Spectroscopy

We investigate the spectral evolution of the cataclysmic stellar object V339 Delphini (Nova Del 2013), using observations made at "Amiral Vasile Urseanu" Astronomical Observatory (A92) in Bucharest, and Stardreams Observatory (L16) in Vǎ lenii de Munte, Romania, between August 2013 and October 2014. Starting with the official announcement on August 14th, 2013, we obtained spectroscopic and photometric data using 0.3 m Schmidt-Cassegrain and respectively 0.2 m Ritchey-Chretien telescopes equipped with Alpy 600 spectrograph. We determined that V339 Del is a Fe II type nova with strong Fe II and P Cygni lines in the aftermath of the cataclysmic event, variable Balmer and Fe II lines intensities and a continuous but slow spectral evolution.

Reflectance spectroscopy is a nondestructive, rapid, and easy-to-use technique which can be used to assess the composition of rocks qualitatively or quantitatively. Although it is a powerful tool, it has its limitations especially when it comes to measurements of rocks with a phaneritic texture. The external variability is reflected only in spectroscopy and not in the chemical-mineralogical measurements that are performed on crushed rock in certified laboratories. Hence, the spectral variability of the surface of an uncrushed rock will, in most cases, be higher than the internal chemical-mineralogical variability, which may impair statistical models built on field measurements. For this reason, studying ore-bearing rocks and evaluating their spectral variability in different scales is an important procedure to better understand the factors that may influence the qualitative and quantitative analysis of the rocks. The objectives are to quantify the spectral variability of three types...

Chitosan is a natural polysaccharide biopolymer which has been widely used in different processes and applications. Chitosan based membranes have been used in reverse osmosis, gas separation, dialysis and pervaporation. The object of this research was investigating the possibility of chitosan membrane used as a filter for removing silver (Ag) from X-ray film processing wastes. Several of chitosan membranes such as M1, M2, M3 and M4 have been prepared for the purpose and filtration was done using dead-end filtration method. The filtration experiments were performed on a flat sheet membrane using pure water and X-ray film processing wastes as feeds. The analysis of silver concentration has been done by atomic absorption spectrometers (AAS). The results show that chitosan membrane M2 gave the highest filtration coefficient (Rcoeff ) i.e. 99.9%, with the pure water flux (PWF) and product flux (PF) are 2972.56 L/m2h and 1761.18 L/m2h respectively. The rejection coefficient of the membranes decreases with increasing the amount of chitosan, while the pure water flux and product flux are increased. The filtration coefficients show that the chitosan membranes are able to filter silver waste from X-ray film processing wastes with performance dependent on their characteristic such as pores size. This suggests that, chitosan membrane can be used as one method that is safe and friendly environment for recovering silver from X-ray film processing waste to improve the quality of treated to an acceptable quality level.

The Faint Object Spectrograph (FOS) aboard Hubble Space Telescope (HST) has been used in the UV to observe the prototypical X-ray pulsar Her X-1 and its companion HZ Her. Optical spectra were also obtained contemporaneously at the Kitt Peak National Observatory (KPNO) 2.1 m. The FOS spectra encompass the 1150-3300 A range near binary orbital phases 0.5 (X-ray maximum) and

Pulmonary surfactant, consisting primarily of phospholipids and four surfactant-specific proteins, is among the first structures that is exposed to inhalation anesthetics. Consequently, changes of pulmonary surfactant due to this exposure could cause respiratory complications after long anesthetic procedures. Fourier transform infrared (FTIR) spectroscopy was used to explore the effects of two inhalation anesthetics, sevoflurane and isoflurane, on a commercially available pulmonary surfactant. The research was primarily focused on the effect of anesthetics on the lipid component of the surfactant. Four different concentrations of anesthetics were added, and the doses were higher from the low clinical doses typically used. Recorded spectra were analyzed using principal component analysis, and the Student’s t-test was performed to confirm the results. The exposure to both anesthetics induced similar changes, consistent with the increase of the anesthetic concentration. The most pronounced effect was on the hydrophilic head group of phospholipids, which is in agreement with the disruption of the hydrogen bond, caused by the anesthetics. A change in the band intensities of CH2 stretching vibrations, indicative of a disordering effect of anesthetics on the hydrophobic tails of phospholipids, was also observed. Changes induced by isoflurane appear to be more pronounced than those induced by sevoflurane. Furthermore, our results suggest that FTIR spectroscopy is a promising tool in studying anesthetic effects on pulmonary surfactant.

Melanin is of interest as a model system of understanding disorder in biological systems. The biological functionality of melanin depends on disorder which is considered as its essential part. This property distinguishes melanin from other much more intensively studied biomolecule systems such as nucleic acid, proteins and carbohydrates. Melanins have been reported to have a diverse number of functions in the biosystem, including photosensitization, metal ion chelation, photoprotection to absorb a broad range of electromagnetic radiation, antibiotic, thermoregulation. Melanins are found all over the body from the skin and blood to the nervous system but the role of melanin in all these system is unclear. FTIR spectroscopy technique is usually one of the most preferred techniques used to give a correct assignment of the observed spectral characteristic of functional groups corresponding to different absorption bands which are responsible of the absorption. FTIR is the characterization technique which is both rapid, non-destructive and requires small sized samples. In the material to be analysed, chemical bonds vibrate at a characteristic frequency representative of their structure, bond angle and length. FTIR spectrometer is important for the interpretation of the structure, binding capacity, affinity and sites of metal ions in melanin. These are important factors for better understanding the metals melanin complexity and its consequences. The analysis of sepia melanin by FTIR reveals that there is existence of functional groups that can be responsible for the binding cites of different metallic ions leading to many new applications of sepia melanin.

Summary form only given. The purpose of this paper is to determine the radial distribution of the emission coefficient from the measured intensity distribution emitted by an extended source of radiation, particularly a plasma source. The source is assumed to be optically thin and axially symmetrical. This problem is solved by inverting Abel's integral equation. A smoothing procedure is made

The content of phenolic compounds determines the state of phenolic ripening of red grapes, which is a key criterion in setting the harvest date to produce quality red wines. Wine phenolics are also important quality components that contribute to the color, taste, and mouth feel of wines. Spectroscopic techniques (e.g., near and mid infrared) offer the potential to simplify and reduce the analytical time for a range of grape and wine analytes. It is this characteristic, together with the ability to simultaneously measure several analytes in the same sample at the same time, which makes these techniques very attractive for use in both industry and research. The objective of this mini review is to present examples and to discuss different applications of visible (VIS), near infrared (NIR) and mid infrared (MIR) to assess and measure phenolic compounds in grape and wines.

Raman spectroscopy (RS) is a powerful tool that allows obtaining significant biochemical information from biological tissue. The fiber optic catheter permits applicationsin vivothat present wide clinical employment. This biochemical analysis is developed through a guide light that furnishes to Raman spectroscopy system the data obtained from tissue. These Raman signals represent the modes of vibration of molecular groups that are present in the biological molecules. Raman measurements undergo the optical influence of the material that constitutes the catheter, mainly Raman scattering of the silica that composes the fiber optic, decreasing signal to noise ratio (SNR) of the resultant spectra. In this work, a dielectric optical filter called “bandpass” was deposited upon the surface of the tip of the central fiber optic (distal probe). Indeed, other six fibers without any optical filter are disposed around this central optical fiber with “bandpass”. This prototype of catheter presente...

Abstract: Some Neolithic pottery fragments excavated in Göytepe-Azerbaijan were investigated using Fourier Transform Infrared (FTIR), micro-Raman, X-ray diffraction (XRD) and statistical chemometric techniques. The firing-temperature and -conditions were inferred from the mineral phases obtained from the FTIR and micro-Raman spectra of the samples. The XRD results confirmed the mineralogical composition determined by FTIR and microRaman analyses. Depending on the spectroscopic results, the firing temperatures of the investigated potteries were estimated to be between 600 oC and 750 oC in oxidizing atmosphere. As the chemometric methods, Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were applied to FTIR spectral data in order to show similarities and dissimilarities of the samples and to extract the most discriminant features.

The coherent time-stretch transform enables high-throughput acquisition of complex optical fields in single-shot  measurements. Full-field spectra are recovered via temporal interferometry on waveforms dispersed in the temporal near field. Real-time absorption spectra, including both amplitude and phase information, are acquired at 37 MHz.

ABSTRACT We investigate the potential of ultraviolet spectroscopy (UV) to monitor cleaning of whey filtration membrane units. Based on sample collections in a full scale production environment two cases of cleaning monitoring by UV are evaluated. The first case demonstrates that UV can measure progress during both recirculation cleaning and the subsequent flushing of cleaning agents. The second case establishes that kinetics during the enzymatic cleaning step can be followed by UV and shows that different cleaning mechanisms are acting simultaneously. We also assess the detection limit for different whey components in a mixture design. Results show that UV in combination with partial least squares regression can quantify whey components down to between 10–20 ppm for whey protein, 5–9 ppm for whey fat, and 60–80 ppm for non-protein/fat solids.

This work examines the oxidation process of Sea buckthorn oil encapsulated in ionotropically cross-linked alginate beads under oxidative conditions. The oxidation of oil was monitored by Fourier Transform Infrared Spectroscopy equipped with the universal ATR (FTIR-ATR) as ...

Analytic potentials are built for all four 2S+1Πu/g states of Li2 dissociating to Li(2S) + Li(3P): 3b(33Πu), 3B(31Πu), 3C(31Πg), and 3d(33Πg). These potentials include the effect of spin-orbit coupling for large internuclear distances, and include state of the art long-range constants. This is the first successful demonstration of fully analytic diatomic potentials that capture features that are usually considered too difficult to capture without a point-wise potential, such as multiple minima, and shelves. Vibrational energies for each potential are presented for the isotopologues 6,6Li2, 6,7Li2, 7,7Li2, and the elusive `halo nucleonic molecule' 11,11Li2. These energies are claimed to be accurate enough for new high-precision experimental setups such as the one presented in {[}Sebastian \emph{et al.} Phys. Rev. A, \textbf{90}, 033417 (2014){]} to measure and assign energy levels of these electronic states, all of which have not yet been explored in the long-range region. Measuring energies in the long-range region of these electronic states may be significant for studying the ab initio vs experiment discrepancy discussed in [Tang et al. Phys. Rev. A, 84, 052502 (2014)] for the C3 long-range constant of Lithium, which has significance for improving the SI definition of the second.

Richard Crocombe of Crocombe Spectroscopic Consulting surveys the use of portable spectrometers in pharmaceutical manufacturing, with an emphasis on vibrational spectroscopy. Ideal and typical features of portable spectrometers are reviewed, alongside explanation of why device characteristics and sample presentation are critical to obtaining meaningful results.

In food industry, vegetable oils are commonly used as functional ingredients. Cold pressed oils containing fatty acids show a variety of chemical properties, which are mainly dependent on the saturation of fatty acids. In this study, we have analyzed meadowfoam seed oil (MSO), obtained from seeds of Limnanthes alba, and extra virgin olive oil (EVO). Firstly, the fatty acids composition, denoted as Cox value, was determined for the oils that are considered as the most stable. The Cox value for MSO reached 0.032, while that for EVO was 1.780. We have also determined the content of fatty acids in both of the oils using gas chromatography, while the use of mid-infrared (MIR) and near-infrared (NIR) spectroscopy allowed us to assign bands corresponding to the vibrations present in the tested functional groups. Significant differences in the shape and intensity of some bands were observed due to different content of unsaturated fatty acids. Vibrational spectroscopy methods confirmed the p...