Read by QxMD icon Read

Applied Spectroscopy

(no author information available yet)
No abstract text is available yet for this article.
April 2017: Applied Spectroscopy
Bader A Alfarraj, Chet R Bhatt, Fang Yu Yueh, Jagdish P Singh
Laser-induced breakdown spectroscopy (LIBS) is a widely used laser spectroscopic technique in various fields, such as material science, forensic science, biological science, and the chemical and pharmaceutical industries. In most LIBS work, the analysis is performed using radiative transitions from atomic emissions. In this study, the plasma temperature and the product [Formula: see text] (the number density N and the absorption path length [Formula: see text]) were determined to evaluate the optical depths and the self-absorption of Sr and Al lines...
April 2017: Applied Spectroscopy
Yonghoon Lee, Jose Chirinos, Jhanis Gonzalez, Dayana Oropeza, Vassilia Zorba, Xianglei Mao, Jonghyun Yoo, Richard E Russo
We evaluated the performance of laser ablation analysis techniques such as laser-induced breakdown spectroscopy (LIBS), laser ablation inductively coupled optical emission spectrometry (LA-ICP-OES), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), in comparison with that of ICP-OES using aqueous solutions for the quantification of sulfur (S) in edible salts from different geographical origins. We found that the laser ablation based sampling techniques were not influenced by loss of S, which was observed in ICP-OES with aqueous solutions for a certain salt upon their dissolution in aqueous solutions, originating from the formation of volatile species and precipitates upon their dilution in water...
April 2017: Applied Spectroscopy
Igancio Rosas-Román, Marco A Meneses-Nava, Oracio Barbosa-García, Jose L Maldonado
This work proposes a method to perform elemental identification on plasmas produced using the laser-induced breakdown spectroscopy (LIBS) technique. The method is based on the preservation of the relative relevance of the spectral line emission intensities, which is lost during the parametric correlation procedure, by the introduction of a similitude coefficient called wavelength similarity coefficient. Furthermore, it was shown that for identification purposes, a simplified plasma model is sufficient to predict adequately the relative emission intensities in LIBS plasmas...
April 2017: Applied Spectroscopy
Lashaundra A Fambro, Deidre D Vandenbos, Matthew B Rosenberg, Christopher R Dockery
This study investigated the use of laser-induced breakdown spectroscopy (LIBS) and scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDX) as means of characterizing gunshot residue (GSR) originating from commercially available lead-free rounds. Data from two experiments are presented in this work. One experiment focused on identifying prominent analytical markers present in lead-free GSR by LIBS while the other applied SEM-EDX to determine the degree of evidence preservation after LIBS analysis...
April 2017: Applied Spectroscopy
Kate H Lepore, Caleb I Fassett, Elly A Breves, Sarah Byrne, Stephen Giguere, Thomas Boucher, J Michael Rhodes, Michael Vollinger, Chloe H Anderson, Richard W Murray, M Darby Dyar
Obtaining quantitative chemical information using laser-induced breakdown spectroscopy is challenging due to the variability in the bulk composition of geological materials. Chemical matrix effects caused by this variability produce changes in the peak area that are not proportional to the changes in minor element concentration. Therefore the use of univariate calibrations to predict trace element concentrations in geological samples is plagued by a high degree of uncertainty. This work evaluated the accuracy of univariate minor element predictions as a function of the composition of the major element matrices of the samples and examined the factors that limit the prediction accuracy of univariate calibrations...
April 2017: Applied Spectroscopy
Stefano Pagnotta, Marco Lezzerini, Laura Ripoll-Seguer, Montserrat Hidalgo, Emanuela Grifoni, Stefano Legnaioli, Giulia Lorenzetti, Francesco Poggialini, Vincenzo Palleschi
The laser-induced breakdown spectroscopy (LIBS) technique was used for analyzing the composition of an ancient Roman mortar (5th century A.D.), exploiting an experimental setup which allows the determination of the compositions of binder and aggregate in few minutes, without the need for sample treatment. Four thousand LIBS spectra were acquired from an area of 10 mm(2), with a 50 µm lateral resolution. The elements of interest in the mortar sample (H, C, O, Na, Mg, Al, Si, K, Ca, Ti, Mn, Fe) were detected and mapped...
April 2017: Applied Spectroscopy
Clayton S-C Yang, Feng Jin, Sudhir B Trivedi, Ei E Brown, Uwe Hommerich, Ashish Tripathi, Alan C Samuels
Thin solid films made of high nitro (NO2)/nitrate (NO3) content explosives were deposited on sand-blasted aluminum substrates and then studied using a mercury-cadmium-telluride (MCT) linear array detection system that is capable of rapidly capturing a broad spectrum of atomic and molecular laser-induced breakdown spectroscopy (LIBS) emissions in the long-wave infrared region (LWIR; ∼5.6-10 µm). Despite the similarities of their chemical compositions and structures, thin films of three commonly used explosives (RDX, HMX, and PETN) studied in this work can be rapidly identified in the ambient air by their molecular LIBS emission signatures in the LWIR region...
April 2017: Applied Spectroscopy
José Chirinos, Dayana Oropeza, Jhanis González, Vassilia Zorba, Richard E Russo
Direct solid sampling by laser ablation into an inductively coupled plasma synchronous vertical dual view optical emission spectroscope (LA-SVDV-ICP-OES) was used for the elemental analysis of nutrient elements Ca, B, Mn, Mg, K, and Zn and essential (non-metallic) elements P and S in plant materials. The samples were mixed with paraffin as a binder, an approach that provides better cohesion of the particles in the pellets in addition to supplying carbon to serve as an internal standard (atomic line C I 193...
April 2017: Applied Spectroscopy
Ammon N Williams, Supathorn Phongikaroon
In the pyrochemical separation of used nuclear fuel (UNF), fission product, rare earth, and actinide chlorides accumulate in the molten salt electrolyte over time. Measuring this salt composition in near real-time is advantageous for operational efficiency, material accountability, and nuclear safeguards. Laser-induced breakdown spectroscopy (LIBS) has been proposed and demonstrated as a potential analytical approach for molten LiCl-KCl salts. However, all the studies conducted to date have used a static surface approach which can lead to issues with splashing, low repeatability, and poor sample homogeneity...
April 2017: Applied Spectroscopy
José A Adame-Siles, Tom Fearn, José E Guerrero-Ginel, Ana Garrido-Varo, Francisco Maroto-Molina, Dolores Pérez-Marín
Control and inspection operations within the context of safety and quality assessment of bulk foods and feeds are not only of particular importance, they are also demanding challenges, given the complexity of food/feed production systems and the variability of product properties. Existing methodologies have a variety of limitations, such as high costs of implementation per sample or shortcomings in early detection of potential threats for human/animal health or quality deviations. Therefore, new proposals are required for the analysis of raw materials in situ in a more efficient and cost-effective manner...
March 2017: Applied Spectroscopy
Donato Conteduca, Francesco Dell'Olio, Thomas F Krauss, Caterina Ciminelli
The ability to manipulate and sense biological molecules is important in many life science domains, such as single-molecule biophysics, the development of new drugs and cancer detection. Although the manipulation of biological matter at the nanoscale continues to be a challenge, several types of nanotweezers based on different technologies have recently been demonstrated to address this challenge. In particular, photonic and plasmonic nanotweezers are attracting a strong research effort especially because they are efficient and stable, they offer fast response time, and avoid any direct physical contact with the target object to be trapped, thus preventing its disruption or damage...
March 2017: Applied Spectroscopy
Peter R Griffiths
The development of Fourier transform infrared (FT-IR) spectrometers in the mid-1960s followed along three lines. Interferometers for far-infrared FT spectrometry typically had a slow scan speed and the beam of radiation was modulated by a rotating chopper. Several instruments based on this system were developed commercially. Very high-resolution near-infrared FT spectrometers were based on cats-eye retroreflectors mounted in a step-scan interferometer; the beam of radiation was usually modulated by dithering one of the cats-eyes (phase modulation)...
March 2017: Applied Spectroscopy
(no author information available yet)
No abstract text is available yet for this article.
March 2017: Applied Spectroscopy
Andreas Ehn, Jiajian Zhu, Xuesong Li, Johannes Kiefer
Gaining information of species, temperature, and velocity distributions in turbulent combustion and high-speed reactive flows is challenging, particularly for conducting measurements without influencing the experimental object itself. The use of optical and spectroscopic techniques, and in particular laser-based diagnostics, has shown outstanding abilities for performing non-intrusive in situ diagnostics. The development of instrumentation, such as robust lasers with high pulse energy, ultra-short pulse duration, and high repetition rate along with digitized cameras exhibiting high sensitivity, large dynamic range, and frame rates on the order of MHz, has opened up for temporally and spatially resolved volumetric measurements of extreme dynamics and complexities...
March 2017: Applied Spectroscopy
Rui-Qiong Luo, Fang Wei, Shu-Shi Huang, Yue-Ming Jiang, Shan-Lei Zhang, Wen-Qing Mo, Hong Liu, Xi Rong
The examination of insulin (Ins) exocytosis at the single-cell level by conventional methods, such as electrophysiological approaches, total internal reflection imaging, and two-photon imaging technology, often requires an invasive microelectrode puncture or label. In this study, high concentrations of glucose and potassium chloride were used to stimulate β cell Ins exocytosis, while low concentrations of glucose and calcium channel blockers served as the blank and negative control, respectively. Laser tweezers Raman spectroscopy (LTRS) was used to capture the possible Raman scattering signal from a local zone outside of the cell edge...
March 2017: Applied Spectroscopy
Peter B Skou, Thilo A Berg, Stina D Aunsbjerg, Dorrit Thaysen, Morten A Rasmussen, Frans van den Berg
Reuse of process water in dairy ingredient production-and food processing in general-opens the possibility for sustainable water regimes. Membrane filtration processes are an attractive source of process water recovery since the technology is already utilized in the dairy industry and its use is expected to grow considerably. At Arla Foods Ingredients (AFI), permeate from a reverse osmosis polisher filtration unit is sought to be reused as process water, replacing the intake of potable water. However, as for all dairy and food producers, the process water quality must be monitored continuously to ensure food safety...
March 2017: Applied Spectroscopy
Mihaela Antonina Calin, Sorin Viorel Parasca, Marian Romeo Calin, Emil Petrescu
Skin texture has become an important issue in recent research with applications in the cosmetic industry and medicine. In this paper, we analyzed the dependence of skin texture features on wavelength as well as on different parameters (age and gender) of human participants using grey-level co-occurrence matrix and hyperspectral imaging technique for a more accurate quantitative assessment of the aging process. A total of 42 healthy participants (men and women; age range, 20-70 years) was enrolled in this study...
March 2017: Applied Spectroscopy
Mika Ishigaki, Akihito Nakanishi, Tomohisa Hasunuma, Akihiko Kondo, Tetsu Morishima, Toshiaki Okuno, Yukihiro Ozaki
In the present study, the high-speed quantitative evaluation of glycogen concentration accumulated in bioethanol feedstock Synechocystis sp. PCC6803 was performed using a near-infrared (NIR) imaging system with a hyperspectral NIR spectral camera named Compovision. The NIR imaging system has a feature for high-speed and wide area monitoring and the two-dimensional scanning speed is almost 100 times faster than the general NIR imaging systems for the same pixel size. For the quantitative analysis of glycogen concentration, partial least squares regression (PLSR) and moving window PLSR (MWPLSR) were performed with the information of glycogen concentration measured by high performance liquid chromatography (HPLC) and the calibration curves for the concentration within the Synechocystis sp...
March 2017: Applied Spectroscopy
Stephen M Anthony, Jerilyn A Timlin
Cosmic ray spikes are especially problematic for hyperspectral imaging because of the large number of spikes often present and their negative effects upon subsequent chemometric analysis. Fortunately, while the large number of spectra acquired in a hyperspectral imaging data set increases the probability and number of cosmic spikes observed, the multitude of spectra can also aid in the effective recognition and removal of the cosmic spikes. Zhang and Ben-Amotz were perhaps the first to leverage the additional spatial dimension of hyperspectral data matrices (DM)...
March 2017: Applied Spectroscopy
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"