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Applied Spectroscopy

Sabrina Stocker, Florian Foschum, Philipp Krauter, Florian Bergmann, Ansgar Hohmann, Claudia Scalfi Happ, Alwin Kienle
Dairy products play an important role in our daily nutrition. As a turbid scattering medium with different kinds of particles and droplets, each alteration of these components changes the scattering properties of milk. The goal of this work is the determination of the amount of main scattering components, the fat droplets and the casein micelles, by understanding the light propagation in homogenized milk and in raw milk. To provide the absolute impact of these milk components, the geometrical and optical properties such as the size distribution and the refractive index (RI) of the components have to be examined...
October 21, 2016: Applied Spectroscopy
Ariel Bohman, Mark A Arnold
Molar absorptivity is a fundamental molecular property that quantifies absorption strength as a function of wavelength. Absolute measurements of molar absorptivity demand accounting for all mechanisms of light attenuation, including reflective losses at interfaces associated with the sample. Ideally, such measurements are performed in nonabsorbing solvents and reflective losses can be determined in a straightforward manner from Fresnel equations or effectively accounted for by path length difference methods...
October 18, 2016: Applied Spectroscopy
Alessandra De Lorenzi Pezzolo, Gabrio Valotto, Alberto Quaranta
Two different types of spectroscopic methods, namely diffuse reflection infrared spectroscopy (DRIFTS) as a vibrational spectroscopy and ion-beam-induced luminescence (IBIL) as an optical spectroscopy, have been exploited for the analysis of three sand samples collected from the Adige, Bacchiglione, and Brenta rivers (Veneto, Northern Italy) with the aim to set up a procedure for the comparison of the relative abundance of silicates, carbonates, and feldspars. By fitting the spectra, the features corresponding to different geological compounds have been identified and descriptive indexes of their relative amount have been obtained by comparing the peak area ratios...
October 18, 2016: Applied Spectroscopy
Luis F Lastras-Martínez, Raul E Balderas-Navarro, Ricardo Castro-García, Karen Hernández-Vidales, Juan Almendarez-Rodríguez, Rafael Herrera-Jasso, Adrian Prinz, Iris Bergmair
The structural characterization of capillary microfluidic chips is important for reliable applications. In particular, nondestructive diagnostic tools to assess geometrical dimensions and their correlations with control processes are of much importance, preferably if they are implemented in situ. Several techniques to accomplish this task have been reported; namely, optical coherence tomography (OCT) jointly with confocal fluorescence microscopy (CFM) to investigate internal features of lab-on-a-chip technologies...
October 18, 2016: Applied Spectroscopy
Yao Tian, Kenneth S Burch
Raman spectroscopy is a powerful technique, widely used in both academia and industry. In part, the technique's extensive use stems from its ability to uniquely identify and image various material parameters: composition, strain, temperature, lattice/excitation symmetry, and magnetism in bulk, nano, solid, and organic materials. However, in nanomaterials and samples with low thermal conductivity, these measurements require long acquisition times. On the other hand, charge-coupled device (CCD) detectors used in Raman microscopes are vulnerable to cosmic rays...
October 17, 2016: Applied Spectroscopy
Seda Keleştemur, Mustafa Çulha
Biofilm formation is a defense mechanism for microorganisms to survive under both natural and stress conditions. Clinically relevant microorganisms threaten patient health through biofilm formation on medical devices and implants. It is very important to identify biofilm formation in order to suppress their pathogenic activities in early stages. With the aim for better understanding biofilm formation and possibility of detection, in this study, biofilm formation of clinically important microorganisms, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Candida albicans are monitored with surface-enhanced Raman scattering (SERS)...
October 5, 2016: Applied Spectroscopy
Barry K Lavine, Collin G White, Matthew D Allen, Andrew Weakley
Multilayered automotive paint fragments, which are one of the most complex materials encountered in the forensic science laboratory, provide crucial links in criminal investigations and prosecutions. To determine the origin of these paint fragments, forensic automotive paint examiners have turned to the paint data query (PDQ) database, which allows the forensic examiner to compare the layer sequence and color, texture, and composition of the sample to paint systems of the original equipment manufacturer (OEM)...
October 5, 2016: Applied Spectroscopy
Mehmet Yesiltas, Julia Sedlmair, Robert E Peale, Carol J Hirschmugl
We demonstrate nondestructive, three-dimensional, microscopic, infrared (IR) spectral in-situ imaging of an extraterrestrial sample. Spatially resolved chemical composition and spatial correlations are investigated within a single 45 µm grain of the Murchison meteorite. Qualitative and quantitative investigation through this analytical technique can help elucidate the origin and evolution of meteoritic compounds as well as parent body processes without damaging or altering the investigated samples.
October 4, 2016: Applied Spectroscopy
Lin Ou, Yang Chen, Ying Su, Changyan Zou, Zhong Chen
Structural changes and chemical modifications in DNA during interactions with X-ray radiation are still not clear within 48 h of incubation. We investigate genomic DNA from the radiated CNE2 cell line within 48 h of incubation using surface-enhanced Raman spectroscopy (SERS). Multivariate methods including principal component analysis (PCA) and random forest are proposed to explore the statistical significance before and after radiation. Our results show that intensities of several bands change after radiation, which indicates backbone damage and base-unstacking...
October 4, 2016: Applied Spectroscopy
Emee Grace Tabares Suarnaba, Yi Fuan Lee, Hiroshi Yamada, Tomohiko Tagawa
An ultraviolet visible (UV-Vis) microspectroscopic system was designed for the in situ characterization of the activity of the silica supported platinum (Pt) catalyst toward the dehydrogenation of 1-methyl-1,4-cyclohexadiene carried out in a custom-designed catalytic microreactor cell. The in situ catalytic microreactor cell (ICMC) with inlet/outlet ports was prepared using quartz cover as the optical window to facilitate UV-Vis observation. A fabricated thermometric stage was adapted to the UV-Vis microspectrophotometer to control the reaction temperature inside the ICMC...
October 3, 2016: Applied Spectroscopy
Tuo Wang, Liankui Dai
In this paper, a novel background subtraction algorithm is presented that can automatically recover Raman signal. This algorithm is based on an iterative polynomial smoothing method that highly reduces the need for experience and a priori knowledge. First, a polynomial filter is applied to smooth the input spectrum (the input spectrum is just an original spectrum at the first iteration). The output curve of the filter divides the original spectrum into two parts, top and bottom. Second, a proportion is calculated between the lowest point of the signal in the bottom part and the highest point of the signal in the top part...
September 30, 2016: Applied Spectroscopy
Pedro Cardoso, Pedro Amaro, José Paulo Santos, Joaquim T de Assis, Maria Luisa Carvalho
In this study, we investigate the capability of energy dispersive X-ray fluorescence (EDXF) spectrometry in a triaxial geometry apparatus as a fast and nondestructive determination method of both dominant and contaminant elements in pharmaceutical iron supplements. The following iron supplements brands with their respective active ingredients were analyzed: Neutrofer fólico (iron gylcinate), Anemifer (iron(II) sulfate monohydrate), Noripurum (iron(III)-hydroxide polymaltose complex), Sulferbel (iron(II) sulfate monohydrate), and Combiron Fólico (carbonyl iron)...
September 30, 2016: Applied Spectroscopy
Yan Cheung, Steven J Ray, Andrew J Schwartz, Gary M Hieftje
Our research group earlier used dispersion that occurs during flow injection to detect and reduce matrix interference in inductively coupled plasma-time-of-flight mass spectrometry. In the absence of a matrix interference, the ratio of signals from any two sample constituents should remain constant, independent of the dilution, over the course of a flow-injection transient. However, when an interferent is present, the signal ratio from different analytes will change with dilution, owing to the difference in severity of the interference on specific analytes...
September 28, 2016: Applied Spectroscopy
Hideyuki Shinzawa, Junji Mizukado, Sergei G Kazarian
A novel technique called disrelation spectroscopic imaging describes the process of identifying an area where a coordinated or out-of-phase change in pattern of spectral absorbance occurs. Disrelation mapping can be viewed as a spatial filter based on the well-established two-dimensional (2D) correlation function to highlight specific areas where disrelated variation occurs between ν1 and ν2 Disrelation intensity develops only if the spectral absorbance measured at ν1 and ν2 vary out of phase with each other within a specific spatial area...
September 28, 2016: Applied Spectroscopy
Menglin Guo, Ping Huang, Fei Yu, Huiqing Yang, Yabin Deng, Guangxin Du, Donghui Li
Tetrasulfonated aluminum phthalocyanine (AlS4Pc), a strongly red-emitting compound, shows high detection sensitivity, little effect of photobleaching, and photochemical stability, making it an excellent red-fluorescent probe. We have observed that in acid media, a low concentration of poly-L-lysine (PLL) has a strong fluorescence-quenching effect on AlS4Pc, forming the ion-pair complex as AlS4Pc-PLL with almost no fluorescence. However, in the presence of Bi(3+), the fluorescence of AlS4Pc-PLL dramatically recovers and the emission is visual because of the remarkable recovery...
September 28, 2016: Applied Spectroscopy
Ozlem Bozkurt, Mehmet Dincer Bilgin, Zafer Evis, Nancy Pleshko, Feride Severcan
Alterations in microstructure and mineral features can affect the mechanical and chemical properties of bones and their capacity to resist mechanical forces. Controversial results on diabetic bone mineral content have been reported and little is known about the structural alterations in collagen, maturation of apatite crystals, and carbonate content in diabetic bone. This current study is the first to report the mineral and organic properties of cortical, trabecular, and growth plate regions of diabetic rat femurs using Fourier transform infrared (FT-IR) microspectroscopy and the Vickers microhardness test...
September 28, 2016: Applied Spectroscopy
Jorge O Oña-Ruales, Yosadara Ruiz-Morales
The annellation theory method has been used to predict the locations of maximum absorbance (LMA) of the ultraviolet-visible (UV-Vis) spectral bands in the group of polycyclic aromatic hydrocarbons (PAHs) C24H14 (dibenzo and naphtho) derivatives of fluoranthene (DBNFl). In this group of 21 PAHs, ten PAHs present a sextet migration pattern with four or more benzenoid rings that is potentially related to a high molecular reactivity and high mutagenic conduct. This is the first time that the locations of maximum absorbance in the UV-Vis spectra of naphth[1,2-a]aceanthrylene, dibenz[a,l]aceanthrylene, indeno[1,2,3-de]naphthacene, naphtho[1,2-j]fluoranthene, naphth[2,1-e]acephenanthrylene, naphth[2,1-a]aceanthrylene, dibenz[a,j]aceanthrylene, naphth[1,2-e]acephenanthrylene, and naphtho[2,1-j]fluoranthene have been predicted...
September 26, 2016: Applied Spectroscopy
Beatrix Udvardi, István J Kovács, Tamás Fancsik, Péter Kónya, Miklósné Bátori, Ferenc Stercel, György Falus, Zoltán Szalai
This study focuses on particle size effect on monomineralic powders recorded using attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy. Six particle size fractions of quartz, feldspar, calcite, and dolomite were prepared (<2, 2-4, 4-8, 8-16, 16-32, and 32-63 µm). It is found that the width, intensity, and area of bands in the ATR FT-IR spectra of minerals have explicit dependence on the particle size. As particle size increases, the intensity and area of IR bands usually decrease while the width of bands increases...
September 26, 2016: Applied Spectroscopy
Mengli Fan, Wensheng Cai, Xueguang Shao
The circulatory protein, human serum albumin (HSA), is widely used as a model protein for the study of protein structure. In this work, the structures of human serum albumin in aqueous solutions are studied using temperature-dependent near-infrared (NIR) spectroscopy with the aid of continuous wavelet transform (CWT). Near-infrared spectra of human serum albumin solutions with different concentrations were measured over a temperature range of 30-85 ℃. Then, continuous wavelet transform was performed on the spectra to enhance the resolution...
September 20, 2016: Applied Spectroscopy
Ionela Raluca Comnea-Stancu, Karin Wieland, Georg Ramer, Andreas Schwaighofer, Bernhard Lendl
This work was sparked by the reported identification of man-made cellulosic fibers (rayon/viscose) in the marine environment as a major fraction of plastic litter by Fourier transform infrared (FT-IR) transmission spectroscopy and library search. To assess the plausibility of such findings, both natural and man-made fibers were examined using FT-IR spectroscopy. Spectra acquired by transmission microscopy, attenuated total reflection (ATR) microscopy, and ATR spectroscopy were compared. Library search was employed and results show significant differences in the identification rate depending on the acquisition method of the spectra...
September 20, 2016: Applied Spectroscopy
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