of the LMC was observed by five imaging bands (each centered at 3.2, 7, 11, 15, and 24 micron) and the low-resolution slitless prism spectroscopy mode (2--5 micron, R~20) equipped with the Infrared Camera on board AKARI. Based on the data obtained in the survey, we constructed the photometric and spectroscopic catalogues of point sources in the LMC. The photometric catalogue includes about 650,000, 90,000, 49,000, 17,000, 7,000 sources at 3.2, 7, 11, 15, and 24 micron, respectively (Ita et al. 2008, PASJ, 60, 435; Kato et al. 2012, AJ, 144, 179), while the spectroscopic catalogue includes 1,757 sources (Shimonishi et al. 2013, AJ, 145, 32). Both catalogs are publicly released and available through a website (AKARI Observers Page, http://www.ir.isas.ac.jp/AKARI/Observation/). The catalog includes various infrared sources such as young stellar objects, asymptotic giant branch stars, giants/supergiants, and many other cool or dust-enshrouded stars. A large number of near-infrared spectral data, coupled with complementary broadband photometric data, allow us to investigate infrared spectral features of sources by comparison with their spectral energy distributions. Combined use of the present AKARI LMC catalogues with other infrared catalogues such as SAGE and HERITAGE possesses scientific potential that can be applied to various astronomical studies. In this presentation, we report the details of the AKARI photometric and spectroscopic catalogues of the LMC.

Qualitative and quantitative analysis of ochratoxin A contamination in green coffee beans using Fourier transform near infrared spectroscopy.

PubMed

Taradolsirithitikul, Panchita; Sirisomboon, Panmanas; Dachoupakan Sirisomboon, Cheewanun

2017-03-01

Ochratoxin A (OTA) contamination is highly prevalent in a variety of agricultural products including the commercially important coffee bean. As such, rapid and accurate detection methods are considered necessary for the identification of OTA in green coffee beans. The goal of this research was to apply Fourier transform near infrared spectroscopy to detect and classify OTA contamination in green coffee beans in both a quantitative and qualitative manner. PLSR models were generated using pretreated spectroscopic data to predict the OTA concentration. The best model displayed a correlation coefficient (r) of 0.814, a standard error of prediction (SEP and bias of 1.965 µg kg -1 and 0.358 µg kg -1 , respectively. Additionally, a PLS-DA model was also generated, displaying a classification accuracy of 96.83% for a non-OTA contaminated model and 80.95% for an OTA contaminated model, with an overall classification accuracy of 88.89%. The results demonstrate that the developed model could be used for detecting OTA contamination in green coffee beans in either a quantitative or qualitative manner. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Cloud point extraction and diffuse reflectance-Fourier transform infrared spectroscopic determination of chromium(VI): A probe to adulteration in food stuffs.

PubMed

Tiwari, Swapnil; Deb, Manas Kanti; Sen, Bhupendra K

2017-04-15

A new cloud point extraction (CPE) method for the determination of hexavalent chromium i.e. Cr(VI) in food samples is established with subsequent diffuse reflectance-Fourier transform infrared (DRS-FTIR) analysis. The method demonstrates enrichment of Cr(VI) after its complexation with 1,5-diphenylcarbazide. The reddish-violet complex formed showed λ max at 540nm. Micellar phase separation at cloud point temperature of non-ionic surfactant, Triton X-100 occurred and complex was entrapped in surfactant and analyzed using DRS-FTIR. Under optimized conditions, the limit of detection (LOD) and quantification (LOQ) were 1.22 and 4.02μgmL -1 , respectively. Excellent linearity with correlation coefficient value of 0.94 was found for the concentration range of 1-100μgmL -1 . At 10μgmL -1 the standard deviation for 7 replicate measurements was found to be 0.11μgmL -1 . The method was successfully applied to commercially marketed food stuffs, and good recoveries (81-112%) were obtained by spiking the real samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Application of Fourier transform infrared spectroscopy with chemometrics on postmortem interval estimation based on pericardial fluids.

PubMed

Zhang, Ji; Li, Bing; Wang, Qi; Wei, Xin; Feng, Weibo; Chen, Yijiu; Huang, Ping; Wang, Zhenyuan

2017-12-21

Postmortem interval (PMI) evaluation remains a challenge in the forensic community due to the lack of efficient methods. Studies have focused on chemical analysis of biofluids for PMI estimation; however, no reports using spectroscopic methods in pericardial fluid (PF) are available. In this study, Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance (ATR) accessory was applied to collect comprehensive biochemical information from rabbit PF at different PMIs. The PMI-dependent spectral signature was determined by two-dimensional (2D) correlation analysis. The partial least square (PLS) and nu-support vector machine (nu-SVM) models were then established based on the acquired spectral dataset. Spectral variables associated with amide I, amide II, COO - , C-H bending, and C-O or C-OH vibrations arising from proteins, polypeptides, amino acids and carbohydrates, respectively, were susceptible to PMI in 2D correlation analysis. Moreover, the nu-SVM model appeared to achieve a more satisfactory prediction than the PLS model in calibration; the reliability of both models was determined in an external validation set. The study shows the possibility of application of ATR-FTIR methods in postmortem interval estimation using PF samples.

[Measurements of stable isotopes in atmospheric CO2 and H2O by open-path Fourier transform infrared spectrometry].

PubMed

Wang, Wei; Liu, Wen-Qing; Zhang, Tian-Shu

2013-08-01

The development of spectroscopic techniques has offered continuous measurement of stable isotopes in the ambient air. The method of measuring environmental stable isotopes based on Fourier transform infrared spectrometry (FTIR) is described. In order to verify the feasibility of the method for continuous measurement of the stable isotopes, an open-path FTIR system was used to measure stable isotopes of CO2 and H2O in ambient air directly in a seven-day field experiment, including 12CO2, 3CO2, H2 16O and HD16 O. Also, the time course of carbon isotopic ratio delta13 C and deuterium isotope composition deltaD was calculated. The measurement precision is about 1.08 per thousand for delta13 C and 1.32 per thousand for deltaD. The measured stable isotopes of CO2 and H2O were analyzed on different time scales by Keeling plot methods, and the deuterium isotopic ratios of evapotranspiration were determined. The results of the field experiment demonstrate the potential of the open-path FTIR system for continuous measurement of stable isotopes in the air.

Evaluation of the microscopic distribution of florfenicol in feed pellets for salmon by Fourier Transform infrared imaging and multivariate analysis.

PubMed

Bastidas, Camila Y; von Plessing, Carlos; Troncoso, José; Del P Castillo, Rosario

2018-04-15

Fourier Transform infrared imaging and multivariate analysis were used to identify, at the microscopic level, the presence of florfenicol (FF), a heavily-used antibiotic in the salmon industry, supplied to fishes in feed pellets for the treatment of salmonid rickettsial septicemia (SRS). The FF distribution was evaluated using Principal Component Analysis (PCA) and Augmented Multivariate Curve Resolution with Alternating Least Squares (augmented MCR-ALS) on the spectra obtained from images with pixel sizes of 6.25 μm × 6.25 μm and 1.56 μm × 1.56 μm, in different zones of feed pellets. Since the concentration of the drug was 3.44 mg FF/g pellet, this is the first report showing the powerful ability of the used of spectroscopic techniques and multivariate analysis, especially the augmented MCR-ALS, to describe the FF distribution in both the surface and inner parts of feed pellets at low concentration, in a complex matrix and at the microscopic level. The results allow monitoring the incorporation of the drug into the feed pellets. Copyright © 2018 Elsevier B.V. All rights reserved.

Nondestructive Handheld Fourier Transform Infrared (FT-IR) Analysis of Spectroscopic Changes and Multivariate Modeling of Thermally Degraded Plain Portland Cement Concrete and its Slag and Fly Ash-Based Analogs.

PubMed

Leung Tang, Pik; Alqassim, Mohammad; Nic Daéid, Niamh; Berlouis, Leonard; Seelenbinder, John

2016-05-01

Concrete is by far the world's most common construction material. Modern concrete is a mixture of industrial pozzolanic cement formulations and aggregate fillers. The former acts as the glue or binder in the final inorganic composite; however, when exposed to a fire the degree of concrete damage is often difficult to evaluate nondestructively. Fourier transform infrared (FT-IR) spectroscopy through techniques such as transmission, attenuated total reflectance, and diffuse reflectance have been rarely used to evaluate thermally damaged concrete. In this paper, we report on a study assessing the thermal damage of concrete via the use of a nondestructive handheld FT-IR with a diffuse reflectance sample interface. In situ measurements can be made on actual damaged areas, without the need for sample preparation. Separate multivariate models were developed to determine the equivalent maximal temperature endured for three common industrial concrete formulations. The concrete mixtures were successfully modeled displaying high predictive power as well as good specificity. This has potential uses in forensic investigation and remediation services particularly for fires in buildings. © The Author(s) 2016.

Applications of free-electron lasers to measurements of energy transfer in biopolymers and materials

NASA Astrophysics Data System (ADS)

Edwards, Glenn S.; Johnson, J. B.; Kozub, John A.; Tribble, Jerri A.; Wagner, Katrina

1992-08-01

Free-electron lasers (FELs) provide tunable, pulsed radiation in the infrared. Using the FEL as a pump beam, we are investigating the mechanisms for energy transfer between localized vibrational modes and between vibrational modes and lattice or phonon modes. Either a laser-Raman system or a Fourier transform infrared (FTIR) spectrometer will serve as the probe beam, with the attribute of placing the burden of detection on two conventional spectroscopic techniques that circumvent the limited response of infrared detectors. More specifically, the Raman effect inelastically shifts an exciting laser line, typically a visible frequency, by the energy of the vibrational mode; however, the shifted Raman lines also lie in the visible, allowing for detection with highly efficient visible detectors. With regards to FTIR spectroscopy, the multiplex advantage yields a distinct benefit for infrared detector response. Our group is investigating intramolecular and intermolecular energy transfer processes in both biopolymers and more traditional materials. For example, alkali halides contain a number of defect types that effectively transfer energy in an intermolecular process. Similarly, the functioning of biopolymers depends on efficient intramolecular energy transfer. Understanding these mechanisms will enhance our ability to modify biopolymers and materials with applications to biology, medecine, and materials science.

Cassini infrared Fourier spectroscopic investigation

NASA Astrophysics Data System (ADS)

Kunde, Virgil G.; Ade, Peter A.; Barney, Richard D.; Bergman, D.; Bonnal, Jean-Francois; Borelli, R.; Boyd, D.; Brasunas, John C.; Brown, G.; Calcutt, S. B.; Carroll, F.; Courtin, R.; Cretolle, Jacky; Crooke, Julie A.; Davis, Martin A.; Edberg, S.; Fettig, R.; Flasar, M.; Glenar, David A.; Graham, S.; Hagopian, John G.; Hakun, C. F.; Hayes, Patricia A.; Herath, L.; Horn, Linda; Jennings, Donald E.; Karpati, G.; Kellebenz, C.; Lakew, Brook; Lindsay, J.; Lohr, J.; Lyons, James J.; Martineau, Robert J.; Martino, Anthony J.; Matsumura, M.; McCloskey, J.; Melak, T.; Michel, G.; Morell, Armando; Mosier, C.; Pack, L.; Plants, M.; Robinson, D.; Rodriguez, Louis; Romani, Paul; Schaefer, W. J.; Schmidt, Steve; Trujillo, C.; Vellacott, Tim; Wagner, K.; Yun, D.

1996-10-01

The composite infrared spectrometer (CIRS) is a remote sensing instrument to be flown on the Cassini orbiter. CIRS will retrieve vertical profiles of temperature and gas composition for the atmospheres of Titan and Saturn, from deep in their tropospheres to high in their stratospheres. CIRS will also retrieve information on the thermal properties and composition of Saturn's rings and Saturnian satellites. CIRS consists of a pair of Fourier Transform Spectrometers (FTSs) which together cover the spectral range from 10-1400 cm-1 with a spectral resolution up to 0.5 cm-1. The two interferometers share a 50 cm beryllium Cassegrain telescope. The far-infrared FTS is a polarizing interferometer covering the 10-600 cm-1 range with a pair of thermopile detectors, and a 3.9 mrad field of view. The mid-infrared FTS is a conventional Michelson interferometer covering 200-1400 cm-1 in two spectral bandpasses: 600-1100 cm- 1100-1400 cm(superscript -1 with a 1 by 10 photovoltaic HgCdTe array. Each pixel of the arrays has an approximate 0.3 mrad field of view. The HgCdTe arrays are cooled to approximately 80K with a passive radiative cooler.

Combined spectroscopic imaging and chemometric approach for automatically partitioning tissue types in human prostate tissue biopsies

NASA Astrophysics Data System (ADS)

Haka, Abigail S.; Kidder, Linda H.; Lewis, E. Neil

2001-07-01

We have applied Fourier transform infrared (FTIR) spectroscopic imaging, coupling a mercury cadmium telluride (MCT) focal plane array detector (FPA) and a Michelson step scan interferometer, to the investigation of various states of malignant human prostate tissue. The MCT FPA used consists of 64x64 pixels, each 61 micrometers 2, and has a spectral range of 2-10.5 microns. Each imaging data set was collected at 16-1 resolution, resulting in 512 image planes and a total of 4096 interferograms. In this article we describe a method for separating different tissue types contained within FTIR spectroscopic imaging data sets of human prostate tissue biopsies. We present images, generated by the Fuzzy C-Means clustering algorithm, which demonstrate the successful partitioning of distinct tissue type domains. Additionally, analysis of differences in the centroid spectra corresponding to different tissue types provides an insight into their biochemical composition. Lastly, we demonstrate the ability to partition tissue type regions in a different data set using centroid spectra calculated from the original data set. This has implications for the use of the Fuzzy C-Means algorithm as an automated technique for the separation and examination of tissue domains in biopsy samples.

Vibrational analysis of carbonyl modes in different stages of light-induced cyclopyrimidine dimer repair reactions

NASA Astrophysics Data System (ADS)

Schmitz, Matthias; Tavan, Paul; Nonella, Marco

2001-11-01

The formation of cyclopyrimidine dimers is a DNA defect, which is repaired by the enzyme DNA photolyase in a light-induced reaction. Radical anions of the dimers have been suggested to occur as short-lived intermediates during repair. For their identification time-resolved Fourier-transform infrared (FTIR) spectroscopy will be a method of choice. To support and guide such spectroscopic studies we have calculated the vibrational spectra of various pyrimidine compounds using density functional methods. Our results suggest that the carbonyl vibrations of these molecules can serve as marker modes to identify and distinguish intermediates of the repair reaction.

Absolute band intensities in the nu19/nu23 (530 cm(-1)) and nu7 (777 cm(-1)) bands of acetone ((CH3)2CO) from 232 to 295 K

NASA Technical Reports Server (NTRS)

Wang, W. F.; Stevenson, A.; Reuter, D. C.; Sirota, J. M.

2000-01-01

Absolute band intensities of acetone ((CH3)2CO) in the nu19/nu23 and nu7 band systems near 530 and 777 cm(-1), respectively, were measured at temperatures of 232, 262 and 295 K, using a Fourier transform infrared (FTIR) spectrometer. No evident temperature dependence for the band intensities was observed. The dipole moments and the fundamental band intensities were derived in the harmonic oscillator approximation. The results are useful for the spectroscopic retrieval of acetone concentrations in the upper atmosphere.

Nano/Micro and Spectroscopic Approaches to Food Pathogen Detection

NASA Astrophysics Data System (ADS)

Cho, Il-Hoon; Radadia, Adarsh D.; Farrokhzad, Khashayar; Ximenes, Eduardo; Bae, Euiwon; Singh, Atul K.; Oliver, Haley; Ladisch, Michael; Bhunia, Arun; Applegate, Bruce; Mauer, Lisa; Bashir, Rashid; Irudayaraj, Joseph

2014-06-01

Despite continuing research efforts, timely and simple pathogen detection with a high degree of sensitivity and specificity remains an elusive goal. Given the recent explosion of sensor technologies, significant strides have been made in addressing the various nuances of this important global challenge that affects not only the food industry but also human health. In this review, we provide a summary of the various ongoing efforts in pathogen detection and sample preparation in areas related to Fourier transform infrared and Raman spectroscopy, light scattering, phage display, micro/nanodevices, and nanoparticle biosensors. We also discuss the advantages and potential limitations of the detection methods and suggest next steps for further consideration.

Molten salt-supported polycondensation of optically active diacid monomers with an aromatic thiazole-bearing diamine using microwave irradiation.

PubMed

Mallakpour, Shadpour; Zadehnazari, Amin

2014-05-01

Microwave heating was used to prepare optically active thiazole-bearing poly(amide-imide)s. Polymerization reactions were carried out in the molten tetrabutylammonium bromide as a green molten salt medium and triphenyl phosphite as the homogenizer. Structural elucidation of the compounds was performed by Fourier transform infrared and NMR spectroscopic data and elemental analysis results. The polymeric samples were readily soluble in various organic solvents, forming low-colored and flexible thin films via solution casting. They showed high thermal stability with decomposition temperature being above 360 °C. They were assembled randomly in a nanoscale size.

A diffuse reflectance infrared Fourier transform spectroscopic study of adsorbed hydrazines

NASA Technical Reports Server (NTRS)

Davis, Dennis D.; Kilduff, Jan E.; Koontz, Steven L.

1988-01-01

Diffuse reflectance spectroscopy of fuel hydrazines adsorbed on silica, silica-alumina and alimina surfaces indicates that the primary surface-hydrazine interaction is hydrogen bonding. Hydrazine, on adsorption to a deuterated silica surface, undergoes a rapid H/D exchange with deuterated surface silanol (Si-OD) groups. Adsorption equilibria are rapidly established at room temperature. Monomethylhydrazine and unsymmetrical dimethylhydrazine are similarly adsorbed. On adsorption, the C-H stretching and methyl deformation modes of the methylhydrazines are shifted to higher frequencies by 10 to 20 cm(-1). These shifts are postulated to be due to changes in the lone-pair electro-density on the adjacent nitrogen atom and an electronegativity effect.

Molten salt-supported polycondensation of optically active diacid monomers with an aromatic thiazole-bearing diamine using microwave irradiation

PubMed Central

Mallakpour, Shadpour; Zadehnazari, Amin

2013-01-01

Microwave heating was used to prepare optically active thiazole-bearing poly(amide-imide)s. Polymerization reactions were carried out in the molten tetrabutylammonium bromide as a green molten salt medium and triphenyl phosphite as the homogenizer. Structural elucidation of the compounds was performed by Fourier transform infrared and NMR spectroscopic data and elemental analysis results. The polymeric samples were readily soluble in various organic solvents, forming low-colored and flexible thin films via solution casting. They showed high thermal stability with decomposition temperature being above 360 °C. They were assembled randomly in a nanoscale size. PMID:25685498

Synthesis and optical properties of polycrystalline Li2Al2B2O7 (LABO)

NASA Astrophysics Data System (ADS)

Dagdale, S. R.; Muley, G. G.

2016-05-01

A polycrystalline lithium aluminum borate (Li2Al2B2O7, LABO) has been synthesized by using simple solid-state technique. The obtained LABO polycrystalline was characterized by powder X-ray diffraction; Fourier transform infrared (FT-IR) spectroscopy and second harmonic generation (SHG) efficiency measurement. The functional groups were identified using the FT-IR spectroscopic data. The SHG efficiency of the polycrystalline material was obtained by the classic Kurtz powder technique using a fundamental wavelength 1064 nm of Nd:YAG laser and it is found to be 1.4 times that of potassium dihydrogen phosphate (KDP).

Atmospheric and Spectroscopic Research in the Far Infrared

NASA Technical Reports Server (NTRS)

Park, Kwangjai

2001-01-01

The University of Oregon (UO) was a participant in a number of far infrared spectroscopic projects over the past three decades. These include Sub-millimeter Infrared Balloon Experiment (SIBEX), the Balloon Intercomparison Campaign (BIC), and the Infrared Balloon Experiment (IBEX). In addition to these field studies, the UO program contained a detector research component and a laboratory spectroscopy element. Through a productive collaboration with Dr. Carli's group in Italy, with Prof. Ade's group in England and with Dr. Chance of Harvard-Smithsonian, we have made substantial contributions to the development of far infrared spectroscopy as a mature measurement technology for the atmospheric science. This report summarizes the activities during the latest grant period, covering the span from February 22, 1998 to February 21, 2002.

Graphene-Based Platform for Infrared Near-Field Nanospectroscopy of Water and Biological Materials in an Aqueous Environment.

PubMed

Khatib, Omar; Wood, Joshua D; McLeod, Alexander S; Goldflam, Michael D; Wagner, Martin; Damhorst, Gregory L; Koepke, Justin C; Doidge, Gregory P; Rangarajan, Aniruddh; Bashir, Rashid; Pop, Eric; Lyding, Joseph W; Thiemens, Mark H; Keilmann, Fritz; Basov, D N

2015-08-25

Scattering scanning near-field optical microscopy (s-SNOM) has emerged as a powerful nanoscale spectroscopic tool capable of characterizing individual biomacromolecules and molecular materials. However, applications of scattering-based near-field techniques in the infrared (IR) to native biosystems still await a solution of how to implement the required aqueous environment. In this work, we demonstrate an IR-compatible liquid cell architecture that enables near-field imaging and nanospectroscopy by taking advantage of the unique properties of graphene. Large-area graphene acts as an impermeable monolayer barrier that allows for nano-IR inspection of underlying molecular materials in liquid. Here, we use s-SNOM to investigate the tobacco mosaic virus (TMV) in water underneath graphene. We resolve individual virus particles and register the amide I and II bands of TMV at ca. 1520 and 1660 cm(-1), respectively, using nanoscale Fourier transform infrared spectroscopy (nano-FTIR). We verify the presence of water in the graphene liquid cell by identifying a spectral feature associated with water absorption at 1610 cm(-1).

A spectroscopic transfer standard for accurate atmospheric CO measurements

NASA Astrophysics Data System (ADS)

Nwaboh, Javis A.; Li, Gang; Serdyukov, Anton; Werhahn, Olav; Ebert, Volker

2016-04-01

Atmospheric carbon monoxide (CO) is a precursor of essential climate variables and has an indirect effect for enhancing global warming. Accurate and reliable measurements of atmospheric CO concentration are becoming indispensable. WMO-GAW reports states a compatibility goal of ±2 ppb for atmospheric CO concentration measurements. Therefore, the EMRP-HIGHGAS (European metrology research program - high-impact greenhouse gases) project aims at developing spectroscopic transfer standards for CO concentration measurements to meet this goal. A spectroscopic transfer standard would provide results that are directly traceable to the SI, can be very useful for calibration of devices operating in the field, and could complement classical gas standards in the field where calibration gas mixtures in bottles often are not accurate, available or stable enough [1][2]. Here, we present our new direct tunable diode laser absorption spectroscopy (dTDLAS) sensor capable of performing absolute ("calibration free") CO concentration measurements, and being operated as a spectroscopic transfer standard. To achieve the compatibility goal stated by WMO for CO concentration measurements and ensure the traceability of the final concentration results, traceable spectral line data especially line intensities with appropriate uncertainties are needed. Therefore, we utilize our new high-resolution Fourier-transform infrared (FTIR) spectroscopy CO line data for the 2-0 band, with significantly reduced uncertainties, for the dTDLAS data evaluation. Further, we demonstrate the capability of our sensor for atmospheric CO measurements, discuss uncertainty calculation following the guide to the expression of uncertainty in measurement (GUM) principles and show that CO concentrations derived using the sensor, based on the TILSAM (traceable infrared laser spectroscopic amount fraction measurement) method, are in excellent agreement with gravimetric values. Acknowledgement Parts of this work have been carried out within the European Metrology Research Programme (EMRP) ENV52 project-HIGHGAS (Metrology for high-impact greenhouse gases). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. References [1] EMRP project ENV52-HIGHGAS (Metrology for high-impact greenhouse gases), available at: http://www.euramet.org/. [2] J. Nwaboh, A. Manninen, J. Mohn, J. C. Petersen, O. Werhahn, and V.Ebert, European Geosciences Union General Assembly 2015, EGU2015-13542, 2015, Vienna Austria

Vibrational spectroscopy reveals the initial steps of biological hydrogen evolution† †Electronic supplementary information (ESI) available: Complementary resonance Raman and infrared spectroscopic data. See DOI: 10.1039/c6sc01098a Click here for additional data file.

PubMed Central

Katz, S.; Noth, J.; Shafaat, H. S.; Happe, T.; Hildebrandt, P.

2016-01-01

[FeFe] hydrogenases are biocatalytic model systems for the exploitation and investigation of catalytic hydrogen evolution. Here, we used vibrational spectroscopic techniques to characterize, in detail, redox transformations of the [FeFe] and [4Fe4S] sub-sites of the catalytic centre (H-cluster) in a monomeric [FeFe] hydrogenase. Through the application of low-temperature resonance Raman spectroscopy, we discovered a novel metastable intermediate that is characterized by an oxidized [FeIFeII] centre and a reduced [4Fe4S]1+ cluster. Based on this unusual configuration, this species is assigned to the first, deprotonated H-cluster intermediate of the [FeFe] hydrogenase catalytic cycle. Providing insights into the sequence of initial reaction steps, the identification of this species represents a key finding towards the mechanistic understanding of biological hydrogen evolution. PMID:28451119

Solution chemistry of carbonate minerals and its effects on the flotation of hematite with sodium oleate

NASA Astrophysics Data System (ADS)

Li, Dong; Yin, Wan-zhong; Xue, Ji-wei; Yao, Jin; Fu, Ya-feng; Liu, Qi

2017-07-01

The effects of carbonate minerals (dolomite and siderite) on the flotation of hematite using sodium oleate as a collector were investigated through flotation tests, supplemented by dissolution measurements, solution chemistry calculations, zeta-potential measurements, Fourier transform infrared (FTIR) spectroscopic studies, and X-ray photoelectron spectroscopy (XPS) analyses. The results of flotation tests show that the presence of siderite or dolomite reduced the recovery of hematite and that the inhibiting effects of dolomite were stronger. Dissolution measurements, solution chemistry calculations, and flotation tests confirmed that both the cations (Ca2+ and Mg2+) and CO3 2- ions dissolved from dolomite depressed hematite flotation, whereas only the CO3 2- ions dissolved from siderite were responsible for hematite depression. The zeta-potential, FTIR spectroscopic, and XPS analyses indicated that Ca2+, Mg2+, and CO3 2- (HCO3 -) could adsorb onto the hematite surface, thereby hindering the adsorption of sodium oleate, which was the main reason for the inhibiting effects of carbonate minerals on hematite flotation.

Spectroscopic studies of anthracyclines: Structural characterization and in vitro tracking

NASA Astrophysics Data System (ADS)

Szafraniec, Ewelina; Majzner, Katarzyna; Farhane, Zeineb; Byrne, Hugh J.; Lukawska, Malgorzata; Oszczapowicz, Irena; Chlopicki, Stefan; Baranska, Malgorzata

2016-12-01

A broad spectroscopic characterization, using ultraviolet-visible (UV-vis) and Fourier transform infrared absorption as well as Raman scattering, of two commonly used anthracyclines antibiotics (DOX) daunorubicin (DNR), their epimers (EDOX, EDNR) and ten selected analogs is presented. The paper serves as a comprehensive spectral library of UV-vis, IR and Raman spectra of anthracyclines in the solid state and in solution. The particular advantage of Raman spectroscopy for the measurement and analysis of individual antibiotics is demonstrated. Raman spectroscopy can be used to monitor the in vitro uptake and distribution of the drug in cells, using both 488 nm and 785 nm as source wavelengths, with submicrometer spatial resolution, although the cellular accumulation of the drug is different in each case. The high information content of Raman spectra allows studies of the drug-cell interactions, and so the method seems very suitable for monitoring drug uptake and mechanisms of interaction with cellular compartments at the subcellular level.

Spectroscopic investigation of different concentrations of the vapour deposited copper phthalocyanine as a "guest" in polyimide matrix.

PubMed

Georgiev, Anton; Yordanov, Dancho; Dimov, Dean; Assa, Jacob; Spassova, Erinche; Danev, Gencho

2015-04-05

Nanocomposite layers 250 nm copper phthalocyanine/polyimide prepared by simultaneous vapour deposition of three different sources were studied. Different concentrations of copper phthalocyanine as a "guest" in polyimide matrix as a function of conditions of the preparation have been determined by FTIR (Fourier Transform Infrared) and UV-VIS (Ultraviolet-Visible) spectroscopies. The aim was to estimate the possibility of the spectroscopic methods for quantitative determination of the "guest" and compare with the quality of the polyimide thin films in relation to the "guest" concentration. The band at 1334 cm(-1) has been used for quantitative estimation of "guest" in polyimide matrix. The concentrations of the copper phthalocyanine less than 20% require curve fitting techniques with Fourier self deconvolution. The relationship between "guest" concentrations and degree of imidization, as well as the electronic UV-VIS spectra are discussed in relation to the composition, imidization degree and the two crystallographic modification of the embedded chromophore. Copyright © 2015 Elsevier B.V. All rights reserved.

Identification of vegetable oil botanical speciation in refined vegetable oil blends using an innovative combination of chromatographic and spectroscopic techniques.

PubMed

Osorio, Maria Teresa; Haughey, Simon A; Elliott, Christopher T; Koidis, Anastasios

2015-12-15

European Regulation 1169/2011 requires producers of foods that contain refined vegetable oils to label the oil types. A novel rapid and staged methodology has been developed for the first time to identify common oil species in oil blends. The qualitative method consists of a combination of a Fourier Transform Infrared (FTIR) spectroscopy to profile the oils and fatty acid chromatographic analysis to confirm the composition of the oils when required. Calibration models and specific classification criteria were developed and all data were fused into a simple decision-making system. The single lab validation of the method demonstrated the very good performance (96% correct classification, 100% specificity, 4% false positive rate). Only a small fraction of the samples needed to be confirmed with the majority of oils identified rapidly using only the spectroscopic procedure. The results demonstrate the huge potential of the methodology for a wide range of oil authenticity work. Copyright © 2014 Elsevier Ltd. All rights reserved.

In Situ Monitoring and Modeling of the Solution-Mediated Polymorphic Transformation of Rifampicin: From Form II to Form I.

PubMed

Guo, Nannan; Hou, Baohong; Wang, Na; Xiao, Yan; Huang, Jingjing; Guo, Yanmei; Zong, Shuyi; Hao, Hongxun

2018-01-01

In this article, the solution-mediated polymorphic transformation of rifampicin was investigated and simulated in 3 solvents at 30°C. The solid-state form I and form II of rifampicin was characterized by powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). To explore the relative stability, solubility data of form I and form II of rifampicin in butan-1-ol were determined using a dynamical method. In addition, Raman spectroscopy and focused beam reflectance measurement were used to in situ monitor the transformation of rifampicin from form II to form I. The liquid state concentration of rifampicin was measured by UV spectroscopic method. To investigate the effect of solvent on transformation, the transformation experiments were carried out in 3 solvents. Furthermore, a mathematical model was built to describe the kinetics of dissolution, nucleation, and growth processes during transformation by using experimental data. By combination of experimental and simulation results, it was found that the transformation process of rifampicin is controlled by dissolution of form II in heptane, whereas the transformation in hexane and octane was firstly controlled by dissolution of solid-state form and then controlled by growth of form I. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Infrared spectroscopic imaging: Label-free biochemical analysis of stroma and tissue fibrosis.

PubMed

Nazeer, Shaiju S; Sreedhar, Hari; Varma, Vishal K; Martinez-Marin, David; Massie, Christine; Walsh, Michael J

2017-11-01

Infrared spectroscopic tissue imaging is a potentially powerful adjunct tool to current histopathology techniques. By coupling the biochemical signature obtained through infrared spectroscopy to the spatial information offered by microscopy, this technique can selectively analyze the chemical composition of different features of unlabeled, unstained tissue sections. In the past, the tissue features that have received the most interest were parenchymal and epithelial cells, chiefly due to their involvement in dysplasia and progression to carcinoma; however, the field has recently turned its focus toward stroma and areas of fibrotic change. These components of tissue present an untapped source of biochemical information that can shed light on many diverse disease processes, and potentially hold useful predictive markers for these same pathologies. Here we review the recent applications of infrared spectroscopic imaging to stromal and fibrotic regions of diseased tissue, and explore the potential of this technique to advance current capabilities for tissue analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterization of PMR-15 polyimide composition in thermo-oxidatively exposed graphite fiber composites

NASA Technical Reports Server (NTRS)

Alston, W. B.

1980-01-01

The contributions of individual resin components to total resin weight loss in 600 F air aged Celion 6000/PMR-15 polyimide composites were determined from the overall resin weight loss in the composite by chemically separating the PMR-15 matrix resin into its monomeric components. The individual resin components were also analyzed by spectroscopic techniques in order to elucidate curing and degradation mechanisms of the PMR-15 matrix resin. The isothermal weight loss of the individual resin components during prolonged 600 F thermo-oxidative aging of the composite was correlated to the changes observed in the Fourier Transform infrared spectra and Fourier Transform nuclear magnetic resonance spectra of the individual resin components. The correlation was used to identify the molecular site of the thermo-oxidative changes in PMR-15 polyimide matrix resin during 600 F curing the prolonged 600 F thermo-oxidative aging.

Probing atomic scale transformation of fossil dental enamel using Fourier transform infrared and nuclear magnetic resonance spectroscopy: a case study from the Tugen Hills (Rift Gregory, Kenya).

PubMed

Yi, Haohao; Balan, Etienne; Gervais, Christel; Ségalen, Loïc; Roche, Damien; Person, Alain; Fayon, Franck; Morin, Guillaume; Babonneau, Florence

2014-09-01

A series of fossil tooth enamel samples was investigated by Fourier transform infrared (FTIR) spectroscopy, (13)C and (19)F magic-angle spinning nuclear magnetic resonance (MAS NMR) and scanning electron microscopy (SEM). Tooth remains were collected in Mio-Pliocene deposits of the Tugen Hills in Kenya. Significant transformations were observed in fossil enamel as a function of increasing fluorine content (up to 2.8wt.%). FTIR spectroscopy revealed a shift of the ν1 PO4 stretching band to higher frequency. The ν2 CO3 vibrational band showed a decrease in the intensity of the primary B-type carbonate signal, which was replaced by a specific band at 864cm(-1). This last band was ascribed to a specific carbonate environment in which the carbonate group is closely associated to a fluoride ion. The occurrence of this carbonate defect was consistently attested by the observation of two different fluoride signals in the (19)F NMR spectra. One main signal, at ∼-100ppm, is related to structural F ions in the apatite channel and the other, at -88ppm, corresponds to the composite defect. These spectroscopic observations can be understood as resulting from the mixture of two phases: biogenic hydroxylapatite (bioapatite) and secondary fluorapatite. SEM observations of the most altered sample confirmed the extensive replacement of the bioapatite by fluorapatite, resulting from the dissolution of the primary bioapatite followed by the precipitation of carbonate-fluorapatite. The ν2 CO3 IR bands can be efficiently used to monitor the extent of this type of bioapatite transformation during fossilization. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Spectroscopic evidence for intermediate species formed during aniline polymerization and polyaniline degradation.

PubMed

Planes, G A; Rodríguez, J L; Miras, M C; García, G; Pastor, E; Barbero, C A

2010-09-21

Spectroscopic methods are used to investigate the formation of low molecular mass intermediates during aniline (ANI) oxidation and polyaniline (PANI) degradation. Studying ANI anodic oxidation by in situ Fourier transform infrared spectroscopy (FTIRS) it is possible to obtain, for the first time, spectroscopic evidence for ANI dimers produced by head-to-tail (4-aminodiphenylamine, 4ADA) and tail-to-tail (benzidine, BZ) coupling of ANI cation radicals. The 4ADA dimer is adsorbed on the electrode surface during polymerization, as proved by cyclic voltammetry of thin PANI films and its infrared spectrum. This method also allows, with the help of computational simulations, to assign characteristic vibration frequencies for the different oxidation states of PANI. The presence of 4ADA retained inside thin polymer layers is established too. On the other hand, FTIRS demonstrates that the electrochemically promoted degradation of PANI renders p-benzoquinone as its main product. This compound, retained inside the film, is apparent in the cyclic voltammogram in the same potential region previously observed for 4ADA dimer. Therefore, applying in situ FTIRS is possible to distinguish between different chemical species (4ADA or p-benzoquinone) which give rise to voltammetric peaks in the same potential region. Indophenol and CO(2) are also detected by FTIRS during ANI oxidation and polymer degradation. The formation of CO(2) during degradation is confirmed by differential electrochemical mass spectroscopy. To the best of our knowledge, this is the first evidence of the oxidation of a conducting polymer to CO(2) by electrochemical means. The relevance of the production of different intermediate species towards PANI fabrication and applications is discussed.

Influence of high-energy milling on structure and microstructure of asbestos-cement materials

NASA Astrophysics Data System (ADS)

Iwaszko, Józef; Zawada, Anna; Lubas, Małgorzata

2018-03-01

Asbestos-Containing Waste (ACW) in the form of a fragment from an asbestos-cement board was subjected to high-energy milling in a planetary mill at a constant rotational speed of 650 rpm and for variable milling times: 1, 2, and 3 h. The initial and the milled materials were subjected to infrared spectroscopic examination to identify the asbestos variety and to evaluate changes in the structure caused by high-energy milling. FT-IR (Fourier Transform Infrared Spectroscopy) examinations followed optical microscopy and SEM (Scanning Electron Microscopy) studies as well as X-ray analysis of the phase composition. It was found that the asbestos fibres present in the asbestos-cement board were respirable fibres with pathogenic properties. Identifying asbestos using the spectroscopic method showed that chrysotile asbestos was present in the as-received ACW while no characteristics of absorption bands from crocidolite or amosite were found. The results of the spectroscopic examinations were confirmed by the X-ray phase analysis. During SEM investigations of the milled ACW, complete loss of the fibrous structure of chrysotile was observed. The FT-IR examinations of the milled material showed that with an increased milling time, the characteristic absorption bands characteristic for chrysotile diminished and already after 2 h of milling their almost complete decay was observed. Thereby, it was confirmed that high-energy milling results in destruction of the crystalline structure of the asbestos phase. The conducted studies have shown that the treatment of asbestos-cement materials using high-energy milling is an effective method for asbestos disposal, capable of competing with other technologies and solutions. Moreover, FT-IR spectroscopy was found to be useful to identify asbestos phases and to assess changes caused by high-energy milling.

Ultra-broadband infrared pump-probe spectroscopy using synchrotron radiation and a tuneable pump.

PubMed

Carroll, Lee; Friedli, Peter; Lerch, Philippe; Schneider, Jörg; Treyer, Daniel; Hunziker, Stephan; Stutz, Stefan; Sigg, Hans

2011-06-01

Synchrotron infrared sources have become popular mainly because of their excellent broadband brilliance, which enables spectroscopically resolved spatial-mapping of stationary objects at the diffraction limit. In this article we focus on an often-neglected further advantage of such sources - their unique time-structure - to bring such broadband spectroscopy to the time domain, for studying dynamic phenomenon down to the 100 ps limit. We describe the ultra-broadband (12.5 to 1.1 μm) Fourier transform pump-probe setup, for condensed matter transmission- and reflection-spectroscopy, installed at the X01DC infrared beam-line of the Swiss Light Source (SLS). The optical pump consists of a widely tuneable 100 ps 1 kHz laser system, covering 94% of the 16 to 1.1 μm range. A thorough description of the system is given, including (i) the vector-modulator providing purely electronic tuning of the pump-probe overlap up to 1 ms with sub-ps time resolution, (ii) the 500 MHz data acquisition system interfaced with the experimental physics and industrial control system (EPICS) based SLS control system for consecutive pulse sampling, and (iii) the step-scan time-slice Fourier transform scheme for simultaneous recording of the dual-channel pumped, un-pumped, and difference spectra. The typical signal/noise ratio of a single interferogram in a 100 ps time slice is 300 (measured during one single 140 s TopUp period). This signal/noise ratio is comparable to that of existing gated Globar pump-probe Fourier transform spectroscopy, but brings up to four orders of magnitude better time resolution. To showcase the utility of broadband pump-probe spectroscopy, we investigate a Ge-on-Si material system similar to that in which optically pumped direct-gap lasing was recently reported. We show that the mid-infrared reflection-spectra can be used to determine the optically injected carrier density, while the mid- and near-infrared transmission-spectra can be used to separate the strong pump-induced absorption and inversion processes present at the direct-gap energy. © 2011 American Institute of Physics

Symposium on Recent Results in Infrared Astrophysics

NASA Technical Reports Server (NTRS)

Dyal, P. (Editor)

1977-01-01

Abstracts of papers presented at a symposium titled Recent Results in Infrared Astrophysics are set forth. The abstracts emphasize photometric, spectroscopic, polarization, and theoretical results on a broad range of current topics in infrared astrophysics.

Powder X-ray diffraction, infrared and 13C NMR spectroscopic studies of the homologous series of some solid-state zinc(II) and sodium(I) n-alkanoates

NASA Astrophysics Data System (ADS)

Nelson, Peter N.; Taylor, Richard A.

2015-03-01

A comparative study of the room temperature molecular packing and lattice structures for the homologous series of zinc(II) and sodium(I) n-alkanoates adduced from Fourier transform infrared and solid-state 13C NMR spectroscopic data in conjunction with X-ray powder diffraction measurements is carried out. For zinc carboxylates, metal-carboxyl bonding is via asymmetric bridging bidentate coordination whilst for the sodium adducts, coordination is via asymmetric chelating bidentate bonding. All compounds are packed in a monoclinic crystal system. Furthermore, the fully extended all-trans hydrocarbon chains are arranged as lamellar bilayers. For zinc compounds, there is bilayer overlap, for long chain adducts (nc > 8) but not for sodium compounds where methyl groups from opposing layers in the lamellar are only closely packed. Additionally, the hydrocarbon chains are extended along the a-axis of the unit cell for zinc compounds whilst for sodium carboxylates they are extended along the c-axis. These packing differences are responsible for different levels of Van der Waals effects in the lattices of these two series of compounds, hence, observed odd-even alternation is different. The significant difference in lattice packing observed for these two series of compounds is proposed to be due to the difference in metal-carboxyl coordination mode, arising from the different electronic structure of the central metal ions.

Spectroscopic And Electrochemical Studies Of Electrochromic Hydrated Nickel Oxide Films

NASA Astrophysics Data System (ADS)

Yu, P. C.; Nazri, G.; Lampert, C. M.

1986-09-01

The electrochrcrnic properties of hydrated nickel oxide thin films electrochemically deposited by anodization onto doped tin oxide-coated glass have been studied by transmittance measurements, cyclic voltammetry, Fourier-transform infrared spectroscopy, and ion-backscattering spectrometry. The spectral transmittance is reported for films switched in both the bleached and colored states. The photopic transmittance (Tp) can be switched from T (bleached) = 0.77 to T (colored) = 0.21, and the solar transmittance (Ts) can be switched from Ts(bleached) = 0.73 to TS (colored) = 0.35. Also reported is the near-infrared transmittance (TNIR)which was found to switch fran T N,IR (bleached) = 0.72 to TNIR (colored) = 0.55. The bleached condition is noted to have very low solar absorption in both the visible and solar regions. Ion-backscattering spectrometry was performed on the hydrated nickel oxide film, yielding a camposition of Ni01.0 (dehydrated) and a film thickness of 125 A. Cyclic voltammetry showed that, for films in the bleached or colored state, the reversible reaction is Ni(0H), = NiOOH + H+ + e . Voltammnetry also showed that the switching of the film is controlled by the diffusion or protons, where OH plays a role in the reaction mechanism. Analysis of the hydrated nickel-oxide thin films by Fourier-transform infrared spectroscopy revealed that both the bleached and colored states contain lattice water and hydroxyl groups. The surface hydroxyl groups play an important role in the coloration and bleaching of the anodically deposited nickel oxide thin films.

Comment on "A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite--a mid-infrared and near-infrared study" and "Infrared and infrared emission spectroscopic study of typical Chinese kaolinite and halloysite" by Hongfei Cheng et al. (2010).

PubMed

Kloprogge, J Theo

2015-02-05

In two papers Cheng et al. (2010) reported in this journal on the mid-infrared, near-infrared and infrared emission spectroscopy of a halloysite from Hunan Xianrenwan, China. This halloysite contains around 8% of quartz (SiO2) and nearly 9% gibbsite (Al(OH)3). In their interpretation of the spectra these impurities were completely ignored. Careful comparison with a phase pure halloysite from Southern Belgium, synthetic gibbsite, gibbsite from Minas Gerais, and quartz show that these impurities do have a marked influence on the mid-infrared and infrared emission spectra. In the near-infrared, the effect is much less pronounced. Quartz does not show bands in this region and the gibbsite bands will be very weak. Comparison still show that the presence of gibbsite does contribute to the overall spectrum and bands that were ascribed to the halloysite alone do coincide with those of gibbsite. Copyright © 2014 Elsevier B.V. All rights reserved.

Atmospheric and spectroscopic research in the far infrared

NASA Technical Reports Server (NTRS)

Park, Kwangjai; Radostitz, James V.

1992-01-01

The University of Oregon (UO) has been a major participant in the development of far infrared spectroscopic research of the stratosphere for the purpose of understanding the ozone layer processes. The UO has had a 15-year collaboration with the Italian group of B. Carli, and have participated in the 1978/79 Sub-millimeter Infrared Balloon Experiment (SIBEX), in the Balloon Intercomparison Campaign, (BIC), in the Infrared Balloon Experiment (IBEX), and in the recently concluded Far Infrared Experiment for UARS Correlative Measurements (FIREX). Both IBEX and FIREX programs were conducted in collaboration with NASA Langley, and were designed as validation flights in support of the Upper Atmosphere Research Satellite (UARS) Program. The technique of atmospheric far infrared spectroscopy offers two important advantages. First, many chemically important species can be measured simultaneously and co-spatially in the atmosphere. Second, far infrared atmospheric spectra can be obtained in thermal emission without reference to the sun's position, enabling full diurnal and global coverage. Recent improvements in instrumentation, field measurements, and molecular concentration retrieval techniques are now making the far infrared a mature measurement technology. This work to date has largely focused on balloon-based studies, but the future efforts will focus also on satellite-based experiments. A program of research in the following general areas was proposed: Laboratory Pressure broadening coefficient studies; specialized detector system assembly and testing; and consultation and assistance with instrument and field support. The proposal was approved and a three-year research grant titled 'Atmospheric and Spectroscopic Research in the Far Infrared' was awarded. A summary of technical accomplishments attained during the grant period are presented.

Application of a novel combination of near-infrared spectroscopy and a humidity-controlled 96-well plate to the characterization of the polymorphism of imidafenacin.

PubMed

Uchida, Hiroshi; Yoshinaga, Tokuji; Mori, Hirotoshi; Otsuka, Makoto

2010-11-01

This study aimed to apply a currently available chemometric near-infrared spectroscopy technique to the characterization of the polymorphic properties of drug candidates. The technique requires only small quantities of samples and is therefore applicable to drugs in the early stages of development. The combination of near-infrared spectroscopy and a patented 96-well plate divided into 32 individual, humidity-controlled, three-well compartments was used in the characterization of a hygroscopic drug, imidafenacin, which has two polymorphs and one pseudo-polymorph. Characterization was also conducted with powder X-ray diffraction and thermal analysis. The results were compared with those from routinely used conventional analyses. Both the microanalysis and conventional analysis successfully characterised the substance (transformation and relative stability among the two polymorphs and a pseudo-polymorph) depending on the storage conditions. Near-infrared spectroscopic analyses utilizing a humidity-controlled 96-well plate required only small amounts of the sample for characterization under the various conditions of relative humidity. Near-infrared microanalysis can be applied to polymorphic studies of small quantities of a drug candidate. The results also suggest that the method will predict the behaviors of a hygroscopic candidate in solid pharmaceutical preparations at the early stages of drug development. © 2010 The Authors. JPP © 2010 Royal Pharmaceutical Society of Great Britain.

Diagnosis of Cell Death by Means of Infrared Spectroscopy

PubMed Central

Zelig, Udi; Kapelushnik, Joseph; Moreh, Raymond; Mordechai, Shaul; Nathan, Ilana

2009-01-01

Abstract Fourier transform infrared (FTIR) spectroscopy has been established as a fast spectroscopic method for biochemical analysis of cells and tissues. In this research we aimed to investigate FTIR's utility for identifying and characterizing different modes of cell death, using leukemic cell lines as a model system. CCRF-CEM and U937 leukemia cells were treated with arabinoside and doxorubicin apoptosis inducers, as well as with potassium cyanide, saponin, freezing-thawing, and H2O2 necrosis inducers. Cell death mode was determined by various gold standard biochemical methods in parallel with FTIR-microscope measurements. Both cell death modes exhibit large spectral changes in lipid absorbance during apoptosis and necrosis; however, these changes are similar and thus cannot be used to distinguish apoptosis from necrosis. In contrast to the above confounding factor, our results reveal that apoptosis and necrosis can still be distinguished by the degree of DNA opaqueness to infrared light. Moreover, these two cell death modes also can be differentiated by their infrared absorbance, which relates to the secondary structure of total cellular protein. In light of these findings, we conclude that, because of its capacity to monitor multiple biomolecular parameters, FTIR spectroscopy enables unambiguous and easy analysis of cell death modes and may be useful for biochemical and medical applications. PMID:19804743

Molecular Shocks Associated with Massive Young Stars: CO Line Images with a New Far-Infrared Spectroscopic Camera on the Kuiper Airborne Observatory

NASA Technical Reports Server (NTRS)

Watson, Dan M.

1997-01-01

Under the terms of our contract with NASA Ames Research Center, the University of Rochester (UR) offers the following final technical report on grant NAG 2-958, Molecular shocks associated with massive young stars: CO line images with a new far-infrared spectroscopic camera, given for implementation of the UR Far-Infrared Spectroscopic Camera (FISC) on the Kuiper Airborne Observatory (KAO), and use of this camera for observations of star-formation regions 1. Two KAO flights in FY 1995, the final year of KAO operations, were awarded to this program, conditional upon a technical readiness confirmation which was given in January 1995. The funding period covered in this report is 1 October 1994 - 30 September 1996. The project was supported with $30,000, and no funds remained at the conclusion of the project.

Comparison between infrared and Raman spectroscopic analysis of maturing rabbit cortical bone.

PubMed

Turunen, Mikael J; Saarakkala, Simo; Rieppo, Lassi; Helminen, Heikki J; Jurvelin, Jukka S; Isaksson, Hanna

2011-06-01

The molecular composition of the organic and inorganic matrices of bone undergoes alterations during maturation. The aim of this study was to compare Fourier transform infrared (FT-IR) and near-infrared (NIR) Raman microspectroscopy techniques for characterization of the composition of growing and developing bone from young to skeletally mature rabbits. Moreover, the specificity and differences of the techniques for determining bone composition were clarified. The humeri of female New Zealand White rabbits, with age range from young to skeletally mature animals (four age groups, n = 7 per group), were studied. Spectral peak areas, intensities, and ratios related to organic and inorganic matrices of bone were analyzed and compared between the age groups and between FT-IR and Raman microspectroscopic techniques. Specifically, the degree of mineralization, type-B carbonate substitution, crystallinity of hydroxyapatite (HA), mineral content, and collagen maturity were examined. Significant changes during maturation were observed in various compositional parameters with one or both techniques. Overall, the compositional parameters calculated from the Raman spectra correlated with analogous parameters calculated from the IR spectra. Collagen cross-linking (XLR), as determined through peak fitting and directly from the IR spectra, were highly correlated. The mineral/matrix ratio in the Raman spectra was evaluated with multiple different peaks representing the organic matrix. The results showed high correlation with each other. After comparison with the bone mineral density (BMD) values from micro-computed tomography (micro-CT) imaging measurements and crystal size from XRD measurements, it is suggested that Raman microspectroscopy is more sensitive than FT-IR microspectroscopy for the inorganic matrix of the bone. In the literature, similar spectroscopic parameters obtained with FT-IR and NIR Raman microspectroscopic techniques are often compared. According to the present results, however, caution is required when performing this kind of comparison.

Chalcogenide glass mid-infrared on-chip sensor for chemical sensing

NASA Astrophysics Data System (ADS)

Lin, Hongtao

Chemical sensing in the mid-infrared (mid-IR) has been considered to be significant for molecular detection for decades, but until recently has mostly relied on benchtop spectroscopic instruments like Fourier transform infrared spectrometers, etc. Recent strides in planar photonic integration envision compact, standalone "sensor-on-a-chip" devices for molecular analysis as a potentially disruptive technology as compared to their conventional bulky counterparts. However, the difficulty of achieving adequate sensitivity in integrated optical sensors is still a key barrier towards their practical application, limited by the weak interactions between photons and molecules over the short optical path length accessible on a chip. To solve the sensitivity challenge, a novel mid-IR photothermal spectroscopic sensing technique was proposed and theoretically examined. Through dramatically amplified photothermal effects in an optical nano-cavity doubly resonant at both mid-IR pump and near infrared probe wavelengths, a device design based on nested 1-D nanobeam photonic crystal cavities is numerically analyzed to demonstrate the technique's potential for single small gas molecule detection without the need for cryogenically cooled mid-IR photo-detectors. Furthermore, since silica becomes opaque at wavelengths beyond 3.5 microm, new material platforms and fabrication techniques are needed for mid-IR on-chip chemical sensors. Chalcogenide glasses (ChG), amorphous compounds containing S, Se and Te, are ideal material choices for mid-IR chemical sensors given their broad mid-IR transparency window, large photothermal figure-of-merit, amorphous structure and low processing temperature. A ChG lift-off process and a nano-fabrication technique using focused ion beam milling have been developed to fabricate mid-IR ChG resonators and photonic crystal waveguide cavities. ChG resonators on CaF2 substrate claimed a high quality factor around 4 x 105. Using these devices, we have also demonstrated mid-IR cavity enhanced absorption spectroscopy for the first time with mass loading limit of detection as low as 0.05 ng for ethanol.

Spectroscopic studies of the mechanism of reversible photodegradation of 1-substituted aminoanthraquinone-doped polymers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hung, Sheng-Ting, E-mail: Sheng-Ting.Hung@jila.colorado.edu; Clays, Koen; Department of Chemistry, University of Leuven, Leuven B-3001

2016-03-21

The mechanism of reversible photodegradation of 1-substituted aminoanthraquinones doped into poly(methyl methacrylate) and polystyrene is investigated. Time-dependent density functional theory is employed to predict the transition energies and corresponding oscillator strengths of the proposed reversibly and irreversibly damaged dye species. Ultraviolet–visible and Fourier transform infrared (FTIR) spectroscopy are used to characterize which species are present. FTIR spectroscopy indicates that both dye and polymer undergo reversible photodegradation when irradiated with a visible laser. These findings suggest that photodegradation of 1-substituted aminoanthraquinones doped in polymers originates from interactions between dyes and photoinduced thermally degraded polymers, and the metastable product may recover ormore » further degrade irreversibly.« less

FT-NIR: A Tool for Process Monitoring and More.

PubMed

Martoccia, Domenico; Lutz, Holger; Cohen, Yvan; Jerphagnon, Thomas; Jenelten, Urban

2018-03-30

With ever-increasing pressure to optimize product quality, to reduce cost and to safely increase production output from existing assets, all combined with regular changes in terms of feedstock and operational targets, process monitoring with traditional instruments reaches its limits. One promising answer to these challenges is in-line, real time process analysis with spectroscopic instruments, and above all Fourier-Transform Near Infrared spectroscopy (FT-NIR). Its potential to afford decreased batch cycle times, higher yields, reduced rework and minimized batch variance is presented and application examples in the field of fine chemicals are given. We demonstrate that FT-NIR can be an efficient tool for improved process monitoring and optimization, effective process design and advanced process control.

Solution properties and spectroscopic characterization of polymeric precursors to SiNCB and BN ceramic materials

NASA Astrophysics Data System (ADS)

Cortez, E.; Remsen, E.; Chlanda, V.; Wideman, T.; Zank, G.; Carrol, P.; Sneddon, L.

1998-06-01

Boron Nitride, BN, and composite SiNCB ceramic fibers are important structural materials because of their excellent thermal and oxidative stabilities. Consequently, polymeric materials as precursors to ceramic composites are receiving increasing attention. Characterization of these materials requires the ability to evaluate simultaneous molecular weight and compositional heterogeneity within the polymer. Size exclusion chromatography equipped with viscometric and refractive index detection as well as coupled to a LC-transform device for infrared absorption analysis has been employed to examine these heterogeneities. Using these combined approaches, the solution properties and the relative amounts of individual functional groups distributed through the molecular weight distribution of SiNCB and BN polymeric precursors were characterized.

Spectroscopic analyses of soil samples outside Nile Delta of Egypt

NASA Astrophysics Data System (ADS)

Fakhry, Ahmed; Osman, Osama; Ezzat, Hend; Ibrahim, Medhat

2016-11-01

Soil in Egypt, especially around Delta is exposed to various pollutants which are affecting adversely soil fertility and stability. Humic Acids (HA) as a main part of soil organic matter (SOM) represent the heart of the interaction process of inorganic pollutants with soil. Consequently, Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonances (NMR) were used to characterize soil, sediment and extracted HA. Resulting data confirmed that the HA was responsible for transporting inorganic pollutants from surface to subsurface reaching the ground water, which may represent a high risk on public health. The transport process is coming as carboxyl in surface soil changed into metal carboxylate then transferred into the carboxyl in bottom soil.

Synergy between hexavalent chromium ions and TiO2 nanoparticles inside TUD-1 in the photocatalytic oxidation of propane, a spectroscopic study

NASA Astrophysics Data System (ADS)

Hamdy, Mohamed S.

2016-02-01

Siliceous TUD-1 mesoporous material was bi-functionalized by titanium dioxide nanoparticles and hexavalent chromium ions. The synthesis was carried out by one-pot procedure based on sol-gel technique. The photocatalytic performance of the prepared material was evaluated in the oxidation of propane under the illumination of ultraviolet light (wavelength = 360 nm) and monitored by in situ Fourier transform infrared spectroscopy. The photocatalytic activity of the prepared material exhibited an extra-ordinary activity than the reference samples that contain either hexavalent chromium ions or titanium dioxide nanoparticles only, confirming the true synergy between hexavalent chromium and tetravalent titanium ions of titanium dioxide nanoparticles.

Technical note: Characterization of lipid constitution in Fourier transform infrared spectra and spectroscopic discrimination of animal-derived feedstuffs from different species.

PubMed

Gao, F; Han, L; Yang, Z; Xu, L; Liu, X

2017-06-01

The objective of the current work was to assess the capability of Fourier transform infrared (FT-IR) spectroscopy in combination with chemometric methods to discriminate animal-derived feedstuffs from different origins based on the lipid characteristics. A total of 82 lipid samples extracted from animal-derived feedstuffs, comprising porcine, poultry, bovine, ovine, and fish samples, were investigated by gas chromatography and FT-IR. The relationship between the lipid constitutions and the responding FT-IR spectral characteristics were explored. Results indicated that high correlations ( > 0.900) were found between the contents of MUFA and PUFA and FT-IR spectral data. In addition, the peak intensity at about 1,116 and 1,098 cm-1 showed a significant difference ( < 0.05) between ruminant and nonruminant animals; the change of peak ratio (1,116:1,098) was proved consistent with the degree of unsaturation of lipid from different animal species. Successful discrimination was further achieved among porcine, poultry, bovine, and ovine meat and bone meal (MBM) and fishmeal based on lipid characteristics by applying the FT-IR spectra coupled with chemometrics, for which the values of sensitivity and specificity were close to 1 and classification error were almost equal to 0.

Proteolytically-induced changes of secondary structural protein conformation of bovine serum albumin monitored by Fourier transform infrared (FT-IR) and UV-circular dichroism spectroscopy

NASA Astrophysics Data System (ADS)

Güler, Günnur; Vorob'ev, Mikhail M.; Vogel, Vitali; Mäntele, Werner

2016-05-01

Enzymatically-induced degradation of bovine serum albumin (BSA) by serine proteases (trypsin and α-chymotrypsin) in various concentrations was monitored by means of Fourier transform infrared (FT-IR) and ultraviolet circular dichroism (UV-CD) spectroscopy. In this study, the applicability of both spectroscopies to monitor the proteolysis process in real time has been proven, by tracking the spectral changes together with secondary structure analysis of BSA as proteolysis proceeds. On the basis of the FTIR spectra and the changes in the amide I band region, we suggest the progression of proteolysis process via conversion of α-helices (1654 cm- 1) into unordered structures and an increase in the concentration of free carboxylates (absorption of 1593 and 1402 cm- 1). For the first time, the correlation between the degree of hydrolysis and the concentration of carboxylic groups measured by FTIR spectroscopy was revealed as well. The far UV-CD spectra together with their secondary structure analysis suggest that the α-helical content decreases concomitant with an increase in the unordered structure. Both spectroscopic techniques also demonstrate that there are similar but less spectral changes of BSA for the trypsin attack than for α-chymotrypsin although the substrate/enzyme ratio is taken the same.

Fourier transform infrared spectroscopy of DNA from Borrelia burgdorferi sensu lato and Ixodes ricinus ticks

NASA Astrophysics Data System (ADS)

Muntean, Cristina M.; Stefan, Razvan; Bindea, Maria; Cozma, Vasile

2013-06-01

In this work we present a method for detection of motile and immotile Borrelia burgdorferi genomic DNA, in relation with infectious and noninfectious spirochetes. An FT-IR study of DNA isolated from B. burgdorferi sensu lato strains and from positive and negative Ixodes ricinus ticks, respectively, is reported. Motile bacterial cells from the species B. burgdorferi sensu stricto, Borrelia garinii and Borrelia afzelii were of interest. Also, FT-IR absorbance spectra of DNA from immotile spirochetes of B. burgdorferi sensu stricto, in the absence and presence of different antibiotics (doxycycline, erythromycin, gentamicin, penicillin V or phenoxymethylpenicillin, tetracycline, respectively) were investigated. FT-IR spectra, providing a high molecular structural information, have been analyzed in the wavenumber range 400-1800 cm-1. FT-IR signatures, spectroscopic band assignments and structural interpretations of these DNAs are reported. Spectral differences between FT-IR absorbances of DNAs from motile bacterial cells and immotile spirochetes, respectively, have been found. Particularly, alterations of the sugar-phosphate B-form chain in the case of DNA from Borrelia immotile cells, as compared with DNA from B. burgdorferi sensu lato motile cells have been observed. Based on this work, specific B. burgdorferi sensu lato and I. ricinus DNA-ligand interactions, respectively, might be further investigated using Fourier transform infrared spectroscopy.

Raman microspectroscopy and FTIR crystallization studies of 2,4,6-TNT in soil

NASA Astrophysics Data System (ADS)

Manrique-Bastidas, Cesar A.; Mina, Nairmen; Castro, Miguel E.; Hernandez-Rivera, Samuel P.

2005-06-01

2,4,6-Trinitrotoluene is a high explosive used in manufacturing landmine, bombs, and other explosive devices. It has been the main source of contamination in groundwater, soil as a result of intentional or accidental releases at many places around the world. Crystallization of TNT in soil from TNT/methanol solutions was carried out and characterized using vibrational spectroscopy. TNT exhibits a series of characteristic bands that allow its detection when in soil. The spectroscopic signatures of neat TNT and TNT in soil samples were determined with Raman Microspectroscopy and Fourier Transform Infrared (FTIR) Microscopy. The spectroscopic signature of neat TNT is dominated by strong bands about 1380 and 2970 cm-1. The intensity and position of these bands are found remarkably different in soil samples spiked with TNT. The 1380 cm-1 band is split into a number of bands in that region. The 2970 cm-1 is reduced in intensity and new bands are observed at about 2880 cm-1. The results are consistent with a different chemical environment for TNT in soil as compared to neat TNT. Further measurements are required to fully understand the spectroscopic signature of TNT in soil samples. Its detection in soil is essential in landmine detection technology, and could address the improvement of the devices in the mentioned technology.

Phase transformation of calcium oxalate dihydrate-monohydrate: Effects of relative humidity and new spectroscopic data

NASA Astrophysics Data System (ADS)

Conti, Claudia; Casati, Marco; Colombo, Chiara; Realini, Marco; Brambilla, Luigi; Zerbi, Giuseppe

2014-07-01

New data on vibrational properties of calcium oxalates and their controversial transformation mechanism are presented. We have focused on whewellite (CaC2O4·H2O) and weddellite [CaC2O4·(2 + x) H2O], the most common phases of calcium oxalate; these compounds occur in many organisms, in kidney stones and in particular kinds of films found on the surface of many works of art. Low temperature experiments carried out by Fourier transform infrared spectroscopy have highlighted both the high structural order in the crystalline state of whewellite and the disordered distribution of the zeolitic water molecules in weddellite. The synthesised nanocrystals of weddellite have been kept under different hygrometric conditions in order to study, by X-ray powder diffraction, the role of “external” water molecules on their stability. Moreover, in order to identify the different kinds of water molecules, a re-investigation, supported by quantum chemical calculations, of the observed vibrational spectra (IR and Raman) of whewellite has been conducted.

MALS–NOT: Identifying Radio-bright Quasars for the MeerKAT Absorption Line Survey

NASA Astrophysics Data System (ADS)

Krogager, J.-K.; Gupta, N.; Noterdaeme, P.; Ranjan, A.; Fynbo, J. P. U.; Srianand, R.; Petitjean, P.; Combes, F.; Mahabal, A.

2018-03-01

We present a preparatory spectroscopic survey to identify radio-bright, high-redshift quasars for the MeerKAT Absorption Line Survey. The candidates have been selected on the basis of a single flux density limit at 1.4 GHz (>200 mJy), together with mid-infrared color criteria from the Wide-field Infrared Survey Explorer. Through spectroscopic observations using the Nordic Optical Telescope, we identify 72 quasars out of 99 candidates targeted. We measure the spectroscopic redshifts based on characteristic, broad emission lines present in the spectra. Of these 72 quasars, 64 and 48 objects are at sufficiently high redshift (z > 0.6 and z > 1.4) to be used for the L-band and UHF-band spectroscopic follow-up with the Square Kilometre Array precursor in South Africa: the MeerKAT.

A methodological approach to study the stability of selected watercolours for painting reintegration, through reflectance spectrophotometry, Fourier transform infrared spectroscopy and hyperspectral imaging

NASA Astrophysics Data System (ADS)

Pelosi, Claudia; Capobianco, Giuseppe; Agresti, Giorgia; Bonifazi, Giuseppe; Morresi, Fabio; Rossi, Sara; Santamaria, Ulderico; Serranti, Silvia

2018-06-01

The aim of this work is to investigate the stability to simulated solar radiation of some paintings samples through a new methodological approach adopting non-invasive spectroscopic techniques. In particular, commercial watercolours and iron oxide based pigments were used, these last ones being prepared for the experimental by gum Arabic in order to propose a possible substitute for traditional reintegration materials. Reflectance spectrophotometry in the visible range and Hyperspectral Imaging in the short wave infrared were chosen as non-invasive techniques for evaluation the stability to irradiation of the chosen pigments. These were studied before and after artificial ageing procedure performed in Solar Box chamber under controlled conditions. Data were treated and elaborated in order to evaluate the sensitivity of the chosen techniques in identifying the variations on paint layers, induced by photo-degradation, before they could be observed by eye. Furthermore a supervised classification method for monitoring the painted surface changes adopting a multivariate approach was successfully applied.

Identifying the Source of Large-Scale Atmospheric Variability in Jupiter

NASA Astrophysics Data System (ADS)

Orton, Glenn

2011-01-01

We propose to use the unique mid-infrared filtered imaging and spectroscopic capabilities of the Subaru COMICS instrument to determine the mechanisms associated with recent unusual rapid albedo and color transformations of several of Jupiter's bands, particularly its South Equatorial Belt (SEB), as a means to understand the coupling between its dynamics and chemistry. These observations will characterize the temperature, degree of cloud cover, and distribution of minor gases that serve as indirect tracers of vertical motions in regions that will be undergoing unusual large-scale changes in dynamics and chemistry: the SEB, as well as regions near the equator and Jupiter's North Temperate Belt. COMICS is ideal for this investigation because of its efficiency in doing both imaging and spectroscopy, its 24.5-mum filter that is unique to 8-meter-class telescopes, its wide field of view that allows imaging of nearly all of Jupiter's disk, coupled with a high diffraction-limited angular resolution and optimal mid-infrared atmospheric transparency.

Univariate and multivariate analysis of tannin-impregnated wood species using vibrational spectroscopy.

PubMed

Schnabel, Thomas; Musso, Maurizio; Tondi, Gianluca

2014-01-01

Vibrational spectroscopy is one of the most powerful tools in polymer science. Three main techniques--Fourier transform infrared spectroscopy (FT-IR), FT-Raman spectroscopy, and FT near-infrared (NIR) spectroscopy--can also be applied to wood science. Here, these three techniques were used to investigate the chemical modification occurring in wood after impregnation with tannin-hexamine preservatives. These spectroscopic techniques have the capacity to detect the externally added tannin. FT-IR has very strong sensitivity to the aromatic peak at around 1610 cm(-1) in the tannin-treated samples, whereas FT-Raman reflects the peak at around 1600 cm(-1) for the externally added tannin. This high efficacy in distinguishing chemical features was demonstrated in univariate analysis and confirmed via cluster analysis. Conversely, the results of the NIR measurements show noticeable sensitivity for small differences. For this technique, multivariate analysis is required and with this chemometric tool, it is also possible to predict the concentration of tannin on the surface.

Accounting for tissue heterogeneity in infrared spectroscopic imaging for accurate diagnosis of thyroid carcinoma subtypes.

PubMed

Martinez-Marin, David; Sreedhar, Hari; Varma, Vishal K; Eloy, Catarina; Sobrinho-Simões, Manuel; Kajdacsy-Balla, André; Walsh, Michael J

2017-07-01

Fourier transform infrared (FT-IR) microscopy was used to image tissue samples from twenty patients diagnosed with thyroid carcinoma. The spectral data were then used to differentiate between follicular thyroid carcinoma and follicular variant of papillary thyroid carcinoma using principle component analysis coupled with linear discriminant analysis and a Naïve Bayesian classifier operating on a set of computed spectral metrics. Classification of patients' disease type was accomplished by using average spectra from a wide region containing follicular cells, colloid, and fibrosis; however, classification of disease state at the pixel level was only possible when the extracted spectra were limited to follicular epithelial cells in the samples, excluding the relatively uninformative areas of fibrosis. The results demonstrate the potential of FT-IR microscopy as a tool to assist in the difficult diagnosis of these subtypes of thyroid cancer, and also highlights the importance of selectively and separately analyzing spectral information from different features of a tissue of interest.

Competition between inter- and intra-molecular hydrogen bonding: An infrared spectroscopic study of jet-cooled amino-ethanol and its dimer

NASA Astrophysics Data System (ADS)

Asselin, Pierre; Madebène, Bruno; Soulard, Pascale; Georges, Robert; Goubet, Manuel; Huet, Thérèse R.; Pirali, Olivier; Zehnacker-Rentien, Anne

2016-12-01

The Fourier transform IR vibrational spectra of amino-ethanol (AE) and its dimer have been recorded at room temperature and under jet-cooled conditions over the far and mid infrared ranges (50-4000 cm-1) using the White-type cell and the supersonic jet of the Jet-AILES apparatus at the synchrotron facility SOLEIL. Assignment of the monomer experimental frequencies has been derived from anharmonic frequencies calculated at a hybrid CCSD(T)-F12/MP2 level. Various thermodynamical effects in the supersonic expansion conditions including molar dilution of AE and nature of carrier gas have been used to promote or not the formation of dimers. Four vibrational modes of the observed dimer have been unambiguously assigned using mode-specific scaling factors deduced from the ratio between experimental and computed frequencies for the monomer. The most stable g'Gg' monomer undergoes strong deformation upon dimerization, leading to a homochiral head to head dimer involving two strong hydrogen bonds.

Fourier transform near-infrared spectroscopy application for sea salt quality evaluation.

PubMed

Galvis-Sánchez, Andrea C; Lopes, João Almeida; Delgadillo, Ivonne; Rangel, António O S S

2011-10-26

Near-infrared (NIR) spectroscopy in diffuse reflectance mode was explored with the objective of discriminating sea salts according to their quality type (traditional salt vs "flower of salt") and geographical origin (Atlantic vs Mediterranean). Sea salts were also analyzed in terms of Ca(2+), Mg(2+), K(+), alkalinity, and sulfate concentrations to support spectroscopic results. High concentrations of Mg(2+) and K(+) characterized Atlantic samples, while a high Ca(2+) content was observed in traditional sea salts. A partial least-squares discriminant analysis model considering the 8500-7500 cm(-1) region permitted the discrimination of salts by quality types. The regions 4650-4350 and 5900-5500 cm(-1) allowed salts classification according to their geographical origin. It was possible to classify correctly 85.3 and 94.8% of the analyzed samples according to the salt type and to the geographical origin, respectively. These results demonstrated that NIR spectroscopy is a suitable and very efficient tool for sea salt quality evaluation.

Reflectance Infrared Spectroscopy on Operating Surface Acoustic Wave Chemical Sensors During Exposure to Gas-Phase Analytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hierlemann, A.; Hill, M.; Ricco, A.J.

We have developed instrumentation to enable the combination of surface acoustic wave (SAW) sensor measurements with direct, in-situ molecular spectroscopic measurements to understand the response of the SAW sensors with respect to the interfacial chemistry of surface-confined sensing films interacting with gas-phase analytes. Specifically, the instrumentation and software was developed to perform in-situ Fourier-transform infrared external-reflectance spectroscopy (FTIR-ERS) on operating SAW devices during dosing of their chemically modified surfaces with analytes. By probing the surface with IR spectroscopy during gas exposure, it is possible to understand in unprecedented detail the interaction processes between the sorptive SAW coatings and the gaseousmore » analyte molecules. In this report, we provide details of this measurement system, and also demonstrate the utility of these combined measurements by characterizing the SAW and FTIR-ERS responses of organic thin-film sensor coatings interacting with gas-phase analytes.« less

Unbiased Large Spectroscopic Surveys of Galaxies Selected by SPICA Using Dust Bands

NASA Astrophysics Data System (ADS)

Kaneda, H.; Ishihara, D.; Oyabu, S.; Yamagishi, M.; Wada, T.; Armus, L.; Baes, M.; Charmandaris, V.; Czerny, B.; Efstathiou, A.; Fernández-Ontiveros, J. A.; Ferrara, A.; González-Alfonso, E.; Griffin, M.; Gruppioni, C.; Hatziminaoglou, E.; Imanishi, M.; Kohno, K.; Kwon, J.; Nakagawa, T.; Onaka, T.; Pozzi, F.; Scott, D.; Smith, J.-D. T.; Spinoglio, L.; Suzuki, T.; van der Tak, F.; Vaccari, M.; Vignali, C.; Wang, L.

2017-11-01

The mid-infrared range contains many spectral features associated with large molecules and dust grains such as polycyclic aromatic hydrocarbons and silicates. These are usually very strong compared to fine-structure gas lines, and thus valuable in studying the spectral properties of faint distant galaxies. In this paper, we evaluate the capability of low-resolution mid-infrared spectroscopic surveys of galaxies that could be performed by SPICA. The surveys are designed to address the question how star formation and black hole accretion activities evolved over cosmic time through spectral diagnostics of the physical conditions of the interstellar/circumnuclear media in galaxies. On the basis of results obtained with Herschel far-infrared photometric surveys of distant galaxies and Spitzer and AKARI near- to mid-infrared spectroscopic observations of nearby galaxies, we estimate the numbers of the galaxies at redshift z > 0.5, which are expected to be detected in the polycyclic aromatic hydrocarbon features or dust continuum by a wide (10 deg2) or deep (1 deg2) blind survey, both for a given observation time of 600 h. As by-products of the wide blind survey, we also expect to detect debris disks, through the mid-infrared excess above the photospheric emission of nearby main-sequence stars, and we estimate their number. We demonstrate that the SPICA mid-infrared surveys will efficiently provide us with unprecedentedly large spectral samples, which can be studied further in the far-infrared with SPICA.

Infrared spectroscopic study of super-critical water across the Widom line

NASA Astrophysics Data System (ADS)

Samanta, Tuhin; Dutta, Rajesh; Biswas, Rajib; Bagchi, Biman

2018-06-01

When density is varied at a constant temperature just above the gas-liquid critical temperature, the system is found to exhibit large scale density fluctuations which are often rationalized in terms of crossing of a Widom line. We use the discrete variable representation (DVR) scheme to construct the spectroscopic maps for transition frequencies and transition dipoles, and obtain the infrared spectrum of the Osbnd H stretch in the said temperature-density region of the phase diagram. The infrared lineshape shows a crossover from Lorentzian to Gaussian as we approach the Widom line. The width of the lineshape displays a pronounced maximum.

Infrared spectroscopic studies of myeloid leukemia (ML-1) cells at different phases of the cell cycle

NASA Astrophysics Data System (ADS)

Boydston-White, Susie; Diem, Max

1999-06-01

Advances in infrared spectroscopic methodology permit excellent infrared spectra to be collected from objects as small as single human cells. These advances have lead to an increased interest of the use of infrared spectroscopy as a medical diagnostic tool. Infrared spectra of myeloid leukemia (ML-1) cells are reported for cells derived from an asynchronous, exponentially-growing culture, as well as for cells that were fractionated according to their stage within the cell division cycle. The observed results suggest that the cells' DNA is detectable by infrared spectroscopy mainly when the cell is in the S phase, during the replication of DNA. In the G1 and G2 phases, the DNA is so tightly packed in the nucleus that it appears opaque to infrared radiation. Consequently, the nucleic acid spectral contributions in the G1 and G2 phases would be mostly that of cytoplasmic RNA. These results suggest that infrared spectral changes observed earlier between normal and abnormal cells may have been due to different distributions of cells within the stages of the cell division cycle.

Infrared Spectroscopy of Star Formation in Galactic and Extragalactic Regions

NASA Technical Reports Server (NTRS)

Smith, Howard A.; Hasan, Hashima (Technical Monitor)

2002-01-01

This report details work done in a project involving spectroscopic studies, including data analysis and modeling, of star-formation regions using an ensemble of archival space-based data including some from the Infrared Space Observatory's Long Wavelength Spectrometer and Short Wavelength Spectrometer, and other spectroscopic databases. We will include four kinds of regions: (1) disks around more evolved objects; (2) young, low or high mass pre-main sequence stars in star-formation regions; (3) star formation in external, bright IR (infrared) galaxies; and (4) the galactic center. During this period, work proceeded fully on track and on time. Details on workshops and conferences attended and research results are presented. A preprint article entitled 'The Far Infrared Lines of OH as Molecular Cloud Diagnostics' is included as an appendix.

Structural-conformational aspects of tRNA complexation with chloroethyl nitrosourea derivatives: A molecular modeling and spectroscopic investigation.

PubMed

Agarwal, Shweta; Tyagi, Gunjan; Chadha, Deepti; Mehrotra, Ranjana

2017-01-01

Chloroethyl nitrosourea derivatives (CENUs) represent an important family of anticancer chemotherapeutic agents, which are used in the treatment of different types of cancer such as brain tumors, resistant or relapsed Hodgkin's disease, small cell lung cancer and malignant melanoma. This work focuses towards understanding the interaction of chloroethyl nitrosourea derivatives; lomustine, nimustine and semustine with tRNA using spectroscopic approach in order to elucidate their auxiliary anticancer action mechanism inside the cell. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), Fourier transform infrared difference spectroscopy, circular dichroism spectroscopy and UV-visible spectroscopy were employed to investigate the binding parameters of tRNA-CENUs complexation. Results of present study demonstrate that all CENUs, studied here, interact with tRNA through guanine nitrogenous base residues and possibly further crosslink cytosine residues in paired region of tRNA. Moreover, spectral data collected for nimustine-tRNA and semustine-tRNA complex formation indicates towards the groove-directed-alkylation as their anti-malignant action, which involves the participation of uracil moiety located in major groove of tRNA. Besides this, tRNA-CENUs adduct formation did not alter the native conformation of biopolymer and tRNA remains in A-form after its interaction with all three nitrosourea derivatives studied. The binding constants (K a ) estimated for tRNA complexation with lomustine, nimustine and semustine are 2.55×10 2 M -1 , 4.923×10 2 M -1 and 4.223×10 2 M -1 respectively, which specify weak type of CENU's binding with tRNA. Moreover, molecular modeling simulations were also performed to predict preferential binding orientation of CENUs with tRNA that corroborates well with spectral outcomes. The findings, presented here, recognize tRNA binding properties of CENUs that can further help in rational designing of more specific and efficient RNA targeted chemotherapeutic agents. Copyright © 2016 Elsevier B.V. All rights reserved.

Impact of grain size and structural changes on magnetic, dielectric, electrical, impedance and modulus spectroscopic characteristics of CoFe2O4 nanoparticles synthesized by honey mediated sol-gel combustion method

NASA Astrophysics Data System (ADS)

Singh Yadav, Raghvendra; Kuřitka, Ivo; Vilcakova, Jarmila; Havlica, Jaromir; Masilko, Jiri; Kalina, Lukas; Tkacz, Jakub; Švec, Jiří; Enev, Vojtěch; Hajdúchová, Miroslava

2017-12-01

In this work CoFe2O4 spinel ferrite nanoparticles were synthesized by honey mediated sol-gel combustion method and further annealed at higher temperature 500 °C, 700 °C, 900 °C and 1100 °C. The synthesized spinel ferrite nanoparticles is investigated by x-ray diffraction, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), field emission scanning electron microscopy, x-ray photoelectron spectroscopy and vibrating sample magnetometer. The x-ray diffraction study reveals face-centered cubic spinel cobalt ferrite crystal phase formation. The crystallite size and lattice parameter are increased with annealing temperature. Raman and Fourier transform infrared spectra also confirm spinel ferrite crystal structure of synthesized nanoparticles. The existence of cation at octahedral and tetrahedral site in cobalt ferrite nanoparticles is confirmed by x-ray photoelectron spectroscopy. Magnetic measurement shows increased saturation magnetization 74.4 emu g-1 at higher annealing temperature 1100 °C, high coercivity 1347.3 Oe at lower annealing temperature 500 °C, and high remanent magnetization 32.3 emu g-1 at 900 °C annealing temperature. The magnetic properties of synthesized ferrite nanoparticles can be tuned by adjusting sizes through annealing temperature. Furthermore, the dielectric constant and ac conductivity shows variation with frequency (1-107 Hz), grain size and cation redistribution. The modulus spectroscopy study reveals the role of bulk grain and grain boundary towards the resistance and capacitance. The cole-cole plots in modulus formalism also well support the electrical response of nanoparticles originated from both grain and grain boundaries. The dielectric, electrical, magnetic, impedance and modulus spectroscopic characteristics of synthesized CoFe2O4 spinel ferrite nanoparticles demonstrate the applicability of these nanoparticles for magnetic recording, memory devices and for microwave applications.

Addition of a Fluoride-containing Radiopacifier Improves Micromechanical and Biological Characteristics of Modified Calcium Silicate Cements.

PubMed

Antonijevic, Djordje; Jeschke, Anke; Colovic, Bozana; Milovanovic, Petar; Jevremovic, Danimir; Kisic, Danilo; vom Scheidt, Annika; Hahn, Michael; Amling, Michael; Jokanovic, Vukoman; Busse, Björn; Djuric, Marija

2015-12-01

Calcium silicate cements (CSCs) with the addition of nanohydroxyapatite and calcium carbonate play a critical role in dental applications. To further improve their properties, particularly radiopacity and biointeractivity, the fluoride-containing radiopacifier ytterbium trifluoride (YbF3) was added to their composition, and biological and mechanical characteristics were evaluated. YbF3 was added to 3 different CSCs: cement I (CSC + calcium carbonate), cement II (CSC + nanohydroxyapatite), and Portland cement. Material characterization encompassed measurements of pH, calcium, ytterbium, and fluoride ion release; radiopacity; setting time; porosity; microindentation properties; wettability; and Fourier transform infrared spectroscopic, x-ray diffraction, and scanning electron microscopic analyses. Osteoblast- and osteoclast-like cells were grown on the materials' surface to evaluate their adherence. The addition of calcium carbonate, nanohydroxyapatite, and 30 wt% of YbF3 improved radiopacity and the setting time of experimental cements. The pH values did not differ among the groups. The greatest ytterbium and fluoride releases occurred in the Portland cement + YbF3 group. Combined x-ray diffraction and Fourier transform infrared spectroscopic analysis showed the presence of calcium hydroxide and calcium silicate hydrates. In addition, the presence of calcium ytterbium fluoride and ytterbium oxide proved that YbF3 reacted with cement compounds. Wettability of cement I + YbF3 was superior to other formulations, but its porosity and microindentation properties were weaker than in the Portland cement + YbF3 mixture. Cement II + YbF3 presented micromechanical indentation and porosity characteristics similar to the Portland-based cement formulation. Osteoclast- and osteoblast-like cells adhered to the cements' surfaces without alteration of the cell structural integrity. YbF3-containing CSCs with nanostructured hydroxyapatite and calcium carbonate are well suited for dental application. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Heterogeneously integrated silicon photonics for the mid-infrared and spectroscopic sensing.

PubMed

Chen, Yu; Lin, Hongtao; Hu, Juejun; Li, Mo

2014-07-22

Besides being the foundational material for microelectronics, crystalline silicon has long been used for the production of infrared lenses and mirrors. More recently, silicon has become the key material to achieve large-scale integration of photonic devices for on-chip optical interconnect and signal processing. For optics, silicon has significant advantages: it offers a very high refractive index and is highly transparent in the spectral range from 1.2 to 8 μm. To fully exploit silicon’s superior performance in a remarkably broad range and to enable new optoelectronic functionalities, here we describe a general method to integrate silicon photonic devices on arbitrary foreign substrates. In particular, we apply the technique to integrate silicon microring resonators on mid-infrared compatible substrates for operation in the mid-infrared. These high-performance mid-infrared optical resonators are utilized to demonstrate, for the first time, on-chip cavity-enhanced mid-infrared spectroscopic analysis of organic chemicals with a limit of detection of less than 0.1 ng.

Infrared and Raman spectroscopic methods for characterization of Taxus baccata L.--Improved taxane isolation by accelerated quality control and process surveillance.

PubMed

Gudi, Gennadi; Krähmer, Andrea; Koudous, Iraj; Strube, Jochen; Schulz, Hartwig

2015-10-01

Different yew species contain poisonous taxane alkaloids which serve as resources for semi-synthesis of anticancer drugs. The highly variable amounts of taxanes demand new methods for fast characterization of the raw plant material and the isolation of the target structures during phyto extraction. For that purpose, applicability of different vibrational spectroscopy methods in goods receipt of raw plant material and in process control was investigated and demonstrated in online tracking isolation and purification of the target taxane 10-deacetylbaccatin III (10-DAB) during solvent extraction. Applying near (NIRS) and mid infrared spectroscopy (IRS) the amount of botanical impurities in mixed samples of two different yew species (R(2)=0.993), the leave-to-wood ratio for Taxus baccata material (R(2)=0.94) and moisture in dried yew needles (R(2)=0.997) can be quantified. By partial least square analysis (PCA) needles of different Coniferales species were successfully discriminated by Attenuated Total Reflectance-Fourier-Transform Infrared Spectroscopy (ATR-FT-IR). The analytical potential of ATR-FT-IR and Fourier Transform-Raman Spectroscopy (FT-RS) in process control of extraction and purification of taxanes is demonstrated for determination of the water content in methanolic yew extracts (R(2)=0.999) and for quantification of 10-DAB (R(2)=0.98) on a highly sophisticated level. The decrease of 10-DAB in the plant tissue during extraction was successfully visualized by FT-IR imaging of thin cross sections providing new perspectives for process control and design. Copyright © 2015 Elsevier B.V. All rights reserved.

Density functional theory and Ab initio studies of vibrational spectroscopic (FT-IR, FT-Raman and UV) first order hyperpolarizabilities, NBO, HOMO-LUMO and TD-DFT analysis of the 1,2-Dihydropyrazolo (4,3-E) Pyrimidin-4-one

NASA Astrophysics Data System (ADS)

Ramachandran, G.; Muthu, S.; Uma Maheswari, J.

2013-02-01

Fourier transform Raman and Fourier transform infrared spectra of 1,2-Dihydropyrazolo (4,3-E) Pyrimidin-4-one were recorded in the regions 3500-100 cm-1 and 4000-400 cm-1 respectively in the solid phase. 1,2-Dihydropyrazolo (4, 3-E) Pyrimidin-4-one is used to treat hyperuricemia and its complication including chronic gout. The equilibrium geometry harmonic vibrational frequencies, infrared intensities and Raman intensities were calculated by Hartee Fock and density functional B3LYP methods with 6-31G (d, p) basis set, using Gaussian 03W program package on a Pentium IV/1.6 GHz personal computer. The thermodynamic functions of the title compound were also performed at the above methods and basis set. A detailed interpretation of the infrared and Raman spectra of 1,2-Dihydropyrazolo (4,3-E) Pyrimidin-4-one is reported. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. UV-vis of the compound was recorded. The calculated HOMO and LUMO energies show that chemical activity of the molecule. The first order hyperpolarizability (β) of this novel molecular system and related properties of 1,2-Dihydropyrazolo (4,3-E) Pyrimidin-4-one are calculated using HF/6-31G (d, p) method on the finite field approach. The experimental spectra also coincide satisfactorily with those of theoretically constructed spectra.

CIRS-lite, a Fourier Transform Spectrometer for Low-Cost Planetary Missions

NASA Technical Reports Server (NTRS)

Brasunas, J.; Bly, V.; Edgerton, M.; Gong, Q.; Hagopian, J.; Mamakos, W.; Morelli, A.; Pasquale, B.; Strojny, C.

2011-01-01

Passive spectroscopic remote sensing of planetary atmospheres and surfaces in the thermal infrared is a powerful tool for obtaining information about surface and atmospheric temperatures, composition, and dynamics (via the thermal wind equation). Due to its broad spectral coverage, the Fourier transform spectrometer (FTS) is particularly suited to the exploration and discovery of molecular species. NASA's Goddard Space Flight Center (GSFC) developed the CIRS (Composite Infrared Spectrometer) FTS for the NASA/ESA Cassini mission to the Saturnian system. CIRS observes Saturn, Titan, icy moons such as Enceladus, and the rings in thermal self-emission over the spectral range of 7 to 1000 ell11. CIRS has given us important new insights into stratospheric composition and jets on Jupiter and Saturn, the cryo-geyser and thermal stripes on Enceladus, and the winter polar vortex on Titan. CIRS has a mass of 43 kg, contrasted with the earlier GSFC FTS, pre-Voyager IRIS (14 kg). Future low-cost planetary missions will have very tight constraints on science payload mass, thus we must endeavor to return to IRIS-level mass while maintaining CIRS-level science capabilities ("do more with less"). CIRS-lite achieves this by pursuing: a) more sensitive infrared detectors (high Tc superconductor) to enable smaller optics. b) changed long wavelength limit from 1000 to 300 microns to reduce diffraction by smaller optics. c) CVD (chemical vapor deposition) diamond beam-splitter for broad spectral coverage. d) single FTS architecture instead of a dual FTS architecture. e) novel materials, such as single crystal silicon for the input telescope primary.

Synthesis and radical scavenging activity of 6-hydroxyl-4-methylcoumarin and its derivatives

NASA Astrophysics Data System (ADS)

Jumal, Juliana; Ayomide, Adetunji Fridaos

2018-06-01

Four compounds of coumarin derivatives namely 6-hydroxyl-4-methylcoumarin (I), 6-hydroxyl-4-methyl-5-(p-nitrophenyl azocoumarin) (II), 6-hydroxyl-4-methyl-5,7-(bis-p-nitrophenyl azocoumarin) (III) and 6-hydroxyl-4-methyl-5,7-(bis-p-chlorophenyl azocoumarin) (IV) were successfully synthesized. These compounds were prepared by reacting hydroquinone with ethylacetoacetate and selected anilines which are chloro and nitro aniline. All synthesized compounds were characterized by CHN micro-elemental analysis, 1H Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopic methods. The infrared spectra of these compounds exhibited five important stretching vibrations: ʋ(-OH), ʋ(C=O), ʋ(C=C), ʋ(C-O) and ʋ(C-N) at 3441-3359 cm-1, 1604-1632 cm-1, 1581-1496 cm-1, 1331-1225 cm-1, 1251-1109 cm-1, respectively. 1H NMR spectra of these compounds show the presence of proton aromatic, proton methyl and proton pyrone ring with the chemical shift at δH 7.00-8.70 ppm, δH 2.20-2.50 ppm and δH 6.10-6.90 ppm, respectively. CHN analysis results of all compounds are in good agreement with the calculated values. All the synthesized compounds were evaluated for their antioxidant activity using DPPH method and ascorbic acid used as the standard. UV-Vis spectroscopic technique was used to investigate the absorbance of these compounds. Compound (II) shows high antioxidant activities compared to compound (I), (III) and (IV) which show moderate to low activities.

Secular trends in plume composition of Erebus volcano, Antarctica

NASA Astrophysics Data System (ADS)

Ilanko, Tehnuka; Oppenheimer, Clive; Kyle, Philip; Burgisser, Alain

2015-04-01

Long-lived active lava lakes, such as that in the summit crater of Erebus volcano, Antarctica, provide a rare insight into sustained magma convection and degassing over long timescales. Erebus lava lake has been persistently active since 1972, and potentially for several decades or more previously (Ross, 1847). Since the 1970s, regular scientific expeditions, lasting a few weeks in the austral summers, have made observations of the lake activity. Annual Fourier transform infrared (FTIR) spectroscopic gas measurements began in 2004 (Oppenheimer and Kyle, 2008; Oppenheimer et al., 2009), yielding an extensive, if discontinuous, time series of infrared absorption spectra. These data, once processed, provide insights into temporal evolution of the gas geochemistry in terms of seven molecular species: H2O, CO2, CO, SO2, HCl, HF, and OCS. FTIR spectroscopic data are now available over ten field seasons, totalling roughly 1.8 million spectra and increasing each year. This period spans changes to crater morphology, fluctuations in lava lake surface area (Jones et al., 2014), and two episodes of increased explosive activity (2005-06 and 2013). The dataset captures both long-term degassing trends and short-lived features, such as cyclicity in gas emissions during passive degassing (Ilanko et al., 2015) and compositions released by explosive bubble-burst eruptions. We consider the longer-term changes to gas ratios occurring within (i.e. over days to weeks) and between annual field seasons, their potential causes, and their relationship to observations of eruptive behaviour and crater morphology.

Structural, spectral, DFT and biological studies on macrocyclic mononuclear ruthenium (II) complexes

NASA Astrophysics Data System (ADS)

Muthukkumar, M.; Kamal, C.; Venkatesh, G.; Kaya, C.; Kaya, S.; Enoch, Israel V. M. V.; Vennila, P.; Rajavel, R.

2017-11-01

Macrocyclic mononuclear ruthenium (II) complexes have been synthesized by condensation method [Ru (L1, L2, L3) Cl2] L1 = (C36 H31 N9), L2= (C42H36N8), L3= (C32H32 N8)]. These ruthenium complexes have been established by elemental analyses and spectroscopic techniques (Fourier transform infrared spectroscopy (FT-IR), 1H- nuclear magnetic resonance (NMR), 13C- NMR and Electrospray ionization mass spectrometry (ESI-MS)). The coordination mode of the ligand has been confirmed and the octahedral geometry around the ruthenium ion has been revealed. Binding affinity and binding mode of ruthenium (II) complexes with Bovine serum Albumin (BSA) have been characterized by Emission spectra analysis. UV-Visible and fluorescence spectroscopic techniques have also been utilized to examine the interaction between ligand and its complexes L1, L2, & L3 with BSA. Chemical parameters and molecular structure of Ru (II) complexes L1H, L2H, & L3H have been determined by DFT coupled with B3LYP/6-311G** functional in both the gaseous and aqueous phases.

[Spectral Analysis about the Pharmaceutical Cocrystal Formation of Piracetam and 3-Hydroxybenzoic Acid].

PubMed

Zhang, Hui-li; Xia, Yi; Hong, Zhi; Du, Yong

2015-07-01

Pharmaceutical cocrystal can improve physical and chemical properties of active pharmaceutical ingredient (API), meanwhile this feature has shown great potential in improving the pharmaceutical's properties and characteristics. In this study, cocrystal formation between piracetam and 3-hydroxybenzoic acid (3HBA) using grinding method has been characterized by Fourier transform infrared (FTIR), Raman and terahertz (THz) spectroscopical techniques. The vibrational modes of different motions are obtained by the assignment of the peaks in the spectra of the starting materials and the cocrystal components. FTIR, Raman and THz spectroscopical results show that the vibrational modes of the cocrystal are different from those of the starting materials. In addition, the dynamic process of the above cocrystal formation is investigated in-depth with Raman and THz spec- tra. Piracetam-3HBA cocrystal is formed pretty fast in first several minutes, and then the formation rate becomes slow. After 35 minutes, such formation process has been completed. The results offer the theoretical benchmark and unique means for real-time monitoring pharmaceutical cocrystal formation and also the corresponding quantitative analysis in the pharmaceutical field.

Spectroscopic Evidence of the Improvement of Reactive Iron Mineral Content in Red Soil by Long-Term Application of Swine Manure

PubMed Central

Huang, Chichao; Liu, Sha; Li, Ruizhi; Sun, Fusheng; Zhou, Ying; Yu, Guanghui

2016-01-01

Mineral elements in soil solutions are thought to be the precursor of the formation of reactive minerals, which play an important role in global carbon (C) cycling. However, information regarding the regulation of mineral elements release in soil is scarce. Here, we examined the long-term (i.e., 23 yrs) effects of fertilisation practices on Fe minerals in a red soil in Southern China. The results from chemical analysis and Fourier-transform infrared spectroscopy showed that long-term swine manure (M) treatment released greater amounts of minerals into soil solutions than chemical fertilisers (NPK) treatment, and Fe played a dominant role in the preservation of dissolved organic C. Furthermore, Fe K-edge X-ray absorption near-edge fine structure spectroscopy demonstrated that reactive Fe minerals were mainly composed of less crystalline ferrihydrite in the M-treated soil and more crystalline goethite in the NPK-treated soil. In conclusion, this study reported spectroscopic evidence of the improvement of reactive Femineral content in the M-treated soil colloids when compared to NPK-treated soil colloids. PMID:26752419

Biochemical Monitoring of Spinal Cord Injury by FT-IR Spectroscopy—Effects of Therapeutic Alginate Implant in Rat Models

PubMed Central

Uckermann, Ortrud; Sitoci-Ficici, Kerim H.; Later, Robert; Beiermeister, Rudolf; Doberenz, Falko; Gelinsky, Michael; Leipnitz, Elke; Schackert, Gabriele; Koch, Edmund; Sablinskas, Valdas; Steiner, Gerald; Kirsch, Matthias

2015-01-01

Spinal cord injury (SCI) induces complex biochemical changes, which result in inhibition of nervous tissue regeneration abilities. In this study, Fourier-transform infrared (FT-IR) spectroscopy was applied to assess the outcomes of implants made of a novel type of non-functionalized soft calcium alginate hydrogel in a rat model of spinal cord hemisection (n = 28). Using FT-IR spectroscopic imaging, we evaluated the stability of the implants and the effects on morphology and biochemistry of the injured tissue one and six months after injury. A semi-quantitative evaluation of the distribution of lipids and collagen showed that alginate significantly reduced injury-induced demyelination of the contralateral white matter and fibrotic scarring in the chronic state after SCI. The spectral information enabled to detect and localize the alginate hydrogel at the lesion site and proved its long-term persistence in vivo. These findings demonstrate a positive impact of alginate hydrogel on recovery after SCI and prove FT-IR spectroscopic imaging as alternative method to evaluate and optimize future SCI repair strategies. PMID:26559822

Evaluation of toxic agent effects on lung cells by fiber evanescent wave spectroscopy.

PubMed

Lucas, Pierre; Le Coq, David; Juncker, Christophe; Collier, Jayne; Boesewetter, Dianne E; Boussard-Plédel, Catherine; Bureau, Bruno; Riley, Mark R

2005-01-01

Biochemical changes in living cells are detected using a fiber probe system composed of a single chalcogenide fiber acting as both the sensor and transmission line for infrared optical signals. The signal is collected via evanescent wave absorption along the tapered sensing zone of the fiber. We spectroscopically monitored the effects of the surfactant Triton X-100, which serves as a toxic agent simulant on a transformed human lung carcinoma type II epithelial cell line (A549). We observe spectral changes between 2800-3000 cm(-1) in four absorptions bands, which are assigned to hydrocarbon vibrations of methylene and methyl groups in membrane lipids. Comparison of fiber and transmission spectra shows that the present technique allows one to locally probe the cell plasma membrane in the lipid spectral region. These optical responses are correlated with cellular metabolic activity measurements and LDH (lactate dehydrogenase) release assays that indicate a loss of cellular function and membrane integrity as would be expected in response to the membrane solubilizing Triton. The spectroscopic technique shows a significantly greater detection resolution in time and concentration.

Near-infrared spectroscopic tissue imaging for medical applications

DOEpatents

Demos,; Stavros, Staggs [Livermore, CA; Michael, C [Tracy, CA

2006-03-21

Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

Near-infrared spectroscopic tissue imaging for medical applications

DOEpatents

Demos, Stavros [Livermore, CA; Staggs, Michael C [Tracy, CA

2006-12-12

Near infrared imaging using elastic light scattering and tissue autofluorescence are explored for medical applications. The approach involves imaging using cross-polarized elastic light scattering and tissue autofluorescence in the Near Infra-Red (NIR) coupled with image processing and inter-image operations to differentiate human tissue components.

Near-infrared and Mid-infrared Spectroscopic Techniques for a Fast and Nondestructive Quality Control of Thymi herba.

PubMed

Pezzei, Cornelia K; Schönbichler, Stefan A; Hussain, Shah; Kirchler, Christian G; Huck-Pezzei, Verena A; Popp, Michael; Krolitzek, Justine; Bonn, Günther K; Huck, Christian W

2018-04-01

In this study, novel near-infrared and attenuated total reflectance mid-infrared spectroscopic methods coupled with multivariate data analysis were established enabling the determination of thymol, rosmarinic acid, and the antioxidant capacity of Thymi herba. A new high-performance liquid chromatography method and UV-Vis spectroscopy were applied as reference methods. Partial least squares regressions were carried out as cross and test set validations. To reduce systematic errors, different data pretreatments, such as multiplicative scatter correction, 1st derivative, or 2nd derivative, were applied on the spectra. The performances of the two infrared spectroscopic techniques were evaluated and compared. In general, attenuated total reflectance mid-infrared spectroscopy demonstrated a slightly better predictive power (thymol: coefficient of determination = 0.93, factors = 3, ratio of performance to deviation = 3.94; rosmarinic acid: coefficient of determination = 0.91, factors = 3, ratio of performance to deviation = 3.35, antioxidant capacity: coefficient of determination = 0.87, factors = 2, ratio of performance to deviation = 2.80; test set validation) than near-infrared spectroscopy (thymol: coefficient of determination = 0.90, factors = 6, ratio of performance to deviation = 3.10; rosmarinic acid: coefficient of determination = 0.92, factors = 6, ratio of performance to deviation = 3.61, antioxidant capacity: coefficient of determination = 0.91, factors = 6, ratio of performance to deviation = 3.42; test set validation). The capability of infrared vibrational spectroscopy as a quick and simple analytical tool to replace conventional time and chemical consuming analyses for the quality control of T. herba could be demonstrated. Georg Thieme Verlag KG Stuttgart · New York.

Structural, vibrational spectroscopic and quantum chemical studies on indole-3-carboxaldehyde

NASA Astrophysics Data System (ADS)

Premkumar, R.; Asath, R. Mohamed; Mathavan, T.; Benial, A. Milton Franklin

2017-05-01

The potential energy surface (PES) scan was performed for indole-3-carboxaldehyde (ICA) and the most stable optimized conformer was predicted using DFT/B3LYP method with 6-31G basis set. The vibrational frequencies of ICA were theoretically calculated by the DFT/B3LYP method with cc-pVTZ basis set using Gaussian 09 program. The vibrational spectra were experimentally recorded by Fourier transform-infrared (FT-IR) and Fourier transform-Raman spectrometer (FT-Raman). The computed vibrational frequencies were scaled by scaling factors to yield a good agreement with observed vibrational frequencies. The theoretically calculated and experimentally observed vibrational frequencies were assigned on the basis of potential energy distribution (PED) calculation using VEDA 4.0 program. The molecular interaction, stability and intramolecular charge transfer of ICA were studied using frontier molecular orbitals (FMOs) analysis and Mulliken atomic charge distribution shows the distribution of the atomic charges. The presence of intramolecular charge transfer was studied using natural bond orbital (NBO) analysis.

Chemical and spectroscopic analyses of organic matter transformation in warming tundra soils

NASA Astrophysics Data System (ADS)

Herndon, E.; Roy Chowdhury, T.; Mann, B. F.; Graham, D. E.; Bargar, J.; Gu, B.; Liang, L.

2013-12-01

Many tundra soils are currently major carbon sinks; however, an increase in temperature may shift these systems to C sources and create a positive feedback for warming. In order to predict future C release from tundra soils, it is necessary to quantify rates of SOM degradation and to identify the reactants and products of microbial decomposition reactions. In this study, multiple spectroscopic techniques are used to investigate SOM during laboratory incubations of tundra soils. We aim to characterize the chemical transformation of organic matter during decomposition as a function of temperature and geochemistry. Frozen soil cores were obtained from the Barrow Environmental Observatory (BEO) in northern Alaska as part of the Next Generation Ecosystem Experiment Arctic project. To investigate the influence of temperature on organic matter degradation and compositional changes, soil horizons from each core were homogenized and soil material was incubated at -2°C, +4°C, or +8°C. Samples were sacrificed periodically over 100 days, and chemical and physical extractions were used to separate SOM into operationally-defined pools, including light (density < 1.6 g cm-2) and mineral-bound, and water-, acid-, base-, and non-soluble fractions. A suite of wet-chemical and spectroscopic analyses was used to measure CO2 and CH4 formation and soil C compositional changes, including techniques such as Fourier transform infrared spectroscopy, high performance liquid chromatography (HPLC), high resolution mass spectrometry, and X-ray absorption spectroscopy. Detailed chemical and spectroscopic analyses reveal significant differences amongst extracts and with depth in the soil. In general, more organic C was extracted in the base than in the acid and water fractions, and mineral-bound organic C increased with depth. The water-soluble C fraction showed the lowest molar absorptivity of the three extracts and consisted of mostly lower-molecular weight organics. Acid-soluble C increased with increasing mineral content of the soil, likely due to the presence of labile organics bound to Fe-oxide minerals. In addition, 13-80% of the total C remained in soil following sequential chemical extractions, suggesting resistance to degradation and strong association with minerals. Soil incubations showed temperature-dependent production of CO2 and CH4, indicating microbial C degradation. The masses of CO2 and CH4 released represent only a small fraction of the total soil organic C, and little change in was observed in bulk SOM. However, the water-soluble C exhibited significant vulnerability to degradation, as revealed by HPLC and spectroscopic analyses, and these results suggest potential pathways for chemical transformation of soil C during decomposition. The results of this study will contribute to a computational modeling framework for understanding sources and rates of C fluxes from soils to the atmosphere and will help elucidate potential changes to Arctic tundra systems subject to warming.

Electron paramagnetic resonance and FT-IR spectroscopic studies of glycine anhydride and betaine hydrochloride

NASA Astrophysics Data System (ADS)

Halim Başkan, M.; Kartal, Zeki; Aydın, Murat

2015-12-01

Gamma irradiated powders of glycine anhydride and betaine hydrochloride have been investigated at room temperature by electron paramagnetic resonance (EPR). In these compounds, the observed paramagnetic species were attributed to the R1 and R2 radicals, respectively. It was determined that the free electron interacted with environmental protons and 14N nucleus in both radicals. The EPR spectra of gamma irradiated powder samples remained unchanged at room temperature for two weeks after irradiation. Also, the Fourier Transform Infrared (FT-IR), FT-Raman and thermal analyses of both compounds were investigated. The functional groups in the molecular structures of glycine anhydride and betaine hydrochloride were identified by vibrational spectroscopies (FT-IR and FT-Raman).

Synthesis, growth, structural, spectroscopic and optical studies of a new semiorganic nonlinear optical crystal: L-valine hydrochloride.

PubMed

Kirubavathi, K; Selvaraju, K; Valluvan, R; Vijayan, N; Kumararaman, S

2008-04-01

Single crystals of a new semiorganic nonlinear optical (NLO) material, L-valine hydrochloride (LVHCl), having dimensions up to 20 mm x 6 mm x 4 mm have been grown by slow evaporation solution growth technique. Single crystal X-ray diffraction studies confirm that the grown crystal belongs to the monoclinic system. The functional groups presented in the crystal were confirmed by Fourier transform infrared (FTIR) technique. Optical transmission spectrum shows very low absorption in the entire visible region. Differential thermal and thermogravimetric analyses confirmed that the crystal is stable up to 211 degrees C. The powder second harmonic generation (SHG) efficiency of LVHCl is 1.7 times efficient as potassium dihydrogen phosphate (KDP).

Adsorption properties of biomass-based activated carbon prepared with spent coffee grounds and pomelo skin by phosphoric acid activation

NASA Astrophysics Data System (ADS)

Ma, Xiaodong; Ouyang, Feng

2013-03-01

Activated carbon prepared from spent coffee grounds and pomelo skin by phosphoric acid activation had been employed as the adsorbent for ethylene and n-butane at room temperature. Prepared activated carbon was characterized by means of nitrogen adsorption-desorption, X-ray powder diffraction, scanning electron microscope and Fourier transform infrared spectroscope. It was confirmed that pore structure played an important role during the adsorption testes. Adsorption isotherms of ethylene and n-butane fitted well with Langmuir equation. The prepared samples owned better adsorption capacity for n-butane than commercial activated carbon. Isosteric heats of adsorptions at different coverage were calculated through Clausius-Clapeyron equation. Micropore filling effect was explained in a thermodynamic way.

Blue light emitting diesel soot for photonic applications

NASA Astrophysics Data System (ADS)

Swapna, M. S.; Sankararaman, S.

2018-01-01

The present work is the first report of producing blue light emission from phosphor free and low-cost material—the diesel soot from the internal combustion engines (ICEs). The structural morphology is analyzed by field emission scanning electron microscopy and high-resolution transmission electron microscopy. The optical characterization is done by recording UV-visible spectrum and photoluminescent Spectrum. The CIE plot and the power spectrum for the sample show blue emission. This is further verified by collecting diesel soot from the ICE of different year of make. A visual confirmation of blue emission is obtained by exciting the sample with UV laser. The presence of various allotropic forms of carbon in the sample is identified by x-ray diffraction, Fourier transform infrared and Raman spectroscopic analysis.

Spectroscopic characterization of cell membranes and their constituents of the plant-associated soil bacterium Azospirillum brasilense

NASA Astrophysics Data System (ADS)

Kamnev, A. A.; Antonyuk, L. P.; Matora, L. Yu.; Serebrennikova, O. B.; Sumaroka, M. V.; Colina, M.; Renou-Gonnord, M.-F.; Ignatov, V. V.

1999-05-01

Structural and compositional features of bacterial membranes and some of their isolated constituents (cell surface lipopolysaccharide, phospholipids) of the plant-growth-promoting diazotrophic rhizobacterium Azospirillum brasilense (wild-type strain Sp245) were characterized using Fourier transform infrared (FTIR) spectroscopy and some other techniques. FTIR spectra of the cell membranes were shown to comprise the main vibration modes of the relevant lipopolysaccharide and protein components which are believed to be involved in associative plant-bacterium interactions, as well as of phospholipid constituents. The role and functions of metal cations in the structural organization and physicochemical properties of bacterial cell membranes are also discussed considering their accumulation in the membranes from the culture medium.

Enhanced Vibrational Spectroscopies as Tools for Small Molecule Biosensing

PubMed Central

Boujday, Souhir; Lamy de la Chapelle, Marc; Srajer, Johannes; Knoll, Wolfgang

2015-01-01

In this short summary we summarize some of the latest developments in vibrational spectroscopic tools applied for the sensing of (small) molecules and biomolecules in a label-free mode of operation. We first introduce various concepts for the enhancement of InfraRed spectroscopic techniques, including the principles of Attenuated Total Reflection InfraRed (ATR-IR), (phase-modulated) InfraRed Reflection Absorption Spectroscopy (IRRAS/PM-IRRAS), and Surface Enhanced Infrared Reflection Absorption Spectroscopy (SEIRAS). Particular attention is put on the use of novel nanostructured substrates that allow for the excitation of propagating and localized surface plasmon modes aimed at operating additional enhancement mechanisms. This is then be complemented by the description of the latest development in Surface- and Tip-Enhanced Raman Spectroscopies, again with an emphasis on the detection of small molecules or bioanalytes. PMID:26343666

A case study of real-time monitoring of solid-state phase transformations in acoustically levitated particles using near infrared and Raman spectroscopy.

PubMed

Rehder, Sönke; Wu, Jian X; Laackmann, Julian; Moritz, Hans-Ulrich; Rantanen, Jukka; Rades, Thomas; Leopold, Claudia S

2013-01-23

The objective of this study was to monitor the amorphous-to-crystalline solid-state phase transformation kinetics of the model drug ibuprofen with spectroscopic methods during acoustic levitation. Chemical and physical information was obtained by real-time near infrared (NIRS) and Raman spectroscopy measurements. The recrystallisation kinetic parameters (overall recrystallisation rate constant β and the time needed to reach 50% of the equilibrated level t(50)), were determined using a multivariate curve resolution approach. The acoustic levitation device coupled with non-invasive spectroscopy enabled monitoring of the recrystallisation process of the difficult-to-handle (adhesive) amorphous sample. The application of multivariate curve resolution enabled isolation of the underlying pure spectra, which corresponded well with the reference spectra of amorphous and crystalline ibuprofen. The recrystallisation kinetic parameters were estimated from the recrystallisation profiles. While the empirical recrystallisation rate constant determined by NIR and Raman spectroscopy were comparable, the lag time for recrystallisation was significantly lower with Raman spectroscopy as compared to NIRS. This observation was explained by the high energy density of the Raman laser beam, which might have led to local heating effects of the sample and thus reduced the recrystallisation onset time. It was concluded that acoustic levitation with NIR and Raman spectroscopy combined with multivariate curve resolution allowed direct determination of the recrystallisation kinetics of amorphous drugs and thus is a promising technique for monitoring solid-state phase transformations of adhesive small-sized samples during the early phase of drug development. Copyright © 2012 Elsevier B.V. All rights reserved.

Detection and identification of bacteria in a juice matrix with Fourier transform-near infrared spectroscopy and multivariiate analysis.

PubMed

Rodriguez-Saona, L E; Khambaty, F M; Fry, F S; Dubois, J; Calvey, E M

2004-11-01

The use of Fourier transform-near infrared (FT-NIR) spectroscopy combined with multivariate pattern recognition techniques was evaluated to address the need for a fast and senisitive method for the detection of bacterial contamination in liquids. The complex cellular composition of bacteria produces FT-NIR vibrational transitions (overtone and combination bands), forming the basis for identification and subtyping. A database including strains of Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Bacillus cereus, and Bacillus thuringiensis was built, with special care taken to optimize sample preparation. The bacterial cells were treated with 70% (vol/vol) ethanolto enhance safe handling of pathogenic strains and then concentrated on an aluminum oxide membrane to obtain a thin bacterial film. This simple membrane filtration procedure generated reproducible FT-NIR spectra that allowed for the rapid discrimination among closely related strains. Principal component analysis and soft independent modeling of class analogy of transformed spectra in the region 5,100 to 4,400 cm(-1) were able to discriminate between bacterial species. Spectroscopic analysis of apple juices inoculated with different strains of E. coli at approximately 10(5) CFU/ml showed that FT-NIR spectralfeatures are consistent with bacterial contamination and soft independent modeling of class analogy correctly predicted the identity of the contaminant as strains of E. coli. FT-NIR in conjunction with multivariate techniques can be used for the rapid and accurate evaluation of potential bacterial contamination in liquids with minimal sample manipulation, and hence limited exposure of the laboratory worker to the agents.

Comparing dried and liquid blood serum samples of depressed patients: An analysis by Raman and infrared spectroscopy methods.

PubMed

Depciuch, J; Parlinska-Wojtan, M

2018-02-20

Depression is a serious mental illness. To study the mechanism of depression and search for new, more effective therapies, animal models are often used. Unfortunately, none of the available models reflects all the symptoms of depression. Therefore researchers are looking for new tools to diagnose depression. Unfortunately, the nowadays-available depression diagnosis methods are only psychological tests. However, it is known, that the amount of phospholipids, proteins and lipids decreases during depression. Raman and FTIR (Fourier Transform Infra Red) spectroscopies provide information on the chemical compounds in the measured sample e.g. blood serum. These spectroscopic techniques may thus become reliable and accurate tools for evaluating changes in the amount of phospholipids and proteins in depression disease. In this study differences between dried and liquid blood serum samples of healthy and depressed individuals measured by Raman (range 0-3000cm -1 ) and FTIR (Fourier Transform Infrared) (range 900-3000cm -1 ) spectroscopy were evaluated. The resulting spectra and accurate analysis led to the conclusion that an appropriate measurement of the background and the elimination of peaks from water had the greatest impact on the reliability of the results. Furthermore, after detailed studies of FTIR and Raman spectra of dried and liquid blood serum samples, including a complete analysis of peaks after Kramers-Kröning (KK) transformation, it was found that the sample preparation did not affect the results obtained by Raman spectroscopy. In FTIR measurements only a minimal effect on peak intensity was observed. Copyright © 2017 Elsevier B.V. All rights reserved.

Using Fourier transform infrared spectroscopy to evaluate biological effects induced by photodynamic therapy.

PubMed

Lima, Cassio A; Goulart, Viviane P; Correa, Luciana; Zezell, Denise M

2016-07-01

Vibrational spectroscopic methods associated with multivariate statistical techniques have been succeeded in discriminating skin lesions from normal tissues. However, there is no study exploring the potential of these techniques to assess the alterations promoted by photodynamic effect in tissue. The present study aims to demonstrate the ability of Fourier Transform Infrared (FTIR) spectroscopy on Attenuated total reflection (ATR) sampling mode associated with principal component-linear discriminant analysis (PC-LDA) to evaluate the biochemical changes caused by photodynamic therapy (PDT) in skin neoplastic tissue. Cutaneous neoplastic lesions, precursors of squamous cell carcinoma (SCC), were chemically induced in Swiss mice and submitted to a single session of 5-aminolevulinic acid (ALA)-mediated PDT. Tissue sections with 5 μm thickness were obtained from formalin-fixed paraffin-embedded (FFPE) and processed prior to the histopathological analysis and spectroscopic measurements. Spectra were collected in mid-infrared region using a FTIR spectrometer on ATR sampling mode. Principal Component-Linear Discriminant Analysis (PC-LDA) was applied on preprocessed second derivatives spectra. Biochemical changes were assessed using PCA-loadings and accuracy of classification was obtained from PC-LDA . Sub-bands of Amide I (1,624 and 1,650 cm(-1) ) and Amide II (1,517 cm(-1) ) indicated a protein overexpression in non-treated and post-PDT neoplastic tissue compared with healthy skin, as well as a decrease in collagen fibers (1,204, 1,236, 1,282, and 1,338 cm(-1) ) and glycogen (1,028, 1,082, and 1,151 cm(-1) ) content. Photosensitized neoplastic tissue revealed shifted peak position and decreased β-sheet secondary structure of proteins (1,624 cm(-1) ) amount in comparison to non-treated neoplastic lesions. PC-LDA score plots discriminated non-treated neoplastic skin spectra from post-PDT cutaneous lesions with accuracy of 92.8%, whereas non-treated neoplastic skin was discriminated from healthy tissue with 93.5% accuracy and post-PDT cutaneous lesions was discriminated from healthy tissue with 89.7% accuracy. PC-LDA was able to discriminate ATR-FTIR spectra of non-treated and post-PDT neoplastic lesions, as well as from healthy skin. Thus, the method can be used for early diagnosis of premalignant skin lesions, as well as to evaluate the response to photodynamic treatment. Lasers Surg. Med. 48:538-545, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Analysis of pork adulteration in beef meatball using Fourier transform infrared (FTIR) spectroscopy.

PubMed

Rohman, A; Sismindari; Erwanto, Y; Che Man, Yaakob B

2011-05-01

Meatball is one of the favorite foods in Indonesia. The adulteration of pork in beef meatball is frequently occurring. This study was aimed to develop a fast and non destructive technique for the detection and quantification of pork in beef meatball using Fourier transform infrared (FTIR) spectroscopy and partial least square (PLS) calibration. The spectral bands associated with pork fat (PF), beef fat (BF), and their mixtures in meatball formulation were scanned, interpreted, and identified by relating them to those spectroscopically representative to pure PF and BF. For quantitative analysis, PLS regression was used to develop a calibration model at the selected fingerprint regions of 1200-1000 cm(-1). The equation obtained for the relationship between actual PF value and FTIR predicted values in PLS calibration model was y = 0.999x + 0.004, with coefficient of determination (R(2)) and root mean square error of calibration are 0.999 and 0.442, respectively. The PLS calibration model was subsequently used for the prediction of independent samples using laboratory made meatball samples containing the mixtures of BF and PF. Using 4 principal components, root mean square error of prediction is 0.742. The results showed that FTIR spectroscopy can be used for the detection and quantification of pork in beef meatball formulation for Halal verification purposes. Copyright © 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

In Situ Infrared Spectroscopic Study of Forsterite Carbonation in Wet Supercritical CO2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loring, John S.; Thompson, Christopher J.; Wang, Zheming

2011-07-19

Carbonation reactions are central to the prospect of CO2 trapping by mineralization in geologic reservoirs. In contrast to the relevant aqueous-mediated reactions, little is known about the propensity for carbonation in the long-term partner fluid: water-containing supercritical carbon dioxide (‘wet’ scCO2). We employed in situ mid-infrared spectroscopy to follow the reaction of a model silicate mineral (forsterite, Mg2SiO4) for 24 hr with wet scCO2 at 50°C and 180 atm, using water concentrations corresponding to 0%, 55%, 95%, and 136% saturation. Results show a dramatic dependence of reactivity on water concentration and the presence of liquid water on the forsterite particles.more » Exposure to neat scCO2 showed no detectable carbonation reaction. At 55% and 95% water saturation, a liquid-like thin water film was detected on the forsterite particles; less than 1% of the forsterite transformed, mostly within the first 3 hours of exposure to the fluid. At 136% saturation, where an (excess) liquid water film approximately several nanometers thick was intentionally condensed on the forsterite, the carbonation reaction proceeded continuously for 24 hr with 10% to 15% transformation. Our collective results suggest constitutive links between water concentration, water film formation, reaction rate and extent, and reaction products in wet scCO2.« less

On the use of band-target entropy minimization to simplify the interpretation of two-dimensional correlation spectroscopy.

PubMed

Widjaja, Effendi; Tan, Boon Hong; Garland, Marc

2006-03-01

Two-dimensional (2D) correlation spectroscopy has been extensively applied to analyze various vibrational spectroscopic data, especially infrared and Raman. However, when it is applied to real-world experimental data, which often contains various imperfections (such as noise interference, baseline fluctuations, and band-shifting) and highly overlapping bands, many artifacts and misleading features in synchronous and asynchronous maps will emerge, and this will lead to difficulties with interpretation. Therefore, an approach that counters many artifacts and therefore leads to simplified interpretation of 2D correlation analysis is certainly useful. In the present contribution, band-target entropy minimization (BTEM) is employed as a spectral pretreatment to handle many of the artifact problems before the application of 2D correlation analysis. BTEM is employed to elucidate the pure component spectra of mixtures and their corresponding concentration profiles. Two alternate forms of analysis result. In the first, the normally vxv problem is converted to an equivalent nvxnv problem, where n represents the number of species present. In the second, the pure component spectra are transformed into simple distributions, and an equivalent and less computationally intensive nv'xnv' problem results (v'

Fourier Transform Infrared Spectroscopy and Photoacoustic Spectroscopy for Saliva Analysis.

PubMed

Mikkonen, Jopi J W; Raittila, Jussi; Rieppo, Lassi; Lappalainen, Reijo; Kullaa, Arja M; Myllymaa, Sami

2016-09-01

Saliva provides a valuable tool for assessing oral and systemic diseases, but concentrations of salivary components are very small, calling the need for precise analysis methods. In this work, Fourier transform infrared (FT-IR) spectroscopy using transmission and photoacoustic (PA) modes were compared for quantitative analysis of saliva. The performance of these techniques was compared with a calibration series. The linearity of spectrum output was verified by using albumin-thiocyanate (SCN(-)) solution at different SCN(-) concentrations. Saliva samples used as a comparison were obtained from healthy subjects. Saliva droplets of 15 µL were applied on the silicon sample substrate, 6 drops for each specimen, and dried at 37 ℃ overnight. The measurements were carried out using an FT-IR spectrometer in conjunction with an accessory unit for PA measurements. The findings with both transmission and PA modes mirror each other. The major bands presented were 1500-1750 cm(-1) for proteins and 1050-1200 cm(-1) for carbohydrates. In addition, the distinct spectral band at 2050 cm(-1) derives from SCN(-) anions, which is converted by salivary peroxidases to hypothiocyanate (OSCN(-)). The correlation between the spectroscopic data with SCN(-) concentration (r > 0.990 for transmission and r = 0.967 for PA mode) was found to be significant (P < 0.01), thus promising to be utilized in future applications. © The Author(s) 2016.

Time, Temperature, and Cationic Dependence of Alkali Activation of Slag: Insights from Fourier Transform Infrared Spectroscopy and Spectral Deconvolution.

PubMed

Dakhane, Akash; Madavarapu, Sateesh Babu; Marzke, Robert; Neithalath, Narayanan

2017-08-01

The use of waste/by-product materials, such as slag or fly ash, activated using alkaline agents to create binding materials for construction applications (in lieu of portland cement) is on the rise. The influence of activation parameters (SiO 2 to Na 2 O ratio or M s of the activator, Na 2 O to slag ratio or n, cation type K + or Na + ) on the process and extent of alkali activation of slag under ambient and elevated temperature curing, evaluated through spectroscopic techniques, is reported in this paper. Fourier transform infrared spectroscopy along with a Fourier self-deconvolution method is used. The major spectral band of interest lies in the wavenumber range of ∼950 cm -1 , corresponding to the antisymmetric stretching vibration of Si-O-T (T = Si or Al) bonds. The variation in the spectra with time from 6 h to 28 days is attributed to the incorporation of Al in the gel structure and the enhancement in degree of polymerization of the gel. 29 Si nuclear magnetic resonance spectroscopy is used to quantify the Al incorporation with time, which is found to be higher when Na silicate is used as the activator. The Si-O-T bond wavenumbers are also generally lower for the Na silicate activated systems.

Central Stars of Mid-Infrared Nebulae Discovered with Spitzer and WISE

NASA Astrophysics Data System (ADS)

Gvaramadze, V. V.; Kniazev, A. Y.

2017-02-01

Searches for compact mid-IR nebulae with the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer (WISE), accompanied by spectroscopic observations of central stars of these nebulae led to the discovery of many dozens of massive stars at different evolutionary stages, of which the most numerous are candidate luminous blue variables (LBVs). In this paper, we give a census of candidate and confirmed Galactic LBVs revealed with Spitzer and WISE, and present some new results of spectroscopic observations of central stars of mid-IR nebulae.

Glucose Oxidase Adsorption on Sequential Adsorbed Polyelectrolyte Films Studied by Spectroscopic Techniques

NASA Astrophysics Data System (ADS)

Tristán, Ferdinando; Solís, Araceli; Palestino, Gabriela; Gergely, Csilla; Cuisinier, Frédéric; Pérez, Elías

2005-04-01

The adsorption of Glucose Oxidase (GOX) on layers of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) deposited on Sequentially Adsorbed Polyelectrolyte Films (SAPFs) were studied by three different spectroscopic techniques. These techniques are: Optical Wave Light Spectroscopy (OWLS) to measure surface density; Fluorescence Resonance Energy Transfer (FRET) to verify the adsorption of GOX on the surface; and Fourier Transform Infrared Spectroscopy in Attenuated Total Reflection mode (FTIR-HATR) to inspect local structure of polyelectrolytes and GOX. Two positive and two negative polyelectrolytes are used: Cationic poly(ethyleneimine) (PEI) and poly(allylamine hydrochloride) (PAH) and anionic poly(sodium 4-styrene sulfonate) (PSS) and poly(acrylic acid) (PAA). These spectroscopic techniques do not require any labeling for GOX or SAPFs, specifically GOX and PSS are naturally fluorescent and are used as a couple donor-acceptor for the FRET technique. The SAPFs are formed by a (PEI)-(PSS/PAH)2 film followed by (PAA/PAH)n bilayers. GOX is finally deposited on top of SAPFs at different values of n (n=1..5). Our results show that GOX is adsorbed on positive ended SAPFs forming a monolayer. Contrary, GOX adsorption is not observed on negative ended film polyelectrolyte. GOX stability was tested adding a positive and a negative polyelectrolyte after GOX adsorption. Protein is partially removed by PAH and PAA, with lesser force by PAA.

Spectroscopic and Spectrometric Methods Used for the Screening of Certain Herbal Food Supplements Suspected of Adulteration

PubMed Central

Mateescu, Cristina; Popescu, Anca Mihaela; Radu, Gabriel Lucian; Onisei, Tatiana; Raducanu, Adina Elena

2017-01-01

Purpose: This study was carried out in order to find a reliable method for the fast detection of adulterated herbal food supplements with sexual enhancement claims. As some herbal products are advertised as "all natural", their "efficiency" is often increased by addition of active pharmaceutical ingredients such as PDE-5 inhibitors, which can be a real health threat for the consumer. Methodes: Adulterants, potentially present in 50 herbal food supplements with sexual improvement claims, were detected using 2 spectroscopic methods - Raman and Fourier Transform Infrared - known for reliability, reproductibility, and an easy sample preparation. GC-MS technique was used to confirm the potential adulterants spectra. Results: About 22% (11 out of 50 samples) of herbal food supplements with sexual enhancement claims analyzed by spectroscopic and spectrometric methods proved to be "enriched" with active pharmaceutical compounds such as: sildenafil and two of its analogues, tadalafil and phenolphthalein. The occurence of phenolphthalein could be the reason for the non-relevant results obtained by FTIR method in some samples. 91% of the adulterated herbal food supplements were originating from China. Conclusion: The results of this screening highlighted the necessity for an accurate analysis of all alleged herbal aphrodisiacs on the Romanian market. This is a first such a screening analysis carried out on herbal food supplements with sexual enhancement claims. PMID:28761827

FTIR and Raman spectroscopic studies of selenium nanoparticles synthesised by the bacterium Azospirillum thiophilum

NASA Astrophysics Data System (ADS)

Tugarova, Anna V.; Mamchenkova, Polina V.; Dyatlova, Yulia A.; Kamnev, Alexander A.

2018-03-01

Vibrational (Fourier transform infrared (FTIR) and Raman) spectroscopic techniques can provide unique molecular-level information on the structural and compositional characteristics of complicated biological objects. Thus, their applications in microbiology and related fields are steadily increasing. In this communication, biogenic selenium nanoparticles (Se NPs) were obtained via selenite (SeO32-) reduction by the bacterium Azospirillum thiophilum (strain VKM B-2513) for the first time, using an original methodology for obtaining extracellular NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed the Se NPs to have average diameters within 160-250 nm; their zeta potential was measured to be minus 18.5 mV. Transmission FTIR spectra of the Se NPs separated from bacterial cells showed typical proteinacious, polysaccharide and lipid-related bands, in line with TEM data showing a thin layer covering the Se NPs surface. Raman spectra of dried Se NPs layer in the low-frequency region (under 500 cm-1 down to 150 cm-1) showed a single very strong band with a maximum at 250 cm-1 which, in line with its increased width (ca. 30 cm-1 at half intensity), can be attributed to amorphous elementary Se. Thus, a combination of FTIR and Raman spectroscopic approaches is highly informative in non-destructive analysis of structural and compositional properties of biogenic Se NPs.

Intermolecular interaction of fosinopril with bovine serum albumin (BSA): The multi-spectroscopic and computational investigation.

PubMed

Zhou, Kai-Li; Pan, Dong-Qi; Lou, Yan-Yue; Shi, Jie-Hua

2018-04-16

The intermolecular interaction of fosinopril, an angiotensin converting enzyme inhibitor with bovine serum albumin (BSA), has been investigated in physiological buffer (pH 7.4) by multi-spectroscopic methods and molecular docking technique. The results obtained from fluorescence and UV absorption spectroscopy revealed that the fluorescence quenching mechanism of BSA induced by fosinopril was mediated by the combined dynamic and static quenching, and the static quenching was dominant in this system. The binding constant, K b , value was found to lie between 2.69 × 10 3 and 9.55 × 10 3  M -1 at experimental temperatures (293, 298, 303, and 308 K), implying the low or intermediate binding affinity between fosinopril and BSA. Competitive binding experiments with site markers (phenylbutazone and diazepam) suggested that fosinopril preferentially bound to the site I in sub-domain IIA on BSA, as evidenced by molecular docking analysis. The negative sign for enthalpy change (ΔH 0 ) and entropy change (ΔS 0 ) indicated that van der Waals force and hydrogen bonds played important roles in the fosinopril-BSA interaction, and 8-anilino-1-naphthalenesulfonate binding assay experiments offered evidence of the involvements of hydrophobic interactions. Moreover, spectroscopic results (synchronous fluorescence, 3-dimensional fluorescence, and Fourier transform infrared spectroscopy) indicated a slight conformational change in BSA upon fosinopril interaction. Copyright © 2018 John Wiley & Sons, Ltd.

Spectroscopic insights into the oxygen-tolerant membrane-associated [NiFe] hydrogenase of Ralstonia eutropha H16.

PubMed

Saggu, Miguel; Zebger, Ingo; Ludwig, Marcus; Lenz, Oliver; Friedrich, Bärbel; Hildebrandt, Peter; Lendzian, Friedhelm

2009-06-12

This study provides the first spectroscopic characterization of the membrane-bound oxygen-tolerant [NiFe] hydrogenase (MBH) from Ralstonia eutropha H16 in its natural environment, the cytoplasmic membrane. The H2-converting MBH is composed of a large subunit, harboring the [NiFe] active site, and a small subunit, capable in coordinating one [3Fe4S] and two [4Fe4S] clusters. The hydrogenase dimer is electronically connected to a membrane-integral cytochrome b. EPR and Fourier transform infrared spectroscopy revealed a strong similarity of the MBH active site with known [NiFe] centers from strictly anaerobic hydrogenases. Most redox states characteristic for anaerobic [NiFe] hydrogenases were identified except for one remarkable difference. The formation of the oxygen-inhibited Niu-A state was never observed. Furthermore, EPR data showed the presence of an additional paramagnetic center at high redox potential (+290 mV), which couples magnetically to the [3Fe4S] center and indicates a structural and/or redox modification at or near the proximal [4Fe4S] cluster. Additionally, significant differences regarding the magnetic coupling between the Nia-C state and [4Fe4S] clusters were observed in the reduced form of the MBH. The spectroscopic properties are discussed with regard to the unusual oxygen tolerance of this hydrogenase and in comparison with those of the solubilized, dimeric form of the MBH.

Gold Nanoparticles Grafted with PLL-b-PNIPAM: Interplay on Thermal/pH Dual-Response and Optical Properties.

PubMed

Li, Hui-Juan; Li, Peng-Yun; Li, Li-Ying; Haleem, Abdul; He, Wei-Dong

2018-04-16

Narrowly distributed poly(l-lysine- b - N -isopropylacrylamide) (PLL- b -PNIPAM) was prepared through ring-opening polymerization of ε-benzyloxycarbonyl-l-lysine N -carboxy-α-amino anhydride and atom transfer radical polymerization of NIPAM, followed with the removal of ε-benzyloxycarbonyl group. Then gold nanoparticles (AuNPs) grafted with PLL- b -PNIPAM (PNIPAM-PLL-AuNPs) were obtained by the reduction of chloroauric acid with sodium citrate in the presence of PLL- b -PNIPAM. PNIPAM-PLL-AuNPs and its precursors were thoroughly characterized by proton magnetic resonance spectroscope, Fourier transform infrared spectroscope, UV-vis spectroscope, transmission electron microscopy, dynamic light scattering, thermogravimetric analysis, and circular dichroism. The obtained PNIPAM-PLL-AuNPs exhibited high colloid stability even at strong alkaline (pH = 12) and acidic (pH = 2) conditions. The thermal and pH dual-responsive behaviors of the grafting PLL- b -PNIPAM chains was observed to be affected by AuNPs, while not for the secondary structure of PLL chains. Correspondingly, the surface plasmon resonance (SPR) of AuNPs was found to be sensitive to both pH value and temperature. A blue shift in the SPR happened both with increasing pH value and increasing temperature. The stimuli-response was reversible in heating-cooling cycles. The gold nanoparticles with both pH and temperature response may have potential applications in biomedical areas and biosensors.

Spectroscopic and Spectrometric Methods Used for the Screening of Certain Herbal Food Supplements Suspected of Adulteration.

PubMed

Mateescu, Cristina; Popescu, Anca Mihaela; Radu, Gabriel Lucian; Onisei, Tatiana; Raducanu, Adina Elena

2017-06-01

Purpose: This study was carried out in order to find a reliable method for the fast detection of adulterated herbal food supplements with sexual enhancement claims. As some herbal products are advertised as "all natural", their "efficiency" is often increased by addition of active pharmaceutical ingredients such as PDE-5 inhibitors, which can be a real health threat for the consumer. Methodes: Adulterants, potentially present in 50 herbal food supplements with sexual improvement claims, were detected using 2 spectroscopic methods - Raman and Fourier Transform Infrared - known for reliability, reproductibility, and an easy sample preparation. GC-MS technique was used to confirm the potential adulterants spectra. Results: About 22% (11 out of 50 samples) of herbal food supplements with sexual enhancement claims analyzed by spectroscopic and spectrometric methods proved to be "enriched" with active pharmaceutical compounds such as: sildenafil and two of its analogues, tadalafil and phenolphthalein. The occurence of phenolphthalein could be the reason for the non-relevant results obtained by FTIR method in some samples. 91% of the adulterated herbal food supplements were originating from China. Conclusion: The results of this screening highlighted the necessity for an accurate analysis of all alleged herbal aphrodisiacs on the Romanian market. This is a first such a screening analysis carried out on herbal food supplements with sexual enhancement claims.

Infrared-spectroscopic single-shot laser mapping ellipsometry: Proof of concept for fast investigations of structured surfaces and interactions in organic thin films

NASA Astrophysics Data System (ADS)

Furchner, Andreas; Kratz, Christoph; Gkogkou, Dimitra; Ketelsen, Helge; Hinrichs, Karsten

2017-11-01

We present a novel infrared-spectroscopic laser mapping ellipsometer based on a single-shot measurement concept. The ellipsometric set-up employs multiple analyzers and detectors to simultaneously measure the sample's optical response under different analyzer azimuths. An essential component is a broadly tunable quantum cascade laser (QCL) covering the important marker region of 1800-1540 cm-1. The ellipsometer allows for fast single-wavelength as well as spectroscopic studies with thin-film sensitivity at temporal resolutions of 60 ms per wavelength. We applied the single-shot mapping ellipsometer for the characterization of metal-island enhancement surfaces as well as of molecular interactions in organic thin films. In less than 3 min, a linescan with 1600 steps revealed profile and infrared-enhancement properties of a gradient gold-island film for sensing applications. Spectroscopic measurements were performed to probe the amide I band of thin films of poly(N-isopropylacrylamide) [PNIPAAm], a stimuli-responsive polymer for bioapplications. The QCL spectra agree well with conventional FT-IR ellipsometric results, showing different band components associated with hydrogen-bond interactions between polymer and adsorbed water. Multi-wavelength ellipsometric maps were used to analyze homogeneity and surface contaminations of the polymer films.

Self- and CO2-broadened line shape parameters for infrared bands of HDO

NASA Astrophysics Data System (ADS)

Smith, Mary-Ann H.; Malathy Devi, V.; Benner, D. Chris; Sung, Keeyoon; Mantz, Arlan W.; Gamache, Robert R.; Villanueva, Geronimo L.

2015-11-01

Knowledge of CO2-broadened HDO line widths and their temperature dependence is required to interpret infrared spectra of the atmospheres of Mars and Venus. However, this information is currently absent in most spectroscopic databases. We have analyzed nine high-resolution, high signal-to-noise spectra of HDO and HDO+CO2 mixtures to obtain broadening coefficients and other line shape parameters for transitions of the ν2 and ν3 vibrational bands located at 7.13 and 2.70 μm, respectively. The gas samples were prepared by mixing equal amounts of high-purity distilled H2O and 99% enriched D2O. The spectra were recorded at different temperatures (255-296 K) using a 20.38 cm long coolable cell [1] installed in the sample compartment of the Bruker IFS125HR Fourier transform spectrometer at the Jet Propulsion Laboratory in Pasadena, CA. The retrieved HDO spectroscopic parameters include line positions, intensities, self- and CO2-broadened half-width and pressure-induced shift coefficients and the temperature dependences for CO2 broadening. These spectroscopic parameters were obtained by simultaneous multispectrum fitting [2] of the same interval in all nine spectra. A non-Voigt line shape with speed dependence was applied. Line mixing was also observed for several transition pairs. Preliminary results compare well with the few other measurements reported in the literature.[1] K. Sung et al., J. Mol. Spectrosc. 162, 124-134 (2010).[2] D. C. Benner et al., J. Quant. Spectrosc. Radiat Transfer 53, 705-721 (1995).The research performed at the College of William and Mary was supported by NASA’s Mars Fundamental Research Program (Grant NNX13AG66G). The research at Jet Propulsion Laboratory, California Institute of Technology, Connecticut College, Langley Research Center, and Goddard Space Flight Center was conducted under contracts and cooperative agreements with the National Aeronautics and Space Administration. RRG is pleased to acknowledge support of this study by the National Science Foundation through Grant No. AGS-1156862.

"Vibrational spectroscopic analysis and molecular docking studies of (E)-4-methoxy-N‧-(4-methylbenzylidene) benzohydrazide by DFT"

NASA Astrophysics Data System (ADS)

Maheswari, R.; Manjula, J.

2016-07-01

(E)-4-methoxy-N‧-(4-methylbenzylidene)benzohydrazide (4MN'MBH) a novel, organic, hydrazone Schiff base compound was synthesized and its structure was characterized by Fourier Transform Infrared (4000-400 cm-1), Fourier Transform Raman (3500-50 cm-1), Ultraviolet-Visible (200-800 nm) and 1H and 13C NMR spectroscopic analysis. Optimized molecular structure, vibrational frequencies and corresponding vibrational assignments regarding 4MN'MBH has become screened tentatively as well as hypothetically utilizing Gaussian09Wprogram package. Potential energy distributions of the normal modes of vibrations connected with vibrations are generally accomplished by applying VEDA program. Natural Bonding Orbital (NBO) assessment was completed with a reason to clarify charge transfer or conjugative interaction, the intra-molecular-hybridization and delocalization of electron density within the molecule. Electronic transitions were studied employing UV-Visible spectrum and the observed values were compared with theoretical values. 1H and13C NMR spectral assessment had been made with choosing structure property relationship by chemical shifts along with magnetic shielding effects of title compound. The first order hyperpolarizability (β0) and related properties (β, α0 and Δα) of 4MN'MBH were calculated. The computed first order hyperpolarizability commensurate with the documented worth of very similar structure and could be an interesting thing for more experiments on non linear optics. Molecular docking study has been performed by in silico method to analysis their antituberculosis aspects against Enoyl acyl carrier protein reductase (Mycobacterium tuberculosis InhA) protein.

Book Review: Reiner Salzer and Heinz W. Siesler (Eds.): Infrared and Raman spectroscopic imaging, 2nd ed.

DOE PAGES

Moore, David Steven

2015-05-10

This second edition of "Infrared and Raman Spectroscopic Imaging" propels practitioners in that wide-ranging field, as well as other readers, to the current state of the art in a well-produced and full-color, completely revised and updated, volume. This new edition chronicles the expanded application of vibrational spectroscopic imaging from yesterday's time-consuming point-by-point buildup of a hyperspectral image cube, through the improvements afforded by the addition of focal plane arrays and line scan imaging, to methods applicable beyond the diffraction limit, instructs the reader on the improved instrumentation and image and data analysis methods, and expounds on their application to fundamentalmore » biomedical knowledge, food and agricultural surveys, materials science, process and quality control, and many others.« less

Infrared Spectroscopic Analyses of Sulfate, Nitrate, and Carbonate-bearing Atacama Desert Soils: Analogs for the Interpretation of Infrared Spectra from the Martian Surface

NASA Technical Reports Server (NTRS)

Dalton, J. B.; Dalton, J. B.; Ewing, S. A.; Amundson, R.; McKay, C. P.

2005-01-01

The Atacama Desert of northern Chile is the driest desert on Earth, receiving only a few mm of rain per decade. The Mars climate may, in the past, have been punctuated by short-lived episodes of aqueous activity. The paleo-Martian environment may have had aqueous conditions similar to the current conditions that exist in the Atacama, and Mars soils may have formed with soil chemistry and mineralogy similar to those found in the Atacama. Remote and in-situ analysis of the Martian surface using infrared technology has a long heritage. Future investigations of the subsurface mineralogy are likely to build upon this heritage, and will benefit from real life lessons to be learned from terrestrial analog studies. To that end, preliminary results from a near- and mid-infrared spectroscopic study of Atacama soil profiled at a range of depths are presented.

Nondestructive multispectral reflectoscopy between 800 and 1900 nm: An instrument for the investigation of the stratigraphy in paintings.

PubMed

Karagiannis, G; Salpistis, Chr; Sergiadis, G; Chryssoulakis, Y

2007-06-01

In the present work, a powerful tool for the investigation of paintings is presented. This permits the tuneable multispectral real time imaging between 200 and 5000 nm and the simultaneous multispectral acquisition of spectroscopic data from the same region. We propose the term infrared reflectoscopy for tuneable infrared imaging in paintings (Chryssonlakis and Chassery, The Application of Physicochemical Methods of Analysis and Image Processing Techniques to Painted Works of Art, Erasmus Project ICP-88-006-6, Athens, June, 1989) for a technique that is effective especially when the spectroscopic data acquisition is performed between 800 and 1900 nm. Elements such as underdrawings, old damage that is not visible to the naked eye, later interventions or overpaintings, hidden signatures, nonvisible inscriptions, and authenticity features can thus be detected with the overlying paint layers becoming successively "transparent" due to the deep infrared penetration. The spectroscopic data are collected from each point of the studied area with a 5 nm step through grey level measurement, after adequate infrared reflectance (%R) and curve calibration. The detection limits of the infrared detector as well as the power distribution of the radiation coming out through the micrometer slit assembly of the monochromator in use are also taken into account. Inorganic pigments can thus be identified and their physicochemical properties directly compared to the corresponding infrared images at each wavelength within the optimum region. In order to check its effectiveness, this method was applied on an experimental portable icon of a known stratigraphy.

New and improved infrared absorption cross sections for chlorodifluoromethane (HCFC-22)

NASA Astrophysics Data System (ADS)

Harrison, Jeremy J.

2016-06-01

The most widely used hydrochlorofluorocarbon (HCFC) commercially since the 1930s has been chloro-difluoromethane, or HCFC-22, which has the undesirable effect of depleting stratospheric ozone. As this molecule is currently being phased out under the Montreal Protocol, monitoring its concentration profiles using infrared sounders crucially requires accurate laboratory spectroscopic data. This work describes new high-resolution infrared absorption cross sections of chlorodifluoromethane over the spectral range 730-1380 cm-1, determined from spectra recorded using a high-resolution Fourier transform spectrometer (Bruker IFS 125HR) and a 26 cm pathlength cell. Spectra of chlorodifluoromethane/dry synthetic air mixtures were recorded at resolutions between 0.01 and 0.03 cm-1 (calculated as 0.9/MOPD; MOPD denotes the maximum optical path difference) over a range of temperatures and pressures (7.5-762 Torr and 191-295 K) appropriate for atmospheric conditions. This new cross-section dataset improves upon the one currently available in the HITRAN (HIgh-resolution TRANsmission) and GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques) databases; in particular it provides coverage over a wider range of pressures and temperatures, has more accurate wavenumber scales, more consistent integrated band intensities, improved signal-to-noise, is free of channel fringing, and additionally covers the ν2 and ν7 bands.

Multidimensional spectrometer

DOEpatents

Zanni, Martin Thomas; Damrauer, Niels H.

2010-07-20

A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

Infrared spectroscopic characterization of dehydration and accompanying phase transition behaviors in NAT-topology zeolites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hsiu-Wen; Bishop, David

2012-01-01

Relative humidity (PH2O, partial pressure of water)-dependent dehydration and accompanying phase transitions in NAT-topology zeolites (natrolite, scolecite, and mesolite) were studied under controlled temperature and known PH2O conditions by in situ diffuse-reflectance infrared Fourier transform spectroscopy and parallel X-ray powder diffraction. Dehydration was characterized by the disappearance of internal H2O vibrational modes. The loss of H2O molecules caused a sequence of structural transitions in which the host framework transformation path was coupled primarily via the thermal motion of guest Na?/Ca2? cations and H2O molecules. The observation of different interactions of H2O molecules and Na?/Ca2? cations with host aluminosilicate frameworks undermore » highand low-PH2O conditions indicated the development of different local strain fields, arising from cation H2O interactions in NAT-type channels. These strain fields influence the Si O/Al O bond strength and tilting angles within and between tetrahedra as the dehydration temperature is approached. The newly observed infrared bands (at 2,139 cm-1 in natrolite, 2,276 cm-1 in scolecite, and 2,176 and 2,259 cm-1 in mesolite) result from strong cation H2O Al Si framework interactions in NAT-type channels, and these bands can be used to evaluate the energetic evolution of Na?/Ca2? cations before and after phase transitions, especially for scolecite and mesolite. The 2,176 and 2,259 cm-1 absorption bands in mesolite also appear to be related to Na?/Ca2? order disorder that occur when mesolite loses its Ow4 H2O molecules.« less

Synchrotron- and focal plane array-based Fourier-transform infrared spectroscopy differentiates the basalis and functionalis epithelial endometrial regions and identifies putative stem cell regions of human endometrial glands.

PubMed

Theophilou, Georgios; Morais, Camilo L M; Halliwell, Diane E; Lima, Kássio M G; Drury, Josephine; Martin-Hirsch, Pierre L; Stringfellow, Helen F; Hapangama, Dharani K; Martin, Francis L

2018-05-09

The cyclical process of regeneration of the endometrium suggests that it may contain a cell population that can provide daughter cells with high proliferative potential. These cell lineages are clinically significant as they may represent clonogenic cells that may also be involved in tumourigenesis as well as endometriotic lesion development. To determine whether the putative stem cell location within human uterine tissue can be derived using vibrational spectroscopy techniques, normal endometrial tissue was interrogated by two spectroscopic techniques. Paraffin-embedded uterine tissues containing endometrial glands were sectioned to 10-μm-thick parallel tissue sections and were floated onto BaF 2 slides for synchrotron radiation-based Fourier-transform infrared (SR-FTIR) microspectroscopy and globar focal plane array-based FTIR spectroscopy. Different spectral characteristics were identified depending on the location of the glands examined. The resulting infrared spectra were subjected to multivariate analysis to determine associated biophysical differences along the length of longitudinal and crosscut gland sections. Comparison of the epithelial cellular layer of transverse gland sections revealed alterations indicating the presence of putative transient-amplifying-like cells in the basalis and mitotic cells in the functionalis. SR-FTIR microspectroscopy of the base of the endometrial glands identified the location where putative stem cells may reside at the same time pointing towards ν s PO 2 - in DNA and RNA, nucleic acids and amide I and II vibrations as major discriminating factors. This study supports the view that vibration spectroscopy technologies are a powerful adjunct to our understanding of the stem cell biology of endometrial tissue. Graphical abstract ᅟ.

A new μ3-oxo-centered tri-nuclear carboxyl bridged iron (III) complex with thio-methyl groups in the periphery: Structural, spectroscopic and electrochemical studies

NASA Astrophysics Data System (ADS)

Lu, Maofeng; Chen, Tingting; Wang, Miao; Jiang, Guomin; Lu, Tianhong; Jiang, Guoqing; Du, Jiangyan

2014-02-01

A tri-nuclear iron (III) complex [Fe3(μ3-O)(O2CC6H4SCH3)6(Py)3]FeCl4 has been synthesized and characterized by X-ray crystallography, Surface enhanced Raman Scattering (SERS), Fourier Transform Infra Red (FT-IR), Ultraviolet-Visible (UV-Vis) spectroscopy and Thermogravimetric analysis (TGA)/Differential scanning calorimetry (DSC). The functionalized thio-methyl groups around the periphery of the complex 1 may provide binding sites to the surface of some specific materials, such as noble metals. The Ag sols and complex 1-Ag sol had been characterized by SERS and UV-Vis spectroscopy. The complex 1 were also self-assembled on gold electrode by AuS bond, exhibiting an irreversible process at E1/2 = 0.967 V (ΔE = 0.525 V). Meanwhile the Raman spectra were compared with FT-IR, and the results indicated that the strong Raman lines either correspond to weak Infrared absorptions or are absent in the Infrared spectra.

VizieR Online Data Catalog: Cyanoacetylene (HC3N) infrared spectrum (Bizzocchi+,

NASA Astrophysics Data System (ADS)

Bizzocchi, L.; Tamassia, F.; Laas, J.; Giuliano, B. M.; Degli Esposti, C.; Dore, L.; Melosso, M.; Cane, E.; Pietropolli Charmet, A.; Muller, H. S. P.; Spahn, H.; Belloche, A.; Caselli, P.; Menten, K. M.; Garrod, R. T.

2018-01-01

A substantial amount of new spectroscopic data of HC3N was col in four laboratories located in Bologna, Italy and in Cologne and Munich, Germany. The infrared spectra in the 450-1100cm-1 range were recorded in Bologna using a Bomem DA3.002 Fourier-transform spectrometer. The resolution was generally 0.004cm-1. New mm-wave spectra in selected frequency intervals between 80 and 400GHz were observed in Bologna using a frequency-modulation (FM) mm-wave spectrometer whose details are reported elsewhere (see, e.g., Bizzocchi+ 2016, J/ApJ/820/L26). Further measurements of the sub-mm-wave spectrum of HC3N in the 200-690GHz frequency range were carried out at the Center for Astrochemical Studies (MPE Garching). The measurements performed in Cologne were carried out with leftover samples from previous studies (Yamada+ 1995ZNatA..50.1179Y ; Thorwirth+ 2000JMoSp.204..133T). Further measurements were made using the Cologne Terahertz Spectrometer. See section 2 for further explanations. (2 data files).

QM/MM methodology, docking and spectroscopic (FT-IR/FT-Raman, NMR, UV) and Fukui function analysis on adrenergic agonist

NASA Astrophysics Data System (ADS)

Uma Maheswari, J.; Muthu, S.; Sundius, Tom

2015-02-01

The Fourier transform infrared, FT-Raman, UV and NMR spectra of Ternelin have been recorded and analyzed. Harmonic vibrational frequencies have been investigated with the help of HF with 6-31G (d,p) and B3LYP with 6-31G (d,p) and LANL2DZ basis sets. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by GIAO method. The polarizability (α) and the first hyperpolarizability (β) values of the investigated molecule have been computed using DFT quantum mechanical calculations. Stability of the molecule arising from hyper conjugative interactions, and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The electron density-based local reactivity descriptors such as Fukui functions were calculated to explain the chemical selectivity or reactivity site in Ternelin. Finally the calculated results were compared to simulated infrared and Raman spectra of the title compound which show good agreement with observed spectra. Molecular docking studies have been carried out in the active site of Ternelin and reactivity with ONIOM was also investigated.

A methodological approach to study the stability of selected watercolours for painting reintegration, through reflectance spectrophotometry, Fourier transform infrared spectroscopy and hyperspectral imaging.

PubMed

Pelosi, Claudia; Capobianco, Giuseppe; Agresti, Giorgia; Bonifazi, Giuseppe; Morresi, Fabio; Rossi, Sara; Santamaria, Ulderico; Serranti, Silvia

2018-06-05

The aim of this work is to investigate the stability to simulated solar radiation of some paintings samples through a new methodological approach adopting non-invasive spectroscopic techniques. In particular, commercial watercolours and iron oxide based pigments were used, these last ones being prepared for the experimental by gum Arabic in order to propose a possible substitute for traditional reintegration materials. Reflectance spectrophotometry in the visible range and Hyperspectral Imaging in the short wave infrared were chosen as non-invasive techniques for evaluation the stability to irradiation of the chosen pigments. These were studied before and after artificial ageing procedure performed in Solar Box chamber under controlled conditions. Data were treated and elaborated in order to evaluate the sensitivity of the chosen techniques in identifying the variations on paint layers, induced by photo-degradation, before they could be observed by eye. Furthermore a supervised classification method for monitoring the painted surface changes adopting a multivariate approach was successfully applied. Copyright © 2018 Elsevier B.V. All rights reserved.

High-pressure stability, transformations, and vibrational dynamics of nitrosonium nitrate from synchrotron infrared and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Song, Yang; Hemley, Russell J.; Liu, Zhenxian; Somayazulu, Maddury; Mao, Ho-kwang; Herschbach, Dudley R.

2003-07-01

The properties of nitrosonium nitrate (NO+NO3-) were investigated following synthesis by laser heating of N2O and N2O4 under high pressures in a diamond anvil cell. Synchrotron infrared absorption spectra of NO+NO3- were measured at pressures up to 32 GPa at room temperature. Raman spectra were obtained at pressures up to 40 GPa at room temperature and up to 14 GPa at temperatures down to 80 K. For both lattice and intramolecular vibrational modes, a smooth evolution of spectral bands with pressure indicates that NO+NO3- forms a single phase over a broad range above 10 GPa, whereas marked changes, particularly evident in the Raman spectra at low temperature, indicate a phase transition occurs near 5 GPa. NO+NO3- could be recovered at atmospheric pressure and low temperature, persisting to 180 K. The Raman and IR spectroscopic data suggest that the NO+NO3- produced by laser heating of N2O followed by decompression may differ in structure or orientational order-disorder from that produced by autoionization of N2O4.

The anharmonic quartic force field infrared spectra of three polycyclic aromatic hydrocarbons: Naphthalene, anthracene, and tetracene.

PubMed

Mackie, Cameron J; Candian, Alessandra; Huang, Xinchuan; Maltseva, Elena; Petrignani, Annemieke; Oomens, Jos; Buma, Wybren Jan; Lee, Timothy J; Tielens, Alexander G G M

2015-12-14

Current efforts to characterize and study interstellar polycyclic aromatic hydrocarbons (PAHs) rely heavily on theoretically predicted infrared (IR) spectra. Generally, such studies use the scaled harmonic frequencies for band positions and double harmonic approximation for intensities of species, and then compare these calculated spectra with experimental spectra obtained under matrix isolation conditions. High-resolution gas-phase experimental spectroscopic studies have recently revealed that the double harmonic approximation is not sufficient for reliable spectra prediction. In this paper, we present the anharmonic theoretical spectra of three PAHs: naphthalene, anthracene, and tetracene, computed with a locally modified version of the SPECTRO program using Cartesian derivatives transformed from Gaussian 09 normal coordinate force constants. Proper treatments of Fermi resonances lead to an impressive improvement on the agreement between the observed and theoretical spectra, especially in the C-H stretching region. All major IR absorption features in the full-scale matrix-isolated spectra, the high-temperature gas-phase spectra, and the most recent high-resolution gas-phase spectra obtained under supersonically cooled molecular beam conditions in the CH-stretching region are assigned.

The anharmonic quartic force field infrared spectra of three polycyclic aromatic hydrocarbons: Naphthalene, anthracene, and tetracene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mackie, Cameron J., E-mail: mackie@strw.leidenuniv.nl; Candian, Alessandra; Tielens, Alexander G. G. M.

2015-12-14

Current efforts to characterize and study interstellar polycyclic aromatic hydrocarbons (PAHs) rely heavily on theoretically predicted infrared (IR) spectra. Generally, such studies use the scaled harmonic frequencies for band positions and double harmonic approximation for intensities of species, and then compare these calculated spectra with experimental spectra obtained under matrix isolation conditions. High-resolution gas-phase experimental spectroscopic studies have recently revealed that the double harmonic approximation is not sufficient for reliable spectra prediction. In this paper, we present the anharmonic theoretical spectra of three PAHs: naphthalene, anthracene, and tetracene, computed with a locally modified version of the SPECTRO program using Cartesianmore » derivatives transformed from Gaussian 09 normal coordinate force constants. Proper treatments of Fermi resonances lead to an impressive improvement on the agreement between the observed and theoretical spectra, especially in the C–H stretching region. All major IR absorption features in the full-scale matrix-isolated spectra, the high-temperature gas-phase spectra, and the most recent high-resolution gas-phase spectra obtained under supersonically cooled molecular beam conditions in the CH-stretching region are assigned.« less

External cavity-quantum cascade laser infrared spectroscopy for secondary structure analysis of proteins at low concentrations

PubMed Central

Schwaighofer, Andreas; Alcaráz, Mirta R.; Araman, Can; Goicoechea, Héctor; Lendl, Bernhard

2016-01-01

Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopy are analytical techniques employed for the analysis of protein secondary structure. The use of CD spectroscopy is limited to low protein concentrations (<2 mg ml−1), while FTIR spectroscopy is commonly used in a higher concentration range (>5 mg ml−1). Here we introduce a quantum cascade laser (QCL)-based IR transmission setup for analysis of protein and polypeptide secondary structure at concentrations as low as 0.25 mg ml−1 in deuterated buffer solution. We present dynamic QCL-IR spectra of the temperature-induced α-helix to β-sheet transition of poly-L-lysine. The concentration dependence of the α-β transition temperature between 0.25 and 10 mg ml−1 was investigated by QCL-IR, FTIR and CD spectroscopy. By using QCL-IR spectroscopy it is possible to perform IR spectroscopic analysis in the same concentration range as CD spectroscopy, thus enabling a combined analysis of biomolecules secondary structure by CD and IR spectroscopy. PMID:27633337

External cavity-quantum cascade laser infrared spectroscopy for secondary structure analysis of proteins at low concentrations.

PubMed

Schwaighofer, Andreas; Alcaráz, Mirta R; Araman, Can; Goicoechea, Héctor; Lendl, Bernhard

2016-09-16

Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopy are analytical techniques employed for the analysis of protein secondary structure. The use of CD spectroscopy is limited to low protein concentrations (<2 mg ml(-1)), while FTIR spectroscopy is commonly used in a higher concentration range (>5 mg ml(-1)). Here we introduce a quantum cascade laser (QCL)-based IR transmission setup for analysis of protein and polypeptide secondary structure at concentrations as low as 0.25 mg ml(-1) in deuterated buffer solution. We present dynamic QCL-IR spectra of the temperature-induced α-helix to β-sheet transition of poly-L-lysine. The concentration dependence of the α-β transition temperature between 0.25 and 10 mg ml(-1) was investigated by QCL-IR, FTIR and CD spectroscopy. By using QCL-IR spectroscopy it is possible to perform IR spectroscopic analysis in the same concentration range as CD spectroscopy, thus enabling a combined analysis of biomolecules secondary structure by CD and IR spectroscopy.

Determination of geographical origin of alcoholic beverages using ultraviolet, visible and infrared spectroscopy: A review

NASA Astrophysics Data System (ADS)

Uríčková, Veronika; Sádecká, Jana

2015-09-01

The identification of the geographical origin of beverages is one of the most important issues in food chemistry. Spectroscopic methods provide a relative rapid and low cost alternative to traditional chemical composition or sensory analyses. This paper reviews the current state of development of ultraviolet (UV), visible (Vis), near infrared (NIR) and mid infrared (MIR) spectroscopic techniques combined with pattern recognition methods for determining geographical origin of both wines and distilled drinks. UV, Vis, and NIR spectra contain broad band(s) with weak spectral features limiting their discrimination ability. Despite this expected shortcoming, each of the three spectroscopic ranges (NIR, Vis/NIR and UV/Vis/NIR) provides average correct classification higher than 82%. Although average correct classification is similar for NIR and MIR regions, in some instances MIR data processing improves prediction. Advantage of using MIR is that MIR peaks are better defined and more easily assigned than NIR bands. In general, success in a classification depends on both spectral range and pattern recognition methods. The main problem still remains the construction of databanks needed for all of these methods.

Spectroscopic study of the dehydration and/or dehydroxylation of phyllosilicate and zeolite minerals

NASA Astrophysics Data System (ADS)

Che, Congcong; Glotch, Timothy D.; Bish, David L.; Michalski, Joseph R.; Xu, Wenqian

2011-05-01

Phyllosilicates on Mars mapped by infrared spectroscopic techniques could have been affected by dehydration and/or dehydroxylation associated with chemical weathering in hyperarid conditions, volcanism or shock heating associated with meteor impact. The effects of heat-induced dehydration and/or dehydroxylation on the infrared spectra of 14 phyllosilicates from four structural groups (kaolinite, smectite, sepiolite-palygorskite, and chlorite) and two natural zeolites are reported here. Pressed powders of size-separated phyllosilicate and natural zeolite samples were heated incrementally from 100°C to 900°C, cooled to room temperature, and measured using multiple spectroscopic techniques: midinfrared (400-4000 cm-1) attenuated total reflectance, midinfrared reflectance (400-1400 cm-1), and far-infrared reflectance (50-600 cm-1) spectroscopies. Correlated thermogravimetric analysis and X-ray diffraction data were also acquired in order to clarify the thermal transformation of each sample. For phyllosilicate samples, the OH stretching (˜3600 cm-1), OH bending (˜590-950 cm-1), and/or H2O bending (˜1630 cm-1) bands all become very weak or completely disappear upon heating to temperatures > 500°C. The spectral changes associated with SiO4 vibrations (˜1000 cm-1 and ˜500 cm-1) show large variations depending on the compositions and structures of phyllosilicates. The thermal behavior of phyllosilicate IR spectra is also affected by the type of octahedral cations. For example, spectral features of Al3+-rich smectites are more stable than those of Fe3+-rich smectites. The high-temperature (>800°C) spectral changes of trioctahedral Mg2+-rich phyllosilicates such as hectorite, saponite, and sepiolite result primarily from crystallization of enstatite. Phyllosilicates with moderate Mg2+ concentration (e.g., palygorskite, clinochlore) and dioctahedral montmorillonites (e.g., SAz-1 and SCa-3) with partial Mg2+-for-Al3+ substitution all have new spectral feature developed at ˜900 cm-1 upon heating to 800°C. Compared with phyllosilicates, spectral features of two natural zeolites, clinoptilolite and mordenite, are less affected by thermal treatments. Even after heating to 900°C, the IR spectral features attributed to Si (Al)-O stretching and bending vibration modes do not show significant differences from those of unheated zeolites.

Simple spectroscope used with solid state image amplifier over wide spectral range

NASA Technical Reports Server (NTRS)

Brown, R. L., Sr.

1971-01-01

Prism plus image amplifier panel provides visual image of many infrared spectral lines from carbon arc impregnated with metal compound. Different metal compounds generate various desired spectra. Panel also aligns and focuses simple spectroscopes for detecting spectral lines inside and outside visible region.

Prediction and interpretation of infrared intensities of polymethylene chain molecules

NASA Astrophysics Data System (ADS)

Jona, P.; Gussoni, M.; Zerbi, G.

1986-03-01

We have calculated the IR intensities of some polymethylene chain molecules containing conformational defects or polar heads. Calculations provide spectroscopic markers of end-TG, GTG', GTG, GG and GGTGG defects. Further, a spectroscopical study of interactions between polar heads and alkyl chain is allowed.

Pollution Police: How to Determine Spectroscopic Selection Rules

ERIC Educational Resources Information Center

Selco, Jodye I.; Beery, Janet

2004-01-01

Students employ mathematics and physical chemistry in a project called Pollution Police to establish spectroscopic selection rules, and apply them to detect environmental contaminants from infrared spectra. This interdisciplinary project enables students to gain multiple information on molecular symmetry, and its role in the development of…

A non-destructive spectroscopic study of the decoration of archaeological pottery: from matt-painted bichrome ceramic sherds (southern Italy, VIII-VII B.C.) to an intact Etruscan cinerary urn

NASA Astrophysics Data System (ADS)

Bruni, Silvia; Guglielmi, Vittoria; Della Foglia, Elena; Castoldi, Marina; Bagnasco Gianni, Giovanna

2018-02-01

A study is presented based on the use of entirely non-destructive spectroscopic techniques to analyze the chemical composition of the painted surface layer of archaeological pottery. This study aims to define both the raw materials and the working technology of ancient potters. Energy-dispersive X-ray analysis, micro-Raman spectroscopy, visible and near infrared (NIR) diffuse reflection spectroscopy and external reflection Fourier-transform infrared (FTIR) spectroscopy were applied to matt-painted bichrome pottery sherds (VIII-VII century B.C.) from the site of Incoronata near Metaponto in southern Italy. Two different raw materials, ochre and iron-rich clay, were recognized for the red decoration, while the dark areas resulted to have been obtained by the so-called manganese black technique. In any case, it was demonstrated that the decoration was applied before firing, in spite of its sometimes grainy aspect that could suggest a post-firing application. For the samples with a more sophisticated decorative pattern a red/black/white polychromy was recognized, as the lighter areas correspond to an ;intentional white; obtained by the firing of a calcium-rich clay. Reflection spectroscopy in the visible-NIR and mid-IR as well as micro-Raman spectroscopy were then employed to characterize the decoration of an intact ceramic urn from the Etruscan town of Chiusi, evidencing a post-firing painting based on the use of red ochre, carbon black and lime, possibly imitating the ;fresco; technique used in wall paintings.

Solid-state NMR study of geopolymer prepared by sol-gel chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsai, Yi-Ling; Hanna, John V.; Lee, Yuan-Ling, E-mail: yuanlinglee@ntu.edu.t

2010-12-15

Geopolymers are a new class of materials formed by the condensation of aluminosilicates and silicates obtained from natural minerals or industrial wastes. In this work, the sol-gel method is used to synthesize precursor materials for the preparation of geopolymers. The geopolymer samples prepared by our synthetic route have been characterized by a series of physical techniques, including Fourier-transform infrared, X-ray diffraction, and multinuclear solid-state NMR. The results are very similar to those obtained for the geopolymers prepared from natural kaolinite. We believe that our synthetic approach can offer a good opportunity for the medical applications of geopolymer. -- Graphical abstract:more » Geopolymer prepared by the sol-gel route has the same spectroscopic properties as the sample prepared from the natural kaolinite. Display Omitted« less

Hydrothermally synthesized flower like MoS2 microsphere: A highly efficient adsorbent for methylene blue dye removal

NASA Astrophysics Data System (ADS)

Panda, Jnanranjan; Tudu, Bharati

2018-05-01

Herein, a flower like MoS2 (M1) microsphere assembled by layered porous nanosheet was successfully prepared by facile hydrothermal synthesis procedure. The structural, chemical and morphological characterizations for the as synthesized sample (M1) were carried out by powder x-ray diffraction (PXRD), Fourier-transform infrared (FTIR) and Field Emission Scanning Electron microscope (FESEM) respectively and spectroscopic characterization was performed by UV-Vis absorption and photoluminescence emission spectroscopy. The photocatalytic activity of the product was evaluated through photocatalytic degradation of Methylene Blue under visible light irradiation. The results indicate that layered MoS2structures possess significant adsorption ability, which may be useful for further research and practical applications of the layered MoS2 adsorbent in wastewater treatment.

Infrared spectroscopic studies of the effect of elevated temperature on the association of pyroglutamic acid with clay and other minerals

NASA Astrophysics Data System (ADS)

Macklin, John W.; White, David H.

Fourier transform i.r. measurements of L-pyroglutamic acid dispersed in a matrix of a clay, silica or alumina have been obtained at various temperatures between 25 and 220°C. The i.r. spectrum of L-pyroglutamic acid varies in a manner slightly dependent upon the matrix material and shows considerable change as the temperature of the mixtures is increased. The differences in the spectrum at elevated temperatures are explained in terms of a chemical reaction between hydroxyl groups in the matrix and the carboxylic acid. The i.r. spectra of trimethylsilyl derivatives of L-pyroglutamic acid and aluminum pyroglutamate were also measured to assist the understanding of spectra and interpretation of the spectral changes dependent upon increasing temperature.

Infrared spectroscopic studies of the effect of elevated temperature on the association of pyroglutamic acid with clay and other minerals

NASA Technical Reports Server (NTRS)

Macklin, J. W.; White, D. H.

1985-01-01

Fourier transform i.r. measurements of L-pyroglutamic acid dispersed in a matrix of a clay, silica or alumina have been obtained at various temperatures between 25 and 220 degrees C. The i.r. spectrum of L-pyroglutamic acid varies in a manner dependent upon the matrix material and shows considerable change as the temperature of the mixtures is increased. The differences in the spectrum at elevated temperatures are explained in terms of a chemical reaction between hydroxyl groups in the matrix and the carboxylic acid. The i.r. spectra of trimethylsilyl derivatives of L-pyroglutamic acid and aluminum pyroglutamate were also measured to assist the understanding of spectra and interpretation of the spectral changes dependent upon increasing temperature.

Spectroscopic investigation of interaction between mangiferin and bovine serum albumin

NASA Astrophysics Data System (ADS)

Lin, Hui; Lan, Jingfeng; Guan, Min; Sheng, Fenling; Zhang, Haixia

2009-09-01

The mechanism of interaction between mangiferin (MA) and bovine serum albumin (BSA) in aqueous solution was investigated by fluorescence spectra, synchronous fluorescence spectra, absorbance spectra and Fourier transform infrared (FT-IR) spectroscopy. The binding constants and binding sites of MA to BSA at different reaction times were calculated. And the distance between MA and BSA was estimated to be 5.20 nm based on Föster's theory. In addition, synchronous fluorescence and FT-IR measurements revealed that the secondary structures of the protein changed after the interaction of MA with BSA. As a conclusion, the interaction between the anti-diabetes Chinese medicine MA and BSA may provide some significant information for the mechanism of the traditional chinese medicine MA on the protein level to cure diabetes or other diseases.

Spectroscopic Analysis of Perfluoropolyether Lubricant Degradation During Boundary Lubrication

NASA Technical Reports Server (NTRS)

Herrera-Fierro, Pilar; Shogrin, Bradley A.; Jones, William R., Jr.

1996-01-01

The degradation of a branched perfluoropolyether (PFPE) under boundary lubrication conditions was studied using mu-FTIR and mu-Raman spectroscopies. Stainless steel (440C) discs coated with thin (600A), uniform films of the PFPE were tested in a ball-on-disc apparatus until various levels of friction coefficient were attained. Discs were then examined using the above techniques. When the friction coefficient surpassed the value obtained with an un-lubricated control, the lubricant film had either been physically displaced or partially transformed in to a 'friction polymer'. Infrared analysis of this 'friction polymer' indicated the presence of a polymeric fluorinated acid species (R(sub f)COOH). Raman spectroscopy indicated the presence of amorphous carbon in the wear track and in the friction polymer. Some reaction mechanisms are suggested to explain the results.

Generation and Reduction of NOx on Air-Fed Ozonizers

NASA Astrophysics Data System (ADS)

Ehara, Yoshiyasu; Amemiya, Yusuke; Yamamoto, Toshiaki

A generation and reduction of NOx on air-fed ozonizers using a ferroelectric packed bed reactor have been experimentally investigated. The reactors packed with CaTiO3, SrTiO3 and BaTiO3 pellets are examined for ozone generation. An ac voltage is applied to the reactor to generate partial discharge. Ozone concentration and the different nitrogen oxides at downstream of the packed bed reactor were measured with UV absorption ozone monitor and a Fourier transform infrared spectroscope respectively. The dielectric constant of packed ferroelectric pellets influences the discharge characteristic, ozone and NOx generations are varied by the dielectric constant value. Focusing on a discharge pulse current and maximum discharge magnitude, the ferroelectric packed bed plasma reactors have been evaluated on nitrogen oxide and ozone generated concentrations.

Micro-Raman and FT-IR spectroscopic studies of ceramic shards excavated from ancient Stratonikeia city at Eskihisar village in West-South Turkey

NASA Astrophysics Data System (ADS)

Bahçeli, Semiha; Güleç, Gamze; Erdoğan, Hasan; Söğüt, Bilal

2016-02-01

In this study, micro-Raman and Fourier transformed infrared (FT-IR) spectroscopies, X-ray diffraction (XRD) and scanning electron microscope with energy dispersive X-ray (SEM-EDX) were used to characterize the mineralogical structures of pigments of four ceramic fragments in which one of them belongs to Hellenistic period (1st - IVth century BC) and other three ceramic shards belong to Early Rome (IVth century BC- 1st century AD) excavated from Stratonikeia ancient city. In the results of investigations on these four ceramic fragments, the various phases were identified: quartz, kaolinite, albit (or Na-feldspar), calcite, anastase, hematite and magnetite. Furthermore, the obtained findings indicate that firing temperature is about 800-850 °C for all the shards.

High-resolution synchrotron FTIR spectroscopic analysis of the Coriolis interaction between the v10 = 1 and v8 = 1 states of ethylene-cis-1,2-d2

NASA Astrophysics Data System (ADS)

Ng, L. L.; Tan, T. L.; Wong, Andy; Appadoo, Dominique R. T.; McNaughton, Don

2016-10-01

The synchrotron Fourier transform infrared (FTIR) spectrum of the b-type ν10 band of ethylene-cis-1,2-d2 (cis-C2H2D2) was recorded at a resolution of 0.00096 cm-1 in the 550-750 cm-1 region. The measured FWHM of the lines was about 0.002 cm-1. The ν10 band, centred at 662.871885(27) cm-1 was found to be perturbed through a b-type Coriolis resonance with the infrared inactive ν8 at 759.9582(20) cm-1. In this work, 1989 infrared transitions of ν10 were assigned for the first time. These perturbed and unperturbed infrared transitions were fitted with an rms deviation of 0.00033 cm-1 using the Watson's A-reduced Hamiltonian in the Ir representation with three Coriolis terms to derive the rovibrational constants for v10 = 1 and v8 = 1 states. Ground state rovibrational constants up to two sextic terms were also derived from a fit of a total of 2532 ground state combination differences with arms deviation of 0.00030 cm-1 from the infrared transitions of the present analysis and those determined previously. The ground state constants compared favourably to the equilibrium state constants from harmonic cc-pVTZ basis set at CCSD(T), MP2 and B3LYP levels. The rotational constants of ν10 and ν8 from this work agree well with those from anharmonic calculations.

Whispering Gallery Optical Resonator Spectroscopic Probe and Method

NASA Technical Reports Server (NTRS)

Anderson, Mark S. (Inventor)

2014-01-01

Disclosed herein is a spectroscopic probe comprising at least one whispering gallery mode optical resonator disposed on a support, the whispering gallery mode optical resonator comprising a continuous outer surface having a cross section comprising a first diameter and a second diameter, wherein the first diameter is greater than the second diameter. A method of measuring a Raman spectrum and an Infra-red spectrum of an analyte using the spectroscopic probe is also disclosed.

Long open-path measurements of greenhouse gases in air using near-infrared Fourier transform spectroscopy

NASA Astrophysics Data System (ADS)

Griffith, David W. T.; Pöhler, Denis; Schmitt, Stefan; Hammer, Samuel; Vardag, Sanam N.; Platt, Ulrich

2018-03-01

In complex and urban environments, atmospheric trace gas composition is highly variable in time and space. Point measurement techniques for trace gases with in situ instruments are well established and accurate, but do not provide spatial averaging to compare against developing high-resolution atmospheric models of composition and meteorology with resolutions of the order of a kilometre. Open-path measurement techniques provide path average concentrations and spatial averaging which, if sufficiently accurate, may be better suited to assessment and interpretation with such models. Open-path Fourier transform spectroscopy (FTS) in the mid-infrared region, and differential optical absorption spectroscopy (DOAS) in the UV and visible, have been used for many years for open-path spectroscopic measurements of selected species in both clean air and in polluted environments. Near infrared instrumentation allows measurements over longer paths than mid-infrared FTS for species such as greenhouse gases which are not easily accessible to DOAS.In this pilot study we present the first open-path near-infrared (4000-10 000 cm-1, 1.0-2.5 µm) FTS measurements of CO2, CH4, O2, H2O and HDO over a 1.5 km path in urban Heidelberg, Germany. We describe the construction of the open-path FTS system, the analysis of the collected spectra, several measures of precision and accuracy of the measurements, and the results a four-month trial measurement period in July-November 2014. The open-path measurements are compared to calibrated in situ measurements made at one end of the open path. We observe significant differences of the order of a few ppm for CO2 and a few tens of ppb for CH4 between the open-path and point measurements which are 2 to 4 times the measurement repeatability, but we cannot unequivocally assign the differences to specific local sources or sinks. We conclude that open-path FTS may provide a valuable new tool for investigations of atmospheric trace gas composition in complex, small-scale environments such as cities.

Chromium oxide coatings with the potential for eliminating the risk of chromium ion release in orthopaedic implants

PubMed Central

Oje, A. M.

2017-01-01

Chromium oxide coatings prepared by radiofrequency reactive magnetron sputtering on stainless steel substrates were exposed to Ringer's physiological solution and tested for their electrochemical corrosion stability using an open circuit potential measurement, potentiodynamic polarization, electrochemical impedance spectroscopy and Mott–Schottky analysis. The coatings were found to be predominantly Cr2O3, based on the observation of the dominance of A1g and Eg symmetric modes in our Raman spectroscopic investigation and the Eu vibrational modes in our Fourier transform infrared spectroscopic measurements on the coatings. We investigated for the presence of chromium ions in Ringer's solution after all of the above electrochemical tests using atomic absorption spectroscopy, without finding a trace of chromium ions at the ppm level for coatings tested under open circuit and at the lower potentials implants are likely to experience in the human body. The coatings were further exposed to Ringer's solution for one month and tested for adhesion strength changes, and we found that they retained substantial adhesion to the substrates. We expect this finding to be significant for future orthopaedic implants where chromium ion release is still a major challenge. PMID:28791150

Binding of caffeine with caffeic acid and chlorogenic acid using fluorescence quenching, UV/vis and FTIR spectroscopic techniques.

PubMed

Belay, Abebe; Kim, Hyung Kook; Hwang, Yoon-Hwae

2016-03-01

The interactions of caffeine (CF) with chlorogenic acid (CGA) and caffeic acid (CFA) were investigated by fluorescence quenching, UV/vis and Fourier transform infrared (FTIR) spectroscopic techniques. The results of the study indicated that the fluorescence quenching between caffeine and hydroxycinnamic acids could be rationalized in terms of static quenching or the formation of non-fluorescent CF-CFA and CF-CGA complexes. From fluorescence quenching spectral analysis, the quenching constant (KSV), quenching rate constant (kq), number of binding sites (n), thermodynamic properties and conformational changes of the interaction were determined. The quenching constants (KSV) between CF and CGA, CFA are 1.84 × 10(4) and 1.04 × 10(4) L/mol at 298 K and their binding site n is ~ 1. Thermodynamic parameters determined using the Van't Hoff equation indicated that hydrogen bonds and van der Waal's forces have a major role in the reaction of caffeine with caffeic acid and chlorogenic acid. The 3D fluorescence, UV/vis and FTIR spectra also showed that the binding of CF with CFA and CGA induces conformational changes in CFA and CGA. Copyright © 2015 John Wiley & Sons, Ltd.

Report on cascade energy relaxation from PVP to Tb3+:Bi2SiO5 nanophosphor through salicylic acid in composite polymeric film

NASA Astrophysics Data System (ADS)

Kumari, Pushpa; Dwivedi, Y.

2018-05-01

The present article reports structural and spectroscopic properties of Tb:Bi2SiO5 nanophosphors dispersed in Polyvinylpyrrolidone polymer film, in presence of Salicylic acid (SA) molecule, which acts as a sensitizer. Detailed structural and spectroscopic characterizations were carried out using X-ray diffraction patterns, Scanning Electron Microscope, Fourier Transform Infrared and Excitation and photoluminescence techniques. The mean crystallite size of Tb3+:Bi2SiO5 nanophosphor and Tb3+:Bi2SiO5 in Polyvinylpyrrolidone polymer composite was estimated ∼22 nm and ∼28 nm, respectively. We have report atleast two times enhancement in Tb3+ ions emission intensity due to the efficient energy transfer from salicylic acid molecule to Tb ions. In addition to energy transfer from salicylic acid, the Polyvinylpyrrolidone polymeric host was also reported to serve as a sensitizer for SA molecule and Tb3+ ions through a cascade energy relaxation process while exciting with 248 nm photons. On 248 nm photon excitation, atleast five improvements in Tb3+ ion emission intensity are reported. Presence of SA molecule facilitates precise colour tuning as obvious from the CIE coordinates.

Spectroscopic studies on the interaction of cinnamic acid and its hydroxyl derivatives with human serum albumin

NASA Astrophysics Data System (ADS)

Min, Jiang; Meng-Xia, Xie; Dong, Zheng; Yuan, Liu; Xiao-Yu, Li; Xing, Chen

2004-04-01

Cinnamic acid and its derivatives possess various biological effects in remedy of many diseases. Interaction of cinnamic acid and its hydroxyl derivatives, p-coumaric acid and caffeic acid, with human serum albumin (HSA), and concomitant changes in its conformation were studied using fluorescence and Fourier transform infrared spectroscopic methods. Fluorescence data revealed the presence of one binding site on HSA for cinnamic acid and its hydroxyl derivatives, and their binding constants ( KA) are caffeic acid> p-coumaric acid> cinnamic acid when Cdrug/ CHSA ranging from 1 to 10. The changes of the secondary structure of HSA after interacting with the three drugs are estimated, respectively by combining the curve-fitting results of amid I and amid III bands. The α-helix structure has a decrease of ≈9, 5 and 3% after HSA interacted with caffeic acid, p-coumaric acid and cinnamic acid, respectively. It was found that the hydroxyls substituted on aromatic ring of the drugs play an important role in the changes of protein's secondary structure. Combining the result of fluorescence quenching and the changes of secondary structure of HSA after interaction with the three drugs, the drug-HSA interaction mode was discussed.

Microbiology neutralization of zearalenone using Lactococcus lactis and Bifidobacterium sp.

PubMed

Król, A; Pomastowski, P; Rafińska, K; Railean-Plugaru, V; Walczak, J; Buszewski, B

2018-01-01

The aim of the study was to neutralize zearalenone by lactic acid bacteria (LAB) such as Lactococcus lactis and Bifidobacterium sp. and investigate the mechanism of zearalenone (ZEA) binding. Neutralization of ZEA by LAB was confirmed by identification of binding kinetics and spectroscopic studies such as Fourier transform infrared spectroscopy (FT-IR) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The obtained results showed that the kinetic process of zearalenone binding to L. lactis is not homogeneous but is expressed with an initial rapid stage with about 90% of ZEA biosorption and with a much slower second step. In case of Bifidobacterium sp., the neutralization process is homogeneous; the main stage can be described with about 88% of ZEA biosorption. MALDI-TOF-MS measurements and FTIR analysis confirmed the uptake of zearalenone molecules by bacterial species. Moreover, the assessment of dead and live lactic acid bacteria cells after zearalenone treatment was performed using fluorescence microscopy. Graphical abstract Microbiology neutralization of zearalenone using Lactococcus lactis and Bifidobacterium sp. was confirmed by identification of binding kinetics and spectroscopic studies such as FT-IR spectroscopy and MALDI-TOF-MS spectrometry. The mechanism of ZEA binding was also investigated.

[Spectroscopic methods applied to component determination and species identification for coffee].

PubMed

Chen, Hua-zhou; Xu, Li-li; Qin, Qiang

2014-06-01

Spectroscopic analysis was applied to the determination of the nutrient quality of ground, instant and chicory coffees. By using inductively coupled plasma atomic emission spectrometry (ICP-ES), nine mineral elements were determined in solid coffee samples. Caffeine was determined by ultraviolet (UV) spectrometry and organic matter was investigated by Fourier transform infrared (FTIR) spectroscopy. Oxidation-reduction titration was utilized for measuring the oxalate. The differences between ground coffee and instant coffee was identified on the basis of the contents of caffeine, oxalate and mineral elements. Experimental evidence showed that, caffeine in instant coffee was 2-3 times higher than in ground coffee. Oxalate in instant coffee was significantly higher in ground coffee. Mineral elements of Mg, P and Zn in ground coffee is lower than in instant coffee, while Cu is several times higher. The mineral content in chicory coffee is overall lower than the instant coffee. In addition, we determined the content of Ti for different types of coffees, and simultaneously detected the elements of Cu, Ti and Zn in chicory coffee. As a fast detection technique, FTIR spectroscopy has the potential of detecting the differences between ground coffee and instant coffee, and is able to verify the presence of caffeine and oxalate.

High-pressure studies on nanocrystalline borderline Co1-xFexS2 (x = 0.4 and 0.5) using Mössbauer spectroscopic and electrical resistivity techniques up to 8 GPa

NASA Astrophysics Data System (ADS)

Chandra, Usha; Sharma, Pooja; Parthasarathy, G.

2016-12-01

Like bulk, Co1-xFexS2 nanoparticles also display an anomaly at x = 0.5. The borderline contiguous Co1-xFexS2 (x = 0.4 and 0.5) nanoparticles were synthesized with colloidal method and characterized for pyrite structure using various techniques, viz., X-ray diffraction, energy dispersive X-ray analysis (EDAX), S K-edge X-ray absorption near edge spectra, transmission electron microscopy (TEM) and Fourier transformed infra-red spectroscopy. The report presents the effect of high pressure on the borderline compositions using the Mössbauer spectroscopic and electrical resistivity techniques. Magnetic measurements on the system showed drastic lowering of Tc due to nanosize of the particles. With increased pressure, quadrupole splitting showed an expected trend of increase to attain a peak representing a second-order phase transition between 4 and 5 GPa for both the compositions. The pressure coefficient of electrical resistivity varied from -0.02 GPa to -0.06 GPa across transition pressure indicating a sluggish nature of transition. This is the first report of pressure effect on nanosized borderline compositions.

Mapping IR Enhancements in Closely Interacting Spiral-Spiral Pairs: I. ISO CAM and ISO SWS Observations

NASA Technical Reports Server (NTRS)

Xu, C.; Gao, Y.; Mazzarella, J.; Lu, N.; Sulentic, J.; Domingue, D.

2000-01-01

Mid-infrared (MIR) imaging and spectroscopic observations are presented for a well defined sample of eight closely interacting (CLO) pairs of spiral galaxies that have overlapping disks and show enhanced far-infrared (FIR) emission.

IR Fine-Structure Line Signatures of Central Dust-Bounded Nebulae in Luminous Infrared Galaxies

NASA Technical Reports Server (NTRS)

Fischer, J.; Allen, R.; Dudley, C. C.; Satyapal, S.; Luhman, M.; Wolfire, M.; Smith, H. A.

2004-01-01

To date, the only far-infrared spectroscopic observations of ultraluminous infrared galaxies have been obtained with the European Space Agency s Infrared Space Observatory Long Wavelength Spectrometer. The spectra of these galaxies are characterized by molecular absorption lines and weak emission lines from photodissociation regions (PDRs), but no far-infrared (greater than 40 microns) lines from ionized regions have been detected. ESA s Herschel Space Observatory, slated for launch in 2007, will likely be able to detect these lines in samples of local and moderate redshift ultra luminous galaxies and to enable measurement of the ionization parameters, the slope of the ionizing continuum, and densities present in the ionized regions of these galaxies. The higher spatial resolution of proposed observatories discussed in this workshop will enable isolation of the central regions of local galaxies and detection of these lines in high-redshift galaxies for study of the evolution of galaxies. Here we discuss evidence for the e.ects of absorption by dust within ionized regions and present the spectroscopic signatures predicted by photoionization modeling of dust-bounded regions.

40 CFR 98.414 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... appropriate detector, infrared (IR), fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR... Compounds by Extractive Direct Interface Fourier Transform Infrared (FTIR) Spectroscopy (incorporated by...

40 CFR 98.414 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... appropriate detector, infrared (IR), fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR... Compounds by Extractive Direct Interface Fourier Transform Infrared (FTIR) Spectroscopy (incorporated by...

40 CFR 98.414 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... appropriate detector, infrared (IR), fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR... Compounds by Extractive Direct Interface Fourier Transform Infrared (FTIR) Spectroscopy (incorporated by...

40 CFR 98.414 - Monitoring and QA/QC requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... appropriate detector, infrared (IR), fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR... Compounds by Extractive Direct Interface Fourier Transform Infrared (FTIR) Spectroscopy (incorporated by...

[Infrared spectroscopic analysis of Guilin watermelon frost products].

PubMed

Huang, Dong-lan; Chen, Xiao-kang; Xu, Yong-qun; Sun, Su-qin; Zhou, Qun; Lu, Wen-guan

2012-08-01

The objective of the present study is to analyze different products of Guilin watermelon frost by Fourier transform infrared spectroscopy (FTIR), second derivative infrared spectroscopy and two-dimensional correlation spectroscopy (2D-IR) under thermal perturbation. The structural information of the samples indicates that samples from the same factory but of different brands had some dissimilarities in the IR spectra, and the type and content of accessories of them were different compared with conventional IR spectra of samples, peaks at 638 and 616 cm(-1) all arise from anhydrous sodium sulfate in watermelon frost spray and watermelon frost capsule; the characteristic absorption peaks of the sucrose, dextrin or other accessories can be seen clearly in the spectra of watermelon frost throat-clearing buccal tablets, watermelon frost throat tablets and watermelon frost lozenge. And the IR spectra of watermelon frost lozenge is very similar to the IR spectra of sucrose, so it can be easily proved that the content of sucrose in watermelon frost lozenge is high. In the 2D-IR correlation spectra, the samples presented the differences in the position, number and relative intensity of autopeaks and correlation peak clusters. Consequently, the macroscopical fingerprint characters of FTIR, second derivative infrared spectra and 2D-IR spectra can not only provide the information about main chemical constituents in medical materials, but also analyze and identify the type and content of accessories in Guilin watermelon frost. In conclusion, the multi-steps IR macro-fingerprint method is rapid, effective, visual and accurate for pharmaceutical research.

An ALMA Survey of Submillimeter Galaxies in the Extended Chandra Deep Field South: Spectroscopic Redshifts

NASA Astrophysics Data System (ADS)

Danielson, A. L. R.; Swinbank, A. M.; Smail, Ian; Simpson, J. M.; Casey, C. M.; Chapman, S. C.; da Cunha, E.; Hodge, J. A.; Walter, F.; Wardlow, J. L.; Alexander, D. M.; Brandt, W. N.; de Breuck, C.; Coppin, K. E. K.; Dannerbauer, H.; Dickinson, M.; Edge, A. C.; Gawiser, E.; Ivison, R. J.; Karim, A.; Kovacs, A.; Lutz, D.; Menten, K.; Schinnerer, E.; Weiß, A.; van der Werf, P.

2017-05-01

We present spectroscopic redshifts of {\\text{}}{S}870μ {{m}} ≳ 2 mJy submillimeter galaxies (SMGs), which have been identified from the ALMA follow-up observations of 870 μm detected sources in the Extended Chandra Deep Field South (the ALMA-LESS survey). We derive spectroscopic redshifts for 52 SMGs, with a median of z = 2.4 ± 0.1. However, the distribution features a high-redshift tail, with ˜23% of the SMGs at z≥slant 3. Spectral diagnostics suggest that the SMGs are young starbursts, and the velocity offsets between the nebular emission and UV ISM absorption lines suggest that many are driving winds, with velocity offsets of up to 2000 km s-1. Using the spectroscopic redshifts and the extensive UV-to-radio photometry in this field, we produce optimized spectral energy distributions (SEDs) using Magphys, and use the SEDs to infer a median stellar mass of {M}\\star = (6 ± 1)× 1010 M {}⊙ for our SMGs with spectroscopic redshift. By combining these stellar masses with the star formation rates (measured from the far-infrared SEDs), we show that SMGs (on average) lie a factor of ˜5 above the so-called “main sequence” at z˜ 2. We provide this library of 52 template fits with robust and uniquely well-sampled SEDs as a resource for future studies of SMGs, and also release the spectroscopic catalog of ˜2000 (mostly infrared-selected) galaxies targeted as part of the spectroscopic campaign.

An Overview of the Evolution of Infrared Spectroscopy Applied to Bacterial Typing.

PubMed

Quintelas, Cristina; Ferreira, Eugénio C; Lopes, João A; Sousa, Clara

2018-01-01

The sustained emergence of new declared bacterial species makes typing a continuous challenge for microbiologists. Molecular biology techniques have a very significant role in the context of bacterial typing, but they are often very laborious, time consuming, and eventually fail when dealing with very closely related species. Spectroscopic-based techniques appear in some situations as a viable alternative to molecular methods with advantages in terms of analysis time and cost. Infrared and mass spectrometry are among the most exploited techniques in this context: particularly, infrared spectroscopy emerged as a very promising method with multiple reported successful applications. This article presents a systematic review on infrared spectroscopy applications for bacterial typing, highlighting fundamental aspects of infrared spectroscopy, a detailed literature review (covering different taxonomic levels and bacterial species), advantages, and limitations of the technique over molecular biology methods and a comparison with other competing spectroscopic techniques such as MALDI-TOF MS, Raman, and intrinsic fluorescence. Infrared spectroscopy possesses a high potential for bacterial typing at distinct taxonomic levels and worthy of further developments and systematization. The development of databases appears fundamental toward the establishment of infrared spectroscopy as a viable method for bacterial typing. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Infrared Spectroscopy of Star Formation in Galactic and Extragalactic Regions

NASA Technical Reports Server (NTRS)

Frogel, Jay (Technical Monitor); Smith, Howard A.

2004-01-01

In this program we proposed to perform a series of spectroscopic studies, including data analysis and modeling, of star formation regions using an ensemble of archival space-based data from the Infrared Space Observatory's Long Wavelength Spectrometer and Short Wavelength Spectrometer, and to take advantage of other spectroscopic databases including the first results from SIRTF. Our empha- sis has been on star formation in external, bright IR galaxies, but other areas of research have in- cluded young, low or high mass pre-main sequence stars in star formation regions, and the galactic center. The OH lines in the far infrared were proposed as one key focus of this inquiry because the Principal Investigator (H. Smith) had a full set of OH IR lines from IS0 observations. It was planned that during the proposed 2-1/2 year timeframe of the proposal other data (including perhaps from SIRTF) would become available, and we intended to be responsive to these and other such spec- troscopic data sets. Three papers are included:The Infrared Lines of OH: Diagnostics of Molecular Cloud Conditions in Infrared Bright Galaxies; The Far-Infrared Spectrum of Arp 220; andThe Far-Infrared Emission Line and Continuum Spectrum of the Seyfert Galaxy NGC 1068.

A spectroscopic comparison of selected Chinese kaolinite, coal bearing kaolinite and halloysite--a mid-infrared and near-infrared study.

PubMed

Cheng, Hongfei; Yang, Jing; Liu, Qinfu; Zhang, Jinshan; Frost, Ray L

2010-11-01

Mid-infrared (MIR) and near-infrared (NIR) spectroscopy have been compared and evaluated for differentiating kaolinite, coal bearing kaolinite and halloysite. Kaolinite, coal bearing kaolinite and halloysite are the three relative abundant minerals of the kaolin group, especially in China. In the MIR spectra, the differences are shown in the 3000-3600 cm⁻¹ between kaolinite and halloysite. It cannot obviously differentiate the kaolinite and halloysite, leaving alone kaolinite and coal bearing kaolinite. However, NIR, together with MIR, gives us the sufficient evidence to differentiate the kaolinite and halloysite, especially kaolinite and coal bearing kaolinite. There are obvious differences between kaolinite and halloysite in all range of their spectra, and they also show some difference between kaolinite and coal bearing kaolinite. Therefore, the reproducibility of measurement, signal to noise ratio and richness of qualitative information should be simultaneously considered for proper selection of a spectroscopic method for mineral analysis. Copyright © 2010 Elsevier B.V. All rights reserved.

Introducing cymantrene labels into scattering scanning near-field infrared microscopy.

PubMed

Kopf, Ilona; N'Dongo, Harmel W Peindy; Ballout, Fouad; Schatzschneider, Ulrich; Bründermann, Erik; Havenith, Martina

2012-11-07

In this paper we investigate metal-organic compounds as infrared (IR) active labels by scattering scanning near-field infrared microscopy (IR s-SNOM, often also abbreviated as s-SNIM) with a lateral resolution of 90 × 90 nm(2). Tailor-made IR spectroscopic probes based on cymantrene (CpMn(CO)(3) with Cp = η(5)-C(5)H(5)) conjugated to a cysteine-modified pseudoneurotensin (pNT-Cys-OH) peptide were prepared by automated microwave-assisted solid phase peptide synthesis (SPPS) and characterized by HPLC, ESI-MS and IR. Well-defined patterned self-assembled monolayers on a gold surface were prepared by microcontact printing of 1-octadecanethiol (ODT) followed by additional incubation in ethanolic solution of the cymantrene-peptide derivative. The self-assembled monolayers have been evidenced by infrared reflection absorption spectroscopy (IRRAS) and AFM. CO laser source radiation was tuned (1944, 1900, 1798 and 1658 cm(-1)) for imaging contrast with good matching correlation between spectroscopic and topographic patterns at specific characteristic metal carbonyl and amide bands (1944 cm(-1) (λ = 5.14 μm) and 1658 cm(-1) (λ = 6.03 μm)). Cymantrene probes provide an attractive method to tag a unique spectroscopic feature on any bio(macro)molecule. Introducing such probes into super-resolution IR s-SNOM will enable molecular tracking and distribution studies even in complex biological systems.

[EMD Time-Frequency Analysis of Raman Spectrum and NIR].

PubMed

Zhao, Xiao-yu; Fang, Yi-ming; Tan, Feng; Tong, Liang; Zhai, Zhe

2016-02-01

This paper analyzes the Raman spectrum and Near Infrared Spectrum (NIR) with time-frequency method. The empirical mode decomposition spectrum becomes intrinsic mode functions, which the proportion calculation reveals the Raman spectral energy is uniform distributed in each component, while the NIR's low order intrinsic mode functions only undertakes fewer primary spectroscopic effective information. Both the real spectrum and numerical experiments show that the empirical mode decomposition (EMD) regard Raman spectrum as the amplitude-modulated signal, which possessed with high frequency adsorption property; and EMD regards NIR as the frequency-modulated signal, which could be preferably realized high frequency narrow-band demodulation during first-order intrinsic mode functions. The first-order intrinsic mode functions Hilbert transform reveals that during the period of empirical mode decomposes Raman spectrum, modal aliasing happened. Through further analysis of corn leaf's NIR in time-frequency domain, after EMD, the first and second orders components of low energy are cut off, and reconstruct spectral signal by using the remaining intrinsic mode functions, the root-mean-square error is 1.001 1, and the correlation coefficient is 0.981 3, both of these two indexes indicated higher accuracy in re-construction; the decomposition trend term indicates the absorbency is ascending along with the decreasing to wave length in the near-infrared light wave band; and the Hilbert transform of characteristic modal component displays, 657 cm⁻¹ is the specific frequency by the corn leaf stress spectrum, which could be regarded as characteristic frequency for identification.

Near-infrared Raman spectroscopy for assessing biochemical changes of cervical tissue associated with precarcinogenic transformation.

PubMed

Duraipandian, Shiyamala; Mo, Jianhua; Zheng, Wei; Huang, Zhiwei

2014-11-07

Raman spectroscopy measures the inelastically scattered light from tissue that is capable of identifying native tissue biochemical constituents and their changes associated with disease transformation. This study aims to characterize the Raman spectroscopic properties of cervical tissue associated with the multi-stage progression of cervical precarcinogenic sequence. A rapid-acquisition fiber-optic near-infrared (NIR) Raman diagnostic system was employed for tissue Raman spectral measurements at 785 nm excitation. A total of 68 Raman spectra (23 benign, 29 low-grade squamous intraepithelial lesions (LSIL) and 16 high grade squamous intraepithelial lesions (HSIL)) were measured from 25 cervical tissue biopsy specimens, as confirmed by colposcopy-histopathology. The semi-quantitative biochemical modeling based on the major biochemicals (i.e., DNA, proteins (histone, collagen), lipid (triolein) and carbohydrates (glycogen)) in cervical tissue uncovers the stepwise accumulation of biomolecular changes associated with progressive cervical precarcinogenesis. Multi-class partial least squares-discriminant analysis (PLS-DA) together with leave-one tissue site-out, cross-validation yielded the diagnostic sensitivities of 95.7%, 82.8% and 81.3%; specificities of 100.0%, 92.3% and 88.5%,for discrimination among benign, LSIL and HSIL cervical tissues, respectively. This work suggests that the Raman spectral biomarkers have identified the potential to be used for monitoring the multi-stage cervical precarcinogenesis, forming the foundation of applying NIR Raman spectroscopy for the early diagnosis of cervical precancer in vivo at the molecular level.

Synthesis of linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite as an adsorbent for removal of Pb(ΙΙ) from aqueous solutions.

PubMed

Irani, Maryam; Ismail, Hanafi; Ahmad, Zulkifli; Fan, Maohong

2015-01-01

The purpose of this work is to remove Pb(II) from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy (FTIR), Solid carbon nuclear magnetic resonance spectroscopy (CNMR)), silicon(-29) nuclear magnetic resonance spectroscopy (Si NMR)), and X-ray diffraction spectroscope ((XRD) were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb(II) from the aqueous solution. The Pb(II)-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy (FTIR)), scanning electron microscopy (SEM)), and X-ray photoelectron spectroscopy ((XPS)). From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb(II). Kinetic studies indicated that the adsorption of Pb(II) followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb(II) ions was 430mg/g. Thus, the waste linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb(II) adsorbent. Copyright © 2014. Published by Elsevier B.V.

Stereochemistry of quinoxaline antagonist binding to a glutamate receptor investigated by Fourier transform infrared spectroscopy.

PubMed

Madden, D R; Thiran, S; Zimmermann, H; Romm, J; Jayaraman, V

2001-10-12

The stereochemistry of the interactions between quinoxaline antagonists and the ligand-binding domain of the glutamate receptor 4 (GluR4) have been investigated by probing their vibrational modes using Fourier transform infrared spectroscopy. In solution, the electron-withdrawing nitro groups of both compounds establish a resonance equilibrium that appears to stabilize the keto form of one of the cyclic amide carbonyl bonds. Changes in the 6,7-dinitro-2,3-dihydroxyquinoxaline vibrational spectra on binding to the glutamate receptor, interpreted within the framework of a published crystal structure, illuminate the stereochemistry of the interaction and suggest that the binding site imposes a more polarized electronic bonding configuration on this antagonist. Similar spectral changes are observed for 6-cyano-7-dinitro-2,3-dihydroxyquinoxaline, confirming that its interactions with the binding site are highly similar to those of 6,7-dinitro-2,3-dihydroxyquinoxaline and leading to a model of the 6-cyano-7-dinitro-2,3-dihydroxyquinoxaline-S1S2 complex, for which no crystal structure is available. Conformational changes within the GluR ligand binding domain were also monitored. Compared with the previously reported spectral changes seen on binding of the agonist glutamate, only a relatively small change is detected on antagonist binding. This correlation between the functional effects of different classes of ligand and the magnitude of the spectroscopic changes they induce suggests that the spectral data reflect physiologically relevant conformational processes.

Function of minerals in the natural radioactivity level of Vaigai River sediments, Tamilnadu, India--spectroscopical approach.

PubMed

Ramasamy, V; Paramasivam, K; Suresh, G; Jose, M T

2014-01-03

Using Gamma ray and Fourier Transform Infrared (FTIR) spectroscopic techniques, level of natural radioactivity ((238)U, (232)Th and (40)K) and mineralogical characterization of Vaigai River sediments have been analyzed with the view of evaluating the radiation risk and its relation to available minerals. Different radiological parameters are calculated to know the entire radiological characterization. The average of activity concentrations and all radiological parameters are lower than the recommended safety limit. However, some sites are having higher radioactivity values than the safety limit. From the FTIR spectroscopic technique, the minerals such as quartz, microcline feldspar, orthoclase feldspar, kaolinite, gibbsite, calcite, montmorillonite and organic carbon are identified and they are characterized. The extinction co-efficient values are calculated to know the relative distribution of major minerals such as quartz, microcline feldspar, orthoclase feldspar and kaolinite. The calculated values indicate that the amount of quartz is higher than orthoclase feldspar, microcline feldspar and much higher than kaolinite. Crystallinity index is calculated to know the crystalline nature of quartz and the result indicates that the presence of ordered crystalline quartz in the present sediment. The role of minerals in the level of radioactivity is assessed by multivariate statistical analysis (Pearson's correlation and Cluster analysis). The statistical analysis confirms that the clay mineral kaolinite is the major factor than other major minerals to induce the important radioactivity variables such as absorbed dose rate and concentrations of (232)Th and (238)U. Copyright © 2013 Elsevier B.V. All rights reserved.

Optical constants of neat liquid-chemical warfare agents and related materials measured by infrared spectroscopic ellipsometry

NASA Astrophysics Data System (ADS)

Yang, C. S.-C.; Williams, B. R.; Hulet, M. S.; Tiwald, T. E.; Miles, R. W., Jr.; Samuels, A. C.

2011-05-01

We studied various liquids using a vertical attenuated total reflection (ATR) liquid sampling assembly in conjunction with Infrared Variable Angle Spectroscopic Ellipsometry (IR-VASE), to determine the infrared optical constants of several bulk liquids related to chemical warfare. The index of refraction, n, and the extinction coefficient, k, of isopropyl methylphosphonofluoridate (Sarin or GB), isopropyl alcohol (IPA) (a precursor of GB), and dimethyl methylphosphonate (DMMP)-a commonly employed simulant for GB, measured by our vertical ATR IR-VASE setup are closely matched to those found in other studies. We also report the optical constants of cyclohexyl methylphosphonofluoridate (GF), 2-(diisopropylamino)ethyl methylphosphonothioate (VX), bis-(2-chloroethyl) sulfide (HD), and 2-chlorovinyl dichloroarsine (L, Lewisite). The ATR IR-VASE technique affords an accurate measurement of the optical constants of these hazardous compounds.

Complementarity in radiochemical and infrared spectroscopic characterization of electrode adsorption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wieckowski, A.

1994-03-01

Radioactive labelling and infrared spectroscopy are frequently used as direct, in situ probes into the structure of the electrochemical solid/liquid interface. These techniques are compared, in a polemical fashion, in the context of a recent publication by Parry et al. (Langmuir 1993, 9, 1878) where the research potential of the former technique was not adequately depicted. It is shown that radiotracers can clearly differentiate between the surface and solution species, both neutrals and anions. In addition to the surface specificity, the radiotracers offer a quantitative determination of adsorbate surface concentrations, a feature not yet demonstrated with surface infrared spectroscopy inmore » electrochemistry. Therefore, these two techniques are complementary. Examples of the combined radiochemical and spectroscopic measurements of adsorption with equivalent (smooth) electrode surfaces are quoted. 11 refs., 2 figs.« less

Mid-Infrared Spectrum of the Zodiacal Emission: Detection of Crystalline Silicates in Interplanetary Dust

NASA Technical Reports Server (NTRS)

Ootsubo, T.; Onaka, T.; Yamamura, I.; Ishihara, D.; Tanabe, T.; Roellig, T. L.

2003-01-01

Within a few astronomical units of the Sun the solar system is filled with interplanetary dust, which is believed to be dust of cometary and asteroidal origin. Spectroscopic observations of the zodiacal emission with moderate resolution provide key information on the composition and size distribution of the dust in the interplanetary space. They can be compared directly to laboratory measurements of candidate materials, meteorites, and dust particles collected in the stratosphere. Recently mid-infrared spectroscopic observations of the zodiacal emission have been made by two instruments on board the Infrared Space Observatory; the camera (ISOCAM) and the spectrophotometer (ISOPHOT-S). A broad excess emission feature in the 9-11 micron range is reported in the ISOCAM spectrum, whereas the ISOPHOT-S spectra in 6-12 microns can be well fitted by a blackbody radiation without spectral features.

Near infrared and optical spectroscopy of FSC10214+4724

NASA Technical Reports Server (NTRS)

Soifer, B. T.; Cohen, J. G.; Armus, L.; Matthews, K.; Neugebauer, G.; Oke, J. B.

1995-01-01

New infrared and optical spectroscopic observations, obtained with the W.M. Keck Telescope, are reported for the highly luminous infrared source FSC10214+4724. The rest frame optical spectrum shows new emission lines of (NeIII, (NeV), (OI), (OII), (SII), and He(+) while the rest frame ultraviolet spectrum shows new lines of OIV+SiIV, NII, NIV, SiII, NeIV and possibly NII and (NeIII), as well as clearly showing the L alpha is self-absorbed. The emission line spectrum is most characteristic of a Seyfert 2 nucleus. The preponderance of spectroscopic evidence strengthens the case of a dust enshrouded AGN powering much or most of the observed luminosity. The various spectral lines lead to a wide range in the inferred reddening and ionization parameter for this system, suggesting that we are viewing several environments through differing extinctions.

Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear

DOEpatents

Westerfield, Curtis L.; Morris, John S.; Agnew, Stephen F.

1997-01-01

Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear. A cell is described which, in combination with Fourier transform IR spectroscopy, permits the spectroscopic investigation of boundary layers under conditions of high temperature, high pressure and shear.

Correlation Between Bulk Material Defects and Spectroscopic Response in Cadmium Zinc Telluride Detectors

NASA Technical Reports Server (NTRS)

Parker, Bradford H.; Stahle, C. M.; Barthelmy, S. D.; Parsons, A. M.; Tueller, J.; VanSant, J. T.; Munoz, B. F.; Snodgrass, S. J.; Mullinix, R. E.

1999-01-01

One of the critical challenges for large area cadmium zinc telluride (CdZnTe) detector arrays is obtaining material capable of uniform imaging and spectroscopic response. Two complementary nondestructive techniques for characterizing bulk CdZnTe have been developed to identify material with a uniform response. The first technique, infrared transmission imaging, allows for rapid visualization of bulk defects. The second technique, x-ray spectral mapping, provides a map of the material spectroscopic response when it is configured as a planar detector. The two techniques have been used to develop a correlation between bulk defect type and detector performance. The correlation allows for the use of infrared imaging to rapidly develop wafer mining maps. The mining of material free of detrimental defects has the potential to dramatically increase the yield and quality of large area CdZnTe detector arrays.

Fourier transform infra-red spectroscopic signatures for lung cells' epithelial mesenchymal transition: A preliminary report

NASA Astrophysics Data System (ADS)

Sarkar, Atasi; Sengupta, Sanghamitra; Mukherjee, Anirban; Chatterjee, Jyotirmoy

2017-02-01

Infra red (IR) spectral characterization can provide label-free cellular metabolic signatures of normal and diseased circumstances in a rapid and non-invasive manner. Present study endeavoured to enlist Fourier transform infra red (FTIR) spectroscopic signatures for lung normal and cancer cells during chemically induced epithelial mesenchymal transition (EMT) for which global metabolic dimension is not well reported yet. Occurrence of EMT was validated with morphological and immunocytochemical confirmation. Pre-processed spectral data was analyzed using ANOVA and principal component analysis-linear discriminant analysis (PCA-LDA). Significant differences observed in peak area corresponding to biochemical fingerprint (900-1800 cm- 1) and high wave-number (2800-3800 cm- 1) regions contributed to adequate PCA-LDA segregation of cells undergoing EMT. The findings were validated by re-analysis of data using another in-house built binary classifier namely vector valued regularized kernel approximation (VVRKFA), in order to understand EMT progression. To improve the classification accuracy, forward feature selection (FFS) tool was employed in extracting potent spectral signatures by eliminating undesirable noise. Gradual increase in classification accuracy with EMT progression of both cell types indicated prominence of the biochemical alterations. Rapid changes in cellular metabolome noted in cancer cells within first 24 h of EMT induction along with higher classification accuracy for cancer cell groups in comparison to normal cells might be attributed to inherent differences between them. Spectral features were suggestive of EMT triggered changes in nucleic acid, protein, lipid and bound water contents which can emerge as the useful markers to capture EMT related cellular characteristics.

[Using 2-DCOS to identify the molecular spectrum peaks for the isomer in the multi-component mixture gases Fourier transform infrared analysis].

PubMed

Zhao, An-Xin; Tang, Xiao-Jun; Zhang, Zhong-Hua; Liu, Jun-Hua

2014-10-01

The generalized two-dimensional correlation spectroscopy and Fourier transform infrared were used to identify hydrocarbon isomers in the mixed gases for absorption spectra resolution enhancement. The Fourier transform infrared spectrum of n-butane and iso-butane and the two-dimensional correlation infrared spectrum of concentration perturbation were used for analysis as an example. The all band and the main absorption peak wavelengths of Fourier transform infrared spectrum for single component gas showed that the spectra are similar, and if they were mixed together, absorption peaks overlap and peak is difficult to identify. The synchronous and asynchronous spectrum of two-dimensional correlation spectrum can clearly identify the iso-butane and normal butane and their respective characteristic absorption peak intensity. Iso-butane has strong absorption characteristics spectrum lines at 2,893, 2,954 and 2,893 cm(-1), and n-butane at 2,895 and 2,965 cm(-1). The analysis result in this paper preliminary verified that the two-dimensional infrared correlation spectroscopy can be used for resolution enhancement in Fourier transform infrared spectrum quantitative analysis.

Tunable far infrared studies of molecular parameters in support of stratospheric measurements

NASA Technical Reports Server (NTRS)

Chance, Kelly V.; Evenson, K. M.; Park, K.; Radostitz, J. V.; Jennings, D. A.; Nolt, I. G.; Vanek, M. D.

1991-01-01

Lab studies were made in support of far infrared spectroscopy of the stratosphere using the Tunable Far InfraRed (TuFIR) method of ultrahigh resolution spectroscopy and, more recently, spectroscopic and retrieval calculations performed in support of satellite-based atmospheric measurement programs: the Global Ozone Monitoring Experiment (GOME), and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY).

Applications of absorption spectroscopy using quantum cascade lasers.

PubMed

Zhang, Lizhu; Tian, Guang; Li, Jingsong; Yu, Benli

2014-01-01

Infrared laser absorption spectroscopy (LAS) is a promising modern technique for sensing trace gases with high sensitivity, selectivity, and high time resolution. Mid-infrared quantum cascade lasers, operating in a pulsed or continuous wave mode, have potential as spectroscopic sources because of their narrow linewidths, single mode operation, tunability, high output power, reliability, low power consumption, and compactness. This paper reviews some important developments in modern laser absorption spectroscopy based on the use of quantum cascade laser (QCL) sources. Among the various laser spectroscopic methods, this review is focused on selected absorption spectroscopy applications of QCLs, with particular emphasis on molecular spectroscopy, industrial process control, combustion diagnostics, and medical breath analysis.

Infrared spectroscopic imaging detects chemical modifications in liver fibrosis due to diabetes and disease

PubMed Central

Sreedhar, Hari; Varma, Vishal K.; Gambacorta, Francesca V.; Guzman, Grace; Walsh, Michael J.

2016-01-01

The importance of stroma as a rich diagnostic region in tissue biopsies is growing as there is an increasing understanding that disease processes in multiple organs can affect the composition of adjacent connective tissue regions. This may be especially true in the liver, since this organ’s central metabolic role exposes it to multiple disease processes. We use quantum cascade laser infrared spectroscopic imaging to study changes in the chemical status of hepatocytes and fibrotic regions of liver tissue that result from the progression of liver cirrhosis to hepatocellular carcinoma and the potentially confounding effects of diabetes mellitus. PMID:27375956

End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

NASA Technical Reports Server (NTRS)

Feinberg, Lee; Bolcar, Matt; Liu, Alice; Guyon, Olivier; Stark,Chris; Arenberg, Jon

2016-01-01

Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance.

Built-in hyperspectral camera for smartphone in visible, near-infrared and middle-infrared lights region (third report): spectroscopic imaging for broad-area and real-time componential analysis system against local unexpected terrorism and disasters

NASA Astrophysics Data System (ADS)

Hosono, Satsuki; Kawashima, Natsumi; Wollherr, Dirk; Ishimaru, Ichiro

2016-05-01

The distributed networks for information collection of chemical components with high-mobility objects, such as drones or smartphones, will work effectively for investigations, clarifications and predictions against unexpected local terrorisms and disasters like localized torrential downpours. We proposed and reported the proposed spectroscopic line-imager for smartphones in this conference. In this paper, we will mention the wide-area spectroscopic-image construction by estimating 6 DOF (Degrees Of Freedom: parallel movements=x,y,z and rotational movements=θx, θy, θz) from line data to observe and analyze surrounding chemical-environments. Recently, smartphone movies, what were photographed by peoples happened to be there, had worked effectively to analyze what kinds of phenomenon had happened around there. But when a gas tank suddenly blew up, we did not recognize from visible-light RGB-color cameras what kinds of chemical gas components were polluting surrounding atmospheres. Conventionally Fourier spectroscopy had been well known as chemical components analysis in laboratory usages. But volatile gases should be analyzed promptly at accident sites. And because the humidity absorption in near and middle infrared lights has very high sensitivity, we will be able to detect humidity in the sky from wide field spectroscopic image. And also recently, 6-DOF sensors are easily utilized for estimation of position and attitude for UAV (Unmanned Air Vehicle) or smartphone. But for observing long-distance views, accuracies of angle measurements were not sufficient to merge line data because of leverage theory. Thus, by searching corresponding pixels between line spectroscopic images, we are trying to estimate 6-DOF in high accuracy.

Chain and mirophase-separated structures of ultrathin polyurethane films

NASA Astrophysics Data System (ADS)

Kojio, Ken; Uchiba, Yusuke; Yamamoto, Yasunori; Motokucho, Suguru; Furukawa, Mutsuhisa

2009-08-01

Measurements are presented how chain and microphase-separated structures of ultrathin polyurethane (PU) films are controlled by the thickness. The film thickness is varied by a solution concentration for spin coating. The systems are PUs prepared from commercial raw materials. Fourier-transform infrared spectroscopic measurement revealed that the degree of hydrogen bonding among hard segment chains decreased and increased with decreasing film thickness for strong and weak microphase separation systems, respectively. The microphase-separated structure, which is formed from hard segment domains and a surrounding soft segment matrix, were observed by atomic force microscopy. The size of hard segment domains decreased with decreasing film thickness, and possibility of specific orientation of the hard segment chains was exhibited for both systems. These results are due to decreasing space for the formation of the microphase-separated structure.

Analysis of Black Bearing Balls from a Space Shuttle Body Flap Actuator

NASA Technical Reports Server (NTRS)

Sovinski, Marjorie F.; Street, Kenneth W.

2005-01-01

A significantly deteriorated ball bearing mechanism from a body flap actuator on Space Shuttle OV-103 was disassembled and the balls submitted for analysis in conjunction with Return to Flight activities. The OV-103 balls, referred to as the "black balls", were subjected to X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) and Raman micro spectroscopy, surface profilometry, and optical and electron microscopy. The spectroscopic results in combination with microscopy analysis allowed a determination of the lubricant degradation pathway. The chemical attack mechanism does not adequately explain the unique visual appearance of the black balls. Numerous efforts have unsuccessfully focused on duplication of the phenomena causing this unique surface structure and appearance of the black balls. Further detail will be presented supporting these conclusions along with plausible explanations of the unique black appearance to the balls.

Enzyme-mediated self-assembly of highly ordered structures from disordered proteins

NASA Astrophysics Data System (ADS)

Athamneh, Ahmad I.; Barone, Justin R.

2009-10-01

Wheat gluten is an amorphous storage protein. Trypsin hydrolysis of wheat gluten produced glutamine-rich peptides. Some peptides were able to self-assemble into fibrous structures extrinsic to native wheat gluten. The final material was an in situ formed peptide composite of highly ordered nanometer-sized fibrils and micron-sized fibers embedded in an unassembled peptide matrix. Fourier transform infrared spectroscopic and x-ray diffraction data suggested that the new structures resembled that of cross- β fibrils found in some insect silk and implicated in prion diseases. The largest self-assembled fibers were about 10 µm in diameter with right-handed helicity and appeared to be bundles of smaller nanometer-sized fibrils. Results demonstrated the potential for utilizing natural mechanisms of protein self-assembly to design advanced materials that can provide a wide range of structural and chemical functionality.

Chemical modification of TiO2 nanotube arrays for label-free optical biosensing applications

NASA Astrophysics Data System (ADS)

Terracciano, Monica; Galstyan, Vardan; Rea, Ilaria; Casalino, Maurizio; De Stefano, Luca; Sbervegleri, Giorgio

2017-10-01

In this study, we have fabricated TiO2 nanotube arrays by the potentiostatic anodic oxidation of Ti foils in fluoride-containing electrolyte and explored them as versatile devices for biosensing applications. TiO2 nanotubes have been chemically modified in order to bind Protein A as a specific target analyte for the optical biosensing. The obtained structures have been characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, water contact angle, fluorescence microscopy, spectroscopic reflectometry and photoluminescence. Investigations show that the prepared TiO2 nanotubes, 2.5 μm long and 75 nm thick, can be easily and efficiently bio-modified, and the obtained structures are strongly photoluminescent, thus suitable for the label-free biosensing applications in the range of μM, due to their peculiar optical properties.

Ground-based infrared spectroscopic measurements of atmospheric hydrogen cyanide

NASA Technical Reports Server (NTRS)

Rinsland, C. P.; Smith, M. A. H.; Rinsland, P. L.; Goldman, A.; Brault, J. W.; Stokes, G. M.

1982-01-01

A number of lines of the nu-3 band of hydrogen cyanide have been detected in solar absorption spectra recorded near sunrise and sunset at Kitt Peak National Observatory (elevation 2095 m) with a 0.01/cm resolution Fourier transform spectrometer. Analysis of two of the strongest and best isolated lines has led to a value of 2.73 x 10 to the 15th molecules/sq cm for the vertical column abundance of HCN above Kitt Peak. The accuracy of this value is estimated as + or - 25%. This result, combined with the stratospheric concentration of HCN derived by Coffey, Mankin, and Cicerone (1981), yields 166 parts per trillion by volume for the average mixing ratio of HCN between 2 and 12 km. This is the first determination of the HCN concentration in the nonurban troposphere.

Selective chloroform sensor using thiol functionalized reduced graphene oxide at room temperature

NASA Astrophysics Data System (ADS)

Midya, Anupam; Mukherjee, Subhrajit; Roy, Shreyasee; Santra, Sumita; Manna, Nilotpal; Ray, Samit K.

2018-02-01

This paper presents a highly selective chloroform sensor using functionalised reduced graphene oxide (RGO) as a sensing layer. Thiol group is covalently attached on the basal plan of RGO film by a simple one-step aryl diazonium chemistry to improve its selectivity. Several spectroscopic techniques like X-ray photoelectron, Raman and Fourier transform infrared spectroscopy confirm successful thiol functionalization of RGO. Finally, the fabricated chemiresistor type sensor is exposed to chloroform in the concentration range 200-800 ppm (parts per million). The sensor shows a 4.3% of response towards 800 ppm chloroform. The selectivity of the sensor is analyzed using various volatile organic compounds as well. The devices show enhanced response and faster recovery attributed to the physiosorption of chloroform onto thiol functionalized graphene making them attractive for 2D materials based sensing applications.

Influence of Hydrogen Bond on Thermal and Phase Transitions of Binary Complex Liquid Crystals

NASA Astrophysics Data System (ADS)

Vijayakumar, V. N.; Rajasekaran, T. R.; Baskar, K.

2017-12-01

A novel supramolecular liquid crystal (LC) is synthesized from the binary complex of 4-decyloxy benzoic acid and cholesteryl acetate. Fourier transform infrared (FTIR) spectroscopic study confirms the formation of intermolecular hydrogen bond between the mesogens. Various mesophases and corresponding textural changes in the complex are observed by comparing with its constituents through polarizing optical microscopic (POM) studies. The thermal stability factor of smectic phase for present complex is calculated. An interesting observation of present work is that investigation of extended thermal span of mesomorphic phases, decreased enthalpy, a nematic phase with a high clearing point and a low melting point. This is due to an arrangement of molecular reorientations and the development of new associations by hydrogen bonding. Optical tilt angle for smectic C phase is determined and the same is fitted to a power law.

Infrared micro-spectroscopic studies of epithelial cells

PubMed Central

Romeo, Melissa; Mohlenhoff, Brian; Jennings, Michael; Diem, Max

2009-01-01

We report results from a study of human and canine mucosal cells, investigated by infrared micro-spectroscopy, and analyzed by methods of multivariate statistics. We demonstrate that the infrared spectra of individual cells are sensitive to the stage of maturation, and that a distinction between healthy and diseased cells will be possible. Since this report is written for an audience not familiar with infrared micro-spectroscopy, a short introduction into this field is presented along with a summary of principal component analysis. PMID:16797481

Diamond anvil cell for spectroscopic investigation of materials at high temperature, high pressure and shear

DOEpatents

Westerfield, C.L.; Morris, J.S.; Agnew, S.F.

1997-01-14

Diamond anvil cell is described for spectroscopic investigation of materials at high temperature, high pressure and shear. A cell is described which, in combination with Fourier transform IR spectroscopy, permits the spectroscopic investigation of boundary layers under conditions of high temperature, high pressure and shear. 4 figs.

Analysis of the structural organization and thermal stability of two spermadhesins. Calorimetric, circular dichroic and Fourier-transform infrared spectroscopic studies.

PubMed

Menéndez, M; Gasset, M; Laynez, J; López-Zumel, C; Usobiaga, P; Töpfer-Petersen, E; Calvete, J J

1995-12-15

The CUB domain is a widespread 110-amino-acid module found in functionally diverse, often developmentally regulated proteins, for which an antiparallel beta-barrel topology similar to that in immunoglobulin V domains has been predicted. Spermadhesins have been proposed as a subgroup of this protein family built up by a single CUB domain architecture. To test the proposed structural model, we have analyzed the structural organization of two members of the spermadhesin protein family, porcine seminal plasma proteins I/II (PSP-I/PSP-II) heterodimer and bovine acidic seminal fluid protein (aSFP) homodimer, using differential scanning calorimetry, far-ultraviolet circular dichroism and Fourier-transform infrared spectroscopy. Thermal unfolding of PSP-I/PSP-II and aSFP were irreversible and followed a one-step process with transition temperatures (Tm) of 60.5 degrees C and 78.6 degrees C, respectively. The calorimetric enthalpy changes (delta Hcat) of thermal denaturation were 439 kJ/mol for PSP-I/PSP-II and 660 kJ/mol for aSFP dimer. Analysis of the calorimetric curves of PSP-I/PSP-II showed that the entire dimer constituted the cooperative unfolding unit. Fourier-transform infrared spectroscopy and deconvolution of circular dichroic spectra using a convex constraint analysis indicated that beta-structure and turns are the major structural element of both PSP-I/PSP-II (53% of beta-sheet, 21% of turns) and aSFP (44% of beta-sheet, 36% of turns), and that the porcine and the bovine proteins contain little, if any, alpha-helical structure. Taken together, our results indicate that the porcine and the bovine spermadhesin molecules are probably all-beta-structure proteins, and would support a beta-barrel topology like that predicted for the CUB domain. Other beta-structure folds, such as the Greek-key pattern characteristic of many carbohydrate-binding protein domains cannot be eliminated. Finally, the same combination of biophysical techniques was used to characterize the residual secondary structure of thermally denatured forms of PSP-I/PSP-II and aSFP, and to emphasize the aggregation tendency of these forms.

Evaluation of PLS, LS-SVM, and LWR for quantitative spectroscopic analysis of soils

USDA-ARS?s Scientific Manuscript database

Soil testing requires the analysis of large numbers of samples in laboratory that are often time consuming and expensive. Mid-infrared spectroscopy (mid-IR) and near-infrared spectroscopy (NIRS) are fast, non-destructive, and inexpensive analytical methods that have been used for soil analysis, in l...

The infrared spectrum of asteroid 433 Eros

NASA Technical Reports Server (NTRS)

Larson, H. P.; Fink, U.; Treffers, R. R.; Gautier, T. N., III

1976-01-01

The mineralogical composition of asteroid Eros has been determined from its infrared spectrum (0.9-2.7 micrometers; 28/cm resolution). Major minerals include metallic Ni-Fe and pyroxene; no spectroscopic evidence for olivine or plagioclase feldspar was found. The IR spectrum of Eros is most consistent with a stony-iron composition.

Mid-Infrared Spectroscopic Properties of Humic Acid and Fulvic Acid-Soil Mixtures

USDA-ARS?s Scientific Manuscript database

The detection of humic materials in soils is essential in order to determine organic matter (SOM) stability and C sequestration on agricultural land. Mid-Infrared (MidIR) spectroscopy has been used to characterize SOM quality [1], study extracted soil humic acids [2], develop calibrations for quanti...

Mid-Infrared Spectroscopic Properties of Humic Acid and Fulvic Acid-Soil Mixtures.

USDA-ARS?s Scientific Manuscript database

The detection of humic materials in soils is essential in order to determine organic matter (SOM) stability and C sequestration on agricultural land. Mid-Infrared (MidIR) spectroscopy has been used to characterize SOM quality [1], study extracted soil humic acids [2], develop calibrations for quanti...

Use of Advanced Spectroscopic Techniques for Predicting the Mechanical Properties of Wood Composites

Treesearch

Timothy G. Rials; Stephen S. Kelley; Chi-Leung So

2002-01-01

Near infrared (NIR) spectroscopy was used to characterize a set of medium-density fiberboard (MDF) samples. This spectroscopic technique, in combination with projection to latent structures (PLS) modeling, effectively predicted the mechanical strength of MDF samples with a wide range of physical properties. The stiffness, strength, and internal bond properties of the...

High resolution infrared spectroscopy from space: A preliminary report on the results of the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment on Spacelab 3

NASA Technical Reports Server (NTRS)

Farmer, Crofton B.; Raper, Odell F.

1987-01-01

The ATMOS (Atmospheric Trace Molecule Spectroscopy) experiment has the broad purpose of investigating the physical structure, chemistry, and dynamics of the upper atmosphere through the study of the distributions of the neutral minor and trace constituents and their seasonal and long-term variations. The technique used is high-resolution infrared absorption spectroscopy using the Sun as the radiation source, observing the changes in the transmission of the atmosphere as the line-of-sight from the Sun to the spacecraft penetrates the atmosphere close to the Earth's limb at sunrise and sunset. During these periods, interferograms are generated at the rate of one each second which yield, when transformed, high resolution spectra covering the 2.2 to 16 micron region of the infrared. Twenty such occultations were recorded during the Spacelab 3 flight, which have produced concentration profiles for a large number of minor and trace upper atmospheric species in both the Northern and Southern Hemispheres. Several of these species have not previously been observed in spectroscopic data. The data reduction and analysis procedures used following the flight are discussed; a number of examples of the spectra obtained are shown, and a bar graph of the species detected thus far in the analysis is given which shows the altitude ranges for which concentration profiles were retrieved.

Characterization of isolated 1-aza-adamantan-4-one (C9H13NO) from microwave, millimeter-wave and infrared spectroscopy supported by electronic structure calculations

NASA Astrophysics Data System (ADS)

Pirali, O.; Goubet, M.; Boudon, V.; D'Accolti, L.; Fusco, C.; Annese, C.

2017-08-01

We have synthesized 1-aza-adamantan-4-one (C9H13NO) starting from commercial 1,4-cyclohexanedionemonoethylene acetal and tosylmethylisocianide, following a procedure already described in the literature. The high degree of sample purity was demonstrated by gas chromatography and mass spectrometric measurements and its structure evidenced by 1H and 13C NMR spectroscopy. Among numerous interests in physical chemistry, this target molecule is of high relevance for mechanistic evaluation and the synthesis of novel pharmaceutical compounds. We present a thorough spectroscopic study of this molecule by gas phase vibrational and rotational spectroscopy. Accurate vibrational frequencies have been determined from infrared and far-infrared spectra. The pure rotational spectrum of the molecule has been recorded both by cavity-based Fourier transform microwave spectroscopy in the 2-20 GHz region by supersonically expanding the vapor pressure of the warm sample and by room-temperature absorption spectroscopy in the 140-220 GHz range. Accurate sets of rotational and centrifugal distortion parameters of 1-aza-adamantan-4-one in its ground state and in five vibrationally excited states have been derived from these measurements and compared to accurate quantum chemical calculations. The hyperfine parameters have been discussed in terms of molecular structure around the nitrogen quadrupole nucleus.

Process analytical technology in continuous manufacturing of a commercial pharmaceutical product.

PubMed

Vargas, Jenny M; Nielsen, Sarah; Cárdenas, Vanessa; Gonzalez, Anthony; Aymat, Efrain Y; Almodovar, Elvin; Classe, Gustavo; Colón, Yleana; Sanchez, Eric; Romañach, Rodolfo J

2018-03-01

The implementation of process analytical technology and continuous manufacturing at an FDA approved commercial manufacturing site is described. In this direct compaction process the blends produced were monitored with a Near Infrared (NIR) spectroscopic calibration model developed with partial least squares (PLS) regression. The authors understand that this is the first study where the continuous manufacturing (CM) equipment was used as a gravimetric reference method for the calibration model. A principal component analysis (PCA) model was also developed to identify the powder blend, and determine whether it was similar to the calibration blends. An air diagnostic test was developed to assure that powder was present within the interface when the NIR spectra were obtained. The air diagnostic test as well the PCA and PLS calibration model were integrated into an industrial software platform that collects the real time NIR spectra and applies the calibration models. The PCA test successfully detected an equipment malfunction. Variographic analysis was also performed to estimate the sampling analytical errors that affect the results from the NIR spectroscopic method during commercial production. The system was used to monitor and control a 28 h continuous manufacturing run, where the average drug concentration determined by the NIR method was 101.17% of label claim with a standard deviation of 2.17%, based on 12,633 spectra collected. The average drug concentration for the tablets produced from these blends was 100.86% of label claim with a standard deviation of 0.4%, for 500 tablets analyzed by Fourier Transform Near Infrared (FT-NIR) transmission spectroscopy. The excellent agreement between the mean drug concentration values in the blends and tablets produced provides further evidence of the suitability of the validation strategy that was followed. Copyright © 2018 Elsevier B.V. All rights reserved.

Photoacoustic FTIR spectroscopic study of undisturbed human cortical bone

NASA Astrophysics Data System (ADS)

Gu, Chunju; Katti, Dinesh R.; Katti, Kalpana S.

2013-02-01

Chemical pretreatment has been the prevailing sample preparation procedure for infrared (IR) spectroscopic studies on bone. However, experiments have indicated that chemical pretreatment can potentially affect the interactions between the components. Typically the IR techniques have involved transmission experiments. Here we report experimental studies using photoacoustic Fourier transform infrared spectroscopy (PA-FTIR). As a nondestructive technique, PA-FTIR can detect absorbance spectrum from a sample at controllable sampling depth and with little or no sample preparation. Additionally, the coupling inert gas, helium, which is utilized in the PA-FTIR system, can inhibit bacteria growth of bone by displacing oxygen. Therefore, we used this technique to study the undisturbed human cortical bone. It is found that photoacoustic mode (linear-scan, LS-PA-FTIR) can obtain basically similar spectra of bone as compared to the traditional transmission mode, but it seems more sensitive to amide III and ν2 carbonate bands. The ν3 phosphate band is indicative of detailed mineral structure and symmetry of native bone. The PA-FTIR depth profiling experiments on human cortical bone also indicate the influence of water on OH band and the cutting effects on amide I and mineral bands. Our results indicate that phosphate ion geometry appears less symmetric in its undisturbed state as detected by the PA-FTIR as compared to higher symmetry observed using transmission techniques on disturbed samples. Moreover, the PA-FTIR spectra indicate a band at 1747 cm-1 possibly resulting from Cdbnd O stretching of lipids, cholesterol esters, and triglycerides from the arteries. Comparison of the spectra in transverse and longitudinal cross-sections demonstrates that, the surface area of the longitudinal section bone appears to have more organic matrix exposed and with higher mineral stoichiometry.

Towards diode-pumped mid-infrared praseodymium-ytterbium-doped fluoride fiber lasers

NASA Astrophysics Data System (ADS)

Woodward, R. I.; Hudson, D. D.; Jackson, S. D.

2018-02-01

We explore the potential of a new mid-infrared laser transition in praseodymium-doped fluoride fiber for emission around 3.4 μm, which can be conveniently pumped by 0.975 μm diodes via ytterbium sensitizer co-doping. Optimal cavity designs are determined through spectroscopic measurements and numerical modeling, suggesting that practical diode-pumped watt-level mid-infrared fiber sources beyond 3 μm could be achieved.

Near-infrared and optical spectroscopy of FSC 10214+4724

NASA Technical Reports Server (NTRS)

Soifer, B. T.; Cohen, J. G.; Armus, L.; Matthews, K.; Neugebauer, G.; Oke, J. B.

1995-01-01

New infrared and optical spectroscopic observations, obtained with the W. M. Keck Telescope, are reported for the highly luminous infrared source FSC 10214+4724. The rest frame optical spectrum shows new emission lines of (Ne III), (Ne V), (O I), (O II), (S II), and He(+), while the rest frame ultraviolet spectrum shows new lines of O IV) + Si IV, N III, N IV), Si II, Ne IV, and possibly N II and (Ne III), as well as clearly showing that Ly-alpha is self-absorbed. The emission-line spectrum is most characteristic of a Seyfert 2 nucleus. The preponderance of spectroscopic evidence strengthens the case for a dust-enshrouded Active galactic nuclei (AGN) powering much or most of the observed luminosity. The various spectral lines lead to a wide range in the inferred reddening and ionization parameter for this system, suggesting that we are viewing several environments through differing extinctions.

Molecular dispersion spectroscopy for chemical sensing using chirped mid-infrared quantum cascade laser.

PubMed

Wysocki, Gerard; Weidmann, Damien

2010-12-06

A spectroscopic method of molecular detection based on dispersion measurements using a frequency-chirped laser source is presented. An infrared quantum cascade laser emitting around 1912 cm(-1) is used as a tunable spectroscopic source to measure dispersion that occurs in the vicinity of molecular ro-vibrational transitions. The sample under study is a mixture of nitric oxide in dry nitrogen. Two experimental configurations based on a coherent detection scheme are investigated and discussed. The theoretical models, which describe the observed spectral signals, are developed and verified experimentally. The method is particularly relevant to optical sensing based on mid-infrared quantum cascade lasers as the high chirp rates available with those sources can significantly enhance the magnitude of the measured dispersion signals. The method relies on heterodyne beatnote frequency measurements and shows high immunity to variations in the optical power received by the photodetector.

Spectroscopic observations with the Stratospheric Observatory for Infrared Astronomy (SOFIA)

NASA Astrophysics Data System (ADS)

Becklin, E. E.; Tielens, A. G. G. M.; Callis, H. H. S.

The joint US and German SOFIA project to develop and operate a 2.5-meter infrared airborne telescope in a Boeing 747-SP is now in its final stages of development. Flying in the stratosphere, SOFIA allows observations through the infrared and submillimeter region, with an average transmission of greater than 80%. SOFIA is characterized by a wide instrument complement ranging from broadband imagers, through moderate resolution spectrographs capable of resolving broad features due to dust and large molecules, to high-resolution spectrometers suitable for kinematic studies of molecular and atomic gas lines at km/s resolution. This broad range in instruments will enable SOFIA to make unique contributions to a broad array of science topics. First science flights will begin in 2009 and the observatory is expected to operate for over 20 years. The sensitivity, characteristics, science instrument complement, and examples of first light spectroscopic science are discussed.

Spectroscopic and Ab Initio Determination of the Ring-Twisting Potential Energy Function for 1,3-Cyclohexadiene

NASA Astrophysics Data System (ADS)

Autrey, Daniel; Choo, Jaebum; Laane, Jaan

2000-10-01

The ring-twisting vibration of 1,3-cyclohexadiene has been studied using Raman and infrared spectroscopy of the molecule in the vapor phase. The Raman spectrum shows five ring-twisting transitions in the 150 - 200 cm-1 region. The far-infrared spectrum shows only two transitions for this vibration, which is infrared forbidden in the C_2v (planar) approximation. Three ring-twisting combination bands were also observed off a fundamental vibration at 926.1 cm-1. A coordinate dependent kinetic energy expansion for the ring-twisting motion was calculated, and this was used to determine the ring-twisting potential function. Ab initio calculations were performed using Moller-Plesset perturbation theory (MP2) using different basis sets. The barrier to planarity of 1150 cm-1 was determined from the spectroscopic data. The various ab initio calculations gave barriers to planarity in the 1197 - 1593 cm-1 range.

A quantitative evaluation of spurious results in the infrared spectroscopic measurement of CO2 isotope ratios

NASA Astrophysics Data System (ADS)

Mansfield, C. D.; Rutt, H. N.

2002-02-01

The possible generation of spurious results, arising from the application of infrared spectroscopic techniques to the measurement of carbon isotope ratios in breath, due to coincident absorption bands has been re-examined. An earlier investigation, which approached the problem qualitatively, fulfilled its aspirations in providing an unambiguous assurance that 13C16O2/12C16O2 ratios can be confidently measured for isotopic breath tests using instruments based on infrared absorption. Although this conclusion still stands, subsequent quantitative investigation has revealed an important exception that necessitates a strict adherence to sample collection protocol. The results show that concentrations and decay rates of the coincident breath trace compounds acetonitrile and carbon monoxide, found in the breath sample of a heavy smoker, can produce spurious results. Hence, findings from this investigation justify the concern that breath trace compounds present a risk to the accurate measurement of carbon isotope ratios in breath when using broadband, non-dispersive, ground state absorption infrared spectroscopy. It provides recommendations on the length of smoking abstention required to avoid generation of spurious results and also reaffirms, through quantitative argument, the validity of using infrared absorption spectroscopy to measure CO2 isotope ratios in breath.

Spectroscopic diagnosis of laryngeal carcinoma using near-infrared Raman spectroscopy and random recursive partitioning ensemble techniques.

PubMed

Teh, Seng Khoon; Zheng, Wei; Lau, David P; Huang, Zhiwei

2009-06-01

In this work, we evaluated the diagnostic ability of near-infrared (NIR) Raman spectroscopy associated with the ensemble recursive partitioning algorithm based on random forests for identifying cancer from normal tissue in the larynx. A rapid-acquisition NIR Raman system was utilized for tissue Raman measurements at 785 nm excitation, and 50 human laryngeal tissue specimens (20 normal; 30 malignant tumors) were used for NIR Raman studies. The random forests method was introduced to develop effective diagnostic algorithms for classification of Raman spectra of different laryngeal tissues. High-quality Raman spectra in the range of 800-1800 cm(-1) can be acquired from laryngeal tissue within 5 seconds. Raman spectra differed significantly between normal and malignant laryngeal tissues. Classification results obtained from the random forests algorithm on tissue Raman spectra yielded a diagnostic sensitivity of 88.0% and specificity of 91.4% for laryngeal malignancy identification. The random forests technique also provided variables importance that facilitates correlation of significant Raman spectral features with cancer transformation. This study shows that NIR Raman spectroscopy in conjunction with random forests algorithm has a great potential for the rapid diagnosis and detection of malignant tumors in the larynx.

Far-infrared Optical Conductivity Gap in Superconducting MgB2 Films

NASA Astrophysics Data System (ADS)

Carnahan, M. A.; Kaindl, R. A.; Chemla, D. S.; Christen, H. M.; Zhai, H. Y.; Paranthaman, M.; Lowndes, D. H.

2002-03-01

The prospect of unconventional coupling in the superconductor MgB2 motivates experiments which probe the density of states around the superconducting gap. The frequency and temperature dependent optical conductivity contains important spectroscopic information about the fundamental gap excitations as well as providing a contactless measure of the superconducting condensate. Here we present the first measurements of the far-infrared conductivity of MgB2 over a broad frequency range which spans excitations across its lowest-energy superconducting gap [1]. Thin films of MgB2 are grown on Al_2O3 substrates through e-beam evaporation and subsequent ex-situ annealing [2]. Both the real and imaginary parts of the conductivity are obtained - without recourse to Kramers-Kronig transformations - from terahertz time-domain spectroscopy. Below Tc we observe a depletion of oscillator strength due to the opening of a superconducting gap. We find a gap size of 2Δ ≈ 5 meV. This result, a value which is only half that expected in weak-coupling BCS theory, disfavors a conventional isotropic single-gap scenario. [1] R. Kaindl et al., Phys. Rev. Lett. (to appear). [2] M. Paranthaman et al., Appl. Phys. Lett. 78, 3669 (2001).

ISO Guest Observer Data Analysis and LWS Instrument Team Activities

NASA Technical Reports Server (NTRS)

Smith, Howard

2002-01-01

This project was granted a no-cost extension prompted by the request of the major subcontractor, the Naval Research Laboratory, which had not yet completed its tasks. As of July 2002, they had made substantial progress. They have successfully fabricated a metal mesh grid on polyimide, and also successfully fabricated a 2-layer metal mesh infrared filter using stacks of these metal mesh grids on polyimide; the actual layering was done at SAO. Both warm and cold spectroscopic tests were done on these fabricated devices. The measurements were in good agreement with the theory, and also reasonable performance in absolute terms. NRL is now working on fabricating a 3-layer metal mesh infrared filter, and a prototype is expected in the next month. Testing should occur before the end of the fiscal year. Finally, NRL has preliminarily agreed to hire a new postdoctoral person to refine the modeling of the filters based on the new measurements. The person should arrive this fall. NRL has a new Fourier Transform Spectrometer which will be delivered in the next month, and which will be used to facilitate the testing which has up to now been done in collaboration with NASA Goddard Space Flight Space Center.

High Resolution Spectroscopy to Support Atmospheric Measurements

NASA Technical Reports Server (NTRS)

Benner, D. Chris; Venkataraman, Malathy Devi

2000-01-01

The major research activities performed during the cooperative agreement enhanced our spectroscopic knowledge of molecules of atmospheric interest such as carbon dioxide, water vapor, ozone, methane, and carbon monoxide, to name a few. Measurements were made using the NASA Langley Tunable Diode Laser Spectrometer System (TDL) and several Fourier Transform Spectrometer Systems (FTS) around the globe. The results from these studies made remarkable improvements in the line positions and intensities for several molecules, particularly ozone and carbon dioxide in the 2 to 17-micrometer spectral region. Measurements of pressure broadening and pressure induced line shift coefficients and the temperature dependence of pressure broadening and pressure induced line shift coefficients for infrared transitions of ozone, methane, and water vapor were also performed. Results from these studies have been used for retrievals of stratospheric gas concentration profiles from data collected by several Upper Atmospheric Research satellite (UARS) infrared instruments as well as in the analysis of high resolution atmospheric spectra such as those acquired by space-based, ground-based, and various balloon- and aircraft-borne experiments. Our results made significant contributions in several updates of the HITRAN (HIgh resolution TRANsmission) spectral line parameters database. This database enjoys worldwide recognition in research involving diversified scientific fields.

High Resolution Spectroscopy to Support Atmospheric Measurements

NASA Technical Reports Server (NTRS)

Benner, D. Chris; Venkataraman, Malathy Devi

2000-01-01

The major research activities performed during the cooperative agreement enhanced our spectroscopic knowledge of molecules of atmospheric interest such as carbon dioxide, water vapor, ozone, methane, and carbon monoxide, to name a few. Measurements were made using the NASA Langley Tunable Diode Laser Spectrometer System (TDL) and several Fourier Transform Spectrometer Systems (FTS) around the globe. The results from these studies made remarkable improvements in the line positions and intensities for several molecules, particularly ozone and carbon dioxide in the 2 to 17-micrometer spectral region. Measurements of pressure broadening and pressure induced line shift coefficients and the temperature dependence of pressure broadening and pressure induced line shift coefficients for infrared transitions of ozone, methane, and water vapor were also performed. Results from these studies have been used for retrievals of stratospheric gas concentration profiles from data collected by several Upper Atmospheric Research satellite (UARS) infrared instruments as well as in the analysis of high resolution atmospheric spectra such as those acquired by space-based, ground-based, and various balloon-and aircraft-borne experiments. Our results made significant contributions in several updates of the HITRAN (HIgh resolution TRANsmission) spectral line parameters database. This database enjoys worldwide recognition in research involving diversified scientific fields.

Integrated gas analyzer for complete monitoring of turbine engine test cells.

PubMed

Markham, James R; Bush, Patrick M; Bonzani, Peter J; Scire, James J; Zaccardi, Vincent A; Jalbert, Paul A; Bryant, M Denise; Gardner, Donald G

2004-01-01

Fourier transform infrared (FT-IR) spectroscopy is proving to be reliable and economical for the quantification of many gas-phase species during testing and development of gas turbine engines in ground-based facilities such as sea-level test cells and altitude test cells. FT-IR measurement applications include engine-generated exhaust gases, facility air provided as input to engines, and ambient air in and around test cells. Potentially, the traditionally used assembly of many gas-specific single gas analyzers will be eliminated. However, the quest for a single instrument capable of complete gas-phase monitoring at turbine engine test cells has previously suffered since the FT-IR method cannot measure infrared-inactive oxygen molecules, a key operational gas to both air-breathing propulsion systems and test cell personnel. To further the quest, the FT-IR sensor used for the measurements presented in this article was modified by integration of a miniature, solid-state electrochemical oxygen sensor. Embedded in the FT-IR unit at a location near the long-effective-optical-path-length gas sampling cell, the amperometric oxygen sensor provides simultaneous, complementary information to the wealth of spectroscopic data provided by the FT-IR method.

Multicomponent hollow tubules formed using phytosterol and gamma-oryzanol-based compounds: an understanding of their molecular embrace.

PubMed

Rogers, Michael A; Bot, Arjen; Lam, Ricky Sze Ho; Pedersen, Tor; May, Tim

2010-08-19

The formation kinetics of self-assembling tubules composed of phytosterol:gamma-oryzanol mixtures were investigated at the Canadian Light Source on the mid-IR beamline using synchrotron radiation and Fourier transform infrared spectroscopy (FT-IR). The Avrami model was fitted to the changing hydrogen bonding density occurring at 3450 cm(-1). The nucleation process was found to be highly dependent on the molecular structure of the phytosterol. The nucleation event for cholesterol:gamma-oryzanol was determined to be sporadic whereas 5alpha-cholestan-3beta-ol:gamma-oryzanol and beta-sitosterol:gamma-oryzanol underwent instantaneous nucleation. One-dimensional growth occurred for each phytosterol:gamma-oryzanol mixture and involved the evolution of highly specific intermolecular hydrogen bonds. More detailed studies on the cholesterol:gamma-oryzanol system indicated that the nucleation activation energy, determined from multiple rate constants, obtained using the Avrami model, was at a minimum when the two compounds were at a 1:1 weight ratio. This resulted in drastic differences to the microscopic structures and affected the macroscopic properties such as turbidity. The formation of the phytosterol:gamma-oryzanol complex was due to intermolecular hydrogen bonding, which was in agreement with the infrared spectroscopic evidence.

Identification of oil residues in Roman amphorae (Monte Testaccio, Rome): a comparative FTIR spectroscopic study of archeological and artificially aged samples.

PubMed

Tarquini, Gabriele; Nunziante Cesaro, Stella; Campanella, Luigi

2014-01-01

The application of Fourier Transform InfraRed (FTIR) spectroscopy to the analysis of oil residues in fragments of archeological amphorae (3rd century A.D.) from Monte Testaccio (Rome, Italy) is reported. In order to check the possibility to reveal the presence of oil residues in archeological pottery using microinvasive and\\or not invasive techniques, different approaches have been followed: firstly, FTIR spectroscopy was used to study oil residues extracted from roman amphorae. Secondly, the presence of oil residues was ascertained analyzing microamounts of archeological fragments with the Diffuse Reflectance Infrared Spectroscopy (DRIFT). Finally, the external reflection analysis of the ancient shards was performed without preliminary treatments evidencing the possibility to detect oil traces through the observation of the most intense features of its spectrum. Incidentally, the existence of carboxylate salts of fatty acids was also observed in DRIFT and Reflectance spectra of archeological samples supporting the roman habit of spreading lime over the spoil heaps. The data collected in all steps were always compared with results obtained on purposely made replicas. © 2013 Elsevier B.V. All rights reserved.

Photochemistry of coronene in cosmic water ice analogs at different concentrations.

PubMed

de Barros, A L F; Mattioda, A L; Ricca, A; Cruz, G; Allamandola, L J

2017-10-20

This work presents the photochemistry of ultraviolet (UV) irradiated coronene in water ices at 15 K, studied using mid-infrared Fourier transform (FTIR) spectroscopy for C 24 H 12 :H 2 O at concentrations of (1:50), (1:150), (1:200), (1:300) and (1:400). Previous UV irradiation studies of anthracene:H 2 O, pyrene:H 2 O and benzo[ghi]perylene:H 2 O ices at 15 K have shown that aromatic alcohols and ketones, as well as CO 2 and H 2 CO are formed at very low temperatures. Like-wise, here, in addition to the coronene cation, hydroxy-, keto-, and protonated coronene (coronene-H + ) are formed. The rate constants for the decay of neutral coronene and for the formation of photoproducts have been derived. It is shown that PAHs and their UV-induced PAH:H 2 O photoproducts have mid-infrared spectroscopic signatures in the 5-8 μ m region that can contribute to the interstellar ice components described by Boogert et al. (2008) as C1-C5. Our results suggest that oxygenated and hydrogenated PAHs could be in UV-irradiated regions of the ISM where water-rich ices are important.

Photochemistry of Coronene in Cosmic Water Ice Analogs at Different Concentrations

NASA Astrophysics Data System (ADS)

de Barros, A. L. F.; Mattioda, A. L.; Ricca, A.; Cruz-Diaz, G. A.; Allamandola, L. J.

2017-10-01

This work presents the photochemistry of ultraviolet (UV) irradiated coronene in water ices at 15 K studied using mid-infrared Fourier transform (FTIR) spectroscopy for C24H12:H2O at concentrations of (1:50), (1:150), (1:200), (1:300), and (1:400). Previous UV irradiation studies of anthracene:H2O, pyrene:H2O, and benzo[ghi]perylene:H2O ices at 15 K have shown that aromatic alcohols and ketones, as well as CO2 and H2CO, are formed at very low temperatures. Likewise, here, in addition to the coronene cation, hydroxy-, keto-, and protonated coronene (coronene H+) are formed. The rate constants for the decay of neutral coronene and for the formation of photoproducts have been derived. It is shown that Polycyclic Aromatic Hydrocarbons (PAHs) and their UV induced PAH:H2O photoproducts have mid-infrared spectroscopic signatures in the 5-8 μm region that can contribute to the interstellar ice components described by Boogert et al. as C1-C5. Our results suggest that oxygenated and hydrogenated PAHs could be in UV-irradiated regions of the interstellar medium where water-rich ices are important.

Evaluation of anthocyanins in Aronia melanocarpa/BSA binding by spectroscopic studies.

PubMed

Wei, Jie; Xu, Dexin; Zhang, Xiao; Yang, Jing; Wang, Qiuyu

2018-05-02

The interaction between Anthocyanins in Aronia melanocarpa (AMA) and bovine serum albumin (BSA) were studied in this paper by multispectral technology, such as fluorescence quenching titration, circular dichroism (CD) spectroscopy and Fourier transform infrared spectroscopy (FTIR). The results of the fluorescence titration revealed that AMA could strongly quench the intrinsic fluorescence of BSA by static quenching. The apparent binding constants K SV and number of binding sites n of AMA with BSA were obtained by fluorescence quenching method. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS), were calculated to be 18.45 kJ mol -1  > 0 and 149.72 J mol -1  K -1  > 0, respectively, which indicated that the interaction of AMA with BSA was driven mainly by hydrophobic forces. The binding process was a spontaneous process of Gibbs free energy change. Based on Förster's non-radiative energy transfer theory, the distance r between the donor (BSA) and the receptor (AMA) was calculated to be 3.88 nm. Their conformations were analyzed using infrared spectroscopy and CD. The results of multispectral technology showed that the binding of AMA to BSA induced the conformational change of BSA.

Infrared Spectroscopy of Pollen Identifies Plant Species and Genus as Well as Environmental Conditions

PubMed Central

Zimmermann, Boris; Kohler, Achim

2014-01-01

Background It is imperative to have reliable and timely methodologies for analysis and monitoring of seed plants in order to determine climate-related plant processes. Moreover, impact of environment on plant fitness is predominantly based on studies of female functions, while the contribution of male gametophytes is mostly ignored due to missing data on pollen quality. We explored the use of infrared spectroscopy of pollen for an inexpensive and rapid characterization of plants. Methodology The study was based on measurement of pollen samples by two Fourier transform infrared techniques: single reflectance attenuated total reflectance and transmission measurement of sample pellets. The experimental set, with a total of 813 samples, included five pollination seasons and 300 different plant species belonging to all principal spermatophyte clades (conifers, monocotyledons, eudicots, and magnoliids). Results The spectroscopic-based methodology enables detection of phylogenetic variations, including the separation of confamiliar and congeneric species. Furthermore, the methodology enables measurement of phenotypic plasticity by the detection of inter-annual variations within the populations. The spectral differences related to environment and taxonomy are interpreted biochemically, specifically variations of pollen lipids, proteins, carbohydrates, and sporopollenins. The study shows large variations of absolute content of nutrients for congenital species pollinating in the same environmental conditions. Moreover, clear correlation between carbohydrate-to-protein ratio and pollination strategy has been detected. Infrared spectral database with respect to biochemical variation among the range of species, climate and biogeography will significantly improve comprehension of plant-environment interactions, including impact of global climate change on plant communities. PMID:24748390

Characterizing Aeroallergens by Infrared Spectroscopy of Fungal Spores and Pollen

PubMed Central

Zimmermann, Boris; Tkalčec, Zdenko; Mešić, Armin; Kohler, Achim

2015-01-01

Background Fungal spores and plant pollen cause respiratory diseases in susceptible individuals, such as asthma, allergic rhinitis and hypersensitivity pneumonitis. Aeroallergen monitoring networks are an important part of treatment strategies, but unfortunately traditional analysis is time consuming and expensive. We have explored the use of infrared spectroscopy of pollen and spores for an inexpensive and rapid characterization of aeroallergens. Methodology The study is based on measurement of spore and pollen samples by single reflectance attenuated total reflectance Fourier transform infrared spectroscopy (SR-ATR FTIR). The experimental set includes 71 spore (Basidiomycota) and 121 pollen (Pinales, Fagales and Poales) samples. Along with fresh basidiospores, the study has been conducted on the archived samples collected within the last 50 years. Results The spectroscopic-based methodology enables clear spectral differentiation between pollen and spores, as well as the separation of confamiliar and congeneric species. In addition, the analysis of the scattering signals inherent in the infrared spectra indicates that the FTIR methodology offers indirect estimation of morphology of pollen and spores. The analysis of fresh and archived spores shows that chemical composition of spores is well preserved even after decades of storage, including the characteristic taxonomy-related signals. Therefore, biochemical analysis of fungal spores by FTIR could provide economical, reliable and timely methodologies for improving fungal taxonomy, as well as for fungal identification and monitoring. This proof of principle study shows the potential for using FTIR as a rapid tool in aeroallergen studies. In addition, the presented method is ready to be immediately implemented in biological and ecological studies for direct measurement of pollen and spores from flowers and sporocarps. PMID:25867755

A HERSCHEL SURVEY OF THE [N II] 205 {mu}m LINE IN LOCAL LUMINOUS INFRARED GALAXIES: THE [N II] 205 {mu}m EMISSION AS A STAR FORMATION RATE INDICATOR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao Yinghe; Gao Yu; Lu, Nanyao

2013-03-01

We present, for the first time, a statistical study of [N II] 205 {mu}m line emission for a large sample of local luminous infrared galaxies using Herschel Spectral and Photometric Imaging Receiver Fourier Transform Spectrometer (SPIRE FTS) data. For our sample of galaxies, we investigate the correlation between the [N II] luminosity (L{sub [N{sub II]}}) and the total infrared luminosity (L{sub IR}), as well as the dependence of L{sub [N{sub II]}}/L{sub IR} ratio on L{sub IR}, far-infrared colors (IRAS f{sub 60}/f{sub 100}), and the [O III] 88 {mu}m to [N II] luminosity ratio. We find that L{sub [N{sub II]}} correlatesmore » almost linearly with L{sub IR} for non-active galactic nucleus galaxies (all having L{sub IR} < 10{sup 12} L{sub Sun }) in our sample, which implies that L{sub [N{sub II]}} can serve as a star formation rate tracer which is particularly useful for high-redshift galaxies that will be observed with forthcoming submillimeter spectroscopic facilities such as the Atacama Large Millimeter/submillimeter Array. Our analysis shows that the deviation from the mean L{sub [N{sub II]}}-L{sub IR} relation correlates with tracers of the ionization parameter, which suggests that the scatter in this relation is mainly due to the variations in the hardness, and/or ionization parameter, of the ambient galactic UV field among the sources in our sample.« less

A Spectroscopic study on the fuel value of softwoods in relation to chemical composition

Treesearch

Chi-Leung So; Thomas L. Eberhardt; Les Groom; Todd F. Shupe

2012-01-01

The recent focus on bioenergy has led to interest in developing alternative technologies for assessing the fuel value of available biomass resources. In this study, both near- and mid-infrared spectroscopic datawere used to predict fuel value in relation to extractives and lignin contents for longleaf pine wood. Samples were analyzed both before and after extraction....

Spectroscopic Imaging with an Uncooled Microbolometer Infrared Camera and Step-Scan FTIR

DTIC Science & Technology

2006-12-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public released; distribution is unlimited SPECTROSCOPIC...Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the...STATEMENT Approved for public release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The purpose of this

Nanoscale Infrared Spectroscopy of Biopolymeric Materials

Treesearch

Curtis Marcott; Michael Lo; Kevin Kjoller; Craig Prater; Roshan Shetty; Joseph Jakes; Isao Noda

2012-01-01

Atomic Force Microscopy (AFM) and infrared (IR) spectroscopy have been combined in a single instrument capable of producing 100 nm spatial resolution IR spectra and images. This new capability enables the spectroscopic characterization of biomaterial domains at levels not previously possible. A tunable IR laser source generating pulses on the order of 10 ns was used...

Development of chipscale chalcogenide glass based infrared chemical sensors

NASA Astrophysics Data System (ADS)

Hu, Juejun; Musgraves, J. David; Carlie, Nathan; Zdyrko, Bogdan; Luzinov, Igor; Agarwal, Anu; Richardson, Kathleen; Kimerling, Lionel

2011-01-01

In this paper, we review the design, processing, and characterization of novel planar infrared chemical sensors. Chalcogenide glasses are identified as the material of choice for sensing given their wide infrared transparency as well as almost unlimited capacity for composition alloying and property tailoring. Three generations of on-chip spectroscopic chemical sensor devices we have developed: waveguide evanescent sensors, micro-disk cavity-enhanced sensors and micro-cavity photothermal sensors are discussed.

The origin, composition and history of cometary ices from spectroscopic studies

NASA Technical Reports Server (NTRS)

Allamandola, L. J.

1989-01-01

The spectroscopic analysis of pristine cometary material provides a very important probe of the chemical identity of the material as well as of the physical and chemical conditions which prevailed during the comet's history. Concerning classical spectroscopy, the spectral regions which will most likely prove most useful are the infrared, the visible and ultraviolet. Newer spectroscopic techniques which have the potential to provide equally important information include nuclear magnetic resonance (NMR) and electron spin resonance (ESR). Each technique is summarized with emphasis placed on the kind of information which can be obtained.

ENVIRONMENTAL ANALYSIS BY AB INITIO QUANTUM MECHANICAL COMPUTATION AND GAS CHROMATOGRAPHY/FOURIER TRANSFORM INFRARED SPECTROMETRY.

EPA Science Inventory

Computational chemistry, in conjunction with gas chromatography/mass spectrometry/Fourier transform infrared spectrometry (GC/MS/FT-IR), was used to tentatively identify seven tetrachlorobutadiene (TCBD) isomers detected in an environmental sample. Computation of the TCBD infrare...

An optical design of the wide-field imaging and multi-object spectrograph for an Antarctic infrared telescope

NASA Astrophysics Data System (ADS)

Ichikawa, Takashi; Obata, Tomokazu

2016-08-01

A design of the wide-field infrared camera (AIRC) for Antarctic 2.5m infrared telescope (AIRT) is presented. The off-axis design provides a 7'.5 ×7'. 5 field of view with 0".22 pixel-1 in the wavelength range of 1 to 5 μm for the simultaneous three-color bands using cooled optics and three 2048×2048 InSb focal plane arrays. Good image quality is obtained over the entire field of view with practically no chromatic aberration. The image size corresponds to the refraction limited for 2.5 m telescope at 2 μm and longer. To enjoy the stable atmosphere with extremely low perceptible water vapor (PWV), superb seeing quality, and the cadence of the polar winter at Dome Fuji on the Antarctic plateau, the camera will be dedicated to the transit observations of exoplanets. The function of a multi-object spectroscopic mode with low spectra resolution (R 50-100) will be added for the spectroscopic transit observation at 1-5 μm. The spectroscopic capability in the environment of extremely low PWV of Antarctica will be very effective for the study of the existence of water vapor in the atmosphere of super earths.

High resolution FTIR spectroscopic study of the ν4 band of CH 3CHF 2 enclosed in a flow of cold N 2 gas

NASA Astrophysics Data System (ADS)

Appadoo, Dominique R. T.; Robertson, Evan G.; McNaughton, Don

2003-01-01

An enclosive flow cooling (EFC) cell has been constructed, and coupled to a Brüker IFS 120HR high resolution Fourier transform spectrometer to record rotationally cold absorption spectra of gases of atmospheric interest at high spectral resolution. The new system has been characterized using N 2O, revealing that rotational temperatures as cold as 110 K are readily attainable using liquid nitrogen as a cryogen. Infrared spectra of the ν4 band of 1,1-difluoroethane (R152a), CH 3CHF 2, cooled in the EFC cell have been measured at a resolution of 0.0019 cm-1. Eight hundred and twenty rovibrational transitions of the weak ν4 band with 2⩽ J'⩽46 and Kc'⩽16 were assigned and fitted to Watson's A-reduced Hamiltonian. The ν4 CH 3 symmetric deformation ( a/c-type) was found to be coupled to the ν13 asymmetric deformation ( b-type) via an a-axis Coriolis interaction. In the ensuing analysis, values of spectroscopic constants were obtained for both the ν4 and dark ν13 states. Supporting ab initio calculations up to the MP2/TZV+(3 df,3 p) level are presented.

Vibrational spectroscopy for imaging single microbial cells in complex biological samples

DOE PAGES

Harrison, Jesse P.; Berry, David

2017-04-13

Here, vibrational spectroscopy is increasingly used for the rapid and non-destructive imaging of environmental and medical samples. Both Raman and Fourier-transform infrared (FT-IR) imaging have been applied to obtain detailed information on the chemical composition of biological materials, ranging from single microbial cells to tissues. Due to its compatibility with methods such as stable isotope labeling for the monitoring of cellular activities, vibrational spectroscopy also holds considerable power as a tool in microbial ecology. Chemical imaging of undisturbed biological systems (such as live cells in their native habitats) presents unique challenges due to the physical and chemical complexity of themore » samples, potential for spectral interference, and frequent need for real-time measurements. This Mini Review provides a critical synthesis of recent applications of Raman and FT-IR spectroscopy for characterizing complex biological samples, with a focus on developments in single-cell imaging. We also discuss how new spectroscopic methods could be used to overcome current limitations of singlecell analyses. Given the inherent complementarity of Raman and FT-IR spectroscopic methods, we discuss how combining these approaches could enable us to obtain new insights into biological activities either in situ or under conditions that simulate selected properties of the natural environment.« less

Syntheses, spectroscopic properties and molecular structure of silver phytate complexes - IR, UV-VIS studies and DFT calculations

NASA Astrophysics Data System (ADS)

Zając, A.; Dymińska, L.; Lorenc, J.; Ptak, M.; Hanuza, J.

2018-03-01

Silver phytate IP6, IP6Ag, IP6Ag2 and IP6Ag3 complexes in the solid state have been synthesized changing the phosphate to metal mole ratio. The obtained products have been characterized by means of chemical and spectroscopic studies. Attenuated total reflection Fourier transform infrared technique and Raman microscope were used in the measurements. These results were discussed in terms of DFT (Density Functional Theory) quantum chemical calculations using the B3LYP/6-31G(d,p) approach. The molecular structures of these compounds have been proposed on the basis of group theory and geometry optimization taking into account the shape and the number of the observed bands corresponding to the stretching and bending vibrations of the phosphate group and metal-oxygen polyhedron. The role of inter- and intra-hydrogen bonds in stabilization of the structure has been discussed. It was found that three types of hydrogen bonds appear in the studied compounds: terminal, and those engaged in the inter- and intra-molecular interactions. The Fermi resonance as a result of the strong intra-molecular Osbnd H⋯O hydrogen bonds was discovered. Electron absorption spectra have been measured to characterize the electron properties of the studied complexes and their local symmetry.

Interaction of collagen with chlorosulphonated paraffin tanning agents: Fourier transform infrared spectroscopic analysis and molecular dynamics simulations.

PubMed

Monti, Susanna; Bramanti, Emilia; Della Porta, Valentina; Onor, Massimo; D'Ulivo, Alessandro; Barone, Vincenzo

2013-09-21

The binding of chlorosulphonated paraffins to collagen triple helices is studied by means of classical molecular dynamics simulations and experimental spectroscopic techniques in order to disclose the principal characteristics of their interaction during the leather fattening process. Indeed, collagen is the main target to develop new leather modifying agents with specific characteristics, and an accurate design of the collagen binders, supported by predictive computational strategies, could be a successful tool to obtain new effective eco-compatible compounds able to impart to the leather the required functionalities and distinctive mechanical properties. Possible effects caused by the tanning agents on the collagen matrix have been identified from both experimental and theoretical points of view. Computational data in agreement with experiment have revealed that chlorosulphonated paraffins can interact favorably with the collagen residues having amine groups in their side chains (Arg, Lys, Asn and Gln) and reduce the tendency of the solvated collagen matrix to swell. However, the interference of chlorosulphonated paraffins with the unfolding process, which is operated mainly by the action of water, can be due both to covalent cross-linking of the collagen chains and intermolecular hydrogen bonding interactions involving also the hydroxyl groups of Hyp, Ser and Thr residues.

Use of spectroscopic and imaging techniques to evaluate pretreated sugarcane bagasse as a substrate for cellulase production under solid-state fermentation.

PubMed

Rodríguez-Zúñiga, Ursula Fabiola; Bertucci Neto, Victor; Couri, Sonia; Crestana, Silvio; Farinas, Cristiane Sanchez

2014-03-01

The enzymatic cocktail of cellulases is one of the most costly inputs affecting the economic viability of the biochemical route for biomass conversion into biofuels and other chemicals. Here, the influence of liquid hot water, dilute acid, alkali, and combined acid/alkali pretreatments on sugarcane bagasse (SCB) used for cellulase production was investigated by means of spectroscopic and imaging techniques. Chemical composition and structural characteristics, such as crystallinity (determined by X-ray diffraction), functional groups (Fourier transform infrared spectroscopy), and microstructure (scanning electron microscopy), were used to correlate SCB pretreatments with enzymatic biosynthesis by a strain of the filamentous fungus Aspergillus niger under solid-state fermentation. The combined acid/alkali pretreatment resulted in a SCB with higher cellulose content (86.7%). However, the high crystallinity (74%) of the resulting biomass was detrimental to microbial uptake and enzyme production. SCB pretreated with liquid hot water yielded the highest filter paper cellulase (FPase), carboxymethyl cellulase (CMCase), and xylanase activities (0.4, 14.9, and 26.1 U g(-1), respectively). The results showed that a suitable pretreatment for SCB to be used as a substrate for cellulase production should avoid severe conditions in order to preserve amorphous cellulose and to enhance the physical properties that assist microbial access.

Vibrational spectroscopy for imaging single microbial cells in complex biological samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrison, Jesse P.; Berry, David

Here, vibrational spectroscopy is increasingly used for the rapid and non-destructive imaging of environmental and medical samples. Both Raman and Fourier-transform infrared (FT-IR) imaging have been applied to obtain detailed information on the chemical composition of biological materials, ranging from single microbial cells to tissues. Due to its compatibility with methods such as stable isotope labeling for the monitoring of cellular activities, vibrational spectroscopy also holds considerable power as a tool in microbial ecology. Chemical imaging of undisturbed biological systems (such as live cells in their native habitats) presents unique challenges due to the physical and chemical complexity of themore » samples, potential for spectral interference, and frequent need for real-time measurements. This Mini Review provides a critical synthesis of recent applications of Raman and FT-IR spectroscopy for characterizing complex biological samples, with a focus on developments in single-cell imaging. We also discuss how new spectroscopic methods could be used to overcome current limitations of singlecell analyses. Given the inherent complementarity of Raman and FT-IR spectroscopic methods, we discuss how combining these approaches could enable us to obtain new insights into biological activities either in situ or under conditions that simulate selected properties of the natural environment.« less

Anti-biofilm efficacy of 100 MeV gold ion irradiated polycarbonate against Salmonella typhi

NASA Astrophysics Data System (ADS)

Joshi, R. P.; Hareesh, K.; Bankar, A.; Sanjeev, G.; Asokan, K.; Kanjilal, D.; Dahiwale, S. S.; Bhoraskar, V. N.; Dhole, S. D.

2017-12-01

Polycarbonate (PC) films were irradiated by 100 MeV gold (Au7+) ions and characterized to study changes in its optical, chemical, surface morphology and thermal properties. UV-Visible spectroscopic results revealed the decrease in the optical band gap of PC after ion irradiation due to chain scission mainly at the carbonyl group which is corroborated by Fourier Transform Infrared spectroscopic results. X-ray diffractogram study showed decrease in crystallinity of PC film after irradiation. Scanning electron microscopic results showed the micropores formation in PC which results in surface roughening. Differential scanning calorimetric results revealed decrease in glass transition temperature indicating the decrease in molecular weight of PC corroborated by rheometric studies. PC films irradiated by 100 MeV Au7+ ions showed increased anti-biofilm activity against the human pathogen, Salmonella typhi (S. typhi). Morphology of S. typhi was changed due to stress of Au7+ irradiated PC. Cells length was increased with increasing fluences. The average cell length, cell volume and surface area was increased significantly (P<0.05) with increasing ion fluences. Biofilm formation was inhibited ≈ 20% at lower fluence and 96% at higher fluence, which observed to be enhanced anti-biofilm activity in Au7+ irradiated PC.

Correcting the effect of refraction and dispersion of light in FT-IR spectroscopic imaging in transmission through thick infrared windows.

PubMed

Chan, K L Andrew; Kazarian, Sergei G

2013-01-15

Transmission mode is one of the most common sampling methods for FT-IR spectroscopic imaging because the spectra obtained generally have a reasonable signal-to-noise ratio. However, dispersion and refraction of infrared light occurs when samples are sandwiched between infrared windows or placed underneath a layer of liquid. Dispersion and refraction cause infrared light to focus with different focal lengths depending on the wavelength (wavenumber) of the light. As a result, images obtained are in focus only at a particular wavenumber while they are defocused at other wavenumber values. In this work, a solution to correct this spread of focus by means of adding a lens on top of the infrared transparent window, such that a pseudo hemisphere is formed, has been investigated. Through this lens (or pseudo hemisphere), refraction of light is removed and the light across the spectral range has the same focal depth. Furthermore, the lens acts as a solid immersion objective and an increase of both magnification and spatial resolution (by 1.4 times) is demonstrated. The spatial resolution was investigated using an USAF resolution target, showing that the Rayleigh criterion can be achieved, as well as a sample with a sharp polymer interface to indicate the spatial resolution that can be expected in real samples. The reported approach was used to obtain chemical images of cross sections of cancer tissue and hair samples sandwiched between infrared windows showing the versatility and applicability of the method. In addition to the improved spatial resolution, the results reported herein also demonstrate that the lens can reduce the effect of scattering near the edges of tissue samples. The advantages of the presented approach, obtaining FT-IR spectroscopic images in transmission mode with the same focus across all wavenumber values and simultaneous improvement in spatial resolution, will have wide implications ranging from studies of live cells to sorption of drugs into tissues.

IDEOS: Fitting Infrared Spectra from Dusty Galaxies

NASA Astrophysics Data System (ADS)

Viola, Vincent; Rupke, D.

2014-01-01

We fit models to heavily obscured infrared spectra taken by the Spitzer Space Telescope and prepare them for cataloguing in the Infrared Database of Extragalactic Observables from Spitzer (IDEOS). When completed, IDEOS will contain homogeneously measured mid-infrared spectroscopic observables of more than 4200 galaxies beyond the Local Group. The software we use, QUESTFit, models the spectra using up to three extincted blackbodies (including silicate, water ice, and hydrocarbon absorption) and PAH templates. We present results from a sample of the approximately 200 heavily obscured spectra that will be present in IDEOS.

Concluding Thoughts on New Directions in Infrared Astronomy

NASA Astrophysics Data System (ADS)

Harwit, Martin

Currently planned infrared space missions are ambitious and bound to be rewarding. We ask whether design criteria of the past still hold for these projects, and suggest that accumulating experience dictates new engineering guidelines for these increasingly sophisticated missions. Striking spectroscopic advances presented at this symposium indicate that generally held beliefs about the chemical evolution of galaxies may need to be revised. Similar changes in attitude may be required by the results of deep infrared surveys and the recent detectedion of a diffuse far-infrared (FIR) extragalactic background

Infrared spectroscopic near-field mapping of single nanotransistors.

PubMed

Huber, A J; Wittborn, J; Hillenbrand, R

2010-06-11

We demonstrate the application of scattering-type scanning near-field optical microscopy (s-SNOM) for infrared (IR) spectroscopic material recognition in state-of-the-art semiconductor devices. In particular, we employ s-SNOM for imaging of industrial CMOS transistors with a resolution better than 20 nm, which allows for the first time IR spectroscopic recognition of amorphous SiO(2) and Si(3)N(4) components in a single transistor device. The experimentally recorded near-field spectral signature of amorphous SiO(2) shows excellent agreement with model calculations based on literature dielectric values, verifying that the characteristic near-field contrasts of SiO(2) stem from a phonon-polariton resonant near-field interaction between the probing tip and the SiO(2) nanostructures. Local material recognition by s-SNOM in combination with its capabilities of contact-free and non-invasive conductivity- and strain-mapping makes IR near-field microscopy a versatile metrology technique for nanoscale material characterization and semiconductor device analysis with application potential in research and development, failure analysis and reverse engineering.

Infrared Spectroscopy of Star Formation in Galactic and Extragalactic Regions

NASA Technical Reports Server (NTRS)

Smith, Howard A.; Hasan, Hashima (Technical Monitor)

2003-01-01

In this program we proposed to perform a series of spectroscopic studies, including data analysis and modeling, of star formation regions using an ensemble of archival space-based data from the Infrared Space Observatory's Long Wavelength Spectrometer and Short Wavelength Spectrometer, and to take advantage of other spectroscopic databases including the first results from SIRTF. Our emphasis has been on star formation in external, bright IR galaxies, but other areas of research have included young, low or high mass pre-main sequence stars in star formation regions, and the galactic center. The OH lines in the far infrared were proposed as one key focus of this inquiry, because the Principal Investigator (H. Smith) had a full set of OH IR lines from IS0 observations. It was planned that during the proposed 2-1/2 year timeframe of the proposal other data (including perhaps from SIRTF) would become available, and we intended to be responsive to these and other such spectroscopic data sets. The program has the following goals: 1) Refine the data analysis of IS0 observations to obtain deeper and better SNR results on selected sources. The IS0 data itself underwent pipeline 10 reductions in early 2001, and the more 'hands-on data reduction packages' have been released. The IS0 Fabry-Perot database is particularly sensitive to noise and can have slight calibration errors, and improvements are anticipated. We plan to build on these deep analysis tools and contribute to their development. Model the atomic and molecular line shapes, in particular the OH lines, using revised montecarlo techniques developed by the Submillimeter Wave Astronomy Satellite (SWAS) team at the Center for Astrophysics. 2) 3) Use newly acquired space-based SIRTF or SOFIA spectroscopic data as they become available, and contribute to these observing programs as appropriate. 4) Attend scientific meetings and workshops. 5) E&PO activities, especially as related to infrared astrophysics and/or spectroscopy.

Comment on the paper ;NDSD-1000: High-resolution, high-temperature nitrogen dioxide spectroscopic Databank; by A.A. Lukashevskaya, N.N. Lavrentieva, A.C. Dudaryonok, V.I. Perevalov, J Quant Spectrosc Radiat Transfer 2016;184:205-17

NASA Astrophysics Data System (ADS)

Perrin, A.; Ndao, M.; Manceron, L.

2017-10-01

A recent paper [1] presents a high-resolution, high-temperature version of the Nitrogen Dioxide Spectroscopic Databank called NDSD-1000. The NDSD-1000 database contains line parameters (positions, intensities, self- and air-broadening coefficients, exponents of the temperature dependence of self- and air-broadening coefficients) for numerous cold and hot bands of the 14N16O2 isotopomer of nitrogen dioxide. The parameters used for the line positions and intensities calculation were generated through a global modeling of experimental data collected in the literature within the framework of the method of effective operators. However, the form of the effective dipole moment operator used to compute the NO2 line intensities in the NDSD-1000 database differs from the classical one used for line intensities calculation in the NO2 infrared literature [12]. Using Fourier transform spectra recorded at high resolution in the 6.3 μm region, it is shown here, that the NDSD-1000 formulation is incorrect since the computed intensities do not account properly for the (Int(+)/Int(-)) intensity ratio between the (+) (J = N+ 1/2) and (-) (J = N-1/2) electron - spin rotation subcomponents of the computed vibration rotation transitions. On the other hand, in the HITRAN or GEISA spectroscopic databases, the NO2 line intensities were computed using the classical theoretical approach, and it is shown here that these data lead to a significant better agreement between the observed and calculated spectra.

EVALUATION OF A PORTABLE FOURIER TRANSFORM INFRARED GAS ANALYZER FOR MEASUREMENTS OF AIR TOXICS IN POLLUTION PREVENTION RESEARCH

EPA Science Inventory

A portable Fourier transform infrared gas analyzer with a photoacoustic detector performed reliably during pollution prevention research at two industrial facilities. It exhibited good agreement (within approximately 6%) with other analytical instruments (dispersive infrared and ...

Fourier-transform infrared spectroscopic study of characteristic molecular structure in cancer cells of esophagus: an exploratory study.

PubMed

Maziak, Donna E; Do, Minh T; Shamji, Farid M; Sundaresan, Sudhir R; Perkins, D Garth; Wong, Patrick T T

2007-01-01

To investigate the structural changes at the molecular level and to assess the usefulness of Fourier-transform infrared (FTIR) spectroscopy in the diagnosis of esophageal cancer. A pilot study was established of 10 consecutive patients with adenocarcinoma of the esophagus. Tissue samples from the diseased and normal sites of the resected specimens were analyzed and compared using FTIR spectroscopy and histopathology. Specific changes were observed in the FTIR spectral features of esophageal cancer and thus spectral criteria were established for the detection of malignancy in esophagus tissues by FTIR spectroscopy. The spectral changes in cancer were the results of characteristic structural alterations at the molecular level in the esophageal cancer specimens. These alternations included an increase in the nuclei-to-cytoplasm ratio, an increase in the relative amount of DNA while a decrease in the relative amount of RNA, an enhancement in the phosphorylation of proteins, a decrease in the glycogen level, a loss of hydrogen bonding of the COH groups in the amino acid residues of proteins, a tighter intermolecular packing and a stronger intermolecular interaction among the DNA molecules, an increase in the distribution of protein segments with the conformation of beta-sheet and unordered turns and a tighter packing of the alpha-helical segments in overall tissue proteins, a decrease in the overall CH(3)-to-CH(2) ratio and an accumulation of triglycerides. FTIR is an automated method that has shown promise in differentiating cancer in the esophagus and may play a role in surveillance programs in premalignant conditions.

Spectroscopic investigation (FTIR spectrum), NBO, HOMO-LUMO energies, NLO and thermodynamic properties of 8-Methyl-N-vanillyl-6-nonenamideby DFT methods

NASA Astrophysics Data System (ADS)

Sherin Percy Prema Leela, J.; Hemamalini, R.; Muthu, S.; Al-Saadi, Abdulaziz A.

2015-07-01

Capsicum a hill grown vegetable is also known as red pepper or chili pepper. Capsaicin(8-Methyl-N-vanillyl-6-nonenamide) is the active component in chili peppers, which is currently used in the treatment of osteoarthritis, psoriasis and cancer. Fourier transform infrared (FT-IR) spectrum of Capsaicin in the solid phase were recorded in the region 4000-400 cm-1 and analyzed. The vibrational frequencies of the title compound were obtained theoretically by DFT/B3LYP calculations employing the standard 6-311++G(d,p) basis set and were compared with Fourier transform infrared spectrum. Complete vibrational assignment analysis and correlation of the fundamental modes for the title compound were carried out. The vibrational harmonic frequencies were scaled using scale factor, yielding a good agreement between the experimentally recorded and the theoretically calculated values. Stability of the molecule arising from hyper conjugative interactions, charge delocalization and intra molecular hydrogen bond-like weak interaction has been analyzed using Natural bond orbital (NBO) analysis by using B3LYP/6-311++G(d,p) method. The results show that electron density (ED) in the σ∗ and π∗ antibonding orbitals and second-order delocalization energies E (2) confirm the occurrence of intra molecular charge transfer (ICT) within the molecule. The dipole moment (μ), polarizability (α) and the hyperpolarizability (β) values of the molecule has been computed. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures were calculated.

Jet-Cooled Spectroscopy on the Ailes Infrared Beamline of the Synchrotron Radiation Facility Soleil

NASA Astrophysics Data System (ADS)

Georges, Robert

2015-06-01

The Advanced Infrared Line Exploited for Spectroscopy (AILES) extracts the bright far infrared (FIR) synchrotron continuum of the third generation radiation facility SOLEIL. This beamline is equipped with a high resolution (10-3 cm-1) Bruker IFS125 Fourier transform spectrometer which can be operated in the FIR but also in the mid and near infrared by using its internal conventional sources. The jet-AILES consortium (IPR, PhLAM, MONARIS, SOLEIL) has implemented a supersonic-jet apparatus on the beamline to record absorption spectra at very low temperature (5-50 K) and in highly supersaturated gaseous conditions. Heatable slit-nozzles of various lengths and widths are used to set properly the stagnation conditions. A mechanical pumping (roots pumps) was preferred for its ability to evacuate important mass flow rates and therefore to boost the experimental sensitivity of the set-up, the counterpart being a non-negligible consumption of both carrier (argon, helium or nitrogen) and spectroscopic gases. Various molecular systems were investigated up to now using the Jet-AILES apparatus. The very low temperature achieved in the gas expansion was either used to simplify the rotation-vibration structure of monomers, such as SF6, CF4 or naphthalene, or to stabilize the formation of weakly bonded molecular complexes such as the trimer of HF or the dimer of acetic acid. The nucleation of water vapor and the nuclear spin conversion of water were also investigated under free-jet conditions in the mid infrared. High-resolution spectroscopy and analysis of the νb{2} + νb{3} combination band of SF6 in a supersonic jet expansion. V. Boudon, P. Asselin, P. Soulard, M. Goubet, T. R. Huet, R. Georges, O. Pirali, P. Roy, Mol. Phys. 111, 2154-2162 (2013) The far infrared spectrum of naphthalene characterized by high resolution synchrotron FTIR spectroscopy and anharmonic DFT calculations. O. Pirali, M. Goubet, T.R. Huet, R. Georges, P. Soulard, P. Asselin, J. Courbe, P. Roy and M. Vervloet, Phys. Chem. Chem. Phys. 15, 10141-10150 (2013) The cyclic ground state structure of the HF trimer revealed by far-infrared jet-cooled Fourier transform spectroscopy. P. Asselin, P. Soulard, B. Madebène, M. Goubet, T. R. Huet, R. Georges, O. Pirali and P. Roy, Phys. Chem. Chem. Phys. 16(10), 4797-806 (2014) Standard free energy of the equilibrium between the trans-monomer and the cyclic-dimer of acetic acid in the gas phase from infrared spectroscopy. M. Goubet, P. Soulard, O. Pirali, P. Asselin, F. Réal, S. Gruet, T. R. Huet, P. Roy and R. Georges, Phys. Chem. Chem. Phys. DOI: 10.1039/c4cp05684a

Polyethylene glycol (PEG) assisted size-controlled SnO{sub 2} nanoparticles by sol-gel process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tripathi, P., E-mail: ptrip71@yahoo.com; Ahmed, Ateeq; Ali, Tinku

2016-05-23

Tetragonal phase tin oxide (SnO{sub 2}) nanoparticles have been synthesized by sol–gel method using SnCl{sub 4}.5H{sub 2}O and polyethylene glycol (PEG) of different concentration. The phase, size and purity of the final products are characterized by X-ray diffraction (XRD). The morphology is confirmed by scanning electron microscopy (SEM) analysis. There exists relationship between the concentration of PEG and particle size of SnO{sub 2} nanoparticles. Increase in concentration of PEG caused the reduction of particle size of tin oxide nanoparticles. The results suggest that the concentration of PEG plays a significant role in determining the size of SnO{sub 2} nanoparticles synthesizedmore » via this method. The optical property of the product has been explored by Ultraviolet (UV-visible) and Fourier Transform Infrared (FTIR) spectroscopic techniques.« less

On the anomalous adsorption of [Pd(edta)]2- at the water/Goethite interface: spectroscopic evidence for two types of surface complexes.

PubMed

Kaplun, Marina; Nordin, Agneta; Persson, Per

2008-01-15

The structure of palladium(II) ethylenediaminetetraacetate (edta) in aqueous solutions and its adsorption on the surface of goethite (alpha-FeOOH) were studied using extended X-ray absorption fine structure spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The obtained results show that in aqueous solutions, Pd-edta exists as a 1:1 complex, [Pd(edta)]2-, with edta acting as a quadridentate ligand. On the surface of goethite, [Pd(edta)]2- forms two different types of complexes over a pH range of 3.40-8.12. At pH < 5, [Pd(edta)]2- adsorbs as an outer-sphere species with possible hydrogen bonding. At higher pH values, the formation of inner-sphere complexes of the cation-type sets in after a cleavage of one glycinate ring and the formation of an (edta)Pd-O-Fe linkage.

Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes, structural characterization and catalytic activity on esterification reaction.

PubMed

Gönül, İlyas; Ay, Burak; Karaca, Serkan; Saribiyik, Oguz Yunus; Yildiz, Emel; Serin, Selahattin

2017-01-01

In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl 2 ]·2H 2 O (1) , [Co(L)Cl 2 (H 2 O) 2 ] (2) and [Ni(L)Cl 2 (H 2 O) 2 ] (3) , having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1 . The esterification of butanol gave butyl acetate with 100% selectivity.

The instrument control unit of SPICA SAFARI: a macro-unit to host all the digital control functionalities of the spectrometer

NASA Astrophysics Data System (ADS)

Di Giorgio, Anna Maria; Biondi, David; Saggin, Bortolino; Shatalina, Irina; Viterbini, Maurizio; Giusi, Giovanni; Liu, Scige J.; Cerulli-Irelli, Paquale; Van Loon, Dennis; Cara, Christophe

2012-09-01

We present the preliminary design of the Instrument Control Unit (ICU) of the SpicA FAR infrared Instrument (SAFARI), an imaging Fourier Transform Spectrometer (FTS) designed to give continuous wavelength coverage in both photometric and spectroscopic modes from around 34 to 210 µm. Due to the stringent requirements in terms of mass and volume, the overall SAFARI warm electronics will be composed by only two main units: Detector Control Unit and ICU. ICU is therefore a macro-unit incorporating the four digital sub-units dedicated to the control of the overall instrument functionalities: the Cooler Control Unit, the Mechanism Control Unit, the Digital processing Unit and the Power Supply Unit. Both the mechanical solution adopted to host the four sub-units and the internal electrical architecture are presented as well as the adopted redundancy approach.

Surface interaction of polyimide with oxygen ECR plasma

NASA Astrophysics Data System (ADS)

Naddaf, M.; Balasubramanian, C.; Alegaonkar, P. S.; Bhoraskar, V. N.; Mandle, A. B.; Ganeshan, V.; Bhoraskar, S. V.

2004-07-01

Polyimide (Kapton-H), was subjected to atomic oxygen from an electron cyclotron resonance plasma. An optical emission spectrometer was used to characterize the atomic oxygen produced in the reactor chamber. The energy of the ions was measured using a retarding field analyzer, placed near the substrate. The density of atomic oxygen in the plasma was estimated using a nickel catalytic probe. The surface wettability of the polyimide samples monitored by contact angle measurements showed considerable improvement when treated with plasma. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopic studies showed that the atomic oxygen in the plasma is the main specie affecting the surface chemistry and adhesion properties of polyimide. The improvement in the surface wettability is attributed to the high degree of cross-linking and large concentration of polar groups generated in the surface region of polyimide, after plasma treatment. The changes in the surface region of polyimide were observed by atomic force microscopic analysis.

Spectroscopic interaction studies of substituted and unsubstituted copper phthalocyanine with adsorbed organic vapours

NASA Astrophysics Data System (ADS)

Ridhi, R.; Kang, Jasmeen; Saini, G. S. S.; Tripathi, S. K.

2018-05-01

The present study deals with comparing the interaction mechanism of adsorbed organic vapours with Copper Phthalocyanine thin films in its substituted and unsubstituted forms. For this purpose, the variations in vibrational levels of substituted CuPc (CuPcS) functionalized with tetrasulfonic acid tetrasodium salt and unsubstituted CuPc after exposure with methanol and benzene vapours is analyzed. Fourier transform infrared (FTIR) is used to study the interaction behaviour. The bulkier group tetrasulfonic acid tetrasodium salt added to CuPc leads to occupation of more space in the molecular arrangement as compared to unsubstituted CuPc and hence alteration of its properties. FTIR spectra of CuPc and CuPcS before and after vapours exposures highlighted the effect of these vapours on the various bonds and the role of functional group in altering the molecular structure of CuPcS during interaction with adsorbed vapours.

Bioactivity of gelatin coated magnetic iron oxide nanoparticles: in vitro evaluation.

PubMed

Gaihre, Babita; Khil, Myung Seob; Kang, Hyo Kyoung; Kim, Hak Yong

2009-02-01

Current research explores formation of bone like apatite on gelatin coated magnetic iron oxide nanoparticles (GIOPs) to evaluate the bioactivity of the material. The GIOPs were soaked in simulated body fluid (SBF) and the apatite formation on the surface was investigated in regular interval of time. Fourier transform-infrared (FT-IR) and x-ray diffraction spectroscopic (XRD) analyses were done to investigate the chemical changes and field emission-scanning electron microscopic (FE-SEM) analysis was done to investigate the morphological changes occurring on the surface of the GIOPs after soaking in different time intervals. The kinetic studies of the apatite growth in SBF suggest that initially calcium and phosphorous ions were deposited to the surface of the GIOPs from the SBF leading to formation of amorphous Ca/P particles. Later, after 9 days of the incubation the amorphous particles were fused to form needle and blade like crystalline structures of bone like apatite.

Wavelet analysis techniques applied to removing varying spectroscopic background in calibration model for pear sugar content

NASA Astrophysics Data System (ADS)

Liu, Yande; Ying, Yibin; Lu, Huishan; Fu, Xiaping

2005-11-01

A new method is proposed to eliminate the varying background and noise simultaneously for multivariate calibration of Fourier transform near infrared (FT-NIR) spectral signals. An ideal spectrum signal prototype was constructed based on the FT-NIR spectrum of fruit sugar content measurement. The performances of wavelet based threshold de-noising approaches via different combinations of wavelet base functions were compared. Three families of wavelet base function (Daubechies, Symlets and Coiflets) were applied to estimate the performance of those wavelet bases and threshold selection rules by a series of experiments. The experimental results show that the best de-noising performance is reached via the combinations of Daubechies 4 or Symlet 4 wavelet base function. Based on the optimization parameter, wavelet regression models for sugar content of pear were also developed and result in a smaller prediction error than a traditional Partial Least Squares Regression (PLSR) mode.

Spectroscopic and microscopic characterization of silver nanoparticles synthesized using Justicia adhatoda flower

NASA Astrophysics Data System (ADS)

Singh, Tej; Shekhawat, Dharmender Singh; Jyoti, Kumari

2018-05-01

The synthesis of silver nanoparticles (SNPs) by chemical and physical methods produce harmful products which may cause various environmental problems, thus, there is an increasing demand to use ecofriendly methods. Therefore, biosynthesis of SNPs using Justicia adhatoda flower extract is demonstrated in the present study. The biosynthesized SNPs were characterized by UV-visible spectroscopy, Fourier transform-infrared spectroscopy (FTIR), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and atomic force microscopy (AFM) analysis. The result of UV-visible spectroscopy peaked at 417 nm corresponding to the plasmon absorbance of SNPs. The TEM and SAED result reveals the crystalline nature of SNPs. FTIR spectroscopy used to identify the possible biomolecules responsible for the conversion of silver ions to SNPs. The study concluded that Justicia adhatoda flower extract act as an excellent reducing agent and the green synthesized SNPs are safer to the environment.

Investigation into the interaction of methylparaben and erythromycin with human serum albumin using multispectroscopic methods.

PubMed

Naik, Keerti M; Nandibewoor, Sharanappa T

2016-03-01

In this paper, the interaction of methylparaben and erythromycin with human serum albumin (HSA) was studied for the first time using spectroscopic methods including Fourier transform infrared (FTIR) spectroscopy and UV absorption spectroscopy in combination with fluorescence quenching under physiological conditions. The binding parameters were evaluated using a fluorescence quenching method. Based on Förster's theory of non-radiation energy transfer, the binding average distance, r between the donor (HSA) and the acceptor (methylparaben and erythromycin) was evaluated. UV/vis absorption, FTIR, synchronous and 3D spectral results showed that the conformation of HSA was changed in the presence of methylparaben and erythromycin. The thermodynamic parameters were calculated according to the van't Hoff equation and are discussed. The effect of some biological metal ions and site probes on the binding of methylparaben and erythromycin to HSA were further examined. Copyright © 2015 John Wiley & Sons, Ltd.

Direct detection of saponins in crude extracts of soapnuts by FTIR.

PubMed

Almutairi, Meshari Saad; Ali, Muhammad

2015-01-01

Direct detection of saponins in soapnuts (Sapindus mukorossi) using Fourier transform infrared (FTIR) spectroscopy is investigated in this project. Potassium bromide powder was mixed with extracted powder of soapnuts and compressed to a thin pellet for examination process. The outcome of the FTIR spectra of saponin demonstrated characteristic triterpenoid saponin absorptions of OH, C = O, C-H, and C = C, while the glycoside linkages to the sapogenins were indicated by the absorptions of C-O. The significance of this study is that saponin absorption peaks are directly detectable in crude aqueous and 95% ethanol extracts of soapnuts powder using FTIR spectroscopy, thereby eliminating the need of further expensive and exhaustive purification steps. The extracts of soapnuts were screened for saponins along with controls by phytochemical tests, and advanced spectroscopic techniques such as ultra fast liquid chromatography and ultra performance liquid chromatography quadrupole-time of flight-mass spectrometry were also implemented to validate the saponins.

Solid state phase change materials for thermal energy storage in passive solar heated buildings

NASA Astrophysics Data System (ADS)

Benson, D. K.; Christensen, C.

1983-11-01

A set of solid state phase change materials was evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol, pentaglycerine and neopentyl glycol. Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature within the range from less than 25 deg to 188 deg. Thermophysical properties such as thermal conductivity, density and volumetric expansion were measured. Computer simulations were used to predict the performance of various Trombe wall designs incorporating solid state phase change materials. Optimum performance was found to be sensitive to the choice of phase change temperatures and to the thermal conductivity of the phase change material. A molecular mechanism of the solid state phase transition is proposed and supported by infrared spectroscopic evidence.

Charge Saturation and Intrinsic Doping in Electrolyte-Gated Organic Semiconductors.

PubMed

Atallah, Timothy L; Gustafsson, Martin V; Schmidt, Elliot; Frisbie, C Daniel; Zhu, X-Y

2015-12-03

Electrolyte gating enables low voltage operation of organic thin film transistors, but little is known about the nature of the electrolyte/organic interface. Here we apply charge-modulation Fourier transform infrared spectroscopy, in conjunction with electrical measurements, on a model electrolyte gated organic semiconductor interface: single crystal rubrene/ion-gel. We provide spectroscopic signature for free-hole like carriers in the organic semiconductor and unambiguously show the presence of a high density of intrinsic doping of the free holes upon formation of the rubrene/ion-gel interface, without gate bias (Vg = 0 V). We explain this intrinsic doping as resulting from a thermodynamic driving force for the stabilization of free holes in the organic semiconductor by anions in the ion-gel. Spectroscopy also reveals the saturation of free-hole like carrier density at the rubrene/ion-gel interface at Vg < -0.5 V, which is commensurate with the negative transconductance seen in transistor measurements.

Biomimetic synthesis of water-soluble conducting copolymers/homopolymers of pyrrole and 3,4-ethylenedioxythiophene.

PubMed

Bruno, Ferdinando F; Fossey, Stephen A; Nagarajan, Subhalakshmi; Nagarajan, Ramaswamy; Kumar, Jayant; Samuelson, Lynne A

2006-02-01

A novel biomimetic route for the synthesis of electrically conducting homopolymers/copolymers of pyrrole and 3,4-ethylenedioxythiophene (EDOT) in the presence of a polyelectrolyte, such as polystyrene sulfonate (SPS), is presented. A poly(ethylene glycol)-modified hematin (PEG-hematin) was used to catalyze the homopolymerization of pyrrole and EDOT as well as copolymerization of EDOT and pyrrole in the presence of SPS to yield homopolymers of polypyrrole/SPS and PEDOT/SPS as well as a polypyrrole-co-poly(3,4-ethylenedioxythiophene)/SPS complex. Spectroscopic characterization [UV-visible, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS)], thermal analysis, (TGA), and electrical conductivity studies for these complexes indicated the presence of a stable and electrically conductive form of these polymers. Furthermore, the presence of SPS that serves as a charge-compensating dopant in this complex provides a unique combination of properties such as processability and water solubility.

Sulfato/thiosulfato reducing bacteria characterization by FT-IR spectroscopy: a new approach to biocorrosion control.

PubMed

Rubio, Celine; Ott, Christelle; Amiel, Caroline; Dupont-Moral, Isabelle; Travert, Josette; Mariey, Laurence

2006-03-01

Sulfato and Thiosulfato Reducing Bacteria (SRB, TRB) can induce corrosion process on steel immersed in seawater. This phenomenon, called biocorrosion, costs approximatively 5 billion euros in France each year. We provide the first evidence that Fourier Transformed InfraRed (FTIR) spectroscopy is a competitive technique to evaluate the sulfurogen flora involved in biocorrosion in comparison with time consuming classical identification methods or PCR analyses. A great discrimination was obtained between SRB, TRB and some contamination bacteria known to be present in seawater and seem to be able to reduce sulfate under particular conditions. Moreover, this preliminary study demonstrates that FTIR spectroscopic and genotypic results present a good correlation (these results are confirmed by other data obtained before or later, data not shown here). The advantages gained by FTIR spectroscopy are to give information on strain phenotype and bacterial metabolism which are of great importance in corrosion processes.

FTIR characterization of Bi2Sr2Can-1(Cu1-xFex)3O10+δ with (n=3, x = 0.01) ceramic superconductor

NASA Astrophysics Data System (ADS)

Kumar, Rohitash; Singh, H. S.; Singh, Yadunath

2018-05-01

We synthesized a ceramic superconductor Bi2Sr2Can-1(Cu1-xFex)3O10+δ with (n = 3, x = 0.01) by usual method of oxides superconductor. In this paper, we report the characterization of the said sample by Fourier Transform Infrared Spectroscopic (FTIR) method. This method provides information about structural and compound bonding formation for the studied sample in powder form. The sharper peaks in the recorded spectra are reflecting with a functional group in the high-frequency stretching and low frequency bending modes. In this study, the interaction between Cu-O and Fe-O bond occupies octahedral and tetrahedral positions due to occupancy of cations and anions. The increasing amount of (Fe) is showing the transmittance (T%) behavior with different bonding vibration modes.

Investigation on the adsorption characteristics of sodium benzoate and taurine on gold nanoparticle film by ATR-FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Kumar, Naveen; Thomas, S.; Tokas, R. B.; Kshirsagar, R. J.

2014-01-01

Fourier transform infrared (FTIR) spectroscopic studies of sodium benzoate and taurine adsorbed on gold nanoparticle (AuNp) film on silanised glass slides have been studied by attenuated total reflection technique (ATR). The surface morphology of the AuNp films has been measured by Atomic Force Microscopy. The ATR spectra of sodium benzoate and taurine deposited on AuNp film are compared with ATR spectra of their powdered bulk samples. A new red-shifted band appeared along with the symmetric and asymmetric stretches of carboxylate group of sodium benzoate leading to a broadening of the above peaks. Similar behavior is also seen in the case of symmetric and asymmetric stretches of sulphonate group of taurine. The results indicate presence of both chemisorbed and physisorbed layers of both sodium benzoate and taurine on the AuNp film with bottom layer chemically bound to AuNp through carboxylate and sulphonate groups respectively.

Structural and optical characterization of pyrolytic carbon derived from novolac resin.

PubMed

Theodoropoulou, S; Papadimitriou, D; Zoumpoulakis, L; Simitzis, J

2004-07-01

The structural and optical properties of technologically interesting pyrolytic carbons formed from cured novolac resin and cured novolac/biomass composites were studied by X-Ray Diffraction Analysis (XRD), and Fourier Transform Infrared (FTIR), Raman and Photoluminescence (PL) spectroscopy. Pyrolysis of the cured materials took place at temperatures in the range 400-1000 degrees C. The most important weight loss, shrinkage and structural changes of pyrolyzed composites are observed at temperatures up to 600 degrees C due to the olive stone component. In the same temperature range, the changes in pyrolyzed novolac are smaller. The spectroscopic analysis shows that novolac pyrolyzed up to 900 ( degrees )C has less defects and disorder than the composites. However, above 900 ( degrees )C, pyrolyzed novolac becomes more disordered compared to the pyrolyzed composites. It is concluded that partial replacement of novolac by olive stone in the composite materials leads to the formation of a low cost, good quality product.

Polyaniline-carboxymethyl cellulose nanocomposite for cholesterol detection.

PubMed

Barik, Abdul; Solanki, Pratima R; Kaushik, Ajeet; Ali, Azahar; Pandey, M K; Kim, C G; Malhotra, B D

2010-10-01

Cholesterol oxidase (ChOx) has been covalently immobilized onto polyaniline-carboxymethyl cellulose (PANI-CMC) nanocomposite film deposited onto indium-tin-oxide (ITO) coated glass plate using glutaraldehyde as a cross-linker. Fourier transform infrared (FTIR) spectroscopic and electrochemical studies have been used to characterize the PANI-CMC/ITO nanocomposite electrode and ChOx/PANI-CMC/ITO bioelectrode. Scanning electron microscopy (SEM) studies reveal the formation of PANI-CMC nanocomposite fibers of size approximately 150 nm in diameter. The ChOx/PANI-CMC/ITO bioelectrode exhibits linearity as 0.5-22 mM, detection limit as 1.31 mM, sensitivity as 0.14 mA/mM cm2, response time as 10 s and shelf-life of about 10 weeks when bioelectrode is stored at 4 degrees C. The low value of Michaelis-Menten constant (K(m)) obtained as 2.71 mM reveals high affinity of immobilized ChOx for PANI-CMC/ITO nanocomposite electrode.

Study of structural, spectroscopic and dielectric properties of multiferroic cadmium doped Samarium manganite synthesized by solid state reaction method

NASA Astrophysics Data System (ADS)

Gupta, Vandana; Raina, Bindu; Verma, Seema; Bamzai, K. K.

2018-05-01

Samarium manganite doped with cadmium having general formula Sm1-xCdxMnO3 for x = 0.05, 0.15 were synthesized by solid state reaction technique. These compositions were characterized by various techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and dielectric. XRD analysis confirms the single phase formation with pervoskites structure having orthorhombic phase. Densities were determined and compared with the results obtained by Archimedes principle. The scanning electron micrograph shows that the particle size distribution is almost homogeneous and spherical in shape. FTIR analysis confirms the presence of various atomic bonds within a molecule. A very large value of dielectric constant was observed at low frequencies due to the presence of grains and interfaces. The dielectric constant value decreases with increase in cadmium doping at samarium site.

Spectroscopic Observation of a Hydrogenated CO Dimer Intermediate During CO Reduction on Cu(100) Electrodes.

PubMed

Pérez-Gallent, Elena; Figueiredo, Marta C; Calle-Vallejo, Federico; Koper, Marc T M

2017-03-20

Carbon dioxide and carbon monoxide can be electrochemically reduced to useful products such as ethylene and ethanol on copper electrocatalysts. The process is yet to be optimized and the exact mechanism and the corresponding reaction intermediates are under debate or unknown. In particular, it has been hypothesized that the C-C bond formation proceeds via CO dimerization and further hydrogenation. Although computational support for this hypothesis exists, direct experimental evidence has been elusive. In this work, we detect a hydrogenated dimer intermediate (OCCOH) using Fourier transform infrared spectroscopy at low overpotentials in LiOH solutions. Density functional theory calculations support our assignment of the observed vibrational bands. The formation of this intermediate is structure sensitive, as it is observed only during CO reduction on Cu(100) and not on Cu(111), in agreement with previous experimental and computational observations. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tamoxifen-model membrane interactions: an FT-IR study

NASA Astrophysics Data System (ADS)

Boyar, Handan; Severcan, Feride

1997-06-01

The temperature- and concentration-induced effects of tamoxifen (TAM) on dipalmitoyl phosphatidylcholine (DPPC) model membranes were investigated by the Fourier transform-infrared (FT-IR) spectroscopic technique. An investigation of the C-H stretching region and the CO mode reveals that the inclusion of TAM changes the physical properties of the DPPC multibilayers by (i) shifting the main phase transition to lower temperatures; (ii) broadening the transition profile slightly; (iii) disordering the system in the gel and in the liquid crystalline phases; (iv) increasing the dynamics in the gel phase and decreasing the dynamics of the acyl chains in the liquid crystalline phase; (v) increasing the mobility of the terminal methyl group region of the bilayer in the gel phase and decreasing it in the liquid crystalline phase; (vi) increasing the frequency of the CO stretching mode both in the gel and in the liquid crystalline phases, i.e. non-bonding with carbonyl groups.

New membranes based on ionic liquids for PEM fuel cells at elevated temperatures

NASA Astrophysics Data System (ADS)

Ye, H.; Huang, J.; Xu, J. J.; Kodiweera, N. K. A. C.; Jayakody, J. R. P.; Greenbaum, S. G.

Proton exchange membrane (PEM) fuel cells operating at elevated temperature, above 120 °C, will yield significant benefits but face big challenges for the development of suitable PEMs. The objectives of this research are to demonstrate the feasibility of the concept and realize [acid/ionic liquid/polymer] composite gel-type membranes as such PEMs. Novel membranes consisting of anhydrous proton solvent H 3PO 4, the protic ionic liquid PMIH 2PO 4, and polybenzimidazole (PBI) as a matrix have been prepared and characterized for PEM fuel cells intended for operation at elevated temperature (120-150 °C). Physical and electrochemical analyses have demonstrated promising characteristics of these H 3PO 4/PMIH 2PO 4/PBI membranes at elevated temperature. The proton transport mechanism in these new membranes has been investigated by Fourier transform infrared and nuclear magnetic resonance spectroscopic methods.

Improved Extraction and Quality Characterization of Water-Soluble Polysaccharide from Gamma-Irradiated Lentinus edodes.

PubMed

Akram, Kashif; Shahbaz, Hafiz Muhammad; Kim, Gui-Ran; Farooq, Umar; Kwon, Joong-Ho

2017-02-01

Gamma irradiation was applied to the improved extraction of water-soluble polysaccharides (WSPs) from dried Lentinus edodes. Irradiation provided a dose-dependent increase in extraction yield (0 kGy, 2.01%; 7.5 kGy, 4.03%; 15 kGy, 7.17%) and purity (0 kGy, 78.8%; 7.5 kGy, 83.1%; 15 kGy, 85.6%) of the WSPs from hot-water extraction. The effect of irradiation was evident in the degraded microstructures and reduced molecular weights of the WSPs. However, nuclear magnetic resonance, Fourier-transform infrared, and X-ray diffraction spectroscopic analyses provided comparable structures of WSPs from nonirradiated and irradiated samples. UV-visible spectra showed a dose-dependent decline in intensity, but an improvement in thermal properties of the WSPs from the irradiated mushroom samples was observed. © 2017 Institute of Food Technologists®.

Optical properties of diamond like carbon nanocomposite thin films

NASA Astrophysics Data System (ADS)

Alam, Md Shahbaz; Mukherjee, Nillohit; Ahmed, Sk. Faruque

2018-05-01

The optical properties of silicon incorporated diamond like carbon (Si-DLC) nanocomposite thin films have been reported. The Si-DLC nanocomposite thin film deposited on glass and silicon substrate by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) process. Fourier transformed infrared spectroscopic analysis revealed the presence of different bonding within the deposited films and deconvolution of FTIR spectra gives the chemical composition i.e., sp3/sp2 ratio in the films. Optical band gap calculated from transmittance spectra increased from 0.98 to 2.21 eV with a variation of silicon concentration from 0 to 15.4 at. %. Due to change in electronic structure by Si incorporation, the Si-DLC film showed a broad photoluminescence (PL) peak centered at 467 nm, i.e., in the visible range and its intensity was found to increase monotonically with at. % of Si.

Aggregation of trypsin and trypsin inhibitor by Al cation.

PubMed

Chanphai, P; Kreplak, L; Tajmir-Riahi, H A

2017-04-01

Al cation may trigger protein structural changes such as aggregation and fibrillation, causing neurodegenerative diseases. We report the effect of Al cation on the solution structures of trypsin (try) and trypsin inhibitor (tryi), using thermodynamic analysis, UV-Visible, Fourier transform infrared (FTIR) spectroscopic methods and atomic force microscopy (AFM). Thermodynamic parameters showed Al-protein bindings occur via H-bonding and van der Waals contacts for trypsin and trypsin inhibitor. AFM showed that Al cations are able to force trypsin into larger or more robust aggregates than trypsin inhibitor, with trypsin 5±1 SE (n=52) proteins per aggregate and for trypsin inhibitor 8.3±0.7 SE (n=118). Thioflavin T test showed no major protein fibrillation in the presence of Al cation. Al complexation induced more alterations of trypsin inhibitor conformation than trypsin. Copyright © 2017 Elsevier B.V. All rights reserved.

Two novel cocrystals of lamotrigine with isomeric bipyridines and in situ monitoring of the cocrystallization.

PubMed

Du, Shichao; Wang, Yan; Wu, Songgu; Yu, Bo; Shi, Peng; Bian, Lin; Zhang, Dejiang; Hou, Jie; Wang, Jingkang; Gong, Junbo

2017-12-15

Crystal engineering strategy was applied to develop new solid forms of lamotrigine. Two novel cocrystals of lamotrigine forming with 4,4'-bipyridine (2:1) and 2,2'-bipyridine cocrystal (1:1.5) were successfully obtained by neat grinding and liquid assisted grinding. The novel cocrystals were fully characterized and confirmed by X-ray diffraction, thermal and spectroscopic analysis. DXRxi Raman microscope was also used to identify the cocrystals. The factors such as solvent and the structure of coformers which influenced the cocrystal formation were discussed. Furthermore, the novel cocrystals were both obtained by slurry crystallization. Process analytical technologies including focused beam reflectance measurement and attenuated total reflectance Fourier Transform Infrared were applied to investigate the cocrystallization process and the mechanism. HPLC analysis showed that the dissolution rate and the solubility of the two novel cocrystals were both improved. Copyright © 2017 Elsevier B.V. All rights reserved.

Non-intercalative, deoxyribose binding of boric acid to calf thymus DNA.

PubMed

Ozdemir, Ayse; Gursaclı, Refiye Tekiner; Tekinay, Turgay

2014-05-01

The present study characterizes the effects of the boric acid binding on calf thymus DNA (ct-DNA) by spectroscopic and calorimetric methods. UV-Vis absorbance spectroscopy, circular dichroism (CD) spectroscopy, transmission electron microscopy (TEM), isothermal titration calorimetry (ITC), and Fourier transform infrared (FT-IR) spectroscopy were employed to characterize binding properties. Changes in the secondary structure of ct-DNA were determined by CD spectroscopy. Sizes and morphologies of boric acid-DNA complexes were determined by transmission electron microscopy (TEM). The kinetics of boric acid binding to calf thymus DNA (ct-DNA) was investigated by isothermal titration calorimetry (ITC). ITC results revealed that boric acid exhibits a moderate affinity to ct-DNA with a binding constant (K a) of 9.54 × 10(4) M(-1). FT-IR results revealed that boric acid binds to the deoxyribose sugar of DNA without disrupting the B-conformation at tested concentrations.

Infrared spectroscopic detection of sulfur hexafluoride (SF6) in the lower stratosphere and upper troposphere

NASA Technical Reports Server (NTRS)

Rinsland, C. P.; Brown, L. R.; Farmer, C. B.

1990-01-01

This paper reports the detection and identification of the unresolved SF6 nu-3 band Q branch at 947.9/cm in high-resolution solar occultation spectra of the lower stratosphere and upper troposphere, which was made from the analysis of data recorded on April 30 to May 1, 1985 by the spaceborne Atmospheric Trace Molecule Spectroscopy Fourier transform spectrometer as part of the Spacelab 3 mission. On the basis of SF6 line-by-line parameters obtained from the laboratory studies of Bobin et al. (1987) and Schatz and Hornig (1953), the measured absorption was analyzed to deduce SF6 volume mixing ratios in the altitude range 12-22 km. It was found that, in this altitude range, the SF6 volume mixing ratio is independent of altitude, with an average measured value of 1.42 parts per trillion by volume (pptv) at 31 deg N latitude.

A spectroscopic study for understanding the speciation of Cr on palm shell based adsorbents and their application for the remediation of chrome plating effluents.

PubMed

Kushwaha, Shilpi; Sreedhar, B; Sudhakar, Padmaja P

2012-07-01

Palm shell based adsorbents prepared under five different thermochemical conditions have been shown to be quite effective for removal of chromium (III and VI) from aqueous solutions. X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FT-IR) have been used to determine information about the speciation and binding of chromium on the adsorbents under study. X-ray photoelectron spectroscopy (XPS) studies indicate that oxidation of lignin moieties takes place concurrently to Cr(VI) reduction and leads to the formation of hydroxyl and carboxyl functions. The maximum adsorption capacity for hexavalent chromium was found to be about 313 mg/g in an acidic medium using PAPSP. This is comparable to other natural substrates and ordinary adsorbents. The efficacy of the adsorbents under study to remove chromium from plating waste water has been demonstrated. Copyright © 2012 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ali Sinag; Melike Sungur; Mustafa Gullu

This study describes the detailed hydrocarbon type characterization of the tar (liquid phase) obtained by copyrolysis of Mustafa Kemal Paa (M.K.P.) lignite (Turkey) and low density polyethylene (LDPE) and by pyrolysis of coal and LDPE individually. Various spectroscopic techniques (gas chromatography-mass spectroscopy (GC-MS), nuclear magnetic resonance spectroscopy ({sup 1}H NMR), Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC)) are used for characterization, and the effect of the experimental conditions (temperature, lignite:low density polyethylene (LDPE) ratio, and catalyst) on the hydrocarbon distributions is discussed. The results show that the tars obtained by copyrolysis have similar properties with commercial gasolinemore » (especially in the presence of Red mud). Red mud and bentonite used as catalysts make a positive effect on the production of olefins instead aromatics. Polyethylene acts as a hydrogenation medium for the coal product as revealed by FTIR results. 18 refs., 9 figs., 5 tabs.« less

Chemical and mineralogical characterization of archaeologicam building materials from Seyitomer Hoyuk Kutahya, Turkey.

NASA Astrophysics Data System (ADS)

Bilgen, Nejat; Olgun, Asim

This paper focuses on the spectroscopic and thermal analysis of the archaeological samples of mortar and plaster from middle Bronze Age and Achaemenid period in Seyitömer Höyük. The composition of the samples was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric thermal analysis (TG-DTA). The results showed that human used different types of raw materials in the preperation of the mortar and plaster in the Middle Bronze Age and Achaemenid period. The material used in middle Bronze Age contains muscovite whereas the material in Achaemenid period contains albite. Although, the chemical composition of the mortar and plaster used in the period were similar, the calcium content of the plaster is relatively higher than the one of the mortar indicating people's awareness of the binding properties of calcite.

Anti-Corrosion Performance of 1,3-BENZOTHIAZOLE on 410 Martensitic Stainless Steel in H2SO4

NASA Astrophysics Data System (ADS)

Loto, Roland Tolulope

The corrosion inhibition effect of synthesized 1,3-benzothiazole at very low concentrations on 410 martensitic stainless steel in 3MH2SO4 solution was studied through potentiodynamic polarization and weight loss measurements. The observation showed that the organic compound performed effectively with average inhibition efficiencies of 94% and 98% at the concentrations studied from both electrochemical methods due to the inhibition action of protonated inhibitor molecules in the acid solution. The amine and aromatics functional groups of the molecules active in the corrosion inhibition reaction were exposed from Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) spectroscopic analysis. Thermodynamic calculations showed cationic adsorption to be chemisorption adsorption, obeying the Langmuir adsorption isotherm. Images from optical microscopy showed an improved morphology in comparison to images from corroded stainless steel. Severe surface deterioration and macro-pits were observed in the uninhibited samples.

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility inspect the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on its handling fixture. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

NASA Image and Video Library

1997-01-18

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility inspect the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) on its handling fixture. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lift the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) prior to its installation in the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

NASA Image and Video Library

1997-01-18

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lift the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) prior to its installation in the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lower the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) into the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

NASA Image and Video Library

1997-01-18

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lower the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) into the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS also is HST's first cryogenic instrument — its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 degrees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lower the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) into the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS is HST's first cryogenic instrument -- its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 derees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

NASA Image and Video Library

1997-01-16

KENNEDY SPACE CENTER, FLA. - Workers in KSC's Vertical Processing Facility lower the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) into the Second Axial Carrier. NICMOS is one of two new scientific instruments that will replace two outdated instruments on the Hubble Space Telescope (HST). NICMOS will provide HST with the capability for infrared imaging and spectroscopic observations of astronomical targets. The refrigerator-sized NICMOS is HST's first cryogenic instrument -- its sensitive infrared detectors must operate at very cold temperatures of minus 355 degrees Fahrenheit or 58 derees Kelvin. NICMOS will be installed in Hubble during STS-82, the second Hubble Space Telescope servicing mission. Liftoff is targeted Feb. 11 aboard Discovery with a crew of seven.

Time-Resolved and Spectroscopic Three-Dimensional Optical Breast Tomography

DTIC Science & Technology

2009-03-01

polarization sensitive imaging 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON R. R...project; • Development of a near-infrared center of intensity time gated imaging approach; and • Polarization sensitive imaging. We provide an...spectroscopic imaging arrangement, and a multi-source illumination and multi- detector signal acquisition arrangement. 5 5.1.1. Time-resolved transillumination

Do Infants Recognize the Arcimboldo Images as Faces? Behavioral and Near-Infrared Spectroscopic Study

ERIC Educational Resources Information Center

Kobayashi, Megumi; Otsuka, Yumiko; Nakato, Emi; Kanazawa, So; Yamaguchi, Masami K.; Kakigi, Ryusuke

2012-01-01

Arcimboldo images induce the perception of faces when shown upright despite the fact that only nonfacial objects such as vegetables and fruits are painted. In the current study, we examined whether infants recognize a face in the Arcimboldo images by using the preferential looking technique and near-infrared spectroscopy (NIRS). In the first…

Electroanalytical and Spectroscopic Studies of Poly(2,2'-bithiophene)-Modified Platinum Electrode to Detect Catechol in the Presence of Ascorbic Acid

ERIC Educational Resources Information Center

Lunsford, Suzanne K.; Speelman, Nicole; Stinson, Jelynn; Yeary, Amber; Choi, Hyeok; Widera, Justyna; Dionysiou, Dionysios D.

2008-01-01

This article describes an undergraduate laboratory for an instrumental analysis course that integrates electroanalytical chemistry and infrared spectroscopy. Modified electrode surfaces are prepared by constant potentiometric electrolysis over the potential range of 1.5-1.8 V and analyzed by cyclic voltammetry and infrared spectroscopy. The…

The Cassini mission: Infrared and microwave spectroscopic measurements

NASA Technical Reports Server (NTRS)

Kunde, V. G.

1989-01-01

The Cassini Orbiter and Titan Probe model payloads include a number of infrared and microwave instruments. This document describes: (1) the fundamental scientific objectives for Saturn and Titan which can be addressed by infrared and microwave instrumentation, (2) the instrument requirements and the accompanying instruments, and (3) the synergism resulting from the comprehensive coverage of the total infrared and microwave spectrum by the complement of individual instruments. The baseline consists of four instruments on the orbiter and two on the Titan probe. The orbiter infrared instruments are: (1) a microwave spectrometer and radiometer; (2) a far to mid-infrared spectrometer; (3) a pressure modulation gas correlation spectrometer, and (4) a near-infrared grating spectrometer. The two Titan probe infrared instruments are: (1) a near-infrared instrument, and (2) a tunable diode laser infrared absorption spectrometer and nephelometer.

A Parallel Spectroscopic Method for Examining Dynamic Phenomena on the Millisecond Time Scale

PubMed Central

Snively, Christopher M.; Chase, D. Bruce; Rabolt, John F.

2009-01-01

An infrared spectroscopic technique based on planar array infrared (PAIR) spectroscopy has been developed that allows the acquisition of spectra from multiple samples simultaneously. Using this technique, it is possible to acquire spectra over a spectral range of 950–1900cm−1 with a temporal resolution of 2.2ms. The performance of this system was demonstrated by determining the shear-induced orientational response of several low molecular weight liquid crystals. Five different liquid crystals were examined in combination with five different alignment layers, and both primary and secondary screens were demonstrated. Implementation of this high throughput PAIR technique resulted in a reduction in acquisition time as compared to both step-scan and ultra-rapid-scanning FTIR spectroscopy. PMID:19239197

Infrared and Raman spectroscopic features of plant cuticles: a review

PubMed Central

Heredia-Guerrero, José A.; Benítez, José J.; Domínguez, Eva; Bayer, Ilker S.; Cingolani, Roberto; Athanassiou, Athanassia; Heredia, Antonio

2014-01-01

The cuticle is one of the most important plant barriers. It is an external and continuous lipid membrane that covers the surface of epidermal cells and whose main function is to prevent the massive loss of water. The spectroscopic characterization of the plant cuticle and its components (cutin, cutan, waxes, polysaccharides and phenolics) by infrared and Raman spectroscopies has provided significant advances in the knowledge of the functional groups present in the cuticular matrix and on their structural role, interaction and macromolecular arrangement. Additionally, these spectroscopies have been used in the study of cuticle interaction with exogenous molecules, degradation, distribution of components within the cuticle matrix, changes during growth and development and characterization of fossil plants. PMID:25009549

Ab initio molecular orbital and infrared spectroscopic study of the conformation of secondary amides: derivatives of formanilide, acetanilide and benzylamides

NASA Astrophysics Data System (ADS)

Ilieva, S.; Hadjieva, B.; Galabov, B.

1999-09-01

Ab initio molecular orbital calculations at HF/4-31G level and infrared spectroscopic data for the frequencies are applied to analyse the grouping in a series model aromatic secondary amides: formanilide; acetanilide; o-methylacetanilide; 2,6-dimethylformanilide, 2,6-dimethylacetanilide; N-benzylacetamide and N-benzylformamide. The theoretical and experimental data obtained show that the conformational state of the molecules studied is determined by the fine balance of several intramolecular factors: resonance effect between the amide group and the aromatic ring, steric interaction between various substituents around the -NH-CO- grouping in the aromatic ring, conjugation between the carbonyl bond and the nitrogen lone pair as well as direct field influences inside the amide group.

3D spectral imaging with synchrotron Fourier transform infrared spectro-microtomography

Treesearch

Michael C. Martin; Charlotte Dabat-Blondeau; Miriam Unger; Julia Sedlmair; Dilworth Y. Parkinson; Hans A. Bechtel; Barbara Illman; Jonathan M. Castro; Marco Keiluweit; David Buschke; Brenda Ogle; Michael J. Nasse; Carol J. Hirschmugl

2013-01-01

We report Fourier transform infrared spectro-microtomography, a nondestructive three-dimensional imaging approach that reveals the distribution of distinctive chemical compositions throughout an intact biological or materials sample. The method combines mid-infrared absorption contrast with computed tomographic data acquisition and reconstruction to enhance chemical...

Infrared Spectroscopy of Explosives Residues: Measurement Techniques and Spectral Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, Mark C.; Bernacki, Bruce E.

2015-03-11

Infrared laser spectroscopy of explosives is a promising technique for standoff and non-contact detection applications. However, the interpretation of spectra obtained in typical standoff measurement configurations presents numerous challenges. Understanding the variability in observed spectra from explosives residues and particles is crucial for design and implementation of detection algorithms with high detection confidence and low false alarm probability. We discuss a series of infrared spectroscopic techniques applied toward measuring and interpreting the reflectance spectra obtained from explosives particles and residues. These techniques utilize the high spectral radiance, broad tuning range, rapid wavelength tuning, high scan reproducibility, and low noise ofmore » an external cavity quantum cascade laser (ECQCL) system developed at Pacific Northwest National Laboratory. The ECQCL source permits measurements in configurations which would be either impractical or overly time-consuming with broadband, incoherent infrared sources, and enables a combination of rapid measurement speed and high detection sensitivity. The spectroscopic methods employed include standoff hyperspectral reflectance imaging, quantitative measurements of diffuse reflectance spectra, reflection-absorption infrared spectroscopy, microscopic imaging and spectroscopy, and nano-scale imaging and spectroscopy. Measurements of explosives particles and residues reveal important factors affecting observed reflectance spectra, including measurement geometry, substrate on which the explosives are deposited, and morphological effects such as particle shape, size, orientation, and crystal structure.« less

A Primer of Fourier Transform NMR.

ERIC Educational Resources Information Center

Macomber, Roger S.

1985-01-01

Fourier transform nuclear magnetic resonance (NMR) is a new spectroscopic technique that is often omitted from undergraduate curricula because of lack of instructional materials. Therefore, information is provided to introduce students to the technique of data collection and transformation into the frequency domain. (JN)

Ultrabroadband infrared nanospectroscopic imaging

PubMed Central

Bechtel, Hans A.; Muller, Eric A.; Olmon, Robert L.; Martin, Michael C.; Raschke, Markus B.

2014-01-01

Characterizing and ultimately controlling the heterogeneity underlying biomolecular functions, quantum behavior of complex matter, photonic materials, or catalysis requires large-scale spectroscopic imaging with simultaneous specificity to structure, phase, and chemical composition at nanometer spatial resolution. However, as with any ultrahigh spatial resolution microscopy technique, the associated demand for an increase in both spatial and spectral bandwidth often leads to a decrease in desired sensitivity. We overcome this limitation in infrared vibrational scattering-scanning probe near-field optical microscopy using synchrotron midinfrared radiation. Tip-enhanced localized light–matter interaction is induced by low-noise, broadband, and spatially coherent synchrotron light of high spectral irradiance, and the near-field signal is sensitively detected using heterodyne interferometric amplification. We achieve sub-40-nm spatially resolved, molecular, and phonon vibrational spectroscopic imaging, with rapid spectral acquisition, spanning the full midinfrared (700–5,000 cm−1) with few cm−1 spectral resolution. We demonstrate the performance of synchrotron infrared nanospectroscopy on semiconductor, biomineral, and protein nanostructures, providing vibrational chemical imaging with subzeptomole sensitivity. PMID:24803431

A Near-Infrared Spectrometer Based on Novel Grating Light Modulators

PubMed Central

Wei, Wei; Huang, Shanglian; Wang, Ning; Jin, Zhu; Zhang, Jie; Chen, Weimin

2009-01-01

A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of the proposed spectroscopic sensor. Secondly, the grating light modulators have been designed and fabricated by micro-machining technology. Finally, the principles of this spectroscopic sensor have been validated and its key parameters have been tested by experiments. The result shows that the spectral resolution is better than 10 nm, the wavelength deviation is less than 1 nm, the deviation of the intensity of peak wavelength is no more than 0.5%, the driving voltage of grating light modulators array device is below 25 V and the response frequency of it is about 5 kHz. With low cost, satisfactory precision, portability and other advantages, the spectrometer should find potential applications in food safety and quality monitoring, pharmaceutical identification and agriculture product quality classification. PMID:22574065

A near-infrared spectrometer based on novel grating light modulators.

PubMed

Wei, Wei; Huang, Shanglian; Wang, Ning; Jin, Zhu; Zhang, Jie; Chen, Weimin

2009-01-01

A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of the proposed spectroscopic sensor. Secondly, the grating light modulators have been designed and fabricated by micro-machining technology. Finally, the principles of this spectroscopic sensor have been validated and its key parameters have been tested by experiments. The result shows that the spectral resolution is better than 10 nm, the wavelength deviation is less than 1 nm, the deviation of the intensity of peak wavelength is no more than 0.5%, the driving voltage of grating light modulators array device is below 25 V and the response frequency of it is about 5 kHz. With low cost, satisfactory precision, portability and other advantages, the spectrometer should find potential applications in food safety and quality monitoring, pharmaceutical identification and agriculture product quality classification.

Spectroscopic Study of Terahertz Generation in Mid-Infrared Quantum Cascade Lasers.

PubMed

Jiang, Yifan; Vijayraghavan, Karun; Jung, Seungyong; Jiang, Aiting; Kim, Jae Hyun; Demmerle, Frederic; Boehm, Gerhard; Amann, Markus C; Belkin, Mikhail A

2016-02-16

Terahertz quantum cascade laser sources based on intra-cavity difference-frequency generation are currently the only room-temperature mass-producible diode-laser-like emitters of coherent 1-6 THz radiation. Device performance has improved dramatically over the past few years to reach milliwatt-level power output and broad tuning from 1.2 to 5.9 THz, all at room-temperature. Terahertz output in these sources originates from intersubband optical nonlinearity in the laser active region. Here we report the first comprehensive spectroscopic study of the optical nonlinearity and investigate its dependence on the mid-infrared pump frequencies. Our work shows that the terahertz generation efficiency can vary by a factor of 2 or greater depending on the spectral position of the mid-infrared pumps for a fixed THz difference-frequency. We have also measured for the first time the linewidth for transitions between the lower quantum cascade laser states, which is critical for determining terahertz nonlinearity and predicting optical loss in quantum cascade laser waveguides.

Probing the Dusty Stellar Populations of the Local Volume Galaxies with JWST/MIRI

NASA Astrophysics Data System (ADS)

Jones, Olivia C.; Meixner, Margaret; Justtanont, Kay; Glasse, Alistair

2017-05-01

The Mid-Infrared Instrument (MIRI) for the James Webb Space Telescope (JWST) will revolutionize our understanding of infrared stellar populations in the Local Volume. Using the rich Spitzer-IRS spectroscopic data set and spectral classifications from the Surveying the Agents of Galaxy Evolution (SAGE)-Spectroscopic survey of more than 1000 objects in the Magellanic Clouds, the Grid of Red Supergiant and Asymptotic Giant Branch Star Model (grams), and the grid of YSO models by Robitaille et al., we calculate the expected flux densities and colors in the MIRI broadband filters for prominent infrared stellar populations. We use these fluxes to explore the JWST/MIRI colors and magnitudes for composite stellar population studies of Local Volume galaxies. MIRI color classification schemes are presented; these diagrams provide a powerful means of identifying young stellar objects, evolved stars, and extragalactic background galaxies in Local Volume galaxies with a high degree of confidence. Finally, we examine which filter combinations are best for selecting populations of sources based on their JWST colors.

Sub-micron phase coexistence in small-molecule organic thin films revealed by infrared nano-imaging

PubMed Central

Westermeier, Christian; Cernescu, Adrian; Amarie, Sergiu; Liewald, Clemens; Keilmann, Fritz; Nickel, Bert

2014-01-01

Controlling the domain size and degree of crystallization in organic films is highly important for electronic applications such as organic photovoltaics, but suitable nanoscale mapping is very difficult. Here we apply infrared-spectroscopic nano-imaging to directly determine the local crystallinity of organic thin films with 20-nm resolution. We find that state-of-the-art pentacene films (grown on SiO2 at elevated temperature) are structurally not homogeneous but exhibit two interpenetrating phases at sub-micrometre scale, documented by a shifted vibrational resonance. We observe bulk-phase nucleation of distinct ellipsoidal shape within the dominant pentacene thin-film phase and also further growth during storage. A faint topographical contrast as well as X-ray analysis corroborates our interpretation. As bulk-phase nucleation obstructs carrier percolation paths within the thin-film phase, hitherto uncontrolled structural inhomogeneity might have caused conflicting reports about pentacene carrier mobility. Infrared-spectroscopic nano-imaging of nanoscale polymorphism should have many applications ranging from organic nanocomposites to geologic minerals. PMID:24916130

Astronomers Set a New Galaxy Distance Record

NASA Image and Video Library

2015-05-06

This is a Hubble Space Telescope image of the farthest spectroscopically confirmed galaxy observed to date (inset). It was identified in this Hubble image of a field of galaxies in the CANDELS survey (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey). NASA’s Spitzer Space Telescope also observed the unique galaxy. The W. M. Keck Observatory was used to obtain a spectroscopic redshift (z=7.7), extending the previous redshift record. Measurements of the stretching of light, or redshift, give the most reliable distances to other galaxies. This source is thus currently the most distant confirmed galaxy known, and it appears to also be one of the brightest and most massive sources at that time. The galaxy existed over 13 billion years ago. The near-infrared light image of the galaxy (inset) has been colored blue as suggestive of its young, and hence very blue, stars. The CANDELS field is a combination of visible-light and near-infrared exposures. Credits: NASA, ESA, P. Oesch (Yale U.)

Miniature, Low-Power, Waveguide Based Infrared Fourier Transform Spectrometer for Spacecraft Remote Sensing

NASA Technical Reports Server (NTRS)

Hewagama, TIlak; Aslam, Shahid; Talabac, Stephen; Allen, John E., Jr.; Annen, John N.; Jennings, Donald E.

2011-01-01

Fourier transform spectrometers have a venerable heritage as flight instruments. However, obtaining an accurate spectrum exacts a penalty in instrument mass and power requirements. Recent advances in a broad class of non-scanning Fourier transform spectrometer (FTS) devices, generally called spatial heterodyne spectrometers, offer distinct advantages as flight optimized systems. We are developing a miniaturized system that employs photonics lightwave circuit principles and functions as an FTS operating in the 7-14 micrometer spectral region. The inteferogram is constructed from an ensemble of Mach-Zehnder interferometers with path length differences calibrated to mimic scan mirror sample positions of a classic Michelson type FTS. One potential long-term application of this technology in low cost planetary missions is the concept of a self-contained sensor system. We are developing a systems architecture concept for wide area in situ and remote monitoring of characteristic properties that are of scientific interest. The system will be based on wavelength- and resolution-independent spectroscopic sensors for studying atmospheric and surface chemistry, physics, and mineralogy. The self-contained sensor network is based on our concept of an Addressable Photonics Cube (APC) which has real-time flexibility and broad science applications. It is envisaged that a spatially distributed autonomous sensor web concept that integrates multiple APCs will be reactive and dynamically driven. The network is designed to respond in an event- or model-driven manner or reconfigured as needed.

Fourier Transform Infrared Spectroscopic Studies Of Wheat In The Mid Infrared

NASA Astrophysics Data System (ADS)

Olinger, Jill M.; Griffiths, Peter R.

1989-12-01

Official grain standards of the United States state that wheat may be divided into seven classes which are: Durum, Red Durum, Hard Red Spring, Hard Red Winter, Soft Red Winter, White, and Mixed.1 Most end uses of wheat involve converting the grain into flour through one of a variety of grinding methods. The quality of wheat-based products is often very dependent upon the type or class of wheat which was used to make the flour. Pasta products, for example, are made almost exclusively from the flour of durum wheats, which are the hardest of the wheats listed above. The highest quality breads are produced using flour from wheats classed as hard, whereas cakes, cookies and pastries are considered best when flour from wheats classed as soft are used. It is obvious then that the capability of determining the class of a particular wheat, especially with respect to hardness, is of economic importance to growers, processors, and merchants of wheat and wheat products. Hardness has been measured in many different ways 2-5 but, as of yet, no one method has become the method of choice. This paper reports on the use of principal components analysis (PCA) of mid infrared diffuse reflectance (DR) spectra of diluted ground wheats to aid in the classification of those wheats with respect to their hardness. The theory and mathematics involved in a principal component analysis have been described elsewhere.9

Near-infrared diode laser based spectroscopic detection of ammonia: a comparative study of photoacoustic and direct optical absorption methods

NASA Technical Reports Server (NTRS)

Bozoki, Zoltan; Mohacsi, Arpad; Szabo, Gabor; Bor, Zsolt; Erdelyi, Miklos; Chen, Weidong; Tittel, Frank K.

2002-01-01

A photoacoustic spectroscopic (PAS) and a direct optical absorption spectroscopic (OAS) gas sensor, both using continuous-wave room-temperature diode lasers operating at 1531.8 nm, were compared on the basis of ammonia detection. Excellent linear correlation between the detector signals of the two systems was found. Although the physical properties and the mode of operation of both sensors were significantly different, their performances were found to be remarkably similar, with a sub-ppm level minimum detectable concentration of ammonia and a fast response time in the range of a few minutes.

Introduction to the Infrared Space Observatory (ISO)

NASA Technical Reports Server (NTRS)

Kessler, M. F.; Sibille, F.

1989-01-01

The Infrared Space Observatory (ISO) is an astronomical satellite, which will operate at infrared wavelengths (2.5 to 200 microns) for a period of at least 18 months. Imaging, spectroscopic, photometric and polarimetric observations will be obtained by four scientific instruments in the focal plane of its 60-cm diameter, cryogenically-cooled telescope. Two-thirds of ISO's observing time will be available to the astronomical community. ISO is a fully approved and funded project of the European Space Agency (ESA) with a foreseen launch date of May 1993.

Modeling Microalgal Biosediment Formation Based on Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Monitoring.

PubMed

Ogburn, Zachary L; Vogt, Frank

2018-03-01

With increasing amounts of anthropogenic pollutants being released into ecosystems, it becomes ever more important to understand their fate and interactions with living organisms. Microalgae play an important ecological role as they are ubiquitous in marine environments and sequester inorganic pollutants which they transform into organic biomass. Of particular interest in this study is their role as a sink for atmospheric CO 2 , a greenhouse gas, and nitrate, one cause of harmful algal blooms. Novel chemometric hard-modeling methodologies have been developed for interpreting phytoplankton's chemical and physiological adaptations to changes in their growing environment. These methodologies will facilitate investigations of environmental impacts of anthropogenic pollutants on chemical and physiological properties of marine microalgae (here: Nannochloropsis oculata). It has been demonstrated that attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy can gain insights into both and this study only focuses on the latter. From time-series of spectra, the rate of microalgal biomass settling on top of a horizontal ATR element is derived which reflects several of phytoplankton's physiological parameters such as growth rate, cell concentrations, cell size, and buoyancy. In order to assess environmental impacts on such parameters, microalgae cultures were grown under 25 different chemical scenarios covering 200-600 ppm atmospheric CO 2 and 0.35-0.75 mM dissolved NO 3 - . After recording time-series of ATR FT-IR spectra, a multivariate curve resolution-alternating least squares (MCR-ALS) algorithm extracted spectroscopic and time profiles from each data set. From the time profiles, it was found that in the considered concentration ranges only NO 3 - has an impact on the cells' physiological properties. In particular, the cultures' growth rate has been influenced by the ambient chemical conditions. Thus, the presented spectroscopic + chemometric methodology enables investigating the link between chemical conditions in a marine ecosystem and their consequences for phytoplankton living in it.

Fourier Transforms Simplified: Computing an Infrared Spectrum from an Interferogram

ERIC Educational Resources Information Center

Hanley, Quentin S.

2012-01-01

Fourier transforms are used widely in chemistry and allied sciences. Examples include infrared, nuclear magnetic resonance, and mass spectroscopies. A thorough understanding of Fourier methods assists the understanding of microscopy, X-ray diffraction, and diffraction gratings. The theory of Fourier transforms has been presented in this "Journal",…

Development of secondary cell wall in cotton fibers as examined with Fourier transform-infrared spectroscopy

USDA-ARS?s Scientific Manuscript database

Our presentation will focus on continuing efforts to examine secondary cell wall development in cotton fibers using infrared Spectroscopy. Cotton fibers harvested at 18, 20, 24, 28, 32, 36 and 40 days after flowering were examined using attenuated total reflection Fourier transform-infrared (ATR FT-...

Topical azithromycin and oral doxycycline therapy of meibomian gland dysfunction: a comparative clinical and spectroscopic pilot study.

PubMed

Foulks, Gary N; Borchman, Douglas; Yappert, Marta; Kakar, Shelley

2013-01-01

Meibomian gland dysfunction (MGD) is a common clinical problem that is often associated with evaporative dry eye disease. Alterations of the lipids of the meibomian glands have been identified in several studies of MGD. This prospective, observational, open-label clinical trial documents the improvement in both clinical signs and symptoms of disease as well as spectroscopic characteristics of the meibomian gland lipids after therapy with topical azithromycin ophthalmic solution and oral doxycycline treatment. Subjects with symptomatic MGD were recruited. Signs of MGD were evaluated with a slit lamp. Symptoms of MGD were measured by the response of subjects to a questionnaire. Meibum lipid-lipid interaction strength, conformation, and phase transition parameters, and meibum protein content were measured using Fourier transform infrared spectroscopy and principal component analysis. Terpenoids, short-chain CH3 moieties, lipid oxidation, wax, cholesterylesters and glycerides were measured with a proton nuclear magnetic resonance (H-NMR) spectrometer. Topical therapy with azithromycin and oral therapy with doxycycline relieved signs and symptoms and restored the lipid properties of the meibomian gland secretion toward normal. Compared with 4 weeks of azithromycin treatment reported in our previous study, oral doxycycline treatment was slightly less effective in improving foreign body sensation and the signs of plugging and secretion. In subjects with clinical evidence of MGD, changes in ordering of the lipids and phase transition temperature were brought closer to normal with azithromycin treatment than doxycycline treatment. Treatment with doxycycline but not azithromycin restored the Fourier transform infrared spectroscopy-principal component analysis scores and relative area of the H-NMR resonance at 1.26 ppm. Both doxycycline and azithromycin treatment restored the levels of the relative areas of the H-NMR resonance at 5.2 and 7.9 ppm to normal levels. The levels of meibum protein and meibum lipid oxidation were not influenced by azithromycin or doxycycline treatment. The mechanism of action of doxycycline may be different from that of azithromycin in therapy of MGD. It is notable that when carotenoids in meibum are low, as in MGD, the tear film is unstable and patients have the signs and symptoms of dry eyes. When carotenoids are restored with azithromycin and doxycycline treatment, tear film stability is restored and patients no longer have the signs and symptoms of dry eyes.

Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy as an Analytical Method to Investigate the Secondary Structure of a Model Protein Embedded in Solid Lipid Matrices.

PubMed

Zeeshan, Farrukh; Tabbassum, Misbah; Jorgensen, Lene; Medlicott, Natalie J

2018-02-01

Protein drugs may encounter conformational perturbations during the formulation processing of lipid-based solid dosage forms. In aqueous protein solutions, attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy can investigate these conformational changes following the subtraction of spectral interference of solvent with protein amide I bands. However, in solid dosage forms, the possible spectral contribution of lipid carriers to protein amide I band may be an obstacle to determine conformational alterations. The objective of this study was to develop an ATR FT-IR spectroscopic method for the analysis of protein secondary structure embedded in solid lipid matrices. Bovine serum albumin (BSA) was chosen as a model protein, while Precirol AT05 (glycerol palmitostearate, melting point 58 ℃) was employed as the model lipid matrix. Bovine serum albumin was incorporated into lipid using physical mixing, melting and mixing, or wet granulation mixing methods. Attenuated total reflection FT-IR spectroscopy and size exclusion chromatography (SEC) were performed for the analysis of BSA secondary structure and its dissolution in aqueous media, respectively. The results showed significant interference of Precirol ATO5 with BSA amide I band which was subtracted up to 90% w/w lipid content to analyze BSA secondary structure. In addition, ATR FT-IR spectroscopy also detected thermally denatured BSA solid alone and in the presence of lipid matrix indicating its suitability for the detection of denatured protein solids in lipid matrices. Despite being in the solid state, conformational changes occurred to BSA upon incorporation into solid lipid matrices. However, the extent of these conformational alterations was found to be dependent on the mixing method employed as indicated by area overlap calculations. For instance, the melting and mixing method imparted negligible effect on BSA secondary structure, whereas the wet granulation mixing method promoted more changes. Size exclusion chromatography analysis depicted the complete dissolution of BSA in the aqueous media employed in the wet granulation method. In conclusion, an ATR FT-IR spectroscopic method was successfully developed to investigate BSA secondary structure in solid lipid matrices following the subtraction of lipid spectral interference. The ATR FT-IR spectroscopy could further be applied to investigate the secondary structure perturbations of therapeutic proteins during their formulation development.

An Infrared Multi-Object Spectrograph (IRMS) with adaptive optics for TMT: the science case

NASA Astrophysics Data System (ADS)

Mobasher, Bahram; Crampton, David; Simard, Luc

2010-07-01

It has been recognized that a Near-Infrared Multi-object Spectrograph (IRMS) as one of the first light instrument on the Thirty Meter Telescope (TMT) would significantly increase the scientific capability of the observatory. The IRMS is planned to be a clone of the MOSFIRE instrument on the Keck telescope. As a result, we use the already available MOSFIRE design and expertise, significantly reducing the total cost and its development time. The IRMS will be a quasi diffraction limited multi-slit spectrograph with moderate resolution (R~4000), fed by Narrow-Field Infrared Adaptive Optics System (NFIRAOS). It images over the 2 arcmin diameter field of view of the NFIRAOS. There are a number of exceedingly important scientific questions, waiting to be addressed by the TMT/IRMS combination. Given its relatively small field of view, it is less affected by the sky background, which is a limiting factor in ground-based observations at near-IR wavelengths. The IRMS is the ideal instrument for studying spectroscopic properties of galaxies at the re-ionization epoch (z > 7), where the Lyman alpha line shifts to the near-ir wavelenghths. It can be used to measure rotation curves of spiral and velocity dispersion of elliptical galaxies at z~2-3 and hence, their spectroscopic mass. It can be used to search for population III stars via their spectroscopic signature and to perform measurement of spectroscopic lines at high redshifts, diagnostic of metallicity. Finally, IRMS allows measurement of the blue shifts in the rest-frame MgII line for high redshift galaxies, used to study the winds, leading to the feedback mechanism, responsible for quenching star formation activity in galaxies.